Stimulus-driven changes in the gain of sensory neurons are well-documented, but relatively little is known about whether analogous gain-control can also be effected in a top-down manner. A recent psychophysical study demonstrated that sensitivity to luminance contrast can be modulated by a priori knowledge (de la Rosa et al., in press). In the present study, event-related potentials were used to resolve the stages of information processing that facilitate such knowledge-driven adjustments. Groupwise independent component analysis identified two robust spatiotemporal patterns of endogenous brain activity that captured experimental effects. The first pattern was associated with obligatory processing of contextual information, while the second pattern was associated with selective initiation of contrast gain adjustment. These data suggest that knowledge-driven contrast gain control is mediated by multiple independent electrogenic sources.

Tetranychus urticae es una especie plaga importante en cítricos que puede también alimentarse de otras especies asociadas a la cubierta vegetal de este cultivo. Para determinar el efecto de la gestión de la cubierta vegetal en el control biológico de este ácaro, hemos estudiado la dinámica tanto de ácaros Tetranychidae como Phytoseiidae en cuatro parcelas comerciales de mandarino clementino en las que se aplicó tres estrategias diferentes de gestión de la cubierta vegetal: (1) suelo desnudo, (2) cubierta espontánea y (3) cubierta sembrada de Festuca arundinacea. Los resultados apuntan a que tanto los enemigos naturales (mecanismos "top-down") como la planta huésped (mecanismos "bottom-up") juegan un papel importante en la regulación de los ácaros Tetranychidae. Por un lado, la selección de dos razas de T. urticae especializadas en F. arundinacea y en Citrus clementina, en la cubierta y en el árbol respectivamente, cuando esta gramínea se utiliza como cubierta podría explicar en parte los resultados obtenidos (regulación "bottom-up") ya que esto impediría a los especímenes de una planta huésped colonizar con éxito la otra. Los ensayos de trasplante recíproco realizados muestran que las dos demos de T. urticae recogidas de clementina y F. arundinacea difieren considerablemente en su éxito en el desarrollo en el huésped alternativo y esto indica la existencia de fenómenos de adaptación local. Esta adaptación se traduciría en mecanismos "bottom-up" que evitarían que los ácaros que habitan en la cubierta colonicen con éxito la copa de los árboles. Por otro lado, la composición cualitativa de las comunidades de Phytoseiidae asociados a las diferentes cubiertas podría ser clave en la regulación de las poblaciones de T. urticae y Panonychus citri (regulación "top-down"). Los ácaros Phytoseiidae tipo I y II, depredadores especializados en Tetranychidae, se encuentran de manera consistente en la cubierta de F. arundinacea y esto puede explicar la mejor regulación de las poblaciones de ácaros Tetranychidae en los árboles asociados a esta cubierta. Por el contrario, la disposición más regular de fuentes de alimentación alternativas (polen) en la cubierta natural en relación con la cubierta de F. arundinacea, podría explicar la mayor abundancia de Phytoseiidae tipo IV en la primera. Como consecuencia, los Phytoseiidae tipo I y II, más eficaces en el control de Tetranychidae, podrían sufrir las consecuencias de ser competitivamente inferiores que el Phytoseiidae generalista tipo IV que explota el polen en la cubierta espontánea. Este hecho, en combinación con los períodos de escasez de presa, podría dar lugar a su desaparición del agroecosistema y resultar en un deficiente control de los ácaros Tetranychidae en los árboles asociados a una cubierta natural. Haciendo balance de gastos e ingresos, la cubierta más favorable fue la de F. arundinacea (entre 44,4 y 74,5% de reducción de costes en relación con la más cara). Festuca arundinacea como cubierta vegetal es una estrategia de control biológico por conservación muy recomendable para los productores de clementina. Aunque su uso no redujo las poblaciones de ácaros en los árboles por debajo del umbral económico, la disminución en la necesidad de tratamientos, hace que la adopción de esta táctica sea una alternativa beneficiosa tanto ecológica como económicamente. Nuestros resultados apuntan a la cubierta de F. arundinacea, que no permitió el establecimiento de Tetranychus evansi y ofrece una mejor regulación de P. citri y T. urticae que en suelo desnudo o cubierta natural, como la más adecuada para un control más sostenible de los ácaros Tetranychidae en cítricos.

