Статті в журналах з теми "ENO (Essentially Non-Oscillatory) and WENO method.]"

Context. Several numerical problems require the interpolation of discrete data that present at the same time (i) complex smooth structures and (ii) various types of discontinuities. The radiative transfer in solar and stellar atmospheres is a typical example of such a problem. This calls for high-order well-behaved techniques that are able to interpolate both smooth and discontinuous data. Aims. This article expands on different nonlinear interpolation techniques capable of guaranteeing high-order accuracy and handling discontinuities in an accurate and non-oscillatory fashion. The final aim is to propose new techniques which could be suitable for applications in the context of numerical radiative transfer. Methods. We have proposed and tested two different techniques. Essentially non-oscillatory (ENO) techniques generate several candidate interpolations based on different substencils. The smoothest candidate interpolation is determined from a measure for the local smoothness, thereby enabling the essentially non-oscillatory property. Weighted ENO (WENO) techniques use a convex combination of all candidate substencils to obtain high-order accuracy in smooth regions while keeping the essentially non-oscillatory property. In particular, we have outlined and tested a novel well-performing fourth-order WENO interpolation technique for both uniform and nonuniform grids. Results. Numerical tests prove that the fourth-order WENO interpolation guarantees fourth-order accuracy in smooth regions of the interpolated functions. In the presence of discontinuities, the fourth-order WENO interpolation enables the non-oscillatory property, avoiding oscillations. Unlike Bézier and monotonic high-order Hermite interpolations, it does not degenerate to a linear interpolation near smooth extrema of the interpolated function. Conclusion. The novel fourth-order WENO interpolation guarantees high accuracy in smooth regions, while effectively handling discontinuities. This interpolation technique might be particularly suitable for several problems, including a number of radiative transfer applications such as multidimensional problems, multigrid methods, and formal solutions.

Essentially non-oscillatory (ENO) and weighted ENO (WENO) schemes were designed for solving hyperbolic and convection–diffusion equations with possibly discontinuous solutions or solutions with sharp gradient regions. The main idea of ENO and WENO schemes is actually an approximation procedure, aimed at achieving arbitrarily high-order accuracy in smooth regions and resolving shocks or other discontinuities sharply and in an essentially non-oscillatory fashion. Both finite volume and finite difference schemes have been designed using the ENO or WENO procedure, and these schemes are very popular in applications, most noticeably in computational fluid dynamics but also in other areas of computational physics and engineering. Since the main idea of the ENO and WENO schemes is an approximation procedure not directly related to partial differential equations (PDEs), ENO and WENO schemes also have non-PDE applications. In this paper we will survey the basic ideas behind ENO and WENO schemes, discuss their properties, and present examples of their applications to different types of PDEs as well as to non-PDE problems.

Purpose The current work aims to present a parallel code using the open multi-processing (OpenMP) programming model for an adaptive multi-resolution high-order finite difference scheme for solving 2D conservation laws, comparing efficiencies obtained with a previous message passing interface formulation for the same serial scheme and considering the same type of 2D formulations laws. Design/methodology/approach The serial version of the code is naturally suitable for parallelization because the spatial operator formulation is based on a splitting scheme per direction for which the flux components are numerically computed by a Lax–Friedrichs factorization independently for each row or column. High-order approximations for numerical fluxes are computed by the third-order essentially non-oscillatory (ENO) and fifth-order weighted essentially non-oscillatory (WENO) interpolation schemes, assuming sparse grids in each direction. The grid adaptivity is obtained by a cubic interpolating wavelet transform applied in each space dimension, associated to a threshold operator. Time is evolved by a third order TVD Runge–Kutta method. Findings The parallel formulation is implemented automatically at compiling time by the OpenMP library routines, being virtually transparent to the programmer. This over simplifies any concerns about managing and/or updating the adaptive grid when compared to what is necessary to be done when other parallel approaches are considered. Numerical simulations results and the large speedups obtained for the Euler equations in gas dynamics highlight the efficiency of the OpenMP approach. Research limitations/implications The resulting speedups reflect the effectiveness of the OpenMP approach but are, to a large extension, limited by the hardware used (2 E5-2620 Intel Xeon processors, 6 cores, 2 threads/core, hyper-threading enabled). As the demand for OpenMP threads increases, the code starts to make explicit use of the second logical thread available in each E5-2620 processor core and efficiency drops. The speedup peak is reached near the possible maximum (24) at about 22, 23 threads. This peak reflects the hardware configuration and the true software limit should be located way beyond this value. Practical implications So far no attempts have been made to parallelize other possible code segments (for instance, the ENO|-WENO-TVD code lines that process the different data components which could potentially push the speed up limit to higher values even further. The fact that the speedup peak is located close to the present hardware limit reflects the scalability properties of the OpenMP programming and of the splitting scheme as well. Consequently, it is likely that the speedup peak with the OpenMP approach for this kind of problem formulation will be close to the physical (and/or logical) limit of the hardware used. Social implications This work is the result of a successful collaboration among researchers from two different institutions, one internationally well-known and with a long-term experience in applied mathematics for industrial applications and the other in a starting process of international academic insertion. In this way, this scientific partnership has the potential of promoting further knowledge exchange, involving students and other collaborators. Originality/value The proposed methodology (use of OpenMP programming model for the wavelet adaptive splitting scheme) is original and contributes to a very active research area in the past years, namely, adaptive methods for conservation laws and their parallel formulations, which is of great interest for the entire scientific community.

ABSTRACT This study proposes the optimization of a low-level assembly code to reconstruct the flux for a splitting flux Harten–Lax–van Leer (SHLL) scheme on high-end graphic processing units. The proposed solver is implemented using the weighted essentially non-oscillatory reconstruction method to simulate compressible gas flows that are derived using an unsteady Euler equation. Instructions in the low-level assembly code, i.e. parallel thread execution and instruction set architecture in compute unified device architecture (CUDA), are used to optimize the CUDA kernel for the flux reconstruction method. The flux reconstruction method is a fifth-order one that is used to process the high-resolution intercell flux for achieving a highly localized scheme, such as the high-order implementation of SHLL scheme. Many benchmarking test cases including shock-tube and four-shock problems are demonstrated and compared. The results show that the reconstruction method is computationally very intensive and can achieve excellent performance up to 5183 GFLOP/s, ∼66% of peak performance of NVIDIA V100, using the low-level CUDA assembly code. The computational efficiency is twice the value as compared with the previous studies. The CUDA assembly code reduces 26.7% calculation and increases 37.5% bandwidth. The results show that the optimal kernel reaches up to 990 GB/s for the bandwidth. The overall efficiency of bandwidth and computation performance achieves 127% of the predicted performance based on the HBM2-memory roofline model estimated by Empirical Roofline Tool.

In this work the essentially non-oscillatory schemes (ENO) and the weighted essentially non-oscillatory schemes (WENO) are implemented in a cell centered finite volume context on unstructured meshes. The 2-D Euler equations will be considered to represent the flows of interest. The ENO and WENO schemes have been developed with the purpose of accurately capturing discontinuities appearing in problems governed by hyperbolic conservation laws. In the high Mach number aerodynamic studies of interest in the present paper, these discontinuities are mainly represented by shock waves and contact discontinuities. The entire reconstruction process of ENO and WENO schemes is described in detail for linear polynomials and, therefore, second-order of accuracy. An extension to higher orders of accuracy is presented in the paper in a straightforward manner and applications for compressible flows are shown. These applications compare the accuracy of the schemes with some related data that appear in the references cited in this paper or that come from analytical solutions.

We present a computational method based on the Spectral Deferred Corrections (SDC) time integration technique and the Essentially Non-Oscillatory (ENO) finite volume method for the conservation laws (one-dimensional Euler equations). The SDC technique is used to advance the solutions in time with high-order of accuracy. The ENO method is used to define high-order cell edge quantities that are then used to evaluate numerical fluxes. The coupling of the SDC method with a high-order finite volume method (Piece-wise Parabolic Method (PPM)) for solving the conservation laws is first carried out by Layton et al. in [Layton, A. T. and Minion, M. L. [2004] “Conservative multi-implicit spectral deferred correction methods for reacting gas dynamics,” J. Comput. Phys. 194(2), 697–714]. Issues about this approach have been addressed and some improvements have been added to it in [Kadioglu et al. [2012] “A gas dynamics method based on the spectral deferred corrections (SDC) time integration technique and the piecewise parabolic method (PPM),” Am. J. Comput. Math. 1–4, 303–317]. Here, we investigate the implications when the PPM method is replaced with the well-known ENO method. We note that the SDC-PPM method is fourth-order accurate in time and space. Therefore, we kept the order of accuracy of the ENO procedure as fourth-order in order to be able to make a consistent comparison between the two approaches (SDC-ENO versus SDC-PPM methods). We have tested the new SDC-ENO technique by solving several test problems involving moderate to strong shock waves and smooth/complex flow structures. Our numerical results show that we have numerically achieved the formally fourth-order convergence of the new method for smooth problems. Our numerical results also indicate that the newly proposed technique performs very well providing highly resolved shock discontinuities and fairly good contact solutions. More importantly, the discontinuities in the flow test problems are captured with essentially no-oscillations. We have numerically compared the fourth-order SDC-ENO scheme to the fourth-order SDC-PPM method for the same test problems. The results are similar for most of the test problems except in some cases the SDC-PPM method suffers from minor oscillations compared to SDC-ENO scheme being completely oscillation free.

AbstractThis paper further considers weighted essentially non-oscillatory (WENO) and Hermite weighted essentially non-oscillatory (HWENO) finite volume methods as limiters for Runge-Kutta discontinuous Galerkin (RKDG) methods to solve problems involving nonlinear hyperbolic conservation laws. The application discussed here is the solution of 3-D problems on unstructured meshes. Our numerical tests again demonstrate this is a robust and high order limiting procedure, which simultaneously achieves high order accuracy and sharp non-oscillatory shock transitions.

In this paper, two unequal-sized weighted essentially non-oscillatory (US-WENO) schemes are proposed for solving hyperbolic conservation laws. First, an alternative US-WENO (AUS-WENO) scheme based directly on the values of conserved variables at the grid points is designed. This scheme can inherit all the advantages of the original US-WENO scheme [J. Zhu and J. Qiu, “A new fifth order finite difference WENO scheme for solving hyperbolic conservation laws,” J. Comput. Phys. 318, 110–121 (2016).], such as the arbitrariness of the linear weights. Moreover, this presented AUS-WENO scheme enables any monotone fluxes applicable to this framework, whereas the original US-WENO scheme is only suitable for the more dissipative smooth flux splitting. Therefore, the method in this paper has a smaller L1 and [Formula: see text] numerical errors than the original scheme under the same conditions. Second, in order to further improve the computational efficiency of the above AUS-WENO scheme, a hybrid AUS-WENO scheme is proposed by combining a hybrid strategy. This strategy identifies the discontinuous regions directly based on the extreme points of the reconstruction polynomial corresponding to the five-point stencil, which brings the important advantage that it does not depend on the specific problem and does not contain any artificial adjustable parameters. Finally, the performance of the above two AUS-WENO schemes in terms of low dissipation, shock capture capability, discontinuity detection capability, and computational efficiency is verified by some benchmark one- and two-dimensional numerical examples.

AbstractIn this paper, we propose a new type of weighted essentially non-oscillatory (WENO) limiter, which belongs to the class of Hermite WENO (HWENO) limiters, for the Runge-Kutta discontinuous Galerkin (RKDG) methods solving hyperbolic conservation laws. This new HWENO limiter is a modification of the simple WENO limiter proposed recently by Zhong and Shu [29]. Both limiters use information of the DG solutions only from the target cell and its immediate neighboring cells, thus maintaining the original compactness of the DG scheme. The goal of both limiters is to obtain high order accuracy and non-oscillatory properties simultaneously. The main novelty of the new HWENO limiter in this paper is to reconstruct the polynomial on the target cell in a least square fashion [8] while the simple WENO limiter [29] is to use the entire polynomial of the original DG solutions in the neighboring cells with an addition of a constant for conservation. The modification in this paper improves the robustness in the computation of problems with strong shocks or contact discontinuities, without changing the compact stencil of the DG scheme. Numerical results for both one and two dimensional equations including Euler equations of compressible gas dynamics are provided to illustrate the viability of this modified limiter.

