• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.191-193
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• 2015

Recently, with the economy and the information communication technology developed, the e-commerce market grows continuously. A meta-analysis refers to a statistical literature synthesis method from the quantitative results of many known empirical studies. We conducted a meta-analysis and review of between perceived risk to criterion variable on e-commerce researches. This study focused a total of 25 research papers that established causal relationships in between perceived risk to criterion variable on e-commerce published in Korean academic journals during 2000 and 2014. The result of the meta-analysis might be summarized that the effect size in the path from perceived risk to the criterion variable with the effect size -0.251. Based on these findings, several theoretical and practical implications were suggested and discussed with the difference from previous researches.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2421-2429
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• 2000

With the advance of wireless communications technology, mobile communications have become more convenient than ever. Nowadays, people can communicate with each other on any place at any time. However, because of the openness of wireless communications, the way to protect the privacy between communicating parties is becoming a very important issue. In this paper, we present a study on the authentication and message encryption algorithm to support roaming service to the GSM network. To propose an authentication and message encryption algorithm applicable to the GSM system, the security architecture of the GSM outlined in the GSM standard is briefly introduced. In the proposed cryptosystems we use a new hash function for user authentication and a stream cipher based on Linear Feedback Shift Register(LFSR) for message encryption and decryption. Moreover, each algorithm is programmed with C language and simulated on IBM-PC system and we analyze the randomness properties of the proposed algorithms by using statistical tests.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.25-37
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• 2009

Recently, according to the epoch-making advancement of the Internet technique, internet using is widely expanded to the social whole not only until quantitative growth but also until qualitative growth. This research is aimed to offer plan about segmentation strategy which could be applied to business strategic establishment and the academic research, and information about solution method. In this paper, we compared similarity among purchasing products by using statistical methods such as positioning and correspondence analysis, and we tried to design predictive model for segmentation of existing customer. In conclusion, we have objective that enterprises create a benefit from the stabilized customer and customers have a benefit from enterprises by providing marketing promotion which fits the property of each person.

• Spatial Information Research
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• v.16 no.3
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• pp.373-383
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• 2008

LiDAR, unlike satellite imagery and aerial photographs, which provides irregularly distributed three-dimensional coordinates of ground surface, enables three-dimensional modeling. In this study, urban area was classified based on 3D information collected by LiDAR. Morphological and spatial properties are determined by the ratio of ground and non-ground point that are estimated with the number of ground reflected point data of LiDAR raw data. With this information, the residential and forest area could be classified in terms of height and density of trees. The intensity of the signal is distinguished by a statistical method, Jenk's Natural Break. Vegetative area (high or low density) and non-vegetative area (high or low density) are classified with reflective ratio of ground surface.

• Journal of Navigation and Port Research
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• v.32 no.3
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• pp.207-213
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• 2008

Ship-handling simulation system has been used for maritime traffic safety assessment for harbor and fairway. There exist various environmental conditions under which ship may navigate along a fairway or in harbor. Due to the time and budget limitations, however, ship-handling simulations are usually carried out for very limited number of environmental conditions. In this paper, statistical method for effective and systematic determination of real time simulation conditions is suggested and applied to the maritime traffic safety assessment problems. In the empirical study, the principal component analysis method and the concept of empirical cumulative distribution function are suggested to estimate synthetic navigational difficulty and to select simulation conditions which would impose high difficulty on shiphandling.

• Journal of KIISE
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• v.42 no.4
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• pp.512-521
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• 2015

Internet users purchase goods on the Internet and express their positive or negative emotions of the goods in product reviews. Analysis of the product reviews become critical data to both potential consumers and to the decision making of enterprises. Therefore, the importance of opinion mining techniques which derive opinions by analyzing meaningful data from large numbers of Internet reviews. Existing studies were mostly based on comments written in English, yet analysis in Korean has not actively been done. Unlike English, Korean has characteristics of complex adjectives and suffixes. Existing studies did not consider the characteristics of the Internet language. This study proposes an emotional classification method which increases the accuracy of emotional classification by analyzing the characteristics of the Internet language connoting feelings. We can classify positive and negative comments about products automatically using the Internet emoticon. Also we can check the validity of the proposed algorithm through the result of high precision, recall and coverage for the evaluation of this method.

• Geophysics and Geophysical Exploration
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• v.1 no.3
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• pp.170-175
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• 1998

A systematic methodology is developed for the prediction of the lithology using electrofacies classification from wireline log data. Multivariate statistical techniques are adopted to segment well log measurements and group the segments into electrofacies types. To consider corresponding contribution of each log and reduce the computational dimension, multivariate logs are transformed into a single variable through principal components analysis. Resultant principal components logs are segmented using the statistical zonation method to enhance the quality and efficiency of the interpreted results. Hierarchical cluster analysis is then used to group the segments into electrofacies. Optimal number of groups is determined on the basis of the ratio of within-group variance to total variance and core data. This technique is applied to the wells in the Korea Continental Shelf. The results of field application demonstrate that the prediction of lithology based on the electrofacies classification works well with reliability to the core and cutting data. This methodology for electrofacies determination can be used to define reservoir characterization which is helpful to the reservoir management.

• Nuclear Engineering and Technology
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• v.20 no.4
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• pp.253-264
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• 1988

Our experience of neutron noise analysis in French-type 900 MWe pressurized water reactor (PWR) is presented. Neutron noise analysis is based on the technique of interpreting the signal fluctuations of ex-core detectors caused by core reactivity changes and neutron attenuation due to lateral core motion. It also provides advantages over deterministic dynamic-testing techniques because existing plant instrumentation can be utilized and normal operation of the plant is not disturbed. The data of this paper were obtained in the ULJIN unit 1 reactor during the start-up test period and the statistical descriptors, useful for our purpose, are power spectral density (PSD), coherence function (CF), and phase difference between detectors. It is found that core support barrel (CSB) motions induced by coolant flow forces and pressure pulsations in a reactor vessel were indentified around 8 Hz of frequency.

• Culinary science and hospitality research
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• v.15 no.1
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• pp.181-190
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• 2009

The purpose of this study was to identify the recognition of traditional wedding food among the women living in Busan. It also investigated the differences of the recognition caused by demographic characteristics among them, which provides the data for a desirable wedding culture. A total of 270 samples for the study were collected from November 10 till 21 in 2007. For the analysis of the data, we used SPSS 14.0 to carry out the analysis of frequency and variance. The findings could be summarized as follows: the older one had more awareness of traditional wedding food. Especially the housewife had relatively more knowledge about Shinhyung-eumsik than any other occupation. The majority of respondents answered that Phaebak-eumsik is positively necessary for the wedding ceremony and simplification of wedding food is needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.134-137
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• 2016

Big data analysis refers the ability to store, manage and analyze collected data from an existing database management tool. In addition, extract value from large amounts of structured or unstructured data set and means the technology to analyze the results. Meta-analysis is a statistical integration method that delivers an opportunity to overview the entire result of integrating and analyzing many quantitative research results. Meta-analysis is sometimes expressed as an analysis of another analysis. Commonly, factors of metabolic syndrome can be defined as abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose. This study will find meaningful mediator variables for criterion variables that affect before and after the metabolic syndrome studies, on the basis of the results of a meta-analysis. We reviewed a total of 5 studies related to metabolic syndrome published in Korea between 2000 and 2016, where a cause and effect relationship is established between variables that are specified in the conceptual model of this study.