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Gao, Yu. "Luminous IR Galaxies: Evolution and Molecular Gas." International Astronomical Union Colloquium 159 (1997): 439–40. http://dx.doi.org/10.1017/s0252921100040690.
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Luminous infrared galaxies (LIRGs), denned by the criterion LIR ≳ 2 × 1011L⊙ (for H0=75 kms−1 Mpc−1), are the most powerful IR sources in the Universe, with most of their emission (~ 90%) in the far-IR. Most LIRGs are interacting/merging galaxies with large amounts of molecular gas as revealed by CO surveys (Sanders et al. 1991; Solomon et al. 1996). However, whether starbursts or dust-enshrouded AGNs/QSOs dominate the IR luminosity is not resolved.CO may not trace the active star-forming regions where gas density is more than one order of magnitude higher than the average. Dense molecular gas is better traced by high dipole-moment molecules like HCN and CS (e.g., Nguyen-Q-Rieu et al. 1992; Gao & Solomon 1996). Therefore, it is essential to survey HCN emission in a large sample of LIRGs to better reveal the nature of LIRGs. We here study IR and molecular gas properties vs. galaxy-galaxy interactions in LIRGs over various merging phases to trace their evolution and explore some links among interactions, starbursts, and AGN phenomena.
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Yi, Huiguo, Jie Yang, Pingxiang Li, Lei Shi, and Fengkai Lang. "A PolSAR Image Segmentation Algorithm Based on Scattering Characteristics and the Revised Wishart Distance." Sensors 18, no. 7 (2018): 2262. http://dx.doi.org/10.3390/s18072262.
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A novel segmentation algorithm for polarimetric synthetic aperture radar (PolSAR) images is proposed in this paper. The method is composed of two essential components: a merging order and a merging predicate. The similarity measured by the complex-kind Hotelling–Lawley trace (HLT) statistic is used to decide the merging order. The merging predicate is determined by the scattering characteristics and the revised Wishart distance between adjacent pixels, which can greatly improve the performance in speckle suppression and detail preservation. A postprocessing step is applied to obtain a satisfactory result after the merging operation. The decomposition and merging processes are iteratively executed until the termination criterion is met. The superiority of the proposed method was verified with experiments on two RADARSAT-2 PolSAR images and a Gaofen-3 PolSAR image, which demonstrated that the proposed method can obtain more accurate segmentation results and shows a better performance in speckle suppression and detail preservation than the other algorithms.
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MacLeod, Morgan, Kishalay De, and Abraham Loeb. "Dusty, Self-obscured Transients from Stellar Coalescence." Astrophysical Journal 937, no. 2 (2022): 96. http://dx.doi.org/10.3847/1538-4357/ac8c31.
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Abstract We discuss the central role that dust condensation plays in shaping the observational appearance of outflows from coalescing binary systems. As binaries begin to coalesce, they shock-heat and expel material into their surroundings. Depending on the properties of the merging system, this material can expand to the point where molecules and dust form, dramatically increasing the gas opacity. We use the existing population of luminous red novae to constrain the thermodynamics of these ejecta, then apply our findings to the progressive obscuration of merging systems in the lead up to their coalescence. Compact progenitor stars near the main sequence or in the Hertzsprung gap along with massive progenitor stars have sufficiently hot circumstellar material to remain unobscured by dust. By contrast, more extended, low-mass giants should become completely optically obscured by dust formation in the circumbinary environment. We predict that 30%–50% of stellar-coalescence transients for solar-mass stars will be dusty, infrared-luminous sources. Of these, the optical transients may selectively trace complete merger outcomes while the infrared transients trace common envelope ejection outcomes.
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Hamasuna, Yukihiro, Ryo Ozaki, and Yasunori Endo. "Two-Stage Clustering Based on Cluster Validity Measures." Journal of Advanced Computational Intelligence and Intelligent Informatics 22, no. 1 (2018): 54–61. http://dx.doi.org/10.20965/jaciii.2018.p0054.
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To handle a large-scale object, a two-stage clustering method has been previously proposed. The method generates a large number of clusters during the first stage and merges clusters during the second stage. In this paper, a novel two-stage clustering method is proposed by introducing cluster validity measures as the merging criterion during the second stage. The significant cluster validity measures used to evaluate cluster partitions and determine the suitable number of clusters act as the criteria for merging clusters. The performance of the proposed method based on six typical indices is compared with eight artificial datasets. These experiments show that a trace of the fuzzy covariance matrixWtrand its kernelizationKWtrare quite effective when applying the proposed method, and obtain better results than the other indices.
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Norris, Dennis, James M. McQueen, and Anne Cutler. "Merging information in speech recognition: Feedback is never necessary." Behavioral and Brain Sciences 23, no. 3 (2000): 299–325. http://dx.doi.org/10.1017/s0140525x00003241.
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Top-down feedback does not benefit speech recognition; on the contrary, it can hinder it. No experimental data imply that feedback loops are required for speech recognition. Feedback is accordingly unnecessary and spoken word recognition is modular. To defend this thesis, we analyse lexical involvement in phonemic decision making. TRACE (McClelland & Elman 1986), a model with feedback from the lexicon to prelexical processes, is unable to account for all the available data on phonemic decision making. The modular Race model (Cutler & Norris 1979) is likewise challenged by some recent results, however. We therefore present a new modular model of phonemic decision making, the Merge model. In Merge, information flows from prelexical processes to the lexicon without feedback. Because phonemic decisions are based on the merging of prelexical and lexical information, Merge correctly predicts lexical involvement in phonemic decisions in both words and nonwords. Computer simulations show how Merge is able to account for the data through a process of competition between lexical hypotheses. We discuss the issue of feedback in other areas of language processing and conclude that modular models are particularly well suited to the problems and constraints of speech recognition.
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Lee, Jin, Jae Hwa Lee, Jung-Il Choi, and Hyung Jin Sung. "Spatial organization of large- and very-large-scale motions in a turbulent channel flow." Journal of Fluid Mechanics 749 (May 23, 2014): 818–40. http://dx.doi.org/10.1017/jfm.2014.249.
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AbstractDirect numerical simulations were carried out to investigate the spatial features of large- and very-large-scale motions (LSMs and VLSMs) in a turbulent channel flow ($\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{Re}_{\tau }=930$). A streak detection method based on the streamwise velocity fluctuations was used to individually trace the cores of LSMs and VLSMs. We found that both the LSM and VLSM populations were large. Several of the wall-attached LSMs stretched toward the outer regions of the channel. The VLSMs consisted of inclined outer LSMs and near-wall streaks. The number of outer LSMs increased linearly with the streamwise length of the VLSMs. The temporal features of the low-speed streaks in the outer region revealed that growing and merging events dominated the large-scale (1–$3\delta $) structures. The VLSMs $({>}3\delta )$ were primarily created by merging events, and the statistical analysis of these events supported that the merging of large-scale upstream structures contributed to the formation of VLSMs. Because the local convection velocity is proportional to the streamwise velocity fluctuations, the streamwise-aligned structures of the positive- and negative-$u$ patches suggested a primary mechanism underlying the merging events. The alignment of the positive- and negative-$u$ structures may be an essential prerequisite for the formation of VLSMs.
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LIN, JA-CHEN. "MULTI-CLASS CLUSTERING BY ANALYTICAL TWO-CLASS FORMULAS." International Journal of Pattern Recognition and Artificial Intelligence 10, no. 04 (1996): 307–23. http://dx.doi.org/10.1142/s0218001496000220.
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This paper proposes a new clustering method based on the hierarchical use of the analytical two-class clustering tool introduced by Lin and Tsai.1 The method comprises two phases. In the first phase, called the splitting phase, the data set is hierarchically decomposed into some subsets. In the second phase, called the merging phase, the set-to-set distances between these subsets are checked so that some subsets can be merged back together to obtain better clustering results. We use the idea of the so-called dense cut to determine when to stop the splitting phase. We also use a trace-following technique for the so-called boundary data to reduce significantly the computational load involved in the merging phase. Two algorithms are provided, and many experiments are included to show that the data being processed are not required to be linearly separable, noiseless, or formed of spherical clusters.
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Hollands, Carolyn, Steve Droho, Steve Crone, and Kamal Sharma. "Merging anterior–posterior and dorsal–ventral markers to trace neuronal lineages in the mouse brainstem." Developmental Biology 356, no. 1 (2011): 239. http://dx.doi.org/10.1016/j.ydbio.2011.05.418.