This paper studies the convergence properties of an arbitrary Lagrangian–Eulerian (ALE) Riemann-based SPH algorithm in conjunction with a Weighted Essentially Non-Oscillatory (WENO) high-order spatial reconstruction, in the framework of the DualSPHysics open-source code. A convergence analysis is carried out for Lagrangian and Eulerian simulations and the numerical results demonstrate that, in absence of particle disorder, the overall convergence of the scheme is close to the one guaranteed by the WENO spatial reconstruction. Moreover, an alternative method for the WENO spatial reconstruction is introduced which guarantees a speed-up of 3.5, in comparison with the classical Moving Least-Squares (MLS) approach.

We construct a localized finite volume method by applying ENO (essentially non-oscillatory) reconstruction to solve hyperbolic conservation laws following the partitions of the spectral volume methods. The main idea is as follows: Firstly, separate the calculating domain into intervals, named main-cells, then divide the intervals into subintervals, named sub-cells. Secondly, use ENO methodology to reconstruct conservative variables in the main-cells by using the cell averages of proper sub-cells. After that, use the TVD Runge-Kutta time discrete method to obtain fully discrete scheme. Several classic numerical tests show that this scheme has capabilities to capture discontinuities in high resolution and robustness.

In this paper we propose a second order hybrid reconstruction strategy for the fully adaptive multi-resolution scheme based on the second order finite volume method. The fully adaptive multi-resolution scheme is an adaptive grid method for solving the hyperbolic conservation laws. To improve its robustness, the third order central reconstruction is replaced by the second order hybrid reconstruction, i.e. the anti-ENO (essentially non-oscillatory) reconstruction and the ENO reconstruction have been adopted for the multi-resolution analysis and the inverse multi-resolution analysis, respectively. Several numerical examples indicate that this new hybrid reconstruction strategy is much less sensitive to the tolerance than the central reconstruction.

AbstractThe weighted essentially non-oscillatory (WENO) methods are popular and effective spatial discretization methods for nonlinear hyperbolic partial differential equations. Although these methods are formally first-order accurate when a shock is present, they still have uniform high-order accuracy right up to the shock location. In this paper, we propose a novel third-order numerical method for solving optimal control problems subject to scalar nonlinear hyperbolic conservation laws. It is based on the first-disretize-then-optimize approach and combines a discrete adjoint WENO scheme of third order with the classical strong stability preserving three-stage third-order Runge–Kutta method SSPRK3. We analyze its approximation properties and apply it to optimal control problems of tracking-type with non-smooth target states. Comparisons to common first-order methods such as the Lax–Friedrichs and Engquist–Osher method show its great potential to achieve a higher accuracy along with good resolution around discontinuities.

Weighted essentially non-oscillatory (WENO) methods are especially efficient for numerically solving nonlinear hyperbolic equations. In order to achieve strong stability and large time-steps, strong stability preserving (SSP) integrating factor (IF) methods were designed in the literature, but the methods there were only for one-dimensional (1D) problems that have a stiff linear component and a non-stiff nonlinear component. In this paper, we extend WENO methods with large time-stepping SSP integrating factor Runge–Kutta time discretization to solve general nonlinear two-dimensional (2D) problems by a splitting method. How to evaluate the matrix exponential operator efficiently is a tremendous challenge when we apply IF temporal discretization for PDEs on high spatial dimensions. In this work, the matrix exponential computation is approximated through the Krylov subspace projection method. Numerical examples are shown to demonstrate the accuracy and large time-step size of the present method.

In this work, we apply adaptive multiresolution (Harten’s approach) characteristic-wise fifth-order Weighted Essentially Non-Oscillatory (WENO) for computing the numerical solution of a polydisperse sedimentation model, namely, the Höfler and Schwarzer model. In comparison to other related works, time discretization is carried out with the ten-stage fourth-order strong stability preserving Runge–Kutta method which is more efficient than the widely used optimal third-order TVD Runge–Kutta method. Numerical results with errors, convergence rates and CPU times are included for four and 11 species.

A numerical study of extremely strong shocks was presented. Various types of numerical schemes with first-order accuracy and higherorder accuracy with adaptive stencils were implemented to solve the one and twodimensional Euler equations based on the explicit finite difference method, including Roe’s first-order upwind, Steger-Warming Flux Vector splitting (FVS), Sweby’s flux-limited and Essentially Non-oscillatory (ENO) scheme. The result comparisons were carried out to discuss which scheme is the most suitable for strong shock problem. The dissipative nature of the firstorder scheme can be easily seen from the numerical solutions. High order ENO scheme had the best resolution for the case having weak discontinuity, but it over- predicted the shock wave location for the case of strong discontinuity.

Purpose The purpose of this work is to present the implementation of weighted essentially non-oscillatory (WENO) wavelet methods for solving multiphase flow problems. The particular interest is gas–liquid two-phase mixture with velocity non-equilibrium. Numerical simulations are carried out on different scenarios of one-dimensional Riemann problems for gas–liquid flows. Results are validated and qualitatively compared with solutions provided by other standard numerical methods. Design/methodology/approach This paper extends the framework of WENO wavelet adaptive method to a fully hyperbolic two-phase flow model in a conservative form. The grid adaptivity in each time step is provided by the application of a thresholded interpolating wavelet transform. This facilitates the construction of a small yet effective sparse point representation of the solution. The method of Lax–Friedrich flux splitting is used to resolve the spatial operator in which the flux derivatives are approximated by the WENO scheme. Findings Hyperbolic models of two-phase flow in conservative form are efficiently solved, as shocks and rarefaction waves are precisely captured by the chosen methodology. Substantial computational gains are obtained through the grid reduction feature while maintaining the quality of the solutions. The results indicate that WENO wavelet methods are robust and sufficient to accurately simulate gas–liquid mixtures. Originality/value Resolution of two-phase flows is rarely studied using WENO wavelet methods. It is the first time such a study on the relative velocity is reported in two-phase flows using such methods.

An immersed boundary method based on the ghost-cell approach is presented in this paper. The compressible Navier-Stokes equations are discretized using a flux-splitting method for inviscid fluxes and second-order central-difference for the viscous components. High-order accuracy is achieved by using weighted essentially non-oscillatory (WENO) and Runge-Kutta schemes. Boundary conditions are reconstructed by a serial of linear interpolation and inverse distance weighting interpolation of flow variables in fluid domain. Two classic flow problems (flow over a circular cylinder, and a NACA 0012 airfoil) are simulated using the present immersed boundary method, and the predictions show good agreement with previous computational results.

AbstractThis paper presents a new and better suited formulation to implement the limiting projection to high-order schemes that make use of high-order local reconstructions for hyperbolic conservation laws. The scheme, so-called MCV-WENO4 (multi-moment Constrained finite Volume with WENO limiter of 4th order) method, is an extension of the MCV method of Ii & Xiao (2009) by adding the 1st order derivative (gradient or slope) at the cell center as an additional constraint for the cell-wise local reconstruction. The gradient is computed from a limiting projection using the WENO (weighted essentially non-oscillatory) reconstruction that is built from the nodal values at 5 solution points within 3 neighboring cells. Different from other existing methods where only the cell-average value is used in the WENO reconstruction, the present method takes account of the solution structure within each mesh cell, and thus minimizes the stencil for reconstruction. The resulting scheme has 4th-order accuracy and is of significant advantage in algorithmic simplicity and computational efficiency. Numerical results of one and two dimensional benchmark tests for scalar and Euler conservation laws are shown to verify the accuracy and oscillation-less property of the scheme.

We consider a second‐order finite difference scheme to solve the eikonal equation. Upwind differences are requisite to sharply resolve discontinuities in the traveltime derivatives, whereas centered differences improve the accuracy of the computed traveltime. A second‐order upwind essentially non‐oscillatory (ENO) scheme satisfies these requirements. It is implemented with a dynamic down ’n’ out (DNO) marching, an expanding box approach. To overcome the instability of such an expanding box scheme, the algorithm incorporates an efficient post sweeping (PS), a correction‐by‐iteration method. Near the source, an efficient and accurate mesh‐refinement initialization scheme is suggested for the DNO marching. The resulting algorithm, ENO-DNO-PS, turns out to be unconditionally stable, of second‐order accuracy, and efficient; for various synthetic and real velocity models having large contrasts, two PS iterations produce traveltimes accurate enough to complete the computation.

The accurate prediction of helicopter rotor blade–vortex interaction (BVI) noise is challenging. This paper presents an implementation of the seventh-order improved weighted essentially non-oscillatory (WENO-Z) scheme for predicting rotor BVI noise using a high-resolution numerical method based on the Reynolds-averaged Navier–Stokes and the Ffowcs Williams–Hawkings equations. The seventh-order improved WENO-Z scheme is utilized to minimize the inherent numerical dissipation of the reconstruction method in the monotone upstream-centered scheme for conservation laws (MUSCL), thereby improving the rotor wake resolution and the BVI noise-prediction accuracy. The three-layer dummy cell method is used to ensure that the flux at the boundary maintains seventh-order accuracy. The effectiveness of the flow solver and the acoustic solver is validated using the Helishape-7A rotor and the UH-1H rotor, respectively. The flow field and BVI noise characteristics of the OLS rotor obtained from the fifth- and seventh-order WENO-Z schemes are compared with that of the third-order MUSCL for coarse and fine background grids. The wake resolution, noise-prediction accuracy, and computational cost of the three schemes are compared. The results show that the high-order WENO scheme provides higher accuracy for flow field simulation and BVI noise prediction than the MUSCL, but the computational cost of the WENO scheme increases substantially as the grid resolution increases. However, the WENO scheme can predict BVI using a coarser grid than the MUSCL. The computational cost of the WENO scheme is relatively low under the same flow field simulation resolution.

AbstractAn idea of designing oscillation-less and high-resolution hybrid schemes is proposed and several types of hybrid schemes based on this idea are presented on block-structured grids. The general framework, for designing various types of hybrid schemes, is established using a Multi-dimensional Optimal Order Detection (MOOD) method proposed by Clain, Diot and Loubère [1]. The methodology utilizes low dissipation or dispersion but less robust schemes to update the solution and then implements robust and high resolution schemes to deal with problematic situations. A wide range of computational methods including central scheme, MUSCL scheme, linear upwind scheme and Weighted Essentially Non Oscillatory (WENO) scheme have been applied in the current hybrid schemes framework. Detailed numerical studies on classical test cases for the Euler system are performed, addressing the issues of the resolution and non-oscillatory property around the discontinuities.

AbstractA hybridization of a high order WENO-Zfinite difference scheme and a high order central finite difference method for computation of the two-dimensional Euler equations first presented in [B. Costa and W. S. Don, J. Comput. Appl. Math., 204(2) (2007)] is extended to three-dimensions and for parallel computation. The Hybrid scheme switches dynamically from a WENO-Zscheme to a central scheme at any grid location and time instance if the flow is sufficiently smooth and vice versa if the flow is exhibiting sharp shock-type phenomena. The smoothness of the flow is determined by a high order multi-resolution analysis. The method is tested on a benchmark sonic flow injection in supersonic cross flow. Increase of the order of the method reduces the numerical dissipation of the underlying schemes, which is shown to improve the resolution of small dynamic vortical scales. Shocks are captured sharply in an essentially non-oscillatory manner via the high order shock-capturing WENO-Zscheme. Computations of the injector flow with a WENO-Zscheme only and with the Hybrid scheme are in very close agreement. Thirty percent of grid points require a computationally expensive WENO-Zscheme for high-resolution capturing of shocks, whereas the remainder of grid points may be solved with the computationally more affordable central scheme. The computational cost of the Hybrid scheme can be up to a factor of one and a half lower as compared to computations with a WENO-Zscheme only for the sonic injector benchmark.

AbstractA new fifth-order, semi-discrete central-upwind scheme with a Lax–Wendroff time discretization procedure for solving Hamilton–Jacobi (HJ) equations is presented. This is an alternative method for time discretization to the popular total variation diminishing (TVD) Runge–Kutta time discretizations. Unlike most of the commonly used high-order upwind schemes, the new scheme is formulated as a Godunov-type method. The new scheme is based on the flux Kurganov, Noelle and Petrova (KNP flux). The spatial discretization is based on a symmetrical weighted essentially non-oscillatory reconstruction of the derivative. Following the methodology of the classic WENO procedure, non-oscillatory weights are then calculated from the ideal weights. Various numerical experiments are performed to demonstrate the accuracy and stability properties of the new method. As a result, comparing with other fifth-order schemes for HJ equations, the major advantage of the new scheme is more cost effective for certain problems while the new method exhibits smaller errors without any increase in the complexity of the computations.

