• 정보처리학회논문지D
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• 제11D권1호
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• pp.61-68
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• 2004

현재 멀티 데이터베이스 시스템에서 실의 처리의 향상을 위해 응용되고 있는 뷰 관리에 대한 대표적인 연구 경향은 실체 뷰 기법과 시그니쳐 뷰인덱스 기법에 관심이 집중되고 있다. 그러나 이들 두 기법의 비교에서 보면, 실체 뷰 기법은 빠른 액세스 시간을 가지지만 많은 저장 공간이 필요하고, 뷰 인덱스 기법은 적은 저장공간을 사용하지만 액세스 시간이 느리다는 상반된 특성을 가지고 있다. 따라서, 본 논문에서는 신체 뷰와 시그니쳐 뷰인덱스 혼용 기법을 제안하여 질의 처리시에 뷰 관리를 사용함으로써 시스템 성능을 향상시키고, 디스크 입/출력에 대한 액세스 비용을 줄이고자 한다. 본 논문에서는 이 기법에 대한 메타데이타 구조와 알고리즘들에 대해 제안하고 있다.

• 유통과학연구
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• 제11권6호
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• pp.59-65
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• 2013

Purpose - Studies of mechanism as a competitive strategy, a relatively new field in the study of strategic management research, has recently drawn the attention of the business management scholars. The literature has so far proposed the subjective-based view, environment-based view, and the resource-based view in its analyses of firm management. Hence, it is highly likely for the firm management to be reasonably thought of as a combination of and interaction among the three key elements of subject, environment, and resources this is the mechanism-based view (MBV). It is reasonable to consider firm management to be the combination of and interaction among the three key elements of subject, environment, and resources. The overall dynamic process that integrates these three elements and creates functional harmony is identified as the mechanism, the principle of firm management. Much of the extant literatures on MBV has mainly focused on case studies, a qualitative approach prone to subjectivity of the researcher, although the intuition from the study may lead to meaningful insights into a firm-specific mechanism. This study's focus is also on case analysis, but it still attempts a quantitative approach in order to reach a scientific and systematic understanding of the MBV. Research design, data, and methodology - I used both a qualitative and quantitative approach to a single model, given the complexity of the innovation processes. I conducted in-depth interviews with POSCO employees-20 from general management, two from human resources, eight from information technology, five from finance and accounting, and five from production and logistics management. Once the innovative events were selected, the interview results were double-checked by the interviewees themselves to ensure the accuracy of the answers recorded. Based on the interview, I then conducted statistical validation using the survey results as well. Results - This study analyzes the building process of innovation and the effect of the mechanism pattern on innovation by examining the case of POSCO, which has survived over the past 21 years. I apply a new analytical tool to study mechanism innovation types, perform a new classification, and describe the interrelationships among the mechanism factors. This process allows me to see how the "Subject"factor interacts with the other factors. I found that, in the innovation process of the adoption stage, Subject had a mediating effect but that the mediating effect of resource and performance was smaller than the effect of Subject on performance alone. During the implementation stage, the mediating effect of Subject increased. Conclusion - Therefore, I have confirmed that the subject utilizes resources reasonably and efficiently. I have also advanced mechanism studies: whereas the field's research methods have been largely confined to single case studies, I have used both qualitative and quantitative methods to examine the relationships among mechanisms.

• 한국영어학회지:영어학
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• 제1권3호
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• pp.457-476
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• 2001

This paper is to reconsider the relation between presupposition and anaphoricity. My proposal goes as follows: First, the anaphoricity view of presupposition is problematic in that it heavily relies on accommodated antecedents, and this will end up depriving the view of much of its content. So, it is suggest that accommodation should be taken as a mechanism to add presupposed new information to the context, like an asserted proposition. Next, I show that, between two prominent theories of presupposition projection, both of which commit themselves to the anaphoricity view, van der Sandt's theory is quite compatible with the revised view of accommodation, but Heim's theory isn't, because anaphoricity is at the heart of its projection mechanism. Finally, I suggest that unaccommodatable presuppositions should be explained not by the properties of presupposition itself, but by the lexical properties of presupposition triggers.

• 한국컴퓨터그래픽스학회논문지
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• 제4권1호
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• pp.1-10
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• 1998

복잡한 가상환경을 렌더링하는 방법으로 다단계 모델을 이용한 LoD (Level-of-Detail) 기법이 널리 이용되고 있다. 효과적인 다단계 모델 생성에 있어, 원래의 모델이 갖고 있는 중요한 시각적 요소를 보존하면서 낮은 상세도의 여러 모델을 생성하는 것이 중요하다. 본 논문에서는 실루엣이나 후면 (backface)와 같은 시점과의 방향관계에 의한 요소들을 고려한 다단계 모델 생성기법을 제안한다. 본 논문에서는 시점과의 방향관계를 가우스 구 (Gaussian sphere) 를 확장한 다단계 관측구로 표현한다. 관측구는 각각의 면과 시점과의 방향관계를 효과적으로 표현함으로써 실루엣과 같은 방향관계를 효율적으로 관리할 수 있다. 또한, 효과적인 자료 관리를 위하여 다단계 관측구를 사진트리 (quad-tree) 의 형태로 표현하였다. 본 논문에서는 제안된 관측구를 이용하여 실시간 단순화 기법을 개발하고 실제 실루엣 보존의 결과를 보인다. 제안된 방법을 사용하여 시점과의 방향관계를 고려한 다단계 모델을 생성하여 실시간 렌더링에 이용할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1722-1741
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• 2017

