About Designing an Observer Pattern-Based Architecture for a Multi-objective Metaheuristic Optimization Framework

Multi-objective optimization with metaheuristics is an active and popular research field which is supported by the availability of software frameworks providing algorithms, benchmark problems, quality indicators and other related components. Most of these tools follow a monolithic architecture that frequently leads to a lack of flexibility when a user intends to add new features to the included algorithms. In this paper, we explore a different approach by designing a component-based architecture for a multi-objective optimization framework based on the observer pattern. In this architecture, most of the algorithmic components are observable entities that naturally allows to register a number of observers. This way, a metaheuristic is composed of a set of observable and observer elements, which can be easily extended without requiring to modify the algorithm. We have developed a prototype of this architecture and implemented the NSGA-II evolutionary algorithm on top of it as a case study. Our analysis confirms the improvement of flexibility using this architecture, pointing out the requirements it imposes and how performance is affected when adopting it.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Ressources cognitives et développement territorial : une analyse textuelle appliquée aux politiques locales de développement durable

International audienceThis paper focuses on how the development of a particular region consistently requires actors to share a certain level of cognitive resources. In the case studied here - the Nord Pas-de-Calais region, this cognitive proximity is built via the local policies involving sustainable development. In order to comprehend the way local communities of the region activate this resource, we used textual data treatment analyzing about thirty interviews. The results suggest that this cognitive proximity relies on two fundamentals elements: on the one hand, valuing the patrimonial infrastructures of the territory; and on the other hand, rebuilding the territorial identity of the region. Then the local policies lean both on the values that underlie these elements and on rhetorical modalities, to impulse in-depth changes that would have been more difficult to implement from the usual political levers.Cet article étudie comment un développement régional cohérent nécessite la mobilisation de ressources cognitives partagées. Dans le cas étudié - la région Nord Pas-de-Calais, cette proximité cognitive se construit via les politiques locales, sur la base du référentiel de développement durable. Pour saisir la manière dont les collectivités de la région activent cette ressource, nous avons mobilisé les outils d'analyse textuelle sur une trentaine d'entretiens auprès des acteurs publics du développement durabe. Les résultats mis en évidence suggèrent que cette proximité cognitive repose sur deux éléments fondamentaux : d'une part la mise en valeur d'un patrimoine infrastructurel territorialisé, et d'autre part la reconstruction d'une identité territoriale. Les politiques locales prennent ainsi appui sur les valeurs qui sous-tendent ces éléments ainsi que sur des modalités rhétoriques, pour impulser en profondeur une dynamique de changement, plus malaisée à mettre en œuvre partir des outils politiques habituels

Efficient and accurate P-value computation for Position Weight Matrices

<p>Abstract</p> <p>Background</p> <p>Position Weight Matrices (PWMs) are probabilistic representations of signals in sequences. They are widely used to model approximate patterns in DNA or in protein sequences. The usage of PWMs needs as a prerequisite to knowing the statistical significance of a word according to its score. This is done by defining the P-value of a score, which is the probability that the background model can achieve a score larger than or equal to the observed value. This gives rise to the following problem: Given a P-value, find the corresponding score threshold. Existing methods rely on dynamic programming or probability generating functions. For many examples of PWMs, they fail to give accurate results in a reasonable amount of time.</p> <p>Results</p> <p>The contribution of this paper is two fold. First, we study the theoretical complexity of the problem, and we prove that it is NP-hard. Then, we describe a novel algorithm that solves the P-value problem efficiently. The main idea is to use a series of discretized score distributions that improves the final result step by step until some convergence criterion is met. Moreover, the algorithm is capable of calculating the exact P-value without any error, even for matrices with non-integer coefficient values. The same approach is also used to devise an accurate algorithm for the reverse problem: finding the P-value for a given score. Both methods are implemented in a software called TFM-PVALUE, that is freely available.</p> <p>Conclusion</p> <p>We have tested TFM-PVALUE on a large set of PWMs representing transcription factor binding sites. Experimental results show that it achieves better performance in terms of computational time and precision than existing tools.</p

ParadisEO-MOEO: A Software Framework for Evolutionary Multi-Objective Optimization

