• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1048-1053
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• 2005

This paper presents design and integration of the ROBHAZ-DT3, which is a newly developed mobile robot system with chained double-track mechanisms. A passive adaptation mechanism equipped between the front and rear body enables the ROBHAZ-DT3 to have good adaptability to uneven terrains including stairs. The passive adaptation mechanism reduces energy consumption when moving on uneven terrain as well as its simplicity in design and remote control, since no actuator is necessary for adaptation. Based on this novel mobile platform, a rescue version of the ROBHAZ-DT3 with appropriate sensors and a semi-autonomous mapping and localization algorithm is developed to participate in the RoboCup2004 US-Open: Urban Search and Rescue Competition. From the various experiments in the realistic rescue arena, we can verify that the ROBHAZ-DT3 is reliable in traveling rugged terrain and the proposed mapping and localization algorithm are effective in the unstructured environment with uneven ground. The another application is an military robot for an EOD(Explosive Ordnance Disposal) and reconnaissance mission. The military version of the ROBHAZ-DT3 with a water disrupter, a thermal scope and a long distance wireless communication device is developed and sent to the area of military tactics in Iraq. Consequently, the feasibility of the military version of ROBHAZ-DT3 is verified.

• 동의신경정신과학회지
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• 제33권4호
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• pp.389-400
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• 2022

Objectives: Depression is a highly prevalent disease, and the market for antidepressant drugs continues to grow at a steady rate. Although current antidepressants are reported to be effective, because of their low remission rate and side effects, new antidepressants are needed. The use of Banhahubak-tang (BHT) to treat the symptoms of depression is supported by experimental evidence. The proposed study will evaluate the efficacy and safety of BHT in treating depression. Methods: A randomized, waitlist-controlled, parallel clinical trial will be conducted to assess the efficacy of BHT in depression. A total of 84 participants with depression will be randomized into the intervention group or waitlist-control group at a 1:1 ratio. Patients in the intervention group will be administered BHT three times a day for four weeks and followed up for four more weeks after therapy completion. Patients in the waitlist-control group will undergo the same intervention and follow-up after a four-week waiting period. The primary outcome is change in the Korean version of the Hamilton Depression Rating Scale (K-HDRS) scores for major depressive disorders after four weeks. The secondary outcomes include scores on the K-HDRS, Korean Symptom Check List 95 (KSCL-95), Insomnia Severity Index (ISI), State-Trait Anxiety Inventory-Korean version (STAI-K), State-Trait Anger Expression Inventory-Korean version (STAXI-K), and the Instrument on Pattern Identifications for Depression and EuroQol-5 Dimension (EQ-5D). Conclusions: This trial will provide high-quality clinical evidence of the efficacy and safety of BHT in the management of depression.

• 대한방사선치료학회지
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• 제24권2호
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• pp.77-84
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• 2012

