Journal articles: 'Context refinement'

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Baumann, Pascal, Moses Ganardi, Rupak Majumdar, Ramanathan S. Thinniyam, and Georg Zetzsche. "Context-Bounded Verification of Context-Free Specifications." Proceedings of the ACM on Programming Languages 7, POPL (January 9, 2023): 2141–70. http://dx.doi.org/10.1145/3571266.

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A fundamental problem in refinement verification is to check that the language of behaviors of an implementation is included in the language of the specification. We consider the refinement verification problem where the implementation is a multithreaded shared memory system modeled as a multistack pushdown automaton and the specification is an input-deterministic multistack pushdown language. Our main result shows that the context-bounded refinement problem, where we ask that all behaviors generated in runs of bounded number of context switches belong to a specification given by a Dyck language, is decidable and coNP-complete. The more general case of input-deterministic languages follows, with the same complexity. Context-bounding is essential since emptiness for multipushdown automata is already undecidable, and so is the refinement verification problem for the subclass of regular specifications. Input-deterministic languages capture many non-regular specifications of practical interest and our result opens the way for algorithmic analysis of these properties. The context-bounded refinement problem is coNP-hard already with deterministic regular specifications; our result demonstrates that the problem is not harder despite the stronger class of specifications. Our proof introduces several general techniques for formal languages and counter programs and shows that the search for counterexamples can be reduced in non-deterministic polynomial time to the satisfiability problem for existential Presburger arithmetic. These techniques are essential to ensure the coNP upper bound: existing techniques for regular specifications are not powerful enough for decidability, while simple reductions lead to problems that are either undecidable or have high complexities. As a special case, our decidability result gives an algorithmic verification technique to reason about reference counting and re-entrant locking in multithreaded programs.

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DE MARCO, GIUSEPPE, and JACQUELINE MORGAN. "FRIENDLINESS AND RECIPROCITY IN EQUILIBRIUM SELECTION." International Game Theory Review 10, no. 01 (March 2008): 53–72. http://dx.doi.org/10.1142/s0219198908001777.

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A concept of altruistic behavior (called friendly behavior) has been defined and used for equilibrium selection in some bargaining models in Rusinowska (2002), "Refinements of Nash Equilibria in view of Jealous and Friendly Behavior of Players", International Game Theory Review, 4, 281–299. In this paper, the situation in which every player has friendly behavior is incorporated into the general context of normal form games by introducing a new refinement concept (called friendliness equilibrium). Existence, properties and connections with another refinement concept, introduced by the authors in a previous paper and which captures an idea of reciprocal altruism, are investigated. Examples and counterexamples are given illustrating concepts, results and links with other classical refinement concepts.

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Tao Li, Tao Li, Yu Wang Tao Li, Zheng Zhang Yu Wang, Xuezhuan Zhao Zheng Zhang, and Lishen Pei Xuezhuan Zhao. "Visual Object Detection with Score Refinement." 網際網路技術學刊 23, no. 5 (September 2022): 1163–72. http://dx.doi.org/10.53106/160792642022092305025.

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<p>Robustness of object detection against hard samples, especially small objects, has long been a critical and difficult problem that hinders development of convolutional object detectors. To address this issue, we propose Progressive Refinement Network to reduce classification ambiguity for scale robust object detection. In PRN, several orders of residuals for the class prediction are regressed from upper level contexts and the residuals are progressively added to the basic prediction stage by stage, yielding multiple refinements. Supervision signal is imposed at each stage and an integration of all stages is performed to obtain the final score. By supervision retaining through the context aggregation procedure, PRN avoids over dependency on higher-level information and enables sufficient learning on the current scale level. The progressive residuals added for refinements adaptively reduce the ambiguity of the class prediction and the final integration of all stages can further stabilize the predicted distribution. PRN achieves 81.3% mAP on the PASCAL VOC 2007 dataset and 31.7% AP (15.6% APS) on MS COCO dataset, which demonstrates the effectiveness and efficiency of the proposed method and its promising capability on scale robustness.</p> <p> </p>

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FUJIOKA, Kaoru. "Refinement of Representation Theorems for Context-Free Languages." IEICE Transactions on Information and Systems E93-D, no. 2 (2010): 227–32. http://dx.doi.org/10.1587/transinf.e93.d.227.

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M. "Model Refinement in the Model Driven Architecture Context." Journal of Computer Science 8, no. 8 (August 1, 2012): 1205–11. http://dx.doi.org/10.3844/jcssp.2012.1205.1211.

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Wang, Zhiyong, Genliang Guan, Yu Qiu, Li Zhuo, and Dagan Feng. "Semantic context based refinement for news video annotation." Multimedia Tools and Applications 67, no. 3 (March 17, 2012): 607–27. http://dx.doi.org/10.1007/s11042-012-1060-x.

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Zhang, Hong, Haojie Li, Zhihui Wang, Yuxin Yue, and Shenglun Chen. "Geometry and context guided refinement for stereo matching." IET Image Processing 14, no. 12 (October 16, 2020): 2652–59. http://dx.doi.org/10.1049/iet-ipr.2019.1636.

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Lee, Myung-Won, and Keun-Chang Kwak. "Optimization by Context Refinement for Development of Incremental Granular Models." Symmetry 12, no. 11 (November 20, 2020): 1916. http://dx.doi.org/10.3390/sym12111916.

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Optimization by refinement of linguistic contexts produced from an output variable in the construction of an incremental granular model (IGM) is presented herein. In contrast to the conventional learning method using the backpropagation algorithm, we use a novel method to learn both the cluster centers of Gaussian fuzzy sets representing the symmetry in the premise part and the contexts of the consequent part in the if–then fuzzy rules. Hence, we use the fundamental concept of context-based fuzzy clustering and design with an integration of linear regression (LR) and granular fuzzy models (GFMs). This GFM is constructed based on the association between the triangular membership function produced both in the input–output variables. The context can be established by the system user or using an optimization method. Hence, we can obtain superior performances based on the combination of simple linear regression and local GFMs optimized by context refinement. Experimental results pertaining to coagulant dosing in a water purification plant and automobile miles per gallon prediction revealed that the presented method performed better than linear regression, multilinear perceptron, radial basis function networks, linguistic model, and the IGM.

