• 한국도시철도학회논문집
• /
• 제6권4호
• /
• pp.279-286
• /
• 2018

최근 열차운행의 안전을 실시간으로 감시하고 통제를 통해 사고 및 위험을 예방하는 안전관제 플랫폼의 연구가 진행 중에 있다. 초기 설계에서 기존 분산된 안전 데이터의 통합에 따른 대용량 데이터의 실시간 처리를 위하여 분산 네트워크를 지원하는 DDS통신 방식을 채택하였으나, 안전관제 플랫폼 내부의 서버와 콘솔 간 통신은 기존의 TCP소켓통신을 그대로 적용하였다. TCP소켓통신의 경우 1대1 통신으로 안전관제 테스트베드의 소규모 시스템을 위한 데이터 처리는 가능하지만, 추후 전국으로 확대되면 방대한 데이터로 인해 통신 트래픽이 발생하는 경우 대처가 어렵게 된다. 본 논문에서는 안전관제 플랫폼의 서버와 콘솔 간 인터페이스 방식을 분산네트워크를 지원하는 DDS통신으로 제안하였으며, TCP소켓방식과 DDS방식의 데모를 구현하고 처리량 및 속도 비교 분석을 수행하였다. 그 결과, DDS통신을 적용하는 경우 향후 변경될 수 있는 시스템에 대비하여 확장성과 유연성이 개선된다는 사실을 도출하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제18권4호
• /
• pp.922-937
• /
• 2024

Maritime activities are on the rise, there is a growing demand for high-quality communication services that can cover larger areas. However, the transmission of high data rates to maritime users is challenging due to path loss from land base stations, which limits the transmission power. To overcome this challenge, researchers have been exploring the use of buoys in a marine environment as relays for communication technology. This paper proposes a simulation-based approach to investigate the impact of various beamwidths on communication performance when using a buoy as a relay. The objective is to determine the optimal beamwidth that yields the highest data rate for the target location. The approach is based on an offshore wave model where the direction of the buoy changes according to the height of the wave. The study investigates the performance of the relay in the downlink situation using receive beamforming, and the capacity at the user in the three-hop situation is verified using an amplify-and-forward (AF) relay that uses transmit beamforming to the user. The simulation results suggest that the beamwidth of the relay should be adjusted according to the wave conditions to optimize the data rate and relay position that satisfies a data rate superior to the direct path to the target position. Using a buoy as a relay can be a promising solution for enhancing maritime communications, and the simulation-based approach proposed in this paper can provide insights into how to optimize beamwidth for effective communication system design and implementation. In conclusion, the study results suggest that the use of buoys as relays for maritime communication is a feasible solution for expanding coverage and enhancing communication quality. The proposed simulation-based approach provides a useful tool for identifying relay beamwidths for achieving higher data rates in different wave conditions. These findings have significant implications for the design and deployment of communication systems in maritime environments.

• Journal of Information Processing Systems
• /
• 제15권1호
• /
• pp.1-6
• /
• 2019

Recently, big data and artificial intelligence (AI) based on communication systems have become one of the hottest issues in the technology sector, and methods of analyzing big data using AI approaches are now considered essential. This paper presents diverse paradigms to subjects which deal with diverse research areas, such as image segmentation, fingerprint matching, human tracking techniques, malware distribution networks, methods of intrusion detection, digital image watermarking, wireless sensor networks, probabilistic neural networks, query processing of encrypted data, the semantic web, decision-making, software engineering, and so on.

• International Journal of Contents
• /
• 제13권1호
• /
• pp.31-37
• /
• 2017

Using the network analysis method, this study investigates the communication structure of Open Data on the Twitter sphere. It addresses the communication path by mapping influential activities and comparing the contents of tweets about Open Data. In the years 2015 and 2016, the NodeXL software was applied to collect tweets from the Twitter network, containing the term "opendata". The structural patterns of social media communication were analyzed through several network characteristics. The results indicate that the most common activities on the Twitter network are related to the subjects such as new applications and new technologies in Open Data. The study is the first to focus on the structural and informational pattern of Open Data based on social network analysis and content analysis. It will help researchers, activists, and policy-makers to come up with a major realization of the pattern of Open Data through Twitter.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2015년도 춘계 종합학술대회 논문집
• /
• pp.33-34
• /
• 2015

