Relevant bibliographies by topics / Gradient-like system

Academic literature on the topic 'Gradient-like system'

Author: Grafiati
Published: 14 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Gradient-like system.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Gradient-like system"

1

Shavlyuk, A. Yu, and V. V. Semenov. "CONVERGENCE OF GRADIENT-LIKE DYNAMICAL SYSTEM." Journal of Numerical and Applied Mathematics, no. 1 (2022): 120–26. http://dx.doi.org/10.17721/2706-9699.2022.1.09.

Full text
Abstract:
The asymptotic behavior of the gradient system, which is a continuous analogue of the variant of the gradient method from [16] for the minimization of strongly convex functions, is studied. Using the Lyapunov analysis, estimates of the rate of convergence of the gradient system were established.
APA, Harvard, Vancouver, ISO, and other styles
2

Cabot, A. "Inertial Gradient-Like Dynamical System Controlled by a Stabilizing Term." Journal of Optimization Theory and Applications 120, no. 2 (February 2004): 275–303. http://dx.doi.org/10.1023/b:jota.0000015685.21638.8d.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wang, Dongqing, Tong Shan, and Rui Ding. "DATA FILTERING BASED STOCHASTIC GRADIENT ALGORITHMS FOR MULTIVARIABLE CARAR-LIKE SYSTEMS." Mathematical Modelling and Analysis 18, no. 3 (June 1, 2013): 374–85. http://dx.doi.org/10.3846/13926292.2013.804889.

Full text
Abstract:
This paper considers identification problems for a multivariable controlled autoregressive system with autoregressive noises. A hierarchical generalized stochastic gradient algorithm and a filtering based hierarchical stochastic gradient algorithm are presented to estimate the parameter vectors and parameter matrix of such multivariable colored noise systems, by using the hierarchical identification principle. The simulation results show that the proposed hierarchical gradient estimation algorithms are effective.
APA, Harvard, Vancouver, ISO, and other styles
4

Torras-Llort, M., J. F. Soriano-García, R. Ferrer, and M. Moretó. "Effect of a lysine-enriched diet onl-lysine transport by the brush-border membrane of the chicken jejunum." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 274, no. 1 (January 1, 1998): R69—R75. http://dx.doi.org/10.1152/ajpregu.1998.274.1.r69.

Full text
Abstract:
The influx ofl-lysine into apical vesicles from the chicken jejunum occurs through two systems, one with low Michaelis constant ( K m) and features of system b0,+ and the other with relatively high K m forl-lysine and with properties of system y+. In the present study the effect of a lysine-enriched diet (Lys, containing 68 g l-lysine/kg dietary protein, control animals 48 g/kg) onl-lysine uptake through both transport systems was investigated. Results show that 1) lysine enrichment had no effect on either body weight or the efficiency of food utilization. 2) In Lys-fed animals, the mediatedl-lysine influx was best fitted to the two-system model with y+and b0,+ activity. 3) In the presence of an Na+ gradient, totall-lysine uptake is significantly higher in Lys-fed animals than in control birds (about 40% increase). 4) Lys diet increases K mb0,+6-fold (KSCN gradient) and 12-fold (NaSCN gradient) and maximum velocity ( V max) by 6- and 20-fold, respectively. The effects of Lys enrichment on the y+-like system are only observed on the V max and in the presence of a Na+ gradient (30% increase). 5) Na+ is involved in the activation of the transport process in the Lys-fed chickens, but there is no correlation between external Na+concentration and l-lysine influx. In conclusion, both b0,+- and y+-like transport systems are upregulated by dietary lysine but with different kinetic profiles; the high-capacity y+-like carrier shows a V maxincrease without changes in K m, whereas the low-capacity b0,+-like system shows an increase in V max as well as in the K m.
APA, Harvard, Vancouver, ISO, and other styles
5

Tran, Minh-Phuong, and Thanh-Nhan Nguyen. "Asymptotic Behavior of Bounded Solutions to a First Order Gradient-like System." Journal of Advanced Engineering and Computation 3, no. 1 (March 31, 2019): 312. http://dx.doi.org/10.25073/jaec.201931.227.

