• Water Engineering Research
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• 제1권4호
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• pp.279-291
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• 2000

A mathematical model using dynamic programming approach is applied to an optimal unit commitment problem. In this study, the units are treated as stages instead of as state dimension, and the time dimension corresponds to the state dimension instead of stages. A considerable amount of computer time is saved as compared to the normal approach if there are many units in the basin. A case study on the Lower Colorado River Basin System is presented to demonstrate the capabilities of the optimal scheduling of hydropower units.

• 산업공학
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• 제16권spc호
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• pp.60-64
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• 2003

This study proposes a method of implementing Six Sigma linking Lean approach and/or TOC(Theory of Constraints). A case study carried out in a PCB production line is examined to compare Lean Six Sigma and TOC Six Sigma. Implementing guidelines are given to achieve the whole company's optimum.

• Archives of Plastic Surgery
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• 제38권1호
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• pp.63-68
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• 2011

Purpose: Mastectomy is one of the operative procedures of female to male transsexuals. It is aimed to excise all of breast tissues and to reconstruct male chest wall, areola, and nipple. Breast sizes are varied by developmental status and their hormonal therapy. There are several approaches for mastectomy. This study is aimed to suggest appropriate mastectomy methods according to breast size in the female to male transgenders. Methods: We retrospectively analysed 46 patients of female to male transgenders. Breast size was categorized by their inner wear size. In A cup size, mastectomy was done with periareolar approach. In C cup size, inframammary fold approach subcutaneous mastectomy was performed. In B cup size, periareolar approach was used for grade A or B ptosis patient, and inframammary fold approach was choosen for the patient with grade C ptosis. Results: Subcutaneous mastectomy was done through semicircular periareolar approach for 26 patients. There were 2 cases of major complications that should be corrected by hematoma evacuation. Circumareolar approach was used for 5 patients, and a case of nipple-areolar complex necrosis was observed. Two cases of another complications which were irregularity of breast and wound disruption could be corrected. Inframammary fold approach was selected for 15 patients. There was a case of wound disruption, so revision surgery whould be done. Four cases of breast irregularity was corrected spontaneously, and 2 cases of partial necrosis of nipple-areolar complex were corrected with secondary healing. Patient satisfaction score for periareolar, cicumareolar, and inframmammary fold approach were 4.5, 4.2 and 4.1, respectively. Some major and minor complications were observed, but satisfactory results could be secured. Conclusion: Semicircular periareolar incision looked adequate for A cup size patient, circumareolar incision was suitable for B cup size with grade A or B ptosis. In B cup size with grade C ptosis patient and C cup patients, inframammary fold incision looked suitable for optimal results.

• 한국지반공학회논문집
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• 제21권5호
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• pp.123-131
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• 2005

우리나라에서는 최근 해안 매립지역에서의 건설공사가 증가하고 있는 추세이다. 이러한 경우 말뚝기초에서는 부마찰력과 관련된 안정성 평가가 중요한 설계요소가 된다. 그럼에도 불구하고 말뚝의 부마찰력 문제는 많은 지반 기술자들에게 충분한 이해가 부족한 실정이다. 그 이유는 부마찰력이 말뚝의 침하와 관련된 문제임에도 불구하고 대부분의 설계기준들은 안전율에 의한 말뚝의 지지력 산정에만 초점을 맞추고 있기 때문이라고 생각된다. LRFD 설계법은 말뚝의 지지력과 관련된 극한한계상태해석 외에 침하량과 관련된 사용성해석을 고려하므로 전통적인 국내 설계기준을 보완하는 방법이 될 수 있다. 본 논문에서는 부마찰력이 작용하는 말뚝에서 LRFD 설계기법을 적용하는 방법에 대해 논의하고 이를 전통적인 설계기법과 비교하여 보았다. 또한, 말뚝 재하시험을 통한 실제 사례분석을 통하여 각 설계기법의 적용성을 비교분석 하였다. 이러한 분석을 통해 부마찰력이 작용하는 말뚝의 안정성 분석 시 접하는 문제를 해결하기 위해 몇 가지 대안을 제시하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권4호
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• pp.192-198
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• 2019