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Ren, Nana, Yuyi Zhang, Wenlong Shu, et al. "Impact of Hydrogen Voiding in Chip-to-Chip Electroless All-Copper Interconnections." Micromachines 15, no. 5 (2024): 612. http://dx.doi.org/10.3390/mi15050612.
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Three-dimensional (3D) integration has become a leading approach in chip packaging. The interconnection density and reliability of micro-bumps in chip stacking are often threatened by high bonding temperatures. The method of building chip-to-chip interconnections by electroless deposition of metal has its distinct merit, while the interfacial defect issue, especially that related to voiding during the merging of opposite sides, remains largely unsolved. In this study, to trace the influencing factors in the voiding, the growth characteristics of the electroless all-copper interconnections were examined by carrying out deposition experiments in a microfluidic channel device. The results show that when the gap between the opposite copper bumps to be electrolessly merged is as low as 10 μm, significant voids appear at the inflow side and the top of the copper bumps because the hydrogen cannot be expelled in time. A finite-element flow model of the plating solution between the chips was established, which showed that the flow rate of the plating solution around the copper bumps was much higher than in the merging gap, causing an uneven supply of reactants. Based on these findings, we proposed two potential solutions, one is to improve the flow mode of the plating solution, and the other is to add the reaction inhibitor, 2,2′-bipyridine. Finally, the combination of these two approaches successfully achieved an improved merging quality of the copper joints.
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Giglio, L., J. T. Randerson, G. R. van der Werf, et al. "Assessing variability and long-term trends in burned area by merging multiple satellite fire products." Biogeosciences Discussions 6, no. 6 (2009): 11577–622. http://dx.doi.org/10.5194/bgd-6-11577-2009.
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Abstract. Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees to develop relationships between burned area and Terra MODIS active fire data. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 12 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.
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Giglio, L., J. T. Randerson, G. R. van der Werf, et al. "Assessing variability and long-term trends in burned area by merging multiple satellite fire products." Biogeosciences 7, no. 3 (2010): 1171–86. http://dx.doi.org/10.5194/bg-7-1171-2010.
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Abstract. Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.
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Kumar, Ankit, Mousumi Das, and Sandeep Kumar Kataria. "The evolution of bulges of galaxies in minor fly-by interactions." Proceedings of the International Astronomical Union 14, S353 (2019): 166–67. http://dx.doi.org/10.1017/s1743921319008251.
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AbstractWe investigate the minor interactions of two disk galaxies with mass ratio of 10:1 in fly-by encounters that do not lead to the merging of the galaxies. In our N-body simulations, we vary only the pericenter distances to see the effect of the fly-by on the bulge of the major galaxy over the course of the trajectory. At different time steps of the evolution, we did two-dimensional fittings of disk, bulge and bar to trace the variation in the sersic index of the bulge. Our results suggest that galaxy bulges can become boxy/disky through flyby interactions of galaxies.
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Guo, Qi, та Simon White. "Disk Sizes in a ΛCDM Universe". Proceedings of the International Astronomical Union 4, S254 (2008): 411–16. http://dx.doi.org/10.1017/s1743921308027890.
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AbstractWe introduce a model which uses semi-analytic techniques to trace formation and evolution of galaxy disks in their cosmological context. For the first time we model the growth of gas and stellar disks separately. In contrast to previous work we follow in detail the angular momentum accumulation history through the gas cooling, merging and star formation processes. Our model successfully reproduces the stellar mass–radius distribution and gas-to-stellar disk size ratio distribution observed locally. We also investigate the dependence of clustering on galaxy size and find qualitative agreement with observation. There is still some discrepancy at small scale for less massive galaxies, indicating that our treatment of satellite galaxies needs to be improved.
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Senatore, Mauro. "Leaving a Trace in the World: Sexuality and Auto-Affection in Of Grammatology." Derrida Today 6, no. 2 (2013): 240–54. http://dx.doi.org/10.3366/drt.2013.0066.
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This essay aims to bring to light a specific movement elaborated by Derrida in Of Grammatology, which goes from the experience of dispossession in speech and the economy of signs that replaces speech itself with writing, through the chains of supplements, to the merging of language and auto-erotism into the differentiated totality of auto-affection as the universal rule of experience or as life itself. I will point out that idealization, as the submission of the world to a certain power of repetition in the living and, thus, as the only condition at which the world can affect the living, marks the becoming-spontaneous of the possibility of auto-affection and, at the same time, the very articulation of life, across its history, into a hierarchy of more and more complex symbolical operations. As I aim to demonstrate throughout my reading, the ultimate task of this movement is that a phenomenology cannot account for the structure of auto-affection insofar as, with a gesture parallel to phonocentrism, it would dissolve the irreducible trait of sexuality into the self-presence of self-touching. 1
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Campbell, David. "Luhmann without tears: complex economic regulation and the erosion of the market sphere." Legal Studies 33, no. 1 (2013): 162–86. http://dx.doi.org/10.1111/lest.12001.
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One of the concepts central to the ‘reconceiving’ of the ‘regulatory state’ during ‘the age of regulatory reform’ which we might trace back to the neoliberal revolution of the 1970s, has been that of the ‘hybrid’ form of economic organisation. Rejection of command-and-control regulation led, in the public sector, to the adoption of ‘marketmimicking’, a technique that claimed to replace the hierarchical direction of planning with the mobilisation of self-interest in ‘quasi-markets’, thereby merging ‘economic’ incentivisation with the ‘political’ stipulation of the markets' outcomes. In the private sector, institutions that had long been recognised to sit between contract and the company, of which the franchise had been the most thoroughly analysed within contract law, began to be regarded as ‘networks’.
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Smilgys, Romas, and Ian A. Bonnell. "Galactic flows and the formation of stellar clusters." Proceedings of the International Astronomical Union 12, S316 (2015): 184–89. http://dx.doi.org/10.1017/s1743921315009394.
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AbstractWe investigate the formation of stellar clusters from a Galactic scale SPH simulation. The simulation traces star formation over a 5.6 Myr timescale, with local gravitational instabilities resulting in ~ 105 solar masses of star formation in the form of sink particles. We investigate the time evolution of the physical properties of the forming clusters including their half-mass radii, their energies and the depletion time of the gas. Star formation is driven by the large scale flows which compress the gas to higher densities where self gravity takes over and collapse occurs. We show that the more massive clusters (up to ~ 2 × 104 solar masses) gather their material from of order 10 pc due to these large scale motions associated with the spiral arm passage and shock. The bulk of the gas becomes gravitationally bound near 1-2 Myr before sink formation, and in the absence of feedback, significant accretion ongoing on longer timescales. We trace the hierarchical merging process of cluster formation which naturally results in age spreads of order the crossing time of the original region which provides the gas reservoir for the cluster.
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Rebotier, Julien. "La dimensión territorial del riesgo urbano en Caracas: características y alcances. Una propuesta integradora para pensar el riesgo en una realidad socio-espacial compleja." Revista Trace, no. 56 (July 9, 2018): 11. http://dx.doi.org/10.22134/trace.56.2009.392.
