999 resultados para Conditional cooperation


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Deep convolutional neural networks (DCNNs) have been employed in many computer vision tasks with great success due to their robustness in feature learning. One of the advantages of DCNNs is their representation robustness to object locations, which is useful for object recognition tasks. However, this also discards spatial information, which is useful when dealing with topological information of the image (e.g. scene labeling, face recognition). In this paper, we propose a deeper and wider network architecture to tackle the scene labeling task. The depth is achieved by incorporating predictions from multiple early layers of the DCNN. The width is achieved by combining multiple outputs of the network. We then further refine the parsing task by adopting graphical models (GMs) as a post-processing step to incorporate spatial and contextual information into the network. The new strategy for a deeper, wider convolutional network coupled with graphical models has shown promising results on the PASCAL-Context dataset.

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In wireless ad hoc networks, nodes communicate with far off destinations using intermediate nodes as relays. Since wireless nodes are energy constrained, it may not be in the best interest of a node to always accept relay requests. On the other hand, if all nodes decide not to expend energy in relaying, then network throughput will drop dramatically. Both these extreme scenarios (complete cooperation and complete noncooperation) are inimical to the interests of a user. In this paper, we address the issue of user cooperation in ad hoc networks. We assume that nodes are rational, i.e., their actions are strictly determined by self interest, and that each node is associated with a minimum lifetime constraint. Given these lifetime constraints and the assumption of rational behavior, we are able to determine the optimal share of service that each node should receive. We define this to be the rational Pareto optimal operating point. We then propose a distributed and scalable acceptance algorithm called Generous TIT-FOR-TAT (GTFT). The acceptance algorithm is used by the nodes to decide whether to accept or reject a relay request. We show that GTFT results in a Nash equilibrium and prove that the system converges to the rational and optimal operating point.

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A better performing product code vector quantization (VQ) method is proposed for coding the line spectrum frequency (LSF) parameters; the method is referred to as sequential split vector quantization (SeSVQ). The split sub-vectors of the full LSF vector are quantized in sequence and thus uses conditional distribution derived from the previous quantized sub-vectors. Unlike the traditional split vector quantization (SVQ) method, SeSVQ exploits the inter sub-vector correlation and thus provides improved rate-distortion performance, but at the expense of higher memory. We investigate the quantization performance of SeSVQ over traditional SVQ and transform domain split VQ (TrSVQ) methods. Compared to SVQ, SeSVQ saves 1 bit and nearly 3 bits, for telephone-band and wide-band speech coding applications respectively.

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This study examines Institutional Twinning in Morocco as a case of EU cooperation through the pragmatic, ethical and moral logics of reason in Jürgen Habermas’s discourse ethics. As a former accession tool, Twinning was introduced in 2004 for legal approximation in the context of the European Neighborhood Policy. Twinning is a unique instrument in development cooperation from a legal perspective. With its long historical and cultural ties to Europe, Morocco presents an interesting case study of this new form of cooperation. We will analyse motives behind the Twinning projects on illegal immigration, environment legislation and customs reform. As Twinning is a new policy instrument within the ENP context, there is relatively little preceding research, which, in itself, constitutes a reason to inquire into the subject. While introducing useful categories, the approaches discussing “normative power Europe” do not offer methodological tools precise enough to analyse the motives of the Twinning cooperation from a broad ethical standpoint. Helene Sjursen as well as Esther Barbé and Elisabeth Johansson-Nogués have elaborated on Jürgen Habermas’ discourse ethics in determining the extent of altruism in the ENP in general. Situating the analysis in the process-oriented framework of Critical Theory, discourse ethics provides the methodological framework for our research. The case studies reveal that the context in which they operate affects the pragmatic, ethical and moral aspirations of the actors. The utilitarian notion of profit maximization is quite pronounced both in terms of the number of Twinning projects in the economic sphere and the pragmatic logics of reason instrumental to security and trade-related issues. The historical background as well internal processes, however, contribute to defining areas of mutual interest to the actors as well as the motives Morocco and the EU sometimes described as the external projection of internal values. Through its different aspects, Twinning cooperation portrays the functioning of the pragmatic, ethical and moral logics of reason in international relations.

