• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.197-201
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• 2007

Oil soluble licorice extract(licorice extract) is an officially approved cosmetic component as a whitening ingredient in Korea. The durability of licorice, during which the whitening effect can be maintained in optimum condition, must be accurately defined. Since the cosmetics durability under real condition is relatively longer than its development time. It is needed to predict the real durability interval from the experimental measurement under simulated operating conditions. We analyzed the relationship between the licorice lifetime and the high temperature condition by using Arrhenius equation. We have established the constant stress test with temperature of $50^{\circ}C$, $55^{\circ}C$, and $60^{\circ}C$ condition, within which no formulation change of licorice products is expected for the accelerated stress test. In this paper, the lifetime of licorice in cosmetics was defined as time period for its 10% contents reduction. We observed that the lifetime of licorice is 580 h at $50^{\circ}C$, 319 h at $55^{\circ}C$ and 166 h at $60^{\circ}C$. Using the above experimental data, we obtained the equation for the relationship between the licorice lifetime and temperature as follows; log(lifetime)=-35.0243 + 1.15322$\times$(11604.83/temperature). From this equation, the lifetime of licorice at $25^{\circ}C$ can be estimated as 26 months. The estimated result was verified by measuring full lifetime of licorice. In fact, there was no significant difference between the estimated lifetime and real measurement within 95 % significance level. This study can be applied to other useful cosmetic components for the fast estimation of the exact durability.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.3
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• pp.178-188
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• 2017

Purpose: We compared the effects of newly developed diode laser (Bison 808 nm Diode laser) on the treatment of peri-implantitis with conventional products (Picasso 810 nm Diode laser) by comparing the surface temperature of titanium disc and bacterial sterilization according to laser power. Materials and Methods: The titanium disc was irradiated for 60 seconds and 1 - 2.5 W using diode laser 808 nm and 810 nm. The surface temperature of the titanium disc was measured using a temperature measurement module and a temperature measurement program. In addition, in order to investigate the sterilizing effect according to the laser power, 808 nm laser was irradiated after application of bacteria to sandblasted large-grit acid-etched (SLA) and resorbable blast media (RBM) coated titanium discs. The irradiated disks were examined with scanning electron microscopy. Results: Both 808 nm and 810 nm lasers increased disk surface temperature as the power increased. When the 810 nm was irradiated under all conditions, the initial temperature rise rate, the descending rate, and the temperature change before and after was higher than that of 808 nm. Disk surface changes were not observed on both lasers at all conditions. Bacteria were irradiated with 808 nm, and the bactericidal effect was increased as the power increased. Conclusion: When applying these diode lasers to the treatment of peri-implantitis, 808 nm which have a bactericidal effect with less temperature fluctuation in the same power conditions would be considered safer. However, in order to apply a laser treatment in the dental clinical field, various safety and reliability should be secured.

• Progress in Medical Physics
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• v.20 no.3
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• pp.139-144
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• 2009

Recently, the mathematical analysis of stent simulation has been improved, with the help of development of various tool which measure mechanical property and location of stent in artery. The most crucial part of the stent modeling is how to design ideal stent and to evaluate the interaction between stent and artery. While there has been great deal of researches on the evaluation of the expansion, stress distribution, deformation of the stent in terms of the various parameters, few verification through computer simulation has been performed about deformation and stress distribution of the stent. In this study, we have produced the corresponding results between experimental test using Universal Testing Machine and computer simulation for the ideal model of stent. Also, we have analyzed and compared stress distribution of stent in the cases of that with membrane and that without membrane. The results of this study would provide minimum change of plan and good quality for ideal stent replacing damaged artery through the analysis using computer simulation in the early stage of stent design.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.209-221
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• 2007

Numerical analysis was performed to investigate the effect of heavy metal contamination on neighboring environment in case a dam is constructed by using rockfill materials contaminated by heavy metals. The numerical simulation carried out in this research includes both subsurface flow and contaminant transport in the inside of the CFRD(Concrete Faced Rockfill Dam), using two commercial programs, SEEP2D and FEMWATER. The three representative cases of scenarios were chosen to consider a variety of cases occurring in a dam site; (1) Scenario 1 : no crack in the concrete face slab, (2) Scenario 2 : a crack In the upper part of face slab, and (3) Scenario 3 : a crack between plinth and face slab in the lower part of face slab. As a result of seepage analysis, the amount of seepage in scenario 2 was calculated as $14.31\sim14.924m^3/day$ per unit width, corresponding to the 1,000 times higher value than that in other scenarios. Also, in the simulation of contaminant transport by using FEMWATER, specified contaminant concentration of 13 ppb in main rockfill zone was set to consider continuous leakage from the rock materials. Through the analysis of contaminant transport, we found that elapsed times to take for the contaminant concentration of about 2 ppb to arrive at the end of a dam are as follows. Scenario 1 has the elapsed time of 55,000 years. In Scenario 2. it is 50 years. Finally, scenario 3 has 27,000 years. The rapid transport of the contaminant in scenario 2 was attributed to greater seepage flow by 500 times than other scenarios. Although, in case of upper crack in the face slab, it was identified that the contaminant might transport to the end of a dam within 100 years with about 2 ppb concentration, however, it happened that the contaminant was hardly transported out of the dam in other scenarios, which correspond to either no crack or a crack between plinth and face slab. In conclusion, the numerical analysis showed that the alternative usage of the contaminated sand and gravel as the dam embankment material can be one of the feasible methods with the assumption that the cracks in a face slab could be controlled adequately.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.17-32
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• 1996

It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The archwire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows : 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.

