Interactive Evolutionary Multi-Objective Optimization Algorithm Using Cone Dominance

As the number of objectives increases, the performance of the Pareto dominance-based Evolutionary Multi-objective Optimization (EMO) algorithms such as NSGA-II, SPEA2 severely deteriorates due to the drastic increase in the Pareto-incomparable solutions. We propose a sorting method which classifies these incomparable solutions into several ordered classes by using the decision maker's (DM) preference information. This is accomplished by designing an interactive evolutionary algorithm and constructing convex cones. This method allows the DMs to drive the search process toward a preferred region of the Pareto optimal front. The performance of the proposed algorithm is assessed for two, three, and four-objective knapsack problems. The results demonstrate the algorithm's ability to converge to the most preferred point. The evaluation and comparison of the results indicate that the proposed approach gives better solutions than that of NSGA-II. In addition, the approach is more efficient compared to NSGA-II in terms of the number of generations required to reach the preferred point.     

接枝梳型高分子的SCF理论模拟

利用Scheutjens—Fleer自洽场（SF—SCF）理论,对表面接枝梳型高分子的体系进行模拟研究。模拟结果表明,柔性梳型高分子主链的链段密度分布仅与支链的总链段数有关,主链随支链链段数目的增加而伸展。当总链段数一定且主链长度相同时,线性高分子表现出较高的接枝率,比接枝的梳型高分子具有更大的分子伸展程度与更厚的接枝层。对于线性高分子的接枝层,提高链长比提高接枝率能得到更厚的接枝层。     

Influence of forming method of blending versus casting layer-by-layer on structural properties and packing performances of casein-gelatin composite edible film under different appending proportion

In order to obtain casein edible films with great packing performance, gelatin as the reinforcing additive with different ratios were loaded via two methods including layer- by- layer and blending. A comparative study on structure properties between double layers and blending films made from casein and gelatin was obtained by scanning electron microscopy and Fourier transform infrared spectroscopy. The difference between the films' packing characters were conducted by water vapor permeability (WVP), optical property, and mechanical properties (including tensile strength (TS) and elongation (EAB)). The results showed that the degree of films roughness increased and the structural stability decreased as the increase of gelatin additive ratio in both double layers and blending films. Thickness and WVP both displayed a trend of increasing first then decreasing at the dividing of gelatin instead of casein in 50%. Importantly, WVP values in double layers film with a largest value of 6.95 gm⁻¹Pa⁻¹s⁻¹ was higher than blending films, observably (P < 0.05). Additionally, TS in blending film was increased by 23.44% than double layers film under the gelatin additive proportion of 70%, and EAB value in double layers film was larger by 207.65% than blending film under the gelatin additive proportion of 10%.     

Thermoelectric properties of mechanically alloyed iron disilicides consolidated by various processes

Mn doped p-type iron disilicide powders have been produced by a mechanical alloying process. As-milled powders were of metastable state and mostly transformed to β-FeSi₂ phase by subsequent isothermal annealing. As-milled powders were consolidated by various processes such as sintering of the cold compact in vacuum, vacuum hot pressing (VHP), and spray drying/atmospheric plasma thermal spraying. Phase transitions during the processes were investigated using XRD, EDS, and SEM. As-consolidated specimens consisted of a mixture of α-Fe₂Si₅ and ε-FeSi phases, which were gradually transformed into a thermoelectric semiconducting α-FeSi₂ phase by subsequent isothermal annealing in the vicinity of 845°C in vacuum. However, some residual α and ε phases remained even after prolonged annealing. Thermoelectric properties were measured as a function of temperature and correlated with phase transformation. They showed optimum values in the vacuum hot pressed specimen due to a higher fraction of β phase and/or higher density.     

机械合金化制备金属间化合物MoSi2

以Si粉和Mo粉为原料采用机械合金化的方法制备了金属间化合物MoSi2.研究了球磨过程中球磨时间、球料比、转速及不同球磨机类型对机械合金化产物的影响.利用SEM观察粉末表面形貌及颗粒大小,利用XRD测定物相结构.研究结果表明,当球磨机提供的能量达到相变所需的能量时,粉末中有MoSi2相生成.通过XRD分析可以看出,随着球磨时间的延长,合金化程度逐渐提高;球磨转速的提高有助于生成MoSi2;较高的球料比可以使生成MoSi2的时间提前.在机械球磨过程中,粉末的颗粒尺寸经历了一个由较粗且不规则、不均匀粉末向细小、均匀、接近球形粉末,然后团聚增大的转化过程.此外,还研究了助磨剂对合金化产物的影响,结果表明助磨剂的加入并不能促进MoSi2的生成,但可以对颗粒的细化起到一定作用.     

A probabilistic alternative to regression suites

Automated regression suites are essential in developing large applications, while maintaining reasonable quality and timetables. The main argument against the automation of regression suites, in addition to the cost of creation and maintenance, is the observation that if you run the same test many times, it becomes increasingly less likely to find bugs. To alleviate such problems, a new regression suite practice, using random test generators to create regression suites on-the-fly, is becoming more common. In this practice, instead of maintaining tests, we generate test suites on-the-fly by choosing several specifications and generating a number of tests from each specification.     

基于Outlook的支持BASE91编码邮件的实现

目前广泛采用的编码方法是Base64,其编码效率达到75%,而由何大可教授提出的一种新编码方法:Base91将进一步减少数据扩展率,使编码效率增加到81.25%.推广Base91在实际中使用,便可大大节省网络带宽.通过监控Outlook2003的发送流程,反汇编其关键文件,查找到与编码有关的函数地址,通过替换目标编码函数地址为Base91编码地址从而达到应用Base91编码的目的,开发出一个具有Base91编码功能的Outlook2003插件包.     

A Survey of Service Discovery Protocols in Multihop Mobile Ad Hoc Networks

An in-depth review of service discovery protocols (SDPs) in multihop mobile ad hoc networks analyzes SDP building blocks and determines SDP suitability based on architecture, mobility, and network size. Mobile ad hoc networks (manets) include a variety of devices, such as cell phones, PDAs, laptops, and other relatively larger devices. These devices can move at high or low speeds or even remain stationary, entering and leaving the system when switched on or off. Such a variety of devices also offers a variety of services. A service is any tangible or intangible facility a device provides that can be useful for any other device. Services comprise those for software and hardware. A software service, for example, can be a simple file, such as an MP3 file, or a software implementation of an algorithm, such as converting one audio file format to another. A hardware service, for example, can be a printer that a mobile device can use wirelessly. To benefit from these services, a device must be able to both locate them in the network and invoke them. Service discovery protocols (SDPs) enable these capabilities.     

电生成Fenton试剂降解活性墨绿B的研究

用活性炭纤维复合铁丝制成电极,在阴阳两极的协同作用下,电生成Fenton试剂处理活性墨绿B模拟废水.研究不同温度时电解过程中活性墨绿B浓度的变化情况,做一级反应线性拟合,初步探索反应机理.证明电催化降解活性墨绿B的过程符合一级反应;反应速率常数随着温度的升高而增大,线性拟合后可以得到阿仑尼乌斯公式,计算出反应活化能为Ea=22.3 kJ·mol-1.比较废水处理的不同方法,发现阴阳两极协同作用的电Fenton法效果最好,色度去除率可以达到90%以上;紫外可见光谱研究发现,活性墨绿B的生色基团受到破坏,有小分子生成;可以确定处理废水是电解-吸附-气浮-絮凝的协同作用.