• 한국수정란이식학회지
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• 제21권3호
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• pp.207-216
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• 2006

Shit-tzu견에서 발정 주기, 교배 적기 및 배란 시기를 정확하게 추정하기 위한 질 세포 검사를 확립하기 위하여 Shih-tzu 견 12두를 대상으로 발정 주기동안 질 세포 검사 및 estradiol-$17{\beta}$와 progesterone 농도를 측정하여 다음과 같은 결과를 얻었다. 발정주기별 질 세포상의 특징적인 변화로서 발정 전기에는 무핵 세포와 적혈구, 발정기에는 표층 세포와 무핵 세포 및 적혈구가 주종을 이루는 세포였으며 발정 휴지기에는 소형 중간 세포와 대형 중간 세포, 무발정기에는 부기저 세포와 소형 중간 세포 및 백혈구가 주종을 이루는 세포이었다. 또한 CI는 발정 전기와 발정기에 높게 나타났으나, 발정 휴지기와 무발정기에는 감소하여 각 기간별 비교에서 발정 전기와 발정기에 유의성 있게 높았다. 발정주기 중 첫 수컷 허용일(Day 0)을 기준으로 하였을 때 CI는 발정 전기 개시일 전후인 Day -9에 $72.4{\pm}2.9%$, Day -4에 $84.0{\pm}3.9%$로 80% 이상으로 증가하였으며 Day 0에 $97.0{\pm}1.1%$로 증가하여 Day 2에는 $98.2{\pm}0.5%$로 최고치를 나타내었으며 CI가 80% 이상을 나타낸 기간은 Day -4에서 Day 6까지(11일간)이었고, 90% 이상을 나타낸 기간은 Day -1에서 Day 5까지(7일간)이었다. 또한 임신 Shih-tzu 견 12두에서 혈장 progesterone 농도가 최초로 4.0 ng/ml 이상으로 증가한 날을 기준(Day 0)으로 발정 주기 중 혈장 progesterone과 estradiol-$17{\beta}$ 및 CI의 관계를 살펴보면 estradiol-$17{\beta}$가 Day -2에 최고치를 나타내었고, CI가 Day -1에 최고치를 나타낸 후 Day 0에 혈장 progesterone 농도가 $5.2{\pm}0.3ng/ml$로 최초로 4.0 ng/ml 이상으로 증가하였다. CI가 최초로 80 % 이상으로 증가하여 지속한 날은 estradiol-$17{\beta}$ peak 5일전인 Day -7이었고, Day -7부터 Day 3까지 11일 동안 80% 이상으로 지속되었다. CI가 최초로 90% 이상으로 증가한 날은 estradiol-$17{\beta}$ peak 2일전인 Day -4이었으며, Day -4부터 Day 2까지 7일 동안 90% 이상으로 지속되었다. 이상의 결과를 종합하여 보면 Shih-tzu 견에서 첫 수컷 허용일(Day 0)을 기준으로 하였을 때 CI 최고치는 Day 2에 나타났으며 이 때가 최상의 교배 적기로 사료되며, 혈장 progesterone농도가 4.0 ng/ml 이상으로 증가한 날(Bay 0)을 기준으로 하였을 때부터 CI는 혈장 estradiol-$17{\beta}$ peak 후 1일째인 최고치를 나타내었고, CI peak 후 1일째인 Day 0에 혈장 progesterone 농도가 최초로 4.0 ng/ml 이상으로 증가하여 CI가 90% 이상으로 지속된 시기가 최상의 교배 적기임이 확인되었다. 따라서 혈장 progesterone농도 측정으로 정확한 배란 시기 및 교배 적기를 판정할 수 있으나, 시설비가 저렴하고 검사 방법이 간단한 질 세포 검사가 Shih-tzu 견에서 발정 주기, 교배 적기 및 배란 시기의 판정에 응용될 수 있음을 시사하는 결과라고 사료된다.

