The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in...The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in Drosophila suggest that the HH protein diffuses from the signaling cells to promote the proliferation of nearby ovarian somatic stem cells by antagonizing the suppression of its receptor PTC towards the CI transcription factor in the stem cells. Consequently, the transcription of CIdependent genes leads to stem cell proliferation. This regulatory pathway appears to function also in vertebrates,where defects in ptc cause basal cell carcinoma, tumors of epidermal stem cell origin. Basal cell carcinoma can also be induced by ectopic expression of Sonic hedgehog (shh) or Glil, the vertebrate homolog of ci. These studies suggest the conservation of the hh signaling pathway in controlling epithelial stem cell divisions among different organisms.展开更多
To analyze and reduce the impact of Machine-to-Machine (M2M) Devices (MDs) on the traditional Human-to-Human (H2H) users for the blending scenario, where both M2M and H2H services coexist in the current Universal Mobi...To analyze and reduce the impact of Machine-to-Machine (M2M) Devices (MDs) on the traditional Human-to-Human (H2H) users for the blending scenario, where both M2M and H2H services coexist in the current Universal Mobile Telecommunication System (UMTS) and perform the Random Access (RA) procedure simultaneously, a comprehensive RA analysis model of RA is proposed in this paper. Further, a power ramping strategy based on the logarithm for M2M is proposed. The efficiency of both the existing and proposed scheme is assessed through a simulation across several metrics, including average target power, throughput, blocking probability, and delay statistics. Numerical results show that the proposed algorithm can ensure a minimal impact on H2H communication while maintaining the throughput of the M2M communication. Meanwhile, because of its low energy consumption, this algorithm has a significant guide value for real-world applications.展开更多
A novel Automatic repeat ReQuest (ARQ) protocol called cooperative ARQ is presented in this let-ter, where a relay terminal is requested to retransmit an erroneously received packet, instead of the source ter-minal. T...A novel Automatic repeat ReQuest (ARQ) protocol called cooperative ARQ is presented in this let-ter, where a relay terminal is requested to retransmit an erroneously received packet, instead of the source ter-minal. The data link layer Packet Error Rate (PER) performance of cooperative ARQ is derived in correlated wireless channel. The results show that even though the relay-destination channel is worse than the source-destination channel, the new protocol outperforms the traditional one as long as the average SNR of the relay-destination channel is better than a certain threshold. It is also demonstrated that a second order diversity gain can be achieved with the cooperative ARQ protocol.展开更多
In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying (NC2R) scheme to improve the performance of downlink transmission for relayaided ...In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying (NC2R) scheme to improve the performance of downlink transmission for relayaided cellular networks. Moreover, systematic performance analysis and extensive simulations are performed for the proposed NC2R and traditional relaying and non-relaying schemes. The results show that NCR outperforms conventional relaying and non-relaying schemes in terms of blocking probability and spectral efficiency, especially for cell-edge users. Additionally, the location selections for relays with NCR are also discussed. These results will provide some insights for incorporating network coding into next-generation broadband cellular relay mobile systems.展开更多
"Without an appropriate research setting, a study cannot be qualified as a reasonable piece", this notion is manifested in the methodological polices. In this research, we attempt to examine previous studies within ..."Without an appropriate research setting, a study cannot be qualified as a reasonable piece", this notion is manifested in the methodological polices. In this research, we attempt to examine previous studies within the scope of technology evolution and market perception in telecommunication industry through extracting research structures, methodologies, corresponding variables, and processing methods. A general process of social scientific research is adopted to analyze eighty-four selected papers; and simultaneously, the framework for doing this analysis is established, as well. In this manner, we inspect the subjects and the issues in these papers according to product types, academic domains, and divisions of technological evolution (from 1G to 4G). Then, their research designs are anatomized into the key dimensions of general research conventions. This research eventually provides an entire picture of a research scenario for mobile telecommunication industry; and apparently, this framewbrk can help scholars to establish specific tendencies for academic scenarios in future research plans. Also, we propose the main streams and emerging issues can be expected to engage in the future within both theacademic and the operational fields.展开更多
