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The system capacity view of aging and longevity

Frontiers of Electrical and Electronic Engineering in China 2017年第3期5卷 251-259页

作者： Jing-Dong J. Han Lei Hou Na Sun Chi Xu Joseph McDermott Dan Wang Key Laboratory of Computational Biology CAS Center for Excellence in Molecular Cell Science Collaborative Innovation Center for Genetics and Developmental Biology Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China

Background： Aging is a complex systems level problem that needs a systems level solution. However, system models of aging and longevity, although urgently needed, are still lacking, largely due to the paucity of conceptual frameworks for modeling such a complex process. Results： We propose that aging can be viewed as a decline in system capacity, defined as the maximum level of output that a system produces to fulfill demands. Classical aging hallmarks and anti-aging strategies can be well-aligned to system capacity. Genetic variants responsible for lifespan variation across individuals or species can also be explained by their roles in system capacity. We further propose promising directions to develop systems approaches to modulate system capacity and thus extend both healthspan and lifespan. Conclusions： The system capacity model of aging provides an opportunity to examine aging at the systems level. This model predicts that the extent to which aging can be modulated is normally limited by the upper bound of the system capacity of a species. Within such a boundary, aging can be delayed by moderately increasing an individual＇s system capacity. Beyond such a boundary, increasing the upper bound is required, which is not unrealistic given the unlimited potential of regenerative medicine in the future, but it requires increasing the capacity of the whole system instead of only part of it.

关键词： systems system capacity aging longevity

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Research on the improved cooperative cellular system capacity

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Journal of Shanghai University(English Edition) 2011年第2期15卷 85-88页

作者：陈惠民解维浩王亮武卓金彦亮 Key Laboratory of Specialty Fiber Optics and Optical Access Networks School of Communication and Information Engineering Shanghai University

Recently, the multi-hop cellular networks have been widely studied in order to enhance the cell performances such as the cell capacity. While most of these works merely use the multi-hop methods instead of direct transmission without considering the co-channel inter-cell interference, signal transmission mode and the effects of the number of antennas. With the consideration of above important elements, this paper proposed an improved cellular system with multi-relay amplifies-andforward （AF） cooperative transmission scheme and the corresponding capacity expression is derived under the corresponding environment. By using the potential space diversity and selecting relays based on maximizing the capacity, the cellular system capacity can be improved effectively. The simulation results show that with the assistance of optimal selected relays, the improved cooperative cellular system capacity with multi-relay AF transmission scheme performs better than single-hop cellular system.

关键词： cooperative scheme amplifies-and-forward (AF) transmission cellular system system capacity

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The capacity Analysis of the CDMA Cellular system

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The Journal of China Universities of Posts and Telecommunications 1996年第1期3卷 1-7,14页

作者： Zhang Ping(Department of Telecommunication Engineering,Beijing University of Posts and Telecommunications,Beijing 100088,P.R.China) Department of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100088 P. R. China

This paper analyzes the CDMA cellular system in which the practical power control processwith errors is modeled as random log-normally distributed variable at the reverse link. The Performance of the CDMA system is measured in terms of outage probability,and the computing results arepresented in this *** work is useful for CDMA system designation and provides the criteria forevaluating CDMA system capacity in a more practical way.

关键词： s:CDMA power control system capacity antenna sector

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OPTIMAL POWER ALLOCATION WITH AF AND SDF STRATEGIES IN DUAL-HOP COOPERATIVE MIMO NETWORKS

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Journal of Electronics(China) 2010年第3期27卷 328-339页

作者： Xu Xiaorong Zheng Baoyu Zhang Jianwu Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Telecommunication Engineering Hangzhou Dianzi University Hangzhou 310018 China

Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network with multi-relay cooperative communication is introduced. Power allocation problem with Amplify-and-Forward (AF) and Selective Decode-and-Forward (SDF) strategies in multi-node scenario are formulated and solved respectively. Optimal power allocation schemes that maximize system capacity with AF strategy are presented. In addition, optimal power allocation methods that minimize asymptotic Symbol Error Rate (SER) with SDF cooperative protocol in multi-node scenario are also proposed. Furthermore, performance comparisons are provided in terms of system capacity and approximate SER. Numerical and simulation results confirm our theoretical analysis. It is revealed that, maximum system capacity could be obtained when powers are allocated optimally with AF protocol, while minimization of system's SER could also be achieved with optimum power allocation in SDF strategy. In multi-node scenario, those optimal power allocation algorithms are superior to conventional equal power allocation schemes.

关键词： Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network Optimal power allocation Amplify-and-Forward (AF) Selective Decode-and-Forward (SDF) system capacity Asymptotic Symbol Error Rate (SER)

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Satellite and high altitude platform-based inter-vehicle communications in vast and desolate areas

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Journal of Southeast University(English Edition) 2012年第2期28卷 135-139页

作者：林元乖王琳沈连丰东南大学移动通信国家重点实验室南京210096 琼州学院电子信息工程学院三亚572022

In order to solve the problem of inter-vehicle communication （IVC） in vast and desolate areas such as the desert and the Gobi, two vehicle network models are proposed. One is based on satellite communication and the other is based on high altitude platform （ HAP ） communication. The system outline and networking modes of the two models are described. In the satellite communication based model, all the vehicles are equipped with vehicle-bone satellite communication on the move terminals and the communication signals between vehicles are forwarded by satellite. In the high altitude platform-based model, the HAPs are equipped with base station facilities to form aerial base stations, and vehicles can communicate with each other via common terrestrial mobile communication devices. Some key parameters such as path loss, link loss and system capacity are also computed. The analysis shows that both the two models can satisfy the requirement of IVC in the descriptive environment.

关键词： inter-vehicle communication satellite communication high altitude platform communication terrestrial mobile communication device system capacity

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