Wave propagation over a semicircular obstacle is studied. This problem is related to the design of semicircular breakwaters. These breakwaters are expected to have enhanced stability and were constructed in various places in China. Enhanced numerical modeling is done taking viscosity into account. The fifth order space accurate weighted essentially non-oscillatory (WENO) method is used to discretize the convection terms. As a result accurate results are obtained using simple options (uniform Cartesian grid, level set method). Wave generation is done using a numerical piston wave maker that is analogous to the real experiment. The model results are compared with free surface visualization and pressure measurements. Various features of the problem including wave drag and the flow field are revealed.

Numerical simulation of the moving interface is widely investigated in the fields of two-phase flow, crystal growth, molten metal casting and so on. To simulate accurately and quickly motion state of the moving interface, two types of interface-capturing method, LSM (level set method) and MCLS (mass-conserving LSM coupled with VOF (volume of fluid)), were comparatively analysed and studied. Two kinds of moving interface, rotation motion of Zaleska slotted disk interface and shearing deformation of the circle interface, were simulated. The level set advection equation was solved with IATVD (the characteristic integral-averaging finite volume method), RK-WENO (the third order Runge-Kutta method with WENO (weighted essentially non-oscillatory)), or the low order method, respectively. The level set function was re-initialized with modified Godunov method. Computation was implemented in different size mesh. When it is independent with mesh size, results show that the high order method, IATVD and RK-WENO, can get higher computing accuracy in LSM without topological geometry change. But computing time cost of RK-WENO is much greater than that of IATVD. For the low order method, LSM captures the moving interface in bad, however, MCLS’s numerical result is very good. But computing time cost of MCLS is much and much greater than that of LSM. For interface-capturing with topological geometry change, these two high order methods all can not capture the moving interface in good in LSM. Nevertheless, the resulting interfaces all are same as original interface in MCLS. These indicate that an appropriate numerical method and interface-capturing method can be chosen to accurately and quickly capture the related moving interface.

AbstractIn this paper we demonstrate the accuracy and robustness of combining the advection upwind splitting method (AUSM), specifically AUSM+-UP, with high-order upwind-biased interpolation procedures, the weighted essentially non-oscillatory (WENO-JS) scheme and its variations, and the monotonicity preserving (MP) scheme, for solving the Euler equations. MP is found to be more effective than the three WENO variations studied. AUSM+-UP is also shown to be free of the so-called “carbuncle” phenomenon with the high-order interpolation. The characteristic variables are preferred for interpolation after comparing the results using primitive and conservative variables, even though they require additional matrix-vector operations. Results using the Roe flux with an entropy fix and the Lax-Friedrichs approximate Riemann solvers are also included for comparison. In addition, four reflective boundary condition implementations are compared for their effects on residual convergence and solution accuracy. Finally, a measure for quantifying the efficiency of obtaining high order solutions is proposed; the measure reveals that a maximum return is reached after which no improvement in accuracy is possible for a given grid size.

In this paper, the specific expression for pressure and sound speed in chemical reaction zone of condensed explosives are theoretically deduced, and a new method for deriving the partial derivative of pressure in respect of every conserved quantity is proposed. Combined with the third-order TVD Runge–Kutta method, we develop a parallel solver using the fifth-order high-resolution weighted essentially non-oscillatory (WENO) finite difference scheme to simulate detonation diffraction for two-dimensional condensed explosives. The numerical simulation results revealed the forming reasons of the low-pressure region, the low-density region, the "vortex" region and the "dead zone" in the vicinity of the corner. Furthermore, it demonstrated that the retonation will generate along the inner wall, and it plays an important role in the process of detonation diffraction.

AbstractIn this paper we generalize a new type of compact Hermite weighted essentially non-oscillatory (HWENO) limiter for the Runge-Kutta discontinuous Galerkin (RKDG) method, which was recently developed in [38] for structured meshes, to two dimensional unstructured meshes. The main idea of this HWENO limiter is to reconstruct the new polynomial by the usage of the entire polynomials of the DG solution from the target cell and its neighboring cells in a least squares fashion [11] while maintaining the conservative property, then use the classical WENO methodology to form a convex combination of these reconstructed polynomials based on the smoothness indicators and associated nonlinear weights. The main advantage of this new HWENO limiter is the robustness for very strong shocks and simplicity in implementation especially for the unstructured meshes considered in this paper, since only information from the target cell and its immediate neighbors is needed. Numerical results for both scalar and system equations are provided to test and verify the good performance of this new limiter.

AbstractA new fourth order accurate centered finite difference scheme for the solution of hyperbolic conservation laws is presented. A technique of making the fourth order scheme TVD is presented. The resulting scheme can avoid spurious oscillations and preserve fourth order accuracy in smooth parts. We discuss the extension of the TVD scheme to the nonlinear scalar hyperbolic conservation laws. For nonlinear systems, the TVD constraint is applied by solving shallow water equations. Then, we propose to use this fourth order flux as a building block in spatially fifth order weighted essentially non-oscillatory (WENO) schemes. The numerical solution is advanced in time by the third order TVD Runge — Kutta method. The performance of the scheme is assessed by solving test problems. The numerical results are presented and compared to the exact solutions and other methods.

In aerospace engineering, high-order computational fluid dynamics (CFD) solvers suitable for three-dimensional unstructured meshes are less developed than expected. The Runge–Kutta discontinuous Galerkin (RKDG) finite element method with compact weighted essentially non-oscillatory (WENO) limiters is one of the candidates, which might give high-order solutions on unstructured meshes. In this article, we provide an efficient parallel implementation of this method for simulating inviscid compressible flows. The implemented solvers are tested on lower-dimensional model problems and real three-dimensional engineering problems. Results of lower-dimensional problems validate the correctness and accuracy of these solvers. The capability of capturing complex flow structures even on coarse meshes is shown in the results of three-dimensional applications. For solving problems containing rotary wings, an unsteady momentum source model is incorporated into the solvers. Such a finite element/momentum source hybrid method eliminates the reliance on advanced mesh techniques, which might provide an efficient tool for studying rotorcraft aerodynamics.

We consider a noisy leaky integrate-and-fire (NLIF) neuron model. The resulting nonlinear time-dependent partial differential equation (PDE) is a Fokker-Planck Equation (FPE) which describes the evolution of the probability density. The finite element method (FEM) has been proposed to solve the governing PDE. In the realistic neural network, the irregular space is always determined. Thus, FEM can be used to tackle those situations whereas other numerical schemes are restricted to the problems with only a finite regular space. The stability of the proposed scheme is also discussed. A comparison with the existing Weighted Essentially Non-Oscillatory (WENO) finite difference approximation is also provided. The numerical results reveal that FEM may be a better scheme for the solution of such types of model problems. The numerical scheme also reduces computational time in comparison with time required by other schemes.

In this paper, a three-dimensional (3D) tsunami flow model was proposed in order to predict a 3D flow field around a harbor accurately when tsunami strikes. In the proposed numerical model, the Cartesian coordinate system was adopted, and the Fractional Area/Volume Obstacle Representation (FAVOR) method, which has the ability to impose boundary conditions smoothly at complex boundaries, was introduced into the governing equations in consideration of applying the estimation to actual harbors with complex shape in the future. Moreover, the fifth-order Weighted Essentially Non- Oscillatory (WENO) scheme, which is a technique for achieving high accuracy even if the calculation mesh is coarse, was applied to discretization of the convection terms of the governing equations. In order to verify the validity of the model, it was applied to a large-scale laboratory experiment with a scale model of harbor. Comparisons between the simulated and experimental results showed that the model was able to reproduce the time variation of the flow field with sufficient accuracy. Moreover, the simulated results showed that a complex 3D flow field with some vertical vortex flows was generated around a harbor when tsunami struck.

Comparative evaluation lies at the heart of science, and determining the accuracy of a computational method is crucial for evaluating its potential as well as for guiding future efforts. However, metrics that are typically used have inherent shortcomings when faced with the under-resolved solutions of real-world simulation problems. We show how to leverage the human visual system in conjunction with crowd-sourced user studies to address the fundamental problems of widely used classical evaluation metrics. We demonstrate that such user studies driven by visual perception yield a very robust metric and consistent answers for complex phenomena without any requirements for proficiency regarding the physics at hand. This holds even for cases away from convergence where traditional metrics often end up with inconclusive results. More specifically, we evaluate results of different essentially non-oscillatory (ENO) schemes in different fluid flow settings. Our methodology represents a novel and practical approach for scientific evaluations that can give answers for previously unsolved problems.

Abstract A 1D1V hybrid Vlasov-fluid model was developed for this study to elucidate discharge current oscillations of Hall thrusters (HTs). The Vlasov equation for ions velocity distribution function with ionization source term is solved using a constrained interpolation profile conservative semi-Lagrangian method. The fourth-order weighted essentially non-oscillatory (4th WENO) limiter is applied to the first derivative value to minimize numerical oscillation in the discharge oscillation analyses. The fourth-order accuracy is verified through a 1D scalar test case. Nonoscillatory and high-resolution features of the Vlasov model are confirmed by simulating the test cases of the Vlasov–Poisson system and by comparing the results with a particle-in-cell (PIC) method. A 1D1V HT simulation is performed through the hybrid Vlasov model. The ionization oscillation is analyzed. The oscillation amplitude and plasma density are compared with those obtained from a hybrid PIC method. The comparison indicates that the hybrid Vlasov-fluid model yields noiseless results and that the steady-state waveform is calculable in a short time period.

AbstractIn order to investigate continuous vortex dynamics based on a Lagrangian-like formulation, we develop a theoretical framework and a numerical method for computation of the evolution of a vortex-surface field (VSF) in viscous incompressible flows with simple topology and geometry. Equations describing the continuous, timewise evolution of a VSF from an existing VSF at an initial time are first reviewed. Non-uniqueness in this formulation is resolved by the introduction of a pseudo-time and a corresponding pseudo-evolution in which the evolved field is ‘advected’ by frozen vorticity onto a VSF. A weighted essentially non-oscillatory (WENO) method is used to solve the pseudo-evolution equations in pseudo-time, providing a dissipative-like regularization. Vortex surfaces are then extracted as iso-surfaces of the VSFs at different real physical times. The method is applied to two viscous flows with Taylor–Green and Kida–Pelz initial conditions respectively. Results show the collapse of vortex surfaces, vortex reconnection, the formation and roll-up of vortex tubes, vorticity intensification between anti-parallel vortex tubes, and vortex stretching and twisting. A possible scenario for understanding the transition from a smooth laminar flow to turbulent flow in terms of topology of vortex surfaces is discussed.

For the high-precision simulation of engine jet effects, an improved delayed detached eddy simulation (IDDES) method based on the two-equation shear stress transport (SST) model is developed, and the fifth-order finite-volume weighted essentially non-oscillatory (WENO) scheme is employed to enhance accuracy of spatial discretization, and then numerical investigation of powered jet effects by RANS/LES hybrid methods is carried out. The effects of the grid distributions and the accuracy of the spatial schemes are discussed during the RANS/LES validation analysis on the fully expanded jet flow and Acoustic Reference Nozzle (ARN) jet flow. The results show that, by enlarging the grid density and improving the accuracy of the spatial schemes, the velocity distributions in the jet flow can be better predicted, the non-physical steady flow after the jet nozzle can be shortened, the instantaneous flow structures are clearer and the turbulent intensities are more accurate. Then IDDES simulation of turbofan engine jet flow is carried out. The mixing characteristics of the external fan jet flow and internal core jet flow as well as the ambient flow are obtained, and the three-dimensional turbulent structures are also given.

In this research, a CFD solver is developed for solving the 2D/3D compressible flow problem: the finite volume method based on multi-block structural grids is used to solve the compressible Reynolds averaged Navier–Stokes equations (RANS). Included in the methodology are multiple high-order reconstruction schemes, such as the 3rd-order MUSCL (Monotone Upstreamcentered Schemes for Conservation Laws), 5th-order WENO (Weight Essentially Non-Oscillatory), and 5th-order MP (Monotonicity-Preserving) schemes. Of the variety of turbulence models that are embedded, this solver is mainly based on the shear stress transport model (SST), which is compatible with OpenMP/MPI parallel algorithms. This research uses the CFD solver to conduct steady-state flow simulation for a two-dimensional supersonic inlet/isolator, incorporating these high-precision reconstruction schemes to accurately capture the shock wave/expansion wave interaction and shock wave/turbulent boundary layer interaction (SWTBLI), among other effects. By comparing the 2D/3D computation results of the same inlet configuration, it is found that the 3D effects of the side wall cannot be ignored due to the existing strong lateral flow near the corner. To obtain a more refined turbulence simulation, the commercial software ANSYS Fluent 18.0 is used to carry out the detached eddy simulation (DES) and the large eddy simulation (LES) of the same supersonic inlet, so as to reveal the flow details near the separation area and boundary layers.

