• 제목/요약/키워드: eccentric

검색결과 893건 처리시간 0.024초

보행 장애인을 위한 능동형 보행훈련 시스템 개발 및 평가 (The Development and Evaluation of the Active Gait Training System for the Patients with Gait Disorder)

  • 황성재;태기식;강성재;김정윤;황선홍;김한일;박시운;김영호
    • 대한의용생체공학회:의공학회지
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    • 제28권2호
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    • pp.218-228
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    • 2007
  • Modem concepts of gait rehabilitation after stroke favor a task-specific repetitive approach. In practice, the required physical effort of the therapists limits the realization of this approach. Therefore, a mechanized gait trainer enabling nonambulatory patients to have the repetitive practice of a gait-like movement without overstraining therapists was constructed. In this study, we developed an active gait training system for patients with gait disorder. This system provides joint movements to patients who cannot carry out an independent gait. It provides a normal stance-swing ratio of 60:40 using an eccentric configuration of two gears. Joint motions of the knee and the ankle were evaluated with using the 3D motion analysis system and compared with the results from the multi-body dynamics simulation. In addition, clinical investigations were also performed for low stroke patients during the 6-week gait training. Results from the dynamics simulation showed that joint movements of the knee and the ankle were affected by the gear size, the step length and the length of the foot plate, except the radius of curvature of the foot guide plate. Also, the 6-week gait training revealed relevant improvements of the gait ability in all low subjects. Functional ambulation category levels of subjects after training were 2 in three patients and 1 in a patient. The developed active gait trainer seems feasible as an adjunctive tool in gait rehabilitation after stroke.

고강도 폴리머 콘크리트 휨부재의 응력블럭 (Stress Block of High Strength Polymer Concrete Flexural Members)

  • 김관호;김남길;연규석
    • 콘크리트학회논문집
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    • 제14권5호
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    • pp.638-644
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    • 2002
  • 본 연구에서는 압축강도 1400 kgf/$\textrm{cm}^2$ 를 갖는 불포화 폴리에스터 폴리머 콘크리트를 이용하여 제작한 C형 시험체에 대한 편심압축 시험을 통하여 폴리머 콘크리트 휨부재의 응력-변형률 관계를 구명하고 등가직사각형 응력블럭의 파라미터 $\alpha$, $\beta$1, ${\gamma}$를 산출하였다. 아울러 인장철근비를 달리하는 5종의 전단스팬비 4.0인 철근 보강 폴리머 콘크리트 보에 대한 휨시험에서 얻어진 극한모멘트 시험값과 C형 시험체 응력-변형률 곡선에서 산출되는 파라미터 $\alpha$=0.61, $\beta$1=0.73 를 이용하여 계산된 이론적인 극한모멘트 값을 비교하여 보았던 바, 인장철근비가 0.50 $\rho$b 이상일때 시험값과 이론값이 비교적 잘 부합됨을 확인 할 수 있었다. 그러나 폴리머 콘크리트 휨 부재에 대한 보다 정확한 설계기준의 마련을 위해서는 압축강도와 크기를 변수로 하는 C형 시험체에 대한 보다 많은 시험을 통한 파라미터의 체계적인 연구가 필요하다.

디지털 게임의 능동서사와 즉흥연기 (Active Narrative of Digital Game and Improvisation)

  • 유희범;성정환
    • 한국게임학회 논문지
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    • 제16권2호
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    • pp.75-86
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    • 2016
  • 연극학을 통한 게임연구는 게임서사의 상호작용적 특성을 인문학적 배경에서 잘 설명해주었다. 이들 연구는 아리스토텔레스의 시학을 바탕으로 게임을 해석하고 있다. 하지만 사용자의 예측 불가능한 서사개입(능동서사)에 의해서 문제를 드러냈다. 본 논문에서는 능동서사가 아리스토텔레스적 모델에 어떠한 영향을 가져다주었는지를 파악하고자 하였다. 그 결과 능동서사는 드라마를 구성하는 질료간의 인과관계를 새롭게 구성한다는 것을 발견했다. 이것은 연극학적으로 보았을 때 '즉흥극'의 한 종류로 정의해 볼 수 있다. 하지만 그 발현의 형태는 행위의 질료와 방식에 의해 근본적인 차이가 있다. 게임의 환경에 특화된 게임 상 즉흥의 형태를 살펴보면 '자가 개성화', '자가 진형화', '기행의 경합', '트롤링', '버그 플레이'등으로 정의해 볼 수 있었다. 마지막으로 게임상 즉흥의 유형들과 예시들을 통해서 게임의 즉흥이 가지는 특성과 이를 통한 발전된 인문학적 게임 해석 모델의 방향성을 제시해 보고자 한다.

