• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.106-118
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• 2009

Satellite imagery with high resolution of about one meter is used widely in commerce and government applications ranging from earth observation and monitoring to national digital mapping. Due to the expensiveness of IKONOS Pro and Precision products, it is attractive to use the low-cost IKONOS Geo product with vendor-provided rational polynomial coefficients (RPCs), to produce highly accurate mapping products. The imaging geometry of IKONOS high-resolution imagery is described by RFs instead of rigorous sensor models. This paper presents four different polynomial models, that are the offset model, the scale and offset model, the Affine model, and the 2nd-order polynomial model, defined respectively in object space and image space to improve the accuracies of the RF-derived ground coordinates. Not only the algorithm for RF-based ground coordinates but also the algorithm for accuracy improvement of RF-based ground coordinates are developed which is based on the four models, The experiment also evaluates the effect of different cartographic parameters such as the number, configuration, and accuracy of ground control points on the accuracy of geopositioning. As the result of a experimental application, the root mean square errors of three dimensional ground coordinates which are first derived by vendor-provided Rational Function models were averagely 8.035m in X, 10.020m in Y and 13.318m in Z direction. After applying polynomial correction algorithm, those errors were dramatically decreased to averagely 2.791m in X, 2.520m in Y and 1.441m in Z. That is, accuracy was greatly improved by 65% in planmetry and 89% in vertical direction.

• Journal of the Korean Society for information Management
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• v.34 no.1
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• pp.177-195
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• 2017

This study attempts to infer research fronts using factor graph model based on heterogeneous features. The model suggested by this study infers research fronts having documents with the potential to be cited multiple times in the future. To this end, the documents are represented by bibliographic, network, and content features. Bibliographic features contain bibliographic information such as the number of authors, the number of institutions to which the authors belong, proceedings, the number of keywords the authors provide, funds, the number of references, the number of pages, and the journal impact factor. Network features include degree centrality, betweenness, and closeness among the document network. Content features include keywords from the title and abstract using keyphrase extraction techniques. The model learns these features of a publication and infers whether the document would be an RF using sum-product algorithm and junction tree algorithm on a factor graph. We experimentally demonstrate that when predicting RFs, the FG predicted more densely connected documents than those predicted by RFs constructed using a traditional bibliometric approach. Our results also indicate that FG-predicted documents exhibit stronger degrees of centrality and betweenness among RFs.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.3
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• pp.13-21
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• 2007

Recently, very short-term rainfall forecast using radar is required for regional flash flood according to climate change. This research is to evaluate the feasibility of GIS based distributed model using radar rainfall which can express temporal and spatial distribution in actual dam watershed during flood runoff period. Vflo model which was developed Oklahoma university was used as physical based distributed model, and Namgang dam watershed ($2,293km^2$) was applied as study site. Distributed rainfall according to grid resolution was generated by using K-RainVieux, preprocess program of radar rainfall, from JIN radar. Also, GIS hydrological parameters were extracted from basic GIS data such as DEM, land cover and soil map, and used as input data of distributed model(Vflo). Results of this research can provide a base for building of real-time short-term rainfall runoff forecast system according to flash flood in near future.

• Journal of the Korea Computer Graphics Society
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• v.8 no.2
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• pp.1-7
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• 2002

The fast extraction of the silhouettes of a model is very useful for many applications in computer graphics and animation. In this paper, we present an efficient algorithm to compute a sequence of perspective silhouettes for a polyhedral model from a moving viewpoint. The viewpoint is assumed to move along a trajectory q(t), which is a space curve of a time parameter t. Then, we can compute the time-intervals for each edge of the model to be contained in the silhouette by two major computations: (i) intersecting q(t) with two planes and (ii) a number of dot products. If q(t) is a curve of degree n, then there are at most of n + 1 time-intervals for an edge to be in a silhouette. For each time point $t_i$ we can extract silhouette edges by searching the intervals containing $t_i$ among the computed intervals. For the efficient search, we propose two kinds of data structures for storing the intervals: an interval tree and an array. Our algorithm can be easily extended to compute the parallel silhouettes with minor modifications.

• The Journal of Information Systems
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• v.25 no.2
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• pp.79-110
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• 2016

Purpose Online Peer-to-peer lending (hereafter P2P lending), is a new method of lending money to unrelated individuals through an online financial intermediary. Usually in the online P2P transaction, individuals who would like to borrow money (hereafter borrowers) and those who would like to lend money (hereafter lenders) have no previous relationship. Based on enormous previous studies, this study develops an integrated model, particularly for the online P2P lending environment in China, to better understand the critical factors that influence lenders' intention to lend money through the online P2P lending platform. Design/methodology/approach In order to verify the hypotheses, we develop a questionnaire with 42 survey items. We measured all the items on a five-point Likert-type scale. We use Sojump.com to collect questionnaire and gather 246 valid responses from registered members of Renrendai.com. We analyzed the main survey data by using SPSS 18.0 and AMOS 20.0. We first estimated the reliability, validity, composite reliability and AVE and then conduct common method bias test. The mediating role of trust in platform and in borrower has been tested. Last we tested the hypotheses through the structural model. Findings The results reveal that service quality, information quality, structural assurance, awareness and reputation significantly impact lenders' trust in the online P2P lending platform. Second, awareness, reputation and perceived risk significantly impact lenders' trust in borrower and lending intention. Third, trust propensity has a positive effect on lenders' trust on borrower. Last, awareness, reputation, perceived risk, platform trust and borrower trust can directly impact lenders' lending intention.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.491-499
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• 2001

