• Journal of the Korea Concrete Institute
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• v.21 no.6
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• pp.797-804
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• 2009

The structural designs of RC flat plates that have insufficient flexural stiffness due to lack of support from boundary beams may be governed by serviceability as well as a strength criteira. Specially, since over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction, a construction sequence and its impact on the slab deflections may be decisive factors in designs of flat plate systems. In this study, the procedure of calculating slab deflections considering construction sequences and concrete cracking effects is proposed. The construction steps and the construction loads are defined by the simplified method, and then the slab moments, elastic deflections, and the effective moment of inertia are calculated in each construction step. The elastic deflections in column and middle strips are magnified to inelastic deflections by the effective moment of inertia, and the center deflection of slab are calculated by the crossing beam method. The proposed method is verified by comparisons with the existing test result and the nonlinear analysis result. Also, by applications of the proposed method, the effects of the slab construction cycle and the number of shored floors on the deflections of flat plates under construction are analyzed.

• Communications of Mathematical Education
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• v.12
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• pp.463-477
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• 2001

국가의 국가경쟁력은 학창시절 학생의 학력만큼 중요하다. 성인의 경우, 학력을 위한 노하우는 체험을 통해 터득할 수 있었다. 그러나 국가경쟁력에 관해서는 우물 안 내부관점을 벗어나기 힘들어 추진 방향과 제도 운영에 자칫 시행착오를 범하기 쉽다. 이는 사안에 대해 본질적인 접근보다 껍데기만을 쫓기 때문이었다. 이 현상을 분석하려면 관점과 보이지 않는 영역의 것들을 다룰 수 있는 수학적 사고법이 필요하며, 이 능력은 현 지식정보화 사회에서 매우 긴요하다. 그러나 현실은 여러 가지 이유로 수학적 사고법을 비롯한 기초학문을 위기로 몰아가고 있고, 안타깝지만 그 중심에 수학교육이 자리잡고 있다. 수학교육의 위기를 유발하는 요인으로 제도 운영에 관한 건이 있다. 제도 운영에서 한 변수의 변화, 예로 대입의 계열교차지원 허용 건, 교원임용고시에서 교과교육학 영역의 출제 건과 복수전공, 부전공 자격소지자에 대한 가산점 부여 건은 수학교육과 교육과정에 직, 간접적으로 영향을 미친다. 이 관계를 사범대학 수학교육과 현장의 사례를 통하여 조명하고, 그 문제점을 지적하고자 한다. 현 사범교육은 졸업이수학점 140학점 체제하에서 제 7차 교육과정에 따른 복수전공, 부전공 우대 정책을 펴고 있다. 수학교육과의 경우, 부전공 열풍이 불어 전공선택 과목이 3학년 1학기부터 폐강될 위기에 처해 있다. 교양교육의 고사 또는 전광교육이 예전보다 반으로 줄어들게 된 사범대학 실상에 비애감을 느끼게 된다. 이는 전문화된 교사 양성, 나아가 미래 국가경쟁력 향상에 심각한 저해 요소로 작용할 것이다. 복잡다단한 세상에서 최적화를 향한 개선 노력이 멈춰서는 안 된다. 현행 교원임용고시 운영상의 문제점을 공론화하고, 수학교육인의 중지를 모아야 할 긴박한 시점이다. 이를 계기로 교원임용고시의 운영개선과 수학교육과 교육과정을 한층 더 견실하게 하는 데에 이바지하고자 한다. 것이라면 후속연구로 이러한 가능성을 실험연구로 검증하고자 한다.toceros 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, 제거속도는 Fw5&6에서 가장 느렸다. 이러한 결과에 근거할 때 벼가 자라고 있고 이분해성 유기물이 풍부한 FW1&2, FW3&4 토양과 상층수에서는 유기물의 분해 활동이 활발하였지만, 벼가 경작되지 않는 FW5&6과 SW 에서는 유기물이 상대적으로 결핍되어 유기물의 분해활동이 적었을 것으로 판단된다

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.717-724
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• 2010