Full text
Abstract:
In this paper, we prove the long time behavior of bounded solutions to a first order gradient-like system with low damping and perturbation terms. Our convergence results are obtained under some hypotheses of KurdykaLojasiewicz inequality and the angle and comparability condition.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
APA, Harvard, Vancouver, ISO, and other styles
6

Alvarez, F., H. Attouch, J. Bolte, and P. Redont. "A second-order gradient-like dissipative dynamical system with Hessian-driven damping." Journal de Mathématiques Pures et Appliquées 81, no. 8 (2002): 747–79. http://dx.doi.org/10.1016/s0021-7824(01)01253-3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Wu, F. Y., and F. Tong. "Gradient optimization p-norm-like constraint LMS algorithm for sparse system estimation." Signal Processing 93, no. 4 (April 2013): 967–71. http://dx.doi.org/10.1016/j.sigpro.2012.10.008.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Smirnova, Vera B., Anton V. Proskurnikov, and Natalia V. Utina. "New results on cycle–slipping in pendulum–like systems." Cybernetics and Physics, Volume 8, 2019, Number 3 (November 30, 2019): 167–75. http://dx.doi.org/10.35470/2226-4116-2019-8-3-167-175.

Full text
Abstract:
n this paper, we examine dynamics of multidimensional control systems obtained as feedback interconnections of stable linear blocks and periodic nonlinearities. The simplest of such systems is the model of mathematical pendulum (with viscous friction), so we call such systems pendulum-like. Other examples include, but are not limited to, coupled vibrating units, networks of oscillators, Josephson junction arrays and numerous synchronization circuits used in radio and telecommunication engineering. Typically, a pendulum-like system has infinite sequence of equilibria, and one of the central problems addressed in the theory of such systems is to find the conditions of “global stability”, or gradient-like behavior ensuring that every solution converges to one of the equilibria points. If a system is gradient-like, another problem arises, being the main concern of this paper: can we find the terminal equilibrium, given the initial condition of the system? It is well known that solutions do not converge, in general, to the nearest equilibrium; this phenomenon is known as cycle-slipping. For a pendulum, cycle-slipping corresponds to multiple rotations of the pendulum about its suspension point. In this paper, we estimate the number of slipped cycles for general pendulum-like systems by means of periodic Lyapunov functions and the Kalman-Yakubovich-Popov lemma.
APA, Harvard, Vancouver, ISO, and other styles
9

Singh, M., and R. K. Gupta. "On thermosolutal convection in presence of compressible fluid with fine dust." International Journal of Applied Mechanics and Engineering 19, no. 1 (February 1, 2014): 133–43. http://dx.doi.org/10.2478/ijame-2014-0010.

Full text
Abstract:
Abstract A layer of a Rivlin-Ericksen elastico-viscous fluid heated and soluted from below in the presence of compressibility and suspended particles (fine dust) effect is considered. For stationary convection, the Rivlin- Ericksen, elastico-viscous fluid behaves like a Newtonian fluid. The oscillatory modes are introduced due to the presence of a stable solute gradient, suspended particles destabilize the system whereas the stable solute gradient has a stabilizing effect on the system and the effect of compressibility is to postpone the onset of thermosolutal convection. The stable solute gradient and compressibility postpone the onset of convection, whereas the suspended particles hasten the onset of convection. The stable solute gradient introduces oscillatory modes in the systems which were non-existent in its absence
APA, Harvard, Vancouver, ISO, and other styles
10

Tran, Phuong Minh, and Nhan Thanh Nguyen. "On the Convergence of Bounded Solutions of Non Homogeneous Gradient-like Systems." Journal of Advanced Engineering and Computation 1, no. 1 (June 8, 2017): 61. http://dx.doi.org/10.25073/jaec.201711.50.

Full text
Abstract:
We study the long time behavior of the bounded solutions of non homogeneous gradient-like system which admits a strict Lyapunov function. More precisely, we show that any bounded solution of the gradient-like system converges to an accumulation point as time goes to infinity under some mild hypotheses. As in homogeneous case, the key assumptions for this system are also the angle condition and the Kurdyka-Lojasiewicz inequality. The convergence result will be proved under a L1 -condition of the perturbation term. Moreover, if the Lyapunov function satisfies a Lojasiewicz inequality then the rate of convergence will be even obtained.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Gradient-like system"

1

Lageman, Christian. "Convergence of gradient-like dynamical systems and optimization algorithms." Doctoral thesis, [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=985588780.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Bortolan, Matheus Cheque. "Atratores para sistemas dinâmicos discretos: dimensão fractal e continuidade da estrutura por perturbações." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-20052009-090139/.

