• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.7-13
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• 2009

Recently, the interest on walking assistances in order to assist aged people has increased due to the increase of the aged. However, most walking aid systems have a weakness for a slope because they don't have power. So, they have a weak point which makes users difficult to move when they are weak in the legs. That is why the interest on walking assistances with power has increased. The use of the walking aid systems should be easy because most users are old people. Thus, we produce module to grasp walking intent of users by using various sensors such as potentiometer, FSR(Force Sensing Resistance) Sensor and Stretch Sensor and calculate the response time to the module. Firstly, the response time of handlebar which is a kind of potentiometer is 420ms and Resilience of it is 140ms. Secondly, the response time of handlebar which use FSR Sensor is 320ms and Resilience of it is 220ms. Finally, the response time of the Stretch Sensor is 160ms and Resilience of it is 140ms. The performance of Stretch Sensor is the best among the three kind of sensors.

• Journal of Korea Water Resources Association
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• v.37 no.8
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• pp.653-662
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• 2004

In this study, the method of Increasing the flood control as well as conservation effects is studied by joint operation of Hwacheon and Peace Dam. After completing the second phase of the construction of the Peace Dam, the dam crest height will be increased from 225m and the storage capacity will also be increased. If storage capacity is increased and gates are installed, it will assist not only flood control but also conservation of the entire Han river basin. Considering the change of conservation levels, the change of the restricted water level of the Hwacheon Dam in flood season, and the inflow change into the Peace Dam through the simulated reservoir operation, the annual average power of Hwacheon Dam with 95% reliability, annual firm power, the volume of water supply is calculated. As a result, when the conservation level of the Peace Dam and the restricted water level of the Hwacheon Dam are increased, the generation capacity will be improved. However, even though the inflow decrease, the generation capacity will not be affected. If the inflow decrease under the same conditions, the water supply capability will be reduced to the range from 35% to 40%. It is necessary to increase conservation level to keep the same water supply capability.

• The Korean Journal of Rehabilitation Nursing
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• v.6 no.2
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• pp.137-151
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• 2003

The purpose of this study was to develop a multidisciplinary team approach program for stroke survivors, and to identify its effects on their rehabilitation. The team was composed of 7 members: a rehabilitation nurse, a physician, a physical therapist, an occupational therapist, a therapeutic recreational therapist, a nutritionist, and a researcher. A quasi-experimental study was performed with 36 subjects: 18 in the experimental group and 18 in the control group, using a noneqivalent control group pretest-posttest design. The experimental group participated 4 times in rehabilitation programsfocused on information and emotional support provided by the rehabilation team-and received telephone counseling from the researcher. The control group did not receive any treatment. The selection criteria for the subjects in this study were: (a) patients who were diagnosed as having had an ischemic stroke within the last year, (b) patients free of any communication disorder, (c) and those having a primary caregiver who could assist in filling out the form assessing the level of ADL. The data were collected from patients who had been discharged from a tertiary hospital, between October 1st, 1999 and September 30th, 2000. The data were analysed by $X^2$ test, Fisher's exact test, ANCOVA, Wilcoxon's rank sum test, and Wilcoxon's signed rank test using an SAS program. The results were as follows: 1. In terms of physical variables (blood pressure, grasp power, and ADL) 1) There was a significant difference in blood pressure between the two groups (systolic pressure P= .012, diastolic pressure P= .050). 2) There was also a significant difference in grasp power between the two groups (affected side : P= .012, unaffected side : P= .010). 3) There was no significant change in the level of ADL between the two groups. 2. In terms of psychosocial variables (depression, self-efficacy, self-esteem, and social activities) 1) There were no significant differences between the two groups. However, all four psychosocial variables showed a tendency to improve in the experimental group, while only two variables (depression and self-efficacy) showed a simalar tendency in the control group. 2) The level of social activities in the control group decreased significantly after a month (P= .050). 3. The level of life satisfaction improved in both groups, but no significant difference was found. Stroke has high recurrence rate and requires considerable follow-up care. The program used in this study was developed and designed for stimulting the rehabilitation process of stroke survivors. Through the program period of one month (meetings were held weekly), a positive effect was detected in physical variables, although the psychosocial variables did not improve significantly. In retrospect, a one month period may not be an adequate length of time to improve the psychosocial variables, as the stroke survivors were complicated cases, and most of them were elderly. Further research is therefore recommended by increasing the length of program, so that its effect can be more noticeable.

