다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

This handbook looks to provide academics and students with a comprehensive and holistic understanding of the phenomenon of innovation. Innovation spans a number of fields within the social sciences and humanities: Management, Economics, Geography, Sociology, Politics, Psychology, and History. Consequently, the rapidly increasing body of literature on innovation is characterized by a multitude of perspectives based on, or cutting across, existing disciplines and specializations. Scholars of innovation can come from such diverse starting points that much of this literature can be missed, and so constructive dialogues missed. The editors of The Oxford Handbook of Innovation have carefully selected and designed twenty-one contributions from leading academic experts within their particular field, each focusing on a specific aspect of innovation. These have been organized into four main sections, the first of which looks at the creation of innovations, with particular focus on firms and networks. Section Two provides an account of the wider systematic setting influencing innovation and the role of institutions and organizations in this context. Section Three explores some of the diversity in the working of innovation over time and across different sectors of the economy, and Section Four focuses on the consequences of innovation with respect to economic growth, international competitiveness, and employment. An introductory overview, concluding remarks, and guide to further reading for each chapter, make this handbook a key introduction and vital reference work for researchers, academics, and advanced students of innovation. Contributors to this volume - Jan Fagerberg, University of Oslo William Lazonick, INSEAD Walter W. Powell, Stanford University Keith Pavitt, SPRU Alice Lam, Brunel University Keith Smith, INTECH Charles Edquist, Linkoping David Mowery, University of California, Berkeley Mary O'Sullivan, INSEAD Ove Granstrand, Chalmers Bjorn Asheim, University of Lund Rajneesh Narula, Copenhagen Business School Antonello Zanfei, Urbino Kristine Bruland, University of Oslo Franco Malerba, University of Bocconi Nick Von Tunzelmann, SPRU Ian Miles, University of Manchester Bronwyn Hall, University of California, Berkeley Bart Verspagen , ECIS Francisco Louca, ISEG Manuel M. Godinho, ISEG Richard R. Nelson, Mario Pianta, Urbino Bengt-Ake Lundvall, Aalborg

The Oxford Handbook of Innovation

Fiber-based structures are highly desirable for wearable electronics that are expected to be light-weight, long-lasting, flexible, and conformable Many fibrous structures have been manufactured by well-established lost-effective textile processing technologies, normally at ambient conditions The advancement of nanotechnology has made it feasible to build electronic devices directly on the surface or inside of single fibers, which have typical thickness of several to tens microns However, imparting electronic functions to porous, highly deformable and three-dimensional fiber assemblies and maintaining them during wear represent great challenges from both views of fundamental understanding and practical implementation This article attempts to critically review the current state-of-arts with respect to materials, fabrication techniques, and structural design of devices as well as applications of the fiber-based wearable electronic products In addition, this review elaborates the performance requirements of the fiber-based wearable electronic products, especially regarding the correlation among materials, fiber/textile structures and electronic as well as mechanical functionalities of fiber-based electronic devices Finally, discussions will be presented regarding to limitations of current materials, fabrication techniques, devices concerning manufacturability and performance as well as scientific understanding that must be improved prior to their wide adoption

Fiber‐Based Wearable Electronics: A Review of Materials, Fabrication, Devices, and Applications

Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. Components and interconnections are intrinsic to the fabric and thus are less visible and not susceptible of becoming tangled or snagged by surrounding objects. E-textiles can also more easily adapt to fast changes in the computational and sensing requirements of any specific application, this one representing a useful feature for power management and context awareness. The vision behind wearable computing foresees future electronic systems to be an integral part of our everyday outfits. Such electronic devices have to meet special requirements concerning wearability. Wearable systems will be characterized by their ability to automatically recognize the activity and the behavioral status of their own user as well as of the situation around her/him, and to use this information to adjust the systems' configuration and functionality. This review focuses on recent advances in the field of Smart Textiles and pays particular attention to the materials and their manufacturing process. Each technique shows advantages and disadvantages and our aim is to highlight a possible trade-off between flexibility, ergonomics, low power consumption, integration and eventually autonomy.

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Wearable Electronics and Smart Textiles: A Critical Review

A dual band textile antenna designed for Digital Television (DTV) and many wireless standards including GSM 900, WLAN 2.45/5.8 GHz, Wimax 3.5 GHz, Hyperlan 5.2 GHz and UMTS-LTE-advanced is described. The impact of the body on antenna performance is assessed for return loss, radiation patterns and antenna efficiency in a wide frequency range. Full three dimensional radiation patterns were measured with the antenna backed by a phantom in order to simulate a human body. While the return loss was found to be only marginally affected when the antenna was mounted at various positions on the human body, the measured efficiency was observed to decrease by up to 90% when the antenna was positioned flush to the phantom. The return loss response was little affected when the antenna was worn on the back and further covered with a number of garments including a thick woolen jumper and a ski jacket. Although antenna efficiency was substantially affected by the presence of the body, interposing a layer of felt fabric between the antenna and the phantom typically improved efficiency by over 50%. This unique soft antenna is a good candidate for receiving digital television and wireless communications in a smart clothing environment.