Area selective atomic layer deposition (ASALD) is demonstrated to be a promising route to perform direct patterned deposition. In particular, methods to modify (or mask) the surface and process parameters to perform selective deposition of titanium dioxide have been developed and investigated in detail. Results indicated that self assembled monolayer based masking methodology posses significant limitations due to challenges associated with obtaining defect free monolayer and absence of traditional patterning techniques. On the other hand, polymer films based masking methodology offer a better alternative to perform ASALD. A number of factors that must be considered in designing a successful ASALD process based on polymer films were identified. These include: reactivity of polymer with ALD precursor, diffusion of ALD precursors through polymer mask and remnant precursor content in the polymer film during ALD cycling. Investigations suggested that ALD nucleation can be successfully blocked on polymer films that do not contain direct OH sites in their backbone. It was observed that sorption of water in the polymer film does not pose a serious limitation however; metal precursor diffusion through the polymer mask was identified as a critical parameter in determining the minimum required masking layer thickness for a successful ASALD process. In addition, a novel ASALD-based top surface imaging (TSI) technique has been developed. The ASALD-TSI process has demonstrated sharp contrast (etch barrier deposition vs exposure dose) and therefore offers the potential to overcome many of the challenges experienced with conventional TSI schemes.

For almost a century, as industrial development and population growth, unrestrained use of fossil fuels, and large-scale deforestation by burning, which produce excessive greenhouse gases, causing global warming and climate change. The author of "The world is flat", Thomas Friedman calls this "the Energy-Climate Era". To confront the crisis of global warming, energy shortages and population explosion, the human need to start a new wave of green energy revolution. In the trend of globalization and regional economic integration, the cross-strait relation has come to a turning point. Taiwan is standing at a critical position, must properly cope with the new era. This case study is to explore the business strategies of a Taiwanese engineering service company in response to the Energy-Climate Era. First, focusing on the case company's top management team and its role in corporate group, to analyze the existing strategic position and business model developed since its establishment. Then, to study the case company¡¦s external environment (including globalization and regional economic integration, Energy-Climate Era, China's twelfth Five-Year-Plan and Taiwan's economic policy) and engineering services industrial environment (including market segmentation and market volume, Key Successful Factors, and Five Forces Analysis). Finally, in-depth analysis of case company's internal resources, capabilities and core competences, to summarize the case company¡¦s internal strengths and weaknesses, and external opportunities and threats, SWOT matrix analysis and strategies formulation. The study results are summarized as follows: First, the case company, with the support of corporate group and their own efforts, is now an integrated engineering company with four core businesses - environmental engineering, biotech engineering, electrical & mechanical integration, and operation & maintenance; and with more competitive advantage in the steel industry and water treatment engineering. Second, the case company¡¦s strategic positioning adjustments in response to the "Energy-Climate Era" are: (1) to consolidate existing core businesses; (2) to establish core competences in order to develop related markets of petrochemical and other industries or areas; (3) to establish core competences and business model innovation in order to seize the white space of multiple water resources development, green energy and energy saving engineering. Third, the case company¡¦s total of seventeen strategic programs can be summarized into four categories: (1) to secure the business of both inside and outside of the corporate group; (2) to integrate resources in order to enhance competitiveness; (3) to strengthen research and development of water technologies; (4) to develop air pollution and energy saving technologies. Each project department, according to their engineering professions, should work out and implement detailed action plans, which are adaptable to external situations, to integrate advantages of the three capabilities - "professional", "project management" and "financial management". Fourth, taking wastewater reclamation and energy saving projects as examples, to explore and elaborate innovative business model for case company¡¦s reference; and to provide four recommendations for organizational restructuring and three proposals for facilitating the implementation of business strategies.