• Korean Journal of Acupuncture
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• v.30 no.2
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• pp.135-142
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• 2013

Objectives : This study aimed to investigate the general effects of low-frequency electrical stimulation of the ankle joint acupuncture points(BL62 and KI6) on the brain waves of elderly women as a pilot study to figure out the possibility of candidate non-invasive and non-chemical stimulation method for the enhancing the brain function. Methods : A randomized, controlled, double-blinded clinical trial was performed in 31 healthy women(mean age, 54.5 years) within a treatment duration of 12 sessions. In the experimental group, low-frequency electrical stimulation was applied using the maximum range of the individual insensible strength(mean current, $0.04{\mu}A$). The control group received sham stimulation. The background electroencephalographic activity was measured before and after the12 sessions. Results : After 12 sessions of stimulation, the relative power of the alpha wave increased(32 of 32 channels: significant difference in 11 channels, p<0.05); the theta(30 of 32 channels: significant difference in 10 channels, p<0.05), beta(31 of 32 channels), and gamma(30 of 32 channels: significant difference in 7 channels, p<0.05) powers were also decreased compared with the sham group. Conclusions : Electrical stimulation on the ankle joint acupuncture points(BL62 and KI6) seemed to stabilize the elderly women brain by inducing the alpha power and reducing beta, theta, and gamma powers. These results provide insight into the action mechanism of the stimulation and can assist the future developement of a non-invasive and non-chemical treatment technique for stressor related cognitive problems.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.61-68
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• 2010

A magnetotelluric (MT) survey has been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Korea. To assist interpretation of the MT data, geological surveying and well logging of existing wells were also performed. The surface geology of the island shows Cretaceous and Jurassic granite in the north and Precambrian schist in the south. The geothermal regime has been found along the boundary between the schist and Cretaceous granite. Because of the deep circulation along the fracture system, geothermal gradient of the target area exceeds $45^{\circ}C/km$, which is much higher than the average geothermal gradient in Korea. 2D and 3D inversions of MT data clearly showed a very conductive anomaly, which is interpreted as a fracture system bearing saline water that extends at least down to 1.5 km depth and is inclined eastwards. After drilling down to the depth of 1280 m, more than 4000 tons/day of geothermal water overflowed with temperature higher than $70^{\circ}C$. This water showed very similar chemical composition and temperature to those from another existing well, so that they can be considered to have the same origin; i.e. from the same fracture system. A new geothermal project for combined heat and power generation was launched in 2009 in Seokmo Island, based on the survey. Additional geophysical investigations including MT surveys to cover a wider area, seismic reflection surveys, borehole surveys, and well logging of more than 20 existing boreholes will be conducted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.330-338
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• 2018

The proportional-integral-derivative(PID) controller has been widely used in the industry because of its robust performance and simple structure in a wide range of operating conditions. However, the AVR(Automatic Voltage Regulator) as a control system is not robust to variations of the power system parameters. Therefore, it is necessary to use PID controller to increase the stability and performance of the AVR system. In this paper, a novel design method for determining the optimal PID controller parameters of an AVR system using the particle swarm optimization(PSO) algorithm is presented. The proposed approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency. In order to assist estimating the performance of the proposed PSO-PID controller, a new performance criterion function is also defined. This evaluation function is intended to reflect when the maximum percentage overshoot, the settling time are given as design specifications. The ITAE evaluation function should impose a penalty if the design specifications are violated, so that the PSO algorithm satisfies the specifications when searching for the PID controller parameter. Finally, through the computer simulations, the proposed PSO-PID controller not only satisfies the given design specifications for the terminal voltage step response, but also shows better control performance than other similar recent studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.517-526
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• 2016

