Academic literature on the topic 'Approach'

In this research effort, we study three exterior penalty function approaches for solving linear programming problems. These methods are an active set l2 penalty approach (ASL2), an inequality-equality based l2 penalty approach (IEL2), and an augmented Lagrangian approach (ALAG). Particular effective variants are presented for each method, along with comments and experience on alternative algorithmic strategies that were empirically investigated. Our motivation is to examine the relative performance of these different approaches based on the basic l2 penalty function in order to provide insights into the viability of these methods for solving linear programs. To test the performance of these algorithms, a set of randomly generated problems as well as a set of NETLIB test problems from the public domain are used. By way of providing a benchmark for comparisons, we also solve the test problems using CPLEX 6.0, an advanced simplex implementation. While a particular variant (ALAG2) of ALAG performed the best for randomly generated test problems, ASL2 performed the best for the NETLIB test problems. Moreover, for test problems having only equality constraints, IEL2, and ASL2 (which is a finer-tuned version of IEL2 in this case) were comparable and yielded a second-best performance in comparison with ALAG2. Furthermore, a set of problems with relatively higher density parameter values, as well as a set of low-density problems were used to determine the effect of density on the relative performances of these methods. This experiment revealed that for linear programs with a high density parameter, ASL2 is the best alternative among the tested algorithms; whereas, for low-density problems ALAG2 is the fastest method. Moreover, although our implementation was rudimentary in comparison with CPLEX, all of the tested methods attained a final solution faster than CPLEX for the set of large-scale low-density problems, sometimes as fast as requiring only 16-23% of the effort consumed by CPLEX. Average rank tests based on the computational results obtained are performed using two different statistics, that assess the speed of convergence and the quality or accuracy of the solution, in order to determine the relative effectiveness of the algorithms and to validate our conclusions. Overall, the results provide insights into selecting algorithmic strategies based on problem structure and indicate that while this class of methods is viable for computing near optimal solutions, more research is needed to design robust and competitive exterior point methods for solving linear programming problems. However, the use of the proposed variant of the augmented Lagrangian method to solve large-scale low-density linear programs is promising and should be explored more extensively.<br>Master of Science

This dissertation focuses on the analysis of the Lean Startup Approach, developed by Eric Ries in 2011, that has become popular among startups and incubators. Based on the Customer Development approach of Steve Blank, the Lean Startup Approach advocates itself as a practical tool that helps startups to find their business model, through customer understanding, continuous testing in a circular loop aimed at obtaining validated learning. The dissertation analyses the theoretical background of the approach, focusing on its limits and potentiality In addition, previous entrepreneurial theories have been explored, offering a deeper overview of the entrepreneurial theroetical background to better understand the origin and the applicability of the Lean Startup Approach. In particular, a chapter is dedicated to the theories that analyse whether opportunities are already existing in the market or created by entrepreneurs. In this scope, the search opportunity theory, the discovery opportunity approach, and finally, the creation opportunity theory have all been explored. Relating to this last theory, the Effectuation model by Sarasvathy and the entrepreneurial bricolage model by Baker and Nelson have been further observed in detail. Finally, in the last part, an empirical study is presented that aims at exploring the adoption and the practical use of the Lean Startup Approach among existing startups and accelertors. The results are useful to clarify potentialities and limitations of the approach observed in a real environment and are useful to offer a better and more practical understanding of this tool.