Web cluster systems provide cost-effective solutions when scalable and reliable web services are required. However, as the number of servers in web cluster systems increase, web cluster systems incur long and unpredictable delays to manage servers. This study presents the efficient management schemes for web cluster systems. First of all, we propose an efficient request distribution scheme in web cluster systems. Distributor-based systems forward user requests to a balanced set of waiting servers in complete transparency to the users. The policy employed in forwarding requests from the frontend distributor to the backend servers plays an important role in the overall system performance. In this study, we present a proactive request distribution (ProRD) to provide an intelligent distribution at the distributor. Second, we propose the heuristic memory management schemes through a web prefetching scheme. For this study, we design a Double Prediction-by-Partial-Match Scheme (DPS) that can be adapted to the modern web frameworks. In addition, we present an Adaptive Rate Controller (ARC) to determine the prefetch rate depending on the memory status dynamically. For evaluating the prefetch gain in a server node, we implement an Apache module. Lastly, we design an adaptive web streaming system in wireless networks. The rapid growth of new wireless and mobile devices accessing the internet has contributed to a whole new level of heterogeneity in web streaming systems. Particularly, in-home networks have also increased in heterogeneity by using various devices such as laptops, cell phone and PDAs. In our study, a set-top box(STB) is the access pointer between the internet and a home network. We design an ActiveSTB which has a capability of buffering and quality adaptation based on the estimation for the available bandwidth in the wireless LAN.

A wide range of additional forward chaining applications could be realized with deductive databases, if their rule formalism, their immediate consequence operator, and their fixpoint iteration process would be more flexible. Deductive databases normally represent knowledge using stratified Datalog programs with default negation. But many practical applications of forward chaining require an extensible set of user–defined built–in predicates. Moreover, they often need function symbols for building complex data structures, and the stratified fixpoint iteration has to be extended by aggregation operations. We present an new language Datalog*, which extends Datalog by stratified meta–predicates (including default negation), function symbols, and user–defined built–in predicates, which are implemented and evaluated top–down in Prolog. All predicates are subject to the same backtracking mechanism. The bottom–up fixpoint iteration can aggregate the derived facts after each iteration based on user–defined Prolog predicates.

Background: Strategic renewal is a phenomenon where companies decide to do strategic alterations with the aim to improve their stasis in the current market (Kiesler & Sproull, 1982). This can be accomplished in several ways; in this report the focus is on management control systems and how they are incorporated in the strategic implementation process in order to drive and generate renewal. Management control systems are considered to be an important aspect of the strategy process (Simons, 1994). Purpose: The purpose of this thesis is to analyze to what extent and in what form interactive and diagnostic management control systems are employed in large organizations in order to drive strategic renewal. Methodology: This is a qualitative research with an abductive approach that is based on a single case study. Through interviews we answer how management control systems are used in the implementation process of strategic renewal on different levels of an organization; we have made ten interviews with top-, middle- and operational management.  Conclusion: Our main finding is that the process of implementing a successful strategic renewal through the adoption of MCS is not a linear one. The process is continuous and conducted in a circular manner; this also implies the interrelation of the variables.

In this study, employees are given autonomy in effort allocation across two tasks - complex and simple tasks, where the return to the organization is significantly higher for the complex task requiring high skill than for the simple task requiring low skill. An unavoidable feature of multi-task settings is that effort expended on one task detracts from effort that can be expended on another task. This effort trade-off among tasks becomes problematic when the returns from different tasks are unequal, with important consequences for a firm's overall performance. The design of management accounting control systems in such multi-task setting is difficult because organizations have to achieve multiple objectives: to improve productivity on both simple and complex tasks (i.e., performance) and to direct employee effort to more complex tasks given that the complex tasks are more valuable to firms (i.e., effort allocation). In a laboratory experiment, I examine the effects of two motivational mechanisms, financial compensation and relative performance information (RPI), on employee performance and effort allocation between simple and complex tasks. I find that the effects of RPI and financial compensation are independent such that each motivational mechanism affects performance and effort allocation separately. In addition, I find that the effects of RPI or financial compensation depend on whether a worker is a top performer or a bottom performer. Also, findings demonstrate that the effects of these motivational mechanisms on employee effort allocation and performance depend on the complexity of the task. Future research studies and managers who design incentive systems should consider the implementation of different types of incentives for different performer levels. Organizations should consider the degree of complexity of the tasks that workers must perform in multi-task settings.

