• Journal of Welding and Joining
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• v.26 no.1
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• pp.63-68
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• 2008

This paper has aimed to prevent excessive heat input by controlling arc distribution and heat input capacity with pulse GTAW in order to improve weld quality in 0.08mm pressure gauge diaphragm and flange welding parts. A design of experiment was designed using Box-Behnken method to optimize a welding process. The pulse GTAW parameters such as pulse current, base current, pulse duty, frequency and welding speed were set to input variables while hydraulic pressure that represents welding characteristics in diaphragm and flange joint were set to output variables. Based on the test result, a second regression equation was obtained between input and output variables and turned out significant. Besides, an influence of parameters has been confirmed through response surface analysis using the second-order regression equation and optimum welding condition was obtained through a grid-search method. The optimum welding condition was set to pulse current 84.4(A), base current 29.6(A), pulse duty 58.8(%), frequency 10(%), and welding speed 596(mm/min). Then, decent bead shape was acquired with no excessive heat input under the $2.3kgf/cm^2$ of hydrostatic pressure.

• Journal of KIISE
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• v.44 no.5
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• pp.553-558
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• 2017

With the rapid growth of Big Data, research on extracting meaningful information is being pursued by both academia and industry. Especially, data characteristics derived from analysis, and researcher intention are key factors for search algorithms to obtain accurate output. Therefore, reflecting both data characteristics and researcher intention properly is the final goal of data analysis research. The data analyzed properly can help users to increase loyalty to the service provided by company, and to utilize information more effectively and efficiently. In this paper, we explore various methods of document-evaluation, so that we can improve the accuracy of searching article one of the most frequently searches used in real life. We also analyze the experiment result, and suggest the proper manners to use various methods.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.779-788
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• 2017

In this study, we analyzed the changes in the echolocation and prey-capture behavior of the horseshoe bat Rhinolophus ferrumequinum from search phase to capture time. The experiment was conducted in an indoor free-flight room fitted with an ultra-high-speed camera. We found that the bats searched for food while hanging from a structure, and capturing was carried out using the flight membrane. In addition, it was confirmed that the mouth and uropatagium were continuously used in tandem during the capturing process. Furthermore, using Constant Frequency (CF), we confirmed that the prey catching method reflected the wing morphology and echolocation pattern of R. ferrumequinum. The echolocation analysis revealed that the pulse duration, pulse interval, peak frequency, start-FM-bandwidth, and CF duration decreased as the search phase approached the terminal phase. Detailed analysis of echolocation pulse showed that the end-FM bandwidth, which increases as it gets nearer to the capture time of prey, was closely related to the accurate grasp of the location of an insect. At the final moment of prey capture, the passive listening that stopped the divergence of the echolocation was identified; this was determined to be the process of minimizing the interruption from the echo of the echolocation call emitted from the bat itself and sound waves emitted from the prey.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.955-969
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• 2019

Analyzing on-line consumer responses is directly related to the management performance of food companies. Therefore, this study collected and analyzed data from an on-line portal site created by consumers about food companies with issues and examined the relationships between the data and the management performance. Through this process, we identified consumers' awareness of these companies obtained from big data analysis and analyzed the relationship between the results and the sales and stock prices of the companies through a time-series graph and correlation analysis. The results of this study were as follows. First, the result of the text mining analysis suggests that consumers respond more sensitively to negative issues than to positive issues. Second, the emotional analysis showed that companies' ethics issues (Enterprise 3 and 4) have a higher level of emotional continuity than that of food safety issues. It can be interpreted that the problem of ethical management has great influence on consumers' purchasing behavior. Finally, In the case of all negative food issues, the number of word frequency and emotional scores showed opposite trends. As a result of the correlation analysis, there was a correlation between word frequency and stock price in the case of all negative food issues and also between emotional scores and stock price. Recently, studies using big data analytics have been conducted in various fields. Therefore, based on this research, it is expected that studies using big data analytics will be done in the agricultural field.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6A
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• pp.584-591
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• 2002

In this paper, we proposed a b1ocking artifact reduction algorithm using similarity and linear combination between blocks. In the proposed method, all of the blocks are classified into low frequency block and high frequency block according to the their DCT coefficients. And we defined range block which shows blocking artifacts, as block centered to block boundary and defied domain block as similar block with range block within search range. In the search procedure, we used sub-block's property of range block and similarity for more accurate searching. Finally blocking artifact reduction algorithm is performed using linear combination between searched domain block and blocky range block. The performance of the proposed method is investigated by computer simulation in comparison with the traditional methods. In the experimental results, Ire confirmed the better performance in the subjective by 0.04∼0.4 dB and objective image quality.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.1-9
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• 2005

