对名义利率和实际利率的再认识

名义利率和实际利率对投资决策、筹资决策和股利分配政策有重要参考价值。该文对名义利率和实际利率进行了重新定义,同时指出影响名义利率和实际利率的因素并非仅是通货膨胀,还包括信用条件、计息方法、投资期限等多种因素,而且进一步阐述,实际利率并非简单地等于名义利率与通货膨胀之差,名义利率并非总大于实际利率。     

Routing and refueling plans to minimize travel time in alternative-fuel vehicles

A driver who drives an alternative-fuel vehicle (AFV) from an origin point to a destination point needs to consider how to get there (i.e., the routing problem), when to stop, and how and when to refuel (i.e., the refueling plan). In this study, models and algorithms are proposed that optimize a one-way-trip path such that the total travel time from the origin to the destination is minimized. The travel time consists of the setup time, the refueling time and the driving time. The setup time includes waiting for the AFV to be served at a refueling station and the preparation time of charging the machine. We categorized the problems into two types: (1) the refueling plan problem when the routing decision is given and (2) an integrated problem of routing and refueling. Another axis of categorization is when (1) setup time and refueling times are site-independent and (2) parameters are site-dependent. We propose optimal algorithms for site-independent problems and the integrated problem of routing and refueling planning with site-independent parameters. We also conduct experiments and sensitivity analyses for the site-dependent integrated problems of routing and refueling.     

The Role of Oil Price Shocks in Causing U.S. Recessions

Although oil price shocks have long been viewed as one of the leading candidates for explaining U.S. recessions, surprisingly little is known about the extent to which oil price shocks explain recessions. We provide a formal analysis of this question with special attention to the possible role of net oil price increases in amplifying the transmission of oil price shocks. We quantify the conditional effect of oil price shocks in the net oil price increase model for all episodes of net oil price increases since the mid‐1970s, analyze its determinants, and show that the linear model fits the data better.     

Análisis del servicio de Urgencias aplicando teoría de líneas de espera

Those responsible for making decisions in hospitals are increasingly aware of the need to efficiently manage hospital systems. An option for analysis is done by queuing models. In this paper is analyzed the service area ER, in a public hospital applying the concepts and relationships of waiting lines. From the model results, it is concluded that in the emergency department does not have the required minimum number of doctors to allow a steady flow of patients. With the model, the minimum required number of doctors is calculated to meet current and future demand for service with the same service time and the same discipline of service. Analytical models, allowing direct understand the relationships between service demand, number of doctors and patient care priority viewed as a queuing system. The work is useful for administrators and managers of hospital systems.     

产业结构调整背景下的区域用电量预测模型库构建

基于产业结构调整宏观环境,构建了区域用电量预测模型初选库,其主要包括基于时间序列的区域用电量预测模型和基于影响因素的区域用电量预测模型。并基于预测效果反馈,建立预测效果评级指标体系,构建预测效果评价模型。在评价结果的基础上,筛选出最优模型作为区域用电量预测模型终选库,以便正确预估地区电网发展趋势,提高企业竞争力。     

英语时、态、体及其语法教学

英语语法是英语学习过程中的一个重点,同时也是一个难点,而英语语法在很多情况下与英语的“时”、“体”、“态”密切相关。了解英语“时”“体”“态”的基本概念和两种“时”、两种“体”和两种“态”的基本构成,对掌握英语语法中常见的时态和语态以及非谓语动词,尤其是不定式和分词结构的构成规则有很大的帮助。     

新时期高校和谐师生关系研究述评

随着我国改革开放和高等教育的深入发展,高校师生关系出现一些新特点、新问题,已日益成为制约我国高等教育发展、提高教育质量的重要因素。在新时期构建和谐师生关系是我国在新世纪建设人力资源强国的一项重要举措。也是一项艰难的课题,需要学术界及社会各界共同努力。     

Proportional scheduling, split-proofness, and merge-proofness

If shortest (respectively longest) jobs are served first, splitting a job into smaller jobs (respectively merging several jobs) can reduce the actual wait. Any deterministic protocol is vulnerable to strategic splitting and/or merging. This is not true if scheduling is random, and users care only about expected wait.The Proportional rule draws the job served last with probabilities proportional to size, then repeats among the remaining jobs. It is immune to splitting and merging. Among split-proof protocols constructed in this recursive way, it is characterized by either one of three properties: job sizes and delays are co-monotonic; total delay is at most twice optimal delay; the worst (expected) delay of any job is at most twice the smallest feasible worst delay. A similar result holds within the family of separable rules,     

Existence of solutions in continuous-time optimal growth models

This paper studies the existence of solutions in continuous time optimization problems. It provides a theorem whose conditions can be easily checked in most models of the optimal growth theory, including those with increasing returns and multi-sector economies.