• 한국의학물리학회지:의학물리
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• 제16권2호
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• pp.82-88
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• 2005

상용화된 방사선 치료계획 장치에서 제공하는 선량보상체(compensator) 설계 기능의 타당성 을 검증하고자 Cerrobend 재료를 대상으로 한 고밀도의 선량보상체 설계 및 제작과 동적다엽콜리메이터를 활용한 전자 선량보상체(Electronic Compensator)의 구현을 통해 그 기능을 분석하였다. 5개의 두께가 다른 영역으로 구성한 팬텀을 대상으로 전산화단층촬영(CT) 영상을 획득하고, 기준 깊이에서 균일한 선량분포를 형성하도록 방사선치료계획장치(RTP)에서 선량보상체를 설계하였다. Cerrobend 선량보상체 주조 틀을 제작하기 위해 컴퓨터로 자동 제어되는 스티로폼 절삭기를 사용하였고, 전자선량보상체를 구현하기 위해 다엽콜리메이터를 사용하였으며, 선량분포의 측정을 위해서 선량측정용 필름을 사용하였다. 선량보상체를 적용하지 않았을 경우, 선량분포에서 $\pm13.93 cGy$의 편차를 보였으나, Cerrobend 선량보상체와 전자선량보상체를 적용하였을 경우, 각각 $\pm0.99 cGy$와 $\pm1.82cGy$의 편차를 보여 선량분포의 균일도를 높이는 선량보상체로서 기능을 구현함을 증명하였다. 방사선치료계획장치에서 계획된 기준 선량값과의 평균 오차를 분석한 결과, Cerrobend 선량보상체는 $+3.83\%$, 전자 선량보상체는 $-4.37\%$의 오차를 보였으며, 이는 Cerrobend 선량보상체 제조과정에서의 오차와 절대 선량측정 도구로서 필름이 갖고 있는 한계성을 고려할 때, 선량보상체 기능의 정확도 입증에 타당성 있는 결과로 생각한다.

• 천문학논총
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• 제34권3호
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• pp.31-40
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• 2019

보루각루를 발전시킨 흠경각루는 세종이 계획하고 장영실이 제작했다. 1438년에 완성한 흠경각루는 수격식 혼의와 혼상의 동력 발생 방식(Lee & Kim, 2012; Mihn et al., 2016)을 채택하였을 뿐만 아니라, 보루각루에서 검증된 구슬 신호 방식과 방목장치를 개량한 걸턱 신호를 활용한 것으로 추론된다. 비록 흠경각루의 내부 구조에 대한 자세한 기술은 없지만, 가산의 상층, 중층, 하층에서 시각에 따라 운행되는 시보시스템 모델을 구체적으로 제시하였다. 본 연구의 흠경각루 모델은 수차의 회전 동력이 기륜 주축에 연결된 세 기륜(4신기륜, 시보기륜, 12신기륜)의 회전력을 기반으로 각종 인형들을 작동시키는 메커니즘으로 구현하였다. 흠경각루 시보시스템 모델을 통한 작동구조와 주요 특징을 정리하면 다음과 같다. 첫째, 4신기륜은 걸턱과 지레를 이용해 4신옥녀의 종을 치고, 4신이 90℃씩 회전하도록 구성했다. 둘째, 시보기륜에서 주전의 역할과 기능을 갖도록 12시진·5경·5점의 걸턱, 밀쇠, 구슬키잡이를 설치해 구슬신호를 발생시키고, 구슬신호 분배기를 통해 경점시간을 알렸다. 셋째, 12신기륜에서 걸턱, 마중쇠, 저울쇠 등을 설치해 12신옥녀와 12신의 작동을 제어했다. 보루각루를 더욱 발전시킨 흠경각루에서는 걸턱, 지레, 주전, 구슬 신호 등을 적용하여 이슬람의 기술요소를 다양한 방식으로 확장하여 적용했다. 이러한 전통은 17세기 조선의 혼천시계 제작 방법에서도 그대로 계승되었다.

