We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thi...We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thisreview is based on the talks given in several schools and programs for the phenomenologists working on nuclear physicsand particle physics.展开更多
We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need h...We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need here to appeal to any unfounded conjecture (as done by other authors). Emphasize that we do not try to modify standard ADS/CFT procedures, but use them to evaluate the corresponding Feynman and Wheeler propagators. Our present calculations are original in the sense of being the first ones undertaken explicitly using distributions theory (DT). They are carried out in two instances: 1) when the boundary is a Euclidean space and 2) when it is of Minkowskian nature. In this last case we compute also three propagators: Feynman’s, Anti-Feynman’s, and Wheeler’s (half advanced plus half retarded). For an operator corresponding to a scalar field we explicitly obtain, for the first time ever, the two points’ correlations functions in the three instances above mentioned. To repeat, it is not our intention here to improve on ADS/CFT theory but only to employ it for evaluating the corresponding Wheeler’s propagators.展开更多
In this study,we extend the surface growth approach for bulk reconstruction into the Ad S spacetime with a boundary in the Ad S/BCFT correspondence.We show that the geometry in the entanglement wedge with a boundary c...In this study,we extend the surface growth approach for bulk reconstruction into the Ad S spacetime with a boundary in the Ad S/BCFT correspondence.We show that the geometry in the entanglement wedge with a boundary can be constructed from the direct growth of bulk extremal surfaces layer by layer.Furthermore,we observe that the surface growth configuration in BCFT can be connected with the defect multi scale entanglement renormalization ansatz(MERA)tensor network.Additionally,we investigate the entanglement of purification within the surface growth process,which not only reveals more refined structure of entanglement entropy in the entanglement wedge but also suggests a selection rule for surface growth in the bulk reconstruction.展开更多
This paper investigates a mobile telecommunications system that supports both ad hoc and infrastructure mode operations. Based on analytic and simulation models, our study investigates how base station (BS) and ad hoc...This paper investigates a mobile telecommunications system that supports both ad hoc and infrastructure mode operations. Based on analytic and simulation models, our study investigates how base station (BS) and ad hoc channel capacity, and the mobility and locality of mobile stations affect the performance of a dual mode system. We show that a dual mode system can significantly outperform a single mode (infrastructure) system when the degree of locality is high. Furthermore, a dual mode system can support much faster mobile users with less BS channels in comparison to an infrastructure mode system. Our study quantitatively identifies the threshold value for the number of ad hoc channels such that beyond this threshold, increasing ad hoc channel capacity will not improve the performance of a dual mode system. Keywords Ad-hoc - infrastructure - dual mode system Yi-Hung Chen received B.S. degree in 2001 and M.S. degree in 2003 of Computer Science and Information Engineering from National Chiao Tung University, HsinChu, Taiwan. He is an engineer of QUALCOMM CDMA technologies Taiwan.His research interests include wireless communication and ad-hoc networking.Hui-Nien Hung received the B.S. degree in mathematics from the National Taiwan University, Taipei, Taiwan, in 1989, the M.S. in mathematics degree from National Tsin-Hua University, Hsinchu, Taiwan, in 1991, and the Ph.D. degree in statistics from the University of Chicago, Chicago, IL, in 1996. He is a Professor at the Institute of Statistics, National Chiao Tung University, Taiwan.His current research interests include applied probability, financial calculus, bioinformatics, statistical inference, statistical computing, and industrial statistics. Yi-Bing Lin (M’96-SM’96-F’04) is Chair Professor and Vice President of Research and Development, National Chiao Tung University.His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. Lin is coauthor of the book Wireless and Mobile Network Architecture (with Imrich Chlamtac; published by John Wiley & Sons). Lin is an IEEE Fellow, an ACM Fellow, an AAAS Fellow, and an IEE Fellow.展开更多
In order to resolve the hidden and exposed terminal problems and improve the probability of concurrent packet transmissions for multihop Mobile Ad Hoc Networks (MANETs), a novel slotted Asymmetric Dual-Channel Medium ...In order to resolve the hidden and exposed terminal problems and improve the probability of concurrent packet transmissions for multihop Mobile Ad Hoc Networks (MANETs), a novel slotted Asymmetric Dual-Channel Medium Access Control (ADC-MAC) protocol is proposed. It exploits simultaneous reservation with less collisions and collision-free data packet transmissions, and achieves optimal transmission balance on the Control Channel (CCH) and Data Channel (DCH) by adjusting the relationship between Reservation Slot (RS) on the CCH and the data packet Transmission Slot (TS) on the DCH. Transmission interferences can be avoided by only observing CCH for the transmission time of a data packet. The proposed RS and contention micro-slot backoff mechanisms also greatly improve channel access efficiency. Simulation results show that compared to IEEE 802.11 DCF and π-Mc protocols, the proposed protocol can achieve a throughput gain of 88% in single-hop networks and 151% in multihop networks at the same total data rate.展开更多
基金Supported by National Natural Science Foundation of China under Grant Nos. 10775002 and 10975005
文摘We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thisreview is based on the talks given in several schools and programs for the phenomenologists working on nuclear physicsand particle physics.
