• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.522-527
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• 2022

Object tracking is a field of signal processing that sequentially tracks the location of an object based on the previous-time location estimations and the present-time observation data. In this paper, we propose an adaptive scaling neural network that can track and adjust the scale of the input data with three recursive neural network (RNN) submodules. To evaluate object tracking performance, we compare the proposed system with the Kalman filter and the maximum likelihood object tracking scheme under an one-dimensional object movement model in which the object moves with piecewise constant acceleration. We show that the proposed scheme is generally better, in terms of root mean square error (RMSE) performance, than maximum likelihood scheme and Kalman filter and that the performance gaps grow with increased observation noise.

• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.161-177
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• 2015

With the rapid evolution of technology, the size, number, and the type of databases has increased concomitantly, so data mining approaches face many challenging applications from databases. One such application is discovery of fraud patterns from agricultural product wholesale transaction instances. The agricultural product wholesale market in Korea is huge, and vast numbers of transactions have been made every day. The demand for agricultural products continues to grow, and the use of electronic auction systems raises the efficiency of operations of wholesale market. Certainly, the number of unusual transactions is also assumed to be increased in proportion to the trading amount, where an unusual transaction is often the first sign of fraud. However, it is very difficult to identify and detect these transactions and the corresponding fraud occurred in agricultural product wholesale market because the types of fraud are more intelligent than ever before. The fraud can be detected by verifying the overall transaction records manually, but it requires significant amount of human resources, and ultimately is not a practical approach. Frauds also can be revealed by victim's report or complaint. But there are usually no victims in the agricultural product wholesale frauds because they are committed by collusion of an auction company and an intermediary wholesaler. Nevertheless, it is required to monitor transaction records continuously and to make an effort to prevent any fraud, because the fraud not only disturbs the fair trade order of the market but also reduces the credibility of the market rapidly. Applying data mining to such an environment is very useful since it can discover unknown fraud patterns or features from a large volume of transaction data properly. The objective of this research is to empirically investigate the factors necessary to detect fraud transactions in an agricultural product wholesale market by developing a data mining based fraud detection model. One of major frauds is the phantom transaction, which is a colluding transaction by the seller(auction company or forwarder) and buyer(intermediary wholesaler) to commit the fraud transaction. They pretend to fulfill the transaction by recording false data in the online transaction processing system without actually selling products, and the seller receives money from the buyer. This leads to the overstatement of sales performance and illegal money transfers, which reduces the credibility of market. This paper reviews the environment of wholesale market such as types of transactions, roles of participants of the market, and various types and characteristics of frauds, and introduces the whole process of developing the phantom transaction detection model. The process consists of the following 4 modules: (1) Data cleaning and standardization (2) Statistical data analysis such as distribution and correlation analysis, (3) Construction of classification model using decision-tree induction approach, (4) Verification of the model in terms of hit ratio. We collected real data from 6 associations of agricultural producers in metropolitan markets. Final model with a decision-tree induction approach revealed that monthly average trading price of item offered by forwarders is a key variable in detecting the phantom transaction. The verification procedure also confirmed the suitability of the results. However, even though the performance of the results of this research is satisfactory, sensitive issues are still remained for improving classification accuracy and conciseness of rules. One such issue is the robustness of data mining model. Data mining is very much data-oriented, so data mining models tend to be very sensitive to changes of data or situations. Thus, it is evident that this non-robustness of data mining model requires continuous remodeling as data or situation changes. We hope that this paper suggest valuable guideline to organizations and companies that consider introducing or constructing a fraud detection model in the future.

• Journal of vocational education research
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• v.30 no.4
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• pp.23-49
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• 2011

Faculty performance evaluation system has been settled down as an uncomfortable but unavoidable system, and it is one of the most important factors to grow the college competitiveness up. In this study, we selected and surveyed faculty evaluation models of several universities and colleges in Korea, and analyzed by comparing each evaluation areas of educational achievement, college-industry collaboration, research, and service. We also identified the properties of the current faculty evaluation models of the junior colleges, and derived several problems from these models such as an imitation of four-year university model, a disorders of job evaluation with respect to the attributes of classified jobs, a large variation of individual item weights, and an insufficient reflection of major characteristics. Based on these surveys and analysis, an improved faculty evaluation model for the junior college is proposed in this study. This model proposed four basic areas-educational achievement, college-industry collaboration, research, and service by considering the importance of the college-industry collaboration in the junior college-as well as the team evaluation area. Weights of the SCI-class paper was selected as a criterion for the arrangement of objective comparison of each evaluation items. We showed the integration method of several different evaluation model with respect to the attributes of classified jobs of each faculties, and evaluation plan of variational characteristics according to the majors of individuals in this model. Finally, we introduced an area fail and rating system to operate efficiently the proposed faculty evaluation model.

