oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 322 )

2018 ( 7237 )

2017 ( 7475 )

2016 ( 7936 )

Custom range...

Search Results: 1 - 10 of 314279 matches for " 王欢博 "
All listed articles are free for downloading (OA Articles)
Page 1 /314279
Display every page Item
uml类图层次化自动布图算法
,,刘超?
软件学报 , 2009,
Abstract: uml类图能够有效地帮助软件工程师理解大规模的软件系统,而优化图元的空间布局可以增强类图的可读性和可理解性.由于类图中继承关系具有明显的层次特性,因此类图自动布局大多采用层次化的布图算法.此外,类图布局需要考虑相关的领域知识以及绘制准则,因而通用嵌套有向图层次化布局算法不能直接用于类图的绘制,它们必须加以扩展.但是,已有的类图层次化方法并没有考虑类图中图元的嵌套关系,这将导致自动布局方法不能处理类图中包与类、接口之间的包含关系.在考虑图绘制美学、uml类图绘制以及软件可视化等相关知识的基础上,选取了一组布
无电极型工频电场传感器的设计
牛犇,曾嵘,,
中国电机工程学报 , 2008,
Abstract: 分析了电力系统中工频电场测量的技术手段和应用现状,指出现有手段的存在的问题;利用集成光学技术研制了一种基于铌酸锂晶片铁电畴反转的无电极电场传感器,该传感器内部没有金属部分,具有集成度高、对被测电场影响较小等优点;分析了传感器的设计要点,针对电力设备工频电场测试的实际需求完成传感器的参数设计,并研究相关的工艺流程;针对传感器半波电场太大的特点设计了合适的方案测试传感器的特性;根据国标GB/T12720-1991建立工频电场测试系统,并利用该系统完成传感器的工频电场标定测量实验。实验结果表明,该传感器在较大测量范围内具有较好的线性度,适合于电力系统工频电场的测量。
聚苯硫醚(PPS)掺炭纤维协同飞灰脱除气态汞的实验研究
,刁永发,,
环境科学学报 , 2011,
Abstract: 利用汞蒸气发生器产生的单质汞和烟气中的一些主要气体成分模拟烟气条件,在固定床实验系统上分别进行了燃煤飞灰、聚苯硫醚(PPS)掺炭纤维及燃煤飞灰和PPS掺炭纤维联合对燃煤烟气中Hg0的脱除实验研究.结果表明:燃煤飞灰和PPS掺炭纤维对Hg0的吸附是物理吸附和化学吸附的共同结果,它们各自的脱汞效率分别可达27%和65%左右;PPS掺炭纤维和飞灰的联合脱汞效率并不是二者单独脱汞效率的代数叠加,它分别受到吸附反应温度、入口汞浓度和烟气停留时间等因素的影响;吸附反应温度越高,燃煤飞灰和PPS掺炭纤维对Hg0的联合脱除效率越低;入口汞浓度的增加并不一定会提高脱除效率;烟气停留时间越大,越有利于Hg0的脱除.
基于平滑控制策略的混合储能优化配置方法
,,胡晓通,况达
高压电器 , 2015, DOI: 10.13296/j.1001-1609.hva.2015.10.008
Abstract: 针对分布式电源的随机性引起的联络线波动,在微电网中加入混合储能装置可以有效平抑该波动,提高电能质量。采用蓄电池与超级电容器组合的混合储能装置,以二阶低通滤波方式确定混合储能装置输出功率,提出一种考虑超级电容器剩余容量的超前控制策略对该功率进行修正,在不影响蓄电池寿命的基础上增加了超级电容器的寿命,建立了混合储能容量配置考虑年最小成本的经济评价模型。仿真实例验证了该方法的有效性。
基于改进遗传算法的蓄电池容量配置及充放电策略研究
况 达, 滕 , , 黄炜果
高压电器 , 2015,
Abstract: 蓄电池作为储能装置,是确保微网稳定经济运行的重要组成部分,为了研究它对微网经济效益的影响,建立了基于微网经济性最优的蓄电池容量配置模型。针对某企业内热电联产型微网系统,构建了孤网和并网下以综合运行成本最低为目标函数的微网经济优化调度模型,在孤网下提出了一种定量分析方法配置蓄电池所需最小容量,通过模型求解确定实现微网总成本最低所需配置的蓄电池容量。在实时电价背景下,采用改进遗传算法优化各时刻蓄电池出力及向外网的购售电量,制定了蓄电池最优充放电策略,仿真结果验证了所提模型、策略的有效性和算法的适用性。
采用函数调用关系的注入型Android恶意应用检测
A Detection Method of Injected Android Malicious Applications Using Function Calling Graphs

