• KIPS Transactions on Software and Data Engineering
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• v.7 no.10
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• pp.387-396
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• 2018

Stock price prediction has been a difficult problem to solve. There have been many studies to predict stock price scientifically, but it is still impossible to predict the exact price. Recently, a variety of types of cryptocurrency has been developed, beginning with Bitcoin, which is technically implemented as the concept of distributed ledger. Various approaches have been attempted to predict the price of cryptocurrency. Especially, it is various from attempts to stock prediction techniques in traditional stock market, to attempts to apply deep learning and reinforcement learning. Since the market for cryptocurrency has many new features that are not present in the existing traditional stock market, there is a growing demand for new analytical techniques suitable for the cryptocurrency market. In this study, we first collect and process seven cryptocurrency price data through Bithumb's API. Then, we use the gradient boosting model, which is a data-driven learning based machine learning model, and let the model learn the price data change of cryptocurrency. We also find the most optimal model parameters in the verification step, and finally evaluate the prediction performance of the cryptocurrency price trends.

• The Journal of Korean Association of Computer Education
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• v.23 no.4
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• pp.49-59
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• 2020

At the beginning of the discussion of AI education in K-12 education, the study was conducted to develop and apply an AI education program based on Design Thinking and analyze the effects of the AI education programs. In the AI education program, students explored and defined the AI problems they were interested in, gathered the necessary data to build an AI model, and then developed a project using scratch. In order to analyze the effectiveness of the AI education program, the change of learner's perception of the value of AI and the change of AI efficacy were analyzed. The overall perception of the AI project was also analyzed. As a result, AI efficacy was significantly increased through the experience of carrying out the project according to the Design Thinking process. In addition, the efficacy of solving problems with AI was influenced by the level of use of programming languages. The learner's overall perception of the AI project was positive, and the perceptions of each stage of the AI project (AI problem understanding and problem exploration, practice, problem definition, problem solving idea implementation, evaluation and presentation) was also positive. This positive perception was higher among students with high level of programming language use. Based on these results, the implications for AI education were suggested.

• International Commerce and Information Review
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• v.16 no.1
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• pp.145-161
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• 2014

The study has try to find out the relationship between airfreight service quality and satisfaction in international forwarding practice which has focused to figure out the mediating role of performance that measured as subjective evaluation on profit. For the purpose of this paper, questionnaire survey has been performed on the relationship among the procedure of the air freight service quality was found to have not only direct influence but also indirect impact through performance on satisfaction. This research made some contribution both academicals and logistic practices. Academically, it is the first research to address the relationship between air freight service quality and profit performance in Korean academic field. Practically, this study provides justification for the investment to improve forwarding service quality. The results of this study bear some implications on international shipping and practice. The quality of the air cargo transportation management system for customer satisfaction and its impact on business performance in the process to make an empirical identifies. The role and influence of the working-level analysis to derive the performance as transportation management, as well as the effectiveness of customer satisfaction for quality and promote a point. Arrange this point take advantage of air cargo companies are composed of service quality management system for the dimension of course aims to foster a competitive advantage in terms of performance. This paper suggest that real-time movement of the consignment route provides information such as verification and business cooperation for the purpose of proper features a reflecting on the stability of cargo air freight management system, that improve the quality of services on this performance to increase the customer satisfaction strategy in connected getting and so on, is in the process of the formation of customer satisfaction.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.251-258
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• 2013

Recently companies are confronted with a much more sophisticated business environment than before and at the same time have to be able to adapt to rapid changes. Accordingly, the need for selecting among alternatives and managing systematic decision-making has been steadily increasing to respond to a more diverse customer needs and keep up with the fierce competition. In this study, we propose a framework that consist of problem solving procedures and techniques and knowledge structure built on processes to support strategic decision making. and discuss how to utilize simulation tools as the knowledge-based problem solving tools. In addition we discuss how to build and advance the knowledge structure to implement the proposed architecture. Management decision support systems architecture consist of three key factors. The first is Problem Solving Approach which is used as reference. The second is knowledge structure on business processes that includes standard and reference business processes. The third is simulators that are able to generate and analyze alternatives using problem solving techniques and knowledge base. In sum, the proposed framework of decision-making support systems facilitates knowledge-intensive consulting processes to promote the development and application of consulting knowledge and techniques and increase the efficiency of consulting firms and industry.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.221-227
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• 2013

RFID is an automatic identification technology that can control a range of information via IC chips and radio communication. Also known as electronic tags, smart tags or electronic labels, RFID technology enables embedding the overall process from production to sales in an ultra-small IC chip and tracking down such information using radio frequencies. Currently, RFID-based application and development is in progress in such fields as health care, national defense, logistics and security. RFID structure consists of a reader that reads tag information, a tag that provides information and the database that manages data. Yet, the wireless section between the reader and the tag is vulnerable to security issues. To sort out the vulnerability, studies on security protocols have been conducted actively. However, due to difficulties in implementation, most suggestions are concerned with theorem proving, which is prone to vulnerability found by other investigators later on, ending up in many troubles with applicability in practice. To experimentally test the security of the protocol proposed here, the formal verification tool, CasperFDR was used. To sum up, the proposed protocol was found to be secure against diverse attacks. That is, the proposed protocol meets the safety standard against new types of attacks and ensures security when applied to real tags in the future.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.42-53
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• 2015

Construction industry has the form of industry progressed through mutual cooperation among participants in various fields. Accordingly, it may be referred to as an aggregate of information where various pieces of information are generated and managed according to each construction phase. Most of the information on the construction project is issued in the form of a document. And document management of the site is critical to successful execution of the project. Therefore, in the construction site to use IT technology for efficient information management. But, most of the information on the construction site is managed by the non-structured document. and Information management in the construction site is difficult to lack of information management systems. In this study, proposed construction information database structure and breakdown structure to the information management of the construction site through the BIM technology. Therefore, previous studies were reviewed about the document management and information link management. and Space breakdown structure and information breakdown structure was proposed to structure the information of the construction site and Database for information storage is designed. And, BIM-based construction information database was examined through the application scenario.

