• 제목/요약/키워드: Focus distance

검색결과 424건 처리시간 0.024초

원격교육의 사용성을 위한 학생 만족도 피드백 분석 (An Analysis of Learners' satisfaction for the Usability of Distance Education System)

  • 최영미;주문원
    • 한국컴퓨터산업학회논문지
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    • 제3권12호
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    • pp.1737-1746
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    • 2002
  • 본 논문은 원격교육의 사용성을 위한 학생 만족도 요소를 분석하고자 한다. 이러한 원격교육의 사용성을 위하여 MLIS 프로그램을 수강하고 있는 학생들을 사례로 5가지 토론주제(전반적인 프로그램의 내용, 친과목의 내용, 상호작용 문제, 캠퍼스 워크샵의 내용, 기술공학적인 문제)를 기획하여 피드백을 통하여 얻은 내용을 분석하였다. 또한 온라인 학생들로부터의 피드백 요소 분석자료에 기초하여 온라인 코스의 교수와 개발을 위한 지침으로 제시한다.

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카메라 렌즈의 초점을 이용한 이동로봇의 장애물 회피 (Obstacle Avoidance for Mobile Robot using Focus of a Camera Lens)

  • 윤기돈;오성남;한철완;김갑일;손영익
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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    • pp.255-257
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    • 2005
  • This paper describes a method for obstacle avoidance and map building for mobile robots using one CCD camera. The captured image from one camera has the feature that some parts where focused look fine but the other parts look blear (this is the out-focusing effect). Using this feature a mobile robot can find obstacles in his way from the captured image. After Processing the image, a robot can not only determine whether an obstacle is in front of him or not, but also calculate the distance from obstacles based on image data and the focal distance of its camera lens. Finally, robots can avoid the obstacle and build the map using this calculated data.

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A Clustering Algorithm Considering Structural Relationships of Web Contents

  • Kang Hyuncheol;Han Sang-Tae;Sun Young-Su
    • Communications for Statistical Applications and Methods
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    • 제12권1호
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    • pp.191-197
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    • 2005
  • Application of data mining techniques to the world wide web, referred to as web mining, has been the focus of several recent researches. With the explosive growth of information sources available on the world wide web, it has become increasingly necessary to track and analyze their usage patterns. In this study, we introduce a process of pre-processing and cluster analysis on web log data and suggest a distance measure considering the structural relationships between web contents. Also, we illustrate some real examples of cluster analysis for web log data and look into practical application of web usage mining for eCRM.

면적비와 거리비가 점용접된 두 사각평판의 굽힘강성에 미치는 영향 (The Effect of the Area Ratio and the Distance Ratio on Bending Stiffness of Two Rectangular Plates Spot-Welded)

  • 한근조;안성찬;심재준;한동섭
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.425-430
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    • 2001
  • The mechanical behavior of two rectangular plates spot-welded under bending is investigated in detail. The focus of the analysis is to evaluate the effect of thickness of reinforced plates with equivalent thickness. The results of this investigation are compared from detailed finite element analysis and experiments of the plates spot-welded for various parameters, such as aspect ratio, area ratio, and distance ratio of spot-welding points. The study is carried out using the equivalent thickness of the reinforced plates spot-welded.

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면적비와 거리비가 점용접된 두 사각평판의 굽힘강성에 미치는 영향 (The Effect of the Area Ratio and the Distance Ratio on Bending Stiffness of Two Rectangular Spot-Welded Plates)

  • 한근조;안성찬;심재준;한동섭
    • 대한기계학회논문집A
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    • 제27권3호
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    • pp.387-392
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    • 2003
  • The mechanical behavior of two rectangular spot-welded plates under bending is investigated in detail. The equivalent thickness of spot-welded plates is introduced in this study and used in explaining the results. The focus of the analysis is to evaluate the effect of spot-welding from the view point of equivalent thickness. The investigation of deflection has been performed as comparing the result from finite element analysis with the measured data of the spot-welded plates for various parameters, such as aspect ratio, area ratio, and distance ratio of spot-welding points. The effect of spot-welding is as large as 62%(at r=1.0) when the area ratio of spot-welding point is just 4.52%.

Architecture Support for Context-aware Adaptation of Rich Sensing Smartphone Applications

  • Meng, Zhaozong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권1호
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    • pp.248-268
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    • 2018
  • The performance of smartphone applications are usually constrained in user interactions due to resource limitation and it promises great opportunities to improve the performance by exploring the smartphone built-in and embedded sensing techniques. However, heterogeneity in techniques, semantic gap between sensor data and usable context, and complexity of contextual situations keep the techniques from seamless integration. Relevant studies mainly focus on feasibility demonstration of emerging sensing techniques, which rarely address both general architectures and comprehensive technical solutions. Based on a proposed functional model, this investigation provides a general architecture to deal with the dynamic context for context-aware automation and decision support. In order to take advantage of the built-in sensors to improve the performance of mobile applications, an ontology-based method is employed for context modelling, linguistic variables are used for heterogeneous context presentation, and semantic distance-based rule matching is employed to customise functions to the contextual situations. A case study on mobile application authentication is conducted with smartphone built-in hardware modules. The results demonstrate the feasibility of the proposed solutions and their effectiveness in improving operational efficiency.

