• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.561-568
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• 2014

The Republic of Korea Army is using R-NAD of MIL-STD-188-220 as a Media Access Control protocol. Under urgent situations, almost all stations transmit data frames and then the network will reach a saturation state. Several articles have been devoted to the study of R-NAD performance. However, most of them focus on comparing the performance of some NADs using network simulation tools. We propose an analytical model to compute the throughput of R-NAD under the assumption of a network traffic saturation. Analytical results were verified by Monte Carlo methods. We have shown that the performance of a success probability and an average idle time remains almost unchanged as the total number of stations increases. We have also shown that Type 1/2/4 operation mode outperforms Type 3 operation mode in throughput. The results showed that the system with a squelch detection achieved a better performance than the one without it. The longer DATA time had a higher throughput.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.245-250
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• 2006

Organizations such as broadcasting stations and libraries which deal with huge amount of information require high-capacity storage systems for archiving their materials and information. It is necessary and urgent for the storage people to develop a compact, high capacity, and low-cost data storage systems. Even though the Blue-ray technology is commercialized and now it is on the market, demand for the compact and low-cost system is still increasing. A flexible disk system has been introduced recently to satisfy above mentioned requirements. The system uses multiple of thin disks and is expected to achieve technical requirements. However, decreasing the disk thickness makes it difficult to read and write data because it decreases the disk rigidity so that the transverse vibration of the rotating disk increases easily due to both the interaction with surrounding air and the vibration characteristics of thin flexible disk itself. In this study, flat-type stabilizer is proposed to suppress the transverse vibration of a $95{\mu}m$-thick polycarbonate disk. Characteristics of disk vibration have been studied through the results of numerical analysis from the fluid mechanics point of view. Numerical simulation is verified through the experiment by measuring the gap between the rotating disk and the stationary flat stabilizer. The axial deflections of the disk are computed for various rotating speeds and reference gap sizes and then a method of regression is applied to those data. As a result, an empirical relation is proposed for the steady deformation shape of the rotating disk.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.775-780
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• 2011

GPS, ARPA, AIS, NAVTEX, VHF as modern aids-to-navigation equipments improve the safe navigation and help to reach a reduction in marine accidents by providing images, numeric values, texts, audio-based information for mates, However, we also noticed that it's complicate and difficult for a mate to acquire and analyze such information from these devices while he should devote himself to bridge watchkeeping especially in the urgent situation. Language is another way to get information and free the eyes and hands, so, to solve the problem above, we are trying to propose a new aids-to-navigation system, which can understand and merge multimedia marine safety information, analyze the situation and provide the necessary information in language. In this paper, we try to fuse data of ARPA/AIS using Euclidean distance for providing integrated information.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.167-172
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• 2022

Currently, ship control, tug, and pilot work in import/export ports including Gwangyang Port are operated according to factors such as the order of arrival and departure regardless of the shipping company. Also, even this is done very inefficiently by hand. Therefore, there is an urgent need to develop a system to increase the efficiency of port and ship operation through standardization and digitalization of tasks related to Berthing and unberthing of ships. In this study, we propose a method to increase the efficiency of port and vessel operation by designing a smart port operation system based on big data such as vessel location information, pilotage and tug schedule, arrival/departure operation information, and weather information.

• The KIPS Transactions:PartA
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• v.18A no.6
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• pp.255-264
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• 2011

A sensor network is a special network that makes physical data sensed by sensor nodes and manages the data. The sensor network is a technology that can apply to many parts of field. It is very important to transmit the data to a user at real-time. The core of the sensor network is a sensor node and small operating system that works in the node. TinyOS developed by UC Berkeley is a sensor network operating system that used many parts of field. It is event-driven and component-based operating system. Basically, it uses non-preemptive scheduler. If an urgent task needs to be executed right away while another task is running, the urgent one must wait until another one is finished. Because of that property, it is hard to guarantee real-time requirement in TinyOS. According to recent study, Priority Level Scheduler, which can let one task preempt another task, was proposed in order to have fast response in TinyOS. It has restrictively 5 priorities, so a higher priority task can preempt a lower priority task. Therefore, this paper suggests Preemptive EDF(Earliest Deadline First) Scheduler that guarantees a real-time requirement and reduces average respond time of user tasks in TinyOS.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.31-37
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• 2017

Recently, governmental authority and local government are looking for a method of utilizing location information of smart phone for urgent rescue in fire and kidnap situation. Under this background, in this study, a method of rapidly collecting, constructing location determination based Wi-Fi AP data utilizing location information of smart phone and mobile mapping system was suggested in order to construct precise positioning information that could be utilized under urgent situation. By performing compensation work for GPS/INS/DMI through collected outcome, position of collected vehicle was acquired. In addition, source data integrating Wi-Fi information and collected position by coupling based on Wi-Fi AP collector and GPS time was constructed and Wi-Fi radiomap was constructed by removing Wi-Fi signal noise that reduces precise position performance. As a result of performing location determination performance assess ment by selecting 10 test positions by each local government, result value of 25.46cm for total local government average and 27.76m for SD could be obtained. It is considered that this result could be utilized as a technology of being able to supplement or substituting GPS location determination technology that is impossible in plocation determination of mobile communication company's base station (200m~2km) and indoor being used at present.