The flash point is one of the most important physical properties used to determine the potential for fire and explosion hazards of flammable liquids. Despite the needs of the experimental flash point data for the design and construction of chemical plants, there is often a significant gap between the demands for the data and their availability. This study have built and compared two models of partial least squares(PLS) and support vector machine(SVM) to predict the experimental flash points of 893 organic compounds out of DIPPR 801. As the independent variables of the models, 65 functional groups were chosen based on the group contribution method that was oriented from the assumption that each fragment of a molecule contributes a certain amount to the value of its physical property, and the logarithm of molecular weight was added. The prediction errors calculated from cross-validation were employed to determine the optimal parameters of two models. And, an optimization technique should be used to get three parameters of SVM model. This work adopted particle swarm optimization that is one of heuristic optimization methods. As the selection of training data can affect the prediction performance, 100 data sets of randomly selected data were generated and tested. The PLS and SVM results of the average absolute errors for the whole data range from 13.86 K to 14.55 K and 7.44 K to 10.26 K, respectively, indicating that the predictive ability of the SVM is much superior than PLS.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.178-186
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• 2020

The purpose of this study is to analyze whether there is a difference in the needs of the prevention program for dating violence according to the gender and major of University students. The subjects of the study were the humanities, social science and health care students in U university, which included 220 male students, 131 female students, and a total of 351 students. The research tool produced and surveyed the questionnaire about the timing, content and method of education about prevention of dating violence through the review of previous studies. For data analysis, independent sample t-test and cross-analysis were conducted to analyze the differences in the demands for dating violence prevention programs according to the gender and major of University students. The results of the study were as follows: First, there was a significant difference in the demands of teaching methods of dating violence prevention programs according to the gender in personal counseling and experience activities using open KakaoTalk. The women were significantly higher than men in all sub-factors of dating violence prevention programs. Second, there was a significant difference in the demands of teaching methods of dating violence prevention programs according to the major in personal counseling and experience activities using open KakaoTalk. The health care students were significantly higher in all sub-factors of dating violence prevention programs than in humanities and social sciences students.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.331-337
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• 2022

Raman spectroscopy is an optical technique that can identify molecules in a label-free manner, and is therefore heavily investigated in various areas ranging from biomedical engineering to materials science. Probe-based Raman spectroscopy can perform minimally invasive chemical analysis, and thus has potential as a real-time diagnostic tool during surgery. In this study, Raman experimentation was calibrated by examining the Raman shifts with respect to the concentrations of chemical substances. Raman signal characteristics, targeted for normal mice and cerebral tissues of the 5xFAD dementia mutant model with accumulated amyloid beta plaques, were measured and analyzed to explore the possibility of diagnosis of Alzheimer's disease. The application to the diagnosis of dementia was cross-validated by measuring Raman signals of amyloid beta. The results suggest the potential of Raman spectroscopy as a diagnostic tool that may be useful in various areas of application.

• 한국체육학회지인문사회과학편
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• v.51 no.3
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• pp.373-382
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• 2012

The purpose of this study is to predict VO₂max with body index and submaximal metabolic responses. The subjects are consisted of 250 male aging from 18 to 34 and we separated them into two groups randomly; 179 for a sample, 71 for a cross-validation group. They went through maximal exercise testing with Bruce protocol, and we measured the metabolic responses in the end of the first(3 minute) and second stage(6 minute). To predict VO₂max, we applied multiple regression analysis to the sample with stepwise method. Model 1's variables are weight, 6 minute HR and 6 minute VO₂(R=0.64, SEE=4.74, CV=11.7%, p<.01), and the equation is VO₂max(ml/kg/min)= 72.256-0.340(Weight)-0.220(6minHR)+0.013(6minVO₂). Model 2's variables are weight, 6 minute HR, 6 minute VO₂, and 6 minute VCO₂(R=0.67, SEE=4.59, CV=11.3%, p<.01), and the equation is VO₂max(ml/kg/min)= 68.699-0.277(Weight) -0.206(6minHR)+0.020(6minVO₂)-0.009(6minVCO₂). And the result did not show multicolinearity for both models. Model 2 demonstrated more correlation compared to Model 1. However, when we conducted cross-validation of those models with 71 men, measured VO₂max and estimated VO₂ Max had statistical significance with correlation (R=0.53, 0.56, P<.01). Although both models are functional with validity considering their simplicity and utility, Model 2 has more accuracy.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.293-300
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• 2012

