• Title/Summary/Keyword: TOUCH DOWN

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Development of the compacted extra high voltage by-pass cable machinery (콤팩트화된 특고압 이동형 케이블 장치의 개발)

  • Ahn, Y.K.;Seo, S.J.;Paeck, H.S.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.268-270
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    • 1991
  • In this paper, we introduce the 22.9kv by-pass cable machinery being developed. This machinery is so desinged as to solve many problems of the conventional one such as the limitation of usage, working space, route length etc. It is, so to speak, one touch-one system. Compared with the conventional system, this has several advantages, which are the cost down, the decreasing working time and space, and the multiusage etc.

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Swirl ratio effects on tornado vortices in relation to the Fujita scale

  • Hangan, H.;Kim, J.D.
    • Wind and Structures
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    • v.11 no.4
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    • pp.291-302
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    • 2008
  • Three-dimensional engineering simulations of momentum-driven tornado-like vortices are conducted to investigate the flow dynamics dependency on swirl ratio and the possible relation with real tornado Fujita scales. Numerical results are benchmarked against the laboratory experimental results of Baker (1981) for a fixed swirl ratio: S = 0.28. The simulations are then extended for higher swirl ratios up to S = 2 and the variation of the velocity and pressure flow fields are observed. The flow evolves from the formation of a laminar vortex at low swirl ratio to turbulent vortex breakdown, followed by the vortex touch down at higher swirls. The high swirl ratios results are further matched with full scale data from the Spencer, South Dakota F4 tornado of May 30, 1998 (Sarkar, et al. 2005) and approximate velocity and length scales are determined.

A Performance Analysis of a Glidepath Tracking Algorithm for Autolanding of a UAV (무인항공기 자동착륙을 위한 활강궤적 추종 알고리듬 성능분석)

  • Choi, Young-Hyun;Koo, Hueon-Joon;Kim, Jong-Sung;Suk, Jin-Young
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.3
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    • pp.262-269
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    • 2005
  • Automatic landing of UAVs receives increasing interest these days, with increasing number of the developed UAV systems. In this paper, a glidepath tracking algorithm of the subscale UAV was proposed and the performance was analyzed. Flight data analysis shows that the existing autolanding flight control algorithm has a classical type glidepath control. This paper presents an alternative glidepath tracking strategy based on embedded flight control law. The performance of the proposed strategy was investigated through the TDP(Touch Down Point) error analysis with regard to various flight environment: steady headwind, atmospheric disturbance, communication transfer delay. It was verified that the proposed glidepath tracking strategy can be successfully applied to the practical autolanding of UAV systems.

Characteristics measurement of fabricated micromirror array with vertical springs (제작된 수직 마이크로미러 어레이의 특성 측정)

  • Shin, Jong-Woo;Kim, Yong-Kweon;Park, Jin-Goo;Shin, Hyung-Jae;Moon, Jae-Ho
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.618-620
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    • 1997
  • A $50{\times}50{\mu}m^2$ aluminum micromirror array is fabricated using shadow evaporation process. The fabrication process is very simple with use of shadow evaporation process, and the micromirror array has a high fill-factor. The static and dynamic characteristics such as deflection angle vs. applied voltage, step response, and frequency response are measured using a contact free optical measurement technique. The downward threshold voltage was 8 V, step response time was $13.5{\mu}s$ when 32 V step voltage applied, and a resonance observed at 11kHz. The lifetime of micromirror with anti-stiction coating was tested and micromirror operated successfully over 200 million cycles of touch-down operations.

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State of The Art of Offshore Survey Technology for Monitoring Underwater Gas Export Pipeline Installation at DongHae-1 Gas Field (동해-1 가스전 해저배관 설치공사에 적용된 최신 해양 측량기술)

