Hierarchical multi-reservoir optimization modeling for real-world complexity with application to the Three Gorges system

High dimensionality in real-world multi-reservoir systems greatly hinders the application and popularity of evolutionary algorithms, especially for systems with heterogeneous units. An efficient hierarchical optimization framework is presented for search space reduction, determining the best water distributions, not only between cascade reservoirs, but also among different types of hydropower units. The framework is applied to the Three Gorges Project (TGP) system and the results demonstrate that the difficulties of multi-reservoir optimization caused by high dimensionality can be effectively solved by the proposed hierarchical method. For the day studied, power output could be increased by 6.79 GWh using an optimal decision with the same amount of water actually used; while the same amount of power could be generated with 2.59 × 10⁷ m³ less water compared to the historical policy. The methodology proposed is general in that it can be used for other reservoir systems and other types of heterogeneous unit generators.     

Improving the multi-objective evolutionary optimization algorithm for hydropower reservoir operations in the California Oroville–Thermalito complex

This study demonstrates the application of an improved Evolutionary optimization Algorithm (EA), titled Multi-Objective Complex Evolution Global Optimization Method with Principal Component Analysis and Crowding Distance Operator (MOSPD), for the hydropower reservoir operation of the Oroville–Thermalito Complex (OTC) – a crucial head-water resource for the California State Water Project (SWP). In the OTC's water-hydropower joint management study, the nonlinearity of hydropower generation and the reservoir's water elevation–storage relationship are explicitly formulated by polynomial function in order to closely match realistic situations and reduce linearization approximation errors. Comparison among different curve-fitting methods is conducted to understand the impact of the simplification of reservoir topography. In the optimization algorithm development, techniques of crowding distance and principal component analysis are implemented to improve the diversity and convergence of the optimal solutions towards and along the Pareto optimal set in the objective space. A comparative evaluation among the new algorithm MOSPD, the original Multi-Objective Complex Evolution Global Optimization Method (MOCOM), the Multi-Objective Differential Evolution method (MODE), the Multi-Objective Genetic Algorithm (MOGA), the Multi-Objective Simulated Annealing approach (MOSA), and the Multi-Objective Particle Swarm Optimization scheme (MOPSO) is conducted using the benchmark functions. The results show that best the MOSPD algorithm demonstrated the best and most consistent performance when compared with other algorithms on the test problems. The newly developed algorithm (MOSPD) is further applied to the OTC reservoir releasing problem during the snow melting season in 1998 (wet year), 2000 (normal year) and 2001 (dry year), in which the more spreading and converged non-dominated solutions of MOSPD provide decision makers with better operational alternatives for effectively and efficiently managing the OTC reservoirs in response to the different climates, especially drought, which has become more and more severe and frequent in California.     

繁峙县孤山水库帷幕灌浆工程施工

文中叙述了繁峙孤山水库险加固工程帷幕灌浆的施工方案选择、施工过程及工程的质量检查。     

三峡水库减淤增容调度方式研究——多汛限水位调度方案

本文建议在汛期中小流量时（Q<35000m3/s），将坝前水位维持在148～151m；出现汛情且流量更较大后，将坝前水位降低到143m；入库流量大于35000m3/s且短期预报将出现大于十年一遇洪水时，预泄洪水到135m.按这一调度，汛期约80％时间可以维持在较高水位，一般洪水期。汛限水位143m不影响坝区通航，135m水位迎洪可大量增加防洪库客。到100年后可减淤30亿m3，增加防洪库容约40亿m3.变动回水区减淤40%，优化了坝区水沙搭配，可改善通航条件。降低库区洪水位，缓解防洪与移民的矛盾。可对发电带来较大好处：提高发电效益，减少粗沙过机。初期水库排沙比大于原方案，可减轻下游冲刷。同时，可减小三峡汛初泄水与鄱阳湖防洪的矛盾。     

中子寿命测井在评价管外窜槽中的应用

管外窜槽已成为制约中原油田注水开发的障碍，并造成了严重的经济损失。文中分析了管外窜槽的形成机理，重点介绍了注硼中子寿命测井技术用于管外窜槽监测的原理、工艺及解释方法。结合中原油田的应用实例，论证了中子寿命测井评价管外窜槽的有效性，为油藏动态监测提供了有效手段。     

大型水轮发电机组励磁变压器参数及绝缘方式的选择--由三峡机组励磁系统投运引起的思考

结合三峡机组励磁系统的调试及投运经验,对大型水电机组静止自励系统选型中存在的一些关键性技术课题进行分析与论证,期望得出的结论有助于在大型水轮发电机组励磁系统参数选择和在提高机组运行安全、可靠性方面提供有益的借鉴。文中提出的励磁系统设计新理念仅代表个人的观点。     

三维地质模型在濮城油田的应用

以濮城油田东区沙二下油藏为研究对象，在储层流动单元细分、微构造、沉积微相、测井曲线二次处理、储层非均质研究、储层动态解释等研究基础上，以数据库为支撑，应用三维可视化技术，建立了研究区油藏三维可视化地质模型。其成果应用于油藏的调整井位设计，并且实现了油藏精细描述—油藏精细数值模拟一体化，效果良好。     

PERFORMANCE OF THREE STAGE TURBO－EQUALIZATION－DECODING

An increasing demand for high data rate transmission and protection over bandlimited channels with severe inter-symbol interference has resulted in a flurry of activity to improve channel equalization. In conjunction with equalization, channel coding-decoding can be employed to improve system performance. In this letter, the performance of the three stageturbo-equalization-decoding employing log maximum a posteriori probability is experimentally evaluated by a fading simulator. The BER is evaluated using various information sequence and interleaver sizes taking into account that the communication medium is a noisy inter symbol interference channel.     

常门铺水库溢洪道设计方案比较

在常门铺水库溢洪道改造中，通过不工模型试验，对其数据成果进行分析并进行方案比较，最终采用即经济又合理的方案二，为国家节省投资50.8万元。