• 항공우주정책ㆍ법학회지
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• 제23권2호
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• pp.137-172
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• 2008

미국에서 자기비판적 분석의 법리에 의한 특권과 면제 이미 항공분야에서도 도입되고 있으나 일관성이 결여되어 있다. FDRs 프로그램은 FAA 또는 항공사에 의한 제제로 부터 공식적으로 보호되지는 아니한다. CVRs 프로그램의 경우 FAA는 집행조치를 위하여 그 데이터를 이용할 수 없으며 공개와 민사소송에서의 개시를 제한하고 있다. 따라서, CVRs은 FDR보다 높은 보호를 받고 있다. ASRS는 최초의 비자동적(non-self-disclosure) 보고시스템이며, 사고 또는 범죄에 관한 정보이외에는 FAA가 집행조치를 취할 수 없다. 다만, 비처벌 요건으로 규정하고 있는 "inadvertent and not deliberate)의 해석을 둘러싸고 FAA, NTSB 및 법원은 일관된 해석 기준이 없는 것으로 보이며, 데이터의 항공사의 징계조치에의 이용, 소송 당사자 또는 대중매체에의 공개 문제를 명확하게 다루고 있지 않다. 1990년대초 ASAP을 시범적으로 개시하였으며 FAA 집행조치 및 회사 징계조치로부터의 면제를 규정하고 있다. FOQA 프로그램은 1995년 시범프로그램을 통하여 최초로 시행되었으며 FAA 집행조치로 부터 면제되지만, 회사의 징계조치로부터의 면제에 대해서는 아무런 규정이 없다. 이러한 점은 ASAP와는 대비된다 할 수 있으며 노조협약에 의하여 FOQA 데이터에 근거한 회사의 징계조치를 배제시킬 수 있을 것이다. ASAP 및 FOQA의 데이터는 모두 2003년 FAA Order 8000.81에 의하여 공개되지 아니한다. 현재, ICAO의 움직임을 보더라도 국제사회에는 항공안전데이터를 보고한 자에 대한 보호의 강화에 대한 컨센서스가 형성되고 있으며 많은 국가들이 관련법을 시행하고 있다. 우리나라의 경우 현재, 항공법 제49조에 의하여 항공안전관리시스템을 도입하도록 되어 있다. 단계적으로 ASAP 또는 QOQA 등과 같은 프로그램의 입법화가 필요하다고 본다. 이와 더불어 미국에서와 같이 집행조치와 징계조치의 면제 규정 및 비공개 특권에 관하여 보다 구체적인 기준을 정하여 입법화하는 것도 필요할 것이다.

• 인터넷정보학회논문지
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• 제14권6호
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• pp.71-84
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• 2013

컴퓨터 시스템 운용 간에 발생하는 많은 정보들이 기록되는 로그데이터는 컴퓨터 시스템 운용 점검, 프로세스의 최적화, 사용자 최적화 맞춤형 제공 등 다방면으로 활용되고 있다. 본 논문에서는 다양한 종류의 로그데이터들 중에서 은행에서 발생하는 대용량의 로그데이터를 처리하기 위한 클라우드 환경 하에서의 MongoDB 기반 비정형 로그 처리시스템을 제안한다. 은행업무간 발생하는 대부분의 로그데이터는 고객의 업무처리 프로세스 간에 발생하며, 고객 업무 프로세스 처리에 따른 로그데이터를 수집, 저장, 분류, 분석하기 위해서는 별도로 로그데이터를 처리하는 시스템을 구축해야만 한다. 하지만 기존 컴퓨팅환경 하에서는 폭발적으로 증가하는 대용량 비정형 로그데이터 처리를 위한 유연한 스토리지 확장성 기능, 저장된 비정형 로그데이터를 분류, 분석 처리할 수 있는 기능을 구현하기가 매우 어렵다. 이에 따라 본 논문에서는 클라우드 컴퓨팅 기술을 도입하여 기존 컴퓨팅 인프라 환경의 분석 도구 및 관리체계에서 처리하기 어려웠던 비정형 로그데이터를 처리하기 위한 클라우드 환경기반의 로그데이터 처리시스템을 제안하고 구현하였다. 