• Journal of the Korean Data and Information Science Society
• /
• v.24 no.2
• /
• pp.303-310
• /
• 2013

Forty two female students whose fat mass ratio was over 30% were participated in the experiment of fat mass loss of two treatments for 8 weeks. They kept diary for foods they ate every day, took a picture of the foods, transmitted the picture to the experimenter by the camera phone. Among those, 28 students took the picture by regular camera phone (Treatment A), and the other students used smart phone (Treatment B). Fat mass weight and its related variables had been measured repeatedly four times at an interval of two weeks during 8 weeks. It was shown from mixed model analysis of repeated measurements data that AR(1) covariance matrix was selected as the optimal covariance matrix pattern. The correlation between two successive times is highly correlated as 0.838. Based upon the AR(1) covariance matrix structure, the students using smart phones were somewhat more effective in losing fat mass weight than the students using regular camera phones. The time effect was highly significant, but the treatment-time interaction effect was insignificant. The baseline effect and total cholesterol were found to be significant, but the calories with taking foods were somewhat significant, but the waist to hip ratio was found to be insignificant.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.4
• /
• pp.329-337
• /
• 2002

Based on the equivalent uniform stress concept presented by Seed and Idriss, sinusoidal cyclic loads which simplified the earthquake loads have been applied in evaluating the liquefaction resistance strength experimentally. However, the liquefaction resistance strength of soil based on the equivalent uniform stress concept can not exactly reflect the dynamic characteristics of the irregular earthquake motion. In this study, the criterion of the liquefaction resistance strength was determined by applying real earthquake loading to the cyclic triaxial test. From the test results, relationships between liquefaction behaviors of saturated sand and earthquake characteristics such as magnitude or time-duration were determined. Magnitude scaling factors to determine the soil liquefaction resistance strength in seismic design were also proposed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.8 no.1
• /
• pp.43-50
• /
• 1979

This experiment was designed to investigate the changes of cadmium content of different foods during cooking. 1. By addition of standard cadmium to different foods, recovery percentage was 98.3% by Dithizone Method and 97.9% by APDC. 2. At various pH levels the highest cadmium was extracted at pH 1.0. 3. Cadmium was contaminated at first to six hours of immersion and did not increased after this period. 4. About 2/3 of added cadmium was extracted by different concentrations of acetic acid.

• Fire Science and Engineering
• /
• v.29 no.1
• /
• pp.60-66
• /
• 2015

The present study was aimed to analyze enclosure integrity test, which is the performance experiment of soaking time, in a fire zone equipped with gaseous extinguishing system in an effort to find understand the effect of precaution factors upon the success of fire extinguishment. To achieve the goal of this study, it divided the fire zones of internal and external power plants into ones taking precaution measures and not taking them and then enclosure integrity test was given respectively. Therefore, this study examined the success rate if the test according to the presence and absence of the precaution measure and confirmed the failure factors, designed concentration soaking time and proportion of leakage area to total volume area by type of gaseous extinguishing system and rooms. Precaution measures were applied to the fire zones without them to confirm the increase of the success rate of enclosure integrity test. By doing so, it was found that reduced number of experiments caused by failure led to cost saving.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.4
• /
• pp.239-245
• /
• 2021

Due to the fourth industrial revolution and the Corona19, the availability of digital devices such as kiosks is a matter directly related to survival for older adults with digital divide. This paper analyzes the problems of existing information service education for older adults and proposes an IT education strategy tailored to aging and life cycle of older adults. The proposed in this study is an educational application-based IT training method that supports repetitive learning regardless of time and place, developing kiosk function as a functional game-type educational application and experimenting with post-training effectiveness. The research method proposed UI usability evaluation frame for older adults, and developed educational applications based on proposed evaluation frame, and conducted kiosk education. As a result of the experiment, the mission success rate after using the IT application was 80.6%, which is a 55.1%P improvement compared to the pre-use(25.5%). This study confirmed that the proposed education for older adults is a way to overcome the limitations of existing IT education in the current situation.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.6
• /
• pp.817-826
• /
• 2001

In this paper, the method of processing a blurred noisy signal has been researched. The conventional method of processing signal has faults which are slow-convergence speed and long time-consuming process at the singular point and in the ill condition. There is the process, the Gauss-Seidel's method to remove these faults, but it takes too much time because it processes signal repeatedly. For overcoming the faults, this paper shows a signal process method which takes shorter than the Tikhnov-Miller's by comparing the Tikhnov-Miller's with proposed algorithm and accelerating convergence speed at the singular point in the ill condition. In this paper, the conventional process method and proposed optimal algorithm were used to get a standard image (256 ＊ 256 ＊ 8bits),and then the results are simulated and compared each other in order to examine the variance of MSE ( Mean-Square Error ) by the acceleration parameter in the proposed two dimensional signal procedures. The result of the signal process and the processing time was measured at all change of acceleration parameter in order to verify the effectiveness of the proposed algorithm.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.201-201
• /
• 2011

