• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.5
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• pp.50-57
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• 2004

For the application of structural health monitoring such as AE detection, a stabilized FBG sensor system with wide dynamic range was proposed. A tunable Fabry-Perot filter with narrow free spectral range(FSR) was used to simplify the multiplexing demodulator for FBG vibration sensors. Stabilization controlling system was also developed for the maintenance of maximum sensitivity of the sensors. In order to verify the performance of the proposed FBG vibration sensor system, we measured sensitivity, and the system showed the average sensitivity of 256 $n{\in}_{mas}/{\sqrt{Hz}}$. Finally, multi-points vibration tests using in-line FBG sensors were conducted to validate the multiplexing performance of the FBG system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.509-515
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• 2004

Pulmonary function tests are widely used to diagnose and determine patients' therapy in clinic. And it was also applied in the research of the physiology and dynamics for lung disease. Among the pulmonary function tests, spirometry is the most easy and economic test. Spirometers are medical instruments that measure the instantaneous rate of volume flow of respired Bas. The mechanical spirometer was mostly used in the past. Up to the present, the most popular method of spirometer is the differential pressure technique with which change in the volume of flow are transferred to change in pressure. This kind of instrument suffers from several limitations, pressure drop, difficulty in maintenance and short period of calibration. Therefore, this study has begun to implement ultrasound spirometer, which is free of pressure loss and has wide range, focusing on the flow measurement technique and diagnostic algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2334-2340
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• 2010

Sun position computed by Michalsky shows maximum $1.5^{\circ}$, $0.88^{\circ}$ and 2 minutes differences in azimuth, altitude, and sunrise and sunset times respectively compared with Korean Almanac. The 2-axis solar tracking system, which consist control panel with ATmega128 CPU, BLDC motor-cylinder actuator and 2-axis link mechanism, was developed. Computed azimuth and altitude of sun for a current time, and latitude and longitude of tracker position built are controlled in real time by BLDC motor-cylinder actuators comparing with the position feed-backed by Hall sensor. The use of BLDC motor is free in maintenance. Implementation of a home-return function by Hall sensor is to minimize the cumulative error.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.2
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• pp.45-52
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• 2006

Mobile Ad-hoc Network(MANET) could be applied to various applications by virtue of its characteristics such as self-organizing and infrastructure-free network. This paper proposes a multimedia application service model for MANET, called multi-hop Relay(mRelay) system. It supports a multi-hop communication-based multimedia service interworked with Internet by using an unmanned moving robot with wireless multimedia communication function as a mRelay terminal. The modified AODV routing protocol was applied to the terminal and it was verified that composition and maintenance of mobile Ad-hoc network in mRelay system under the various indoor scenarios were successful and stable multi-hop multimedia services were possible. The mRelay system can be applicable to various application services of mobile Ad-hoc networks.

• Journal of Korean Society of Rural Planning
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• v.11 no.3 s.28
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• pp.19-27
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• 2005

Rural Korea has been becoming heavily aged societies from the end of 20th century due to the massive depopulation of young generation and extension of the average span of human beings. Although rural communities in Korea had been traditionally based on closely webbed social relations, almost all of community self-help organizations disappeared in recent time with very strong urbanization trend. However, almost all rural villages in Korea have the village seniors' union -'NO-IN-HOE' in Korean speaking- of which members usually use, operate and maintain community facilities in terms of voluntary base. Using these facilities, most of public/common/private services and community activities have been being served or provided. So, the purpose of this study is to investigate the usage tendency of community facilities and needs of the rural elderly and to propose the improvement strategies for their optimum usage. For this purpose, data was gathered both from community (107 villages) and individual level surveys(881 older people). The statistical method used for data analysis was descriptive statistics. The major findings were as follows : It was found that the dominant family type of the rural elderly was elderly-only household (75%) with very limited economic capability. There are 2$\sim$3 common community facilities with village including the seniors' center -'KYOUNG-RO-DANG' in Korean speaking. Many of the elderly (74%) use the center once or twice per week. There are several rooms in the center, like as kitchen bathroom and health room, of which usage frequency differs respectively. Many rural elderly want assistance from out-of-village for good maintenance and free use of these facilities.

• Safety and Health at Work
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• v.2 no.2
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• pp.87-96
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• 2011

In 1967, the problem of occupational lead exposure came to public attention in Korea. Since then, regular progress has been made in lowering workplace lead exposures, instituting new workplace controls, and implementing health examinations of exposed workers. Past serious lead poisoning episodes made it possible to introduce biological monitoring programs on a voluntary basis in high-lead-exposure facilities in Korea. Industry-specific occupational health services for lead workers in Korea during the last 22 years can be categorized into three phases. During the first phase (1988-1993), efforts were directed at increasing awareness among workers about the hazards of lead exposure, biological monitoring of blood zinc protoporphyrin began, and a respiratory protection program was introduced. During the second phase (1994-1997), a computerized health management system for lead workers was developed, blood-lead measurement was added to biologic monitoring, and engineering controls were introduced in the workplace to lower air-lead levels to comply with air-lead regulations. Finally, during the third phase (1998-present), a new biomarker, bone-lead measurement by X-ray fluorescence, was introduced. Bone-lead measurement proved to be useful for assessing body burden and to demonstrate past lead exposure in retired workers. Occupational health service practice for lead workers, including the industry-specific group occupational health system, has brought considerable success in the prevention of lead poisoning and in reducing the lead burden in Korean lead workers during the last several decades. The successful achievement of prevention of lead poisoning in Korea was a result of the combined efforts of lead workers, employers, relevant government agencies, and academic institutes.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.401-407
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• 2011

