• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.93-108
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• 2014

To support business decision making, interests and efforts to analyze and use transaction data in different perspectives are increasing. Such efforts are not only limited to customer management or marketing, but also used for monitoring and detecting fraud transactions. Fraud transactions are evolving into various patterns by taking advantage of information technology. To reflect the evolution of fraud transactions, there are many efforts on fraud detection methods and advanced application systems in order to improve the accuracy and ease of fraud detection. As a case of fraud detection, this study aims to provide effective fraud detection methods for auction exception agricultural products in the largest Korean agricultural wholesale market. Auction exception products policy exists to complement auction-based trades in agricultural wholesale market. That is, most trades on agricultural products are performed by auction; however, specific products are assigned as auction exception products when total volumes of products are relatively small, the number of wholesalers is small, or there are difficulties for wholesalers to purchase the products. However, auction exception products policy makes several problems on fairness and transparency of transaction, which requires help of fraud detection. In this study, to generate fraud detection rules, real huge agricultural products trade transaction data from 2008 to 2010 in the market are analyzed, which increase more than 1 million transactions and 1 billion US dollar in transaction volume. Agricultural transaction data has unique characteristics such as frequent changes in supply volumes and turbulent time-dependent changes in price. Since this was the first trial to identify fraud transactions in this domain, there was no training data set for supervised learning. So, fraud detection rules are generated using outlier detection approach. We assume that outlier transactions have more possibility of fraud transactions than normal transactions. The outlier transactions are identified to compare daily average unit price, weekly average unit price, and quarterly average unit price of product items. Also quarterly averages unit price of product items of the specific wholesalers are used to identify outlier transactions. The reliability of generated fraud detection rules are confirmed by domain experts. To determine whether a transaction is fraudulent or not, normal distribution and normalized Z-value concept are applied. That is, a unit price of a transaction is transformed to Z-value to calculate the occurrence probability when we approximate the distribution of unit prices to normal distribution. The modified Z-value of the unit price in the transaction is used rather than using the original Z-value of it. The reason is that in the case of auction exception agricultural products, Z-values are influenced by outlier fraud transactions themselves because the number of wholesalers is small. The modified Z-values are called Self-Eliminated Z-scores because they are calculated excluding the unit price of the specific transaction which is subject to check whether it is fraud transaction or not. To show the usefulness of the proposed approach, a prototype of fraud transaction detection system is developed using Delphi. The system consists of five main menus and related submenus. First functionalities of the system is to import transaction databases. Next important functions are to set up fraud detection parameters. By changing fraud detection parameters, system users can control the number of potential fraud transactions. Execution functions provide fraud detection results which are found based on fraud detection parameters. The potential fraud transactions can be viewed on screen or exported as files. The study is an initial trial to identify fraud transactions in Auction Exception Agricultural Products. There are still many remained research topics of the issue. First, the scope of analysis data was limited due to the availability of data. It is necessary to include more data on transactions, wholesalers, and producers to detect fraud transactions more accurately. Next, we need to extend the scope of fraud transaction detection to fishery products. Also there are many possibilities to apply different data mining techniques for fraud detection. For example, time series approach is a potential technique to apply the problem. Even though outlier transactions are detected based on unit prices of transactions, however it is possible to derive fraud detection rules based on transaction volumes.

• Journal of IKEEE
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• v.15 no.2
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• pp.179-189
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• 2011

This paper presents an SVC based multi-channel transmission technique. Transmission of high definition multimedia and its service efficiency can be significantly improved by the proposed method. In this method, the HD stream is divided into the two layer streams, i.e., a base layer stream and an enhancement layer stream. The divided streams are transmitted through a primary channel and an auxiliary channel, respectively. The proposed technique provides a noble mode switching technique which enables a seamless service of HD multimedia even under the conditions of abrupt and intermittent deterioration of the auxiliary channel. When the enhancement layer stream is disrupted by the channel monitoring in the mode switching algorithm, the algorithm works further to maintain the spatial and time resolution of the HD multimedia by upsampling and interpolating the base layer stream, consequently serving for the non disrupted play of the media. Moreover, the adoption of an adaptive switching algorithm significantly reduces the frequency of channel disruption avoiding the unnecessary switching for the short period variations of the channel. The feasibility of the proposed technique is verified through the simulation study with an example application to the simultaneous utilization of both Ku and Ka bands for HD multimedia broadcasting service. The rainfall modeling and the analysis of the satellite channel attenuation characteristics are performed to simulate the quality of service performance of the proposed HD broadcasting method. The simulation results obtained under a relatively poor channel (weather) situations show that the average lasting period of enhancement layer service is extended from 9.48[min] to 23.12[min] and the average switching frequency is reduced from 3.84[times/hour] to 1.68[times/hour]. It is verified in the satellite example that the proposed SVC based transmission technique best utilizes the Ka band channel for the service of HD broadcasting, although it is characterized by its inherent weather related poor reliability causing severe limitations in its independent application.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.75-91
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• 2020