Impact of Body and Clothing on a Wearable Textile Dual Band Antenna at Digital Television and Wireless Communications Bands

The performance of a textile patch antenna designed on a small ground plane for wireless off-body communication applications is assessed when the antenna is brought in close proximity to a human body. The study looks at the effects on the reflection coefficient and efficiency of the antenna as it is placed on the body. Simulated and measured results show that the antenna does not experience any signifiant detuning effects when it is placed on the phantom. The on body 3D radiation patterns were measured along with the efficiency compared to a monopole antenna. It was found that increasing textile ground plane size had a relatively small impact on efficiency. Spacing the antenna away from the body however produced over 75% increase in efficiency and may therefore constitute a robust solution in order to increase the overall efficiency of a wearable communication system. The performance of the antenna was compared to two patch antennas printed on substrates of FR4 and RT/Duroid 5880.

Influence of body proximity on the efficiency of a wearable textile patch antenna

Recently, spatiotemporally modulated metamaterial has been theoretically demonstrated for the design of Doppler cloak, a technique used to cloak the motion of moving objects from the observer by compensating for the Doppler shift. Linear Doppler effect has an angular counterpart, i.e., the rotational Doppler effect, which can be observed by the orbital angular momentum (OAM) of light scattered from a spinning object. In this work, we predict that the spatiotemporally modulated metamaterial has its angular equivalent phenomenon. We therefore propose a technique to observe the rotational Doppler effect by cylindrical spatiotemporally modulated metamaterial. Conversely, such a metamaterial is able to cloak the Doppler shift associated with linear motion by generating an opposite rotational Doppler shift. This novel concept is theoretically analyzed, and a conceptual design by spatiotemporally modulating the permittivity of a voltage-controlled OAM ferroelectric reflector is demonstrated by theoretical calculation and numerical simulation. Finally, a Doppler cloak is experimentally demonstrated by a spinning OAM metasurface in radar system, which the spatiotemporal reflection phase are mechanically modulated. Our work presented in this paper may pave the way for new directions of OAM carrying beams and science of cloaking, and also explore the potential applications of tunable materials and metasurfaces.

Design and experimental demonstration of Doppler cloak from spatiotemporally modulated metamaterials based on rotational Doppler effect.

Modern communication systems will require antennas with adaptive functionality that are able to modify their performance based on the requirements of the channel. For example, mobile ad hoc networks need directive antennas that are able to radiate in any direction across the 360° azimuth plane. Conformal antennas that can be simply operated to have multifunctional performance characteristics are therefore of interest. In this communication, we present a gradient-index lens antenna designed to radiate with a 45° beamwidth across eight different sectors. When fed by a simple switched feeding network, the lens is able to provide 360° azimuth coverage in 45° segments. Further analysis of the radiation patterns shows how two distinct multibeam patterns can be produced from simple feed networks and simultaneous excitation of each feeding element. The proposed lens is fabricated by multimaterial 3-D printing. The final lens radiates with a gain of 8.5 dBi when a single sector is excited, and with a maximum gain of 5.9 dBi in multibeam mode. Finally, it is shown how the lens can also radiate omnidirectionally when optimized phase and amplitude weightings are applied to each port.

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Multibeam Graded Dielectric Lens Antenna From Multimaterial 3-D Printing

Dielectric materials, with high tunability at microwave frequencies, are key components in the design of microwave communication systems. Dense Ba0.6Sr0.4TiO3 (BST) ceramics, with different grain sizes, were prepared in order to optimise the dielectric tunability via polar nano cluster effects. Dielectric permittivity and loss measurements were performed at both high and low frequencies and were supported by results from X-ray powder diffraction, scanning and transmission electron microscopies, Raman spectroscopy and piezoresponse force microscopy. The concentration of polar nano clusters, whose sizes are found to be in the range 20–50 nm, and the dielectric tunability increase with increasing grain size. A novel method for measurement of the microwave tunability in bulk dielectrics is presented. The highest tunability of 32 % is achieved in ceramics with an average grain size of 10 μm. The tunability of BST ceramics with applied DC field is demonstrated in a prototype small resonant antenna.

Henry Giddens

Papers

Impact of Body and Clothing on a Wearable Textile Dual Band Antenna at Digital Television and Wireless Communications Bands

Influence of body proximity on the efficiency of a wearable textile patch antenna

Design and experimental demonstration of Doppler cloak from spatiotemporally modulated metamaterials based on rotational Doppler effect.

Multibeam Graded Dielectric Lens Antenna From Multimaterial 3-D Printing

Polar nano-clusters in nominally paraelectric ceramics demonstrating high microwave tunability for wireless communication