,,李国栋,田达,
- , 2015, DOI: 10.7652/xjtuxb201510014
Abstract: 针对注入型Android恶意应用日益泛滥、传统检测方法依赖大量已知特征的问题,提出了采用函数调用关系的注入型Android恶意应用检测方法。该方法无须依赖大量已知特征,仅通过分析注入型Android恶意应用的自身结构特征即可实现对该类恶意应用的有效检测,并能够实现对未知恶意代码家族的识别。所提方法在smali代码的基础上构建函数调用关系图,并进一步进行子图划分,通过判定各子图威胁度确定是否存在恶意行为。检测过程无需动态行为分析辅助,因此分析检测时间短、效率高。该方法不仅可以检测出Android应用是否存在恶意行为,还可根据子图威胁度确定包含恶意行为的具体代码。经过对1 260个Android恶意应用和1 000个正常应用的实验分析发现:所提方法能够很好地检测注入型Android恶意应用,当误报率为8 90%的时候,检测率达到95 94%,相对于主流Android恶意应用检测系统Androguard,检测效果有显著提升。
The number of injected Android malicious applications is increasing, and the traditional detection method heavily relies on lots of extracted characteristics. A static analysis method based on function calling graph is proposed to detect injected Android malicious applications. The method can efficiently detect injected Android malicious applications only by analyzing the application’s structure, and there is no need for known characteristics. The method constructs a function calling graph based on decompiled smali code, and sub??graphs will be further processed to tell whether the Android application is malicious or not. The period of analysis is much shorter than that of any other dynamic detection method. The detection method not only detects whether the Android application is malicious or not, but also has the ability to tell which part of the Android application contains malicious code. The approach is tested on 1 260 Android malicious applications and 1 000 Android normal applications, and the test results show that the approach is effective in detecting injected Android malicious applications. The detection rate of the method for the injected Android malicious applications is 95??94% when the false positive rate is 8??90%. A comparison with the mainstream Android malware detection system Androguard shows that the detection performance of the proposed method has a remarkable promotion
Automatic Hierarchical Layout Algorithm for UML Class Diagram
UML类图层次化自动布图算法

WANG Xiao-Bo,WANG Huan,LIU Chao,
,,刘超

软件学报 , 2009,
Abstract: UML class diagrams are helpful for understanding complicated object-oriented software systems. The reasonable placement of diagram elements can make class diagrams more readable and understandable. As inheritance is regarded as a hierarchical relation, the hierarchical layout method is usually adopted to draw UML class diagrams. Because the domain specific knowledge and drawing criteria related to class diagrams must be considered in the layout of diagrams, general hierarchical layout algorithms for nested digraphs should be extended according to these criteria. But existing hierarchical layout algorithms for class diagrams cannot handle the nested relations among packages, classes, and interfaces, and existing compound layout methods for digraphs cannot be used directly to draw class diagrams. Layout criteria are selected based on the knowledge of graph drawing aesthetics, UML class diagram semantics and software visualization. In addition, the nested constraints in rank assignment, edge crossing, and coordinate assignment of hierarchical layout method were also analyzed in this paper. Then, existing hierarchical layout algorithm was extended to cope with nested graphs according to nested criteria. Experiment results show that the drawings of the reversed class diagrams are more readable and understandable with proper hierarchies, nested relations, less crossings and optimal drawing area.
Removal of mercury vapor by fly ash and C-doped polyphenylene sulfide (PPS) fiber
聚苯硫醚(PPS)掺炭纤维协同飞灰脱除气态汞的实验研究

