• 제목/요약/키워드: 탄성문제

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A Model-Fitting Approach of External Force on Electric Pole Using Generalized Additive Model (일반화 가법 모형을 이용한 전주 외력 모델링)

  • Park, Chul Young;Shin, Chang Sun;Park, Myung Hye;Lee, Seung Bae;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.11
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    • pp.445-452
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    • 2017
  • Electric pole is a supporting beam used for power transmission/distribution which accelerometer are used for measuring a external force. The meteorological condition has various effects on the external forces of electric pole. One of them is the elasticity change of the aerial wire. It is very important to perform modelling. The acceleration sensor is converted into a pitch and a roll angle. The meteorological condition has a high correlation between variables, and selecting significant explanatory variables for modeling may result in the problem of over-fitting. We constructed high deviance explained model considering multicollinearity using the Generalized Additive Model which is one of the machine learning methods. As a result of the Variation Inflation Factor Test, we selected and fitted the significant variable as temperature, precipitation, wind speed, wind direction, air pressure, dewpoint, hours of daylight and cloud cover. It was noted that the Hours of daylight, cloud cover and air pressure has high explained value in explonatory variable. The average coefficient of determination (R-Squared) of the Generalized Additive Model was 0.69. The constructed model can help to predict the influence on the external forces of electric pole, and contribute to the purpose of securing safety on utility pole.

The Experimental Study of Distribution Life-Force Impact on Piles and Landing Pier (잔교식 안벽의 상부와 Pile에 작용하는 파압분포에 관한 실험적 연구)

  • Park, Sang-Kil;Kim, Ki-Hyun;Kim, Woo-Seang;Park, Byung-Yul;Kang, Deok-Hun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.552-556
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    • 2006
  • 항만건설에 있어서 항만의 내부시설 중에서 무엇보다도 가장 중요한 시설물은 선박을 안전하게 접안시켜 하역할 수 있는 안벽시설물이다. 안벽구조 형식의 결정은 항만의 이용목적 등에 따라서 달라지지만 항만의 건설입지조건 등에 의해서도 달라진다. 안벽구조형식 중에서 잔교 식 안벽은 무엇보다도 단기간에 건설이 용이하여 지금까지 각국에서 널리 사용되어 왔고 장래에도 이용도가 증가되리라 생각한다. 최근에는 해안선을 이용한 위락시설이 건설되면서 잔교 식 안벽구조물을 설치하여 보조시설물로 이용하는 경우가 많다. 과거에 설계되어 잔교를 설계할 경우는 일반적으로 항내의 정온이 잘 유지되는 경우에 대해서 설치하는 경우가 많기 때문에 파랑에 의한 반사율과 잔교 상부에 작용하는 양압력을 고려해야할 필요성이 거의 없었다. 그러나 최근에는 태풍이 내습할 경우 기존의 항내로 높은 파랑이 침입하는 경우가 발생하고 있어 항내에서도 잔교의 파괴로 인한 자연재해가 대형화되는 경우가 발생하고 있다. 또, 처음부터 안벽을 설계할 때에 대형화의 잔교 식 안벽구조물을 설치하는 경우도 있다. 이런 잔교 식 안벽 구조물을 잔교의 상부 판에 작용하는 양압력 분포와 잔교 전면의 반사율 등이 구조물의 유지관리 등에 미치는 영향이 매우 크기 때문에 반사율 검토와 양압력을 고려한 설계가 필요하다. 본연구의 대상은 일정 해역에 잔교 식 안벽을 설계하고자 할때 최적의 안벽 설계가 될 수 있도록 수리모형실험을 실시하여 구조물의 안전과 항내정온에 기초가 되는 자료를 도출하고자 하였다. 따라서 본 수리모형실험으로 인한 연구는 잔교 식 안벽에 대한 반사율과 상부에 작용하는 양압력, 잔교말뚝(pile)에 작용하는 수평압력을 검토하여 잔교 식 안벽 설계에 기초자료를 제공하고자 한다. 혈청을 이용한 동결보존을 대체할 수 있을 것으로 생각된다.지에 더해주면 세포의 증식이 개선될 것이다. 그래서 몇 가지 첨가물을 이용해 세포의 증식력에 변화가 나타나는지 알아보았다. 첨가물을 이용한 실험에서 IGF-I의 경우 장기간 배양에서 세포의 수를 안정적으로 유지하고 계대 횟수를 증가시키는 효과를 보였다. 이는 IGF-I이 어느정도 세포의 증식을 유지시켜주는 역할을 하기 때문인 것으로 생각된다. 무혈청 배지에서 비적응 CHO 세포의 계대 배양에 한계가 있는 것은 세포주기가 멈추기 때문인 것으로 생각된다. 세포주기가 멈추는 growth factor와 같이 세포의 증식을 지속적으로 유도할 수 있는 물질이 무혈청 배지에서는 부족하기 때문인 것으로 생각되고, IGF-I과 같은 첨가물을 통해 극복할 수 있는 문제라고 여겨진다.관점과 주거교육가치관 요소와의 관계를 알아본 결과, 전통적 관점은 주거교육가치관 요소 중 오직 주거관리적 요소와 관계가 있었으나 그 정도는 낮으며 실천적 관점과 구조적 관점은 주거가치관의 각 요소에 따라 약간 다르기는 했으나 주로 보통의 관계를 보였다.군 순으로 높게 관찰되었다. 이상의 결과를 종합할 때, 임상에서 니켈-티타늄 합금 와이어에 굴곡을 부여하기 위해 열처리하는 경우 초탄성 특성은 유지될 수 있으나, 부하-변위 곡선의 상방 증가가 나타나므로, 와이어에 의한 교정력이 증가될 수 있음에 유의하여야 한다. $day^{-1}$인 인공습지), scenario 2(면적 4.2ha인 저류지)가 각각 연평균 6.9%, 4.8%, 7.1%의 감소를 보였다. TN은 4.7%, 3.4%, 13.4%의 삭감율을 나타내었으며, TP는 5.6%, 3.9%, 7.3%의 삭감율을 나타내었다. 본 연구에서는

