• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.221-221
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• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.288-293
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• 2016

Purpose: The purpose of this study was to investigate the key factors in designing a three-wheeled two-row soybean reaper (riding type) that is suitable for soybean production, and ensure worker safety by proposing optimal work conditions for the prototype of the designed machine in relation to the slope of the road. Methods: A three-wheeled two-row soybean reaper (riding type) was designed and its prototype was fabricated based on the local soybean-production approach. This approach was considered to be closely related to the prototype-designing of the cutter and the wheel driving system of the reaper. Load distribution on the wheels of the prototype, its minimum turning radius, static lateral overturning angle, tilt angle during driving, and The working and rear overturning (back flip) angle were measured. Based on the gathered information, investigations were conducted regarding optimal work conditions for the prototype. The investigations took into account driving stability and worker safety. Results: The minimum ground clearance of the prototype was 0.5 m. The blade height of the prototype was adjusted such that the cutter was operated in line with the height of the ridges. The load distribution on the prototype's wheels was found to be 1 (front wheel: F): 1.35 (rear-left wheel: RL): 1.43 (rear-right wheel: RR). With the ratio of load distribution between the RL and RR wheels being 1: 1.05, the left-to-right lateral loads were found to be well-balanced. The minimum turning radius of the prototype was 2.0 m. Such a small turning radius was considered to be beneficial for cutting work on small-scale fields. The sliding of the prototype started at $25^{\circ}$, and its lateral overturning started at $39.3^{\circ}$. Further, the critical slope angle for the worker to drive the prototype in the direction of the contour line on an incline was found to be $12.8^{\circ}$, and the safe angle of slope for the cutting was measured to be less than $6^{\circ}$. The critical angle of slope that allowed for work was found to be $10^{\circ}$, at which point the prototype would overturn backward when given impact forces of 1,060 N on its front wheel. Conclusions: It was determined that farmers using the prototype would be able to work safely in most soybean production areas, provided that they complied with safe working conditions during driving and cutting.

• Strategy21
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• s.37
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• pp.5-31
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• 2015

The Republic of Korean Navy (ROKN) started from scratch. However, ROKN demonstrated its Blue Navy capabilities successfully to the entire world by conducting "Operation Early Dawn" at the Aden Bay, Yemen in Jan 2011. On the event of the 70th anniversary of the ROKN, I would like to retrospect past gleaning from voyages and challenges we had in the past. At the very inception of the ROKN, Korean government as well as senior military leaders recognized that it had no time to spare to clean up military those were insinuated deeply by communist agents. It was the top priority of the government. The Mongumpo Operation which was not well known, conducted by ROKN was one of the clean-up drive. The Korean War sometimes called as "a fire from land put-off at the sea". The world famous "Incheon Landing" which reversed war situation from the Nakdong Perimeter also done by Sea Power. ROKN conducted various maritime operations including not only Incheon Landing, but amphibious operation at Hungnam, mine sweeping, sea convoy, Wonsan Withdrawal. On the same day of the Korean War started, 25th June 1950, unless the victory of the ROKNS Baekdusan (PC 701) at the Korean Strait, the waning lamp light of Korea could not be rekindled by the participation of the U.N. The ROKN rescued the 17th regiment of Korean Army from the isolation at the Ongjin Peninsular and transported gold and silver bars stored at the Bank of Korea to the Navy supply deposit in Jinhae safely. ROKN special intelligence unit conducted critical HUMINT which led Incheon Landing success. One of important mission ROKN conducted successfully was not only transporting war fighting materials but also U.S. provided grains to starving Koreans. ROKN participated Vietnam campaign from 1960s and conducted numerous maritime transportation operations supplying materials to Vietnam military forces along the long coastal lines. Experienced Naval Officers and enlisted men who discharged and acquired as merchant marine certificate supported most of the U.S. sea lift operations throughout the Vietnam campaign. ROK-US Combined Forces which had been honed and improved its war fighting capabilities through the Korean War and out of Vietnam jungle playing key deterrent against threat from north Korea. However, those threat level will be completely different when north Korea finish its nuclear weapon ambition. In order to stand firm against north Korean nuclear threat, I would like to expect strong political leadership supporting nuclear submarine for ROKN.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.456-456
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• 2010

