• International Journal of Human Ecology
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• 제10권2호
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• pp.71-78
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• 2009

Efforts were made to improve the efficiency of college education through the use of information technology. This paper investigates student perceptions of a lecture club provided on a social networking website. For the empirical study, the instructor ran a lecture club for two consecutive semesters on Cyworld (www.cyworld.co.kr), a popular website among Korean youth. The research subjects were students enrolled in a Popular Culture & Fashion class. A questionnaire was distributed on the last day of the lectures. After excluding students with perfunctory responses and those who did not sign up for the community website, a total number of 297 questionnaires were used for analysis. Descriptive statistics, Pearson correlation analysis, one-way ANOVA analysis, Duncan test, and t-test were carried out, with the SPSS for Windows 12.0 being used for statistical analysis. The findings show that most students subscribed to the website and responded with a favorable attitude that the lecture club was helpful.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.401-403
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• 1996

In this paper, a new control strategy is presented that combines sliding mode control theory with a neural network. Sliding mode control theory requires the complete knowledge of the dynamics of the controlled system. However, in practice, one often bas only a small number of state measurements. This could be a serious limitation on the practical usefulness of sliding mode control theory. A multilayer neural network is employed to solve this kind of problem. The neural network serves as a compensator without a prior knowledge about the system. The proposed control algorithm is applied to a class of uncertain nonlinear system. The robustness against parameter uncertainty, nonlinearity and external disturbances, and the effectiveness is verified by the simulation results.

• 센서학회지
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• 제30권5호
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• pp.286-289
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• 2021

Image classification is one of the fundamental applications of computer vision. It enables a system to identify an object in an image. Recently, image classification applications have broadened their scope from computer applications to edge devices. The convolutional neural network (CNN) is the main class of deep learning neural networks that are widely used in computer tasks, and it delivers high accuracy. However, CNN algorithms use a large number of parameters and incur high computational costs, which hinder their implementation in edge hardware devices. To address this issue, this paper proposes a lightweight image classifier that provides good accuracy while using fewer parameters. The proposed image classifier diverts the input into three paths and utilizes different scales of receptive fields to extract more feature maps while using fewer parameters at the time of training. This results in the development of a model of small size. This model is tested on the CIFAR-10 dataset and achieves an accuracy of 90% using .26M parameters. This is better than the state-of-the-art models, and it can be implemented on edge devices.

• Communications for Statistical Applications and Methods
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• 제28권1호
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• pp.21-37
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• 2021

There is a direct connection between linear discriminant analysis (LDA) and linear regression since the direction vector of the LDA can be obtained by the least square estimation. The connection motivates the penalized LDA when the model is high-dimensional where the number of predictive variables is larger than the sample size. In this paper, we study the penalized LDA for a class of penalties, called the moderately clipped LASSO (MCL), which interpolates between the least absolute shrinkage and selection operator (LASSO) and minimax concave penalty. We prove that the MCL penalized LDA correctly identifies the sparsity of the Bayes direction vector with probability tending to one, which is supported by better finite sample performance than LASSO based on concrete numerical studies.

• Communications for Statistical Applications and Methods
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• 제29권5호
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• pp.603-614
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• 2022

The naive Bayes classifier is one of the most straightforward classification tools and directly estimates the class probability. However, because it relies on the independent assumption of the predictor, which is rarely satisfied in real-world problems, its application is limited in practice. In this article, we propose employing sufficient dimension reduction (SDR) to substantially improve the performance of the naive Bayes classifier, which is often deteriorated when the number of predictors is not restrictively small. This is not surprising as SDR reduces the predictor dimension without sacrificing classification information, and predictors in the reduced space are constructed to be uncorrelated. Therefore, SDR leads the naive Bayes to no longer be naive. We applied the proposed naive Bayes classifier after SDR to build a recommendation system for the eyewear-frames based on customers' face shape, demonstrating its utility in the top-k classification problem.

• 대한치과기공학회지
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• 제44권3호
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• pp.97-103
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• 2022

Purpose: This study sought to identify the factors influencing learning motivation and demotivation in online dental technology students. Methods: A survey was conducted from October 1 to 30, 2021, on 188 dental technology students. The collected data were processed using the IBM SPSS IBM SPSS Statistics ver. 22.0 statistical program (IBM), and frequency, factor, and one-way ANOVA analyses were performed, for which the significance was set at 0.05. Results: It was found that the main online learning motivation factors were the usefulness of the learning content, interest, and confidence in the activities, the relationships with the teachers and friends, the feedback, and learning satisfaction. The factors that reduced the students' online learning motivation were interaction difficulties, maladaptation to the self-directed learning environment, the inadequate number of learning activities, and activity difficulty. Conclusion: Based on the identified online class motivation and demotivation factors, better systematic management and increased research are needed to improve the quality of non-face-to-face classes.

