• Journal of Chest Surgery
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• 제16권2호
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• pp.157-163
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• 1983

Ebstein's anomaly is a rare congenital cardiac malformation oand the ideal surgical correction seems controversial at present, and some problems are left unsolved in the surgical correction of this anomaly. Between June 1978 and June 1982, 12 patients with Ebsteins' anomaly underwent corrective open heart surgery at Seoul National University Hospital. Except for one patient, who had no ASD, all had a huge right atrium, secundum type ASD, and definite atrialized right ventricle. Typically, displaced tricuspid valve leaflets were found in all cases, but the degree of displacement and deformity were variable. In the point of NYHA functional classification, five were in class II, six were in class III, and one was in class IV. Ten patients were operated on by tricuspid valve replacement and pication. Two patients were operated on only by plication and annuloplasty techniques, and in all cases, ASD was closed. Postoperatively, four patients suffered from complete A-V block, and two of them died immediately. The remaining two patients took pacemaker generator implantation with good results. The other eight patients were in good condition. Tricuspid valve replacement using tissue valve and plication of the atrialized rght ventricle seems to be a good method of surgical correction for Ebstein's anomaly.

• 한국게임학회 논문지
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• 제11권6호
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• pp.81-93
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• 2011

온라인상에서 사용자의 개인정보를 불법적으로 취득, 악용하는 계정도용 문제는 금전적인 이득을 얻을 수 있는 MMORPG(Massively Multi-player Online Role Playing Games)에서 특히 빈번하게 발생하고 있다. 많은 사람들이 게임을 이용하여 심각한 피해로 이어질 수 있기 때문에 이에 대한 대책마련이 시급함에도 불구하고, 이를 예방하거나 탐지하는 기법에 대한 연구가 많이 부족한 실정이다. 본 연구에서는 온라인게임에서 발생했던 실제 계정도용 사례 분석을 통해 계정도용의 유형을 체계적으로 정의하고, 유형별로 계정도용을 분류하는 자동화된 탐지모델을 제안한다. 실 계정도용 사례를 분석한 결과 속전속결형, 신중형, 대담무쌍형의 3가지로 구분되었으며 이 분류 체계와 탐지모델을 국내 주요 온라인게임회사 중 한 곳에 적용하였다. 본 연구에서 제시한 유형별 탐지모델은 해킹의 유무만을 판정하던 기존의 모델보다 탐지에 있어서 향상된 성능을 보였다.

• 한국정보통신학회논문지
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• 제22권11호
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• pp.1435-1441
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• 2018

온라인 서명 검증은 간단하면서도 효율적인 본인 확인 방법의 하나로 생체 인식에 따른 거부감이 적은 장점으로 본인 확인 용도로 사용되고 있다. 서명 검증을 분류 문제로 접근하기 위해서는 모조서명이 필요하지만, 대부분의 실용적인 응용에서 모조서명을 확보하기는 쉽지 않으며 진서명 역시 많은 양을 확보하기는 쉽지 않다. 이 논문에서는 모조서명의 확보가 어려운 문제를 해결하기 위해 단일 클래스 SVM을 사용하고, 진서명의 양이 제한되는 문제는 다른 사람의 서명 데이터를 일반 필기 데이터로 사용하여 해결하는 방법을 제시한다. 다른 사람의 서명 데이터는 검증하고자 하는 서명과 형태적인 유사점을 찾을 수 없지만, 서명에서의 일반적인 특징을 반영하고 있으므로 적은 수의 진서명만을 확보할 수 있는 경우에 사용하면 검증률을 높일 수 있으며 이는 실험 결과를 통해서 확인할 수 있다.

