• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.4
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• pp.240-245
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• 2000

The self-field losses in a long multifilamentary Bi-2223/AgMgNi tape with varying transport current, voltage tap configurations, frequency and tape arrangements were investigated. Experimental results show that the measured losses are strongly dependent on voltage gap configurations but independent on tape arrangements. All voltage taps except the center tap are found to agree well with those predicted by Norris for an elliptical conductor. The self-field losses are purely hysteretic in nature in the range of applied frequencies for the transport currents below the critical current.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.190-195
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• 2004

An exhaust brake system is composed of a gate valve, a pneumatic cylinder and an on-off solenoid valve. An on-off solenoid valve which is a key component of the exhaust brake system ought to have characteristics such as high reliability and long life for reducing the foot brake and tires damage, and for driver's fatigue relief of middle/large size vehicles running a long distance. In this paper, an on-off solenoid valve which is used for vehicle brake system was studied. For the performance evaluation of the on-off solenoid, electromagnetic characteristics and dynamic characteristics are analyzed. On the basic study for the performance improvement of exhaust brake system, pneumatic circuit and pneumatic valve of on-off solenoid type were suggested and the performance of pneumatic valve through the test procedure was evaluated.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.179-187
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• 2022

The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1356-1362
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• 2005

The purpose of this study os to investigative the effect of Carrageenan-Induced Pain on lower limb muscle and ligament of rat. To evaluate pain mechanism in muscle and ligament, pain was induced by the injection of 2% $0.1m{\ell}$ carrageenan into the left lower limb muscle of rats after rats were anesthesized with 3% enflurane. Rats were killed on 72 hours after pain induction under the anesthesia. anterior rectus femoris muscle and its ligament were removed from rat hind limb. Morphological changes of them were peformed by the observation of light and electron microscopes. In the light microscopic findings, the muscle cells were polyheadral and situated with each other without small gap in control group. nucleus of cell was seen along the cell margin, and muscle cell groups were divided by regular narrow gap in cross section. In the pain-induced group, muscle cell groups were divided each other by the irregular gap, and some of groups formed larger than other cell groups by the fusion. Intercellular gap of most cell groups were increased compared with control groups. And also, perimysium of muscle cell groups was swollen in cross section. In control group, muscle cells contacted each other closely and each cell was divided by perimysium. The intracellular gaps were not seen between myofibrills, and also striations were well defined between muscle cells in longitudinal section. In pain-induced group, muscle cells were divided by the small intracellular gaps. And also, muscle cell showed many a short cross or longitudinal intercellular gaps in longitudinal section. In light microscopic findings of control group, tendon was composed with many tendon fibers contacted each other closely without gap. The free margin of tendon was fused, and apso the tendon fibers did not invaded between muscles. In pain-induced group, tendon was divided small groups by intertendinous gap, and also the margin of tendon divided by small groups. In the free margin, tendon invaded into muscle cells, and also fibroblasts between tendon fibers were long and lance-shaped. From these results, it is suggested that pain induction by carrageenan injured rat skeletal muscle and ligament by the morphological changes.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.405-418
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• 2007

The purpose of this study was to examine the interest level of mothers in oral health. The subjects in this study were 184 mothers whose children attended daycare centers in the city of K. A survey was conducted from March 15 through April 30, 2007, and SPSS WIN 11.5 program was employed to analyze their answer sheets. The findings of the study were as follows: 1. A group of mothers whose children brushed their teeth three times a day on the average made up 55.7 percent of those who were at the age of 35 and under. Among the mothers having three or more children, those mothers accounted for 59.1 percent. The daily mean toothbrushing frequency of children was higher among the better-educated mothers. 2. Concerning dietary and oral guidance, the mothers whose academic background was better curbed their children's excessive sugar intake more often, and the gap between them and the others was statistically significant(pE.05). As to the importance of oral health by the number of child and academic credential, those who had two children(36.0%) taught them the importance of oral health frequently(pE.01), and the better-educated mothers taught about it often(pE.05). The gap between the groups and the others was significant. 3. As for experience of visiting dental institutions, the working mothers visited dental institutions more often than the stay-at-home mothers, and the gap between them was statistically significant(pE.05). Regarding purpose of the visit, the largest group aimed to get treatment(64.6%), followed by having a dental checkup(14.6%) and receiving preventive treatment(13.5%). As to any inconveniences in using dental institutions, those who were working and who were in the upper income bracket found it more inconvenient to do that because of a long distance or time constraints. The gap between them and the others was significant. 4. In regard to concern for dental care, the mothers who were better educated(pE.001) and whose family income was 3 million won or more had their teeth scaled more often, and the gap between them and the others was statistically significant(pE.01). The rate of the regular visitors of dental institutions stood at 32.7 percent of the junior-college graduates, 31.0 percent of the mothers receiving college or higher education and 10.1 percent of the high-school graduates(pE.01). And those who earned larger income paid a visit to dental institutions more often and on a regular basis. The gap between them and the others was statistically significant(pE.05).

