• Title/Summary/Keyword: 착지점

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Extraction of the landing point of the bucket on the stockpile (야적파일위의 버킷 착지점 추출)

  • Choe, Jin-Tae;An, Hyeon-Sik;Lee, Gwan-Hui;Sin, Gi-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.273-279
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    • 1998
  • 철강석 또는 석탄의 적치장에서는 이들 원석을 퍼내어 용광로로 보내주는 불출기(reclaimer)가 사용되고 있다. 불출기를 자동화하려면 야적파일에 불출용 회전 버킷(bucket)을 자동착지시키는 방법이 요구된다. 본 논문에서는 야적 파일 표면위의 버킷 착지점을 추출하는 방법을 제시한다. 이 방법은 파일의 3차원 형상 검출, 파일의 등고선 추출, 불출기의 역기구학해의 도출 및 착지점 추출 알고리즘으로 이루어진다. 파일의 3차원 형상과 거리를 측정하기 위한 3차원 형상 검출기가 2차원 레이저 검출기에 수평주사(scanning)용 모터를 부착하여 개발하였고, 다 단계의 영상처리를 통해 버킷이 작업할 수 있도록 파일의 작업 등고선을 추출하였다. 불출기가 회전 버킷에 의해 기구학적으로 여유자유도로 이루어 졌음을 보였으며, 역기구학 해를 구하는 방법을 아울러 제시하였다. 그리고 버킷의 착지점을 과부하 방지와 단위 시간당 생산성을 최대화하는 성능기준에 근거하여 구하였다. 또한 개발된 시스템을 제철소 원석 야적장의 불출기에 설치 시험하여 타당성을 입증하였다.

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The characteristics of eye-movement in Korean sentence reading: cluster length, word frequency, and landing position effects (우리 문장 읽기에서 안구 운동의 특성: 어절 길이, 단어 빈도 및 착지점 관련 효과)

  • Koh, Sung-Ryongng;Yoon, Nak-Yeong
    • Korean Journal of Cognitive Science
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    • v.18 no.4
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    • pp.325-350
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    • 2007
  • This study investigated global and local characteristics of eye movement while 16 college students read 48 easy Korean sentences. It was found that readers lusted for about 225ms at the word cluster(eojeol), made a forward saccade of about 3.6 characters to the next word, skipped short and high-frequent words about 25% during the first-pass reading, and regressed backward at 19%. There were also individual differences in readers' pattern of fixation and saccade. In addition, the effects of word cluster length and word frequency and the effects related to landing position were examined. The eyes landed on the center of a word cluster more frequently than on the boundaries. When the eyes landed at the boundaries, the eyes fixated the word cluster again more frequently. The word clusters with high-frequency words were read faster than those with low-frequency words.

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A Study on the Footholds Selection for Quadruped Walking Vehicle (4족 보행 로봇의 착지점 선정에 관한 연구)

  • 정경민;박윤창
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.7-10
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    • 2000
  • Inadequate footholds selection may result in deadlock state where the walking vehicle can not anymore to the desired direction. This paper concerns about the footholds selection for quadruped v, vehicle to walk with the leg lifting sequence of crawl gait which is desired for straight motion. supporting states for lifting a leg are defined and the proper supporting condition for quadruped c: also proposed. When selecting a footholds of swing leg within the proposed footholds searching are; supporting states after the swing legs are placed, satisfy the proper supporting condition. So it can I for quadruped to execute continuous walking with the lifting sequence of crawl gait.

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The characteristics of eye-movement during children read Korean texts (어린이 글 읽기에서 나타나는 안구 운동의 특징)

  • Koh, Sung-Ryong;Yoon, So-Jeong;Min, Chul-Hong;Choi, Kyung-Soon;Ko, Sun-Hee;Hwang, Min-A
    • Korean Journal of Cognitive Science
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    • v.21 no.4
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    • pp.481-503
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    • 2010
  • In the present study, we examined global and local characteristics of eye movements while 17 Korean third-graders read a Korean story and an expository text. In story reading, children fixated for about 213ms at an eojeol(word cluster), made a forward saccade of about 3.6 characters to the next eojeol, and regressed backward at 30.8% on average. In expository text reading, children fixated for about 214ms at an eojeol, made a forward saccade of about 3.3 characters to the next eojeol, and regressed backward at 31% on average. In addition, the effects of eojeol length, word frequency and landing position were examined. The gaze duration in the long ejoels was longer than in the short eojeols. In a further analysis where the repeatedly used eojeols were excluded, the eojeol length effect appeared in the low-frequency words, but seemed to disappear in the high-frequency words. In terms of landing position, the eyes seemed to land near the center of an eojeol more frequently than on the boundaries. When the eyes landed at the boundary of an eojeol, the eyes tended to fixate the eojeol again.

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Fault Tolerant FTL Gaits for Walking over Irregular Terrain (비평탄 지형 보행을 위한 내고장성 FTL 걸음새)

  • Yang Jung-Min
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.3 s.309
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    • pp.16-24
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    • 2006
  • In this paper, fault-tolerant gait planning of a hexapod robot for walking over irregular terrain is presented. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. Based on the previously proposed fault-tolerant tripod gait for walking over even terrain, fault-tolerant follow-the-leader(FTL) gaits are proposed for a hexapod robot with a failed leg to be able to walk over two-dimensional rough terrain, maintaining static stability and fault tolerance. The proposed FTL gait can have maximum stride length for a given foot position of a failed leg, and yields better ditch crossing ability than the previously developed gaits. The applicability of the proposed FTL gait is verified by using computer graphics simulations.

