• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.1031-1033
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• 2013

Radiation protection, as well as finding the location of the radiation source, such as the Fukushima radiation leak accident, it is important for the early and safe disposal of nuclear accident. The three-dimensional position of the radiation source detection distance of the radiation source can provide additional information to the existing radiation detectors radiation of a two-dimensional position detection function and then it can play a decisive role in the radiation contaminant removal and decontamination work. In this research, three-dimensional semiconductor sensor based on dual radiation detectors radiation source device visible part of the research and development of efficient radiation sensor unit on the design of the shielding structure.The lightweight, high-efficiency radiation source locator implementation was attempted for the structure and thickness of the shielding and collimator to perform the simulation of the radiation shielding for the various parameters of the shape model through design the optimal structure of the MCNP-based heavy-duty tungsten shielding, lead shielding The results of this study, is a compact, lightweight three-dimensional radiation source detection and future of silicon - based sensors will be used in the study.

• Atmosphere
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• v.19 no.4
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• pp.345-370
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• 2009

Numerical experiments using the Weather Research and Forecasting (WRF) model were done to identify the role of the mountain ranges in the northern part of the Peninsula (referred as "the northern mountain complex"), in the occurrence of two heavy snowfall events over the Yeongdong region on 7-8 December 2002 and 20-21 January 2008. To this end, control simulations with the topography of the northern mountain complex and other simulations without the topography of the mountain complex were performed. It was revealed that the amount of snowfall over the Yeongdong region from the control simulation much more exceeded that of the simulation without the topography of the mountain complex. This increase of the snowfall amount over the Yeongdong region can be explained as follows: As the upstream flow approached the northern mountain complex, it deflected around the northern mountain complex due to the blocking effect of the mountains with a low Froude number less than ~0.16. This lead to the strengthening of northeasterly over the East Sea and over the Yeongdong region. The strong northeasterly is accompanied with much more snowfall over the Yeongdong region by intensifying air-mass modification over the sea and the orographic effect of the Taeback mountains. Thus, it was concluded that the topography of the northern mountain complex is one of the main factors in determining the distribution and amount of precipitation in the Yeongdong region when there is an expansion of the Siberian High toward the East Sea.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.163-171
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• 2012

Demand Responsive Transit (DRT) services are becoming necessary as part of not only alternative transportation means for elderly and mobility impaired passengers, but also sustainable and flexible transportation options in urban area due to the development of communication technologies and Location Based Services (LBS). It is difficult to investigate the system performance regarding vehicle operational schemes and vehicle routing algorithms due to the lack of commercial software to support door-to-door vehicle simulation for larger area. This study proposes a simulation framework to evaluate innovative and flexible transit systems focusing on various vehicle routing algorithms, which describes data-type requirements for simulating door-to-door service on demand. A simulation framework is applied to compare two vehicle dispatch algorithms, Nearest Vehicle Dispatch (NVD) and Insertion Heuristic (IH) for real-time shared-taxi service in Seoul. System productivity and efficiency of the shared-taxi service are investigated, comparing to the conventional taxi system.

• Journal of the Korean School Mathematics Society
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• v.12 no.2
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• pp.151-170
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• 2009

The purpose of the study is to analyze the sixth graders' understanding of concepts and operation about fraction. The test was administered and analyzed to 707 sixth graders' performance on fractions after the fraction instructions in elementary schools in Seoul, Korea. The participants are asked to answer two sets of questions for 40 minutes. First, they are asked to answer to 16 problems about the concepts of fraction with respect to part-whole, ratio, operator, measure, quotient, equivalent, and operations. Second, specially, to investigate sixth graders' ability of drawing and describing the situation of division including fraction, the descriptive problem asked students (1) to describe $3\;{\div}\;\frac{1}{2}$ into pictorial representation and (2) to write the solving process. The participants of this study didn't show deep understandings about the concepts and operation of fraction. The degree of understanding of subconstructs of fraction shows that their knowledge of ratio concept with respect to fraction was highest while their understanding of measure with respect to fraction was lowest. Considering their wrong answers, about 59% of participants showed misconception to the question of naming one fraction that appears between $\frac{1}{5}$ and $\frac{1}{6}$. Further, they didn't explain their understanding with drawing about the division of fraction ($3\;{\div}\;\frac{1}{2}$).

