857 resultados para complexity of agents
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The source, fate and diagentic pathway of sedimentary organic matter in estuaries are difficult to delineate due to the complexity of organic matter sources, intensive physical mixing and biological processes. A combination of bulk organic matter techniques and molecular biomarkers are found to be successful in explaining organic matter dynamics in estuaries. The basic requirement for these multi-proxy approaches are (i) sources have significantly differing characteristics, (ii) there are a sufficient number of tracers to delineate all sources and (iii) organic matter degradation and processing have little, similar or predictable effects on end member characteristics. Although there have been abundant researches that have attempted to tackle difficulties related to the source and fate of organic matter in estuarine systems, our understanding remains limited or rather inconsistent regarding the Indian estuaries. Cochin estuary is the largest among many extensive estuarine systems along the southwest coast of India. It supports as much biological productivity and diversity as tropical rain forests. In this study, we have used a combination of bulk geochemical parameters and different group of molecular biomarkers to define organic matter sources and thereby identifying various biogeochemical processes acting along the salinity gradient of the Cochin estuary
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This paper presents a new approach to the design of combinational digital circuits with multiplexers using Evolutionary techniques. Genetic Algorithm (GA) is used as the optimization tool. Several circuits are synthesized with this method and compared with two design techniques such as standard implementation of logic functions using multiplexers and implementation using Shannon’s decomposition technique using GA. With the proposed method complexity of the circuit and the associated delay can be reduced significantly
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This paper explains the Genetic Algorithm (GA) evolution of optimized wavelet that surpass the cdf9/7 wavelet for fingerprint compression and reconstruction. Optimized wavelets have already been evolved in previous works in the literature, but they are highly computationally complex and time consuming. Therefore, in this work, a simple approach is made to reduce the computational complexity of the evolution algorithm. A training image set comprised of three 32x32 size cropped images performed much better than the reported coefficients in literature. An average improvement of 1.0059 dB in PSNR above the classical cdf9/7 wavelet over the 80 fingerprint images was achieved. In addition, the computational speed was increased by 90.18 %. The evolved coefficients for compression ratio (CR) 16:1 yielded better average PSNR for other CRs also. Improvement in average PSNR was experienced for degraded and noisy images as well
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Bioethanol is a liquid fuel obtained from fermentation of sugar/starch crops. Lignocellulosic biomass being less expensive is considered a future alternative for the food crops. One of the main challenges for the use of lignocellulosics is the development of an efficient pre-treatment process. Pretreatments are classified into three - physical, chemical, and biological pretreatment. Chemical process has not been proven suitable so far, due to high costs and production of undesired by-products. Biologically, hydrolysis can be enhanced by microbial or enzymatic pretreatment. Studies show that the edible mushrooms of Pleurotus sp. produce several extracellular enzymes which reduce the structural and chemical complexity of fibre. In the present study, P. ostreatus and P. eous were cultivated on paddy straw. Spent substrate left after mushroom cultivation was powdered and used for ethanol production. Saccharomyces sp. was used for fermentation studies. Untreated paddy straw was used as control. Production of ethanol from P. ostreatus substrate was 5.5 times more when compared to untreated paddy straw, while the spent substrate of P. eous gave 5 times increase in ethanol yield. Assays showed the presence of several extracellular enzymes in the spent substrate of both species, which together contributed to the increase in ethanol yield
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In natural languages with a high degree of word-order freedom syntactic phenomena like dependencies (subordinations) or valencies do not depend on the word-order (or on the individual positions of the individual words). This means that some permutations of sentences of these languages are in some (important) sense syntactically equivalent. Here we study this phenomenon in a formal way. Various types of j-monotonicity for restarting automata can serve as parameters for the degree of word-order freedom and for the complexity of word-order in sentences (languages). Here we combine two types of parameters on computations of restarting automata: 1. the degree of j-monotonicity, and 2. the number of rewrites per cycle. We study these notions formally in order to obtain an adequate tool for modelling and comparing formal descriptions of (natural) languages with different degrees of word-order freedom and word-order complexity.
