• Journal of Chest Surgery
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• v.31 no.6
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• pp.598-603
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• 1998

Excessive sweating of the palms, axillae, and face has a strong negative impact on the quality of life for many people. The existing non-operative therapeutic options seldom give sufficient relief and have a transient effect. But a definitive cure can be obtained by upper thoracic sympathectomy. From June 1997 to October 1997, 117 cases of the needle (2 mm) thoracoscopic thoracic sympathectomies were performed in the Department of Thoracic and Cardiovascular Surgery in the Respiratory Center Yong-dong Severance Hospital in Seoul, Korea. We have followed up on 94 cases which include palmar hyperhidrosis (n=85), facial hyperhidrosis(n=5) and axillary hyperhidrosis(n=4). There were 42 males and 52 females whose ages ranged from 14 to 63 years(median:23 years). The T2 ganglia and T3-4 ganglia were excised by electrocuting with a hook and endoscissors and were removed for histologic examination. There have been no mortalities or life-threatening complications. The surgical results were classified as excellent(much improvement,very dry) in 93.6%, good(some improvement, minimally wet) in 2.1%, and fair(slight improvement, still wet) in 4.2%. Five patients(5.3%) required closed thoracostomy drainage because of pneumothorax in the immediate postoperative day. Horner's syndrome occurred in one case. The compensatory sweating occurred in 67 cases(71.2%) and was embarrassing in 21 cases(22.3%) and disabling in 9 cases(9.6%) of these cases. Primary failure occurred in one case. The patient with primary failure underwent successful operation. Fifty-one patients had concomitant hyperhidrosis. Our experiences indicate needle thoracoscopic sympathectomy is a very effective, safe, and time- saving procedure for essential hyperhidrosis.

• Journal of Intelligence and Information Systems
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• v.9 no.1
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• pp.227-249
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• 2003

Prediction of corporate failure using past financial data is a well-documented topic. Early studies of bankruptcy prediction used statistical techniques such as multiple discriminant analysis, logit and probit. Recently, however, numerous studies have demonstrated that artificial intelligence such as neural networks can be an alternative methodology for classification problems to which traditional statistical methods have long been applied. In building neural network model, the selection of independent and dependent variables should be approached with great care and should be treated as model construction process. Irrespective of the efficiency of a teaming procedure in terms of convergence, generalization and stability, the ultimate performance of the estimator will depend on the relevance of the selected input variables and the quality of the data used. Approaches developed in statistical methods such as correlation analysis and stepwise selection method are often very useful. These methods, however, may not be the optimal ones for the development of neural network model. In this paper, we propose a genetic algorithms approach to find an optimal or near optimal input variables fur neural network modeling. The proposed approach is demonstrated by applications to bankruptcy prediction modeling. Our experimental results show that this approach increases overall classification accuracy rate significantly.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.123-129
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• 2011

The pig has been considered to serve as an appropriate model of human disease. Therefore, establishment of porcine embryonic stem cell lines is important. The purpose of the present study was to further work in this direction. We produced porcine parthenogenetic embryos, and separately aggregated two of each of two-cell ($2{\times}2$), four-cell ($2{\times}4$), and eight-cell ($2{\times}8$) embryos derived by parthenogenesis. After culture for 4 days, the developmental ability of the aggregates and total blastocyst cell numbers were evaluated. The percentage of blastocysts was significantly higher in both $2{\times}4$- and $2{\times}8$-aggregated embryos ($58.3{\pm}1.9%$ and $37.2{\pm}2.8%$, respectively) than in the control or $2{\times}2$-aggregated embryos ($23.6{\pm}1.1%$ and $12.5{\pm}2.4%$, respectively). Total blastocyst cell numbers were increased in the $2{\times}4$- and $2{\times}8$-aggregated embryos (by $44{\pm}3.0%$ and $45{\pm}3.3%$, respectively) compared with those of control or $2{\times}2$-aggregated embryos ($30.5{\pm}2.1%$ and $30.7{\pm}2.6%$, respectively; p<0.05). The levels of mRNA encoding Oct-4 were higher in both the $2{\times}4$- and $2{\times}8$-aggregated embryos than in the control. When blastocysts derived from $2{\times}4$- aggregated embryos or intact normal embryos were cultured on mouse embryonic fibroblast feeder cells to obtain porcine stem cells, blastocysts from aggregated embryos formed colonies that were better in shape compared with those derived from intact blastocysts. Together, the data show that aggregation of porcine embryos not only improves blastocyst quality but also serves as an efficient procedure by which porcine embryonic stem cells can become established.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.539-542
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• 2002

