365 research outputs found
Opportunistic secret communication in wireless systems:
No full textThis thesis examines the challenges of information-theoretic secret communication that exploits the temporal and spatial variations of the wireless medium to improve secret communication rates.
We first examine the secrecy capacity of a system consisting of independent parallel channels with one transmitter, one intended receiver and one eavesdropper. We show that the secrecy capacity of the system is the sum of the secrecy capacities of the individual subchannels. We further derive the optimal power allocation strategy for a system of parallel AWGN channels subject to a total power constraint, and also extend the results to random fading channels with additive Gaussian noise.
We then study the achievable secrecy rate with Gaussian random codes for the situation where the channel of the intended receiver is a constant AWGN channel, while the eavesdropper's channel is fast Rayleigh fading with unknown realizations but known statistics to the transmitter. The proposed method with artificial noise and bursting provides ways to achieve positive secrecy rate even when Bob's channel is worse than Eve's channel on average.
We also examine the achievable secrecy rate for a multiple antenna system, and the optimal input structure needed to achieve this rate. For the multiple input single output case, an analytical solution is derived. Multiple antenna systems provide extra degrees of freedom to the transmitter so that a beamforming-like approach can be used to provide advantage to the intended receiver against the eavesdropper.
Next we derive a secrecy capacity outer bound region for a class of one-sided interference channels. The outer bound is shown to be tight for a class of binary deterministic one-sided interference channels, and can be achieved within one bit for some Gaussian one-sided interference channels.
Finally, as Gaussian random codes are impractical, we evaluate achievable secrecy rates with discrete signaling. We observe that with discrete signaling, there exists an optimal power that maximizes the achievable secrecy rate. For the AWGN channel, larger constellation is always better. While for fading channel, the optimal constellation size varies with the power constraint, and discrete signaling can perform better than random Gaussian coding.Ph.D.Includes bibliographical references (p. 129-134)by Zang L
Engaging in Drama Criticism: Zang Maoxun and His Four New Musical Texts from the Jade Tea Hall
No full textabstract: This dissertation focuses on the corpus of Zang Maoxun’s literary creations in The Collection from the Fubao Hall and investigates his involvement in the cultural activities of the Jinling Poetry Society. Unearthing how Zang and this Society, as self and community, played an instrumental role in creating and sustaining a network of dramatists and drama critics in the Jiangnan region, a careful review of his poems and prose shows the extent to which text preparation, commentary, and printing were at the center of his communications with his social circle. Moreover, this dissertation unpacks Zang’s contribution to the promotion of dramatic texts through a thorough examination of his ardent editorial work in revising Tang Xianzu’s The Four Dream Plays from the Jade Tea Hall, the epitome of the southern musical drama. By using Zang’s 1618 Diaochong guan edition of his adaptations as a focal point, this dissertation compares it with three late Ming editions of Tang’s plays printed in the dual colors of red-and-black ink. In light of their innovative editorial designs, and the varying evaluations formed in their pages about Zang’s editorial work, this dissertation reveals the importance of Zang’s adaptations in the history of The Four Dream Plays’ textual transmission, as well as the interplay between the tradition of drama criticism and the new technology of multicolor printing and consequent innovation in editorial principles.Dissertation/ThesisDoctoral Dissertation East Asian Languages and Civilizations 201
Wettability of molten Sn-Bi-Cu solder on Cu substrate
No full textThe wetting behavior of a new Sn-Bi-Cu Pb-firee solder on Cu substrate was investigated by sessile drop method under an Ar-H(2) flow in the temperature range from 493 K to 623 K. The contact angle curves tested at 548 K and 623 K are found to fit exponential rule very well. However. the contact angle curve tested under493 K is not well consistent with exponential rule, for which the spreading course may be classified into three stages. Equilibrium contact angles between Sn-Bi-Cu solder and Cu substrate decrease monotonously with the increase in temperature, which are 28 degrees, 24 degrees and 18 degrees at 493 K. 548 K and 623 K, respectively. The results show that 69.5Sn30Bi-0.5Cu/exhibits good wettability on Cu substrate. Intermetallics formed at the 69.5Sn-30Bi-0.5Cu/Cu interface are identified as Cu(6)Sn(5) adjacent to the solder and Cu(3)Sn adjacent to the Cu substrate, respectively. Formation of intermetallic seems to improve strong wetting of the substrate by the solder. (C) 2009 Elsevier B.V. All rights reserved
Zang-Shu(『葬書』) - Its Context and Meaning
No full textThis study is about Jin Nang Jing (錦襄經), so-called, the most respected canon of feng-shui (風水) .Jin Nang Jing and Qing Wu Jing (靑鳥經) are the representatives of feng-shui texts. I think that 靑鳥經 is the 'metaphoric' description of feng-shui while 錦襄經 is the 'narrative.' They can be referred as "Zang Jing 葬經" and "Zang Shu 葬書" respectively.
Kui Zhang Ge (奎章閣) version of 『錦襄經』 is selected for this analysis. Generally, the author of 『錦襄經』 is known to be Guo Pu (郭璞, 晋, 276-324), but according to several datum, this assertion is doubtable. Nevertheless, it can be found that there was a cultural context and a desire to consider 郭璞 as the author of 『葬書』. I have inspected this problem through his biographies and writings. 郭璞 as a historic person came to be considered as the founder of
feng-shui because the practice had been already prevalent in the Han (漢) Dynasty and because his academic ability was highly evaluated during the Jin (晋) Dynasty.
