초음파 영상 시스템에서의 슈도랜덤 부호에 대한 신호대 잡음비와 대역폭

김원기(Won Ky Kim),박송배(Song Bae park) 대한전자공학회 1984 대한전자공학회 학술대회 Vol.1984 No.10

환자 감시 장치의 자동화 전망

金源麒(Won-Ky Kim) 대한전기학회 1985 전기의 세계 Vol.34 No.9

황토를 이용한 수중의 인 제거에 관한 기초 연구

김원기(Won Ky Kim),강선홍(Seon Hong Kang) 한국물환경학회 2000 한국물환경학회지 Vol.16 No.5

Since phosphorus can play an important role in eutrophication as well as nitrogen, pollution due to phosphorus has been issued globally. To remove phosphorous in water and wastewater, chemical precipitation has been generally used. However, this method needs high cost and further treatment to remove chemical sludge. In this work it was studied whether loess can be used as an adsorbent to remove phosphorous in wastewater. Synthetic wastewater was made in the laboratory. To investigate phosphorus removal efficiency, loess dosage, particle size, temperature, and pH were varied. To investigate adsorption efficiency of loess, results were applied to Freundlich and Langmuir Isotherm. As a result of this study, removal efficiency of phosphorus increased as dossage of loess and temperature increased. When loess was used in removing phosphorus in wastewater, the removal efficiency was lower than that of CaO or Ca(OH)₂. But the removal rate was higher than that of CaCO₃ or CaCl₂ · 2H₂O at 2% as weight/volume base. Isotherm experiments results using phosphorus were reasonably suitable to Freundlich and Langmuir isotherm respectively. As a conclusion, loess has a potential value as an adsorbent to remove phosphorus in wastewater.

마이크로프로세서를 이용한 분리형 임의파형발생기의 개발

김남현,김원기,유선국,양호,Kim, Nam-Hyun,Kim, Won-Ky,Yoo, Sun-Kook,Yang, Ho 대한의용생체공학회 1989 의공학회지 Vol.10 No.1

An arbitrary waveform generator was developed for the experiment of electro-physiology and the electrical stimulator. This system has been constructed three parts. (1 ) Data input parts (2) Data processing and control parts (3) Analog signal output parts The system characteristics were as follows. (1) System based on Microprocessor (2) Input using Thumbwheel switch (3) Isolated output signal (4) System flexibility

잡음동기형 표본화 제어기에 의한 전력선 잡음의 적응제거

고한우,김원기,이건기,Ko, Han-Woo,Kim, Won-Ky,Lee, Gun-Ki 대한의용생체공학회 1988 의공학회지 Vol.9 No.1

A new implementation of a noise tracking filter is prposed to eliminate time-varying 60 Hz noise and its harmonics and baselins wandering in biological signals. This technique was applied to ECG. Filter's notch frequency could track the power line frequency well and it showed much better characteristics than the conventional method.

선형 Octree에 의한 CT영상의 3차원 재구성 및 표현

유선국,김남현,김원기,김선호,박상희,Yoo, Sun-Kook,Kim, Nam-Hyun,Kim, Won-Ky,Kim, Sun-Ho,Park, Sang-Hui 대한전자공학회 1989 전자공학회논문지 Vol. No.

본 논문에서는 2차원적인 CT영상의 단면으로부터 3차원 영상을 재구성하고 수정하기 위한 시스템을 구성하기 위하여 선형 octree를 이용하였다. 선형 octree를 소형 컴퓨터 시스템에 적용할 경우, 재구성하기 위하여 소요되는 많은 데이터를 효율적으로 압축할 수 있었다. 특히 이러한 트리구조는 공간적인 개념이 포함되어 있는 계층적인 표현방식을 갖기 때문에 3차원 영상을 2차원 화면에 표현하기 위한 은면제거를 효율적으로 수행할 수 있었으며, 관측위치의 변환 및 명암표시의 실현이 가능하였다. 실제 CT에 의하여 획득된 인체기관을 재구성하여 봄으로서 기술적 기법들 확인하였으며, 임상적인 치료와 외과 수술계획에 사용될 가능성을 확인하여 보았다. In this paper, linear octree is used to reconstruct and to modify the 3-dimensional image from 2-dimensional cross sections provided by computed tomography. Linear octree introduces a considerable data saving of the memory storage required by small computer system. This structure allows the hidden surface removal utilizing the spatial presortedness of hierarchical octree structure and implementation of graphical operations that include viewing transform and shading. An actual human organ is used to illustrate this technique and its implications for theraphy and surgical planning.