제안한 본 시스템은 IaaS(Infrastructure as a Service) 클라우드 환경을 도입하여 컴퓨팅 자원의 유연한 확장성을 제공하며 실제로, 로그데이터가 장기간 축적되거나 급격하게 증가하는 상황에서 스토리지, 메모리 등의 자원을 신속성 있고 유연하게 확장을 할 수 있는 기능을 포함한다. 또한, 축적된 비정형 로그데이터의 실시간 분석이 요구되어질 때 기존의 분석도구의 처리한계를 극복하기 위해 본 시스템은 하둡 (Hadoop) 기반의 분석모듈을 도입함으로써 대용량의 로그데이터를 빠르고 신뢰성 있게 병렬 분산 처리할 수 있는 기능을 제공한다. 게다가, HDFS(Hadoop Distributed File System)을 도입함으로써 축적된 로그데이터를 블록단위로 복제본을 생성하여 저장관리하기 때문에 본 시스템은 시스템 장애와 같은 상황에서 시스템이 멈추지 않고 작동할 수 있는 자동복구 기능을 제공한다. 마지막으로, 본 시스템은 NoSQL 기반의 MongoDB를 이용하여 분산 데이터베이스를 구축함으로써 효율적으로 비정형로그데이터를 처리하는 기능을 제공한다. MySQL과 같은 관계형 데이터베이스는 복잡한 스키마 구조를 가지고 있기 때문에 비정형 로그데이터를 처리하기에 적합하지 않은 구조를 가지고 있다. 또한, 관계형 데이터베이스의 엄격한 스키마 구조는 장기간 데이터가 축적되거나, 데이터가 급격하게 증가할 때 저장된 데이터를 분할하여 여러 노드에 분산시키는 노드 확장이 어렵다는 문제점을 가지고 있다. NoSQL은 관계형 데이터베이스에서 제공하는 복잡한 연산을 지원하지는 않지만 데이터가 빠르게 증가할 때 노드 분산을 통한 데이터베이스 확장이 매우 용이하며 비정형 데이터를 처리하는데 매우 적합한 구조를 가지고 있는 비관계형 데이터베이스이다. NoSQL의 데이터 모델은 주로 키-값(Key-Value), 컬럼지향(Column-oriented), 문서지향(Document-Oriented)형태로 구분되며, 제안한 시스템은 스키마 구조가 자유로운 문서지향(Document-Oriented) 데이터 모델의 대표 격인 MongoDB를 도입하였다. 본 시스템에 MongoDB를 도입한 이유는 유연한 스키마 구조에 따른 비정형 로그데이터 처리의 용이성뿐만 아니라, 급격한 데이터 증가에 따른 유연한 노드 확장, 스토리지 확장을 자동적으로 수행하는 오토샤딩 (AutoSharding) 기능을 제공하기 때문이다. 본 논문에서 제안하는 시스템은 크게 로그 수집기 모듈, 로그 그래프생성 모듈, MongoDB 모듈, Hadoop기반 분석 모듈, MySQL 모듈로 구성되어져 있다. 로그 수집기 모듈은 각 은행에서 고객의 업무 프로세스 시작부터 종료 시점까지 발생하는 로그데이터가 클라우드 서버로 전송될 때 로그데이터 종류에 따라 데이터를 수집하고 분류하여 MongoDB 모듈과 MySQL 모듈로 분배하는 기능을 수행한다. 로그 그래프생성 모듈은 수집된 로그데이터를 분석시점, 분석종류에 따라 MongoDB 모듈, Hadoop기반 분석 모듈, MySQL 모듈에 의해서 분석되어진 결과를 사용자에게 웹 인터페이스 형태로 제공하는 역할을 한다. 실시간적 로그데이터분석이 필요한 로그데이터는 MySQL 모듈로 저장이 되어 로그 그래프생성 모듈을 통하여 실시간 로그데이터 정보를 제공한다. 실시간 분석이 아닌 단위시간당 누적된 로그데이터의 경우 MongoDB 모듈에 저장이 되고, 다양한 분석사항에 따라 사용자에게 그래프화해서 제공된다. MongoDB 모듈에 누적된 로그데이터는 Hadoop기반 분석모듈을 통해서 병렬 분산 처리 작업이 수행된다. 성능 평가를 위하여 로그데이터 삽입, 쿼리 성능에 대해서 MySQL만을 적용한 로그데이터 처리시스템과 제안한 시스템을 비교 평가하였으며 그 성능의 우수성을 검증하였다. 또한, MongoDB의 청크 크기별 로그데이터 삽입 성능평가를 통해 최적화된 청크 크기를 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제6권2호
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• pp.1-8
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• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
• /
• pp.17-17
• /
• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• 한국포장학회지
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• 제24권2호
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• pp.65-71
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• 2018

생산자 책임 재활용제도(EPR)의 재활용의무대상 품목은 포장재군에 따라 종이팩, 유리병, 금속캔, 합성수지포장재 구분되어질 수 있다. 폐종이팩의 경우 압축된 종이팩을 해리하여 폴리에틸렌 필름 및 기타 이물질을 분리하고 세척, 분쇄, 건조과정을 거쳐 화장지 원단으로 제작한 후 다양한 화장지로 가공 생산하고 있다. 그러나 알루미늄 호일이 첩합된 종이팩은 재활용 공정 중 잔유물이 발생하여 화장지의 품질을 저해하고 제품 편의성을 위해 부착된 마개, 스트로우와 같은 새로운 성형구조의 제품들은 재활용 공정에서 수작업의 과정을 추가하여 재활용 수율을 낮추는 문제점이 있다. 유리병은 재사용과 재활용으로 구분가능하며 재사용은 주류, 음료병들이 대상이고 재활용은 1회용 유리병이나 깨진 유리병을 대상으로 하고 있다. 유리병 재활용은 폐유리병 회수 과정, 이물질 제거, 색상별 분류, 파쇄, 원료화 과정을 거쳐 제병업체에 공급되며, 철금속성분 제거, 저비중 물질 제거 등을 제외하고 대부분 수작업에 의존한다. 유리병은 무색 계열, 갈색 계열, 녹색 계열의 색상이 주를 이루고 있으며 재활용 과정에서 주된 3색 이외의 색상의 경우 재생원료의 품질을 저해시키는 원인이 되고 있다. 합성수지 라벨의 다량 접착제와 병의 직접 인쇄는 잉크의 색상에 의하여 품질저하가 발생하며, 유리병에 사용되는 플라스틱 마개 또한 재활용 공정에서 이물질 제거과정을 어렵게 한다. 금속캔은 자동선별기를 통해서 철캔과 알루미늄캔을 분류한 후 압축하여 용광로를 통해 철, 알루미늄으로 재생산된다. 재활용 공정에서 가공육 알루미늄 캡의 플라스틱 뚜껑은 선별이 어렵기 때문에 플라스틱 뚜껑을 사용하지 않거나 분리 배출할 수 있는 방안이 필요하며 금속캔 또한 금속이 아닌 마개, 라벨이 재활용 공정에서 수작업 공정을 추가로 필요하게 하고 있다. 합성수지 포장재 중 복합재질의 경우 선별된 압축품을 파쇄한 뒤 용융성형을 통한 물질 재활용, 열분해를 통한 유화, 압축성형을 통한 고형연료 제조단계를 통해 재생제품을 생산하며, 단일 합성수지는 자력선별, 풍력선별, 비중선별 등 다양한 방법을 통해 선별공정을 거처 압축, 파쇄, 세척, 용융압출, Pellet 형태의 재생 원료를 만드는 물질 재활용 과정을 거친다. 종이, 금속 라벨, 복합재질 리드 등은 합성수지 재활용에 문제를 발생시키는 요인으로 비중 1미만의 비수분리성 접(참)착식 라벨의 경우가 이에 해당한다. 이 연구를 통해 종이팩, 유리병, 금속캔, 합성수지의 재활용 공정 모두 재활용 대상과 다른 물질의 유입이 재활용공정을 방해하거나 재활용 비용, 시간을 증대시키고 있음을 확인하였다. 각 포장재별로 종이팩 포장재의 스트로우를 비롯한 합성수지 성형구조물과 금속과 유리병 포장재의 이물질을 포함한 라벨과 마개 및 잡자재 그리고 합성수지 포장재의 금속, 종이 복합재질이 이에 해당하였다. 따라서 재활용 산업의 활성화를 위해서는 제품이나 포장재의 설계 단계에서부터 재활용에 용이한 재질 구조가 요구되어지며, 정부차원의 지원과 관련 법 제도 개선이 필요하다.