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Niu, Dan, Junhao Huang, Zengliang Zang, Liujia Xu, Hongshu Che, and Yuanqing Tang. "Two-Stage Spatiotemporal Context Refinement Network for Precipitation Nowcasting." Remote Sensing 13, no. 21 (October 25, 2021): 4285. http://dx.doi.org/10.3390/rs13214285.

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Precipitation nowcasting by radar echo extrapolation using machine learning algorithms is a field worthy of further study, since rainfall prediction is essential in work and life. Current methods of predicting the radar echo images need further improvement in prediction accuracy as well as in presenting the predicted details of the radar echo images. In this paper, we propose a two-stage spatiotemporal context refinement network (2S-STRef) to predict future pixel-level radar echo maps (deterministic output) more accurately and with more distinct details. The first stage is an efficient and concise spatiotemporal prediction network, which uses the spatiotemporal RNN module embedded in an encoder and decoder structure to give a first-stage prediction. The second stage is a proposed detail refinement net, which can preserve the high-frequency detailed feature of the radar echo images by using the multi-scale feature extraction and fusion residual block. We used a real-world radar echo map dataset of South China to evaluate the proposed 2S-STRef model. The experiments showed that compared with the PredRNN++ and ConvLSTM method, our 2S-STRef model performs better on the precipitation nowcasting, as well as at the image quality evaluating index and the forecasting indices. At a given 45 dBZ echo threshold (heavy precipitation) and with a 2 h lead time, the widely used CSI, HSS, and SSIM indices of the proposed 2S-STRef model are found equal to 0.195, 0.312, and 0.665, respectively. In this case, the proposed model outperforms the OpticalFlow method and PredRNN++ model.

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Maier, Georg, Benjamin Bross, Dan Grois, Detlev Marpe, Heiko Schwarz, Remco C. Veltkamp, and Thomas Wiegand. "Context-Based Fractional Sample Refinement for HEVC Compliant Encoding." IEEE Transactions on Circuits and Systems for Video Technology 28, no. 2 (February 2018): 528–39. http://dx.doi.org/10.1109/tcsvt.2016.2613910.

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Sridharan, Manu, and Rastislav Bodík. "Refinement-based context-sensitive points-to analysis for Java." ACM SIGPLAN Notices 41, no. 6 (June 11, 2006): 387–400. http://dx.doi.org/10.1145/1133255.1134027.

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Jha, Kunal Kumar, Barbara Gruza, Michał Leszek Chodkiewicz, Christian Jelsch, and Paulina Maria Dominiak. "Refinements on electron diffraction data of β-glycine in MoPro: a quest for an improved structure model." Journal of Applied Crystallography 54, no. 4 (July 7, 2021): 1234–43. http://dx.doi.org/10.1107/s160057672100580x.

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The advancement in 3D electron diffraction (3D ED) techniques that lead to a revolution in molecular structure determination using nano-sized crystals is now achieving atomic resolution. The structures can be obtained from 3D ED data with tools similar to those used for X-ray structure determination. In this context, the MoPro software, originally designed for structure and charge density refinements using X-ray diffraction data, has been adapted. Structure refinement on 3D ED data was achieved via implementation of electron scattering factors available in the literature and by application of the Mott–Bethe equation to X-ray scattering factors computed from the multipolar atom model. The multipolar model was parametrized using the transferable pseudoatom databanks ELMAM2 and UBDB. Applying the independent atom model (IAM), i.e. spherical neutral atom refinement, to 3D ED data on β-glycine in MoPro resulted in structure and refinement statistics comparable to those obtained from other well known software. Use of the transferred aspherical atom model (TAAM) led to improvement of the refinement statistics and a better fit of the model to the 3D ED data as compared with the spherical atom refinement. The anisotropic displacement parameters of non-H atoms appear underestimated by typically 0.003 Å2 for the non-H atoms in IAM refinement compared with TAAM. Thus, MoPro is shown to be an effective tool for crystal structure refinement on 3D ED data and allows use of a spherical or a multipolar atom model. Electron density databases can be readily transferred with no further modification needed when the Mott–Bethe equation is applied.

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Huang, Zhifeng, Qian Zhang, and Guixu Zhang. "MLCRNet: Multi-Level Context Refinement for Semantic Segmentation in Aerial Images." Remote Sensing 14, no. 6 (March 20, 2022): 1498. http://dx.doi.org/10.3390/rs14061498.

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In this paper, we focus on the problem of contextual aggregation in the semantic segmentation of aerial images. Current contextual aggregation methods only aggregate contextual information within specific regions to improve feature representation, which may yield poorly robust contextual information. To address this problem, we propose a novel multi-level context refinement network (MLCRNet) that aggregates three levels of contextual information effectively and efficiently in an adaptive manner. First, we designed a local-level context aggregation module to capture local information around each pixel. Second, we integrate multiple levels of context, namely, local-level, image-level, and semantic-level, to aggregate contextual information from a comprehensive perspective dynamically. Third, we propose an efficient multi-level context transform (EMCT) module to address feature redundancy and to improve the efficiency of our multi-level contexts. Finally, based on the EMCT module and feature pyramid network (FPN) framework, we propose a multi-level context feature refinement (MLCR) module to enhance feature representation by leveraging multi-level contextual information. Extensive empirical evidence demonstrates that our MLCRNet achieves state-of-the-art performance on the ISPRS Potsdam and Vaihingen datasets.

