• 산업융합연구
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• 제20권11호
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• pp.27-34
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• 2022

본 연구에서는 뇌졸중 환자의 어떤 의학적 요인이 간병인 부담에 영향을 미치는지 알아보기 위해 8주간의 치료 전후 환자의 신경학적 상태, 인지, 일상생활수행능력, 보행, 균형 지표와 간병인의 부담감을 측정하여 그 변화를 비교하였습니다. 간병인은 8주간의 재활 치료 기간 동안 경도-중등도의 부담감을 느끼고 있었으며, 환자의 신경학적 상태, 인지 상태가 간병인 부담과 연관이 있었습니다. 전체 환자군 및 아급성기 뇌졸중 환자군의 의학적 지표와 간병인의 부담감을 다중회귀분석 하였을 때, 신경학적 상태와 균형 능력이 보호자 부담감에 영향을 주는 요소로 나타났습니다. 이에 입원한 뇌졸중 환자의 재활 치료 시 간병인 부담 경감을 위해 환자의 균형 능력 향상에 중점을 둘 것을 제안합니다.

• 공학교육연구
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• 제13권6호
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• pp.143-151
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• 2010

본 논문은 서울과학기술대학교(구 서울산업대학교) 기계설계자동화공학부에서 16년간의 캡스톤디자인 운영경험과 개선을 바탕으로 캡스톤디자인 교과목 기반의 프로그램 학습성과의 평가 사례에 대해 서술하였다. 우선, 캡스톤디자인 교과목과 관련된 프로그램 학습성과를 소개하였고, 평가 방법 및 항목에 대해서 설명하였다. 이를 바탕으로 하여 2008년도의 학습성과 평가 결과를 도출하였고, 이를 분석한 후 개선 전략을 수립하였다. 전략으로서 학생들에게 심사 기준과 모범사례를 온라인상에 미리 공개하였고, 그 결과 2009년도에는 전반적으로 약 3.3% 개선된 학습성과 평가 결과를 얻을 수 있었다. 마지막으로 코스 임베디드 평가 개념 측면에서 캡스톤디자인 교과목을 이용한 프로그램 학습성과 평가의 타당성, 효율성, 내실성, 그리고 지속가능성에 대해서도 논의하였다.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.264-269
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• 2002

In this paper, Η$_{\infty}$ depth and course controller of an AUV(Autonomous Underwater Vehicle) using Η$_{\infty}$ servo control is proposed. The Η$_{\infty}$ servo problem is formulated to design the controllers satisfying a robust tracking property with modeling errors and disturbances. The solution of the Η$_{\infty}$ servo problem is as fellows: first, this problem is modified as an Η$_{\infty}$ control problem for the generalized plant that includes a reference input mode, and then a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach. The Η$_{\infty}$ depth and course controller are designed to satisfy with the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under disturbances(wave force, wave moment, tide). The performances of the designed controllers are evaluated with computer simulations, and finally these simulation results show the usefulness and application of the proposed Η$_{\infty}$ depth and course control system.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.123-131
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• 2018

본 연구는 ${\bigcirc}{\bigcirc}$ 고속국도 공사 중 발생된 이암 절토 사면의 붕괴 요인 분석 및 대책방안을 제시하였다. 기반암인 이암에 대해 실내시험을 수행하고, 국제 기준에 의거해 공학적인 특성을 규명하였다. 그리고 설계 시 수행되었던 사면안정해석을 재검토 하였다. 또한, Swelling-Slaking 현상으로 인해 기반암인 이암의 강도열화특성을 고려한 안정해석을 추가적으로 수행하였다. 기반암인 이암에 대해 Swelling-Slaking Test 결과, 풍화내구성은 낮음-보통으로 나타났으며, 팽창변형률은 매우 낮음으로 나타났다. 설계 안정해석 검토 결과, 이암의 공학적 특성을 고려하지 않고, 한계평형해석을 이용해 실제와 상이한 결과가 나타났다. 강도열화특성을 고려한 추가안정해석 결과, 사면의 붕괴지점과 안정해석의 최대전단변형률 발생지점이 동일하게 나타났으며, 건기시 우기시 모두 기준 안전율을 만족하지 못하였다. 붕괴 사면의 대책방안으로는 사면경사완화공법이 가장 적절하였다. 유한요소해석을 통해 완화 경사를 산정하였다. 완화 경사의 현장 적용성을 위해 시추공영상촬영과 비교한 결과, 미고결된 이암의 대부분이 제거되는 것으로 나타나 미고결된 이암으로 인한 추가적인 붕괴 위험성은 현격히 저하되는 것으로 나타났다.

