• Title/Summary/Keyword: Leg shape

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Analysis on the Walking Volumes of a Hexapod System with General 3R Link Legs (일반적 3R 링크를 갖는 6각 보행로봇 다리의 보행체적에 대한 해석)

  • Han, Gyu-Beom;Yang, Chang-Il;Baek, Yun-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.7
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    • pp.2205-2212
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    • 1996
  • In order to move the body of a walking robot translationally, and step over the obstacles, the walking robot must have at least 3 degrees of freedom for each leg. Therefore each leg of the general walking robots can be composed of 3-link system with 3 revolute joints. In this paper, the colsed form of inverse kinimatic solutions is shown for this general 3R linkage. Moreover, in order to have efficient walking volume in rough terrain, the workspace of each log is obtained considering the twist angles and the offsets in D-H parameters. When we design a walking robot, the information of the walking volume is needed for planning desired trajectories of the feet effectively. Appropriate knowledge of the walking volume can also be used to maximize linear or angular velocity of minimize power of stress. However, since it is impossible to obrain the information of walking volume in 3-D space directly from the kinematic equations, the walking volume can be searched through the edge detection algorithm using the triangle tracer with closed from inverse kinematic solutions. In this study, we present the closed form inverse kinematic solutions for 3R linkage model, and the walking volume of 6 legged walking robot which is modeled after the darking bettle, Eleodes obscura sulcipennis, through the method of edge detection for an arbitrary 2 dimensional shape using triangle tracer.

Development of a Sizing System of Mass-customized Clothing for Wheelchair Users: Men's Suit Sizes (휠체어 장애인의 대량맞춤복을 위한 사이즈 체계 개발: 남성 정장 사이즈)

  • Park, Kwangae;Park, Jangwoon;Yang, Chungeun;Jeon, Eunjin;You, Heecheon
    • The Korean Fashion and Textile Research Journal
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    • v.16 no.4
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    • pp.625-634
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    • 2014
  • This study develops a sizing system of mass-customized male suits for wheelchair users. One hundred and three male wheelchair users' 21 anthropometric dimensions were measured to identify body shapes and develop a sizing system. The measured wheelchair users' body sizes were compared with the average body sizes of Korean males from the $6^{th}$ Korean Body Size Survey to understand the body size differences between two groups. As a result of body shape classification using the KS's Drop method, wheelchair user body shapes were classified into four shapes for upper-body (A: 32%, B: 26%, BB: 24%, and Y: 18%), and two shapes for lower-body (B: 70% and A: 30%). The upper-body of wheelchair users was relatively developed than Korean males; however, the lower-body was relatively stunted. The key dimensions of a sizing system were selected as chest circumference, waist circumference, and trunk length, outside leg length based on the correlation analysis between anthropometric measures. The top sizes were determined considering chest and waist circumferences for horizontal sizes, and additionally the trunk length was divided into short, medium, and long groups for vertical sizes. The bottom sizes were selected considering the waist and hip circumferences for horizontal sizes, and additionally their outside leg length was divided into short, medium, and long groups for vertical sizes.

Identification of Irradiated Crabs by ESR Spectrometry

  • Nam, Hye-Seon;Ly, Sun-Yung;Yang, Jae-Seung
    • Journal of Food Hygiene and Safety
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    • v.15 no.1
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    • pp.1-4
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    • 2000
  • Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose on the ESR signal intensity of irradiated crabs and the stability of these radicals under 9 weeks of storage. Swimming and small crabs were irradiated with doses of 0, 1, 3, 5 and 7 kGy using a Co-60 irradiator at ambient temperature. A claw, a walking leg and a cars- pace of the crab pieced and dried were placed in a resonant quart tube within an EPR X-band spectrometer. The irradiated crabs presented an asymmetric absorption in shape at g$_1$=2.002 $\pm$ 0.003 and g$_2$=1.998$\pm$0.005, and were different from the non-irradiated ones. The intensity of the ESR signals was greatest in the claw, intermediate in the carapace and lowest in the walking leg. Samples given low and high doses of irradiation could also be distinguished. The ESR signal after irradiation was stable, even after a 9-week storage.