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Las mutaciones urbanas contemporáneas, en particular en países del Sur, hacen del riesgo mucho más que un mero objeto de estudio. Además de una contextualización necesaria para poder pensar su construcción en el espacio urbano, según aspectos materiales e inmateriales, es importante subrayar la dimensión causal del riesgo urbano en la construcción del espacio urbano. Los enfoques sectoriales y técnicos de estudio de riesgo no permiten abarcar ampliamente dicha complejidad. Afianzar la construcción territorial y construcción de riesgos en una combinación sistémica ayuda a explorar las relaciones complejas entre territorios y riesgos urbanos. El análisis de un “contexto geográfico” dentro del cual se articulan situaciones de riesgo entonces historizadas, en calidad de “momentos geográficos”, favorece la comprensión de las condiciones de construcción de los riesgos. Estudiar la dimensión territorial del riesgo urbano en Caracas permite fundamentar y articular en un trabajo de campo diferentes influencias epistemológicas mediante la asociación de enfoques territoriales y de una postura constructivista y eminentemente social. Los territorios de riesgo urbano son la traducción geográfica de un orden social a través de una categoría unánime y poco cuestionable: el riesgo urbano. Uno no se limita a un estudio local circunscrito en el espacio, sino que se puede valer de una lectura geopolítica, muy reveladora del orden socio-espacial que caracteriza el contexto urbano. Elaborar una metodología de reflexión a propósito del riesgo partiendo de los retos planteados por la realidad socio-ambiental urbana es una manera de cuestionar las ciencias sociales, su epistemología y su práctica, afirmándose la vocación crítica de dichas ciencias.Abstract: Current urban transformations, especially in southern countries, turn risk into something more complex than a mere topic. “Making context” is a key point to think about risk construction in urban space, as regards both material and intangible aspects, and it is important to underline the place of urban risk in the construction of urban space. Fragmental and technical surveys of risks do not allow us to take into account such a complex relationship. By merging territorial and risk constructions into a systemic model, we hope to know better the territory / risk interactions. The analysis of “geographical context” where historicized situations of risks can take place as a “geographical moment” makes the understanding of conditions of risk construction easier. Based on fieldwork, the study of territorial dimensions of urban risk in Caracas is a way to strengthen and articulate different epistemological perspective. It has been the opportunity to articulate territorial approaches and socio-historical ones. Territories of urban risks are a geographical translation of a social order based on a unanimous and hard-toquestion category: urban risks. This is not just a limited study isolated in space. It is rather a way to put forward a geopolitics approach, very meaningful about the urban socio-spatial order at stake. Drawing a methodology about risk analysis which starts from the challenges of the urban socio-environmental reality is a way to question social sciences, their epistemological basis, and it is also a way to strengthen their critical aspects.Résumé : Les mutations urbaines contemporaines, en particulier dans les pays du Sud, font du risque beaucoup plus qu’un simple objet d’étude. En plus d’une contextualisation nécessaire pour penser sa construction dans l’espace urbain, selon des aspects matériels et immatériels, il est important de souligner la dimension causale du risque urbain dans la construction de l’espace urbain. Les approches sectorielles et techniques du risque ne permettent pas d’embrasser une telle complexité. Associer la construction territoriale et la construction des risques dans un modèle systémique aide à explorer les relations complexes entre territoires et risques urbains. L’analyse d’un “contexte géographique” dans lequel s’articulent des situations de risque alors historicisées, en tant que “moments géographiques”, favorise la compréhension des conditions de construction des risques. Étudier la dimension territoriale du risque urbain à Caracas permet d’assoir et d’articuler, sur un travail de terrain, différentes influences épistémologiques grâce à l’association d’approches territoriales et d’une posture constructiviste et éminemment sociale. Les territoires de risque urbain sont la traduction géographique d’un ordre social par le biais d’une catégorie unanime et difficile à remettre en question: le risque urbain. On ne se limite pas à une étude ponctuelle circonscrite dans l’espace, mais on peut valoriser une lecture géopolitique, très révélatrice de l’ordre socio-spatial qui caractérise le contexte urbain. Elaborer une méthodologie d’étude du risque en partant des défis posés par la réalité socioenvironnementale urbaine est un moyen de mettre en question les sciences sociales, leur épistémologie, et leurs pratiques, en affirmant toujours plus leur vocation critique.
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Cobelli, C., M. P. Saccomani, E. Ferrannini, R. A. Defronzo, R. Gelfand, and R. Bonadonna. "A compartmental model to quantitate in vivo glucose transport in the human forearm." American Journal of Physiology-Endocrinology and Metabolism 257, no. 6 (1989): E943—E958. http://dx.doi.org/10.1152/ajpendo.1989.257.6.e943.
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Glucose transport is a critical step in the control of glucose disposal that, until presently, has not been quantitated in vivo in humans. We have employed the perfused forearm and euglycemic insulin-clamp techniques in combination with a dual-tracer injection to measure basal and insulin-mediated glucose transport in six normal subjects. L-[3H]glucose, which is not transported, was used to trace extracellular glucose kinetics; 3-O-[14C]-methyl-D-glucose, transportable but not metabolizable, was used to monitor glucose movement across the cell membrane. After bolus intra-arterial injection of the two tracers, plasma samples were obtained every 15-30 s for 10 min from a deep forearm vein to determine the washout curves. A linear compartmental model was developed that accounts for blood flow heterogeneity. It consists of three parallel, two-compartment chains merging into the sampling compartment to which cellular compartments are appended. A priori identifiability analysis was performed. The uniquely identifiable parameterization includes the transport rate constants of glucose into and out of the cell. The model was identified using nonlinear least-squares parameter estimation. Transport parameters are estimated with very good precision, and their reproducibility is satisfactory. The model also allows the estimation of the mean arteriovenous transit times of both the extracellular and the transported tracer. The compartmental model provides a novel approach to investigate glucose transport in vivo in humans.
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Brunson, Wesley. "Dragonfly." UnderCurrents: Journal of Critical Environmental Studies 21 (October 18, 2022): 49–52. http://dx.doi.org/10.25071/2292-4736/40294.
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This prose poem explores autobiography as a trace site for the affective encounters between life and non-life. Using my own memories of making a childhood bug collection, I attempt to answer a question Povinelli asks in Geontologies—What does life desire? —by merging it with a question raised in my own ethnographic fieldwork—What do I desire? The affective resonance between my childhood bug collection, my ethnographic fieldwork as part of my PhD program in anthropology, and Povinelli’s 2016 book disrupts linear notions of time and argues that desire for difference itself produces the distinction between life and non-life. Original PublicationBrunson, Wesley. “Dragonfly.” Anthropology and Humanism, vol. 47, no. 1, 2022, pp. 235–239. © 2022 by the American Anthropological Association. All rights reserved.DOI: 10.1111/anhu.12372.
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Makowski, Dominique, and Philip D. Waggoner. "Where Are We Going with Statistical Computing? From Mathematical Statistics to Collaborative Data Science." Mathematics 11, no. 8 (2023): 1821. http://dx.doi.org/10.3390/math11081821.
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The field of statistical computing is rapidly developing and evolving. Shifting away from the formerly siloed landscape of mathematics, statistics, and computer science, recent advancements in statistical computing are largely characterized by a fusing of these worlds; namely, programming, software development, and applied statistics are merging in new and exciting ways. There are numerous drivers behind this advancement, including open movement (encompassing development, science, and access), the advent of data science as a field, and collaborative problem-solving, as well as practice-altering advances in subfields such as artificial intelligence, machine learning, and Bayesian estimation. In this paper, we trace this shift in how modern statistical computing is performed, and that which has recently emerged from it. This discussion points to a future of boundless potential for the field.
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Yang, Xiaodong, Omar Ali Beg, Matthew Kenigsberg, and Taylor T. Johnson. "A Framework for Identification and Validation of Affine Hybrid Automata from Input-Output Traces." ACM Transactions on Cyber-Physical Systems 6, no. 2 (2022): 1–24. http://dx.doi.org/10.1145/3470455.
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Automata-based modeling of hybrid and cyber-physical systems (CPS) is an important formal abstraction amenable to algorithmic analysis of its dynamic behaviors, such as in verification, fault identification, and anomaly detection. However, for realistic systems, especially industrial ones, identifying hybrid automata is challenging, due in part to inferring hybrid interactions, which involves inference of both continuous behaviors, such as through classical system identification, as well as discrete behaviors, such as through automata (e.g., L*) learning. In this paper, we propose and evaluate a framework for inferring and validating models of deterministic hybrid systems with linear ordinary differential equations (ODEs) from input/output execution traces. The framework contains algorithms for the approximation of continuous dynamics in discrete modes, estimation of transition conditions, and the inference of automata mode merging. The algorithms are capable of clustering trace segments and estimating their dynamic parameters, and meanwhile, deriving guard conditions that are represented by multiple linear inequalities. Finally, the inferred model is automatically converted to the format of the original system for the validation. We demonstrate the utility of this framework by evaluating its performance in several case studies as implemented through a publicly available prototype software framework called HAutLearn and compare it with a membership-based algorithm.
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Camargo, Denilso. "NGC 1605a and NGC 1605b: An Old Binary Open Cluster in the Galaxy." Astrophysical Journal 923, no. 1 (2021): 21. http://dx.doi.org/10.3847/1538-4357/ac2835.
