• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.999-1010
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• 2003

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulators because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electric lines is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H$\_$$\infty$/ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.3
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• pp.39-47
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• 2016

PURPOSE : This study attempts to find the effects of water perturbation exercise performed on stroke patients in their physiological cost index and gait ability tests. METHOD : The subjects were 30 stroke patients, water perturbation exercise group was performed 3 day per week, for 40 minutes a day, for a period of eight weeks. The physiological cost index and gait of all subjects were assessed by using the polar, 6 Minute Walk Test (6MWT), and 10 meter Walk Test(10mWT) at pre training and post training. Paired t-test was used to analyze change before and after intervention in group. Pearson's correlation was used to analyze correlation of all variables. RESULT : Water perturbation exercise group showed increased physiological cost index. Water perturbation exercise increased gait ability, showing a significant difference. Showing the correlation between the relatively high amount between physiological cost index and 6 minutes walking test. CONCLUSION : From the result of the study, we found that water perturbation exercise was effective in improving physiological cost index and gait ability. The patient is considered to be used by itself to involve the treatment and the risk of falling from the lowered state into the treatment method for the intensive treatment of stroke patients to be useful in improving the cardiovascular system and ability to walk. Through underwater training for stroke patients in the future on the basis of this study it is considered to require additional clinical studies on the impact on daily living and quality of life of stroke patients.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.137-147
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• 2017

An accident during pilotage may cause several problems such as crippling the harbour function, environmental disruption, loss of life. Since the pilot plays an important role in the safe operation of the port, securing their safety is directly connected to the vessel's safety coming into port in Korea. Pilotage service is offered on request without distinction of day and night. And traveling by helicopter and boarding/disembarking using a pilot ladder from and to a pilot boat have a high risk of falling into the sea. So, pilots can fall into the sea while boarding/disembarking from ship which can lead to serious injury by cardiac arrest. A number of pilots have died or severely injured due to fall from the pilot ladder during embarkation and disembarkation up to now. Current safety measures at embarkation and disembarkation required by pilotage act and IMO resolutions could not prevent all the pilot related accidents. Therefore, to prevent pilot accident during boarding/disembarking from ship, it is necessary to include safety training requirement for new pilots under the requirements for licensing of pilotage act. It is also necessary to compel pilots to take necessary personal protective equipment when they use a pilot ladder. In addition, the placement of emergency kit on pilot boats and first-aid training are required in order to deal with emergency situation promptly.

• PNF and Movement
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• v.15 no.3
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• pp.253-257
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• 2017

Purpose: This study was conducted to predict the risks that arise while standing on mediolateral ramps at various ramp angles by identifying the ratio of medial to lateral gastrocnemius muscle activities. Methods: The subjects were 20 healthy adult men. Seven mediolateral ramp angles ($0^{\circ}$, $2^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$, and $25^{\circ}$) were applied for the experiment. The ratio of medial to lateral gastrocnemius muscle activities in each condition was measured using electromyography, and the measured data were converted to root mean square values to calculate the activity ratios. Results: The study results showed statistically significant differences in the ratio of mediolateral gastrocnemius muscle activities according to the selected mediolateral ramp angles. The results of a post hoc test confirmed that the multifidus muscles were asymmetrically used on the two sides at mediolateral ramp angles of $5^{\circ}$ or higher. Conclusion: This study found that an asymmetric use of the multifidus muscles began at a mediolateral ramp angle of $5^{\circ}$, and the provision of propulsion using the ankle joints on mediolateral ramps at $5^{\circ}$ or steeper was maneuvered differently from that on flat ground. This suggests that individuals with balance control disorder have the risk of falling due to ankle sprains and unstable balance control. Therefore, patients and elderly people are required to exercise caution when crossing $5^{\circ}$ or steeper ramps.

• Quality Improvement in Health Care
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• v.3 no.1
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• pp.78-93
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• 1996

Background : The goal of this study was to establish the QA items and guidelines for preventing and improving of safety management. Therefore we investigated the nurses' recognition and knowledge of the safety and risk procedures and policies, and the agreement between the nurses beliefs on the degree of importance of those procedures and policies, with actual implementation in hospitals. Method : The subjects of this study were 201 nurses who participated in a program called continuing education for nurses, which held in December, 1993. Result: The results of this study were as follows: 1. Among 18 types of hospital risks, the items that scored highest or the need of closer attention in safety management was the needle stick, medication errors, falling, and bed sores. 2. In most questions of the 18 incidences, the nurses showed that the estimated result would have positive signs except for hospital infections, burns, and bed sores. 3. Even though the survey shows that incidences and types of occurences varies according to the person's age and the time of incident, they mostly occur between midnight to 6AM. Falls and bed sores can be seen more in the elderly. Medications errors, hospital infections and burns are frequently found between the ages of one through twenty. 4. There was a higher mean score for recognizing the importance of those items than the importance of implementing them. Conclusion : In summary, nurses did perceive the need of safety management but the hospital policy for proper safety management was not established. So we recommended that the hospital administration would undertake an early detection and proper management system for hospital precautions, based on QA items & guidelines presented in this study.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1561-1572
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• 2016

