• 제목/요약/키워드: Rough Ground

검색결과 91건 처리시간 0.024초

무당개구리 (Bombina orientalis) 진피 상처치유반응의 형태적 분석 (Morphological Analysis of the Dermal Wounds Healing Responses in Bombina orientalis)

  • 정문진;문명진
    • Applied Microscopy
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    • 제28권3호
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    • pp.379-390
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    • 1998
  • Dermal wound healing responses in the skin of the toad, Bombina orientalis, were examined using transmission electron microscopy. At 12 hours after wounding, debridement and collagenolysis occurred in damaged dermis. Histocyte has a large nucleus and long cytoplasm process. Phagocytic vesicle and lysosome were observed in the cytoplasm. Damaged blood cells were transformed spindle to irregular shape. Autolysis was observed in their cytoplasm. Histocytes are found in poly-band. The irregularly shaped nucleus is located peripheral region in cytoplasm. At 2 days after wounding, partial aggregation of blood cells is observed. Phagocytic, activity is observed in histocyte and collagenolytic collagen fibers are scattered. Fibroblast is observed in the dermis at 3 days after wounding. Clusters of ribosomes and some short cisternae of rough-surfaced endoplasmic reticulum are found in the cytoplasm. In histocyte at 7 days post wounding, various size granules composed of moderately dense material are found the cytoplasm. In this period histocyte is round to rod in profile, with slender processes projecting from the surface. At 7 day after injury, it was observed that formation of connective tissue fibers and amorphous ground substance in regenerating skin.

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자동차부품(시트,도어) 6축 진동 재현을 위한 가진 프로파일 생성 기법 (Generation of the Input Profile for Fatigue Vibration Testing in MAST System)

  • 김찬중;백경원;이봉현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.413-418
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    • 2005
  • Vibration test using the MAST(Multi Axial Simulation Table) is more reliable test than conventional testing process focused on one directional vibration test. The former test could be possible with a advanced control algorithm and hardware supports so that most of the operation is automatically conducted by MAST system itself except the input information that is derived from the measured data. That means the reliability of the vibration test is highly depended on the input profile than any other cases before. In this paper, the optimal algorithm based on energy method is introduced so that the best combination of candidated input PSD data could be constructed. The optimal algorithm renders time information so that the vibration fatigue test is completely possible for any measured signals one wants. The real road test is conducted in short intervals containing some rough roads and the candidated input PSD is obtained from the extra road in proving ground. The testing is targeted for the electronically operated door and seat.

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애리조나 주의 F. L. Wright 주택작품 디자인 특성 분석 (A Study on the Analysis of Design Characteristic of Works of Frank Lloyd Wright in Arizona State)

  • 황용운
    • 한국실내디자인학회논문집
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    • 제27권3호
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    • pp.90-99
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    • 2018
  • The purpose of this study is to study how F.L. Wright reflected the climatic properties and materials of the region into creative ways of designing his architecture. The research method examined the design methods and use of materials by Wright in existing research literature and compares the space plans of housing works in Arizona. The research results will be summarized as follows : 1) For two-story houses, pilotis was used to avoid the hot air and the walls on the ground floor were often planned as thick wall. 2) In the fifties, F.L. Wright's design method changed in a circle from the vertical and horizontal lines. 3) F.L.Wright's Architectural form concepts and design concepts were extracted from local symbolic forms and natural forms. 4) F.L.Wright avoided Arizona's direct light but Indirect sunlight enters into the interior space. 5)External space was expressed as a closed space, while internal space was expressed as an open space. It's like an organic space. 6) Most of the housing materials used are stone and cement from rough deserts, and wood with low heat conductivity and thick concrete blocks to prevent the sunlight from rising above.

양방향말뚝 재하시험을 통한 현장타설말뚝의 연직지지력 설계정수 산정 (Evaluation of Design Parameters for Axial Bearing Capacity of Drilled Shafts by Bi-directional Loading Tests)

  • 정경자;조종석;김명모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 추계 학술발표회
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    • pp.574-584
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    • 2006
  • Bi-directional loading test data are available to evaluate the design parameters which reflect the characteristics of a construction method and the variations of ground at the site where drilled shafts are installed. The method to obtain the design parameters of a real bridge by hi-directional loading test was introduced. The plans of multi-level testing and installation of measuring instruments should be made according to the rough estimation of axial bearing capacity, the length of pile, and the construction method. While the relationship between end bearing resistance and displacement was obtained directly from the hi-directional loading test, the relationship between unit side resistance and displacement was calculated through the measuring values. 1% displacement of pile diameter was adopted as the criteria of failure for ultimate resistance. As the settlement of pile head at the total ultimate bearing capacity obtained from these method was less than 1.5 % of pile diameter, this method was conservative to use in the field.

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비정형 건축물 외장패널의 최적화에 관한 연구 (A Study on the Optimization of the Free-Form Buildings Façade Panels)

  • 임장식;옥종호
    • 한국CDE학회논문집
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    • 제19권2호
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    • pp.91-102
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    • 2014
  • The outer surface of an irregular structure contains panels with two-directional curvature called NURBS. To construct these forms of exterior materials, complex geometric surface should be divided into forms and sizes that can be manufactured and constructed. Because the bigger the curvatures of these divided exterior panel, the more expensive the construction costs, these complex two-directional curvatures should go through optimal process of reinterpretation to minimize the curved surfaces with complex two-directional curvatures. Yet, to gain higher ground in technological competition in the field of irregular structure construction, companies do not share know-how that they obtained. Accordingly, small construction and design companies have trouble calculating even rough estimate and cannot adjust expected construction cost based on comparison of design alternatives. Given this situation, this study conducted the research that can support decision-making in the design stage of the construction and provide basic material for optimal range to reduce manufacturing cost by the minimizing the distorted plane of the irregular structure.