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Analysis on the Physical Property of Para-Aramid Filament according to the ATY processing Cordition (ATY 공정조건에 따른 Para Aramid 필라멘트의 물성분석)

  • Kim, Seung-Jin;Park, Mi-Ra;Ma, Hye-Young;Choi, La-Hee;Park, Sung-Woo;Kang, Yoon-Hwa
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2011.03a
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    • pp.29-29
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    • 2011
  • 아라미드 섬유는 열에 강한 튼튼한 방향족 폴리아마이드 섬유이다. 아마이드는 "85%이상의 아미드(CO-NH)기가 두 개의 방향족 고리에 직접 연결된 합성 폴리아미드로부터 제조된 섬유"로 정의된다. 아라미드 섬유는 크게 파라계와 메타계로 대별되는데 본 연구에서 사용한 파라계 아라미드는 인장강도, 강인성, 내열성이 뛰어나며 고강력 고탄성률을 지니고 있다. 일반적인 유기 섬유와는 다른 우수한 성질을 바탕으로 부직포, UD laminatig, staple 등의 형태로 크게 섬유보강 고무 복합재료 등의 각종 복합재료, 로프, 케이블, 방탄방호용과 같은 산업자재의 용도로 자동차, 우주항공, 정보통신, 국방, 등 다양한 관련 산업분야에서 사용이 확대되고 있는 고부가 소재이며 가격대비 성능비가 우수하기 때문에 세계적으로 산업용 섬유 및 초고성능 섬유시장에서 비중이 증가될 것으로 예상되고 있다. 본 연구에서는 Para-Aramid 필라멘트를 이용하여 ATY를 생산할 때 제조공정조건에 따른 ATY 물성을 알아보고 고강도를 요구하는 방화복, 고무 보강용 섬유 등의 소재에 맞는 ATY 사가공 최적공정조건을 도출하여 체계화된 data-base를 구축하여 생산성 향상 및 품질개선과 함께 산업자재용 직물개발에 응용하고자 한다. 아라미드를 ATY로 제조할 경우, 표면에 생기는 loop로 인하여 타소재와 접착시, 접착제 담지 성능이 향상되어 접착력이 상승되는 반면, 아라미드 ATY가 기존의 아라미드의 물성보다 저하되는 약점을 가지고 있으므로 이를 보완하기 위해 본 연구에서는 ATY 제조공정에서 중요 공정인자인 사속, heater 온도, over feed ratio를 변화시켜 시료를 제조하여 이들의 물성을 분석하여 최적의 물성을 갖는 ATY 사가공 공정을 도출함으로써 물성이 저하되는 문제를 보완 가능할 것으로 기대된다. 물성분석은 강신도, 초기탄성률을 각각 측정하여 인장특성을 확인하였으며, 습열수축률과 건열수축률을 측정하여 시료의 열수축률에 대해 측정을 하였다. 표면의 루프 발현 정도를 보기 위하여 Crimp Rigidity(CR%), 형태 불안정성(instability)등을 측정하였으며, 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 표면특성을 측정하였다.