This study was to investigate the unsuitable rate of the storage facilities, the changes in corrosion process over time after installation according to the status, the time to install the facilities, years elapsed after facilities installation, inspection of methods and motivation, and so on, based on the results of the inspection at the petroleum storage facilities conducted by domestic soil-relate specialized agency to derive optimal management plans which meet the status of soil contamination facilities. The results showed that the facilities more than 5 years after the initial leak test at the time of the installation need to be inspected periodically by considering costs of leak test and remediation of polluted soil. The inspection period can be decided by cost and leak test methods showing discrepancies for the results obtained from individual test whether it was direct or indirect. To compensate these matters, we suggested that the direct inspection method on regular schedule is recommended. On the other hand, the inspection can be voluntarily completed to ease burden of the results by inspection or equivalent level to this inspection method. Also, it may need improved construction supervision and performance test system to minimize the occurrence of the nature defects in installing the facilities as well as the upgrade program for the facilities during intervals of inspection period.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.25-37
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• 2017

The purpose of this study is to analyze the effects on particulate concept formation based on abductive reasoning model for elementary science class. For this study, an author selected two groups in the sixth grade. One group is an ordinary textbook-based control group (N=26) and the other group is an abductive reasoning model-based treatment group (N=26). After twelve lessons, the scores of Concepts Test for Gas were analyzed by t-test and two-way ANOVA. The result of t-test showed both the control and treatment groups have higher score than before they take the lesson. But after the lesson, an author found out that the treatment group had higher score than that of the control group. And compared to the number of particles expressed, the number of the treatment group were higher than that of the control class. The two-way ANOVA result revealed that the interaction effect between their cognitive level and treatment was not significant. And regardless of the level of cognition, the scores of treatment group are higher than those of control group. Therefore, abductive reasoning model-based elementary science class were found to be more effective for particulate concept formation. Based on the results, an author concluded that abductive reasoning model is very effective in teaching particulate concepts to elementary students.

• Culinary science and hospitality research
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• v.21 no.2
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• pp.154-170
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• 2015

In this study, the real state of local foods was examined targeting Gyeongju citizens to help in developing distinguishing foods and to promote cultural to excellence of local foods widely. Ultimately, this study aims to promote cultural excellence of Gyeongju's local foods widely by examining the kinds of local foods in Gyeonggju area. In addition, current study was conducted to provide basic data of local foods which inherit and develop our precious assets, in order to keep up with the Korean Wave as well as globalization. For this study, a survey was performed with the 274 sample of local food consumers, and analyzed the data using descriptive, cross tabulation analysis, and t-test. Results shown that Janchi guksu(banquet noodles) and Jeonbok juk(abalone rice porridge) obtained the highest awareness and preference when awareness and preference of Gyeongju local foods were analyzed depending on the marital status. Significant implication in the study is that there is a need to develop and promote local foods and open local food restaurants for local residents. More discussion and limitations are suggested.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.11
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• pp.527-536
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• 2017

With the recent development of smart grid industry, the necessity for efficient EMS(Energy Management System) has been increased. In particular, in order to reduce electric load and energy cost, sophisticated electric load forecasting and efficient smart grid operation strategy are required. In this paper, for more accurate electric load forecasting, we extend the data collected at demand time into high time resolution and construct an artificial neural network-based forecasting model appropriate for the high time resolution data. Furthermore, to improve the accuracy of electric load forecasting, time series data of sequence form are transformed into continuous data of two-dimensional space to solve that problem that machine learning methods cannot reflect the periodicity of time series data. In addition, to consider external factors such as temperature and humidity in accordance with the time resolution, we estimate their value at the time resolution using linear interpolation method. Finally, we apply the PCA(Principal Component Analysis) algorithm to the feature vector composed of external factors to remove data which have little correlation with the power data. Finally, we perform the evaluation of our model through 5-fold cross-validation. The results show that forecasting based on higher time resolution improve the accuracy and the best error rate of 3.71% was achieved at the 3-min resolution.