• Fire Science and Engineering
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• v.28 no.2
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• pp.14-19
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• 2014

A current standard exist only on the surface tension in the current domestic wetting agent technology standards, so it is difficult to the performance evaluation of the wetting agent through the standard. So this study presents the optimized performance evaluation methods by scale model experimental equipment in order to present techniques for performance evaluation of wetting agents. The purpose of this study is to investigate validity of experimental results of the self-designed scale model experiment equipment by a comparative analysis of experimental results of the NFPA 18 experiment and the experiment using the self-designed scale model experiment equipment. As a result of a comparative analysis of experimental results of the NFPA 18 experiment that evaluate only the permeation performance on the contton and the experiment using the self-designed scale model experiment equipment that evaluate the permeation performance and fire extinguishing performance on wood flour, the discrimination of the permeation performance was confirmed in both the NFPA 18 experiment and the self-designed scale model experiment equipment. And a result of self-designed experiment equipment have clear discriminatory more than NFPA 18 by internal temperature measurement using the thermocouples.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.145-153
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• 2018

Recently the Korean society has suffered severe conflicts over the rate of increase in the minimum wage, while academics have failed to provide appropriate standards through reliable research. Recent foreign studies using natural experimentation or meta-regression analysis show that the increase in minimum wage has little effect on employment. Domestic studies are not yet numerous in number, and they present different conclusions on employment effects depending on the data used, sample period, and research model. To properly assess the employment effects of the minimum wage, future studies should minimize measurement errors in minimum wage dataset, and appropriately consider the endogenous change of minimum wage, economic situation and trends of employment changes. It is also necessary to utilize natural experiment methods before and after the increase of the minimum wage.

• Journal of the Korean earth science society
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• v.26 no.8
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• pp.836-843
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• 2005

Two data sets of repeated hydrographic surveys with a single beam echo-sounder were obtained to investigate morphological changes on a sand mining site within EEZ near the Eocheong Islands, West Sea of Korea. Their accuracies of depth measurement, estimated from the crossover analysis, correspond to the Oder 2 of IHO standards. Bathymetric maps show a feature of 300m wide and 10m deep hollow, whose evolution can be seen in difference grids of the two bathymetric maps. However, data of higher accuracy and resolution enable precise quantification of extracted sand volume. Since this morphological change could affect sedimentary environment as well as benthic ecology, environmental impact assessment based on scientific research data is required for management and sustainable development of limited sand resource.

• Journal of Periodontal and Implant Science
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• v.47 no.1
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• pp.13-19
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• 2017

Purpose: The purpose of this study was to examine whether periodontal pocket could be satisfactorily visualized by optical coherence tomography (OCT) and to suggest quantitative methods for measuring periodontal pocket depth. Methods: We acquired OCT images of periodontal pockets in a porcine model and determined the actual axial resolution for measuring the exact periodontal pocket depth using a calibration method. Quantitative measurements of periodontal pockets were performed by real axial resolution and compared with the results from manual periodontal probing. Results: The average periodontal pocket depth measured by OCT was $3.10{\pm}0.15mm$, $4.11{\pm}0.17mm$, $5.09{\pm}0.17mm$, and $6.05{\pm}0.21mm$ for each periodontal pocket model, respectively. These values were similar to those obtained by manual periodontal probing. Conclusions: OCT was able to visualize periodontal pockets and show attachment loss. By calculating the calibration factor to determine the accurate axial resolution, quantitative standards for measuring periodontal pocket depth can be established regardless of the position of periodontal pocket in the OCT image.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.133-136
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• 2008

Moment redistribution problem that reflects plasticity concept is foundation of limit state design and it has been interested to design engineers and researchers for a long time, because it enables the reasonable estimation of strength of structures through amount of reinforcement control about negative moment in support. Many researchers find that moment redistribution closely related to ductility of degree of structure and there are a lot of difficulties in achieving the reliable experimental results because of a lot of restriction of experiment. So, studies are achieved for indirect estimate methods about ductility ability of structures. Each design standards limits that the degree of redistribution of bending moment is based on the measurement of ductility of structure, and it shows conservative results. In this study, with these results, present the basic data for reasonable strength estimation methods and allowed moment redistribution of reinforced concrete continuous beams.