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The Study on the Lower Limb Surface Changes Caused by the Limb Movements (Part 1) (동작에 따른 하지피부면의 변화에 관한 연구 (제일보) - 탈관절과 슬관절 굴신을 중심으로 -)

  • 박영득
    • Journal of the Korean Home Economics Association
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    • v.20 no.4
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    • pp.1-12
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    • 1982
  • This study was to investigate the changes of shape of the lower limb surface, the rate of the measurement of expansion and contraction and correlation coefficient between variables caused by hip joint and knee joint movements. The results of the investigation are as follows; 1. According to the development figure of shell when the leg was raised $45^{\circ}$forward($M_{2}$), total length of F.L shortened while B.L lengthened. This result is contarary to $M_{3}$raising the leg $15^{\circ}$ backward. In both $M_{2}$, $M_{3}$movements, the rate of expansion and contraction to the course direction was insignificant. When hip joint was bent $15^{\circ}$ with knee joint $120^{\circ}$bent ($M_{4}$) and hip joint was bent $30^{\circ}$ with knee joint $90^{\circ}$ bent($M_{5}$), upper section of back hip expanded while the front hip section contracted slightly. In the Movement of sitting on the chair($M_{6}$), abdomen, front hip section and upper thight section contracted to the wale direction remarkably while the back hip section expanded conspicuously. 2. According to the rate of expansion and contraction of skin (surface) by the somatometry. In $M_{2}$, C.F.L. upper and middle thight girth contracted and B.L, C.L, L.L expanded. This fact is contarary to M3. In M4, M5, C.F.L showed remarkable contraction and C.B.L expanded remarkably. In $M_{6}$, C.B.L contracted most of all the items measured and knee girth, F.L, L.L, C.B.L, hip girth expanded conspicuously. 3. According to the correlation coefficient between variables. In various movements, the correlation among girth items commonly showed a high or middle grade, the correlation among length items also commonly showed a low grade and that girth and length items showed a very low grade commonly. Waist girth, hip grith, F.L, B.L, L.L items showed that there were significant correlation.

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Early Resurfacing Using Gastrocnemius Muscle Flap Transposition for Degloving Injury with Exposure of Proximal Tibia (근위부 경골 노출을 동반한 벗겨진 손상의 장딴지 근육 피판을 이용한 조기 피복 치험례)

  • Jeong, Hii Sun;Lee, Hye Kyung
    • Journal of Trauma and Injury
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    • v.21 no.2
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    • pp.140-143
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    • 2008
  • Degloving injuries result from the tangential force against the skin surface, with resultant separation of the skin and the subcutaneous tissue from the rigid underlying muscle and fascia. These injuries are associated with extensive soft tissue loss and occasionally with exposure of bone, and they require reconstructive modality for resurfacing and successful rehabilitation that considers the vascular anatomy and the timing of the operation. A 19-year-old male patient was transferred to our facility with degloving injury extending from the lower third of the right thigh to the malleolar area. The tibial bone was exposed to a size of $2{\times}3.5cm^2$ on the upper third of the lower leg at the posttraumatic third day. The exposed soft tissue was healthy, and the patient did not have any other associated disease. At the posttraumatic sixth day, one-stage resurfacing was performed with a medial gastrocnemius muscle flap transposition for the denuded bone and a split-thickness skin graft for the entire raw surface. The transposed gastrocnemius muscle attained its anatomical shape quickly, and the operating time was relatively short. No transfusion was needed. This early reconstruction prevented the accumulation of chronic granulation tissue, which leads to contracture of the wound and joint. The early correction of the gastrocnemius muscle flap transposition made early rehabilitation possible, and the patient recovered a nearly full range of motion at the injured knee joint. The leg contour was almost symmetric at one month postoperatively.

