• Title/Summary/Keyword: 도르래

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A Pulley-Type VR Interface that Efficiently Conveys a Sense of Weight to the User in a Virtual Environment (가상환경에서 무게감을 효율적으로 사용자에게 전달하는 도르래 방식의 VR 인터페이스)

  • Seong-A Park;YeRin Moon;Soyeon Park;Jong-Hyun Kim
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2023.01a
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    • pp.381-384
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    • 2023
  • 본 논문에서는 마이크로소프트의 홀로렌즈를 이용한 손 위치 추적 및 모션 인식과 아두이노를 통해 상황에 맞는 무게감을 사용자에게 전달할 수 있는 VR 인터페이스를 제안한다. 홀로렌즈는 혼합현실을 체험할 수 있지만 홀로렌즈를 이용해 가상의 물체를 잡았을 때 현실과의 물리적인 상호작용이 없기 때문에 현실감이 떨어져 몰입을 저하하는 원인이 된다. 본 논문에서는 혼합현실에서 사용자의 몰입을 개선하기 위해 아두이노를 이용하여 사용자에게 무게감을 효율적으로 전달하여 현실과 같은 몰입을 줄 수 있는 도르래 방식의 VR 인터페이스를 제안한다.

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Trochlear Nerve Palsy Caused by Quadrigeminal Cistern Lipoma (사구수조지방종에 의한 도르래신경마비 1예)

  • Choi, Nam Hyeon;Kim, Won Jae;Kim, Myung-Mi
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.11
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    • pp.1087-1090
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    • 2018
  • Purpose: To report a case of trochlear nerve palsy caused by quadrigeminal cistern lipoma located in the dorsal midbrain. Case summary: A 65-year-old male visited our clinic for intermittent vertical diplopia over 2-year period. Symptoms of diplopia had worsened over the past two weeks. He had no previous medical history except having had diabetes for 1 month. The best-corrected visual acuity was 20/25 in the right eye and 20/20 in the left eye. Pupillary examination was not remarkable. Extraocular examination showed 4 prism diopters (PD) left hypertropia at distant gaze and 4 PD exotropia at near gaze, with adduction elevation of the left eye. The Bielschowsky head tilt test revealed 6 PD left hypertropia on the left gaze and orthotropia on the right tilt. Fundus examination showed excyclotorsion of the right eye and incyclotorsion of the left eye. Brain magnetic resonance imaging revealed quadrigeminal cistern lipoma. Prism glasses were prescribed to alleviate diplopia, and we followed up the lesions without further treatment. Conclusions: Trochlear nerve palsy can be caused by quadrigeminal cistern lipoma; however, it is uncommon for this condition to be caused by a compressive lesion. Prompt neuroimaging can be helpful to rule out the causes of this condition in patients with atypical symptoms.

Development of the Prototype of Wave Energy Converter by a Pulley System (도르래를 이용한 파력발전기 프로토 타입 개발에 관한 연구)

  • Jung, Hyun-Seok
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.133-139
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    • 2010
  • From the ancient times, there are waves in the ocean. And all the moving body have energy. We have a kind of hope to convert the wave energy into electric one. Finally we can find out a power generator mechanism that mainly use the principle of pulleys. We have made drawings for this and completed the wave energy converter. This wave energy converter consists of several pulleys, rope, generator, buoys and anchors. The distance between an anchor and buoy is changed according to the hight of waves. Several sets of anchors, pulleys and buoys can make the movement of rope, and the ropes wind up a converter axis. In case of 1 meter movement of the buoy, the winding distance will be amplified 2 or 3 times if we use several moving and fixed pulleys. Based on this concept, we developed 2 kind of prototypes. One is for the test in the laboratory and the other is for the field test. Through the two test, we could confirm the usability of this mechanism.

Safety Analysis of Wire rope in the RPSD (RPSD에 설치된 와이어로프의 안전성 해석)

  • Park, Sang-Kyu;Peng, Lu;Kim, Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.2
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    • pp.313-319
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    • 2013
  • This study shows the results of safety analysis obtained from the three different wire rope connections in the RPSD (Rope Platform Screen Door) system, which are the rope connected at both ends, the ropes connected by a pulley at both ends, and the ropes connected by many pulleys at both ends. With a constant load applied, the displacements in the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends are smaller than that in the rope connected at both ends. There are no any special different displacements between the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends. The displacement in the wire rope diameter of 6mm is smallest of 4.83mm and the strains from the displacements in the ropes connected by a pulley at both ends and the ropes connected by many pulleys at both ends are very small.

