• Title/Summary/Keyword: 등속도

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Optimum Design of Rubber Injection Molding Process (고무사출성형의 적정설계)

  • Lee, Eun-Ju;Lim, Kwang-Hee;Giang, Vu Tai
    • Korean Chemical Engineering Research
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    • v.49 no.1
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    • pp.47-55
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    • 2011
  • The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW (Ver. 5.2) in order to solve the process-problems of K company relating to cracks, which occurs at the inner cavity wall of C. V. joint boots. As a result it was confirmed that the real cracks occurs at the exactly same position of the cavity as exhibits the defects of weld and meld line and unsatisfactory curing according to the result of simulation. In order to prevent the occurrence of weld and meld line at the defect-position, the location of gate was altered to the optimum position of the cavity. Consequently the filling pattern was established to minimize the degree of the melt-fronts confronting or the melt-flows melding to prevent the occurrence of weld and meld line at the defect-position. It was observed that both gate-positions to maximize the degree of the formation of weld and meld line and air traps are located, respectively, in opposite direction each other with reference to the optimum gate position. In addition, the temperature of mold was raised by $10^{\circ}C$ and maintained at $170^{\circ}C$ for satisfactory curing.

Pre-seasonal Physical Examination of Professional Soccer Team (프로 축구팀의 시즌 전 체력검사)

  • Lee, Kyung-Tai;Choi, Byung-Ok
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.5 no.2
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    • pp.129-134
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    • 2006
  • Purpose: In the professional soccer team, we performed pre-seasonal physical examination and analyzed the results to establish a standardization data in relation to their position. Materials and Methods: We performed physical examination to the professional soccer team, consisted 34 player's average age 24.9 years. The examination performed were questionnaire on history, musculoskeletal examination, muscle power test, physiologic test, functional test. Results: According to the relationship between player position and injury pattern,. Knee injuries are most frequent on history. Physical examination outcome was that forward were prone to flexor hallucis longus tendinitis, midfielder for chronic ankle instability, defender for achilles tendinitis. Isokinetic test was done at dominant side, Peak torque to body weight ratio was 55.1%. Physiologic test checked body fat percentage was midfielder was superior as 19.8 (SD 2.9). Functional test out-come was that back strength 125 N. sergeant jump 59.6 cm, reaction time 208.5 sec, flexibility 19.2 m/s, side step 39.9 cm. Conclusion: Pre-seasonal physical examination gave us the standardization data and preventive measurement could be advocated from this results.

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The Differential Effects of Plyometric Training and Weight Training on Muscular Power, Agility and Maximal Muscular Strength of the Male and Female High-school Throwers (고등학교 투척선수들의 plyometric training과 weight training이 순발력, 민첩성 및 최대 근력에 미치는 영향)

  • Kim, Hyung-Don;Kim, Duk-Jung;Kwak, Yi-Sub
    • Journal of Life Science
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    • v.19 no.12
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    • pp.1821-1828
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    • 2009
  • The purpose of this research was to investigate how the plyometric training and weight training program, applied in the field for exercise performance of throwing players, influenced improvement of athletic abilities, including agility, maximum muscular power, and strength. After implementing plyometric training and weight training to 21 high school throwing players for 10 weeks, we designed the next step. The 21 subjects were divided into two groups - women's group and men's group. All subjects were tested to determine agility using sidestep, burpee test, reaction time, lower body power and strength using standing long jump, standing jump, 30 m running, squats and leg presses. Additionally, isokinetic strength was measured using Cybex isokinetic dynamometer. The results showed that both groups demonstrated improvement in the standing long jump, standing jump and 30 m running after training. Particularly, the women's group indicated better improvement. Second, women's groups showed higher improvement in the sidestep and burpee test. However, in the reaction time test, the men's group indicated better improvement. Third, both groups showed better improvement in squats and leg presses after training. Particularly, the women's group indicated better improvement. Fourth, in the left and right side extension torque and flexion torque at a velocity of $60^{\circ}$/sec, both groups showed better improvement after training. In the left side extension peak torque, the men's group showed higher improvement, but the women's group showed higher improvement in the left side flexion and extension peak torque. Fifth, both groups showed better improvement in bench pressing and back strength after training. Particularly, the women's group indicated higher improvement.