The purpose of this study was to investigate the self-resilience, professional self-concept, and major satisfaction on nursing students' adjustment to college life and to present the basic data to assist in healthy adaption of college life. The study included 310 students from two universities in Gwangju and Jeonnam. A questionnaire survey was conducted on the subjects to determine their self-resilience, professional self-concept, major satisfaction, and adjustment to college life with nursing as a major. The data were collected from 1, April, 2016 to 15, April using self-report, questionnaires and analyzed through descriptive statistics, percentage, mean, standard deviation, t-test, ANOVA, and Pearson correlation coefficient, using SPSS 20.0. As a result, self-esteem, professional self-concept, major satisfaction, and adjustment to college life averaged 3.80 (out of 4), 2.81 (4), 3.86 (5), and 2.75 (5) respectively. In terms of correlations, there was a significant positive correlation between adjustment to college life and self-resilience (r=.404, p<.001) and professional self-concept (r=.404, p<.001) and major satisfaction(r=.455, p<.001). In addition, self-resilience (${\beta}=.252$, p<.001) and major satisfaction (${\beta}=.309$, p<.001) of variance in adjustment to college life and the explanatory power of the model was 27.2%. Based on these results, improvement programs are necessary to help nursing students get adjusted to college life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.563-573
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• 2020

This study aimed to provide basic data to assist in developing programs to improve the quality of life after identifying the factors affecting aging anxiety among middle-aged women. The subjects were 256 middle-aged women in Korea. Data were collected from March 8 to April 11, 2019, and analyzed using descriptive statistics, independent t-test, One-way ANOVA, Pearson correlation, and stepwise multiple regression with SPSS/WIN 18.0. This study found that the aging anxiety of the subjects differed significantly according to job and marriage satisfaction. Aging anxiety had a negative correlation with health perceived health (r=-.300, p<.001), resilience (r=-.537, p<.001), satisfaction of married life (r=-.316, p<.001), and self-esteem (r=-.424, p<.000). The factors affecting aging anxiety were as follows: resilience (β=-.47, p<.001), occupation (β=-.19, p=.003), and self-esteem (β=-.19, p=.014) with 36.9% explanatory power (F=14.34, p<.001). To reduce the aging anxiety of middle-aged people, programs will be needed to improve participation in post-middle-aged jobs or social activities and resilience, self-esteem, thereby providing education and mediation that can allow middle-aged women to accept aging positively.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.61-81
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• 2003

There can be little dissension that the ultimate goal of all physical therapy interventions with the elderly is to restore or maintain the highest level of function possible for the individual. Whenever physical therapists take on this challenge, they assist elders in maintaining their identities as competent adults. Advancing age is associated with profound changes in body composition, including increased fat mass, decreased fat-free mass(particularly muscle), decreased total body water and decreased bone density. Along with these changes in body compositions, and perhaps as a direct result of them, elderly people have lower energy needs, reduced strength and functional capacity and a greatly increased risk for such diseases as noninsulin-dependent diabetes mellitus and osteoporosis. Resistance training is considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure that is associated with advanced age. This reversal is thought to result in improvements in functional abilities and health status in the elderly by increasing muscle mass, strength and power and by increasing bone mineral density. In the past couple of decades, many studies have examined the effects of Resistance training on risk factors for age-related diseases or disabilities. We have explored the positive and negative aspects of older adults' participation in resistance training programs. The benefits to older adults are reported to be increased strength, endurance, muscle capacity, and flexibility; more energy; and improved self-image and confidence. The negative aspects include some pain or stiffness and other nonspecific problems. The positive and negative aspects of resistance training are therefore very similar to those in younger populations. Scientific investigations over the past 10 years have demonstrated that resistance training can be safely and successfully implemented in older populations. Even the frail and very sick elderly can benefit and improve their quality of life. Proper design and progression of a resistance training program for older adults is vital to optimal benefits from resistance exercise. The results of data provided by this research on resistance training for health shows that there is enough existing evidence to conclude that resistance training, particularly when incorporated into a comprehensive fitness program, can offer substantial health benefits which can be obtained by persons of all ages. These benefits, including improvements in functional capacity, translate into an improved quality of life.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.67-92
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• 2009

A tugboat (tug) is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that should not move themselves alone, such as ships in a crowded harbor or a narrow canal, or those that cannot move themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for their size and strongly built, some are ocean-going. Historically tugboats were the first seagoing vessels to receive steam propulsion, freedom from the restraint of the wind, and capability of going in any direction. As such, they were employed in harbors to assist ships in docking and departure. Towage is in essence a service by one vessel to another vessel for a fixed remuneration. The most common reason for requiring this service is the lack of its own motive power. Conventionally, towage is defined as "the employment of one vessel to expedite the voyage of another, when nothing more is required than the accelerating of her progress". Apart from accelerating vessels, acquiring towage service is a common practice for towing barges, platform of drilling oil, floating ship yards, etc.