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Spek, Anthony. "The Extended PLATON/SQUEEZE Tool in the Context of Twinning and SHELXL2014." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1436. http://dx.doi.org/10.1107/s2053273314085635.

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The completion of a single crystal structure determination is often hampered by the presence of disordered solvent molecules of crystallization. The often not interesting details of that solvent disorder and its contribution to the calculated structure factors has to be modelled in some way in order to obtain publishable results. Current refinement programs include suitable constraints and restraints for a stable refinement of a discrete disorder model. This is often the preferred procedure, in particular when charge balances and valence states are relevant. Unfortunately, a discrete disorder model is not always feasible. Examples include solvent molecules in infinite channels or structures including unknown solvents or solvent mixtures. In such cases the iterative back-Fourier transformation of the content of the disordered solvent volume in a difference density map can be attempted as the contribution to the calculated structure factors. Back-Fourier transformation of disordered solvent regions was prototyped by us nearly 25 years ago (van der Sluis & Spek, 1990) around the, at that time widely used, SHELX76 refinement program. The original reason for its development was the structure determination of a pharmaceutical that contained infinite channels filled with ridges of electron density in the difference density map rather than discrete density peaks (van der Sluis & Spek, 1990). The preliminary implementation of a successful prototype procedure (called BYPASS) was complex and found not to be easily distributable due to its dependence on many (local) ad-hoc programs. A new distributable version, compatible with the next generation refinement program SHELXL97, was implemented as the SQUEEZE tool in the program package PLATON Spek, 2009). The new SHELXL2014 refinement program allows for an even more elegant implementation of the SQUEEZE tool including the possibility to apply it also for twinned structures. Examples and restrictions will be discussed.

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Bae, Crystal, Jennifer L. Pigoga, Megan Cox, Bonaventure Hollong, Joseph Kalanzi, Gamal Abbas, Lee A. Wallis, and Emilie J. Calvello Hynes. "Evaluating emergency care capacity in Africa: an iterative, multicountry refinement of the Emergency Care Assessment Tool." BMJ Global Health 3, no. 5 (October 2018): e001138. http://dx.doi.org/10.1136/bmjgh-2018-001138.

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Healthcare facilities in low-income and middle-income countries lack an objective measurement tool to assess emergency care capacity. The African Federation for Emergency Medicine developed the Emergency Care Assessment Tool (ECAT) to fulfil this function. The ECAT assesses the provision of key medical interventions (signal functions) that emergency units (EUs) should be able to perform to adequately treat six common, life-threatening conditions (sentinel conditions). We describe the piloting and refinement of the ECAT, to improve usability and context-appropriateness. We undertook iterative, multisite refinement of the ECAT. After pilot testing at a South African referral hospital, subsequent studies occurred at district, regional and central facilities across four countries representing the major regions of Africa: Cameroon, Uganda, Egypt and Botswana. At each site, the tool was administered to three participants: one senior physician, one senior nurse and one other clinical provider. Feedback informed refinements of the ECAT, and an updated tool was used in the next-studied country. Iteratively implementing refined versions of the tool in various contexts across Africa resulted in a final ECAT that uses signal functions, categorised by sentinel conditions and evaluated against discrete barriers to emergency care service delivery, to assess EUs. It also allowed for refinement of administration and data analysis processes. The ECAT has a total of 71 items. Advanced facilities are expected to perform all 71 signal functions, while intermediate facilities should be able to perform 53. The ECAT is the first tool to provide a standardised method for assessing facility-based emergency care in the African context. It identifies where in the maturation process a hospital or system is and what gaps exist in delivery of care, so that a comprehensive roadmap for development can be established. Although validity and feasibility testing have now occurred, reliability studies must be conducted prior to amplification across the region.

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COLVIN, ROBERT, IAN J. HAYES, and PAUL STROOPER. "Calculating modules in contextual logic program refinement." Theory and Practice of Logic Programming 8, no. 01 (May 15, 2007): 1–31. http://dx.doi.org/10.1017/s1471068407003043.

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AbstractThe refinement calculus for logic programs is a framework for deriving logic programs from specifications. It is based on a wide-spectrum language that can express both specifications and code, and a refinement relation that models the notion of correct implementation. In this paper we extend and generalise earlier work oncontextual refinement. Contextual refinement simplifies the refinement process by abstractly capturing the context of a subcomponent of a program, which typically includes information about the values of the free variables. This paper also extends and generalisesmodule refinement. Amoduleis a collection of procedures that operate on a common data type; module refinement between a specification moduleAand an implementation moduleCallows calls to the procedures ofAto be systematically replaced with calls to the corresponding procedures ofC. Based on the conditions for module refinement, we present a method forcalculatingan implementation module from a specification module. Both contextual and module refinement within the refinement calculus have been generalised from earlier work and the results are presented in a unified framework.

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Duarte Alonso, Abel, and Ian Patrick Austin. "The significance of organisational learning in a global context." Review of International Business and Strategy 27, no. 1 (March 6, 2017): 53–69. http://dx.doi.org/10.1108/ribs-09-2016-0054.

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Purpose The purpose of this study is to examine organisational learning (OL) among firms involved in global-trade relationships. The study adopts the stakeholder theory (ST) and the knowledge-based theory (KBT) of the firm to illuminate the research and facilitate the understanding of the areas under investigation. The study, therefore, makes contributions to the extant international business and strategy literature, both in new empirical evidence and in theoretical refinement. Design/methodology/approach In-depth, unstructured, face-to-face and telephone interviews were conducted with owners/co-owners of nine Western Australian firms operating internationally. Findings Collectively, participants perceive improvements in trade relationships through increased understanding and knowledge. Importantly, OL is significantly affected by systematic and dramatic/strategic quantum change. Alignments with ST and KBT emerged, emphasising the usefulness of these frameworks to understand owners/co-owners’ best-practice stakeholder management. Furthermore, the study proposes a refinement of these frameworks to facilitate understanding of the participating firms’ OL-related strategies. Originality/value While there is a rich body of literature on OL, various knowledge gaps have been identified in contemporary research. The study provides value by contributing to new knowledge in these areas and by proposing a refinement of the used theoretical frameworks in explaining OL among Western Australian global firms. In addition, despite Western Australia’s geographic proximity to various overseas consumer markets, very few empirical studies have examined the above areas in the context of this state’s firms. By focusing on Western Australian firms, the study also provides an element of originality.