  • Park, Joseph
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.722-740
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    • 2005
  • 본 논문은 최근의 석유탐사 및 개발사업 현장에서 사용되고 있는 최신의 측량기술 및 해양공사의 측량 기술 표준화 동향을 소개하고, 이에 기반하여 동해1 가스전 해저배관 공사에 적용한 사례를 기술하였다. 해저배관 시설공사를 수행하기 위한 사전측량 및 시공지원 측량은 다양한 탐사장비가 동원되며, 각 장비들의 운영, 자료처리, 해석, 도면화를 위하여 실시간지원이 가능한 시스템을 운영하는 기술이 요구된다. 이를 위하여 해저배관 시공단계별(Pre-Installation Survey, Touch-down Monitoring, As-laid As-Built Survey, Post-installation Survey) 요구되는 측량성과 및 이를 획득하기 위한 소해측량 시스템의 성능평가 및 정확도 분석을 수행하였다. 또한, 해저지형 탐사를 위해 동원된 소해측량시스템(Swath Sonar System)에서 취득되는 수심(Bathymetry) 및 후방산란 음압(Backscattered Amplitude) 자료를 맵핑하여 해저배관의 설치 경로를 측량하는 기법에 대하여 소개하고, 추후 해저배관 보호 및 관리시의 효율적인 모니터링 기법을 제시한다.

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Estimation of the Frictional Coefficient of Contact Point between the Terrain and the Wheel-Legged Robot with Hip Joint Actuation (고관절 구동 방식을 갖는 바퀴-다리형 로봇과 지면 간 접촉점에서의 마찰계수 추정)

  • Shin, Dong-Hwan;An, Jin-Ung;Moon, Jeon-Il
    • The Journal of Korea Robotics Society
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    • v.6 no.3
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    • pp.284-291
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    • 2011
  • This paper presents the estimation of the frictional coefficient of the wheel-legged robot with hip joint actuation producing maximum tractive force. Slip behavior for wheel-legged robot is analytically explored and physically understood by identification of the non-slip condition and derivation of the torque limits satisfying it. Utilizing results of the analysis of slip behavior, the frictional coefficients of the wheel-legged robot during stance phase are numerically estimated and finally this paper suggests the pseudo-algorithm which can not only estimate the frictional coefficients of the wheel-legged robot, but also produce the candidate of the touch down angle for the next stance.

Development of high-power haptic vibration actuator module and interface based on bidirectional electrostatic force driving structure (양방향 정전기력 구동 구조에 기반한 고출력 햅틱 진동 액추에이터 모듈 및 인터페이스 개발)

  • Kim, Jae-Ik;Lee, Jae-Kyung;Park, Young-Hwan;Seo, Jeong-Tae;Yang, Tae-Heon
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.662-667
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    • 2021
  • Vibrotactile feedback is a major function of the latest touch displays, which greatly improves the user's operability and immersion when interacting with the interface on the screen. In this study, we propose a vibrotactile actuator suitable for mounting on the back side of a mid- to large-sized display because it can generate a strong vibration output by applying an electrostatic force-based mechanism and can be manufactured in a thin flat panel type. The proposed actuator was developed in a structure capable of amplifying the vibration force by alternating up and down with electrostatic force by the upper and lower electrodes that are spaced apart from the electrically grounded mass suspended from a radial leaf spring. As a result of the performance evaluation, the developed bar-type module with two built-in actuators showed excellent vibration output of up to 3.3 g at 170 Hz, confirming the possibility of providing haptic feedback in medium and large touch displays.

The Kinematic Analysis on The Stand Long Jump of Visually Impaired Persons (시각장애인의 제자리멀리뛰기 동작에 대한 운동학적 분석)

