• Title/Summary/Keyword: fundamental principles

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Radiology of Magnetic Resonance Spectroscopy (진단방사선에서의 자기공명분광)

  • Park, Bo-Young
    • Progress in Medical Physics
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    • v.3 no.2
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    • pp.33-42
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    • 1992
  • The fundamental principles of MRS, one of the most powerful analytical tools in seience, is introduced as the promising methodology in the diagnostic radiology of medical science. A variety of applications of MRS indicates the possibility of more accurate and sensitive diagnosis in medicine. The combination of anatomical informations by MRI and biochemical informations by MRS provides the bright prospect in the diagnostic radiology.

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MAC Protocols for Energy Harvesting Wireless Sensor Networks: Survey

  • Kosunalp, Selahattin
    • ETRI Journal
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    • v.37 no.4
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    • pp.804-812
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    • 2015
  • Energy harvesting (EH) technology in the field of wireless sensor networks (WSNs) is gaining increasing popularity through removing the burden of having to replace/recharge depleted energy sources by energy harvester devices. EH provides an alternative source of energy from the surrounding environment; therefore, by exploiting the EH process, WSNs can achieve a perpetual lifetime. In view of this, emphasis is being placed on the design of new medium access control (MAC) protocols that aim to maximize the lifetime of WSNs by using the maximum possible amount of harvested energy instead of saving any residual energy, given that the rate of energy harvested is greater than that which is consumed. Various MAC protocols with the objective of exploiting ambient energy have been proposed for energy-harvesting WSNs (EH-WSNs). In this paper, first, the fundamental properties of EH-WSN architecture are outlined. Then, several MAC protocols proposed for EH-WSNs are presented, describing their operating principles and underlying features. To give an insight into future research directions, open research issues (key ideas) with respect to design trade-offs are discussed at the end of this paper.

Difference of Customer Satisfaction Variables with the Student Characteristics (학생특성에 따른 고객만족변수의 차이)

  • Kim Yong-Ho
    • Management & Information Systems Review
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    • v.4
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    • pp.285-308
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    • 2000
  • Marketing is a topic of growing interest to nonprofit organizational managers(for example, hospitals, museums, charities and, churches, universities and colleges) as their organizations confront new, complex marketplace problems. These organization heads(specially in university and college) are laking their first, tentative steps toward marketing, often confusing it with its advertising and selling subfunctions. A genuine marketing response has been undertaken by a relatively small number of college in america. Their approach is best described as market-oriented institutional planning. In these approach, marketing is recognized as much more then mere promotion, and indeed, the issue of promotion cannot be settled in principles until more fundamental issues are resolved. According to market-oriented institutional planning customer satisfaction is one of the most important concept in university(college) marketing. Therefore, this study reviews literatures about university(college) marketing and general customer satisfaction. The literature study suggests some research hypotheses about customer satisfaction in college. Next, these hypotheses are tested empirically using ${\chi}^2-test$, multiple linear regression analysis and t-test. The research results worth explorative study on the customer satisfaction in the college.

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Fundamental magnetic and elastic properties of Fe-Si alloys: A first-principles study

  • Yun, Won-Seok;Lee, Jee-Yong;Kim, In-Gee;Hong, Soon-Cheol;Lee, Jae-Il
    • Proceedings of the Korean Magnestics Society Conference
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    • 2011.12a
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    • pp.39-40
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    • 2011
  • In this study, the magnetism and the elastic properties of Fe-Si alloys have been investigated using the all-electron FLAPW method based on the GGA. The local magnetic moment of Fe atoms decreases gradually. From the Pugh's relation and $C_P$, in the ordered $D0_3$ $Fe_3Si$, we predict that it presents intrinsic ductility.

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A Directional Relay Algorithm Using Positive-Sequence Superimposed Quantity for Transmission Line Protection (정상 성분 변화량을 이용한 송전선로 보호용 방향 계전 알고리즘)

  • 이명수;유석구
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.4
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    • pp.226-233
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    • 2003
  • Directional elements are fundamental to protection scheme security and selectivity, performing such critical tasks as supervising distance elements and controlling overcurrent elements. But, conventional operating principles for directional detection based on negative or zero sequence quantify do not satisfy the requirements for improved sensitivity and fast operation under any fault conditions. In this paper, new algorithm for directional elements is proposed. The proposed algorithm use the positive-sequence superimposed voltages and currents in order to be used in all fault conditions. Also, because this algorithm uses a voltage compensation method. it can be well operated under strong source conditions.