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A better understanding of stock price changes is important in guiding many economic activities. Since prices often do not change without good reasons, searching for related explanatory variables has involved many enthusiasts. This book seeks answers from prices per se by relating price changes to their conditional moments. This is based on the belief that prices are the products of a complex psychological and economic process and their conditional moments derive ultimately from these psychological and economic shocks. Utilizing information about conditional moments hence makes it an attractive alternative to using other selective financial variables in explaining price changes. The first paper examines the relation between the conditional mean and the conditional variance using information about moments in three types of conditional distributions; it finds that the significance of the estimated mean and variance ratio can be affected by the assumed distributions and the time variations in skewness. The second paper decomposes the conditional industry volatility into a concurrent market component and an industry specific component; it finds that market volatility is on average responsible for a rather small share of total industry volatility — 6 to 9 percent in UK and 2 to 3 percent in Germany. The third paper looks at the heteroskedasticity in stock returns through an ARCH process supplemented with a set of conditioning information variables; it finds that the heteroskedasticity in stock returns allows for several forms of heteroskedasticity that include deterministic changes in variances due to seasonal factors, random adjustments in variances due to market and macro factors, and ARCH processes with past information. The fourth paper examines the role of higher moments — especially skewness and kurtosis — in determining the expected returns; it finds that total skewness and total kurtosis are more relevant non-beta risk measures and that they are costly to be diversified due either to the possible eliminations of their desirable parts or to the unsustainability of diversification strategies based on them.

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In today’s business one can say that competition does not take place inside the network, but between networks. Change and dynamics are central issues in network studies, and a company, due its changing environment, can identify opportunities and threats and respond to them accordingly. These opportunities are vital, but also complex and demanding for the management. Earlier research has identified a shortcoming in explanations of how the micro-level interactions to macro-level patterns are connected. The IMP-group has been trying to fill this research gap with research on interactions within business networks. In this area of research lies the focus of research on relationships between organizations. Adaptation in cooperation is a central concept within business network research. Adaptation has been dealt with in previous literature, but the focus of the studies has mainly been outside this phenomenon, and it has mostly had a supporting role. Most literature has also described the buyers' point of view in studied supply networks, whereas much less attention has been paid to the suppliers' view on them. This study focuses on this research gap. The results of the study stress that adaptation should be included to a greater extent in the strategy work of companies. The adaptations should be carefully planned and, as far as possible, made consciously. Conscious, well-planned adaptations can be seen as investments into present and future relationships, and resources should be invested into something that does not increase the company’s dependence, but divides the power in the relationship between the companies. Adaptations should be planned so that they result in a more offensive way of responding to the demands that are placed upon the companies. In this way, the actions can be viewed and analyzed in accordance with whether the actions make the company weaker or stronger.

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In this study, it is argued that the view on alliance creation presented in the current academic literature is limited, and that using a learning approach helps to explain the dynamic nature of alliance creation. The cases in this study suggest that a wealth of inefficiency elements can be found in alliance creation. These elements can further be divided into categories, which help explain the dynamics of alliance creation. The categories –combined with two models brought forward by the study– suggest that inefficiency can be avoided through learning during the creation process. Some elements are especially central to this argumentation. First, the elements related to the clarity and acceptance of the strategy of the company, the potential lack of an alliance strategy and the elements related to changes in the strategic context. Second, the elements related to the length of the alliance creation processes and the problems a long process entails. It is further suggested that the different inefficiency elements may create a situation, where the alliance creation process is –sequentially and successfully– followed to the end, but where the different inefficiencies create a situation where the results are not aligned with the strategic intent. The proposed solution is to monitor and assess the risk for inefficiency elements during the alliance creation process. The learning, which occurs during the alliance creation process as a result of the monitoring, can then lead to realignments in the process. This study proposes a model to mitigate the risk related to the inefficiencies. The model emphasizes creating an understanding of the other alliance partner’s business, creating a shared vision, using pilot cooperation and building trust within the process. An analytical approach to assessing the benefits of trust is also central in this view. The alliance creation approach suggested by this study, which emphasizes trust and pilot cooperation, is further critically reviewed against contracting as a way to create alliances.

