• Journal of the Korea Society of Computer and Information
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• v.13 no.3
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• pp.15-25
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• 2008

Recently, with the growing use of e-learning, instructors develop new online courses using a variety of contents and then store the results on their computers. These contents should be updated with new information as time goes on, and a new content also can be produced by reusing these ones. However, a lot of time will be needed for instructors to search, edit, and manage various contents stored from place to place on their computers. Currently, the development of the e-learning content management tool. which performs efficiently these functions on the PC environment, leaves much to be desired. Therefore, in this paper, we proposed an e-learning content creation and management system which can manage efficiently a variety of contents stored from different locations on an instructor's computer and can develop easily new online courses. The proposed system can be used widely to develop contents for instructors based on the PC environment. For performance evaluation, this paper compared the proposed system with the previous system according to the retrieval time of content keyword, and the experiment showed that our system is much better than the previous one.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.195-201
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• 1999

The repassivation characteristics of Fe-Cr steels in deaerated 0.1 M $Na_2SO_4$ solution have been investigated with the variation of Cr content, applied potential and Cl- concentration. In the absence of chloride ion, abrading electrode test showed that, slope -n, of log i=k -n log t, a parameter of repassivation rate, approached to -1, regardless of Cr content but as Cr content increased, repassivation current density decreases with increasing Cr content. A.C. Impedance spectroscopy showed that the charge transfer resistance of passive film became higher as Cr content and applied potential increased. However, in the presence of chloride ion, it was observed that chloride ion suppressed the passive film formation, whose effect became greater with increasing applied potential.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.75-83
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• 2004

We live in the information technology era and experience the rapid global information environment change through Internet. Therefore, as distribution channels and service qualities in our daily lives are provided through Internet, these changes have been the foundation of constructing a new society. Naturally, the use of computer is widely spread out and it is hard to find any company that doesn't use computer in its work. However, the computer skills of those who are in their fifties cannot reach to what the companies need for them even though they are main working groups in our society. In addition, the Internet access rate of homemakers in their late forties and over fifties are low due to their lack of computer knowledge even though they are the target customers of the Internet service. Under these circumstances, we offer a lecture using simulation techniqe through which anybody can easily follow the instructions via the "Help" menu not a boring lecture that just show the text and reads it. Besides, each class will show you how to start Internet/ how to finish it, how to register a website, how to use e-mail, etc. So, it will let you know every detailed aspect that average people may disregard but a beginner may be afraid of starting the Internet.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1619-1623
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• 2008

현재 섬진강 수계에서는 댐방류에 따른 하류하천의 하도추적은 수문학적 모형에 의해 운영되고 있으나, 하구의 조위 및 하천내 존재하는 수공구조물의 영향 그리고 지류에 의한 흐름분석을 위해서는 정교한 수리학적 모형이 필요하게 된다. 섬진강으로 유입하는 대표수계는 경천, 요천, 그리고 보성강이 있으며, 보성강의 상류에는 주암댐이 보성강의 유하량을 조절하게 되는 데 이를 반영한 모형구축을 지속적으로 수행할 예정이다. 또한 섬진강 하구유역에서는 조위에 의해 본류의 홍수위가 영향을 받게 되므로 이에 대한 영향도 분석하였다. 섬진강 하구에서는 여수관측소와 광양조위지점이 있는데, 두 지점 모두 일년치의 예측이 가능하게 되며 여수지점에서는 실시간 조위관측이 수행되고 있기 때문에 향후 두 지점의 조위결과값을 이용한 최적의 조위산정방법을 결정하게 된다. 본 모형은 하천에서 발생하는 부정류 수리학적 해석모형에 의해 다양한 수행결과를 제시하게 된다. 각각의 관측수위표지점과 비교한 결과 전체적인 경향에서는 합리적인 결과를 나타냄으로서 모형의 적합성을 확인할 수 있었다. 본 연구를 통하여 대상구간의 전체하도에 대한 적용절차 및 분석기법 등을 참조하여 다른 수계로의 확장이 가능하게 되었다. 단면변환 및 경계조건 산정방법, 모형의 수행 및 결과 분석 등이 댐방류 또는 지류의 유입을 고려한 합리적인 하천관리를 위한 방향을 제시할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.111-111
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• 2016

