事实、价值与道德选择

在道德选择的理论与实践中,必然遇到事实与价值的关系问题。事实与价值统一于"实际活动着的人"自身。正确的道德选择应建立在价值判断与事实判断统一的基础上,忽视了事实判断作用的道德选择,必然会最终导致对道德价值自身的否定。从人格完善过程的角度来分析,道德选择又是德行与智慧的统一。     

An oracle-based algorithm for robust planning of production routing problems in closed-loop supply chains of beverage glass bottles

The demand for glass bottles is exhibiting an upward trend over time. The manufacturing of glass bottles is costlier in terms of time and resources and is associated with a higher level of heat generation and environmental pollution compared to recycling processes. In response to the aforementioned challenges, companies that use glass bottles need to implement strategies to manage their reverse supply chains in conjunction with their traditional supply chains, as the economic and environmental benefits of returned products are unquestionable. Closed-loop supply chains (CLSCs) integrate forward and reverse flows of products and information. This integration helps companies to have a broader view of the whole chain. Despite these advantages, managing CLSCs can be challenging as they are exposed to many uncertainties regarding supply and demand processes, travel times, and quantity/quality of returned products.In this study, we consider the production planning, inventory management, and vehicle routing decisions of a CLSC of beverage glass bottles. We propose an MILP model and rely on a multi-stage adjustable robust optimization (ARO) formulation to deal with the randomness in both the demand for filled bottles and the requests for pickups of empty bottles. We develop an exact oracle-based algorithm to solve the ARO problem and propose a heuristic search algorithm to reduce the solution time. Our numerical experiments not only show the incompetency of the customary method, namely the affine decision rule approach, but also illustrate how our algorithms can solve the small-size problems and significantly improve the quality of the obtained solution for large problems. Furthermore, our numerical results show that robust plans tend to be sparse, meaning the routes are chosen so that empty bottles are transported to production sites in such a way that fewer new bottles need to be ordered. Thus, robust planning makes the CLSCs more environmentally friendly.     

Vehicle routing–scheduling for municipal waste collection system under the “Keep Trash off the Ground” policy

This paper investigates the waste collection problem and characterizes the problem as a set-covering and vehicle routing problem (VRP) complicated by inter-arrival time constraints. The study proposes a bi-level optimization formulation to model the split delivery VRP with multiple trips to determine the minimum-distance route. The first stage optimally plans the collection points that cover all residential blocks. The second stage applies a heuristics method to solve the minimum vehicles used and minimum distance traveled for collecting residential waste. This research contributes to model this period VRP and to introduce the heuristics method to solve the problem efficiently. The study is important in laying the groundwork for understanding the possibility of improving the service level of municipal solid waste collection.     

我国灾后废墟管理的进程、问题与趋势初探

废墟管理和垃圾废物处理,是灾后恢复重建以及环境保护工作的难点和重要内容。近年来,我国自然灾害频繁,废墟量不断增多,废墟垃圾若不综合利用、处理,不仅影响灾后恢复重建,而且还会加重生态灾难。而我国在废墟管理方面还相对落后,在废墟处理、管理等环节存在突出问题和技术难题。借鉴日本废墟管理有益经验,废墟管理呈现向专业化、市场化、智能化和法制化方向发展的趋势。     

传媒商业化带来的相关问题分析

传媒商业化是当前中国传媒变革中的热点问题.尽管商业化成为传媒业发展的加速器,但其带来的社会负面效应也必须正视:传媒产品娱乐化、低俗化现象严重,商业炒作无处不在,主流媒体"喉舌"功能减弱等,由此造成媒体的社会责任感不断弱化.对于这些问题,应根据我国传媒业发展的阶段性特点进行系统分析,并借鉴发达国家的相关管制经验,找出一个适用性的解决方案.     

Estimation and Inference for Linear Panel Data Models Under Misspecification When Both n and T are Large

This article considers fixed effects (FE) estimation for linear panel data models under possible model misspecification when both the number of individuals, n, and the number of time periods, T, are large. We first clarify the probability limit of the FE estimator and argue that this probability limit can be regarded as a pseudo-true parameter. We then establish the asymptotic distributional properties of the FE estimator around the pseudo-true parameter when n and T jointly go to infinity. Notably, we show that the FE estimator suffers from the incidental parameters bias of which the top order is O(T^{? 1}), and even after the incidental parameters bias is completely removed, the rate of convergence of the FE estimator depends on the degree of model misspecification and is either (nT)^{? 1/2} or n^{? 1/2}. Second, we establish asymptotically valid inference on the (pseudo-true) parameter. Specifically, we derive the asymptotic properties of the clustered covariance matrix (CCM) estimator and the cross-section bootstrap, and show that they are robust to model misspecification. This establishes a rigorous theoretical ground for the use of the CCM estimator and the cross-section bootstrap when model misspecification and the incidental parameters bias (in the coefficient estimate) are present. We conduct Monte Carlo simulations to evaluate the finite sample performance of the estimators and inference methods, together with a simple application to the unemployment dynamics in the U.S.     

Expert Systems

Summary

Expert systems are computer programs which embody the expertise of a human expert in order to consult and advise on a specific problem. It is now becoming feasible to apply expert systems technology to problems in the human services. This article describes what expert systems technology is and how it may be applied in human service practice. Finally, some of the promises and pitfalls of this new technology are addressed.     

论琼南黎族地区中学数学教师培训中的瓶颈问题

通过对琼南黎族地区中学数学教师培训现状的分析,研究了制约教师培训效果的瓶颈问题,分析了产生瓶颈问题的原因,并对突破瓶颈问题的关键进行了探讨。     

Computing the probability of hash table/urn overflow

We analyze the probability of a random distribution of n balls into m urns of size b resulting in no overflows. This solves the computational problem associated with a classical combinatorial extreme-value distribution. The problem arose during the analysis of a technique, called perfect hashing, for organizing data in computer files. The results and techniques presented can be used to solve several problems in the analysis of hashing techniques     

Testing for a change in covariance operator

The paper considers a problem of equality of two covariance operators. Using functional principal component analysis, a method for testing equality of K largest eigenvalues and the corresponding eigenfunctions, together with its generalization to a corresponding change point problem is suggested. Asymptotic distributions of the test statistics are presented.