Purpose: A number of flap for nipple reconstruction have been well described in the literature. However, most of these techniques do not permit the reconstruction of a projecting nipple and all are hampered to some extent by long-term loss of nipple projection. The objective of this study is to evaluate the long-term result and clinical efficacy of nipple reconstruction using skate flap technique after breast reconstruction. Methods: A retrospective chart review was carried out on 23 patients who underwent 25 nipple reconstructions. In those patients with greater than 10 mm nipple projection, reconstruction with skate flap and full-thickness skin graft and/or tattooing was performed. Maintenance of nipple projection was then carefully assessed over one-year follow-up. The following factors were analyzed: type of breast reconstruction, type of areola reconstruction, followup period, decrease in nipple projection, complication, and whether secondary nipple reconstruction was necessary and/or performed. Results: Breast reconstructions were performed in 17 patients with free transverse rectus abdominis musculocutaneous flap, 3 patients with extended latissimus dorsi musculocutaneous flap, and 3 patients with expander and implant. The mean follow-up after nipple reconstruction was 17 months. Mean loss of projection were $17.0{\pm}13.99%$, $25.0{\pm}12.70%$, $30.0{\pm}12.57%$ and $30.8{\pm}12.49%$ at 3, 6, 9 months and over one year, respectively. The greatest decrease in projection was noted in the first 3 months following surgery. Conclusion: These results indicated that nipple reconstruction with skate flap showed about 70 percent of the projection achieved over one year postoperation. Therefore, the skate flap may be a reliable method of nipple reconstruction in those patients with greater than 10 mm nipple projection.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1472-1479
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• 2018

The purpose of this study was to investigate the ability to maintain dynamic posturography(EquiTest) in gymnastic, freestyle skier, and figure skater. A total of 32 subjects(22 athletic woman and 10 collegiate woman) were participated in this study. Computerized dynamic posturography(EquiTest) was adopted to test sensory organization and motor control. EquiTest facilitated the quantification of the role of somatosensory, visual and vestibular systems in the maintenance of postural balance and was also pertinent to measure the reaction time to the stimulus to change center of gravity on force platform. As a result were as follow. There was not difference among with exercise group. But there was a significantly difference with between groups. It was suggested that the acrobatic and physical activity developed the function of visual system and the role of the combination of visual and vestibular system in maintaining postural balance to surrounding stimulus, and presented shorter reaction time in automatic postural response.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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• pp.127-135
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• 2021

Background: Dialysis patients are prone to having disabilities. We aimed to evaluate the association between disability and various clinical outcomes in Korean dialysis patients. Methods: This study consisted of 1,615 dialysis patients from 27 centers. We evaluated disability by using four questions on the activities of daily living (ADLs) concerning whether help was needed for feeding, dressing/undressing, getting in/out of bed, or taking a bath/shower. We divided the patients into three groups: no disability (Non-D, none of the four ADL domains required help; n=1,312), mild disability (Mild-D, one ADL domain required some/full help; n=163), or moderate to severe disability (MS-D, two or more ADL domains required some/full help; n=140). We evaluated falls, frailty, health-related quality of life (HRQoL), mortality, and hospitalization. Results: The numbers of participants with a fall during the last 1 year were 199 (15.2%), 42 (25.8%), and 44 (31.4%) in the Non-D, Mild-D, and MS-D groups, respectively (p<0.001). The numbers of participants with frailty in the Non-D, Mild-D, and MS-D groups were 381 (29.0%), 84 (51.5%), and 93 (66.4%), respectively (p<0.001). In both univariate and multivariate analyses, the physical component scale and mental component scale scores decreased as the grade of disability increased (p<0.001 for both scores). Hospitalization-free survival rate at 500 days was 64.2%, 56.7%, and 51.1% in the Non-D, Mild-D, and MS-D, respectively (p=0.001 for trend). Patient survival rate at 500 days was 95.3%, 89.5%, and 92.3% in the Non-D, Mild-D, and MS-D, respectively (p=0.005 for trend). Conclusion: Disability was associated with falls, frailty, HRQoL scales, and survival trends in Korean dialysis patients.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.1
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• pp.27-35
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• 2022

In the most IPS (Indoor Positioning System), it is available to specify the user's movement by sending a specific signal from a tag such as a beacon to multiple receivers. This method is very efficiently used in places where the number of people is limited. On the other hand, in large commercial facilities, it is nearly difficult to apply the existing IPS method because it is necessary to attach a tag to each customer. In this paper, we propose a system that uses an external sensor grid to identify people's movement without using tags. Each sensor node uses both an ultrasonic sensor and an infrared sensor to monitor people's movements and sends collected data to the main server through wireless transmission for easy system maintenance. The operation was verified using the FPGA board, and we designed a VLSI circuit in 180nm process.