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991.
992.
Darko Skorin-Kapov 《Annals of Operations Research》2001,106(1-4):63-78
We consider telecommunication network design in which each pair of nodes can communicate via a direct link and the communication flow can be delivered through any path in the network. The cost of flow through each link is discounted if and only if the amount of flow exceeds a certain threshold. This exploitation of economies of scale encourages the concentration of flows and use of relatively small number of links. We will call such networks hub-like networks. The cost of services delivered through a hub-like network is distributed among its users who may be individuals or organizations with possibly conflicting interests. The cooperation of these users is essential for the exploitation of economies of scale. Consequently, there is a need to find a fair distribution of the cost of providing the service among users of such network. In order to describe this cost allocation problem we formulate the associated cooperative game, to be referred to as the hub-like game. Special attention is paid to users' contribution to economies of scale. We then demonstrate that certain cost allocation solutions (the core and the nucleolus of the hub-like game), which provide users with the incentive to cooperate, can be efficiently characterized. 相似文献
993.
994.
量子安全直接通信研究进展 总被引:1,自引:0,他引:1
简要地介绍了量子安全直接通信的必要条件,初步介绍了两个量子安全直接通信模型,即Two-Step和Quantum-One-Time-Pad模型。 The requirements of quantum secure direct communication (QSDC) are briefly introduced. Two QSDC schemes i. e. , the Two-Step QSDC scheme and the Quantum-One-Time-Pad QSDC scheme, are discussed in brief. 相似文献
995.
水声信道的严重双扩特性极大地限制了水声高速通信的稳健性。针对近程高速水声通信技术的需求,该文基于水声毫米波频段,提出了一种基于超奈奎斯特发射技术及高阶调制技术的单载波的水声毫米波通信技术。而超奈奎斯特发射技术以及高阶调制给接收机带来了极大的挑战:一是超奈奎斯特发射技术引入了严重的符号间干扰,二是高阶调制系统的符号检测对信道估计的精度要求很高。针对以上问题,该文提出了一种基于迭代信道估计技术的迭代软反馈DFE接收机技术。仿真实验表明:采用128QAM高阶调制时,在较为严重的多途衰落信道条件下,采用所提出的接收机可以在15 dB时实现无误码传输。信道水池试验证明:当通信带宽为300 kHz,通信符号率为300k符号/秒且采用64QAM调制时,在发射平台慢速运动的条件下可以实现900 kbps的净数据率,其相应的频谱利用率高达6 Bits/s/Hz。 相似文献
996.
Victoria Kobernik Dr. Inbal Berkovich Dr. Avishai Levy Prof. Dr. N. Gabriel Lemcoff Prof. Dr. Charles E. Diesendruck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15835-15838
Chemical communication between macromolecules was studied by observing the controlled single chain collapse that ensues the exchange of a metal cross-linker between two polymer chains. The rhodium (I) organometallic cross-linker transfer from a low molecular weight collapsed polybutadiene to a larger polymer was followed using size exclusion chromatography. The increased effective molarity in the larger polymer seems to be the driving force for the metal migration. Thus, we demonstrate here a strategy for transferring a molecular signal that induces chain collapse of a polymer chain based on non-covalent interactions, mimicking biological behaviors reminiscent of signal transductions in proteins. 相似文献
997.
In this paper, Turbo Code is proposed in optical OFDM multimode fiber communication system in order to decrease the bit error rate (BER) of the system, which is mainly affected by the deep nulls of the magnitude response of multimode fiber in the high frequency region (above 3 dB). A simulation system in SIMULINK is established. Based on the system, the BER of the system with Turbo Code is compare to the systems with another two typical coding schemes including convolutional code (CC) and serially concatenated code (SCC) which uses a concatenation of convolutional and RS codes when transmitting 10 Gbps data over various length multimode fibers. Different transmitting rate is also considered. The results show that Turbo coded system has a lower BER than the other two systems and the Turbo coded system can transmit 10 Gbps data to the distance of 300 m with BER below 1e−6. 相似文献
998.
In free-space optical communication links, atmospheric turbulence causes fluctuations in both the intensity and the phase of the received signal, affecting link performance.Influence of Kolmogorov and non-Kolmogorov turbulence statistics on laser communication links are analyzed for different propagation scenarios, and effects of different turbulence spectrum models on optical communication links are presented. Statistical estimates of the communication parameters such as the probability of fade (miss) exceeding a threshold dB level, the mean number of fades, and BER are derived and examples provided. The presented quantitative data suggest that the non-Kolmogorov turbulence effects on lasercom channels are more severe in many situations and need to be taken into account in wireless optical communication. Non-Kolmogorov turbulence is especially important for elevations above the boundary layer as well as for even low elevation paths over water. 相似文献
999.
1000.
Jozef Chovan Martin Tomáška František Uherek Daniel Haško Dana Seyringer Lenka Gajdošová 《Fiber and Integrated Optics》2020,39(1):24-38
ABSTRACTProgress in integrated photonics enables development of photonics integrated circuits (PIC) with new unique properties and overcomes current limits in information and communication technologies. The effective coupling of optical radiation between telecom optical fiber and photonic integrated circuits is necessary. To address these challenges, we present our concept of photonics integrated circuit (PIC) fully customized packaging with microwave, direct current, and fiber array ports with automated active alignment system. Automated adjustment and coupling of single-mode fiber (SMF) arrays with 8 fibers to PIC based on the detection of edges and markers on PIC and SMF arrays were successfully realized. 相似文献