• Journal of Conservation Science
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• v.35 no.3
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• pp.237-244
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• 2019

In this study, we applied terahertz imaging technology to three Korean modern oil paintings ('Boy,' 'Girl,' and 'Hyehwadong Landscape'); investigated the types of inner layer information in the pictures that can be extracted with terahertz imaging technology; and analyzed the conditions for extracting them. The biggest problem in the terahertz imaging analysis we encountered was the image distortion caused by the change of the distance between the target surface and the terahertz detector, depending on the surface curvature of the target paintings. We then developed a 'working distance maintaining device' to solve this problem. As a result, the terahertz imaging technique was used to identify the base material characteristics and any patterns of damage inside, and presented the optimal conditions for identifying each characteristic. In addition, it was useful to employ the terahertz frequency-division image to check the characteristics of the background materials. To confirm coloring techniques such as brush strokes, it is effective to compare the maximum reflection peak image with the cross-section image; and to detect damage information inside the paintings that cannot be observed on the surface, to compare the cross-section image with the frequency-division image. On the other hand, according to the terahertz imaging analysis of the oil paintings, the internal structural damage marks of 'Boy' and 'Girl' were confirmed, and the artist's painting style was confirmed in 'Hyehwadong Landscape.' The above results are expected to be useful for the analysis and diagnosis of Korean modern oil paintings for their preservation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.498-505
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• 2020

Aggregate occupies about 70-85% of the concrete volume and is an important factor in reducing the drying shrinkage of concrete. However, when constructing high-rise buildings, it acts as a problem due to the high load of natural aggregates. If the load becomes large during the construction of a high-rise building, creep may occur and the ground may be eroded. Material costs increase and there are financial problems. In order to reduce the load on concrete, we are working to reduce the weight of aggregates. However, artificial lightweight aggregates affect the interface between the aggregate and the paste due to its higher absorption rate and lower adhesion strength than natural aggregates, affecting the overall strength of concrete. Therefore, in this study, in order to grasp the interface between natural aggregate and lightweight aggregate by type, we adopted a method of measuring electrical resistance using an EIS measuring device, which is a non-destructive test, and lightweight bone. The change in the state of the interface was tested on the outside of the material through a blast furnace slag coating. As a result of the experiment, it was confirmed that the electric resistance was about 90% lower than that in the air-dried state through the electrolyte immersion, and the electric resistance differs depending on the type of aggregate and the presence or absence of coating. As a result of the experiment, the difference in compressive strength depending on the type of aggregate and the presence or absence of coating was shown, and the difference in impedance value and phase angle for each type of lightweight aggregate was shown.

• 재활복지
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• v.15 no.4
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• pp.351-375
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• 2011

The purpose of this study is to research the actual condition of on-line and off-line computer education in order to create more opportunities for the possibility of effective learning and u-Learning - based IT vocational education development of persons with hearing impairments. To carry out this study, we had a preliminary education of this study for a sign language interpreters who had working in a association of the deaf in Daegu, and had conducted a survey study participating for 100 persons with hearing impairments living in Daegu-Kyungbook Region. The results of this study were as follows: First, during on-line and offline education environment for persons with hearing impairments, factors such as teaching methods and contents, screen organization, learning effects, offering lecture material and subtitle, subtitle and sign language video of position and size, offering computer instructor who have a sign language interpreter with IT mentoring, on-line educational user environment setting must be considered factors for u-Learning - based IT vocational education development. Second, 74% of the subjects showed their interest in taking a course, after u-Learning contents are developed for persons with hearing impairments. Third, the subjects preferred IT device was a tablet PCs and IT certification related courses as their IT vocational education curriculum. Also, to link between professional training and job opportunity, subjects will need a IT vocational education courses such as computer intermediate and advanced levels.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.76-84
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• 2002

