基于WiMAX的调度算法综述

随着无线网络的发展,网络服务质量（Qos）也越来越成为用户和运营商共同关心的问题。保障Qos的问题实质上是一个分配和调度用户间资源的问题。调度算法的目的在于最优化系统的资源分配从而保障Qos,最大化系统的吞吐量,最小化系统能量消耗。本文简要综述在信道状态已知的情况下的调度算法。     

Online scheduling on parallel machines with two GoS levels

This paper investigates the online scheduling problem on parallel and identical machines with a new feature that service requests from various customers are entitled to many different grade of service (GoS) levels. Hence each job and machine are labeled with the GoS levels, and each job can be processed by a particular machine only when the GoS level of the job is not less than that of the machine. The goal is to minimize the makespan. In this paper, we consider the problem with two GoS levels. It assumes that the GoS levels of the first k machines and the last m−k machines are 1 and 2, respectively. And every job has a GoS level of 1 alternatively or 2. We first prove the lower bound of the problem under consideration is at least 2. Then we discuss the performance of algorithm AW presented in Azar et al. (J. Algorithms 18:221–237, 1995) for the problem and show it has a tight bound of 4−1/m. Finally, we present an approximation algorithm with competitive ratio . Research supported by Natural Science Foundation of Zhejiang Province (Y605316) and its preliminary version appeared in Proceedings of AAIM2006, LNCS, 4041, 11-21.     

Assessment of Patient Classification in Appointment System Design

This paper investigates two approaches to patient classification: using patient classification only for sequencing patient appointments at the time of booking and using patient classification for both sequencing and appointment interval adjustment. In the latter approach, appointment intervals are adjusted to match the consultation time characteristics of different patient classes. Our simulation results indicate that new appointment systems that utilize interval adjustment for patient class are successful in improving doctors' idle time, doctors' overtime and patients' waiting times without any trade‐offs. Best performing appointment systems are identified for different clinic environments characterized by walk‐ins, no‐shows, the percentage of new patients, and the ratio of the mean consultation time of new patients to the mean consultation time of return patients. As a result, practical guidelines are developed for managers who are responsible for designing appointment systems.     

Job satisfaction and ‘welfare‐to‐work‘: is any job a good job for Australian single mothers?

This exploratory study sought to assess the job satisfaction of employed Australian single mothers who had mandatory employment participation requirements. In particular, we sought to identify the characteristics of the job and the individual that were closely associated with participant's job satisfaction. Self‐report data on job satisfaction, employment characteristics and parenting stress were collected from 155 employed single mothers. Participant job satisfaction was compared to female Australian population norms and linear regression analyses determined the job‐related and individual predictors of single mothers' job satisfaction. Findings from this exploratory study revealed that single mothers involved in a mandatory welfare‐to‐work program experienced significantly lower job satisfaction than the Australian female population. The individual variable, parental distress, negatively predicted each of the six job satisfaction domains while being employed on a casual basis was inversely associated with three domains (job security, work hours and overall job satisfaction). The Australian government purported that making the transition from welfare to work would improve wellbeing for program participants, under the assumption that ‘any job's a good job‘. However, the relatively low levels of job satisfaction experienced by single mothers in the current study provide little support for this assumption.     

How long is the queuing for public childcare facilities in Korea? An empirical analysis of Korean households' childcare mode choice with the limited availability of public childcare facilities

This paper empirically investigates Korean households' choice of childcare mode using the Korean Childcare Users Survey (2012). A multivariate logit model with partial observability (hereafter, PO‐logit model) is employed to address the issue of Korean households' demand for public childcare facilities exceeding capacity limits. Our estimation result rejects the hypothesis of no queueing at conventional significance levels to advocate use of the PO‐logit model in explaining Korean households' childcare choices. We decompose choice probabilities of public childcare facilities to estimate the size of queuing. Our results imply that 31.8% of parents preferring public childcare facility are forced to choose other childcare modes due to capacity limit.     

