• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.143-150
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• 2015

At present, the actual condition is that Korean modular structures are limited to a low rise detached house and military barracks. And there is no standardized structural design method of stacked modular structure. Accordingly, in general, they don't review impact force in the stage of stacking and installing a module, the effect which wind load has on a structure in the stage of lifting, and inertial force occurring in the stage of lifting or transporting a module in the process of constructing a structure. Therefore, this study investigated the construction method of modular system to be studied in stages, and decided on the position to which load was applied and boundary condition in structural analysis at each construction stage. Besides, inertial force according to each speed was calculated in the lifting and wheeled transport of module. And we calculated impact load according to lifting speed in module stacking and installation work and wind load due to instantaneous wind speed in the installation work by lifting. On the basis of the suggested method, in the modular system to be studied, it carried out review of structure by changing determining conditions of load being applied by construction stage, such as in the stage of lifting, in the stage of transport, and in the stage of installation, and drew construction conditions securing stability structurally.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.147-157
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• 2011

Purpose: The present study was conducted to investigate the actual condition of circle lens wear and the differences caused by the pigmentation in blinking rate, non-invasive tear break-up time (NIBUT), and lens surface between circle and soft contact lens wear during clinical application. Methods: Eighty subjects were surveyed to know the actual condition of wearing circle lens. Blink rate, NIBUT of 20 subjects in twenties were measured after separately wearing soft contact lens and circle lens for 5 days. Their lens surfaces were also observed by scanning electron microscope. Results: Fifty percent of circle lens wearers answered that major reason for changing circle lens was discomfort and 67% of answerers wore circle lens more than 6 hours a day. The tendency of increased blink rates in both wearers of circle and soft contact lens at 30 minutes later when tear film stabilized and 3 hour after lens wearing was shown on the 1st, 3rd and 5th day with expanding wearing time. Especially at 3 hours after lens wearing on the 3rd and 5th day, the difference of blink rates was statistically different in circle lens wear and soft contact lens wear. The NIBUTs of soft contact lens wearers and circle lens wearers were 6.0 and 3.7 secs, respectively, at 30 min later on 1st day and were significantly different. NIBUTs of soft contact lens wearers and circle lens wearers were also statistically different 3 hrs after lens wearing on the 1st day and the similar pattern of NIBUTs was shown on the 3rd and 5th day. The roughness of both surfaces in soft contact lens and front surface in circle lens was same. However, pigmented front surface of circle lens was rougher and uneven. Conclusions: As the results, the circle lens wearers might feel discomfort in clinical application since the difference in lens surface of circle lens would change lens wettability during wearing. The difference by tinting contact lens was shown from the result, which could help better wearing circle lens.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.79-91
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• 2009

The government separated and established the industrial safety and health law from the Labor Standard law since 1981 to promote the labor's working environment and to improve the conditions of laborers. The government made a lot of effort to discharge the industrial safety and health law by continuous revision of the law thereafter. it is, however, difficult to establish clear-cut lines of authority and responsibility due to the fact that the substantial application of the industrial safety and health law is adapted by enterprise's autonomous management. There are frequent industrial disasters on the small and medium enterprises which have financial difficulty and it means this causes much more social cost. Finally, for the improvement of laborer's safety, health and working environment in the small and medium enterprises we need to raise the effectiveness of the industrial safety and health law through enhancing a government-office's administration and surveillance with the changing mind of a business proprietor. On this paper, we research on the actual condition of the administration, inspection and regulation of safety and health by means of the industrial safety and health law. Thereafter we analyze how much the Korea Occupational Safety & Health Agency and vicarious businesses of safety & health management help. we used the survey method to gather data from 380 laborers directly and analysed the data by SPSS v17.0.