Crack sealing is a maintenance procedure that is commonly used to reduce pavement degradation. If cracks in pavements are not sealed, surface water penetration can reduce the strength of the sub-base layers, which can result in increased deflections of the pavement. Reduced strength of the sub-base also accelerates the deterioration of the surface, due to development of greater cracking and potholes. Crack sealing is performed to reduce water and debris penetration, thereby helping to maintain pavement structural capacity and limiting future degradation. The process of sealing cracks in pavements is however dangerous, costly, and labor-intensive operation. Labor turnover and training are increasing problems related to crack sealing crews, and as traffic volumes increase. Automating crack sealing can reduce labor and road user costs, improve work quality, and decrease worker exposure to roadway hazards. The main objective of this research is to develop an automated system for sealing cracks in pavement. Extension of the algorithms and tools presented in this research is also recommended for future study.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.1
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• pp.29-38
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• 2005

The fluid animation procedure consists of physical simulation and visual rendering. In the physical simulation of fluids, the most frequently used practices are the numerical simulation of fluid particles using particle dynamics equations and the continuum analysis of flow via Wavier-Stokes equation. Particle dynamics method is fast in calculation, but the resulting fluid motion is conditionally unrealistic The method using Wavier-Stokes equation, on the contrary, yields lifelike fluid motion when properly conditioned, yet the complexity of calculation restrains this method from being used in real-time applications. Global illumination is generally successful in producing premium-Duality rendered images, but is also excessively slow for real-time applications. In this paper, we propose a rapid fluid animation method incorporating enhanced particle dynamics simulation method and pre-integrated volume rendering technique. The particle dynamics simulation of fluid flow was conducted in real-time using Lennard-Jones model, and the computation efficiency was enhanced such that a small number of particles can represent a significant volume. For real-time rendering, pre-integrated volume rendering method was used so that fewer slices than ever can construct seamless inter-laminar shades. The proposed method could successfully simulate and render the fluid motion in real time at an acceptable speed and visual quality.

• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.127-143
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• 1996

Advanced countries are very active in deploying the National Information I infrastructure which provides universal service to promise fruitful quality of futuree life. Even in the distributed environment, we can closely converse, work together, and share information in a very convenient way. This is actually enabled with the help of groupware technology, which are currently focused and researched in a larger popularity. The aim of this study is to design a portable pack for group communications management to support the development of groupware application. In the paper we begin with technical survey, continue to build our own model for group communications man agement, and design its architecture and procedure. We also suggest group addressing mechanism under Internet environment such as how to create IP multicast address and IP port number dynamically and as a globally unique value for the communication session, with the help of the hierarchical and distributed address managers. We also indicate the reliable data transmission services to remedy the unreliable feature of the UDP multicast services, and finally the architecture/ applied to support the practical applications is briefly discussed for verification of the designed concept.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.209-222
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• 2014

The purpose of this study was to discuss the papers of social welfare field that were published in Korea, from a research methodology aspect in accordance with the meta-analysis reporting standard proposed by the United States Psychological Association. To this end, an analysis was conducted according to 5 types of conformity (title and abstract, introduction, methods, results and discussion) on the target subjects of 26 meta-analysis papers of social welfare field. The analysis results showed, first, the conformity in the title and abstract showed good results except for the suggested topics for meta-analysis methods. Second, in terms of the conformity of the introduction, the descriptions seemed to be good in a number of items. Third, for the conformity in the methods, the overall reporting standard was seen to be lacking and, in particular, the reporting standard for the coding procedure was seen as being very deficient. Fourth, the conformity in the results showed that the assessment of research quality and the magnitude of efficacy for each individual study, sample size, and the contents of the provided tables, summary of tables and graphs, including the study results, were not being properly reported. Fifth, the conformity in discussions was seen to be generally sound. Based on such results, by providing a reporting standard and perspective needed for ensuring feasibility that can be used to assess meta-analysis study materials, this study was aimed at presenting implications for the academic advancement of field of social welfare.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.625-629
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• 2008