컷오프 진단법은 프로브 형태로 제작된 마이크로 웨이브 진단법으로, 간단한 수식을 통해 전자밀도, 전자온도 등의 측정이 가능하며, 장치나 분석방법이 매우 간단한 장점을 지닌다. 또한, 측정에 약 1 mW 정도의 적은 파워를 사용하여 플라즈마 상태를 거의 변화시키지 않으며, 공정 플라즈마에서도 사용이 가능하다. 그러나 컷오프 진단법을 사용한 측정은 다른 종류의 프로브와 마찬가지로, 약 1초 정도의 긴 시간이 필요로 하는 단점이 있다. 따라서 기존의 컷오프 진단법은 펄스 플라즈마나 토카막과 같이 빠르게 변하는 플라즈마를 측정하기에는 무리가 있다. 본 발표에서는 컷오프 진단법을 새로운 방법으로 구현하여 더욱 빠르게 측정할 수 있는 방법을 소개하고자 한다. 컷오프 프로브는 방사 안테나, 측정 안테나와 네트워크 분석기로 구성되어 있다. 네트워크 분석기는 두 안테나 사이의 플라즈마 투과 스펙트럼을 만드는데 쓰이며, 주파수 스캔 방법을 사용하여 스펙트럼을 만든다. 컷오프 진단법의 측정시간은 주파수 스캔에 걸리는 시간에 의해 결정된다. 본 발표에서는 측정을 빠르게 하고자 전혀 새로운 방법을 도입하였다. 펄스 형태의 단일신호를 플라즈마 투과 특성을 살피는데 이용하면 측정을 매우 빠르게 할 수 있다. 그래서 펄스제조기와 오실로스코프를 이용하여 스펙트럼을 얻는데 사용하였다. 이론적으로는 이 방법을 통해 측정시간을 수 nano second 수준으로 줄일 수 있다. 실험적으로는 micro second 정도의 시간으로 측정을 할 수가 있었으며, 동일한 스펙트럼 및 측정결과를 얻을 수 있었다. 또한 이 방법을 펄스플라즈마에 적용할 경우 수십 nano second 수준의 시간분해능으로 측정을 할 수가 있었다. 이 방법을 응용하면 토카막 언저리와 같이 매우 빠르게 변하며 반복되지 않는 플라즈마의 측정도 가능할 것으로 예상된다.

• Korean Journal of Ecology and Environment
• /
• v.41 no.spc
• /
• pp.77-85
• /
• 2008

Grazing rates (GR) and pseudofaeces production (PFP) of native snail, Chinese mystery snail (Cipangopaludina chinensis malleata Reeve) on natural colonial morphs of Microcystis aeruginosa was measured. C. chinensis was collected from the upstream of the Geum River (Boryeong, Korea), where they co-habituated with Unio douglasiae and Lanceolaria acrorhyncha. The experiments were performed to evaluate the GR and PFP at different conditions such as; incubation time (1, 3, 5, 7, 9 and 11 hr), body size (3 to 6.1 cm, n=28), snail density (0.5, 1, 1.5 and 2.0 ind. $L^{-1}$) and prey concentration (168.3, 336.7, 505.0 and $673.0{\mu}g\;Chl-{\alpha}L^{-1}$). All experiments were triplicated, and conducted in transparent acrylic vessel (3L in volume). Regarding feeding time, a highest GR (0.538L $gAFDW^{-1}h^{-1}$) and PFP $(7.18mgAFDW^{-1})$ appeared at 1hr and 7hr after snail stocking, respectively. Interestingly, the snail, smaller than 4.5cm in body size, showed a wide range of GR ($-4.173{\sim}1.087L\;gAFDW^{-1}h^{-1}$) for the initial period (1 and 4hrs of stocking), compared to those greater than 4.5cm, which showed a stable FR, higher than 0.5L $gAFDW^{-1}h^{-1}$. Upon density effect, the density of 1.5 ind. $L^{-1}$ induced the most effective inhibition on Microcystis biomass with highest PFP. On the prey concentration, highest GR (0.897L $gAFDW^{-1}h^{-1}$) and PFP (3.67 mg $gAFDW^{-1}h^{-1}$) were induced at the level of $168.3{\mu}g\;Chl-{\alpha}L^{-1}$ and $673{\mu}g\;Chl-{\alpha}L^{-1}$, respectively. GR and PFP of this freshwater snail on the cyanobacterial bloom (M. aeruginosa) varied with the feeding conditions, and they were comparatively high for a short period of time less than 7hrs regardless of the stocking condition. Our results suggest that this freshwater snail has a potential to control cyanobacterial bloom when provided with suitable condition.

