• Journal of the Society of Naval Architects of Korea
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• v.36 no.2
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• pp.61-71
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• 1999

This paper resents a novel cargo system adapted for a sea port subjected to severe time-varying tide. The proposed system can perform loading or unloading by using a sort of hydraulic elevator associated with real-tim position control. As a preliminary phase, a small-sized model of the cargo system is designed and constructed. The model consists of three principal components ; container palette transfer(CPT) car, platform with lifting columns and cargo ship. The platform activated by the electro-rheological(ER) valve-cylinder is actively controlled to track the position of the cargo ship subjected to be varied due to the time-varying tide and wave motion. Following the derivation of the dynamic model for the platform and cargo ship motions, an appropriate control scheme incorporating time sequence and PID(proportional-integral-derivative) controller is formulated and implemented. Both the simulated and the measured control results are presented to demonstrate the effectiveness of the proposed cargo system.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.285-290
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• 2016

To identify virtual reality (VR) interventions used for upper extremity rehabilitation in stroke patients. The Medline database was searched up to February 11, 2015. Randomized controlled and clinical trials that included a VR intervention for upper extremity rehabilitation in stroke patients were included. The Physiotherapy Evidence Database (PEDro) scale was used to assess the quality of the included studies. In total, 8 studies were included. PEDro scores varied from 5 to 8/10. All studies showed significant improvement in outcomes in favor of the VR group. This review suggests that VR applications used for upper extremity rehabilitation in stroke patients predominantly mediate learning through providing task-oriented and graduated learning with variable and unpredictable practice.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.661-667
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• 2017

The purpose of this study is to examine the effects of therapeutic horse riding on adult with intellectual disability in terms of adaptive behavior. The subjects were 16 adults with intellectual disability. They participated in a therapeutic horse riding program of 60 minutes long, Twice a week for 12 weeks. The participants' adaptive behavior level were measured before and after 12 weeks of program with Social Maturity Scale. The data was analyzed by paired t-test using the SPSS. After 12 weeks of therapeutic horse riding program, there was a significant improvements on self-help, task, self-regulation & socialization. However, locomotion, communication changes did not reach statistical significance. The result indicates that therapeutic horse riding has a positive effect on adults with intellectual disability in self-help, task, self-regulation & socialization. This study suggests that therapeutic horse riding could be considered an effective method on adults with intellectual disability to improve adaptive behavior.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.373-380
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• 2015

This study which was conducted on male tennis player on one hand(OH) & two hand(TH) backhand stroke and how both motion differed on low extremity movement with each feature analyzed in detail, the result as follow. The motion of TH based on resultant velocity, appeared to be a higher than OH, which was important variable in determining the ball speed. Contrary to TH where the player minimized the motion in the lower body and finalized a stroke through the turn of the trunk as if sticking the ball closed to the body, OH was carried out such that the player appeared to chase the ball. Whereas in OH, the knee joint extension moment was not found to be larger than TH, the opposite result came out for abduction moment and internal rotation moment. In the case of hip joint, consisted of extension, abduction and internal rotation moment, the outcome emerged to be greater for TH with conspicuous difference in abduction moment. Flection moment for TH overwhelmed in TH though both adduction and external rotation moment brought about similar outcome for both strokes.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.531-536
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• 2018

The purpose of this study is to investigate eye fatigue and analyze symptoms of visual discomfort according to near work in young adults. A survey was conducted on 347 young adults aged 25.37 years (142 male and 205 female participants). The eye fatigue using Conlon questionnaire were surveyed and near work was investigated amounts of daily computer and smartphone. The score of eye fatigue was $13.65{\pm}7.11$ in less than 2 h/d, $16.83{\pm}6.77$ in 2~4 h/d, $18.88{\pm}6.60$ in 4~6 h/d, and $18.83{\pm}5.62$ in more than 6 hours(p=0.001). Also, headache(p<0.030), re-reading(p<0.036), and movement and fading(p<0.001) symptoms increased according to amounts of near work.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.597-604
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• 2014

This research aimed at comparative analysis of body composition and basic physical strength of model majored female college students and general female college students. The research object was composed of 15 model majored female college students of D University, who learned the purpose of this research enough and wrote the consent form of voluntary participation and 15 general female college students, who have no medical history and currently no special disease, and no experience in regular exercise. They underwent body composition inspection, left right grasping power which is the basic physical strength, back muscle strength, flexibility, rapidity, muscle endurance, and the researcher performed descriptive statistics to calculate the average standard deviation, and analyzed to verify difference between groups by using independent t-test. With statistical significance level p<.05, the results are as follows. model majored female college students and general female college students showed meaningful difference between groups in weight, skeletal muscles, body fat volume, BMI and left right grasping power, back muscle strength, rapidity(p<.05). between groups in flexibility and muscle endurance(p>.05).

• Journal of Digital Convergence
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• v.11 no.11
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• pp.651-659
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• 2013

Purpose: This study was to analyze research reports published in Korea on physical activity for adult. Method: Based on inclusion criteria, 11 research reports were included in this review. Published year of selected articles was between 1990 and 2012. Eleven studies were analyzed by guidelines of the physical activity program done by experimental and quantitative research. Result: The characteristics of objects were mostly of non disease adult, over 65 years old, and female. Most educational content were about physical activity understanding, diet, nutrition. A large percentage of outcome indicators were body composition, physical function. Conclusion: Various types of physical activity program in Korea were performed by researchers. Therefore, we need to develop the standard protocol, to add educational intervention, and to study cost effectiveness of healthy.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.491-498
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• 2013

The purpose of this study was to evaluate the economy and efficiency of two trained athlete groups of different training status. The subjects were 20 elite athletes composed of the cyclists group (n=10) and triathlon group (n=10). All subjects performed steady state testing at 50, 100, and 150 watts, with ample time to reach resting $VO_2$ and ventilation values between stages. The efficiency of two groups appears to be quite different, with triathlon competitors displaying superior efficiency values for the transitions from 0 to 50 and 100 watts. This same principle likely explains the economy of the groups, as triathlon competitor was again more economic at 50 and 100 watts. As though this matching of oxygen consumption and workload they can reduce the amount of oxygen deficit that must be repaid post exercise.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.3
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• pp.26-37
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• 1998

In this study, the motion control techniques allied to the test ship NARAE are summarized and the results of sea trials are resented. NARAE adopted a hybrid hull form with lower hull and submerged foils. This type of ship has a substantial instability in heave, pitch and roll modes at the foil-borne stage due to little restoring force, so an active control is indispensable to keep the stability. 4-hydraulic actuators with servo valves were installed to drive foils, and several sensors were used to measure the motion of the ship. PID controller was adopted as a motion controller, and for the real-time control, Pentium-class industrial PC was used. Sea trials including take-off, landing, and banked turn maneuvering were carried out for a period of over 3 months and quite satisfactory results were obtained.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.237-244
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• 2015

Export-led policies, FTA signed and economics of scale through a variety of market-oriented policies, such as regulations to improve market grew constantly. Accordingly, the correct decision making accurately analyze the economics market for decision, a problem has been an important issue in predicting. For accurate analysis and decision-making of the most common indicators of the stock market by proposing a number of indicators of economic transformation techniques were applied to the convergence model combining estimation and forecasts problem confirmed its effectiveness. Experimental result, gave the model estimation method to apply a transform to show the valid combinations proposed model state estimation result was confirmed in a very similar exercise aspect of the physical problem and the KOSPI index prediction.