• 웰빙융합연구
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• 제7권1호
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• pp.43-50
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• 2024

Purpose: People must express their feelings and thoughts to maintain mental health and stability. Expressing one's emotions, experiences, and thoughts in writing relieves inner feelings, promotes self-exploration, and improves individual well-being, resulting in a pleasant state on physical, mental, and social levels. This study aims to reveal the learning experiences of university students who participated in a self-expressive writing course to improve their well-being. Method: To explore the learning experiences of university students who took a self-expressive writing course, this study used qualitative research methods to analyze the students' written reflection notes. Results: Self-expressive writing was found to resolve university students' negative emotions, regulate their emotions, improve their self-reflection and self-awareness, contributing to their problem-solving skills and ability to set new goals, and strengthen their social communication. The meaning of this class experience can be summarized as healing, awareness, reflection, change, and growth. Conclusion: The results of this study provide concrete data on expressive writing classes and are valuable when designing the writing programs.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.993-998
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• 2002

Ultra precision processing technology is the field which is seriously protected its technology by advanced nations. Because of this reason, this technology is very difficult to supply for domestic companies, also domestic companies are revealed the limit of technology development by itself. And then, those are depend on the technology development of advanced nation, domestic companies are not conquer application step with already developed parts. Of course, some cases of its research are succeed. those are included element technology, system technology and so on, for development of ultra precision processing system. To conquer technology holding ultra precision processing accuracy of no level, active research are needed. In this paper, stability of ultra precision cutting unit is analyzed, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for un it control.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.899-910
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• 2013

This paper presents a novel lateral stability control system for electric vehicle based on sideslip angle estimation through Kalman filter using the integration of a single antenna GPS receiver and yaw rate sensor. Using multi-rate measurements including yaw rate and course angle, time-varying parameters disappear from the measurement equation of the proposed Kalman filter. Accurate sideslip angle estimation is achieved by treating the combination of model uncertainties and external disturbances as extended states. Active front steering and direct yaw moment are integrated to manipulate sideslip angle and yaw rate of the vehicle. Instead of decoupling control design method, a new control scheme, "two-input two-output controller", is proposed. The extended states are utilized for disturbance rejection that improves the robustness of lateral stability control system. The effectiveness of the proposed methods is verified by computer simulations and experiments.

• 한국항공우주학회지
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• 제32권3호
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• pp.95-101
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• 2004

액체 로켓엔진 개발과정에서 수행되는 여러 가지 시험 중 연소 안정성 평가 시험을 통해, KSR-III 로켓엔진의 연소 안정성을 평가하였다. 안정성 평가시험에서, 엔진이 외부 교란에 의한 압력 진동을 감쇠시켜 본래의 안정한 연소를 회복하는 경우, 그 엔진은 연소 안정 화 능력을 가지고 있다고 판정할 수 있다. 로켓엔진은, 교란의 크기를 예측하기 어려운 외부 섭동에 노출될 수 있으므로, 연소 안정화 가능 여부를 확인하는 것과 더불어 엔진이 갖고 있는 연소 안정화 성능을 정량화하여 파악하는 작업이 필요하다. 이를 위해 몇 가지 주요 인자를 도입하였고, 이를 평가하는 방법을 검토하였다. 성공적으로 완료된 KSR-III 로켓 개발과정에서 로켓엔진의 안정성 확보를 위해 6회의 안정성 평가 시험이 수행되었다. 이를 토대로, 연소 안정화 성능의 정량화 방법을 KSR-III 엔진에 적용하여 엔진의 안정화 성능을 분석하였다.

• Journal of Radiation Protection and Research
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• 제41권3호
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• pp.260-267
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• 2016

Background: This study analyzes the differences in the annual averaged atmospheric dispersion factor and ground deposition factor produced using two classification methods of atmospheric stability, which are based on a vertical temperature difference and the standard deviation of horizontal wind direction fluctuation. Materials and Methods: Daedeok and Wolsong nuclear sites were chosen for an assessment, and the meteorological data at 10 m were applied to the evaluation of atmospheric stability. The XOQDOQ software program was used to calculate atmospheric dispersion factors and ground deposition factors. The calculated distances were chosen at 400 m, 800 m, 1,200 m, 1,600 m, 2,400 m, and 3,200 m away from the radioactive material release points. Results and Discussion: All of the atmospheric dispersion factors generated using the atmospheric stability based on the vertical temperature difference were shown to be higher than those from the standard deviation of horizontal wind direction fluctuation. On the other hand, the ground deposition factors were shown to be same regardless of the classification method, as they were based on the graph obtained from empirical data presented in the Nuclear Regulatory Commission's Regulatory Guide 1.111, which is unrelated to the atmospheric stability for the ground level release. Conclusion: These results are based on the meteorological data collected over the course of one year at the specified sites; however, the classification method of atmospheric stability using the vertical temperature difference is expected to be more conservative.

• 한국해양공학회지
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• 제25권5호
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• pp.27-32
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• 2011

Recently, a ship-shaped barge has been developed to improve the resistance performance, as well as course-keeping capability. However, the stern of the barge is still similar to a box shape, and the vortex generated at the side of the barge creates drag and yaw instability. In order to solve this problem, stern skegs are normally used. The present paper deals with the correlation between the size of the stern skegs and the barge dimensions and hull coefficient. A stern skeg was designed to prevent yaw instability and minimize any additional resistance. The resistance test and course keeping test were performed in the towing tank at Pusan National University. To determine the correlation parameters between the designed stern skeg size and barge dimensions, a parametric study was also performed. Based on the experimental data from five barges, the optimum skeg dimensions were successfully derived. It is expected that the validation of the present study will be carried out by further experiments and computational comparisons in the near future.