• 한국태양에너지학회 논문집
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• 제33권5호
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• pp.105-112
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• 2013

The new renewable energy became popular as a clean and sustainable alternative energy under the circumstances that the entire world is facing severe abnormal climate due to the use of fossil fuel, and among which, solar energy can be obtained anywhere and is not difficult to apply it into the existing buildings, which makes it possible to be widely distributed. However, as PV module is installed into a single plate system, it shows structural weaknesses which are vulnerable to wind load and give loss to design elements in external appearance. Accordingly, this study planned one-step parallel system to complement the problems occurring from a single plate system and used STAR-CCM+ V.8 made by CD-Adapco, a computational fluid dynamics(CFD) simulation tool to measure wind load stability and support based on the design standards for a single plate system and one-step parallel system. Building height was limited to less than 10m and wind speed was given when increasing from 35m/s to 50m/s by 5m/s on PV system installed into the flat roof. In this case, our analysis suggested that step-one parallel system was in class 7-9 according to Beaufort's wind power classification, which did not have an impact on the fixed PV system, and the single plate system is considered to cause risks in designing wind speed in central districts because it is more than wind power class 12.

• 기술혁신학회지
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• 제17권3호
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• pp.467-489
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• 2014

본 연구는 창조경제시대에서 창조도시와 도시 성장의 핵심 자본인 창조계급에 대해 우리나라에 적합한 창조계급을 탐색하는데 목적을 두었다. 이를 위해 Florida(2002)의 창조계급과 Mcgranahan & Wojan(2007)이 재구성한 창조계급을 국내 통계청의 2010년 자료를 활용하여 한국직업분류기준표를 기준으로 분류하고 각각의 창조계급과 혁신지수, 하이테크지수, 경제적 성과(임금)의 지역적 차이를 분석하였다. 또한, 각각의 창조계급과 국내 혁신지수, 하이테크지수의 상관관계 분석을 실시하였고, 그 결과 Mcgranahan & Wojan(2007)의 창조계급이 더 높은 상관관계를 가지는 것으로 조사되어, Flordia 보다 Mcgranahan & Wojan 창조계급이 적절하다고 판단하였다. 따라서 Mcgranahan & Wojan(2007)의 창조계급에 대해 혁신 및 하이테크지수, 경제성장과의 경로분석을 실시하여 창조계급이 혁신, 하이테크, 경제성장에 미치는 영향을 분석하였다. 이러한 결과는 현재 국내의 다양한 창조계급에 대한 기준을 제시하였으며, 경제적 성장과의 분석을 통해 중앙 및 지방정부의 정책입안자에게 창조계급 유입을 위한 근거를 마련하였다. 또한 창조계급 유입을 위한 도시환경과 지역경제성장과의 관계 및 한국의 창조계급 지표 수립에 관한 다양한 후속연구를 촉진할 것으로 기대된다.

• Journal of Preventive Medicine and Public Health
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• 제31권3호
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• pp.540-563
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• 1998

This Study has been carried out to make a recommendation for the next amendment of the Infectious Disease Prevention Act with a specific focus on the kind of notifyable disease. Korean, Japanese, German, U.S, English and French acts on infectious diseases prevention were reviewed, compared with and analized in regards of numbers and kinds of notifyable infectious diseases and their tendency of amendments. An criteria was designed to assess the level of validity of diseases to be designated in the act. Four items, the fatality (greater than 10% or not), the possibility to make a big epidemic, the availability of efficient vaccination and the usefulness of isolation, are used in the assessment. This index is applied to the diseases in Korean and other countries' Infectious Disease Prevention Acts. Results are as follows: 1. The Korean Infectious Disease Preventon Act has a unique way of classifying the notifyable infectious disease, that is, the first, the second and the third class. But the author cannot find the basis of classification. No other countries reviewed have the similar classification. 2. The ten diseases, cholera, plague, yellow fever, diphtheria, typhoid fever, poliomyelitis, rabies, tetanus, malaria, and meningococcal meningitis are designated as the notifyable diseases not only in Korea but also in Japan, Germany, United States, England and france. 3. Thirty seven diseases including small pox, Lassa fever, anthrax, influenza, German measles, Legionellosis, infection with E. coli O157:H7, Q-fever, brucellosis, Lyme disease are designated as legal disease at least one of the above mentioned countries. 4. The Korea has been coped with the change of the infectious disease occurrence for last fifty years in amendment of the Infectious Disease Prevention Act. 5. Japan has a special infectious surveillance system composed of 3,880 clinics throughout the whole country. 6. Germany has classified infectious diseases in five categories which are based on seriousness of disease. Any confirmed death, cases and suspected cases in class I should be reported within 24 hours. But only confirmed death and cases in class II, but not suspected cases, are reportable in Germarny. 7. Plague, bacillary dysentery, pertussis, mumps, Japanese encephaltis and Korean hemorrhagic fevers are diseases with high credits validity index among Korean legal disease. 8. German measles, anthrax, E. coli O157 : H7 infection, Lassa fever, Q-fever, brucellosis are high in validity index among those which are not designated in Korea but designated in other countries. In conclusion, the Korean Infectious Disease Prevention Act has well been coped with the changes of infectious disease occurrence for last fifty years, but the classification basis and the validity of diseases to be designated as legal diseases is worth reevaluating.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1244-1244
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• 2001

