• 천문학회지
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• 제52권6호
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• pp.217-225
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• 2019

We apply a modified Convolutional Neural Network (CNN) model in conjunction with transfer learning to predict whether an active region (AR) would produce a ≥C-class or ≥M-class flare within the next 24 hours. We collect line-of-sight magnetogram samples of ARs provided by the SHARP from May 2010 to September 2018, which is a new data product from the HMI onboard the SDO. Based on these AR samples, we adopt the approach of shuffle-and-split cross-validation (CV) to build a database that includes 10 separate data sets. Each of the 10 data sets is segregated by NOAA AR number into a training and a testing data set. After training, validating, and testing our model, we compare the results with previous studies using predictive performance metrics, with a focus on the true skill statistic (TSS). The main results from this study are summarized as follows. First, to the best of our knowledge, this is the first time that the CNN model with transfer learning is used in solar physics to make binary class predictions for both ≥C-class and ≥M-class flares, without manually engineered features extracted from the observational data. Second, our model achieves relatively high scores of TSS = 0.640±0.075 and TSS = 0.526±0.052 for ≥M-class prediction and ≥C-class prediction, respectively, which is comparable to that of previous models. Third, our model also obtains quite good scores in five other metrics for both ≥C-class and ≥M-class flare prediction. Our results demonstrate that our modified CNN model with transfer learning is an effective method for flare forecasting with reasonable prediction performance.

• 비교문화연구
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• 제25권
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• pp.549-596
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• 2011

This paper aims to introduce some useful multimedia freewares, and also support Chinese instructor with discussing how to operate them for instructional design of multimedia language learning class. For this aims, this paper consists of three parts: First, instructional design. This part is focused to what kind of instructional model to be based on, for example, Dick & Carey model, ADDIE model, ASSURE model etc. This part introduces these models, and modifies ADDIE and ASSURE model to D.D.A.I.E.S and S.S.A.U.R.E.S as 'A(nalysis)' in these model may apply to the next 'D(evelopment)' on ADDIE, 'S(elect Methods, Media and Materials)' on ASSURE in the practical Chinese class. Second, Programme: What to use. This part is focused to what kind of free software we can use. In the web site online, there are huge free softwares so we usually hesitate to select and also don't know how to operate even though selected one of them. This part, accordingly, introduces ten of useful freewares and compares each other in terms of usefulness for Chinese instructors. Third, Programme: How to use. It is of no use just to know what to use but not to know how to operate, so this part describes how to use freewares like a kind of manual in detail as far as possible. In conclusion, we hope more Chinese instructors to learn and use more useful freewares for designing the better multimedia Chinese class by this paper.

• 한국경영과학회지
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• 제38권1호
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• pp.139-152
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• 2013

The purpose of this study is to claim the validity of tuning the architecture of neural network models for multi-class classification. A neural network model for multi-class classification is basically constructed by building a series of neural network models for binary classification. Building a neural network model, we are required to set the values of parameters such as number of hidden nodes and weight decay parameter in advance, which draws special attention as the performance of the model can be quite different by the values of the parameters. For better performance of the model, it is absolutely necessary to have a prior process of tuning the parameters every time the neural network model is built. Nonetheless, previous studies have not mentioned the necessity of the tuning process or proved its validity. In this study, we claim that we should tune the parameters every time we build the neural network model for multi-class classification. Through empirical analysis using wine data, we show that the performance of the model with the tuned parameters is superior to those of untuned models.

• 대한치과교정학회지
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• 제45권3호
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• pp.113-120
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• 2015

Objective: This study compared occlusal contact areas of ideally planned set-up and accomplished final models against the initial in class I and II molar relationships at finishing. Methods: Evaluations were performed for 41 post-orthodontic treatment cases, of which 22 were clinically diagnosed as class I and the remainder were diagnosed as full cusp class II. Class I cases had four first premolars extracted, while class II cases had maxillary first premolars extracted. Occlusal contact areas were measured using a three-dimensional scanner and RapidForm 2004. Independent t-tests were used to validate comparison values between class I and II finishings. Repeated measures analysis of variance was used to compare initial, set up, and final models. Results: Molars from cases in the class I finishing for the set-up model showed significantly greater contact areas than those from class II finishing (p < 0.05). The final model class I finishing showed significantly larger contact areas for the second molars (p < 0.05). The first molars of the class I finishing for the final model showed a tendency to have larger contact areas than those of class II finishing, although the difference was not statistically significant (p = 0.078). Conclusions: In set-up models, posterior occlusal contact was better in class I than in class II finishing. In final models, class I finishing tended to have larger occlusal contact areas than class II finishing.

• 한국컴퓨터정보학회논문지
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• 제24권1호
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• pp.239-246
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• 2019

In this paper, we propose an effective software education donation model for the social care class. The types of software education for elementary, middle, and high school for the social care class are in the order of after school classes, club activities, creative experiences, and regular classes. In elementary school students, it is effective to precede visual programming education based on block coding and to conduct curriculum convergence with SW and HW at the beginning, and high school students are carrying out text programming education like Python. Software education for social care class The contribution activity model can be classified into five types such as geographically difficult area, multicultural family areas, orphanage, reformatory, and basic livelihood security recipient. In addition, the survey results show that the students' interest in software education and their satisfaction are all very high at 96%. Effective software education for the social care class In the donation model, the lecturers consist of responsible professors, lecturers, and assistant instructors. Software training for the social care class is effective on a year-by-year basis, so that students can feel authenticity and trust. Software education contents focus on visual programming and physical computing education in elementary or middle school, and text programming and physical computing education in high school. It is necessary to construct a software education donor matching system that helps efficient management of software education donations by efficiently matching schools (consumers: elementary, middle, high school) and software education donors(suppliers).

