• 한국정보통신학회논문지
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• 제11권2호
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• pp.316-321
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• 2007

[ $H{\infty}$ ] 제어기는 외란이나 잡음에 대해서 강인한 성능을 가지고 있지 만 파라미터 불확실성이 존재하면 제어입력을 구하기가 쉽지 않으며 불확실성의 영향에 따라서 제어 성능에 큰 차이를 보인다. 하지 만 슬라이딩 모드제어는 파라미터 불확실성에 대하여 우수한 강인성을 가지고 있는 제어 기법이다. 그러므로 본 논문에서는 슬라이딩 모드 제어기법을 도입하여 LMI를 이용한 $H{\infty}$ 제어기의 강인성을 향상시킬 수 있는 제어 기법을 제안한다.

• 한국기계가공학회지
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• 제18권6호
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• pp.106-112
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• 2019

Rotary swaging is a method of forging automotive drive shafts. In this paper, we propose a new two-hammer forging technique by applying the problem-solving approach TRIZ to improve the efficiency and productivity of the rotary swaging automation process. We will simplify the materials and hammers via the 3D modeling tool SolidWorks for high accuracy of a comparative analysis of existing and proposed methods under the same boundary conditions. In addition, we will compare the stress trends of the proposed model using ANSYS Workbench and verify the feasibility through a comparison of the simulation results using DEFORM. Relative to the existing method, the proposed method can decrease production costs and improve efficiency of the automation process by reducing the power source.

• Clinical Pain
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• 제19권2호
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• pp.138-141
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• 2020

Clay-shoveler's fractures are rare stress-type avulsion fractures of the spinous processes especially in sports. There have been two case reports that discussed clay-shoveler's fractures in golf. A 36-year-old beginner golfer presented with a pain in the back after practicing golf swing. No fractures were detected using cervical radiography; however, computed tomography (CT) and magnetic resonance imaging (MRI) revealed T2~T3 spinous process fractures. The patient was treated conservatively and his pain subsided. The mechanism of injury is speculated to that of clay-shoveler's fractures. Therefore, if a golfer suffers persistent pain in the cervicothoracic region, clay-shoveler's fracture is one possibility to consider.

• 한국기계가공학회지
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• 제21권3호
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• pp.36-42
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• 2022

Whereas the necessity for recycling and reuse is being emphasized owing to the depletion of resources and waste disposal problems caused by the continuous development of the industry, the importance of remanufacturing has been highlighted recently. Re-manufacturing involves a series of processes in which failed disposal or aging goods are recovered to a state similar to that of a new product. In this regard, machine tools, which are large structures, can achieve the effect of remanufacturing. Among the various elements constituting the machine tool, the main spindle portion that affects the processing precision is critical. Therefore, this study is conducted to derive improvement measures for the main axis of an old Miller planner via reverse engineering and central composite design, which is one of the core processes of remanufacturing.

• 한국산업융합학회 논문집
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• 제27권2_2호
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• pp.415-424
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• 2024

This study analyzes trends and characteristics of the machine tool remanufacturing industry and proposes a standard process that considers environmental impact assessment during the remanufacturing process. First, trends in remanufacturing and environmental regulations are reviewed. And the current status of the machine tool remanufacturing industry and cases of national R&D projects related to machine tools are analyzed. Machine tool remanufacturing has a high resource saving effect, and remanufacturing is carried out as a finished product rather than as a part. And the scope of remanufacturing work is very wide due to the performance improvement of the machine and the addition of features. In order for the machine tool remanufacturing industry to be competitive, it is necessary to create products with high added value. In addition, in order to respond to international environmental regulations, it is necessary to secure related data by conducting an environmental impact assessment together during remanufacturing.

• 한국정보통신학회논문지
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• 제11권10호
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• pp.1899-1909
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• 2007

본 논문에서는 TFT-LCD 구동 IC 모듈의 소형화 측면에서 유리한 DC-DC 변환기 회로인 펌핑 커패시터 내장형 크로스-커플드 전하펌프(Cross-Coupled Charge Pump with Internal Pumping Capacitor) 회로가 새롭게 제안되었다. VGH 및 VGL 전하펌프 각각의 입력단과 전하 펌핑 노드를 연결하는 NMOS 및 PMOS 다이오드를 두어, 초기 동작 시 전하 펌핑 노드를 서로 같은 값으로 프리차지하여 대칭 적으로 전하 펌핑을 하도록 하였다. 그리고 첫 번째 전하 펌프의 구조를 다르게 설계하여 펌핑된 전하가 입력단으로 역류되는 현상을 방지하였다. 또한, 펌핑 클럭 구동 드라이버의 위치를 펌핑 커패시터 바로 앞에 두어 기생 저항으로 인한 펌핑 클럭 라인의 전압강하를 방지하여 구동능력을 향상 시켰다. 마지막으로 내장형 펌핑 커패시터를 Stack-MIM 커패시터를 사용하여 기존의 크로스-커플드 전하펌프 보다 레이아웃 면적을 최소화하였다. 제안된 TFT-LCD 구동 IC 용 전하펌프 회로를 $0.13{\mu}m$ Triple-Well DDI 공정을 사용하여 설계하고, 테스트 칩을 제작하여 검증하였다.