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Iguana motion synthesis using soft body simulation (연체 시뮬레이션 기반 이구아나 동작 생성)

  • Moon, Jaeseok;Kwon, Taesoo
    • Journal of the Korea Computer Graphics Society
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    • v.23 no.1
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    • pp.33-38
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    • 2017
  • In this paper, we suggest a method to simulate high-quality iguana animation by using low-quality motion capture data. Iguana motion data captured using a small number of markers cannot express its movement precisely, and even with a realistic skin mesh, it shows unnatural movement because of limited degrees of freedom. In order to solve this problem, we propose to simulate a natural and flexible movement by applying a soft-body simulation technique which models the movement of an iguana according to muscle forces and body's elastic forces. We construct a motion graph from the motion capture data to describe the iguana's various movements, and utilize it to select appropriate movements when the iguana moves. A target point on a terrain is set from the user's input, and a graph path is planned based on it. As a result, the input movement of iguana walking on a flat ground transforms to a movement that is adapted in an online manner to the irregular heights of the terrain. Such a movement is used to calculate the ideal muscle lengths that are needed for soft-body simulation. Lastly, a tetrahedral mesh of the iguana is physically simulated to adapt to various situations by applying a soft-body simulation technique.

Evaluation of the Cytotoxicity and Mechanical Strength of Dental Duplex Stainless Steel Orthodontic Wire (치과 교정용 듀플렉스 스테인리스 스틸 와이어의 기계적 강도 및 세포독성 평가)

  • Lee, Myung-Kon;Kim, Chi-Young
    • The Journal of the Korea Contents Association
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    • v.10 no.9
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    • pp.309-317
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    • 2010
  • The stainless steel wire is extensively used for the orthodontic treatment. But, the stainless steel wire that has commonly superior corrosion resistance has caused hypersensitive reaction or allergy as side effects because of corrosion in the oral environment. For improving the problem of corrosion, we was evaluated the suitability of the duplex stainless steel(DSS) as orthodontic wire through this study. The DSS wire was evaluated the mechanical strength and bio-stability for suitability and bio-compatibility as orthodontic wire. In this work, the DSS and stainless steel(SS) as common use of medical grade were prepared for the tensile strength test. The DSS wire were treated by heat. and Temperature conditions of the heat treatment were $28^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$, $700^{\circ}C$, $800^{\circ}C$, $900^{\circ}C$, respectively. And the DSS wires that treated by heat on the optimum temperature condition were conducted the bending moment test and calculated the S-Max value and the modulus of elasticity. For evaluating the bio stability, each materials were conducted in vitro test for measuring the cell survival rate. The most interesting results was that the tensile strength test of SS wire($8.17\times10^4\;N/mm^2$) and DSS wire($8.05\times10^4\;N/mm^2$) that treated at $500^{\circ}C$ by heat were similar in mechanical strength. In the bio-stability study, the DSS has no cytotoxicity (p=0.05) Thus, we could make a conclusion that the duplex stainless steel wire has vastly superior corrosion resistance was suitable as orthodontic wire.

An Analytical Study on the Buckling of Orthotropic Plates and Local Buckling of Compression Members (직교이방성 판의 좌굴 및 압축재의 국부좌굴에 대한 해석적 연구)

  • Choi, Jin-Woo;Lee, Kang-Yeon;Park, Jung-Hwan;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.3 no.1
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    • pp.21-28
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    • 2012
  • In this paper, we present the analytical study results pertaining to the buckling of the orthotropic plates and local buckling of structural compression members composed of orthotropic plate components. Fiber reinforced polymeric plastic (FRP) materials, have many advantages over conventional structural materials such as steel and concrete. The advantages of the FRP materials are high specific strength and stiffness, high corrosion resistance, right weight, etc. Among the various manufacturing methods, pultrusion process is one of the best choices for the mass production of structural plastic members. Since the major reinforcing fibers are placed along the axial direction of the member, this material is usually considered as an orthotropic (tranversely isotropic, more specifically) material. However, pultruded fiber reinforced plastic structural members have low modulus of elasticity and are composed of orthotropic thin plate components the members are prone to buckle. Therefore, stability is an important issue in the design of the pultruded FRP structural members. In this paper, the buckling of orthotropic plates and the local buckling of pultruded FRP structural members are investigated by following the previous research results and the local buckling strength of the member produced in the domestic manufacturer is found.

A Study of Meshless Method Programming (무요소법 프로그래밍에 관한 연구)

  • 김학수;배동명
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.2
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    • pp.110-118
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    • 2002
  • The element free Galerkin method has been suggested by Belyschko, etc. it is applied for linear elastic analysis of solid problems and its convergence characteristics and stability are shown according to the weight function, influence domain and scattered points. The various numerical examples are performed to check the efficiency of 1D EFG and 2D EFG program by changing factors. As a result it have the best results when it used the cubic spline weight function and the scaling parameter d$_{max}$=2. These programs were developed by mixed language programming method using Visual Basic and the C language. so it is fast and efficient. and visually shown the result.t.

