• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.123-135
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• 2006

Alzheimer's disease (AD) is the most common form of dementia in the aging population and is clinically characterized by a progressive loss of cognitive abilities. Pathologically, it is defined by the appearance of senile plaques - extracellular insoluble, congophilic protein aggregates composed of amyloid $\beta$ (A$\beta$) and neurofibrillary tangles (NFTs) - inyracellular lesions consisting of paired helical filaments from hyperphosphorylated cytoskeletal tau protein as described by Alois Alzheimer a century ago. These hallmarks still serve as the major criteria for a definite diagnosis of the disease. Consequently, one of the key strategy for drug development in this disease area focuses on reducing the concentration of cerebral A$\beta$ plaque by using substances that inhibit A$\beta$ fibril formation. We focused on developing inhibitors by synthesizing several kinds of aromatic molecules. The synthetic compounds were initially screened to evaluate the effective compound by tioflavin T fluorescence assay. The selected effective compounds were tested cytotoxicity and protective effect from A$\beta$-induced neuronal toxicity by cell based MTT assay with HT22 hippocampal neurons. The BBB permeability on effectors was also tested in in vitro co-culture model(HUVEC/C6 cell line). The behavior test wea carried out in mutant APP/PS1 transgenic mouse model of Alzheimer's disease. And inhibition of A$\beta$ fibril formation by the effective compound was monitored with transmitted electron microscopic images.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.56-62
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• 2015

Recently, one of countermeasures against aging SOC infrastructures, performance-focused management including the serviceability, functionality, durability, and economics has been changed from the structural safety-focused evaluation has changed into The current inspection and diagnosis for the major SOC facilities in Korea has been carried out by the specific principle of details, and most of them checked by the visual inspection are focused on the repair and rehabilitation of the damaged structures, thus they are the preventive maintenance. However, the performance-focused management should be replaced for the effective and economic maintenance as wells as for the minimization of the damage. In this regard, this study the appropriacy of the current evaluation items about the concrete retaining wall, one of SOC infrastructures as the previous step forward the performance-focused management. In order to deduct the effective evaluation items in order, the entropy, analytic hierachy process (AHP), and promethee analysis were peformed and the results were compared and discussed.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.177-191
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• 1982

The study was performed to establish the cephalometric standards of Hellman dental age III B, IV A, IV C groups of the age of puberty and to aid for the case analysis and diagnosis of malocclusion. A roentgenocephalometric study was made from 365 subjects, that consist of 162 males, 203 females with normal occlusion, acceptable profile and no history of orthodontic and prosthodontic treatment. The results of this study were obtained as follows: 1. The tables of standards from the measurements by age, sex group were made. 2. All linear measurements of skeletal pattern in male were greater than in females. 3. The Bjork's sum was reduced gradually by aging in group I $396^{\circ}$, group II $395^{\circ}$, and group III $393^{\circ}$. 4. Posterior facial height to anterior facial height was 63% in group I, 64% group II, and 67% in group III. 5. The angulation of SNA and SNB were $81^{\circ}$ & $78^{\circ}$ in group I, $81^{\circ}$ & $78^{\circ}$ in group II, and $82^{\circ}$ & $79^{\circ}$ in group III.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.178-183
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• 2012

We investigated the latest trend of u-Health and relations with clinical technologist. Since 2000, Korea has become an aging society. Korea will become an aged society by 2018, and it is expected to enter the ultra-high aged society by 2026. Increase in over 65 years population means that the desire of medical service and care demand for the elderly is greatly required. In addition, many predicted Korean national health insurance would falter financially. Medical suppression policies and regulations are also amended continuously. U-Health based on the IT industry and development of related technologies and industries contains the variety concepts of telemedicine, telehealth, e-health, u-healthcare and POCT. Especially, the use of POCT supplied quick clinical examination is extending steadily in medical center and hospital, which will generate the field friction between nurses and medical technologists. In the transition situation from provider-centric service to consumer-driven health care system, this study recommended the principal role and correspondence of clinical laboratory workers and offered information about changes in healthcare market and the basic concept of expert system, measurement and the diagnosis principle to clinical technicians throughout the investigation of the recent research and government policy trends.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.485-491
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• 2015

This paper shows the design improvement and test model of FAU (Frequency Analysis Unit) in PDD (Partial Discharge Diagnosis system) for 800kV GIS (Gas Insulated Switchgear). We found some problems during operation of previous FAU, such as the aging of fiber-optic converter that can cause communication error, the malfunction of signal analysis circuit etc. And then we solved those problems by design improvement and verified the performance through type test. To monitor partial discharge, the performance of UHF sensor is important but the performance of frequency analysis unit is also very important. So we solved communication error, the malfunction of signal analysis circuit and then increased the operation reliability of FAU by improving fiber-optic converter and signal analysis circuit. Accredited testing laboratory carried out the performance verification test according to performance test criteria and procedure of reliability test standards, IEC-60225, 61000 and 60068 etc. We confirmed the test results which correspond with the performance test criteria.

• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.76-78
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• 2005

Moisture contents measurement is frequently used as one of parameters for degradation diagnosis of transformer insulation. In general Karl-Fisher method is mainly used for moisture contents till now. But this method is inconvenient because of dismounting transformer for sampling oil or paper, and also partial sampling. At latest Recovery Voltage Method(RVM) is noticed for complement of this method. RVM can directly estimate moisture contents of transformer insulations in field without dismounting transformer. In this paper the accelerated aging process of oil-paper samples have been investigated at a temperature up to 140$^{\circ}C$ for 500 hours. The oil-paper insulation samples have been measured at intervals of 100 hours. Next to, we have estimated moisture contents using both Karl-Fisher Titration Method and RVM. And we have compared with Karl-Fisher Titration Method and RVM for estimating moisture contents. At last we have verified reliability of RVM which is new measurement method.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.4
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• pp.105-115
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• 2016

Purpose: This study is a case study of a small-mid sized hospital to promote a full-scale remodeling to ensure the quality and competitiveness of the medical services and trying to arrange the remodeling characteristics of small-mid sized hospital which is suffering from aging facilities as well as chronic congestion and lack of spaces. Methods: Research was conducted by consultation with hospital executives and each department operators, and on-site investigation, Results: The result of this study can be summarized into two points. The first one is that existing statistical value like area per bed, in the remodeling of the small-mid hospitals may not mean much. planners have to verify the necessary room space areas in close consultation with the department operators. And after confirming layout possibilities, they have to create the program. The second one is that remodeling planning can be a realistic plan with structural and installation diagnosis at the same time. If so, it is advisable to proceed architectural design from the beginning for cost and time savings. Implications: This results can be applied to small-mid hospitals to apply to the medical law revision and others.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1369-1374
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• 2014

Most accidents of medium-voltage cables installed in nuclear power plants result from the initial defect of internal insulators or the initial failure due to poor construction. However, as the service years of plants increase, the possibility of cable accidents is also rapidly increases. This is primarily caused by electric, mechanical, thermal, and radiation stresses. Recently, much attention is paid to the study of cable diagnoses. To date, partial discharge and Tan${\delta}$ measurements are known as reliable methods to diagnose the aging of medium-voltage cables. High frequency partial discharge measurement techniques have been widely used to diagnose cables in transmission and distribution systems. However, the on-line high frequency partial discharge technique has not been used in the nuclear power plants because of the plant shutdown risk, degraded measurement sensitivity, and application problems. In this paper, the partial discharge measurement with a portable device was tried to evaluate the integrity of the 4.16kV and 13.8kV cable lines. The test results show that the high detection sensitivity can be achieved by the high frequency partial discharge technique. The present technique is highly attractive to diagnose medium voltage cables in nuclear power plants.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.6
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• pp.50-56
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• 1997

As the purpose of the breakdown prediction of three degradation of insulating materials caused by partial discharge occurring at various defects in the polymer insulator itself and at the interfaces between electrodes and the insulating materials. Treeing due to partial discharge os one of the main causes of breakdown of the insulating materials. Recently, the necessity of establishing the way to diagnoses the aging of insulation materials and to predict of insulation breakdown become improtant. The purpose of our work are to use acoustic emission System and fractal dimension and to investigated the treeing phenomena in polymeric insulation under appliec AC voltage 11[kV] with an artificial needleshaped void(1.5[mm]) using the above system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.76-81
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• 2004

This paper presents the results of spectral analysis of leakage current waveforms on contaminated insulators under various fog and environment conditions(salt fog, clean fog, rain) The larger the leakage current during 200ms, the higer the power spectrum at 60Hz. For almost equal maximum current during 200ms, however, the spectrum at 60hz and the odd order harmonics increase emphatically when discharges occur continuously for several half-waves. If contaminated insulators suffers from high salt-density fog, the leakage current occurs with high crest value intermittently, results in the low spectrum. Analysis of leakage current data showed that this electrical activity was characterized by transient arcing behavior contaminants are deposited on the insulator surface during salt fog tests. This provides a path for the leakage current to flow along the surface of the insulator. It is important to have an indication of the pollution accumulation in order to evulate the test performance of a particular insulator. If the drop in surface resistivity is severe enough, then the leakage current may escalate into s service interrupting flashover that degrade power quality.