• 한국산학기술학회논문지
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• 제17권12호
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• pp.253-261
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• 2016

본 연구는 혼합연령학급의 현황과 학급 운영 실태를 파악하여, 혼합연령학급의 교사가 효과적으로 학급을 운영할 수 있도록 정책적 지원 방안을 모색하는데 목적이 있다. 이를 위해 먼저 전국 유치원의 혼합연령학급 운영현황 및 학급편성 기준을 분석하여 그 현황을 살펴보고, 다음으로 혼합연령학급 교사를 대상으로 설문조사를 통해 구체적인 어려움과 요구사항을 분석하였다. 설문조사는 유치원의 교육과정시간에 혼합연령학급을 운영하고 있는 담임교사 300명을 대상으로 웹조사로 실시하였으며, 빈도, 백분율, 교차분석을 실시하였다. 그 결과는 다음과 같다. 첫째 유치원의 혼합연령학급 편성이유는 취원 대상 유아의 수가 부족하다는 것이 가장 큰 이유였다. 둘째, 혼합연령학급 운영에서 지원인력의 부족, 교육(연수)제공 및 활용 기회 부족 등이 어려운 점으로 나타났다. 셋째, 혼합연령학급 운영에서 가장 필요한 운영지원으로는 수업인력 지원, 행정인력 지원 순으로 나타났다. 현재 이루어지고 있는 혼합연령학급 인력지원은 수업도우미, 행정도우미 순이었고, 유치원과 관련이 있는 유관 기관으로 지원 유무는 약 23.0%로 나타났고, 지원의 종류로는 교사연수, 인력예산, 컨설팅장학, 교재교구 등 수업자료 지원 순으로 나타났다. 이를 바탕으로 혼합연령학급 편성 시, 연령별 비율구성제시, 단계적 단일연령학급 편성유도, 혼합연령학급 교사 연수 기회제공 확대 등의 정책 지원방안을 제시하였다.

• 지능정보연구
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• 제27권3호
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• pp.175-197
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• 2021

최근 딥 러닝 기술의 발전으로 뉴스, 블로그 등 다양한 문서에 포함된 텍스트 분석에 딥 러닝 기술을 활용하는 연구가 활발하게 수행되고 있다. 다양한 텍스트 분석 응용 가운데, 텍스트 분류는 학계와 업계에서 가장 많이 활용되는 대표적인 기술이다. 텍스트 분류의 활용 예로는 정답 레이블이 하나만 존재하는 이진 클래스 분류와 다중 클래스 분류, 그리고 정답 레이블이 여러 개 존재하는 다중 레이블 분류 등이 있다. 특히, 다중 레이블 분류는 여러 개의 정답 레이블이 존재한다는 특성 때문에 일반적인 분류와는 상이한 학습 방법이 요구된다. 또한, 다중 레이블 분류 문제는 레이블과 클래스의 개수가 증가할수록 예측의 난이도가 상승한다는 측면에서 데이터 과학 분야의 난제로 여겨지고 있다. 따라서 이를 해결하기 위해 다수의 레이블을 압축한 후 압축된 레이블을 예측하고, 예측된 압축 레이블을 원래 레이블로 복원하는 레이블 임베딩이 많이 활용되고 있다. 대표적으로 딥 러닝 모델인 오토인코더 기반 레이블 임베딩이 이러한 목적으로 사용되고 있지만, 이러한 기법은 클래스의 수가 무수히 많은 고차원 레이블 공간을 저차원 잠재 레이블 공간으로 압축할 때 많은 정보 손실을 야기한다는 한계가 있다. 이에 본 연구에서는 오토인코더의 인코더와 디코더 각각에 스킵 연결을 추가하여, 고차원 레이블 공간의 압축 과정에서 정보 손실을 최소화할 수 있는 레이블 임베딩 방법을 제안한다. 또한 학술연구정보서비스인 'RISS'에서 수집한 학술논문 4,675건에 대해 각 논문의 초록으로부터 해당 논문의 다중 키워드를 예측하는 실험을 수행한 결과, 제안 방법론이 기존의 일반 오토인코더 기반 레이블 임베딩 기법에 비해 정확도, 정밀도, 재현율, 그리고 F1 점수 등 모든 측면에서 우수한 성능을 나타냄을 확인하였다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2004년도 추계학술발표회 논문집
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• pp.274-275
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• 2004

The majority of dyes belong to the chromophoric class known as donor-acceptor systems, the essential structural feature of such systems being the presence of one or more electron donating groups conjugated to one or more electron withdrawing groups via an unsaturated bridge. The indigo molecule may be formally divided into two identical electron donor/acceptor subsystems, each containing an add number of pi electrons, two subsystems being joined by carbon-carbon double bond. Indigoid type dyes which show a strong colour change on protonation or dissociation have many potential functional applications, for example as analytical pH indicators, solvent polarity indicators, and in various imaging and reprographic systems.

• 기술사
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• 제34권4호
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• pp.41-47
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• 2001

The paper describes SR3 (Synchronous Round Robin with Reservations), a collision-free medium access control protocol for all-optical slotted packet networks based on WDM multi-channel ring topologies where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter SR3 is derived from the SRR and MMR protocols previously proposed by the same authors for the same class of all-optical networks. SRR and MMR already achieve an efficient exploitation of the available bandwidth, while guaranteeing a throughput-fair access to each node. SR3, In addition, allows nodes to reserve slots. thereby achieving a stronger control on access delays; it is thus well suited to meet tight delay requirements, as it is the case for multimedia applications. Simulation results show that SR3 provides very good performance to guaranteed qualify traffic, but also brings signigicant performance improvements for best-effort traffic. Energy effciency is an important issue for optical network since they must rely on their batteries. We present a novel MAC protocol that achieves a good energy efficiency of optical interface of the network and provides support for diverse traffic types and QoS. The scheduler of the base station is responsible to provide the required QoS to connections on the optical link and to minimise the amount of energy spend by the High speed Network. The main principles of the MaC protocol are to avoid unsuccessful actions, minimise the number of transitions , and synchronise the mobile and the base-station. We will show that considerable amounts of energy can be saved using these principles.