Excision of Calcinosis Cutis Caused by Moxibustion Burn Injury Using Intraoperative Ultrasonography Determining the Complete Resection Range (뜸 화상으로 발생한 피부석회증을 수술중 초음파를 이용하여 절제한 사례)

  • Ryu, Hyeong Rae;Choi, Hwan Jun;Kim, Jun Hyuk;Lee, Da Woon;Ahn, Hyein
    • Journal of the Korean Burn Society
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    • v.24 no.2
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    • pp.34-37
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    • 2021
  • A 46-year-old female presented a mass on her right lower leg where she had a burn injury due to moxibustion 10 years ago. Physical examination revealed a 3 cm sized firm nodule with tenderness. Plain radiograph was performed and it revealed well-defined calcifications. According to the history of moxibustion burn injury and the result of plain radiograph, dystrophic calcinosis cutis caused by burn injury was suspected. The patient underwent excisional biopsy using pre-,intra-, and post-operative ultrasonography (USG). There was no sign of recurrence. Herein, we report a case of a 46-year-old healthy woman who presented with single hard nodule on the right lower leg. Our case is worthwhile in two respects. First, It is first case report of dystrophic calcinosis cutis due to moxibustion burn injury. In east asian culture, moxibustion is a commonly conducted procedure and it often induces burn injury. Second, USG was used pre-, intra-, and post-operatively to assess the shape, location, and depth of the calcinosis cutis and to determine the surgical margin.

Evaluating Joint Motion Sensing Efficiency According to the Implementation Method of CNT-Based Fabric Sensors (CNT 기반의 직물센서 구현 방법에 따른 관절동작 센싱 효율 평가)

  • Cho, Hyun-Seung;Yang, Jin-Hee;Lee, Joo-Hyeon
    • Science of Emotion and Sensibility
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    • v.24 no.4
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    • pp.129-138
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    • 2021
  • This study aimed to determine the effects of the shape and attachment position of stretchable textile sensors coated with carbon nanotube on their performance when used to measure children's joint movements. Moreover, the child-safe requirements for fabric motion sensors are established. The child participants were advised to wear integrated clothing equipped with the sensors of various shapes (rectangular and boat-shaped) and attachment positions (at the knee and elbow joints or 4 cm below the joints). The voltage change induced by the elongation and contraction of the fabric sensors was determined for arm and leg flexion-extension motions at 60 deg/s (three measurements of 10 repeats each for 60°and 90°angles, for a total of 60 repetitions). Their dependability was determined by comparing the fabric motion sensors to the associated acceleration sensors. The experimental results indicate that the rectangular-shaped sensor affixed 4 cm below the joint is the most effective fabric motion sensor for measuring children's arm and leg motions. In this study, we designed a textile sensor capable of tracking children's joint motion and analyzed the sensor shape and attachment position on motion sensing clothing. We demonstrated that flexible fabric sensors integrated into garments may be used to detect the joint motions of the human body.

A Study on the Changes of the Ancient Underclothes (시대 변천에 따른 속옷에 관한 연구(I) -고대를 중심으로-)