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Globalization is widely regarded as the rise of the borderless world. However in practice, true globalization points rather to a “spatial logic” by which globalization is manifested locally in the shape of insular space. Globalization in this sense is not merely about the creation of physical fragmentation of space but also the creation of social disintegration. This study tries to proof that global processes also create various forms of insular space leading also to specific social implications. In order to examine the problem this study looks at two cases: China’s Pearl River Delta (PRD) and Jakarta in Indonesia. The PRD case reveals three forms of insular space namely the modular, concealed and the hierarchical. The modular points to the form of enclosed factories where workers are vulnerable for human-right violations due to the absent of public control. The concealed refers to the production of insular space by subtle discrimination against certain social groups in urban space. And the hierarchical points to a production of insular space that is formed by an imbalanced population flow. The Jakarta case attempts to show more types of insularity in relation to the complexity of a mega-city which is shaped by a culture of exclusion. Those are dormant and hollow insularity. The dormant refers to the genesis of insular– radical – community from a culture of resistance. The last type, the hollow, points to the process of making a “pseudo community” where sense of community is not really developed as well as weak social relationship with its surrounding. Although global process creates various expressions of territorial insularization, however, this study finds that the “line of flight” is always present, where the border of insularity is crossed. The PRD’s produces vernacular modernization done by peasants which is less likely to be controlled by the politics of insularization. In Jakarta, the culture of insularization causes urban informalities that have no space, neither spatially nor socially; hence their state of ephemerality continues as a tactic of place-making. This study argues that these crossings possess the potential for reconciling venue to defuse the power of insularity.
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Cooperative behaviour of agents within highly dynamic and nondeterministic domains is an active field of research. In particular establishing highly responsive teamwork, where agents are able to react on dynamic changes in the environment while facing unreliable communication and sensory noise, is an open problem. Moreover, modelling such responsive, cooperative behaviour is difficult. In this work, we specify a novel model for cooperative behaviour geared towards highly dynamic domains. In our approach, agents estimate each other’s decision and correct these estimations once they receive contradictory information. We aim at a comprehensive approach for agent teamwork featuring intuitive modelling capabilities for multi-agent activities, abstractions over activities and agents, and a clear operational semantic for the new model. This work encompasses a complete specification of the new language, ALICA.
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In drawing a conclusion for this study, care must be taken in generalizing findings since the population of students and teachers investigated were limited to certain levels in the different schools and countries. This study recognized some complexity of the factors underlying the status of school gardening instruction and activities in Germany, Nigeria and the U.S. as inadequate time for decision-making in the process of gardening, motivation of teachers and students. This was seen as the major impediments that influenced the status of gardening in the three countries. However, these factors were considered to have affected students’ mode of participation in the school gardening projects. This research finding suggests that the promotion and encouragement of students in gardening activities will promote vegetable production and increasing the numbers of practical farmers. Gardening has the potential to create opportunities for learning in an environment where children are able to experience nature first hand and to use the shared experience for communication (Bowker & Tearle, 2007). Therefore, the need for students to be encouraged to participate in gardening programs as the benefit will not only reduce the rate of obesity currently spreading among youths, but will contribute to the improve knowledge on science subjects. To build a network between community, parents and schools, a parent’s community approach should be used as the curriculum. The community approach will tighten the link between schools; community members, parents, teachers and students. This will help facilitate a better gardening projects implementation. Through a close collaboration, teachers and students will be able to identify issues affecting communities and undertake action learning in collaboration with community organizations to assess community needs and plan the implementation strategies as parents are part of the community. The sense of efficacy is a central factor in motivational and learning processes that govern educational improvement, standard and performance on complex tasks of both teachers and students. Dedication and willingness are the major stimulator and achievement of a project. Through a stimulator and provision of incentives and facilities, schools can achieve the best in project development. Teachers and principals should be aware that students are the lever for achieving the set goals in schools. Failure to understand what students need will result in achieving zero result. Therefore, it is advised that schools focus more on how to lure students to work through proper collaboration with the parents and community members. Principals and teachers should identify areas where students need to be corrected, helping them to correct the problem will enable them be committed in the schools’ programs.
