• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.185-193
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• 2021

Objectives: Inhalation toxicity testing of chemical substances to identify carcinogenicity requires a long time and considerable cost, so the selection of test candidates is a very important aspect. This study was performed to determine optimal procedures for selecting carcinogenic inhalation toxicity test substances as conducted by the Occupational Safety and Health Research Institute (OSHRI). Methods: At the beginning, a database was constructed containing complex information such as usage amount, hazard, carcinogenicity prediction, and testability in order to select chemicals requiring carcinogenicity testing. Selection of test substances was carried out with priority given to usage, carcinogenicity, and testability. Results: Chemicals used in large quantities in industrial fields and strongly suspected of carcinogenicity were winnowed down to 12 substances, and these substances were scheduled for future testing by OSHRI. Conclusions: For the stable and reliable operation of carcinogenicity tests as conducted by OSHRI, this study standardized the procedures for selecting carcinogenicity test substances and suggested the introduction of various carcinogenicity prediction techniques.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4252-4265
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• 2023

In the case of nuclear power plants near end of their design life, a reassessment of the performance of safetyrelated equipment may be necessary to determine whether to shut down or extend the operation of the power plant. Therefore, it is necessary to evaluate the level of performance decline due to degradation. Electrical cabinets, including MCC and switchgear, are representative safety-related equipment. Several studies have assessed the degradation and seismic performance of nuclear power plant equipment. Most of those researches are limited to individual components due to the size of safety-related equipment and test equipment. However, only a few studies assessed the degradation performance of electrical cabinets. The equipment of various nuclear power plants is anchored to concrete foundations, and crack in concrete foundations is one of the most representative of degradation that could be visually confirmed. However, it is difficult to find a study for analysis through testing the effect of cracks in concrete foundations on the response of electrical cabinet internal equipment fixed by anchors. In this study, using a simple cabinet model considering cast-in-place anchor in uncracked and cracked concretes, a tri-axial shaking table tests were performed and the seismic behavior were observed.

• Journal of the Korean Vacuum Society
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• v.16 no.2
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• pp.153-159
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• 2007

In-cryostat helium lines are under installation to transfer a cryogenic helium into cold components in KSTAR device. In KSTAR, three kinds of helium should be supplied into the cold components, which are supercritical helium Into superconduction(SC) magnet system, liquid helium into current lead system, and gas helium into thermal shields. Cryogenic helium lines consist of transfer lines outside the cryostat, in-cryostat helium lines, and electrical breaks. In-cryostat helium lines should be guaranteed of leak tightness for tong time operation at high internal helium pressure of 20 bar. We wrapped the helium line with multi-layer insulator(MLI) to reduce radiation heat and insulated the surface of the high potential part with prepreg tape. The electrical break was fabricated by brazing ceramic tube with stainless steel tube. To ensure the operation reliability at operation temperature, all the electrical break have been examined by the thermal cycle test at liquid nitrogen and by the hydraulic test at 30 bar. And additional surface insulation was prepared with prepreg tape to give structural safety. At present most of the in-cryostat helium lines have been installed and the final inspection test is progressing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.386-393
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• 2019

In this study, we investigated the cause of a voltage controller failure that occurred in the operation of a combat vehicle and attempted to establish a solution for the failure. The failure in the voltage controller was found to be related to thermal resistance, which could be identified by disassembly analysis and a high temperature operation test. Especially, in the disassembly analysis, there was damage caused by high temperature such as soot on the molding material and cracking of the resisters. In addition, in the high temperature operation test, the test results show that the internal temperature of the voltage controller was relatively higher than the external temperature. This means that the voltage controller failure could be attributed to the excessive heat and insufficient thermal resistance. In order to improve the thermal resistance of the voltage controller, several designs with changing circuits and structures were devised. Improvement of thermal resistance was verified by measuring reduction of internal temperatures in the high temperature comparison test.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.351-360
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• 2016

Purpose: The purpose of this study was to identify the nursing needs of elderly patients who got a surgical operation under regional anesthesia(spinal, epidural, nerve block). Methods: The participants were 126 elderly patients who completed a questionnaire. The data were collected October 1 and October 31, 2012, and analyzed using descriptive statistics, t-test and ANOVA, $Scheff{\acute{e}}$ test. Results: The mean score for the nursing needs of elderly patients administered regional anesthesia during surgery was $3.08{\pm}0.38$, The scores for specific nursing needs were as follows: educational needs ($3.47{\pm}0.50$), spiritual needs ($3.37{\pm}0.78$), physical needs ($3.31{\pm}0.46$), emotional needs ($2.72{\pm}0.50$), and environmental needs ($2.51{\pm}0.47$). There were significant differences in nursing needs relative to gender, religion, and spouse status. Additionally, there were significant differences in nursing needs according to surgery department, the length of time the surgery, and the ASA(American Society of Anesthesiologists) physical classification. of the operation-related characteristics. Conclusion: When caring for elderly patients during the surgery, nurses must provide adequate information about the surgery and anesthesia. Further studies are needed to develop and evaluate nursing interventions to provide quality surgical care for the elderly patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.736-741
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• 2017

This paper examines the design for improving the wiper system of rotorcraft. During rotorcraft operation, the wiping performance and excessive clearance can decrease. The wiper system consists of a wiper arm assembly, motor, convertor and flex drive. If there is a problem with the wiper system, the operation ability decreases because the operation is restricted in a rainy environment. There are two main causes of the problem of the wiper system: the lifting forces acting on the wiper arm in aircraft flight and the excessive gap of the components. To remedy these two problems, the wiper arm was improved. The improvements included increased contact pressure on the wiper arm (spring tension), improved gear clearance, and material and shape changes. Durability test, aircraft ground test and flight test were carried out to verify the improved shape, and it was confirmed that the wiping performance and clearance problems were solved. Currently, the rotorcraft is operated without problem by applying the improved shape, and this design improvement process will be a useful reference for future rotorcraft development.

