HL7과 IEEE 1451 기반 센서 네트워크와의 연동에 관한 연구

김우식,임수영,안진수,나지영,김남현,Kim, Woo-Shik,Lim, Su-Young,Ahn, Jin-Soo,Nah, Ji-Young,Kim, Nam-Hyun 대한의용생체공학회 2008 의공학회지 Vol.29 No.6

HL7(Health Level 7) is a standard for exchanging medical and healthcare data among different medical information systems. As the ubiquitous era is coming, in addition to text and imaging information, a new type of data, i.e., streaming sensor data appear. Since the HL7 is not covering the interfaces among the devices that produces sensor data, it is expected that sooner or later the HL7 needs to include the biomedical sensors and sensor networks. The IEEE 1451 is a family of standards that deals with the sensors, transducers including sensors and actuators, and various wired or wireless sensor networks. In this paper, we consider the possibility of interoperability between the IEEE 1451 and HL7. After we propose a format of messages in HL7 to include the IEEE 1451 TEDS, we present some preliminary results that show the possibility of integrating the two standards.

윈도우 함수를 이용한 2차원 신호의 위상복원

김우식,Kim, Woo-Shik 대한전자공학회 1998 電子工學會論文誌, S Vol.s35 No.10

이 논문에서는 윈도우를 이용한 위상복원에 관하여 다룬다, 구하고자 하는 신호의 푸리에 크기와 이 원하는 신호에 서로 보완 (complementary) 윈도우가 곱해진 신호의 푸리에 크기로부터 원하는 신호를 구하는 문제에 대하여 알아본다. 여기서는 유일 조건을 만족하기 위한 여러 조건을 제시하고 Gerchberg-Saxton 알고리즘을 응용한 새로운 복원 알고리즘을 제시한다. 이 연구의 결과는 광학, 특히 천문학에서 Ground-based Telescope의 성능 개선에 이용할 수 있을 것으로 생각된다. In this paper, we consider the problem of reconstructing a two-dimensional signal from its Fourier intensity and the Fourier intensities of two windowed signals: one by a window w(m,n) and the other by its complementary window [1-w(m,n)]. We develop several conditions under which a signal can be uniquely specified to within several trivial ambiguities such as sign, translation,and time-reversal from the given conditions. We present two possible reconstruction algorithms derived from the Gerchberg-Saxton algorithm.

MPEG-4 동영상 압축에서 비트율과 오류 내성을 고려한 인트라 업데이트

김우식,박래홍,Kim, Woo-Shik,Park, Rae-Hong 대한전자공학회 2002 電子工學會論文誌-SP (Signal processing) Vol.39 No.6

동영상 압축에서 움직임 보상은 뛰어난 압축 효율을 보이는 반면에 어느 한 시점에서 오류가 발생할 경우 그 시점 이후로 계속해서 오류가 확산된다는 단점이 있다. 인트라 업데이트 방법은 이러한 오류의 확산을 차단하는 방법이다. 그러나 인트라 업데이트 방법은 압축의 효율을 떨어뜨린다는 단점이 있다. 본 논문에서는 오류의 영향과 비트율 제어를 함께 고려하여 인트라 업데이트를 할 수 있는 방법을 제안한다. 제안된 방법은 비트율과 왜곡의 값을 추정하고 라그랑지안 최적화를 통해 부호화 모드와 양자화 파라메터를 선택하는 방법으로 MPEG-4 코덱에 적용하여 실험하였다. 실험 결과는 제안된 방법이 기존의 방법보다 패킷 손실과 같은 오류 환경에서 더 좋은 화질을 나타내는 것을 보여준다. Motion compensation is a powerful method to compress an image sequence. Its main drawback is that once an error is occurred, the error propagates through the frames. Recently, the intra update method was proposed to stop the error propagation at the expense of reduction in compression efficiency. This paper proposes an intra update method based on a rate-distortion optimization in error prone environments. The rate and the distortion are estimated using the Lagrangian optimization to select the coding mode and the quantization step size. The proposed method is applied to MPEG-4 codec, and the experimental results show that it is robust to the error such as packet losses comparing with the conventional ones.

증기발생기의 표준형 습분분리기 내부 유동 특성에 관한 수치해석

김우식(Woo-Shik Kim),최청열(Choengryul Choi),김기환(Kihwan Kim) 한국동력기계공학회 2021 동력시스템공학회지 Vol.25 No.3

지방정부조직에서 멘티의 멘토관계 구조 및 경험과 멘토링효과

김우식(Kim Woo-Shik) 서울행정학회 2005 한국사회와 행정연구 Vol.15 No.4

Researches and studies about mentorship effectiveness in private organizations have filed up. But investigations into mentoring in governmental organizations are starting now in academic arena. The present study focused on the influence of mentor-protege relationship structure and experience factors on perceptions of mentoring functions from the perspective of protege(or mentee). It was examined for 294 samples of public officers in three local governmental organizations(Chungbuk Province, Chongju City, and Chungjoo City) in Chungbuk Area. The mentoring relationship structure(mentor's cognition of protege's mentorship) and experience with mentor (maintaining relationship and number of relationships of protege) significantly affected reports of the amount of career developmental function and psychosocial function which were perceived by proteges.