• Korean Journal of Health Education and Promotion
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• v.15 no.1
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• pp.195-204
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• 1998

The purpose of this study was to develop cardiovascular health related percent body-fat standards that may be applied to epidemiologic investigations of the prevalence and incidence of obesity in adolescents, pediatric health screenings, and youth fitness tests. The subjects included 102 males and 80 females aged 19～22years. All subject were Honam University Students Total body fat was derived from body density which was estimated from age and the triceps and subscapular skinfold thickness measured with Lang calipers to the nearst l.0mm. Serum total cholesterol and lipoprotein cholesterol fraction(HDL-CLDL-C) were measured from blood obtained from fore arm vein after blood pressure measurement. In analyses to determine critical fat levels associated with elevated CDD(Chronic Degenerative Disease) risk factors;male and female were grouped by level of percent fat as follows: male, 〈 10%, 10-14.9%, 15-19.9%, 20-24.9%, and $\geq$ 25%;female, 〈 20%, 20-24.9%, 25-29.9%, 30-34.9%, and $\geq$ 35%. As the results of the data, the conclusions were as follows: 1. A dose respones effect was observed between blood pressure and percent body fat in males and females; in contrast, total cholesterol and lipoprotein ratios were relatively independant of percent fat among the lower four fatness group in males and the lower three fatness groups in females. 2. The percentage of subjects in the uppermost quintile for S-Bp, D-Bp, TC, LDL/H was significantly(P〈.05) greater than expected by change alone(20%) in males with $\geq$ 25% fat and in females with $\geq$ 30% fat females with $\geq$35% had even greater representation in the uppermost quintile of all CDD risk factors compared to females with 30-34.9% fat.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.339-344
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• 2014

The quality control items of mammography devices in South Korea do not include the linearity, which is required by international standards. The linearity is a requirement for the adjustment of radiation dose and radiation quality. This study tested the linearity, which was suitable for the IEC 60601-2-45 standard, of the 5 mammography devices. All showed adequate results. Consistent measurement management is required for more developed quality control in the future.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.135-138
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• 2004

Conventional piezoelectric lead-zirconate-titanate (PZT) senor has high sensitivity, but it is very brittle. Recently polymer films such as polyvinylidene fluoride (PVDF) and poly(vinylidene fluoride­trifluoroethylene) (P(VDF-TrFE)) copolymer have been used as a sensor. The advantages of polymer sensor are the flexibility and mechanical toughness. Simple process and possible several shapes are also additional advantages. Polymer sensor can be directly embedded in a structure. In this study, nondestructive damage sensitivity of single basalt fiber/epoxy composites was investigated with sensor type and thermal damage using AE and oscilloscope. And AE waveform for epoxy matrix with various damage types was compared to each other. The damage sensitivity of two polymer sensors was rather lower than that of PZT sensor. The damage sensitivity of PVDF sensor did not decrease until thermal damage temperature at $80^{\circ}C$ and they decreased significantly at $110^{\circ}C$ However, the damage sensitivity of P(VDF-TrFE) sensor at $110^{\circ}C$ was almost same in no damage sensor. For both top and side impacts, the difference in arrival time increased with increasing internal and surface damage density of epoxy matrix.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.321-331
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• 2013

Objective: The aim of this study is to review the literatures on the regulation, standard and guideline for the human vibration in Korea and other countries. Background: This review can be used to prevent various diseases caused by the human vibration as a basis for the development of the policy. Results: In Korea, the general employers' duties related to human vibration are set forth the Health Measures(Article 24) in the Occupational Safety and Health Act. And then an employer shall take measures to protect the health of the workers concerned by improving other working conditions relating to working hours for the vibration prevention measures referred to in Article 24 of the Act. The European Union adopted a Directive in 2002 on minimum requirements for the health and safety of workers exposed to vibration. New Regulations on Vibration at Work will be introduced in Great Britain on 2005 to implement the Directive. In the U.S., both ANSI and ACGIH adopted the ISO standard for measurement and suggested exposure action and limit values. In Japan, the Ministry of Labor decided that the vibration syndrome among operators of rock drills and riveters etc. could be included in an occupational disease(1947). In addition, ISO standard was based on proposals and draft documents of many countries such as U.K, Japan and European, etc. Conclusion: In Korea, Occupational Safety and Health Act prevent vibration to health, but do not include exposure limits. It is therefore important to consider the new duties regarding to vibration risks added to the general duties.

• Journal of Digital Contents Society
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• v.9 no.3
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• pp.389-398
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• 2008

There has been some research into a speech system for communications between those who are hearing impaired and those who hear normally, but the system has been pursued in inefficient teaching ways in which existing teachers teach each individual due to social indifference and a lack of marketability. In order to overcome such a weakness, there appeared to be a need to develop contents utilizing 3D animation and digital technology. For the investigation of a standard face and a standard spherical shape for the preparation of a character, the study collected sufficient data concerning students in the third-sixth grades in elementary schools in Seoul and Gyeonggi, Korea, and drew up standards for a face and a spherical shape of such students. This data is not merely the basic data of content development for the hearing impaired, but it can also offer a standard measurement and a standard type realistically applicable to them. As a system for understanding conversations by applying 3D character animation and educating self-expression, the character speech animation system supports effective learning for language education for hearing impaired children who need language education within their families and in special education institutions with the combination of 3D technology and motion capture.