• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.184-190
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• 2008

Various ECT techniques have been applied basically to assess the integrity of steam generator tithing in nuclear power plant. Among these techniques, the bobbin probe technique is applied generally to examine the volumetric flaws such as a crack-like defect and wear which is generally occurred on steam generator tubing, and additionally MRPC probe is used to examine closely tile top of tubesheet and bending regions due to the high possibility of cracking. Dent and bulge also may be formed on tube during installation process and operation of steam generator, but the dent and bulge indications greater than specific size criteria are recorded on examination report because these indications are not considered as flaw. These indications can be easily detected with bobbin probe and approximately sized with profile bobbin probe, but the size and shape can not be accurately verified. Accordingly, in this study, the $8{\times}1$ multi-array EC probe was designed to increase the measurement accuracy of the sectional profiling EC testing of tube. As a result, we would like to propose the application of $8{\times}1$ multi-array EC probe for the measurement of size and shape of profile change on steam generator tube in OPR-1000 nuclear power plant.

• Therapeutic Science for Rehabilitation
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• v.5 no.2
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• pp.57-69
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• 2016

Objective: The purpose of this study was to systematically review the articles using accelerometer to measure activity of daily living of patients with stroke. Methods: Depending on selection criteria, 13 studies were searched for PubMed, EMBASE, and Cochrane library database from February 2014 to March 2014. A total of 331 papers were searched, and 13 of these were selected. Results: In studies of 13 selected, acute, subacute, and chronic patients with stroke were enrolled. The kind of accelerometer was uniaxial, biaxial, and triaxial, activity monitor. Measurement activities were mainly arm activity, walking activity, and attachment sites were also various depending on the measurement activities. A measured variable was the total number of activities, the movement speed of the patients, ratio between affected and non-affected, and motion analysis. The result indicated that significant correlation with the other assessment tools in all studies. Conclusions: Accelerometer will be applied with a tool for measuring activity of daily living of patients with stroke, depending on activities characteristics. Further, we need accelerometer studies to apply with a variety of assessment in clinical practice or community settings.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.208-215
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• 2018

The causes of column shrinkage and the codes that have been studied up to now are discussed. The documents mentioned in the code deal with the drying shrinkage, creep, compressive strength and elastic modulus of the specimen, and the elastic deformation calculated from the structural analysis. However, the deformation due to the temperature caused by the long term monitoring is less than that caused by the factors generated by the previous studies. In the previous studies, it was found that dehydration shrinkage, creep, and elastic deformation were not considered for temperature-induced deformation, while for the specimen experiments, the temperature-related items were replaced with the humidity-related terms The compensation value by the proposed equation showed error of 4.9 mm in the upper direction and 1.0mm in the lower direction when calculating column shortening, and it was found that its value by the proposed equation almost coincided with the measurement value in Site. Therefore, it is necessary to further study the temperature that can be omitted in calculating the existing column shortening, to consider the influence factors, and to supplement the criteria for the temperature measurement of the structure as well as the specimen tests.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.380-389
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• 2012

In this study, Systematic review and meta-analysis using the correlation coefficients was carried out to integrate precedent studies on factors affecting domestic occupational therapists' job stress. It aims at providing basic information resources of preventing and reducing stress of occupational therapists and effective counter-measurement to improve quality of occupational therapy and to establish efficient human resource management policy. Systematic review and meta-analysis were performed on eight thesis proven relevant to selection criteria in order to figure out correlation coefficients value by total, and factors correlation coefficients value. Also homogeneity test and publication bias test was performed too. The total correlation coefficients value of occupational therapists was .30 which was statistically significant. As to job stress factors, the organization related factor showed the highest correlation of coefficiency, followed by factors other than the organization related, physical environment, job related factor and personal factor. This research result can be used as a reference to prevent and reduce job stress of occupational therapists and to develop an effective measurement scheme.

• Journal of Korea Technology Innovation Society
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• v.13 no.4
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• pp.638-655
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• 2010

The importance of international science and technology cooperation is growing more and more, but we do not know much about what criteria could be used to choose a science or a technology that needs international cooperation first and foremost among many kinds of competing sciences and technologies. Moreover, this selection process is affected by evaluators' or science/technology experts' perception, but we do not quite know what they actually see when they evaluate the needs of international cooperation. This study investigates the conditions that international science and technology cooperation is encouraged by scholars and researchers in various areas. Based on theoretical arguments of Transaction Cost Economics, Measurement View, and Knowledge-Based View, we drew hypotheses on when experts perceive greater needs of international cooperation. Using the classification categories of 10 major sciences and technologies, we collected data from 151 respondents from scientists in research institutions and colleges. As a result, we found that experts in science and technology areas perceive strong needs of international cooperation when the importance of focal science or technology is high and the relative national level of focal science or technology is low. Also, we found that the importance and relative level of focal science and technology have positive moderating effects each other. Lastly, we found that when experts evaluate their own major areas, the strength of positive relationship between the importance of science and technology and needs of international cooperation is diminished.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.577-585
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• 1996

To seek effective methods for evaluating air pollution and acid rain injury, artificial acid mist(pH 2.5, 3.5 and 4.5) and ground water(pH 6.5) were treated on the potted seedlings of Ligustrum obtusifolium, Cercis chinensis, Hibiscus syriacus and Sophora japonica. Leaf chlorophyll contents, characteristics of leaf-injury, wettability-measurement of diameter of water-droplets on the leaf surface-among treatments were investigated. The results were summarized as follows. 1. Chlorophyll contents of Ligustrum obtusifolium and Hibiscus syriacus measured on June 3 were highest in pH 2.5 plot, but those of Cercis chinensis and Sophora japonica were relatively low level. Chlorophyll contents of Ligustrum obtusifolium measured on August 24 was highest in pH 2.5 plot, but those of Cercis chinensis, Hibiscus syriacus and Sophora japonica were highest in the control. 2. Changes of chlorophyll contents with acid mist treatments were differed among tree species. 3. For all the tested species, leaf injury(injured leaf number and rate, and injured leaf area) increased with decreasing pH levels of acid mist. 4. Leaf tissue injury seemed to be related with the wettability of the leaf surface. Measurement of diameter of water-droplets on the leaf surface might be useful criteria for acid rain or acid mist injury for the glabrous leaved species, such as, Cercis chinensis, Sophora japonica, etc.