The ability to handle materials from one location to another, whether during transit or at the worksite is vital to all segments of industry. To varying degrees, many personnel in numerous workplaces take part in materials handling. Consequently, some employees are injured. In fact, rigging & slinging is a dangerous work using a crane and sling equipment to carry a cargo and the mishandling of materials is the single largest cause of accidents and injuries in the workplace. The majority of accidents associated with cranes and other lifting appliances are caused by faulty slinging, overloading, unbalanced loads, etc. which result in the load falling or tipping out of control, causing injury to people, damage to plant, machinery and the load. Therefore, recognizing the dangers of the works, there are much technical support including skill training in various institutes to minimize accidents during works on land. Although rigging work at sea is much dangerous than on land work because it needs to take account of the movements of the ships and waves, etc. in addition to land based rigging hazards, it is insufficient in appropriate actions that can improve the safety of the workers at sea. Therefore, this study suggested a rigging and slinging course for seafarers to improve their safety at sea by researching hazards and risk of rigging works and related skill training conducted on land.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.217-223
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• 2019

The relationship between balance and ankle muscle characteristics (strength and flexibility) may be important to identify those at an increased risk of falling and to develop fall-prevention training programs. The association between ankle muscle characteristics (strength and flexibility) and balance has not previously been studied. The purpose of this study assessed the relationship between ankle muscle characteristics and balance. Sixteen healthy participants volunteered to participate in the study. Dynamic balance measured using Y-balance kit. Ankle muscle characteristics (strength and flexibility) measured using hand-held dynamometer and goniometry. The results indicated a positive correlation between ankle invertor muscle strength and Y-balance test performance. Clinicians should consider ankle muscle strength during therapeutic interventions to improve dynamic balance.

• Safety and Health at Work
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• v.12 no.4
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• pp.511-516
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• 2021

Background: Difficulties in walking and balance are risk factors for falling. This study aimed to predict dynamic balance based on demographic information and anthropometric dimensions in construction workers. Methods: This descriptive-analytical study was conducted on 114 construction workers in 2020. First, the construction workers were asked to complete the demographic questionnaire determined in order to be included in the study. Then anthropometric dimensions were measured. The dynamic balance of participants was also assessed using the Y Balance test kit. Dynamic balance prediction was performed based on demographic information and anthropometric dimensions using multiple linear regression with SPSS software version 25. Results: The highest average normalized reach distances of YBT were in the anterior direction and were 92.23 ± 12.43% and 92.28 ± 9.26% for right and left foot, respectively. Both maximal and average normalized composite reach in the YBT in each leg were negatively correlated with leg length and navicular drop and positively correlated with the ratio of sitting height to leg length. In addition, multiple linear regressions showed that age, navicular drop, leg length, and foot surface could predict 23% of the variance in YBT average normalized composite reach of the right leg, and age, navicular drop, and leg length could predict 21% of that in the left leg among construction workers. Conclusion: Approximately one-fifth of the variability in the normalized composite reach of dynamic balance reach among construction workers using method YBT can be predicted by variables age, navicular drop, leg length, and foot surface.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.334-344
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• 2021

The study has suggested a way to minimize safety accidents found in on-site firefighting activity by analyzing firefighters' [investigation report on accidents to on-sie workers]. The study result is described as follows. First, the result of [investigation report on on-site workers] shows that while accidents are found to most frequently have occurred to low-ranking firefighting officers such as Sobangsa and Sobanggyo and firefighting officers with career of less than 5 years, fire-extinguishing activity proved to be the most prone to accidents in the category of activity. Second, analysis performed to identify variance between injury extent and area based on cause of accident shows statistically significant variance. In addition, the result of verifying difference in cause of accident based on category of activity shows significant difference with 'falling over and sliding' being the highly likely cause of accident in fire containment and rescue activities and 'reckless move' being highly likely case of accident in emergency activities. Third, the result of verifying factors behind the extent of injury done to on-site workers shows that when accident is caused by 'incomplete behavior', it was found that the extent of injury is substantial. It was also found that rescue activity is accompanied by substantial extent of injury. As a solution to this, the study suggested ways to establish, extend and operate safety-specific curriculum for entrants, develop materials regarding risk prognosis training and explicate training-related regulations, set up safety management measure for a single squad team, upgrade performance of private protection equipment, institutionalize SOP by on-site activity stage, materialize and activate swift rescue team and increase objectivity and proficiency of safety accident investigation.

• Journal of Convergence for Information Technology
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• v.9 no.3
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• pp.44-55
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• 2019

The purpose of this study was to investigate the experiences of male college students through sport toto gambling and to provide basic data on the prevention program for male college gambling addicts. Participants in the study were eight male college students who were interviewed in depth and analyzed according to Colaizzi's phenomenological study method. As a result of this study, four categories of experiences were derived as follows: Like the wind that rushes to the sea, Tears of remorse, A locked down life and On a dream day. Research shows that sports toto is easy to access and has a lot of interesting factors, however it has been found out that male college students have a great risk of falling into addiction aiming to win at once like ordinary gamblers. Therefore, this study suggests that gambling preventive education and counseling are necessary for male college students who like sports.