CMOS 소자가 서브마이크론($0.1\;{\mu}m$) 이하로 스케일다운 되면서 단채널 효과(short channel effect), 게이트 산화막(gate oxide)의 누설전류(leakage current)의 증가와 높은 직렬저항(series resistance) 등의 문제가 발생한다. CMOS 소자의 구동전류(drive current)를 높이고, 단채널 효과를 줄이기 위한 가장 효율적인 방법은 소스 및 드레인의 얕은 접합(shallow junction) 형성과 직렬 저항을 줄이는 것이다. 플라즈마 도핑 방법은 플라즈마 밀도 컨트롤, 주입 바이어스 전압 조절 등을 통해 저 에너지 이온주입법보다 기판 손상 및 표면 결함의 생성을 억제하면서 고농도로 얕은 접합을 형성할 수 있다. 그리고 얕은 접합을 형성하기 위해 주입된 불순물의 활성화와 확산을 위해 후속 열처리 공정은 높은 온도에서 짧은 시간 열처리하여 불순물 물질의 활성화를 높여주면서 열처리로 인한 접합 깊이를 얕게 해야 한다. 그러나 접합의 깊이가 줄어듦에 따라서 소스 및 드레인의 표면 저항(sheet resistance)과 접촉저항(contact resistance)이 급격하게 증가하는 문제점이 있다. 이러한 표면저항과 접촉저항을 줄이기 위한 방안으로 실리사이드 박막(silicide thin film)을 형성하는 방법이 사용되고 있다. 본 논문에서는 (100) p-type 웨이퍼 He(90 %) 가스로 희석된 $PH_3$(10 %) 가스를 사용하여 플라즈마 도핑을 실시하였다. 10 mTorr의 압력에서 200 W RF 파워를 인가하여 플라즈마를 생성하였고 도핑은 바이어스 전압 -1 kV에서 60 초 동안 실시하였다. 얕은 접합을 형성하기 위한 불순물의 활성화는 ArF(193 nm) excimer laser를 통해 $460\;mJ/cm^2$의 에니지로 열처리를 실시하였다. 그리고 낮은 접촉비저항과 표면저항을 얻기 위해 metal sputter를 통해 TiN/Ti를 $800/400\;{\AA}$ 증착하고 metal RTP를 사용하여 실리사이드 형성 온도를 $650{\sim}800^{\circ}C$까지 60 초 동안 열처리를 실시하여 $TiSi_2$ 박막을 형성하였다. 그리고 $TiSi_2$의 두께를 측정하기 위해 TEM(Transmission Electron Microscopy)을 측정하였다. 화학적 결합상태를 분석하기 위해 XPS(X-ray photoelectronic)와 XRD(X-ray diffraction)를 측정하였다. 접촉비저항, 접촉저항과 표면저항을 분석하기 위해 TLM(Transfer Length Method) 패턴을 제작하여 I-V 특성을 측정하였다. TEM 측정결과 $TiSi_2$의 두께는 약 $580{\AA}$ 정도이고 morphology는 안정적이고 실리사이드 집괴 현상은 발견되지 않았다. XPS와 XRD 분석결과 실리사이드 형성 온도가 $700^{\circ}C$에서 C54 형태의 $TiSi_2$ 박막이 형성되었고 가장 낮은 접촉비저항과 접촉저항 값을 가진다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.27-31
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• 2006

GNSS Services and Applications are today in permanent evolution in all the market sectors. This evolution comprises: ${\bullet}$ New constellations and systems, being GALILEO probably the most relevant example, but not the only one, as other regions of the world also dwell into developing their own elements (e.g. the Chinese Beidou system). ${\bullet}$ Modernisation of existing systems, as is the case of GPS and GLONASS ${\bullet}$ New Augmentation services, WAAS, EGNOS, MSAS, GRAS, GAGAN, and many initiatives from other regions of the world ${\bullet}$ Safety of Life services based on the provision of integrity and reliability of the navigation solutions through SBAS and GBAS systems, for aeronautical or maritime applications ${\bullet}$ New Professional applications, based on the unprecedented accuracies and integrity of the positioning and timing solutions of the new navigation systems with examples in science (geodesy, geophysics), Civil engineering (surveying, construction works), Transportation (fleet management, road tolling) and many others. ${\bullet}$ New Mass-market applications based on cheap and simple GNSS receivers providing accurate (meterlevel) solutions for daily personal navigation and information needs. Being on top of this evolving market requires an active participation on the key elements that drive the GNSS development. Early access to the new GNSS signals and services and appropriate testing facilities are critical to be able to reach a good market position in time before the next evolution, and this is usually accessible only to the large system developers as the US, Europe or Japan. Jumping into this league of GNSS developers requires a large investment and a significant development of technology, which may not be at range for all regions of the world. Bearing in mind this situation, MAGIC appears as a concept initiated by a small region within Europe with the purpose of fostering and supporting the development of advanced applications for the new services that can be enabled by the advent of SBAS systems and GALILEO. MAGIC is a low cost platform based on the application of technology developed within the EGNOS project (the SBAS system in Europe), which encompasses the capacity of providing real time EGNOS and, in the near future, GALILEO-like integrity services. MAGIC is designed to be a testing platform for safety of life and liability critical applications, as well as a provider of operational services for the transport or professional sectors in its region of application. This paper will present in detail the MAGIC concept, the status of development of the system within the Madrid region in Spain, the results of the first on-field demonstrations and the immediate plans for deployment and expansion into a complete SBAS+GALILEO regional augmentation system.