Full text
Abstract:
Neste trabalho, estudamos uma generalização dos semigrupos gradientes, os semigrupos gradiente-like, algumas de suas propriedades e a sua invariância por pequenas perturbações; isto é, pequenas perturbações de sistemas gradiente-like continuam sendo gradiente-like. Como consequência da caracterização dos atratores para este tipo de sistema, estudamos a atração exponencial de atratores. Por fim, estudamos o concetio de dimensão de Hausdorff e dimensão fractal de atratores e apresentamos alguns resultados sobre este assunto, e estudamos a construção de uma nova classe de atratores, os atratores exponenciais fractais
In this work, we study a generalization of gradient discrete semigroups, the gradientlike semigroups, some of its properties and its invariance under small perturbations; that is, small perturbations of gradient-like semigroups are still gradient-like semigroups. As a consequence of the characterization of the attractors for this sort of semigroups, we study the exponential attraction of attractors. Finally, we study some concepts of Hausdorff dimension and fractal dimension and present some results about this subject, and we studied the construction of a new class of attractors, the exponential fractal attractors
APA, Harvard, Vancouver, ISO, and other styles
3

Costa, Éder Rítis Aragão. "Sistemas gradientes, decomposição de Morse e funções de Lyapunov sob perturbação." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-13042012-162303/.

Full text
Abstract:
Neste trabalho investigamos a existência de uma função de Lyapunov associada a um sistema de tipo gradiente, semigrupos ou processos de evolução. Para isso, um estudo detalhado da teoria de Morse desempenha um papel decisivo. Como principal consequência deste estudo obtemos a estabilidade dos sistemas gradientes sob perturbação (autônoma ou não). A aplicabilidade dos resultados abstratos que aqui discutimos é exemplificada estudando-se sistemas de equações diferenciais em espaços de Banach com acoplamento unilateral
In this work we investigated the existence of a Lyapunov function associated to a gradient-like system, semigroups or evolution processes. For that, a detailed study of Morse theory plays a central role. As the main consequence of this study we obtain the stability of gradient systems under perturbation (autonomous or not). The applicability of the abstract results discussed here is exemplified by studying systems of differential equations in Banach spaces with unilateral coupling
APA, Harvard, Vancouver, ISO, and other styles
4

Lageman, Christian [Verfasser]. "Convergence of gradient-like dynamical systems and optimization algorithms / vorgelegt von Christian Lageman." 2007. http://d-nb.info/985588780/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Gradient-like system"

1

Gradient inequalities with applications to asymptotic behavior and stability of gradient-like systems. Providence, R.I: American Mathematical Society, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Gradient-like system"

1

Haraux, Alain, and Mohamed Ali Jendoubi. "Gradient-Like Systems." In SpringerBriefs in Mathematics, 67–76. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-23407-6_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Huang, Sen-Zhong. "Applications to semilinear gradient-like systems in Hilbert spaces." In Mathematical Surveys and Monographs, 101–62. Providence, Rhode Island: American Mathematical Society, 2006. http://dx.doi.org/10.1090/surv/126/04.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Peng, Jie, Shi Shu, Chunsheng Feng, and Xiaoqiang Yue. "BPX-Like Preconditioned Conjugate Gradient Solvers for Poisson Problem and Their CUDA Implementations." In Advances in Intelligent Systems and Computing, 633–43. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-38789-5_70.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Tuomi, P., K. Suominen, and R. Autio. "Phytoplankton and bacterioplankton production and bacterial biomass in a fjord-like bay — open sea gradient." In Biological, Physical and Geochemical Features of Enclosed and Semi-enclosed Marine Systems, 141–50. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-0912-5_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Heiskanen, Anna-Stiina, and Petra Tallberg. "Sedimentation and particulate nutrient dynamics along a coastal gradient from a fjord-like bay to the open sea." In Biological, Physical and Geochemical Features of Enclosed and Semi-enclosed Marine Systems, 127–40. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-0912-5_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Dubey, Deepika, and Uday Pratap Singh. "Momentum- and Resilient-Based Level Set for Medical Image Segmentation." In Advances in Multimedia and Interactive Technologies, 280–305. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-5246-8.ch011.

