• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.64-68
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• 2010

In this paper, we studied the novel synchronization algorithm for cooperative communication system over fading. We research mainly on the decode-and-forward scheme. Also, we inserted spreading sequence in origin data frame to control efficiently data synchronization. In mobile station, inserted spreading sequence in data frame passed through the corelation process. We had decide the delay value of received data through result of correlation process. In simulation, We applied that channel gain of three node had different value in various fading environment. Finally we will be possible to control the received data synchronization using result of corelation value in each node between relay to mobile station and base station to mobile station. The results of this paper can be applicable to the cooperative systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.12-23
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• 2014

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

• ETRI Journal
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• v.32 no.3
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• pp.440-446
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• 2010

Array-based gas sensors now offer the potential of a robust analytical approach to odor measurement for medical use. We are developing a fast reliable method for detection of microbial infection by monitoring the headspace from the infected wound. In this paper, we present initial results obtained from wound-state monitoring for burn patients using an electronic nose incorporating an automated solid-phase microextraction (SPME) desorption system to enable the system to be used for clinical validation. SPME preconcentration is used for sampling of the headspace air and the response of the sensor module to variable concentrations of volatiles emitted from SPME fiber is evaluated. Gas chromatography-mass spectrometry studies prove that living bacteria, the typical infectious agents in clinical practice, can be distinguished from each other by means of a limited set of key volatile products. Principal component analysis results give the first indication that infected patients may be distinguished from uninfected patients. Microbial laboratory analysis using clinical samples verifies the performance of the system.

• The Journal of Fisheries Business Administration
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• v.45 no.2
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• pp.1-13
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• 2014

This study analyzes patent trends regarding farming-related technologies such as breeding or nursery technology, production systems, and new cultivation methods in order to provide objective patent information about the trends of R&D on marine products' proliferation or farming. Presently, in Korea, we try to secure marine living resources through the formation of artificial resources instead of environmental improvement policy or resource management policy. However, this is not about eliminating the causes of marine environment destruction but just the policy for improvement, so it is needed to revise the related policy with more ultimate measures. And it is necessary to develop technology that can secure the rights by integrating patent application strategies from the stage of R&D for medicine that can be utilized in chief farming countries and provide intensive support for the research centering around strategic varieties for farming in each region as well as strategic national farming varieties afterwards. Also, the analysis shows that it is urgent to make applications overseas based on domestic applications in order to develop technology that can be commercialized in not just Korean but overseas market as well.

• Journal of National Security and Military Science
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• s.2
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• pp.237-260
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• 2004

As the research work about XML based on the development of Internet and according to the information exchange standard is being carried out, the need of discovering new methods to store XML documents and manage them efficiently according to the frequency of large-capacity XML documents increases. Consequently, as a kind of back-end database system, XML storage systems such as RDBMS, OODBMS and Native XML DBMS etc. are coming forth in order to save XML documents. It is an urgent task to make comparisons among usage expense, function comparison storage, inquiry, and manage dimension for each DBMS. This paper makes an analysis and comparison of DTD-independent XML document access methods in RDBMS, OODBMS and Native XML DBMS for XML storage and management. After analyzing the advantages and disadvantages of each access method and comparing the function of typical commerce DBMS such as Oracle 8i, eXcelon and Tamino for finding the possibility of military applications, an another appropriate method to save XML documents is proposed as to find an implementation approach to save structural XML documents.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.9-15
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• 2018

This study is intended to investigate that it is possible to analyze the public awareness and satisfaction of the weather forecast service provided by the Korea Meteorological Administration (KMA) through social media data as a way to overcome limitations of the questionnaire-based survey in the previous research. Sentiment analysis and association rule mining were used for Twitter data containing opinions about the weather forecast service. As a result of sentiment analysis, the frequency of negative opinions was very high, about 75%, relative to positive opinions because of the nature of public services. The detailed analysis shows that a large portion of users are dissatisfied with precipitation forecast and that it is needed to analyze the two kinds of error types of the precipitation forecast, namely, 'False alarm' and 'Miss' in more detail. Therefore, association rule mining was performed on negative tweets for each of these error types. As a result, it was found that a considerable number of complaints occurred when preventive actions were useless because the forecast predicting rain had a 'False alarm' error. In addition, this study found that people's dissatisfaction increased when they experienced inconveniences due to either unpredictable high winds and heavy rains in summer or severe cold in winter, which were missed by weather forecast. This study suggests that the analysis of social media data can provide detailed information about forecast users' opinion in almost real time, which is impossible through survey or interview.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.276-281
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• 2010

In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.

• Human Ecology Research
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• v.55 no.4
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• pp.351-362
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• 2017

Collaborative consumption (CC) occurs in organized systems or networks in which participants conduct sharing activities in the form of renting, lending, trading, bartering, and swapping of goods, services, transportation solutions, space, or money. Information and communications technologies (ICTs) that have emerged with CC. CC is expected to alleviate social problems such as hyper-consumption, pollution, and poverty by lowering the cost of economic coordination. In this study, we investigate the influence of educational experience and expected benefits of CC participation (intended to using and providing CC) of Adolescent Consumers. The subjects for the study were 418 high school students. Data was analyzed through frequency analysis, mean, standard deviation, t-test, ANOVA, Pearson's correlation, and hierarchical multiple regression analysis using SPSS Win 21.0. The results of this study are as follows. First, the significant positive relationship found between CC participants (intent to use and provide CC), educational experience (home education, school education, and mass media) and expected benefits (social benefit, economic benefit, enjoyment, community effect, and reputation). Second, enjoyment, mass media, reputation, social benefit, home education and school education values were variables that influenced the using participation intention for CC. Third, the major variables influencing the providing participation intention CC were home education, enjoyment, gender, community effect, and mass media values.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.10
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• pp.421-426
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• 2013

As a greater amount of traffic have been generated on the Internet, it becomes more important to know the size of each flow. Many research studies have been conducted on the traffic measurement, and mostly they have focused on how to increase the measurement accuracy with a limited amount of memory. In this paper, we propose an explicit flow labeling technique that can be used to find out the names of the top flows and to increase the counting upper bound of the existing scheme. The labeling technique is applied to CSM (Counter Sharing Method), the most recent traffic measurement algorithm, and the performance is evaluated using the CAIDA dataset.

• Journal of Information Display
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• v.2 no.4
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• pp.1-7
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• 2001

This paper investigates the characteristics of a newly developed high density hollow cathode plasma(HCP) system and its application for the etching of silicon wafers. We used $SF_6$ and $O_2$ gases in the HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}cm^{-3}$ at a discharge current of 20 rna, Silicon etch rate of 1.3 ${\mu}m$/min was achieved with $SF_6/O_2$ plasma conditions of total gas pressure of 50 mTorr, gas flow rate of 40 seem, and RF power of200W. This paper presents surface etching characteristics on a crystalline silicon wafer and large area cast type multicrystlline silicon wafer. We obtained field emitter tips size of less than 0.1 ${\mu}m$ without any photomask step as well as with a conventional photolithography. Our experimental results can be applied to various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this research, we studied silicon etching properties by using the hollow cathode plasma system.