  • Oh, Cheong-Hwan;Choi, Jung-Kyu;Jeong, Ik-Su;Lee, Dong-Gin;Choi, Su-Nam;Nam, Taek-Gil
    • Korean Journal of Applied Biomechanics
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    • v.16 no.4
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    • pp.39-47
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    • 2006
  • This study long jump action to each situation on a chessboard and section of sight disabled person and normal person through third dimension reflex analysis mechanical special quality because do comparative analysis sight disabled person's exercise ability and technology structure of action that run understand. As can do better without danger of injury map and training of exercise item that action that run is included, do offer of pabulum by purpose. Through this study, conclusion is as following. 1. Sight disabled persons' long jump average recording (121.84cm) showing normal persons' average recording (259.27cm) and much differences, show that motion of body is not big to Touch-down from Ready action. 2. Each phase body center composition(r) average speed displayed result that it is more meaning more than Each phase time required. 3. Began in line carriage without body back stretching in 1 situation on Event one are sight disabled persons. Was expose that do not bend enough knee and ankle than normal person in Event two. Was expose that body is not drooped for surface of land in Event three, and knee and ankle were expose that do not unfold easily than normal person. Was expose that do not bend enough on Touch-down knee by relation that can not grasp position of the floor in Event four. 4. When taking off, the average of horizontal speed of body center are 1.80m/sec for blind people and 3.53m/sec for the normal. In this connection, the study shows that the difference of horizontal speed between the blind and the normal is bigger than difference of vertical speed, which are 1.56m/sec for the blind and 1.98m/sec for the normal. Also, composite speed also shows us big difference between 2.41m/sec of the blind and 4.07m/sec of the normal. The speed body center of take-off was expose that average adjuster are big width of deceleration than average - beginning disabled person's average by 2.23m/sec - 1.71m/sec in the vertical speed. 5. If examine change of high and low for z Sign of right hand, change of high and low showed as is small than normal person is sight obstacle, and all hand movements are small and was expose that do not use enough reaction of body as well as in ready action.

A Study on Purchasing Conditions and Consumer Complaint of Outdoor Sportswear (아웃도어 스포츠 의류 제품의 구매실태와 소비자 불만에 관한 연구)

  • Park, Young-Hee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.15 no.3
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    • pp.85-97
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    • 2013
  • The purpose of this study was to examine purchasing conditions and consumer complaint for outdoor sportswear items. The data used for a study were the complaint facts of 256 cases that were received at the Consumer Complaint Center of Gyeongnam YWCA during the period from July 2011 to April 2013. The statistical methods used to analyze data were Frequency Analysis and $x^2$-test by SPSS 14. The results of purchasing conditions analysis for outdoor sportswear items were as follows. According to outdoor sportswear items, purchasing place, purchasing price, and materials showed significant difference. The department store showed the highest ratio, but the ratio showed difference according to items. The price between over 100,000 won and under 200,000 won was most in case of T-shirts, padding, down jumper, aloha shirts, and pants. It showed as T-shirts and pants mixed spinning materials the most, jacket, padding, and down jumper used polyester the most, aloha shirts used cotton the most. The results of consumer complaint analysis for outdoor sportswear items were as follows. As a result of difference analysis for complaint occurrence place according to outdoor sportswear items, a laundry showed the highest ratio. As a result of difference analysis for the period used outdoor sportswear items until complaint occur, there was no significant difference. As a result of difference analysis for complaint type and contents according to outdoor sportswear items, the complaint types and contents were classified largely as change of color, change of shape, change of surface and touch, breakdown of subsidiary materials, and others.

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The Development of Rhythmic Balance Training Equipment and its Effect on Performance for Elderly

  • Park, Da Won;Won, Cho Rong;Lee, Sung Ro;Park, Yang Sun
    • Korean Journal of Applied Biomechanics
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    • v.26 no.3
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    • pp.323-331
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    • 2016
  • Objective: The aims of this study were 1) to develop easy-to-use rhythmic balance training equipment for the elderly and 2) to investigate the effect of training with the equipment on balance and physical function. Method: Twenty-one elderly individuals (age: $75.4{\pm}3.34yrs$, height: $152.07{\pm}4.81cm$, weight: $58.35{\pm}8.34kg$) participated in this study. Each participant underwent balance and physical function testing before and after 12 weeks of training with the equipment. Y-balance (i.e. dynamic balance) and one leg static balance tests were used for balance testing, and timed up- and-down-stairs and five times sit-to-stand tests were used for physical function testing. A paired t test was used to determine whether there was a significant pre- and post-training difference. Results: The rhythmic balance training equipment provided a fun and motivating training program with age-friendly music, dance movements for lower extremity strength training, and touch screen controls with simple features. Post-training left foot dynamic balance was significantly greater (p<.05), and static balance with eyes open was significantly improved (p<.05) compared to pre-training. Completion of the timed up-and-down-stairs and the five times sit-to-stand tests was significantly shorter (p<.05) compared to pre-training. Conclusion: Training using the equipment developed in this study improved balance and physical function in elderly participants.