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Benouhiba, Toufik. "A Multi-level Refinement Approach for Structural Synthesis of Optimal Probabilistic Models." Fundamenta Informaticae 179, no. 1 (February 9, 2021): 1–33. http://dx.doi.org/10.3233/fi-2021-2011.

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Probabilistic models play an important role in many fields such as distributed systems and simulations. Like non-probabilistic systems, they can be synthesized using classical refinement-based techniques, but they also require identifying the probability distributions to be used and their parameters. Since a fully automated and blind refinement is generally undecidable, many works tried to synthesize them by looking for the parameters of the distributions. Syntax-guided synthesizing approaches are more powerful, they try to synthesize models structurally by using context-free grammars. However, many problems arise like huge search space, the complexity of generated models, and the limitation of context-free grammars to define constraints over the structure. In this paper, we propose a multi-step refinement approach, based on meta-models, offering several abstraction levels to reduce the size of the search space. More specifically, each refinement step is divided into two stages in which the desired shape of models is first described by context-sensitive constraints. In the second stage, model templates are instantiated by using global optimization techniques. We use our approach to a synthesize a set of optimal probabilistic models and show that context-sensitive constraints coupled with the multi-level abilities of the approach make the synthesis task more effective.

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Coelho, A. A., P. A. Chater, and A. Kern. "Fast synthesis and refinement of the atomic pair distribution function." Journal of Applied Crystallography 48, no. 3 (May 22, 2015): 869–75. http://dx.doi.org/10.1107/s1600576715007487.

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A fast method for calculating the atomic pair distribution function is described in the context of performing refinements of structural models. Central to the speed of synthesis is the approximation of Gaussian functions of varying full widths at half-maximum using a narrower Gaussian with a fixed full width at half-maximum. The initial Gaussians are first laid down as delta functions which are then convoluted with the narrower Gaussian to form the final pattern. The net result is an algorithm, which has been included in the Rietveld refinement computer programTOPAS, that synthesizes and refines structural parameters a factor of 300–1000 times faster than alternative algorithms/programs, with speed advantages increasing as the number of atomic pairs increases.

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Damnjanović, Kaja, Sandra Ilić, Irena Pavlović, and Vera Novković. "Refinement of outcome bias measurement in the parental decision-making context." Europe’s Journal of Psychology 15, no. 1 (February 28, 2019): 41–58. http://dx.doi.org/10.5964/ejop.v15i1.1698.

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The aim of this study was twofold: one was to test the impact of the involvement on the parental outcome bias, and the second was to refine the measurement of outcome bias, normally reported as the difference between evaluations of a single decision, with different outcomes assigned to it. We introduced the evaluation of a decision without an outcome, to induce theoretically normative evaluation, unbiased by outcome, from which the evaluation shift could be calculated in either direction. To test this refinement in the parental decision-making context, we produced childcare dilemmas with varying levels of complexity, since the rise of complexity induces stronger bias. Complexity was determined by the particular combination of two factors: parental involvement in a decision - the amount of motivation, interest and drive evoked by it – and whether the decision was health-related or not. We presented parents with the decisions for evaluation, followed by a positive and a negative outcome, and without an outcome. The results confirm the interaction between involvement and domain on decision evaluation. Highly involving decisions yielded weaker outcome bias than low-involvement decisions in both health and non-health domain. Results also confirm the validity of the proposed way of measuring OB, revealing that in some situations positive outcomes skew evaluations more than negative outcomes. Also, a highly-involving dilemma followed by negative outcome did not produce significantly different evaluation compared to evaluation of a decision without outcome. Thus, adding a neutral position rendered OB measurement more precise and our involvement-related insights more nuanced.

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Gange, Graeme, Jorge A. Navas, Peter Schachte, Harald Søndergaard, and Peter J. Stuckey. "A complete refinement procedure for regular separability of context-free languages." Theoretical Computer Science 625 (April 2016): 1–24. http://dx.doi.org/10.1016/j.tcs.2016.01.026.

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Tan, Jiahai, Ming Gao, Kai Yang, and Tao Duan. "Remote Sensing Road Extraction by Road Segmentation Network." Applied Sciences 11, no. 11 (May 29, 2021): 5050. http://dx.doi.org/10.3390/app11115050.

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Road extraction from remote sensing images has attracted much attention in geospatial applications. However, the existing methods do not accurately identify the connectivity of the road. The identification of the road pixels may be interfered with by the abundant ground such as buildings, trees, and shadows. The objective of this paper is to enhance context and strip features of the road by designing UNet-like architecture. The overall method first enhances the context characteristics in the segmentation step and then maintains the stripe characteristics in a refinement step. The segmentation step exploits an attention mechanism to enhance the context information between the adjacent layers. To obtain the strip features of the road, the refinement step introduces the strip pooling in a refinement network to restore the long distance dependent information of the road. Extensive comparative experiments demonstrate that the proposed method outperforms other methods, achieving an overall accuracy of 98.25% on the DeepGlobe dataset, and 97.68% on the Massachusetts dataset.

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Hu, Jingyuan, and Zhouwang Yang. "Single-Shot Global and Local Context Refinement Neural Network for Head Detection." Future Internet 14, no. 12 (December 19, 2022): 384. http://dx.doi.org/10.3390/fi14120384.