• Korean Security Journal
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• no.21
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• pp.95-120
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• 2009

This study was designed to investigate the relationship between the stages of exercise behavior change and physical self-concept and self-efficacy of security employees in hotel casinos. The sampling was drawn from employees at 8 casinos which had more than 30 employees. Participants were selected by convenience sampling method and they completed questionnaires about Physical Self-Concept and Self- Efficacy by self-administration method under supervision of trained researchers SPSS 16.0 (Statistical Package for the Social Science) was used for data analysis in the present study. Reliability and validity were examined for the present study. The principle component factor analysis and varimax rotation were used for the present study. Eigen value 1.0 was the criterion for selecting factors. Chi-square (X) 2 test was utilized for measuring the difference in gender and types of job duties at the stages of exercise behavior change. One-way ANOVA was employed to examine the relationship between the stages of exercise behavior change as an independent variable and physical self-concept and self-efficacy as dependent variables. The Scheffe method was used to determine mean differences of groups as a follow-up test. Multiple regression analysis was utilized to test the difference of physical self-concept as dependent variable and self-efficacy as independent variable. To verify hypothesis for the study, a statistical significance level of $\alpha$=.05 was used. The results were as follow: first, there were differences found for gender and types of job responsibilities in the stages of exercise behavior change. Secondly, as security employees progressed through the stages of exercise behavior change, their physical self-concept and self-efficacy improved. Finally, physical activity and body fat had significant main effects on self-efficacy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.3
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• pp.159-165
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• 1997

This paper presents the optimum dimension of 89 ton class stow-net vessel with stern-fishing. The model of basic design is developed by using the optimization techniques referring to objective function and numerous constraints as follows; speed, fishing quantity, fishing days, catch per unit effort(CPUE), and weight/ratio of main dimensions, etc. Thus, the basic design of stow-net fishing vessel is built up by using the optimization of the design variables called the economic optimization criteria, and the objective function represents the criterion which is cost benefit ratio(CBR). The main conclusions are as follows. 1. S/W for decision of optimum hull size is developed in 89 ton class stow-net fishing vessel which is constructed with optimization of the design variables called the economic optimization criteria. 2. For optimum ship dimensions in 89 ton class stow-net fishing vessel, the hull dimensions can be obtained in the range of L= 27.3m, B = 6.6m, D = 2.80m, Cb = 0.695, T/D = 0.80, $\Delta$(displacement)=281.7ton with 10 knots.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.357-368
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• 2008

On July 31, 2008, the Government issued the construction and operation permit for the first low and intermediate level radioactive waste disposal facility in the Republic of Korea. In this paper, the fundamental regulatory framework, regulatory requirements and technical standards of the disposal facility are introduced, and the phased review process adopted for evaluation of the safety of the facility is briefly described. The Atomic Energy Act sets forth a stepwise regulatory framework for the whole life-cycle of the disposal facility such as siting, design, construction, operation, closure and institutional control. More detailed regulatory requirements and technical standards are stipulated in the subsequent regulations of the Atomic Energy Act and a series of Notices issued by the Ministry of Eduction, Science and Technology. The Korea Institute of Nuclear Safety, as entrusted by the Ministry under the Atomic Energy Act, conducted safety review on the disposal facility, and evaluated the compliance with relevant criteria in all technical elements(i.e. siting and structural safety, radiological environmental impact, operational safety, systems and components, quality assurance, and total systematic performance assessment, etc.). The overall safety review process can be phased into inception phase, initial review phase, main review phase and completion phase. The review results were reported to and deliberated by the five Sub-committees of the Special Committee on Nuclear Safety, and then reported to the Ministry. The Ministry issued the construction and operation permit of the disposal facility through the deliberation of the review results by the Nuclear Safety Commission. Hereafter, the safety of the repository will be reassured by a series of subsequent regulatory inspections and reviews under the Atomic Energy Act. In addition, the licensee's continuous implementation of the "Safety Promotion Plan" may also enhance the long-term safety of the repository and contribute to build-up the confidence of the safety case.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.148-155
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• 2002

Multithreaded models improve the efficiency of parallel systems by combining inner parallelism, asynchronous data availability and the locality of von Neumann model. This model executes thread code which is generated by compiler and of which quality is given by the method of generation. But multithreaded models have the demerit that execution model is restricted to a specific platform. On the contrary, Java has the platform independency, so if we can translate from threads code to Java bytecode, we can use the advantages of multithreaded models in many platforms. Java executes Java bytecode which is intermediate language format for Java virtual machine. Java bytecode plays a role of an intermediate language in translator and Java virtual machine work as back-end in translator. But, Java bytecode which is translated from multithreaded models have the demerit that it is not secure. This paper, multhithread code whose feature of platform independent can execute in java virtual machine. We design and implement translator which translate from thread code of multithreaded code to Java bytecode and which check secure problems from Java bytecode.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.345-350
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• 2012

To investigate the exposure and health risk assessment for the residents near the D-asbestos mine in Chungbuk, Korea. We analyzed asbestos in the 20 ambient air and 23 activity based samples near the mine. The airborne sample results are showed that 8 of 20 samples ranged between 0.0025 to 0.0029 f/cc (fiber per cubic centimeter) and the others were below the detection limit by phase contrast microscopy (PCM). In addition, asbestos fibers were under the detection limit or not being by transmission electron microscopy (TEM). Based on interview and survey targeting the local residents, we made the activity based sampling (ABS) scenarios fit to the conditions of field. At the same time, we calculated the excess lifetime cancer risk (ELCR) of these ABS scenarios according to the ELCR average value and 95% upper confidence limit (UCL). At the case of weed whacking, soil digging and sweeping yard scenario, 95% UCL of ELCR exceeded the $1{\times}10^{-4}$, acceptable risk range for exposure. Based on our study results, it is necessary safety measures such as risk communication, abatement or management of naturally occurring asbestos (NOA).