• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.677-684
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• 2016

With the increase of multimedia information such as image, researches on extracting high-level semantic information from low-level visual information has been realized, and in order to automatically generate this kind of information. Various technologies have been developed. Generally, image retrieval is widely preceded by comparing colors and shapes among images. In some cases, images with similar color, shape and even meaning are hard to retrieve. In this article, in order to retrieve the object in an image, technical value of middle level is converted into meaning value of middle level. Furthermore, to enhance accuracy of segmentation, K-means algorithm is engaged to compute k values for various images. Thus, object retrieval can be achieved by segmented low-level feature and relationship of meaning is derived from ontology. The method mentioned in this paper is supposed to be an effective approach to retrieve images as required by users.

• Journal of Digital Contents Society
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• v.19 no.6
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• pp.1185-1195
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• 2018

Industrial Control System (ICS) is a system that carry out monitoring and controls of industrial control process and is applied in infrastructure such as water, power, and gas. Recently, cyber attacks such as Brutal Kangaroo, Emotional Simian, and Stuxnet 3.0 have been continuously increasing in ICS, and these security risks cause damage of human life and massive financial losses. Attacks on the control layer among the attack methods for ICS can malfunction devices of the field device layer by manipulating control commands. Therefore, in this paper, we propose a mechanism that apply the SDN between the control layer and the field device layer in the industrial control system and to determine whether the control command is legitimate or not and we show simulation results on a simply composed control system.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1421-1434
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• 2006

Spatial data warehouses provide analytical information for decision supports using SOLAP (Spatial On-Line Analytical Processing) operations. Many researches have been studied to reduce analysis cost of SOLAP operations using pre-aggregation methods. These methods use the index composed of fixed size nodes for supporting the concept hierarchy. Therefore, these methods have many unused entries in sparse data area. Also, it is impossible to support the concept hierarchy in dense data area. In this paper, we propose a dynamic pre-aggregation index method based on the spatial hierarchy. The proposed method uses the level of the index for supporting the concept hierarchy. In sparse data area, if sibling nodes have a few used entries, those entries are integrated in a node and the parent entries share the node. In dense data area, if a node has many objects, the node is connected with linked list of several nodes and data is stored in linked nodes. Therefore, the proposed method saves the space of unused entries by integrating nodes. Moreover it can support the concept hierarchy because a node is not divided by linked nodes. Experimental result shows that the proposed method saves both space and aggregation search cost with the similar building cost of other methods.

• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.216-224
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• 1997

In this paper, we propose a depth information extraction method for intermediate image synthesis. As stereo matching method, MBS(Multiple-Baseline Stereo) method has been proposed, in which the matching accuracy increases by using the multiple camera, but there are some inherent problems such as computational complexity, boundary overreach(BO) in depth map, and occlusion. So, we propose the modified version of MBS so called Multi-Resolution MBS(MR-MBS). Moreover, we also propose an adaptive occlusion area processing technique to improve the accuracy of the depth information in occlusion area.

• Korean Journal of Culture and Social Issue
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• v.11 no.spc
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• pp.57-67
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• 2005

This paper attempted to explore the plausible reasons why change activities to build up organizational trust might be often short-lived, even though it can become the most valuable social capital for an organization. Based upon a reference data collected from a large company in various methods, retrospective rationalization, difficulties embedded in the processes of realizing the five bases of organizational trust (such as openness, consistence, fairness, consideration, and pride), and top management's negative conviction were identified and discussed as fundamental reasons for the distrust in the usefulness of organizational trust. In addition, middle managers' overcautiousness about their superiors' feeling and organizational cynicism as contributing factors for the distrust in the form of vicious circle were discussed.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.85-91
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• 1999

The purpose of this study is to investigate phonetic realization of flap [r], one of the allophones of Korean /l/. Phonetic realization of a segment is affected by not only its neighboring segments but also its prosodic position in an utterance. This study examined how various prosodic positions affect the phonetic realization of [r]. Effects of the four prosodic positions on the phonetic realization of [r] were examined: utterance initial, Intonation Phrase initial, Accentual Phrase initial, and Accentual Medial positions. Word positional effect was also examined: word initial, medial, and final positions. Acoustic and statistical analyses showed that flap [r] was realized in a variety of phonetic forms: from sonorant(the most reduced form) to short stop(the least reduced form). It was shown that generally. word-initial position is stronger than word-medial position. It was also shown that in many cases, utterance-initial position and intonation-phrase-initial position are stronger than accentual-phrase-initial and accentual-phrase-medial positions. Sonorants were observed more often in the prosodically weaker portions. VOT duration was also shorter in accentual-phrase-initial and accentual-phrase-medial positions.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.221-235
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• 2020