Full text
Abstract:
In this chapter, the authors present the technique of medical image segmentation which means to partition an image into non-overlapping regions based on intensity. The active contour is one of the most successful level set methods for segmentation and it is widely applicable in various image processing applications including medical image segmentation. Biomedical image segmentation and analysis plays an important role in medical science and healthcare. This chapter proposes a momentum term and resilient propagation-based gradient descent method which will remove the sensitivity of local minima of gradient descent. Proposed method is applicable in case of diseases like retinal, diabetic, and glaucoma, etc. Medical image segmentation via momentum and resilient propagation based gradient descent method can be optimized and effectively used. Extensive experiments have been performed over medical images to test the ability of the system. The proposed method is able to present the segmented medical image with clear and smooth boundary also it is simple to design and implementation.
APA, Harvard, Vancouver, ISO, and other styles
7

Bikram Hamal, Achyut. "Brief Review of Portal Hypertension Related Complications." In Portal Hypertension - Recent Advances. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96646.

Full text
Abstract:
The pathologic increase in the pressure gradient between portal vein and inferior venacava is called portal hypertension. Increased portal blood flow and increased resistance in the portal venous system cause portal hypertension. The structural components and the functional components contribute to the resistance. Hepatic venous pressure gradient (HVPG) reflects the degree of portal pressure in liver disease. HVPG is calculated as the difference between the wedged hepatic venous pressure (WHVP) and the free hepatic venous pressure (FHVP). Clinically significant portal hypertension (CSPH) is defined as HVPG ≥10. Different values of HVPG have been defined as threshold for different consequences of portal hypertension. Variceal hemorrhage, portal hypertensive gastropathy, ascites, colopathy, biliopathy and hepatopulmonary syndrome are main complications of portal hypertension. Besides nonselective beta blockers, other drugs like statins, antioxidants, antidiabetic, anti-inflammatory and antiapoptotic drugs have also been seen to be effective in reducing portal pressure.
APA, Harvard, Vancouver, ISO, and other styles
8

Panagou, Dimitra, Dušan M. Stipanović, and Petros G. Voulgaris. "Distributed Control of Robot Swarms." In Robotic Systems, 1450–88. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1754-3.ch070.

Full text
Abstract:
This chapter considers the problem of multi-agent coordination and control under multiple objectives, and presents a set-theoretic formulation which is amenable to Lyapunov-based analysis and control design. A novel class of Lyapunov-like barrier functions is introduced and used to encode multiple control objectives, such as collision avoidance, proximity maintenance and convergence to desired destinations. The construction is based on recentered barrier functions and on maximum approximation functions. Thus, a single Lyapunov-like function is used to encode the constrained set of each agent, yielding simple, gradient-based control solutions. The derived control strategies are distributed, i.e., based on information locally available to each agent, which is dictated by sensing and communication limitations. The proposed coordination protocol dictates semi-cooperative conflict resolution among agents, as well as conflict resolution with respect to an agent (the leader) which is not actively participating in collision avoidance, except when necessary. The considered scenario is pertinent to surveillance tasks and involves nonholonomic vehicles. The efficacy of the approach is demonstrated through simulation results.
APA, Harvard, Vancouver, ISO, and other styles
9

Kelly, Alan. "Heating and Cooling of Food." In Molecules, Microbes, and Meals. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190687694.003.0014.

Full text
Abstract:
As we have seen, heating of food is one of the oldest and most powerful ways of making food safe and stable, whether cooking a burger on a barbecue or pasteurizing juice, but is also a potentially highly damaging thing to do to many food products. So, it makes sense that a key principle of processing food is to understand how to control the flow of heat as precisely as possible. In Chapter 8, I introduced how we can maximize the efficient transfer of heat into and out of food in a kitchen in simple systems, like pots on stoves. In practice, in large-scale processes, to transfer heat efficiently from hot to cold, and in this way keep the lords of thermodynamics happy while minimizing damage to the food being heated, we need to use clever pieces of equipment, called heat exchangers (reflecting the fact that, just as the cold part of the system gets hotter, so the hot part gets colder in the deal; fair exchange is no robbery). To visualize a heat exchanger, imagine a simple metal tube, through which a cold liquid is flowing from one end to the other. Now surround that tube with a larger one, through which a hot liquid flows (as shown in Figure 11.1). The wall of the inner tube is exposed to cold on the inside and hot on the outside, and this temperature gradient is the pump that transfers heat across that wall, in nature’s obsessive quest for equality in all things temperature-y. So, now we have two tubes laid horizontally in concentric neatness, say with a hot and a cold liquid flowing in from the left-hand side; as they exit at the right-hand side, the outer hot liquid will be colder, and the inner liquid will have gained the lost heat and thus become hotter. If the tubes were sufficiently long, then both would come out at exactly the same temperature.
APA, Harvard, Vancouver, ISO, and other styles
10

Furbish, David Jon. "Fluid Statics and Buoyancy." In Fluid Physics in Geology. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195077018.003.0010.