Objectives：This study was conducted to investigate the effect of oxygen on attention and memory functions in healthy adolescents. Methods：The participant subjects were recruited from local advertisement. All subjects are students attending ordinary middle and high school. Their degree of achievement was average or below average. Before the study, its nature and purpose were fully explained to the patients and their parents, and a written informed consent was obtained from each child's parent and a written assent from each child for entire the procedure. The Ethics Committee and Clinical Research Committee of Gyeongsang National University Hospital approved the protocol. For baseline assessment, all subjects received tests for attention and memory. All tests were conducted by a certified psychologist. Stroop test, continuous performance test and trail making test A and B were used for evaluation of attention. As memory tests, we used memory assessment scale(MAS), standardized memory assessment tools. Ten to fourteen days after initial assessments, same tests was applied to the same subjects after prior 5 minute oxygen inhalation. Results：1) Attention test：Improved performances in trail making part B, and stroop test were found in normobaric oxygen inhalation group compared to air inhalation group. Improved reaction time in those tests seemed to reflect the enhanced executive prefrontal activity. 2) Memory test：More words and digits memorization were found in short-term memory subscale score in MAS in oxygen inhalation group compared to air inhalation group. This finding suggested the improved working memory function after oxygen inhalation. Conclusion：Though interpreted cautiously, these results suggested that normobaric oxygen inhalation could enhance executive function and working memory of prefrontal lobe. Further study, however, should be performed to investigate the mechanism of effects of oxygen on cognitive enhancement.

• Asia pacific journal of information systems
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• v.20 no.3
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• pp.191-204
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• 2010

Recently, the CO2 emission and energy consumption have become critical global issues to decide the future of nations. Especially, the spread of IT products and the increased use of internet and web applications result in the energy consumption and CO2 emission of IT industry though information technologies drive global economic growth. EU, the United States, Japan and other developed countries are using IT related environmental regulations such as WEEE(Waste Electrical and Electronic Equipment), RoHS(Restriction of the use of Certain Hazardous Substance), REACH(Registration, Evaluation, Authorization and Restriction of CHemicals) and EuP(Energy using Product), and have established systematic green business/IT strategies to enhance the competitiveness of IT industry. For example, the Japan government proposed the "Green IT initiative" for being compatible with economic growth and environmental protection. Not only energy saving technologies but energy saving systems have been developed for accomplishing sustainable development. Korea's CO2 emission and energy consumption continuously have grown at comparatively high rates. They are related to its industrial structure depending on high energy-consuming industries such as iron and steel Industry, automotive industry, shipbuilding industry, semiconductor industry, and so on. In particular, export proportion of IT manufacturing is quite high in Korea. For example, the global market share of the semiconductor such as DRAM was about 80% in 2008. Accordingly, Korea needs to establish a systematic strategy to respond to the global environmental regulations and to maintain competitiveness in the IT industry. However, green competitiveness of Korea ranked 11th among 15 major countries and R&D budget for green technology is not large enough to develop energy-saving technologies for infrastructure and value chain of low-carbon society though that grows at high rates. Moreover, there are no concrete action plans in Korea. This research aims to deduce the priorities of the Korean green business/IT strategies to use multi attribute weighted average method. We selected a panel of 19 experts who work at the green business related firms such as HP, IBM, Fujitsu and so on, and selected six assessment indices such as the urgency of the technology development, the technology gap between Korea and the developed countries, the effect of import substitution, the spillover effect of technology, the market growth, and the export potential of the package or stand-alone products by existing literature review. We submitted questionnaires at approximately weekly intervals to them for priorities of the green business/IT strategies. The strategies broadly classify as follows. The first strategy which consists of the green business/IT policy and standardization, process and performance management and IT industry and legislative alignment relates to government's role in the green economy. The second strategy relates to IT to support environment sustainability such as the travel and ways of working management, printer output and recycling, intelligent building, printer rationalization and collaboration and connectivity. The last strategy relates to green IT systems, services and usage such as the data center consolidation and energy management, hardware recycle decommission, server and storage virtualization, device power management, and service supplier management. All the questionnaires were assessed via a five-point Likert scale ranging from "very little" to "very large." Our findings show that the IT to support environment sustainability is prior to the other strategies. In detail, the green business /IT policy and standardization is the most important in the government's role. The strategies of intelligent building and the travel and ways of working management are prior to the others for supporting environment sustainability. Finally, the strategies for the data center consolidation and energy management and server and storage virtualization have the huge influence for green IT systems, services and usage This research results the following implications. The amount of energy consumption and CO2 emissions of IT equipment including electrical business equipment will need to be clearly indicated in order to manage the effect of green business/IT strategy. And it is necessary to develop tools that measure the performance of green business/IT by each step. Additionally, intelligent building could grow up in energy-saving, growth of low carbon and related industries together. It is necessary to expand the affect of virtualization though adjusting and controlling the relationship between the management teams.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.45-54
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• 2021