• 청정기술
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• 제26권2호
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• pp.102-108
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• 2020

오늘날 석유화학, 정밀화학, 대기오염 방지산업 등에서 증류, 흡수, 추출, 탈거 등 물질분리 단위공정으로 주로 충전탑을 사용해 왔다. 충전탑은 가스-액체, 가스-가스 시스템에서의 물질들과의 접촉에 의해 운전되어 진다. 이러한 충전탑은 낮은 압력손실, 경제적 효율, 고온성 액체물질 적용, 유지보수 용이, 유해가스 처리 등의 운영에서 장점들을 가진다. 충전탑의 성능은 충진물을 통해 가스와 액체를 고르게 분산함으로써 우수한 성능을 보이며, 이는 충전탑 설계에 있어 중요한 인자로 고려되어진다. 본 실험에서는 충진물에 대한 액체부하 및 가스용량인자에 따른 건조압력손실, 수력학적 압력손실, 액체함량 변화에 대한 기하학적 특성에 대하여 연구하였다. 결과로부터 설계인자와 운전조건 등의 유해가스 처리에 필요한 인자를 도출하였다. 임의 충진물인 raschig super-ring에 대한 건조압력손실을 측정한 결과, 가스용량인자가 증가할수록 일정하게 선형적으로 증가하였고, 가스용량인자가 0.630 ~ 3.448 kg^-1/2 m^-1/2 S^-1에서 건조압력손실은 1.892 ~ 47.312 mmH₂O m^-1로 기존 산업현장에서 보편적으로 사용되는 35 mm pall-ring보다도 낮은 압력손실을 보였다. 그리고 raschig super-ring에 대한 수력학적 압력손실을 측정한 결과, 고유 액체부하에 대하여 가스용량인자가 증가할수록 압력손실도 함께 증가함을 확인하였고, 액체부하 변화에 따른 가스용량인자가 1.855 ~ 2.323 kg^-1/2 m^-1/2 S^-1으로 20% 증가할 때, 압력손실은 약 17% 증가하는 것으로 나타났다. 마지막으로, 충진물 체적에 관한 액체함량은 가스용량인자에 의존된 액체부하 매개변수로서 액체부하 변화에 따른 가스용량인자 약 3.84 kg^-1/2 m^-1/2 S^-1까지는 거의 일정한 액체함량을 보였으나, 그 이상에서는 급격하게 증가하였다.

• 한국수정란이식학회지
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• 제21권2호
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• pp.109-119
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• 2006