상이한 스펙트럼을 가지는 객체간의 RGB 색상 차이를 최대학화기 위한 최적조명 (Optimal Illumination for Maximizing the RGB Distance between Objects with Different Spectra)

  • 서동균;이문현;서병국;박종일
    • 대한의용생체공학회:의공학회지
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    • 제30권3호
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    • pp.263-269
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    • 2009
  • An object's color and intensity are determined by its spectral reflectance and illumination. Therefore, the illumination plays a key role in forming the appearance of the object in a scene. In this paper, we focus on color distinction of objects and derive the optimal illumination conditions to maximize the distance between objects in the RGB color space. As a practical approach the optimal illumination is composed by deriving the optimal linear combinations given a set of LED light sources. The effectiveness of our approach is shown through experimental results using an endoscope system.

레이저 유기 충격파를 이용한 웨이퍼 표면 미소입자 제거 (Removal of small particles from silicon wafers using laser-induced shock waves)

  • 이종명;조성호
    • 한국레이저가공학회지
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    • 제5권2호
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    • pp.9-15
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    • 2002
  • Basic principles and unique characteristics of laser-induced shock cleaning have been described compared to a conventional laser cleaning method and the removal of small tungsten particles from silicon wafer surfaces was attempted using both methods. It was found that the conventional laser cleaning was not feasible to remove the tungsten particles whereas a successful removal of the particles was carried out by the laser-induced shock waves. From the quantitative analysis using a surface scanner, the average removal efficiency of the particles was more than 98% where smaller particles were slightly more difficult to remove probably due to the increased adhesion force with a decrease of the particle size. It was also seen that the gap distance between the laser focus and the wafer surface is an important processing parameter since the removal efficiency is strongly dependent on the gap distance.

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판독성 향상을 위한 자동차 번호판의 개선에 관한 연구 (The Study on the Automobile License Plate for the improvement of Readability in Korea)

  • 이창민;이윤홍
    • 산업공학
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    • 제14권3호
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    • pp.296-301
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    • 2001
  • The focus of this study is to redesign the Korean license plate by comparing the USA's plate with European plate formed by 1-line system in order to increase a read rate of Korea license plate. And we have compared the read rate of the new design license plate with that of the present license plate and that of the license plate studied so far. As an experimental method (used in a precedent research), we use three kinds of methods that are the measurement of the read-distance, the measurement reading-rate under the short-term exposure and the measurement of the reading-rate when driving. First, three kinds of measurements for plates of five nations are performed. Then we redesign the new Korean license plate under the base of read rates obtained by five nation's plate. As alternatives, we choose five license plates. Those alternatives are the redesigned license plate, the present license plate, the license plate studied so far, and two types of eternity license plates made by the Korea Transport Institute. When we compare results of the read-distance, there is no significant in term of different the read-distance between the alternatives. But there is a significant difference in term of the misreading-rate and the read-rate when diving. Therefore, it is necessary to redesign the present license plates because of a high misreading-rate.

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개선된 거리변환 알고리즘을 이용한 이동 로봇의 경로 계획 및 추적 (Path Planning and Tracking for Mobile Robots Using An Improved Distance Transform Algorithm)

  • 박진현;박기형;최영규
    • 한국정보통신학회논문지
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    • 제9권4호
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    • pp.782-791
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    • 2005
  • 본 연구는 개선된 거리변환 알고리즘을 사용하여 로봇이 이동해야 할 경로를 생성하고, 퍼지 시스템을 사용하여 경로추적 행위기와 장애물 회피 행위기를 구현해서 로봇이 그 경로를 안전하고 효율적으로 추적하는 것을 목적으로 하였다. 개선된 거리변환 알고리즘을 이용하여 로봇의 유연한 주행을 가능하게 했으며, 또한 주행거리와 주행시간도 단축되는 것을 확인할 수 있었다. 경로생성 후 경로를 추적할 때는 퍼지 시스템을 이용한 경로추적 행위기와 장애물 회피 행위기를 선택적으로 사용해서 경로추적 중에 예상치 못한 장애물이 발견되었을 경우에도 장애물을 회피한 후에 계속해서 경로를 추적하는 것을 확인함으로써 경로생성 후의 외부환경변화에도 강인함을 볼 수 있었다.