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Abstract This work communicates the discovery of a binary open cluster within the Galaxy. NGC 1605 presents an unusual morphology with a sparse stellar distribution and a double core in close angular proximity. The 2MASS and Gaia-EDR3 field-star decontaminated color–magnitude diagrams (CMDs) show two distinct stellar populations located at the same heliocentric distance of ∼2.6 kpc, suggesting that there are two clusters in the region, NGC 1605a and NGC 1605b, with ages of 2 Gyr and 600 Myr, respectively. Both Gaia parallax and PM distributions are compact and very similar indicating that they are open clusters (OCs) and share the same kinematics. The large age difference, 1.4 Gyr, point to a formation by tidal capture during a close encounter and the close spatial proximity and similar kinematics suggest an ongoing merger event. There is some prominent tidal debris that appears to trace the cluster's orbits during the close encounter and, unexpectedly, some of them appear to be bound structures; this may suggest that in addition to the evaporation, the merging clusters are being broken apart into smaller structures by the combination of the Galactic disk, the Perseus arm, and mutual tidal interactions. In this sense, the newly found binary cluster may be a key object in the observational validation of theoretical studies on binary cluster pairs formation by tidal capture as well as in the formation of massive clusters by merging, and tidal disruption of stellar systems.
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Zeng, Hongliu. "Geologic significance of anomalous instantaneous frequency." GEOPHYSICS 75, no. 3 (2010): P23—P30. http://dx.doi.org/10.1190/1.3427638.
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Anomalous frequency spikes derived from complex-trace analysis have long been considered more as a flaw of algorithms than a valuable seismic attribute. However, synthetic models and field data show that instantaneous frequency spikes are clearly linked to physical models that could help geologic interpretations of seismic data. Frequency spikes are related to relative amplitude minima along a seismic trace that occur either at the merging point of the top and base reflections of a wedge (type I) or at the tip of the wedge (type II). A type II spike is indicative of a seismically thin bed (average [Formula: see text] or thinner in this study; [Formula: see text] denotes wavelength), although the bed thickness tends to decrease with the data frequency and bed spacing in a multibed acoustic-impedance profile (in the range of [Formula: see text] to [Formula: see text] in this study). Interpretive values of instantaneous frequency include recognizing thin reservoirs that are otherwise difficult to detect, mapping relative thickness changes of lithofacies, detecting lithofacies boundaries and faults, and locating a stratal discontinuity or flow barrier. Uncertainties caused by type I spikes, noise-derived fake spikes, and the lack of lithologic and time-stratigraphic information can be reduced by integrating well data, local geologic models, lithology-indicative seismic attributes (e.g., 90°-phase data), and facies-oriented seismic displays (e.g., stratal slices).
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Kaper, Lex. "Gamma-ray bursts: the most powerful cosmic explosions." Symposium - International Astronomical Union 212 (2003): 106–14. http://dx.doi.org/10.1017/s0074180900211704.
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With the detection of gamma-ray burst (GRB) afterglows, the cosmological origin of GRBs has been firmly established. Recent observations suggest that (long-duration) GRBs are due to the collapse of a massive star forming a black hole. Besides theoretical arguments, observational evidence supporting this hypothesis comes from the coincidence of several GRBs with a supernova. Also, all accurately located GRBs are contained in the optical (restframe UV) extent of distant, blue galaxies. Some of these host galaxies show relatively high star-formation rates, which is expected when massive stars and GRBs are physically linked. Alternatively, GRBs can be produced by the merging of a binary neutron star system, such as the Hulse-Taylor binary pulsar. Very likely GRBs trace the massive-star populations in distant galaxies. With their enormous brightness, GRBs are powerful probes of the early universe, providing information on the properties of their host galaxies, the cosmic star-formation history, and potentially the first generations of massive stars.
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Svyd, I. V., and M. G. Tkach. "Synthesis and analysis of the trace detector of air objects of an interrogating radar system." Radiotekhnika, no. 212 (March 28, 2023): 175–85. http://dx.doi.org/10.30837/rt.2023.1.212.17.
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The paper considers the features of tracking air objects in existing information networks of radar systems for monitoring airspace. It is shown that the tracking is carried out according to the information of the primary radar surveillance systems, and the secondary radar surveillance systems are used as sources of additional radar information. But the transition to automatic dependent surveillance implies the mandatory use of only request radar surveillance systems. Therefore, the problems of formulating methods and algorithms for tracking air objects based on information from secondary radar surveillance systems are relevant. The specifics of the construction and operation of secondary radar surveillance systems differ significantly from primary radar surveillance systems. The work carried out the synthesis and analysis of the structure of the tracks detector of air objects by interrogating radar systems for monitoring the airspace, namely: a comparative analysis of the quality of identifying the tracks of air objects was carried out; the quality of information support to consumers of the airspace control system with the proposed structure was improved in comparison with the used information processing structure; it is shown that the quality of information support for consumers has more preferable indicators when using the signal processing method during acquisition with subsequent information merging; the influence of the readiness factor of aircraft transponders of interrogative radar systems on the quality of information support for consumers of the airspace control system was evaluated.
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Shin, Jihye, Jong Chul Lee, Ho Seong Hwang, et al. "Spatial Distribution of Dark Matter in and Around Galaxy Clusters Traced by Galaxies, Gas, and Intracluster Stars in a Simulated Universe." Astrophysical Journal 934, no. 1 (2022): 43. http://dx.doi.org/10.3847/1538-4357/ac7961.
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Abstract To understand how well galaxies, gas, and intracluster stars trace dark matter in and around galaxy clusters, we use the IllustrisTNG cosmological hydrodynamical simulation and compare the spatial distribution of dark matter with that of baryonic components in clusters. To quantify the global morphology of the density distribution of each component in clusters, we fit an ellipse to the density contour of each component and derive shape parameters at different radii. We find that the ellipticity of dark matter is better correlated with that of galaxy mass-weighted number density, rather than with that of galaxy number density or galaxy velocity dispersion. We thus use the galaxy mass-weighted number density map as representative of the galaxy maps. Among three different density maps from galaxies, gas, and intracluster stars, the ellipticity of dark matter is best reproduced by that of the galaxy map over the entire radii. The virialized galaxy clusters show a better correlation of spatial distribution between dark matter and other components than the unvirialized clusters, suggesting that it requires some time for each component to follow the spatial distribution of dark matter after merging events. Our results demonstrate that galaxies are still good tracers of dark matter distribution even in the nonlinear regime corresponding to the scales in and around galaxy clusters, being consistent with the case where galaxies trace well the matter distribution on cosmologically large scales.
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Tan, Kefeng, and Gang Zhao. "Two distinct halo populations in the solar neighborhood: evidence from stellar abundance of beryllium." Proceedings of the International Astronomical Union 9, S298 (2013): 83–85. http://dx.doi.org/10.1017/s1743921313006248.
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AbstractIt is now generally believed that the Galaxy was formed through hierarchical merging, which means that different components of the Galaxy may have experienced different chemical evolution histories. Since alpha elements are mainly produced by core collapse supernovae, they are closely associated with the star formation history of the Galaxy. In this regard, Galactic components with different alpha elemental abundance patterns may show different behaviors in beryllium abundances since the production of beryllium is correlated with the cosmic rays and thus the supernovae. A recent study by Nissen & Schuster (2010) has revealed the existence of two distinct halo populations in the solar neighborhood based on the alpha elemental abundances and kinematics of 94 dwarf stars. We determined beryllium abundances for some of these stars and find systematic differences in beryllium abundances between these two halo populations. Our results consolidate the conclusion of two distinct halo populations in the solar neighborhood. Our results also show that beryllium abundance is a very good indicator of star formation rate, and could be used to trace the substructures of the Galactic halo.
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Burger, C., Á. Bazsó, and C. M. Schäfer. "Realistic collisional water transport during terrestrial planet formation." Astronomy & Astrophysics 634 (February 2020): A76. http://dx.doi.org/10.1051/0004-6361/201936366.