Wave breaking is a complex two-phase flow process that strongly influences the air-water interaction. A number of physical processes are involved in the exchange of mass, momentum and energy between air and water interaction during the wave breaking process. In shallow waters, waves undergo different transformation processes such as shoaling, refraction, diffraction and breaking due to their non-linear interaction with the seabed. Thus, the associated hydrodynamics are rather complicated to understand when compared to wave breaking in deep water (Lin, 2008). In the present numerical study, a two phase flow CFD model REEF3D (Bihs et al. 2016) is used to model and investigate the hydrodynamics of spilling and plunging breakers over a slope. An accurate modeling of the wave breaking process is still highly demanding due to the strong non-linear air-water interaction and turbulent production at the free surface. The numerical wave tank is based on the incompressible Reynolds Averaged Navier-Stokes (RANS) equations together with the level set method for free surface and the k-ω model for turbulence (Alagan Chella et al. 2015). The model uses the 5th-order Weighted Essentially Non- Oscillatory (WENO) scheme for the convective discretization and the 3rd-order TVD Runge Kutta Scheme for the time discretization. A staggered grid method is employed in the model in order to achieve a stronger coupling between the pressure and velocity. The model is fully parallelized with the domain decomposition method and MPI (Message passing interface).

In this paper, by adopting a fifth-order weighted essentially non-oscillatory (WENO) scheme with a third-order TVD Runge–Kutta time stepping method for two-dimensional reactive Euler equations, a parallel code is developed, and reignition behavior after a self-sustaining detonation from the tube into free space filled with H2/O2 mixtures is investigated. The numerical results show that the initial pressure has a great influence on the detonation cellular width, and that as the initial pressure increases, the cellular width gradually decreases and the cellular shape changes from irregular structure to regular structure, demonstrating the detonation instability to stability transition. When the initial pressure is larger than 1.2 atm, the detonation wave expands over the edge of the splitter plate, reignition can come into being because enough transverse waves collide with each other at the leading edge of the expanding front. When the initial pressure is 1.2 atm, hot spots appear on the front, and ignite the combustible gas near the hot spots after detonation diffraction. When the initial pressure is 1.0 atm, reignition fails. These findings hint that a critical initial pressure exists between 1.0–1.2 atm for direct reignition after detonation diffraction.

The topic of this paper is the Kelvin-Helmholtz instability, a phenomenon which occurs on the interface of a stratified fluid, in the presence of a parallel shear flow, when there is a velocity and density difference across the interface of two adjacent layers. This paper focuses on a numerical simulation modelled by the Taylor-Goldstein equation, which represents a more realistic case compared to the basic Kelvin-Helmholtz shear flow. The Euler system is solved with new modelled smooth velocity and density profiles at the interface. The flux at cell boundaries is reconstructed by implementing a third order WENO (Weighted Essentially Non-Oscillatory) method. Next, a Riemann solver builds the fluxes at cell interfaces. The use of both Rusanov and HLLC solvers is investigated. Temporal discretization is done by applying the second order TVD (total variation diminishing) Runge-Kutta method on a uniform grid. Numerical simulations are performed comparatively for both Kelvin-Helmholtz and Taylor-Goldstein instabilities, on the same simulation domains. We find that increasing the number of grid points leads to a better accuracy in shear layer vortices visualization. Thus, we can conclude that applying the Taylor-Goldstein equation improves the realism in the general fluid instability modelling.

AbstractThe high order inverse Lax-Wendroff (ILW) procedure is extended to boundary treatment involving complex geometries on a Cartesian mesh. Our method ensures that the numerical resolution at the vicinity of the boundary and the inner domain keeps the fifth order accuracy for the system of the reactive Euler equations with the two-step reaction model. Shock wave propagation in a tube with an array of rectangular grooves is first numerically simulated by combining a fifth order weighted essentially non-oscillatory (WENO) scheme and the ILW boundary treatment. Compared with the experimental results, the ILW treatment accurately captures the evolution of shock wave during the interactions of the shock waves with the complex obstacles. Excellent agreement between our numerical results and the experimental ones further demonstrates the reliability and accuracy of the ILW treatment. Compared with the immersed boundary method (IBM), it is clear that the influence on pressure peaks in the reflected zone is obviously bigger than that in the diffracted zone. Furthermore, we also simulate the propagation process of detonation wave in a tube with three different widths of wall-mounted rectangular obstacles located on the lower wall. It is shown that the shock pressure along a horizontal line near the rectangular obstacles gradually decreases, and the detonation cellular size become large and irregular with the decrease of the obstacle width.

AbstractNumerical simulation based on the Euler equation and one-step reaction model is carried out to investigate the process of deflagration to detonation transition (DDT) occurring in a straight duct. The numerical method used includes a high resolution fifth-order weighted essentially non-oscillatory (WENO) scheme for spatial discretization, coupled with a third order total variation diminishing Runge-Kutta time stepping method. In particular, effect of energy release on the DDT process is studied. The model parameters used are the heat release atq= 50,30,25,20,15,10 and 5, the specific heat ratio at 1.2, and the activation temperature atTi= 15, respectively. For all the cases, the initial energy in the spark is about the same compared to the detonation energy at the Chapman-Jouguet (CJ) state. It is found from the simulation that the DDT occurrence strongly depends on the magnitude of the energy release. The run-up distance of DDT occurrence decreases with the increase of the energy release forq= 50 ~ 20, and increases with the increase of the energy release forq= 20 ~ 5. This phenomenon is found to be in agreement with the analysis of mathematical stability theory. It is suggested that the factors to strengthen the DDT would make the detonation more stable, and vice versa. Finally, it is concluded from the simulations that the interaction of the shock wave and the flame front is the main reason for leading to DDT.

This paper presents the development of an accurate and robust numerical modeling of instability of an interface separating two-phase system, such as liquid–gas and/or solid–gas systems. The instability of the interface can be refereed to the buoyancy and capillary effects in liquid–gas system. The governing unsteady Navier–Stokes along with the stress balance and kinematic conditions at the interface are solved separately in each fluid using the finite-volume approach for the liquid–gas system and the Hamilton–Jacobi equation for the solid–gas phase. The developed numerical model represents the surface and the body forces as boundary value conditions on the interface. The adapted approaches enable accurate modeling of fluid flows driven by either body or surface forces. The moving interface is tracked and captured using the level set function that initially defined for both fluids in the computational domain. To asses the developed numerical model and its versatility, a selection of different unsteady test cases including oscillation of a capillary wave, sloshing in a rectangular tank, the broken-dam problem involving different density fluids, simulation of air/water flow, and finally the moving interface between the solid and gas phases of solid rocket propellant combustion were examined. The latter case model allowed for the complete coupling between the gas-phase physics, the condensed-phase physics, and the unsteady nonuniform regression of either liquid or the propellant solid surfaces. The propagation of the unsteady nonplanar regression surface is described, using the Essentially-Non-Oscillatory (ENO) scheme with the aid of the level set strategy. The computational results demonstrate a remarkable capability of the developed numerical model to predict the dynamical characteristics of the liquid–gas and solid–gas flows, which is of great importance in many civilian and military industrial and engineering applications.

PurposeThe purpose of this paper is to develop and apply a high-order numerical method based on finite volume approximation for quadratic integrate-and-fire (QIF) neuron model with the help of population density approach.Design/methodology/approachThe authors apply the population density approach for the QIF neuron model to derive the governing equation. The resulting mathematical model cannot be solved with existing analytical or numerical techniques owing to the presence of delay and advance. The numerical scheme is based along the lines of approximation: spatial discretization is performed by weighted essentially non-oscillatory (WENO) finite volume approximation (FVM) and temporal discretization are performed by strong stability-preserving explicit Runge–Kutta (SSPERK) method. Compared with existing schemes of orders 2 and 3 from the literature, the proposed scheme is found to be more efficient and it produces accurate solutions with few grid cells. In addition to this, discontinuity is added in the application of the model equation to illustrate the high performance of the proposed scheme.FindingsThe developed scheme works nicely for the simulation of the resulting model equation. The authors discussed the role of inhibitory and excitatory parts in variation of neuronal firing. The validation of the designed scheme is measured by its comparison with existing schemes in the literature. The efficiency of the designed scheme is demonstrated via numerical simulations.Practical implicationsIt is expected that the present study will be a useful tool to tackle the complex neuron model and related studies.Originality/valueThe novel aspect of this paper is the application of the numerical methods to study the modified version of leaky integrate-and-fire neuron based on a QIF neuron. The model of the current study is inspired from the base model given in Stein (1965) and modified version in Kadalbajoo and Sharma (2005) and Wang and Zhang (2014). The applicability was confirmed by taking some numerical examples.

Abstract Abstract 4689 Background: Supportive care for dying hemato-oncological patients in the hospital remains an unmet need. The Liverpool Care Pathway (LCP) has been developed in Europe for patients in the final 24–72 h of life to help physicians and nurses in the end-of-life care (ELC). We evaluated appropriately timed cessation of treatment in a Hemato-Oncology Department after integration of a modified LCP in a tertiary Munich cancer center. The End-of-life Care Pathway was modified to suit local conditions. The aim of the trial was to include over 40% of dying patients in the ELC. The effectiveness of symptom control which included termination of not necessary drugs, sufficient pain relief, control of agitation, bronchial fluid secretion, dyspnoea, nausea and emesis was compared with a control group (CG). The ELC was in accordance to local ethics. Nurses and physicians were trained. The ELC was periodically reviewed by a local multidisciplinary steering group for improvements. Patients and Methods: From 01/10 until 06/11 a total of 228 cancer deaths were observed. Criteria for entry onto the ELC were that the multidisciplinary team agreed the patient was dying, and was at least two of the following: bedbound; semi-comatose; only able to take sips of fluid; no longer able to take tablets. 96 pts (41 male/55 female) went on the ELC (42%), while 132 dying cancer pts were not enrolled due to a variety of reasons (e.g. lack of informed consent, rapid deterioration). The mean age was 72,6 ys (range 33 to 91 ys). The median duration of ELC use was 41,3 hours (range 0.5 to 189 h). Six patients improved after they had entered the ELC and left the ELC consecutively. Out of these four patients reentered the ELC and died, one of these six patients died without being reentered on the ELC. Symptom control (ELC/CG in %) was achieved in pain in 92/50%; agitation 89/50%, nausea 96/40%, dyspnoea 92/55% while unnecessary medication was terminated in 95/90%. All patients had current medication assessed and non-essential drugs were discontinued. Inappropriate interventions with antibiotics (85/65%), blood tests (95/75%), iv fluids (90/70%) were terminated more often when pts entered the ELC. Conclusion: Integration of an ELC in a hematology unit provides a better symptom control for dying patients. Inappropriate interventions could be reduced. Appropriate template design and supervision are the keys to success for end-of-life care in cancer patients. Disclosures: No relevant conflicts of interest to declare.

