• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.289-309
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• 2014

A rotor blade is an important device that converts kinetic energy of wind into mechanical energy. Rotor blades affect the power performance, energy conversion efficiency, and loading and dynamic stability of wind turbines. Therefore, considering the characteristics of a wind turbine system is important for achieving optimal blade design. This study examined the general blade design procedure for a wind turbine system and aero-structure design results for a 2-MW class wind turbine blade (KR40.1b). As suggested above, a rotor blade cannot be designed independently, because its ultimate and fatigue loads are highly dependent on system operating conditions. Thus, a reference 2-MW wind turbine system was also developed for the system integrated load calculations. All calculations were performed in accordance with IEC 61400-1 and the KR guidelines for wind turbines.

• Women's Health Nursing
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• v.13 no.3
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• pp.165-173
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• 2007

Purpose: The purpose of this study was to exam me the effects of aquatic exercise on pain, fatigue, body composition, physical fitness and psychological variables in women with arthritis. Method: With a quasi-experimental design, 37 women who had arthritis were assigned into an experimental group (n=19) or a control group (n=18). Aquatic exercise consisted of one hour of exercise in water, two days per week, for six weeks and a self-help process. Measures included physiologic and psychological variables before and after the exercise. Data was analyzed with the SPSS WIN using descriptive statistics, t-test, and ANCOVA. Result: The mean age of the subjects was 59 years in the experimental group and 52 years in the control group. Pretest scores in outcome variables were similar in both groups except BMI and body fat(%). After controlling for age, shoulder flexibility scores in the experimental group improved more than the control group (Rt: F=10.58, p=.003; Lt: F=5.91, p= .02; Waist: F=4.95, p= .03). Depression scores in the experimental group decreased (F=12.96, p= .001), and self efficacy and quality of life improved more than the others (F=5.07, p= .03; F=6.9l, p= .01). Conclusion: Aquatic exercise can improve waist flexibility and shows consistent findings of improved shoulder flexibility and psychological function in women with arthritis.

• The Journal of Korean Medicine
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• v.22 no.4
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• pp.90-100
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• 2001

Objectives : Bambusae Caulis in Liquamen (BCL) has been used for stamina fortification in Oriental Medicine for thousand years. The goal of the present study was to investigate the muscle antifatigue effect of BCL. Methods : The mice were divided into three groups. The control group was allowed to swim for 10 minutes without BCL infusion. For the preventive effect of BCL, another group referred to BCL-1 was fed with BCL an hour before the swimming exercise. BCL-2 group for the reversion effect was forced to swim for 10 minutes at first, then fed with BCL followed by half an hour rest and another 10 minute swimming exercise. All the serum samples collected by heart puncture were used for the measuring biochemical factors such as LDH, CPK, glucose, lactate, triglycerides and total cholesterol. Results : In the BCL-2 group, lactate and LDH were significantly reduced compared to the control. BCL infusion during the exercise was effective in metabolizing LDH, reducing the conversion ratio of pyruvate into lactate. In the BCL-1 group, it was not effective in antifatigue function. The level of glucose was significantly reduced in BCL-1 group compared to the control. When the BCL was infused before the exercise, it is assumed that glycogenolysis seen during the exercise was prevented. When the BCL was infused during the exercise, the triglycerides and total cholesterol were increased significantly compared to the control. BCL seems to cause the increase of lipolysis to utilize the fat as an energy source. Unlike other parameters, CPK did not show any changes from BCL infusion. Conclusions : Based on the above results, BCL is found to be involved in energy metabolism. Further studies are needed to find out the underlying mechanism of BCL for its effect on stamina fortification.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.455-460
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• 2007

Majority of toothache is caused by abnormality of pulpal or periodontal tissues. However, there are numerous nonodontogenic sources that may be responsible for pain felt in the tooth. Nonodontogenic toothache may result from muscle, maxillary sinus, neuropathic, neurovascular, even cardiac and psychogenic problems. Myofascial pain is one of the most common abnormality characterized by palpation of a hard band which acts as the trigger point that causes stiffness and fatigue of the muscle, referral pain in tooth, tension-type headache, and hyperalgesia. Masseter muscle particularly induce referral pain in maxillary and mandibular molars. This case reported the treatment of the pain in right mandibular molar originated from myofascial pain of the right masseter. The pain is improved by general and reversible treatments such as muscle exercise, physical therapy, and medication. Nonodontogenic toothache should undergo proper differential diagnosis in order to avoid unnecessary dental treatments, such as endodontic, periodontic treatment, and tooth extraction, which would fail to alleviate the symptom of the patient.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.95-100
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• 2003

Purpose: To evaluate the incidence, contributing factors, and clinical results of refracture of proximal 5th metatarsal stress fracture treated operatively in athletes Materials and Methods: This study included 8 patients who had been treated for refracture of proximal 5th metatarsal stress fracture with operaton. Their charts & radiologic findings were evaluated retrospectively. Results: The overall incidence of refracture was 13%. Main contributing factors were time of return to sports activity and associated deformities such as cavus foot or flat foot. Seven cases were managed with nonoperative treatment, and we added percutaneous pin fixation under local anesthesia in one case. Bony union was seen at average 8. 5 weeks in 7 cases except 1 nonunion and all of 8 patient returned to athletics at average 16 weeks. Conclusion: The incidence of refracture of proximal 5th metatarsal stress fracture treated operatively in athletes was relatively high. Time of rerum to sports activity must be decided very carefully on individual situation and further imaging study may be helpful for bony union evaluation. The non-operative treatment may have a good result if bone graft was done initially.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.100-104
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• 2006