Full text
Abstract:
Fluid statics concerns the behavior of fluids that possess no linear acceleration within a global (Earth) coordinate system. This includes fluids at rest as well as fluids possessing steady motion such that no net forces exist. Such motions may include steady linear motion within the global coordinate system as well as rotation with constant angular velocity about a fixed vertical axis. In this latter case, centrifugal forces must be balanced by centripetal forces (which arise, for example, from a pressure gradient acting toward the axis of rotation). Moreover, we assert that no relative motion between adjacent fluid elements exists. Fluid motion, if present, is therefore like that of a rigid body. In addition, we neglect molecular motions that lead to mass transport by diffusion. Thus, the idea of a static fluid is a macroscopic one. The developments in this chapter clarify how pressure varies with coordinate position in a static fluid. Both compressible and incompressible fluids are treated. In the simplest case in which the density of a fluid is constant, we will see that pressure varies linearly with vertical position in the fluid according to the hydrostatic equation. In addition, we will consider the possibility that fluid density is not constant. Then, variations in density must be taken into account when computing the pressure at a given position in a fluid column; the pressure arising from the weight of the overlying fluid no longer varies linearly with depth. In the case of an isothermal fluid, whose temperature is constant throughout, any variation in density must arise purely from the compressible behavior of the fluid in response to variations in pressure. In the case where temperature varies with position, fluid density may vary with both pressure and temperature. We will in this regard consider the case of a thermally stratified fluid whose temperature varies only with the vertical coordinate direction. Because fluid statics requires treating how fluid temperature, pressure, and density are related, the developments below make use of thermodynamical principles developed in Chapter 4.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Gradient-like system"

1

Li, Linwei, Xianglong Liu, Fengxian Wang, Xuemei Ren, Hangli Ren, and Mo Zhou. "Internal Reconstruction Gradient Blind Estimation Method for Hammerstien-like System." In 2021 IEEE 10th Data Driven Control and Learning Systems Conference (DDCLS). IEEE, 2021. http://dx.doi.org/10.1109/ddcls52934.2021.9455365.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Hua, Minh-Duc, Tarek Hamel, Robert Mahony, and Jochen Trumpf. "Gradient-like observer design on the Special Euclidean group SE(3) with system outputs on the real projective space." In 2015 54th IEEE Conference on Decision and Control (CDC). IEEE, 2015. http://dx.doi.org/10.1109/cdc.2015.7402523.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Morelle, Patrick, and Alain Remouchamps. "Comparison of Gradient and Non Gradient Based Methods for Crash Optimisation." In ASME 2002 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/detc2002/dac-34045.

Full text
Abstract:
The BOSS Quattro system (developed by Samtech s.a.) is an open architecture allowing to run various optimisation engines including gradient based methods (SQP, GCMMA, Conlin, MDAQ, ...), DOE and Response Surfaces, and Genetic Algorithms. This system has been used and various optimisation strategies compared for the resolution of non linear optimisation problems including crash worthiness and airbags opening simulation. Thanks to BOSS Quattro open architecture, using neutral or specific drivers so to read information from models, software like MADIMO, Pam Crash, LS-Dyna, but also NASTRAN, SAMCEF and Abaqus can been used in order to model the non linear behaviour of the optimised vehicles. One or several models were used and computation distributed by BOSS parallel architecture on network of workstations. Direct parallel mode can be used, or the tasks distributed on the network through a Task Manager like for example LSF. As a first example, the optimisation of a stiffened box is performed using one (dynamic) then two models (static but elasto-plastic/dynamic). The external software used are NASTRAN and ABAQUS. A second example deals with the optimisation of a Golf crash model using MADIMO to represent a sequence of events including opening of air bags. Mixed optimisation is performed using as design variables : the time to open a given airbag (continuous) or the type of wheel configuration (pure discrete variable). Constraints are related to safety of the passenger (sternum invasion, various criteria related to accelerations).
APA, Harvard, Vancouver, ISO, and other styles
4

Karajgikar, Saket, Jasper Kidger, Andrew Shaw, Neil Edmunds, and Veerendra Mulay. "Single-Phase Immersion Cooling Study of a High-Density Storage System." In ASME 2022 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/ipack2022-97490.

