Geometrically Induced Force Interaction for Three-Dimensional Deformable Models

This work introduces a novel 3D deformable model that is based on a geometrically induced external force field, which can be conveniently generalised to arbitrary dimensions. This external force field is based on hypothesised interactions between the relative geometries of the deformable model and the object boundary. The relative geometrical configurations contribute to a dynamic vector force field that changes accordingly as the deformable model evolves. In addition, we show that by enhancing the geometrical interaction field with a nonlocal edge preserving algorithm, the new model can effectively overcome image noise. We provide a comprehensive comparative study and show that the proposed method achieves significant improvements against existing techniques

Multi-fidelity reduced-order surrogate modeling

High-fidelity numerical simulations of partial differential equations (PDEs) given a restricted computational budget can significantly limit the number of parameter configurations considered and/or time window evaluated for modeling a given system. Multi-fidelity surrogate modeling aims to leverage less accurate, lower-fidelity models that are computationally inexpensive in order to enhance predictive accuracy when high-fidelity data are limited or scarce. However, low-fidelity models, while often displaying important qualitative spatio-temporal features, fail to accurately capture the onset of instability and critical transients observed in the high-fidelity models, making them impractical as surrogate models. To address this shortcoming, we present a new data-driven strategy that combines dimensionality reduction with multi-fidelity neural network surrogates. The key idea is to generate a spatial basis by applying the classical proper orthogonal decomposition (POD) to high-fidelity solution snapshots, and approximate the dynamics of the reduced states - time-parameter-dependent expansion coefficients of the POD basis - using a multi-fidelity long-short term memory (LSTM) network. By mapping low-fidelity reduced states to their high-fidelity counterpart, the proposed reduced-order surrogate model enables the efficient recovery of full solution fields over time and parameter variations in a non-intrusive manner. The generality and robustness of this method is demonstrated by a collection of parametrized, time-dependent PDE problems where the low-fidelity model can be defined by coarser meshes and/or time stepping, as well as by misspecified physical features. Importantly, the onset of instabilities and transients are well captured by this surrogate modeling technique

A Survey of Search-Based Refactoring for Software Maintenance

Abstract This survey reviews published materials related to the specific area of Search-Based Software Engineering that concerns software maintenance and, in particular, refactoring. The survey aims to give a comprehensive review of the use of search-based refactoring to maintain software. Fifty different papers have been selected from online databases to analyze and review the use of search-based refactoring in software engineering. The current state of the research is analyzed and patterns in the studies are investigated in order to assess gaps in the area and suggest opportunities for future research. The papers reviewed are tabulated in order to aid researchers in quickly referencing studies. The literature addresses different methods using search-based refactoring for software maintenance, as well as studies that investigate the optimization process and discuss components of the search. There are studies that analyze different software metrics, experiment with multi-objective techniques and propose refactoring tools for use. Analysis of the literature has indicated some opportunities for future research in the area. More experimentation of the techniques in an industrial environment and feedback from software developers is needed to support the approaches. Also, recent work with multi-objective techniques has shown that there are exciting possibilities for future research using these techniques with refactoring. This survey is beneficial as an introduction for any researchers aiming to work in the area of Search-Based Software Engineering with respect to software maintenance and will allow them to gain an understanding of the current landscape of the research and the insights gathered

Orientalism and intelligence analysis: deconstructing Anglo-American notions of the ‘Arab’

Despite revived notions of a ‘cultural divide’ between East and West, Edward's Said's ‘Orientalism’ has received little attention from scholars of intelligence and diplomacy. This article brings to light for the first time a number of recently declassified documents of a different nature to usual assessments produced by Anglo-American analytic bodies: those focussed primarily on the issue of ‘national character’. Using and critiquing Said's thesis of Western ‘Orientalism’ it reveals some critical and enduring conceptualizations articulated by the diplomatic and intelligence community about Arab culture such as the role of Islam, rhetoric, political motivation and notions of ‘honour’. Such a critical approach demonstrates how diplomatic and intelligence history can also be a history of culture, ideas and institutional mentalité