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This study examines Institutional Twinning in Morocco as a case of EU cooperation through the pragmatic, ethical and moral logics of reason in Jürgen Habermas’s discourse ethics. As a former accession tool, Twinning was introduced in 2004 for legal approximation in the context of the European Neighborhood Policy. Twinning is a unique instrument in development cooperation from a legal perspective. With its long historical and cultural ties to Europe, Morocco presents an interesting case study of this new form of cooperation. We will analyse motives behind the Twinning projects on illegal immigration, environment legislation and customs reform. As Twinning is a new policy instrument within the ENP context, there is relatively little preceding research, which, in itself, constitutes a reason to inquire into the subject. While introducing useful categories, the approaches discussing “normative power Europe” do not offer methodological tools precise enough to analyse the motives of the Twinning cooperation from a broad ethical standpoint. Helene Sjursen as well as Esther Barbé and Elisabeth Johansson-Nogués have elaborated on Jürgen Habermas’ discourse ethics in determining the extent of altruism in the ENP in general. Situating the analysis in the process-oriented framework of Critical Theory, discourse ethics provides the methodological framework for our research. The case studies reveal that the context in which they operate affects the pragmatic, ethical and moral aspirations of the actors. The utilitarian notion of profit maximization is quite pronounced both in terms of the number of Twinning projects in the economic sphere and the pragmatic logics of reason instrumental to security and trade-related issues. The historical background as well internal processes, however, contribute to defining areas of mutual interest to the actors as well as the motives Morocco and the EU sometimes described as the external projection of internal values. Through its different aspects, Twinning cooperation portrays the functioning of the pragmatic, ethical and moral logics of reason in international relations.

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We propose an efficient and parameter-free scoring criterion, the factorized conditional log-likelihood (ˆfCLL), for learning Bayesian network classifiers. The proposed score is an approximation of the conditional log-likelihood criterion. The approximation is devised in order to guarantee decomposability over the network structure, as well as efficient estimation of the optimal parameters, achieving the same time and space complexity as the traditional log-likelihood scoring criterion. The resulting criterion has an information-theoretic interpretation based on interaction information, which exhibits its discriminative nature. To evaluate the performance of the proposed criterion, we present an empirical comparison with state-of-the-art classifiers. Results on a large suite of benchmark data sets from the UCI repository show that ˆfCLL-trained classifiers achieve at least as good accuracy as the best compared classifiers, using significantly less computational resources.

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In this paper, an improved probabilistic linearization approach is developed to study the response of nonlinear single degree of freedom (SDOF) systems under narrow-band inputs. An integral equation for the probability density function (PDF) of the envelope is derived. This equation is solved using an iterative scheme. The technique is applied to study the hardening type Duffing's oscillator under narrow-band excitation. The results compare favorably with those obtained using numerical simulation. In particular, the bimodal nature of the PDF for the response envelope for certain parameter ranges is brought out.

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A systematic assessment of the submodels of conditional moment closure (CMC) formalism for the autoignition problem is carried out using direct numerical simulation (DNS) data. An initially non-premixed, n-heptane/air system, subjected to a three-dimensional, homogeneous, isotropic, and decaying turbulence, is considered. Two kinetic schemes, (1) a one-step and (2) a reduced four-step reaction mechanism, are considered for chemistry An alternative formulation is developed for closure of the mean chemical source term , based on the condition that the instantaneous fluctuation of excess temperature is small. With this model, it is shown that the CMC equations describe the autoignition process all the way up to near the equilibrium limit. The effect of second-order terms (namely, conditional variance of temperature excess sigma(2) and conditional correlations of species q(ij)) in modeling is examined. Comparison with DNS data shows that sigma(2) has little effect on the predicted conditional mean temperature evolution, if the average conditional scalar dissipation rate is properly modeled. Using DNS data, a correction factor is introduced in the modeling of nonlinear terms to include the effect of species fluctuations. Computations including such a correction factor show that the species conditional correlations q(ij) have little effect on model predictions with a one-step reaction, but those q(ij) involving intermediate species are found to be crucial when four-step reduced kinetics is considered. The "most reactive mixture fraction" is found to vary with time when a four-step kinetics is considered. First-order CMC results are found to be qualitatively wrong if the conditional mean scalar dissipation rate is not modeled properly. The autoignition delay time predicted by the CMC model compares excellently with DNS results and shows a trend similar to experimental data over a range of initial temperatures.

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The half-duplex constraint, which mandates that a cooperative relay cannot transmit and receive simultaneously, considerably simplifies the demands made on the hardware and signal processing capabilities of a relay. However, the very inability of a relay to transmit and receive simultaneously leads to a potential under-utilization of time and bandwidth resources available to the system. We analyze the impact of the half-duplex constraint on the throughput of a cooperative relay system that uses rateless codes to harness spatial diversity and efficiently transmit information from a source to a destination. We derive closed-form expressions for the throughput of the system, and show that as the number of relays increases, the throughput approaches that of a system that uses more sophisticated full-duplex nodes. Thus, half-duplex nodes are well suited for cooperation using rateless codes despite the simplicity of both the cooperation protocol and the relays.