This study was written to create educational content in non-destructive fields based on Mixed Reality. Currently, in the field of radiation, there is almost no content for educational Mixed Reality-based educational content. And in the field of non-destructive inspection, the working environment is poor, the number of employees is often 10 or less for each manufacturer, and the educational infrastructure is not built. There is no practical training, only practical training and safety education to convey information. To solve this, it was decided to develop non-destructive worker education content based on Mixed Reality. This content was developed based on Microsoft's HoloLens 2 HMD device. It is manufactured based on the resolution of 1280 ⁎ 720, and the resolution is different for each device, and the Side is created by aligning the Left, Right, Bottom, and TOP positions of Anchor, and the large image affects the size of Atlas. The large volume like the wallpaper and the upper part was made by replacing it with UITexture. For UI Widget Wizard, I made Label, Buttom, ScrollView, and Sprite. In this study, it is possible to provide workers with realistic educational content, enable self-directed education, and educate with 3D stereoscopic images based on reality to provide interesting and immersive education. Through the images provided in Mixed Reality, the learner can directly operate things through the interaction between the real world and the Virtual Reality, and the learner's learning efficiency can be improved. In addition, mixed reality education can play a major role in non-face-to-face learning content in the corona era, where time and place are not disturbed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1102-1139
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• 2002

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2000 and 2001 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD technologies were widely applied for developing facilities and their systems. (2) Most of papers related with heat transfer analysis and heat exchanger shows dealt with convection, evaporation, and channel flow for the design application of heat exchanger. The numerical heat transfer simulation studies have been peformed and reported to show heat transfer characteristics. Experimental as well as numerical studies on heat exchanger were reported, while not many papers are available for the system analysis including heat exchanger. (3) A review of the recent studies on heat pump system shows that performance analysis and control of heat pump have been peformed by various simulations and experiments. The research papers on multi-type heat pump system increased significantly. The studies on heat pipe have been examined experimently for change of working characteristics and strut lure. Research on the phase change has been carried out steadily and operation strategies of encapsulated ice storage tank are reported experimentally in several papers. (4) A review of recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. Evaporation and condensation heat transfer characteristics are investigated for tube shapes and new alternative refrigerants. Studies on components of refrigeration/air conditioning system are carried to examine efficiency for various compressors and performance of new expansion devices. In addition to thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out, however research works on two-phase flow seemed to be insufficient. (5) A review of the recent studies on absorption cooling system indicates that heat and mass transfer phenomena have been investigated to improve absorber performance. Various experimental data have been presented and several simulation models have been proposed. A review of the recent studies on duct and ventilation shows that ventilation indices have been proposed to quantify the ventilation performance in buildings and tunnels. Main efforts have been focused on the applications of ventilation effectiveness in practice, either numerically using computational fluid dynamics or experimentally using tracer gas techniques. (6) Based on a review of recent studies on indoor thermal environment and building service systems, research issues have mainly focused on many innovative ideas such as underfloor air-conditioning system, personal environmental modules, radiant floor cooling and etc. Also, the new approaches for minimizing energy consumption as well as improving indoor environmental conditions through predictive control of HVAC systems, various activities of building energy management and cost-benefit analysis for economic evaluation were highlighted.