Objectives: Oral and maxillofacial surgeons must gain mastery of various approaches to the midface due to the increasing incidence, complexity, and severity of presenting midfacial fractures. Unlike in the case of other body parts, the need to preserve facial aesthetics makes it more difficult for the surgeon to select an approach for managing the facial injuries. The midfacial degloving (MFD) approach is a combination of intraoral and intranasal incisions made to access the midface without any external incision. The aim of the present study was to evaluate the efficacy of MFD in maxillofacial surgery and to assess its advantages and complications. Materials and Methods: The MFD approach was used in five cases, with three cases treated with open reduction and internal fixation and two cases operated on for posttraumatic deformity. Nasal dorsum augmentation was completed in three cases and nasal osteotomy was performed in one case. The bicoronal flap technique was combined with MFD for frontal bone augmentation in one case. The intraoperative time required for flap completion and the ease of performing the planned procedures were noted. Postoperative evaluation was done for reduction, aesthetics, function, and complications. Results: Access was excellent for performing all planned procedures. Average time spent for flap elevation and exposure of the midface was 63 minutes. Complications like postoperative swelling, infraorbital nerve paresthesia, and intranasal crusting were all transient. No long-term complications like stenosis of the nose, sneer deformity, or weakness of the facial muscles were noticed. Additionally, no complications were noted when MFD was combined with bicoronal flap. Conclusion: Though the MFD approach is technically demanding and takes more time than other facial approaches, it should be learned and applied by maxillofacial surgeons in selective cases, as it provides complete exposure of the midface without facial scarring.

• 한국IT서비스학회지
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• 제11권3호
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• pp.1-16
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• 2012

This paper is aimed to present a fuzzy decision-making approach to deal with disaster recovery priority decision problem in information system. We derive an evaluation approach based on TOPSIS(Technique for Order Performance by Similarity to Ideal Solution), to help disaster recovery priority decision of total information system for port logistics in a fuzzy environment where the vagueness and subjectivity are handled with linguistic terms parameterized by trapezoidal fuzzy numbers. This study applies the fuzzy multi-criteria decision-making method to determine the importance weight of evaluation criteria and to synthesize the ratings of candidate disaster recovery system. Aggregated the evaluators' attitude toward preference, then TOPSIS is employed to obtain a crisp overall performance value for each alternative to make a final decision. This approach is demonstrated with a real case study involving 4 evaluation criteria(system dependence, RTO, loss, alternative business support), 7 information systems for port logistics assessed by 5 evaluators from Maritime Affairs and Port Office.

• 한국영어학회지:영어학
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• 제2권4호
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• pp.471-494
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• 2002

May(1985) argued that the regress problem of antecedent-contained deletion (ACD) construction could be resolved easily by positing QR. But the proposal has some conceptual and empirical problems. To resolve the problems of QR account on ACD, Hornstein(1994) suggested a new approach viz. LF A-movement approach. In the Minimalist framework, an object raises to the [Spec, Agro] to check the accusative case. Through this movement, the regress problem can be resolved naturally without QR. But the LF A-movement account has the same conceptual problem as the QR approach. In addition to the conceptual problem, it has also empirical problems which were pointed out by Kennedy(1997). To solve the problems, I propose that the object raise to [Spec Agro] overtly as Koizumi(1993, 1995) and Lasnik(1995) insisted. In addition to the proposal, I adopt another assumption that only the copy of a quantifier could become a variable by the vehicle change, which was suggested by Brody(1995). With the above proposals, the unnatural QR operation could be dispensed with and the conceptual and empirical problems which were made concerning the LF A-movement approach could be resolved.

