• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1657-1661
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• 2005

The velocity dipole field method is presented for real-time collision avoidance of mobile robots. The direction of motion of the obstacle is used as the axis of the dipole field, and the speed of the obstacle is used to proportionally strengthen the dipole field. The elliptical field lines of the dipole field are useful to skillfully guide the robot around obstacles, quite similar to the way humans avoid moving obstacles. Field modulation coefficient is also introduced to weaken the field effect as the obstacle recedes. The real-time algorithm of the velocity dipole field has been devised and experimentally tested on the robot soccer test-bed. The results show the capability of the new real-time collision avoidance strategy and how it can overcome the weaknesses in the conventional potential field method. The new method makes an explicit and proactive action of collision avoidance, unlike the conventional method, which forces the robot merely away from the obstacle aimlessly. The proposed method delivers greater capability with no considerable computational overhead

• Journal of Power Electronics
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• 제8권4호
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• pp.291-300
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• 2008

In this paper power system and drive-train for omni-directional autonomous mobile robots with multiple energy storage units are presented. Because in proposed system, which is implemented in soccer robots, the ability of power flow control from of multiple separated energy storage units and speed control for each motor are combined, these robots can be derived by more than one power source. This capability, allow robot to diversify its energy source by employing hybrid power sources. In this research Lithium ion polymer batteries have been used for main and auxiliary energy storage units because of their high power and energy densities. And to protect them against deep discharge, over current and short circuit, a protection circuit was designed. The other parts of our robot power system are DC-DC converters and kicker circuit. The simulation and experimental results show proposed scheme and extracted equations are valid and energy management and speed control can be achieved properly using this method. The filed experiments show robot mobility functions to perform the requested motion is enough and it has a high maneuverability in the field.

• 보건교육건강증진학회지
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• 제33권3호
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• pp.71-82
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• 2016

Objectives: In this study, it was analyzed which marketing activity strategy multinational tobacco companies established against Republic of Korea through their internal documents and it was checked out how the marketing activities mentioned in the documents turned out to be actually. Methods: For that, analyzed the internal documents of tobacco companies after connecting Legacy Tobacco Documents Library(LTDL). Three documents were selected finally out of total searched 1,752 documents except the ones that did not include the theme or not appropriate. Results: Internal documents analysis showed that people smoke because the filter of cigarette shown in the movies looks nice. Tobacco companies carried out the marketing through sponsorship of soccer games, F1 Grand Prix was found in the internal documents. Conclusions: The legal restriction on marketing activities of tobacco companies should be enhanced by removing the articles of allowing advertisement and promotion for tobacco companies in Korean domestic law.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권4호
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• pp.223-232
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• 2003

This paper presents a new method driving multiple robots to their goal position without collision. Each robot adjusts its motion based on the information on the goal location, velocity, and position of the robot and the velocity and position of the .other robots. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the following factors: the distance from the robot to the other robots, velocity of the robot and the other robots. To implement the concept in moving robot avoidance, relative distance between the robots is derived. Our method combines the relative distance with an artificial potential field method. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, the usual potential field method sometimes fails preventing collision or causes hasty motion, because it initiates avoidance motion later than the proposed method. The proposed method can be used to move robots in a robot soccer team to their appropriate position without collision as fast as possible.

• 한국언론정보학보
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• 제40권
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• pp.321-348
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• 2007

본 논문은 국내의 수용자들이 2006년 독일 월드컵 당시 한국의 매스미디어를 통해 관람한 월드컵 경기가 그들의 월드컵 후유증에 어떠한 영향을 미쳤는가를 분석하기 위한 것이다. 이를 위해, 2006년 한국과 16강 예선전을 펼쳤던 3개 국가와의 경기와 관련한 보도에 대한 응답자들의 미디어별 노출을 측정했으며, 직 간접적 차원의 월드컵 후유증에 대해 조사했다. 또한 순수한 미디어의 영향력을 검증하고자 응답자의 인구학적 특성과 스포츠 및 월드컵에 대한 호감도와 같은 가외 변인을 상정하여 측정했다. 계층 회귀 방법을 사용하여 일부 효과가 검증되었는데, 4대 매체 중 라디오가 간접적 후유증에 영향을 미친 것으로 분석되었다.

• 로봇학회논문지
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• 제2권3호
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• pp.275-281
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• 2007

This paper presents a motion planning strategy for legged robots using locomotion primitives in the complex 3D environments. First, we define configuration, motion primitives and locomotion primitives for legged robots. A hierarchical motion planning method based on a combination of 2.5 dimensional maps of the 3D workspace is proposed. A global navigation map is obtained using 2.5 dimensional maps such as an obstacle height map, a passage map, and a gradient map of obstacles to distinguish obstacles. A high-level path planner finds a global path from a 2D navigation map. A mid-level planner creates sub-goals that help the legged robot efficiently cope with various obstacles using only a small set of locomotion primitives that are useful for stable navigation of the robot. A local obstacle map that describes the edge or border of the obstacles is used to find the sub-goals along the global path. A low-level planner searches for a feasible sequence of locomotion primitives between sub-goals. We use heuristic algorithm in local motion planner. The proposed planning method is verified by both locomotion and soccer experiments on a small biped robot in a cluttered environment. Experiment results show an improvement in motion stability.

