• 제목/요약/키워드: Skeletal Structure

검색결과 191건 처리시간 0.022초

Fourier descriptor를 이용한 주문진표준사의 형상특성분석 (Analysis on Particle Shape Characteristics of Jumunjin Sand using Fourier Descriptor)

  • 민덕기;김성곤
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.1182-1189
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    • 2010
  • The mechanical behavior of a granular material is governed by the applying effective stresses and its skeletal structure which is considered to be the packing of particles giving overall density and degree of anisotropic. Factors that affect soil packing are the particle size, size distribution and shape, and the arrangement of grain contact. Soil particle size and shape are the most important factor, but difficult to quantify. In this study, 2D Fourier analysis is applied to quantify the shape of granular particles. Jumunjin sand was used in the experiment and particle images are captured using an optical microscope. The results showed that three lower order Fourier descriptor are closely related with roundness, sphericity of the granular particle. Also statistical approach is used to determine roundness, form factor, elongation ratio, roughness of Jumunjin sand.

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도마뱀 생체 데이터를 이용한 속보 걸음새 생성 (Trotting Gait Generation Based on the Lizard Biometric Data)

  • 김창회;신호철;이흥호
    • 전기학회논문지
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    • 제62권10호
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    • pp.1436-1443
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    • 2013
  • A variety of studies on imitating the skeletal structure and the gait of legged animals have been done in order to develop walking robots which have an ability to adapt to atypical environments. In this paper, we analyzed the gait of a Bearded dragon lizard using the motion capture system, proposed a calibration scheme of the motion data and generated the trotting gait of a lizard based on the calibrated data. Also, we constructed the dynamic model based on the biometric data of a Bearded dragon lizard and applied the trotting gait of the lizard to the dynamic model. We verified the validity of the gait with the commercial dynamic simulation software.

Four New Species of the Genus Hyattella (Dictyoceratida: Spongiidae) from Korea

  • Sim, Chung Ja;Lee, Kyung Jin
    • Animal Systematics, Evolution and Diversity
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    • 제30권1호
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    • pp.16-21
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    • 2014
  • Four new species of the genus Hyattella (Dictyoceratida: Spongiidae); H. sinchangensis n. sp., H. mara n. sp., H. chuja n. sp. and H. lendenfeldi n. sp., were collected from Jeollanam-do and Jeju-do, Korea. Hyattella sinchangensis n. sp., H. mara n. sp., H. chuja n. sp. and H. grobosa Lendenfeld, 1889 are very similar to each other in some characters. However, Hyattella sinchangensis n. sp. characterized by no special dermal lamella and no tertiary fibres, and more thin secondary fibres than H. globosa. Hyattella mara n. sp. is differs in having well developed dermal lamella, slightly fasciculated primary fibres, and thick tertiary fibres. Hyattella chuja n. sp. differs in surface characters with a slightly elevated part, skeleton with abundant spongine, and very complex meshes. Hyattella lendenfeldi n. sp. is similar to H. tenella (Lendenfeld, 1889) in skeletal structure, thickness of primary and secondary fibres, but differs in growth form.

교정치료시기에 관한 연구 (ORTHODONTIC TREATMENT TIMING)

  • 장영일
    • 대한치과의사협회지
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    • 제22권12호통권187호
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    • pp.1067-1073
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    • 1984
  • In the treatment of functional orthodontic problems, timing is not an issue. All orthodontists start as soon as the condition is recognized. However, there is an active dialogue concerning treatment timing for structure problems. The major points in contention center around the operator's ability is to control the growth of the facial bones and to maintain post-treatment tooth position through the maturation period (especially when this position was gained by techniques involving arch expansion or distal driving of posterior segments). Factors taken into account to determine the best time of orthodontic treatment include diagnosis, interception, growth rate, patient cooperation, eruptive state and treatment period. With those exceptions of all functional problems, mild dental discrepancies and skeletal deficiencies with a predictably excellent growth potential (early treatment), the period immediately following the eruption of the permanent second molars is the period during which most orthodontic treatment should be initiated. At this time the full volume of tooth substances is present, the individual growth pattern in well established, there are sufficient teeth to receive nearly any type of appliances and the patient can easily tolerate the wearing of appliances.

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최소노름 응력장를 이용한 구조물의 소성해석법 (Plastic Design Method for Steel Skeletal Structure based on the Least Norm Stress Field)

  • 이승재
    • 한국공간구조학회논문집
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    • 제6권3호
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    • pp.131-137
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    • 2006
  • 본 연구는 소성이론의 하계정리를 이용하여 구조설계자의 부재의 응력장에 대한 만족도를 고려한 구조해석 프로그램을 제안한다. 구조물에 작용하는 계수하중과 평형을 이루는 임의의 응력장 중에서 최소노름 응력장을 이용하여 찾아내고, 구조물의 모든 부위에서 부재의 설계내력이 부재력을 상회하도록 부재 단면을 결정하는 방법을 제안한다.