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Context. According to the latest theoretical and isotopic evidence, Earth’s water content originates mainly from today’s asteroid belt region, or at least from the same precursor material. This suggests that water was transported inwards to Earth, and to similar planets in their habitable zone, via (giant) collisions of planetary embryos and planetesimals during the chaotic final phase of planet formation. Aims. In current dynamical simulations water delivery to terrestrial planets is still studied almost exclusively by assuming oversimplified perfect merging, even though water and other volatiles are particularly prone to collisional transfer and loss. To close this gap we have developed a computational framework to model collisional water transport by direct combination of long-term N-body computations with dedicated 3D smooth particle hydrodynamics (SPH) collision simulations of differentiated, self-gravitating bodies for each event. Methods. Post-collision water inventories are traced self-consistently in the further dynamical evolution, in accretionary or erosive as well as hit-and-run encounters with two large surviving bodies, where besides collisional losses, water transfer between the encountering bodies has to be considered. This hybrid approach enables us for the first time to trace the full dynamical and collisional evolution of a system of approximately 200 bodies throughout the whole late-stage accretion phase (several hundred Myr). As a first application we choose a Solar System-like architecture with already formed giant planets on either circular or eccentric orbits and a debris disk spanning the whole terrestrial planet region (0.5–4 au). Results. Including realistic collision treatment leads to considerably different results than simple perfect merging, with lower mass planets and water inventories reduced regularly by a factor of two or more. Due to a combination of collisional losses and a considerably lengthened accretion phase, final water content, especially with giant planets on circular orbits, is strongly reduced to more Earth-like values, and closer to results with eccentric giant planets. Water delivery to potentially habitable planets is dominated by very few decisive collisions, mostly with embryo-sized or larger objects and only rarely with smaller bodies, at least if embryos have formed throughout the whole disk initially. The high frequency of hit-and-run collisions and the differences to predominantly accretionary encounters, such as generally low water (and mass) transfer efficiencies, are a crucial part of water delivery, and of system-wide evolution in general.
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Zhang, Tianran, Martin Wooster, David C. Green, and Bruce Main. "A Mathematical Approach to Merging Data from Different Trace Gas/Particulate Sensors Having Dissimilar (T90) Response Times: Application to Fire Emission Factor Determination." Aerosol and Air Quality Research 20, no. 2 (2020): 281–90. http://dx.doi.org/10.4209/aaqr.2019.02.0061.
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Kornder, Lisa, and Ineke Mennen. "Longitudinal Developments in Bilingual Second Language Acquisition and First Language Attrition of Speech: The Case of Arnold Schwarzenegger." Languages 6, no. 2 (2021): 61. http://dx.doi.org/10.3390/languages6020061.
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The purpose of this investigation was to trace first (L1) and second language (L2) segmental speech development in the Austrian German–English late bilingual Arnold Schwarzenegger over a period of 40 years, which makes it the first study to examine a bilingual’s speech development over several decades in both their languages. To this end, acoustic measurements of voice onset time (VOT) durations of word-initial plosives (Study 1) and formant frequencies of the first and second formant of Austrian German and English monophthongs (Study 2) were conducted using speech samples collected from broadcast interviews. The results of Study 1 showed a merging of Schwarzenegger’s German and English voiceless plosives in his late productions as manifested in a significant lengthening of VOT duration in his German plosives, and a shortening of VOT duration in his English plosives, closer to L1 production norms. Similar findings were evidenced in Study 2, revealing that some of Schwarzenegger’s L1 and L2 vowel categories had moved closer together in the course of L2 immersion. These findings suggest that both a bilingual’s first and second language accent is likely to develop and reorganize over time due to dynamic interactions between the first and second language system.
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Bergerot, L., J. Y. Blaise, A. Pamart, and I. Dudek. "VISUAL CROSS-EXAMINATION OF ARCHITECTURAL AND ACOUSTIC DATA: THE 3D INTEGRATOR EXPERIMENT." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVI-2/W1-2022 (February 25, 2022): 81–88. http://dx.doi.org/10.5194/isprs-archives-xlvi-2-w1-2022-81-2022.
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Abstract. This paper presents an online application called 3D integrator enabling visual cross-examinations of architectural and acoustic data on web browsers, and explains the rationale behind its development. The tool consists of a series of overlays developed over the Potree 3D point cloud renderer. The 3D integrator is used to display visually, in an interactive environment, the 3D point clouds resulting from a survey protocol tailored to the specific needs of the corpus under scrutiny – fifteen small scale edifices often referred to as “minor heritage assets - and to the research’s overall ambition, co-reasoning on architectural and acoustic features at an interdisciplinary level. One of the tool’s distinctive features is to project abstract information (acoustic indicators) in a “close to real” 3D space (point clouds), hence merging scientific visualisation and information visualisation practices. The paper shortly sums up the particularities of the survey protocol, and discusses in detail the implementation of the analytical add-ons that have been introduced (visual trace of the survey protocol itself, exploitation of panoramas, volume calculation, and exploratory 3D representation of acoustic indicators). Finally, early uses of the tool are summarised and the services it actually offers at this stage are commented.
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Lindberg, Annika. "The Production of Precarity in Denmark’s Asylum Regime." Zeitschrift für Sozialreform 66, no. 4 (2020): 413–39. http://dx.doi.org/10.1515/zsr-2020-0018.
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Abstract The special issue discusses the intersections between social welfare and migration control, as well as how stratified access to welfare services is used to govern ‘unwanted’ groups. This article explores these intersections in Denmark’ deterrence-oriented asylum policy regime, analysing the discourses and practices whereby people seeking protection are constructed as ‘undeserving’ poor. Drawing on ethnographic fieldwork in different sites of enforcement of Denmark’s asylum regime as well as interviews with street-level workers and people who sought asylum in Denmark, I trace how the Danish deterrence approach operates through the production of poverty and precarity among people seeking protection in asylum reception camps, deportation-oriented integration programmes, and finally, deportation camps. I show how the Danish welfare state, as a result of the merging of external and internal bordering practices, produces a condition of precarity and (non)deportability that extends from the asylum camps to those awarded temporary protection status. Hence, while the deterrence-oriented Danish policy regime has not proven ‘effective’ from the point of view of immigration control, it has served to reinforced a dualised, hierarchically ordered welfare rights’ regime that gradually erodes the rights and life opportunities of unwanted noncitizen ‘others’.
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Jones, A., F. de Gasperin, V. Cuciti, et al. "Radio relics in PSZ2 G096.88+24.18: a connection with pre-existing plasma." Monthly Notices of the Royal Astronomical Society 505, no. 4 (2021): 4762–74. http://dx.doi.org/10.1093/mnras/stab1443.
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ABSTRACT Giant radio relics are arc-like structures of diffuse, non-thermal synchrotron radiation that trace shock waves induced by galaxy cluster mergers. The particle (re-)acceleration mechanism producing such radio relics is unclear. One major open question is whether relics can be formed directly from a population of thermal seed electrons, or if pre-existing relativistic seed electrons are required. In some cases, active galactic nuclei (AGNs) can provide such a population of sub-GeV electrons. However, it is unclear how common this connection is. In this paper, we present LOFAR 140 MHz and Very Large Array L-band radio observations, as well as Chandra data of PSZ2 G096.88+24.18, a merging galaxy cluster system hosting a pair of radio relics. A large patch of diffuse emission connects a bright radio galaxy with one of the relics, likely affecting the properties of the relic. We find that the most plausible explanation for the connection is that the merger shock wave has passed over an AGN lobe. The shock passing over this seed population of electrons has led to an increased brightness in the relic only in the region filled with seed electrons.
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KÖSTER, KLAUS, and MICHAEL SPANN. "UNSUPERVISED SEGMENTATION OF 3D AND 2D SEISMIC REFLECTION DATA." International Journal of Pattern Recognition and Artificial Intelligence 13, no. 05 (1999): 643–63. http://dx.doi.org/10.1142/s0218001499000380.
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An unsupervised method to extract 2D and 3D inner earth structures from seismic reflection measurements is described. The application is a typical texture segmentation problem, which can be split up into a feature extraction stage and a segmentation stage. As a texture feature, the locally emergent frequency is estimated by a Gabor filter bank. The instantaneous frequency (IF) has already been successfully used for seismic trace analysis21 and will be compared with the results of the filter bank. The second stage of the algorithm involves a region-growing method to compute the final object structure. The extremely flexible segmentation scheme is appropriate for application to 2D and 3D images of arbitrary vectorial dimension. The merging decision is based on the mutual inlier ratio of two adjacent regions. This ratio is computed by robust regression techniques19 to avoid noise artifacts. A mutual inlier ratio discrimination function to recognize identical Gaussian distributions, guaranteeing a 97.5% certainty, is derived. This method is compared with the Kolmogorov–Smirnov test and results of the application in a segmentation algorithm are shown. The segmentation stage is also tested with different benchmark data sets from other computer vision problems to demonstrate its general flexibility.
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Lozano-Fernandez, Jesus, Robert Carton, Alastair R. Tanner, et al. "A molecular palaeobiological exploration of arthropod terrestrialization." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1699 (2016): 20150133. http://dx.doi.org/10.1098/rstb.2015.0133.
