• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.523-531
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• 2018

An analysis technique for detecting moving targets on a single-channel airborne frequency-modulated continuous-wave (FMCW) technology and synthetic aperture radar (SAR) image is presented. To analyze the relative velocities of moving targets, an FMCW-based signal model for stationary and moving targets was studied, and a SAR ambiguity function considering its signal model was simulated. The relative velocities of the moving targets on a reconstructed SAR image can be estimated by peak searching of the SAR ambiguity function, and the stationary and moving targets are easily distinguished when there is a large variation of the relative velocity. Analysis results of the moving targets on a reconstructed FMCW-SAR image, using practical airborne data and a SAR ambiguity process, are compared with the in situ testing in the study area.

• Journal of the Korean Society of Costume
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• v.59 no.5
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• pp.71-82
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• 2009

The purpose of this study is to help understanding of patterns and to play a guideline's role in the development of designs and the prediction of trends for present and future fashion designers and textile designers. The methods of this study are the study of academic literatures as well as practical study through the analysis about actual works. The results of study are like followings. An inquiry of Pattern history in 20c is divided into six periods by the classification of styles and the styles of fashion culture according to other artistic formative will. Main trends of Pattern's image in each period and characteristics in each dimensions of Pattern image positioning are like followings. Art Nouveau style period from 1900 to 1910 is , Art Deco style period from 1910 to 1920 is , Elegance style period of 1930s is , and New Romantic style period from 1945 to mid 1950s and Pop style period from late 1950s to mid 1970s does not show main Pattern image but they are shown in four Pattern image of , , , . Compromising style period from late 1980s to 1990s shows all of four Pattern image, at the same time shows intensive main Pattern's image, .

• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.409-416
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• 2007

The ambiguity and performance of range measurement for COMS using tone standard was analyzed with assuming that satellite is operating at transfer-station and on-station. From the results of analysis, it was shown that the ambiguity was reduced when low frequency ratio between tone signals and large number of minor tones are applied. It was also found that using the narrow noise bandwidth leads to decrease the ambiguity. As a result, required performance of range measurement for COMS can be satisfied when the noise bandwidth is set as 2Hz for transfer-station and 1Hz for on-station, respectively.

• Journal of KSNVE
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• v.7 no.5
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• pp.747-756
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• 1997

Wigner-Ville distribution which is a time-frequency analysis has a fatal drawback, when the signal has multiple components. This is the cross-talk and often causes a neagative value in the distribution. Wingner-Ville distriution is an expression of power, therefore the cross-talk must be avoided. Smoothing the Wigner-Ville distribution by convoluting it with a window, is most commonly used to reduce the cross-talk. There can be infinite number of distributions depending on the windows. But, the smoothing reduces resolution in time-frequency plane; this motives to design a more effective window in reducing cross-talk while remaining resolution. The domain in which the cross-talk and legitimate components can be easily distinguished, is the ambiguity function. In the ambiguity function domain, the legitimate components appear as linear lines passing through the orgine. But, the cross-talk is widely distributes in the ambiguity function plane. Based on the relative distributions of cross-talk and legitimate components, rotating window can be designed to minimize cross-talk. Applying the rotating window to the ambiguity function corresponds to smoothing the Wigner-Ville distribution. Therefore, the effects of rotating window is estimated in terms of the bias error due to smooting the Wigner-Ville distribution. By applying the rotating window, not only the Wigner-Ville distribution but also its properties are changed. The properties of the new distribution are checked, in order to complete analyzing the rotating window.

• Language and Information
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• v.7 no.2
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• pp.59-79
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• 2003

Coordination in natural language is often syntactically explained by the rule schema X \longrightarrow X′ and X", where X′ and X" refer to expressions of a like syntactic type. While this schema does explain a lot of instances of coordination, it is well known that this schema also gives rise to serious structural ambiguity, leading not only to numerous unintended interpretations but also to a high degree of unnecessary computational complexity. In order to identify intended interpretations, we need to take into account a number of clues at all the levels of morphology, syntax, semantics, and pragmatics/discourse. In this paper, we propose, with an accompanying data analysis, principles of symmetry and coherency for an effective and reasonable identification of intended interpretations from coordination-bearing sentences.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.769-776
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• 1987

A method of on-line recognition of Korean characters (Hangeul) by augmented conterxt free grammar is described in this paper. Syntactic analysis with context free grammar oftern has ambiguity. Insufficient description of relations among Hangrul sub-patterns causes this ambiguity can be determined through repetition of experiments. Flexible syntactic analysis is executed by adapting the condition to the (advice)part of augmented context free grammar. The ratio of correct recognition of this method is more than 99%.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.783-787
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• 2012

It is not easy to find out syntactic error in a spelling checker systems of Korean, because the spelling checker is generally to correct each phrase and it cannot check the errors of contextual ill-matched words. Spelling checker system tests errors based on a words. Disambiguation of lexical ambiguities is important in natural language processing. Its outputs is used in syntactic analysis. For accurate analysis of a sentence, syntactic analysis system must find out the ambiguity of morphemes in a word. In this paper, we suggest several rules to resolve the ambiguities of morphemes in a word. Using these methods, we can reduce many lexical ambiguities in Korean.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1211-1215
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• 2005

In the GPS attitude determination system, the baseline length constraints can be used efficiently to reduce the search space. It is possible by adopting the assumptions that the baseline length doesn't change and the true baseline length is precisely known. But in real situation, the baseline length might be changed by many reasons and it is impossible to measure the true baseline length because there exists measurement error and antenna phase centre movement. In order to analyze the effect of the baseline length accuracy, one needs to know the relation between the accuracy of the baseline length and success rates of the integer ambiguity resolution. In this paper, the effect of the baseline length accuracy to the integer ambiguity resolution in the attitude determination system is analyzed by empirical method. The results show that the margins in the baseline length accuracy is less than a few cm which implies that one should take great cares when applying the attitude determination system to the flexible structures.

• Journal of Agricultural Extension & Community Development
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• v.12 no.1
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• pp.69-81
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• 2005

The objectives of this study were to measure role conflict of 4-H leaders and to verify the differences of role conflict and self-efficacy according to individual characteristics. The data were collected from 99 leaders who took charge of guiding 4-H youth organization in school as teacher advisor. The statistical techniques used for this study were frequency, t-test, one-way analysis of variance and correlation. The major findings of this study were as follows; 1) The 4-H leaders had some role conflict and role ambiguity in guiding youth activities in the school. 2) The leader advisor group with teaching experience of $5{\sim}9$ years showed higher role conflict and lower role ambiguity. 3) The 4-H leaders with age over 45 felt higher role conflict and lower role ambiguity. 4)The leaders' self-efficacy was positively correlated with self esteem, and negatively associated with role ambiguity.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.111-129
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• 1994

In this study, we develope a revised model as well as application of decision problem under ambiguity based on the subjectively weighted linear utility medel. Bayes'rule is used when there are ambiguous probabilities on a decision problem and test information is available. A procedure for assessing the ambiguity aversion function is also presented. Decision problem of chemical corporation is used for an illustration of the application of the subjectively weighted linear utility model using Bayesian approach. We present the optimal decisiond using newly developed model. We also perform the sensitivity analysis to assure ourselves about the conclusion we obtianed on degree of ambiguity aversion due to characterize parameter of subjectively weighted linear utility model.