A novel method of determining reservoir characteristic curves based on high-resolution resource satellite data was proposed in this paper, using remote sensing processing and analysis technology. According to the physical characteristics of absorption, radiation and reflection of surface water on ultraviolet, visible, near-infrared bands, etc., the satellite images at different reservoir water level and different periods were processed to analyze the relationship of measured water level corresponding to the water area. Based on the relationship, the relevance among reservoir water level, water surface area, and reservoir capacity was established, so as to determine the reservoir characteristic curve. The method was applied and validated at Jinshuitan Reservoir and Shitang Reservoir in the Ou River Basin. The results show that this method has high accuracy, and the maximum relative error between calculating values and measured values at different water level are −2.33% and −2.11% in Jinshuitan Reservoir and Shitang Reservoir, respectively. The method improves the convenience of determining the reservoir characteristic curve greatly, and the storage capacity of the reservoir can be calculated rapidly by this method.

In this paper, the resource allocation problem for device-to-device (D2D) communications underlaying cellular networks is formulated and analyzed. In our scenario, we consider that the number of D2D user equipment (DUE) pairs is far larger than that of cellular user equipments (CUEs). Meanwhile, the resource blocks are divided into two types: resource blocks for CUEs and the ones for CUEs and DUEs. Firstly, the system model is presented, and the resource allocation problem is formulated. en, a resource allocation scheme based on the genetic algorithm is proposed. To overcome the problem that the dedicated resource is not fully shared in the genetic algorithm, an improved harmony search algorithm is proposed for resource allocation. Finally, the analysis and simulation results show that the performances of the proposed genetic algorithm and the improved harmony search algorithm outperform than that of the random algorithm and are very close to that of the exhaustive algorithm. is result can provide an effective optimization for resource allocation of D2D communications.

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The relationship between water resources and the social economy has become a restricting factor for the sustainable development of cities around the world. Based on the urban development demand and water resources condition of Linhai City in eastern China, which has the fastest economic growth and population boom, the system dynamics model of water resources carrying capacity was established to analyze the interaction between society, economy and water resources. According to the different development emphases, six different modes of water resource utilization were designed. Taking total population, GDP, industrial output value, tertiary industry output value, water consumption, water supply and sewage discharge as the measurement indexes, the research predicted the development status of water resources carrying capacity of Linhai City from 2015 to 2030 under different development modes. Through the simulation results, it is found that the water-saving measures can reduce the gap between water supply and demand only in a short term. In the long run, the adjustment of industrial structure can improve the water resources carrying capacity and simultaneously promote the economy. In addition, increasing the water income sources as well as strengthening sewage treatment are also necessary to balance the water supply and demand.

Abstract.A tooth of the input helical gear of an intermediate gearbox in a helicopter fractured during testing. In order to find out the failure mode and cause, macro and micro observation, hardness and carburized depth testing, microstructure examination, surface roughness and round angle testing were carried out. The results show that the failure mode of the gear is fatigue failure . The crack initiated from the round angle of the tooth root at the working-face side. The round angle radius is smaller than the requried value, leading to the increase of stress concentration, which is the main cause for the fatigue fracture of the tooth. The machining process of the round angles should be concisely controlled so that such failure can be avoided.

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Device to device (D2D) multi-hop communication in multicast networks solves the contradiction between high speed requirements and limited bandwidth in regional data sharing communication services. However, most networking models demand a large control overhead in eNodeB. Moreover, the topology should be calculated again due to the mobility of terminals, which causes the long delay. In this work, we model multicast network construction in D2D communication through a fuzzy mathematics and game theory based algorithm. In resource allocation, we assume that user equipment (UE) can detect the available frequency and the fuzzy mathematics is introduced to describe an uncertain relationship between the resource and UE distributedly, which diminishes the time delay. For forming structure, a distributed myopic best response dynamics formation algorithm derived from a novel concept from the coalitional game theory is proposed, in which every UE can self-organize into stable structure without the control from eNodeB to improve its utilities in terms of rate and bit error rate (BER) while accounting for a link maintenance cost, and adapt this topology to environmental changes such as mobility while converging to a Nash equilibrium fast. Simulation results show that the proposed architecture converges to a tree network quickly and presents significant gains in terms of average rate utility reaching up to 50% compared to the star topology where all of the UE is directly connected to eNodeB.