• Proceedings of the KSR Conference
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• 2008.11b
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• pp.498-508
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• 2008

TECA(Terminal Cabin) has train information, fault display, maintenance function and training function for driver, as sub-device of Seoul-Pusan Express train's on-board computerized device. Concerning KTX train's driving, signal driving is required for high speed driving, and it is true that we have difficulty in troubleshooting and acquisition of basic information through long train and one-man driving. Therefore, rapid and correct processing about various information and TECA device for maintenance are indispensable for its utilization. But there is not study example in hardware, maintenance about this device and device development according to new requirements. Therefore, this study will help understanding of driver assistance terminal device's maintenance performance development, describing TECA's basic functions necessary for device development and its requirements. Accordingly, I suppose that this thesis will be utilized to complete specification, necessary for new driver assistance terminal device development.

• Toxicological Research
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• v.35 no.1
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• pp.9-12
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• 2019

One of the major challenges in methadone maintenance therapy (MMT) for drug dependence is the physiological side effects on endocrine hormones. Because of the key role of the thyroid gland in the normal functioning of the human body and brain, this study examined the effect of MMT on thyroid function. Thyroid hormones (T3, T4, and thyroid-stimulating hormone (TSH)) were evaluated in normal and user treated with MMT who were referred to the Province Clinical & Pathology Center of Urmia, Iran. The study was conducted for three months using the Case Series method. A total of 270 samples were collected, 215 were from individuals who were not treated, whereas 55 were from men treated with methadone. Average levels of T3 and T4 in non-treated sample of men are $1.34{\pm}0.02ng/mL$ and $90.96{\pm}1.38ng/mL$ while the corresponding values for patients treated with methadone are $1.39{\pm}0.04ng/mL$ for T3 and $94.57{\pm}2.72ng/mL$ for T4. Mean TSH levels of the non-treated group and the methadone consuming group were $1.75{\pm}0.08{\mu}IU/mL$ and $3.17{\pm}0.45{\mu}IU/mL$, respectively. These results indicate that although men treated with methadone had higher levels of T3, T4, and TSH than normal individuals, only the difference in TSH level was significant. The importance of this difference among individuals on methadone maintenance programs should be investigated in larger samples over long periods of time. Additionally, the effects of methadone treatment on women should be examined.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.125-133
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• 2019

A microscope is the fundamental research and diagnostic apparatus for clinical investigation of signaling transduction, morphological changes and physiological tracking of cells and intact tissues from patients in the biomedical laboratory science. Proper use, care and maintenance of microscope with comprehensive understanding in mechanism are fully requested for reliable image data and accurate interpretation for diagnosis in the clinical laboratory. The standard operating procedure (SOP) for light microscopes includes performance procedure, brief information of all mechanical parts of microscopes with systematic troubleshooting mechanism depending on the laboratory capacity. Maintenance program encompasses cleaning objective, ocular lenses and inner optics; replacement and calibration of light source; XY sample stage management; point spread function (PSF) measurement for confocal laser scanning microscope (CLSM); quality control (QC) program in fluorescent microscopy; and systematic troubleshooting. Laser safety is one of the concern for medical technologists engaged in CLSM laboratory. Laser safety guideline based on the laser classification and risk level, and advisory lab wear for CLSM users are also expatiated in this overview. Since acquired image data presents a wide range of information at the moment of acquisition, well-maintained microscopes with proper microscopic maintenance program are impulsive for its interpretation and diagnosis in the clinical laboratory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.611-620
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• 2021

The maintenance industry is mainly progressing based on condition-based maintenance after corrective maintenance and preventive maintenance. In condition-based maintenance, maintenance is performed at the optimum time based on the condition of equipment. In order to find the optimal maintenance point, it is important to accurately understand the condition of the equipment, especially the remaining useful life. Thus, using simulation data (C-MAPSS), a prediction model is proposed to predict the remaining useful life of a turbofan engine. For the modeling process, a C-MAPSS dataset was preprocessed, transformed, and predicted. Data pre-processing was performed through piecewise RUL, moving average filters, and standardization. The remaining useful life was predicted using principal component analysis and the k-NN method. In order to derive the optimal performance, the number of principal components and the number of neighbor data for the k-NN method were determined through 5-fold cross validation. The validity of the prediction results was analyzed through a scoring function while considering the usefulness of prior prediction and the incompatibility of post prediction. In addition, the usefulness of the RUL prediction model was proven through comparison with the prediction performance of other neural network-based algorithms.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.1-11
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• 2005