In linear discriminant analysis there are two important properties concerning the effectiveness of discriminant function modeling. The first is the separability of the discriminant function for different classes. The separability reaches its optimum by maximizing the ratio of between-class to within-class variance. The second is the stability of the discriminant function against noises present in the measurement variables. One can optimize the stability by exploring the discriminant variates in a principal variation subspace, i. e., the directions that account for a majority of the total variation of the data. An unstable discriminant function will exhibit inflated variance in the prediction of future unclassified objects, exposed to a significantly increased risk of erroneous prediction. Therefore, an ideal discriminant function should not only separate different classes with a minimum misclassification rate for the training set, but also possess a good stability such that the prediction variance for unclassified objects can be as small as possible. In other words, an optimal classifier should find a balance between the separability and the stability. This is of special significance for multivariate spectroscopy-based classification where multicollinearity always leads to discriminant directions located in low-spread subspaces. A new regularized discriminant analysis technique, the principal discriminant variate (PDV) method, has been developed for handling effectively multicollinear data commonly encountered in multivariate spectroscopy-based classification. The motivation behind this method is to seek a sequence of discriminant directions that not only optimize the separability between different classes, but also account for a maximized variation present in the data. Three different formulations for the PDV methods are suggested, and an effective computing procedure is proposed for a PDV method. Near-infrared (NIR) spectra of blood plasma samples from mastitic and healthy cows have been used to evaluate the behavior of the PDV method in comparison with principal component analysis (PCA), discriminant partial least squares (DPLS), soft independent modeling of class analogies (SIMCA) and Fisher linear discriminant analysis (FLDA). Results obtained demonstrate that the PDV method exhibits improved stability in prediction without significant loss of separability. The NIR spectra of blood plasma samples from mastitic and healthy cows are clearly discriminated between by the PDV method. Moreover, the proposed method provides superior performance to PCA, DPLS, SIMCA and FLDA, indicating that PDV is a promising tool in discriminant analysis of spectra-characterized samples with only small compositional difference, thereby providing a useful means for spectroscopy-based clinic applications.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1042-1042
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• 2001

In linear discriminant analysis there are two important properties concerning the effectiveness of discriminant function modeling. The first is the separability of the discriminant function for different classes. The separability reaches its optimum by maximizing the ratio of between-class to within-class variance. The second is the stability of the discriminant function against noises present in the measurement variables. One can optimize the stability by exploring the discriminant variates in a principal variation subspace, i. e., the directions that account for a majority of the total variation of the data. An unstable discriminant function will exhibit inflated variance in the prediction of future unclassified objects, exposed to a significantly increased risk of erroneous prediction. Therefore, an ideal discriminant function should not only separate different classes with a minimum misclassification rate for the training set, but also possess a good stability such that the prediction variance for unclassified objects can be as small as possible. In other words, an optimal classifier should find a balance between the separability and the stability. This is of special significance for multivariate spectroscopy-based classification where multicollinearity always leads to discriminant directions located in low-spread subspaces. A new regularized discriminant analysis technique, the principal discriminant variate (PDV) method, has been developed for handling effectively multicollinear data commonly encountered in multivariate spectroscopy-based classification. The motivation behind this method is to seek a sequence of discriminant directions that not only optimize the separability between different classes, but also account for a maximized variation present in the data. Three different formulations for the PDV methods are suggested, and an effective computing procedure is proposed for a PDV method. Near-infrared (NIR) spectra of blood plasma samples from daily monitoring of two Japanese cows have been used to evaluate the behavior of the PDV method in comparison with principal component analysis (PCA), discriminant partial least squares (DPLS), soft independent modeling of class analogies (SIMCA) and Fisher linear discriminant analysis (FLDA). Results obtained demonstrate that the PDV method exhibits improved stability in prediction without significant loss of separability. The NIR spectra of blood plasma samples from two cows are clearly discriminated between by the PDV method. Moreover, the proposed method provides superior performance to PCA, DPLS, SIMCA md FLDA, indicating that PDV is a promising tool in discriminant analysis of spectra-characterized samples with only small compositional difference.