This chapter presents ParadisEO-MOEO, a white-box object-oriented software framework dedicated to the flexible design of metaheuristics for multi-objective optimization. This paradigm-free software proposes a unified view for major evolutionary multi-objective metaheuristics. It embeds some features and techniques for multi-objective resolution and aims to provide a set of classes allowing to ease and speed up the development of computationally efficient programs. It is based on a clear conceptual distinction between the solution methods and the problems they are intended to solve. This separation confers a maximum design and code reuse. This general-purpose framework provides a broad range of fitness assignment strategies, the most common diversity preservation mechanisms, some elitistrelated features as well as statistical tools. Furthermore, a number of state-of-the-art search methods, including NSGA-II, SPEA2 and IBEA, have been implemented in a user-friendly way, based on the fine-grained ParadisEO-MOEO components

No Evidence for Shared Representations of Task Sets in Joint Task Switching

Action Contro

Lay beliefs of TB and TB/HIV co-infection in Addis Ababa, Ethiopia: a qualitative study

<p>Abstract</p> <p>Background</p> <p>Knowledge about lay beliefs of etiology, transmission and treatment of TB, and lay perceptions of the relationship between TB and HIV is important for understanding patients' health seeking behavior and adherence to treatment. We conducted a study to explore lay beliefs about TB and TB/HIV co-infection in Addis Ababa, Ethiopia.</p> <p>Findings</p> <p>We conducted a qualitative study using in-depth interviews with 15 TB/HIV co-infected patients and 9 health professionals and focus group discussions with 14 co-infected patients in Addis-Ababa, Ethiopia. We found that a predominant lay belief was that TB was caused by exposure to cold. Excessive sun exposure, exposure to mud, smoking, alcohol, khat and inadequate food intake were also reported as causes for TB. Such beliefs initially led to self-treatment. The majority of patients were aware of an association between TB and HIV. Some reported that TB could transform into HIV, while others said that the body could be weakened by HIV and become more susceptible to illnesses such as TB. Some patients classified TB as either HIV-related or non-HIV-related, and weight loss was a hallmark for HIV-related TB. The majority of patients believed that people in the community knew that there was an association between TB and HIV, and some feared that this would predispose them to HIV-related stigma.</p> <p>Conclusion</p> <p>There is a need for culturally sensitive information and educational efforts to address misperceptions about TB and HIV. Health professionals should provide information about causes and treatment of TB and HIV to co-infected patients.</p

Knowledge and perception of pulmonary tuberculosis in pastoral communities in the middle and Lower Awash Valley of Afar region, Ethiopia

<p>Abstract</p> <p>Background</p> <p>Afar pastoralists live in the northeast of Ethiopia, confined to the most arid part of the country, where there is least access to educational, health and other social services. Tuberculosis (TB) is one of the major public health problems in Afar region. Lack of knowledge about TB could affect the health-seeking behaviour of patients and sustain the transmission of the disease within the community. In this study, we assessed the knowledge and perception of apparently healthy individuals about pulmonary tuberculosis (PTB) in pastoral communities of Afar.</p> <p>Methods</p> <p>Between March and May 2009, a community-based cross-sectional questionnaire survey involving 818 randomly selected healthy individuals was conducted in pastoral communities of Afar region. Moreover, two focus group discussions (FGDs), one with men and one with women, were conducted in each of the study area to supplement the quantitative study.</p> <p>Results</p> <p>The majority (95.6%) of the interviewees reported that they have heard about PTB (known locally as "Labadore"). However, the participants associated the cause of PTB with exposure to cold air (45.9%), starvation (38%), dust (21.8%) or smoking/chewing Khat (<it>Catha edulis</it>) (16.4%). The discussants also suggested these same factors as the cause of PTB. All the discussants and the majority (74.3%) of the interviewees reported that persistent cough as the main symptom of PTB. About 87.7% of the interviewees and all the discussants suggested that PTB is treatable with modern drugs. All the discussants and the majority (95%) of the interviewees mentioned that the disease can be transmitted from a patient to another person. Socio-cultural practices, e.g. sharing cups (87.6%), and house type (59.8%) were suggested as risk factors for exposure to PTB in the study areas, while shortage of food (69.7%) and chewing khat (53.8%) were mentioned as factors favouring disease development. Almost all discussants and a considerable number (20.4%) of the interviewees thought that men were the highest risk group to get PTB as well as playing a major role in the epidemiology of the disease.</p> <p>Conclusion</p> <p>The findings indicate that pastoral communities had basic awareness about the disease. Nevertheless, health education to transform their traditional beliefs and perceptions about the disease to biomedical knowledge is crucial.</p