• 대한지리학회지
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• 제49권2호
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• pp.178-199
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• 2014

본 논문은 창원공단이 1973년 '중화학공업화정책추진선언'에 따라 중앙정부 주도로 '공업기지'로 일사분란하게 건설되었다는 기존 설명을 지리정치경제학적 관점에서 비판하고, 1960-70년대 마산, 창원의 기계공단조성 과정을 새로이 해석하고자 한다. 구체적으로 1960년대 기계공업육성안의 변천과 창원공단의 전사前史를 분석하는데 촛점은 크게 3가지이다. 첫째, 다중스케일적 관점에서 60년대 마산 창원지역 공단 조성 계획안의 변화를 추적한다. 둘째, 60년대 제출된 기계공업 육성안들의 내용과 이를 둘러싼 여러 사회세력들의 경합 과정을 살펴보고 그 결과가 73년 창원공단설립에 끼친 영향을 살펴본다. 세째, '4대핵공장사업'의 실패과정을 현대조선의 성공과 대비해 살펴보고 이것이 기계공업 육성에 끼친 영향을 밝히고자 한다. 이러한 사례분석을 통하여, 중앙정부의 역할에 방점이 주어진 기존 연구를 비판하고 다양한 스케일의 행위자들의 주도성을 복원하고 한국 발전주의 시기 공업단지 개발의 계급적 성격을 밝히고자 한다.

• 한국군사과학기술학회지
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• 제22권3호
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• pp.299-310
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• 2019

Increase of combat capability through the lightweighting of vehicles has been internationally issued. One of the methods for lightening is applying high hardness armor(HHA) steel which is outstanding ballistic performance and protection performance compared to weight. Development of HHA steel is currently completed in America, United Kingdom, Australia and Germany. It is used for not only combat vehicle, but also various combat device. Korea is developing new material of HHA steel according to this trend. When such HHA steel is applied to structure, welding process is used for connection of the structure. Cracks from hydrogen embrittlement and cold cracking are easily generated in welds of HHA steel and it greatly affects the strength of all structure. Decrease of strength from welding defect is critical to combat capability. Therefore, welding process optimization is important for performing the role of structure. In this study, international welding technology is reviewed through scientific research paper and patent.

• 대한간호학회지
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• 제49권2호
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• pp.181-190
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• 2019

Purpose: This study aimed to confirm the mediating effect of job involvement in the relationship between grit and turnover intention among nurses working at university hospitals. Methods: Participants included 437 nurses from university hospitals located in C city, Gyeongnam. Data were collected from January 8 to 19, 2018, using self-report questionnaires. Data were analyzed using the t-test, analysis of variance, Scheffe's test, Pearson's correlation coefficient, and multiple regression, with the SPSS/22.0 program. A mediation analysis was performed according to the Baron and Kenny, and bootstrapping methods. Results: There were significant relationships between grit and job involvement (r=.40, p<.001), grit and turnover intention (r=-.29, p<.001), and turnover intention and job involvement (r=-.52, p<.001). Job involvement showed partial mediating effects in the relationship between grit and turnover intention. Conclusion: Grit increased job involvement and lowered turnover intention. Therefore, to reduce nurses' turnover intention, it is necessary to develop a program and strategies to increase their grit.

• 한국수소및신에너지학회논문집
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• 제31권6호
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• pp.509-521
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• 2020

This study aims to propose a mid- to long-term fostering plan for the hydrogen industry customized to Changwon City by reviewing the government's policy and the status of the domestic and foreign hydrogen industry. The adopted methodologies were policy analysis, literature review, field investigation, and committee operation that could consider institutions, knowledge (technology), and networking between activity subjects. The short-term projects and long-term projects for the fostering plan are established using these methodologies. The short-term projects were structured so that the ongoing hydrogen industry fostering plan leads to a successful result, and the hydrogen mobility field is expanded to not only land vehicles but also marine and air vehicles. The long-term projects consist of a high proportion of the hydrogen utilization field to take advantage of the industrial strength of Changwon City, and a support system for new and turning companies for localization of parts was added to provide industrial competitiveness.