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本文根据江西省赣州市中型灌区节水配套改造项目原则和要求,针对兴国县长龙灌区渠系及其建筑物目前存在的问题,分别提出了相应的整治措施,为确保灌区渠道输水安全,进一步提高灌区水的利用率和灌溉保证率,从设计方法上提供有益的经验. 相似文献
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动态联盟企业中面向复杂零件的工艺分工规划问题是网络化制造中的一个关键问题。针对该问题,提出了逻辑制造单元的概念,通过它在工艺分工规划和制造资源之间建立联系,研究了基于逻辑制造单元的制造资源能力建模、逻辑加工路线设计,以及面向逻辑加工路线的制造资源优化配置。最后面向复杂零件的制造,进行了基于制造资源优化配置的工艺分工规划系统体系结构设计,并给出了工作流程。 相似文献
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For partial discharge, PD, allocating utilizing acoustic emission, AE, sensors, the arrival time of acoustic waves to the sensors forms the calculation basics, therefore, it is crucial that distance calculations are based on direct acoustic path. Considering structure-borne waves of higher speed, this would imply an incorrect distance between the source and sensor, because, AE signals of indirect path me be considered as AE signals of direct path. Therefore, a heuristic algorithm has been developed to consider the possible indirect paths. By comparing the time taken in each path of propagation, to reach the specified sensor location, the indirect path of shortest time for AE signal is determined. For experimental verification, a test oil chamber has been fabricated. PD signals are generated at different points inside the tank. The estimation results of algorithm have been compared with results of classic Time Difference of Arrivals method, TDOA. The proposed method considerably increases the PD allocation precision. 相似文献
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One of the important features of database fragmentation and allocation techniques is the fact that they depend not only on the entries of a database relation, but also on their empirical frequencies of use. Distributed processing is an effective way to improve performance of database systems. However, for a Distributed Database System (DDBS) to function efficiently, fragments of the database need to be allocated carefully at various sites across the relevant communications network. Therefore, fragmentation and proper allocation of fragments across network sites is considered as a key research area in distributed database environment. However, fragments allocation to the most appropriate sites is not an easy task to perform. This paper proposes a synchronized horizontal fragmentation, replication and allocation model that adopts a new approach to horizontally fragment a database relation based on attribute retrieval and update frequency to find an optimal solution for the allocation problem. A heuristic technique to satisfy horizontal fragmentation and allocation using a cost model to minimize the total cost of distribution is developed. Experimental results are consistent with the hypothesis and confirm that the proposed model can efficiently solve dynamic fragmentation and allocation problem in a distributed relational database environment. 相似文献
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结合常州市主城区发展实际,选取了常州市主城边缘区3个在20世纪80年代末至2010年代期间经历了快速城镇化进程的典型区块作为案例,分析常州市主城边缘区快速发展期间建设用地规模、结构、空间布局演变的特征,总结得出3种不同的建设用地配置模式并讨论利弊。作为结论,提出3点建议:转变发展方式,减少经济发展对土地的依赖;完善市场配置为主体、行政干预为补充的土地配置机制;快速城镇化地区城乡规划工作的重点应是适度超前的引导发展。 相似文献
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This paper models the allocation of energy inputs in the US petroleum and coal products industry by allocating combustible fuel and renewable energy inputs among generic end-uses, including intermediate conversions through onsite power and steam generation. This analysis, called an energy end-use model, showed that 72% of the fuel input in the US petroleum and coal products industry goes to onsite steam and power generation, whereas 28% goes directly to end-uses. Eight percent of the boiler output is used for power generation, 72% goes directly to end-uses, and 20% is waste heat. Among the end-uses, process heating is the biggest energy user with a total energy consumption of 2338 PJ, whereas machine drive is the biggest electricity consumer with a consumption of 168 PJ. This paper also provides estimates of the uncertainty of the data. The approach to create this model is applicable to all other industries for which data is available and the model is consistent with US Department of Energy data for 1998. When used in conjunction with similar models for other years, it can be used to identify the changes and trends in energy utilization even at the prime mover level of detail. 相似文献
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The problem of "rich topics get richer"(RTGR) is popular to the topic models,which will bring the wrong topic distribution if the distributing process has not been intervened.In standard LDA(Latent Dirichlet Allocation) model,each word in all the documents has the same statistical ability.In fact,the words have different impact towards different topics.Under the guidance of this thought,we extend ILDA(Infinite LDA) by considering the bias role of words to divide the topics.We propose a self-adaptive topic model to overcome the RTGR problem specifically.The model proposed in this paper is adapted to three questions:(1) the topic number is changeable with the collection of the documents,which is suitable for the dynamic data;(2) the words have discriminating attributes to topic distribution;(3) a selfadaptive method is used to realize the automatic re-sampling.To verify our model,we design a topic evolution analysis system which can realize the following functions:the topic classification in each cycle,the topic correlation in the adjacent cycles and the strength calculation of the sub topics in the order.The experiment both on NIPS corpus and our self-built news collections showed that the system could meet the given demand,the result was feasible. 相似文献
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