• Title/Summary/Keyword: 인공근육

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Experimental Study on Global Buckling of Singly Symmetric FRP Members (일축대칭 FRP 부재의 전체좌굴에 관한 실험적 연구)

  • Lee, Seungsik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.99-106
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    • 2006
  • Due to single symmetry of cross section, T-shaped members are likely to buckle in a flexural-torsional mode when they are subjected to axial compression. Therefore, the flexural-torsional buckling can be regarded as a governing mode of global buckling. An experimental program has been carried out to investigate the flexural-torsional buckling behavior of pultruded T-shaped members. Two types of pultruded members were tested in the experiment, and they were made of either E-glass/vinylester or E-glass/polyester. Lay-up and thickness of reinforcing layers, volume fractions of each constituents in layers, mechanical properties were experimentally determined. Two sets of knife edge fixure were used to simulate simple support condition for flexure and twisting, and the lateral displacements and the angle of twist were measured using three potentiometers. Every specimen buckled in a flexural-torsional mode, and most of the specimens showed post-buckling strength.

Micropatterning of Polyimide and Liquid Crystal Elastomer Bilayer for Smart Actuator (스마트 액추에이터를 위한 폴리이미드 및 액정 엘라스토머 이중층의 미세패터닝)

  • Yerin Sung;Hyun Seung Choi;Wonseong Song;Vanessa;Yuri Kim;Yeonhae Ryu;Youngjin Kim;Jaemin Im;Dae Seok Kim;Hyun Ho Choi
    • Journal of Adhesion and Interface
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    • v.25 no.1
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    • pp.169-274
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    • 2024
  • Recent attention has been drawn to materials that undergo reversible expansion and contraction in response to external stimuli, leading to morphological changes. These materials hold potential applications in various fields including soft robotics, sensors, and artificial muscles. In this study, a novel material capable of responding to high temperatures for protection or encapsulation is proposed. To achieve this, liquid crystal elastomer (LCE) with nematic-isotropic transition properties and polyimide (PI) with high mechanical strength and thermal stability were utilized. To utilize a solution process, a dope solution was synthesized and introduced into micro-printing techniques to develop a two-dimensional pattern of LCE/PI bilayer structures with sub-millimeter widths. The honeycomb-patterned LCE/PI bilayer mesh combined the mechanical strength of PI with the high-temperature contraction behavior of LCE, and selective printing of LCE facilitated deformation in desired directions at high temperatures. Consequently, the functionality of selectively and reversibly encapsulating specific high-temperature materials was achieved. This study suggests potential applications in various actuator fields where functionalities can be implemented across different temperature ranges without the need for electrical energy input, contingent upon molecular changes in LCE.

Therapeutic Effect of Bee-Venom and Dexamethasone in Dogs with Facial Nerve Paralysis (개 안면신경마비에 대한 봉독과 덱사메타손의 치료효과)

  • Jun, Hyung-Kyou;Oh, Hyun-Uk;Han, Ji-Won;Lee, Hyun-Hwa;Jeong, Seong-Mok;Choi, Seok-Hwa;Kim, Cristopher Mun-Ho;Kim, Duck-Hwan
    • Journal of Veterinary Clinics
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    • v.24 no.4
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    • pp.503-508
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    • 2007
  • Although canine facial nerve paralysis(FNP) occurs similarly in humans, there is no properly recognized therapy using Western medicine for idiopathic causes. To elucidate therapeutic measures by acupuncture(AP) on canine FNP, we examined the therapeutic effect of injection-AP on the artificially induced canine FNP. Twelve dogs on artificially induced canine FNP were divided into a control group(4 dogs), an experimental dexamethasone-treated group(dexamethasone group, 4 dogs) and an experimental bee venom-treated group(apitoxin group, 4 dogs). Saline (1 ml) was intramuscularly injected into the head muscle after the induction of FNP in the control group. On the other hand, injection-AP with dexamethasone was performed on such acupoints as LI04, LI20, ST02, ST07, TH17, SI18, GB03 and GB34, twice per week after induction of FNP in the dexamethasone group. In addition, injection-AP with $100{\mu}g$ of apitoxin was performed on the same acupoints as the dexamethasone group twice per week after the induction of FNP in the apitoxin group, respectively. The changes of the clinical symptoms of FNP with each treatment during the experimental period were recorded by using clinical scores, respectively. The changes of serum creatine kinase(CK) activities along with each treatment were determined using an autoanalyzer. The significant differences of clinical scores were detected on day 14(p<0.05) in the apitoxin and dexamethasone groups, compared with those in the control group, respectively. However, significant difference was not detected between the apitoxin and dexamethasone groups. Significant differences of serum CK activities were detected on day 7(p<0.05) and day 14(p<0.05) in the dexamethasone and apitoxin groups, compared with those in the control group, respectively. However, significant difference was not detected between the dexamethasone and apitoxin groups. In condition, injection-APs with apitoxin and dexamethasone were all effective for treatment of canine FNP and the therapeutic effect by injection-AP with apitoxin was similar to that of injection-AP with dexamethasone.