• Journal of the Korean Data and Information Science Society
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• v.24 no.1
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• pp.41-51
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• 2013

In the Information age, internet addiction has been a big issue in a modern society. The adverse effects of the internet addiction have been increasing at an exponential speed. Along with a great variety of internet-connected device supplies, K-scale diagnostic criteria have been used for the internet addiction self-diagnose tests in the high-speed wireless Internet service, netbooks, and smart phones, etc. The K-scale diagnostic criteria needed to be changed to meet the changing times, and the diagnostic criteria of K-scale was changed in March, 2012. In this paper, we analyze the internet addiction and K-scale features on the actual condition of Gyeongbuk collegiate areas using the revised K-scale diagnostic criteria in 2012. The diagnostic method on internet addiction is measured by the respondents' subjective estimation. Willful error of the respondents can be occurred to hide their truth. In this paper, we add the survey response to the trusted reliability values to reduce response errors on the K-scale on the K-scale, and enhance the reliability of the analysis.

• Journal of Technologic Dentistry
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• v.12 no.1
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• pp.15-21
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• 1990

This research was to investigate and study on 92 Dental Technicians who had had some experience of working or being employed at dental craft-shops or craft-rooms in Seoul area and had transferred to other types of occupation, with regard to their reasons for changing their profession. For an approach to the study, some questionnaires and interview including 3 aspects of in quiriesmental, economic and social backgrounds-were administered, and major findings are as follows ; 1. The ages in which transferring to other kinds of job happened occurred mostly from 20 to 30(78.26%) an a group of subjects whose ages ranged from 20 to 30 years old. And, with regard to their experience of working or being employed at dental craft-shops or craftrooms, the transfer of their profession to the other kinds mosty happened in a group of subjects(94.56%) whose experience of working in the dental field is less than 4 years. 2. The reason of transfer with reference to the mental background was mostly mattered in a group that expressed "Excessive Work Duties"(34.78%), and most lowly mattered in a group of subjets who had "Certain Relations with Dentists"(8.70%). Thus, it appeared that the biggest reason of transfer by the mental background was, due to the excessive duty work, not to have Sufficient time to be usualized by dental technicians for their own purpose. 3. With reference to the economical background, a group that declared there was "No Wage Standards in Ratio to Their Labor" was the most in the separation rate as shown 45.56%. And, a group suspecting "No Guarantee for Their Living after Retirement" Showed a separation rate, 9.78%. In other words, the reason for transfer was that they did not receive due wage according to their amount of labor. 4. With reference to the social background, a group making a subject for no good working environments or conditions had a separation rate, 41.30%, which was the most among others, and a group with a subject of "The Rarity of Employment because of Excessive Supply of Dental Technicians" had the rate, 10.87%, which was the lowest. This meant that the major cause of transfer by the social background was a phenomenon for dental technicans to escape from unclean working places.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.188-196
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• 2015

Areas of forensic have been used as a tool in many fields of police investigation, detective, such as research relating to the criminal investigation. Despite it is failure to obtain a central role and status, forensic is nonetheless necessary. This study recognizes the importance of police and forensic activities, and in reviewing the level of support for actual condition of science and forensic investigations, and it has tried to find the problems. Based on this, this study discusses development plans of the working system to explore whether it can improve the efficiencies of forensic activities from the realistic restrictions. These days, one of the main problems that police forensic activities encounter is lack of labor and human resources on the arrested. Therefore, this study aimed to looking for realistic ways to improve efficiencies of forensic agents First, changing the working system and the restructuring the command system requires a long-term perspective. In other words, a regional forensic system is required. Second, the establishment of a Police Investagation Specialization to ensure the professionalism of the investigation is necessary. Third, the system should improve forensic specialties. Fourth, the R&D organization should established to improve the capability for forensic investigations.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.437-447
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• 2020

