MIMO Decode-and-Forward Relay Beamforming for Secrecy with Cooperative Jamming

In this paper, we consider decode-and-forward (DF) relay beamforming for secrecy with cooperative jamming (CJ) in the presence of multiple eavesdroppers. The communication between a source-destination pair is aided by a multiple-input multiple-output (MIMO) relay. The source has one transmit antenna and the destination and eavesdroppers have one receive antenna each. The source and the MIMO relay are constrained with powers P-S and P-R, respectively. We relax the rank-1 constraint on the signal beamforming matrix and transform the secrecy rate max-min optimization problem to a single maximization problem, which is solved by semidefinite programming techniques. We obtain the optimum source power, signal relay weights, and jamming covariance matrix. We show that the solution of the rank-relaxed optimization problem has rank-1. Numerical results show that CJ can improve the secrecy rate.

MIMO Decode-and-Forward Relay Beamforming for Secrecy with Cooperative Jamming

In this paper, we consider decode-and-forward (DF) relay beamforming for secrecy with cooperative jamming (CJ) in the presence of multiple eavesdroppers. The communication between a source-destination pair is aided by a multiple-input multiple-output (MIMO) relay. The source has one transmit antenna and the destination and eavesdroppers have one receive antenna each. The source and the MIMO relay are constrained with powers P-S and P-R, respectively. We relax the rank-1 constraint on the signal beamforming matrix and transform the secrecy rate max-min optimization problem to a single maximization problem, which is solved by semidefinite programming techniques. We obtain the optimum source power, signal relay weights, and jamming covariance matrix. We show that the solution of the rank-relaxed optimization problem has rank-1. Numerical results show that CJ can improve the secrecy rate.

横向流动CO_2激光器振动和平动温度的确定

<正> 一、前言 振动温度和上、下激光能级粒子数密度对了解激光器件的性能是非常重要的,它们决定了从该器件可以得到的最大能量。用测量激光介质对各振转跃迁的增益系数来确定这些参数是简单易行的办法。我们在电激励横向流动CO_2激光器中垂直于光轴截面上的三个位置测量了00°1-10°0带P支和R支共30条谱线的增益系数,并由此计算出平动温度(即气体温度)和振动温度。 二、实验结果 　 实验装置和光腔结构与[3]基本相同,只是用CO_2激光光谱仪代替探测器I,以便随时监视激光谱

关于大型浮顶式油罐的设计问题

<正> 本文探讨用16Mn钢材和相当于建造5万米~3浮顶式油罐的工艺水平,从力学上解决10万、30万、50万米~3浮顶式油罐的设计问题。1.按薄膜应力状态设计5万米~3的浮顶式油罐,贮存液体的侧向压力主要是靠罐壁周向受力来承受的。周向应力σ_θ=pR/t,其中P为液压,R为罐半径,t为壁厚。由于p是沿

Epanaphoras de varia historia portugueza a El Rey Nosso Senhor D. Afonso VI : em cinco relaçoens de sucessos pertencentes a este reyno que contem negocios publicos, politicos, tragicos, amorosos, belicos, triunfantes