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Understanding animal terrestrialization, the process through which animals colonized the land, is crucial to clarify extant biodiversity and biological adaptation. Arthropoda (insects, spiders, centipedes and their allies) represent the largest majority of terrestrial biodiversity. Here we implemented a molecular palaeobiological approach, merging molecular and fossil evidence, to elucidate the deepest history of the terrestrial arthropods. We focused on the three independent, Palaeozoic arthropod terrestrialization events (those of Myriapoda, Hexapoda and Arachnida) and showed that a marine route to the colonization of land is the most likely scenario. Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record, Myriapoda are inferred to have colonized land earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’.
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Bergerot, Laurent, Jean-Yves Blaise, Iwona Dudek, et al. "Combined Web-Based Visualisation of 3D Point Clouds and Acoustic Descriptors: An Interdisciplinary Challenge." Heritage 5, no. 4 (2022): 3819–45. http://dx.doi.org/10.3390/heritage5040197.
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This paper presents an online application—called 3D integrator—enabling visual cross-examinations of architectural and acoustic data on web browsers and explains the rationale behind its development. The tool consists of a series of overlays developed over the Potree 3D point cloud renderer. It is used to display visually, in an interactive environment, the 3D point clouds resulting from a survey protocol tailored to the specific needs of the corpus under scrutiny—15 small-scale edifices often referred to as “minor heritage assets”—and to the research’s overall ambition, reasoning on architectural and acoustic features at an interdisciplinary level. One of the tool’s distinctive features is to project abstract information (acoustic descriptors) in a “close to real” 3D space (point clouds), hence merging scientific visualisation and information visualisation practices. The paper first shortly sums up the particularities of the survey protocol and discusses the implementation of the analytical add-ons that have been introduced (visual trace of the survey protocol itself, volume calculation, and exploratory 3D representation of acoustic descriptors). It then focuses on use cases that illustrate what the approach helps to observe concerning the interiors of edifices when capturing and co-examining dimensional and acoustic features.
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Nishtha Kishore. "Revisiting Anita Desai’s Fiction: Tracing Generational Relevance towards a Third Culture/Third Space Spectrum." Creative Saplings 1, no. 9 (2022): 26–35. http://dx.doi.org/10.56062/gtrs.2022.1.9.185.
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The paper attempts to trace the generational relevance of produced fiction by Anita Desai (b. 1937) towards the possibility of locating third culture subjectivity and the scope of the third space spectrum. The association ranges from the character aesthetics to strategic spatial intervention in her fiction, and the scope of extending the same to new pressures of readership pertaining to constantly mobile and restructured locales. The world around shows signs of disintegration of the individual vis-a-vis dislocation, migration, and dynamic forms of locomotion. It is, therefore, imperative that the modern Indian-English novel should seek new techniques to articulate the experienced inner and outer realities, merging textuality, spatiality, and subjectivity. Desai's preoccupation with the individual highlights their psychological motivations, identity constructs, organizational logic of family institutions, disintegration, sense of failure, the absence to offer a clear binary, and her keen awareness of the futility of existence radiates from most of her novels. The paper tries to fathom such possibilities through analyses of her major fiction into a third culture spectrum, which may serve as a major constituent to tackle her oeuvre and accommodate her major themes.
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van Marle, Margreet J. E., Silvia Kloster, Brian I. Magi, et al. "Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750–2015)." Geoscientific Model Development 10, no. 9 (2017): 3329–57. http://dx.doi.org/10.5194/gmd-10-3329-2017.
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Abstract. Fires have influenced atmospheric composition and climate since the rise of vascular plants, and satellite data have shown the overall global extent of fires. Our knowledge of historic fire emissions has progressively improved over the past decades due mostly to the development of new proxies and the improvement of fire models. Currently, there is a suite of proxies including sedimentary charcoal records, measurements of fire-emitted trace gases and black carbon stored in ice and firn, and visibility observations. These proxies provide opportunities to extrapolate emission estimates back in time based on satellite data starting in 1997, but each proxy has strengths and weaknesses regarding, for example, the spatial and temporal extents over which they are representative. We developed a new historic biomass burning emissions dataset starting in 1750 that merges the satellite record with several existing proxies and uses the average of six models from the Fire Model Intercomparison Project (FireMIP) protocol to estimate emissions when the available proxies had limited coverage. According to our approach, global biomass burning emissions were relatively constant, with 10-year averages varying between 1.8 and 2.3 Pg C yr−1. Carbon emissions increased only slightly over the full time period and peaked during the 1990s after which they decreased gradually. There is substantial uncertainty in these estimates, and patterns varied depending on choices regarding data representation, especially on regional scales. The observed pattern in fire carbon emissions is for a large part driven by African fires, which accounted for 58 % of global fire carbon emissions. African fire emissions declined since about 1950 due to conversion of savanna to cropland, and this decrease is partially compensated for by increasing emissions in deforestation zones of South America and Asia. These global fire emission estimates are mostly suited for global analyses and will be used in the Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations.
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Bogdanov, Andrei Ivanovich, and Sergey Vladimirovich Kvashuk. "Analysis of the operation of the railway track in conditions of low-draining mares and high-temperature permafrost (on the example of the area of the Bureysky reservoir bypass)." Арктика и Антарктика, no. 1 (January 2022): 95–108. http://dx.doi.org/10.7256/2453-8922.2022.1.37649.
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The subject of research is the earthwork of the railway track and artificial structures on hazy weak-draining areas in the areas of permafrost distribution on the bypass of the Bureyskaya HPP reservoir within the Verkhnebureinskaya depression. The purpose is to identify the conditions and causes of adverse processes and phenomena that have arisen during operation. The objectives of the research are to identify the main causes and conditions for the manifestation of unfavorable geocryological processes and phenomena – waterlogging, flooding, stagnation of water, degradation of permafrost, sediment of the roadbed. Design errors are analyzed and recommendations are given for the application of design solutions in accordance with the state and dynamics of geocryological conditions and the requirements of the current regulatory documents for the areas of distribution of low-level marys and high-temperature permafrost. For the first time, a comprehensive analysis of the conditions and causes causing adverse processes and phenomena was carried out for the described territory. Inefficient constructions and design solutions have been identified. Optimal design solutions and measures are recommended to ensure the stable and safe operation of transport facilities in the region in conditions of low-drainpipe and high-temperature permafrost. For the studied area, the characteristic features are the significant swampiness of the territory, and the wide distribution of low– and high-temperature permafrost soils of the merging type. There are cases of irrational and inefficient design. It is not uncommon to use unsuitable soils for filling the roadbed and its elements. Also, the excess of the volume of earthworks during construction. Under these conditions, it is recommended: When designing a railway track plan, trace the line through local elevated terrain areas, in order to ensure the necessary slope of the design profile of drainage ditches of at least 4 ppm. Drainage ditches along the path should be located at a distance that excludes the inflow of water into the base of the roadbed.
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Goss, David. "The Invention of a Chair Tradition in Ethiopia: A Case Study of Liminoid Design." Journal of Design History 33, no. 3 (2020): 243–58. http://dx.doi.org/10.1093/jdh/epaa026.
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Abstract Both design and invention deal with future materializations, facilitating the environment and artefacts into different categories. These categories are conceptual constructs and any transgression of, combination of, or entering interstices between their imagined conceptual borders is Liminoid Design. Liminoid design is defined in this article as a momentary state of liminality: unstructuredness, transience, inter-categorical or uncategorizable. Though a very common phenomenon, it potentially creates new configurations of reality and new categories in design. This article describes manifestations of liminoid design, through the development of a contemporary Ethiopian chair with the merging of two categories: a side chair with imagery of the historic Aksum stelae. The Aksum stelae are monolithic stone monuments in northern Ethiopia erected during the ancient Kingdom of Aksum (in the early Christian period between the fourth and sixth centuries AD). This amalgamation emphasizes the contemporary connection to the past with a significant moment in Ethiopian history. Though seemingly traditional, this article identifies these chairs as a newly invented design type—the Aksum chair. During several visits to Ethiopia, I visited furniture workshops in Addis Ababa and Aksum and visited purchasers of the chairs as well. This helped the research to trace the proliferation and initiation of an invented traditional style.
