• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.524-526
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• 2022

Considering QoS only considering real-time multimedia service, it is possible to adjust the number of terminals and ensure them appropriately, but this study considers complex services considering real-time multimedia service and general data service. Since the amount of physical network resources is limited, the guarantee of the desired QoS can not be achieved unless the appropriate CAC is done. However, given the traffic profile and QoS spec of the entire network resource and the current service being provided, and the traffic profile and QoS spec of the newly requested service, it is quite difficult to determine exactly whether the new service request is acceptable from this. To do this, it is necessary to study in various directions from mathematical analysis to various simulations and statistical research based on data obtained from actual network operation.

• Journal of Information Technology and Architecture
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• v.11 no.1
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• pp.11-23
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• 2014

Kill Chain is getting attention due to North Korea's recent nuclear test and missile launches and has emerged the need for an early build up. In order to build a materialized kill chain, you should review the unique kill chain to support operations effectively using various sensors and striking weapon system. Especially, you need a suitable network to reduce a reaction time against the enemy attack under joint operations environment etc. Currently there are many communication ways(e.g. data link, voice, video and text message) used in operations through satellite, wired and wireless and so on. Now, this paper contains analysis on various means for target information exchange which are used in the kill chain. And appropriate network of the kill chain for target information transmission is addressed to confirm feasibility of its alternatives, which is developed using AHP(Analytic Hierarchy Process). Finally, this paper is suggesting network and means of its building up for target information transmission of kill chain which can be implemented under the situation of joint battle field.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.106-114
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• 2015

Despite a series of various developments in underwater acoustic sensor networks, there are still occasions of loss of connection over the network. Because sufficient amounts of drawbacks causing disconnections posed particularly in the middle of connection over the network emerge in the ocean environment, there is a need of new testing mechanism for underwater acoustic networks. In this paper, we proposed to investigate the most vital parts of the network deployment whether they function well in order, without any failure so as to identify where exactly communication process problems and failures are. We introduce step-wised out-test mechanism for UWASNS and accomplished the mechanism by implementing experiments and rigorously checked all the underwater devices utilizing out-test function. Experimental results and out-test function are evinced by implementing, in order to explain our system and conclude with possible future improvements.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.1-7
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• 2020

The demand on the underwater communications is extremely increasing in searching for underwater resources, marine expedition, or environmental researches, yet there are many problems with the wireless communications because of the characteristics of the underwater environments. Especially, with the underwater wireless networks, there happen inevitable delay time and spacial inequality due to the distances between the nodes. To solve these problems, this paper suggests a new solution based on ALOHA-Q. The suggested method use random NAV value. and Environments take reward through communications success or fail. After then, The environments setting NAV value from reward. This model minimizes usage of energy and computing resources under the underwater wireless networks, and learns and setting NAV values through intense learning. The results of the simulations show that NAV values can be environmentally adopted and select best value to the circumstances, so the problems which are unnecessary delay times and spacial inequality can be solved. Result of simulations, NAV time decreasing 17.5% compared with original NAV.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.86-93
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• 2010

RFID has been used as an identification tool that substitutes for bar codes. Its areas of application are increasing due to its suitability in ubiquitous environment. In this paper, first, we review various aspects of RFID, including standards, characteristics, and relationships with wireless sensor networks. Then, we review the technical aspects of RFID and its areas of application, e.g., supply chain management (SCM) and manufacturing since 2005. SCM, in which RFIDs can shorten lead time and ensure the quality of products, is one of the most active application areas. Manufacturing is a relatively new area for RFID applications, but it is believed that it can enhance the productivity and the reliability of the products. Also, the authors suggest research issues and limitations of RFID, as well as possible application areas related to marine engineering.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.957-968
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• 2021

To improve the data on reliability of the onshore fish farm water quality monitoring system and operate the system efficiently, the water quality data of the onshore seawater fish farms which are progressing test operation, and the marine environmental information network(Wando tidal station) were compared and analyzed. Furthermore, data validation, data range filters, and data displacement checks were applied to analyze the data in a way that eliminates the data errors in water quality monitoring systems and increases the reliability of measurement data.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.111-112
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• 2022

자율운항 선박, 무인선 개발과 동 분야 디지털트윈 구현을 위해서는 선박 내부 데이터의 수집을 담당할 고신뢰성 선내 통신망 확보가 필수적이다. WiFi와 같은 전파 기반의 무선통신 시스템은 금속 구조물로 구성되는 선박 내 환경 자체가 원활한 통신의 장애 요소이다. 이러한 극한 환경 극복을 위해 자기장을 금속 표면에 유기하여 비 전파 기반으로 무선통신을 가능하게 하는 표면파 통신이 대안이 될 수 있다. 선박 전체의 일반 배치 관점에서 표면파 통신은 상갑판을 통해 크게 거주구역, 화물구역, 선수구역 및 기관구역 간 백본 통신망을 구성할 수 있으며 각 구역 별로는 부재의 개구부를 통해 금속 표면의 연속면을 확보하여 통신할 수 있다. 수밀 격벽의 표면파 통신 관통을 위해 비 도전체로 수밀은 유지한 채 아주 미세한 구멍을 확보하는 것으로도 금속 표면의 연속성을 확보할 수 있다. 이러한 표면파 통신을 활용하면 전파 기반의 무선통신, 비 전파 기반의 무선통신을 통합적으로 구성하여 선박 전체로는 선내 무선 백본망 구성, 그리고 각 구역 별로는 IoT 센서 네트워크 등의 선박 내부 고신뢰성 무선통신 확보가 가능하다.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.79-86
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• 2006

Data transmission in poor environment like underwater has considerably serious delay rate and ewer rate. Like this environment usually has heavy fluctuation of error rate and limited wireless communication state. Therefore, mechanism using in such environment has to be efficient and simple. This paper suggests a new block ack mechanism, called the Pervasive Block ACK (PBA), which transmits aggregated ACKs. This mechanism takes effect on reducing number of traffic, decreasing overhead and delay rate in poor environment networks like underwater. Additionally, we can expect energy consumption. We verify propriety and efficiency of PBA through describing numerical result based analytical formula in this paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.527-528
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• 2022

It is not easy to identify the location of mobile terminals based on drones in the mountainous area, the densely populated urban area, or the space where mobile terminals can easily move by using equipments or modules that can recognize the location of sensors or mobile terminals with LBS (Location-Based Service). However, although the performance of GPS has developed due to the development of technology, it is still widely used in position recognition systems using GPS modules in the sea and onshore, and there is much room for more utilization. Currently, most of the existing sensor networks need to send at least three location information messages to mobile terminals with location information that a plurality of mobile base stations depend on GPS. However, location recognition of mobile repeaters that maintain a certain movement speed using acceleration sensors is necessary for efficient communication network connection.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.563-572
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• 2020

Tidal flats provide important indicators that inform the condition of the environment, so we need to monitor them systematically. Currently, the projects to monitor tidal flats by periodically observing the creatures in tidal flats are underway. Still, it is done in a way that people observe directly, so it is not systematic and efficient. In this paper, we propose a background modeling method for tidal flat images that can be applied to a system that automatically monitors creatures living in tidal flats using sensor network technology. The application of sensor network technology makes it difficult to collect enough images due to the limitation of transmission capacity. Therefore, in this paper, we propose a method to effectively model the background and generate foreground maps by reflecting the characteristics of tidal flat images in the situation where the number of images to be used for analysis is small. Experimental results show that the proposed method models the background of a tidal flat image easily and accurately.