The Localization of the Excretory, Purified and Infected Antigenic Protein in the Tissue of Trichinella spiralis Larval Worm (선모충(Trichinella spiralis) 유충의 조직 내 배설, 분리 및 감염항원 단백의 분포)

  • Kim, Soo-Jin;Joo, Kyoung-Hwan;Chung, Myung-Sook;Rho, Young-Bok
    • Applied Microscopy
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    • v.37 no.1
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    • pp.43-52
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    • 2007
  • In order to observe the localization of excretory, purified and infected antigenic protein in the tissue of Trichinella spiralis larvae, immunogoldlabeling methodology using IgG and protein A-gold complex was implemented. T. spiralis larvae obtained from rat muscle were initially cultured in medium, and secreted excretory antigen was collected for 1 or 3 days. Purified antigenic protein was obtained from homogenized T. spiralis larvae. Rabbits were then immunized with 1 or 3 days secreted excretory protein and purified 45 kDa protein, and IgG was purified from collected serum. Serum, against infected antigen, collected from rat on 1 and 4 weeks after infection with T. spiralis larvae, and IgG was purified from collected serum. T. spiralis larvae were embedded in Lowicryl HM20 medium. Then they were finally treated with immunized IgG and protein A-gold complex (particle size; 15 nm) and observed under electron microscope. In T. spiralis larvae tissue, the tissue antigen reacted with rabbit IgC antigen Day 1 secreted excretory protein, infected antigenic protein and purified 45 kDa protein. But different distribution pattern of labeled gold particles were observed. When Day 1 secreted excretoy protein was used, gold particle labeling was observed specifically on the cuticle, basal layer, esophagus interstitial matrix (EIM) and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. In a separate group of tissue, the antigen reacted with rabbit IgG against Day 3 secreted excretory protein. Labeled gold particles were specifically distributed on the surface layer of cuticle, EIM and ${\alpha}_0$ granules of stichocyte of the worm. In case of using infected antigenic protein, gold particle labeling was specifically distributed on the cuticle and EIM of the worm. When purifed 45 kDa protein was used gold particle labeling was specifically distributed on the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. Therefore, excretory antigens appeared to originate from the cuticle and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte for the first day but the cuticle layer associated with globular proteins and ${\alpha}_0$ granules of stichocyte after 3 days and infected antigens appeared to originate from the cuticle for 1 and 4 weeks after infection. These results suggest that excretory and infection specific antigens are secreted into the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte and 45 kDa protein may be contained these specific antigens.

Case report: Full mouth rehabilitation for patient with heavy occlusal force and excessive abrasion (강한 교합력과 과도한 마모를 보이는 환자의 전악수복 증례)

  • Park, Ji-Hee;Vang, Mong-Sook;Yang, Hong-So;Park, Sang-Won;Yun, Kwi-Dug;Lim, Hyun-Pil
    • The Journal of Korean Academy of Prosthodontics
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    • v.51 no.2
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    • pp.119-124
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    • 2013
  • Many of the patients with extensive abrasion need comprehensive restorative treatment. The abrasion is usually caused by attrition, besides of it, there are many reasons for it. The plan of treatment should be started on assessment of the type of attrition and the etiologic analysis. Patient with well-developed masticatory muscle, alveolar process, and high occlusal force and also with little muscle length difference between the stable and the contracted state should be carefully assessed for the vertical dimensional loss and the restoration should be carefully designed. Decrease of tooth length can be compensated by the growth of the alveolar bone height; therefore, consistency of the occlusal vertical dimension is maintained. Accordingly, a careless increase of the vertical dimension can produce muscle fatigue, depressed tooth and pain, and fracture of the restoration. In this case, the patient with multiple tooth abrasion and clenching habit, the edentulous maxillary area is restored with amalgam inserted RPD, and the dentulous area of the maxilla and mandible are treated with fixed restoration accompanying with the increase of vertical dimension. Consequently, we are going to report about the satisfying result in both functional and esthetic aspects.