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Die Wissenschaft weist im Zuge der Entwicklung von der Industrie- zu einer Wissensgesellschaft einschneidende Veränderungen in der Wissensordnung auf, welche sich bis hin zu einem zunehmenden Verlust der wissenschaftlichen Selbststeuerungsmechanismen bemerkbar machen und einen veränderten Umgang mit dem generierten Wissensschatz erfordern. Nicht nur Änderungen in der Wissensordnung und -produktion stellen die Psychoanalyse vor neue Herausforderungen: In den letzten Jahrzehnten geriet sie als Wissenschaft und Behandlungsverfahren zunehmend in die Kritik und reagierte mit einer konstruktiven Diskussion um ein dem Forschungsgegenstand – die Untersuchung unbewusster Prozesse und Fantasien – adäquates psychoanalytisches Forschungsverständnis. Die Auseinandersetzung mit Forderungen gesellschaftlicher Geldgeber, politischer Vertreter und Interessensgruppen wie auch der wissenschaftlichen Community stellt die Psychoanalyse vor besondere Herausforderungen. Um wissenschaftsexternen wie -internen Gütekriterien zu genügen, ist häufig ein hoher personeller, materieller, finanzieller, methodischer wie organisatorischer Aufwand unabdingbar, wie das Beispiel des psychoanalytischen Forschungsinstitutes Sigmund-Freud-Institut zeigt. Der steigende Aufwand schlägt sich in einer zunehmenden Komplexität des Forschungsprozesses nieder, die unter anderem in den vielschichtigen Fragestellungen und Zielsetzungen, dem vermehrt interdisziplinären, vernetzten Charakter, dem Umgang mit dem umfangreichen, hochspezialisierten Wissen, der Methodenvielfalt, etc. begründet liegt. Um jener Komplexität des Forschungsprozesses gerecht zu werden, ist es zunehmend erforderlich, Wege des Wissensmanagement zu beschreiten. Tools wie z. B. Mapping-Verfahren stellen unterstützende Werkzeuge des Wissensmanagements dar, um den Herausforderungen des Forschungsprozesses zu begegnen. In der vorliegenden Arbeit werden zunächst die veränderten Forschungsbedingungen und ihre Auswirkungen auf die Komplexität des Forschungsprozesses - insbesondere auch des psychoanalytischen Forschungsprozesses - reflektiert. Die mit der wachsenden Komplexität einhergehenden Schwierigkeiten und Herausforderungen werden am Beispiel eines interdisziplinär ausgerichteten EU-Forschungsprojektes näher illustriert. Um dieser wachsenden Komplexität psychoanalytischer Forschung erfolgreich zu begegnen, wurden in verschiedenen Forschungsprojekten am Sigmund-Freud-Institut Wissensmanagement-Maßnahmen ergriffen. In der vorliegenden Arbeit wird daher in einem zweiten Teil zunächst auf theoretische Aspekte des Wissensmanagements eingegangen, die die Grundlage der eingesetzten Wissensmanagement-Instrumente bildeten. Dabei spielen insbesondere psychologische Aspekte des Wissensmanagements eine zentrale Rolle. Zudem werden die konkreten Wissensmanagement-Tools vorgestellt, die in den verschiedenen Forschungsprojekten zum Einsatz kamen, um der wachsenden Komplexität psychoanalytischer Forschung zu begegnen. Abschließend werden die Hauptthesen der vorliegenden Arbeit noch einmal reflektiert und die geschilderten Techniken des Wissensmanagements im Hinblick auf ihre Vor- und Nachteile kritisch diskutiert.
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Segmentation of medical imagery is a challenging problem due to the complexity of the images, as well as to the absence of models of the anatomy that fully capture the possible deformations in each structure. Brain tissue is a particularly complex structure, and its segmentation is an important step for studies in temporal change detection of morphology, as well as for 3D visualization in surgical planning. In this paper, we present a method for segmentation of brain tissue from magnetic resonance images that is a combination of three existing techniques from the Computer Vision literature: EM segmentation, binary morphology, and active contour models. Each of these techniques has been customized for the problem of brain tissue segmentation in a way that the resultant method is more robust than its components. Finally, we present the results of a parallel implementation of this method on IBM's supercomputer Power Visualization System for a database of 20 brain scans each with 256x256x124 voxels and validate those against segmentations generated by neuroanatomy experts.
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Each player in the financial industry, each bank, stock exchange, government agency, or insurance company operates its own financial information system or systems. By its very nature, financial information, like the money that it represents, changes hands. Therefore the interoperation of financial information systems is the cornerstone of the financial services they support. E-services frameworks such as web services are an unprecedented opportunity for the flexible interoperation of financial systems. Naturally the critical economic role and the complexity of financial information led to the development of various standards. Yet standards alone are not the panacea: different groups of players use different standards or different interpretations of the same standard. We believe that the solution lies in the convergence of flexible E-services such as web-services and semantically rich meta-data as promised by the semantic Web; then a mediation architecture can be used for the documentation, identification, and resolution of semantic conflicts arising from the interoperation of heterogeneous financial services. In this paper we illustrate the nature of the problem in the Electronic Bill Presentment and Payment (EBPP) industry and the viability of the solution we propose. We describe and analyze the integration of services using four different formats: the IFX, OFX and SWIFT standards, and an example proprietary format. To accomplish this integration we use the COntext INterchange (COIN) framework. The COIN architecture leverages a model of sources and receivers’ contexts in reference to a rich domain model or ontology for the description and resolution of semantic heterogeneity.