목 적: 필름평가방법을 대신하여 전자포탈영상을 이용한 기하학적 정도관리 실시간 분석 프로그램을 개발하고자 한다. 대상 및 방법: 전자포탈영상장치(Electronic Portal Image Device, EPID)가 선형가속기(CL-iX, Varian, USA)의 하부에 고정된 구조 때문에 발생되는 문제를 해결한 후 Eclipse treatment planning system (Version 8.1, Varian, USA)으로 기하학적 정도관리 항목을 생성하였다. 치료실의 4DTC (Version 10.2, Varian, USA)에서 전자포탈영상(single exposure before plan)을 생성하고 항목별로 빔을 조사하였다. Off-line review에서 전자포탈영상을 획득하고 이를 자체 개발한 기하학적 정도관리 실시간 분석 프로그램으로 평가하였다. 평가 방법으로 치료 중 오차(Intra-fraction error)는 모든 절차를 같은 날에 동일 조건으로 5회 연속 실시하여 분석하였고 치료 간 오차(Inter-fraction error)의 확인을 위해 모든 절차를 동일 조건에서 10일간 실시한 후 Iso-align$^{TM}$ quality control device를 이용한 필름평가방법과 비교하였다. 측정 및 분석 시간은 장치의 셋업에서 데이터 획득까지의 시간과 이후 분석완료까지 소요된 시간으로 구분하여 측정한 후 사용자와 수행과정의 편의성도 비교하였다. 결 과: 빛-방사선조사면 일치, 콜리메이터 회전축, 환자테이블 회전축, 갠트리 회전축 항목에서 각각 평균 0.1, 0.2, 0.3, 0.2 mm의 치료 중 오차 값을 확인하였다. 10일간의 연속된 정도관리를 통해 치료 간 오차를 확인한 결과 항목별로 각각 평균 1.7, 1.4, 0.7, 1.1 mm의 오차 값을 얻었다. 그리고 측정 시간은 필름평가방법과 전자포탈영상을 이용한 방법에서 각각 평균 36분, 15분이 걸렸고 분석 시간은 평균 30분, 22분이 소요되었다. 결 론: 전자포탈영상을 이용하여 기하학적 정도관리를 실시할 경우 정도관리 도구로서 유용함을 알 수 있었다. 필름 미사용에 따른 비용 절감의 이점뿐만 아니라 측정 및 분석 시간도 줄일 수 있어 사용자 편의성이 커지고 필름 현상 과정 등의 생략으로 수행과정도 개선할 수 있었다. 또 자체 개발한 기하학적 정도관리 실시간 분석 프로그램으로 평가가 완료된 영상은 데이터화가 가능하여 자료의 보관이 용이해진다.

• The Journal of the Acoustical Society of Korea
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• 제15권3E호
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• pp.74-77
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• 1996

In this paper we implement the Discrete Rotational Fourier Transform(DRFT) which is a discrete version of the Angular Fourier Transform and its inverse transform. We simplify the computation algorithm in [4], and calculate the complexity of the proposed implementation of the DRFT and the inverse DRFT, in comparison with the complexity of a DFT (Discrete Fourier Transform).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1492-1495
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• 2005

This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the affine control scheme is employed to increase the degree of freedom; 2) the fuzzy-model-based periodic control is employed; and the control input is changed n times during one sampling period; 3) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system; but its discretization error vanishes as n approaches the infinity. 4) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

• 한국항공우주학회지
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• 제35권6호
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• pp.496-502
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• 2007

본 논문에서는 비선형적 다물체 시스템의 유한요소 해석프로그램인 DYMORE의 새로운 버전을 이용하여 압전 재료(piezoelectric)를 삽입한 능동 비틀림 로터(Active Twist Rotor)의 개별 블레이드 제어(Individual Blade Control)에 의한 로터 블레이드의 진동 감소 효과를 해석하고 이를 풍동실험 및 이전 버전의 DYMORE 결과와 비교하였다. 본 연구에서는 로터 허브와 네 개의 블레이드만으로 구성된 단순한 로터시스템과 스워시 판, 피치링크 등을 모두 포함하는 개선된 로터시스템에 대한 해석이 각각 수행되었다. 사용된 실험 결과 자료들은 NASA Langley의 Transonic Dynamics Tunnel(TDT)에서 수행되었던 결과들을 사용하였다. 그 결과 새로운 버전의 DYMORE를 이용한 경우 실험값과는 여전히 차이가 있지만 이전 버전의 DYMORE를 통해 얻어진 수치해석 결과에 비해서 오차가 개선되는 것을 확인할 수 있었다. 또한 개별 블레이드 제어 방식의 로터 시스템의 모델링을 수행하고 전진 비행 시의 진동 하중 감소 효과를 확인하였다.