Following the extension of human life expectancy, the number of elderly traffic accidents that have been increasing at a rapid pace since 2018 has also emerged as a social problem. The traffic accident rate among those aged 65 and older is increasing, but traffic safety policies are insufficient. Based on the analysis of traffic accident status for senior citizens and traffic accident for the past five years from 2014, the reduction plan is to be presented in three main aspects. First, the system needs systematic management by strengthening the system of senior citizens' transport policy departments and driver's license for senior citizens in government agencies, such as the United States, Britain and Japan, from an institutional perspective, so that the walking time and crosswalk traffic environment for the vulnerable should be improved from an environmental perspective. In addition, in human terms, the ability to cope with real-time changes in traffic conditions should be enhanced by training transportation safety experts to secure the effectiveness of education for elderly drivers and by strengthening safety education for those with driver's license and expanding experienced traffic safety facilities to enhance the ability of senior citizens to cope with the changing traffic conditions in real time.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.429-437
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• 2007

This study aims to develop a sulfur-using denitrification process which is possible a renovation to advanced treatment plant submerging a simple module in activated sludge aeration tank. At first, the impact factor of sulfur-using denitrification was appreciated by the batch test. Secondly, reflecting a dissolved oxygen effect of sulfur-using denitrification that was confirmed by the batch test, in a continuous nitrification/sulfur-using denitrification, high-rate nitrogen removal reaction was induced at optimum condition controlling DO concentration according to phases. Also, inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. Result of batch test for sulfur-using denitrification, $NO_2{^-}N$ was lower for consumption of alkalinity and sulfur than that of $NO_3{^-}-N$. These results revealed the accordance of theoretical prediction. In continuous nitrification/sulfur-using denitrification experiment, actual wastewater was used as a influent, and influent nitrogen loading rates were increased 0.04, 0.07, 0.11, $0.14kg\;N/m^3-day$ by changing hydraulic retention times. At this time, nitrogen loading rates of packed sulfur were increased 0.23, 0.46, 0.69, $0.93kg\;N/m^3-day$. As a result, nitrification efficiency was about 100% and denitrification efficiency was 93, 81, 79, 72%. Accordingly, nitrogen removal was a high-rate. Also the module of sulfur-using denitrification covered with microfilter did not make a fouling phenomena according to increased flux. And the module was achieved effluent suspended solids of below 10 mg/L without a clarifier. In conclusion, it is possible a renovation to advanced treatment plant submerging a simple module packed sulfur in activated sludge aeration tank of traditional facilities. And the plant used the module packed sulfur is expected as a effective facilities of high-rate and the smallest.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.5
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• pp.202-207
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• 2016

Experimental studies for an indirect R404A-$CO_2$ refrigeration system and a direct R404A refrigeration system were conducted. The configurations of the indirect R404A-$CO_2$ refrigeration system are a R404A refrigeration system as a top cycle and a circulating $CO_2$ system as a bottom cycle. The direct R404A system was modified from indirect R404A-$CO_2$ refrigeration system by removing circuit for $CO_2$ circulation. Various tests for both systems were conducted by changing load side brine temperature from 0 to 5 and $10^{\circ}C$ with cooling brine temperatures for R404A system at 15, 20, or $25^{\circ}C$. The indirect R404A-$CO_2$ refrigeration system showed the highest COP when load side brine temperature was at $10^{\circ}C$ in the evaporator and at cooling brine temperature of $15^{\circ}C$. The COP of 3.04 under that condition was the highest. This indirect R404A-$CO_2$ refrigeration system showed 9.02% higher COP than the direct R404A system that had increased pipeline length of 15 m, which simulated actual installation in a supermarket.

• Korean Journal of Construction Engineering and Management
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• v.23 no.6
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• pp.21-29
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• 2022

Productivity estimation of construction operations is crucial to successful project delivery. Especially in the preconstruction phase, the adequacy and effectiveness of plans directly affect the actual performance of operations. Currently, productivity estimation is conducted by referring to existing references such as the Construction Standard Production Rate. However, it is difficult to promptly apply changing conditions of operations when using such references. Moreover, it is difficult to deduce the optimal combination of construction machinery for the given condition. This paper presents a simple simulation model that can be used to generate productivity data that considers site conditions and construction equipment combination. The suggested method is expected to be used as a decision making assisting tool for practitioners who rely on estimations using the Construction Standard Production Rate when establishing construction plans using heavy machinery such as backhoes, loaders and dumptrucks.