The impeller of turbo machinery is a typical nonlinear multi-oscillator system.The vibration of each module is coupling, including fluid-solid coupling of the blade.The subject of our investigation was a KDF-5 mine fa...The impeller of turbo machinery is a typical nonlinear multi-oscillator system.The vibration of each module is coupling, including fluid-solid coupling of the blade.The subject of our investigation was a KDF-5 mine fan for which we analyzed air vibration signals and axial vibration signals by using correlation dimension analysis under five variable working conditions.The results indicate that their correlation dimension curves show a uniform trend.That is to say, the characteristics of the variation signals of the integral structure are correlated and mutually embodied.It proves that it is possible to monitor the working state of a mine fan by coupling the vibration signals and air vibration signals for these are more sensitive in representing the status of the impeller system.展开更多
The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,b...The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,based on the estimation of channels and the power allocation for each relay node by comparing it with the pre-set threshold.This scheme is used to choose the cooperative relay dynamically for a multiple relay scenario.Simulation results show that this proposed relay selection scheme decreases the outage probability effectively,maintains system capacity well,and improves the performance of the relay system.展开更多
Office environments have recently adopted ubiquitous computing for collaboration and mobile communication to promote real-time enterprises. Ubiquitous offices, introduced by Weiser and adopted as emerging computationa...Office environments have recently adopted ubiquitous computing for collaboration and mobile communication to promote real-time enterprises. Ubiquitous offices, introduced by Weiser and adopted as emerging computational technology to support office works, have already affected the practice of companies and organizations. Within this context, this study deals with a work service model of the ubiquitous office environments by understanding human behaviors and works in their workspace. We propose a ubiquitous office model considering the correlation between ubiquitous computing technologies and work services in the office. Two attributes are emphasized, collaboration and mobility, as identifiers for categorizing the work types. The types of work services have variations in the amount of communication and the proportion of working outside of the office. The proposed work service model of the ubiquitous office includes territorial and non-territorial services to enable workers in and out of the office to interact with each other effectively. The findings in this paper would be a theoretical basis for embodying an intelligent office which supports office works efficiently.展开更多
文摘The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in Drosophila suggest that the HH protein diffuses from the signaling cells to promote the proliferation of nearby ovarian somatic stem cells by antagonizing the suppression of its receptor PTC towards the CI transcription factor in the stem cells. Consequently, the transcription of CIdependent genes leads to stem cell proliferation. This regulatory pathway appears to function also in vertebrates,where defects in ptc cause basal cell carcinoma, tumors of epidermal stem cell origin. Basal cell carcinoma can also be induced by ectopic expression of Sonic hedgehog (shh) or Glil, the vertebrate homolog of ci. These studies suggest the conservation of the hh signaling pathway in controlling epithelial stem cell divisions among different organisms.
基金supported in part by the National Natural Science Foundation of Chinaunder Grants No.60971125, No.61121001Major National S&T Project under Grant No. 2012ZX03005010 the project under Grant No.201105
文摘To analyze and reduce the impact of Machine-to-Machine (M2M) Devices (MDs) on the traditional Human-to-Human (H2H) users for the blending scenario, where both M2M and H2H services coexist in the current Universal Mobile Telecommunication System (UMTS) and perform the Random Access (RA) procedure simultaneously, a comprehensive RA analysis model of RA is proposed in this paper. Further, a power ramping strategy based on the logarithm for M2M is proposed. The efficiency of both the existing and proposed scheme is assessed through a simulation across several metrics, including average target power, throughput, blocking probability, and delay statistics. Numerical results show that the proposed algorithm can ensure a minimal impact on H2H communication while maintaining the throughput of the M2M communication. Meanwhile, because of its low energy consumption, this algorithm has a significant guide value for real-world applications.
基金Supported by the National Natural Science Foundation of China (No.60472079), and Natural Science Founda-tion of Zhejiang Province (No.Z104252).
文摘A novel Automatic repeat ReQuest (ARQ) protocol called cooperative ARQ is presented in this let-ter, where a relay terminal is requested to retransmit an erroneously received packet, instead of the source ter-minal. The data link layer Packet Error Rate (PER) performance of cooperative ARQ is derived in correlated wireless channel. The results show that even though the relay-destination channel is worse than the source-destination channel, the new protocol outperforms the traditional one as long as the average SNR of the relay-destination channel is better than a certain threshold. It is also demonstrated that a second order diversity gain can be achieved with the cooperative ARQ protocol.