• Journal of The Korean Association of Information Education
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• v.12 no.4
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• pp.437-448
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• 2008

As the importance of knowledge is emphasized and the environment of battlefields is changing, the military also demands competent people equipped with creativity, cooperativeness and communication ability, and in this situation it is required to apply PBL to education in the navy. The present study went through three stages in order to develop a prototype to implement a naval e PBL support system for knowledge creation. First, databases in Korea Education and Research Information Service, National Assembly Library, etc. were searched using keywords such as PBL, e-PBL, knowledge creation and knowledge ecosystem. In addition, we selected and analyzed frequently quoted literature and recent research reports related to this study among domestic and foreign theses, books, research papers, etc. recommended by specialists in contents, and derived the key values of a knowledge creation type e-PBL support system and design strategies. Second, we developed a primary prototype based on the contents of analysis and, revising it according to teaching design specialists' opinions, we proposed the final prototype of knowledge creation type naval e PBL support system and it has values as follows. First, the knowledge creation type naval e PBL support system provides learners with opportunities to apply e PBL and helps them improve their creativity, cooperativeness and communication ability and accumulate know how of services. Second, it improves work efficiency by circulating knowledge through sharing among individuals or groups, and produces synergy that promotes the organizational culture of learning. Third, the knowledge creation type naval e-PBL support system enables teachers who apply PBL to school education to find new applications of PBL in constructing knowledge bases.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.12-28
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• 2017

The core of the transportation service, so-called Mobility 4.0 is the flexibility of the entire mobility and its implementation. By doing so, the most essential element is to build a platform to link a supply and a demand simultaneously. In other word, a comprehensive analytical framework is to be set with a data repository which can be periodically updated. With such circumstances, the entire trip chain including pedestrian movements is required to be thoroughly investigated and constructed at the viewpoint of the intermodal transit station. A few studies, however, have been attempted. In this study, the comprehensive analytical framework with the integrated mobility at intermodal transit station was proposed, which consisted of the three modules; 1) Data Repository Extracting from Smart Card DB, 2) Framework of Analyzing Integrated Mobility, and 3) Interpretation of the Integrated Mobility with GIS information and the other factors. A case study with the seven railway stations (Sadang, Sindorom, Samseong, Gwanghwanoon, Gangnam, Jamsil, Seoul Nat'l Univ. of Education) was conducted. The stations of the case study were clustered by the three groups with the statistical ground, and it is most likely to understand the effect of a variety of factors and a comprehensive data-driven analyses with the entire trip stages.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.38-46
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• 2012

Atrial fibrillation is needed to be detected at paroxysmal stage and to be treated. But, paroxysmal atrial fibrillation ECG is hardly obtained with 12-lead electrocardiographs but Holter systems. Presently, the averaged beat subtraction(ABS) method is solely used to estimate atrial fibrillatory waves even with somewhat large residual error. As an alternative, in this study, we suggested an ESAF(event-synchronous adaptive filter) based algorithm, in which the AF ECG was treated as a primary input and event-synchronous impulse train(ESIT) as a reference. And, ESIT was generated so to be synchronized with the ventricular activity by detecting QRS complex. We tested proposed algorithm with simulated AF ECGs and real AF ECGs. As results, even with low computational cost, this ESAF based algorithm showed better performance than the ABS method and comparable performance to algorithm based on PCA(principal component analysis) or SVD(singular value decomposition). We also proposed an expanded version of ESAF for some AF ECGs with multi-morphologic ventricular activities and this also showed reasonable performance. Ultimately, with Holter systems including our proposed algorithm, atrial activity signal can be precisely estimated in real-time so that it will be possible to calculate atrial fibrillatory rate and to evaluate the effect of anti-arrhythmic drugs.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.209-218
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• 2012

Recently, the Field Programmable Stateful Logic Array (FPSLA) was proposed as one of the most promising system integration technologies which will extend the life of the Moore's law. This work is the first proposal of the FPSLA design automation flow, and the approaches to logic synthesis, synchronization, physical mapping, and automatic placement of the FPSLA designs. The synchronization at each gate for pipelining determines the x-coordinates of cells, and reduces the placement to 1-dimensional problems. The objective function and its gradients for the non-linear optimization of the net length and placement density have been remodeled for the reduced global placement problem. Also, a recursive algorithm has been proposed to legalize the placement by relaxing the density overflow of bipartite bin groups in a top-down hierarchical fashion. The proposed model and algorithm are implemented, and validated by applying them to the ACM/SIGDA benchmark designs. The output state of a gate in an FPSLA needs to be duplicated so that each fanout gate can be connected to a dedicated copy. This property has been taken into account by merging the duplicated nets into a hyperedge, and then, splitting the hyperedge into edges as the optimization progresses. This yields additional 18.4% of the cell count reduction in the most dense logic stage. The practicality of the FPSLA can be further enhanced primarily by incorporating into the logic synthesis the constraint to avoid the concentrated fains of gates on some logic stages. In addition, an efficient algorithm needs to be devised for the routing problem which is based on a complicated graph. The graph models the nanowire crossbar which is trimmed to be embedded into the FPSLA fabric, and therefore, asymmetric. These CAD tools can be used to evaluate the fabric efficiency during the architecture enhancement as well as automate the design.