The Incidence of groin injury was about 10% in football player These injuries occur most commonly in athletes participating in sports Involving cutting, quick accelerations and decelerations and sudden directional changes. Symptoms may range from intermittent episodes of mild discomfort to severe and chronic career-ending pain. Groin injuries may result from a variety of causes. We must keep in mind that many other conditions may also affect the groin. Because of the anatomy of the region is so complex. Ligament/muscle strains, nerve entrapment syndromes, sportsman's hernia, symphysitis, stress fractures and various hip pathologies are reviewed as causes of groin pain are reviewed as common causes of groin pain.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.176-191
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• 2004

The purpose of this study was to find the effects of the eccentric exercise induced delayed muscle soreness on proprioception, muscle strength, muscle fatigue, and muscle pain of the elbow flexor muscles. Thirty one healthy male subjects were participated in this study. Before resisted eccentric exercise of the elbow flexors and immediately and at 1, 3, 5, and 7 days post-exercise, pain threshold, proprioception, tension tracking, initial median frequency, and fatigue index were measured. Pain pressure threshold and visual analog scale (VAS) was used to measure muscle pain. Proprioception of the elbow joint was measured by using 3 dimension motion analysis system. Maximum isometric contraction was measured by using digital tensiometer. Electromyography and power spectrum analysis was used to measure initial median frequency (IMF) and fatigue index (FI). Immediately post-exercise, a significant decrease pain threshold was observed that continued to 5 days post-exercise. VAS score was significantly increased at 1 and 3 days post-exercise compared to that of immediately post-exercise. Maximum isometric contraction, IMF, tension tracking ability of the exercised elbow joint were significantly decreased at 1, 3, and 5 days post-exercise compared to that of pre-exercise. FI was significantly increased at 1 and 3 days post-exercise compared that of pre-exercise. Proprioception sense of exercised elbow joint was significantly decreased immediately and at 1, 3, and 5 days post-exercise compared to that of pre-exercise. Proprioception sense of the contralateral elbow joint was significantly decreased immediately post-exercise compared to that of pre-exercise. However, proprioception sense that was measured in close chain kinematic position was not significantly difference between pre-exercise and post-exercise. These results could be useful to determine the resume time for exercising and participating sports activities.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1453-1459
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• 2011

A roller pinion gear (RPG) system composed of either a pin or a roller and its conjugated cam gear can improve the gear endurance from that of a conventional gear system by reducing the sliding contact while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection condition obtained when the profile shift coefficient is introduced. Then, we investigated the Hertzian contact stresses and the load stress factors while the varying the shape design parameters to predict the gear surface fatigue life, which is strongly related to the gear noise and vibration at the contact patch. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.252-257
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• 2004

The purpose of this study was to investigate the variation in constituent element of blood between the massage group and non-massage group in the period of convalescence after giving intense physical exercise for ten T'ae-Kwondo martial artists. In the variations of red blood cells, white blood cells, hematocrit, hemoglobin and blood platelet, levels decreased during the rest time after physical exercise, but the subjects in the massage group showed lower tendency than the subjects in the non-massage group after physical exercise. The variation of calcium showed an ascension tendency in the massage group after physical exercise. Creatine phosphokinase was increased after physical exercise, but it showed a tendency of rapid decrease in the massage group. Lactic acid showed a variation increase after physical exercise. It showed a tendency of decrease during the rest time in the non-massage group, but it was increased after sports massage. The variation of blood glucose was increased after physical exercise. It was maintained in the massage group after physical exercise in contrast to the non-massage group whose levels decreased during the rest time.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.1
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• pp.21-28
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• 2015

Background: The purpose is to investigate the immediate effects of kinesio taping on quadriceps induced fatigue by short-term squat. Methods: This research is cross-over designed study and conducted as a single-blind. Eleven students (Age: $18.91{\pm}0.49yrs$, height: $167.09{\pm}8.46cm$, $62.55{\pm}11.32kg$) were participated in this study. All the participants were applied short-term squat for inducing fatigue, and then intervented all three conditions (kinesio taping applied condition, placebo taping applied condition, non-taping applied condition). The interval of each intervention was at least a seven days to prevent carry-over effects. The participants were tested peak torque (isometric contracture) and active joint position sense (active JPS) pre-post intervention. A paired t-test was used to find the significance of pre-post intervention results and one-way ANOVA was used to find the significance between interventions with significant level as .05. Results: Peak torque was significantly increased on KT condition (p<.05). But there were no significant effects on active JPS. Because kinesio taping facilitates Ia afferent by tactile stimulation with stretched skin, reduced muscle power by short term squat which induce muscle fatigue was increased. But kinesio taping does not affect mechanoreceptor in muscles, induced active JPS by short-term squat had no changes.