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3668-3674
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• 2009

유즈케이스 다이어그램은 사용자와 시스템간의 상호작용을 정의하는데 사용되어 진다. 소프트웨어 개발에 있어서 사용자의 요구사항을 도출하고 정의하는 것은 가장 중요한 일중에 하나이다. 본 논문에서는 클래스 추출 및 정의를 위하여 계층화 된 유즈케이스 모델링 과정을 제안하였다. 본 논문에서 제안하는 모델링 과정에서는 먼저, 여러 계층에 걸쳐서 유즈케이스 다이어그램을 정의하고 다음단계로서 각 계층별 클래스를 추출하고자 하였다. 즉, 소프트웨어 개발에 있어서의 사용자 요구사항 정의단계에서 도출된 유즈케이스 다이어그램과 클래스 다이어그램들의 상호작용을 비교 검증함으로써 보다 효율적인 객체지향모델링 과정을 수행할 수 있게 된다.

• 터널과지하공간
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• 제21권3호
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• pp.216-224
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• 2011

본 연구에서는 Class II 거동에 대해 입자결합모델을 이용하여 수치해석적인 방법으로 살펴보았으며, 횡방향 변형률 제어 압축시험을 수치해석적으로 모사할 수 있는 방법을 제시하였다. 수치해석에서 사용된 미시변수는 스웨덴 Aspo Hard Rock Laboratory에서 수행한 일축압축시험을 이용하여 결정하였다. 제시된 수치해석 기법을 이용해 Aspo 암석의 Class II 거동을 효과적으로 모사할 수 있었으며, 수치해석의 결과는 실험실 시험 결과와 잘 일치하였다.

• 수산해양교육연구
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• 제28권5호
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• pp.1478-1491
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• 2016

This study has designed to find out the effects of a project-based flipped learning model at universities on the self-directed learning ability, the self-leadership, and the learning competency. For the study, two procedures were performed. First, a flipped learning model for a project-based learning was developed on the basis of the literature reviews. The flipped learning model has three different steps: the pre-class, the in-class, and the post-class. In the pre-class, instructors provide mini-core courses using various technologies for learners outside the class. The in-class is the step to check whether learners prepare their learning or not. Also, in this step, the in-death learning and the teaching-learning process by interaction between instructors and learners would be performed. In the post-class, learners would be able to sustain the extended learning to develop the learning tasks and activities after flipped learning class. Through this step, the learners could be experienced integrated thinking and application, documentation and management, as well as sharing and spread of their learning. Second, the effectiveness of the developed flipped learning model on the self-direction, the self-leadership, and the learning competency was examined. The quantitative research method and the qualitative research method were used for this study. The results indicated that the flipped learning model showed improvement on the self-direction, the self-leadership, and the learning competency.

• 한국컴퓨터정보학회논문지
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• 제23권6호
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• pp.15-21
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• 2018

The purpose of this study is to design a Content-based Korean Class model using Flipped learning for foreign students. The class model that presents on this paper will lead the language learning through content learning, also it will be enable the student more active and to have an initiative in the class. Prior to designing a Content-based Korean Class model using Flipped learning, the concepts and educational significance and characteristics of flip learning were reviewed through previous studies. Then, It emphasizes the necessity of teaching method adapting Flipped learning to Content-based teaching method in Korean language education. It also suggests standards and principles of composition in Contents-based teaching method using Flipped learning. After designing the instructional model based on the suggested standards and principles, it presents a course of instruction about how learning methods, contents and activities should be done step by step. The Content-based Korean class model using the Flipped learning will be an alternative approach to overcome the limitations of teacher-centered teaching methods and lecture-teaching methods which are the dominant of present classroom environment.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.177-183
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• 1999

본 논문에서는, Class-2 PRS 모델의 전달함수인 Raised-Cosine 펄스를 이용하여 극초단 레이저펄스의 전송특성을 분석하였다. 이는 Class-1 PRS 모델에서와 같이 부분응답시스템의 수정된 모델로부터 얻어지는 고차원펄스를 이용하여 그 차수의 증가에 따라 FWHM폭이 현저히 감소하여 분석하고자 하는 극초단펄스의 형태에 근접하는 펄스를 제시하였으며, 그 스펙트럼과 전송대역폭도 차수에 따라 일률적으로 유도되므로 Gaussian, Sech형태의 펄스 같은 고전적인 방법과는 달리 광범위하고 정확한 전송특성을 분석하는데 매우 유용함을 밝혔다. 먼저, 부분응답시스템의 일반적인 모델을 수정하여 어떤 형태의 고차원펄스도 적용할 수 있는 새로운 방법을 제안하였다. 그리고 제안된 모델을 이용하여 어떠한 형태의 FWHM을 가지는 극초단펄스의 전송에 대한 새로운 분석 방법을 제안하였다. 제안된 방법을 사용하여, 설정 펄스 폭을 $\tau$=1(ps)으로 설정, 고차원펄스의 차수 n=1-100에서 얻어지는 FWHM 1(ps)-100(fs)의 극초단펄스의 스펙트럼을 제시하였고, Class-2 PRS 모델의 FWHM 폭이 Class-1 PRS 모델보다는 차수 n에 따라서 약 50-100(fs)정도 좁은 FWHM 폭을 가짐을 밝혔다. 이에 대한 전송특성은 레이저펄스의 보편적인 신호방식인 Unipolar 체계로 설정하여, 가능한 펄스 간격에 따른 PSD를 유도하여 제시하였다. 이러한 결과들은 고전적인 실험 방법과는 일치함을 물론 미래 극초단펄스 연구에 대한 혁신적인 방법으로 사용될 수 있을 것이다.