Generally, several hydrological characteristics which can be obtained from geographic processing in GIS S/W would be utilized to actual hydrological applications such as landslide stability or drainage analysis. Furthermore, by using practical GIS extension programs, it can be possible that automatic extraction task of those information, which was time-consuming and complex processing, is performed as systematical and automatic processing. In this study, using ArcView GIS S/W and its extensions concerning hydrological processing, some waterflow and surface factors in the area of Yemi sheet scaled 1:50,000 were extracted. Then, assessment of landslide stability, determined by DEM-based variables were carried out in order to investigate practical applicability of extension programs. It is thought that several hydrological factors extracted by this study were significant information to predict field model or hydrological hazardous events. It also reveals that landslide potential is overall stable with stability index mapping and S-A plot, with theoretical basis. This methodology can be applicable to other areas related to hydrological characteristics with measurements in fields.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.231-240
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• 2010

The major purpose of this study is to examine how the perfectionism of dance majors affect self-efficacy and performance satisfaction. The sampling of this study was done in 2009, by using purposive sampling method with the subjects who are currently the students of an arts high school and dance majors of a college in Daejeon and Chungcheongnam-do. Specifically, by dividing the district in Chungnam and Daejeon, one arts high school and one college were selected from each district, and 75 dance majors from 4 schools respectively, total 300 students were examined for the study. Among these 300 students, the number of students' questionnaires used in the final analysis is 274, excluding the questionnaires containing inadequate answers. The adequacy of the questionnaire was verified by factor analysis, and the reliability of the questionnaire by reliability analysis. In the matter of reliability, Cronbach's ${\alpha}$ turned up to be over .602. In this study, factor analysis, reliability analysis, regression analysis, and course analysis were done by using SPSS16.0. With the above research method and results, I could come to a conclusion as following. Above all, perfectionism affects the subordinate variable of self-efficacy, the self-control efficacy. That is, with the higher self-oriented perfectionism and the other-oriented perfectionism, self-efficacy increases more as well. Secondly, perfectionism affects performance satisfaction. In other words, the higher self-oriented perfectionism, the higher performance satisfaction. Thirdly, self-efficacy affects performance satisfaction. That is, higher self-control efficacy makes the performance satisfaction higher. Lastly, perfectionism affects self-efficacy and performance satisfaction either directly or indirectly. Now it is obvious that self-efficacy is the variable that intermediate performance satisfaction.

• Journal of Korean Society of Steel Construction
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• v.18 no.6
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• pp.793-804
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• 2006

Various PSC and steel-concrete composite railway bridges are being developed for short-medium spans with structural and economic efficiency. According to the design concept, the prestressed composite girder bridge has the advantages of being lightweight and having low girder depth, with the capacity for long spans. However, the dynamic behavior under a passing train is one of the critical issues concerning these railway bridges designed with more flexibility. Therefore, it is very important to evaluate the modal parameters before performing dynamic analyses. In this paper, real-scale prestressed composite girders were fabricated as a test model and modal testing was carried out to evaluate modal parameters including natural frequency and modal damping ratio. During the modal testing, a digitally controlled vibration exciter as well as an impact hammer was applied to obtain frequency-response functions, and the modal parameters were also evaluated after the fracture of test models. With application of reliable properties from modal tests, the estimation of dynamic performances of prestressed composite girder railway bridges can be obtained from various parametric studies on dynamic behavior under the passage of a moving train.

• Convergence Security Journal
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• v.15 no.1
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• pp.37-47
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• 2015

This study aims at exploring effects of airport special guard's security service value on customers' satisfaction and customers' loyalty. Users of airport facilities located in Incheon were selected as the population in Jun. 2013 and the sample was extracted using cluster random sampling and 460 people were used for a final analysis. The questionnaire used for the study was composed of total 22 items including 6 items of socio-demographical characteristics, 6 items of security service value, 6 items of customers' satisfaction and 4 items of customers' loyalty etc. and using SPSSWIN 18.0, factor analysis, reliability analysis, multiple regression analysis, path analysis etc. were used. The credibility of the questionnaire was indicated to be over ${\alpha}$=.809. The findings are as follows. First, security service value has an effect on customers' satisfaction. if monetary value is enhanced, satisfaction with service composition is high. second, security service value has an effect on customers' loyalty. If monetary value and time value are enhanced, will of continuous use and will of recommendation of others are high. Third, customers' satisfaction has an effect on customers' loyalty. If satisfaction with service composition and satisfaction with use decision are increased, will of continuous use and will of recommendation of others are high. Fourth, airport special guard's security service value has a direct and indirect effect on customers' satisfaction and customers' loyalty. That is, it means customers' satisfaction is an important variable to mediate security service value and customers' loyalty.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.902-912
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• 2013

This study on the training of police officers job satisfaction and job performance is to identify the relationship. This study of 2012 Police Training Institute courses in related expenses 5 population in the process of initiation of a national police officer selection, and note that the sampling method used to extract a total of 300 samples, but the number of cases that were used in the final analysis, 268 people. Data processing by the SPSSWIN 18.0 factor analysis, reliability analysis, multiple regression, path analysis. Conclusions are as follows. First, the police officer's training affects job satisfaction. In other words, work-related, of course the more positive the evaluation of job training job satisfaction is high, education, the stronger the motivation and job satisfaction also higher education can be. Second, the education and training of police officers affects job performance. In other words, work-related, educational motivation, job training curriculum for the more positive job performance rating is also high. Third, the police officer's job satisfaction affects job performance. In other words, education can be a higher job performance and job satisfaction also high. Fourth, the training of police officers on the job satisfaction and job performance directly or indirectly affected. That is, the internal job satisfaction and job performance, job training parameters are the important variables.