The purposes of this study are 1) to develop a pre-education program for teaching the basic concepts of systems thinking and STEAM program based on systems thinking and 2) to investigate the effects of the program on middle school students' systems thinking. The subjects were 4 seventh-graders and 4 ninth-graders in a middle school located in the province of Gyeongsangbuk-do. Data related to students' systems thinking was analyzed using the rubrics developed by Hung(2008). The results were reviewed by experts to verify the validity of the rubrics and the reliability of students' system thinking. In addition, the data analyzed with the rubrics, students' awareness of systems thinking, word associations, causal maps and interviews were systematically analyzed to investigate the effects of the program on students' systems thinking. The findings of this study were as follows: First, a pre-education program and teachers' guidebook for teaching and learning the concept of systems thinking and causal maps were developed. The pre-education program consisted of familiar TV entertainment program-Infinite Challenge (Muhandojeon)-with a theme of Global Warming. Second, a STEAM education program based on systems thinking which was composed of 5 steps: Analysis-Design-Build-Assessment-Systems thinking. The major theme of the program was an air extinguisher. The developed STEAM education program had positive effects on improving middle school students' systems thinking abilities such as understanding systems, relations within a system and system generalization. Therefore, it was concluded that the STEAM program could be instrumental for cultivating students' STEAM literacy with improved systems thinking.

• Journal of the HCI Society of Korea
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• v.8 no.1
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• pp.1-9
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• 2013

This is to develop a new way of testing self-esteem by adopting DAP(Draw a Person) test and to make a platform to digitalize it for young people in the adolescent stage. This approach is to get high effectiveness of the self-esteem measurement using DAP test, including some personal inner situations which can be easily missed in the large statistical analysis. The other objective of this study is digitalize to recover limits of DAP test in the subjective rating standard. It is based on the distribution of the figure drawing expressed numerically by the anxiety index of Handler. For these two examinations, we made experiment through 4 stages with second grade middle school 73 students from July 30th to October 31th in 2009 during 4 months. Firstly, we executed 'Self Values Test' for all 73 people, and divided them into two groups; one is high self-esteem group of 36 people, the other is low self-esteem group of 37 people. Secondly, we regrouped them following D (Depression), Pd (Psychopathic Deviate), Sc (Schizophrenia) scales of MMPI; one is high self-esteem group of 7 people, the other is low self-esteem group of 13 people. Thirdly, we conducted DAP test separately for these 20 people. We intended to verify necessity and appropriateness of direction of 'Digitalizing Measurement System' by comparing and analyzing relation between DAP and Self-esteem following evaluation criteria which has similarity in 3 tests, after executing DAP to reflect peculiarity of adolescents sufficiently. We compared and analyzed result abstracted by sampling DAP test of two groups; One is high self-esteem group of 2 people, the other is low self-esteem group of 2 people; to confirm whether we can improve limitation that original psychological testing has by comparing mutual reliance of measurement test. Finally, with DAP test gained from correlations between self-esteem and melancholia following as above-mentioned steps, we discovered possibility of realization to get a concrete and individual criteria of evaluation based on Expert System as a way of enhancing accessibility in quantitative manner. 'Digitalizing Measurement Program' of DAP test suggested in this study promote results' reliability based on existing tests and measurement.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.37-48
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• 2017