비글개 6두에서 11회(임신견 7두, 비 임신견 4두)의 발정 주기 및 임신 기간 동안 질 상피 세포 검사 및 혈장 progesterone과 estradiol-$17{\beta}$ 농도를 측정하여 질 상피 세포상과 번식 호르몬의 관계를 조사하고 배란 및 교배 적기 판정을 위한 기초 자료를 제공하고자 본 실험을 실시하였다. 임신 예와 비 임신 예에 있어서 발정 전기, 발정기 및 발정 휴지기의 기간은 각각 $8.5{\pm}1.4(Mean{\pm}SD),\;10.0{\pm}1.4$ 및 $54.0{\pm}2.8$ 그리고 $7.9{\pm}2.1,\;9.5{\pm}0.7$ 및 $62.0{\pm}11.3$일이었다. 임선 예에 비해 비 임신견의 발정 휴지기가 길었으며, 발정 주기 사이의 간격은 임선 예가 $246.2{\pm}24.5$일, 비 임신 예은 $175.3{\pm}34.5$일을 나타내어 임신이 되었던 예가 임신이 되지 않았던 예보다 길었다. 발정 주기별 질 상피 세포상의 변화를 보면 발정 전기와 발정기에는 superficial cell, anuclear cell 및 적혈구가, 발정 휴지기에는 parabasal cell, small intermediate cell, large intermediate cell 및 백혈구가, 그리고 무발정기에는 parabasal cell과 small intermediate cell이 주종을 이루었다. Cornification index(CI)는 발정 주기와 발정기에 유의하게 높았다. 발정 주기 중 혈장 progesterone과 estradiol-$17{\beta}$의 농도 사이의 관계를 혈장 progesterone 농도가 최초로 4.0 ng/ml 이상으로 상승한 날을 기준(Day 0)으로 살펴보면, 혈장 progesterone 농도는 발정 출혈 개시 일에 1.0 ng/ml 이하였으나 Day -2에 2.0 ng/ml 이상으로 상승하였으며, 혈장 progesterone 농도가 최초로 4.0 ng/ml 이상으로 상승한 날은 최초 교배 허용 후 2일이었다. Day 20일 경에 임신 예 및 비임신 예 모두 40 ng/ml 이상으로 최고치를 나타내었으며 Day 35 일까지 임신 예와 비 임신 예 사이에 차이가 인정되지 않았으나 이후 임신 예가 비 임신 예에 비해 높게 유지된 기간이 걸었다. 혈장 estradiol-$17{\beta}$ 농도는 발정 출혈 개시 일에 9 pg/ml 이상을 나타냈으며 이후 급증하여 Day -2 에 26.4 pg/ml로 peak를 나타내었다. CI와 혈장 progesterone 및 estradiol-$17{\beta}$ 농도 사이의 관계를 살펴보면, 혈장 estradiol-$17{\beta}$ 농도는 최초 교배 허용 일(Day 0)에 peak를 나타냈고 혈장 progesterone 농도는 Day 2에 4.0 ng/ml 이상으로 처음 상승하였다. CI 는 혈장 estradiol-$17{\beta}$ peak 이후 l일(Day 1)에 최고치를 나타냈으며 80% 및 90% 이상으로 증가한 날은 각각 Day -1 및 Day 1이었다. CI가 80% 및 90% 이상을 지속한 기간은 각각 Day -1에서 Day 8(10 일간 ) 및 Day 1에서 Day 6(6 일간)이었다. CI가 최고치를 나타낸 후 l일 (Day 2)에 혈장 progesterone 농도가 4.0 ng/ml 이상으로 처음 증가하였다. 결과를 종합하면 본 연구에서 비글개의 배란은 혈장 estradiol-$17{\beta}$ peak 이후 3일 및 혈장 progesterone 농도가 4.0 ng/ml 이상으로 처 음 상승한 날에 일어나며, 교배 적기는 CI가 90% 이상으로 증가한 후 2일 이후와 혈장 progesterone 농도가 $2{\sim}25\;ng/ml$인 시기로 생각된다.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.235-243
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• 2007

Hepatocellular carcinoma is significant worldwide public health problem with an estimated annually mortality of 1,000,000 people. Radiofrequency (RF) ablation is an interventional technique that in recent years has come to be used for treatment of the hepatocellualr carcinoma, by destructing tumor tissues in high temperatures. Numerous studies have been attempted to prove excellence of RF ablation and to improve its efficiency by various methods. However, the attempts are sometimes paradox to advantages of a minimum invasive characteristic and an operative simplicity in RF ablation. The aim of the current study is, therefore, to suggest an improved RF ablation technique by identifying an optimum RF pattern, which is one of important factors capable of controlling the extent of high temperature region in lossless of the advantages of RF ablation. Three-dimensional finite element (FE) model was developed and validated comparing with the results reported by literature. Four representative Rf patterns (sine, square, exponential, and simulated RF waves), which were corresponding to currents fed during simulated RF ablation, were investigated. Following parameters for each RF pattern were analyzed to identify which is the most optimum in eliminating effectively tumor tissues. 1) maximum temperature, 2) a degree of alteration of maximum temperature in a constant time range (30-40 second), 3) a domain of temperature over $47^{\circ}C$ isothermal temperature (IT), and 4) a domain inducing over 63% cell damage. Here, heat transfer characteristics within the tissues were determined by Bioheat Governing Equation. Developed FE model showed 90-95% accuracy approximately in prediction of maximum temperature and domain of interests achieved during RF ablation. Maximum temperatures for sine, square, exponential, and simulated RF waves were $69.0^{\circ}C,\;66.9^{\circ}C,\;65.4^{\circ}C,\;and\;51.8^{\circ}C$, respectively. While the maximum temperatures were decreased in the constant time range, average time intervals for sine, square, exponential, and simulated RE waves were $0.49{\pm}0.14,\;1.00{\pm}0.00,\;1.65{\pm}0.02,\;and\;1.66{\pm}0.02$ seconds, respectively. Average magnitudes of the decreased maximum temperatures in the time range were $0.45{\pm}0.15^{\circ}C$ for sine wave, $1.93{\pm}0.02^{\circ}C$ for square wave, $2.94{\pm}0.05^{\circ}C$ for exponential wave, and $1.53{\pm}0.06^{\circ}C$ for simulated RF wave. Volumes of temperature domain over $47^{\circ}C$ IT for sine, square, exponential, and simulated RF waves were 1480mm3, 1440mm3, 1380mm3, and 395mm3, respectively. Volumes inducing over 63% cell damage for sine, square, exponential, and simulated RF waves were 114mm3, 62mm3, 17mm3, and 0mm3, respectively. These results support that applying sine wave during RF ablation may be generally the most optimum in destructing effectively tumor tissues, compared with other RF patterns.