Bien que l’importance du pilotage des compétences soit reconnue, les approches existantes en la matière révèlent des déficits méthodologiques, la portée opératoire du concept compétence est souvent limitée et les chercheurs sont souvent désarmés face aux demandes des entreprises qui veulent s’engager dans cette démarche. C’est dans ce cadre que s’inscrit cette recherche dont l’objectif est d’apporter une contribution par le développement d’outils et méthodes opérationnelles pour un pilotage efficient des compétences. Nous proposons une formalisation du concept compétence décliné en trois niveaux : individuel, collectif et organisationnel. Nous contribuons à la modélisation du modèle générique de compétence et nous choisissons le modèle sur lequel nous nous appuyons dans ces travaux. Nous proposons d’une part une méthodologie d’identification des compétences basée sur l’analyse fonctionnelle permettant d’identifier les compétences individuelles requises en vue d’aider à la construction du référentiel de compétence et d’autre part une démarche globale intitulée « Roue des compétences » supportant le pilotage des compétences en s’appuyant sur la technique d’amélioration continue qui facilite les ajustements nécessaires et permet de construire un modèle de référence plus cohérent et mieux adapté à l’organisation. Cette démarche est structurée en cinq phases : Initialisation, planification, intégration et déploiement, évaluation et développement. L’identification des compétences constitue une étape inéluctable dont dépendent les décisions de pilotage des compétences dans le cadre de cette démarche. Ces deux approches peuvent fonctionner en complémentarité. Elles apportent une aide aux gestionnaires et preneurs de décisions pour gérer au mieux le recrutement, la formation et la mobilité afin de répondre aux besoins en compétences des entreprises et d’attacher une attention particulière à ses besoins en compétences critique. Différentes études empiriques ont été menées en entreprise dans le cadre de ce travail. De manière encourageante, elles confirment la cohérence et la pertinence des approches proposées. Elles ont permis entre autre de tester ces approches mais aussi de formuler des recommandations pour le développement d'un outil logiciel pour les gestionnaires des ressources humaines. Cet outil sera un support à l'identification des compétences requises et à la mise à jour du référentiel. Néanmoins, des études supplémentaires à l’échelle de l’entreprise entière nécessitent d’être réalisées pour garantir le meilleur impact de l’ensemble des travaux présentés. Finalement, ce travail reste une plate-forme pour des recherches futures pour expérimenter davantage les démarches proposées, et tester leur applicabilité au sein d’autres entreprises appartenant à d’autres secteurs industriels<br>Although the importance of competence management is recognized, existing approaches in this area reveal methodological deficits, the operating range of the competence concept is often limited and researchers are often helpless when faced with requests from companies that want to engage in this approach. It is in this context that this research aimed to contribute by developing tools and operational methods for efficient competence management. We propose a formalization of the concept of competence available in three levels: individual, group and organizational. We contribute to the modeling of generic competency model and we choose the model on which we rely in this work. Firstly, we propose a competence identification methodology based on the functional analysis to identify requisite individual competencies. This allows us to design and update the competence framework in response to changing work situations. Secondly, we present a comprehensive approach on "Wheel competencies "supporting the competence management based on the technique of continuous improvement that makes the necessary adjustments and helps to build a more coherent reference model and better suited to the organization. This approach is structured into five phases: initialization, planning, integration and deployment, evaluation and development. The competence identification is an inevitable stage whose depends competence management decisions under this approach. Both approaches can work in complementary. They provide support to managers and decision makers to manage better the recruitment, training and mobility to meet the competencies enterprises needs and to pay special attention to their needs in critical competencies. Various empirical studies have been conducted in company in the course of this work. In another encouraging development, they confirm the consistency and relevance of the proposed approaches. They have, among other test these approaches, but also to make recommendations for the development of a software tool for HR managers. This tool will support the competence identification and update the competence framework. However, further studies across the entire enterprise need to be done to ensure the greatest impact of all work submitted. Finally, this work is a platform for future research to test further the proposed approaches and test their applicability in the firms in other industries

Introduction : la période de l’adolescence constitue la tranche d’âge pour laquelle les consommations de cannabis sont les plus élevées en France. L’usage problématique de cannabis à l’adolescence représente un facteur de stress important pour les parents. Cette recherche a pour premier objectif d’identifier une dynamique familiale spécifique ainsi que les stratégies de coping (individuelles et dyadiques) mobilisées par les parents dont l’adolescent est consommateur de cannabis. Le second objectif vise à investiguer les facteurs associés à la détresse psychologique en termes de dynamique familiale et de stratégies de coping (individuelles et dyadiques). Méthode : au cours de cette étude quantitative et qualitative, 50 parents consultant pour l’usage problématique de leur adolescent et 67 parents témoins ont répondu à un questionnaire sociodémographique, au Family Adaptability and Cohesion Scale (FACES IV) et au Family Relationship Index (FRI) pour évaluer la dynamique familiale, à la Brief Cope pour estimer les stratégies de coping situationnelles et au Dyadic Coping Inventory (DCI) pour relever les stratégies de coping dyadique mobilisées par les parents de l’échantillon en couple. Résultats : les parents d’adolescents consommateurs de cannabis présentaient une détresse psychologique élevée et ont obtenu des scores significativement différents aux dimensions de la dynamique familiale en comparaison des parents du groupe contrôle. Ainsi, le fonctionnement familial des parents d’adolescents consommateurs de cannabis était défini par une cohésion et des capacités de communication plus basses mais aussi une intensité de conflit élevée par rapport aux parents du groupe contrôle. Une dimension de la dynamique familiale (conflits) et quatre stratégies de coping situationnelles (expression des sentiments, blâme, utilisation de substances, désengagement comportemental) étaient positivement liées à la détresse psychologique. Les stratégies de coping dyadique (communication autour du stress, stratégies négatives, ect) étaient positivement liées à la détresse psychologique ressentie par les parents en couple. Conclusion : ces résultats montrent l’intérêt de mieux comprendre le vécu des parents confrontés à l’usage problématique de cannabis de l’adolescent et suggèrent des pistes de futures prises en charge<br>Introduction: the period of adolescence is the age group for which cannabis use is highest in France. Cannabis use in adolescence is an important stressor for parents. The first aim of the present study was to better identify specific family dynamics and coping strategies (individual and dyadic) mobilized by parents of adolescent cannabis users. Second, was to investigate the factors associated with psychological distress (family dynamics, coping strategies). Method: during this quantitative and qualitative study, 50 parents consult for a problematic adolescent cannabis use and 67 control parents answered at a sociodemographic questionnaire, the Family Adaptability and Cohesion Scale (FACES IV) and the Family Relationship Index (FRI) to assess family dynamics, the Brief Cope to estimate situational coping strategies and dyadic coping Inventory (DCI) to address the dyadic coping strategies mobilized by the sample's parents couple. Results: parents of adolescent cannabis users had a high psychological distress and have obtained significantly different scores on the dimensions of family dynamics, compare at parental control group. Thus, family functioning of parents of adolescent cannabis users was defined as cohesion and lower communication capabilities but also high intensity conflict from parents in the control group. A dimension of family dynamics (conflicts) and four situational coping strategies (expressing feelings, blame, substance use, behavioral disengagement) were positively related to psychological distress. Dyadic coping strategies (communication about the stress, negative strategies, ect) were positively related to psychological distress experienced by parents couple. Conclusion: these results show the interest of better understanding the experiences of parents facing the adolescent problem cannabis use and suggest directions for future supported