2036 Background: Docosahexaenoic acid-paclitaxel (DHAP) is a covalent conjugate of paclitaxel and the essential fatty acid, docosahexaenoic acid. Preclinical studies have demonstrated increased activity relative to paclitaxel with the potential for an improved therapeutic ratio. We performed a phase 1 and pharmacokinetics (PK) study of DHAP in patients with resistant solid tumor malignancies. Methods: Patients were treated with DHAP administered by 2-hour intravenous infusion weekly for three out of four weeks. Dose escalation started at DHAP 200 mg/m2 and was increased by 100 mg/m2 per dose level ending at 600 mg/m2. Blood samples for PK of DHAP and paclitaxel derived from DHAP were collected in cycle 1 at 0 (prior to the start of the infusion), 2 (prior to the end of the infusion), 3, 4, 9, 26 hours and just prior to the next weekly treatment on days 8, 15 and 29. Results: Twenty-one patients enrolled and received 39 cycles of treatment (mean = 2). Three patients received DHAP at 200 mg/m2 (dose level 1), four at 300 mg/m2 (dose level 2), three at 400 mg/m2 (dose level 3) and 500 mg/m2 (dose level 4) each, and eight at 600 mg/m2 (dose level 5). In cycle 1, grade 2/3 neutropenia resulted in treatment delays for 8 patients, 6 of whom received treatment at dose level 4 and 5. Two of the 8 patients, treated with DHAP 600 mg/m2, went on to experience grade 4 neutropenia lasting < five days on later cycles. Only one patient had grade 2 sensory neuropathy, which occurred after 3 cycles of treatment. Preliminary PK analyses on all patients demonstrated that there is not a substantial accumulation of DHAP or paclitaxel with weekly treatment. Detailed PK analyses will be presented. Eighteen of the 21 patients were evaluable for response. Three patients, one each with esophageal and lung carcinoma and melanoma, had stable disease for 11, 16, and 17 weeks, respectively. Conclusions: DHAP administered weekly at 600 mg/m2 was well-tolerated and the maximum dose administered in this study. The slow release of paclitaxel from DHAP and the weekly schedule approximates continuous infusion paclitaxel which should be more active than every 3 week or weekly taxanes. Further studies with DHAP in non-small cell lung carcinoma and melanoma are on-going. [Table: see text]

Abstract Background Primary refractory myeloma is an important therapeutic challenge; understanding its clinical course and biology is essential if we are to recognize it early and target it therapeutically. Immunomodulatory (IMiD) drugs are widely used as induction therapy with good response rates but a small proportion of patients are refractory. The mechanism underlying IMiD resistance is poorly defined. Mutations in the cereblon pathway are a clear candidate but have not been widely looked for or reported. An important question is whether the primary refractory clone carries class-specific intrinsic resistance biology, leaving it sensitive to other non-cross reactive drugs, or if it is a universal resistance mechanism. We have examined the clinical course of patients with primary IMiD resistance, and whether they respond adequately to subsequent proteasome inhibition (PI), using the results of the largest clinical study in myeloma to date. Methods Myeloma XI is a UK based, open-label, parallel group, randomized controlled trial for newly diagnosed symptomatic myeloma patients of all ages. Treatment was with a combination of cyclophosphamide and dexamethasone plus either lenalidomide or thalidomide (CRD or CTD) for a minimum of 4 cycles (transplant eligible, TE) or 6 cycles (transplant non-eligible, TNE) or to maximum response. Those patients who had not achieved at least a minimal response or who had progressed during induction (PD) subsequently received a PI triplet (cyclophosphamide, bortezomib and dexamethasone, CVD). This abstract summarizes a preliminary analysis of these primary refractory cases, final data will be presented at the meeting. Results The study randomized 3894 patients of all ages giving adequate numbers to identify clinical/biological features in subgroups. Overall 207/3894 (5.3%) of patients had stable disease (SD) or PD at the end of the IMiD triplet. There was no significant difference between those who received thalidomide compared to lenalidomide (CTD: 110/1945, 5.7% CRD: 97/1949, 5.0%). A higher proportion of patients were refractory in the TNE pathway than TE (TE: 79/2042, 3.9%, TNE: 128/1852, 6.9%) 139 patients in the ITT population went on to receive treatment with bortezomib as part of the CVD regimen. The remainder n=69 were treated off protocol or died prior to treatment. CVD was well-tolerated in these patients with a median of 4 (1-8) cycles delivered. Of these patients 22/139 (16%) were also refractory to PI therapy whilst 57% upgraded their response compared to baseline: 32% [95%CI 24-40] to PR/MR and 25% [95%CI 18-33] to CR/VGPR. Patients with IMiD refractory disease had a significantly shorter PFS than those who responded to initial treatment median 8 vs 27 months, HR 2.10 [95% CI 1.77-2.49], p<0.001. For those who received subsequent CVD (n=139) and responded the median PFS was 19 months vs 7 months for double refractory patients. 32/50 transplant eligible patients who responded to CVD were able to go on and receive a transplant and had a PFS of 27 months. We compared the clinical and biological features of the double-refractory (n=22), IMiD refractory (n=185) and responsive (n=3349) patient groups. There was no significant difference in patient sex or median age (66 [range 41-78], 70 [38-88] and 67 [28-92] respectively). Laboratory measures suggested refractory patients had a higher burden of disease at diagnosis with a lower hemoglobin level and a higher proportion of patients with >20% plasma cells in their bone marrow biopsy. There was a higher proportion of patients with light chain only disease and the percentage of patients with ISS stage III was double-refractory 41%, IMiD refractory 45% and responsive 29%. The proportions of patients with adverse translocations and high-risk copy number abnormalities will be presented at the meeting. Conclusions We present the first detailed analysis of IMiD refractory myeloma patients at diagnosis. There was no difference in the percentage of patients refractory to the different IMiDs thalidomide and lenalidomide. Very few patients were primarily refractory to both IMiDs and proteasome inhibitors, suggesting the mechanisms of primary resistance to IMiDs and PIs do not significantly overlap. However, where this did occur outcomes were poor. The biological mechanisms behind resistance will be further informed by molecular studies of these patients' tumour samples. On behalf of the NCRI Haem Onc CSG Disclosures Pawlyn: Takeda Oncology: Consultancy; Celgene: Consultancy, Honoraria, Other: Travel Support. Davies:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Kaiser:Takeda: Consultancy, Other: Travel Support; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; BMS: Consultancy, Other: Travel Support; Celgene: Consultancy, Honoraria, Research Funding; Chugai: Consultancy. Jones:Celgene: Honoraria, Research Funding. Kishore:celgene: Other: travel grant. Garg:Janssen: Other: Travel support, Research Funding, Speakers Bureau; Takeda: Other: Travel support; Novartis: Other: Travel support, Research Funding. Williams:Novartis: Honoraria; Janssen: Honoraria, Other: Travel support, Speakers Bureau; Celgene: Honoraria, Other: Travel support, Speakers Bureau; Takeda: Honoraria, Other: Travel support, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Karunanithi:Celgene: Other: Travel support, Research Funding; Janssen: Other: Travel support, Research Funding. Lindsay:BMS: Consultancy, Other: Travel support; Novartis: Other: Travel support; Takeda: Other: Travel support; Janssen: Consultancy; Celgene: Honoraria, Other: Travel support. Jenner:Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Other: Travel support; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel support, Research Funding; Takeda: Consultancy, Honoraria, Other: Travel support. Cook:Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; Glycomimetics: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria. Drayson:Abingdon Health: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Owen:Takeda: Honoraria, Other: Travel support; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Other: Travel support. Jackson:Takeda: Consultancy, Honoraria, Other: Travel support, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Other: Travel support, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Morgan:Takeda: Consultancy, Honoraria; Bristol Meyers: Consultancy, Honoraria; Univ of AR for Medical Sciences: Employment; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding.