Francisco Manuel de Melo nasceu em Lisboa, e m 23 de novembro de 1608. e morreu na sua quinta em Alcântara, em 13 de outubro de 1666. Estudou em colégio Jesuíta, especializando-se em Filosofia e Teologia. Aos dezessete anos, decidiu seguir carreira militar. Condenado por instigar homicídio, esteve preso por onze anos e, em 1655, foi degredado para o Brasil, para onde partiu na armada de Francisco de Brito Freire. Retornou a Portugal em 1658. De lá foi pua a Itália, onde permaneceu p r alguns anos e começou, em 1664, a fazer uma edição completa de suas obras as quais por motivo ignorado não deu continuidade. Transferiu-se para Lisboa onde veio a falecer. Historiador, poeta, orador e crítico moralista, Francisco Manuel foi um dos escritores mais eruditos e polidos. ‘Epanaphoras de varia historia portugueza...’ na sua primeira edição publicada em 1660 trazia dedicatória do autor ao Rei D. Afonso Vl, substituída, pelo editor Craesbeeck, na segunda edição, por dedicatória a D. João da Silva, Marquês de Gouvêa. A obra é composta de cinco epanaforas. Em três delas, Francisco Manuel relata acontecimentos que testemunhou: na Epanáfora Política conta o levante ocorrido em Evora em 1637; na Epanáfora Bélica narra a batalha naval da armada de D. Antonio ocorrida contra os holandeses no Canal da Mancha, em 1637; na Epanáfora Trágica descreve o naufrágio da frota de D. Manuel de Meneses na costa francesa. Outras duas Epanáforas - a Amorosa e a Triunfante - não fazem parte do gênero das memórias; referem-se, respectivamente, a uma lenda sobre o descobrimento da Ilha da Madeira e a restauração de Pernambuco, em 1654. Inocêncio afirma que a primeira edição é ‘infinitamente superior a esta em correção’, onde se podem verificar vários erros, muito embora ambas sejam igualmente raras e tenham o mesmo valor .

Submarine landslides : selected studies in the U.S. Exclusive Economic Zone

Submarine Landslides: An Introduction 1 By RIo Lee, W.C. Schwab, and J.S. Booth U.S. Atlantic Continental Slope Landslides: Their Distribution, General Anributes, and Implications 14 By J.S. Booth, D.W. O'Leary, Peter Popenoe, and W.W. Danforth Submarine Mass Movement, a Formative Process of Passive Continental Margins: The Munson-Nygren Landslide Complex and the Southeast New England Landslide Complex 23 By D.W. O'Leary The Cape Fear Landslide: Slope Failure Associated with Salt Diapirism and Gas Hydrate Decomposition 40 By Peter Popenoe, E.A. Schmuck, and W.P. Dillon Ancient Crustal Fractures Control the Location and Size of Collapsed Blocks at the Blake Escarpment, East of Florida 54 By W.P. Dillon, J.S. Risch, K.M. Scanlon, P.C. Valentine, and Q.J. Huggett Tectonic and Stratigraphic Control on a Giant Submarine Slope Failure: Puerto Rico Insular Slope 60 By W.C. Schwab, W.W. Danforth, and K.M. Scanlon Slope Failure of Carbonate Sediment on the West Florida Slope 69 By D.C. Twichell, P.C. Valentine, and L.M. Parson Slope Failures in an Area of High Sedimentation Rate: Offshore Mississippi River Delta 79 By J.M. Coleman, D.B. Prior, L.E. Garrison, and H.J. Lee Salt Tectonics and Slope Failure in an Area of Salt Domes in the Northwestern Gulf of Mexico 92 By B.A. McGregor, R.G. Rothwell, N.H. Kenyon, and D.C. Twichell Slope Stability in Regions 01 Sea-Floor Gas Hydrate: Beaufort Sea Continental Slope 97 By R.E. Kayen and H.J. Lee Mass Movement Related to Large Submarine Canyons Along the Beringian Margin, Alaska 104 By P.R. Carlson, H.A. Karl, B.D. Edwards, J.V. Gardner, and R. Hall Comparison of Tectonic and Stratigraphic Control of Submarine Landslides on the Kodiak Upper Continental Slope, Alaska 117 By M.A. Hampton Submarine Landslides That Had a Significant Impact on Man and His Activities: Seward and Valdez, Alaska 123 By M.A. Hampton, R.W. Lemke, and H.W. Coulter Processes Controlling the Style of Mass Movement in Glaciomarine Sediment: Northeastern Gulf of Alaska 135 By W.C. Schwab and H.J. Lee Contents V VI Contents Liquefaction of Continental Shelf Sediment: The Northern California Earthquake of 1980 143 By M.E. Field A Submarine Landslide Associated with Shallow Sea-Floor Gas and Gas Hydrates off Northern California 151 By M.E. Field and J.H. Barber, Jr. Sur Submarine Landslide, a Deep-Water Sediment Slope Failure 158 By C.E. Gutmacher and W.R. Normark Seismically Induced Mudflow in Santa Barbara Basin, California 167 By B.D. Edwards, H.J. Lee, and M.E. Field Submarine Landslides in a Basin and Ridge Setting, Southern California 176 By M.E. Field and B.D. Edwards Giant Volcano-Related Landslides and the Development of the Hawaiian Islands 184 By W.R. Normark, J.G. Moore, and M.E. Torresan Submarine Slope Failures Initiated by Hurricane Iwa, Kahe Point, Oahu, Hawaii 197 By W.R. Normark, Pat Wilde, J.F. Campbell, T.E. Chase, and Bruce Tsutsui (PDF contains 210 pages)

