• 한국정보교육학회:학술대회논문집
• /
• 2007.01a
• /
• pp.359-364
• /
• 2007

Wiki 웹토론 시스템의 목적은 지식을 공유하고 자기 주도적으로 학습을 가능하게 하는 토론을 활성화시키는 데 있다. 그러나 이러한 장점에도 불구하고 가정의 컴퓨터 보급률이라든지 인터넷 사용 등의 제반환경여건에 따라 원활한 수업이 이루어지지 않았다. 따라서 면대면 현장학습뿐만 아니라 온라인 환경과 기술요소에 따른 다양한 학습활동들이 필요하다. 블렌디드 러닝 (Blended Learning)이란 적합한 시간에 적합한 사람에게 적합한 기술을 개인에 적합한 학습스타일에 맞추기 위해 적합한 학습관련의 기술을 적용함으로써 학습목표 성취에 초점을 두는 학습형태이다. 블렌디드 러닝에 있어서 학습은 지속적인 과정이며 오프라인학습공간과 결합하여 학습의 장을 넓히는 것이다. 학습자의 관심을 끌어내어 교육의 효과성을 극대화하며 학습 프로그램의 개발이나 과정실행에서 적절한 방법으로 혼합함으로써 시간과 비용을 최적화할 수 있다. 본 연구에서 제시한 블렌디드 러닝 교수학습모형은 Wiki 웹토론 시스템을 보다 효율적으로 활용할수 있게 하였다. 본 모형의 특징은 첫째, 토론에 앞서 오프라인 학습으로 학습목표확인과 수업안내를 하여 학생들로 하여금 학습목표인지와 수업의 흐름을 보다 잘 파악할 수 있게 하였다. 둘째, 토론 후 교사의 강의가 오프라인 학습으로 이루어지도록 하여 학생들에게 배운 내용을 정리할 수 있는 기회를 제공하여 보다 충실한 수업이 될 수 있었다. 셋째, 토론 후 학습자-교사자 및 학습자 상호피드백이 이루어질 수 있도록 하였다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.6
• /
• pp.1227-1237
• /
• 1988

A practically useful CAD system for mold design in the plastic injection molding processes has been developed. Even though many efforts have been tried to simulated the injection molding process, this is the first attempt toward an automatic mold design system instead of a manufacturing or a simulation system. In this system the computational routines, the data base for mold design, and the routines for three dimensional modeling are blended together so that the designed mold is obtained as a solid model. For this development, the following problems have been solved. First, the modeling capability of the plastic parts has been implemented by incorporating the modeling routines of a constructive solid geometric modeling system and developing a constant thickness modeling conditions, and that of standard mold bases have been established. Third, the experimental know-how and the empirical formulae have been collected and blended together with the modeling routines of a geometric modeling system to provide the high level commands for designing mold.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.262-263
• /
• 2006

The free sintering of metallic powders blended with non sintering inclusions is investigated by the Discrete Element Method (DEM). Each particle, whatever its nature (metallic or inclusion) is modeled as a sphere that interacts with its neighbors. We investigate the retarding effect of the inclusions on the sintering kinetics. Also, we present a simple coarsening model for the metallic particles, which allows large particles to grow at the expense of the smallest.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.7
• /
• pp.651-658
• /
• 2020

The basic medical subjects are essential for the understanding of the major in the department of health science and are very important. Anatomy is one of the fundamental areas of medical education. On the other hand, the application of new teaching method is being attempted in various fields. Station rotation model, one of the blended learning, is also one of the popular teaching method. Station rotation model allows students to rotate through stations on a fixed schedule, where at least one of the stations is an online learning station. This study investigate the satisfaction of students when applying station rotation model to anatomy class. Each station in the station rotation model consisted of VR application learning, online problem solving, model observation and oral test. After applying station rotation model (2 weeks) to the 'Functional anatomy and Practice' course taken by 37 students of the'Department of Occupational Therapy'at H University, this study conducted a satisfaction survey compare with lecture class for students taking the course. At the result, station rotation model was significantly higher than lecture class in both understanding, interest, concentration and diversity degree. Based on these results, I suggest applying the station rotation model to the anatomy class because it also showed high satisfaction in that.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.565-566
• /
• 2009

Supplementary cementing materials (SCM), such as silica fume, slag, and low-calcium fly ash, have been widely used as mineral admixtures in high strength and high performance concrete. Due to the chemical and physical effect of SCM on hydration, compared with Portland cement, hydration process of cement incorporating SCM is much more complex. This paper presents a numerical hydration model which is based on multi-component concept and can simulate hydration of cement incorporating SCM. The proposed model starts with mixture proportion of concrete and considers both chemical and physical effect of SCM on hydration. Using this proposed model, this paper predicts the following properties of hydrating cement-SCM blends as a function of hydration time: reaction ratio of SCM, calcium hydroxide content, heat evolution, porosity, chemically bound water and the development of the compressive strength of concrete. The prediction results agree well with experiment results.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.2
• /
• pp.180-202
• /
• 2012