We’ll have trouble now!The Archaeological Society of Jutland was founded on Sunday, 11 March 1951. As with most projects with which P.V Glob was involved, this did not pass off without drama. Museum people and amateur archaeologists in large numbers appeared at the Museum of Natural History in Aarhus, which had placed rooms at our disposal. The notable dentist Holger Friis, the uncrowned king of Hjørring, was present, as was Dr Balslev from Aidt, Mr and Mrs Overgaard from Holstebro Museum, and the temperamental leader of Aalborg Historical Museum, Peter Riismøller, with a number of his disciples. The staff of the newly-founded Prehistoric Museum functioned as the hosts, except that one of them was missing: the instigator of the whole enterprise, Mr Glob. As the time for the meeting approached, a cold sweat broke out on the foreheads of the people present. Finally, just one minute before the meeting was to start, he arrived and mounted the platform. Everything then went as expected. An executive committee was elected after some discussion, laws were passed, and then suddenly Glob vanished again, only to materialise later in the museum, where he confided to us that his family, which included four children, had been enlarged by a daughter.That’s how the society was founded, and there is not much to add about this. However, a few words concerning the background of the society and its place in a larger context may be appropriate. A small piece of museum history is about to be unfolded.The story begins at the National Museum in the years immediately after World War II, at a time when the German occupation and its incidents were still terribly fresh in everyone’s memory. Therkel Mathiassen was managing what was then called the First Department, which covered the prehistoric periods.Although not sparkling with humour, he was a reliable and benevolent person. Number two in the order of precedence was Hans Christian Broholm, a more colourful personality – awesome as he walked down the corridors, with his massive proportions and a voice that sounded like thunder when nothing seemed to be going his way, as quite often seemed to be the case. Glob, a relatively new museum keeper, was also quite loud at times – his hot-blooded artist’s nature manifested itself in peculiar ways, but his straight forward appearance made him popular with both the older and the younger generations. His somewhat younger colleague C.J. Becker was a scholar to his fingertips, and he sometimes acted as a welcome counterbalance to Glob. At the bottom of the hierarchy was the student group, to which I belonged. The older students handled various tasks, including periodic excavations. This was paid work, and although the salary was by no means princely, it did keep us alive. Student grants were non-existent at the time. Four of us made up a team: Olfert Voss, Mogens Ørsnes, Georg Kunwald and myself. Like young people in general, we were highly discontented with the way our profession was being run by its ”ruling” members, and we were full of ideas for improvement, some of which have later been – or are being – introduced.At the top of our wish list was a central register, of which Voss was the strongest advocate. During the well over one hundred years that archaeology had existed as a professional discipline, the number of artefacts had grown to enormous amounts. The picture was even worse if the collections of the provincial museums were taken into consideration. We imagined how it all could be registered in a card index and categorised according to groups to facilitate access to references in any particular situation. Electronic data processing was still unheard of in those days, but since the introduction of computers, such a comprehensive record has become more feasible.We were also sceptical of the excavation techniques used at the time – they were basically adequate, but they badly needed tightening up. As I mentioned before, we were often working in the field, and not just doing minor jobs but also more important tasks, so we had every opportunity to try out our ideas. Kunwald was the driving force in this respect, working with details, using sections – then a novelty – and proceeding as he did with a thoroughness that even his fellow students found a bit exaggerated at times, although we agreed with his principles. Therkel Mathiassen moaned that we youngsters were too expensive, but he put up with our excesses and so must have found us somewhat valuable. Very valuable indeed to everyon e was Ejnar Dyggve’s excavation of the Jelling mounds in the early 1940s. From a Danish point of view, it was way ahead of its time.Therkel Mathiassen justly complained about the economic situation of the National Museum. Following the German occupation, the country was impoverished and very little money was available for archaeological research: the total sum available for the year 1949 was 20,000 DKK, which corresponded to the annual income of a wealthy man, and was of course absolutely inadequate. Of course our small debating society wanted this sum to be increased, and for once we didn’t leave it at the theoretical level.Voss was lucky enough to know a member of the Folketing (parliament), and a party leader at that. He was brought into the picture, and between us we came up with a plan. An article was written – ”Preserve your heritage” (a quotation from Johannes V. Jensen’s Denmark Song) – which was sent to the newspaper Information. It was published, and with a little help on our part the rest of the media, including radio, picked up the story.We informed our superiors only at the last minute, when everything was arranged. They were taken by surprise but played their parts well, as expected, and everything went according to plan. The result was a considerable increase in excavation funds the following year.It should be added that our reform plans included the conduct of exhibitions. We found the traditional way of presenting the artefacts lined up in rows and series dull and outdated. However, we were not able to experiment within this field.Our visions expressed the natural collision with the established ways that comes with every new generation – almost as a law of nature, but most strongly when the time is ripe. And this was just after the war, when communication with foreign colleagues, having been discontinued for some years, was slowly picking up again. The Archaeological Society of Jutland was also a part of all this, so let us turn to what Hans Christian Andersen somewhat provocatively calls the ”main country”.Until 1949, only the University of Copenhagen provided a degree in prehistoric archaeology. However, in this year, the University of Aarhus founded a chair of archaeology, mainly at the instigation of the Lord Mayor, Svend Unmack Larsen, who was very in terested in archaeology. Glob applied for the position and obtained it, which encompassed responsibility for the old Aarhus Museum or, as it was to be renamed, the Prehistoric Museum (now Moesgaard Museum).These were landmark events to Glob – and to me, as it turned out. We had been working together for a number of years on the excavation of Galgebakken (”Callows Hill”) near Slots Bjergby, Glob as the excavation leader, and I as his assistant. He now offered me the job of museum curator at his new institution. This was somewhat surprising as I had not yet finished my education. The idea was that I was to finish my studies in remote Jutland – a plan that had to be given up rather quickly, though, for reasons which I will describe in the following. At the same time, Gunner Lange-Kornbak – also hand-picked from the National Museum – took up his office as a conservation officer.The three of us made up the permanent museum staff, quickly supplemented by Geoffrey Bibby, who turned out to be an invaluable colleague. He was English and had been stationed in the Faeroe Islands during the war, where he learned to speak Danish. After 1945 he worked for some years for an oil company in the Gulf of Persia, but after marrying Vibeke, he settled in her home town of Aarhus. As his academic background had involved prehistoric cultures he wanted to collaborate with the museum, which Glob readily permitted.This small initial flock governed by Glob was not permitted to indulge inidleness. Glob was a dynamic character, full of good and not so good ideas, but also possessing a good grasp of what was actually practicable. The boring but necessary daily work on the home front was not very interesting to him, so he willingly handed it over to others. He hardly noticed the lack of administrative machinery, a prerequisite for any scholarly museum. It was not easy to follow him on his flights of fancy and still build up the necessary support base. However, the fact that he in no way spared himself had an appeasing effect.Provincial museums at that time were of a mixed nature. A few had trained management, and the rest were run by interested locals. This was often excellently done, as in Esbjerg, where the master joiner Niels Thomsen and a staff of volunteers carried out excavations that were as good as professional investigations, and published them in well-written articles. Regrettably, there were also examples of the opposite. A museum curator in Jutland informed me that his predecessor had been an eager excavator but very rarely left any written documentation of his actions. The excavated items were left without labels in the museum store, often wrapped in newspapers. However, these gave a clue as to the time of unearthing, and with a bit of luck a look in the newspaper archive would then reveal where the excavation had taken place. Although somewhat exceptional, this is not the only such case.The Museum of Aarhus definitely belonged among the better ones in this respect. Founded in 1861, it was at first located at the then town hall, together with the local art collection. The rooms here soon became too cramped, and both collections were moved to a new building in the ”Mølleparken” park. There were skilful people here working as managers and assistants, such as Vilhelm Boye, who had received his archaeological training at the National Museum, and later the partners A. Reeh, a barrister, and G.V. Smith, a captain, who shared the honour of a number of skilfully performed excavations. Glob’s predecessor as curator was the librarian Ejler Haugsted, also a competent man of fine achievements. We did not, thus, take over a museum on its last legs. On the other hand, it did not meet the requirements of a modern scholarly museum. We were given the task of turning it into such a museum, as implied by the name change.The goal was to create a museum similar to the National Museum, but without the faults and shortcomings that that museum had developed over a period of time. In this respect our nightly conversations during our years in Copenhagen turned out to be useful, as our talk had focused on these imperfections and how to eradicate them.We now had the opportunity to put our theories into practice. We may not have succeeded in doing so, but two areas were essentially improved:The numerous independent numbering systems, which were familiar to us from the National Museum, were permeating archaeological excavation s not only in the field but also during later work at the museum. As far as possible this was boiled down to a single system, and a new type of report was born. (In this context, a ”report” is the paper following a field investigation, comprising drawings, photos etc. and describing the progress of the work and the observations made.) The instructions then followed by the National Museum staff regarding the conduct of excavations and report writing went back to a 19th-century protocol by the employee G.V. Blom. Although clear and rational – and a vast improvement at the time – this had become outdated. For instance, the excavation of a burial mound now involved not only the middle of the mound, containing the central grave and its surrounding artefacts, but the complete structure. A large number of details that no one had previously paid attention to thus had to be included in the report. It had become a comprehensive and time-consuming work to sum up the desultory notebook records in a clear and understandable description.The instructions resulting from the new approach determined a special records system that made it possible to transcribe the notebook almost directly into a report following the excavation. The transcription thus contained all the relevant information concerning the in vestigation, and included both relics and soil layers, the excavation method and practical matters, although in a random order. The report proper could then bereduced to a short account containing references to the numbers in the transcribed notebook, which gave more detailed information.As can be imagined, the work of reform was not a continuous process. On the contrary, it had to be done in our spare hours, which were few and far between with an employer like Glob. The assignments crowded in, and the large Jutland map that we had purchased was as studded with pins as a hedge hog’s spines. Each pin represented an inuninent survey, and many of these grew into small or large excavations. Glob himself had his lecture duties to perform, and although he by no means exaggerated his concern for the students, he rarely made it further than to the surveys. Bibby and I had to deal with the hard fieldwork. And the society, once it was established, did not make our lives any easier. Kuml demanded articles written at lightning speed. A perusal of my then diary has given me a vivid recollection of this hectic period, in which I had to make use of the evening and night hours, when the museum was quiet and I had a chance to collect my thoughts. Sometimes our faithful supporter, the Lord Mayor, popped in after an evening meeting. He was extremely interested in our problems, which were then solved according to our abilities over a cup of instant coffee.A large archaeological association already existed in Denmark. How ever, Glob found it necessary to establish another one which would be less oppressed by tradition. Det kongelige nordiske Oldsskriftselskab had been funded in 1825 and was still influenced by different peculiarities from back then. Membership was not open to everyone, as applications were subject to recommendation from two existing members and approval by a vote at one of the monthly lecture meetings. Most candidates were of course accepted, but unpopular persons were sometimes rejected. In addition, only men were admitted – women were banned – but after the war a proposal was brought forward to change this absurdity. It was rejected at first, so there was a considerable excitement at the January meeting in 1951, when the proposal was once again placed on the agenda. The poor lecturer (myself) did his best, although he was aware of the fact that just this once it was the present and not the past which was the focus of attention. The result of the voting was not very courteous as there were still many opponents, but the ladies were allowed in, even if they didn’t get the warmest welcome.In Glob’s society there were no such restrictions – everyone was welcome regardless of sex or age. If there was a model for the society, it was the younger and more progressive Norwegian Archaeological Society rather than the Danish one. The main purpose of both societies was to produce an annual publication, and from the start Glob’s Kuml had a closer resemblance to the Norwegian