Development of Multi-rotational Prosthetic Foot for Lower Limb Amputee (하지 절단자를 위한 다축 회전이 가능한 인공발의 개발)

  • Shin, Hyunjun;Park, Jin-Kuk;Cho, Hyeon-Seok;Ryu, Jei-Cheong;Kim, Shin-Ki
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.10 no.4
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    • pp.305-313
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    • 2016
  • Movements of the lower limb are important for normal walking and smooth oscillation of the center of gravity. The ankle rotations such as dorsi-flexion, plantar-flexion, inversion and eversion allows the foot to accommodate to ground during level ground walking. Current below knee (B/K) prostheses are used for replacing amputated ankle, and make it possible for amputees to walk again. However, most of amputees with B/K prostheses often experience a loss of terrain adaptability as well as stability because of limited ankle rotation. This study is focused on the development of multi-rotational prosthetic foot for lower limb amputee. Our prosthesis is possible for amputees to easily walk in level ground by rotating ankle joint in sagittal plane and adapt to the abnormal terrain with ankle rotation in coronal plane. The resistance of ankle joint in the direction of dorsi/plantar-flexion can be manually regulated by hydraulic damper with controllable nozzle. Furthermore, double layered rubber induce the prosthesis adapt to irregular ground by tilting itself in direction of eversion and inversion. The experimental results highlights the potential that our prosthesis induce a normal gait for below knee amputee.

Skeletal Muscle Ventricle Mechanics (골격근 심실의 역학)

  • 오중환
    • Journal of Chest Surgery
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    • v.32 no.5
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    • pp.428-432
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    • 1999
  • Background: It has been shown that low-grade electrical stimulus can transform fatigue resistant muscles which then can be used to protect the heart. The bulky and cumbersome power sources of the artificial heart or implantable ventricular assist devices are still in need of solution; however, on the other hand, the implantable ventricular assist devices using the resistant muscles as the power source have the advantages of using its own muscle contractions. The purpose of this study was to determine the possibility of a clinical application of the skeletal muscle ventricle. Material and Method: Latissimus dorsi muscles (LDM) of 8 canines were used for skeletal muscle ventricle. A latex chamber was wrapped one and a half times with LDM. The chamber was attached to a pressure transducer via Tygon tube. An electrode stimulator was placed around the thoracodorsal nerve and LDM was stimulated in cyclic bursts of 0.31 sec on time and 6.0 sec off time using 3.0 volt Itrel stimulator. The preload volume was added to the system in 25cc increments. Ejection volumes, pressures, and peak power outputs were measured. Result: Ejection volume was 76.3cc with 0cc of preload. Ejection volumes were less than 70ml with increments of preload over 75cc Pressures were more than 107 mmHg when the preloads were less than 75cc and less than 100 mmHg when the preloads were more than 100cc. Peak power output of 16.6 W/kg was observed at 50cc preload. Conclusion: Depending on the changes of preload, the volumes ejected from skeletal muscle ventricle and pressures from the skeletal muscle contraction surpassed those of the normal heart. These data suggest that there are clinical applications for skeletal muscle ventricular assist system.

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Clincal Studies on the Gangrenous Mastitis Caused by Mircrococus pyogenes var aureus in Goats (Micrococcus pyogenes var aureus에 의한 유산양(乳山羊)의 괴저성유방염(壞疽性乳房炎)에 관한 임상학적(臨床學的) 연구(硏究))