• 대한치과보철학회지
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• 제55권2호
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• pp.198-204
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• 2017

악안면부의 결손은 선천적으로 결손을 가지고 있거나 외상이나 수술적인 절제 등에 의한 후천적 원인에 의해 발생할 수 있다. 특히 구강 내 결손을 가진 환자 중 상악의 결손과 연관되어 있는 경우가 높은 비중을 차지하고 있으며 보철적 치료의 필요성이 높다. 하악의 부분적 결손을 가질 경우 기능적 회복에 상당한 한계점을 보이나 양측 턱관절이 정상적으로 남아 있을 경우 국소의치를 이용한 악안면 보철물을 제작함으로써 양호한 결과를 기대할 수 있다. 본 증례의 환자는 58세 남자 환자로서 안면부 총상으로 인한 구개부 및 좌측 하악 구치부 결손을 가진 분으로 obturator와 하악 RPD 재제작을 위해 내원하였다. 환자의 상악 결손 범위는 Aramany 분류법 Class IV에 해당되는 상태이며, 하악은 Cantor와 Curtis 분류법 Type V resection 상태이다. 상, 하악의 우측 구치부가 잔존하였으나, 수술 후 악골 변형으로 인해 서로 교합되지 않았으며 치주상태 불량으로 인한 동요도도 존재하는 상태였다. Obturator의 유지를 위해 잔존 지대치를 최대한 활용하였고 안정적인 교합이 형성되도록 치아를 배열하였다. 하악 RPD는 하악 절제술로 변형된 연조직에 적합하도록 제한된 범위를 피개하는 RPD를 제작하였다. 이에 환자분의 저작, 연하, 발음 기능이 많이 개선되었으며 만족할 만한 결과를 보여주어 본 증례를 발표하는 바이다.

• Advances in pediatric surgery
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• 제12권2호
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• pp.137-146
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• 2006

Pediatric surgery could establish a definitive position in the medical field on the basis of a stable patient population. Neonatal surgery, the core of pediatric surgery, requires highly skilled surgeons. However, recent advancement of prenatal diagnosis followed by intervention and decreased birth rate has resulted in a significant decrease in the neonatal surgical population and the number of surgical operations. The purpose of this study is to examine the outcome of neonatal surgeries and to propose a guide for the future surgeries. A total of 359 neonatal surgical patients operated upon at the Department of Surgery, Ewha Medical Center, during past 21 years were studied. The study period hasbeen divided into two time periods: from 1983 to 1993 and from 1994 to 2004. Analysis was based on the Clinical Classification System and mortality pattern, frequency of disorders, occurrence and cause of death, and other changes. Neonatal surgery was 6.4 % of all pediatric surgery during the total 21 year period, 9.9 % in the first period and 4.8 % in the second. Male to female ratio increased from 2.7:1 to 2.1:1. The overall mortality was 6.7 %, and there was significant decrease from 7.4 % in the first period to 6.0 % in the second. The clinical classification system (CCS) for death cases included class II 2, III 4, and IV 7 during the first period and class III 3, and IV 8 during the second, respectively. According to the mortality pattern by Hazebroek, there were 6 preventable death cases during the first period, and only one in the second, and 2 non-preventable death cases during the first period and 8 in second, respectively. Although the patients in the second period had more serious diseases, surgical mortality has been decreased in the second period, which may be the result of improved surgery methods for newborns and advanced patient care.