Viking than to the Danish Aarbøger for nordisk Oldkyndighed og Historie. The name of the publication caused careful consideration. For a long time I kept a slip of paper with different proposals, one of which was Kuml, which won after having been approved by the linguist Peter Skautrup.The name alone, however, was not enough, so now the task became to find so mething to fill Kuml with. To this end the finds came in handy, and as for those, Glob must have allied him self with the higher powers, since fortune smiled at him to a considerable extent. Just after entering upon his duties in Aarhus, an archaeological sensation landed at his feet. This happened in May 1950 when I was still living in the capital. A few of us had planned a trip to Aarhus, partly to look at the relics of th e past, and partly to visit our friend, the professor. He greeted us warmly and told us the exciting news that ten iron swords had been found during drainage work in the valley of lllerup Aadal north of the nearby town of Skanderborg. We took the news calmly as Glob rarely understated his affairs, but our scepticism was misplaced. When we visited the meadow the following day and carefully examined the dug-up soil, another sword appeared, as well as several spear and lance heads, and other iron artefacts. What the drainage trench diggers had found was nothing less than a place of sacrifice for war booty, like the four large finds from the 1800s. When I took up my post in Aarhus in September of that year I was granted responsibility for the lllerup excavation, which I worked on during the autumn and the following six summers. Some of my best memories are associated with this job – an interesting and happy time, with cheerful comradeship with a mixed bunch of helpers, who were mainly archaeology students. When we finished in 1956, it was not because the site had been fully investigated, but because the new owner of the bog plot had an aversion to archaeologists and their activities. Nineteen years later, in 1975, the work was resumed, this time under the leadership of Jørgen Ilkjær, and a large amount of weaponry was uncovered. The report from the find is presently being published.At short intervals, the year 1952 brought two finds of great importance: in Februar y the huge vessel from Braa near Horsens, and in April the Grauballe Man. The large Celtic bronze bowl with the bulls’ heads was found disassembled, buried in a hill and covered by a couple of large stones. Thanks to the finder, the farmer Søren Paaske, work was stopped early enough to leave areas untouched for the subsequent examination.The saga of the Grauballe Man, or the part of it that we know, began as a rumour on the 26th of April: a skeleton had been found in a bog near Silkeborg. On the following day, which happened to be a Sunday, Glob went off to have a look at the find. I had other business, but I arrived at the museum in the evening with an acquaintance. In my diary I wrote: ”When we came in we had a slight shock. On the floor was a peat block with a corpse – a proper, well-preserved bog body. Glob brought it. ”We’ll be in trouble now.” And so we were, and Glob was in high spirits. The find created a sensation, which was also thanks to the quick presentation that we mounted. I had purchased a tape recorder, which cost me a packet – not a small handy one like the ones you get nowadays, but a large monstrosity with a steel tape (it was, after all, early days for this device) – and assisted by several experts, we taped a number of short lectures for the benefit of the visitors. People flocked in; the queue meandered from the exhibition room, through the museum halls, and a long way down the street. It took a long wait to get there, but the visitors seemed to enjoy the experience. The bog man lay in his hastily – procured exhibition case, which people circled around while the talking machine repeatedly expressed its words of wisdom – unfortunately with quite a few interruptions as the tape broke and had to be assembled by hand. Luckily, the tape recorders now often used for exhibitions are more dependable than mine.When the waves had died down and the exhibition ended, the experts examined the bog man. He was x-rayed at several points, cut open, given a tooth inspection, even had his fingerprints taken. During the autopsy there was a small mishap, which we kept to ourselves. However, after almost fifty years I must be able to reveal it: Among the organs removed for investigation was the liver, which was supposedly suitable for a C-14 dating – which at the time was a new dating method, introduced to Denmark after the war. The liver was sent to the laboratory in Copenhagen, and from here we received a telephone call a few days later. What had been sent in for examination was not the liver, but the stomach. The unfortunate (and in all other respects highly competent) Aarhus doctor who had performed the dissection was cal1ed in again. During another visit to the bogman’s inner parts he brought out what he believed to be the real liver. None of us were capable of deciding th is question. It was sent to Copenhagen at great speed, and a while later the dating arrived: Roman Iron Age. This result was later revised as the dating method was improved. The Grauballe Man is now thought to have lived before the birth of Christ.The preservation of the Grauballe Man was to be conservation officer Kornbak’s masterpiece. There were no earlier cases available for reference, so he invented a new method, which was very successful. In the first volumes of Kuml, society members read about the exiting history of the bog body and of the glimpses of prehistoric sacrificial customs that this find gave. They also read about the Bahrain expeditions, which Glob initiated and which became the apple of his eye. Bibby played a central role in this, as it was he who – at an evening gathering at Glob’s and Harriet’s home in Risskov – described his stay on the Persian Gulf island and the numerous burial mounds there. Glob made a quick decision (one of his special abilities was to see possibilities that noone else did, and to carry them out successfully to everyone’s surprise) and in December 1952 he and Bibby left for the Gulf, unaware of the fact that they were thereby beginning a series of expeditions which would continue for decades. Again it was Glob’s special genius that was the decisive factor. He very quickly got on friendly terms with the rulers of the small sheikhdoms and interested them in their past. As everyone knows, oil is flowing plentifully in those parts. The rulers were thus financially powerful and some of this wealth was quickly diverted to the expeditions, which probably would not have survived for so long without this assistance. To those of us who took part in them from time to time, the Gulf expeditions were an unforgettable experience, not just because of the interesting work, but even more because of the contact with the local population, which gave us an insight into local manners and customs that helped to explain parts of our own country’s past which might otherwise be difficult to understand. For Glob and the rest of us did not just get close to the elite: in spite of language problems, our Arab workers became our good friends. Things livened up when we occasionally turned up in their palm huts.Still, co-operating with Glob was not always an easy task – the sparks sometimes flew. His talent of initiating things is of course undisputed, as are the lasting results. He was, however, most attractive when he was in luck. Attention normally focused on this magnificent person whose anecdotes were not taken too seriously, but if something went wrong or failed to work out, he could be grossly unreasonable and a little too willing to abdicate responsibility, even when it was in fact his. This might lead to violent arguments, but peace was always restored. In 1954, another museum curator was attached to the museum: Poul Kjærum, who was immediately given the important task of investigating the dolmen settlement near Tustrup on Northern Djursland. This gave important results, such as the discovery of a cult house, which was a new and hitherto unknown Stone Age feature.A task which had long been on our mind s was finally carried out in 1955: constructing a new display of the museum collections. The old exhibitio n type consisted of numerous artefacts lined up in cases, accompaied ony by a brief note of the place where it was found and the type – which was the standard then. This type of exhibition did not give much idea of life in prehistoric times.We wanted to allow the finds to speak for themselves via the way that they were arranged, and with the aid of models, photos and drawings. We couldn’t do without texts, but these could be short, as people would understand more by just looking at the exhibits. Glob was in the Gulf at the time, so Kjærum and I performed the task with little money but with competent practical help from conservator Kornbak. We shared the work, but in fairness I must add that my part, which included the new lllerup find, was more suitable for an untraditional display. In order to illustrate the confusion of the sacrificial site, the numerous bent swords and other weapons were scattered a.long the back wall of the exhibition hall, above a bog land scape painted by Emil Gregersen. A peat column with inlaid slides illustrated the gradual change from prehistoric lake to bog, while a free-standing exhibition case held a horse’s skeleton with a broken skull, accompanied by sacrificial offerings. A model of the Nydam boat with all its oars sticking out hung from the ceiling, as did the fine copy of the Gundestrup vessel, as the Braa vessel had not yet been preserved. The rich pictorial decoration of the vessel’s inner plates was exhibited in its own case underneath. This was an exhibition form that differed considerably from all other Danish exhibitions of the time, and it quickly set a fashion. We awaited Glob’s homecoming with anticipation – if it wasn’t his exhibition it was still made in his spirit. We hoped that he would be surprised – and he was.The museum was thus taking shape. Its few employees included Jytte Ræbild, who held a key position as a secretary, and a growing number of archaeology students who took part in the work in various ways during these first years. Later, the number of employees grew to include the aforementioned excavation pioneer Georg Kunwald, and Hellmuth Andersen and Hans Jørgen Madsen, whose research into the past of Aarhus, and later into Danevirke is known to many, and also the ethnographer Klaus Ferdinand. And now Moesgaard appeared on the horizon. It was of course Glob’s idea to move everything to a manor near Aarhus – he had been fantasising about this from his first Aarhus days, and no one had raised any objections. Now there was a chance of fulfilling the dream, although the actual realisation was still a difficult task.During all this, the Jutland Archaeological Society thrived and attracted more members than expected. Local branches were founded in several towns, summer trips were arranged and a ”Worsaae Medal” was occasionally donated to persons who had deserved it from an archaeological perspective. Kuml came out regularly with contributions from museum people and the like-minded. The publication had a form that appealed to an inner circle of people interested in archaeology. This was the intention, and this is how it should be. But in my opinion this was not quite enough. We also needed a publication that would cater to a wider public and that followed the same basic ideas as the new exhibition.I imagined a booklet, which – without over-popularsing – would address not only the professional and amateur archaeologist but also anyone else interested in the past. The result was Skalk, which (being a branch of the society) published its fir t issue in the spring of 1957. It was a somewhat daring venture, as the financial base was weak and I had no knowledge of how to run a magazine. However, both finances and experience grew with the number of subscribers – and faster than expected, too. Skalk must have met an unsatisfied need, and this we exploited to the best of our ability with various cheap advertisements. The original idea was to deal only with prehistoric and medieval archaeology, but the historians also wanted to contribute, and not just the digging kind. They were given permission, and so the topic of the magazine ended up being Denmark’s past from the time of its first inhabitant s until the times remembered by the oldest of us – with the odd sideways leap to other subjects. It would be impossible to claim that Skalk was at the top of Glob’s wish list, but he liked it and supported the idea in every way. The keeper of national antiquities, Johannes Brøndsted, did the same, and no doubt his unreserved approval of the magazine contributed to its quick growth. Not all authors found it easy to give up technical language and express themselves in everyday Danish, but the new style was quickly accepted. Ofcourse the obligations of the magazine work were also sometimes annoying. One example from the diary: ”S. had promised to write an article, but it was overdue. We agreed to a final deadline and when that was overdue I phoned again and was told that the author had gone to Switzerland. My hair turned grey overnight.” These things happened, but in this particular case there was a happy ending. Another academic promised me three pages about an excavation, but delivered ten. As it happened, I only shortened his production by a third.The 1960s brought great changes. After careful consideration, Glob left us to become the keeper of national antiquities. One important reason for his hesitation was of course Moesgaard, which he missed out on – the transfer was almost settled. This was a great loss to the Aarhus museum and perhaps to Glob, too, as life granted him much greater opportunities for development.” I am not the type to regret things,” he later stated, and hopefully this was true. And I had to choose between the museum and Skalk – the work with the magazine had become too timeconsuming for the two jobs to be combined. Skalk won, and I can truthfully say that I have never looked back. The magazine grew quickly, and happy years followed. My resignation from the museum also meant that Skalk was disengaged from the Jutland Archaeological Society, but a close connection remained with both the museum and the society.What has been described here all happened when the museum world was at the parting of the ways. It was a time of innovation, and it is my opinion that we at the Prehistoric Museum contributed to that change in various ways.The new Museum Act of 1958 gave impetus to the study of the past. The number of archaeology students in creased tremendously, and new techniques brought new possibilities that the discussion club of the 1940s had not even dreamt of, but which have helped to make some of the visions from back then come true. Public in terest in archaeology and history is still avid, although to my regret, the ahistorical 1960s and 1970s did put a damper on it.Glob is greatly missed; not many of his kind are born nowadays. He had, so to say, great virtues and great fault s, but could we have done without either? It is due to him that we have the Jutland Archaeological Society, which has no w existed for half a century. Congr tulat ion s to the Society, from your offspring Skalk.Harald AndersenSkalk MagazineTranslated by Annette Lerche Trolle