团体心理辅导提升留守经历大学生心理资本研究——以西南石油大学为例

为了了解团体心理辅导对留守经历大学生心理资本水平的干预和提升效果,以心理资本问卷作为评估工具,采用实验组对照组前后测的实验设计,在西南石油大学公开招募留守经历大学生作为被试。研究发现：实验组前后测的心理资本得分有显著的差异,表现为实验组的心理资本及各维度的后测得分显著高于前测得分,对照组的心理资本前后测得分无显著差异;实验组与对照组的心理资本后测得分差异显著,表现为实验组的心理资本及各维度的后测得分显著高于前测得分;实验组中,绝大多数学生对整个团体活动感到满意,认为在活动中有所收获,觉得团体辅导对重新看待自己的过去和成长经历有较大帮助。     

考虑最坏中断损失下的P-中位设施选址问题的模型与算法研究

蓄意突袭以及恐怖袭击会造成设施服务的突然中断成为网络系统的主要危害之一,因此网络设施选址决策应该同时考虑正常和紧急状态下系统的运作成本.本文研究考虑最坏中断损失下的网络设施选址问题,建立了该问题的双层规划模型,上层规划涉及设施选址决策,下层规划研究确定设施位置后,设施中断产生最大损失的问题.本文运用基于拉格朗日松弛的混合遗传算法来求解该双层规划问题.将European150数据集作为研究对象,对比研究了本文研究问题与传统的P-中位选址问题的结果,分析不同选址策略下网络系统的效率被中断影响的程度是不同的.最后通过改变一些关键参数,比如常规运作权重、设施数量、中断设施数量,对相关结果进行了分析.     

面向多灾点需求的应急资源调度博弈模型及优化

非常规突发事件爆发后经常会造成多个灾点,而各灾点的需求往往是不同的,单独的应急资源中心很难同时满足这种要求,因此如何把多个应急资源中心所储备的应急资源公平合理地调配到各个灾点成为应急决策者亟待解决的现实问题。本文首先描述了各灾点对应急资源需求变化的动态过程即按照应急资源需求信息的变化将整个应急资源调度过程划分成若干阶段,在此基础上构建了基于多灾点多阶段的应急资源调度过程理论模型。随后以博弈论为工具,在进行一系列模型假设和确定各灾点灾情的前提下,建立面向多灾点需求的应急资源博弈调度模型,并采用改进的蚁群算法进行求解,实现对各灾点以最小的“虚拟成本”进行所需应急资源的调度。最后的模型仿真测试和算例分析验证了所建模型的有效性和可行性。该模型与算法也为商业物流中的资源配送提供了新的解决方案和实现途径。     

基于改进遗传算法的置换装配线调度问题研究

企业的置换装配线调度问题（Permutation Assembly-line Scheduling Problem,PASP）是一类典型的NP-hard型生产调度问题,是现代集成制造系统CIMS极为关心的问题。该问题可以具体描述为n个工件要在m台机器上加工,每个工件需要经过m道工序,每道工序要求不同的机器,这n个工件通过m台机器的顺序相同,它们在每台机器上的加工顺序也相同,问题的主要目标是找到n个工件在每台机器上的最优加工顺序,使得最大完工时间最小。由于PASP问题的NP-hard性质,本文使用遗传算法对其进行求解。尽管遗传算法常用以求解调度问题,但其选择与交叉机制易导致局部最优及收敛慢。因此,本文提出基于区块挖掘与重组的改进遗传算法用于求解置换装配线调度问题。首先通过关联规则挖掘出不同的优秀基因,然后将具有较优结果的基因组合为优势区块,产生具优势的人工解,并引入高收敛性的局部搜索方法,提高搜索到最优解的机会与收敛效率。本文以OR-Library中Taillard标准测试例来验证改进遗传算法的求解质量与效率,结果证明：本文所提算法与其它求解调度问题的现有5种知名算法相比,不仅收敛速度较快,同时求解质量优于它们。     

基于失效情景的应急设施选址评估指标体系与模型

突发事件具有巨大的破坏性、不确定性,应急设施有可能失效,本文研究基于失效情景的应急设施选址评估指标体系与评估模型。首先基于定义的失效情景研究应急设施选址评估指标。构建全局性、可靠性、时效性、均衡性、经济性评估指标。可靠性作为重要评估指标有助于提高应急设施对需求区域的物资保障程度,保证系统的稳定性,采用多重覆盖率刻画。然后,设计具有不同侧重评估目标的一般情景评估指标体系、设施失效情景评估指标体系以及多区域情景评估指标体系。最后,由于应急设施选址评估具有多影响因素特征,涉及输入和输出多个指标的测度,选取处理多输入\多输出问题具有优势的评估方法—数据包络法,对应急设施选址的合理性进行评估。实例验证评估指标体系的实用性和有效性。