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Head detection is a fundamental task, and it plays an important role in many head-related problems. The difficulty in creating the local and global context in the face of significant lighting, orientation, and occlusion uncertainty, among other factors, still makes this task a remarkable challenge. To tackle these problems, this paper proposes an effective detector, the Context Refinement Network (CRN), that captures not only the refined global context but also the enhanced local context. We use simplified non-local (SNL) blocks at hierarchical features, which can successfully establish long-range dependencies between heads to improve the capability of building the global context. We suggest a multi-scale dilated convolutional module for the local context surrounding heads that extracts local context from various head characteristics. In comparison to other models, our method outperforms them on the Brainwash and the HollywoodHeads datasets.

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Ewert, Sigrid, and Andries van der Walt. "Generating Pictures Using Random Forbidding Context." International Journal of Pattern Recognition and Artificial Intelligence 12, no. 07 (November 1998): 939–50. http://dx.doi.org/10.1142/s0218001498000518.

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We use random context picture grammars to generate pictures through successive refinement. At any stage a picture consists of a shape divided into smaller shapes, each containing a variable or terminal. A variable may be rewritten according to a production of the underlying grammar. This entails either dividing the shape containing it into smaller shapes, or substituting a variable or terminal for it. For visualization purposes every terminal is associated with a color, and its shape is filled with that color. We show pictures generated with random context picture grammars, then concentrate on grammars which use forbidding context only and present a shrinking lemma for the corresponding languages.

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Montgomery, Allen A., Brian E. Walden, and Robert A. Prosek. "Effects of Consonantal Context on Vowel Lipreading." Journal of Speech, Language, and Hearing Research 30, no. 1 (March 1987): 50–59. http://dx.doi.org/10.1044/jshr.3001.50.

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The effects of consonantal context on vowel lipreading were assessed for 30 adults with mild-to-moderate sensorineural hearing loss who lipread videotape recordings of two female talkers. The stimuli were the vowels /i, I ,, U ,u/ in symmetric CVC form with the consonants /p,b,f,v,t,d,∫,g/ and in the asymmetric consonantal contexts /h/-V-/g/, /w/-V-/g/, /r/-V-/g/. Analyses of the confusion matrices from each talker indicated that vowel intelligibility was significantly poorer in most contexts involving highly visible consonants, although the utterances of one talker were highly intelligible in the bilabial context. Among the visible contexts, the fricative and labiodental contexts in particular produced the lowest vowel intelligibility regardless of talker. Lax vowels were consistently more difficult to perceive than tense vowels. Implications for talker selection and refinement of the concept of viseme were drawn.

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Kimber, Ian. "Reduction, Refinement and Replacement: Putting the Immune System to Work." Alternatives to Laboratory Animals 30, no. 6 (November 2002): 571–78. http://dx.doi.org/10.1177/026119290203000603.

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Many chemicals are known to be, or have been implicated as, contact allergens, and allergic contact dermatitis is an important occupational and environmental health issue. It is the responsibility of toxicologists to identify those chemicals that have the potential to induce skin sensitisation, and to assess the conditions under which there will exist a risk to human health. This article describes progress that has been made in the development of new approaches to the toxicological evaluation of skin sensitisation, and the benefits to animal welfare that such developments have already produced, and are likely to produce in the future. In this context, the local lymph node assay is described with regard to hazard identification and risk assessment, and possible strategies for the development of in vitro approaches to safety assessment are discussed.

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Srinivasan, Sudarshan K., Koushik Sarker, and Rajendra S. Katti. "Token-Aware Completion Functions for Elastic Processor Verification." Research Letters in Electronics 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/480740.

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We develop a formal verification procedure to check that elastic pipelined processor designs correctly implement their instruction set architecture (ISA) specifications. The notion of correctness we use is based on refinement. Refinement proofs are based on refinement maps, which—in the context of this problem—are functions that map elastic processor states to states of the ISA specification model. Data flow in elastic architectures is complicated by the insertion of any number of buffers in any place in the design, making it hard to construct refinement maps for elastic systems in a systematic manner. We introduce token-aware completion functions, which incorporate a mechanism to track the flow of data in elastic pipelines, as a highly automated and systematic approach to construct refinement maps. We demonstrate the efficiency of the overall verification procedure based on token-aware completion functions using six elastic pipelined processor models based on the DLX architecture.

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Zhai, Yongping, Junhua Wang, Jinsheng Deng, Guanghui Yue, Wei Zhang, and Chang Tang. "Global context guided hierarchically residual feature refinement network for defocus blur detection." Signal Processing 183 (June 2021): 107996. http://dx.doi.org/10.1016/j.sigpro.2021.107996.

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Awan, Mehwish, and Jitae Shin. "A Robust Context-Aware Proposal Refinement Method for Weakly Supervised Object Detection." IEEE Access 8 (2020): 199768–80. http://dx.doi.org/10.1109/access.2020.3035606.

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Jaffal, Ali, Bénédicte Le Grand, and Manuele Kirsch-Pinheiro. "Refinement Strategies for Correlating Context and User Behavior in Pervasive Information Systems." Procedia Computer Science 52 (2015): 1040–46. http://dx.doi.org/10.1016/j.procs.2015.05.103.

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Lebreuilly, U., B. Commerçon, and G. Laibe. "Small dust grain dynamics on adaptive mesh refinement grids." Astronomy & Astrophysics 626 (June 2019): A96. http://dx.doi.org/10.1051/0004-6361/201834147.

