Incorporation of municipalities and population growth: A propensity score matching approach

During the 1960s and 1970s, the German state governments reduced the number of municipalities. Many independent municipalities in the outskirts of cities became districts of the respective cities. Using propensity score matching, I examine how the reforms influenced population growth in these incorporated units. The results show that the population of small incorporated municipalities grew by about 47 percentage points faster than the population of small municipalities that remained independent. The results do not show that large incorporated municipalities grew faster than large municipalities that remained independent. Population growth was stronger in municipalities that were incorporated later.     

Gzip压缩的硬件加速电路设计

硬件无损压缩技术可以发挥专用电路的速度和功耗优势,被广泛应用于大数据计算以及通信领域.本文以GNUzip（Gzip）数据无损压缩技术为原型设计了一种硬件压缩电路.通过采用双Hash函数、并行匹配处理、面向硬件存储的LZ77压缩存储格式、高效数据拼接器等加速方法,发挥并行计算和流水线结构优势,提升压缩速率.该硬件压缩电路基于Verilog HDL设计,使用现场可编程门阵列（FPGA）进行测试和验证.测试数据表明：与软件压缩方式相比,该硬件压缩电路在获得适中压缩率（65.9%）的同时,其压缩速率得到显著提升,平均压缩速率达171Mb/s,满足网络通信、数据存储等实时压缩应用需求.     

基于字符串匹配的通用数据压缩算法

本文主要介绍基于字符串匹配的数据压缩算法原理，该算法从多方面时著名ＬＺ７７算法进行了改进，我们的算法所用到的工作缓冲区是一个循环历史表，摈弃了输入符号超前缓冲区；结果，匹配过程是边接收输入边进行，无需等待一组输入数据填满超前缓冲区才开始，同时，最大争配长度不再受超前缓冲区大小的限制，而且，不再需要做大量的平移工作缓立足点冲区的操作，另外，还涉及一些其他方面的改进，包括改等长压缩码为变长码和引入匹配     

Effect of Killer Impurities on Optical Properties of ZnO at Low Temperature

Optical characterizations for ZnO doped with killer impurities (Co or Fe or Ni) having doping concentrations 0.05–1.00% by weight have been carried out at 77 K. Optical properties such as excited state lifetime, trap-depth and decay constant values have been measured using the pulse excitation method. The effect of killer dopants, concentration of killer ions as well as the effect of temperature on various optical parameters values has been observed. Multi-exponential decay curves have been observed. Lifetime values are found to be in the micro- and nano-second time domain and a reverse trend is obtained with increase in concentration of killer impurities. With decreases in temperature from 300 to 77 K, lifetime shortening takes place. The effect of killer impurities is more prominent at higher concentrations. A mixed trend in decay constant values is observed with the increase proportional to the concentration of killer impurities. The values of the decay constant show a mixed effect with change in impurity concentrations. The value of the decay constant 0.76, corresponding to ZnO: Ni (0.7%) is the highest among all the doped ZnO phosphors.      

通用数据库备份恢复构件的设计

在当前流行的各种规模的数据库中，对其数据库中的原始数据进行各种形式备份恢复是最基本的功能，但往往只有专职数据库管理员才能在后台直接进行数据库管理。本文介绍了一种能在前台方便实现对数据库备份恢复的功能构件，并阐述其主要设计思想。     

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。     

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.     

Assembling curvature continuous surfaces from triangular patches

We assemble triangular patches of total degree at most eight to form a curvature continuous surface. The construction illustrates how separation of local shape from representation and formal continuity yields an effective construction paradigm in partly underconstrained scenarios. The approach localizes the technical challenges and applies the spline approach, i.e. keeping the degree fixed but increasing the number of pieces, to deal with increased complexity when many patches join at a central point.     

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.