Full text
Abstract:
Abstract In this paper, a standard air-cooled high-density storage system is reengineered to demonstrate the use of single-phase immersion cooling. The storage system consists primarily of seventy-two hard drives, two single socket nodes, two SAS expander cards, NIC and a power distribution board in a 4OU form factor. It is successfully demonstrated that the storage systems can be designed to support single phase immersion cooling while supporting hot swap and cooling redundancy requirement like an air-cooled system. In an air-cooled system, temperature gradient between the drives was as high as 19°C. The drives placed at the front of the system received cooler air while the drives placed in the rear received preheated air thus resulting in a temperature gradient. The drives used for the study were 20GB Helium filled sealed drives. For immersion cooling, seventy-two drives were cooled in parallel with temperature variance of less than 3°C. The other system components such as CPU, DIMMs, SAS chip and NIC had sufficient thermal margin. It was demonstrated that the system can operate reliably for facility coolant supply temperature as high as 40°C. The resulting power consumption of the pump was less than five percent of the total IT power. In addition, the proposed cooling solution may help mitigate acoustic vibrational issues for drives often encountered in air-cooling solution. The solution is virtually silent in operation.
APA, Harvard, Vancouver, ISO, and other styles
5

Chang, Pen-Lun, Meng-Ju Lin, and Tsung-Li Fan. "Deformation Analysis of Center-Anchored Square Plate Induced by Residual Gradient Stress." In ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73430.

Full text
Abstract:
For optical MEMS or Micro-Electro-Mechanical-Optical System (MEMOS) devices, as depositing metal on the structure plate, the mismatch of thermal expansion coefficients between the metal layer and structure layer will induce residual gradient stress after release. Therefore, the residual gradient stress will deform the structure layer. The deformation could be used as profile of micro focusing mirror due to its parabolic-like shape. In this work, the effect of structure sizes and material properties on residual stress for center-anchored square plate focusing mirror is investigated. The center-anchored circular plate focusing mirror is designed and analyzed. In numerical analysis using finite element method, it is found that the deformation is circular shape in axial direction and parabolic-like profile in the radial direction, even the mirror being square shape. And the radial shape determines the focal length. In general, the thinner plate and the thicker metal layer will cause larger deformation. The larger square sizes will cause larger deformation. However, it is found that the effect of anchor sizes on deformation could be neglected. Only in the anchor near region, the deformation would be affected. And the depositing temperature will have obvious effect on deformation. It is also found in literature review, the deformation would be unsymmetrical and called warpage. Warpage is a serious problem to destroy the devices. Therefore, the warpage is also discussed. The thicker structure layer and thinner metal layer need higher temperature to cause warpage phenomena. The warpage temperature increases nonlinearly as the structure layer increasing. However, in thinner structure layer condition, the warpage temperature decreases first and increases following. In general, from the results it could be considered that as the ratio of structure and depositing metal layer thickness increasing, the deformation will reach to a limit value due to the saturation of stress gradient.
APA, Harvard, Vancouver, ISO, and other styles
6

Aly, Mohamed, and Thomas Alberts. "De-Centralized and Centralized Control for EMS Maglev System Levitation and Guidance." In ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control. ASMEDC, 2011. http://dx.doi.org/10.1115/dscc2011-6166.

Full text
Abstract:
The comparison between PD de-centralized and centralized control for an EMS maglev system that uses combined magnets with an inverted U-rail for levitation and guidance is presented. A simple 2-DOF maglev system model (rigid and flexible body cases) that comprises heave and lateral modes is used. The comparison is based on two aspects. First, by sketching the multi-input multi-output (MIMO) root loci with every controller individually for system rigid and flexible body cases. Second, a gradient-like search algorithm based on an optimal criterion for PD de-centralized and centralized controllers’ gains tuning is used. Simulation results of the maglev system with these tuned controllers show that the centralized control scheme is capable of lateral displacements suppression that may result from disturbing lateral forces than the de-centralized one.
APA, Harvard, Vancouver, ISO, and other styles
7

Liao, Hanlin, Hao Deng, and Christian Coddet. "Conjugated Gradient Method for Estimating Inversely the Flux Distribution of Cooling Jets." In ITSC2003, edited by Basil R. Marple and Christian Moreau. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.itsc2003p0981.