• 지식경영연구
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• 제17권2호
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• pp.131-163
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• 2016

The purpose of this study is to empirically analyze how social comparative learning of forum participants affects learning effects with an emphasis on participants' characteristics. As today's society is changing at a fast pace, the desire for new knowledge and information has grown accordingly. To quench this thirst for knowledge and information, seminars, symposiums, conferences, forums, conventions, exhibitions, and more are taking place as part of knowledge sharing events across the world. Also, the increased need for knowledge and information exchange has led the development and growth of the convention industry and Meetings, Incentives, Conferences, and Events (Exhibitions)(MICE) industry. Especially, forum is a type of event which invites professionals and specialists to discuss diverse topics and share their knowledge and experience with the audience. The participants utilize it as an opportunity to get close to information providers and enjoy the pleasure of knowledge exchange. However, there have been few empirical analyses on who the participants are, why they attend forum, how they pick up and learn new information and knowledge, and what kinds of learning effects they achieve after the event. This paper is to analyze how social comparative learning of the forum's participants influences learning effects based on Albert Bandura's Social Learning Theory (1977, 1997, 1982. 2001) and Leon Festinger's Social Comparative Theory (1950, 1954). By dividing the participants into two groups, one with high level of self-efficacy and the other with low level of self-efficacy, we have examined the differences in learning effects between the two groups using them as moderating variables. This study was conducted in 'MBN Y Forum 2016,' which is one of the most representative knowledge exchange forums of South Korea. An online survey was distributed out and, 1,307(39.2%) out of the total participants of 3,338 have completed the survey. The survey included questions about whether the participants have gained positive or negative motivations by comparing themselves to the speakers (upward comparison learning) and other participants (lateral comparison learning). The results have shown the quality of messages that the speakers are presenting as knowledge providers is the most significant factor that acts on learning effects. Particularly, the participants had higher levels of self-efficacy and self-esteem than average people. They had a clear goal to learn from the speakers (upward comparison) and received positive motivations from them. In other words, no negative learning effects had been found. This presents a managerial implication that having a qualified speaker is necessary for a forum to be successful. On the other hand, the results from the comparison with the other participants (lateral comparison) were different. The participants were likely to compare themselves to the other participants through observational learning. They could compare listening attitudes, language skills, or capabilities to ask a question. The results have showed the participants received positive motivations from the lateral group but at the same time were jealous of abilities of the others. When the quality of a question by a participant is not good enough, it can have a negative influence on the participants' learning effects. The first group with high levels of self-efficacy and self-esteem had no correlation to negative learning effects from the speakers. They rather had a strong desire to learn from the speakers. On the contrary, the participants perceived the lateral group as a learning subset and competitor. The second group with low levels of self-efficacy and self-esteem saw the quasi-group as a rival. This presents that the individual learning effects can be different depending on the participants' characteristics.