Measurement of the Size Distribution of Smoke Particles with Plastic Types Under Various Fire Conditions (다양한 화재조건에서 플라스틱 종류에 따른 연기입자의 크기분포 변화 측정)

  • Goo, Jaehark;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.8-15
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    • 2017
  • Most fire victims succumb to smoke inhalation, and fire smoke toxicity from interior materials is increasing with increased use of plastics. Large amounts of hazardous effects of smoke are related to deposition of smoke particles in respiratory tracts, and deposition characteristics are influenced by size distribution of particles. Thus, it is essential to know the size distribution of smoke particles from plastics for hazard analysis of fire smoke. In a recent study, it has been shown that size distributions of smoke particles from PP are different from wood in many aspects. In order to know whether other plastics show the same characteristics as PP, size distributions of smoke particles from four plastic materials (LDPE, PA66, PMMA, and PVC) were measured in real time under each fire type with various temperature and oxygen supply. In this study, smoke particles from different plastics were generated uniformly by using steady-state tube furnace method provided in ISO/TS 19700. Their size distributions were measured by using an electrical low pressure impactor (ELPI). Results of measurements showed that size distributions of smoke particles from these four plastic materials were similar to those from PP in many aspects. However, they were distinctively different from those of wood.

Performance of High Temperature Filter System for Radioactive Waste Vitrification Plant (방사성폐기물 유리화 플랜트 고온여과시스템의 성능 특성)

  • Seung-Chul, Park;Tae-Won, Hwang;Sang-Woon, Shin;Jong-Hyun, Ha;Hey-Suk, Kim;So-Jin, Park
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.3
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    • pp.201-209
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    • 2004
  • Important operation parameters and performance of a high temperature ceramic candle filter system were evaluated through a series of demonstration tests at a pilot-scale vitrification plant. At the initial period of each test, due to the growth of dust cake on the surface of ceramic candles, the pressure drop across the filter media increased sharply. After that it became stable to a certain range and varied continuously proportion to the face velocity of off-gas. On the contrary, at the initial period of each test, the permeability of filter element decreased rapidly and then it became stable. Back flushing of the filter system was effective under the back flushing air pressure range of 3∼5 bar. Based on the dust concentrations measured by iso-kinetic dust sampling at the inlet and outlet point of HTF, the dust collection efficiency of HTF evaluated. The result met the designed performance value of 99.9%. During the demonstration tests including a hundred hour long test, no specific failure or problem affecting the performance of HTF system were observed.

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Effects of Combined Resistance Training Program of Concentric and Eccentric Contraction Using Theraband on Shoulder Rotation Torque Max and Peak Power (Thera-Band를 이용한 단축성 & 신장성 수축 저항 훈련 프로그램이 어깨의 최대 토크와 최대 파워에 미치는 영향)

  • Han, Dong-Wook;Ahn, Yi-Rae;Lee, Na-Jung;Lee, Eun-Ju
    • Korean Journal of Applied Biomechanics
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    • v.19 no.1
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    • pp.139-148
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    • 2009
  • D. W. HAN. Y. R. AHN., N. J. LEE and E. J. LEE. Effects of Combined Restistance Training Program of Concentric and Eccentric Contraction Using Theraband on Shoulder Rotation Torque Max and Peak Power. Korean Joumal of Sport Biomechanics, Vol. 19, No. 1, pp. 139-148, 2009. The purpose of this study was to find out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power. 30 female students were randomly assigned to 3 equal group; concentric and eccentric, concentric, non training group. Subjects were tested in concentric and eccentric torque max and peak power of internal and external rotation using a CON-TERX isokinetic dynamometer. Subjects in training group participated in their regular five times a week for 4 weeks. After exercise, in concentric and eccentric training group, concentric and eccentric torque max, and peak power of internal rotator at 60 deg/sec were increased significantly. concentric peak power at 120 deg/sec were increased significantly. In concentric training group, only concentric peak power of internal rotator at 60 and 120 deg/sec was increased. In conclusion, we found out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power.

Effects of Isoflurane/Remifentanil and Isoflurane/Fentanyl Anesthesia in Beagle Dogs (비글견에서 아이소플루란/레미펜타닐 및 아이소플루란/펜타닐 조합의 마취 효과)