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Context. Small dust grains are essential ingredients of star, disk and planet formation. Aims. We present an Eulerian numerical approach to study small dust grain dynamics in the context of star and protoplanetary disk formation. It is designed for finite volume codes. We use it to investigate dust dynamics during the protostellar collapse. Methods. We present a method to solve the monofluid equations of gas and dust mixtures with several dust species in the diffusion approximation implemented in the adaptive-mesh-refinement code RAMSES. It uses a finite volume second-order Godunov method with a predictor-corrector MUSCL scheme to estimate the fluxes between the grid cells. Results. We benchmark our method against six distinct tests, DUSTYADVECT, DUSTYDIFFUSE, DUSTYSHOCK, DUSTYWAVE, SETTLING, and DUSTYCOLLAPSE. We show that the scheme is second-order accurate in space on uniform grids and intermediate between second- and first-order on non-uniform grids. We apply our method on various DUSTYCOLLAPSE simulations of 1 M⊙ cores composed of gas and dust. Conclusions. We developed an efficient approach to treat gas and dust dynamics in the diffusion regime on grid-based codes. The canonical tests were successfully passed. In the context of protostellar collapse, we show that dust is less coupled to the gas in the outer regions of the collapse where grains larger than ≃100 μm fall significantly faster than the gas.

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Vilane, V. N., R. D. Knutsen, and J. E. Westraadt. "Submicron Grain Size Formation in Thermohydrogenated and Deformed Ti-6Al-4V: The Effect of Processing Route on the Degree of Grain Refinement." Advanced Materials Research 1019 (October 2014): 266–72. http://dx.doi.org/10.4028/www.scientific.net/amr.1019.266.

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The aim of this work was to refine the as-cast Ti-6Al-4V grain size and its Widmanstätten morphology to optimise the mechanical performance of Ti-6Al-4V castings. Hydrogenation and deformation were used as variables in processing routes aimed at assessing the degree of refinement in the as-cast Ti-6Al-4V microstructure. Thermohydrogen processing (THP) refined the Widmanstätten morphology and not the prior beta grain boundary network. Therefore, the degree of refinement in THP processing is limited to morphology refinement within pre-existing prior beta grains. Deformation processing and recrystallisation is necessary to eliminate the indelible influence of the prior beta grain boundary network on the extent of THP refinement. In this context, a substantial degree of refinement is achieved from thermohydrogen and deformation processing (THDP). The as-cast Ti-6Al-4V grain boundary network was refined from an average diameter of 2000μm to 20μm. In addition, the Widmanstätten morphology was refined to submicron equiaxed alpha and beta grains.

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KLEIN, ANDREAS, and MARTIN KUTRIB. "CONTEXT-FREE GRAMMARS WITH LINKED NONTERMINALS." International Journal of Foundations of Computer Science 18, no. 06 (December 2007): 1271–82. http://dx.doi.org/10.1142/s0129054107005315.

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We introduce a new type of finite copying parallel rewriting system, i. e., grammars with linked nonterminals, which extend the generative capacity of context-free grammars. They can be thought of as having sentential forms where some instances of a nonterminal may be linked. The context-free-like productions replace a nonterminal together with its connected instances. New links are only established between symbols of the derived subforms. A natural limitation is to bound the degree of synchronous rewriting. We present an infinite degree hierarchy of separated language families with the property that degree one characterizes the family of regular and degree two the family of context-free languages. Furthermore, the hierarchy is a refinement of the known hierarchy of finite copying rewriting systems. Several closure properties known from equivalent systems are summarized.

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Qu, Yingjie, Qingsong Yan, Junxing Yang, Teng Xiao, and Fei Deng. "Total Differential Photometric Mesh Refinement with Self-Adapted Mesh Denoising." Photonics 10, no. 1 (December 24, 2022): 20. http://dx.doi.org/10.3390/photonics10010020.

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Variational mesh refinement is a crucial step in multiview 3D reconstruction. Existing algorithms either focus on recovering mesh details or focus on suppressing noise. Approaches with consideration of both are lacking. To address this limitation, we proposed a new variational mesh refinement method named total differential mesh refinement (TDR), which mainly included two improvements. First, the traditional partial-differential photo-consistency gradient used in the variational mesh refinement method was replaced by the proposed total-differential photo-consistency gradient. With consideration of the photo-consistency correlation between adjacent pixels, our method can make photo-consistency achieve a more effective convergence than traditional approaches. Second, we introduced the bilateral normal filter with a novel self-adaptive mesh denoising strategy into the variational mesh refinement. This strategy maintains a balance between detail preservation and effective denoising via the zero-normalized cross-correlation (ZNCC) map. Various experiments demonstrated that our method is superior to traditional variational mesh refinement approaches in both accuracy and denoising effect. Moreover, compared with the mesh generated by open-source and commercial software (Context Capture), our meshes are more detailed, regular, and smooth.

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EWERT, SIGRID, and ANDRIES VAN DER WALT. "GENERATING PICTURES USING RANDOM PERMITTING CONTEXT." International Journal of Pattern Recognition and Artificial Intelligence 13, no. 03 (May 1999): 339–55. http://dx.doi.org/10.1142/s0218001499000197.

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We use random context picture grammars to generate pictures through successive refinement. At any stage a picture consists of a shape divided into smaller shapes, each containing a variable or terminal. A variable may be rewritten according to a production of the underlying grammar, which entails either dividing the shape containing it into smaller shapes, or substituting a variable or terminal for it. A production may depend on context randomly distributed in the intermediate picture. Context is classified as either permitting or forbidding, the former enabling the application of a production, the latter inhibiting it. For visualization purposes every terminal is associated with a color, and its shape filled with that color. We show examples of pictures generated with random context picture grammars. Then we concentrate on grammars which use permitting context only and present a pumping lemma for the corresponding picture sets.

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Costa, Elisabetta. "Affordances-in-practice: An ethnographic critique of social media logic and context collapse." New Media & Society 20, no. 10 (February 19, 2018): 3641–56. http://dx.doi.org/10.1177/1461444818756290.