Purpose: The most basic conditions of radiation therapy is to prevent unnecessary exposure of normal tissue. The risk factors that are important o evaluate the dose emitted to the lung and heart from radiation therapy for breast cancer. Therefore, comparing the dose factors of a normal tissue according to the radion treatment position and Seeking an effective radiation treatment for breast cancer through the analysis of the correlation relationship. Materials and Methods: Computed tomography was conducted among 30 patients with left breast cancer in supine and prone position. Eclipse Treatment Planning System (Ver.11) was established by computerized treatment planning. Using the DVH compared the incident dose to normal tissue by position. Based on the result, Using the SPSS (ver.18) analyzed the dose in each normal tissue factors and Through the correlation analysis between variables, independent sample test examined the association. Finally The HI, CI value were compared Using the MIRADA RTx (ver. ad 1.6) in the supine, prone position Results: The results of computerized treatment planning of breast cancer in the supine position were V20, $16.5{\pm}2.6%$ and V30, $13.8{\pm}2.2%$ and Mean dose, $779.1{\pm}135.9cGy$ (absolute value). In the prone position it showed in the order $3.1{\pm}2.2%$, $1.8{\pm}1.7%$, $241.4{\pm}138.3cGy$. The prone position showed overall a lower dose. The average radiation dose 537.7 cGy less was exposured. In the case of heart, it showed that V30, $8.1{\pm}2.6%$ and $5.1{\pm}2.5%$, Mean dose, $594.9{\pm}225.3$ and $408{\pm}183.6cGy$ in the order supine, prone position. Results of statistical analysis, Cronbach's Alpha value of reliability analysis index is 0.563. The results of the correlation analysis between variables, position and dose factors of lung is about 0.89 or more, Which means a high correlation. For the heart, on the other hand it is less correlated to V30 (0.488), mean dose (0.418). Finally The results of independent samples t-test, position and dose factors of lung and heart were significantly higher in both the confidence level of 99 %. Conclusion: Radiation therapy is currently being developed state-of-the-art linear accelerator and a variety of treatment plan technology. The basic premise of the development think normal tissue protection around PTV. Of course, if you treat a breast cancer patient is in the prone position it take a lot of time and reproducibility of set-up problems. Nevertheless, As shown in the experiment results it is possible to reduce the dose to enter the lungs and the heart from the prone position. In conclusion, if a sufficient treatment time in the prone position and place correct confirmation will be more effective when the radiation treatment to patient.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1565-1576
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• 2023

An atmospheric correction algorithm based on the radiative transfer model is required to obtain remote-sensing reflectance (R_rs) from the Geostationary Ocean Color Imager-II (GOCI-II) observed at the top-of-atmosphere. This R_rs derived from the atmospheric correction is utilized to estimate various marine environmental parameters such as chlorophyll-a concentration, total suspended materials concentration, and absorption of dissolved organic matter. Therefore, an atmospheric correction is a fundamental algorithm as it significantly impacts the reliability of all other color products. However, in clear waters, for example, atmospheric path radiance exceeds more than ten times higher than the water-leaving radiance in the blue wavelengths. This implies atmospheric correction is a highly error-sensitive process with a 1% error in estimating atmospheric radiance in the atmospheric correction process can cause more than 10% errors. Therefore, the quality assessment of R_rs after the atmospheric correction is essential for ensuring reliable ocean environment analysis using ocean color satellite data. In this study, a Quality Assurance (QA) algorithm based on in-situ R_rs data, which has been archived into a database using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Bio-optical Archive and Storage System (SeaBASS), was applied and modified to consider the different spectral characteristics of GOCI-II. This method is officially employed in the National Oceanic and Atmospheric Administration (NOAA)'s ocean color satellite data processing system. It provides quality analysis scores for R_rs ranging from 0 to 1 and classifies the water types into 23 categories. When the QA algorithm is applied to the initial phase of GOCI-II data with less calibration, it shows the highest frequency at a relatively low score of 0.625. However, when the algorithm is applied to the improved GOCI-II atmospheric correction results with updated calibrations, it shows the highest frequency at a higher score of 0.875 compared to the previous results. The water types analysis using the QA algorithm indicated that parts of the East Sea, South Sea, and the Northwest Pacific Ocean are primarily characterized as relatively clear case-I waters, while the coastal areas of the Yellow Sea and the East China Sea are mainly classified as highly turbid case-II waters. We expect that the QA algorithm will support GOCI-II users in terms of not only statistically identifying R_rs resulted with significant errors but also more reliable calibration with quality assured data. The algorithm will be included in the level-2 flag data provided with GOCI-II atmospheric correction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.682-690
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• 2016

