• Korean Journal of Radiology
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• 제24권11호
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• pp.1114-1130
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• 2023

Magnetic resonance neurography (MRN) is increasingly used to visualize peripheral nerves in vivo. However, the implementation and interpretation of MRN in the brachial and lumbosacral plexi are challenging because of the anatomical complexity and technical limitations. The purpose of this article was to review the clinical context of MRN, describe advanced magnetic resonance (MR) techniques for plexus imaging, and list the general categories of utility of MRN with pertinent imaging examples. The selection and optimization of MR sequences are centered on the homogeneous suppression of fat and blood vessels while enhancing the visibility of the plexus and its branches. Standard 2D fast spin-echo sequences are essential to assess morphology and signal intensity of nerves. Moreover, nerve-selective 3D isotropic images allow improved visualization of nerves and multiplanar reconstruction along their course. Diffusion-weighted and diffusion-tensor images offer microscopic and functional insights into peripheral nerves. The interpretation of MRN in the brachial and lumbosacral plexi should be based on a thorough understanding of their anatomy and pathophysiology. Anatomical landmarks assist in identifying brachial and lumbosacral plexus components of interest. Thus, understanding the varying patterns of nerve abnormalities facilitates the interpretation of aberrant findings.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.64-68
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• 2007

Commercial WiBro and 3G HSDPA services are launched last year in order to provide high speed wireless Internet access and multimedia service. Currently mobile communication service providers concentrate on the deployment of indoor mobile network since indoor traffic is remarkably increased. For fine indoor wireless communication, an installation of access point system via Public IP network which is called Femtocell is required. The development of indoor Femtocell system must be considered in the viewpoint of low hardware complexity, cost reduction, interlocking with WiBro/HSDPA network without change of network component and easy element management. In this paper, we review the implementation issue and technology of dual mode AP which provides WiBro and HSDPA signal to the user simultaneously. Especially, we describe on the HSDPA Femtocell standardization status and possible 3 types of HSDPA communication module development design. Furthermore we analyze the merits and demerits of each HSDPA Femtocell design type and propose a system which enables handover between indoor HSDPA Femtocell and outdoor commercial HSDPA mobile network.

• 한국항공우주학회지
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• 제40권7호
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• pp.623-628
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• 2012

임무탑재장비 체계는 한국형 기동헬기의 임무 수행을 위해 전자장비 구성품들을 통합한 항공전자 체계다. 자체진단 시험은 숙련된 요원, 특수 시험장비의 필요성을 감소시키주며 체계의 정비를 위한 비가동 시간을 줄여준다. 갈수록 복잡성이 증가하고 있는 항공전자 장비에 대한 자체진단 시험 기능의 필요성이 더욱 커지고 있다. 본 논문은 한국형 기동헬기 항공전자 체계에 구현한 자체진단 시험 설계 및 입증에 대해 설명한다.

• 한국통신학회논문지
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• 제40권7호
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• pp.1257-1265
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• 2015

본 논문은 투영 행렬을 이용한 높은 채널 용량을 획득할 수 있는 사용자 선택 기법을 제안한다. 기존의 Frobenius norm기반의 사용자 선택 기법이 다수의 사용자를 선택할수록 정확도가 감소하는 점을 투영 행렬의 근사화 형태를 이용하여 개선하였다. Flop count를 이용한 제안 기준의 계산복잡도를 분석하였고, 모의 실험을 통하여 안테나 구성에 따른 획득 가능한 채널 용량에 대해서 비교하였다. 모의 실험 결과를 통해 제안한 사용자 선택 기법이 더 높은 채널 용량을 획득하는 것을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.305-325
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• 2014

In cloud computing infrastructure, current virtual machine trust measurement methods have many shortcomings in dynamism, security and concurrency. In this paper, we present a new method to measure the trust of virtual machine. Firstly, we propose "behavior trace" to describe the state of virtual machine. Behavior trace is a sequence of behaviors. The measurement of behavior trace is conducted on the basis of anticipated trusted behavior, which not only ensures security of the virtual machine during runtime stage but also reduces complexity of the trust measurement. Based on the behavior trace, we present a Dynamic Tree Style Trust Measurement Model (DTSTM). In this model, the measurement of system domain and user domain is separated, which enhances the extensibility, security and concurrency of the measurement. Finally, based on System Call Interceptor (SCI) and Virtual Machine Introspection (VMI) technology, we implement a DTSTM prototype system for virtual machine trust measurement. Experimental results demonstrate that the system can effectively verify the trust of virtual machine and requires a relatively low performance overhead.

• 한국컴퓨터정보학회논문지
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• 제14권6호
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• pp.99-106
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• 2009

최근 수십 년 동안 개념도는 의미 있는 교수 및 학습 도구로써 사용되어지고 있다. 많은 기존의 연구는 개념도가 학습자의 학습에 긍정적인 영향을 준다는 사실을 입증하였다. 그러나 기존 방법의 단점은 개념도를 평가하거나 학습자에게 피드백을 제공하는 과정이 평가자에 의해 수작업으로 이루어지도록 설계되어 있어 매우 시간 소모적인 작업이 된다는 것이다. 따라서 온라인 학습 활동을 통하여 개념도를 자동으로 처리하여 시간 복잡성을 줄이는 방법을 개발하는 것이 필요하다. 이미 기존 연구의 결과로써 오프라인 환경에서 개념도 평가를 위한 많은 점수 부여 방법이 제안되었다. 본 논문에서는 온라인 환경에 적합하도록 시멘틱 웹 기술을 적용하여 기존의 방법들을 효과적으로 구현한 자동화된 평가 시스템을 제시하였다. 본 논문을 통하여 시멘틱 웹 기술이 개념도의 효율적인 관리 및 자동화된 점수 부여를 위하여 이용될 수 있음을 확인하였다.