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Drawing on data gathered during ethnographic fieldwork in Mardin, a medium-sized town in southeast Turkey, this article shows that social media users actively appropriate online platforms and change privacy settings in order to keep different social spheres and social groups apart. Keeping different online social contexts distinct from each other is taken for granted as a way of using social media in Mardin. By contrast, social media scholars have extensively discussed the effects of social media in terms of context collapse. The article highlights how context collapse is the result of patterns of usage within Anglo-American contexts and not the consequence of a platform’s architecture or social media logic. It then suggests a theoretical refinement of affordances, and proposes the concept of affordances-in-practice.

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Wörndl, Wolfgang, and Béatrice Lamche. "User Interaction with Context-aware Recommender Systems on Smartphones." icom 14, no. 1 (April 15, 2015): 19–28. http://dx.doi.org/10.1515/icom-2015-0007.

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SummaryIn this article we give an overview on selected aspects of user interaction with context-aware recommender systems on smartphones. We discuss these according to the three steps of user interaction with recommender systems using subjective and objective evaluation criteria: 1. Preference elicitation: how input methods on mobile devices can influence the users’ rating behavior, 2. Result delivery and presentation: how results can be adapted to the mobile context, 3. Feedback, critiquing and refinement: how interactive explanation can improve the user experience. The selection of examples is based on several studies we did in different mobile scenarios.

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Kline, Theresa J. B. "Refinement and Evaluation of the Decision-Making Questionnaire." Psychological Reports 78, no. 1 (February 1996): 151–62. http://dx.doi.org/10.2466/pr0.1996.78.1.151.

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The psychometric properties of the Decision-making Questionnaire which was designed to assess decision-making in an organizational context were investigated by administering the questionnaire to 54 undergraduate students. The dimensions measured are Effectiveness, Confidence, and Information used in making both tactical and strategic organizational decisions. The assessment of the Effectiveness scores consisted of examining item-to-total correlations, principal components analyses, and internal consistencies. Also, the relationships amongst all three dimensions measured by the scale as well as relationships of all three dimensions with measures of perceived opportunities and threats are reported.

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Lou, Meng, Jie Meng, Yunliang Qi, Xiaorong Li, and Yide Ma. "MCRNet: Multi-level context refinement network for semantic segmentation in breast ultrasound imaging." Neurocomputing 470 (January 2022): 154–69. http://dx.doi.org/10.1016/j.neucom.2021.10.102.

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Ho, Jessie, and Paul L. Nesbit. "A refinement and extension of the self‐leadership scale for the Chinese context." Journal of Managerial Psychology 24, no. 5 (June 26, 2009): 450–76. http://dx.doi.org/10.1108/02683940910959771.

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Srinivasan, Sudarshan K. "Optimization Techniques for Verification of Out-of-Order Execution Machines." Journal of Electrical and Computer Engineering 2010 (2010): 1–7. http://dx.doi.org/10.1155/2010/515021.

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We develop two optimization techniques,flush-machineand collapsed flushing, to improve the efficiency of automatic refinement-abased verification of out-of-order (ooo) processor models. Refinement is a notion of equivalence that can be used to check that an ooo processor correctly implements all behaviors of its instruction set architecture (ISA), including deadlock detection. The optimization techniques work by reducing the computational complexity of the refinement map, a function central to refinement proofs that maps ooo processor model states to ISA states. This has a direct impact on the efficiency of verification, which is studied using 23 ooo processor models.Flush-machine, is a novel optimization technique. Collapsed flushing has been employed previously in the context of in-order processors. We show how to apply collapsed flushing for ooo processor models. Using both the optimizations together, we can handle 9 ooo models that could not be verified using standard flushing. Also, the optimizations provided a speed up of 23.29 over standard flushing.

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David, W. I. F. "Robust Rietveld refinement in the presence of impurity phases." Journal of Applied Crystallography 34, no. 6 (November 17, 2001): 691–98. http://dx.doi.org/10.1107/s0021889801011396.

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A modified least-squares analysis is presented that allows reliable structural parameters to be extracted from a powder diffraction pattern even in the presence of a substantial unmodelled impurity contribution. The algorithm is developed within the context of Bayesian probability theory. Experimental points that fall above those calculated, and are thus more probably from impurity peaks, are systematically down-weighted. This approach is illustrated with a two-phase example.

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Lundqvist, Magnus, Kurt Sandkuhl, and Ulf Seigerroth. "Modelling Information Demand in an Enterprise Context." International Journal of Information System Modeling and Design 2, no. 3 (July 2011): 75–95. http://dx.doi.org/10.4018/jismd.2011070104.

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Information overload is perceived as a common problem in organisations and enterprises, which calls for new organisational and technological approaches for more pertinent and accurate information supply. The paper contributes to addressing this problem by proposing a method for information demand modelling, which contributes to capturing and understanding the information demand of roles in organisations. This method consists to a large extent of an application of enterprise modelling techniques. Illustrated by a case from automotive industries, lessons learned from information demand modelling are presented and discussed. This includes the specific perspective taken in the method for information demand analysis, common challenges experienced in demand modelling, and the validity of recommendations from participative enterprise modelling for information demand modelling. Furthermore, the paper introduces the notation applied for information demand models and discusses refinement process of this notation.

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Saint-Bauzel, Roxane, Audrey Pelt, Laura Barbier, and Valérie Fointiat. "Disrupt-Then-Reframe is in the Air: A French Replication and Refinement." Psychology of Language and Communication 19, no. 2 (October 1, 2015): 162–73. http://dx.doi.org/10.1515/plc-2015-0010.

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Abstract Initiated by Davis and Knowles (1999), the-disrupt-then-reframe technique is based on the linking of two moments in time. First of all, slipping an unexpected element into a communication situation that is likely to provoke a disruption in communication. Once this disruption has been achieved, proposing a target behaviour by insisting on the benefit that the individual could derive from it. We wanted to verify that this technique, effective in American, Dutch, and Polish contexts and naturally dependent on the culture of individuals and the communication norms which prevail there, could be effective in a French context. In accordance with the literature, our results show that when the two phases of the technique are linked, a greater persuasive effect is observed. A theoretically interesting way to interpret the effectiveness of the technique is proposed.

