Enhanced Topology Error Processing via Optimal Measurement Design

Topology errors constitute one of the significant source of problems for today's state estimators. They may cause significant biases in state estimation solutions and may occasionally lead to divergence of the numerical solution algorithms. Existing methods of detecting and identifying topology errors rely on the measurement residuals which are in turn dependent on the measurement configuration and network topology. Hence, the capability to effectively process topology errors is closely linked to proper measurement design. In particular, detection of a topology error associated with a given branch may or may not be possible depending upon the existing measurement configuration. Hence, it is possible to efficiently improve the topology error processing capability for a given system by strategically placing few extra measurements. In this paper, a systematic procedure will be developed in order to accomplish this by using not only the traditional power flow and injection measurements but also the newly emerging phasor measurement units (PMUs). Numerical examples will be provided in order to illustrate the proposed measurement placement strategy.      

一种矿山用钢筋网自动化焊接生产线的设计

设计一条钢筋网自动化焊接生产线，包括经料送料平台、纬料自动分料及上料机构、多点电阻点焊机、接料平台、卸料机械手。从上料到出料依靠电机、汽缸之间的协调工作来实现。并由单片机和PLC实现控制功能，上位机用MCGS组态软件在整个过程监视现场，采集工作状态及参数，起到监控作用。     

Surgical treatment of unilateral alveolar cleft

In this study, 16 cases of unilateral alveolar cleft with cleft lip and palate were repaired with autografts of cancellous bone (13 cases) or hydroxyapatite (3 cases). The grafts were covered by reflected mucoperiosteal flaps and a mucosal flap from the upper lip. Twelve of the thirteen cases were followed up for 1-5 years. Nine of whom using cancellous bone had bony continuity of the maxilla and 7 cases erupted permanent maxillary canines within the area of autografts. None of the 3 cases using hydroxyapatite erupted a canine tooth. The results showed that autograft was better than hydroxyapatite in terms of maxillary canine eruption.     

High-transconductance n-type Si/SiGe modulation-doped field-effecttransistors

The authors report on the fabrication and the resultant device characteristics of the first 0.25-μm gate-length field-effect transistor based on n-type modulation-doped Si/SiGe. Prepared using ultrahigh vacuum/chemical vapor deposition (UHV/CVD), the mobility and electron sheet charge density in the strained Si channel are 1500 (9500) cm²/V-s and 2.5×10¹² (1.5×10¹² ) cm^-2 at 300 K (77 K). At 77 K, the devices have a current and transconductance of 325 mA/mm and 600 mS/mm, respectively. These values far exceed those found in Si MESFETs and are comparable to the best results achieved in GaAs/AlGaAs modulation-doped transistors     

Group decision support system for assessment of problem-basedlearning

Assessment is an important task in problem-based learning (PBL). It has a strong influence on students' approaches to learning and their outcomes. In order to provide an open and fair method of PBL assessment, a group decision support system (GDSS) has been developed. The system uses mathematical decision methods for collecting assessment criteria and their appropriate weights, and databases for storing students' details and data on the assessment criteria. It integrates databases with model bases in a cooperative decision-making environment and is implemented on a client-server platform using a relational database management system. The GDSS has been developed and used to improve the efficiency and quality of assessing students' PBL outcomes     

Efficient Skyline and Top-k Retrieval in Subspaces

Skyline and top-k queries are two popular operations for preference retrieval. In practice, applications that require these operations usually provide numerous candidate attributes, whereas, depending on their interests, users may issue queries regarding different subsets of the dimensions. The existing algorithms are inadequate for subspace skyline/top-k search because they have at least one of the following defects: 1) they require scanning the entire database at least once, 2) they are optimized for one subspace but incur significant overhead for other subspaces, or 3) they demand expensive maintenance cost or space consumption. In this paper, we propose a technique SUBSKY, which settles both types of queries by using purely relational technologies. The core of SUBSKY is a transformation that converts multidimensional data to one-dimensional (1D) values. These values are indexed by a simple B-tree, which allows us to answer subspace queries by accessing a fraction of the database. SUBSKY entails low maintenance overhead, which equals the cost of updating a traditional B-tree. Extensive experiments with real data confirm that our technique outperforms alternative solutions significantly in both efficiency and scalability.     

医患和谐与建筑设计

我们经常会发现，同样一位医护人员在医院工作场所和在其它地方会表现出不同的性格特质，无论是多么和善的人，到了那种医院环境有时就表现得面目可憎。其实，倒不是个人特质有所改变，而是医疗机构流程的流水线和环境造成的，恶劣的医患关系也因此而愈发不可调和。     

A simplified dispersion limit formula for IM/DD systems and itscomparison with experimental results

A simplified formula for the dispersion limit of single-mode-fiber intensity modulation/direct detection (IM/DD) systems is derived for arbitrary given normalized pulse width U, eye opening penalty X and source linewidth enhancement factor α. From the comparison with published theoretical analyses, computer simulation and experimental data, its validity and the limits of existing formulae are shown. Using this simple and general formula, one can easily obtain the dispersion limit of various fiber types under different working conditions in IM/DD systems     

温度,压力对漂移室气体增益的影响

研究了温度及气体压力对漂移室（工作于正比区）气体放大倍数的影响，温度和气体压力的变化范围分别是５￣４０℃及９０￣１０５ｋＰａ。用实验数据拟合得到了函数关系并测量了几种饱和度下函数中的参数值。     

IC封装模流道平衡CAE应用

分析了热固性塑料的流动行为特点和IC封装充填过程中料流对金丝的冲击状态。用CAE软件Moldflow公司的MPA对流道的平衡进行分析模拟 ,优化浇注系统 ,为提高IC封装产品合格率寻找一种简便有效的途径。