• 정보관리연구
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• 제37권4호
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• pp.93-104
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• 2006

디지털 비디오 압축과 인터넷 기술의 발전으로 비디오에 대한 수요가 폭발적으로 늘어나고 있으며, 사용자 제작 콘텐트(UCC)도 대량으로 생산되고 있다. 따라서, 디지털 비디오 라이브러리 구축과 검색에 대한 기술 연구가 어느 때보다 시급하게 요구되고 있다. 그러나 사용자가 전체 비디오의 일부 내용을 의미기반으로 검색해서 보고 싶은 욕망을 충족시켜주기는 매우 어려운 상황이다. 본고에서는 디지털 비디오를 의미 검색하기 위하여 장면을 뽑아내고, 내용을 분석하는 방법을 제안하고, 5개의 스포츠(축구, 야구, 골프, 농구, 배구) 뉴스 비디오를 자동 분류한 실험 결과를 소개하였다.

• 수산해양교육연구
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• 제27권1호
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• pp.63-73
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• 2015

The purpose of this study was to examine EMG activities and VMO/VL ratio of the vastus medialis oblique, and vastus lateralis during step up exercise according to ankle and knee positions in soccer players with patellofemoral pain syndrome. Methods: Subject(patellofemoral pain syndrome, PFPS: n=8 and without PFPS, non PFPS; NPFPS: n=8) perfomed step up exercise at each knee and ankle position(knee flexion $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$, ankle internal rotation $30^{\circ}$, neutral, and external rotation $30^{\circ}$) while EMG activity was collected. The EMG signals were expressed by the % maximal voluntary isometric Contraction(%MVIC) values. Statistical analysis consisted of two way repeated measures analysis of variance with post hoc analysis. Results: Main results were as follows: 1) EMG of VMO, and VL was tend to be lower in PFPS compared to NPFPS. 2) EMG of VMO and VL with knee flexrion $60^{\circ}$ was significantly higher the results with knee flexion $30^{\circ}$, and $90^{\circ}$. VMO and VL with ankle external rotation $30^{\circ}$ was significantly higher the results with internal rotation $30^{\circ}$ and neutral position. Conclusion: Considering the EMG activity was reduced due to the to the PFPS and that performing step up with knee flexion $60^{\circ}$ with ankle external rotation $30^{\circ}$ position may provide the most effective condition for patients with patellofemoral pain syndrome.

• 한국학교보건학회지
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• 제22권2호
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• pp.147-156
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• 2009

Purpose: The purpose of this study was to analyze students' expectance demand towards high school physical education teaching. Methords : 392 participants randomly selected from one girls' middle school and one girl's high school in each of five tracts and then selected two classes from each of the schools. They were asked to respond to a simple questionnaire about their views on the present physical education teaching. Results : Results showed that about one third of the participants would not choose physical education if the program were offered as an optional subject. Both male and female students ranked psychomotor domain as the top priority among the various learning objectives. Male students favored soccer and basketball while their counterparts liked badminton and volleyball. Over three-fourths of the participants suggested that students' opinions should be considered when teachers plan their program. Conclusion : The results of this study recommended that physical education teaching should be designed with considerations for professional values, societal changes as well as students' expectance on the design of physical education.

• 대한족부족관절학회지
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• 제7권2호
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• pp.218-222
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• 2003

Purpose: The objective of this study was to define the Os submalleolare as an any ossicles below medial malleolus of tibia and to determine the characteristics of clinical and radiological characteristics and to evaluate results of surgical treatment of Os submalleolare in sports player group. Materials and Methods: Twenty-two patients with Os submalleolare were identified between November, 1, 1998 and June, 30, 2002. Results: The mean age was 18.3 years. All patient were male and soccer players comprised 71%(20 cases). Associated disease were 8 cases(29%) of chronic ankle instabilities, one case(4%) of anterior impingement syndrome and one (4%) of plantar fascitis. The most common clinical symptom was pain during walking and sports activity and sign was tenderness around medial malleolus. Only simple radiograph could reveal presence of ossicle and differentiate with acute fracture. If symptom and sign obscured, Bone scan(7 cases) and MRI(3 cases) identify causes of pain and tenderness. As a surgical treatment, all bony fragment caused symptom and sign were eliminated and medial collateral ligament was reattached meticulously. Associated chronic ankle instability were present, modified Brostrom procedure was done simultaneously. On follow-up, The symptomatic pain were wholly disappeared at average 2.2 months (1-6months) after operation. On one year follow-up, all patients have been daily life without any complaints and have gone back to the game within three months. Conclusion: as submalleolare have relatively rare incidence in sports players and most common clinical symptom and sign is tenderness on medial malleolar area of ankle, can be diagnosed both physical examination and plain X-ray film. As a treatment, Removal of ossicle and reattachment of MCL could obtain excellent or good results.