This study identified the latent groups according to smartphone addiction tendency and examined the factors affecting the latent group identification. The best-fitting LCA solution had three classes. The first group was 'non-academic stressed group, immersed in smartphone' It was characterized low scores on academic stress and average scores on smartphone addiction tendency. The second group was 'medium level academic stressed group, immersed in smartphone' which scored slightly above average in academic stress and smartphone addiction tendency. The third group was 'medium level academic stressed group, non-immersed in smartphone'. It showed higher scores than average in academic stress, but students with far lower scores in smartphone addiction tendency. Logistic analysis result showed that gender and grade were significant. This study is meaningful in analyzing academic related variable(academic stress) and mental health related variable(smartphone addiction tendency) to classify the groups according to patterns between the two variables and suggest appropriate intervention for each group in a convergence way.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.733-736
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• 2013

The sensor network technology for core technology of ubiquitous computing is in the spotlight recently, the research on sensor network is proceeding actively which is composed many different sensor node. The major traffic patterns of plenty of sensor networks are composed of collecting types of single directional data, which is transmitting packets from several sensor nodes to sink node. One of the important condition for design of sensor node is to extend for network life which is to minimize power-consumption under the limited resources of sensor network. In this paper analysis used routing protocols using the network simulation that was used second level cluster structure to reduce delay and power-consumption of sensor node.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.138-142
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• 2007

컴포넌트 기반 개발 방법론이 지향하는 목표는 독립적으로 개발된 컴포넌트들을 소스 수정 없이 바이너리 형태로 조립하여 소프트웨어를 개발하는 것이다. 그러나 기존 컴포넌트 모델 기반으로 개발된 컴포넌트들은 자신이 제공하는 서비스에 대해서는 그 사용계약을 독자적인 인터페이스를 통하여 정의하는 반면, 하위 컴포넌트와의 연동은 하위 컴포넌트가 정의한 인터페이스에 따르는 코딩을 통해 이루어진다. 이러한 컴포넌트 모델들은 다계층 구조로 개발되고 있는 현대 엔터프라이즈 정보시스템에서 상위 컴포넌트들이 하위 컴포넌트가 정의한 인터페이스에 정적으로 단단히 결합되는 문제점을 갖고 있다. 따라서 하위 컴포넌트에 의존하지 않는 간단한 GUI용 컴포넌트들만 재사용되고 비즈니스 논리를 처리하는 중간 계층 컴포넌트들의 재사용율은 지극히 낮은 실정이다. 본 논문은 하위 컴포넌트가 정의한 인터페이스 규격에 따르는 대신 독자적으로 호출규격을 정의하여 사용하고 이에 대한 메타데이터를 공개함으로써 독립적으로 개발된 바이너리 컴포넌트들간의 연동을 보장하는 새로운 컴포넌트 모델을 제안하고 이 모델에 따라 개발된 컴포넌트들을 조립하는 방법을 제안하였다. 또한 이들을 구현함으로써 이미 개발된 컴포넌트를 실제 소스 수정 없이 바이너리 코드 형태로 조립 가능한 것을 증명하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.5
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• pp.993-1000
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• 2017

When the availability of embedded device is considered, combined countermeasure such as first-order masking and hiding countermeasures is quite attractive because the security and efficiency can be provided at the same time. Especially, combined countermeasure can be applied to the confusion and diffusion layers of the first and last rounds in order to provide the efficiency. Also, the middle rounds only employs first-order masking countermeasure or no countermeasure. In this paper, we suggest a novel side channel analysis with low complexity in the output of diffusion layer. In general, the attack target cannot be set to the output of diffusion layer owing to the high complexity. When the diffusion layer of block cipher is composed of AND operations, we show that the attack complexity can be reduced. Here, we consider that the main algorithm is SEED. Then, the attack complexity with $2^{32}$ can be reduced by $2^{16}$ according to the fact that the correlation between the combination of S-box outputs and that of the outputs of diffusion layer. Moreover, compared to the fact that the main target is the output of S-box in general, we demonstrate that the required number of traces can be reduced by 43~98% in terms of simulated traces. Additionally, we show that only 8,000 traces are enough to retrieve the correct key by suggested scheme, although it fails to reveal the correct key when performing the general approach on 100,000 traces in realistic device.