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We present a technique for the rapid and reliable evaluation of linear-functional output of elliptic partial differential equations with affine parameter dependence. The essential components are (i) rapidly uniformly convergent reduced-basis approximations — Galerkin projection onto a space WN spanned by solutions of the governing partial differential equation at N (optimally) selected points in parameter space; (ii) a posteriori error estimation — relaxations of the residual equation that provide inexpensive yet sharp and rigorous bounds for the error in the outputs; and (iii) offline/online computational procedures — stratagems that exploit affine parameter dependence to de-couple the generation and projection stages of the approximation process. The operation count for the online stage — in which, given a new parameter value, we calculate the output and associated error bound — depends only on N (typically small) and the parametric complexity of the problem. The method is thus ideally suited to the many-query and real-time contexts. In this paper, based on the technique we develop a robust inverse computational method for very fast solution of inverse problems characterized by parametrized partial differential equations. The essential ideas are in three-fold: first, we apply the technique to the forward problem for the rapid certified evaluation of PDE input-output relations and associated rigorous error bounds; second, we incorporate the reduced-basis approximation and error bounds into the inverse problem formulation; and third, rather than regularize the goodness-of-fit objective, we may instead identify all (or almost all, in the probabilistic sense) system configurations consistent with the available experimental data — well-posedness is reflected in a bounded "possibility region" that furthermore shrinks as the experimental error is decreased.
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One of the tantalising remaining problems in compositional data analysis lies in how to deal with data sets in which there are components which are essential zeros. By an essential zero we mean a component which is truly zero, not something recorded as zero simply because the experimental design or the measuring instrument has not been sufficiently sensitive to detect a trace of the part. Such essential zeros occur in many compositional situations, such as household budget patterns, time budgets, palaeontological zonation studies, ecological abundance studies. Devices such as nonzero replacement and amalgamation are almost invariably ad hoc and unsuccessful in such situations. From consideration of such examples it seems sensible to build up a model in two stages, the first determining where the zeros will occur and the second how the unit available is distributed among the non-zero parts. In this paper we suggest two such models, an independent binomial conditional logistic normal model and a hierarchical dependent binomial conditional logistic normal model. The compositional data in such modelling consist of an incidence matrix and a conditional compositional matrix. Interesting statistical problems arise, such as the question of estimability of parameters, the nature of the computational process for the estimation of both the incidence and compositional parameters caused by the complexity of the subcompositional structure, the formation of meaningful hypotheses, and the devising of suitable testing methodology within a lattice of such essential zero-compositional hypotheses. The methodology is illustrated by application to both simulated and real compositional data
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In this paper we present a novel approach to assigning roles to robots in a team of physical heterogeneous robots. Its members compete for these roles and get rewards for them. The rewards are used to determine each agent’s preferences and which agents are better adapted to the environment. These aspects are included in the decision making process. Agent interactions are modelled using the concept of an ecosystem in which each robot is a species, resulting in emergent behaviour of the whole set of agents. One of the most important features of this approach is its high adaptability. Unlike some other learning techniques, this approach does not need to start a whole exploitation process when the environment changes. All this is exemplified by means of experiments run on a simulator. In addition, the algorithm developed was applied as applied to several teams of robots in order to analyse the impact of heterogeneity in these systems
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This paper proposes a parallel architecture for estimation of the motion of an underwater robot. It is well known that image processing requires a huge amount of computation, mainly at low-level processing where the algorithms are dealing with a great number of data. In a motion estimation algorithm, correspondences between two images have to be solved at the low level. In the underwater imaging, normalised correlation can be a solution in the presence of non-uniform illumination. Due to its regular processing scheme, parallel implementation of the correspondence problem can be an adequate approach to reduce the computation time. Taking into consideration the complexity of the normalised correlation criteria, a new approach using parallel organisation of every processor from the architecture is proposed