• Title/Summary/Keyword: 4 자유도

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A Study on New Mathematical Model of Ship Manoeuvring Motion Taking Coupling Effect of Roll into Consideration (횡동요를 고려한 선박조종운동의 새로운 수학모델에 관한 연구)

  • Sohn, Kyoung-ho;Kim, Yong-min
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.451-458
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    • 2003
  • A ship with small metacentric height or high speed vessel performs relatively large roll angles in her manoeuvring motion. Roll coupling effect should be taken into consideration for accurate prediction of manoeuvring motion of such a ship. This paper proposes a new mathematical model of ship manoeuvring motion taking coupling effect of roll into consideration. Some kinds of manoeuvring motion are simulated by computer, based upon the proposed model. The simualted results by proposed model here are compared with those by existing model. The proposed model is found to be practical and useful for prediction of manoeuvring motion with roll effect.

A Control System of 4 d.o.f Human Arm type Redundant Robot (인간형 4자유도 로봇팔 제어 시스템)

  • Hwang, Sung-Ri;Park, Jae-woo;Na, Sang-min;Hyun, Woong-keun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.301-303
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    • 2018
  • This paper describes a robot control system and control method of a human arm type redundant manipulator. The control of a redundant manipulator suffer from computational complexity and singularity problem because of numerical inverse kinematics. To deal with such problems, analytical methods for a redundant robot arm have been researched to enhance the performance of inverse kinematics. In this research, we propose a numerical control method and weighted pseudo inverse kinematics algorithm. Using this algorithm, it is possible to generate a trajectory passing through the singular points and intuitively move the elbow without regard to the end-effector pose. Performance of the proposed algorithm was verified by various simulations. It is shown that the trajectory planning and using this algorithm provides correct results near the singular points and can utilize redundancy intuitively. We proved this system's validity through field test.

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The Performance of Grant-type Government R&D Project: Focusing on SME's R&D (자유공모형 국가연구개발 과제의 특성 및 효과성 분석 : 중소기업 R&D를 중심으로)

  • Seulki Hong;Sung Joo Bae
    • Journal of Technology Innovation
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    • v.30 no.4
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    • pp.57-82
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    • 2022
  • As the strategy to support SMEs' innovation has shifted to induce market-oriented innovation, the Korean government increasingly invests in grant-type R&D projects proposed by SME firms. This study reveals the characteristics of grant-type R&D projects proposed by SME firms through a transition of national R&D strategy and demand-pull innovation perspectives. This study also examines the differences between grant-type R&D projects proposed by firms and R&D projects led by the government through logit-analysis and propensity score matching methods. As a result, we found that a national R&D project for SMEs yields better innovation performance when the project is proposed by a company than led by the government.

Design and Analysis of 4-Degree-Freedom Robotic Arm based on Machine Learning for Accurate Throwing (정확한 던지기를 위한 기계학습 기반의 4자유도 로봇팔 설계 및 분석)

  • Jung, Ungyeol;Shin, Dong-min;Yoo, In-jae;Yoon, Ji-yong;Lee, Kwang-hyeon;Lee, Young-Jun
    • Proceedings of The KACE
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    • 2017.08a
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    • pp.189-192
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    • 2017
  • 던지기는 시간 효율이 높은 물체 수송 방법이나 그 정확성을 위해서는 다양한 물리적인 변인들을 고려해야 한다. 따라서 본 연구에서는 정확한 던지기에 영향을 주는 변인들을 설정하여 물체를 정확하게 던지는 해를 찾는 유전 알고리즘을 설계하고, 이를 4자유도 로봇팔에 적용시켰다. 하드웨어는 TETRIX와 EV3 플랫폼을 이용하여 설계하였고, 소프트웨어는 LabVIEW 2014를 이용하여 구현하였다. 또한 물체가 던져질 때마다 위치와 각 변인들의 값을 수집하고, 이를 통계적으로 분석하여 던지기의 정확성에 대한 각 관절의 기여도를 분석하였다. 본 연구의 결과는 물체를 정확히 던지는 기계를 설계하거나 사람의 던지는 동작을 이해하는 데 도움이 될 것으로 기대된다.

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Estimation Of System Parameters With Arma Model (자기회귀-이중평균모델에 의한 시스템 파라미터 추정)

  • Hwang, Won-Geol
    • Journal of the Korean Society for Precision Engineering
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    • v.8 no.4
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    • pp.76-83
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    • 1991
  • 자기회귀-이동평균모델에 의하여 시스템의 파라미터를 추정할 수 있는 벡터채널 원형 격자 필터(vector channel circular lattice filter)의 알고리즘을 제시하였다. 이 알고리즘은 스칼라 연산만으로 이루어져 계산이 간단한 장점이 있다. 3자유도 시스템의 시뮬레이션 결과로부터 격자 필터의 성능을 검증하였으며, 1자유도 팔의 고유진동수와 감쇄비를 추정하였다.

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Transient State Theory of Significant Liquid Structure applied to Water (액체구조에 관한 천이상태이론의 물에 대한 적용)

  • Pak, Hyung-Suk;Chang, Sei-Hun
    • Journal of the Korean Chemical Society
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    • v.10 no.2
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    • pp.91-97
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    • 1966
  • The partition function for liquid water is developed according to the transient state theory of significant liquid structure proposed by Pak, Ahn and Chang. This theory assumes that the molecules may possess solid-like, transient and gas-like degrees of freedom in liquid state. Although liquid water has several special properties, for example, minimum molar volume at 4^{\circ}C$, the general theory of liquid can be applied successfully. The theoretically calculated values for thermodynamic properties at the liquid temperature range and for the critical properties are in good agreement with the observed values.

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Kinematic Based Walking Pattern of Biped robot (기구학을 이용한 이족보행 로봇의 보행패턴)

  • Kim, Dong Won
    • Journal of Internet of Things and Convergence
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    • v.4 no.2
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    • pp.7-11
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    • 2018
  • In this paper, kinematic based walking pattern generation of biped walking robot is reviewed. Biped walking robot should be consisted of 6 Degree of Freedom(DOF) for each leg to walk properly in 3 dimensional circumstance. In this paper, simple structure of biped robot is depicted for walking pattern firstly. After fixing path of ankle of the robot, angle joints are coming from kinematic equatioins. Coordination of joints of a robot was set for dynamic analysis also. So walking pattern of a robot will be designed using dynamic equations of coordination of joint angles. Finally, setting of ankle of robot and pattern generation are key procedures of the robot walking.

Progressive Librarian 'Zoia M. Horn' and Her Library Freedom Ideologies (진보사서 '조이아 혼'과 그녀의 도서관 자유 사상)

  • Kim, Seon-Ho
    • Journal of Korean Library and Information Science Society
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    • v.47 no.4
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    • pp.43-68
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    • 2016
  • Uncovering ideological trends and varieties embedded in contemporary progressive librarianship, the depth and breath of the librarians' thoughts should be more expandable than before. That is the purpose of the study. To accomplish the purpose, this study analyzed key ideologies of American progressive librarian Zoia M. Horn(1918-2014) as reviewing carefully her biography with the inductive approach for qualitative data analysis. As a result, author suggests that the core values of Z.M. Horn's library freedom ideologies have identified as equality, intellectual freedom, and pacifism. In addition, the ingredients of these core ideologies also were identified.