• Physical Therapy Korea
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• v.19 no.3
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• pp.20-30
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• 2012

The purpose of this study was to determine the effect of ankle joint mobilization with movement (MWM) on the range of motion (ROM) in the ankle, on the muscle strength of lower extremities, and on spatiotemporal gait parameters in chronic hemiplegic patients. Fifteen subjects with chronic stroke were divided into two groups: an experimental group (8 subjects) and a control group (7 subjects). Both groups attended two or three sessions of physical therapy each week. The experimental group also attended additional MWM training sessions three times a week for five weeks. For both groups, the ROM of the ankle, the muscle strength of the lower extremities, and the spatiotemporal gait parameters in paretic limbs were evaluated before and after the training period. The results showed that the experimental group experienced more significant increases than did the control group in terms of passive (6.10%) and active (21.96%) ROM of the ankle, gait velocity (12.96%), and peak torque, of the knee flexor (81.39%), the knee extensor (24.88%), and the ankle plantar flexor (41.75%)(p<.05). These results suggest that MWM training in patients with chronic stroke may be beneficial in increasing ROM in the ankle, muscle strength in the lower extremities, and gait speed.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.129-143
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• 1997

This study was carried out to assess the relationship between job characteristics(job strain) and psychosocial distress, and to find out the effect of social support on psychosocial distress. The study design was cross-sectional, and included 1,211 industrial workers in middle-sized city. A self-administered questionnaire measured job characteristics(jod demand, job control), and social support(coworker support, supervisor support) at work. Psychosocial distress was measured using PWI(Psychosocial Well-being Index), a 45-item self-administered instrument. Among the 1,211 respondents, the prevalence of psychosocial distress was 24.8% High job stram (high job demand + low job control) was present in 8% of the subjects. The crude odds ratio of high job strain was 4.76 (95% CI : 2.60-8.74), and those of active group and passive group were 3.81(95% CI : 1.82-3.95) and 2.64(95% CI : 1.77-3.94), respectively. The odds ratios of each group adjusted for sex, age, support, and religion were still significant. Our results supported the association between job strain and psychosocial distress. Social support at work, although significantly associated with psychosocial distress, did not modify the association between job strain and psychosocial distress.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.91-98
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• 2013

The degradation of durability and increase of fatigue on the ship are mainly caused by vibration of the engine and rotating machineries. The damper to minimize the influence from vibration is usually attached between the machineries and its base. General damper applied on the vessel is passive damper which is designed to attenuate specified frequency signals, i.e, high frequency vibration signals. But it is hard to anticipate its performance for low frequency signals. In this research, active vibration isolator using VCM is developed to suppress wide band vibration signals. Routh-Huritz's stable condition, ultimate sensitivity method and parameter tuning are applied to derive PID parameters and 2 and 4 phase choppers are also adapted to drive VCM. Simulation and experiments are executed to confirm the effectiveness of the proposed control schemes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1447-1453
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• 2012

For an electromagnetic suspension (EMS)-type urban Maglev train using U-shaped electromagnets, both the vertical and the lateral air gaps for levitation are maintained only by the electromagnet. The train can run over curved rails without active lateral air gap control because the U-shaped electromagnet simultaneously produces both a levitation force and a guidance force, which is dependent on the levitation force. Owing to the passive control of the lateral air gap, the lateral vibration could exceed the limits of the lateral air gap and acceleration. In this study, dynamic analysis of a Maglev train is carried out, and the effectiveness of a lateral damper for vibration reduction is investigated. To more accurately predict the lateral vibration, a Maglev vehicle multibody model including air-sparing, guideway irregularities, electromagnets, and their controls is developed.

• Journal of the Korean Solar Energy Society
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• v.30 no.1
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• pp.50-60
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• 2010

Today, the amount of energy consumption in the university campuses is huge. The effort for the energy consumption reduction in university campuses is certainly needed by the following reason; first, contribution to the greenhouse gas discharge reduction demand. Second, energy cost reduction in university campus. Third, contribution to the improvement of the social awareness as the maximum higher educational institutions. The energy consumption analysis of current situation has to be executed for the energy consumption reduction in university campus. The energy reduction possibility in which it exists in university campuses can be understood through the energy consumption analysis. And the application is possible as fundamental data of the policy establishment for the effective energy reduction in university campuses. Especially, the best way to reduce the energy consumption in university campuses that is the energy consumption reduction of buildings. Accordingly, this study derived the plans for improving the performance of energy in the university building by analyzing case study, so this study analyzed the performance of energy for the university building through VE, a program for the analysis of building energy. Based on this result, this study classified the plans improving the efficiency of energy in university building into the plan for passive control and active control respectively, and suggested some concrete plans, and finally evaluated the performance of decreasing energy consumption for each plan.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.199-208
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• 2017