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Macera, Margarita, Bruno De Meulder, and Kelly Shannon. "Cajamarca: Mapping (Post)Mining Palimpsests of the Peruvian Andes." Urban Planning 5, no. 2 (2020): 172–90. http://dx.doi.org/10.17645/up.v5i2.2797.
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Mining, in addition to other human activities and natural phenomena, has repeatedly reshaped the landscapes of the Peruvian Andes. Long-standing, significantly modified and new Andean landscapes have resulted in a complex reading of the ‘land as palimpsest’ (Corboz, 1983). In recent decades, large-scale modern mining has disturbed headwater landscapes and broader Andean ecologies, as exemplified in Cajamarca’s gold mines. This article critically reads past and present spatial transformations induced by gold mining in the headwaters of the Cajamarca Basin. Through archival documentation, fieldwork and interpretative cartography, it analyses the large-scale surface mining operations in Cajamarca from 1993 to 2020, as well as their impact on downstream rural and urban ecologies. A cross-scalar mapping investigation discloses the spatial-ecological outcomes of twenty-seven years of mining (and closure) operational procedures. As a conclusion of the palimpsest reading, a design-research question is posed as to how Cajamarca’s post-mining landscapes can be opportunely premeditated. It hypothesizes that, already during exploitation, the post-mining landscapes can be consciously constructed by an intelligent manipulation of mining procedures and create a layer of the territory that is more robust. Environmental reconstruction after mining closure recreates a pseudo-natural environment that supposedly erases the traces of mining and restores natural condition—literally back to nature, with no cultural trace. In this regard, reconstruction is merely theoretical since the repairing to a natural state would mean no palimpsests. However, despite the most imaginative and ecological repair, the territory remains a mega palimpsest, cruelly violated and disrupted. Therefore, at best, the proposition can be to build a cultural, consciously conceived and tailored post-mining landscape, merging mining and post-mining landscape construction into one movement, where the remaining (palimpsest) is part-and-parcel of the newly constructed.
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Werner, Klaus, Nicole Reindl, Stephan Geier, and Max Pritzkuleit. "Discovery of hot subdwarfs covered with helium-burning ash." Monthly Notices of the Royal Astronomical Society: Letters 511, no. 1 (2022): L66—L71. http://dx.doi.org/10.1093/mnrasl/slac005.
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Abstract Helium-rich subdwarf O stars (sdOs) are hot compact stars in a pre-white dwarf evolutionary state. Most of them have effective temperatures and surface gravities in the range Teff = 40 000–50 000 K and log g = 5.5–6.0. Their atmospheres are helium dominated. If present at all, C, N, and O are trace elements. The abundance patterns are explained in terms of nucleosynthesis during single star evolution (late helium core flash) or a binary He-core white dwarf merger. Here we announce the discovery of two hot hydrogen-deficient sdOs (PG1654+322 and PG1528+025) that exhibit unusually strong carbon and oxygen lines. A non-LTE model atmosphere analysis of spectra obtained with the Large Binocular Telescope and by the LAMOST survey reveals astonishingly high abundances of C ($\approx 20{{\ \rm per\ cent}}$) and O ($\approx 20{{\ \rm per\ cent}}$) and that the two stars are located close to the helium main sequence. Both establish a new spectroscopic class of hot H-deficient subdwarfs (CO-sdO) and can be identified as the remnants of a He-core white dwarf that accreted matter of a merging low-mass CO-core white dwarf. We conclude that the CO-sdOs represent an alternative evolutionary channel creating PG1159 stars besides the evolution of single stars that experience a late helium-shell flash.
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TOMALIA, DONALD A., and SHIV N. KHANNA. "IN QUEST OF A SYSTEMATIC FRAMEWORK FOR UNIFYING AND DEFINING NANOSCIENCE." Modern Physics Letters B 28, no. 03 (2014): 1430002. http://dx.doi.org/10.1142/s0217984914300026.
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This is an invited overview of a lecture presented at the American Physical Society (APS) Meeting, Boston, USA (March 1, 2012). The primary focus of this APS lecture was to trace the historical emergence of Hard and Soft nanoscale superatoms (i.e. nano-element categories) as well as a recent merging of these concepts/entities by chemists/physicists into a unified system and framework for defining nanoscience. The convergence of these quantized, organic/inorganic superatom entities involved the application of traditional "first principles" and their nanoscale "atom mimicry" features as a criteria for evolving a roadmap of quantized nano-elemental categories, nano-compound/assemblies and nano-periodic patterns, etc., much as was observed in traditional chemistry. This simple perspective was used to define a nanoscale taxonomy of hard/soft superatom/nano-element categories, as well as to explain the dependency of a broad range of nano-periodic properties/features on one or more of six Critical Nanoscale Design Parameters (CNDPs) associated with these nano-building blocks, namely: (1) size, (2) shape, (3) surface chemistry, (4) rigidity/flexibility, (5) architecture and (6) elemental composition. Validation and support of this systematic nano-periodic perspective has appeared in many recent publications describing CNDP dependent nano-periodic property patterns/trends, rules and Mendeleev-like nano-periodic tables which may unify and provide first steps toward a "central paradigm" for nanoscience.
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Park, Sung Hoon. "Simulation of the Formation and Growth of Soot Aerosol Particles in a Premixed Combustion Process Using a Soot Aerosol Dynamics Model." Atmosphere 13, no. 5 (2022): 847. http://dx.doi.org/10.3390/atmos13050847.
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Recently, an aerosol dynamics model—the Soot Aggregate Moment Model (SAMM)—that can efficiently trace the size distribution and morphology of soot particles was developed. In order to examine the applicability of SAMM in association with open-source CFD and combustion chemistry solvers, the formation and growth of soot particles in a premixed ethylene/air combustion were simulated by connecting SAMM with OpenSMOKE++ in this study. The simulation results were compared with available measurements and with the results of a previous study conducted using SAMM connected with an in-house CFD code and the CHEMKIN combustion chemistry package. Both CHEMKIN and OpenSMOKE++ underestimated C2H2 concentration compared to previous measurements, with deviation from the measured data being smaller for OpenSMOKE++. The chemical mechanism adopted in the CHEMKIN package was found to underestimate pyrene concentration by a factor of several tens. OpenSMOKE++ predicted much higher soot precursor concentrations than CHEMKIN, leading to a higher nucleation rate and a faster surface growth in the latter part of the reactor. This resulted in a reasonable soot production rate without introducing an artificial condensation enhancement factor. The overestimation of low-molecular-weight polycyclic aromatic hydrocarbons in the latter part of the reactor and the neglect of sintering led to an overprediction of soot production and primary particle number. This result indicates that accounting only for obliteration without sintering in SAMM could not simulate the merging of primary particles sufficiently. This indication merits further investigation.
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Tallis, Benjamin, and Xymena Kurowska. "EU Border Assistance Mission: Beyond Border Monitoring?" European Foreign Affairs Review 14, Issue 1 (2009): 47–64. http://dx.doi.org/10.54648/eerr2009004.
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On 1 December 2005, the EU deployed its Border Assistance Mission to Moldova and Ukraine (EUBAM), an innovative concept merging border monitoring and capacity–building. The improvised launch of the mission reflected the urge to put it in place against all odds and despite the presence of many practical obstacles. The hectic beginnings of the mission similarly reflected the impromptu character of the enterprise. Yet at present EUBAM has come to be seen as a fully fledged success story and a showcase for the EU’s constructive engagement with its Eastern neighbours. The mission exceeded the expectations placed upon it at the time of the inception. To such an extent are the mission’s achievements taken for granted that it is no longer an eligible case for routine inventories of successful project implementation used as public relations material by the EU and EC: it is simply too obvious. This contribution seeks to trace and unpack this ‘path to glory’. It enquires into the pre–history of the mission and follows its ambiguous institutional background. Through analysis of the mission’s development so far it tries to map EUBAM’s role in, and impact on, the regional situation. Grasping the mission’s position and positioning, it also aims to put the project in context and pinpoint lessons, if not necessarily learned, then at least identified at this point. Some of them may question the received wisdom of EUBAM as immaculate in conception and implementation.
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Noys, Benjamin. "Vital Texts and Bare Life: The Uses and Abuses of Life in Contemporary Fiction." CounterText 1, no. 2 (2015): 169–85. http://dx.doi.org/10.3366/count.2015.0016.
