Approximation algorithm for the parallel-machine scheduling problem with release dates and submodular rejection penalties

In this paper, we consider the parallel-machine scheduling problem with release dates and submodular rejection penalties. In this problem, we are given m identical parallel machines and n jobs. Each job has a processing time and a release date. A job is either rejected, in which case a rejection penalty has to be paid, or accepted and processed on one of the m identical parallel machines. The objective is to minimize the sum of the makespan of the accepted jobs and the rejection penalty of the rejected jobs which is determined by a submodular function. Our main work is to design a 2-approximation algorithm based on the primal-dual framework.

     

A joint optimization of data ferry trajectories and communication powers of ground sensors for long-term environmental monitoring

Recently, various hybrid wireless sensor networks which consist of several robotic vehicles and a number of static ground sensors have been investigated. In this kind of system, the main role of the mobile nodes is to deliver the messages produced by the sensor nodes, and naturally their trajectory control becomes a significant issue closely related to the performance of the entire system. Previously, several communication power control strategies such as topology control are investigated to improve energy-efficiency of wireless sensor networks. However, to the best of our knowledge, no communication power control strategy has been investigated in the context of the hybrid wireless sensor networks. This paper introduces a new strategy to utilize the communication power control in multiple data ferry assisted wireless sensor network for long-term environmental monitoring such that the lifetime of the sensor network is maximized. We formally define the problem of our interest and show it is NP-hard. We further prove there exists no approximation algorithm for the problem which can produce a feasible solution for every possible problem instance even though there is a feasible solution. Then, we propose heuristic algorithms along with rigorous theoretical performance analysis for both the single data ferry case and the multiple data ferry case under certain condition.     

序贯疗法治疗幽门螺杆菌阳性消化性溃疡82例疗效分析

目的：分析序贯疗法治疗幽门螺杆菌阳性消化性溃疡的临床疗效.方法随机将164例就诊的幽门螺杆菌阳性消化性溃疡患者分为两组,治疗组82例给予序贯疗法治疗,对照组82例给予传统三联疗法治疗,比较两组疗效.结果治疗组Hp根除率(84.15%)明显优于对照组(67.07%),治疗组治愈50例(60.97%),总有效率为91.46%,对照组治愈35例(42.68%),总有效率为74.39%,治疗组明显好于对照组,差异具有统计学意义.结论应用序贯疗法治疗幽门螺杆菌阳性消化性溃疡效果显著,可有效缓解患者的临床症状,提高幽门螺杆菌的根除率,并且无不良反应.     

睡眠质量与人格特征相关研究

为了探讨学生的睡眠质量与人格特征之间的关系,我们采用匹兹堡睡眠质量指数（PSQI）问卷和艾森克人格测验（EPQ）对高中生进行调查。结果发现,有24．9％的学生存在睡眠质量问题,不同年级之间学生的睡眠质量存在显著差异,高三学生的睡眠质量显著差于高一、高二学生。不同睡眠质量组别的学生在EPQ中的N（神经质）因子得分上存在非常显著的差异。相关分析表明,N（神经质）和P（精神质）在睡眠质量各因子中均现正相关,并大多数达到显著或十分显著的差异。     

科学发展观:马克思主义中国化的又一重大理论成果

一个国家坚持什么样的发展观对这个国家的发展会产生重大影响。科学发展观是马克思主义中国化的又一重大理论成果,它的理论特色、范畴体系和统领地位值得我们深刻理解和全面把握。     

关于广义测度正负集的性质与Hahn的分解

本讨论了关于广义测度正、负集的定义和性质，并利用它证明了Hahn分解定理。     

采用分级教学模式提高课堂教学效果

文中阐述了大学英语分级教学及其现状、目的和意义；分析了在普通高校实施分级教学的必要性；重点总结讨论了实施分级教学模式对课堂教学效果的影响，并提出了有待解决的问题。     

Improved construction for pooling design

Pooling design is a mathematical tool with many applications in molecular biology, specially to reduce the number of tests for DNA library screening. In this note, we study construction of pooling design and present an improvement to a recent new construction given by Du et al. (J. Comput. Biol. 13:990–995, 2006). P. Deng and W. Wu supported in part by National Science Foundation under grants CCF-0514796 and CNS-0524429. T. Znati supported in part by National Science Foundation under grant CCF-0548895.