A branch and bound algorithm for dynamic resource allocation in population disease management

We embed an approximate dynamic program into a branch-and-bound framework to solve sequential resource allocation problems in population disease management. The proposed algorithm is capable of providing an optimality guarantee and getting bounds on the optimality gap of healthcare interventions. A numerical study on screening and treatment policy implementation for chronic hepatitis C virus (HCV) infection provides useful insights regarding HCV elimination for baby boomers.     

工业互联网环境下预防性维修管理多目标协同优化

工期、成本、质量通常作为传统项目管理过程中三大目标,而工业互联网环境下预防性维修管理除了以上三大目标之外还更多的考虑了安全因素.根据设备机群内不同设备分析了其四大目标不同构成和内涵,四大目标决策权重采用经改进的带置信度的专家确定方法,根据工期约束等因素导出资源使用均衡条件.在此基础上构建了非线性条件下四方关系多属性效用函数模型.采用线性递减收敛因子改进下的多点交叉遗传算法进行优化求解,促使种群快速寻找最优解,算法表现出较好的收敛性和多样性使得寻优过程更加合理.     

Genus Chloranthus: A comprehensive review of its phytochemistry,pharmacology, and uses

This paper is intended to review advances in the botanical, traditional uses, phytochemical, pharmacological and development and utilization studies of the genus Chloranthus. Chloranthus, a genus of the family Chloranthaceae, which is mainly distributed in the temperate and tropical regions of Asia, has been used as a folk remedy for swollen boils, snake bites and bruises. Up to now, 418 compounds have been reported from the genus Chloranthus, including 383 terpenoids, 4 coumarins, 6 lignans, 2 simple phenylpropanoids, 4 flavonoids, 6 amides, 5 organic acids and some other types of compounds. Among them, the main chemical constituents are sesquiterpenes and their diterpenoids. Modern pharmacological studies have shown that most of the Chloranthus plants possessed anti-cancer, anti-inflammatory, antibacterial, antiviral, and antimalarial activities. As one of the most important genera in China, Chloranthus should be paid further attention to gathering information about the pharmacological mechanism and value active compounds. This paper summarized the phytochemistry, pharmacology, and uses of genus Chloranthus in order to lay a foundation and provide reference for the follow-up research and wide application of the genus.     

天然气水化合物的声学探测进展

天然水合物是一种未来的新型能源,与此相关的研究正日益成为能源勘探领域的热点。本文对 天然水合物及其特点、分布和探测技术进行了简要的介绍,在此基础上从声学技术研究角度出发, 介绍了声波测井、地震探测、海底地貌声波检测技术等在探测天然水合物中的应用;并探讨了声学方 法和技术在评价天然水合物储层方面的研究内容、进展和侧重点。     

Domestic petroleum-related expertise utilization and Nigeria's oil industry survival: A multicriteria decision analysis

Despite Nigeria's current economic crisis and the need to remove control structures which were originally designed to protect national interest so as to attract foreign investment in upstream activities of its oil sector, the notion of an indigenously controlled oil sector is still alive in the country. The current paper utilizes a multiperiod goal programming model to examine the effect the enforcement of Nigeria's Petroleum Decree on the utilization of domestic petroleum-related expertise would have on the survival of the multinational oil companies and, therefore, of the oil industry. The results indicate that there are some benefits to the nation in enforcing the Decree, but that to do so now will trigger a chain of events that will culminate in the demise of the oil industry. The results also highlight the danger in using legislation to regulate strategic industries and the role operational researchers can play in public policy design and decisions in the future.     

侧柏林下主要植物对资源的利用特征研究

本文应用数学分析方法,研究了侧柏林下三层十二种主要植物的资源利用特征,定量研究了各种环境因子对林下植物的作用。发现土壤因子的作用超过光因子的作用而成为影响植物生长和分布的主要因子,土壤因子中作用最大的是土壤质地和土壤水分。最后,建立了灌木层、草本层和十二种主要植物生长量与环境因子的数学模型。为侧柏林的保护和利用提供了科学依据。     

Scheduling uniform parallel machines subject to a secondary resource to minimize the number of tardy jobs

This research investigates the problem of scheduling jobs on a set of parallel machines where the speed of the machines depends on the allocation of a secondary resource. The secondary resource is fixed in quantity and is to be allocated to the machines at the start of the schedule. The scheduling objective is to minimize the number of tardy jobs. Two versions of the problem are analyzed. The first version assumes that the jobs are pre-assigned to the machines, while the second one takes into consideration the task of assigning jobs to the machines. The paper proposes an Integer Programming formulation to solve the first case and a set of heuristics for the second.     

Periodic load balancing

Multiprocessor load balancing aims to improve performance by moving jobs from highly loaded processors to more lightly loaded processors. Some schemes allow only migration of new jobs upon arrival, while other schemes allow migration of jobs in progress. A difficulty with all these schemes, however, is that they require continuously maintaining detailed state information. In this paper we consider the alternative of periodic load balancing, in which the loads are balanced only at each T time units for some appropriate T. With periodic load balancing, state information is only needed at the balancing times. Moreover, it is often possible to use slightly stale information collected during the interval between balancing times. In this paper we study the performance of periodic load balancing. We consider multiple queues in parallel with unlimited waiting space to which jobs come either in separate independent streams or by assignment (either random or cyclic) from a single stream. Resource sharing is achieved by periodically redistributing the jobs or the work in the system among the queues. The performance of these systems of queues coupled by periodic load balancing depends on the transient behavior of a single queue. We focus on useful approximations obtained by considering a large number of homogeneous queues and a heavy load. When the number of queues is sufficiently large, the number of jobs or quantity of work at each queue immediately after redistribution tends to evolve deterministically, by the law of large numbers. The steady-state (limiting) value of this deterministic sequence is obtained as the solution of a fixed point equation, where the initial value is equal to the expected transient value over the interval between successive redistributions conditional on the initial value. A refined approximation based on the central limit theorem is a normal distribution, where the mean and variance are obtained by solving a pair of fixed-point equations. With higher loads, which is natural to consider when load balancing is performed, a heavy-traffic limit theorem shows that one-dimensional reflected Brownian motion can be used to approximately describe system performance, even with general arrival and service processes. With these approximations, we show how performance depends on the assumed arrival pattern of jobs and the model parameters. We do numerical calculations and conduct simulation experiments to show the accuracy of the approximations. This revised version was published online in June 2006 with corrections to the Cover Date.     

Performance analysis of a constrained resource sharing system

We consider a queueing system where the servers are arranged in a circle, and each arriving customer requires a pair of resources that is shared by its server with the respective neighbors on either side. If either resource is being used, the customer is denied service. Customers arrive at each server according to independent Poisson processes, and lengths of service times at each server have an exponential distribution. We derive a closed-form formula for the expected fraction of busy servers at any time in terms of the number of servers and the utilization factor (defined as the arrival rate times the mean service-time duration). This allows us to evaluate system performance when these parameters are varied, and to determine whether denying service to arrivals at alternate servers improves performance. We relate the system to Dijkstra's dining philosophers problem, which is an abstraction for resource sharing in an operating system. This revised version was published online in June 2006 with corrections to the Cover Date.