• Smart Structures and Systems
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• v.14 no.4
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• pp.679-697
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• 2014

The strain data acquired from structural health monitoring (SHM) systems play an important role in the state monitoring and damage identification of bridges. Due to the environmental complexity of civil structures, a better understanding of the actual strain data will help filling the gap between theoretical/laboratorial results and practical application. In the study, the multi-scale features of strain response are first revealed after abundant investigations on the actual data from two typical long-span bridges. Results show that, strain types at the three typical temporal scales of $10^5$, $10^2$ and $10^0$ sec are caused by temperature change, trains and heavy trucks, and have their respective cut-off frequency in the order of $10^{-2}$, $10^{-1}$ and $10^0$ Hz. Multi-resolution analysis and wavelet shrinkage are applied for separating and extracting these strain types. During the above process, two methods for determining thresholds are introduced. The excellent ability of wavelet transform on simultaneously time-frequency analysis leads to an effective information extraction. After extraction, the strain data will be compressed at an attractive ratio. This research may contribute to a further understanding of actual strain data of long-span bridges; also, the proposed extracting methodology is applicable on actual SHM systems.

• STI Policy Review
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• v.1 no.3
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• pp.1-15
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• 2010

This paper makes the case that a new policy strategy to enhance a global green recovery is needed urgently. The new strategy requires two essential elements. First, G20 economies should follow the lead of South Korea and China and turn their green stimulus investments into a serious long-term commitment, and to support these investments, they should adopt environmental pricing policies and instigate pricing and regulatory reforms to reduce carbon dependency. Second, the G20 also needs to target and coordinate assistance to developing economies in science, technology and innovation (STI) for clean energy. Such assistance is essential to help developing economies to overcome the skills, technological and capital gap that they face in clean energy technologies over the long term. Reform of the Clean Development Mechanism (CDM) is also necessary to establish a long-term global price signal for carbon, and to increase the coverage of developing economies, the sectors and technologies and the overall financing of clean energy projects. Formulating such a policy strategy should appeal to both the Asian-Pacific and Western economies comprising the G20, and by working together to formulate such a strategy, the G20 could lead the way toward a new era of global economic management and STI cooperation in clean energy.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.825-837
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• 2017

Due to the severe impacts of recent earthquakes, the use of seismic isolation is paramount for the safety of nuclear structures. The diversity observed in seismic events demands ongoing research to analyze the devastating attributes involved, and hence to enhance the sustainability of base-isolated nuclear power plants. This study reports the seismic performance of a seismically-isolated nuclear reactor containment building (NRCB) under strong short-period ground motions (SPGMs) and long-period ground motions (LPGMs). The United States Nuclear Regulatory Commission-based design response spectrum for the seismic design of nuclear power plants is stipulated as the reference spectrum for ground motion selection. Within the period range(s) of interest, the spectral matching of selected records with the target spectrum is ensured using the spectral-compatibility approach. NRC-compliant SPGMs and LPGMs from the mega-thrust Tohoku earthquake are used to obtain the structural response of the base-isolated NRCB. To account for the lack of earthquakes in low-to-moderate seismicity zones and the gap in the artificial synthesis of long-period records, wavelet-decomposition based autoregressive moving average modeling for artificial generation of real ground motions is performed. Based on analysis results from real and simulated SPGMs versus LPGMs, the performance of NRCBs is discussed with suggestions for future research and seismic provisions.

• Asia-Pacific Journal of Business
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• v.10 no.4
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• pp.65-75
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• 2019

We point out the limitations of Bloomberg Adjustment beta, shows that long-term beta does not converge with 1 and suggests an alternative to using proxy beta as beta's long-term forecast. We analyze whether the beta produced in the manner proposed by Bloomberg beta or proxy beta meets the purpose of calculating capital costs, for example, for the evaluation of corporate value. In particular, We apply in impairment valuations of assets and some analysis of how it affects. The proposal of the article applied in cases of analysis results are as follows : First, unlike the Bloomberg approach, long-term beta does not converge with market beta and therefore is not suitable as market forecast by beta. Second, estimating the suggested proxy beta as beta's predictive value resulted in Bloomberg beta and other adjustment Beta in the case categories, and the gap was large. Third, applying proxy beta results in a more appropriate valuation of the impairment loss on assets.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.14-17
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• 2007

The slot-die coating & calcination process was adopted to fabricate the long YBCO precursor films on the buffered metal tape for the $2^{nd}$ generation coated conductors. To obtain the smooth and crack-free surface of long YBCO precursor films, the parameters of slot-die coating and the process variables of calcination step must be optimized simultaneously in reel-to-reel method. Among the parameter of slot-die coating process, the viscosities of the precursor solution was controlled from 60cP to 200cP to obtain the thicker films from on single coating. The slot-die gap, the injection rate of precursor solution, the moving speed of buffered metal tape etc. are controlled lot the full coverage and smooth surface of YBCO precursor films. The slot-die coated films are moved through the tube furnace with predetermined heating profiles in humid oxygen ambient The YBCO precursor films was identifed with $Y_2O_3,\;BaF_2$, and CuO phase by XRD and consisted of fine grains of about 20nm size observed by FE-SEM. The YBCO films show the critical current density over $MA/cm^2$ using the precursor films formed by the continuous slot-die coating & calcination process.