Full text
Abstract:
Abstract It is necessary to cool specimens during spraying in the case APS or HVOF, because process-induced heat rises the specimen temperature and leads to oxidation and spalling of coatings. A reasonable cooling just after spraying improves some properties such as microhardness, adhesion and cohesion of the coating/substrate system. In the modelling of specimen temperature and residual stress, it is necessary to know the flux distribution of the cooling jet like compressed air, CO2 liquid jet etc. Therefore, the evaluation of the flux becomes important. In order to measure and analyse the distribution of cooling flux imposed on the substrate, the theory of the inverse problem of heat conduction was applied and an experimental apparatus was designed to mesure the transient temperature. Because of its insensibility to the effect of measuring error, the conjugate gradient method, an effective method of inverse problems was chosen among several mathematical optimisation methods. The flux distributions of cooling jet can be estimated by using the measured data and a program written according to the conjugate gradient method.
APA, Harvard, Vancouver, ISO, and other styles
8

Yerram, Ravinder, Richard Watkins, and Balakrishnan Ponnuraj. "Aeroderivative Gas Turbine Enclosure Ventilation System." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-59136.

Full text
Abstract:
Abstract GE Aeroderivative Gas Turbines are derived from GE’s Aircraft engine family and converted to Land and Marine applications. As these Aeroderivative Gas Turbines are relatively smaller in size for similar power capacity in comparison to Heavy Duty Gas Turbines, there is a great need of developing efficient and compact turbine enclosure ventilation system for proper cooling and ventilation. Ineffective ventilation flow distribution inside the gas turbine enclosure causes engine circumferential nonuniform temperature distribution and it allows the formation of explosive fuel gas pockets inside the enclosure in the unlikely event of fuel leaks. Also, the engine nonuniform circumferential temperature gradient has an adverse impact on the operational efficiency and/or the mechanical integrity of the turbine. Proper cooling and ventilation system will also protect the sensitive equipment, like fuel valve actuators or any other instruments inside the turbine enclosure due to excessive radiation heat from engine hot surfaces, mainly near combustor and power turbine region. All the expected but significant engine leakages into the enclosure are estimated and considered for selection of right size, type, placing of ventilation fan at different operating conditions like full load, part load, elevation and ambient conditions. For first step, a 3D Computational Fluid Dynamics (CFD) analyses were done for turbine enclosure with mass/volumetric flow rate, temperature, and pressure boundary conditions to understand the flow/temperature distribution inside the enclosure. Radiation boundary conditions are applied on the engine casing external surfaces, enclosure walls and roof. The convective heat transfer from the hot surfaces are computed by CFD model based on the velocity and temperature predictions. In next step, from CFD analysis, identified the poor ventilation/stagnation zones using low velocity and recirculation areas close to the gas fuel components. After identifying the poor ventilation regions, a gas leak was introduced to see whether gas cloud volume is within the ISO 21789 – 2009 limits. From gas leak analysis results, enclosure outlet IR detector settings were decided and implemented to monitor the gas leak amount and feedback to control system in the form of ALARM/SHUTDOWN so that Gas Turbine operates safely.
APA, Harvard, Vancouver, ISO, and other styles
9

Ying Yang and Lin Huang. "Gradient-like behavior analysis and synthesis of uncertain pendulum-like systems." In Proceedings of the 2004 American Control Conference. IEEE, 2004. http://dx.doi.org/10.23919/acc.2004.1384682.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Li, Zhenlei, Hao Xu, Duoqi Shi, Chaoshuo Yang, and Xiaoguang Yang. "High Cycle Bending Fatigue Failure Mechanism of a Blade-Like Specimen at High Stress Ratios." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-81906.