• Journal of Service Research and Studies
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• v.14 no.2
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• pp.117-137
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• 2024

ESG has become a necessity for all companies, and major Korean banks are actively practicing ESG management. Banks are playing a role in providing ESG finance as intermediaries in the supply of funds. Recently, they have launched ESG digital banking products that offer preferential interest rates for eco-friendly activities in combination with digital technologies. However, indiscriminate provision of preferential interest rates can adversely affect profitability of banks, and they may face the problem of 'Greenwashing' if they do not contribute to improving environmental awareness. Therefore, this study selected ESG digital savings products linked to electricity savings as the subject of the study, and empirically analyzed consumers' environmental awareness and savings behavior through actual data of consumers (N=2,478). The main findings of this study are as follows First, the analysis of the consumer status of ESG digital banking products shows that the 30-50s are the main consumer base, and the MZ generation shows relatively high performance in achieving preferential interest rates through electricity saving practices. Second, consumers' environmental awareness has a significant impact on achieving the goals of ESG banking products. ESG banking products can contribute to environmental awareness while fulfilling the basic function of saving. Third, environmental awareness did not drive consumers' savings contribution behavior, suggesting the need for continued consumer engagement. Based on environmental awareness and the theory of saving behavior, this study provides a theoretical explanation in ESG financial products. The results suggest that the appropriateness of the preferential interest rate design of ESG financial products is important.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.201-219
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• 1989

Rice culture in Korea has a long history ranging over two thousand years. In the agriculture economy of pre-mordern Korea, however, its importantce was not as great as generally assumed. In fact, rice culture reached full development only after the 1920s when the Japanese colonial government carried out its drive to increase rice production in the Korea peninsula. It was not until the mid-1930s that rice became the staple in Korean diet. This can be attributed to two factors : (1) a mountainous topography that provides little irrigated fields and (2) a climate characterized by droughts in spring and heavy precipitation in summer. The present paper attempts to answer some of these questions. Specifically it will focus on these : Did the development of rice culture actually result in population growth? What are the salient features of agricultural develdpment and population grow in traditional Korea? Does the case of Korea conform the prevailing generalization about the agriculture in East Asia? I have discussed the development of rice culture and population growth in the Chos$\breve{o}$n dynasty, focusing on the relation between the rapid spread of transplanting and the rapid growth of population from the seventeenth to the nineteenth century. Here are my conclusions. (1) The spread of transplanting and other technological innovationsc contributed to the rapid growth of population in this period. However, we should also note that the impact of rice culture on population growth was rather limited, for rice culture was not the mainstay of agricultural economy in pre-modern Korea. Indeed we should consider the influence of dry field cropsn population growth. Nevertheless, it is obvious that the proliferation of rice culture was a factor crucial to population growth and regional concentration. (2) How should we characterize the spread of rice culture in the whole period? Evidently rice culture spread from less then 20% of cultivated fields in the fifteenth century to about 36% of them in the early twentieth century. Although rice as a single crop outweighed other crops, rice culture was more then counter-balanced by dry field crops as a whole, due to Korea's unique climate and geography. Thus what we have here in not a typical case of competition between rice culture and day field culture. Besides, the spread of rice culture in the seventeenth and eighteenth centuries accomplished by technological innovations that overcame severe springtime drought, rather than extensive irrigation. Althougt irrigarion facilities did proliferate to some extent, this was achieved by local landlords and peasants rather than the state. This fact contradicts the classical thesis that the productivity of rice culture increased through the state management of irrigation and that this in turn determined the type of society. (3) We should further study other aspects of the transition from the stable population and production struture in the fifteenth and sixteenth centuries to the rapid population growth and excessive density of population thereafter. We should note that there were continuing efforts to reclaim the land in order to solve the severe shortage of land. Changes also took place in the agricultural production relations. The increase in land producrivity developed tenancy based on rent in kind, and this in turn increased the independence of tenants from their landlords. There were changes in family relations-such as the shift to primogeniture as an effort to prevent progressive division of property among multiplying offspring. The rapid population growth also produced a great mass of propertyless farm laborers. These changes had much to do with the disintegration of traditional social institutions and political structure toward the end of the Chos$\breve{o}$n dynasty.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.34-45
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• 2002