Lithium polymer batteries are used in energy storage systems (ESS), electric vehicles (EVs), etc. due to their high safety, fast charging and long lifecycle, and now they are used in agricultural drones. However, when overcharging and overdischarging, the lithium-polymer battery is destroyed in the gap structure in the lithium-ion battery and the battery life is reduced. In order to prevent overcharge and overdischarge, uneven cell voltage Cell balancing system is needed. In this paper, a fuzzy controller suitable for nonlinear systems is proposed by detecting the unbalanced cells by detecting the voltage difference between charging and discharging of each cell, and suggesting the applied cell balancing algorithm. In this paper, we have designed the cell balancing of the battery pack of agricultural drones by fuzzy control and it is designed for equal control between cells. As a final result, we checked whether cell balancing is good, and when there are two cells, Cell balancing was confirmed. We tested whether it could be used for other products. As a result, we confirmed that cell balancing is good regardless of the number of cells used.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.4
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• pp.205-221
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• 2018

This systematic review aimed to analyze the efficacy of corticosteroid premedication compared to placebo or no treatment to reduce postoperative pain in endodontic patients. Randomized controlled trials (RCTs) assessing corticosteroids via oral, intramuscular, subperiosteal, intraligamentary or intracanal route compared to passive or active placebo, or no treatment were included. Four databases were searched: PubMed, Web of Science, Cochrane Library and Embase up to 2/21/2018. Risk of bias was assessed with Cochrane Risk of bias tool. Fourteen RCTs with 1,462 generally healthy adults in need of endodontic treatment were included. 50% of the studies were at unclear risk and 50% at high risk of bias. Meta-analysis showed Visual Analog Scale (VAS) pain at 4-6 hours after Inferior Alveolar Nerve Block (IANB) was significantly lower by 21 points (0-100 scale) in the corticosteroid group compared to the control group (95% CI -35 to -7; P = 0.003), however this difference was not statistically significant after 24 hours (P = 0.116). The route of administration was oral and intraligament injection. Patients who received corticosteroids prior to IANB were 70.7% more likely to have none or mild pain 4-8 hours after treatment (P = 0.001) and 13.5% more likely 24 hours after IANB (P = 0.013) than patients in the control group. In conclusion, corticosteroid administration (oral or intraligamental) may clinically reduce the level of postoperative pain at 4-8 hours after IANB, however the quality of the evidence was low/moderate due to risk of bias and heterogeneity. Further studies are recommended.

• Journal of the Korean Society of School Health
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• v.25 no.1
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• pp.122-132
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• 2012

Purpose: The purpose of this study is to determine the effectiveness of cooperative learner-centered methods of sex education. Methods: This study was carried out on 5th grade elementary school students in D-district. Nine classes were divided into 3 groups using each different teaching methods: group A (a cooperative learning), group B (a lecture) and group C (a control group for a comparison). The study period was from Oct. 17 to Dec. 2 in 2011. Both groups A and B received sex education lessons for 40 minutes for 4 weeks and were tested their sex knowledge and attitude to compare the differences. Results: The scores of sex knowledge for all three groups were increased and their sex attitude was increased as well. The points of sex knowledge between pre and post test in group A are greater than the group B's. Thus, the cooperative learning approach with Group A was more effective to improve student's sex knowledge. But the difference between the sex attitude scores was not statistically significant. Group A and B showed a positive improvement in both their sex knowledge and attitudes compared with the control group. Conclusion: This experiment shows that an active teaching methods is more effective to improve student sex knowledge than a passive approach. Thus, a cooperative learning method results in increases of both student's sex knowledge and interests in learning sex education. It needs to develop more diverse teaching methods and programs on sex education that are more systematic and tailored.

• Journal of Korean Physical Therapy Science
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• v.2 no.4
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• pp.817-822
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• 1995

Even though back pain therapy has greatly improved as spinal bio-mechanics is introduced, many patients still have difficulties due to low back pain. At the initial therapeutic stage, the aim of rehabilitation therapy for low back pain is pain control, but, at the later therapeutic stage, the prime aims are to reduce the late complication and to prevent the recurrence of low back pain. Accurate diagnosis should be a first step before any therapy is planned. Thus, accurate physical, neurologic, E.M.G. and radiologic tests are required to give prescription for therapeutic exercise to the patients. In addition to this, the roles of theraphists and therapeutic exercise should be re-evaluated after the therapeutic exercise is performed. Fist of all, the most important things are to educate the patients to understand the low back pain and to let the patients join the therapeutical planning. 1. Bed rest and muscle relaxing exercise for releasing the muscle tention are required for the treatment of acute low back pain. An active exercise is recommended rather than a passive exercise. If the therapeutic exercise depravate the low back pain, the exercise should be immediately terminated and the therapeutical exercise should be replanned. 2. For the treatment of the chronic back pain, stretching exercise and para-spinal muscle strengthening exercise should be performed steadily and actively to prevent the recurrence of low back pain and the low back injury due to minor damage. The patients should be educated to do proper exercise and to maintain good posture in everyday life. 3. As the low back pain is released and the body function is recovered, control of whole body function is necessary. Swiming, bicycling and walking for $30\sim40$ minutes a day and $3\sim4$ days a week are recommended. Other exercise could be recommended depending on the patients condition.

• Physical Therapy Korea
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• v.24 no.1
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• pp.1-8
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• 2017

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group ($n_2=15$). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.