Introduction Such symptoms as hard, complex, bodily or mental feelings, that turn our everyday life into a hell, at first, lead us to a doctor, and then - to a psychotherapist. A sick man is keen to get rid of a symptom. A doctor prescribes medication, that is ought to eliminate a symptom. A psychotherapist searches for a reason of the problem that needs to be removed. There is such an idea that a neurotic symptom, in particular, an anxiety - is a pathological (spare or extra) response of a body. It is generally believed that such anxiety doesn’t have some real, objective reasons and that it is the result of a nervous system disorder, or some disruption of a cognitive sphere etc. Meanwhile, it is known that in the majority of cases, medical examinations of anxious people show that they don’t have any organic damages, including nervous system. It often happens that patients even wish doctors have found at least any pathology and have begun its treatment. And yet - there is no pathology. All examinations indicate a high level of functionality of a body and great performance of the brain's work. Doctors throw their hands up, as they can't cure healthy people. One of my clients told me her story of such medical examinations (which I’ll tell you with her permission). She said that it was more than 10 years ago. So, when she told her doctor all of her symptoms - he seemed very interested in it. He placed a helmet with electrodes on her head and wore some special glasses, when, according to her words, he created some kind of stressful situation for her brain, as she was seeing some flashings of bright pictures in her eyes. She said that he had been bothered with her for quite a long time, and at the end of it he had told her that her brain had been performing the best results in all respects. He noted that he’d rarely got patients with such great health indicators. My client asked the doctor how rare that was. And he answered: “one client in two or three months.” At that moment my client didn’t know whether to be relieved, flattered or sad. But since then, when someone told her that anxiety was a certain sign of mental problems, or problems with the nervous system, or with a body in general, she answered that people who had anxiety usually had already got all the required medical examinations sufficiently, and gave them the advice to go through medical screening by themselves before saying something like that. Therefore, we see a paradoxical situation, when some experts point to a neurotic anxiety as if it is a kind of pathology, in other words - some result of a nervous system disorder. Other specialists in the same situation talk about cognitive impairments. And some, after all the examinations, are ready to send such patients into space Main text I don’t agree with the statement that any neurotic anxiety that happens is excessive and unfounded. It often happens that there is objective, specific and real causes for appearance of anxiety conditions. And these causes require solutions. And it’s not about some organic damages of the brain or nervous system. The precondition that may give a rise to anxiety disorder is the development of such a life story that at some stage becomes too toxic - when, on the one hand, a person interacts with the outside world in a way that destroys his or her personality, and, on the other hand, this person uses repression and accepts such situation as common and normal. Repression - is an essential condition for the development of a neurotic symptom. Sigmund Freud was the first who pointed this out. Repression is such a defense mechanism that helps people separate themselves from some unpleasant feelings of discomfort (pain) while having (external or internal) irritations. It is the situation when, despite the presence of irritations and painful feelings, a person, however, doesn't feel any of it and is not aware of them in his or her conscious mind. Repression creates the situation of so-called emotional anesthesia. As a result, a displacement takes place, so a body starts to signal about the existing toxic life situation via a symptom. Anxiety disorder is usually an appropriate response (symptom) of a healthy body to an unhealthy life situation, which is seen by a person as normal. And it’s common when such a person is surrounded by others (close people), who tend to benefit from such situation, and so they actively maintain this state of affairs, whether it is conscious for them or not. At the beginning of a psychotherapy almost all clients insist that everything is good in their lives, even great, as it is like in everyone else’s life. They say that they have only one problem, which is that goddamn symptom. So they focus all of their attention on that symptom. They are not interested in all the other aspects of their life, and they show their irritation when it comes to talking about it. People want to get rid of it, whatever it takes, but they often tend to keep their lives the way that it was. In such cases a psychotherapist is dealing with the resistance of clients, trying to turn their attention from a symptom to their everyday situation that includes their way of thinking, interactions with themselves and with others and with the external world in order to have the opportunity to see the real problem, to live it through, to rethink and to change the story of their lives. For better understanding about how it works I want to tell you three allegorical tales. The name of the first tale is “A frog in boiling water”. There is one scientific anecdote and an assumption (however, it is noted that such experiments were held in 19 century), that if we put a frog in a pot with warm water and start to slowly heat the water, then this frog get used to the temperature rise and stays in a hot water, the frog doesn’t fight the situation, slowly begins to lose its energy and at the last moment it couldn’t find enough strength and energy to get out of that pot. But if we throw a frog abruptly in hot water - it jumps out very quickly. It is likely that a frog, that is seating in boiling water, will have some responses of the body (symptoms). For example, the temperature of its body will rise, the same as the color of it, etc., that is an absolutely normal body response to the existing situation. But let us keep fantasizing further. Imagine a cartoon where such a frog is the magical cartoon hero, that comes to some magical cartoon doctor, shows its skin, that has changed the color, to the doctor, and asks to change the situation by removing this unpleasant symptom. So the doctor prescribes some medication to return the natural green color of the frog’s skin back. The frog gets back in its hot water. For some period of time this medication helps. But then, after a while, the frog’s body gets over the situation, and the redness of the frog's skin gets back. And the magical cartoon doctor states that the resistance of the body to this medication has increased, and each time prescribes some more and more strong drugs. In this example with the frog it is perfectly clear that the true solution of the problem requires the reduction of the water temperature in that pot. We could propose that magical cartoon frog to think and try to realize that: 1) the water in that pot is hot, and that is the reason why the skin is red; 2) the frog got used to this situation and that is why it is so unnoticeably for this frog; 3) if the temperature of the water in the pot still stay so hot, without any temperature drop, then all the medication works only temporarily; 4) if we lower the temperature in that pot - the redness disappears on its own, automatically and without any medication. Also this cartoon frog, that will go after the doctor to some cartoon physiotherapist, will face the necessity to give itself some answers for such questions as: 1) What is going on? Who has put this frog in that pot? Who is raising the temperature progressively? Who needs it? And what is the purpose or benefit for this person in that? Who benefits? 2) Why did the frog get into the pot? What are the benefits in it for the frog? Or why did the frog agree to that? 3) What does the frog lose when it gets out of this pot? What are the consequences of it for the frog? What does the frog have to face? What are the possible difficulties on the way? Who would be against the changes? With whom the frog may confront? 4) Is the frog ready to take control over its own pot in its own hands and start to regulate the temperature of the water by itself, so to make this temperature comfortable for itself? Is this frog ready to influence by itself on its own living space, to take the responsibility for it to itself? The example “A frog in boiling water” is often used as a metaphorical portrayal of the inability of people to respond (or fight back) to significant changes that slowly happen in their lives. Also this tale shows that a body, while trying to adjust to unfavorable living conditions, will react with a symptom. And it is very important to understand this symptom. Symptom - is the response of a body, it’s a way a body adjusts to some unfriendly environment. Symptom, on the one hand, informs about the existence of a problem, and from the other hand - tries to regulate this problem, at least in some way (like, to remove or reduce), at the level on which it can do it. The process is similar to those when, for example, in a body, while it suffers from some infectious disease, the temperature rises. Thus, on the one hand, the temperature informs about the existence of some infection. On the other hand, the temperature increase creates in a body the situation that is damaging for the infection. So, it would be good to think about in what way does an anxiety symptom help a body that is surrounded by some toxic life situation. And this is a good topic for another article. Here I want to emphasize that all the attempts to remove a symptom without a removal of a problem, without changing the everyday life story, may lead to strengthening of the symptom in the body. Even though the removal of a symptom without elimination of its cause has shown success, it only means that the situation was changed into the condition of asymptomatic existence of a problem. And it is, in its essence, a worse situation. For example, it can cause an occurrence of cancer. The tale “A frog in boiling water” is about the tendency of people to treat a symptom, instead of seeing their real problems, as its cause, and trying to solve it. People don’t want to see their problems, but it doesn’t mean that the problem doesn’t exist. The problem does exist and it continues to destroy a person, unnoticeably for him or her. A person with panic disorder could show us anxiety that is out of control (fear, panic), which, by its essence, seems to exist without any logical reason. Meanwhile the body of such a person could be in such processes that are similar to those that occur in the conditions of some real dangers, when the instinct for self-preservation is triggered and an automatic response of a body to fight or flight implements for its full potential. We can see or feel signs of this response, for example, in cases when some person tries to avoid some real or imaginary danger via attempts to escape (the feeling of fear), or tries to handle the situation by some attempts to fight (the feeling of anger). As I mentioned before, many doctors believe that such fear is pathological, as there is no real reason for such intense anxiety. They may see the cause of the problem in worrisome temper, so they try to remove specifically anxiety rather than help such patients to understand specific reason of their anxiety, they use special psychotherapeutic methods that are designed to help clients to develop logical thinking, so it must help them to realize the groundlessness of their anxiety. In my point of view, such anxiety often has specific, real reasons, when this response of a body, fight or flight, is absolutely appropriate, but not excessive or pathological. Inadequacy, in fact, is in the unconsciousness, but not in the reactions of a body. For a better understanding of the role of anxiety in some toxic environment, that isn’t realized, I want to tell you another allegorical tale called “The wolf and the hare”. Let us imagine that two cages were brought together in one room. The wolf was inside one cage and the hare was in another. The cages were divided by some kind of curtain that makes it impossible for them to see each other. At this point a question arises whether the animals react to each other in some way in such a situation, or not? I think that yes, they will. Since there are a lot of other receptors that participate in the receiving and processing of the sensory information. As well as sight and hearing, we have of course a range of other senses. For example, animals have a strong sense of smell. It is well known that people, along with verbal methods of communicating information, like language and speaking, also have other means of transmitting information - non-verbal, such as tone of voice, intonation, look, gestures, body language, facial expressions etc., that gives us the opportunity to receive additional information from each other. The lie detector works by using this principle: due to detecting non-verbal signals, it distinguishes the level of the accuracy of information that is transmitted. It is assumed, that about 30% of information, that we receive from the environment, comes through words, vision, hearing, touches etc. This is the information that we are aware of in our consciousness, so we could consciously (logically) use it to be guided by. And approximately 70% of everyday information about the reality around us we receive non-verbally, and this information in the majority of cases could remain in us without any recognition. It is the situation when we’ve already known something, and we even have already started to respond to it via our body, but we still don’t know logically and consciously that we know it. We can observe the responses of our own body without understanding what are the reasons for such responses. We can recognize this unconscious information through certain pictures, associations, dreams, or with the help of psychoanalysis. Psychoanalysis is a great tool that can help to recognize the information from the unconscious mind, so that it can be logically processed further on, in other words, a person then receives the opportunity to indicate the real problems and to make right decisions. But let us return to the tale where the hare and the wolf stay in one room and don’t see each other, and, maybe, don’t hear, though - feel. These feelings (in other words - non-verbal information that the hare receives) activate a certain response in the hare’s body. And it reacts properly and adequately to the situation, for instance, the body starts to produce adrenaline and runs the response “fight or flight”. So the hare starts to behave accordingly and we could see the following symptoms: the hare is running around his cage, fussing, having some tremor and an increased heart rate, etc.. And now let us imagine this tale in some cartoon. The hare stays in its house, and the wolf wanders about this house. But the hare doesn’t see the wolf. Though the body of the hare gives some appropriate responses. And then that cartoon hare goes to a cartoon doctor and asks that doctor to give it some pill from its tremor and the increased heart rate. And in general asks to treat in some way this incomprehensible, confusing, totally unreasonable severe anxiety. If we try to replace the situation from this fairy-tale to a life story, we could see that it fits well to the script of interdependent relationships, where there are a couple “a victim and an aggressor”, and where such common for our traditional families’ occurrences as a domestic family violence, psychological and physical abuse take place. Only in 2019 a law was passed that follows the European norms and gives a legislative definition of such concepts as psychological domestic abuse, sexual abuse, physical abuse, bullying, that criminalizes all of these occurrences, establishes the punishment and directly points to people that could be a potential abuser. Among them are: a husband towards his wife, parents towards their children, a wife towards her husband, a superior towards a subordinate, a teacher towards his or her students, children towards each other etc.. When it comes to recognition of something as unacceptable, it seems more easy to put to that category such occurrences as physical and sexual abuse, as we could see here some obvious events. For example, beating or sexual harassment. Our society is ready to respond to these incidents in more or less adequate way, and to recognize them as a crime. But it is harder to deal with the recognition of psychological abuse as an offence. Psychological abuse in our families is common. Psychological abuse occurs through such situations, when one person, while using different psychological manipulations, such as violation of psychological borders, imposition of feeling of guilty or shame, etc., force another person to give up his or her needs and desires, and so in such a way make this person live another’s life. Such actions have an extremely negative effect on the mental health of these people, just as much as physical abuse. It can destroy a person from the inside, ruin self-esteem and a feeling of self-worth, create the situation of absolute dependence such victim from an abuser, including financial dependence etc.. It often happens that psychological abuse takes place against the backdrop of demonstrations of care and love. So you've got this story about the wolf and the hare, that are right next to each other, and the shield between two of them is a repression - a psychological defense mechanism, when a person turns a blind eye to such offences, that take place in his or her own life and towards him or her. And this person considers this as normal, doesn't realize, doesn't have a resource to realize, that it is a crime. Most importantly - doesn’t feel anything, as a repression takes place. But a body responds in a right way - from a certain point of the existence of such a toxic situation the response “fight or flight” is launched in a body at full, in other words - the fear and anxiety with the associated symptoms. The third allegorical tale I called “Defective suit”, which I read in the book of Clarissa Pinkola Estés with the name “Running With the Wolves". “Once one man came to a tailor and started to try on a suit. When he was standing in front of a mirror, he saw that the costume had uneven edges. - Don’t worry, - said the tailor. - If you hold the short edge of the suit by your left hand - nobody notices it. But then the man saw that a lapel of a jacket folded up a little bit. - It's nothing. You only need to turn your head and to nail it by your chin. The customer obeyed, but when he put on trousers, he saw that they were pulling. - All right, so just hold your trousers like this by your right hand - and everything will be fine, - the tailor comforts him. The client agreed with him and took the suit. The next day he put on his new suit and went for a walk, while doing everything exactly in the way that the tailor told him to. He waddled in a park, while holding the lapel by his chin, and holding the short edge of the suit by his left hand, and holding his trousers by his right hand. Two old men, who were playing checkers, left the game and started to watch him. - Oh, God! - said one of them. - Look at that poor cripple. - Oh, yes - the limp - is a disaster. But I'm wondering, where did he get such a nice suit?” Clarissa wrote: “The commentary of the second old man reflects the common response of the society to a woman, who built a great reputation for herself, but turned into a cripple, while trying to save it. “Yes, she is a cripple, but look how great her life is and how lovely she looks.” When the “skin” that we put on ourselves towards society is small, we become cripples, but try to hide it. While fading away, we try to waddle perky, so everyone could see that we are doing really well, everything is great, everything is fine”. As for me, this tale is also about the process of forming a symptom in a situation when one person tries very hard to match to another one, whether it is a husband, a wife or parents. It’s about a situation when such a person always tries to support the other one, while giving up his or her own needs and causing oneself harm in such a way by feeling a tension every day, that becomes an inner normality. And so this person doesn’t give oneself a possibility to relax, to be herself (or himself), to be spontaneous, free. As a result, in this situation the person, who was supported, looks perfect from the outside, but those who tried to match, arises some visible defect, like a limp - a symptom. And so this person lives like a cripple, under everyday stress and tension, trying to handle it, while sacrificing herself (or himself) and trying to maintain this situation, so not to lose the general picture of a beautiful family and to avoid shame. The tailor, who made this defective suit and tells how to wear the suit properly, in order to keep things going as they are going, often is a mother who raised a problematic child and then tells another person how to deal with her child in the right way. It is the situation when a mother-in-law tells her daughter-in-law how to treat her son properly. In other words, how to support him, when to keep silent, to handle, how to fit in, so that her problematic son and this relationship in general looks perfect. Or vice versa, when a mother-in-law tells her son-in-law how to support her problematic daughter, how to fit in etc.. When, for example, a woman acts like this in her marriage and with her husband, with these excessive efforts to fit in - then after a while everybody will talk like: “Look at this lovely man: he lives with his sick wife, and their family seems perfect!”. But when such a woman becomes brave enough to relax and to just let the whole thing go, everybody will see that the relationship in her marriage isn’t perfect, and it is the other one who has problems. Each time when someone tries excessively to match up to another one, while turning oneself in some kind of a cripple, - he or she, on the one hand, supports the comfort of that person, to whom he or she tries to match up, and on the other hand - such a situation always arises in that person such conditions as a continuous tension, anxiety, fear to act spontaneously. A symptom - is like a visible defect, that shows itself through the body (and may look like some kind of injury). It is the result of a hidden inner prison. As a result of evolution, a pain tells us about a problem that is needed to be solved. When we repress our pain we can’t see our needs and our problems at full. And then a body starts to talk to us via a symptom. Psychotherapy aims for providing a movement from a symptom to a resumption of sensitivity to feelings, a resumption of the ability to feel your psychological pain, so you can realize your own toxic story. In this perspective another fairy-tale looks interesting to analyze - it is Andersen's fairytale “Princess and the Pea”. In the tale a prince wanted to find a princess to marry. There was one requirement for women candidates, so the prince could select her among commoner - high level of sensitivity, as the real princess would feel a pea through the mountain of mattresses, and so she could have the ability to feel discomfort, to be in a good contact with her body, to tell about her discomfort without such feeling as shame and guilt, and to refuse that discomfort, so to have the readiness to solve her problems and to demand from others the respect for her needs. It is common for our culture that the expression “a princess on a pea” very often uses for a negative meaning. So people who are in good contact with their body and who can demand comfort for themselves are often called capricious. At the same time the heroes who are ready to suffer and to tolerate their pain, who are able to repress (stop to feel) their pain represents a good example to be followed in our society. So, we may see the next algorithm in cases of various anxiety disorders: the existence of some toxic situation that brings some danger to a person. And we need not to be confused: a danger exists not for a body, but for a personality. A toxic live situation as well as having a panic attack is not a threat for the health of a body (that is what medical examinations show), and vice versa - it’s like every day intensive sport training, that could be good for your health only to some degree. A toxic situation destroys a person as a personality, who longs for one self’s expression; the existence of such a defense mechanism as repression - it’s a life with closed eyes, in pink glasses, when there is inability (or the absence of the desire) to see its own toxic story; 3.the presence of a symptom - a healthy response of a body “fight or flight” to some toxic situation; displacement - it’s replacement of the attention from the situation to a symptom, when a person starts to see and search for the problem in some other place, not where it really is. A symptom takes as some spare, pathological reaction that we need to get rid of. The readiness to fight the symptom arises, and that is the goal of such methods of therapy as pharmacological therapy, CBT and many others; the absence of adequate actions that are directed towards the change of a toxic situation itself. The absence of the readiness to show aggression when it comes to protect its space. All of it is a mechanism of formation of primary anxiety and preparation for launch of secondary anxiety. A complete anxiety disorder is the interaction between a primary and a secondary anxiety.