• Communications of Mathematical Education
• /
• v.11
• /
• pp.259-277
• /
• 2001

본 연구는 개방형 문제를 활용한 평가가 수학적 창의력에 미치는 효과를 분석함으로써 수학적 창의력을 신장시킬 수 있는 평가 방법을 찾는데 그 목적이 있다. 이를 위해 대구광역시 소재의 C중학교 2학년 1개반과 S중학교 2학년 1개반을 임의로 선정하여 한 반은 개방형 문제를 활용한 평가 집단으로 하고 다른 한 반은 전통적 평가 집단으로 무선 할당하여 실험연구를 실시하였다. 실험처치는 두 집단에게 서로 다른 유형의 평가를 실시하는 것으로, 실험집단은 개방형 문제를 평가과제로 하여 실험집단 담임 교사가 평가를 실시하였으며, 비교집단은 객관식 및 주관식 단답형 문제를 평가과제로 하여 비교집단 담임교사가 전통적인 평가를 실시하였다. 본 연구에서 사용한 검사도구는 수학적 창의력 검사로 사전 사후검사 모두 같은 검사지를 사용하였다. 사후 수학적 창의력 검사의 평균의 차를 t-검정한 결과 유의도p=.025(p < .05)로 실험집단과 비교집단 사이에는 통계적으로 유의미한 차가 있는 것으로 나타났다. 수학적 창의력의 각 요소별로 차이가 있는지 알아보기 위해 사후 창의력 검사의 각 요소별로 평균의 차를 t-검정한 결과, 유창성과 융통성은 각각 유의도 p=.030, p=.040으로 p < .05 수준에서 통계적으로 유의미한 차이가 있었으며, 독창성은 유의도 p=.052로 p < .1 수준에서 통계적으로 유의미한 차이를 보였다. 연구결과 개방형 문제를 활용한 평가가 전통적 평가보다 수학적 창의력 향상에 더 효과적이며, 수학적 창의력의 세 가지 요소(유창성, 융통성, 독창성)의 향상에도 효과적인 것으로 나타났다. 결론적으로 개방형 문제를 활용한 평가가 수학적 창의력 신장에 효과적인 방법임을 시사한다.질공학적 특성의 위도별, 깊이별 변화는 탄산질 퇴적물과 규질 퇴적물의 분포, 수층의 생산성 및 수심변화에 따른 용해도와 퇴적을 차이 그리고 침식 및 재퇴적작용 등 퇴적 과정이 위도별로 달랐기 때문으로 판단된다.haetoceros resting spores/Chaetoceroe vegetative cells도 80 cm 보다 상층에서는 높게 나타나 규조온도지수 분포와도 일치하는 경향을 보인다. 이상의 규조군집 분석 결과에 의하면, 홀로세의 후빙기동안 본 연구 지역인 동해 북동부에는 대마 난류의 유입이후 현재와 유사한 환경이 우세하게 발달했으나, 난류종 P. doliolus의 변화는 동해내에서 대마난류의 세기가 반복되었음을 지시하고 있다./3 수준으로 높다. 결론적으로 풍부한 화학물질들을 함유한 제주해류는 남해 및 동해의 생지화학적 과정들에 있어 상당히 중요함을 시사한다.다. 수조 상층수 중 Cu, Cd, As 농도는 모든 FW, SW수조에서 시간이 지남에 따라 일관성 있게 감소하였고, 제거속도는 Cu가 다른 원소에 비해 빨랐다. 제거속도는 FW 3개 수조 중 FW5&6에서 세 원소 모두 가장 느렸고, SW 3개 수조 중에서는 SW1&2에서 가장 빨랐다. SW와 FW간 제거속도 차이는 세 원소 모두 명확치 않았다 Cr은 FW에서 전반적으로 감소하는 경향을 보였지만 SW에서는 실험 초기에 감소하다 24시간 이후에는 증가 후 일정한 양상을 보였다. Pb은 FW에서 전반적으로 감소했지만 SW에서는 초기에 급격히 증가 후 다시 급격히 감소하는 양상을 보였다 Pb 또한 Cu, Cd, As와 마찬가지로 SW1&2에서 제거속도가 가장 빠르게 나타났다. FW 상층수 중 Hg는 시간에 따라 급격히 감소했고,

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.2
• /
• pp.443-453
• /
• 2013

The hybrid test is one of the most advanced test methods to predict the structural dynamic behavior with the interaction between a physical substructure and a numerical modeling in the hybrid control system. The purpose of this study is to perform the multi-directional dynamic test of a steel frame structure with the real-time hybrid system and to evaluate the validation of the results. In this study, FEAPH, nonlinear finite element analysis program for hybrid only, was developed and the hybrid control system was optimized. The inefficient computational time was improved with a fixed number iteration method and parallel computational techniques used in FEAPH. Furthermore, the previously used data communication method and the interface between a substructure and an analysis program were simplified in the control system. As the results, the total processing time in real-time hybrid test was shortened up to 10 times of actual measured seismic period. In order to verify the accuracy and validation of the hybrid system, the linear and nonlinear dynamic tests with a steel framed structure were carried out so that the trend of displacement responses was almost in accord with the numerical results. However, the maximum displacement responses had somewhat differences due to the analysis errors in material nonlinearities and the occurrence of permanent displacements. Therefore, if the proper material model and numerical algorithms are developed, the real-time hybrid system could be used to evaluate the structural dynamic behavior and would be an effective testing method as a substitute for a shaking table test.