最大最小蚁群算法在实际GSM系统中频率规划的应用

探讨了应用最大最小蚁群算法（MMAS）来解决移动通讯系统（GSM）的频率规划问题。基于MMAS提出了一个可方便地控制算法的探索和开发能力并使之平衡的参数。实验结果表明,通过优化该参数,显著提高了算法的性能。     

Windows堆保护机制及绕过的可能性分析

Windows堆管理器是一个用于动态分配内存的子系统。堆溢出是指在动态分配堆内存过程中堆块块首中的前向指针和后向指针被上一堆块中的溢出数据修改,这样在被溢出堆块被分配时可转去执行恶意代码。微软针对这种堆溢出提出了一系列安全机制,先简要叙述这一系列安全机制的工作原理,然后分析了这些安全机制存在的弱点,并对利用这些弱点绕过安全机制的可能性做了简要的分析。     

Groundwater Exploitation and Its Impact on the Environment in the North China Plain

Abstract

The North China Plain (NCP) is one of China's most important social, economic, and agricultural regions. Currently, the Plain has 17,950 thousand ha of cultivated land, 71.1 percent of which is irrigated, consuming more than 70 percent of the total water supply. Increasing water demands associated with rapid urban and industrial development and expansion of irrigated land have led to overexploitation of both surface and the ratio of groundwater resources, particularly north of the Yellow River. In 1993, the ratio of groundwater exploitation to recharge in many parts of the NCP exceeded 1.0; in some areas, the ratio exceeded 1.5. Consequently, about 1.06 million ha of water-short irrigated areas in the NCP also have poor water quality. Persistent groundwater overexploitation in the northern parts of the NCP has resulted in water-level declines in both shallow and deep aquifers. According to data from 600 shallow groundwater observation wells in the Hebei Plain, the average depth to water increased from 7.23 m in 1983 to 11.52 m in 1993, indicating an average water-table decline of 0.425 m/year. Water table declines are not uniformly distributed throughout the area. Depletion rates are generally greatest beneath cities and intensively groundwater-irrigated areas. Water-table declines have also varied over time. With the continued decline of groundwater levels, large depression cones have formed both in unconfined and confined aquifers beneath the Hebei Plain. Groundwater depletion in the NCP has severely impacted the environment. Large tracts of land that overlie cones of depression have subsided, seawater has intruded into previously freshwater aquifers in coastal plains, and ground-water quality has deteriorated due to salinization, seawater intrusion, and untreated urban and industrial wastewater discharge. In order to balance groundwater exploitation with recharge, the major remedial measures suggested are to strengthen groundwater management, to raise water use efficiency, to adjust the water-consumed structure, and to increase water supply     

石油开发中污水的环境危害

石油开发所带来的污水给自然环境和人类健康可能造成很大危害。本文就石油开发中水污染的污染,污染物对环境危害的生物毒性检测及污染物对环境的危害进行了综述。     

Feeling duped: Emotional, motivational, and cognitive aspects of being exploited by others.

Feeling duped is an aversive emotional response to the perception of having been taken advantage of in a interpersonal transaction (primarily those involving economic exchange), partly as a result of one's own decisions. The actual likelihood of being duped, as well as the heightened vigilance for it, should increase as a function of opportunity (e.g., information asymmetry that gives one side a big advantage in knowledge) and motivation (e.g., an exceptionally huge payoff may make it worth defrauding a long-term business partner). Being duped produces an aversive self-conscious emotion with a threat of self-blame. There appears to be stable individual differences in the motivation (called sugrophobia) to avoid being a sucker. High sugrophobes will be vigilant and skeptical of potential deals. Low sugrophobes may not even realize in some instances that they were duped. The aversive reaction to feeling duped stimulates counterfactual ruminations that may intensify sugrophobia but also aids in extracting useful lessons. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

三江平原地下水循环演化特征

对三江平原20世纪50—60年代、70—80年代和90年代至今的地下水资源量进行了调查对比,结果表明:低山丘陵区和平原区主要接受大气降水的补给,平原区还接受丘陵区的地下水侧向流补给及河水补给,排泄在早期以蒸发为主,后期以人工开采为主;三江平原地下水循环演化是从20世纪70—80年代开始发生负均衡变化的,而在农业经济发展的90年代负均衡更加显著,形成了一些地下水超采区。     

二进制翻译中解析多目标分支语句的图匹配方法

二进制翻译技术现已成为实现软件移植的重要手段.在二进制翻译系统中,如何有效地挖掘程序的代码并对其进行高效翻译是影响系统性能的关键,而二进制代码中间接跳转语句的存在,使得静态时难以得到它的跳转目标,影响了代码的发掘率和最终的翻译效果.在通常的应用程序中,间接跳转指令经常用来实现多目标分支语义,分支目标存放在跳转表中.提出了一种解析多目标分支语句及其跳转表的方法,能够挖掘出间接跳转的目标,进而对其进行有效翻译并提高二进制翻译系统的性能.该方法提出使用语义图来对预期语义进行刻画和表达.语义图能够对考察的指令序列进行语义提取,识别出与预期语义相匹配的指令流,还可以应对编译器在不同优化选项下生成的指令,并能有效滤除不相关指令带来的干扰.实验结果表明,对于SPEC CINT2000中的部分测试用例,代码翻译的覆盖率可以提高9.85%～22.13%,相应带来的性能提升可达到8.30%～17.71%,而使用的算法时间复杂度仅为O(1).     

闵28块E1f3滚动开发实践认识

闵桥地区E1f3构造复杂,断层发育,T31反射层不明显,滚动开发难度大.从闵28块油藏开发疑点入手,经过反复的地质构造再认识,使区域油藏规模扩大.认为老油田滚动开发需要反复认识,提出了开发中存在的疑点即为滚动开发的潜力的观点.     

神经优化计算模型求解油田开发中的优化问题

阐述了线性优化计算和非线性优化计算的神经网络模型，该模型可以在电路时间常数数量级(几百纳秒)内求解复杂的优化问题，且能克服一般数学理论求解优化问题的缺点。之后对油田开发中使用典型曲线自动拟合产量衰减曲线进行了分析，并讨论了油田开发规划模型的建立与求解，并论证这些优化问题可以由神经优化计算模型来实现。     

历史街区的保护与开发模式研究——以景德镇三闾庙历史街区保护开发规划为例

以联合国教科文组织关于历史城镇及城市地区保护的《ICOMOS宪章》为出发点,分析总结出历史街区价值的衡量标准和保护原则;将体验经济的原理与历史街区的价值分析相结合,提出历史街区旅游开发主题的确定方法和功能分布的组织原则;最后结合景德镇三闾庙历史街区保护开发规划实例进行详细说明,从而为历史街区的开发提供依据.