A method for trajectory landing position of bucket of reclaimer (원료 불출기 자동화를 위한 원료 불출 착지점 결정 방법)

  • 이관희;안현식;신기태
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.363-366
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    • 1996
  • A Reclaimer is used to dig raw material from a pile and transfer it to the blast furnaces. In this paper, we propose the method for trajectory landing position of bucket of reclaimer to fully automate the reclaimer. We use 3-dimensional range finder to detect the shape of a pile. From the image which was detected by 3-dimensional range finder, we extract the outline paths which has same height, and then determine digging height. Finally, we compute the landing point from the outline path. We can prevent overload which can occur on the bucket wheel and guarantee maximum production rate by using the algorithm for determining the landing position on the piles.

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A study on walking algorithm of quadruped robot used stroke control method in the irregular terrain (비평탄 지형에서 스토로크 제어법을 이용한 4족 로봇의 보행 알고리즘에 관한 연구)

  • Ahn, Young-Myung
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.52-59
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    • 2006
  • Walking robot is able to move in regular or irregular terrain. It can walk that change adaptive algorithms according to the terrain. Existing papers about adaptive gaits of blind robot are based on intelligent foothold selection. However, this paper proposes a algerian that is based on the variations of stroke and period to adapt the irregular terrain. If thus adaptive algorithms is used, robot can maintain periodic gait walking and constant speed using only force sensor even in the irregular terrain without external sophisticated sensor. In this paper Quadruped robot with 2 DOF in each leg, is walk experiment with the wave gait in regular and irregular terrain. So the adaptive algorithm is proved useful through walk experiment.

Muscle Length and Shortening Velocity Changes during the Different Types of Vertical Jumps (수직점프 동작시 근육길이와 수축속도 변화)

  • Chae, Woen-Sik
    • Korean Journal of Applied Biomechanics
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    • v.14 no.1
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    • pp.161-172
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    • 2004
  • 본 연구의 목적은 각기 다른 수직 점프 동작 시 근육의 길이와 근육의 수축속도 변화를 비교 분석하는데 있다. 피험자의 운동학적 변인들을 분석하기 위해 2대의 고감도 카메라를 (60 Hz, Panasonic AG455) 사용하여 점프 동작을 촬영하였다. 대퇴직근, 내측광근, 외측광근, 중간광근, 대퇴이두근(단두), 내측과 외측 비복근의 길이와 근수축 속도는 Brand et al. (1982)에 의해 제시되어진 하지근 기시 정지점의 3차원 좌표값과 동작분석을 통한 하지 분절간의 회전 및 변환행렬을 사용하여 측정되어졌다. 일반적인 근육 길이와 수축속도의 변화 형태는 각기 다른 점프간에 매우 유사한 형태를 보였다. 상승기 초기에 대퇴사두근의 길이가 최대인것으로 나타났으며, 이에 반해 대퇴이두근과 내외측 비복근은 공중 동작이 발생하는 시점에 근의 길이가 최대인 것으로 나타났다. 근육의 길이 변화 범위는 대퇴직근이 35.9에서 47.5 cm, 외측광근이 29.4에서 38.8 cm, 중간광근이 31.5에서 38.0 cm, 내측광근이 30.9에서 38.6 cm, 대퇴이두근이 21.3에서 39.1 cm, 외측비복근이 31.4에서 33.5 cm, 내측비복근이 30.5에서 33.2 cm인 것으로 나타났다. SQ와 CMJ에서는 대퇴사두근의 최대 단축성 수축 속도와 대퇴이두근과 내외측 비복근의 최대 신장성 수축이 공중동작이 발생하기 바로 전에 이루어졌다. 대퇴사두근의 최대 신장성 수축과 대퇴이두근과 내외측 비복근의 최대 단축성 수축은 일반적으로 피험자가 착지하는 순간에 발생되어졌다. 그러나 HJ와 DJ에서는 대퇴사두근의 최대 신장성 추축과 대퇴이두근과 내외측 비복근의 최대 신장성 수축이 하강기 초반에 발생되어졌다.

A Study on Sustainable Packaging for Flower Basket Design (지속 가능한 꽃바구니 디자인 패키징에 관한 연구)

  • Ahn, Hye Kyung;Kim, Heung Ryeol
    • Journal of the Korean Society of Floral Art and Design
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    • no.43
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    • pp.81-100
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    • 2020
  • Since sustainable packaging of flower basket designs that are sold from florist shops is needed for both the seller and the buyer, studying of second packaging of flower basket design has begun. In this study, based on the survey that has been done in 2019, and the analysis of the interview that has been done in 2020, the suggestion of sustainable packaging development is the purpose. The definition of flower basket design was done and surveys of the status of domestic flower basket designs' second packaging were done in accordance with the type of basket which is an object, transportation, and characteristic of a florist shop. For sustainable packaging, based on physical theory, second packaging which depends on the packaging that includes design factor, transportation final destination has to be different. The factors to be considered as sustainable packaging are the quality of opaque paper, the necessity of first packaging, packaging structure that can fix an object, the form of second packaging influenced by types of transportation. Suggestions for packaging development included new materials for first packaging, eco-friendly objects that can be recycled and reused, structural packaging design, standardization and variability of packaging, protection of floristry which is the fundamental purpose of packaging, and brand advertisement effect. Based on the result of this study further designs of packaging will be commercialized. This study is significant for serving the opportunity of new packaging design for futuristic floristry that fit for unmanned system and studying of categories of products.