• 제목/요약/키워드: Two Segment Leg

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A new cyclopoid copepod from Korean subterranean waters reveals an interesting connection with the Central Asian fauna (Crustacea: Copepoda: Cyclopoida)

  • Karanovic, Tomislav;Yoo, Hyunsu;Lee, Wonchoel
    • Journal of Species Research
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    • 제1권2호
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    • pp.156-174
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    • 2012
  • Monchenkocyclops gen. nov. was erected to accommodate M. changi sp. nov. from South Korea (type species), M. mirabdullayevi sp. nov. from Kazakhstan, M. biarticulatus (Monchenko, 1972) comb. nov. from Uzbekistan, and M. biwensis (Ishida, 2005) comb. nov. from Japan. The latter species was originally described from surface-water habitats of the ancient Lake Biwa in the genus Diacyclops Kiefer, 1927, while two Central Asian species were previously collected from groundwater habitats and assigned to the genus Acanthocyclops Kiefer, 1927. Monchenkocyclops changi is also found in subterranean waters, and described here in detail. It is morphologically most similar to its Uzbek congener (not to the Japanese one), which rises some interesting zoogeographical questions about the disjunct distribution of this genus. Range fragmentation is a more plausible explanation for this distribution pattern than range expansion, and we emphasize four lines of evidence that support this hypothesis. Four species of Monchenkocyclops share not only the same segmentation of the swimming legs, but also the exact same armature formula of all swimming legs, in addition to many other morphological characters, such as the caudal rami shape and armature, absence of exopod on the antenna, similar shape of the seminal receptacle, fifth leg, etc. They can be distinguished mostly by the relative length of different armature elements, such as the innermost terminal caudal setae, and inner setae and apical spines on the third endopodal segment of the fourth leg. A dichotomous key to species is provided.

하지의 동역학 모델 (A Dynamic Model of the Human Lower Extremity)

  • 최기영;손권;정민근
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1993년도 춘계학술대회논문집
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    • pp.1-9
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    • 1993
  • A human gait study is required for the biomechanical design of running shoes. A tow-dimensional dynamic model was developed in order to analyze lower extremity kinematics and loadings at the right ankle, knee, and hip joints. The dynamic model consists of three segments, the upper leg, the lower leg, and the foot. Each segment was assumed to be a rigid body with one or two frictionless hinge joints. The lower extremity motion was assumed to be planar in the sagittal plane. A young male subject was involved in the gait test and his anthropometric data were measured for the calculation of segement mass and moment of inertia. The experimental data were obtained from three trials of walking at 1.2m/s. The foot-floor reaction data were measured from a Kistler force plate. The kinematic data were acquired using a three-dimensional motion measurement system (Expert Vision) with six markers, five of which were placed on the right lower extremity segments and the rest one was attached to the force plate. Based on the model and experimental data for the stance phase of the right foot, the calculated vertical forces reached up to 492, 540, and 561 N at the hip, knee, ankle joints, respectively. The flexion-extension moments reached up to 155, 119, and 33 Nm in magnitude at the corresponding joints.

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2자유도 동작범위를 고려한 reach volume의 해석적 생성 (Analytic Generation of Reach Volume Based on Range of Two Degrees of Freedom Motion)

  • 기도형
    • 대한산업공학회지
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    • 제23권1호
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    • pp.147-162
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    • 1997
  • When designing workplaces or arranging controls on panel, devices and controls should be placed within the reach of operator's arm or foot to guarantee effective performances. Most of the existing research on the reach volume were based on measurements of a few subject's arm reach, and limited to Caucasian and Chinese populations. Furthermore, reach volume considering foot or trunk motion have not been investigated. Range of human joint motion and that of two degrees of freedom motion are needed to generate reach volume analytically using the sweeping algorithm. However, range of two degrees of freedom motion has not been measured up to now. Therefore, range of two degrees of freedom motion was measured in this research, where 47 college students were participated voluntarily as subjects. The results showed that the motion of one joint can be limited by the motion of another motion, that is to say, the shoulder flexion was decreased significantly when the shoulder was adducted or abducted. Second, new approximate algorithms generating reach volumes were suggested, in which range of two degrees of freedom motion was used as input data. Depending upon the body segment included such as trunk, arm and leg, three types of reach volume were provided, in which the human body was modeled as a multilink system based on the robot kinematics and the sweeping method was employed. Reach volume generated analytically in this study showed statistically reasonable results when compared with that obtained from direct measurement.

