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991.
The continuously growing number of applications competing for resources in current communication networks highlights the necessity for efficient resource allocation mechanisms to maximize user satisfaction. Optimization Theory can provide the necessary tools to develop such mechanisms that will allocate network resources optimally and fairly among users. The aim of this paper is to provide a starting point for researchers interested in applying optimization techniques in the resource allocation problem for current communication networks. To achieve that we, first, describe the fundamental optimization theory tools necessary to design optimal resource allocation algorithms. Then, we describe the Network Utility Maximization (NUM) framework, a framework that has already found numerous applications in network optimization, along with some recent advancements of the initial NUM framework. Finally, we summarize some of our recent work in the area and discuss some of the remaining research challenges towards the development of a complete optimization-based resource allocation protocol. 相似文献
992.
The thread whirling is an efficient and precise machining process for manufacturing of screws. The shaping motion of whirling is complex and difficult to model. In this paper, a novel model basing on equivalent cutting volume is proposed. The cutting force and the chip morphology are investigated to validate the model. The simulation of cutting force is in good agreement with the experimental results with error less than 16.5%. A chip with saw-toothed edges is obtained from simulation and for experimental verification. A case study on the effect of the tool edge geometry on cutting forces is also presented. The simulation results show that the tool edge geometry greatly influences the cutting forces. The tool with round edge is a good choice for reducing the cutting forces. The ratio of ac/Re holds the balance in selecting the parameter of cutting conditions. The model is applicable for the simulation of whirling process and can be used for parameter optimisation of the cutting tool edge. 相似文献
993.
994.
It is desirable to minimize burr formation for improving part quality. This paper presents an investigation on the burr formation mechanism in micro cutting by taking into consideration the stress distribution around the cutting edge arc. The influences of the uncut chip thickness and the cutting edge radius on burr formation were investigated. Poisson burr is attributed to the side flow of the stagnation material at the bottom of the cutting edge arc. The stress distribution at the cutting edge arc has great influence on Poisson burr formation. The burr height decreases to the minimum value and then increases with reducing the uncut chip thickness due to the change of the maximum stress distribution. An optimum machining strategy also is suggested in micro milling of snake-shaped groove microstructure. 相似文献
995.
The Grover's a1gorithm was used for fau1t attack against the pub1ic key cryptography.A fixed phase rotation based Grover's a1gorithm was proposed,and the probabi1ity of success achieved 99.23% with 0.1π phase rotation.Combined with the fau1t attack further,ECC(e11iptic curve cryptography)vo1tage burr attack a1gorithm based on Grover a1gorithm with 0.1π phase rotation was proposed.Then a safety Kob1itz curve,K-163,pub1ished successfu11y attacked by NIST on binary domain in simu1ation and the success rate was 100%.The comp1exity of the attack great1y reduces on the exponentia1.It was a new effective way,except the Shor's a1gorithm,to attack pub1ic key cryptography by quantum computing,and it contributed to extend the attack ways to the other pub1ic key cryptography. 相似文献
996.
Physical inactivity has gained a wide attention due to its negative influence on human wellness. Physical activity advisory systems consider a promising solution for this phenomenon. In this paper, we propose a mobile cloud-based physical activity advisory system utilizing biofeedback sensors and environmental context data based on calories expenditure from performing various activities by tracking user’s physical movements. To evaluate the proposed system, we conducted in total a three-month experiment on six users. For each user, we tracked the amount of burnt calories from the physical movements for a two-week period. During the first week, the system did not send any advice, while during the second week, the system was advising the user on activities to perform. The compared results of the two weeks collected data (without and with advice) reflect the positive effect of the proposed system on participants’ physical activity level. The system motivates them to reach or exceed the recommended number of calories to be burned daily. 相似文献
997.
为了提高油层的动用程度,实现油层的精细划分,研究出一种采出井6段以上细分层产量控制工艺。通过油管和套管之间的环形空间下入电控式测调仪,与井下可调式分层配产器进行对接,依据监测数据对高产液层段状态进行直观分析判断,实现一次下井完成各层段产液量的合理控制,使各层段均保持合理流压,充分发挥产油潜力。通过配套细分工艺的研究,满足了采出井6段以上的细分控制,达到了剩余油深度挖潜的目的。 相似文献
998.
以岢临高速公路施工工程为例,介绍了滑模施工设备在岢临高速公路路缘石施工中的全过程、注意事项及控制措施,并与预制安装法进行了成本对比,指出滑模施工路缘石法施工效率高、经济效益好,值得推广应用。 相似文献
999.
《Expert systems with applications》2014,41(5):2300-2308
A novel Italian Sign Language MultiWordNet (LMWN), which integrates the MultiWordNet (MWN) lexical database with the Italian Sign Language (LIS), is presented in this paper. The approach relies on LIS lexical resources which support and help to search for Italian lemmas in the database and display corresponding LIS signs. The lexical frequency analysis of the lexicon and some newly created signs approved by expert LIS signers are also discussed. The larger MWN database helps to enrich the variety and comprehensiveness of the lexicon. We also describe the approach which links the Italian lemmas and LIS signs to extract and display bilingual information from the collected lexicon and the semantic relationships of LIS Signs with MWN. The users can view the meanings of almost one fourth of the lemmas of MWN in LIS. 相似文献
1000.
通过对华阴市近年来水资源使用量资料及农田水利现状的分析,探讨了农田水利建设的发展方向,指出只有实行高效节水灌溉措施,才能节约有限的水资源,达到实行最严格水资源管理制度和实现农田水利项目建设节水效益最大化的和谐统一。 相似文献