임피던스 심장기록기의 개발과 응용

김덕원,김정열,김원기,박상희,Kim, Deok-Won,Kim, Jeong-Yeol,Kim, Won-Ky,Park, Sang-Hui 대한전자공학회 1990 전자공학회논문지 Vol. No.

The thermodiluton is a standard method to measure cardiac output in clinical medicine. However it has many disadvantages such as expensive instrument and measurement, limited number of measurement, pain, safety problem, and side-effect due to insertion of catheter into heart. Electrical Impedance Cardiography has no such disadvantages and that it can continuously monitor stroke volume, contractility of cardiac muscle, and systolic time interval (STI) as well as cardiac output. While this impedance technique has been widely used and vigorously studied adroad, it is not introduced yet in Korea. Thus an Impedance Cardiograph has been developed in order to introduce this new technique. Its accuracy also has been verified by simultaneous measurement of cardiac output with the thermodilution technique. Finally changes of cardiac function during exercise were also measured. 현재 임상에서 환자의 심박출량(cardiac output)을 측정하는데 널리 쓰이는 열희석법(thermodilution)은 카테터(catheter)의 심장주입에 따르는 위험성, 부작용 및 고도의 기술요구와 측정장비 및 비용의 고가, 측정 횟수의 제한, 환자의 고통등 여러 가지 문제점을 내포하고 있다. 한편 Electrical Impedance Cardiography는 이러한 열의석법의 단점들을 해결하고 나아가서 열희석법과는 달리 계속적으로 심박출량 뿐만 아니라 박동량(stroke volume) 및 심근육의 수축력등 심장의 기계적 기능을 감시할 수 있는 방법으로서, 외국에서는 널리 쓰이고 있고 이에 대한 연구도 활발한 상태이나 국내에서는 거의 보급이 안되어 있는 설정이다. 그리하여 본 연구에서는 이 새로운 분야의 국내 보급을 위하여 시제품을 완성하고 임상에서의 표준방법인 열희석법과 동시에 측정하여 기기의 정확성을 확인하였으며 운동 중에 운동부하 증가에 따른 심장기능의 변화도 측정하였다.

업종별 산업폐수중 수질오염물질 배출 특성 및 개연성 평가 연구

안태웅(Tae Ung Ahn),김원기(Won Ky Kim),손대희(Dae Hee Son),염익태(Ick Tae Yeom),김재훈(Jae Hoon Kim),유순주(Soon Ju Yu) 大韓環境工學會 2016 대한환경공학회지 Vol.38 No.1