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.192-198
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• 2016

Motion planning problem is still one of the important issues in robotic applications. In many real-time motion planning problems, it is advisable to find a feasible solution quickly and improve the found solution toward the optimal one before the previously-arranged motion plan ends. For such reasons, sampling-based approaches are becoming popular for real-time application. Especially the use of a rapidly exploring random $tree^*$ ($RRT^*$) algorithm is attractive in real-time application, because it is possible to approach an optimal solution by iterating itself. This paper presents a modified version of informed $RRT^*$ which is an extended version of $RRT^*$ to increase the rate of convergence to optimal solution by improving the sampling method of $RRT^*$. In online motion planning, the robot plans a path while simultaneously moving along the planned path. Therefore, the part of the path near the robot is less likely to be sampled extensively. For a better solution in online motion planning, we modified the sampling method of informed $RRT^*$ by combining with the sampling method to improve the path nearby robot. With comparison among basic $RRT^*$, informed $RRT^*$ and the proposed $RRT^*$ in online motion planning, the proposed $RRT^*$ showed the best result by representing the closest solution to optimum.

• 수산해양교육연구
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• 제28권1호
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• pp.235-247
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• 2016

The purpose of this study is to analyze elementary school students' pre-concept of electromagnet and to investigate effects of instruction through social interactions on conceptual changes of the electromagnet. For the purpose, 108 elementary school students of 3 classes were selected from the 6th grade. They were divided into the control group I, control group II and experimental group. The control group I was treated through traditional instruction on the basis of text book. The control group II was instructed with a modified version of the textbook to help them better understand the concept of electromagnet. The experimental group was treated through instruction on the basis of the above modified version of the text book and social interactions. Conceptual changes on electromagnet before and after the treatment were quantitatively and qualitatively analyzed using the identical test. The students' styles of social interaction were qualitatively analyzed with tape records of their discussions and work sheets. Effects of instruction through social interactions based on radical constructivism on the 6th-grade elementary school students' concept of electromagnet were examined here. The results were described as follows. Firstly, after the treatment, the experimental group was statistically significantly higher in mean values of conceptual understanding and academic achievement than both the control group I and II. Secondly, styles of social interaction in the three sub-groups of the experimental group were qualitatively analyzed, among the threes, high- and medium-level sub-groups were higher in the frequency of linguistic social interaction than the low-level sub-group. Those students who were excellent in communication skills actively participated in linguistic social interactions. In discussions among the three sub-groups, students of the high- and medium-level sub-groups provided explanations or information while those of the other sub-group sometimes were passive by just listening, but in large actively participated in communication. In conclusion, instruction through social interactions was effectively changed in the 6th-grade elementary school students' concept of electromagnet.

• 한국콘텐츠학회논문지
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• 제21권11호
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• pp.576-585
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• 2021

본 연구는 대학생의 사이버불링 경향성에 영향을 미치는 요인을 확인하기 위한 서술적 조사연구이다. 연구를 위해 2020년 7월 31일부터 8월 13일까지 전국의 대학교에 재학중인 396명을 대상으로 자료를 수집하였다. 자료분석은 SPSS Statistic version 20.0과 PROCESS macro를 이용하여 빈도, 백분율, 평균, 표준편차, Pearson 상관계수, PROCESS MACRO model 4, Bootstrap, Sobel test를 이용하여 분석하였다. 연구 결과는 다음과 같다. 첫째, 학업스트레스는 자기통제력과 유의한 부적 상관관계를 보였고(r=-.246, p<.001), 사이버불링 경향성과는 정적 상관관계를 보였으나 유의하지 않았다(r=.096, p=.055). 둘째, 학업스트레스와 사이버불링 경향성 간의 관계에서 자기통제력의 매개 효과는 유의하였다(R2=.039, p=<.001). 따라서 대학생의 사이버불링을 예방하기 위해서는 학업스트레스와 자기통제력을 고려한 예방 프로그램이 요구되며, 본 연구를 바탕으로 사이버불링 예방 프로그램을 개발 후 효과 검증을 위한 후속 연구가 필요하다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.85-88
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• 1997

Fieldbus is the real-time communication network for process control and manufacturing automation systems. IEC/ISA fieldbus was proposed as an international standard of fieldbus network. This protocol is operated on the basis of token-passing and scheduling mechanism. In this paper, we analyze the performance characteristics of the 1996 version of IEC/ISA fieldbus systems.