• 제목/요약/키워드: Weightless

검색결과 23건 처리시간 0.024초

압축공기를 이용한 에어호이스트의 무중력화 제어 (Weightless Control of Air Hoist using Compressed Air)

  • 이강호;배상일;홍대선;정원지
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
    • /
    • pp.144-144
    • /
    • 2000
  • Air balance hoists are widely used in handling of heavy materials in industry. Currently used air balance hoists adopt manual switches for vertical motion, thus the operator has a difficulty in operating of the switches and handling of material simultaneously. To overcome this difficulty, this study develops a weightless air-balance-hoist system using compressed air. This system memorizes the weight of material in terms of pneumatic pressure with a pneumatic circuit. Such memory of the material weight is used for achieving weightless handling of materials. Through a series of experiments, handling forces and the response of the system for various material weights are analyzed. The results show that the developed system can be used for weightless handling o( heavy materials.

  • PDF

무중력 운동기구를 활용한 하이플랭크 운동의 효과성 검증 (Verification of the Effectiveness of High Plank Exercise using Weightless Exercise Equipment)

  • 김유신
    • 한국응용과학기술학회지
    • /
    • 제40권2호
    • /
    • pp.342-347
    • /
    • 2023
  • 본 연구의 목적은 무중력 운동기구를 활용한 하이플랭크 운동 동작 차이에 따른 상완, 체간 및 코어근육의 근활성도를 비교하는 것이었다. 본 연구의 대상자는 20대 남성 6명을 대상으로 진행하였고(연령, 23.00±0.73 세; 신장, 172.95±2.05 cm; 체중, 66.83±2.75 kg; 신체질량지수, 22.33±0.72 kg/m2), 4가지(HP, HPAW, HPSB 및 HPWT)의 하이플랭크 동작을 수행하였으며, 근활성도 분석을 위하여 구체적인 표면전극의 부착 부위는 신체 근육의 우측 삼각근, 상완삼두근, 광배근 및 외복사근으로 설정하였다. 본 실험 결과, 삼각근, 상완삼두근, 광배근 및 외복사근의 근활성도는 HPSB 동작 시 가장 높게 나타났다(p=.000). 따라서 본 연구의 결과는 추후 무중력 운동기구를 활용한 하이플랭크 동작 시 효과적인 운동 프로그램의 기초자료가 될 것으로 기대된다.

RAM 기반 신경망을 이용한 필기체 숫자 분류 연구 (A Study on Handwritten Digit Categorization of RAM-based Neural Network)

  • 박상무;강만모;엄성훈
    • 한국인터넷방송통신학회논문지
    • /
    • 제12권3호
    • /
    • pp.201-207
    • /
    • 2012
  • RAM 기반 신경망은 2진 신경망(Binary Neural Network, BNN)에 복수개의 정보 저장 비트를 두어 교육의 반복 횟수를 누적하도록 구성된 가중치를 가지지 않는(weightless) 신경회로망으로서 한 번의 교육만으로 학습이 이루어지는 효율성이 뛰어난 신경회로망이다. 지도 학습에 기반을 둔 RAM 기반 신경망은 패턴 인식 분야에는 우수한 성능을 보이는 반면, 비지도 학습에 의해 패턴을 구분해야 하는 범주화 연구에는 적합하지 않은 모델로 분류된다. 본 논문에서는 비지도 학습 알고리즘을 제안하여 RAM 기반 신경망으로 패턴 범주화를 수행한다. 제안된 비지도 학습 알고리즘에 의해 RAM 기반 신경망은 입력 패턴에 따라 자율 학습하여 스스로 범주를 생성할 수 있으며, 이를 통해 RAM 기반 신경망이 지도 학습과 비지도 학습이 모두 가능한 복합 모델임을 증명한다. 실험에 사용한 학습 패턴으로는 0에서 9까지의 오프라인 필기체 숫자로 구성된 MNIST 데이터베이스를 사용하였다.

수평 및 낙하 운동에 대한 과학사적 대립개념의 대비적 토론이 무중력 상황 도입을 통한 중학교 1학년 학생의 개념 변화에 미친 효과 (The Effect of Contrastive Discussion Based on the Historically Debated Concepts of Falling and Horizontal Motion on the Conceptual Change of 7 Year Pupils by Introducing Weightless Context)

  • 김재우;오원근;박승재
    • 한국과학교육학회지
    • /
    • 제17권1호
    • /
    • pp.31-44
    • /
    • 1997
  • One class of grade 7 was chosen as a control group, and the other as an experimental group. The control group watched only a film of motion in weightless situation, but the experimental group had a contrastive discussion before watching the film. In pretest, pupils were given contrasted views between the pre-Galilean and post-Galilean about falling and horizontal motion of bodies, and asked to choose one from two points of view and to write the reason why they choose it. After the pretest, control group students watched the same film as the experimental group did. On the falling problem, the control group ignored the contents of the film or regarded related contents as not related contents. However, through the contrastive discussion, experimental group pupils reconstructed their past vague ideas and noticed the cause of falling which was not perceived by the control group. On the horizontal motion, some in the control group agreed with post-Galilean view points after watching the film. Some of the pupils in the experimental group agreed with the post-Galilean viewpoint after performing the contrastive discussion. However, most of them agreed after watching the film. So we can conclude that the contrastive discussion which helped students to reconstruct their ideas made the difference between the two groups.

