The physics of accelerator driven sub-critical reactors

In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future nuclear energy generation. The physics of ADS is quite different from that of critical reactors. As such, physics studies on ADS reactors are necessary for gaining an understanding of these systems. Development of theoretical tools and experimental facilities for studying the physics of ADS reactors constitute important aspect of the ADS development program at BARC. This includes computer codes for burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods. The paper discusses the physics issues specific to ADS reactors and presents the status of the reactor physics program and some of the ADS concepts under study.      

Negotiation and Equilibria in User Competition for Resources: A Dynamic Plot Approach

We consider a scenario where two users are competing for substitutable facilities and where the costs to a user for using a facility depend on its usage as well as the usage by the other user. This results in a nonlinear dynamic game the solution of which implies an allocation that satisfies both users. Games with four different types of solution spaces are presented where the equilibria and the process to reach a negotiated compromise solution have different characterizations. Nash equilibria and nondominated points are discussed in this context and an interactive graphical dynamic plot approach is presented for obtaining negotiated solutions in such nonlinear dynamic games.     

The Logic of Organizational Markets: Thinking Through Resource Partitioning Theory

Resource partitioning theory claims that Increasing concentration enhances the life chances of specialist organizations. We systematically think through this theory, specify implicit background assumptions, sharpen concepts, and rigorously check the theory's logic. As a result, we increase the theory's explanatory power, and claim—contrary to received opinion'that under certain general conditions, resource partitioning and the proliferation of specialists can take place independently of organizational mass and relative size effects, size localized competition, diversifying consumer tastes, increasing number of dimensions of the resource space, and changing niche widths. Our analysis makes furthermore clear that specialist and generalist strategies are asymmetric, and shows that not concentration enhances the life chances of specialists but economies of scale instead. Under the conditions explicated, we argue that if scale economies come to dominate, the number of organizations in the population increases, regardless of the incumbents' sizes.     

Constructing optimal maps for Monge's transport problem as a limit of strictly convex costs

Given two densities on with the same total mass, the Monge transport problem is to find a Borel map rearranging the first distribution of mass onto the second, while minimizing the average distance transported. Here distance is measured by a norm with a uniformly smooth and convex unit ball. This paper gives a complete proof of the existence of optimal maps under the technical hypothesis that the distributions of mass be compactly supported. The maps are not generally unique. The approach developed here is new, and based on a geometrical change-of-variables technique offering considerably more flexibility than existing approaches.

     

Envelope Theorems in Dynamic Programming

The envelope theorem is a statement about derivatives along an optimal trajectory. In dynamic programming the envelope theorem can be used to characterize and compute the optimal value function from its derivatives. We illustrate this here for the linear-quadratic control problem, the resource allocation problem, and the inverse problem of dynamic programming.     

可拓营销理论研究

利用物元理论、事元理论和可拓集合理论 ,对需要、产品、市场、资源、企业等进行可拓分析 ,提出可拓营销的基本理论——产品开拓规律、可拓市场、可拓资源、健全企业等     

水资源时延控制模型及研究

水资源系统是由水资源自然分系统和人工分系统合成的复杂大系统.把设计修建的水资源工程视作安装于自然系统上的一个控制器,同时考虑当前状态量与时延量的制约关系.首次建立了一个由流域、湖泊及引水工程等组成的非线性水资源时延控制数学模型,讨论了该类系统的稳定性、最优控制、次优控制等理论,最后给出次优控制的数值计算及结果.     

Optimal dynamical balance harvesting for a class of renewable resources system

An optimal utilization problem for a class of renewable resources system is investigated. Firstly, a control problem was proposed by introducing a new. utility function which depends on the harvesting effort and the stock of resources. Secondly, the existence ofoptimal solution for the problem was discussed. Then, using a maximum principle for infinite horizon problem, a nonlinear four-dimensional differential equations system was attained. After a detailed analysis of the unique positive equilibrium solution, the existence of limit cycles for the system is demonstrated. Next a reduced system on the central manifold is carefully derived, which assures the stability of limit cycles. Finally significance of the results in bioeconomics is explained.     

Resource use efficiency of closed plant production system with artificial light: Concept,estimation and application to plant factory

Extensive research has recently been conducted on plant factory with artificial light, which is one type of closed plant production system (CPPS) consisting of a thermally insulated and airtight structure, a multi-tier system with lighting devices, air conditioners and fans, a CO₂ supply unit, a nutrient solution supply unit, and an environment control unit. One of the research outcomes is the concept of resource use efficiency (RUE) of CPPS.This paper reviews the characteristics of the CPPS compared with those of the greenhouse, mainly from the viewpoint of RUE, which is defined as the ratio of the amount of the resource fixed or held in plants to the amount of the resource supplied to the CPPS.It is shown that the use efficiencies of water, CO₂ and light energy are considerably higher in the CPPS than those in the greenhouse. On the other hand, there is much more room for improving the light and electric energy use efficiencies of CPPS. Challenging issues for CPPS and RUE are also discussed.     

Channel resource allocation and availability prediction in hybrid access femtocells

In this paper, three channel assignment models are proposed for channel resource allocation in femtocells. The models proposed are based on the Markov chain process. According to the access mechanisms in femtocells, the Third-Generation Partnership Project (3GPP) has described two kinds of users in the femtocell application; open users and the closed subscriber group (CSG). In hybrid access mechanism for femtocells, both CSG users and open users are usually referred as subscribers and non-subscribers respectively. So, in this work, for all the proposed models, the CSG and open users are categorized into two groups; the subscriber group (SG) and the non-subscriber group (NSG) respectively. The proposed models provide priority based channel resource allocation strategies between the SG and NSG. Furthermore, the focus of this research is to provide variable channel resource sharing among the SG and NSG to keep the wastage of channel resources minimum for better quality of service (QoS). The analysis is conducted in terms of channel resource blocking management for all the models and to validate the analysis, simulations are performed at the end of this paper. Further, channel resource blocking prediction, based on the blocking probability results for SG and NSG users, is also provided at the end. The prediction is done through risk analysis using the @ Risk tool. The simulations are provided in two parts; 1) the probability curves for SG and NSG against the total number of channels and 2) the risk analysis results for blocked channels prediction using the @ Risk tool.