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The problem of writing life is one that has not dissipated in contemporary literature, if anything it has intensified. Past forms of countertexts turned to the subversive power of life, either with the avant-garde dissolution of text into life or by the modernist merging of life into the text. These forms often deployed a literary vitalism, which claimed a countertextual force through staking a claim on the power of life to overflow textual and political determinations. These currents, however, risk reinforcing forms of literary and capitalist value that draw on the powers of life. Instead, I argue, a different form of countertextuality can be found in contemporary autobiographical or confessional works, which by foregrounding the life of the author render the smooth translation of life into the text problematic. In particular, the work of the contemporary US writer Chris Kraus probes the relation between ‘vital texts’ and the experience of ‘bare life’ – life left exposed to power. Reconstructing her intervention, especially in her novel Summer of Hate (2012), reveals the possibilities of a new countertextual sensibility that turns to subjectivity and life without simply celebrating the expressive powers of life as the ground of literary and cultural value. Instead of a countertext that claims to express the power of life beyond the literary, Kraus develops a countertext in which life is exposed to abstract forms of power and so she allows us to trace the entanglement of life with value.
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De Wolff, Kim. "Plastic Naturecultures." Body & Society 23, no. 3 (2017): 23–47. http://dx.doi.org/10.1177/1357034x17715074.
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A jellyfish surrounds a plastic fragment, merging the synthetic material with its body; a water agency poster warns of dangerous plastic bottle ‘fish’ in the Mediterranean; marine organisms take shelter on and under synthetic materials. These are the denizens of a growing realm marine ecologists call the ‘plastisphere’, where sea life and plastics meet. Building upon multispecies ethnography, science and technology studies interrogations of nature/culture divides and the practical work of classification, this article explores the indeterminacy – the very plasticity – of the category of ‘species’ as it is engaged in seriousness and irony, with living and nonliving bodies. First, I draw on participant observation at a nonprofit marine institute laboratory in California to trace the travels of plastic-creatures through attempts to disentangle them in the pursuit of scientific knowledge. Here volunteers sort tiny plastic bits from animal ones under the microscope, enacting material boundaries as they decide what gets counted as life (not plastic) and what does not (plastic). Second, I follow movements of plastic-creatures through public education campaigns, paying particular attention to assumptions about belonging and agency enacted with assumptions about whether and when plastic-species should or should not meet. I argue that the ‘danger’ of plastic relationships lurks not in associations but in the very categories used to know and live with forms of plastic and forms of life, in the kinds of belonging that emerge with kinds of materials, and in the failure to recognize the impossibility of their separation.
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Costa, Cristina D'Ancona. "Porphyry, Universal Soul and the Arabic Plotinus." Arabic Sciences and Philosophy 9, no. 1 (1999): 47–88. http://dx.doi.org/10.1017/s0957423900002605.
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Scholars working in the field of Graeco-Arabic Neoplatonism often discuss the role Porphyry, the editor of Plotinus, must be credited with in the formation of the Arabic Plotiniancorpus. A note in thiscorpusapparently suggests that Porphyry provided a commentary to the so-calledTheology of Aristotle, i.e., parts of some treatises ofEnneadsIV-VI. Consequently, Porphyry has been considered as responsible for the (sometimes relevant) doctrinal shifts which affect the Arabic Plotinian paraphrase with respect to the original text. This article aims at submitting this hypothesis to trial on a specific doctrinal point where Porphyry parts company with Plotinus: the relationship between the Demiurgic Intellect and World Soul. The ancient doxographical sources testify that Porphyry, in his conviction to be in agreement with Plotinus, in fact parted company with him in so far as he merged the World Soul into the Demiurgic Intellect, while Plotinus always kept them apart. There are in theEnneadssome baffling passages where the role of Intellect as the Demiurge of the sensible world is not clearly distinguishable from the role of World Soul. Notwithstanding that, these passages in the Arabic paraphrase do not bear any trace of the characteristically Porphyrian merging of World Soul into Intellect. The Arabic paraphrase of Plotinus’ writings never confuses Intellect and World Soul, as Porphyry did. This fact seems to disprove, at least on this point, the hypothesis of Porphyry's intervention as the explanation for the doctrinal differences between the original Plotinus’ text and its Arabic tradition.
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Ramos Padilla, Andrés F., M. L. N. Ashby, Howard A. Smith, et al. "The AGN contribution to the UV–FIR luminosities of interacting galaxies and its role in identifying the main sequence." Monthly Notices of the Royal Astronomical Society 499, no. 3 (2020): 4325–69. http://dx.doi.org/10.1093/mnras/staa2813.
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ABSTRACT Emission from active galactic nuclei (AGNs) is known to play an important role in the evolution of many galaxies including luminous and ultraluminous systems (U/LIRGs), as well as merging systems. However, the extent, duration, and exact effects of its influence are still imperfectly understood. To assess the impact of AGNs on interacting systems, we present a spectral energy distribution (SED) analysis of a sample of 189 nearby galaxies. We gather and systematically re-reduce archival broad-band imaging mosaics from the ultraviolet to the far-infrared using data from GALEX, SDSS, 2MASS, IRAS, WISE, Spitzer, and Herschel. We use spectroscopy from Spitzer/IRS to obtain fluxes from fine-structure lines that trace star formation and AGN activity. Utilizing the SED modelling and fitting tool cigale, we derive the physical conditions of the interstellar medium, both in star-forming regions and in nuclear regions dominated by the AGN in these galaxies. We investigate how the star formation rates (SFRs) and the fractional AGN contributions (fAGN) depend on stellar mass, galaxy type, and merger stage. We find that luminous galaxies more massive than about $10^{10} \,\rm {M}_{*}$ are likely to deviate significantly from the conventional galaxy main-sequence relation. Interestingly, infrared AGN luminosity and stellar mass in this set of objects are much tighter than SFR and stellar mass. We find that buried AGNs may occupy a locus between bright starbursts and pure AGNs in the fAGN–[Ne v]/[Ne ii] plane. We identify a modest correlation between fAGN and mergers in their later stages.
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Schneider, Matthias, Benjamin Ertl, Qiansi Tu, et al. "Synergetic use of IASI profile and TROPOMI total-column level 2 methane retrieval products." Atmospheric Measurement Techniques 15, no. 14 (2022): 4339–71. http://dx.doi.org/10.5194/amt-15-4339-2022.
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Abstract. The thermal infrared nadir spectra of IASI (Infrared Atmospheric Sounding Interferometer) are successfully used for retrievals of different atmospheric trace gas profiles. However, these retrievals offer generally reduced information about the lowermost tropospheric layer due to the lack of thermal contrast close to the surface. Spectra of scattered solar radiation observed in the near-infrared and/or shortwave infrared, for instance by TROPOMI (TROPOspheric Monitoring Instrument), offer higher sensitivity near the ground and are used for the retrieval of total-column-averaged mixing ratios of a variety of atmospheric trace gases. Here we present a method for the synergetic use of IASI profile and TROPOMI total-column level 2 retrieval products. Our method uses the output of the individual retrievals and consists of linear algebra a posteriori calculations (i.e. calculation after the individual retrievals). We show that this approach has strong theoretical similarities to applying the spectra of the different sensors together in a single retrieval procedure but with the substantial advantage of being applicable to data generated with different individual retrieval processors, of being very time efficient, and of directly benefiting from the high quality and most recent improvements of the individual retrieval processors. We demonstrate the method exemplarily for atmospheric methane (CH4). We perform a theoretical evaluation and show that the a posteriori combination method yields a total-column-averaged CH4 product (XCH4) that conserves the good sensitivity of the corresponding TROPOMI product while merging it with the high-quality upper troposphere–lower stratosphere (UTLS) CH4 partial-column information of the corresponding IASI product. As a consequence, the combined product offers additional sensitivity for the tropospheric CH4 partial column, which is not provided by the individual TROPOMI nor the individual IASI product. The theoretically predicted synergetic effect is verified by comparisons to CH4 reference data obtained from collocated XCH4 measurements at 14 globally distributed TCCON (Total Carbon Column Observing Network) stations, CH4 profile measurements made by 36 individual AirCore soundings, and tropospheric CH4 data derived from continuous ground-based in situ observations made at two nearby Global Atmospheric Watch (GAW) mountain stations. The comparisons clearly demonstrate that the combined product can reliably detect the actual variations of atmospheric XCH4, CH4 in the UTLS, and CH4 in the troposphere. A similar good reliability for the latter is not achievable by the individual TROPOMI and IASI products.