Trust negotiation policy management for service-oriented applications

Service-oriented architectures (SOA), and in particular Web services, have quickly become a popular technology to connect applications both within and across enterprise boundaries. However, as services are increasingly used to implement critical functionality, security has become an important concern impeding the widespread adoption of SOA. Trust negotiation is an approach to access control that may be applied in scenarios where service requesters are often unknown in advance, such as for services available via the public Internet. Rather than relying on requesters' identities, trust negotiation makes access decisions based on the level of trust established between the requester and the provider in a negotiation, during which the parties exchange credentials, which are signed assertions that describe some attributes of the owner. However, managing the evolution of trust negotiation policies is a difficult problem that has not been sufficiently addressed to date. Access control policies have a lifecycle, and they are revised based on applicable business policies. Additionally, because a trust relationship established in a trust negotiation may be long lasting, their evolution must also be managed. Simply allowing a negotiation to continue according to an old policy may be undesirable, especially if new important constraints have been added. In this thesis, we introduce a model-driven trust negotiation framework for service-oriented applications. The framework employs a model for trust negotiation, based on state machines, that allows automated generation of the control structures necessary to enforce trust negotiation policies from the visual model of the policy. Our policy model also supports lifecycle management. We provide sets of operations to modify policies and to manage ongoing negotiations, and operators for identifying and managing impacts of changes to trust negotiation policies on ongoing trust negotiations. The framework presented in the thesis has been implemented in the Trust-Serv prototype, which leverages industry specifications such as WS-Security and WS-Trust to offer a container-centric mechanism for deploying trust negotiation that is transparent to the services being protected

Effects of the time course of negative affective priming on moral judgment: the shortest the soa, the lesser the severity

Although a number of studies report that disgust exerts a special influence on moral judgments by making them more severe, these studies have not properly explained whether (a) the influence of disgust is moral-specific and (b) whether such influence results from specific disgust appraisals or if it is caused by a more basic affective computation. In this context, in the present investigation we test how affective priming by disgust and horror influences participant’s moral and nonmoral judgments. Additionally, by varying the stimulus-onset asynchrony (SOA) duration, the present study tests the way such an influence varies through the time course of affective priming. This is, to our knowledge, the first research testing the effects of the time course of affective priming on moral judgments.Tot i que diferents investigacions suggereixen que l’emoció de repugnància incrementa la severitat dels judicis morals, aquests estudis no han acabat d’explicar prou si: (a) l’esmentada influència de la repugnància resulta específica dels judicis morals o afecta també als judicis no morals; (b) si l’efecte susdit resulta d’un procés de valoració (appraisal) específica o es tracta més aviat d’una influència de l’afecte. En el context descrit, aquesta investigació contrasta si el priming afectiu (a partir d’estímuls prime de repugnància i horror) influeix sobre els judicis morals i no morals, analitzant, alhora, si aquest efecte canvia segons els paràmetres temporals del priming, tot investigant com influeix la durada de l’interval entre l’aparició del prime i la del target (Stimulus-Onset Asynchrony, SOA). Aquest treball constitueix el primer estudi en torn dels efectes del priming afectiu de repugnància i horror (i del seu curs temporal) sobre els judicis morals i no moralsAunque diversas investigaciones sugieren que la repugnancia incrementa la severidad de los juicios morales, estos estudios explican suficientemente: (a) si dicha influencia es específica de los juicios morales o afecta también a los no morales; (b) si el efecto descrito resulta de un proceso de valoración (appraisal) o se trata de una mera influencia del afecto. En el contexto descrito, esta investigación contrasta si el priming afectivo, utilizando primes de repugnancia y de horror, influye sobre los juicios morales y sobre los no morales, estudiando asimismo si dicho efecto cambia según los parámetros temporales del priming a partir del análisis de la influencia del intervalo entre la aparición del prime y la del target (stimulus-onset asynchrony, SOA). Este trabajo constituye el primer estudio en torno a los efectos del priming afectivo de repugnancia y horror, así como de su curso temporal, sobre los juicios morales vs. no morales