Development of a Pulley-type Tensioning Device (도르래식 장력조정장치 개발)

  • Lee, Ki-Won;Cho, Yong-Hyeon;Park, Young
    • Journal of the Korean Society for Railway
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    • v.12 no.5
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    • pp.663-669
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    • 2009
  • In the electrical railway, the increase of tensions in an overhead contact lines is essential to speed-up of train, because current collection quality largely depends on the ratio of a wave propagation speed to a train speed. For Kyungbu high-speed line, a pulley-type tensioning device is required to have a tension variation of maximum 3%. Therefore we developed a pulley-type tensioning device in order to meet tension variation requirement of the high-speed tensioning device. To verify the performance of the developed device, a performance test, overload test and failure test were carried out according to the factory test procedure of the Kyung-Bu High-speed line. Furthermore, we also performed reliability performance through not only a fatigue test in a factory, but also on-line verification test in Chungbuk line for over 1 year. These tests verified that the tensioning device had applicability to a main line.

역사속 과학인물 - 큰 거울로 배를 태운 그리스 과학자 '아르키메데스(287~212BC)

  • Park, Seong-Rae
    • The Science & Technology
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    • v.30 no.7 s.338
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    • pp.32-34
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    • 1997
  • 목욕하다 알몸으로 뛰어나와 "발견했다"를 외친 기원전 그리스 과학자 아르키메데스는 우리나라에도 일찍이 소개된 인물이다. 거울로 적의 배를 태우고 도르래를 이용해 큰 배를 이동시켰으며 천체를 관측한 혼천의를 발명해 명성을 떨친 과학문명의 개척자이다.

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A Study on the Elevator Overbalance-Ratio Control and Improved Scheme for Safety (엘리베이터 오버밸런스율 제어와 안전을 위한 개선방안 연구)

  • Lee, Ho-Cheol;Choi, Young-Kiu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.12
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    • pp.2785-2792
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    • 2013
  • An elevator is driven by the friction between the pulley and wire rope. A balancing counter weight is connected to the elevator car with a wire rope. This structure is essential to drive elevators while it always has weight unbalance problems on each side. The overbalance-ratio of elevators may be an important factor for safety and structural efficiency; however, it is not yet clearly defined in the Requirements of Korea Elevator Inspection. This paper describes these "weight unbalance ratio" for control of elevators to reduce the number of accidents. It includes the analysis of current elevator maintenance situations and also proposes some fundamental improvement schemes for safety.

A Study on the Development of Sidewall-pressure Measuring Device for Conduit Type Laying of Underground Cable (초고압케이블 관로 포설 측압 측정용 기기 개발에 관한 연구)

  • Lee, Ji-Hun;Hong, Dong-Suk;Kang, Seung-Hun;Kang, Gi-Hyeog
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.562-563
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    • 2011
  • 초고압케이블을 관로식으로 포설할 경우 케이블 포설장력이 증가함에 따라 측압은 커지게 된다. 측압은 지중관로 내 케이블 포설시 도르래 및 굴곡부에서 발생하는 관로 내면과 케이블 사이의 압력을 의미하며, 단심배열의 경우 곡률반경과 장력에 의존한다. 케이블의 측압을 정확하게 알고 안전성에 기초하여 장경간 포설을 한다면, 케이블 포설 시 긴 케이블 조장에 따라 접속함과 굴착개소의 감소로 이어지기 때문에 원가절감 뿐 아니라 공기 단축 차원에서도 큰 역할을 할 수 있다. 그러나 현재 케이블 측압은 포설 장력을 이용하여 계산되기 때문에 실제 측압과 오차가 발생할 수 있으며, 정확한 장력을 케이블에 인가하는것 또한 어려운 일이다. 따라서 본 논문에서는 케이블 포설시 발생하는 측압을 작용시키며, 장력을 케이블에 정확히 인가할 수 있는 측정기기 개발에 관한 내용을 정리하였다.

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Experimental Performance Evaluation of Displacement Amplification Damping Systems Using Cables and Pulleys (케이블과 도르래를 이용한 변위증폭형 감쇠시스템의 실험적 성능평가)

  • Oh, Jintak;Jung, In Yong;Ryu, Jaeho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.3
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    • pp.149-156
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    • 2020
  • The vibration control device such as the damper can be used to reinforce the seismic performance of structures. The damper is activated by the deformation of structures during earthquake; however, the deformation of structures is extremely small, causing difficulty in using the damper. Therefore, there is a need for a method capable of amplifying small deformities and transmitting them to the damper. The purpose of this paper is to develop and evaluate a displacement amplification seismic system using cable-pulley. The appropriate cable was selected through a cable tensile performance test and the results of the frame experiment were compared with theoretical displacement amplification ratio values. As a result, it may be said that the proposed system using cable-pulley is useful for displacement amplification.