Biocompatible Bacterial Cellulose-Poly(2-hydroxyethyl methacrylate) Nanocomposite Films

A series of bacterial cellulose-poly(2-hydroxyethyl methacrylate) nanocomposite films was prepared by in situ radical polymerization of 2-hydroxyethyl methacrylate (HEMA), using variable amounts of poly(ethylene glycol) diacrylate (PEGDA) as crosslinker. Thin films were obtained, and their physical, chemical, thermal, and mechanical properties were evaluated. The films showed improved translucency compared to BC and enhanced thermal stability and mechanical performance when compared to poly(2-hydroxyethyl methacrylate) (PHEMA). Finally, BC/PHEMA nanocomposites proved to be nontoxic to human adipose-derived mesenchymal stem cells (ADSCs) and thus are pointed as potential dry dressings for biomedical applications.

Influences of Structural Damping and Buoyancy-Weight Ratio on Dynamic Responses of Submerged Floating Tunnel

The recent progress of submerged floating tunnel (SFT) investigation and SFT prototype (SFTP) project in Qiandao Lake (Zhejiang Province, P.R. China) is the background of this research. Structural damping effect is brought into present computation model in terms of Rayleigh damping. Based on the FEM computational results of SFTPs as a function of buoyancy-weight ratio (BWR) under hydrodynamic loads, the effect of BWR on the dynamic response of SFT is illustrated. In addition, human comfort index is adopted to discuss the comfort status of the SFTP.

The relative abundances of Sn, Te, Xe, Ba, and Ce in the cosmic radiation

Elements with even atomic number (Z) in the interval 50 ≤ Z ≤ 58 have been resolved in the cosmic radiation using the Heavy Nuclei Experiment on the HEAO-3 satellite. Their relative abundances have been compared with the results expected from pure r-process material, pure s-process material, and solar system material, both with and without a modification due to possible first ionization potential effects. Such effects may be the result of the preferential acceleration, and hence enhancement in the cosmic rays, or those elements having low first ionization potentials. We find that our measurements are inconsistent with pure r-process material at the greater than 98% confidence level whether or not the first ionization potential adjustments are made.

In addition, we have compared our results with mixtures having varying ratios of pure r-process material to pure s-process material. We find that, if no first ionization potential effects are included,

(r/s)CRS/(r/s)SS = 0.20^+0.18_-0.14

where CRS refers to the cosmic ray source and SS refers to the solar system, consistent with having an almost pure s-process source. If the first ionization potential adjustments are applied

(r/s)CRS/(r/s)SS = 1.5^+1.1_-0.7

consistent with a solar system mixture.

Caracterización a impacto de caucho reciclado mediante elementos finitos

Análisis de caucho reciclado de manera hiperelástica mediante métodos de ajuste de Mínimos Cuadrados con programa MATLAB y Curve fitting mediante ANSYS. Para la parte viscoelástica se usa Algoritmo de Optimicación con MATLAB. Comprobación de resultados y fiabilidad.