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실리카 에어로겔의 표면 개질 (Surface Modification of Silica Aerogels)

  • 현상훈;이찬호;김동준
    • 한국세라믹학회지
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    • 제33권12호
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    • pp.1319-1324
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    • 1996
  • Silica aerogels were synthesis by the sol-gel-supercritical drying process using isopropanol as a solvent. Effets of the heat-treatment and the surface modification through propoxylation on the structural reinforcement as well as the surface hydrophobic/hydrophilic characteristics of aerogels were investigated. Silica aerogels synthesized by supercritical drying were hydrophobic but aerogels heat-treated above 20$0^{\circ}C$ were transformed to be hydrophilic. In particular it was found that the skeletal structure of aerogels heat-treated at 50$0^{\circ}C$ was strong enough not to crack after adsorbing a large amount of water vapor. Hydrophilic aerogels modified by propoxylation at 28$0^{\circ}C$ for 20 h were reversed to the hydrophobic form. Transition between hydrophobicity and hydrophilicity was reversible. The hydrophobicvity and the hydrophilicity of silica aerogels were attributed to the Si-Oh bond and the nonpolar C-H bond groups of orgainc species respectively.

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Palmar Hand Wound Coverage with the Free Flaps

  • Roh, Si Young;Lee, Kyung Jin;Lee, Dong Chul;Kim, Jin Soo;Yang, Jae-Won
    • Archives of Reconstructive Microsurgery
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    • 제23권2호
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    • pp.45-50
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    • 2014
  • Palmar soft tissue defects are best reconstructed using a replacement flap of proper size with adequate soft tissue stability for mechanical resistance as well as with protective sensation. Reconstructive approaches are dictated by injury mechanism, defect size and location, and the status of the wound bed and tendino-skeletal structure. While uninjured portions of the hand can be used as a source for local flaps, the use of free flaps allows for maximal access for selection of the most ideal replacement tissue for the defect to be restored as close to the initial state as possible. Here, we review the garden variety of free flaps used in reconstruction of palmar soft tissue defects.

Two New Marine Sponges of the Genus Halichondria (Halichondrida: Halichondriidae) from Uljin, Korea

  • Kang, Dong-Won;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • 제27권1호
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    • pp.19-23
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    • 2011
  • Two new marine sponges, Halichondria jangseungenesis n. sp. and H. nagokenesis n. sp., of the family Halichondriidae, were collected from Uljin-gun, Gyeongsangbuk-do, Korea by SCUBA diving during the period from Apr 2007 to Aug 2007. Based on their spicule composition and skeletal structure, H. jangseungenesis n. sp. appears to have a close similarity with H. panicea (Pallas, 1766); however, they differ in length of spicule. The spicule length of oxea of H. jangseungenesis n. sp. is shorter than that of H. panicea. Based on their spicule composition and growth form, H. nagokenesis n. sp. is quite similar to H. cylindrata Tanita and Hoshino, 1989; however, but they differ in length of spicule. The spicule length of oxea of H. nagokenesis n. sp. is longer than that of H. cylindrata.

경직상태의 근육막에 MgADP를 첨가시킨 결과에 대한 연구 (A Study on The Effect of Added MgADP to The Rigor Muscle Membrane)

  • 김덕술
    • 한국응용과학기술학회지
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    • 제24권4호
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    • pp.362-368
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    • 2007
  • To study the relationship between elementary biochemical states and structural states of the actomyosin crossbridges in muscle, the effects of binding of MgADP to myosin heads in the rigor muscle were examined by X-ray diffraction using synchrotron radiation. X-ray diffraction studies have been made to investigate the effects of binding of ADP on the structure of glycerinated rabbit skeletal muscle in the rigor state. The intensity increase was accompanied by a slight but distinct decrease in the 5.9 am layer-line intensity close to the meridian. These results strongly suggest that myosin heads altered their attached conformation in the proximal end toward the plane perpendicular to the fiber axis when MgADP was bound to them. We found that the intensity of the 14.5 nm-based meridional reflections increase by 20-50% when MgADP was added to the rigor muscle in the presence of hexokinase and myokinase inhibitor.

Two New Sponges of the Genus Haliclona (Demospongiae: Haplosclerida: Chalinidae) from Korea

  • Kang, Dong-Won;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • 제23권2호
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    • pp.169-173
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    • 2007
  • Two new marine sponges in the family Chalinidae, Haliclona (Haliclona) uljinensis n. sp. and Haliclona (Reniera) hongdoensis n. sp., are collected from Uljin and Hongdo Island, Korea during 2004-2007. H. (H.) uljinensis n. sp. is closely related to H. (H.) oculata in type of spicules. However, ectosomal skeleton of H. (H.) uljinensis n. sp. is reticulated and isodictyal reticulated type but H. (H.) oculata has not any dermal specialization in skeleton. The growth form of H. (H.) uljinensis n. sp. is thin encrusting with numerous cylindrical tubes on the surface but H. (H.) oculata is solid branch form. Haliclona (R.) hongdoensis n. sp. is closely related to H. (R.) aquaeductus in skeletal structure and growth form. However, oxeas of H. (R.) hongdoensis n. sp. are larger than H. (R.) aquaeductus's.