• Progress in Medical Physics
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• v.15 no.4
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• pp.186-191
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• 2004

The periodic Quality Assurance (QA) of each radiation treatment related equipments is important one, but quality assurance of the radiation treatment planning system (RTPS) is still not sufficient rather than other related equipments in clinics. Therefore, this study will present and test the periodic QA program to compare, evaluation the efficiency of the treatment planning systems. This QA program is divided to terms for the input, output devices and dosimetric data and categorized to the weekly, monthly, yearly and non-periodically with respect to the job time, frequency of error, priority of importance. CT images of the water equivalent solid phantom with a heterogeneity condition are input into the RTPS to proceed the test. The actual measurement data are obtained by using the ion chamber for the 6 MV, 10 MV photon beam, then compared a calculation data with a measurement data to evaluate the accuracy of the RTPS. Most of results for the accuracy of geometry and beam data are agreed within the error criteria which is recommended from the various advanced country and related societies. This result can be applied to the periodic QA program to improve the treatment outcome as a proper model in Korea and used to evaluate the accuracy of the RTPS.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.4
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• pp.319-345
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• 2011

In case of tunnels in cold regions, a freeze of groundwater around tunnel may act as a barrier of tunnel drainage in winter, or may cause the inner extrusion of lining. In spite of that, a design of insulation for preventing the frost damage of tunnel lining has not been introduced in Korea, while foreign countries such as Norway and so on have a standard on insulation. In this study, a few freezing cases of road tunnels have been reviewed, and the results show that the freezing protection is necessary. In order to characterize the thermal distribution in the tunnel, following measurements have been performed at Hwa-ak tunnel; the temperature distribution by longitudinal lengths, the internal temperature of lining and the temperature distribution of the ground under pavement. From these measurements, the characteristics of the tunnel's internal temperature distribution due to temperature change in the air has been analyzed. Based on the measurement results on the temperature distribution at Hwa-ak tunnel, thermal flow tests on the rock specimen with and without insulation have been performed in the artificial climate chamber to investigate the performance of the insulation. Also, a number of 3D numerical analyses have been performed to propose appropriate insulation and insulation thicknesses for different conditions, which could prevent the frost damage of tunnel lining. As a result of the numerical analysis, air freezing index of 291$^{\circ}C{\cdot}$ Hr has been suggested as the threshold value for freezing criteria of groundwater behind the tunnel lining.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.398-409
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• 2021

Background: The types and effects of hazardous pollutants in indoor air may vary depending on the characteristics of the sources and pollutants caused by physical and chemical properties of buildings, the influence of outdoor air, and the exposure and use characteristics of residents. Objectives: This study was conducted to provide basic data on the establish of indoor air quality management for different classes of public-use facilities by presenting the characteristics of concentration distribution of hazardous pollutants by different public-use facilities and the status of the excess proportion of exceeding standards. Methods: This study analyzed self-measurement data from public-use facilities taken from 2017 to 2019 A total of 133,525 facilities were surveyed. A total of 10 types of pollutants that have maintenance and recommended standards stipulated in the Indoor Air Quality Control Act from the Ministry of Environment were investigated. The excess proportion and the substances exceeding the criteria for each type of public-use facilities for these pollutants were investigated. Results: As a result of the analysis of the proportion of exceeding the standard for each type of public-use facility, the facilities with the highest excess proportion of the standards for each hazardous pollutant were: PM₁₀ in railway stations (8.93%), PM_2.5 in daycare centers (7.36%), CO₂ in bus terminals (2.37%), HCHO in postpartum care centers (4.11%), total airborne bacteria in daycare centers (0.69%), CO in museums (0.1%), NO₂ in postpartum care centers (1.15%), Rn in museums (0.78%), total volatile organic compounds in postpartum care centers (7.20%) and mold in daycare centers (1.44%). Conclusions: Although uncertainty may arise because this study is a result of self-measurement, it is considered that this study has significance for providing basic data on the establishment in the future of indoor air quality management measures customized for each type of public-use facility.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.715-721
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• 2021

In radiation brachytherapy, the wrong source location may cause excessive dose to normal tissue. Therefore, research on digital dosimeters is being made to replace the analog detection method. Therefore, in this study, a lead (II) oxide (PbO) dosimeter applied with a passive layer (PL) was fabricated as a basic study to improve the dosimeter performance. Afterwards, reproducibility, linearity, and distance dependence were evaluated to analyze the performance of the Ir-192 source under irradiation conditions. The reproducibility of the PL-PbO dosimeter was 0.40%, which satisfies the evaluation criteria of 1.5%, and showed improved results compared to the PbO dosimeter. Linear function R2 showed excellent results as 0.9995, and slope analysis through regression analysis of the linear function was excellent in PL-PbO. The distance dependence of the PL-PbO dosimeter was +0.599 higher than that of PbO when the slope obtained through regression analysis of the power function was compared with the inverse square value. This study presents the effects and measurement variables according to the measurement configuration of the solid-state dosimeter, and can be used in various radiation detection fields.