La transition florale est un évènement clef dans la vie d’une plante. Chez le fraisier, la compréhension des mécanismes génétiques de cette transition est un enjeu majeur pour mieux contrôler la production de fruits. La transition florale peut être étudiée à travers la remontée florale, qui est la capacité d’une plante à fleurir tout au long de la période végétative. Le fraisier cultivé octoploïde, F. x ananassa, comme le fraisier diploïde, F. vesca, présentent des génotypes remontants capables de fleurir en continu. L’objectif de cette thèse est de comprendre le déterminisme génétique et moléculaire de la remontée florale chez Fragaria. Ce travail a montré que chez les fraisiers diploïde et octoploïde, le caractère ‘remontée florale’ est contrôlé par deux verrous génétiques différents localisés à des positions non orthologues. Chez le fraisier diploïde, le gène FvKSN responsable de la remontée florale a été identifié et code pour un homologue du répresseur floral TFL1. Chez les génotypes remontants, ce gène présente une délétion dans la partie codante conduisant à une protéine non fonctionnelle, incapable de réprimer la floraison. Chez le fraisier octoploïde, le QTL majeur détecté contrôlant la remontée florale est lié à la production de stolons de manière antagoniste, suggérant l’existence d’une région génomique où s'exerce une compétition entre multiplication végétative et la reproduction sexuée. Cette région génomique comprend plusieurs gènes candidats intéressants dont FT, activateur de la floraison.Une hypothèse suggérée par ce travail est que chez le fraisier, l’alternance entre phase végétative et phase reproductive est liée à l’équilibre entre les gènes FvKSN, homologue de TFL1, et FvFT, homologue de FT. La remontée florale serait la conséquence d’une modification de cet équilibre entre ces deux gènes en faveur du développement reproductif<br>The floral transition is a key event in plant life. In strawberry, understanding the genetic mechanisms of floral transition is a major issue for better control of fruit production. This transition is studied through the continuous flowering, which is the ability to flower throughout the growing season. Both, the octoploid cultivated strawberry, F. x ananassa, as the woody diploid strawberry, F. vesca, displayed continuous flowering genotypes. The objective of this work is to decipher the genetic and molecular mechanism of the continuous flowering in Fragaria.This work has shown that in diploid and octoploid strawberry the continuous flowering is controlled by two different genetic 'keys' located at non-orthologous position. In diploid strawberry, the gene FvKSN responsible of continuous flowering was identified and encodes a homologous to the TFL1 floral repressor. In the continuous flowering genotypes, this gene has a deletion in the coding region leading to a nonfunctional protein unable to repress flowering. In the octoploid strawberry, the major QTL controlling both the recurrent flowering and the runner production was identified. These traits were antagonist, which suggests competition between vegetative propagation and sexual reproduction in this region. This genomic region contains several interesting candidate genes whose FT, an activator of flowering.A hypothesis could be proposed. In strawberry, the switch between vegetative and reproductive phase is linked to balance between two genes, FvKSN, homologous to TFL1 and FvFT homologous to FT. Continuous flowering would be the consequence of balance modification between this two genes to the benefit of floral development