• Information Systems Review
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• v.8 no.1
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• pp.125-139
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• 2006

Recently, as mobile internet users grow rapidly, mobile internet companies are experiencing a fierce competition to capture new customers. Under this business environment, they try to identify factors that make people use mobile internet in order to satisfy customers by providing better and diversified services. There has been enormous effort to analyze customers' behavior in choose and use mobile internet services. However, there is no one best methodology to identify factors to attract customers yet. Thus, the study applied the flow construct proposed by Csikszentmihalyi(1977) and expanded by Hoffman and Novak(1996) to identify environmental factors of internet which has impact on users' mobile internet usage. To implement the study, the following activities have been done: literature reviews on service acceptance model and flow structure, questionnaire survey, suggestion of the flow model on mobile internet, and hypothesis test. For the study, 242 out of 307 samples collected were statistically analyzed using SPSS 10.0, AMOS 4.0 statistics package. The findings of this study are as follows: First, mobile internet environment factors influencing on challenge of flow antecedent were media characteristics(use of convenience, transmission quality), contents characteristics(uniqueness, timeliness, simplicity). Second, mobile internet environment factors influencing on skill of flow antecedent were contents(uniqueness, timeliness, simplicity), charge(definiteness and diversity of charge), usage(security, instant connectivity). Third, challenge of flow antecedent had a significant effect on flow of mobile internet usage. But it was not statistically significant that skill has an influence on flow. This study discovered the relationship between mobile internet environment factors(media characteristics, contents characteristics, charge characteristics, usage characteristics) and flow experience of mobile internet users which would be a valuable insight for marketing strategies. Results shows that challenge of flow antecedent have a significant impact on flow experience in mobile internet environment. Additional, media characteristics, contents characteristics of mobile internet environment factors is positively correlated with challenge of flow antecedent. In other words, mobile internet companies should provide customers with diverse service and take a challenging attitude to get customers show aggressive attitude in mobile internet usage.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.107-116
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• 2018

Since 2010, Korea's overseas construction orders have seen dramatic fluctuations. I propose causes and remedies for the industry as a whole. Orders have recorded an annual average of $63.8 billion dollars from 2011 to 2014, reaching its highest at $71.6 billion dollars(2010) which marked the peak of Korea's overseas construction. However, due to a decline in international oil prices, starting in the last half of 2014, Korea's overseas construction orders have followed suit recording $46.1 billion dollar in 2014, $28.2 billion dollars in 2016, and $29.0 billion dollars in 2017. Facing uncertainty in Korea's overseas construction market, caused by continued slow growth of the global economy, Korean EPC contractors are at a critical point in regards to their award-winning capabilities. Together with declining oil prices, the challenges have never been bigger. To mitigate the challenges, I would suggest policy direction as a way to grow and develop the overseas construction industry. Proper counterplans are needed to foster Korea's overseas construction industry. Forecasting total order amount for overseas construction projects is essencial. Analyzing contract award & tender structure and its changing trends in both overseas and world construction markets should also be included. Korea has great potential and global competitiveness. These measures will serve to enhance Korea's overall export strategy in uncertain overseas markets and global economy.

• International Commerce and Information Review
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• v.16 no.5
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• pp.343-359
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• 2014

This study investigates how cultural differences between countries affect bilateral trade volumes, using Hofstede's cultural index that reflects nations' cultural characteristics. Empirical analyses of the impacts of Hofstede's five cultural characteristics on bilateral trade volumes are conducted either in each separate equation or simultaneously. Bilateral trade data of OECD countries plus China as of year 2010 is used for regression analysis on gravity model. Regression results from individual equation for each cultural index variable show tthe smaller the index gaps of power distances and uncertainty avoidance among countries, the larger bilateral trade volumes. On the contrary, the larger the index gaps of long-term orientation among countries, the larger bilateral trade volumes. If five Hofstede cultural indexes are regressed in a single equation, however, only variables of power distance and long-term orientation are significant. The analysis largely confirms that bilateral trade among countries with similar culture have much potrential to grow. It implies that policy actions for cultural proximity are very important for furthering bilateral trade.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.131-138
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• 2015

One of the most conspicuous characteristics of a business model that pursues expanding customer relationship is that it tries to lock in customers by encouraging them to repeat purchase in the long-term with the help of "Follow" function in Social Networking Service (SNS), which enables producers to automatically register the customers as potentially important ones and to offer them customized marketing services. In the value chain of the agriculture sector, producers of agricultural products can use SNS functions to provide loyal customers with valuable information and experiences such as the real-time information of their farm and products, hidden stories about the whole process from seeding to harvesting, and the storage and cooking methods of their products. These activities help the producers invoke customers' desire to live in the farm and to grow the products themselves. They also raise the accessibility of the producers' websites as customers are able to share a variety of news and knowledge such as the release of new products. This means that the producers's websites are now functioning to enable the producers to perform sales and promotion related activities. It is a big leap from the traditional e-commerce business model where sales and promotion of a product were separated and could be connected only through outside links. This two-way, viral characteristics of marketing services using SNS facilitate customers to share product information and their purchase experience with each other, which leads to more effective and efficient communication within the customer community.