  • Kim, Kyo Jun
    • Korean Journal of Agricultural Science
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    • v.3 no.1
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    • pp.85-94
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    • 1976
  • Six cases of gangreous mastitis of goats infected spontaneously were observed clinically and pathologically in Daegu and Daejeon district. and with strain isolated purely from the infected goats, the artificial infection to the animal was examined, the sensitivity of strain to the antibiotics was tested and clinical treatment was carried out. The results obtained are summarized as follows: 1. In the six cases approximately same clinical findings were observed as the previously published literatures on gangrenous mastitis of cattle, sheep and goats. 2. The micrococcus pyogenes var aureus was highly virulent strain which was the causative organism for the gangrenous mastitis by inoculating in the udder. 3. The gangrenous mastis was probably occured by the formation of thrombosis in veins of udder. 4. In the sensitivity test, the micrococcus pyogenes var aureus resited for penicillin in 2 cases among the 6 strains, but sensitived for streptomycin, chloromycin, oxyteracycline, erythromycin, achromycin, neomycin and kanamycin in other 4 and in all case. 5. The treatment for gangrenous mastitis may be extirpated the gangrenous region surgically in the case of unilaterally or locally affected, treated by muscle injection or teat-operation in the case of severely or diffusely affected and infused antibiotics up to teat canal or treated by mammary tissue injection in the case of slightly affected.

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Physiological Effects of Seamustard Supplement Diet on the Growth and Body Composition of Young Rockfish, Sebastes schlegeli (조피볼락, Sebastes schlegeli 어린 시기의 성장 및 체성분 조성에 미치는 미역첨가 사료의 생리적 효과)

  • YI Young-Ho;CHANG Young-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.1
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    • pp.69-82
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    • 1994
  • In order to find out physiological effects of diets supplemented with seamustard (Undaria pinnatifida) on the growth, survival rate, body compositions and blood properties of young rockfishes (Sebastes schlegeli) in range of average total length from $2.99{\pm}0.23\;cm\;to\;18.52{\pm}1.07\;cm$ and average body weight from $1.03{\pm}0.18\;g\;to\;120.64{\pm}19.32\;g$, experiments were performed for 140 days by feeding four experimental diets supplemented with $0\%,\;3\%,\;5\%\;and\;7\%$ of seamustard powder. In addition, the tests on tolerance of the fishes against low $O_2$ saturation and starvation were carried out after the feeding experiments. The fishes fed diet supplemented with $5\%$ of seamustard powder revealed the best results in growth of total length and body weight. Crude lipid content in the whole viscera of fishes fed diets supplemented with seamustard powder was higher than that of fishes fed diet without seamustard powder, while the moisture, crude protein, crude lipid and crude ash composition in the dorsal muscle did not show any remarkable differences among diet groups with or without seamustard powder. Hematocrit and mean number of red blood cell in fishes fed diets supplemented with seamustard powder was elevated, despite of no notable changes in mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. The resistance of the fish to low $O_2$ saturation was elevated by feeding seamustard powder. Upon the starvation of fish for 31 days after the feeding experiments, body weight loss of three groups fed diets with seamustard was smaller compared with the group fed diet without seamustard.

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Technical Survey on the Real Time Eye-tracking Pointing Device as a Smart Medical Equipment (실시간 시선 추적기반 스마트 의료기기 고찰)

  • Park, Junghoon;Yim, Kangbin
    • Smart Media Journal
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    • v.10 no.1
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    • pp.9-15
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    • 2021
  • The eye tracking system designed in this paper is an eye-based computer input device designed to give an easy access for those who are uncomfortable with Lou Gehrig's or various muscle-related diseases. It is an eye-based-computer-using device for users whose potential demand alone amounts to 30,000. Combining the number of Lou Gehrig's patients in Korea estimated at around 1,700, and those who are unable to move their bodies due to various accidents or diseases. Because these eye input devices are intended for a small group of users, many types of commercial devices are available on the market. It is making them more expensive and difficult to use for these potential users, less accessible. For this reason, each individual's economic situation and individual experience with smart devices are slightly different. Therefore, making it difficult to access them in terms of cost or usability to use a commercial eye tracking system. Accordingly, attempts to improve accessibility to IT devices through low-cost but easy-to-use technologies are essential. Thus, this paper proposes a complementary superior performance eye tracking system that can be conveniently used by far more people and patients by improving the deficiencies of the existing system. Through voluntary VoCs(Voice of Customers) of users who have used different kinds of eye tracking systems that satisfies it through various usability tests, and we propose a reduced system that the amount of calculation to 1/15th, and eye-gaze tracking error rate to 0.5~1 degree under.