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Copepodid Stages of Ergasilus hypomesi Yamaguti(Copepoda, Poecilostomatoida, Ergasilidae) from a Brackish Lake in Korea

  • Kim, Il-Hoi
    • Animal cells and systems
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    • 제8권1호
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    • pp.1-12
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    • 2004
  • All copepodid stages and free-swimming adults of Ergasilus hypomesi Yamaguti collected from plankton samples from a brackish lake in Korea are described. The antennule remains a four-segmented appendage until copepodid V. The antenna of copepodid I carries a vestigial exopod. Sexual dimorphism first appears at copepodid IVwhose males bear primodial maxillipeds. Leg 5 also is sexually dimorphic from copepodid IV onwards, with its free segment bearing three setae in the female and two setae in the male. Morphological features of some appendages appearing during copepodid development are discussed. It is noticed that the early copepodids of the Ergasilidae show the characteristic setation on the biramous legs and proximal segments of the antennule.

Three New Species of Collocheres (Copepoda, Siphonostomatoida, Asterocheridae) Associated with Crinoids and Ophiuroids from Korea

  • Shin, Sook;Kim, Il-Hoi
    • Animal cells and systems
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    • 제8권4호
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    • pp.267-280
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    • 2004
  • Three new species of Collocheres are described as associates of crinoid and ophiuroid echinoderms from Cheju Island, Korea: Collocheres brevipes n. sp. from the crinoids Comanthus solaster A. H. Clark and Decametra tigrina (A. H. Clark); C. solidus n. sp. from two species of the crinoids Comanthus solaster and Comanthus japonicus (Muller) and one species of ophiuroid-Ophiomastax mixta (Lutken); and C. tamladus n. sp. from the crinoid Catoptometra rubroflava (A. H. Clack). The three species are distinguished from one another and other congeners by the body size, dimension of caudal ramus and free segment of leg 5, and shape and ornamentation of urosome.

New host and first description of a male Anchistrotos kojimensis Do and Ho, 1983 (Copepoda: Cyclopoida: Taeniacanthidae) from Korean waters

  • Moon, Seong Yong;Choi, Jung Hwa;Lim, Yang Jae;Kim, Jung-Nyun
    • Journal of Species Research
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    • 제6권spc호
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    • pp.8-14
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    • 2017
  • Taeniacanthid copepods Anchistrotos kojimensis Do and Ho, 1983 were collected from the branchial cavities of stichaeid fish, Ernogrammus hexagrammus (Schlegel) and yellowfin goby, Acanthogobius flavimanus (Temminck and Schlegel) in Korean waters. Here, we provide the first description of a male of Anchistrotos Do and Ho, 1983. A close comparison of the specimens of A. kojimensis collected from Korea with the original description revealed differences in the adult female: (1) the caudal ramus bears seven setae (seta I minute); (2) the maxillule with small knob-like process anteriorly; (3) leg 5 ornamented with patched spinules distally and having row of spinules at base of each spine and distal seta. The first description of the adult male reveals the following features: (1) the distal abdominal somite had rows of spinules anteriorly and near insertion of each caudal ramus; (2) the postantennal process is more elongate than in the female; (3) the basis of maxilliped is with two prosimomedial setae, two longitudinal rows of stout denticles found on posteromedial surface and row of spinules on anteromedial surface; and (4) the second endopodal segment is a strongly curved claw, with a row of stout denticles along a concave margin, two long and one small setae.

Structural health rating (SHR)-oriented 3D multi-scale finite element modeling and analysis of Stonecutters Bridge

  • Li, X.F.;Ni, Y.Q.;Wong, K.Y.;Chan, K.W.Y.
    • Smart Structures and Systems
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    • 제15권1호
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    • pp.99-117
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    • 2015
  • The Stonecutters Bridge (SCB) in Hong Kong is the third-longest cable-stayed bridge in the world with a main span stretching 1,018 m between two 298 m high single-leg tapering composite towers. A Wind and Structural Health Monitoring System (WASHMS) is being implemented on SCB by the Highways Department of The Hong Kong SAR Government, and the SCB-WASHMS is composed of more than 1,300 sensors in 15 types. In order to establish a linkage between structural health monitoring and maintenance management, a Structural Health Rating System (SHRS) with relevant rating tools and indices is devised. On the basis of a 3D space frame finite element model (FEM) of SCB and model updating, this paper presents the development of an SHR-oriented 3D multi-scale FEM for the purpose of load-resistance analysis and damage evaluation in structural element level, including modeling, refinement and validation of the multi-scale FEM. The refined 3D structural segments at deck and towers are established in critical segment positions corresponding to maximum cable forces. The components in the critical segment region are modeled as a full 3D FEM and fitted into the 3D space frame FEM. The boundary conditions between beam and shell elements are performed conforming to equivalent stiffness, effective mass and compatibility of deformation. The 3D multi-scale FEM is verified by the in-situ measured dynamic characteristics and static response. A good agreement between the FEM and measurement results indicates that the 3D multi-scale FEM is precise and efficient for WASHMS and SHRS of SCB. In addition, stress distribution and concentration of the critical segments in the 3D multi-scale FEM under temperature loads, static wind loads and equivalent seismic loads are investigated. Stress concentration elements under equivalent seismic loads exist in the anchor zone in steel/concrete beam and the anchor plate edge in steel anchor box of the towers.

