• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2821-2835
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• 2020

The phenomenon identification and ranking table (PIRT) is an important basis in the nuclear power plant (NPP) thermal-hydraulic analysis. This study focuses on the importance ranking of the input parameters when lacking the PIRT, and the target scenario is the small break loss of coolant accident (SBLOCA) in a pressurized water reactor (PWR) CPR1000. A total of 54 input parameters which might have influence on the figure of merit (FOM) were identified, and the sensitivity measure of each input on the FOM was calculated through an optimized moment-independent global sensitivity analysis method. The importance ranking orders of the parameters were transformed into the Savage scores, and the parameters were categorized based on the Savage scores. A parameter importance ranking table for the SBLOCA scenario of the CPR1000 reactor was obtained, and the influences of some important parameters at different break sizes and different accident stages were analyzed.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.4
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• pp.253-259
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• 2018

Structure behaviors resulting from an earthquake are experimentally simulated mainly through a shaking table test. As for large-scale structures, however, size effects over a miniature may make it difficult to assess actual behaviors properly. To address this problem, research on the hybrid simulation is being conducted actively. This method is to implement numerical analysis on framework members that affect the general behavior of the structure dominantly through an actual scale experiment and on the rest parts by applying the substructuring technique. However, existing studies on hybrid simulation focus mainly on Slow experimental methods, which are disadvantageous in that it is unable to assess behaviors close to the actual level if material properties change depending on the speed or the influence of inertial force is significant. The present study aims to establish a Real-time hybrid simulation system capable of excitation based on the actual time history and to verify its performance and applicability. The hybrid simulation system built up in this study utilizes the ATS Compensator system, CR integrator, etc. in order to make the target displacement the same with the measured displacement on the basis of MATLAB/Simulink. The target structure was a 2-span bridge and an RC pier to support it was produced as an experimental model in order for the shaking table test and Slow and Real-time hybrid simulations. Behaviors that result from the earthquake of El Centro were examined, and the results were analyzed comparatively. In comparison with the results of the shaking table test, the Real-time hybrid simulation produced more similar maximum displacement and vibration behaviors than the Slow hybrid simulation. Hence, it is thought that the Real-time hybrid simulation proposed in this study can be utilized usefully in seismic capacity assessment of structural systems such as RC pier that are highly non-linear and time-dependent.

• Journal of the Korean GEO-environmental Society
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• v.14 no.2
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• pp.43-50
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• 2013

In this study, the tests were carried out for the behavior according to method of constrained nail head of slope reinforced with soil nail under dynamic loading, by using shaking table. Shaking table tests were carried out by applying Hachinohe seismic wave having the long-period characteristics and Ofunato seismic wave having short-period characteristics, as changing constrained and unconstrained condition of nail head, and so on. Failure mode, ground acceleration characteristics, vertical displacement and horizontal displacement of slope were compared and analyzed on the basis of results obtained from the test. Results of carrying out shaking table test showed that both short-period wave and long-period wave had large effects on slope, and constraint of nail head was found to have large shear resistance for dynamic load. And it was confirmed that stability of slope under seismic loading was largely improved by constrained head of soil nail.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.49-54
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• 1973

Surveys of stock volume on steep and vast expanse of mountains, involves various difficulties. And it is extremely uneconomical in forest management point of view, to spend lots of time and man power for surveying such tree volume as the value is much cheaper in comparison with volume and weight. Therefore, a stand volume table estimate easely stock volume per hectare basis from aerial photographs was prepared and correlations to stand volume among factors affecting tree volumation, were studied. Data were 114 places selected from planted Korean white pine, Pinus koreiensis Sieb. et Zucc. stands in Kwangnung Experiment Forest and were computed and analysed by the means of the quantification in the multi-variate statistical analysis. Electronic Data Processing System was applied for data processing at Korean Instiute of Science and Technology. Coefficients of multiple correlations of stand volume table was ranged 0.85~0.88.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1382-1391
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• 2022

White-box cryptography can respond to white-box attacks that can access and modify memory by safely hiding keys in the lookup table. However, because the size of lookup tables is large and the speed of encryption is slow, it is difficult to apply them to devices that require real-time while having limited resources, such as IoT(Internet of Things) devices. In this work, we propose a scheme for collecting short-length plaintexts and processing them at once, utilizing the characteristics that white-box ciphers process encryption on a lookup table size basis. As a result of comparing the proposed method, assuming that the table sizes of the Chow and XiaoLai schemes were 720KB(Kilobytes) and 18,000KB, respectively, memory usage reduced by about 29.9% and 1.24% on average in the Chow and XiaoLai schemes. The latency was decreased by about 3.36% and about 2.6% on average in the Chow and XiaoLai schemes, respectively, at a Traffic Load Rate of 15 Mbps(Mega bit per second) or higher.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.316-324
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• 1996