In order to present a realistic alternative to agricultural product brands which achieve quantitative growth but minimal qualitative growth, this study attempted to identify the structural factors that affect the agricultural product brand equity and quantitatively analyze the effects of the structural factors on the brand equity. For the quantitative analysis, a survey was conducted among customers with a structured questionnaire. The major results of the analysis are as follows. First, the structural factors of the agriculture product brand equity were theoretically reviewed through many preceding studies in regard to the brand and brand equity. Awareness, quality and loyalty were selected as the structural factors of the agriculture brand equity. Second, when the sub-structural factors of the agriculture product brand equity were analyzed, it was found that awareness includes familiarity, first reminding level, general awareness, sub-awareness, frequency of reference and level of people's logo recollection. Quality includes quality consistence, quality reliability, quality stability, general quality and quality for price. Loyalty includes recommendation, purchase intention, cost premium and repurchase intention. Third, in the analysis of the factors of awareness, quality and loyalty were found to be statistically significant at the 1% level of significance, and it turned out that the higher the awareness, quality and loyalty, the higher the brand equity. Fourth, the factors most influencing the brand equity differed from those obtained using the standardized coefficients. The highest standardized coefficients of the factors on rice and condiment vegetables were those for quality with values of 0.486 and 0.581, respectively, and the highest standardized coefficients of the factors on fruits and fruit vegetables were those for loyalty with values of 0.536 and 0.490, respectively. Finally, it was found to be more effective to develop brand policies using an approach based on awareness, quality and loyalty by item. Also, focusing on enhancing the quality when developing brand policies for rice and vegetables, or focusing on enhancing loyalty when developing brand policies for fruit and vegetables was found to be more efficient using the limited resources.

• Asia pacific journal of information systems
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• v.19 no.2
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• pp.195-221
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• 2009

According to an industry report, a large number of organizations have invested in Organizational Information System(OIS) in the past few years. Several research results indicate that successful investments in OIS lead to productivity enhancement, while failed ones result in undesirable consequences such as financial losses and dissatisfaction among employees. In spite of huge investments, however, many organizations have failed in achieving the hoped-for returns from OIS. Thus, understanding user acceptance, adoption, and usage of new IS(Information Systems) is an important issue for IS practitioners. Indeed, study of the user acceptance of new information system has been one of the most important research topics in the contemporary IS literature. Several theoretical models are tested to examine 'user acceptance' and 'usage behavior' in IS context. While many research models incorporate 'ease of use' or 'usefulness' as important factors in explaining user acceptance, Technology Acceptance Model(TAM) has been one of the most widely applied models in user acceptance and usage behavior. Even in recent IS studies that employ theories of innovation diffusion in the area of IS implementation, a major focus has been on the user's perception of information technologies. In this research, we study 'voluntariness' as an important factor in IS acceptance by users. Voluntariness is defined as "the degree to which the use of the innovation is perceived as being voluntary, or of free will" When examining the diffusion of accepting OIS, a thoughtful consideration should be given to 'perceived voluntariness.' Current article has following research questions: 1) What models are appropriate to explain the success of OIS? and 2) How does the 'voluntariness' affect the success of OIS? In order to answer these questions, a research model is proposed to describe the detailed nature of association among three independent variables (IT usage level, task interdependency, and organizational support), a mediating variable (IS usage), a dependent variable (perceived performance), and a moderating variable(perceived voluntariness). The central claim of this article is that organizations hardly realize expected returns from OIS investments unless perceived voluntariness is effectively managed after operating OIS. As an example of OIS in this study we have selected the Intranet of Republic of Korea Air Force (ROKAF). ROKAF has implemented the Intranet in an attempt to improve communication and coordination within the organization. To test our research model and hypotheses, survey questionnaires were first sent out to 400 Intranet users. With the assistance of ROKAF, Intranet users were initially identified among its members, and subjects were randomly drawn from the pool. 377 survey responses were finally returned. The unit of measurement and analysis in this research is a personal level. Path analysis based on structural equation modeling was used to test research hypotheses. Construct validity represents accordance between the theoretical base concept of constructs and its measurement items. Tests for the reliability and discriminant validity are accepted, thus verifying our survey instrument. In this research, we have proposed a conceptual framework to highlight the importance of perceived voluntariness after organization deploys OIS. The results of our analysis present several key finding. First, all three independent variables (IT usage level, task interdependency, and organizational support) have significant effects on IS usage, which will eventually improve performance. Thus, IS usage plays a mediating role between antecedent variables (IT usage level. task interdependency, and organizational support) and performance improvement. Second, the effect of the task dependency was the highest for IS usage among the three antecedent variables. This is highly plausible since one of the Intranet's major capabilities is to facilitate communication among members within an organization. Accordingly, we conclude that the higher the task dependency, the higher Intranet usage. The effect of user's IT usage level was the second, while the effect of the organizational support was the third. Finally, the perceived voluntariness plays a pivotal role in enhancing perceived performance in personal level after launching the Intranet. Relationships among investigated variables were significantly different between groups with a high level and a low level of voluntariness. The impact of the Intranet usage on the performance was greater in the higher level voluntariness group than in the lower one. For the lower level voluntariness group, the user's IT usage had the highest effect on the Intranet usage among the three antecedent variables. In short, our study suggests that the higher the perceived voluntariness is the more IS usage will be. Perceived voluntariness was found to have a moderating effect on the relationships among user IT usage level, task interdependency, IS usage, and perceived performance, supporting all the hypotheses on the moderating effect. Most of all, user IT usage level has the strongest influence on IS usage, indicating that users with superior IT usage are more likely to enjoy a high level of perceived performance.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.52-64
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• 2011