택견 낚시걸이 동작 시 엉덩질 유무에 따른 운동역학적 차이 (A Comparative Study on the Kinetic Factors in Taekkyon Nakcyguri with and without Hip Bending)

  • 오성근;이재훈
    • 한국운동역학회지
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    • 제24권3호
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    • pp.277-285
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    • 2014
  • Nakcyguri is one of the offensive weapons most often used in Taekkyon games, The purpose of this study was to investigate kinetic factors on two types of Nakcyguri, one of which uses hip bending and the other uses little it. 12 taekkyoners (males) who are the students of Y University participated in this study. They have been practicing on Taekkyon for five years or more. Positions of CoM, the elapsed time of each phase, ROM of joint and segment angles, ground reaction forces, joint moments of supporting leg were analyzed for this study. The results were as follows; in Nakcyguri with hip bending than without hip bending, anterior/posterior ROM of pelvis, head and swing foot were larger by flexing-extending more, and both vertical and posterior components of GRF were larger during phase 4. It was considered that hip bending produced posterior momentum as well as vertical momentum of trunk during Nakcyguri. In conclusion hip bending was essential and so useful to the successful attack.

사이클링 초최대운동(Supra maximal training)시 RPM과 족관절의 운동학적 분석 (Kinematic characteristics of the ankle joint and RPM during the supra maximal training in cycling)

  • 이용우
    • 한국운동역학회지
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    • 제15권4호
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    • pp.75-83
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    • 2005
  • The purpose of this study was to determine the kinematic characteristics of the ankle joint and RPM(repetition per minutes) during the supra maximal training in cycling. For this study, 8 national representative cyclists, distance cyclists in track and road, were selected. During the super-maximum pedalling, kinematic data were collected using a six-camera(240Hz) Qualisys system. the room coordinate system was right-handed and fixed in the back of a roller for cycle, with right-handed orthogonal segment coordinate systems defined for the leg and foot. Lateral kinematic data were recorded at least for 3 minutes while the participants pedal on a roller. Two-dimensional Cartesian coordinates for each marker were determined at the time of recording using a nonlinear transformation technique. Coordinate data were low-pass filtered using a fourth-order Butterworth recursive filter with cutoff frequency of 15Hz. Variables analyzed in this study were compared using a one factor(time) ANOVA with repeated measures. The results of investigation suggest that the number of rotating pedal was decreased with time phase during the super-maximum pedaling. Maximum angle of the ankle joint showed little in change with time phase compared with minimum angle of that.

방패광대노린재 국내 분포, 기주식물 및 기초 생태 보고 (A Report of Basic Ecology and Distribution, Host Plants of Cantao ocellatus (Hemiptera: Scutelleridae) in Korea)

  • 김동언;길지현;이도훈
    • 한국응용곤충학회지
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    • 제52권2호
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    • pp.93-100
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    • 2013
  • 방패광대노린재는 2012년 제주도, 진도, 통영, 광주, 태안에서 분포가 확인되었다. 성충은 6월 하순에서 7월 초순경에 예덕나무에 출현하며 10월 말까지 관찰이 가능하다. 실내 사육은 온도 $25^{\circ}C({\pm}2)$, 습도 65%(${\pm}2$), 광주기 16L:8D의 조건에서 성충의 암 수 형태 측정, 발육특성, 기주 및 산란선호성을 조사하였다. 체장(female: 26.20 mm, male: 23.88 mm), 체폭(female: 11.35 mm, male: 10.57 mm ), 두폭(female: 3.84 mm, male: 3.64 mm), 주둥이(female: 7.90 mm, male: 7.27 mm). 더듬이(female: 9.87 mm, male: 9.69 mm), 앞다리(female: 12.50 mm, male: 12.27 mm), 가운뎃다리(female: 14.61 mm, male: 13.12 mm), 뒷다리(female: 16.90 mm, male: 16.53 mm), 생체중(female: 0.46 g, male: 0.31 g)으로 각각 조사되었다. 우리나라에는 앞가슴등판 끝에 가시가 있는 개체가 있고, 가시의 유무는 마지막 5령 탈피시 생겨난다. 암 수 구분은 생식기와 배마디의 점무늬로 구별된다. 기주선호성은 예덕나무, 무늬예덕나무, 피마자, 털인동, 감귤나무, 느티나무의 열매, 엽병, 주맥, 가지를 흡즙하였다.