The purpose of this study was to extract an u-PBL support system core value and design strategy based upon field experience learning. To accomplish this the study, first of all, analyzed the core values, design strategy which was selected after needs analysis and literature review of theories and cases regarding the PBL, e-PBL, blended-PBL, Field experience learning based on ubiquitous environment, and learning model based on ubiquitous technology. This study identified the three core values as; systemic support for instructional activity, just in time support for instructional activity and support for interaction facilitation. As further research areas, it might be useful to develop u-PBL instructional support system based upon the model designed from this study. Also, research concerning the verification of the model based upon implementation of the program case might be necessary.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.3
• /
• pp.273-284
• /
• 2014

Ultra-high-performance concrete (UHPC) consists of cement, silica fume (SF), sand, fibers, water and superplasticizer. Typical water/binder ratios are 0.15 to 0.20 with 20 to 30% silica fume. In the production of ultra-high performance concrete, a significant temperature rise at an early age can be observed because of the higher cement content per unit mass of concrete. In this paper, by considering the production of calcium hydroxide in cement hydration and its consumption in the pozzolanic reaction, a numerical model is proposed to simulate the hydration of ultra-high performance concrete. The heat evolution rate of UHPC is determined from the contributions of cement hydration and the pozzolanic reaction. Furthermore, by combining a blended-cement hydration model with the finite-element method, the temperature history in the hardening of UHPC is evaluated using the degree of hydration of the cement and the silica fume. The predicted temperature-history curves were compared with experimental data, and a good correlation was found.

• Computers and Concrete
• /
• v.31 no.4
• /
• pp.315-325
• /
• 2023

Calcium leaching is one of the main deterioration factors in concrete structures contact with water, such as dams, water treatment structures, and radioactive waste structures. It causes a porous microstructure and may be coupled with various harmful factors resulting in mechanical degradation of concrete. Several numerical modeling studies focused on the calcium leaching depth prediction. However, these required a lot of cost and time for many experiments and analyses. This study presents an artificial neural network (ANN) approach to predict the leaching depth quickly and accurately. Totally 132 experimental data are collected for model training and validation. An optimal ANN model was proposed by ANN topology. Results indicate that the model can be applied to estimate the calcium leaching depth, showing the determination coefficient of 0.91. It might be used as a simulation tool for engineering problems focused on durability.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.6 no.1
• /
• pp.1-12
• /
• 2001

Tidal computations of $M_2,\;S_2,\; K_1$ and $O_1$ constituents in the northeast Asian sea are presented by blending the Topex/Poseidon (T/P) altimeter data into a hydrodynamic model with $5'{\times}5'$ resolution. A series of sensitivity experiments on a weighting factor, which is the control parameter in the blending method, are carried out using $M_2$ constituent. The weighting factor is set to be in inverse proportion to the square root of water depth to reduce noises which could occur in data-assimilative model by blending T/P data. Model results obtained by blending the T/P-derived $M_2,\;S_2,\; K_1$ and $O_1$ constituents simultaneously are compared with all T/P-track tidal data; Average values of amplitude and phase errors are close to zero. Standard deviations of amplitude and phase errors are approximately 2 cm and less than 10 degrees respectively. The data-assimilative model results show a quite good agreement with T/P-derived tidal data, particularly in shallow water region (h<250m). In deep water regions, T/P-derived tidal data show unreasonable spatial variations in amplitude and phase. The data-assimilative model results differ from T/P-derived data, but are improved to show reasonable spatial variations in amplitude and phase. In addition, the T/P-blended model results are in good agreement with coastal tide gauge data which are not blended into the model.

• Environmental and Resource Economics Review
• /
• v.23 no.3
• /
• pp.515-551
• /
• 2014

Recently, there has been a debate as to whether bioethanol should replace some portion of gasoline for fuels in South Korea, as energy security as well as climate change issues are rising as a significant national agenda. However, a considerable amount of subsidy will be required to compensate for the higher price of bioethanol-blended gasoline. In this context, government subsidy will obtain justification only when the positive social gains from consuming bioethanol for fuels can exceed the negative social costs. Through a nation-wide choice experimental survey, we examine if South Koreans have a positive value as well as non-linear preferences on substituting bioethanol for gasoline. The results reveal that the willingness to pay for purely domestic bioethanol-blended gasoline within 10% is about 52 KRW; Koreans have concave preferences on the blending ratio of bioethanol to gasoline. The turning point of the blending ratio of bioethanol was 6.5%. Also, we found inverse U-shaped curve between income and bioethanol choice probability and the turning point of the income was calculated as 250~299million KRW. Politically conservative propensity advocates uses of bioethanol blended gasoline, but awareness on bioethanol or more weights on environmental conservation have significantly negative effects on the choice of bioethanol. However, the design of the survey questionnaire is incompatible with the RFS of Korea and assumes orthogonality among the following four interrelated attributes: (i) domestic or offshore procurement of feedstocks in the case of domestic production, (ii) domestic production or import of bioethanol, (iii) the blending ratios, and (iv) the retail price increases. In addition, the results of model estimation and of model selection test are not definite. Hence, the results in this study should not be directly applied to the design of the specifics of the Korean RFS. Hence, the results in this study require cautions in applying to the design of the Korean RFS policy.