In this paper, we suggest multi colony interaction ant reinforcement learning model. This method is a hybrid of multi colony interaction by elite strategy and reinforcement teaming applying Temporal Difference(TD) learning to Ant-Q loaming. Proposed model is consisted of some independent AS colonies, and interaction achieves search according to elite strategy(Intensification, Diversification strategy) between the colonies. Intensification strategy enables to select of good path to use heuristic information of other agent colony. This makes to select the high frequency of the visit of a edge by agents through positive interaction of between the colonies. Diversification strategy makes to escape selection of the high frequency of the visit of a edge by agents achieve negative interaction by search information of other agent colony. Through this strategies, we could know that proposed reinforcement loaming method converges faster to optimal solution than original ACS and Ant-Q.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11B
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• pp.1013-1019
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• 2008

Recently, various information and data are efficiently used by the rapid growth of its Internet in our real life. But, users have spent lots of time finding necessary information for the increased amounts of information. To solve this problem, it can be provided the speed, accuracy of information search with development of intelligent search engines, agent system etc. In this paper, we propose the method of getting the best tender price in the analysis of the construction bid information that needs its professionalism by on the purpose to maximize users' satisfaction. Of course, if it is not under the unit of a results in the future, we put target of this paper on part to heighten supreme successful bid success rate. Therefore, this paper embodies offered system of web based on producing tender price of most suitable through techniques to produce tender price about successful bid that compare with bidder fare by statistical analysis incidental and value approaching successful bidder fare by frequency analysis method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.195-202
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• 2011

RFID(Radio Frequency IDentification) is a system to identify objects and its usage is being extended to distribution, healthcare, and air&port etc. RFID is a contactless system environment, and reducing tag authentication time is important because multiple tags are identified at the same time. Studies about RFID system so far is, however, mostly to improve security vulnerability in the tag authentication process. Therefore, this paper suggests an efficient scheme to decrease the time of tag authentication which is also safe for the security of tag authentication process. The proposed scheme cuts down on the tag ID search time because it searches only the classified relevant ID in the database, which is one of many components of RFID system, by using identification bits for tag ID search. Consequently, the suggested scheme decreases process time for tag ID authentication by reducing the processing time and the load of the database. It also brings performance improvement of RFID system as it improves the energy applicability of passive tag.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.3
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• pp.373-384
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• 1999

The purposes of this study were 1) to test the differences between two groups who have high and low purchase of apparel in low-price retailing concerning consumers' beliefs and attitude toward low-prce retailing 2) to identify differences between these two groups in type of information search and use of information sources and 3) to investigate differences between department store and low-price retailing in consumers' satisfaction toward products and purchase frequencies of apparel items and differences between two groups in demographic variables. The data were collected via a self-administeered questionnaire from 474 femail adults in Seoul Korea and analyzed by factor analysis t-test and paired t-test. The results of this study were as follows : First based on a series of t-test and paired t-test. the results showed that those who had a high purchase of apparel in low-price retailing had significantly higher belief scores on all of the five store attributes and a more favorable attitude toward low-price retailing than did those who had low purchase. Second those who had high purchase of apparel in low-price retailing had significantly higher scores on ongoing and prepurchase information search and on use of mass media information and interpersonal information source than did those who had low purchase. Third in case of high purchase consumers of apparel in low-price retailing there were not found significant differences between department store and low-price retailing there were not found significant differences between department store and low-price retailing in purchase frequency on man's and women's casual wear of department stores than low-price retailing. However low purchase consumers of apparel in low-price retailing revealed significantly higher purchase frequency on all of seven apparel items of department stores than low-price retailing. Finally there were significant differences between two groups in demographic variables. The papers discussed theoretical implications as well as manageral implications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.6
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• pp.555-563
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• 2015

This paper presents signal processing algorithms of a frequency-modulated continuous-wave(FMCW) radar altimeter and provides a practical assessment technique. The radar altimeter is initially operated in search mode, when the radar altimeter detects a valid altitude, search mode is switched to track mode and a altitude being tracked is displayed. The sweep bandwidth in each mode is a function of altitude to narrow the beat frequency bandwidth. In addition, transmit power and receiver gain in each mode are controlled to compensate for the dynamic range of wide altitude range. To assess more realistic operation, the radar altimeter was tested using the crane setup. The crane test demonstrated that signal processing algorithms described in this paper resulted in a reduced measurement error rate.