• 대한토목학회논문집
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• 제29권5A호
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• pp.467-475
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• 2009

기존의 연구들은 댐퍼만에 의한 부가감쇠비의 Universal Curve만을 제공하였기 때문에 실무에서는 케이블의 구조감쇠 및 공기역학적감쇠와 같은 자체감쇠를 독립적으로 고려하곤 한다. 즉, 케이블에 발생하는 자체감쇠비와 댐퍼에 의해 부여되는 Universal Curve로부터 얻은 부가감쇠비를 산술적으로 합하여 케이블-댐퍼 시스템의 전체감쇠비를 결정해 왔다. 하지만 이러한 선형조합 접근법은 이론적인 근거가 미약하며 관련된 연구도 찾아볼 수 없는 실정이므로 이에 관한 유효성을 검증해 볼 필요가 있다. 이것을 위해 본 연구에서는 자체감쇠를 고려한 전체감쇠비 해석법을 개발하여 정해를 제시하고 이것을 기존의 선형조합 접근법에 의해 얻어진 전체감쇠비와 비교하여 선형조합 접근법의 유효성 여부를 검증하였다. 본 연구의 결과에 의하면, 강성은 작고 최적감쇠계수와 비슷한 감쇠계수를 갖는 댐퍼가 지점에서 가깝게 설치되어 있으며, 케이블의 진동이 저차 모드 위주로 발생하고 케이블의 자체감쇠가 크지 않은 일반적인 풍환경에서는 기존의 연구그룹에서 제시하는 연구결과나 선형조합 접근법을 적용하는 것에 무리가 따르지 않는다. 하지만 외부댐퍼나 예기치 못한 고차 진동모드의 발생, 강성이 큰 댐퍼가 사용되는 경우에는 본 연구를 적용하는 것이 바람직한 것으로 나타났다. 본 연구는 케이블의 자체감쇠를 고려한 전체감쇠비의 정해를 제시하고 이것을 토대로 선형조합 접근법에 대한 적용근거를 제시하였다는 점에서 의미를 찾을 수 있다. 차후 본 연구를 발전시켜 공기역학적감쇠에 대응하는 최적감쇠계수를 실시간으로 제시할 수 있게 된다면 MR(Magneto-rheological) 댐퍼와 같은 준능동 댐퍼의 케이블-댐퍼 시스템 제어의 중요한 알고리즘이 될 것으로 기대된다.

• Journal of Chest Surgery
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• 제35권7호
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• pp.553-555
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• 2002

경복부 접근법은 관상동맥우회술후 재수술시 정중 흉골절개에 동반될 수 있는 위험성을 피할 수 있다는 장점 때문에 선택적으로 적용될 수 있는 접근법 중의 하나이다. 관상동맥우회술 후 협심증이 재발한 59세 여자 환자에서 경복부 접근법을 통하여 심폐바이패스를 이용하지 않는 관상동맥우회술을 시행하였다. 검상돌기하 부위 에 경복부 절개술을 시행하고 개복한 후 이식혈관으로 우위 대망동맥을 준비하였으며, 우심실과 횡격막 사이의 유착을 박리한 뒤, 심폐바이패스를 이용하지 않고 심박동하에서 우위대망동맥을 우관상동맥에 문합하였다. 술후 1일째 시행한 관상동맥조영술에서 문합부위에 이상이 없음을 확인하였고, 합병증 없이 술 후 4일째 퇴원하였다. 정중 흉골절개가 아닌 경복부 접근법을 통해 심폐바이패스를 이용하지 않는 관상동맥 우회 재수술을 시행하고 만족할 만한 결과를 얻었기에 이 증례를 보고하는 바이다.

• 경영과학
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• 제16권2호
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• pp.13-32
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• 1999

Concurrent Engineering is one of the information-based product development approach. Yet, the method of organizing the project team for the concurrent engineering is not clear. This study focuses on deriving a method to organize an information-based project team. The model consists of 4 layers : IT infrastructure, organization of the information-based project team, operation of the project team, an organization culture. Based on an analysis of new product development case, this study attempts to verify the model and to suggest more effective way of organization design and management for new product development.