期刊：
Journal of Systems Architecture,2005年51(1):45-61 ISSN：1383-7621
通讯作者：
Wang, HY
作者机构：
[Li, GH; Wang, HY] Huazhong Univ Sci & Technol, Coll Comp Sci & Technol, Wuhan 430074, Hubei, Peoples R China.;[Wang, HY] Cent China Normal Univ, Dept Informat & Technol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wang, HY] C;Cent China Normal Univ, Dept Informat & Technol, Wuhan 430079, Hubei, Peoples R China.
关键词：
Mobile computing system;Concurrent checkpointing algorithm;Consistent global checkpoint
摘要：
In distributed computing systems, processes in different hosts take checkpoints to survive failures. For mobile computing systems, due to certain new characteristics such as mobility, low bandwidth, disconnection, low power consumption and limited memory, conventional distributed checkpointing schemes need to be reconsidered. In this paper, a novel min-process coordinated checkpointing algorithm that makes full use of the computation ability and power of mobile support stations is proposed. During normal computation message transmission, the checkpoint dependency information among mobile hosts is recorded in the corresponding mobile support stations. When a checkpointing procedure begins, the initiator concurrently informs relevant mobile hosts, which minimizes the identifying time. Moreover, compared with the existing coordinated checkpointing schemes, our algorithm blocks the minimum number of mobile support stations during the identifying procedure, which leads to the improvement of the system performance. In addition, the proposed algorithm is a min-process, domino-free checkpointing algorithm, which is especially desirable for mobile computing systems. Quantitative analysis and experimental simulation show that our algorithm outperforms other coordinated checkpointing schemes in terms of the identifying time and the number of blocked mobile support stations and then can provide a better system performance for mobile computing systems.
期刊：
Proceedings of SPIE - The International Society for Optical Engineering,2004年5283:122-128 ISSN：0277-786X
通讯作者：
Wu, YW
作者机构：
[Liu, ZH; Wu, YW; Zhou, GY] Cent China Normal Univ, Dept Informat & Technol, Wuhan, Peoples R China.
通讯机构：
[Wu, YW] C;Cent China Normal Univ, Dept Informat & Technol, Wuhan, Peoples R China.
关键词：
GSM;CDMA;network;optimization;contrast
摘要：
With the development of mobile telecommunication network, users of CDMA advanced their request of network service quality. While the operators also change their network management object from signal coverage to performance improvement. In that case, reasonably layout & optimization of mobile telecommunication network, reasonably configuration of network resource, improvement of the service quality, and increase the enterprise's core competition ability, all those have been concerned by the operator companies. This paper firstly looked into the flow of CDMA network optimization. Then it dissertated to some keystones in the CDMA network optimization, like PN code assignment, calculation of soft handover, etc. As GSM is also the similar cellular mobile telecommunication system like CDMA, so this paper also made a contrast research of CDMA and GSM network optimization in details, including the similarity and the different. In conclusion, network optimization is a long time job; it will run through the whole process of network construct. By the adjustment of network hardware (like BTS equipments, RF systems, etc.) and network software (like parameter optimized, configuration optimized, capacity optimized, etc.), network optimization work can improve the performance and service quality of the network.
摘要：
Besides minimizing the total cost of the system and the total time of delivery, the design of distribution system should also meet the capacity limit of the plants. After listing the assumptions of the model, we constructed the multi-objective model for distribution system in the environment of time-based competition. According to the specific characters of the model, a heuristic algorithm was developed. At the end of this paper, the flow chart of the algorithm was given.