Intrusion detection techniques based on virtual machine introspection (VMI) provide high temper-resistance in comparison with traditional in-host anti-virus tools. However, the presence of semantic gap also leads to the performance and compatibility problems. In order to map raw bits of hardware to meaningful information of virtual machine, detailed knowledge of different guest OS is required. In this work, we present VDSM, a lightweight and general approach based on driver separation mechanism: divide semantic view reconstruction into online driver of view generation and offline driver of semantics extraction. We have developed a prototype of VDSM and used it to do intrusion detection on 13 operation systems. The evaluation results show VDSM is effective and practical with a small performance overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권6호
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• pp.1833-1848
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• 2022

Named entity recognition (NER) is an important basic task in the field of Natural Language Processing (NLP). Recently deep learning approaches by extracting word segmentation or character features have been proved to be effective for Chinese Named Entity Recognition (CNER). However, since this method of extracting features only focuses on extracting some of the features, it lacks textual information mining from multiple perspectives and dimensions, resulting in the model not being able to fully capture semantic features. To tackle this problem, we propose a novel Multi-view Semantic Feature Fusion Model (MSFM). The proposed model mainly consists of two core components, that is, Multi-view Semantic Feature Fusion Embedding Module (MFEM) and Multi-head Self-Attention Mechanism Module (MSAM). Specifically, the MFEM extracts character features, word boundary features, radical features, and pinyin features of Chinese characters. The acquired font shape, font sound, and font meaning features are fused to enhance the semantic information of Chinese characters with different granularities. Moreover, the MSAM is used to capture the dependencies between characters in a multi-dimensional subspace to better understand the semantic features of the context. Extensive experimental results on four benchmark datasets show that our method improves the overall performance of the CNER model.

• 한국컴퓨터정보학회논문지
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• 제11권5호
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• pp.19-27
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• 2006

본 논문에서는 XML 뷰 트리 기반 랩퍼의 질의 처리 모델을 제시한다. 질의 처리과정은 뷰 합성, 지역 정보원에 대한 질의 변환, 그리고 결과 문서 생성으로 이루어지며, 이를 위해 XML 뷰와 XNL 질의어를 XML 뷰 트리로 표현하는 XML 뷰 트리 기반의 질의 처리 모델을 제시한다. XML 뷰 트리는 가상의 XML 문서의 구조를 그대로 반영하기 때문에 경로식의 탐색이 쉽고, XML 뷰에 대응되는 XML 스키마 생성과 질의 결과 문서 생성을 위한 템플릿으로 사용될 수 있다. 또한, XML 뷰와 XML 질의의 XML 뷰 트리를 통한 개념적 통일은 다단계 XML 뷰 정의와 합성을 쉽게 지원한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.291-304
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• 2019

This paper proposes a dynamic-tiling-based bandwidth-efficient (DTBE) virtual reality (VR) streaming scheme. We consider 360-degree VR contents with multiple view points such as the front, back, upper, and bottom sides. At a given time, the focus of a client is always bound to a certain view among multiple view points. By utilizing this perspective, under our proposed scheme, tiles with high encoding rates are selectively assigned to the focused view where multiple view points consist of multiple tiles with different encoding rates. The other tiles with low encoding rates are assigned to the remaining view points. Furthermore, for reducing view adaptation delay, we design a novel rapid view adaptation mechanism that selectively delivers an I-frame during view point updates by using frame indexing. We implement the proposed scheme on a commercial VR test bed where we adopt the MPEG media transport (MMT) standard with high-efficiency video coding (HEVC) tile modes. The measurement-based experiments show that the proposed scheme achieves an average data usage reduction of almost 65.2% as well as average view adaptation delay reduction of almost 57.7%.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.195-198
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• 2007

GOCI(Geostationary Ocean Color Imager) is the core paryload of the geostationary satellite COMS(Communication, Ocean and Meteological Satellite) for ocean monitoring. It is scheduled to be launched at the end of 2008. GOCI observes ocean color around the Korean Peninsula over $2500km{\times}2500km$ area. Whole field of view is divided into 16 solts and scan mechanism enables to point each slot position. Tilted two-axis scan method is used to observe entire field of view with great pointing stability. Vignetting of the optical system appears when the partial obscuration by intermediate optical components occurs. It leads to the variation of the illumination in the image and gradual fading near the edge of the field. It should be prohibited for the stable radiometric performances. In this work, vignetting analysis of GOCI optical system is performed. For the systematic approach, GOCI optical system is divided into scan mechanism part and telescope part. Vignetting analysis of each part is performed and each result is combined for the overall vignetting performances. The analyzed results can be applied to the selection of slot acquisition angle of scan mechanism to minimize vignetting effects.

• 방송공학회논문지
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• 제17권6호
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• pp.976-989
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• 2012

본 논문에서는 SVC와 MVC의 부호화 구조를 결합하여 구현된 스케일러블 다시점 비디오 부호화를 위한 효율적인 움직임 추정 기법과 DPB 설계 메카니즘에 대해 제안한다. 제안된 움직임 추정 기법에서는 부호화 과정에서 필요한 예측 부호화의 성능 향상을 위해서 서로 다른 시점 (view)의 픽처 정보를 참조픽처의 후보로서 활용한다. 제안된 움직임 예측 구조에 의해서 압축된 비디오 데이터의 크기를 감소시켜 압축 효율을 증대시킬 수 있다. 또한, 스케일러블 다시점 비디오 부호화를 수행할 때 SVC와 MVC의 DPB (Decoded Picture Buffer)를 통합한 통합형 DPB 설계 메카니즘에 대해 제안한다. 다양한 실험을 통해서 제안된 예측 구조를 적용함으로써 스케일러블 다시점 비디오 부호화에서의 압축 효율의 향상을 얻어낼 수 있음을 확인하였다.