• Strategy21
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• 통권46호
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• pp.239-276
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• 2020

유엔 안전보장이사회(UNSC, United Nations Security Council) 주도의 경제제재는 초창기 '포괄적 경제제재(comprehensive sanctions)' 모델에서 '스마트 경제제재(smart sanctions)' 모델로 발전하고 있다. 유엔 안보리는 직접적인 무력개입(military intervention)보다 규범적 비용(normative costs)과 부담이 덜한 경제제재를 통해 대상 국가의 손익계산법(cost-benefit calculation)을 바꿔 행동변화를 이끌어내려고 했으나, '포괄적 경제제재'에 따른 비용 대부분이 일반 대중에게 전가되면서, 인도적 위기(humanitarian crisis) 사태를 초래하고, 대상 국가의 내부 결속력을 강화하는 역설적인 상황을 만들었다. 이에 따라 정책 결정 과정에 직접적으로 관여하는 지도자와 정치 엘리트를 대상으로 자산을 동결(asset freeze)하거나 여행금지(travel ban) 조치 등을 집중적으로 하는 '스마트 제재'가 탄생하였다. 대북한 경제제재 또한 '스마트 경제제재' 모델로 점차 발전하여 그 효과성을 나타내고 있다. 특히 최근의 결의안(resolutions)을 통해 석탄 수출을 전면 금지하고, 원유 수입을 제한함에 따라 지표상 가시적인 성과가 나타나고 있고, 2018년부터 한국, 미국과 평화협상에 나서면서 제재완화를 촉구하는 등, 위와 같은 '스마트' 대북제재가 북한의 행동변화를 이끌어내고 있음을 알 수 있다. 대북제재의 효과성은 북한의 대외무역규모(total trade volume) 변화량을 통해 측정할 수 있는데, '포괄적 경제제재'의 성격에 가까운 초기의 대북제재 결의안 채택 이후에는 북한 대외무역규모가 감소한 경우도 있지만 도리어 증대된 경우도 있었다. 그러나 석탄 수출 금지 및 원유 수입 제한 조치를 담은 2016, 2017년의 결의안 이후에는 북한 대외무역규모가 2016년 약 65억 달러에서 2017년 약 55억 달러로, 2018년에는 약 28억 달러로 대폭 감소한 사실을 발견할 수 있다. 북한의 대외무역은 정권의 자금줄과 같기 때문에 대외무역규모의 감소는 곧 '스마트 제재'의 효과와 같다. 대북경제제재의 효과성에 영향을 미치는 두 번째 조건은 중국의 대북제재 레짐(sanctions regime)에의 참여 여부다. 북한은 경제적으로 중국에 상당히 의존하고 있고, 이는 지표상으로도 명백히 나타나고 있다. 중국은 그 동안 북한의 지정학적인 가치 및 급변 사태 시 북-중 국경에서의 대규모 난민 발생 우려 등에 따라 직간접적으로 북한을 지지해왔지만, 북한 핵능력의 고도화에 따른 동북아시아 지역에서의 핵확산(nuclear proliferation) 우려, 미-중 무역분쟁에 따른 여파 등으로 대북제재 레짐에 성실히 참여할 것을 밝혔다. 실제로 중국의 대북한 석유 수출량이 감소하고, 북-중간 대외무역 총량 또한 2016년부터 지속적으로 감소하며, 대북경제제재에 중국의 참여가 제재 성공의 중요한 변수임을 증명했다. 