Solving an integrated employee timetabling and job-shop scheduling problem via hybrid branch-and-bound

We propose exact hybrid methods based on integer linear programming (ILP) and constraint programming (CP) for an integrated employee timetabling and job-shop scheduling problem. Each method we investigate uses a CP formulation associated with an LP relaxation. Under a CP framework, the LP relaxation is integrated into a global constraint using in addition reduced cost-based filtering techniques. We propose two CP formulations of the problem yielding two different LP relaxations. The first formulation is based on a direct representation of the problem. The second formulation is based on a decomposition in intervals of the possible operation starting times. We show the theoretical interest of the decomposition-based representation compared to the direct representation through the analysis of dominant schedules. Computational experiments on a set of randomly generated instances confirm the superiority of the decomposition-based representation. In both cases, the hybrid methods outperform pure CP for employee cost minimization while it is not the case for makespan minimization. The experiments also investigate the interest of the proposed integrated method compared to a sequential approach and show its potential for multiobjective optimization.     

电力线窄带通信报文压缩算法研究

电力线载波通信报文传输易受噪声干扰从而影响传输效率,扩频技术的采用避免了信号的衰减但同时也降低了通信速率,因此提出通过对报文数据的压缩来提高通信速率、降低误码率.然而由于电力线载波通信报文短小,不易从统计模型角度进行压缩,因此探索了通用的顺序压缩算法LZ77在电力线载波通信报文压缩中的应用.     

XCfde：高压缩率的XML文档压缩技术

本文提出了一种用于数据交换的XML压缩技术XCfde。XCfde采取四步压缩方案：把XML文档分离为结构数据和内容数据;自动识别数据类型并自动分类数据;对不同类型的数据采用不同的编码策略;将初步编码后的结构数据和内容数据使用7Zip进行整体压缩。XCfde拥有较高的压缩率,改善了XML数据交换的传输效率和存档中的空间利用率。     

井下人员定位硬件系统设计与实现

针对煤矿目前普遍存在的人员出入井管理困难、井上管理人员难以及时掌握井下人员的动态分布及作业情况、灾后救援效率低并且缺乏可靠的人员定位信息等现状。我们利用2．4G高频射频芯片NRF24E1和增强51内核的W77E58单片机．设计了井下人员定位系统,将辜位信息实时传送到上位机,方便井上管理人员对井下人员的跟踪、定位与管理。     

BENQ23G的彩信发送及编码格式分析

中国移动将MMS（Multimedia Messaging Service）命名为＂彩信＂,大多数手机都支持彩信的发送和接收。本文介绍一种采用Winbond公司的77E58单片机控制台湾BenQ公司的GSM/GPRS模块BENQ23G发送MMS彩信的方法,深入分析了通过中国移动梦网发送MMS彩信时与网关服务器之间的通信方式、方法,以及传输协议命令格式和传输数据格式。     

空间仪器锂离子蓄电池管理控制器研究

为了满足实验类空间仪器对空间电源系统的低成本、高集成度、微型化的需求,设计了以C8051F040芯片为控制核心的空间仪器电源控制器。该控制器与传统设计方式的最大区别是采用高集成度的锂离子电池控制芯片(bq77PL900)代替了原有的模拟电路。通过使用该芯片不仅大大降低了控制器所占体积,减小了控制器的功耗,而且提高了控制器的抗干扰能力。为了提高系统的可靠性,该系统还采用在线EEPROM充注技术,可以及时发现控制器内部被打翻的数据并进行恢复。通过实验证明该设计简单可靠,而且能量转换效率也提高了5%左右。该设计可广泛应用于低成本的空间仪器的电源、微小型卫星的电源系统。     

油罐液位信息采集系统的设计

介绍了以单片机W77E58为核心的油罐液位信息采集系统.该系统采用磁致伸缩液位计,精确度高,能自动采集信息并进行处理.介绍了系统的工作原理、组成及功能,并给出了原理图及部分程序代码.     

77MnA高碳钢盘条拉拔断裂原因及控制措施

研究了造成77MnA高碳钢盘条拉拔断裂的主要原因，结果表明：钢材纯净度和均匀度、索氏体率、盘条表面和内部质量以及用户的加工工艺各方面的不足均会导致拉拔断裂。     

Negotiation versus manipulation: The impact of alternate forms of LDC government behavior on the design of international environmental agreements

This article addresses the problem faced by an asymmetrically informed supra-national governmental authority (SNGA) with limited funds that wishes to design an international environmental agreement (IEA) for less developed countries (LDCs). The SNGA can only deal with polluting firms in the LDCs through their national governments. This tripartite hierarchical interaction is studied for two LDCs. The private information of the firms and the governments across the two countries is perfectly correlated. In this setting, we study the effects of two kinds of behavior by the governments of the LDCs. We show that despite the perfect correlation in the private information of governments and firms across the two countries, the SNGA cannot design a first-best IEA. Our analysis suggests that problems arising from the SNGA's inability to monitor the actions of the polluting firms and the national governments are less salient than is commonly believed. However, there is no denying the fact that the succ ess of IEAs is dependent not only on the funds available for environmental protection, but also on the manner in which LDC governments represent polluting firms in their countries. Received 15 January 2000 / Accepted 28 June 2000     

77K低温下MOSFET非固有电容参数提取研究

77 K 低温参数是制冷型碲镉汞红外焦平面探测器读出电路设计与精确仿真的关键点之一.通过研究 MOSFET 非固有电容的特性,并基于 BSIM3通用模型对电容的描述,在77 K 低温下进行测试提取,得到了相关的模型参数.嵌入 SPICE 软件仿真对比,证明了参数的准确性.