• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.21-32
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• 2015

Since spatio-temporal local features for video representation have become an important issue of modeless bottom-up approaches in action recognition, various methods for feature extraction and description have been proposed in many papers. In particular, BoF(bag of features) has been promised coherent recognition results. The most important part for BoF is how to represent dynamic information of actions in videos. Most of existing BoF methods consider the video as a spatio-temporal volume and describe neighboring 3D interest points as complex volumetric patches. To simplify these complex 3D methods, this paper proposes a novel method that builds BoF representation as a way to learn 2D interest points directly from video data. The basic idea of proposed method is to gather feature points not only from 2D xy spatial planes of traditional frames, but from the 2D time axis called spatio-temporal frame as well. Such spatial-temporal features are able to capture dynamic information from the action videos and are well-suited to recognize human actions without need of 3D extensions for the feature descriptors. The spatio-temporal BoF approach using SIFT and SURF feature descriptors obtains good recognition rates on a well-known actions recognition dataset. Compared with more sophisticated scheme of 3D based HoG/HoF descriptors, proposed method is easier to compute and simpler to understand.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.300-304
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• 2020

본 논문에서는 원격 탐사 영상 정합에서 정확도는 유지하면서 특징점 매칭 (Matching) 복잡도를 줄이기 위해 입력 영상을 전처리하는 구조물 검출 네트워크를 이용한 원격 탐사 영상 정합 방법을 제안한다. 영상 정합의 기존 방법은 입력 영상에서 특징점을 추출하고 설명자 (Descriptor)를 생성한다. 본 논문에서 제안하는 방법은 입력 영상에서 특징점 매칭에 영향을 미치는 구조물만 추출하여 새로운 영상을 만들어 특징점을 추출한다. 추출된 특징점은 필터링 (Filtering)을 거쳐 원본 영상에 매핑 (Mapping)되어 설명자를 생성하여 특징점 매칭 속도를 향상시킨다. 또한 구조물 검출 네트워크에서 학습 영상과 시험 영상의 특성의 차이로 생기는 성능 저하 문제를 개선하기 위해 히스토그램 매핑 기법을 이용한다. 아리랑 3 호가 획득한 원격 탐사 영상에 대한 실험을 통해 제안하는 방법은 정확도를 유지하면서 계산 시간을 SURF 보다 87.5%, SIFT 보다 92.6% 감소시킬 수 있다.

• Journal of Internet Computing and Services
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• v.22 no.4
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• pp.1-11
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• 2021

As the Internet developed, various and complex cyber attacks began to emerge. Various detection systems were used outside the network to defend against attacks, but systems and studies to detect attackers inside were remarkably rare, causing great problems because they could not detect attackers inside. To solve this problem, studies on the lateral movement detection system that tracks and detects the attacker's movements have begun to emerge. Especially, the method of using the Remote Desktop Protocol (RDP) is simple but shows very good results. Nevertheless, previous studies did not consider the effects and relationships of each logon host itself, and the features presented also provided very low results in some models. There was also a problem that the model could not explain why it predicts that way, which resulted in reliability and robustness problems of the model. To address this problem, this study proposes an interpretable RDP-based lateral movement detection system using page rank algorithm and SHAP(Shapley Additive Explanations). Using page rank algorithms and various statistical techniques, we create features that can be used in various models and we provide explanations for model prediction using SHAP. In this study, we generated features that show higher performance in most models than previous studies and explained them using SHAP.

• Journal of Labour Economics
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• v.36 no.3
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• pp.29-64
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• 2013

This paper documents the recent changes in wage density and decomposes them. Middle group is found to have shrunk, one-third of which reflects the changes in worker composition. The rest mostly reflects insufficient supply response to the rising skill demand within jobs. The pattern is more pronounced among manufacturing, large and unionized firms, and production workers.

• 전기의세계
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• v.32 no.7
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• pp.388-394
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• 1983

초전도 교류발전기에는 여러 종류의 구조가 있는데 본 해설에서는 현재 가장 많이 개발되고 있는 2중 차폐형 단일 회전자 발전기에 대하여 중점적으로 취급한다. 먼저 그 구조를 설명하고 초전도 교류발전기의 특징을 다루며 현재 개발현황을 소개한다.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.23-36
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• 2008

Polymer-clay nanocomposites, a novel organic-inorganic hybrid, attract much attention from both scientific fields and engineering fields due to their balanced improvements in mechanical properties as well as diffusion behaviors, including flame-retarding and barrier properties, with small amounts of clay. Preparation of polymer-clay nanocomposites, summarized as a process for uniform dispersion of hydrophilic layered clays in hydrophobic polymer matrixes, includes several technologies and scientific phenomena, such as surface-modifications of clay layers, physical properties of clays in liquids and dried states, polymer synthesis, polymer rheology, behaviors of polymer solutions/or monomers in the confined geometry, mechanical properties of polymers and clays. To comprehend complicated physical/chemical phenomena involved in the fabrication of nanocomposites, we reviewed physical properties of clays, structures of clays in nanocomposites, characterization of nanocomposites, the relation between morphology and physical property of nanocomposites, surveyed recent research trends, and then suggested a few strategies or methods for fabrication of nanocomposites reflecting future research directions.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.201-209
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• 2020