최근 전 세계적으로 이상기후로 인해 극한 사상의 기후현상이 잦아지고 있으며 그로인한 피해가 확산되면서 관심이 높아지고 있다. 특히, 국내하천의 경우 높은 하상계수를 가지고 있는 만큼 수자원보전에 취약하고 수질의 문제 또한 대두되고 있다. 4대강 중 하나인 낙동강에는 8개의 보가 설치되었고 유역에 안동, 임하, 합천, 남강, 밀양댐 등 다기능댐이 있어 댐의 방류량이 낙동강의 유량에 큰 영향을 미치고 있다. 낙동강의 유량 및 수질을 관리하기 위해서는 이러한 현황들을 반영하여 유역관리를 포함한 통합적인 유량 및 수질관리가 필요하다. 본 연구에서는 IPCC에서 제공하는 AR5 RCP4.5 시나리오를 분위사상법(Quantile mapping)과 CF 다운스케일링 기법을 사용하여 유역에 맞게 상세화를 수행하였으며, 검 보정을 거친 SWAT 모형의 입력자료로 사용하여 낙동강 유역의 본류 및 지류의 미래 유출량 및 오염부하량을 예측하였다. 낙동강 유역에서의 미래기후변화 시나리오를 분석한 결과, 비홍수기에 32.3%, 홍수기에 31.1% 증가하는 것으로 나타났고, 2041 ~ 2070년도에 6%까지 증가하였다가 2071 ~ 2100년에 0.4% 감소하였다. 미래기후변화 시나리오를 SWAT 모형에 적용한 결과로는 주요 8개 지류에서 비슷한 패턴을 보였으며, 위천과 남강에서 각각 최대 45.5%, 16.6% 유출량이 증가하는 것으로 나타났다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.215-221
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• 2023

If the C++ programming class, an object-oriented language capable of modeling similar to the real world, is developed as a curriculum that introduces the flipped learning model, students' active problem-solving skills can be cultivated. In this subject development case, it is significant that the flipped learning technique was applied to the programming class and was effective in improving students' active problem-solving skills. First, the lectures in the 4th session were divided into Pre-Class, In-Class, and Post-Class, and the class was conducted in a way that suggested class goals suitable for the subject and formed a team to discuss. At the end of the lecture, a follow-up survey was conducted to check whether the learners learned effectively.

• Journal of KIISE
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• v.44 no.6
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• pp.607-612
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• 2017

This paper presents an attempt to apply Deep Learning technology to solve the problem of forecasting floods in urban areas. We employ Recurrent Neural Networks (RNNs), which are suitable for analyzing time series data, to learn observed data of river water and to predict the water level. To test the model, we use water observation data of a station in the Trinity river, Texas, the U.S., with data from 2013 to 2015 for training and data in 2016 for testing. Input of the neural networks is a 16-record-length sequence of 15-minute-interval time-series data, and output is the predicted value of the water level at the next 30 minutes and 60 minutes. In the experiment, we compare three Deep Learning models including standard RNN, RNN trained with Back Propagation Through Time (RNN-BPTT), and Long Short-Term Memory (LSTM). The prediction quality of LSTM can obtain Nash Efficiency exceeding 0.98, while the standard RNN and RNN-BPTT also provide very high accuracy.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.153-160
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• 2018

This study suggests the development and the application of cognitive apprenticeship to instructional design for the 'computer and presentation skill' among the liberal arts computer courses in H university. The purpose of this paper is to show effects of instructional design on learning of the liberal arts computer courses employing cognitive apprenticeship, and examine earner's satisfaction of instructional planning, lecture contents, and teaching methods, which are evaluation elements of the content evaluation area. As a result of the study, cognitive apprenticeship theory has improved the satisfaction of the lesson plan, lecture contents and teaching method. Therefore, this study has significance in that it recognizes that cognitive apprentice theory is effective for general computer class. It is expected that it will be applied to effective teaching methods of liberal arts computer related subjects in the future.

• Journal of Korea Water Resources Association
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• v.39 no.3 s.164
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• pp.253-259
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• 2006

In almost all previous hydrological studies, the standard approach adopted for nonlinear time series analysis is to perform system characterization first followed by forecasting. However, a practical inverse approach for forecasting nonlinear hydrological time series was proposed recently To investigate the applicability standard approach method and inverse approach, this study used a theoretical time series (Mackey-Glass time series) and daily streamflows of the Bear River in Idaho. To predict a theoretical time series and daily streamflow, this study used local approximation method. From chaos analysis, chaotic characteristics are found in daily streamflow of the Bear River in Idaho. Resulting from 1, 3 and 5-day prediction, inverse approach method is shown to be better than the standard approach for a theoretical chaotic time series and daily streamflow.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2127-2134
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• 2007

The electronic learning helped a learner to overcome the time restriction by providing mobility, instantly and flexibility but the restriction in connection with space on cable computer remained unsolved. Accordingly, the electronic learning has tendency to change into mobile learning environment which allows a learner to overcome time and spatial restriction. However, these mobile devices have a limitation to awareness of learning contents provided over the realtime video movie due to its small display size. Therefore, this paper suggests a technique according to the following priority: for a real time learning image, extract region of study for region of interest, rescale the real time image to its proper size suitable for the display device, and then make it displayed on a wireless PDA. As a result of the experiment, we reduced the calculating time by sampling the field centering on learning contents adaptively and computing the field best suited for device size of the user effectively.