• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.201-208
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• 2010

The classical iterated hash function is vulnerable to a multi-collision attack. Gauravaram et al. proposed 3C and 3C+ hash functions, in which an accumulation chain is added to usual Merkle-Damgard changing. Their goal is to design composition schemes resistant to generic attacks of Joux's type, but Joscak and Tuma have shown that 3C and 3C+ schemes are not better than Merkle-Damgard scheme in term of security against multi-collision attacks under some mild assumptions. In this dissertation, in order to increase security of 3C hash function, we proposed secure double pipe hash function which was effectively using XOR and XNOR operations per blocks of message. We seek to improve on the work of Lucks in a way. Proposed secure double pipe hash function takes resistance to multi-block collision, fixed point and pre-image attacks.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.9
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• pp.407-418
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• 2023

The Multi-Object Goal Visual Navigation(MultiOn) is a visual navigation task in which an agent must visit to multiple object goals in an unknown indoor environment in a given order. Existing models for the MultiOn task suffer from the limitation that they cannot utilize an integrated view of multimodal context because use only a unimodal context map. To overcome this limitation, in this paper, we propose a novel deep neural network-based agent model for MultiOn task. The proposed model, MCFMO, uses a multimodal context map, containing visual appearance features, semantic features of environmental objects, and goal object features. Moreover, the proposed model effectively fuses these three heterogeneous features into a global multimodal context map by using a point-wise convolutional neural network module. Lastly, the proposed model adopts an auxiliary task learning module to predict the observation status, goal direction and the goal distance, which can guide to learn the navigational policy efficiently. Conducting various quantitative and qualitative experiments using the Habitat-Matterport3D simulation environment and scene dataset, we demonstrate the superiority of the proposed model.

• 정보화사회
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• s.13
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• pp.32-35
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• 1988

정보통신회선 사용제도가 대폭적으로 개선되었다. 그동안 협회가 “민간 VAN활성화 방안의 연구”, “전기통신 관계법령 정비에 관한 워크샾”. “공중전기통신사업 개정안에 대한 공청회” 등의 활동을 통해 회원사들의 요구사항을 수렴. 집약하여 체신부로 하여금 현행의 불합리한 회선사용의 제한을 완화토록 누차에 걸쳐 촉구한 결과 이번 개선조치를 얻어냈다. 이번 조치는 지난 1일 협회 법제분과위원회 석상에서 정부당국자에 의해 최초로 발표되어 회의참석자(회원사 임직원) 모두로부터 전폭적인 환영을 받았다. 특히 이제까지 그룹 VAN에만 허용하던 정보의 교환행위를 중소기업 대상 전산망 서비스분야까지 확대 허용한 점, 다중화 장치 접속 허용, 긴밀관계자 인정범위 확대 등의 내용은 업계측을 크게 고무하고 정보통신사업의 활성화를 촉진하는 획기적인 조치라는 것이 중평이다. 아울러 중소기업기본법 제2조의 기중에 관련한 확대허용 조치는 자칫 대규모 VAN업체에 대한 영세 S/W 업체들의 자본적, 기술적 예속을 가속화시킬 가능성을 잉태하고 있어 이들에 대한 육성.지원대책을 서둘러야 할 때임을 암시하고 있다. 이번 조치에 따라 체신부는 ‘89.1.1일자 시행을 목표로 공중통신사업자로 하여금 다중화장치 접속기준을 제정토록 지침을 하달한 것으로 알려졌다. 한편, 정부는 국내 정보통신사업 육성방안에 대한 연구.검토와 함께 전기통신관련법령의 전면적인 개편을 추진키 위해 이미 전문연구기관단체 등에 연구용역을 주는 등 본격적인 준비작업에 들어갔다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.445-458
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• 2012

The objective of GPS control surveying is ultimately to determine coordinate sets of control points within targeted accuracy through a series of observations and network adjustments. To this end, it is of equivalent importance for the accuracy of these coordinates to be realistically represented by using an appropriate method. The accuracy representation can be quantitively made by the variance-covariance matrices of the estimates, of which features are sensitive to the mathematical models used in the adjustment. This paper deals with impact of functional and stochastic modeling techniques into the accuracy representation of the GPS control surveying with a view of gaining background for its standardization. In order to achieve this goal, mathematical theory and procedure of the single-baseline based multi-session adjustment has been rigorously reviewed together with numerical analysis through processing real world data. Based on this study, it was possible to draw a conclusion that weighted-constrained adjustment with the empirical stochastic model was among the best scheme to more realistically describe both of the absolute and relative accuracies of the GPS surveying results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.759-764
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• 2011

This paper deals with the method of using the amended virtual force field technique to avoidance the front environment(wall, obstacles etc.) in navigating by using the environmental informations recognized by a ultrasonic-ring and pan/tilt CCD camera equipped on a mobile robot. we will give an explanation for the robot system architecture designed and implemented in this study and a short review of existing techniques, since there exist several recent thorough books and review paper on this paper. It is proposed the rusult from the experimental run based on a virtual force field(VFF) method to support the validity of the aforementioned architecture of mobile service robot for local navigation and obstacle avoidance for autonomous mobile robots. We will conclude by discussing some possible future extensions of the project. The results show that the proposed algorithm is apt to identify obstacles in an indoor environments to guide the robot to the goal location safely.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.817-820
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• 2002

인간과 기계와의 인터페이스에 있어서 궁극적 목표는, 인간과 기계가 마치 사람과 사람이 대화하듯 자연스런 인터페이스가 이루어지도록 하는데 있다. 이에 본 논문에서는 사람의 음성속에 깃든 6개의 기본 감정을 인식하는 알고리듬을 제안하고자 한다. 이를 위하여 뛰어난 주파수 분해능력을 갖고 있는 웨이블렛 필터뱅크를 이용하여 음성을 여러 개의 서브밴드로 나누고 각 밴드에서 특징점을 추출하여 감정을 이식하고 이를 최종적으로 융합, 단일의 인식값을 내는 다중의사 결정 구조를 갖는 알고리듬을 제안하였다. 이를 적용하여 실제 음성 데이타에 적용한 결과 기존의 방법보다 높은 90%이상의 인식률을 얻을 수 있었다.

• Korean Journal of Cognitive Science
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• v.26 no.3
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• pp.301-322
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• 2015

This study examined the effect of emotional sounds on satisfaction of search (SOS). SOS occurs when detection of a target results in a lesser chance of finding subsequent targets when searching for an unknown number of targets. Previous studies have examined factors that may influence the phenomenon, but the effect of emotional sounds is yet to be identified. Therefore, the current study investigated how emotional sound affects magnitude of the SOS effect. In addition, participants' eye movements were recorded to determine the source of SOS errors. The search display included abstract T and L-shaped items on a cloudy background and positive and negative sounds. Results demonstrated that negative sounds produced the largest SOS effect by definition, but this was due to superior accuracy in low-salient single target trials. Response time, which represents efficiency, was consistently faster when negative sounds were provided, in all target conditions. On-target fixation classification revealed scanning error, which occurs because targets are not fixated, as the most prominent type of error. These results imply that the two dimensions of emotion - valence and arousal - interactively affect cognitive performance.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.301-302
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• 2015

케이블 방송망에서 멀티-Gbps(Giga bit per second) 초고속 인터넷 서비스 제공을 위해 최근 북미에서 DOCSIS 3.1(Data over Cable Service Interface Specifications Version 3.1) 표준을 발표하였다. DOCSIS 3.1 은 최대 10Gbps 하향 데이터 전송과 최대 2Gbps 의 상향 데이터 전송을 목표로 한다. DOCSIS 3.1 이 이전 DOCSIS 표준들과 다른 점은 전송 효율을 높이기 위해 물리계층 전송 방식에 큰 변화를 주었다는 점이다. 기존 6MHz 대역폭의 단일 반송파 전송 방식에서 최대 192MHz 광역 채널의 다중 반송파 전송 방식으로 변경하였다. 또한 채널 오류정정 방식으로 BCH(Bose, Chaudhuri, and Hocquenghem)와 LDPC(Low Density Parity Check) 연접부호를 적용하여, 이로 인한 SNR 성능 이득 통해 4096-QAM 의 고차 변조를 지원한다. 본 논문에서는 최대 192MHz 의 광역 채널로 전송되는 약 2Gbps 의 전송 데이터에 대한 채널 오류 정정을 위해 고속의 LDPC 복호기 구현 방법을 제시한다.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.171-183
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• 2016

It is often reported that foreign tourists visiting Korea are not satisfied with dining in a Korean restaurant, and the reason is assumed that most of the Korean restaurants are targeting Koreans and operating in a traditional way; thus, this study suggests the need of a new type of Korean restaurant such as quick service restaurant, where foreign tourists could have Korean food in a more familiar way. It is attempted to examine foreign tourists' visit intention toward Korean quick service restaurant (QSR) applying the model of goal-oriented behavior (MGB). The survey was conducted with foreign tourists and total 275 data was gathered. Structural equation modeling was used for analysis. Among MGB variables, attitude, subjective norm, perceived behavioral control had significant effect on desire, while postive and negative anticipated emotions did not had significant effect. Also, involvement showed a significant moderating effect as positive anticipated emotion had much stronger effect on desire in a high involvement group.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.497-504
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• 2018

The purpose of this study was to investigate the relationship between college students' work hope, career attitude maturity and career decision-making self-efficacy. For this, correlation analysis, variance analysis and multiple regression analysis were conducted using 299 data collected from 8 universities in the metropolitan area, Yeongnam, Honam, Gangwon and Chungcheong provinces. As a result of correlation analysis between work hope and career variables, there was a positive correlation between r=.64 and .73 in each sub-factor. After performing a variance analysis to explore the differences in work hope between gender, grades and major fields, there were no gender and grade differences found, but there were significant differences between major fields. Also, as a result of multiple regression analysis, it was found that work hope affecting career attitude maturity was pathways, and in career decision-making self-efficacy, agency, pathways thinking, and goal were influenced. On the analysis result, the limitations and implications of this study were discussed using college students' work hope scale.