사질토 지반에서 말뚝의 수평거동 (Lateral Behavior of Sin811e and Group Piles in Sand)

  • 김영수;김병탁
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 가을 학술발표회 논문집
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    • pp.3-44
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    • 1999
  • This paper discusses the lateral behavior of single and group piles in homogeneous and non-homogeneous(two layered) soil. In the single pile, the model tests were conducted to investigate the effects on ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer, boundary rendition of pile head and tip, embedded pile length, pile construction condition, ground condition with saturate and moisture state in Nak-Dong river sand. Also, in the group pile, the model tests were to investigate the effects on spacing-to-diameter ratio of pile, pile array, ratio of pile spacing, boundary condition of pile head and tip, eccentric load and ground condition. The maximum bending moment and deflection induced in active piles were found to be highly dependent on the relative density, pile construction condition, boundary condition of pile head and tip. Based on the results obtained, it was found that the decrease of lateral bearing capacity in saturated sand was in the range of 31% - 53% as compared with the case of dry sand. Also, in the group pile, a spacing-to-diameter of 6.0 seems to be large enough to eliminate the group effect for the case of relative density of 61.8%, and 32.8%, and then each pile in such a case behaves essentially the same as a single pile. In this study, the program is developed by using the modified Chang method which used p - y method and the exact solution of governing equation of pile and it can be used to calculate the deflection, bending moment and soil reaction with FDM in non-homogeneous soil. In comparing the modified Chang method with field test results, the predict results shows better agreement with measured results in field tests.

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경사진 임플란트 고정체의 응력 분석 (Stress analysis on the implant fixture with the angulated placement)

  • 김창현;강재석;부수붕;오상호;안옥주;강동완
    • 구강회복응용과학지
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    • 제20권2호
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    • pp.71-81
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    • 2004
  • The purpose of this study was to compare the distributing pattern of stress on the finite element models of two units implant prosthesis with one angulated placement of two implant fixtures. The two unit implant crowns simulated to mandibular first and second molars were made. The two kinds of finite element models were designed according to angulation of fixture ($4.0mm{\times}11.5mm$) : Model 1($15^{\circ}$ buccally angulated placement of one fixture on second molar area), Model 2($15^{\circ}$ lingually angulated placement of one fixture on second molar area). Axial loads of 200N were applied to the center of central fossa and to distance of 2mm and 4mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the fixtures, and buccolingual section of implants. The results were as follows: 1. Under axial loading at the central fossa, the stress was distributed along the straight fixture except apical portion, while on buccally or lingually angulated placement, the highest stresses were concentrated in the neck portion on the opposite side of the angulated fixture. 2. With offset distance increasing, the stresses were concentrated greater in buccal neck of lingually angulated fixture than in lingual neck of buccally angulated fixture. From the above results, in designing of the occlusal scheme for implant prosthesis with the angulated fixture, occlusal contacts should be placed to distribute stress axially in maximum intercuspation and to avoid offset force during eccentric movements.

시험조건과 고강도콘크리트의 압축강도 관계에 관한 실험적 연구 (An Experimental Study on the Compressive Strength of High Strength Concrete According to Testing Condition)

  • 진영길;이용수;김광서
    • 한국건축시공학회지
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    • 제2권2호
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    • pp.129-134
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    • 2002
  • The strength and durability of concrete are affected by various factors such as the quality of material, mixing ratio, construction, the method of cure, time elapsed. the condition of test and etc., it is very difficult to pre-estimate the strength of concrete with the use of experimental specimen. The domestic standard of specimen cylindrical type and its sizes are both l0cm$\times$20cm and 15cm$\times$30cm, which are prescribed in KS F2405, and the loading speed is prescribed to test with 2~3kgf/$\textrm{cm}^2$ per second. The loading speed should have great effect on the compressive strength, but in reality in the construction site sometimes the loading speed is applied so dubiously that the value of the compressive strength can be unreliable. And the cross sectional area of a specimen should be level and smooth, otherwise it can be broken at a lower stress than the real strength through the eccentric or intensive working of the load. Capping should be carried out in order to measure the strength correctly. And used for capping are various materials such as capping compound, cement glue, plaster, mechanical grinding and etc. In this study, therefore, I have carried out an experiment on the relationship among the loading speed, the ratio of height to diameter of specimen, the method of capping, and the compressive strength, for the efficient quality control of concrete structures. So this study has been purposed to provide some basic data that can be used effectively at construction sites.

드롭랜딩 시 높이 변화에 따른 인체 분절의 충격흡수 전략에 관한 연구 (The Study of Strategy for Energy Dissipation During Drop Landing from Different Heights)

  • 조준행;고영철;이대연;김경훈
    • 한국운동역학회지
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    • 제22권3호
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    • pp.315-324
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    • 2012
  • The purpose of current study was to investigate the effects of the heights on the lower extremities, torso and neck segments for energy dissipation during single-leg drop landing from different heights. Twenty eight young healthy male subjects(age: $23.21{\pm}1.66yr$, height: $176.03{\pm}4.22cm$, weight: $68.93{\pm}5.36kg$) were participated in this study. The subjects performed the single-leg drop landing from the various height(30, 45 & 60 cm). Force plates and motion-capture system were used to capture ground reaction force and kinematics data, respectively. The results were as follows. First, the ROM at the ankle, knee, hip and trunk was increased with the increased heights but the ROM at the neck was increased in the 60cm. Second, the angular velocity, moment and eccentric work at the ankle, knee, hip, trunk, and neck was increased with the increased heights. Third, the contribution to total work at the knee joint was not significantly different, while the ankle joint rate was decreased and hip and neck rate was increased in the 60cm, and trunk rate was increased with the increased heights. Lastly, the increase in landing height was able to augment the level of energy dissipation not only at the lower extremities but also at the trunk and neck. The findings showed that drop landing affect trunk and neck with lower extremity joints. Therefore, we need to consider that trunk and neck strengthening including stability should be added to reduce sports injury during prevention training.