A probabilistic assessment of ground condition prediction ahead of TBM tunnels combining each geophysical prediction method (TBM 현장에서 막장전방 예측기법 결과의 확률론적 분석을 통한 지반상태 평가)

  • Lee, Kang-Hyun;Seo, Hyung-Joon;Park, Jeongjun;Park, Jinho;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.3
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    • pp.257-272
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    • 2016
  • It is usually not an easy task to counter-measure on time and appropriately when confronting with troubles in mechanized tunnelling job-sites because of the limitation of available spaces to perform those actions with the existence of disk cutter, cutter head, chamber and other various apparatus in Tunnel Boring Machine (TBM). So, it is important to predict the ground condition ahead of a tunnel face during tunnel excavation. Efforts have been made to utilize geophysical methods such as elastic wave survey, electromagnetic wave survey, electrical resistivity survey, etc for predicting the ground condition ahead of the TBM tunnel face. Each prediction method among these geophysical methods has its own advantage and disadvantage. Therefore, it might be needed to apply several geophysical methods rather than just one to predict the ground condition ahead of the tunnel face in the complex and/or mixed grounds since those methods will compensate among others. The problem is that each prediction method will give us different answer on the predicted ground condition; how to combine different solutions into a most reasonable and representative predicted value might be important. Therefore, in this study, we proposed a methodology how to systematically combine each prediction method utilizing probabilistic analysis as well as analytic hierarchy process. The proposed methods is applied to a virtual job site to confirm the applicability of the model to predict the ground condition ahead of the tunnel face in the mechanized tunnelling.

Derivation and verification of electrical resistivity theory for surrounding ground condition prediction of TBM (TBM 주변 지반상태예측을 위한 전기비저항 이론식 유도 및 검증)

  • Hong, Chang-Ho;Lee, Minhyeong;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.1
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    • pp.135-144
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    • 2020
  • Since the depth of tunneling with tunnel boring machine (TBM) becomes deeper and deeper, the expense for site investigation for coring and geophysical survey increases to obtain the sufficient accuracy. The tunnel ahead prediction methods have been introduced to overcome this limitation in the stage of site investigation. Probe drilling can obtain the core and borehole images from a borehole. However, the space in TBM for the probe drilling equipment is restricted and the core from probe drilling cannot reflect the whole tunnel face. Seismic methods such as tunnel seismic prediction (TSP) can forecast over 100 m ahead from the tunnel face though the signal is usually generated using the explosive which can affect the stability of segments and backfill grout. Electromagnetic methods such as tunnel electrical resistivity prospecting system (TEPS) offer the exact prediction for a conductive zone such as water-bearing zone. However, the number of electrodes installed for exploration is limited in small diameter TBM and finally the reduction of prediction ranges. In this study, the theoretical equations for the electrical resistivity survey whose electrodes are installed in the face and side of TBM to minimize the installed electrodes on face. The experimental tests were conducted to verify the derived equations.

Development of the Novel Cosmetics Impregnation Material and Study on Makeup W/O Emulsions using It (새로운 화장료 함침재의 개발과 이를 활용한 메이크업 유중수형 에멀전에 관한 연구)

  • Kang, Sungsoo;Kim, Hyeon Jeong;Oh, Se Woong;Park, Sang Wook;Kim, Kyung Seob
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.1
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    • pp.27-33
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    • 2017
  • Up to now, better convenience and portability were important factors in the development of the cosmetics and achieved by immersing low viscosity makeup water-in-oil (W/O) emulsion into the impregnation material. Conventionally, polyurethane sponges having porous network structures and hard textures have been dominantly used. It has an advantage of easy to manufacture because of its good impregnation property due to its structural characteristics. However, it releases emulsion too much at first use, and shows unexpected dramatic decline during the period of usage. In this study, we studied on makeup W/O emulsion with various features and developed the new foaming sponge, which showed excellent formability and proper absorption and discharge ability of cosmetic composition through the combination of natural rubber (NR) and styrene butadiene rubber (SBR). This impregnation material is characterized by the softness of elasticity like a rubber, high elongation and uniform output. We confirmed that this material can be used to develop makeup products using various oils depending on polarity and controlling the viscosity of the makeup W/O emulsion. Thus, it is concluded that these results provide valuable information in developing new cosmetics impregnation materials.