• Management Science and Financial Engineering
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• 제22권1호
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• pp.5-12
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• 2016

We consider a time-cost tradeoff problem with multiple milestones under a chain precedence graph. In the problem, some penalty occurs unless a milestone is completed before its appointed date. This can be avoided through compressing the processing time of the jobs with additional costs. We describe the compression cost as the convex or the concave function. The objective is to minimize the sum of the total penalty cost and the total compression cost. It has been known that the problems with the concave and the convex cost functions for the compression are NP-hard and polynomially solvable, respectively. Thus, we consider the special cases such that the cost functions or maximal compression amounts of each job are identical. When the cost functions are convex, we show that the problem with the identical costs functions can be solved in strongly polynomial time. When the cost functions are concave, we show that the problem remains NP-hard even if the cost functions are identical, and develop the strongly polynomial approach for the case with the identical maximal compression amounts.

• 문화기술의 융합
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• 제1권3호
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• pp.83-85
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• 2015

최근 가전제품, 모바일 장비, 웨어러블 컴퓨터 등의 IoT 분야에서 센서 정보를 주고 받는 직렬 통신 방식이 사용된다. 기존의 SPI와 I2C 직렬 통신 방식은 클럭과 데이터 2개의 핀을 사용하여 비교적 빠른 속도로 데이터를 전송하는 방식이다. 사용되는 사물들이 점차 작아지고, 데이터 전송 정보의 양이 적어지면서 전송 속도보다는 하드웨어의 단순화가 중요한 설계요소가 되는 응용분야가 늘어나고 있다. 본 논문에서는 단일 핀을 사용하여, 데이터를 직렬로 송 수신하는 회로를 설계하고 FPGA로 구현하였다. 제안된 단일 핀 직렬 통신 프로토콜은 적은 양의 데이터를 저속으로 통신하는 IoT 제품에 적합하다.

• 한국위성정보통신학회논문지
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• 제9권2호
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• pp.63-68
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• 2014

본 논문에서는 멀티콥터의 효율적 영상 전송을 위해 필요한 압축센싱 기법을 제안한다. 제안된 구조는 압축센싱에 기반한 데이터 용량을 줄이는 것에 중점을 둔다. 우선 Spectrum sensing의 기본원리를 설명하고 AMP(Approximate Message Passing)와 CoSaMP(Compressive Sampling Matched Pursuit)을 수학적 분석과 모의실험 결과를 통해서 비교한다. 또한 두 알고리즘을 계산시간과 복잡도 관점에서 평가하고 멀티콥터 동작에 적합한 알고리즘을 제안한다. 본 논문의 실험결과는 AMP 알고리즘이 CoSaMP 알고리즘보다 계산시간이 적고 이미지 에러 확률도 낮다는 것을 보여준다.

• 대한간호학회지
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• 제22권3호
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• pp.297-315
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• 1992

Caring has been identified as the essence and unifying domin of nursing(Leininger). Many nurses believe that the art of nursing is comprised of actions that are predominantly caring in nature. Although caring has been the traditional ideology of nurses, it is only now beginning to emerge as the central construct for the development of nut sing research, theory and practice. The problem addressed by this study was to identify how hospitalized children and their nurses express the meaning of caring, how they think nurses should care for children and to describe their experiences of being cared for. The purpose was to provide theoretical understanding of caring as perceived in Korea to contribute to the development of Korean nursing knowledge. The subjects were 76 hospitalized children admitted to pediatric units in five teaching hospitals and 66 nurses who were caring for these children. In this descriptive study, data were collected from Nov 11, 1991 to Jan 30, 1992 by interviews and an open-ended questionnaire and analysed by van Kaam's method. Caring themes perceived by the children and their nurses were classified into eight categories, -helping, comfort, love, warmth(only by children), recovery from illness, health maintenance (only by nurses), presence, nurturance and responsibility. Ideal caring behaviors perceived by the children and their nurses were six categories, -to give help, provide comfort, give love, stay with, treat warmly and aid recovery. Subcategories of giving help were promptness and competence, detailed explanations and support and encouragement. Other subcategories of giving help reported only by nurses were individualizing care, recognizing needs and providing a familiar enviornment. Subcategories of maintaining comfort were making comfortable, alleviating pain ; one subcategory reported only by children was consolating. A subcategory of giving love was concern, two subcategories reported only by nurses were compassion and respect. Subcategories of staying with were playing with and touching : only nurses reported empathy, Subcategories of treating warmly were tenderness and kindness. In the experience of caring, there were 4 categories, -to give help, stay with, show concern and provide comfort. Both the hospitalized children and their nurses had experienced caring primarily from their mothers. Mothers' caring behaviors were direct, personal, basic, supportive nursing acts. On the other hand, nurses caring behaviors were task oriented skilled procedures and medically delegated acts. This study contributes understanding of the complexity of caring, more specifically the meaning and experience of caring and ideal caring behaviors. Research may be able to move into verification when instruments are developed to measure the complexity of caring beliefs, values and behaviors in Korea and other cultural settings.