개혁정책, 최고결정권자, 그리고 정책관료와의 관계

김우식(Kim Woo-Shik) 서울행정학회 2000 한국사회와 행정연구 Vol.11 No.1

개혁은 개인ㆍ집단ㆍ제도ㆍ구조 및 환경의 역동적인 연속적 상호작용과정 속에서 일어난다. 본 논문에서는 환경을 통제하고 개혁정책의 구조적 메카니즘을 ‘사람’에 초점을 맞추어 개혁의 성공적 조건을 탐색하는 데에 연구의 목적을 두고 있다. 따라서 개혁추진 중심인물을 중심으로 개혁 추진자들의 동기, 개혁 추진 세력의 세력화, 최고 의사결정자의 支持를 주요 변수로 선정하여 분석하였다. 본 연구는 세 사례를 중심으로 異時的 비교분석(diachronic comparative analysis)을 시도하였다. 비교의 세 사례는 조선 중종조의 조광조의 개혁과 숙종조의 윤휴의 개혁 그리고 전두환 정권하의 김재익의 경제개혁이며, 그들 개혁의 성패와 관련하여 공통점과 차이점을 비교분석함으로써 개혁성공의 조건(conditions)을 탐색하였다.

미립화 및 분무장치 : 다공성 표면에 충돌하는 액적 거동에 대한 실험/수치해석적 연구

김우식 ( Woo Shik Kim ),이상용 ( Sang Yong Lee ) 한국액체미립화학회 2013 한국액체미립화학회 학술강연회 논문집 Vol.2013 No.-

Behavior of a water drop impinging on heated porous surfaces was investigated experimentally and then a numerical solver was developed to predict the spreading/penetrating motion. Four porous substrates were prepared by sintering the glass particles with different sizes (60 - 270 μm in diameter). A water droplet was directed to the porous substrates with the initial wall temperature varying from 60ºC to 300ºC. The impinging Weber numbers ranged from 25 to 200 that correspond to the impact velocities from 0.8 m/s to 2.3 m/s for a water drop of 2.6 mm in diameter. The post-impingement behavior was visualized by using a high-speed camera, and the time variation of the surface temperature distribution was measured with the aid of a high-speed IR camera. The post-impingement regime map was constructed based on the observation. Basically three impingement regimes were identified: full-contact regime in the low temperature range and non-contact regime in the high temperature range, and the partial-contact regime between them. The full-contact regime, in which the drop evaporated or boiled while in contact with the surface without any disintegration, was divided into two sub-regimes: internal evaporation and internal boiling. In the partial-contact regime, a vigorous vapor nucleation was observed at the interface between the drop and the surface, which resulted in formation of the secondary droplets. In the non-contact regime, the drop was levitated but at a lower wall temperature with the larger-bead substrates due to more active nucleation on the rougher surfaces. The increase in the Weber number resulted in the higher transition temperature to the non-contact regime. This is considered to be due to the increase of the dynamic pressure at the liquid-solid interface at the instant of impact. Time variation of the surface temperature was also examined. The temperature sharply decreased right after the drop impact, and then increased with time to reach a thermal equilibrium between the penetrated liquid drop and the porous solid structure (phase I). Then the surface temperature decreased again along with the evaporation of the liquid (phase II), and finally increased up to the initial wall temperature upon completion of evaporation (phase III). The total evaporation time decreased with the larger wet-area diameter, which could be achieved with the larger impact velocity. However, there existed an optimum pore size (or size of particles) to show the maximum wet-area diameter and the shortest evaporation time. The spreading diameter and the wet-area diameter turned out to be the major indicators of the cooling performance, which were strongly influenced by both the impact condition and the characteristics of the porous substrates. In order to examine the spreading/penetrating behavior of the impinging drop against porous substrates in detail, a simulation solver (porousInterFoamWoo) was developed. The solver is based on the open source code, OpenFOAM, but the governing equations were modified from those in a pre-adapted VOF solver (porousInterFoam). The effects of the porosity on the displacement of the liquid-vapor interface and the capillary wicking force were additionally considered in the solver. A capillary-rise experiment and a one-dimensional pressure drop measurement were performed to validate the porousInterFoamWoo solver. Finally, the spreading/penetrating behavior of an impinging water drop against the porous substrates was simulated and compared with the experimental data. The solver predicted the time variations of the spreading and the wet-area diameters with a reasonable accuracy. An improved version of the solver that can predict the temperature distribution as well is currently under construction.

이중 에너지 영상 방법에 의한 기본 물질의 분리에 관한 연구

김우식(Woo Shik Kim),이태수(Tae Su Lee),민병구(Byoung Goo Min),이충웅(Choong Woong Lee) 대한전자공학회 1985 대한전자공학회 학술대회 Vol.1985 No.6

정부-기업조직 간 멘토링 기능의 효과 차이

김우식(Woo Shik Kim),하민철(Min Cheol Ha) 서울행정학회 2007 한국사회와 행정연구 Vol.18 No.2

Mentoring as a knowledge transfer and translation is useful for newcomers to organizations. Newcomers could get formal and tacit knowledge through mentoring in organization context. Mentoring is good for individuals' career development and psychological support. It is also important for organizational effectiveness. Through mentoring relationships, mentor and mentee interact f or k nowledge t ransfer, which i s important t o them f or f ulfilling t heir n eeds a nd organizational success as a whole. On this position, this study was to investigate differences between public and private organizations in structure, process, and functional effectiveness of mentoring relationships. From outcomes of our study, we gained several informations about similarities and differences between two sectors. And for preparing formal mentoring program in public sector, some policy implications were discussed.

Observation of Injection Characteristics of Core Makeup Tank during SBLOCA Test Using SMART-ITL

Woo Shik Kim(김우식),Hwang Bae(배황),Sung Uk Ryu(류성욱),Yong-Cheol Shin(신용철),Kyoung-Ho Min(민경호),Hyo Bong Ryu(유효봉),Sung-Jae Yi(이성재),Hyun-Sik Park(박현식) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.열공학 No.-