CHEN Bo,DIAO Yongfa,SU Bo,WANG Huan,
,刁永发,,

环境科学学报 , 2011,
Abstract: The simulated flue gas which contains elemental mercury and flue gas as the major composition is made up by using the mercury vapor generator. This paper carries out the experiments about the removing from the flue gas in a laboratory-scale packed bed reactor system. The materials used in the paper are fly ash, PPS C-doped fibers and the combined effects of the two substances. The results find that the adsorption is the synergy of physical adsorption and chemical adsorption by using fly ash mixed with the PPS C-doped fibers. The mercury removal efficiency is 27% and 65% respectively. The mercury adsorption efficiency of the mixed C-doped PPS fiber with fly ash is not simply superposed the two components together. It is affected by the reaction temperature, concentration, and flue gas flow rate at the import of mercury and other factors. The higher adsorption temperature, the lower Hg0 removal efficiency of fly ash mixed with C-doped PPS fiber; increase the concentration of mercury at the entrance will not necessarily improve the removal efficiency; the greater flue gas flow rate, the less Hg0 removal efficiency.
芳烃抽提过程多目标优化
,廖祖维,靖岱,,阳永荣
化工学报 , 2012, DOI: 10.3969/j.issn.0438-1157.2012.03.025
Abstract: 芳烃抽提是芳烃生产过程的重要环节,其生产调优对提高整个芳烃联合装置的效益具有重要意义。基于流程模拟及响应面分析方法,得到了芳烃抽提过程的产品纯度模型及能耗模型。建立了以产品纯度最大化及过程能耗最小化的多目标优化模型。提出了一种改进的自适应加权求和算法,并用于多目标优化模型的求解。求解结果表明新算法在Pareto最优解分布的均匀性上与原算法相当,但求解效率要高于原算法。给出了不同产品等级下的最佳操作参数,采用优化后的操作参数可有效地提高产品纯度并降低过程能耗。提出的多目标优化模型及求解算法用于芳烃抽提过程的操作调优,可有效地提高决策的准确性。
北京冬季雾霾天气下颗粒物及其化学组分的粒径分布特征研究
常清,杨复沫,李兴华,曹阳,,田密
环境科学学报 , 2015,
Abstract: 为认识雾霾天气下颗粒物及其化学组分的粒径分布特征,利用13级低压撞击采样器采集北京城区冬季一次典型雾霾天气下的大气颗粒物,采用离子色谱和元素碳/有机碳分析仪分析了PM10中不同粒径的水溶性离子、元素碳和有机碳组分,获得了颗粒物及其化学成分的粒径分布特征.结果表明,不同天气下颗粒物质量浓度大小为:雾霾>多云>雪天>晴天,4种天气下PM2.5/PM10均大于74%,说明冬季污染主要是由细颗粒物污染引起.SO42-、NO3-、NH4+、Cl-、Ca2+是最主要的水溶性离子.SO42-、NO3-、NH4+在0.76μm出现单峰;Ca2+和Mg2+在0.31和5.13~8.09μm出现双峰,主要分布在粗模态;Cl-和K+在0.76和5.13μm出现双峰,主要分布在细粒径段.OC、EC也富集于细粒子,显单峰结构.随污染程度增加,二次无机离子及碳组分浓度均显著增加,SO2、NO2的表观转化率(SOR、NOR)以及OC/EC在灰霾期间都远远高于二级良,可见二次无机源及有机源是污染的主要来源.在空气流动性差的灰霾持续期,机动车尾气排放的EC等一次污染物贡献增加.分析NO3-/SO42-的粒径分布发现,机动车尾气对爱根核模态及凝结模态的亚微米模态(<1μm)贡献大于固定源,机动车尾气排放对大气污染的贡献已十分凸显.此外,燃煤污染的区域输送对污染的形成也有重要贡献,重污染期间土壤扬尘的贡献较小.
Page 1 /314279
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.