On the nonemptiness of approximate cores of large games

We provide a new proof of the nonemptiness of approximate cores of games with many players of a finite number of types. Earlier papers in the literature proceed by showing that, for games with many players, equal-treatment cores of their “balanced cover games,” which are nonempty, can be approximated by equal-treatment \varepsilon ? -cores of the games themselves. Our proof is novel in that we develop a limiting payoff possibilities set and rely on a fixed point theorem

Measuring productivity in networks: A game-theoretic approach

Measuring individual productivity (or equivalently distributing the overall productivity) in a network structure of workers displaying peer effects has been a subject of ongoing interest in many areas ranging from academia to industry. In this paper, we propose a novel approach based on cooperative game theory that takes into account the peer effects of worker productivity represented by a complete bipartite network of interactions. More specifically, we construct a series of cooperative games where the characteristic function of each coalition of workers is equal to the sum of each worker intrinsic productivity as well as the productivity of other workers within a distance discounted by an attenuation factor. We show that these (truncated) games are balanced and converge to a balanced game when the distance of influence grows large. We then provide an explicit formula for the Shapley value and propose an alternative coalitionally stable distribution of productivity which is computationally much more tractable than the Shapley value. Lastly, we characterize this alternative distribution based on three sensible properties of a logistic network. This analysis enhances our understanding of game-theoretic analysis within logistics networks, offering valuable insights into the peer effects’ impact when assessing the overall productivity and its distribution among workers

On the Core of Dynamic Cooperative Games

We consider dynamic cooperative games, where the worth of coalitions varies over time according to the history of allocations. When defining the core of a dynamic game, we allow the possibility for coalitions to deviate at any time and thereby to give rise to a new environment. A coalition that considers a deviation needs to take the consequences into account because from the deviation point on, the game is no longer played with the original set of players. The deviating coalition becomes the new grand coalition which, in turn, induces a new dynamic game. The stage games of the new dynamical game depend on all previous allocation including those that have materialized from the deviating time on. We define three types of core solutions: fair core, stable core and credible core. We characterize the first two in case where the instantaneous game depends on the last allocation (rather than on the whole history of allocations) and the third in the general case. The analysis and the results resembles to a great extent the theory of non-cooperative dynamic games.Comment: 25 page

The effect of reverse current on the dark properties of photovoltaic solar modules

AbstractForward and reverse dark current-voltage (I-V) and capacitance-voltage (C-V) characteristics of commercial amorphous silicon solar modules, were measured in order to study their performance under the influence of induced reverse currents. Maximum module surface temperatures were directly related to each value of the induced reverse current and in to the amount of current leakage respectively. Microscopic changes as a result of hot spots defects and overheating of the solar module, linked to reverse current effects, were also documented and discussed. Experimental evidence showed that different levels of reverse currents are confirmed to be a major degrading factor affecting the performance, efficiency, and power of solar modules

TRIZ effect exploitation on engineering students thinking skills in product design

Product design is a creative and multidisciplinary activity that often necessitates the application of analytical and innovative support tools to enhance the concept research phase and solutions development. The TRIZ theory, a highly effective innovation method, has demonstrated its efficacy in supporting innovation across various fields. In this context, our focus has been on integrating TRIZ into the product design process involving engineering designers. This article provides a descriptive and critically assessed evaluation of the operational impact of TRIZ on the design activity, specifically in the development of a "Wastewater Screening and Filtration System" during the preliminary design phases. The objective of this research is to assess the influence of TRIZ utilization on the engineering designers' ability to address a design problem. The ultimate goal is to establish an innovative design support approach based on the use of TRIZ tools that is easily comprehensible and applicable to future designers. Within this article, we present both quantitative and qualitative results of the exploitation of TRIZ tools combined with an energy analysis of the requirement in the product design field

Review of Person Re-identification Techniques

Person re-identification across different surveillance cameras with disjoint fields of view has become one of the most interesting and challenging subjects in the area of intelligent video surveillance. Although several methods have been developed and proposed, certain limitations and unresolved issues remain. In all of the existing re-identification approaches, feature vectors are extracted from segmented still images or video frames. Different similarity or dissimilarity measures have been applied to these vectors. Some methods have used simple constant metrics, whereas others have utilised models to obtain optimised metrics. Some have created models based on local colour or texture information, and others have built models based on the gait of people. In general, the main objective of all these approaches is to achieve a higher-accuracy rate and lowercomputational costs. This study summarises several developments in recent literature and discusses the various available methods used in person re-identification. Specifically, their advantages and disadvantages are mentioned and compared.Comment: Published 201