• Nuclear Engineering and Technology
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• 제52권12호
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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.

• 한국지진공학회논문집
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• 제22권4호
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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.

• 한국지반환경공학회 논문집
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• 제14권2호
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• pp.43-50
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• 2013

본 연구는 진동대 모형실험기를 이용하여 동하중 재하 시 네일 두부 구속방식에 따른 쏘일네일 보강사면의 거동에 관한 실험을 실시하였다. 진동대 모형실험은 네일 두부의 구속과 비구속조건 등을 변화시키면서 장주기 특성을 지닌 Hachinohe 지진파와 단주기 특성을 지닌 Ofunato 지진파를 적용하여 실험을 실시하였다. 실험으로부터 얻어진 결과를 바탕으로 사면의 파괴유형과 지반 가속도특성, 수직변위 및 수평변위를 비교 분석하였다. 진동대 모형실험을 수행한 결과 단주기파가 장주기파 보다 사면에 미치는 영향이 큰 것으로 나타났고, 네일 두부의 구속이 동하중에 대하여 전단저항력이 크게 발휘하는 것을 알 수 있었다. 또한 쏘일 네일 두부를 구속함으로써 지진하중 작용 시 사면의 안정성이 크게 향상됨을 확인할 수 있었다.

• 한국산림과학회지
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• 제19권1호
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• pp.49-54
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• 1973

면적(面積)이 광대(廣大)하며 지형(地形)은 험준(險峻)한 산림(山林)에서 그의 축적(蓄積)을 조사(調査)하기에는 여러 난점(難點)이 많다. 중량(重量)과 용적(容積)에 비(比)하여 그 가격(價格)이 저렴(低廉)한 임목(林木)의 축적(蓄積)을 조사(調査)하는데 많은 시간(時間)과 노력(勞力)을 소비(消費)함은 산림경영상(山林經營上) 아주 비경제적(非經濟的)이다. 그러므로 항공사진(航空寫眞)만을 가지고 용이(容易)하게 ha 당(當) 임분재적(林分材積)을 추정(推定)할 수 있도록 임분재적표(林分材積表)를 작성(作成)하고 임분재적(林分材積)과 관련(關聯)있는 인자(因子)의 재적추정(材積推定)에의 관여성(關與性)을 구명(究明)하였다. 재료(材料)는 임업시험장(林業試驗場) 광릉시험림내(光陵試驗林內)에 식재(植栽)한 잣나무림(林) 114개소(個所)이며 근래(近來)에 발달(發達)한 통계학(統計學)의 일종(一種)인 다변량해석(多變量解析)과 수량화(數量化)의 이론(理論)을 응용(應用)하였으며 계산(計算)은 한국과학기술연구소(韓國科學技術硏究所)(K.I.S.T.)의 전자계산기연구실(電子計算機硏究室)에서 행(行)하였다. 조제(調製)된 임분재적표(林分材積表)의 중상관계수(重相關係數)는 0.85~0.88 로 상당(相當)히 높은 정확도(正確度)를 갖고 있다.

• 한국정보통신학회논문지
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• 제26권9호
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• pp.1382-1391
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• 2022

화이트박스 암호는 룩업 테이블 안에 키를 안전하게 숨기는 방법으로 메모리 접근 및 수정이 가능한 화이트박스 공격에 대응할 수 있다. 그러나, 룩업 테이블의 크기가 크고 암호화 속도가 느리기 때문에 IoT(Internet of Things) 기기같이 자원이 제한되어 있으면서도 실시간성이 필요한 장치에는 적용이 어렵다. 본 연구에서는 화이트박스 암호가 룩업 테이블 크기 기준으로 암호화를 처리하는 특성을 활용하여 짧은 길이의 평문을 모아서 한 번에 처리하는 방안을 제안한다. Chow와 XiaoLai 방식의 테이블 크기를 각각 720 KB(Kilobytes), 18,000KB로 가정한 제안 방식을 기존 방식과 비교한 결과, 메모리 사용량은 Chow와 XiaoLai 방식에서 평균 약 29.9%, 약 1.24% 감소하였다. 시간 지연도는 15Mbps(Mega bit per second) 이상의 트래픽 로드 속도일 때, Chow와 XiaoLai 방식에서 각각 평균 약 3.36%, 약 2.6% 감소하였다.

• 한국산림과학회지
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• 제85권2호
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• pp.316-324
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• 1996

본(本) 연구(硏究)는 몇가지 침엽수중(針葉樹中) 소나무, 낙엽송, 리기다소나무, 잣나무 간벌림(間伐林)에서 기준적(基準的)인 1인(人) 1조(組)의 작업방법(作業方法)을 통하여 임금구성상(賃金構成上) 또는 작업공정구성상(作業功程構成上) 기본적(基本的)인 작업시간(作業時間)과 더불어 대별되는 일반시간(一般時間)을 관계시간연구(關係時間硏究)에 의하여 구명(究明)하였다. 1. 시간연구(時間硏究)에 의해 4가지 수종별(樹種別)로 산출(算出)된 일반시간(一般時間)을 침엽수(針葉樹)에 일반적(一般的)으로 적용(適用)하기 위하여 일반시간(一般時間)의 동일구성(同一構成)으로 부터 최대값을 선정(選定)한 결과 인적여유시간(人的餘裕時間) 1.8%, 휴식시간(休息時間) 14.1%, 물적여유시간(物的餘裕時間) 12.5%, 대기시간(待機時間) 0.4%로 산출(算出)되었으며, 이로부터 작성(作成)된 조정일반시간(調整一般時間)의 비율합계(比率合計)는 28.8%로 나타났다. 2. 시간연구(時間硏究)를 통한 표준작업시간(標準作業時間) 추정식(推定式)을 수종별(樹種別)로 산출(算出)하여 관계시간연구(關係時間硏究)로 부터 조정(調整)된 일반시간(一般時間)을 합산(合算)함으로써 임금표(賃金表)나 공정표(工程表)에 사용(使用)되는 "예상임금(豫想賃金) 기준시간(基準時間)"을 표로 작성(作成)하였다.

• 한국물환경학회지
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• 제25권2호
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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.

• 대한지역사회영양학회지
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• 제14권3호
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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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• 제33권1호
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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)

• 동아시아식생활학회지
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• 제3권1호
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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.