• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.50-55
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• 2014

Recently, importance of digital forensics has increased and using analysis methods of digital evidence in the analysis of evidence of various types. However, analysis time and effort is steadily increasing because personal disk capacity is too big and it has many number of files. Most digital evidence has time property, such as access time, creation time, and modification time. These time information of digital evidence is one of most important factors in the digital forensic area. But if digital examiner simply analyze based on binary source only, it is possible to have wrong result because time has various types. In this paper, we classify various type of time in the digital evidence and describe advanced analysis method based on timeline chart for digital forensic investigation.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.04a
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• pp.142-145
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• 1986

The traffic characteristics of digital switch network depend on the structure, blocking probability, path searching method and etc. This paper presents the study of TDX-1 switch network traffic capacity by considering some decisive factors such as call processing software, switch network structure and control scheme. Conclusively the study shows that the switch network of TDX-1 can handle approximatly up to 1650 Erlang.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.665-672
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• 2000

This paper described the measurement technology to analyze the partial discharge characteristics for long term aging of insulations. This system was consisted of high voltage generation and measurement part, PD detection part, digital conversion and signal processing part. We used the VXI system for digital conversion and signal processing part. In the digital conversion part, we studied the error of partial discharge magnitude and memory capacity for reading digital signal with the sampling rate. In the signal processing part, we showed the program algorithm to count pulses and read peak values of partial discharge. The allowable minimum sampling rate of digizer was decided to 250kS/s through analyzing test. We confirmed that this system was very useful in the study of $\phi-q-n$ characteristics of long term PD experiments with specimens being consisted of internal void defects and CIGRE II electrodes.

• Journal of Korea Multimedia Society
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• v.8 no.8
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• pp.1023-1031
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• 2005

LBS(Location Based Service) and GIS (Geographic Information System) are supporting necessary services for system which provides geographic information using location information based on various platforms. However the mobile computing environments such as PDA system have serious limitations in functional viewpoints compare of general computing environments, it has problems for developing GIS system which is providing various information. In this paper, we suggest the reduced methods of digital map and format of web-linked digital mao in order to fit in mobile environment. As a result of map generation, the total capacity of the supported digital map was diminished about $99.34\%$ than the original map.

• Journal of Digital Contents Society
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• v.17 no.6
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• pp.471-477
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• 2016

ICT capacity building education in developing countries with poor infrastructure is a solution to help solve ICT gaps and improve economic performance. However, there is a clear difference between countries' geographical and industrial level in terms of geographical and industrial aspects. Therefore, it is necessary to design customized educational contents for each country according to the status of various industries in each country rather than uniform and unilateral ICT capacity building education. This should be followed by a basic understanding of the current situation. The purpose of this study is to identify the level of ICT technology and curricula for female students at Life University of Cambodia among developing countries, and to find out the subjects related to industry in that region and to propose policies for continuous operation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.39-46
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• 2005

The present study concerns an experimental study of a R-22 heat pump system consisted of liquid and liquid heat exchangers. The test was performed for various systems of a single-, tandem-, and two stage-cycle at the same environmental conditions of temperature. Various experiments of the heat pump system were peformed to compare the heating capacity and COP, when the outdoor temperature is near $-15^{\circ}C$ and the indoor temperature is $20^{\circ}C.$ As the results of the present study, the system of Tandem(parallel) cycle showed the best heating performance, while the discharge temperature of refrigerant was too high. In case of the system of two stage cycle, the performance characteristics were significantly improved by employing the inter cooler.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1260-1263
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time. Today any data storage system cannot satisfy these conditions, however holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System can be constructed without mechanical actuating part therefore fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this research, to reduce errors of binary data stored in holographic data storage system, a new method for bit error reduction is suggested. First, find fuzzy rule using experimental system for Element of Holographic Digital Data System. Second, make fuzzy rule table using Genetic algorithm. Third, reduce prior error element and recording Digital Data. Recording ratio and reconstruction ratio will be very good performance

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.19-26
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• 2009

Recently, the Main Memory DBMS is gradually being expanded by the appearance of a large capacity of a Main Memory System, the increase in business area where it requires a real time process, and the rise of the users' required level. The Main Memory DBMS, which is able to go through a large capacity data process of the disk-based DBMS and guarantees a high efficiency, has domestically developed and has been put to a practical use. This paper presents an examination of the applied technologies and the limits of Altibase system, which is Main Memory DBMS. Moreover, it evaluated and performed a comparative analysis on the performance level of the Main Memory DBMS and the disk-based DBMS based on the same application. After five trials of the experiment based on the operating application, it was confirmed that the performance level of the Main Memory DBMS is enhanced and is higher by 4.13 to 7.89 times than the disk-based DBMS.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.184-188
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• 2008

It has been recognized that friction coefficient decreased with decreasing viscosity of oil in lubrication. In general, the more viscosity decreases, the more wear rate increases due to decrease load carrying capacity. It has been proposed that nano particles in oil decrease friction coefficient and wear rate. The purpose of this study is to apply oil of lower viscosity that mix with nano particles at the compressor used in a refrigerator to decrease friction coefficient keeping Load carrying capacity. Mineral oil of 8 cSt were used and mixed with nano particle. Friction coefficient was evaluated by a disk-on-disk tester. As a result, friction coefficient of nano oil decreased by 90% in comparison with raw oil. These results lead us to the conclusion that nano oil is new plan to raise efficiency of the compressor.

• Journal of Digital Convergence
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• v.8 no.2
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• pp.29-42
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• 2010

To improve the performance of R&D investments, government has taken great efforts for advancing the structure and process in R&D systems. However, due to the drastic internal/external changes in the technological environment and the steady increase of investment scale, the necessity for a innovative approach which accomplishes returns to scale through the utilization of various external resources is emerging. In this regard, open innovation approach can minimize the possibility of government failures by strengthening the absorptive capacity of external resources and enhancing the cooperation and participation of diverse innovative participants within the R&D system. This paper evaluates the previous researches and government policies concerning the performances of government R&D investments, and presents the connectivity between open innovation and its possible contribution to the improvement of R&D investment performances.