The contents of 『葬書』 includes Qi Gan Bian (氣感編) as a core section that describes the character and condition of 氣(qi), the metaphysical concept of feng-shui, Yin Shi Bian (因勢編) ․ Ping Zhi Bian (平支編) ․ Shan Shi Bian (山勢編) ․ Si Shi Bian (四勢編) that describes techniques for grasping and distinguishing of expressive form of 氣 Gui Xue Bian (貴穴編) describes Xue 穴 itself as a core of 氣, Xing Shi Bian (形勢編) as a supplementary section of 因勢․山勢․四勢編, and Qu Lei Bian (取類編) as a c oncrete Xiang Di (相地) practice.
The result of this analysis is that the most desirable places corresponding with 『葬書』isn't acquired by divine power. Only if 氣 is ensured as a creative power and metaphysical proposition, 『葬書』can be the system of explanation about techniques to find good places and it can be the object of 'knowledge.
Numerical Simulation of Grid-Generated Turbulence Interaction with a NACA0012 Airfoil
No full textThe present study assesses the ability to numerically predict turbulence-interaction noise of a NACA0012 airfoil with grid-generated turbulence by utilizing the Lattice Boltzmann solver PowerFLOW. Both the near-field flow characteristics and far field noise are bench-marked against an existing experimental study. The grid was chosen to match that from the experiment to provide evidence that the present numerical approach in physically placing a grid upstream of the airfoil can reproduce the turbulence characteristics observed from the benchmark experiment and thus accurately capture the turbulence-interaction noise generated. The comparison of the results show that the turbulence statistics, including turbulence intensity, integral length scales and anisotropy are highly consistent with the experiment. Moreover, far field acoustics of the turbulence interaction as well as the near-field flow properties near the leading-edge and the unsteady wall pressure fluctuations of the airfoil are also analyzed and the results agreed well with the experimental measurements. The present study confirms that the grid-generated approach is suitable for numerical investigation of turbulence-interaction noise and its potential mitigation strategies
Technology capabilities, marketing capabilities and innovation ambidexterity
No full textLinking the literature of resource-based view (RBV) with ambidexterity, we construct an integrative framework of technology capabilities, marketing capabilities, innovation ambidexterity, and organisational performance. Using data from a sample of 190 Chinese hospitals, we find that both technology capabilities and marketing capabilities have an inverse U-shape relationship with innovation ambidexterity. And they can complementarily improve innovation ambidexterity, which further enhances organisational performance. This study deepens our understanding of RBV and ambidexterity by investigating the antecedent roles of technological and marketing capabilities on innovation ambidexterity. We also investigate their interactive role on improving innovation ambidexterity.National Science Foundation Committee of China [71132006, 71402139]; Humanities and Social Sciences Program of the Ministry of Education [14XJC630009]SSCIARTICLE123-372
Legal socialization -- myth or reality? : a case study on the ZANG Armenian Legal Socialization Project
No full textLegal socialization is a process of enforcing rule-of-law in a community through attitude and behavioral support of each community member. The present paper examines the means and ways in which this process could be conducted. The author of the paper, an Armenian National, has been a part of the ZANG Armenian Legal Socialization project supported by the US Department of State\u27s Bureau for Narcotics, and International Law Enforcement Affairs (INL), and implemented by Project Harmony. The goal of the project is the creation of educational material for the schools of Armenia that will promote and encourage the process of legal socialization in Armenia. As a part of that project, a delegation of Armenian Ministry officials spent two weeks during December of 2003 in Vermont and Massachusetts to study the American model of Legal Socialization. Being a part of the Project Harmony staff, the author of this study spent her time on studying the attitudes of Armenian 9th grade children towards the Armenian police and teachers. She met with U.S. professionals prior to the Armenian delegation\u27s arrival to USA, elaborated the program to host the Armenian delegation in USA, and to find out which parts of the US model of legal socialization may work best in Armenia. In evaluating the situation of Armenia, the author has tried to apply a more holistic approach in her analysis, and to look at the problems in that country within the context of contemporary structural adjustments and poverty reduction strategies. The method of research included the analysis of115 questionnaires completed by 9th grade students, and 12 questionnaires completed by their teachers in four various regions of Armenia; observations of 15 meetings between US and Armenian specialists in the USA, and various interviews in Armenia and the United States
Mantle discontinuities beneath Izu-Bonin and the implications
No full textThe SdP, pdP and sdP phases are picked up with the Nth root slant stack method from the digital waveform data recorded by the networks and arrays in USA, Germany and Switzerland for the earthquakes occurring beneath Izu-Bonin and Japan Sea. The mantle discontinuities and the effects of subducting slab on the 660 km and 410 km discontinuities are studied. It is found that there are mantle discontinuities existing at the depths of 170, 220, 300, 410, 660, 850 and 1150 km. Beneath Izu-Bonin, the 410 km discontinuity is elevated, while the 660 km discontinuity is depressed; for both discontinuities, there are regionalized differences. Beneath Japan Sea, however, there is no depth variation of the 410 km discontinuity, and the 660 km discontinuity is depressed Without obvious effect of the subducting slab.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000186314200001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Geosciences, MultidisciplinarySCI(E)EI3ARTICLE121201-12114
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