A study on CAD-work Standardization of design practical field - centering drawing management system - (디자인 실무를 위한 캐드작업 표준화 연구 1 - 도면관리체계를 중심으로 -)

  • 홍관선;김석태
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2002.04a
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    • pp.111-115
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    • 2002
  • CAD System, which has been actively applied since late 80's, has become one of the most important tools in architectural design and has taken the central position in practical design processes. However, it is widely known that AutoCAD, the market-leading general-use CAD System, resulted in hindering the standardization of CAD System. This has been causing problems in communication among designers and inefficiency in their uses. The standardization in CAD System becomes an urgent issue. The study attempts to build up fundamental principles in standardization of CAD System, and to suggest a combinational model of international and domestic standards.

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Reliable Overlay Multicast with Loosely Coupled TCP Connections

  • Kwon, Gu-In;Byers, John
    • Journal of Communications and Networks
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    • v.11 no.3
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    • pp.306-317
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    • 2009
  • We consider the problem of architecting a reliable content delivery system across an overlay network using TCP connections as the transport primitive. We first argue that natural designs based on store-and-forward principles that tightly couple TCP connections at intermediate end-systems impose fundamental performance limitations, such as dragging down all transfer rates in the system to the rate of the slowest receiver. In contrast, the ROMA architecture we propose incorporates the use of loosely coupled TCP connections together with fast forward error correction techniques to deliver a scalable solution that better accommodates a set of heterogeneous receivers. The methods we develop establish chains of TCP connections, whose expected performance we analyze through equation-based methods. We validate our analytical findings and evaluate the performance of our ROMA architecture using a prototype implementation via extensive Internet experimentation across the PlanetLab distributed testbed.

Introduction of Principles for Disaster Prevention Planning in u-City (u-방재 City 기본방향 연구)

  • Kim, Hyun-Joo;Park, Young-Jin;Lee, Won-Sung;Yeon, Kyung-Hwan
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.127-130
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    • 2008
  • This study demonstrates a basic concept and designing direction for the realisation of disaster prevention planning in u-City(u-BangjaeCity) that is from establishing a planning system in terms of the areas of professional disaster and safety management for the national disaster management. and designing disaster or safety management system via using ubiquitous technology for the scientific disaster management. In order to realise u-City it is necessary to maps out interrelation amongst various services such as traffic, environment and disaster prevention. Domestic and international case studies regarding the tendency of disaster prevention planing in u-City and its analysis could be the fundamental resource in order to develop the standard model of u-BangjaeCity.

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A Study on the architectural composition of Giorgio Grassi (죠르죠 그라씨 건축형태 구성원리에 관한 연구)

  • 곽기표
    • Korean Institute of Interior Design Journal
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    • no.32
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    • pp.13-20
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    • 2002
  • This study is purposed to find fundamental characteristics in Grassi's architecture which has architectural principles in architecture itself and in the general frame of the historical facts of architecture. His architectural theories can be explained for rationality, historicity, universality. The method of architectural composition can be divided into urban morphological characteristic and compositional characteristic of architecture. The characteristics of the former are the reconstruction of the urban structure by the readjustment of an urban axis which is based on historical continuity of the city, the open court which is a passage transformed from colonnade that is the historical vernacular type and the respect for the city-line which goes with historical context. The characteristics of the latter are the use transformed of nine square which gives consideration to centrality and typology at the same time and the hierarchic division of the principal space and the subordinate space for the functional typical purpose. This analysis shows that Grassi's architecture is on the base of historical continuity and urban reality and for him architectural work is mental work which conflict with the real world for the reconstruction of the city.

Optical Properties of Sulfur and NaI by Microwave Discharge (마이크로파 방전에 의한 Sulfur와 NaI의 광학적 특성)

  • Lee, Jong-Chan;Hwang, Myung-Keun;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.109-111
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    • 2002
  • The fundamental principles of the operation of microwave discharges that are used to convert microwave energy to broad spectrum visual light are known. In this paper, emission dependance of microwave discharges in mixture content of sulfur with noble gases was studied. It is shown that the excitation of this gaseous mixture is carried out in two phases; (1) ionization of noble gas atoms by a microwave field and (2) the consequent maintenance of slightly ionized nonequilibrium plasma by the field. These two processes have essentially various thresholds for the microwave pump. The purpose of this work is to investigate spectral properties of the high frequency discharges in a mixture sulfur vapors with noble gases.

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