Background: When it comes to esophageal cancer operations, the prevalence of anastomotic complications that adversely affect quality of life is related to the type of anastomotic procedure and the operative site. We studied outcomes related to a safe anastomotic method used in Ivor Lewis esophagogastrectomy for preventing anastomotic leakage and stricture formation. Material and Method: Between May 2003 and April 2007, 18 patients with esophageal cancer underwent this type of esophagogastrectomy. Four people were lost to follow-up. There were 17 men (94.4%) and 1 woman. The mean patient age was 61 years (range, $46{\sim}73$ years). Result: The mean follow-up period was 17.2 months (range, $1{\sim}45$ months). There was no anastomotic leakage. There was one benign anastomotic stricture (5.6%) requiring esophageal balloon dilatation, which was accomplished with a 25 mm circular stapler. Conclusion: We experienced relatively good postoperative results using a safe anastomotic method in the Ivor lewis operation for preventing anastomotic complications. These results suggest that this anastomotic method is effective in reducing the incidence of benign anastomotic complications.

• Archives of design research
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• v.20
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• pp.61-72
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• 1997

This study aims to promote understanding level for mathematical model, to improve methods and necessity of application in the process of product design and also to promote approaching and applying methods as a guideline for beginners. For the procedure and method of study first, it was emphasized by linking method and necessity of scientific analysis and a quality of product design and design process. Next, the corresponding relations between mathematical model and design probelem was desciebed, the mathematical model was examinated appeying process of product design. Lastly, approaching and applying methods for beginners was presented based on the discribed studied contents. As the result of the study, some points are by a result or problem : frist, the point that mathematical model is useful to grasp the design problems which various elements are complicately involved quantitatively and structurally, and its necessity can be especially utilized as a tool to justify and convince the convince the conclusion of the designer himself to the persons concerned. Second, the point that in order to apply mathematical model to the design process skillfully, first of all, the substance of all mathematical models which can be applid, and it is not easy to command in perfect method without using computer. Third, the point that since there are many kindsof mathematical models used is mathematical modeland the models which can be applidied to solve design problems differ in accordance with the design types and design process, its applying method can be presented as one kind of standardization or concretely. Fourth the point that in case of approaching mathematical model for the first time, it can start to select model corresponding with design type by stage of design process bassed on understanding for some mathematical knowledge and computer program.

• Journal of Environmental Impact Assessment
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• v.16 no.4
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• pp.301-310
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• 2007

For the improvement of air quality in the metropolitan area, Korea has enforced the air pollutant emission cap regulation from the 1st of July, 2007, and the companies that intend to install a new or an enlarged facility in the metropolitan area will be restricted. However, the current regulation on permission does not describe a standard of judgement distinctly. In this study, therefore, a method of permission on the installation of a new or an enlarged facility was developed by supplementing the law in force based on the foreign cases. To develop a specific permit regulation and procedure, the developed nations' cases such as US, Canada, EU were reviewed thoroughly. Also, an appropriate method was suggested to apply domestically for a new or an enlarged facility permit within the regulations of the metropolitan special law. The method consists of first, calculating the possible permit quantity from the difference between an estimated annual emission cap and the annual emission provided by the implementation plan in each region. Second, permitting a new or an enlarged facility construction within the difference of the emission between the regional emission cap and the implementation plan in 2014. Third, distributing emissions allowable to each performance year based on the regional emission cap and the implementation plan in 2014. Fourth, making use of the emission difference between the implementation plan and the performance result in each year. Considering the general domestic conditions, the convenience of the permit authority and permitted companies, the most reasonable method was to use the fourth. To enforce the suggested permit method in a more flexible way, parts of the related regulations need to be revised and continuous research and analysis on the results from the implemented system and on foreign cases is necessary to develop this method a suitable system for domestic conditions and to settle the air pollutant emission cap system.