Of the four tidal flat areas(Yeocha-ri, Dongmak-ri, Sundu-ri and Donggum-ri) on Southern Ganghwa Island, the distribution of migratory waterbirds showed a difference in the numbers of individuals and species. Higher numbers of individuals and species were observed on the Yeocha-ri tidal flat. The dominant waterbirds species at the four areas was the Dentin(Calidris alpina). This species showed an occupancy rate(42.0-79.1%) on the Yeocha-ri tidal flat, which was much higher relative to the other areas. The Yeocha-ri tidal flats were higher relative to MSL than the other tidal flats. When the Dongmak-ri tidal flat was covered by sea water, the Yeocha-ri tidal flat was 0.0317$\textrm{km}^2$ in area and on this space we observed many resting waterbirds. The biomass of the waterbirds' potential prey on the Yeocha-ri tidal flat was higher(1.6~2.5$\times$) than other tidal flats. Twenty-three species and 266 individuals were found on the Yeocha-ri tidal flat, which was higher than the tidal flats. The food of Dunlin, which was the dominant species in these four areas, was mainly Reticunassa festiva and Umbonium thomasi(Gastropoda) and Perinereis aibuitensis(Polychaeta). A Dunlin(38.11g) used to eat 1,295 individuals of these food items for daily basal energy. Gastropod, its density was highest on Yeocha-ri tidal flats. The distribution of waterbirds seemed to be closely related with the distribution of the benthos, space and safety of resting site. We suggest that the environments of tidal flats, which are rich foraging habitats, are important factors for conservation of waterbirds.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.123-136
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• 2014

Recently, online shopping has further developed as the use of the Internet and a variety of smart mobile devices becomes more prevalent. The increase in the scale of such shopping has led to the creation of many Internet shopping malls. Consequently, there is a tendency for increasingly fierce competition among online retailers, and as a result, many Internet shopping malls are making significant attempts to attract online users to their sites. One such attempt is keyword marketing, whereby a retail site pays a fee to expose its link to potential customers when they insert a specific keyword on an Internet portal site. The price related to each keyword is generally estimated by the keyword's frequency of appearance. However, it is widely accepted that the price of keywords cannot be based solely on their frequency because many keywords may appear frequently but have little relationship to shopping. This implies that it is unreasonable for an online shopping mall to spend a great deal on some keywords simply because people frequently use them. Therefore, from the perspective of shopping malls, a specialized process is required to extract meaningful keywords. Further, the demand for automating this extraction process is increasing because of the drive to improve online sales performance. In this study, we propose a methodology that can automatically extract only shopping-related keywords from the entire set of search keywords used on portal sites. We define a shopping-related keyword as a keyword that is used directly before shopping behaviors. In other words, only search keywords that direct the search results page to shopping-related pages are extracted from among the entire set of search keywords. A comparison is then made between the extracted keywords' rankings and the rankings of the entire set of search keywords. Two types of data are used in our study's experiment: web browsing history from July 1, 2012 to June 30, 2013, and site information. The experimental dataset was from a web site ranking site, and the biggest portal site in Korea. The original sample dataset contains 150 million transaction logs. First, portal sites are selected, and search keywords in those sites are extracted. Search keywords can be easily extracted by simple parsing. The extracted keywords are ranked according to their frequency. The experiment uses approximately 3.9 million search results from Korea's largest search portal site. As a result, a total of 344,822 search keywords were extracted. Next, by using web browsing history and site information, the shopping-related keywords were taken from the entire set of search keywords. As a result, we obtained 4,709 shopping-related keywords. For performance evaluation, we compared the hit ratios of all the search keywords with the shopping-related keywords. To achieve this, we extracted 80,298 search keywords from several Internet shopping malls and then chose the top 1,000 keywords as a set of true shopping keywords. We measured precision, recall, and F-scores of the entire amount of keywords and the shopping-related keywords. The F-Score was formulated by calculating the harmonic mean of precision and recall. The precision, recall, and F-score of shopping-related keywords derived by the proposed methodology were revealed to be higher than those of the entire number of keywords. This study proposes a scheme that is able to obtain shopping-related keywords in a relatively simple manner. We could easily extract shopping-related keywords simply by examining transactions whose next visit is a shopping mall. The resultant shopping-related keyword set is expected to be a useful asset for many shopping malls that participate in keyword marketing. Moreover, the proposed methodology can be easily applied to the construction of special area-related keywords as well as shopping-related ones.

• Bulletin of the Korean Space Science Society
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• 1993.10a
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• pp.17-17
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• 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.