• Korean Security Journal
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• no.14
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• pp.367-388
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• 2007

Some of individuals working at various fields of security guard are given the legal right to use a gun to cope with expected risks and crimes. Not only in Korea but also throughout the world, a pistol is being used as a device for the workers of security guard such as the army, the police and intelligence agencies to keep the law and social order. A pistol, which is regarded as the last safety measure of security guard, is easy to carry but, because of its short barrel for high portability, its hit ratio and long-range shooting performance are much lower than ordinary guns. Despite such weak points, a pistol can be a great tool because of its high portability and if the users make steady efforts to improve their skills and, for this reason, it has been being used widely until now. National agency workers' pistol shooting skills depend on several important factors, but for the fast and accurate shooting, the mot important factor is how to aim at the target. Because it takes a relatively longer time to align the sight on the target, the change of the sight alignment method is expected to improve pistol shooting skills a lot. In Korea, however, most of national agency training centers teach the basic aiming method that crosses the foresight and the backsight and aligns the crossing to the target. That is, they teach the sight alignment method for fixed targets. Some agencies in Korea and foreign countries that have used guns more frequently and longer than us are teaching different sight alignment methods as well. Representative ones of them are aiming only with the foresight and pointing shooting. These aiming methods are expected to produce good results against moving targets. While the basic sight alignment method has to cross the foresight and the backsight and then to align the crossing to the target, so takes a longer time than other aiming methods, the other two aiming methods are expected to be effective in fields where both swiftness and accuracy are require. Because domestic agencies are teaching mainly the basic sight alignment method, the present study purposed to examine the effects of different aiming methods on shooting records and ultimately to contribute to national agency workers' operation. For this purpose, we selected 20 policemen from local police commandos under the National Police Agency who were accustomed to pistol shooting and measured their pistol shooting. According to the results, the pointed shooting method showed the best record in 5m short.range shooting. As to hit ratio in 15m shooting, which is relatively long.range for pistol shooting, the basic aiming method showed the best record, but the results of statistical analysis showed that pointed shooting is most superior. Of course, the results were obtained from a group who were used to and skillful in pistol shooting, but they are considered meaningful in that all the police and national agency workers should have such high shooting skills.

• Journal of Preventive Medicine and Public Health
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• v.35 no.3
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• pp.205-213
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• 2002

Objective : Whether exposure to chronic noise induces an increase in blood pressure, or the development of hypertension, has not been established. A cohort study was performed to identify the effects of chronic noise exposure on blood pressure. Methods : 530 males working at a metal manufacturing factory in Busan, Korea were enrolled for the study. They were monitored for 9 consecutive years, from 1991 to 1999, with an annual health check-up. The subjects were divided into 4 groups, which were determines by noise level categories(NLC) according to noise intensity ; NLC-I: office workers, exposed to noise a level below 60dB(A) ; NLC-II: field technical supporters or supervisors, frequently exposed to workplace noise, wearing no hearing protection device; NLC-III: workers, exposed to workplace noise below 85dB(A), wearing ear plugs or muffs; NLC-IV: workers, exposed to workplace noise over 85 dB(A), wearing both ear plugs and muffs. Results : After controlling possible confoundens, such as baseline age, smoking, alcohol intake, exercise, family history of hypertension, systolic(SBP) of diastolic blood pressure(DBP) and changes in BMI (body mass index), the pooled mean for the systolic blood pressures, over the duration of the study period, were 3.8mmHg, 2.0mmHg and 1.7mmHg higher in NLC-IV, NLC-III NLC-II groups, respectively, than in the NLC-I group. There were no significant differences in the diastolic blood pressures between the groups. Conclusion : This study suggests that chronic noise exposure increases systolic blood pressure independently, among male workers.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.39-50
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• 2004

This study was carried out to evaluate the effect of general and occupational characteristics musculoskeletal symptoms in Radiological Technologist who working in present department more than 1 year. Standardized questionnaire of NIOSH and organized questionnaire for 재rk-related musculoskeletal was to 72Radiological Technologist, employed in 6general hospital in Seoul in September, 2003. The symptom prevalence rate of musculoskeletal symptoms were neck ($33.3\%$), shoulder ($33.3\%$), arm($12.5\%$), hand($13.9\%$), spine($34.7\%$)leg/knee/foot ($31.9\%$), arm/wrist/hand ($16.5\%$).