The problem for women in the work market has been and is still being widely studied from different domains and fields, there is however still countless fissures linked to it. Even though the gender equality has comprehensively increased in recent decades, it is still apparent in high responsibility positions. This situation caught our attention and stimulated us to analyse the women’s condition within organizations. Scholars have developed different theories linked to organizations, but our complex and fast developing society has surpassed most of these classical theories, making them either partially or totally irrelevant. For instance standards such as hierarchical organizations, individualism and aggressiveness are no longer considered as the most efficient values. This work investigates the barriers that women have to overcome in order to break though leading positions, as well as the identification of female and male leadership and their stereotypes’ consequences. Accordingly, we intend to propose solutions and new approaches liable to help integrating more women in high profile positions. We are aspiring to create a new trend representing successful leadership that is no longer correlated to the male stereotype. The theoretical part engages in theories surrounding female gender leadership as well as gender related barriers, while the empirical method involves the conduction of semi structured interview with women in high management positions, with the aim of setting up a solid ground for analysis and discussion. Due to this fact, we believe that the woman is the future of the organization, therefore we firstly call for the implementation and the reinforcement of the female “role model” and secondly encourage companies to adopt and promote our new concept of “the ecological organization” in order to achieve a more flexible, balanced and sane organizational culture in a foreseeable future.

Le développement des techniques de traitement des requêtes de classement est un axe de recherche très actif dans le domaine de la recherche d'information. Plusieurs applications nécessitent le traitement des requêtes de classement multicritères, telles que les méta-moteurs de recherche sur le web, la recherche dans les réseaux sociaux, la recherche dans les bases de documents multimédia, etc. Contrairement aux requêtes booléennes traditionnelles, dans lesquelles le filtrage est basé sur des prédicats qui retournent vrai ou faux, les requêtes de classement utilisent des prédicats de similarité retournant un score de pertinence. Ces requêtes spécifient une fonction d'agrégation qui combine les scores individuels produits par les prédicats de similarité permettant de calculer un score global pour chaque objet. Les k objets avec les meilleurs scores globaux sont retournés dans le résultat final. Dans cette thèse, nous étudions dans un premier temps les techniques et algorithmes proposés dans la littérature conçus pour le traitement des requêtes top-k multicritères dans des contextes spécifiques de type et de coût d'accès aux scores, et nous proposons un cadre générique capable d'exprimer tous ces algorithmes. Ensuite, nous proposons une nouvelle stratégie en largeur "breadth-first", qui maintient l'ensemble courant des k meilleurs objets comme un tout, à la différence des stratégies en profondeur habituelles qui se focalisent sur le meilleur candidat. Nous présentons un nouvel algorithme "Breadth-Refine" (BR), basé sur cette stratégie et adaptable à n'importe quelle configuration de type et de coût d'accès aux scores. Nous montrons expérimentalement la supériorité de l'algorithme BR sur les algorithmes existants. Dans un deuxième temps, nous proposons une adaptation des algorithmes top-k à la recherche approximative, dont l'objectif est de trouver un compromis entre le temps de recherche et la qualité du résultat retourné. Nous explorons l'approximation par arrêt prématuré de l'exécution et proposons une première étude expérimentale du potentiel d'approximation des algorithmes top-k. Dans la dernière partie de la thèse, nous nous intéressons à l'application des techniques top-k multicritères à la recherche par le contenu dans les grandes bases de données multimédia. Dans ce contexte, un objet multimédia (une image par exemple) est représenté par un ou plusieurs descripteurs, en général sous forme de vecteurs numériques qui peuvent être vus comme des points dans un espace multidimensionnel. Nous explorons la recherche des k plus proches voisins (k-ppv) dans ces espaces et proposons une nouvelle technique de recherche k-ppv approximative "Multi-criteria Search Algorithm " (MSA) basée sur les principes des algorithmes top-k. Nous comparons MSA à des méthodes de l'état de l'art dans le contexte des grandes bases multimédia où les données ainsi que les structures d'index sont stockées sur disque, et montrons qu'il produit rapidement un très bon résultat approximatif.