• Journal of Gifted/Talented Education
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• v.24 no.6
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• pp.975-1000
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• 2014

This study is a case study about the status of science gifted follow-up management systems for nation-level institutes for gifted and talented education. The aim of the study is to develop the theoretical model that establishes the basis of follow-up management systems for scientifically gifted to support in order to grow the beneficiaries of nation- level scientifically gifted education into globally competitive talented. Specifically, this study says the components of the systematic and efficient structure for nation-level gifted follow-up management. For this, we collect the experts' opinions on gifted education for follow-up management of the beneficiaries on national level science gifted, and gifted and talented education institutions conducted the case study for follow-up management. The collecting of experts' opinion have participated 11 persons, and 6 institutes were involved in the case study of follow-up management institutes. As a result, it reports for scientifically gifted follow-up management systems to be made by forming of the upper systems and each lower systems. Resources system was found to be composed of human information system and education information system. Operating system was found to be composed of input system, analysis system, and management system. Application system was found to be composed of prediction system, verification system and improvement system.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.5-5
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• 1999

The Principal deficiency of the existing notion about the sintering-mixtures consists in the fact that almost no attention is focused on the Phenomenon of alloy formation during sintering, its connection with dimensional changes of powder bodies, and no correct ideas on the driving force for the sintering process in the stage of establishing chemical equilibrium in a system are available as well. Another disadvantage of the classical sintering theory is an erroneous conception on the dissolution mechanism of solid in liquid. The two-particle model widely used in the literature to describe the sintering phenomenon in solid state disregards the nature of the neighbouring surrounding particles, the presence of pores between them, and the rise of so called arch effect. In this presentation, new basic scientific principles of the driving forces for the sintering process of a two-component powder body, of a diffusion mechanism of the interaction between solid and liquid phases, of stresses and deformation arising in the diffusion zone have been developed. The major driving force for sintering the mixture from components capable of forming solid solutions and intermetallic compounds is attributed to the alloy formation rather than the reduction of the free surface area until the chemical equilibrium is achieved in a system. The lecture considers a multiparticle model of the mixed powder-body and the nature of its volume changes during solid-state and liquid-phase sintering. It explains the discovered S-and V-type concentration dependencies of the change in the compact volume during solid-state sintering. It is supposed in the literature that the dissolution of solid in liquid is realised due to the removal of atoms from the surface of the solid phase into the melt and then their diffusicn transfer from the solid-liquid interface into the bulk of liquid. It has been shown in our experimental studies that the mechanism of the interaction between two components, one of them being liquid, consist in diffusion of the solvent atoms from the liquid into the solid phase until the concentration of solid solutions or an intermetallic compound in the surface layer enables them to pass into the liquid by means of melting. The lecture discusses peculimities of liquid phase formation in systems with intermediate compounds and the role of the liquid phase in bringing about the exothermic effect. At the frist stage of liquid phase sintering the diffusion of atoms from the melt into the solid causes the powder body to grow. At the second stage the diminution of particles in size as a result of their dissolution in the liquid draws their centres closer to each other and makes the compact to shrink Analytical equations were derived to describe quantitatively the porosity and volume changes of compacts as a result of alloy formation during liquid phase sinteIing. Selection criteria for an additive, its concentration and the temperature regime of sintering to control the density the structure of sintered alloys are given.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.37-47
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• 2018

The number of capabilities of Internet of Things (IoT) devices will exponentially grow over the next years. These devices may generate a vast amount of time-constrained data. In the context of IoT, data management should act as a layer between the objects and devices generating the data and the applications accessing the data for analysis purposes and services. In addition, most of IoT services will be content-centric rather than host centric to increase the data availability and the efficiency of data delivery. IoT will enable all the communication devices to be interconnected and make the data generated by or associated with devices or objects globally accessible. Also, fog computing keeps data and computation close to end users at the edge of network, and thus provides a new breed of applications and services to end users with low latency, high bandwidth, and geographically distributed. In this paper, we propose Edge-Fog cloud-based Hierarchical Data Delivery ($EFcHD^2$) method that effectively and reliably delivers IoT data to associated with IoT applications with ensuring time sensitivity. The proposed $EFcHD^2$ method stands on basis of fully decentralized hybrid of Edge and Fog compute cloud model, Edge-Fog cloud, and uses information-centric networking and bloom filters. In addition, it stores the replica of IoT data or the pre-processed feature data by edge node in the appropriate locations of Edge-Fog cloud considering the characteristic of IoT data: locality, size, time sensitivity and popularity. Then, the performance of $EFcHD^2$ method is evaluated through an analytical model, and is compared to fog server-based and Content-Centric Networking (CCN)-based data delivery methods.