De trop nombreux évènements survenus la décennie passée illustrent la gravité et l’étendue des impacts auxquels les territoires peuvent être confrontés. L'atteinte aux infrastructures critiques peut induire de très nombreux dysfonctionnements en cascade pouvant plonger ce territoire et sa société dans une crise de grande ampleur. Les interdépendances entre ces activités essentielles et celles avec la population accentuent leur fragilité. Afin d'évaluer les impacts directs et indirects d'une perturbation majeure, la méthodologie développée étudie la problématique sous un angle multisectoriel répondant ainsi à une prise en compte de la complexité des territoires. Dans un premier temps, le territoire via ses activités essentielles et sa population est modélisé en s'appuyant sur les liens d'interdépendance existants. Sur la base d'un évènement initial donné, la méthode identifie les scénarios de propagation possibles et leurs conséquences sur les "usagers" concernés par la délivrance des services touchés. Cette simulation permet ainsi d'apprécier la résilience systémique des enjeux du territoire. Basé sur une approche systémique et spatiale, ce travail a pour objectif de fournir une aide à la décision à la planification des mesures de continuité et de rétablissement d'activité ou à la mise en place de mesures de traitement des risques<br>Too many dramatic events occurred over the last ten years have demonstrated the severity and extent of impacts that territories may be confronted with. Damages to critical infrastructures may have a variety of downfall disturbing effects, which can lead territories and society into a huge crisis. Interdependency between these essential activities on the one hand, and between these activities and the population on the other hand, increases their vulnerability. This thesis presents a methodology to better assess direct and indirect impacts of a major disturbance. The issue is addressed from a multi-activity perspective, to take into account territories complexity.In the first stage, a territory is modeled using existing interdependency links between essential activities and the population. The methodology then identifies, based on a defined initial event, possible propagation scenarios and their consequences on services “users”. Finally, this simulation gives an assessment of the territory stakes resilience. This works provides a decision-making tool for the development of activity continuity plans, or risk assessment and mitigation policies

Le système immunitaire de chaque individu doit faire face à des agressions répétées d'un environnement en constante évolution, constituant ainsi un nombre de menaces virtuellement infini. Afin de mener ce rôle à bien, le système immunitaire adaptatif s'appuie sur une énorme diversité de lymphocytes T et B. Chacune de ces cellules exhibe à sa surface un récepteur unique, créé aléatoirement via le processus de recombinaison V(D)J, et spécifique à un petit nombre de pathogènes seulement. La diversité initiale générée lors de ce processus de recombinaison est ensuite réduite par une étape de sélection fonctionnelle basée sur les propriétés de repliement du récepteur ainsi que ses capacités à interagir avec des protéines du soi. Pour les cellules B, cette diversité peut être à nouveau étendue après rencontre d'un pathogène lors du processus de maturation d'affinité durant lequel le récepteur subit des cycles successifs d'hypermutation et sélection. Ces travaux présentent des approches probabilistes visant à inférer les distributions de probabilités sous-tendant les processus de recombinaison et d'hypermutation à partir de données de séquençage haut débit. Ces approches ont donné naissance à IGoR, un logiciel polyvalent dont les performances dépassent celles des outils existants. En utilisant les modèles obtenus comme base, je présenterai comment ces derniers peuvent être utilisés afin d'étudier le vieillissement et évolution du répertoire immunitaire, la présence d'emprunte parentale lors de la recombinaison V(D)J ou encore pour démontrer que les jumeaux échangent des lymphocytes au cours de la vie fœtale<br>An individual’s adaptive immune system needs to face repeated challenges of a constantly evolving environment with a virtually infinite number of threats. To achieve this task, the adaptive immune system relies on large diversity of B-cells and T-cells, each carrying a unique receptor specific to a small number of pathogens. These receptors are initially randomly built through the process of V(D)J recombination. This initial generated diversity is then narrowed down by a step of functional selection based on the receptors' folding properties and their ability to recognize self antigens. Upon recognition of a pathogen the B-cell will divide and its offsprings will undergo several rounds of successive somatic hypermutations and selection in an evolutionary process called affinity maturation. This work presents principled probabilistic approaches to infer the probability distribution underlying the recombination and somatic hypermutation processes from high throughput sequencing data using IGoR - a flexible software developed throughout the course of this PhD. IGoR has been developed as a versatile research tool and can encode a variety of models of different biological complexity to allow researchers in the field to characterize evermore precisely immune receptor repertoires. To motivate this data-driven approach we demonstrate that IGoR outperforms existing tools in accuracy and estimate the sample sizes needed for reliable repertoire characterization. Finally, using obtained model predictions, we show potential applications of these methods by demonstrating that homozygous twins share T-cells through cord blood, that the public core of the T cell repertoire is formed in the pre-natal period and finally estimate naive T cell clone lifetimes in human

