Experimental technique using FTIR to estimate IR optical properties at variable temperatures: application to PMDA-ODA polyimide thin films from 100 to 380 degrees C

An experimental technique is presented to measure reflectance at high sample temperature with respect to room temperature in the infrared using Fourier transform infrared fitted with a reflectometer. Sample temperature artifacts are accounted for by sequential measurements taken with the lamp source on and with the lamp source off. The sequential measurements are shown mathematically to correct for the modulation of sample and detector thermal emissions. Further, the technique is applied to a polyimide (PMDA-ODA) film on a layer of gold deposited on a thermally oxidized Si wafer. It is shown that the optical properties (index of refraction and extinction coefficient) remain relatively constant with temperature (from room temperature to 380 degrees C) in the 4000-6000 cm(-1) spectral region. The significant changes that occur with temperature are the change in thickness of the film and also the spectral properties in the 2000-4000 cm(-1) region. Also, by using a Lorentz oscillator model, it is shown that this method is able to discern that spectral features corresponding to the OH stretching bands at 3630 and 3470 cm(-1) show significant variation with increasing temperature.     

Apportioning: a technique for efficient reachability analysis ofconcurrent object-oriented programs

The object-oriented paradigm in software engineering provides support for the construction of modular and reusable program components and is attractive for the design of large and complex distributed systems. Reachability analysis is an important and well-known tool for static analysis of critical properties in concurrent programs, such as deadlock freedom. It involves the systematic enumeration of all possible global states of program execution and provides the same level of assurance for properties of the synchronization structure in concurrent programs, such as formal verification. However, direct application of traditional reachability analysis to concurrent object-oriented programs has many problems, such as incomplete analysis for reusable classes (not safe) and increased computational complexity (not efficient). We propose a novel technique called apportioning, for safe and efficient reachability analysis of concurrent object-oriented programs, that is based upon a simple but powerful idea of classification of program analysis points as local (having influence within a class) and global (having possible influence outside a class). We have developed a number of apportioning-based algorithms, having different degrees of safety and efficiency. We present the details of one of these algorithms, formally show its safety for an appropriate class of programs, and present experimental results to demonstrate its efficiency for various examples     

Evaluation of a workplace technology for mental health assessment: A meaning-making process

This paper describes the results of a summative evaluation conducted to explore the usability and acceptability of an automated telephone-based technology, designed and developed as a screening tool for mental health disorders in the workplace. The system screens employees for symptoms and subsequently provides educational information and referrals to improve mental health and enhance productivity. The qualitative evaluation was a sub-study of a larger randomized controlled trial (RCT). We conducted in-depth interviews with 15 individuals who participated in the RCT and had used the system. A phenomenological theoretical framework was utilized to analyze the narrative data. Results indicated that participants had mostly positive experience with the system and perceived it as a confidential program that allowed them to reflect on their symptoms without inhibition, fear of judgment or embarrassment. We also learned that asking mere questions about mental health symptoms can be a positive, instructive and possibly a restorative experience. There is a likelihood that for many participants, exposure to questions about their emotional and mental distress validated their feelings about their symptoms and was sufficiently compelling to promote help-seeking behavior. This evaluation study demonstrates that computers can be utilized in the workplace as effective screening and educational tools to improve employees’ mental health.     

Combining genetic approach and integer programming to solve multi-facility economic lot-scheduling problem

Economic lot-scheduling problem (ELSP) has been studied since the 1950??s. ELSP deals with the scheduling of the production of several items on a single facility in a cyclical pattern. The facility can only produce one single item at a time, and there is a set-up cost and set-up time associated with each item. Because of the rapid development of many emerging markets nowadays, many common items are produced in different places in order to satisfy the demands in different markets. This becomes the multi-facilities ELSP problems. In ELSP problems, it is known that if more items types to be produced by the facility, the production frequency of each item type will increase because of the balancing of the production rate and the demand rate. Consequently, the number of set-up time and set-up cost increases accordingly. Thus, reallocating the common items, which can be produced in any facilities, to be produced only on certain facility can certainly reduce the number of production frequency, and lead to lower related costs. The objective of this paper is to propose an optimization methodology combining Integer Programming and Genetic Algorithm to solve multi-facility ELSP problems. This paper proposes to divide the main problem into a master problem and sub-problems, which are solved by Integer Programming and Genetic Algorithm respectively. To demonstrate the significance of reallocating the common items and aggregating them to produce in certain facility, several models have been designed and tested. The comparison of the models demonstrates the reduction of the costs benefited by result of common items reallocation.     

改进D-P算法在图像轮廓平滑中的应用

针对传统D-P算法速度较慢、编程不方便的问题,提出一种改进算法。以一定步长对轮廓进行遍历,根据轮廓上点到所选轮廓段首末点连线最大距离与距离阈值的大小关系,按轮廓遍历顺序获取曲线轮廓的特征点,并在相邻的特征点之间采用贝塞尔曲线进行平滑。实验结果表明,改进算法的速度比传统算法提高10%以上。     

办公建筑用电设备末端节能控制系统设计

随着建筑面积不断增加,人们对室内环境要求日益增强,建筑用电能耗也随之增加.办公建筑中设备末端节能控制设计是减少用电能耗浪费的重要途径和内容.系统结合办公特点、实际需求和室内动态环境,将室内温度、光照度、室内有无人员存在作为主要控制参数,结合办公作息时间表并考虑加班等特殊影响因素,对室内照明、办公插座以及空调等用电设备进行了节能控制设计;同时,系统设置通讯接口,实现数据外传功能,进而对接能耗监测平台.结果表明：在满足办公人员对舒适度要求的前提下,能最大限度的提高建筑用电能效比具有一定的社会和环境效益,开发前景较好.     

染料敏化纳米晶MgO/TiO2薄膜太阳能电池

染料敏化TiO2薄膜太阳能电池被认为是硅基太阳能电池的潜在替代产品,但其光电转化效率较低.为了提高光电转化效率,采用物理吸附的方法,利用宽禁带半导体MgO对TiO2光阳极进行表面修饰.研究表明:大部分MgO进入到TiO2的表面结构中,复合薄膜形成的表面势垒改变了TiO2的禁带结构,有效的抑制了电池内部复合反应的进行,使电池的光电转化效率提高.MgO与TiO2之间的界面效应,增加了光在薄膜内的传输路径,使电池吸光度、染料吸附量增加.其中光电转化效率同未经修饰的染料敏化TiO2薄膜太阳能电池相比,提高了24.5%.     

新的相互正交二元零相关区序列集构造法

提出了一种基于任意相同阶的Hadamard矩阵,交织递归构造相互正交二元零相关区序列集的新方法,构造的序列集能达到二元零相关区序列集的理论界.利用参数矩阵对Hadamard序列进行加权,经交织递归构造出零相关区序列集,集合内序列数量是Hadamard矩阵阶数的2倍,且序列集间满足相互正交关系.构造结果表明,参数矩阵取值的多样性可提高相互正交零相关区序列集的数量,能获得大量新的相互正交二元零相关区序列集,为准同步码分多址系统提供更多便于硬件实施的二元地址码集.