The purpose of this study is to investigate the effect of narrative and expository texts on incidental vocabulary learning of Korean university EFL learners while reading. The experimental groups were divided into 3 groups. The first experimental group were exposed to narrative texts and second group received expository texts. And the third group were administered narrative and expository texts alternately. The vocabulary tests were conducted after the last session to assess the incidental vocabulary gains of the learners. The results indicated the superiority of the expository texts over narratives in terms of enhancing learners' incidental acquisition of unknown words. Moreover, the results showed that the blended reading group of expository and narrative texts did better on the vocabulary gains than those of narrative reading group and expository reading group. However, in the essay writing assessment, the expository group committed the most vocabulary errors in writing.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.355-358
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• 2001

본 논문에서는 객체의 움직임에 의한 모양 변화를 표현하기 위하여 MPEG-7 에 제안된 모양 시퀀스 기술자(Shape Sequence Descriptor)에 대하여 설명하고, 모양 시퀀스 기술자 추출에 필요한 Shape Variation Map 생성을 위한 두 가지 방법을 비교하였다. 기존의 방법은 물체의 평균 적인 모양에 가중치를 두어 생성되며, 새로운 방법은 물체의 움직임에 의해 변화되는 부분에 더 가중치를 두는 방법으로 생성된다. 또한 최종적으로 사용되는 특징 값으로 Zernike moment를 이용하는 방법과 ART(Angular Radial Transform)을 이용하는 방법을 비교하여 모양 시퀀스 검색을 위한 가장 효율적인 방법을 제안하였다.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.83-94
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• 2011

Main researching issue in affective computing is to give a machine the ability to recognize the emotion of a person and to react it properly. Efforts in that direction have mainly focused on facial and oral cues to get emotions. Postures have been recently considered as well. This paper aims to discriminate emotions posture by identifying and measuring the saliency of posture features that play a role in affective expression. To do so, affective postures from human subjects are first collected using a motion capture system, then emotional features in posture are described with spatial ones. Through standard statistical techniques, we verified that there is a statistically significant correlation between the emotion intended by the acting subjects, and the emotion perceived by the observers. Discriminant Analysis are used to build affective posture predictive models and to measure the saliency of the proposed set of posture features in discriminating between 6 basic emotional states. The evaluation of proposed features and models are performed using a correlation between actor-observer's postures set. Quantitative experimental results show that proposed set of features discriminates well between emotions, and also that built predictive models perform well.

• The Journal of Korean Philosophical History
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• no.38
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• pp.129-162
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• 2013

Noju Oh Hui-sang was a Confucian who was active during the reign of King Sunjo in late Joseon Dynasty and he also was a master of the Sallim faction. Though he is known as an eclectic Neo-Confucian, he had profound knowledge in the study of Confucian classics as well through succeeding the family study handed down by his father Oh Jae-sun and his oldest brother Oh Yun-sang. This thesis hereby examines Noju's Confucianism doctrine and its characteristics. Noju's Confucianism doctrine is characterized significantly with the following aspects. First, its analyses are detailed overall and it annotates chapters and verses mostly related to Neo-Confucian theories on interpretation of the Confucian classics. Second, it conducts in-depth study not only on Chu Hsi's annotation but also on the small commentaries (小注) in Compendium of the Commentaries on Four Chinese Classics (四書集註大全). In terms of Chu Hsi's theory, however, Noju interprets Confucian classics while supplementing shortcomings on Chu Hsi's theory rather than opposing it. For opinions of all philosophers and scholars on small commentaries, it expresses rather critical theories than supporting ones. Third, it quotes many theories not only of Chinese Confucians but also of Korean ones. It mainly introduces theories of Namdang Han Won-jin, including those of Yi Yulgok. Among them, it particularly has frequent quotations from Han Won-jin's Kyoungyigimunrok (經義記聞錄). Fourth, Noju actively acknowledges senior Confucians' theories many times in quoting them but he also daringly points out their errors when a theory is thought not to be appropriate. He indicates errors one by one in theories not only of Uam and Yulgok but even of Mencius. Fifth, it especially discusses Book of Changes (周易) in depth. It tends to criticize Chengzi's I-Chuan (易傳) but accept Chu Hsi's Benyi (本義). It roughly explains Book of Changes in general but seldom directly accounts for trigrams of it other than Qian trigram and it has detailed explanation especially on Xicizhuan (繫辭傳).