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111.
基于智能工程的思想,提出了一种并行分层结构的集成化智能CAD系统,并在钟表CAD中得到成功应用,同时还首次将布局理论应用到钟表机芯设计中。 相似文献
112.
TAP6是一个能求解稳态或非稳热传导的程序系统,可解热传导,对流换热,热辐射,热源等问题,又可作为SAP6程序的前处理热分析程序,给出结构温度场供SAP6进行热应力计算。 相似文献
113.
基于网络数据管理的研究与设计 总被引:1,自引:0,他引:1
基于网络的数据管理是网络存储领域中的关键性前沿技术,在讨论网络数据管理的体系结构、信息流和其工作机制的基础上,分析了目前网络数据管理协议的不足,由此提出了myNDMP原型.对该原型的设计原理及其实现机制进行了阐述.研究结果表明,该原型提高了网络数据管理的可扩展性. 相似文献
114.
115.
Zhicong Zhang Li Zheng Michael X. Weng 《The International Journal of Advanced Manufacturing Technology》2007,34(9-10):968-980
In this paper, we discuss a dynamic unrelated parallel machine scheduling problem with sequence-dependant setup times and machine–job qualification consideration. To apply the Q-Learning algorithm, we convert the scheduling problem into reinforcement learning problems by constructing a semi-Markov decision process (SMDP), including the definition of state representation, actions and the reward function. We use five heuristics, WSPT, WMDD, WCOVERT, RATCS and LFJ-WCOVERT, as actions and prove the equivalence of the reward function and the scheduling objective: minimisation of mean weighted tardiness. We carry out computational experiments to examine the performance of the Q-Learning algorithm and the heuristics. Experiment results show that Q-Learning always outperforms all heuristics remarkably. Averaged over all test problems, the Q-Learning algorithm achieved performance improvements over WSPT, WMDD, WCOVERT, RATCS and LFJ-WCOVERT by considerable amounts of 61.38%, 60.82%, 56.23%, 57.48% and 66.22%, respectively. 相似文献
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117.
Abstract This paper investigates the characteristics of acoustic emission (AE) signals generated from hydrogen induced cracking (HIC) and sulfide stress corrosion cracking (SSCC) for a medium strength steel in hydrogen sulfide (H2S) solution. The experiments performed in this study include the constant load test (CLT) and the constant extension rate test (CERT). From the results of the CLT, the AE count rate caused by SSCC was found to be much higher than that resulted from the HIC; and the increase of the AE count rate was observed to be approximately proportional to the increase of the applied loading. In addition, the AE frequency distribution diagrams obtained from these tests were found to contain potential information for distinguishing the mechanisms of HIC and SSCC. From the results of CERT, the AE signals detected from the specimens tested in the H2S solution were compared with those obtained from the specimens tested in the air. In addition, the AE count rate detected from the tensile specimens was studied according to the different deformation stages of the specimens. From this study, the variation of the AE count rate in each deformation stage was described. 相似文献
118.
In Crypto 1992, Chaum and Pedersen introduced a protocol (CP protocol for short) for proving the equality of two discrete logarithms (EQDL) with unconditional soundness, which is widely used nowadays and plays a central role in DL-based cryptography. Somewhat surprisingly, the CP protocol has never been improved for nearly two decades since its advent. We note that the CP protocol is usually used as a non-interactive proof by using the Fiat-Shamir heuristic, which inevitably relies on the random oracle model (ROM) and assumes that the adversary is computationally bounded. In this paper, we present an EQDL protocol in the ROM which saves approximately 40% of the computational cost and approximately 33% of the prover??s outgoing message size when instantiated with the same security parameter. The catch is that our security guarantee only holds for computationally bounded adversaries. Our idea can be naturally extended for simultaneously showing the equality of n discrete logarithms with O(1)-size commitment, in contrast to the n-element adaption of the CP protocol which requires O(n)-size. This improvement benefits a variety of interesting cryptosystems, ranging from signatures and anonymous credential systems, to verifiable secret sharing and threshold cryptosystems. As an example, we present a signature scheme that only takes one (offline) exponentiation to sign, without utilizing pairing, relying on the standard decisional Diffie-Hellman assumption. 相似文献
119.
Ning Sun Yong Jiang XiaoXiang Weng JianMing Gong 《Journal of Failure Analysis and Prevention》2017,17(5):882-889
The mechanical properties and microstructure evolution of P92 steel were investigated after aging up to 11,000 h at 923 K. Charpy impact and tensile tests were carried out to study the strength and ductility of aged P92 steel. In addition, microstructure evolution of the samples during long-term aging was investigated with X-ray diffraction, optical microscopy and scanning electron microscope (SEM). Then, statistical quantitative image analysis based on SEM images was used to evaluate the precipitation during long-term aging. The mechanical properties were found to be associated with the evolution of precipitation, especially the coarsening of Laves-phase. Results show that the ductility and strength of P92 steel decrease with the growth of Laves-phase during short-term aging (shorter than 1000 h). However, as the aging time further increasing, the ductility and strength of P92 steel decrease slowly with the coarsening of Laves-phase. 相似文献
120.
Yinxiang Wang Muhammad Zaki Memon Majid Ali Seelro Weng Fu Yuan Gao Yingchao Dong Guozhao Ji 《International Journal of Hydrogen Energy》2021,46(45):23358-23379
Sorption-enhanced-steam-reforming (SESR) is a thermochemical conversion technology that produces a high-purity hydrogen stream by utilizing in-situ removal of CO2 with a sorbent. In this paper, the advantages and disadvantages of CaO based sorbents, alkali-metal based sorbents (Na2ZrO3, Li2ZrO3 and Li4SiO4), hydrotalcite based sorbents, bifunctional materials and sorbents prepared from wastes are briefly discussed, and the techniques to improve the sorption properties of these CO2 sorbents are summarized. In the process of hydrogen production by sorption-enhanced-steam-reforming, the selection of suitable high-temperature CO2 sorbent is the key to produce high purity hydrogen. Furthermore, the hydrogen-production performance of the above-mentioned sorbents in the SESR process is investigated and summarized. Finally, a future perspective and some suggestions regarding these five types of sorbents are put forward. 相似文献