  • PDF

Derivation of design charts based on the two-dimensional structural analysis of geotextile tubes

  • Kim, Hyeong-Joo;Won, Myoung-Soo;Park, Tae-Woong;Choi, Min-Jun;Jamin, Jay C.
    • Structural Engineering and Mechanics
    • /
    • 제55권2호
    • /
    • pp.349-364
    • /
    • 2015
  • Analytical solutions for modeling geotextile tubes during the filling process and approximation method to determine the densified tube shape are reviewed. The geotextile tube filling analysis is based on Plaut & Suherman's two-dimensional solution for geotextile tubes having a weightless and frictionless inextensible membrane resting on a rigid horizontal foundation subjected to internal and external hydrostatic pressures. The approximation for the densified tube shape developed by Leshchinsky et al. was adopted. A modified method for approximating the densified tube shape based on an areal-strain deformation analysis is introduced. Design diagrams useful for approximating geotextile tube measurements in the design process are provided.

리튬고분자 이차전지의 전기적 전기화학적 특성

  • 박수길;박종은;손원근;류부형;이주성
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
    • /
    • pp.159-162
    • /
    • 1998
  • The new type polymer electrolyte composed of polyacrylonitrile(PAN) baed polymer electrolyte contain LiClO$_4$-EC/PC and LiPF$\sub$6/-EC/PC were developed for the weightless and long or life time of lithium polymer battery system with using polyaniline electrode. The gel type electrolytes were prepared by PAN at different lithium salts in the glove box. We prepared for polymer electrolyte with knife casting method. The minimum thickness of PAN gel electrolyte for the slim type is about <400∼500$\mu\textrm{m}$. These gel electrolytes showed good compatibility with lithium electrode. The test cell of Li/polymer electrolyte/Lithium cobalt oxide solid state cell which was prepared by different lithium salt was researched by electrochemical technique. Resistance of polymer electrolyte which consist of LiClO$_4$ is more less than that of LiPF$\sub$6/ and cycle life is more longer than that of LiPF$\sub$6/.

  • PDF

Electric and Electrochemical Characteristic of PMMA-PEO Gel Electrolyte for Rechargeable Lithium Battery

  • 박수길;박종은;이홍기;이주성
    • 한국전기전자재료학회논문지
    • /
    • 제11권10호
    • /
    • pp.768-772
    • /
    • 1998
  • The new type polymer electrolyte composed of polymethyl methacrylate(PMMA) - polyethy leneoxide(PEO) contain $LiClO_4$ -EC/PC was developed for the weightless and long or life time of lithium polymer batery system with using polyaniline electrode. the gel type electrolytes were prepared by PMMA with PEO at different lithium salts in the glove box. The minimum thickness of PMMA-PEO gel electrolyte for the slim type is about(400~450$\mu\textrm{m}$. These gel electrolyte showed good compatibility with lithium electrode. The test cell Li/polymer electrolyte/polyaniline solid state cell which was prepared by different lithium salt was researched by electrochemical technique.

  • PDF

Horizontal pullout capacity of a group of two vertical plate anchors in clay

  • Bhattacharya, Paramita;Kumar, Jyant
    • Geomechanics and Engineering
    • /
    • 제5권4호
    • /
    • pp.299-312
    • /
    • 2013
  • The horizontal pullout capacity of a group of two vertical strip plate anchors, placed along the same vertical plane, in a fully cohesive soil has been computed by using the lower bound finite element limit analysis. The effect of spacing between the plate anchors on the magnitude of total group failure load ($P_{uT}$) has been evaluated. An increase of soil cohesion with depth has also been incorporated in the analysis. For a weightless medium, the total pullout resistance of the group becomes maximum corresponding to a certain optimum spacing between the anchor plates which has been found to vary generally between 0.5B and B; where B is the width of the anchor plate. As compared to a single plate anchor, the increase in the pullout resistance for a group of two anchors becomes greater at a higher embedment ratio. The effect of soil unit weight has also been analyzed. It is noted that the interference effect on the pullout resistance increases further with an increase in the unit weight of soil mass.

Design of Simple Controller for Minicar BLDC Motor Based on Low Cost Microprocessor

  • Tao, Yu;Song, Doo-Young;Lei, Zhang;Park, Sung-Jun;Jung, Tae-Uk;Kim, Cheul-U
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2007년도 하계학술대회 논문집
    • /
    • pp.7-9
    • /
    • 2007
  • If used to drive the minicar, the BLDC Motor has advantages of weightless, efficient, small-size and credibleness. In this paper at first the position detecting method for BLDC was introduced, secondly the simulation of control algorithm was done and at last the prototype controller based one chip processor MEGA48 was fabricated. The controller proposed has characteristic of cheap cost, reliable performance and totally meeting demands of minicar control.

  • PDF

RAM을 이용한 경험유관축적 신경망 모델 (Experience Sensitive Cumulative Neural Network Using RAM)

  • 김성진;권영철;이수동
    • 전자공학회논문지CI
    • /
    • 제41권2호
    • /
    • pp.95-102
    • /
    • 2004
  • 제안된 경험 유관 축적 신경회로망은 입력 패턴의 교육 회수를 누적시킬 수 있는 구조를 가지고 있어, 누적된 교육을 통한 공통된 경험에 대해서는 강한 반응을 보이는 주의 집중 기능을 가진다. 그리고 잡음이 많은 패턴에 대하여 선행처리 과정을 거치지 않고 바로 교육을 시켜도 상대적으로 유용한 정보를 누적시켜 일반화 패턴을 추출할 수 있다 본 논문에서는 추가 교육 뿐만 아니라 반복 교육도 가능한 경험 유관 축적 신경회로망 모델을 제안하고, 이 신경회로망이 가지는 기본 특성인 망각 및 주의 집중기능에 대하여 기술하였으며, 또한 교육된 정보로부터 일반화 패턴의 추출 과정과 일반화 패턴의 생성 및 반복교육에 관한 것을 기술하였다.