  • Park, Jiyoung;Oh, Seung-June;Lee, Hae-Beom;Jeong, Seong Mok
    • Journal of Veterinary Clinics
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    • v.32 no.2
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    • pp.148-153
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    • 2015
  • This study was performed to compare two opioid drugs with isoflurane and to determine the difference between isoflurane/remifentanil anesthesia and isoflurane/fentanyl anesthesia in terms of the anesthetic effects in beagle dogs. Isoflurane was maintained at 0.5 MAC, and the opioid drug was administered as a constant rate infusion. The anesthesia was maintained for 2 hours, and isoflurane and opioid drugs were discontinued 2 hours later. After discontinuing the anesthetics, the extremity movement time, eye global positioning time, gag reflex time, head up time, sternal recumbency time, standing time, walking time and complete recovery times were recorded for each dog. Both of the studied anesthetic protocols were suitable in beagle dogs because the anesthetic status was well maintained until the end of the procedure, and rapid recovery times were demonstrated in this experiment. And this study shows that the isoflurane/remifentanil group was more reliable than the isoflurane/fentanyl group because the recovery time CV was lower. Therefore, isoflurane/remifentanil combination anesthesia could be a better choice than isoflurane/fentanyl anesthesia if the patient is severely ill and stable recovery time is needed.

Certification and Quality Control of the Official Test Facilities of Dioxins in Korea (국내 다이옥신 측정분석기관 지정 및 정도관리)

  • Jang, Seong-Ki;Kim, Tae-Seung;Lee, Won-Seok;Chung, Young-Hee;Choi, Doug-Il
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.675-682
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    • 2000
  • The concentration of dioxins from flue gases of municipal waste incineration facilities with capacities over 50 tons/day are regulated by the guideline: $0.1ng-TEQ/Nm^3$ for new facilities, and $0.5ng-TEQ/Nm^3$ for existing facilities and it will be strengthened to $0.1ng-TEQ/Nm^3$ until 2003 year. Dioxins from these incineration facilities have to be measured more than 2 times annually by the Official Test Facilities of Dioxins. Seven institutions have been certified so far as the Official Test Facilities of Dioxins. These facilities have to be evaluated by the quality control program provided by National Institute of Environmental Research every year. We reported the results of quality control test performed in 1999. Four institutions certified in 1998 sampled flue gases at stack of M incineration facilitiy and analyzed dioxins by Official Methods of Air Pollution. The isokinetic coefficients, the parameter for evaluation of sampling ability were excellent for all four institutions. They were 100.9%, 102.4%, 102.1% and 99.2%, respectively. The criteria required are as follows; resolution over 10,000, mass calibration within ${\pm}5ppm$, ion abundance ratio within 15%, and the recovery of 50-120%. As results, those institutions also met these parameters of Official Method of Air Pollution.

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The Effect of Kinesio Taping on Muscle Strength Improvement, Blood Fatigue Factors, Muscle Fatigue and Damage Index (Kinesio taping이 근력, 혈중 피로물질 및 근 손상 물질 농도변화에 미치는 영향)

  • Lee, Min-Sun;Paik, Il-Young;Kwak, Yi-Sub;No, Hee-Tae;Jin, Hwa-Eun
    • Journal of Life Science
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    • v.20 no.6
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    • pp.870-876
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    • 2010
  • The purpose of this study was to examine the effect of kinesio taping on muscle strength and changes of muscle fatigue and damage. 10 male subjects participated in 1-RM and isometric cybex muscle strength tests with and without taping application. Muscle strength (bench press, leg press) and extension (knee, shoulder) strength were significantly increased after taping, but there was no significant difference in flexion (knee, shoulder) strength. The concentration of fatigue factors (ammonia, phosphorous), muscle damage index substances (CK, LDH), IGF-I and creatinine were reduced after taping, but there were no significant differences.

Isokinetic Evaluation of Plantarflexors with Knee Position (슬관절의 자세에 따른 족관절 저측굴곡근의 등속성 근력 평가)

  • Bae Sung-Soo;Lee Hyun-Ok;Lee Keun-Heui
    • The Journal of Korean Physical Therapy
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    • v.12 no.2
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    • pp.145-152
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    • 2000
  • Pcak torque. angle of peak torque occurrence. total work, average power. endurance of the ankle plantar flexors were studied with the knee positioned $0^{\circ}\;and\;90^{\circ}$ flexion. Plantar flexors of 20 students were tested on Cybex 6000 dynamometer. The results were as fallows ; 1. The peak torque values were significantly higher with knee extension than knee $90^{\circ}$ flexion. 2. The angle of peak torque occurrence were earlier with knee extension than knee $90^{\circ}$ flexion, but no significant. 3. The total work were significantly higher with knee extension than knee $90^{\circ}$ flexion. at$30^{\circ}/sec$, but no significant at $90^{\circ}/sec$ 4. The endurance ratio were higher significantly with knee $90^{\circ}$ flex ion than knee extension 5. The mean average power were significantly higher with knee extension than knee $90^{\circ}$ flextion

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