Continuous improvements of network infrastructures and mobile data offloading strategies are among the solutions of cellular providers to cope with the increase in mobile data demand. These options requires a lot of cost and time to implement. Few researches have been conducted to assess the applicability of Pocket Switched Network (PSN) to support mobile data offloading. In this paper, we present a PSN mobile data-offloading scheme that utilizes mobile users with available connectivity to deliver content-aware data to other mobile users. This paper also aims to evaluate the applicability and feasibility of PSN routing schemes to improve the current strategies in mobile data offloading. The simulation results show admirable results in terms of message delivery and latency.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2007년도 하계종합학술대회 논문집
• /
• pp.133-134
• /
• 2007

The effective data processing mechanism in the sensor network means data stream model and real-time query processing model for real-time processing of stream data. This mechanism can improve satisfaction of users and reduce delay rate of data processing. In this paper, we explain the problem which is occurred when users need to search certain information among information of stream data and describe reduction model of delay rate according to data transmission.

• International Journal of Internet, Broadcasting and Communication
• /
• 제13권3호
• /
• pp.25-33
• /
• 2021

Energy-harvesting wireless sensor networks(EH-WSNs) can collect energy from the environment and overcome the technical limitations of existing power. Since the transmission distance in a wireless sensor network is limited, the data are delivered to the destination node through multi-hop routing. In EH-WSNs, the routing protocol should consider the power situations of nodes, which is determined by the remaining power and energy-harvesting rate. In addition, in applications such as environmental monitoring, when there are urgent data, the routing protocol should be able to transmit it stably and quickly. This paper proposes an adaptive routing protocol that satisfies different requirements of normal and urgent data. To extend network lifetime, the proposed routing protocol reduces power imbalance for normal data and also minimizes transmission latency by controlling the transmission power for urgent data. Simulation results show that the proposed adaptive routing can improve network lifetime by mitigating the power imbalance and greatly reduce the transmission delay of urgent data.

• International journal of advanced smart convergence
• /
• 제12권3호
• /
• pp.13-18
• /
• 2023

This paper aims to investigate data features for neighbor path selection (NPS) in computer network with regional failures. It is necessary to find an available alternate communication path in advance when regional failures due to earthquakes or forest fires occur simultaneously. We describe previous general heuristics and simulation heuristic to solve the NPS problem in the regional fault network. The data features of general heuristics using proximity and sharing factor and the data features of simulation heuristic using machine learning are explained through examples. Simulation heuristic may be better than general heuristics in terms of communication success. However, additional data features are necessary in order to apply the simulation heuristic to the real environment. We propose novel data features for NPS in computer network with regional failures and Keras modeling for computing the communication success probability of candidate neighbor path.

• Journal of Advanced Marine Engineering and Technology
• /
• 제36권1호
• /
• pp.179-184
• /
• 2012

기존의 무선 RF 통신은 근거리에서 전력손실이 상대적으로 크고, 전파간섭 및 방해, 재밍 등에 민감하다. 이러한 단점을 보완하는 대안으로 자외선을 이용한 통신 방식에 대한 연구가 최근 관심을 받고 있다. 본 논문에서 자외선을 이용한 비가시거리 통신의 data rate 특성에 대해 시뮬레이션한 결과를 제시하였다. On-off keying 방식을 사용하는 비가시거리 자외선 통신에서 data rate는 송신 빔의 방향, 수신빔의 빔 폭, 송신 전력에 의해 큰 영향을 받는다는 것을 확인하였다.

• 한국군사과학기술학회지
• /
• 제10권1호
• /
• pp.44-54
• /
• 2007

In the military field, according to the MIL-STD-188-220, which is an Ad-Hoc communication protocol used for sending out or receiving data and voice smoothly among nodes in the situation that wireless communication nodes move arbitrarily, data communication is cut off because nodes can not know topology changes perpetually in the link disconnection state due to node movement in the case that transmitters do not confirm whether data is delivered to receivers or not, and transmit only the data having routine precedence continuously. In order to solve this problem, we have proposed the technique that makes efficient data communication possible by achieving a rapid topology change detection and link information update using TEST frame. We have analyzed TEST frame application effects in the two aspects of the topology update delay time and the data transmission success ratio.