• 유기물자원화
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• 제14권1호
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• pp.151-159
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• 2006

런던협약의 영향으로 슬러지 처리의 중요성이 대두되고 있는 실정이므로 본 연구는 슬러지 처리에 대한 개선방안의 제시를 목적으로 유기성 폐수 및 하수처리장 슬러지를 대상으로 JAR test 및 교반장치를 부착한 침강 column을 이용하여 응집효율이 침강특성에 미치는 영향에 대한 실험을 실시하였으며 다음과 같은 결과를 얻었다. 최적의 침강효율을 얻기 위한 최소의 응집제 투여농도는 200mg/L의 경우로 나타났으며. 200mg/L 이상으로 PAC가 투여될 경우 각각의 임계슬러지 영역의 크기에서는 큰 변화가 없는 것으로 나타났다. 따라서 200mg/L로 투여되었을 때의 Clarification Rate(CR)은 임계슬러지 침강높이 비율이 0.4로 나타났으므로 CR = (Ho-Ht) / Ho = 1-0.4=0.6 로 산정되었다. MLSS농도가 높아질수록 슬러지 계면 침강속도는 감소하였으나 MLSS농도가 1,000mg/l 이상으로 증가하면 오히려 침강속도는 증가하는 것으로 나타났다. 이는 슬러지 농도가 1,000mg/l 이상으로 증가하게 되면 압밀침전영역으로 전이되어 상호작용에 의한 응집에 영향을 미치게 됨으로써 오히려 floc 형성에 긍정적인 영향을 미치기 때문이다. 슬러지 응집계면의 침강속도는 유기폐수 활성슬러지의 평균 침강속도 $4.25{\times}10^{-3}/min$보다 하수처리장 슬러지의 평균 침강속도가 $28.66{\times}10^{-3}/min$로 6.7배 높은 것으로 나타났다. 유기성 폐수 활성슬러지는 PAC의 투여량이 200mg/l 이하일 때는 침강속도 증가율보다 CR의 증가율이 더 컸으나 200mg/l 이상일 때는 CR의 증가율보다 침강속도 증가율이 더 커졌음을 알 수 있었다. 그러나 하수슬러지의 경우는 PAC 투여량이 증가함에 따라 CR의 변화율에는 차이가 적었으나 침강속도는 200m/l 이상일 때 차이가 급격히 증가하였다. 따라서 응집제 투여효과는 상등수의 SS제거율 효과보다는 MLSS의 침강속도에 더 큰 영향을 미치는 것을 알 수 있다.

• KDI Journal of Economic Policy
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• 제32권4호
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• pp.115-151
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• 2010

본 논문은 대학의 연구활동을 특허라는 창을 통하여 들여다보고자 하였다. 특허인용정보가 있는 미국 특허를 이용하여 우리나라의 대학 특허를 기업 특허와 대비시켜 대학 특허의 특성을 분석하였다. 일반적으로 기업 특허와 대학 특허는 전자는 전유성(appropriability) 측면에서 그리고 후자는 기초성(basicness) 측면에서 차이가 있는 것으로 본다. 그런데 기초성 측면에서 우리나라 대학 특허는 기업 특허와 크게 두드러진 차이를 보이지 않는 것으로 나타났다. 다음으로 특허인용함수모형을 이용하여 특허의 질 또는 수준을 기업과 대학 사이에 비교해 보았다. 기업 특허는 자체인용이 상당수 포함되어 있는데, 이를 감안하면 전방인용에 있어서는 대학 특허와 기업 특허는 큰 차이를 보이지 않는 것으로 나타났다. 자체인용 비중이 높을수록 특허의 전유성 정도가 높은 경향이 있다는 선행연구를 상기하면, 기업 특허의 전유성 정도가 높게 나오는 것을 확인할 수도 있었다. 미국과 유럽을 대상으로 한 선행연구에서는 대학 특허가 대체로 기업 특허와 비교하여 인용빈도 측면에서 뒤지지 않는 것으로 분석되고 있다. 외국의 대학 특허 분석결과와 본 논문의 우리나라 대학 특허 분석결과를 대비시키면, 우리나라 대학 특허는 전반적인 수준이나 영향력 측면에서는 기업 특허에 미치지 못하며, 이는 우리나라대학의 특허활동이 최근에야 활성화된 데 기인한 것으로 추론된다. 이러한 분석 결과는 향후 대학의 연구수준을 제고하기 위한 노력을 보다 체계화해야 한다는 것을 시사하며, 최근 진행되고 있는 정부의 기초연구 정책방향 전환이나 대학 내의 자체적인 개혁 움직임을 간접적으로 지지한다. 정부의 정책 전환과 함께 학내의 개선 노력이 합치되면 향후 우리나라 대학의 특허인용도 및 영향력이 훨씬 높아지게 될 것으로 기대할 수 있다.