보행 시 신발의 아웃솔 형태가 하지 관절 운동과 발의 압력에 미치는 영향 (The Effect of Form and Hardness of Outsoles on the Motion of the Lower Extremity Joints and on Foot Pressure during Gait)

  • 김의환;김성섭;권문석;위웅량;임정;정재욱
    • 한국운동역학회지
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    • 제21권2호
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    • pp.223-230
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    • 2011
  • The purpose of this study was to analysis the effect of form and hardness of outsoles on the motion of the lower extremity joints and on foot pressure during gait. The subjects were 15 women(mean age, $48.5{\pm}2.4$ years), who had no serious musculoskeletal, coordination, balance or joint/ligament problems within 1 year prior to the study. The pelvic tilt, joint angles at the lower extremities and the vertical ground reaction force(GRF) were compared during gait with 3 types of shoes (A, B, C) by using one-way repeated ANOVA(p<.05). During gait, the peak tilt angle and the range of motion(ROM) of the ankle and knee joints were found to be significantly different among the 3 types of shoes. The type C shoes showed a significantly lower mean second maximum vertical GRF than types A and B. The curved outsoles of type C shoes, which had a form and hardness different from those of A and B, was designed strategically for walking shoes to provide stability to the Additionally, type C induced the dispersion of eccentric pressure and made the center of pressure roll over to the center line of the foot.

접촉궤도요소로부터 변환된 NORAD TLE를 이용한 정지위성의 안테나 포인팅 (ANTENNA POINTING TO THE GEO SATELLITE USING CONVERTED NORAD TLE FROM OSCULATING ORBITAL ELEMENTS)

  • 이병선;김해연;황유라;김재훈
    • Journal of Astronomy and Space Sciences
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    • 제24권2호
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    • pp.145-154
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    • 2007
  • 접촉 케플러 궤도요소로부터 변환된 NORAD TLE를 정지궤도 위성의 안테나 포인팅에 직접 사용하기 위한 분석을 수행하였다. 일주일에 한번씩 동서방향과 남북방향의 위치유지를 위한 궤도조정을 수행하고 하루에 두 번씩 추력기를 이용한 모멘텀 덤핑을 통해서 궤도가 계속 변하는 통신해양기상 위성에 대해서 변환된 NORAD TLE를 이용한 안테나 포인팅 오프셋 각을 계산하여 위성신호를 수신할 수 있는지 검토하였다. 이를 통해 변환된 NORAD TLE를 사용하여 위성 관제시스템의 안테나 포인팅에 관련된 인터페이스를 간단하게 수행할 수 있음을 보였다. 또한 이심률이 큰 천이궤도에 있어서 위성의 평균 근점각에 따른 변환된 NORAD TLE 값의 차이를 분석하여 천이궤도의 원지점 근처에서의 NORAD TLE 변환 값이 더 좋은 결과를 나타내는 것을 알 수 있었다.

패션 일러스트레이션에서의 콜라주 표현의 특성과 의미 (Characteristics and Meanings of Collage Expressed in Fashion Illustrations)

  • 김순자
    • 한국의상디자인학회지
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    • 제13권4호
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    • pp.111-126
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    • 2011
  • Cultural collage phenomena came to the fore where various differing elements combined to make a reality in the post-modern culture. Collage, a technique with which to express a unique sense of texture has been used since a long time ago by fashion illustrators, finds itself expressed in much more diverse forms and characteristics, and its meanings changed, too. The purpose of this study is to analyze the formative characteristics of collage as expressed in fashion illustrations since 2000s and look into its aesthetic meanings, and in doing so, examine effects of changes along the times that have sought plural diversity on fashion illustrations. This study selected and examined from various collage techniques three collage expression techniques including papier colle, photo montage and assemblage frequently used as techniques of fashion illustrations. Papier colle technique expressed in fashion illustration simplify forms, thereby stressing linear elements, and express lines and planes At the same time, such works provide depth to planar spaces by overlapping objects and putting together differing elements, In fashion illustrations utilizing photo montage more than one images taken from photos are cut up and reconstructed, where illusory and sometimes shocking images are conveyed through particular forms or unrealistic compositions created by casual combination of unrelated images. Unique and eccentric images are conveyed by means of assemblage through the combination of various kinds of heterogeneous materials in fashion illustrations. This not only conveys fashion images sensitively but presents each fragment as objets regardless of its original functions, and attempts at new concepts.

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