  • 김주애
    • The Research Journal of the Costume Culture
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    • v.5 no.4
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    • pp.12-31
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    • 1997
  • This is a study on the changes of the ancient underclothes. Underclothing includes all such articles, worn by either sex, as were completely or mainly concealed from the spectator by the external costume. Functions of underclothes are follow ; to protect the body from cold, to support the shape of the costume, to cleanliness, to erotic use of underclothes and as a method of class distinction. Linen is the oldest as materials and cotton came into general use after the Restoration of 1660. We must suppose that woolen petticoat was at least as old as the Middle Ages and silk was rarely used until late in Victorian times. Until the middle of the last century underclothes were necessarily hand-made, and the absence of fit was noticeable until the introduction of man\`s drawers, fitting the leg, at the close of the eighteen century. Strings and ribbons were the fastenings for underclothes until the middle of the seventeenth century, when they were replaced by buttons. One outstanding example of the first type of figures is a Babylonian girl of about 3000 BC from Sumeria who wears that today would immediately be described as briefs. Female statues show no trace of anything being worn under the chiton, but there is literary evidenced that the Greeks. A band of linen of kid was bound round the waist and lower torso to shape and control it. It was known as the Zone or girdle. The apodesmos, meaning a band, breast band, occurs in a fragment of Aristophanes. A Roman mosaic shows female athletes wearing a bikini-briefs and bra in the fourth century AD. A similar band, called the mastodeton, or breast band, was also worn round the bust, apparently to flatten or minimise it, as in the 1920s, and not, to stress its curves. In Rome, too, women sometimes wore bands of material round the hips and bust-a cestus or girdle is referred to by the poet Martial and seems to have been similar to the zone, but wider, and the strophium, or breast band, is mentioned by Cicero.

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Design and Simulation of Small Bio-Inspired Jumping Robot (생체모방 소형 점핑로봇의 설계 및 시뮬레이션)

  • Ho, Thanhtam;Choi, Sung-Hac;Lee, Sang-Yoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.9
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    • pp.1145-1151
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    • 2010
  • In this paper, we discuss the design and simulation of a jumping-robot mechanism that is actuated by SMA (shape memory alloy) wires. We propose a jumping-robot mechanism; the structure of the robot is inspired by the musculoskeletal system of vertebrates, including humans. Each robot leg consists of three parts (a thigh, shank, and foot) and three kinds of muscles (gluteus maximus, rectus femoris, and gastrocnemius). The jumping capability of the robot model was tested by means of computer simulations, and it was found that the robot can jump to about four times its own height. This robot model was also compared with another model with a simpler structure, and the performance of the former, which was based on the biomimetic design, was 3.3 times better than that of the latter in terms of the jumping height. The simulation results also verified that SMA wires can be suitable actuators for small jumping robots.

A new species of Parastenocaris from Korea, with a redescription of the closely related P. biwae from Japan (Copepoda: Harpacticoida: Parastenocarididae)

  • Karanovic, Tomislav;Lee, Wonchoel
    • Journal of Species Research
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    • v.1 no.1
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    • pp.4-34
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    • 2012
  • Parastenocaris koreana sp. nov. is described based on examination of numerous adult specimens of both sexes from several localities in Korea. Scanning electron micrographs are used to examine intra- and interpopulation variability of micro-characters, in addition to light microscopy. The new species is most closely related to the Japanese P. biwae Miura, 1969, which we redescribe based on newly collected material from the Lake Biwa drainage area. The two species differ in size, relative length of the caudal rami, shape of the anal operculum, shape of the genital double somite, relative length of the inner distal process on the female fifth leg, as well as relative length of the apical setae on the second, third, and fourth legs exopods in both sexes. Detailed examinations of three disjunct populations of P. koreana reveal also some geographical variation, especially in the surface ornamentation of somites, which may indicate some population structuring or even cryptic speciation. Lack of intraspecific variability in the number and position of sensilla on somites, as well as their potential phylogenetic significance, is a novel discovery. Both species examined here belong to the brevipes group, which we redefine to include 20 species from India (including Sri Lanka), Australia, East Asia, Northern Europe, and North America. A key to species of this group is also provided. In order to test the monophyly of the redefined brevipes group with highly disjunct distribution, as well as relationship between different species, a cladistics analysis is performed based on 39 morphological characters and with help of three outgroup taxa. Six equally parsimonious cladograms are generated, all of which show that the ingroup is well defined by at least three synapomorphies. Reconstructed phylogeny questions the previously suggested hypothesis about the origin of this group in South East Asia, with one Australian species showing the most basal position. We speculate that the present distribution of this group may be a combination of ancient vicariance and subsequent dispersal, with a possible origin in the Gondwanaland, in the rift valley between Australia and India.