• 방사성폐기물학회지
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• 제9권4호
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• pp.207-217
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• 2011

UV-Vis 분광광도법과 시간분해 레이저 유도 형광분광법(TRLFS)을 이용하여 흄산의 모사 리간드로 사용한 2,6-Dihydroxybenzoate(DHB)와 U(VI)의 착물형성반응을 조사하였다. U(VI)-DHB 착물 고유의 전하이동 흡수 스펙트럼을 분석한 결과, 착물형성반응은 우라늄-리간드 비가 1:1 또는 1:2 착물을 형성하는 이중 평형반응이며, 산도에 따라 착물종의 분포가 변한다는 것을 밝혔다. 계산된 착물형성상수 (log $K_1$ and log $K_2$)는 $12.4{\pm}0.1$과 $11.4{\pm}0.1$이다. 이에 더하여, TRLFS 방법으로 조사한 결과, DHB는 U(VI) 화학종들의 형광 소광제(quencher)로서 역할을 한다는 것을 확인하였다. 특히, 확인된 U(VI) 화학종 모두(${UO_2}^{2+}$, $(UO_2)_2{(OH)_2}^{2+}$과 $(UO_2)_3(OH)_5{^+})$에서 정적 (static) 및 동적 (dynamic) 소광작용이 공존하는 것으로 관찰되었다. 시간분해 형광 스펙트럼으로부터 리간드 농도에 따른 U(VI) 화학종의 형광세기와 형광수명을 측정하였으며, Stern-Volmer 식을 이용하여 분석하였다. 결정된 정적소광계수(KS)는 ${UO_2}^{2+}$, $(UO_2)_2{(OH)_2}^{2+}$ 과 $(UO_2)_3(OH)_5+$에 대하여 각각 $4.2{\pm}0.1$, $4.3{\pm}0.1$ 과 $4.34{\pm}0.08$이다. Stern-Volmer 식을 이용한 분석 결과, 단일 또는 이중 배위자 구조(mono- and bi-dentate)의 U(VI)-DHB 착물이 모두 정적소광효과에 관여하는 바닥상태 착물임을 확인하였다.

• 헤리티지:역사와 과학
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• 제52권2호
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• pp.122-141
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• 2019

고려궁성은 개성에 위치하고 있다는 유적의 특수성으로 인해 유물에 대한 단편적인 접근만이 가능하였으나, 본고에서는 고려궁성 내 전각군의 배치와 역사 기록들에 대한 이해를 바탕으로 출토 자기들을 해석해보았다. 그중 명문 기호 자기는 유적에 대한 보다 구체적인 정보들을 제공하므로 해당 건물지의 시기와 성격, 궁궐의 운영 등을 종합적으로 추정해볼 수 있다. 8차에 걸쳐 진행된 고려궁성의 발굴조사에서 출토된 자기들의 전반적인 양상을 살펴보았으며, 고려궁성에서 출토된 18종의 명문 기호 청자들을 특징 시기별로 분류하였다. 본고에서는 13세기 후반으로 편년되었던 '소전(燒錢)'명 청자들을 고려궁성 발굴조사 결과와 문헌 기록에 근거하여 13세기 전반에 사용되었던 것으로 보았다. 이는 '소전'명 청자와 공반하는 기호(${\circ}$, ${\odot}$) 청자, '성(成)'명 청자의 편년, 그리고 이들 청자가 중앙건축군의 선경전(宣慶殿, 회경전) 뒤편에서 출토되었다는 점을 종합적으로 검토한 결과이다. 13세기 후반에는 초제가 서부건축군의 강안전(康安殿, 대관전)에서 대부분 행해졌고, '소전'명 청자가 출토된 선경전 구역에서 초제가 거행된 것은 강화 천도(1232~1270) 직전인 13세기 전반에 집중되어 있기 때문이다. 따라서 8차 발굴조사에서 출토된 '소전'명 청자 잔을 비롯한 다수의 잔과 잔탁은 13세기 전반 선경전에서 거행된 초제에서 사용되었을 가능성이 크다.

• 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.