文摘We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need here to appeal to any unfounded conjecture (as done by other authors). Emphasize that we do not try to modify standard ADS/CFT procedures, but use them to evaluate the corresponding Feynman and Wheeler propagators. Our present calculations are original in the sense of being the first ones undertaken explicitly using distributions theory (DT). They are carried out in two instances: 1) when the boundary is a Euclidean space and 2) when it is of Minkowskian nature. In this last case we compute also three propagators: Feynman’s, Anti-Feynman’s, and Wheeler’s (half advanced plus half retarded). For an operator corresponding to a scalar field we explicitly obtain, for the first time ever, the two points’ correlations functions in the three instances above mentioned. To repeat, it is not our intention here to improve on ADS/CFT theory but only to employ it for evaluating the corresponding Wheeler’s propagators.
基金Supported by the National Natural Science Foundation of China(11675272)。
文摘In this study,we extend the surface growth approach for bulk reconstruction into the Ad S spacetime with a boundary in the Ad S/BCFT correspondence.We show that the geometry in the entanglement wedge with a boundary can be constructed from the direct growth of bulk extremal surfaces layer by layer.Furthermore,we observe that the surface growth configuration in BCFT can be connected with the defect multi scale entanglement renormalization ansatz(MERA)tensor network.Additionally,we investigate the entanglement of purification within the surface growth process,which not only reveals more refined structure of entanglement entropy in the entanglement wedge but also suggests a selection rule for surface growth in the bulk reconstruction.
文摘This paper investigates a mobile telecommunications system that supports both ad hoc and infrastructure mode operations. Based on analytic and simulation models, our study investigates how base station (BS) and ad hoc channel capacity, and the mobility and locality of mobile stations affect the performance of a dual mode system. We show that a dual mode system can significantly outperform a single mode (infrastructure) system when the degree of locality is high. Furthermore, a dual mode system can support much faster mobile users with less BS channels in comparison to an infrastructure mode system. Our study quantitatively identifies the threshold value for the number of ad hoc channels such that beyond this threshold, increasing ad hoc channel capacity will not improve the performance of a dual mode system. Keywords Ad-hoc - infrastructure - dual mode system Yi-Hung Chen received B.S. degree in 2001 and M.S. degree in 2003 of Computer Science and Information Engineering from National Chiao Tung University, HsinChu, Taiwan. He is an engineer of QUALCOMM CDMA technologies Taiwan.His research interests include wireless communication and ad-hoc networking.Hui-Nien Hung received the B.S. degree in mathematics from the National Taiwan University, Taipei, Taiwan, in 1989, the M.S. in mathematics degree from National Tsin-Hua University, Hsinchu, Taiwan, in 1991, and the Ph.D. degree in statistics from the University of Chicago, Chicago, IL, in 1996. He is a Professor at the Institute of Statistics, National Chiao Tung University, Taiwan.His current research interests include applied probability, financial calculus, bioinformatics, statistical inference, statistical computing, and industrial statistics. Yi-Bing Lin (M’96-SM’96-F’04) is Chair Professor and Vice President of Research and Development, National Chiao Tung University.His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. Lin is coauthor of the book Wireless and Mobile Network Architecture (with Imrich Chlamtac; published by John Wiley & Sons). Lin is an IEEE Fellow, an ACM Fellow, an AAAS Fellow, and an IEE Fellow.
基金Acknowledgements This work was supported partially by the National Natural Science Foundation of China under Gants No. 60872011, No. 61171074 the National S＆T Major Project of China under Gant No. 2010ZX03003-003-03+1 种基金 the Program for New Century Excellent Talents in University the Fundamental Research Funds for the Central Universities.
文摘In order to resolve the hidden and exposed terminal problems and improve the probability of concurrent packet transmissions for multihop Mobile Ad Hoc Networks (MANETs), a novel slotted Asymmetric Dual-Channel Medium Access Control (ADC-MAC) protocol is proposed. It exploits simultaneous reservation with less collisions and collision-free data packet transmissions, and achieves optimal transmission balance on the Control Channel (CCH) and Data Channel (DCH) by adjusting the relationship between Reservation Slot (RS) on the CCH and the data packet Transmission Slot (TS) on the DCH. Transmission interferences can be avoided by only observing CCH for the transmission time of a data packet. The proposed RS and contention micro-slot backoff mechanisms also greatly improve channel access efficiency. Simulation results show that compared to IEEE 802.11 DCF and π-Mc protocols, the proposed protocol can achieve a throughput gain of 88% in single-hop networks and 151% in multihop networks at the same total data rate.