This study was conducted by relative time study to identify the allowance time and basic work time, which is together composed of the total work time, in the wage composition and work process composition. This study was done for the case of a basic one person a group from thinning treatment for some conifer species such as Japanese red pine, Japanese larch, pitch pine and Korean pine. 1. In order to apply the Japanese allowance time of four species to the general conifer case, the maximum value of allowance time composition value among those of four species was selected. The results are as follows: delay time for person 1.8%, rest time 14.1%, delay time for machine 12.5% and wating time 0.4%. The some of ratios of adjustment allowance time is 28.8%. 2. Estimated wage basis time table, which can be used for wage table or process table, was prepared by adding up adjusted general allowance time and standard work time estimated by estimation equation for each species through the time study.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.268-280
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• 2009

Oncheon basin which are located in Busan is divided into 43 basin on the basis of main pipe, constructed with Storm Water Management Model (SWMM). Occurrence situation for Outflow and pollutant loads by long-term continuous rainfall is examined for treatment district and river analysis point of Oncheon basin and a reduction vs effectiveness table for effective CSOs managements is made for each of treatment districts according to each of managements. In case that treatment equipment is located at the discharge point of CSO, treatment efficiency is analysed. It is supposed that treatment equipment have an efficiency on the basis of a concentration and runoff discharge over a critical flow is discharged with it untreated and treating runoff discharge with treatment equipment at each of runoff discharge points and treating it gathered at sewage treatment plant (STP) through trunk sewer is compared for a relative treatment efficiency.

• Korean Journal of Community Nutrition
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• v.14 no.3
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• pp.295-305
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• 2009

In order to investigate how to maintain normal weight under independent living conditions, twenty female university students were enrolled and asked to complete a questionnaire over a 10- day study period. T-test, Spearman's correlation and multiple regression analysis were applied to describe characteristics of weight maintainers' habits on a daily basis. The results were as follows: They always comsumed small or moderate-sized meals. $2{\sim}3$ co-eaters usually had dinner together at home while not watching TV. They also showed healthy eating behaviors such as no snacking, very little amounts of soft drinks, coffee and alcohol consumption. The always normal weight maintainers, however, were not physically active at all. When being with co-eater(s), they ate larger-sized dinners (${\beta}$ = 0.585, $R^2$= 30.6), and the more co-eaters they had at the dinner table, the greater BMI they got (${\beta}$ = 0.547, $R^2$= 29.9). As a result of this study, encouraging young adult people to exercise on a regular basis is required, even though they seem to succeed in maintaining normal weight without being active physically. Further study is necessary to investigate how co-eaters would influence the amount of food eaten.

• Journal of Nutrition and Health
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• v.33 no.1
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• pp.68-79
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• 2000

This study was developed the nutrition education program for kindergarten children and was evaluated its educational effect by 'Non-equivalent control group design'. Nutrition education program was developed on the basis of the concept which consisted of nutrition, nutrients, food handling, life cycle and social$.$psychological needs. And it was developed on the basis of the theme which consisted of kind of foods, relation between food and body, importance of food, food and sanitation, food and environment, Korean traditional food and good table manners. Subjects consisted of 157 kindergarten children, with 48 in control group and 109 in treatment group. All the subjects completed a pretest and a posttest and the posttest means between control and treatment group were compared. The control group had a adjusted posttest mean score of nutrition knowledge of 50.64 and the treatment group had that of 75.19 and the difference was significant(p<0.001). The control group had a adjusted posttest mean score of food attitude of 65.49 and the treatment group had that of 85.40 and the difference was significant(p<0.001). (Korean J Nutrition 33(1) : 68-79, 2000)

• Journal of the East Asian Society of Dietary Life
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• v.3 no.1
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• pp.27-36
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• 1993

To point out the Confucian Influence in Chosun, we deal with religious ceremonies, the decline of drinking tea, the spread of dog meat and the development of nutrition for the aged. The result is follows. First, the chosun confucianism changed the Buddhist familty ceremonies of Koryeo period into the confucian cermonies formed by Chu-Tzu's influence. So, buddhist sacrificial table turned into confucian one which was more systematric and more formal on the basis of chosun culture of food. Second, Chosun confucian scholars shrank from drinking tea because tea was the symbol of Buddhism. As a result, our people came to drink " Sung-nyung(scorched-rce tea)" and the common people drank Maggeolli instead of syung-nyung. Furthermore, this resulted in developing some kind of beverages. third, the people of Chosun had little rejection to dog meat and it was popularized in Chosun, Dog maet was popular in Chinese countries, Chu. Chin. and early Han. Later, dong meat almost disappeared except the purpose if healing. the reason why people had little rejection to dong meat in Chosun was that Chosun Conflucianism was the revival of Chu. Fourth, Chosun's state religion was confucianism which emphasize filial duty, the basis of humanity. The gentry researched into medication and nursing I case their old parents got sick. As a result, nutrition for the aged was developed.