효과적인 대북제재를 위한 마지막 요건은 북한의 경제제재 회피 노력 방지(prevention of North Korea's economic sanctions evasion efforts)다. 앞서 밝힌 바와 같이 석탄 수출과 원유 수입은 북한 정권의 자금줄이자 핵무력 고도화를 위한 필수 에너지원이다. 중국이 대북제재 레짐에의 참여를 선언한 상태에서 중국으로부터의 원유 수입량이 급감함에 따라 중동지역 등지로부터 바닷길을 통해 원유를 수입해야 하는데, 원유 수입량 제한에 따라 동중국해(East China Sea) 및 공해(high seas)상에서 선박 대 선박간 불법 환적(ship-to-ship illegal transshipment)을 실시하면서 대북제재를 무력화하고 있다. 유엔 대북제재위 산하 전문가 패널(Panel of Experts), 미 국무부(U.S. Department of State), 미 재무부 외부자산통제국(U.S. Department of the Treasury's Office of Foreign Assets Control, OFAC) 등은 보고서를 통해 북한의 해상 불법 환적 실태를 상세히 밝히고 있는데, 자동 선박 식별 장치(AIS, Automatic Identification System)의 허위 신호 송출(false signaling), 선박 등록 문서 위조(false certificate of registry)와 같은 방식으로 감시 및 단속을 회피하고 있는 실정이다. '스마트'한 대북제재 설계 및 중국의 참여로 대북제재가 북한의 행동 변화를 이끌어낼 수 있음이 확인되었지만, 국제사회의 눈을 피해 해상에서 만연하고 있는 불법 환적과 같은 행위는 효과적인 대북제재 실행의 마지막 퍼즐이라고 할 수 있다. 앞으로 해상에서의 불법 환적 행위를 막기 위해 다음 세 가지 정책적 함의를 도출해낼 수 있다. 첫 번째는 가장 강력한 조치라고 할 수 있는 해상봉쇄(maritime blockade)에 대한 고려다. 전세계 물동량의 40%가 지나가는 말라카 해협(Malacca Strait)은 북한에게도 중요한 해상 교통로이다. 북한이 계속해서 결의안을 위반하고 공해상에서 불법 환적 행위를 자행할 경우, 말라카 해협에서 북한과 연계된 의심 선박을 검문 검색하고 차단(interdiction)하여 강제적인 방식으로 북한의 제재 회피 노력을 근절할 수 있다. 남중국해(South China Sea)에서 중국과 미국 간, 중국과 주변국 간 갈등이 격화됨에 따라 다국적군의 말라카 해협 봉쇄는 중국에게 달갑지 않겠지만, 유엔 대북제재 결의안에 명시되어 있는 의심 선박에 대한 검문 검색 행위임을 명백히 함과 동시에 다자간의 협조를 바탕으로 하여 규범적 정당성(normative justification)을 높인다면 충분히 실현 가능한 방안이다. 두 번째는 공해상에서의 불법 해상 환적에 대한 감시 강화와 증거 수집이다. 마지막 세번째는 대한민국의 다국적 해상 감시 활동에의 참여다. 북한의 대북제재 이행 여부는 한국의 안보와 직결되는 사안이다. 대북제재의 최종 목표는 북한 비핵화에 있고, 협상 테이블에 북한을 이끌어내는 데 제재가 효과적이라는 것이 드러났기 때문에 핵 위협의 당사자인 대한민국 또한 효과적인 제재 이행 여부 감시에 책임감을 가져야 한다.