• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1517-1518
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• 2006

This paper describes the design and fabrication of a partial discharge(PD) analyzer to evaluate insulation performance for low-voltage electrical and electronic devices. The analyzer consists of an adjustable AC power supply, a coupling network, an amplifier, a shielding encloser, a sample-hold (S/H) circuit and a data acquisition (DAQ) board. The analyzer holds the height of PD pulse for $10{\mu}s$ by the S/H circuit, and this makes possible to measure PD pulses having fast rise and short duration by a low speed analog-to-digital (A/D) converter. The data are transmitted to the personal computer through the DAQ board, and the designed analysis program calculate apparent charges, discharge inception and extinction voltages.

• Journal of the Ergonomics Society of Korea
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• v.36 no.2
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• pp.69-86
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• 2017

Objective: The present study is intended to develop an improved bus seat armrest design by evaluating various bus armrest designs from ergonomic aspects. Background: An ergonomic armrest design which considers the sitting postures and body shapes of passengers can improve the convenience and comfort of a bus seat. Method: Subjective satisfaction of each of five design dimensions (length, width, height from seatpan, shape, and angle) was evaluated for seven bus seat armrest designs in various sizes and shapes by 58 participants (28 males and 33 females) using a 7-point scale (1: very dissatisfied, 4: neutral, and 7: very satisfied). Improved bus seat armrest designs adjustable in length and rotatable to the left or right (sliding and rotating armrest, SRA) with a concave, flat, or convex shape of the upper part were developed by considering the preferred design features and the body size and shape in sitting posture and needs of passengers and then compared with a conventional armrest. Results: A bus seat armrest with a wide width (40~50mm), a long length (360mm), a lower height (213mm), and a curved shape was found significantly preferred in terms of comfort. The proposed armrest designs (SRA-convex, SRA-flat, and SRA-concave) improved satisfaction by 46~62% for length suitability, 184~216% for width suitability, 205~214% for angle suitability, 138~181% for contact area suitability, and 49~64% for height suitability, 138~174% for comfort, and 93~111% for overall satisfaction. Conclusion: The preferred design features and passengers' needs of bus seat armrest were identified and the SRA designs were recommended for better usability. Application: The ergonomic design process of bus seat armrest employed in the present study can be applied to designing armrests in various vehicles for better convenience and comfort.

• Journal of radiological science and technology
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• v.46 no.5
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• pp.395-399
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• 2023

The knee arthritis patients are generally performed standing position radiography. However, patients with pain caused by degenerative diseases or injuries in the knee have difficulty maintaining a standing position. Therefore, this study aims to develop a knee joint standing weight bearing projection assist device to solve these problems when patients undergo knee radiography due to various diseases. The design of the knee joint weight-bearing radiography assist device is carried out with 3D design and drawing production to secure basic data, electric support and frame manufacture. A fixed device for maintaining the patient's knee standing weight-bearing projection, an electric digital height device, a digital protractor, and a safety device were designed. The arm support is made of PVC with a cushion to relieve the impact and make it easier to remove debris. The digital electric device can be moved up and down according to the patient's height, and a remote control is attached. The safety device is made to be adjustable in size by attaching metal hooks on both sides of the frame and to shield the scrotum. A digital protractor was attached to the side frame to set the desired knee angle. When a self-made assist device was used to perform a knee joint standing weight bearing projection, it helped maintain arm support and lower extremities position. In addition, the height could be adjusted using an assist device during standing projections, which helped the patient maintain the position.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.465-470
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• 2024

Kitchen cabinets are widely used for their spacious storage and efficient use of space, but their high installed location makes it difficult for the elderly and disabled to access. Therefore, in this paper, we propose a new height-adjustable kitchen cabinet that can be used more easily and safely. The lift-down range of cabinet was set considering the installation location of cabinet for efficient use of kitchen space and the maximum height accessible to the elderly and disabled, and the link geometry and driving method of the complex link mechanism were determined through the mechanism design procedure to ensure that the selected floor come down safely along the optimal descend path. In addition, the appropriate motor and control algorithm were added to allow the user to descend to the desired height with a simple button operation. It was confirmed through actual production that the proposed linkage mechanism performs the desired lift-down motion.

• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.537-557
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• 2005

The purpose of this study was to investigate the effect of pelvic traction and muscle energy technique(MET) for hemiplegic patients on static standing balance. The scale for static standing balance is measured by using mean balance(%), frequence(Hz), sway area($mm^2$), sway path(mm), max sway velocity(mm/s), ant/post sway angle($^{\circ}$), lateral sway angle($^{\circ}$), sway number, change of pelvic height is measured in relation to the height of ASIS and PSIS. The subjects of this study were thirty hemiplegic patients: 15men and 15 women, with an average ages of 50.80 years. The thirty subjects were divided into 3 group of 10 at random ; ten subjects had pelvic traction after bobath therapy (the pelvic traction group), ten subjects had muscle energy technique after bobath therapy (the MET group), and ten subjects had only bobath therapy (the control group). Static standing balance was measured using BPM (balance performance monitor; data print software version 5.3), pelvic height was measured using height measuring with an adjustable horizontal arm. In order to assure the statistical significant of the result, an one-way ANOVA, the paired t-test, and a person's correlation were applied at the.05 level of significance. The results of this study were as follows: 1) The change in pelvic height were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 2) The change in affected and non-affected on weight bearing were not statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p>.05). 3) The change in frequency were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 4) The change in sway area were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 5) The change in sway pa1h were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 6) The change in max sway velocity were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 7) The change in ant/post sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 8) The change in lateral sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 9) The change in sway number were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). In conclusion, there was a difference between the experimental group and the control group. In the future, we have to study continuously about pelvic traction and muscle energy technique in hemiplegic patients.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.110-118
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• 2016

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.7-10
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• 2010

Objective: In this study, we present a simple closed head injury model as a two-stage experiment. The height of the weight drop enables gradation of head trauma severity. Methods: The head injury device consists of three parts and there are three adjustable parameters-weight (100-600 g). height of fall (5-100 cm) and elasticity of the springs. Thirty male Wistar rats underwent monitoring of intracranial pressure with and without induction of the head injury. Results: The weight drop from 45 to 100 cm led to immediate seizure activity and early death of the experimental animals. Severe head injury was induced from 40 cm weight drop. There was 50% mortality and all surviving rats had behavioral deterioration. Intracranial pressure was 9.3${\pm}$3.76 mmHg. Moderate head injury was induced from 35 cm, mortality decreased to 20-40%, only half of the animals showed behavioral pathology and intracranial pressure was 7.6${\pm}$3.54 mmHg. Weight drop from 30 cm caused mild head injury without mortality and neurological deterioration. Intracranial pressure was slightly higher compared to sham group- 5.5${\pm}$0.74 mmHg and 2.9${\pm}$0.81 mmHg respectively. Conclusion: This model is an eligible tool to create graded brain injury with stepwise intracranial pressure elevation.

• Journal of the Korean housing association
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• v.19 no.4
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• pp.1-10
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• 2008

According to the Korean National Statistics Office(KNSO), more than 90% of Korean adolescents aged from 15 to 19 use a computer for more than 10 hours per week. The KNSO also reveals that this age group mostly uses a computer in their own room, followed by a commercial place. It is also found that the house for the adolescent is not simply a physical environment, but is rather a center of their personal lives where their personal and social developments are formed. Therefore, the physical environment where computers are used is very important. The purpose of this study was to investigate the characteristics and needs of computer furniture for the adolescent. Data were collected through self-administered questionnaires and 414 adolescents participated. The results of this study are as follows: (1) Most of the respondents(42%) used the internet for less than one hour per day and it was used for community visits and operations, game, and chat rooms. (2) The desks where computers were used were specially designed and made of wood. Chairs were typically height adjustable with armrests and there was no task lighting for computer use. (3) The preferences of computer furniture were chairs with a high back, casters and armrests. The overall satisfaction of individual computer rooms was low. However, it is important for an adolescent to be provided with a user friendly environment for sound growth and development. Further study is therefore needed regarding environmental variables through empirical study.

• Transactions of Materials Processing
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• v.19 no.1
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• pp.17-24
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• 2010

A stretch forming method has been widely used in sheet metal forming process. Especially, this process has been adopted in aircraft and high-speed train industries for skin structure forming having a variety of curvature. Until now, solid dies, which are designed with respect to the specific shapes and manufactured as a single piece, have been usually applied to stretch forming process. Therefore, a great number of solid dies has to be developed according to the shapes of the curved skin structure. Accordingly, a flexible die is proposed in this study. It replaces the conventional solid dies with a set of height adjustable punch array. A usefulness of the flexible die is verified through a formability comparison with the solid die using finite element method considering an elastic recovery and the stretch forming apparatus with the flexible die is developed.

• The Journal of Korea Robotics Society
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• v.4 no.3
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• pp.243-249
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• 2009

In modern society, people spend most of their time on various types of chairs. However, it is not easy for a designer to design a comfortable chair because satisfaction with the chair depends not only on the quantitative elements such as size, but also on the qualitative element such as the user's feeling. To deal with these problems, there have been many studies on designing ergonomic chairs. This paper proposes the haptic-aided design (HAD) system to design an ergonomic chair. Based on the HAD system, the designer can experience whether the chair is comfortable or not through the haptic device, and also can modify the design parameters instantaneously. The haptic chair capable of controlling the design parameters in real time was proposed as a haptic simulator. The controllable parameters, such as seat height, reclining angle, stiffness of the backrest, and so on were selected based on the previous research related to ergonomic chairs. The proposed methodology will help reduce the development cost and time by replacing the process of making the real mock-ups and prototypes with the haptic chair.