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BAZILEVS, Y., L. BEIRÃO DA VEIGA, J. A. COTTRELL, T. J. R. HUGHES, and G. SANGALLI. "ISOGEOMETRIC ANALYSIS: APPROXIMATION, STABILITY AND ERROR ESTIMATES FOR h-REFINED MESHES." Mathematical Models and Methods in Applied Sciences 16, no. 07 (July 2006): 1031–90. http://dx.doi.org/10.1142/s0218202506001455.

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We begin the mathematical study of Isogeometric Analysis based on NURBS (non-uniform rational B-splines). Isogeometric Analysis is a generalization of classical Finite Element Analysis (FEA) which possesses improved properties. For example, NURBS are capable of more precise geometric representation of complex objects and, in particular, can exactly represent many commonly engineered shapes, such as cylinders, spheres and tori. Isogeometric Analysis also simplifies mesh refinement because the geometry is fixed at the coarsest level of refinement and is unchanged throughout the refinement process. This eliminates geometrical errors and the necessity of linking the refinement procedure to a CAD representation of the geometry, as in classical FEA. In this work we study approximation and stability properties in the context of h-refinement. We develop approximation estimates based on a new Bramble–Hilbert lemma in so-called "bent" Sobolev spaces appropriate for NURBS approximations and establish inverse estimates similar to those for finite elements. We apply the theoretical results to several cases of interest including elasticity, isotropic incompressible elasticity and Stokes flow, and advection-diffusion, and perform numerical tests which corroborate the mathematical results. We also perform numerical calculations that involve hypotheses outside our theory and these suggest that there are many other interesting mathematical properties of Isogeometric Analysis yet to be proved.

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Hruby, D. E. "Vaccinia virus vectors: new strategies for producing recombinant vaccines." Clinical Microbiology Reviews 3, no. 2 (April 1990): 153–70. http://dx.doi.org/10.1128/cmr.3.2.153.

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The development and continued refinement of techniques for the efficient insertion and expression of heterologous DNA sequences from within the genomic context of infectious vaccinia virus recombinants are among the most promising current approaches towards effective immunoprophylaxis against a variety of protozoan, viral, and bacterial human pathogens. Because of its medical relevance, this area is the subject of intense research interest and has evolved rapidly during the past several years. This review (i) provides an updated overview of the technology that exists for assembling recombinant vaccinia virus strains, (ii) discusses the advantages and disadvantages of these approaches, (iii) outlines the areas of outgoing research directed towards overcoming the limitations of current techniques, and (iv) provides some insight (i.e., speculation) about probable future refinements in the use of vaccinia virus as a vector.

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Parsons, Simon, Trixie Wagner, Oliver Presly, Peter A. Wood, and Richard I. Cooper. "Applications of leverage analysis in structure refinement." Journal of Applied Crystallography 45, no. 3 (May 16, 2012): 417–29. http://dx.doi.org/10.1107/s0021889812015191.

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Leverages measure the influence that observations (intensity data and restraints) have on the fit obtained in crystal structure refinement. Further analysis enables the influence that observations have on specific parameters to be measured. The results of leverage analyses are discussed in the context of the amino acid alanine and an incomplete high-pressure data set of the complex bis(salicylaldoximato)copper(II). Leverage analysis can reveal situations where weak data are influential and allows an assessment of the influence of restraints. Analysis of the high-pressure refinement of the copper complex shows that the influence of the highest-leverage intensity observations increases when completeness is reduced, but low leverages stay low. The influence of restraints, notably those applying the Hirshfeld rigid-bond criterion, also increases dramatically. In alanine the precision of the Flack parameter is determined by medium-resolution data with moderate intensities. The results of a leverage analysis can be incorporated into a weighting scheme designed to optimize the precision of a selected parameter. This was applied to absolute structure refinement of light-atom crystal structures. The standard uncertainty of the Flack parameter could be reduced to around 0.1 even for a hydrocarbon.

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Liu, Jingjing, Ao Wei, Zhigang Guo, and Chang Tang. "Global Context and Enhanced Feature Guided Residual Refinement Network for 3D Cardiovascular Image Segmentation." IEEE Access 9 (2021): 155861–70. http://dx.doi.org/10.1109/access.2021.3129333.

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Li, Tengpeng, Huihui Song, Kaihua Zhang, and Qingshan Liu. "Learning residual refinement network with semantic context representation for real-time saliency object detection." Pattern Recognition 105 (September 2020): 107372. http://dx.doi.org/10.1016/j.patcog.2020.107372.

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Dumitrof, Luiza Cristina, Igor Nedelciuc, Mihai Roca, Daniela Boișteanu, Radu Crișan-Dabija, Traian Mihăescu, Grigore Tinică, and Florin Mitu. "Evolution of Biological Parameters in Patients with Severe Aortic Stenosis Undergoing TAVI - Results at One Month." Internal Medicine 19, no. 4 (December 1, 2022): 47–58. http://dx.doi.org/10.2478/inmed-2022-0228.

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Abstract Aortic stenosis is one of the most common valve diseases in patients over 60 years of age. Lack of prompt surgical correction by conventional valve replacement or interventional transcatheter aortic valve implantation (TAVI) increases the risk of morbidity and mortality, in the context of worsening clinical picture. Since the first interventional transcatheter valve implantation procedure in 2012 and to date, the evolution of technology and refinement of medical techniques has led to the refinement of the treatment method and thus to the improvement of the prognosis of patients with aortic stenosis undergoing TAVI after only one month.

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Journal articles on the topic 'Context refinement'

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