• Journal of Korea Water Resources Association
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• v.50 no.10
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• pp.673-679
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• 2017

In this paper a method for estimating the 'service life' and 'residual life' of a water pipe based on the Water Pipe Network Performance Evaluation(WPNPE) results of Water Supply Technical Diagnosis was developed for efficient maintenance of water pipes. The residual life of a pipe was defined as the difference between the service life and elapsed time since installation. The service life was defined as the time when a pipe reaches the reference score for determining deteriorated pipes that was used in the WPNPE. The pipe evaluation criteria and deterioration scores used in the WPNPE for the case study area were considered as independent variables in the multiple regression model for estimating the service life and residual life of the pipes in the area. To estimate the service life for the pipes the reference scores for determining deteriorated pipes were used as the values of the variables that represent the deterioration scores in the constructed regression models. Subsequently, the statistics of the service life and residual life of the pipes in the case study area were presented and analyzed in comparison with the service life defined by the Local Public Enterprizes Act.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.102-110
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• 2023

PSC-I girder bridges constitute the largest proportion among highway bridges in Korea. According to the precision safety diagnosis data for the past 10 years, approximately 41.3% of the PSC-I bridges have been graded as C. Furthermore, with the increase in the aging of bridges, preemptive management is becoming more important. Damage and deterioration to the deck and girder with a long replacement cylce can have considerable impacts on the service and deterioration of a bridge. In addition, the high rate of device damages, including expansion joints and bearings, necessitates an investigation into the influence of the device damage in the structural members of the bridge. Therefore, this study defined representative PSC-I girder bridges with single and multiple spans to evaluate heterogeneous damages that incorporate the damage of the bridge member and device with the deterioration of the deck. The heterogeneous damages increased a crack area ratio compared to the individual single damage. For the single-span bridge, the occurrence of bearing damage leads to the spread of crack distribution in the girder, and in the case of multi-span bridges, expansion joint damage leads to the spread of crack distribution in the deck. The research underscores that bridge devices, when damaged, can cause subsequent secondary damage due to improper repair and replacement, which emphasizes the need for continuous observation and responsive action to the damages of the main devices.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.197-203
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• 2014

The technology to predict and prevent an accident of the cable system in power station is required. The techniques of inactivated diagnosis, partial discharge and $tan{\delta}$, have been adopted to diagnoze the operating characteristics of cables, but it is not so easy to find out problems in cables in an inactive state before the cable accident happens. In this paper, we did a research on the 6.6kV high-power cables, installed at Korean Western Power Station Co., Ltd. in order to diagonize the cables, playing a major role at the station. We have developed an equipment to measure an insulation resistance based on the temperature and current of the cable. By installing the system in a power station, we could find abnormal status for evaluation of the lifetime. In the short term, by analyzing the data, we apply the research result to the diagnosis and evaluation of the 6.6kV power cables. In the long run, however, we plan to reduce the cost of the installation and operation of cable systems at power stations.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.162-165
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• 2014

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.492-498
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• 2016

It is well known that since abrupt faults in induction motors tend to lead to subsequent faults and deterioration of the drive apparatus, motor faults may lead to several operating restrictions, such as security problems and economic loss. A lot of research has been done in the area of diagnosis to detect machine faults and to prevent catastrophic hazards in the motor drive system. This paper presents a new method of motor current signature analysis in which the DC-link current of the inverter-driven induction motor system, where a single current sensor is employed instead of three AC current sensors, is measured, and fast Fourier transform analysis is performed. This proposed method makes it possible to easily discern and clearly separate the motor fault current signature from the normal operation current flowing through the stator and rotor windings.

• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.307-312
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• 2016

Alzheimer's disease is the most common degenerative brain diseases that causes dementia. ${\beta}$-amyloid neuritic plaque density that accumulates in the brain is difficult to perform daily living, such as memory loss, language ability deterioration. It is used to estimate ${\beta}$-amyloid neuritic plaque density in adult patients with cognitive impairment who are being evaluated for Alzheimer's disease and other causes of cognitive impairment. Using the $^{18}F$-Florbetaben with high sensitivity and specificity for the ${\beta}$-amyloid neuritic plaque density to evaluate the usefulness for the early diagnosis of Alzheimer's disease. In $^{18}F$-FDG Brain imaging shows no specific findings. And it appeared on the MR-Brain imaging without atrophy of the hippocampus. However, the intake of ${\beta}$-amyloid neuritic plaque density in $^{18}F$-Florbetaben informs that it is the progress of Alzheimer's disease. Therefore, $^{18}F$-Florobetaben is very useful for early diagnosis of Alzheimer's disease.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.10
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• pp.421-428
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• 2014

Like Alzheimer's disease, Parkinson's Disease(PD) is one of the most common neurodegenerative brain disorders. PD results from the deterioration of dopaminergic neurons in the brain region called the substantia nigra. Currently there is no cure for PD, but diagnosing in its early stage is important to provide treatments for relieving the symptoms and maintaining quality of life. Unlike many diagnosis methods of PD which use a single biomarker, we developed a diagnosis method that uses both biochemical biomarkers and imaging biomarkers. Our method uses ${\alpha}$-synuclein protein levels in the cerebrospinal fluid and diffusion tensor images(DTI). It achieved an accuracy over 91.3% in the 10-fold cross validation, and the best accuracy of 72% in an independent testing, which suggests a possibility for early detection of PD. We also analyzed the characteristics of the brain fiber pathways of Parkinson's disease patients and normal elderly people.

• Quality Improvement in Health Care
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• v.27 no.2
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• pp.30-44
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• 2021

Purpose: The aim of this study was to investigate the changes in perception of the New Diagnosis-Related Group (DRG)-based payment system, make overall evaluation after participation, and examine opinions on further policy improvement among employees of a public hospital participating in the pilot project in Korea. Methods: We investigated changes in perception of the New DRG-based payment system before and after participation in the pilot project using a qualitative research method. We conducted individual in-depth interviews with the management and healthcare professionals and Focus Group Interviews (FGIs) with the staff in the nursing and administrative departments. Results: Before implementing the pilot project of the New DRG-based payment system, the management was in favor of participating in the pilot project, whereas the healthcare professionals were strongly opposed to participation in the pilot project, and the staff in the nursing and administrative departments were slightly opposed to participation. After implementing the pilot project, there were remarkable changes in the perception of the New DRG-based payment system among healthcare professionals and the administrative staff. Healthcare professionals' perception was altered in a positive way, while the administrative staff's perception of the system became negative. Conclusion: There were no restrictions on clinical practice or deterioration of quality of care observed in association with the participation in the New DRG-based payment system. However, certain unintended consequences of the New DRG-based payment system may arise as well. Therefore, the government needs to examine the problems identified in this study to reflect on and improve the New DRG-based payment system for stable expansion.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1353-1355
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• 1995

While the modern society has been highly diversified and civilized, the demand for the safty of a power transmission has been greatly increased. For the underground cable, the performance of the electrical equipments is being improved by developing a new technology, and the reliability of the power supply is being up graded by impressing the diagnostic and monitoring technology of the system. In this paper the aging procedure of O.F and XLPE cables are described, including the diagnostic and monitoring equipments and the future subject.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.339-347
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• 2018

Acute kidney injury (AKI) is characterized by abrupt deterioration of renal function, and its diagnosis relies on creatinine measurements and urine output. AKI is associated with higher morbidity and mortality, and is a risk factor for development of chronic kidney disease. There is no proven medication for AKI. Therefore, prevention and early detection are important. Physicians should be aware of the risk factors for AKI and should monitor renal function in high-risk patients. Management of AKI includes optimization of volume status and renal perfusion, avoidance of nephrotoxic agents, and sufficient nutritional support. Continuous renal replacement therapy is widely available for critically ill children, and this review provides basic information regarding this therapy. Long-term follow-up of patients with AKI for renal function, blood pressure, and proteinuria is recommended.