Full text
Abstract:
Abstract In the present study, the behavior of high cycle bending fatigue (HCBF) with high stress ratio at elevated temperature was experimentally investigated. A Ni-based blade-like specimen was designed and manufactured to represent the structural details between the airfoil and the platform of turbine blade. Then, a novel test rig was developed for the application of axial loading and transversal vibration. Then, the biaxial HCBF test system was constructed, including the axial loading, transverse excitation, electromagnetic induction heating, water cooling, control and on-line measurement subsystems. HCBF experiments were performed on the bladelike specimen under high frequency vibration at 850°C, using a novel biaxial experimental methodology. Test results show that the HCBF life was significantly shorter than axial high cycle fatigue (AHCF) in Haigh diagram. Compared with the conventional AHCF, the bending stress gradient and high stress ratio lead to a different fatigue behavior and damage process of HCBF. Scanning electron microscopy (SEM) observations reveal that creep-induced microstructure degradation and voids significantly accelerate the damage process of HCBF at high temperature.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Gradient-like system"

1

Meir, Shimon, Michael S. Reid, Cai-Zhong Jiang, Amnon Lers, and Sonia Philosoph-Hadas. Molecular Studies of Postharvest Leaf and Flower Senescence. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592657.bard.

Full text
Abstract:
Original objectives: To understand the regulation of abscission by exploring the nature of changes of auxin-related gene expression in tomato (Lycopersicon esculatumMill) abscission zones (AZs) following organ removal, and by analyzing the function of these genes. Our specific goals were: 1) To complete the microarray analyses in tomato flower and leaf AZs, for identifying genes whose expression changes early in response to auxin depletion; 2) To examine, using virus-induced gene silencing (VIGS), the effect of silencing target genes on ethylene sensitivity and abscission competence of the leaf and flower AZs; 3) To isolate and characterize promoters from AZ-specific genes to be used in functional analysis; 4) To generate stable transgenic tomato plants with selected genes silenced with RNAi, under the control of an AZ-specific promoter, for further characterization of their abscission phenotypes. Background: Abscission, the separation of organs from the parent plant, results in postharvest quality loss in many ornamentals and other fresh produce. The process is initiated by changes in the auxin gradient across the AZ, and is triggered by ethylene. Although changes in gene expression have been correlated with the ethylene-mediated execution of abscission, there is almost no information on the initiation of the abscission process, as the AZ becomes sensitized to ethylene. The present project was focused on elucidating these early molecular regulatory events, in order to gain a better control of the abscission process for agricultural manipulations. Major conclusions, solutions, achievements: Microarray analyses, using the Affymetrix Tomato GeneChip®, revealed changes in expression, occurring early in abscission, of many genes with possible regulatory functions. These included a range of auxin- and ethylene-related transcription factors (TFs), other TFs that are transiently induced just after flower removal, and a set of novel AZ-specific genes. We also identified four different defense-related genes, including: Cysteine-type endopeptidase, α- DOX1, WIN2, and SDF2, that are newly-associated with the late stage of the abscission process. This supports the activation of different defense responses and strategies at the late abscission stages, which may enable efficient protection of the exposed tissue toward different environmental stresses. To facilitate functional studies we implemented an efficient VIGS system in tomato, and isolated two abscission-specific promoters (pTAPG1 and pTAPG4) for gene silencing in stable transformation. Using the VIGS system we could demonstrate the importance of TAPGs in abscission of tomato leaf petioles, and evaluated the importance of more than 45 genes in abscission. Among them we identified few critical genes involved in leaf and flower abscission. These included: PTRP-F1, PRP, TKN4, KNOTTED-like homeobox TF, KD1, and KNOX-like homeodomain protein genes, the silencing of which caused a striking retardation of pedicel abscission, and ERF1, ERF4, Clavata-like3 protein, Sucrose transporter protein, and IAA10 genes, the silencing of which delayed petiole abscission. The importance of PRPand KD1 genes in abscission was confirmed also by antisense–silencing using pTAPG4. Experiments testing the effects of RNAi silencing of few other genes are still in progress, The analysis of the microarray results of flower and leaf AZs allowed us to establish a clear sequence of events occurring during acquisition of tissue sensitivity to ethylene, and to confirm our hypothesis that acquisition of ethylene sensitivity in the AZ is associated with altered expression of auxin-regulated genes in both AZs. Implication, both scientific and agricultural: Our studies had provided new insights into the regulation of the abscission process, and shaded light on the molecular mechanisms that drive the acquisition of abscission competence in the AZ. We pointed out some critical genes involved in regulation of abscission, and further expanded our knowledge of auxin-ethylene cross talk during the abscission process. This permits the development of novel techniques for manipulating abscission, and thereby improving the postharvest performance of ornamentals and other crops.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Gradient-like system' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography