• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.3B
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• pp.323-331
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• 2001

새로운 변환 방식으로 최근 많이 사용하고 있는 웨이블릿 변환은 영상을 시간(위치정보)와 주파수 공간(주파수 정보)에서 동시에 표현함으로서 다른 변환 방식과는 큰 차이를 보여준다. 이런 웨이블릿 변환의 통계적 특성을 이용한 제로트리 분호화 기법은 영상 전체에서 의미 있는 영상 계수를 선별하여 약속된 우선 순위대로 부호화함으로서 매입 파일(embedded file)을 생성한다. 본 논문에서는 압축율이 큰 경우 제로 트리 부호화 과정 중 불확실 구간에서 발생하는 오차를 측정하여 최적의 오차 코드북을 생성한 후 복원시 참조함으로서 결과의 향상을 보이고자 하였다. 오차 교정은 제로트리 부호화 과정에서 손실되기 쉬운 고주파수 밴드에 적용하여 복원시 영상의 자세한 성분을 살리는데 효과적이었다. JPEG과 DCT기반 영상압축 결과에 비하여 화질에서 더 좋은 성분을 보일 뿐 아니라 고압축 복원시 발생하는 DCT 특유의 블록화 현상도 제거되었다.

• Journal of Korea Multimedia Society
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• v.6 no.2
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• pp.301-308
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• 2003

In this paper, we propose a multicast ATM switch that reduces traffic load by using the method of storing unicast cells and multicast cells separately according to the type of the cells. The switch is based on a shared memory type to reduce HOL blocking and deadlock. In the proposed switch, we use a control scheme that schedules stored cells to output ports to reduce the loss of traffic cells and to output effectively. We analyzed the Performance of the proposed switch through the computer simulation and the results have shown the effectiveness of the switch.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.66-79
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• 2009

In this paper, we propose a new adaptive intra coding technique using 1-D and 2-D integer transforms for improving coding efficiency of H.264/AVC. Proposed technique selects the most effective transform and prediction mode for each block after processing 1-D and 2-D transforms of all prediction modes. In case of using 1-D transform, $4{\times}4$ block is divided into four $1{\times}4$ or $4{\times}1$ subblocks and then each subblock is predicted and subtracted by using the decoded subblock located at the nearest position in the direction of prediction. After prediction error subblock is processed by 1-D transform and quantization, four subblocks are merged back into original $4{\times}4$ block and then, reordered as 1-D signal by a DC biased zigzag scanning pattern according to the prediction mode. Finally, comparing the coding efficiency between bitstreams based on 1-D transform and conventional 2-D transform, prediction mode and quantized coefficients for each block are decided and corresponding quantized coefficients are transmitted. Experimental results show that the proposed adaptive technique increases 0.34dB in BD-PSNR and decreases 4.03% in BD-Bitrate on the average compared with H.264/AVC.

• Journal of Korea Port Economic Association
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• v.35 no.2
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• pp.109-126
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• 2019

The Panmunjom Declaration adopted by the leaders of South and North Korea on April 27, 2018, has created an environment conducive for peace and cooperation in the Korean Peninsula. In the June of last year, South Korea has joined the Organization for Cooperation between Railways (OSJD). The membership of OSJD has established a solid foundation for restoring a multimodal logistics system that connects the Korean peninsula to Eurasia countries, including China and Russia. In this paper, a questionnaire survey targeting working-level experts was conducted to find the barriers in constructing multimodal logistics that efficiently connect the port-continental railways of the Korean peninsula and the Eurasian nations. Survey items were divided into five categories-border crossing procedures, technology, facilities, operation, and government support. As a result, among the most important problems of international multimodal logistics in Eurasia that need to be solved on priority include improving transshipment facilities, eliminating inspection carried out at every country for transit, simplifying documents for customs clearance, and minimizing the changes in freight rates. In conclusion, for vitalizing the connection between the Korean peninsula and the continental railways, it is necessary to develop a transshipment system to facilitate the changes in tracks at the borders by making a joint effort with the international community. Second, railway and operational systems in South Korea, North Korea, China, and Russia should be standardized. Third, international cooperation among South Korea, North Korea, China, and Russia is essential for simplifying customs clearance at borders, priority departure of domestic cargo, sharing information about the changes in freight rates, and so on. Finally, the government should come up with measures to secure the quantity of cargo required to form block trains, while developing new business models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2B
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• pp.146-153
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• 2006

It is required to have researches on efficient resource allocation schemes in an integrated voice and data CDMA system with the spreading of high-speed wireless internets. In this paper, we proposed a efficient resouce allocation scheme for providing a high speed data service in an integrated CDMA system. In an integrated voice/data CDMA system, resources for voice users are allocated with high priority and residual resources are allocated to the data service. In this case, it is necessary to use a resource allocation scheme for minimizing interference. In this paper, we first explain about a interference minimizing method and define QoS requirements. Based on the method, we proposed a efficient resource allocation scheme which satisfy the QoS requirements. The proposed scheme controls the transmission rate and delay of data users with a priority information such as the number of packets in a queue. From the simulation results, we show that the proposed scheme reduce the blocking probability and delay and improve the performance.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.140-146
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• 2021

As the environment using intelligent IoT devices increases, various studies are underway to ensure the integrity of information sent and received from intelligent IoT devices. However, all IoT information generated in heterogeneous environments is not fully provided with reliable protocols and services. In this paper, we propose an intelligent-based multi-blockchain model that can extract only critical information among various information processed by intelligent IoT devices. In the proposed model, blockchain is used to ensure the integrity of IoT information sent and received from IoT devices. The proposed model uses the correlation index of the collected information to trust a large number of IoT information to extract only the information with a high correlation index and bind it with blockchain. This is because the collected information can be extended to the n-tier structure as well as guaranteed reliability. Furthermore, since the proposed model can give weight information to the collection information based on blockchain, similar information can be selected (or bound) according to priority. The proposed model is able to extend the collection information to the n-layer structure while maintaining the data processing cost processed in real time regardless of the number of IoT devices.

• Annual Conference of KIPS
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• 2005.11a
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• pp.721-724
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• 2005

본 논문은 육각 탐색에 기반한 고속 블록 정합 알고리즘의 성능 개선에 관한 것으로, 육각 탐색과정에서 추출한 정합점에 대해 정합 검증 패턴을 이용하여 정합도를 검증함으로써 국부 최소 문제를 효과적으로 개선한 고속 움직임 벡터 추정 기법에 관한 것이다. 제안된 방법은 우선, 적응형 육감 탐색에 있어서 차순위 국부 정합점을 이용하여 탐색 패턴을 확장한다. 이후 이렇게 확장된 탐색 패턴에서 추출한 임시 전역 정합점을 대상으로 정합 검증 패턴을 이용하여 정합도의 비교우위를 재차 검증한다. 이 검증 결과에 따라 추가 탐색 과정을 계속적으로 진행할 것인지 또는 현 임시 전역 정합점을 최종 전역 정합점으로 확정할 것인지 여부를 결정하는 과정을 반복적으로 수행함으로써 움직임 보상화질을 개선한 것이다. 제안된 방법에 따르면, 정합 검증 패턴을 적용한 검증 과정에서 추가적인 연산량 증가가 초래되지만 이를 상호타협적으로 보상할 수 있는 화질 측면에서의 성능 개선 효과를 기대 할 수 있다.

• Journal of Platform Technology
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• v.11 no.5
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• pp.126-135
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• 2023

Demand for NFT is expanding along with Blockchain. And cyber security threats are also increasing. Therefore, this study derives security level inspection items by analyzing status related to NFT security such as NFT features, security threats, and compliance for the purpose of strengthening NFT security. Based on this, the relative importance was confirmed by applying it to the AHP model. As a result of the empirical analysis, the priority order of importance was found in the order of Security management system establishment and operation, encryption, and risk management, etc. The significance of this study is to reduce NFT security incidents and improve the NFT security management level of related companies by deriving NFT-related security level check items and demonstrating the research model. And If you perform considering relative importance of the NFT check items, the security level can be identified early.

• Journal of Korea Water Resources Association
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• v.39 no.1 s.162
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• pp.35-46
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• 2006

In this study, we proposed a layout of the integrated decision support system in order to prevent the contamination and to manage risk in water supply networks for safe and smooth water supply. We evaluated the priority of risk factors to detect anomaly in water supply networks using PROMETHEE and ANP techniques, which are applied to various Multi-Criteria Decision Making area in Europe and America. To develop the model, we selected pH, residual chlorine concentration, discharge, hydraulic pressure, electrical conductivity, turbidity, block leakage and water temperature as the key data item. We also chose pipe corrosion, pipe burst and water pollution in pipe as the criteria and then we present the results of PROMETHEE and ANP analysis. The evaluation results of the priority of risk factors in water supply networks will provide basic data to establish a contingency plan for accidents so that we can establish the specific emergency response procedures.

• Journal of The Korean Association of Information Education
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• v.25 no.5
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• pp.673-681
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• 2021

This study is a case study of artificial intelligence education subjects in the graduate school of education. The main educational contents consisted of understanding and practice of machine learning, data analysis, actual artificial intelligence using Entries, artificial intelligence and physical computing. As a result of the survey on the educational effect after the application of the curriculum, it was found that the students preferred the use of the Entry AI block and the use of the Blacksmith board as a physical computing tool as the priority applied to the elementary education field. In addition, the data analysis area is effective in linking math data and graph education. As a physical computing tool, Husky Lens is useful for scalability by using image processing functions for self-driving car maker education. Suggestions for desirable AI education include training courses by level and reinforcement of data collection and analysis education.