연삭가공조건에 따른 티타늄 합금의 물성치 향상에 관한 연구 (A Study on the Improvement of Physical Properties for Titanium Alloy by the Grinding Conditions)

  • 김원일;이윤경;왕덕현;허순
    • 한국산업융합학회 논문집
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    • 제4권3호
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    • pp.237-242
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    • 2001
  • Ti-6Al-4V alloy can be obtained the stability of organization and product treasure, the evaluation of the cutting ability and the mechanical characteristics after the heat treatment of annealing, solution and aging. The difficulty in machining titanium alloy is how treat the heat generated during the process. Because the heat conductivity of titanium alloy is regardfully low, the heat generated during grinding is accumulated in workpiece. and it causes the increasing of grinding wheel grits' wear and makes the ground surface rough. So, these characteristics in grinding of titanium alloy will change the mechanical properties of the titanium alloy. From this study. the mechanical characteristics of annealed one and solution and aging one treated Ti-6Al-4V alloy after grinding was concerned with checking out the bending strength and hardness. For the result, both of bending strength and hardness were increased at the burned area on the surface. Roughness value was remarkably high at the table speed of 10m/min.

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다양한 예측기법을 이용한 현장타설말뚝의 최적길이 산정 (Estimation of Optimum Pile length Using Various Prediction)

  • 최영석;임형준;송명준;장학성
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.700-707
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    • 2008
  • As plan connecting island to island or island to land is needed, a lot of long-span bridge is being designed lately in Southern part of Korea. With development of pile equipment, overhanging large-scaled concrete pile are adopted to foundation type of main tower or pylon. About the number of 15~30 group piles per tower foundation is designed to resist long-spaning super-structure load, but by restricted condition of site investigation cost, a few boring-hole tests are performed to identify sub-ground layers. Up to now, direct-curved method connecting two or three known boring logs and representative interval method are usually used to evaluate unknown depth and rock properties at locations where piles are constructed. Because this approach is not logical and so rough, much difference occurs between designed length of piles and real length of it. In this paper, using a lot of various prediction method(reciprocal distance method, inverse square distance method and kriging method etc.), we suggest optimum length of group piles.

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다각 보행로보트의 순응 제어를 위한 힘의 최적 분배 (Optimal Force Distribution for Compliance Control of Multi-legged Walking Robots)

  • 라인환;양원영;정태상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.874-876
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    • 1995
  • Force and compliance control has been used in the control of legged walking vehicles to achieve superior terrain adaptability on rough terrains. The compliance control requires distribution of the vehicle load over the supporting legs. However, the constraint equations for ground reaction forces of supporting legs are generally underdetermined, allowing an infinite number of solutions. Thus, it is possible to apply an optimization criteria in solving the force setpoint problem. It has been observed that the previous force setpoint optimization methods sometimes cause a system stability problem and/or the load distribution among supporting legs is not well balanced due to a memory effect on the solution trajectory, This paper presents an iterative force setpoint method to solve this problem using an interpolation technique. By simulation it was shown that an excessive load unbalance among supporting legs and the memory effect in the force trajectory are alleviated much with the proposed method.

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Box-Cox 변환에 의한 I-D-F 곡선의 평활화 (The Smoothing of Rainfall Intensity - Duration - frequency Relationships curve by the Box-Cox Transformation)

  • 이희창;성기원
    • 한국수자원학회논문집
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    • 제36권2호
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    • pp.153-159
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    • 2003
  • I-D-F곡선을 유도할 때 강우자료의 보유연한이 충분하지 않을 경우 지속시간별 강우강도의 변화가 매끄럽게 연결되지 못하는 경우가 발생하기도 한다. 특히 곡선에서, 상대적인 장시간에 강우강도가 크게 되는 문제는 실무적으로 I-D-F 곡선을 이용하는데 큰 혼란을 야기 시킨다. 본 연구에서는 강우자료를 Box-Cox변환을 이용하여 지속시간과 강우강도의 상관관계를 통해 이러한 문제를 해결하는 방법을 제시한다. 산청과 영천의 강우자료에 대한 분석결과 Box-Cox 변환의 실효성을 확인할 수 있었다.

이동 로봇의 서스펜션 댐핑계수 변화에 따른 장애물이 있는 경사로 주행에 관한 연구 (Study on Driving a Bumped Slope of Mobile Robot According to Changing the Damping Coefficient of Suspensions)

  • 전봉수;김자영;이지홍
    • 로봇학회논문지
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    • 제11권2호
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    • pp.83-91
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    • 2016
  • Most of outdoor mobile robots have a suspension on each wheel in order to relieve the shock by ground obstacles and to improve the driving stability. Typically, in the actual operations, the suspensions have been used under a given set of conditions as all the damping and spring coefficients of the suspensions are fixed. However, it is necessary to readjust the coefficients of the suspensions according to surface conditions that may cause the unstable shaking of a robot body at high speed driving. Therefore, this paper is focused on the mobility analysis of an outdoor robot when the coefficients of suspensions (in particular, damping coefficients) are changed while driving on an uneven road surface. In this paper, a semi-active suspension with twelve damping coefficient levels was used and a small sized vehicle with the suspensions was employed to analyze the mobility dependent on a change of the damping coefficient. And the mobility was evaluated through driving experiments on a bumped slope.