Backgrounds : Gamichungsangboha-tang extract has been known to improve pulmonary functions and quality of life within four weeks of treatment. Cessation of treatment causes recurrence of symptoms and regression of pulmonary function and poorer quality of life. Long-term herbal therapy is difficult to maintain due to economic burden and other reasons. AF-365 is made with reduced dosage of Gamichungsangboha-tang extract. This study was designed to evaluate the effectiveness of AF-365 for maintenance therapy. Materials and Methods : The subjects consisted of 27 patients with asthma who had beed treated with AF-365 for four weeks. First, patients were treated with Gamichungsangboha-tang extract for four weeks. Second patients stopped herbal medicine for four weeks and after that they took AF-365. Pulmonary function test(PFT) was checked before and after four weeks of treatment. Quality of Life Questionnaire for Adult Korean Asthmatics(QLQAKA) was checked every two weeks from the beginning. The effects of AF-365 were analysed throughout the last four weeks. Results : Treatment of AF-365 for four weeks resulted in significant increase in PEFR%, QLQAKA. The QLQAKA of the step3, step4 group classified by Global initiative for asthma(GINA) showed significant improvement, and the QLQAKA of the step2 group showed no significant difference. In step3 group, PEFR% increased significantly. Conclusions : This study supports a role for AF-365 in maintenance of pulmonary function and quality of life, especially in persistent symptomatic asthmatics.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.241-248
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• 2022

A guideline for determining the optimal catheter length according to the patient's physique during tunnel-type dialysis catheter insertion used in renal failure patients is presented, and the maintenance of the function of the dialysis catheter is evaluated. From October 1, 2015 to February 31, 2016, a total of 110 (male : female = 73 : 37) patients who underwent tunnel-type dialysis catheterization performed at our hospital were treated without using guidelines. The group was divided into A group, and the group treated using the guideline into B group. Results were analyzed statistically using SPSS 20.0. As a result of the dialysis catheter insertion procedure according to the use of guidelines, the function maintenance rate of group A was 81.8%, and the function maintenance rate of group B was 96.3%. In the case of tunnel dialysis catheter procedure, the function maintenance effect was statistically significant in the group treated using the guideline compared to the group not using it (p<0.05). It can be said that it is more effective when information on the patient's underlying disease is reflected in addition to the use of guidelines.

• International Journal of Reliability and Applications
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• v.13 no.2
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• pp.81-90
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• 2012

Engineering systems are usually repairable. The reliability of a repairable system can be represented by failure intensity function. A type of shape of failure intensity function is called a failure pattern. Reliability-Centred Maintenance (RCM) presents six typical failure patterns but its definition is unclear. It is an open issue how to recognize the failure pattern of repairable systems. This paper first discusses the problems of RCM with the notion of failure pattern; then presents the method for failure pattern recognition; and finally proposes a flexible failure intensity function model. The appropriateness of the model is illustrated by a real-world example.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2108-2110
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• 2001

Used analog control systems have been converted into digital control systems due to performance degradation and difficulty of maintenance. There are few domestic DCS (Distribued Control System)s that have been applied to power plant. To apply a domestic DCS to power plant, the reliability, redundacny, and fault tolerance of DCS is important. Besides those items, the control action of control function block is also important. In this paper, we describe the requirements that PID control function block has to have, and implement a PID control function block that satisfies those requirements. Finally, real control result using an implemented PID function block in thermal power plant shows the validity of an implemented PID control function block.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.719-726
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• 2005

The optimal design was performed for the bridge superstructure composed of steel box girders and concrete deck considering life cycle cost. The service life of the superstructure was estimated, after load carry capacity curves for steel girder and concrete deck were derived on the basis of condition grade curves and maintenance histories. The object function was determined as life cycle cost, including initial cost, total maintenance cost, disposal cost and user cost, for a period of the estimated service life. The optimal design of the superstructure was performed for the various service lifes. The annual costs were used to compare calculated results and to get the most economical design. Also this paper presents reasonable idea for the use of user cost with uncertainty.

• International Journal of Reliability and Applications
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• v.1 no.1
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• pp.15-26
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• 2000

This paper considers an aperiodic preventive maintenance (PM) model for repairable systems, in which the time intervals between two consecutive preventive maintenances are unequal. To propose such an aperiodic PM model, we assume that each PM reduces the current hazard rate by a certain amount which depends on the number of PMs performed previously. If the system fails between PMs, the minimal repair is performed and the hazard rate remains unchanged after the repair. We give the exact expressions for the hazard rate function for the aperiodic PM model. Based on the proposed aperiodic PM model, we suggest the maximum likelihood method to estimate the parameters characterizing the model and apply the method to the case of Weibull distribution. Numerical examples for estimating the parameters are presented for the purpose of illustration.