基金supported by the State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University under Grant No.RCS2012ZT008the National Key Basic Research Program of China(973Program)under Grant No.2012CB316100(2)+1 种基金the National Natural Science Foundation of China under Grants No.61201203,No.61171064the Fundamental Research Funds for the Central Universities under Grant No.2012JBM030
文摘In this paper, we first overview some traditional relaying technologies, and then present a Network Coding-Aware Cooperative Relaying (NC2R) scheme to improve the performance of downlink transmission for relayaided cellular networks. Moreover, systematic performance analysis and extensive simulations are performed for the proposed NC2R and traditional relaying and non-relaying schemes. The results show that NCR outperforms conventional relaying and non-relaying schemes in terms of blocking probability and spectral efficiency, especially for cell-edge users. Additionally, the location selections for relays with NCR are also discussed. These results will provide some insights for incorporating network coding into next-generation broadband cellular relay mobile systems.
文摘"Without an appropriate research setting, a study cannot be qualified as a reasonable piece", this notion is manifested in the methodological polices. In this research, we attempt to examine previous studies within the scope of technology evolution and market perception in telecommunication industry through extracting research structures, methodologies, corresponding variables, and processing methods. A general process of social scientific research is adopted to analyze eighty-four selected papers; and simultaneously, the framework for doing this analysis is established, as well. In this manner, we inspect the subjects and the issues in these papers according to product types, academic domains, and divisions of technological evolution (from 1G to 4G). Then, their research designs are anatomized into the key dimensions of general research conventions. This research eventually provides an entire picture of a research scenario for mobile telecommunication industry; and apparently, this framewbrk can help scholars to establish specific tendencies for academic scenarios in future research plans. Also, we propose the main streams and emerging issues can be expected to engage in the future within both theacademic and the operational fields.
基金Projects BK2005018 supported by the Natural Science Foundation of Jiangsu Province CX07B-061z by the Graduate Research and Innovation Plan of Jiangsu Province
文摘The impeller of turbo machinery is a typical nonlinear multi-oscillator system.The vibration of each module is coupling, including fluid-solid coupling of the blade.The subject of our investigation was a KDF-5 mine fan for which we analyzed air vibration signals and axial vibration signals by using correlation dimension analysis under five variable working conditions.The results indicate that their correlation dimension curves show a uniform trend.That is to say, the characteristics of the variation signals of the integral structure are correlated and mutually embodied.It proves that it is possible to monitor the working state of a mine fan by coupling the vibration signals and air vibration signals for these are more sensitive in representing the status of the impeller system.
基金Supported by the National Natural Science Foundation of China(No.61172073)the State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University(No.RCS2011ZT003)+2 种基金the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2012D19)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.2013JBZ001)the Program for New Century Excellent Talents in University of Ministry of Education of China(No.NCET-12-0766)
文摘The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,based on the estimation of channels and the power allocation for each relay node by comparing it with the pre-set threshold.This scheme is used to choose the cooperative relay dynamically for a multiple relay scenario.Simulation results show that this proposed relay selection scheme decreases the outage probability effectively,maintains system capacity well,and improves the performance of the relay system.
文摘Office environments have recently adopted ubiquitous computing for collaboration and mobile communication to promote real-time enterprises. Ubiquitous offices, introduced by Weiser and adopted as emerging computational technology to support office works, have already affected the practice of companies and organizations. Within this context, this study deals with a work service model of the ubiquitous office environments by understanding human behaviors and works in their workspace. We propose a ubiquitous office model considering the correlation between ubiquitous computing technologies and work services in the office. Two attributes are emphasized, collaboration and mobility, as identifiers for categorizing the work types. The types of work services have variations in the amount of communication and the proportion of working outside of the office. The proposed work service model of the ubiquitous office includes territorial and non-territorial services to enable workers in and out of the office to interact with each other effectively. The findings in this paper would be a theoretical basis for embodying an intelligent office which supports office works efficiently.