업종별 수질오염물질 배출 목록은 산업폐수 배출시설을 인허가할 때, 해당 시설 또는 업종에서 관리해야 하는 배출가능한 수질오염물질을 정확히 검토하기 위함은 물론이고, 오염방지시설의 설계에도 필수적인 가장 기초적인 자료이다. 본 연구에서는 우리나라 폐수배출시설 3개 업종을 대상으로 수질오염물질 배출목록을 작성하기 위하여 해당 사업장의 일반현황 및 처리시설 운영 등에 대한 기초자료 수집과 해당 사업장에서 배출하고 있는 산업폐수중 특정수질유해물질을 비롯한 수질오염물질에 대한 수질 분석을 수행하였다. 본 연구의 조사대상 업종별 수질오염물질 배출목록을 확정하기 위해서 정상적인 시설운영 과정에서 해당물질이 폐수중으로 실제 배출될 수 있는 개연성을 확인하였다. 이를 위해, 먼저 원폐수 및 최종배출수의 시료 분석에서 검출된 모든 수질오염물질을 평가대상으로 하고, 검출되지 않은 물질은 대상에서 제외한다. 다음으로 이들 평가대상 수질오염물질에 대하여 제조공정상에서 사용하는 각종 원료, 부원료, 불순물 등에서 포함될 가능성을 확인하고, 여기에서 확인될 경우 수질오염물질 배출목록으로 확정한다. 본 연구에서는 3개 업종을 대상으로 하였으며, 석유화학계 기초화합물 제조시설은 조사대상 물질 42종 중 특정수질유해물질 16종을 포함한 31종, 기타 기초유기화합물 제조시설은 특정수질유해물질 14종을 포함한 30종, 화력발전시설은 특정수질유해물질 8종을 포함한 20종의 수질오염물질이 배출목록으로 확정되었다. 본 연구에서는 수질분석과 개연성 평가를 통해 보다 객관적이고 타당성 있는 업종별 수질오염물질 배출목록을 작성하였다. Information on the lists of pollutants from industrial wastewater discharge are essential not only to specify the key pollutants to be managed in permission process but to design the treatment facilities by the dischargers. In this study, wastewater quality analysis was conducted for three industrial categories including the specified hazardous water pollutants. The general description of the wastewater occurrence, major sources, treatment facilities are also investigated to obtain integrated database on the pollutant inventories for the industrial categories. In addition Based on the analysis of raw wastewater and final effluent, the detected pollutant items are confirmed by analyzing their presence in the raw or supplement materials, the potential of formation as byproducts, and the possibility of inclusion as impurities. The three industrial categories include petrochemical basic compounds, basic organic compounds, and thermal power generation. The water pollutants emitted from petrochemical basic compound manufacturing facilities are 31 items including 16 specified hazardous water pollutants. Basic organic compound manufacturing facilities discharge 30 kinds of pollutants including 14 specified hazardous water pollutants. Thermal power generation facilities emit 20 pollutants, 8 specified hazardous water pollutants among them. These substances were decided as emission inventories of water pollutants finally through the probability evaluation. The compounds detected for each categories are screened through investigation on the possible causes of their occurrence and confirmed as the final water pollutant inventories.

MF-BIA Analyzer를 이용한 경혈의 세포 내액과 외액에 의한 저항성분 추정 방법 제시 및 반영률 평가

김수병 ( Soo Byeong Kim ),이나라 ( Na Ra Lee ),김원기 ( Won Ky Kim ),이용흠 ( Yong Heum Lee ) 경락경혈학회 2012 Korean Journal of Acupuncture Vol.29 No.4

Objectives: The aim of this study was to suggest a new method to estimate the resistance by acupoint compositions by using the multi-frequency bioelectrical impedance analysis(MF-BIA) of 5 kHz, 50 kHz and 200 kHz within 2 cm of acupoints as a local segment. Moreover, we try to confirm the relation to between measured resistance at skin surface and measured resistance by various manual acupuncture needle insertion depth. Methods: Ten male subjects participated in this study. We measured the resistance at left/ right ST36 at skin surface and various manual acupuncture needle insertion depth(skin, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm and 30 mm). Results: It was also observed that the all measured resistances were the highest at 5 kHz and the lowest at 200 kHz. There were significant differences at 5 kHz, 50 kHz and 200 kHz between measured resistance at skin surface and measured resistance by various manual acupuncture needle insertion depth(p<0.05). There was no significant difference in the left and right identical acupoints under the identical condition(p>0.05). Conclusions: We conclude that the measured resistance at skin surface has limitation as to reflect the information of tissue. However, the measured resistance at each frequency was changed as similar pattern by different insertion depth. Hence, we confirmed the possibility of assumption on information of tissue which was expected to locate an acupoint.

임피던스 방법을 위한 심장 기능의 측정

김정열(Jeong Yeol Kim),김덕원(Deok Won Kim),김원기(Won Ky Kim),박상희(Sang Hui Park) 대한전기학회 1988 대한전기학회 학술대회 논문집 Vol.1988 No.7