In this study, the effects of street improvement projects in particular regions are carefully scrutinized, classified, and compared based on the types of citizen participation in those projects which are offered as one of several urban regeneration methods. The Wonju and Siheung Street Improvement Projects were selected for case studies, and in-depth interviews and a survey are conducted in both regions. As a result of in-depth interviews, the Wonju project is the community initiative type in which the community has responsibilities and decision-making abilities. On the other hand, Siheung is the community participative type in which the opinions of the community have been limited The survey targeted more than 100 local merchants, and they were asked to answer to the questions which were categorized into 21 items with a 5-point Likert scale. The analysis method was carried out through a reliability test, regression. average analysis on each group, and a T-test by SPSS 18.0. Factor analysis results show four factors: physical, partnership, community, and economical revitalization. These results reveal that the social factor can be sub-divided into a community factor and partnership factor. As a result of revitalization factors by citizen participation type, the resident initiative type is more revitalized than the resident participative type in all four factors, and shows positive responses in physical and economical revitalization factors. In particular, the physical revitalization factor has a big impact on resident satisfaction regardless of type. The community revitalization factor also has an impact on two types. It reveals that the communication is as important as physical improvement. However, it shows that no type of project affects partnership revitalization. As a result of this study, if we considered only physical improvement as project achievement, you can achieve the desired outcome without consideration of residents' participation types. Furthermore, if regional revitalization is the goal of a street improvement project, we must consider other factors such as a partnership and community revitalization.

• Education of Primary School Mathematics
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• v.16 no.3
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• pp.229-250
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• 2013

The purpose of this study is analyzing 'observation and recommendation letter by teacher', which is being submitted to screen and enhance the utilization of gifted students in accordance with recently introduced gifted students observation, recommendation and screening system. For the purpose, this study will provide with objective securing plan of 'observation and recommendation letter by teacher' by developing an optimum evaluation model. The research findings were as follows: First, the result of analysis on the mathematically gifted students behavior characteristic as appeared in 'observation and recommendation letter by teacher' suggested that the recommending teachers have the tendency of giving superficial statement instead of giving concrete case description. When it was analyzed for frequency by the 'observation and recommendation letter by teacher' analysis framework devised by the author, the teachers showed the tendency of concentrating on specific questions. Meanwhile, there was a tendency that teachers concentrate on specific gifted behavior characteristic or area for which concrete case had been suggested. The reason is believed that such part is easy to observe and state while others are not, or, teachers did not judge the other part as the characteristic of gifted students. Second, the gifted students behavior characteristics as appeared in 'observation and recommendation letter by teacher' were made into scores by Rubric model. When the interrater reliability was analyzed based on these scores, the correlation coefficient of 1st scoring was .641. After a discussion session was taken and 2nd scoring was done 3 weeks later, the correlation coefficient of 2nd scoring increased to .732. The reason is believed that; i) the severity among scorers was adjusted by the discussion session after the 1st scoring, ii) the scorers established detail judgment standard on various situations which can appear because of the descriptive nature, and, (iii) they found a consensus on scoring for a new situation appeared. It implies that thorough understanding and application of scorers on evaluation model is as important as the development of optimum model for the differentiation of mathematically gifted elementary students.