• Journal of Climate Change Research
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• v.3 no.4
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• pp.259-270
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• 2012

Mobile air conditioning(MAC) systems of light-duty vehicles consume the most energy among auxiliary parts. Vehicle $CO_2$ reduction policies in Korea, US EPA and EU include the strategies to reduce additional $CO_2$ by MAC operation with providing incentive for the high-efficient MAC technologies. It is under development how to estimate MAC $CO_2$ and to differentiate advanced or high-efficient MAC system in US EPA and EU. The additional energy by MAC operation would beaffected by not only driving patterns but also environmental conditions such as temperature and humidity. In this study, we estimated MAC $CO_2$ of Korean light-duty vehicles with various driving cycles and environmental conditions. Test results were corrected to reference conditions for varied temperature and humidity during tests to get the comparable data for test vehicles. The test results showed that high-efficient MAC technologies have potential to reduce MAC $CO_2$ approximately by 50%. Considering the rate of MAC $CO_2$ to vehicle $CO_2$, it is expected that the introduction of high-efficient MAC technologies would considerably reduce vehicle $CO_2$ emission in MAC operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.117-125
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• 2004

This paper describes the test technique for the full-scale airframe durability test according to the military handbook(MIL-HDBK-1530) and ASIP(Aircraft Structure Integrity Program) to evaluate structural integrity and to obtain basic data for IPA(Initial Production Approval) of the Korean advanced trainer(T-50). This paper covers the full-scale airframe floating setup technique, the optimized test load simulation method, test rig design technique, test setup design and installation techniques, test safety device design and operation technique, and durability test results. As 1st life durability test was successfully performed, it was confirmed that this method is available in a full-scale airframe structural test.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.1006-1017
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• 2000

The purpose of this study was to provide basic information for developing a nursing intervention that helps patients learn how to acquire coping to reduce post operation uncertainty and anxiety by investigating the level of uncertainty and anxiety experienced by mastectomy patients. The subjects were 134 patients selected from St. Mary's Kangnam and St. Mary's hospital, and the data collection period was from October to December of 1998. Uncertainty was measured by using Mishel Uncertainty in Illness Scale (MUIS), anxiety measured by using State-Trait Anxiety Inventory(STAI), and coping by using a questionnaire developed by Kim & Yoo (1996). Data were analyzed with SAS program by t-test, ANOVA, Duncan's multiple range test, Pearson correlation coefficients, and stepwise multiple regression. The results were as follows : 1. The mean uncertainty score was 57.6. The results of the correlation between the compliance of medical regimen and demographic characteristics were as follows ; Those who monthly income over 2,010,000 won had lower than above 1,000,000 won, and those with the experience of chemotherapy had higher than those without, and the patient who has 7∼12 months(1 yr.) post operation period had higher than the one below 6months, 25∼36 months(3 yrs.), 37∼60 months(5 yrs.), and over 61 months. 2. The mean anxiety score was 45.9. Anxiety tended to be increased slightly in subjects with low educational background, poor monthly income, experience of chemotherapy, and 7∼12 months(1 yr.) post operation period, but there was no significant difference by general characteristics 3. The mean value of the coping score was 100.7. The study revealed higher score in problem-focused coping than emotion-focused coping. In regard to coping by demographic characteristics were as follows ; those who had monthly income over 2,010,000 won had higher level of coping than those whose monthly income was between 1,010,000 and 2,000,000 won. In terms of problem- focused coping, those who had 25∼36 months of post operation period showed significantly lower level of coping than those below 6 months or 37∼60 months(5 yrs.) or over 61 months of post operation period. Regarding the emotion-focused coping, those with the christianity had significantly lower level of coping than those without it. Also, those whose monthly income over 2,010,000 won had significantly higher coping level than those with income of between 1,010,000 and 2,000,000 won. 4. A positive relationship was found between uncertainty and anxiety. Patients who experienced more uncertainty also showed more anxiety. Problem-focused coping was inversely related to uncertainty and anxiety. 5. The major variable that affected uncertainty was anxiety, explaining 63.3% of the uncertainty. In addition to this, it would explain 66.4% in total when experience of chemotherapy was added.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.131-138
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• 2019

The world's electricity production ratio is 40% for coal, 20% for natural gas, 16% for hydroelectric power, 15% for nuclear power and 6% for petroleum. Fossil fuels also cause serious problems in terms of price and supply because of the high concentration of resources on the earth. Solar energy is attracting attention as a next-generation eco-friendly energy that will replace fossil fuels with these problems. In this study, we test the charge-operation plan and the discharge operation plan for peak-cut operation by applying the maximum power demand reduction simulation. To do this, we selected the electricity usage from November to February, which has the largest amount of power usage, and applied charge / discharge logic. Simulation results show that the contract power decreases as the peak demand power after the ESS Peak-cut service is reduced to 50% of the peak-target power. As a result, the contract power reduction can reduce the basic power value of the customer and not only the economic superiority can be expected, but also contribute to the improvement of the electric quality and stabilization of the power supply system.