Dissertation submitted for a PhD degree in Electrical Engineering, speciality of Robotics and Integrated Manufacturing from the Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia<br>This thesis addresses the problem of shop floor agility. In order to cope with the disturbances and uncertainties that characterise the current business scenarios faced by manufacturing companies, the capability of their shop floors needs to be improved quickly, such that these shop floors may be adapted, changed or become easily modifiable (shop floor reengineering). One of the critical elements in any shop floor reengineering process is the way the control/supervision architecture is changed or modified to accommodate for the new processes and equipment. This thesis, therefore, proposes an architecture to support the fast adaptation or changes in the control/supervision architecture. This architecture postulates that manufacturing systems are no more than compositions of modularised manufacturing components whose interactions when aggregated are governed by contractual mechanisms that favour configuration over reprogramming. A multiagent based reference architecture called Coalition Based Approach for Shop floor Agility – CoBASA, was created to support fast adaptation and changes of shop floor control architectures with minimal effort. The coalitions are composed of agentified manufacturing components (modules), whose relationships within the coalitions are governed by contracts that are configured whenever a coalition is established. Creating and changing a coalition do not involve programming effort because it only requires changes to the contract that regulates it.

The South African Competition Commission has analysed most levels of the food supply chain by investigation of alleged anti-competitive behaviour by producers, input suppliers, storage companies, processors and retailers. The numbers of these cases include cartels and, to a lesser extent, restrictive vertical constraints and abuse of dominance position. Sexton (2012) states that the recent development in the agricultural market, where large companies are vertically integrating, renders the perfect competition model inappropriate. This brings doubt that the law based on perfect competition will work in oligopolistic markets. Despite the identified number of detected cartels in the grain industry, it might be possible that some cartels in other food chains are still undetected. Through the application of the market screening approach, the aim of this study is to establish whether the National Agricultural Marketing Council (“NAMC”) and the Competition Commission could have detected the bread cartel using secondary data in the absence of the information from the whistle-blower. As the first step, the study carried out a structural assessment of the bread industry. This assessment indicated that the bread market has a number of factors that may facilitate collusive behaviour. The study found that the history of information sharing played a crucial role for bakeries to coordinate their conduct. The second step was to conduct an in-depth behavioural assessment that focused on bread prices to see whether there has been a structural break in the period under investigation. The idea was to estimate the price equation of brown bread as a function of the SAFEX wheat price, petrol price (cost shifters), and 1 kg of maize meal (demand shifters). The study used the OLS to estimate three regressions using the data for the whole period and two sub-breaks (before the break point, and after the break point) to perform a Chow test. The question that the Chow test asked is: was there a structural break in March 2007, after the Competition Commission received the information from the whistle-blower? In other words, had the price of bread increased or decreased at a certain period without any changes in the demand or cost variable. The Null hypothesis states that there was no structural break, while the alternative hypothesis states that there was a structural break in March 2007. The Chow test result shows that at a 5 per cent significant level, the F-critical value is F_5, 90 = 2.68 and the F test statistics is 20.59 with a p value of 0.00. This indicates that we cannot reject the null hypothesis and conclude that a structural break did not occur in March 2007. The screening approached failed to prove the existence of cartel in the bread industry. Therefore, the study concludes that in the absence of the whistle-blower, it would not have been easy for the Competition Commission and the NAMC (2009) to detect a cartel by just using secondary data. This proves that screening alone cannot prove the existence of cartel without prior knowledge of the conduct and of the industry as a whole. Nevertheless, a market screening approach is important as it can be used as a warning mechanism to detect an emerging cartel, since it can flag potentially suspicious behaviour. Nevertheless, this calls for the policy makers to combine the scoping study by the Competition Commission and the monitoring of food prices by the NAMC, as this will provide the best enforcement tool in detecting cartel behaviour in the food industry.<br>Dissertation (MInst Agrar)--University of Pretoria, 2014.<br>tm2015<br>Agricultural Economics, Extension and Rural Development<br>MInst Agrar<br>Unrestricted