• Journal of Distribution Science
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• v.10 no.11
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• pp.61-70
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• 2012

Purpose - The entry of Super Supermarkets (SSM), operated by large corporations, into the retail distribution market weakens the competitive power of local supermarkets (SM) and their families leading to a rapid collapse of the local-SM market. Accordingly, this is a very sensitive and urgent issue in Korean society and politics. Therefore, the government is required to take steps to activate a local-SM market and regain the loyalty of their customers. However, in spite of the urgent need of a comparative study on the advantages and competitive power of local-SM in relation to the SSM, little research has been done on this issue to date. One purpose of this study is to analyze the differences in store characteristics of the local SM and SSM, and to explore the relationships amongst various store characteristics, such as consumption emotion, relation quality, and store loyalty between store types to provide an efficient solution to activate a local-SM market. Research design, data, methodology - To analyze the differences in the evaluation of store characteristics between store types, and to test the moderator and mediator effects, data were collected from 488 customers in Seoul, Incheon,and Gyeonggi Province. The theoretical model consists of four hypotheses, and data was processed to test these using factor analysis, t-test, regression analysis, hierarchical regression, and the three step regression proposed by Baron and Kenny. Results - First, the analysis shows that local-SM customers evaluate location characteristic factors significantly higher compared to SSM customers. However, SSM customers evaluate quality of merchandise, sales promotion activities, and store environment significantly higher. Yet, there are no significant differences in the evaluation of consumption emotion, relation quality,and store loyalty between the store types. Second, the analysis of moderator effects of the store type show that sales promotion and store atmosphere factors have a significantly negative moderating effecton positive consumption emotion, while positive consumption emotion has a significantly positive moderating effect on absorption of relation quality, while there are no significant moderating effects between consumption emotion and store loyalty. Third, while both trust and absorption of relation quality are partially mediated between consumption emotion and store loyalty, only absorption is partially mediated between positive consumption emotion and store loyalty. There are no significant mediating effects of absorption between negative consumption emotion and store loyalty. Conclusions - We strongly recommend that location restrictions on entrance of SSM into local-SM market should either be further strengthened or sustained for the activation of the local store market. Government should strengthen financial support to improve the quality of merchandise, sales promotion, employee education, store environment of the local-SM by providing appropriate business consulting. Moreover, the result implies that the owners of alocal-SM should take measures to increase customers' absorption and store loyalty, such as store cleanliness, maintaining a delightful atmosphere at the store, and training employees on attitudes towards customers. As this study is restricted within Seoul, Incheon, and Gyeonggi Province, care needs to be taken in generalizing the interpretation and application to the national level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.732-733
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• 2014

This study aims to examine the R&D trends on Big Data sector through patent analysis and to suggest directions of the R&D activities in Korea. According to the results of analysis, the R&D trends of Big Data sector have shown two characteristics. First, the US has monopolized the world market of Big Data Sector. The patent activities of US have shown relatively even throughout every technology. And the average share of each technology is over 40%. Second, the trends of R&D have been changed. In the past, data analysis and processing technologies were the mainstream, whereas data operations and management technologies are mainly featured. However, the patent applications in Korea have been concentrated on storage technologies, while the applications for data operations and management technologies are correspondingly low; therefore, it seemingly needs urgent research and development of relevant technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2354-2360
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• 2009

Healthcare is a field where ubiquitous computing is most widely used. We propose a mining-based healthcare multi-agent system for ubiquitous computing environments. This proposed scheme select diagnosis patterns using mining in the real-time biosignal data obtained from a patient's body. In addition, we classify them into normal, emergency and be ready for an emergency. This proposed scheme can deal with the enormous quantity of real-time sensing data and performs analysis and comparison between the data of patient's history and the real-time sensory data. We separate Association rule exploration into two data groups: one is the existing enormous quantity of medical history data. The other group is real-time sensory data which is collected from sensors measuring body temperature, blood pressure, pulse. Proposed system has advantage that can handle urgent situation in the far away area from hospital through PDA and mobile device. In addition, by monitoring condition of patient in a real time base, it shortens time and expense and supports medical service efficiently.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.377-381
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• 2006

The purpose of this study was to suggest the improvement plan for IAQ of the combined officetel and residence through analyzing demands, satisfaction, subjective symptoms and device of residents. For this study, the data was collected from 110 residents by questionnaire survey and an experienced planner by interview. The result showed that the IAQ improvement of the combined officetel and residence was urgent. The educational program about maintenance of IAQ for residents was essentially needed. To recommend eco-friendly materials in process of construction wasimportant so as to take precaution against ‘sick building syndrome'. It was also necessary to improve on the size and shape of ventilation window.