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.761-770
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• 2013

This study was carried out to forecast the flow rate and water quality at the inlet of the Saemangeum bay in Korea using the SWMM(Storm Water Management Model) and the WASP(Water Analysis Simulation Program), and to analyze the impacts of pollutant loading from non-point source on the water quality of the bay. The calibration and validation of flow rate and water quality were performed using those from two monitoring points in the Mankyeong river administrated by Korean Ministry of Environment as part of the national water quality monitoring network. When the river flow rate was calibrated and validated using the rainfall intensities during 2011-2012, $R^2$ (i.e., coefficient of determination) was ranged from 0.91 to 0.96. For water qualities, it was shown that $R^2$ of BOD(Biochemical Oxygen Demand) was ranged from 0.56 to 0.86, and $R^2$ of T-N(Total Nitrogen) was from 0.64 to 0.75, and $R^2$ of T-P(Total Phosphorus) was from 0.67 to 0.89. The integrated modeling system showed significant advances in the accuracy to estimate the water quality. Finally, further simulations showed that annual average flow of the river running into the bay was estimated to be $1.439{\times}10^9m^3/year$. The discharged load of BOD, T-N, and T-P into the bay were anticipated to be 618.7 ton/year, 331.5 ton/year, and 40.4 ton/year, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.1
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• pp.12-16
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• 1988

The observation of the tidal current and the bottom contour around the set net fishing ground were carried out at four different regions of the southern part of Korea in order to obtain the basic information on the migrating course of fishes. The bottom contour was surveyed with portable echo sounder, and the tidal current was observed by two different methods at the same time. One was 25 hour observation at the fixed position with self-recording current meter (Inter Ocean Model 135 type) and the other was the drift observation of radar reflectors. Most of the set nets have been set near bottom valleys. It was regarded that the fish school became to dense easily near the valley according to the combined effect of the tidal current and the bottom contour.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.371-380
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• 2007

Objectives: To determine the impact of cigarette prices on the decision to initiate and quit smoking by taking into account the interdependence of smoking and other behavioral risk factors. Methods: The study population consisted of 3,000 male Koreans aged ${\ge}20$. A survey by telephone interview was undertaken to collect information on cigarette price, smoking and other behavioral risk factors. A two-part model was used to examine separately the effect of price on the decision to be a smoker, and on the amount of cigarettes smoked. Results: The overall price elasticity of cigarettes was estimated at -0.66, with a price elasticity of -0.02 for smoking participation and -0.64 for the amount of cigarettes consumed by smokers. The inclusion of other behavioral risk factors reduced the estimated price elasticity for smoking participation substantially, but had no effect on the conditional price elasticity for the quantity of cigarettes smoked. Conclusions: From the public health and financial perspectives, an increase in cigarette price would significantly reduce smoking prevalence as well as cigarette consumption by smokers in Korea.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.12
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• pp.935-942
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• 2014

The ride quality investigation is on-going topic in the car industry since its global standard has not evaluated and it is difficult to point out one part that hinders the ride quality. Since the traditional transfer path analysis that is widely used in car industry to investigate the ride quality requires a lot of test time to process the full data so that there are problems to conduct in industry. Based on these disadvantages, new approaches have developed such as OPAX(operational path analysis with eXogeneous inputs) and OTPA(operational transfer path analysis) for last decades. The OTPA only requires the operational data for evaluate the contribution of vibration sources and the OPAX has advantage of using parametric model to estimate the operating load and needs a minimum set of extra tests with excitation. In this paper, for evaluating the hindrance of ride quality two methods are used and the result is compared with another result of a car having higher ride quality.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.606-613
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• 2007

This study investigates the behavior of a plunging wave and its associated runup and overtopping through velocity measurements and suggests an empirical formula for overtopping velocities on a structure. The plunging wave breaking in front of the structure generates very bubbly flow fields. For measurements of the two phase flow field of the breaking wave, particle image velocimetry and a modified optical method were employed. The obtained velocity fields were discussed in respect of the process of wave impinging, runup and overtopping. The overtopping velocity distribution is found to have a nonlinear profile showing a maximum magnitude at its front part. The relationship of self-similarity among dimensionless parameters is observed and used to obtain the regression formula to depict the overtopping velocity.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.4 s.152
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• pp.567-581
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• 2006

The purpose of this research is to provide the basic data for the development of make-up color application system, based of Korean's skin tone and the preference in make-up color to enhance the effectiveness of the education of beauty in universities. The research was conducted by the previous studies, the analyses of sale's rate of hue-cosmetics, the analytic experiment of color of cosmetics by using Spectrum Color Analyzer and other experimental researches. This research, based on the results of three preliminary researches, shows the result of evaluation from perceivers which has been come out from the experiment of having one model in her twenties being changed with twenty-two different conditions of make-up. Here follows the result of the research. Firstly, there was difference on perceiving images in terms of the gender of perceivers and especially male-group tend to have clearly perceived the gap between elegance-greyish purple, orange-natural, red-classic on monochrome make-up and contrast make-up. Secondly, in terms of lip-colors, salmon pink and pink was regarded positively to both female and male subjects and to male subjects, greyish purple was thought to be better on darker skin-tone and to female subjects, better on lighter skin-tone. Thirdly, on image make-up, romantic gives intelligent image regardless of skin-tone and gender, especially gives more positive looks to male subjects. Natural and classic elements were perceived more positively on darker skin-tone and had bigger perceiving gap in female subjects. Fourthly, in preference rate, male subjects normally preferred the look with make-up than female subjects did and salmon pink and pink lip color was preferred on the darker skin-tone.