• 경영과학
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• 제21권2호
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• pp.273-289
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• 2004

Although the Internet is useful for transferring information, Internet auction environments make fraud more attractive to offenders, because the chance of detection and punishment is decreased. One of these frauds is the phantom transaction, which is a colluding transaction by the buyer and seller to commit the illegal discounting of a credit card. They pretend to fulfill the transaction paid by credit card, without actually selling products, and the seller receives cash from the credit card corporations. Then the seller lends it out with quite a high interest rate to the buyer, whose credit rating is so poor that he cannot borrow money from anywhere else. The purpose of this study is to empirically investigate the factors necessary to detect phantom transactions in an online auction. Based upon studies that have explored the behaviors of buyers and sellers in online auctions, the following have been suggested as independent variables: bidding numbers, bid increments, sellers' credit, auction lengths, and starting bids. In this study. we developed Internet-based data collection software and collected data on transactions of notebook computers, each of which had a winning bid of over W one million. Data analysis with a logistic regression model revealed that starting bids, sellers' credit, and auction length were significant in detecting the phantom transactions.

• 유통과학연구
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• 제18권12호
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• pp.91-100
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• 2020

Purpose: The objective of this study is to deepen our understanding of the key factors that determine sustainability in terms of suppliers based on the transactions between suppliers (pharmaceutical companies) and buyers (medical institutions) in the pharmaceutical distribution industry. Research design, data and methodology: Transaction justice factors were derived from three main components: distributive, procedural and interpersonal, five hypotheses were set up. The respondents from the data collected through an online survey are sales staff of pharmaceutical companies. Total of 319 questionnaires are collected and used to verify the hypotheses through the SPSS 22.0 and AMOS 22.0 programs. Results: Justice of transactions perceived by the salesperson of pharmaceutical companies was found to have a significant effect on the relationship commitment. Among them, procedural justice was found to have greatest relative influences. In addition, relationship commitment was found to have a significant effect on sustainability performance. Thus, all hypotheses were adopted. Conclusions: The results of this study, can be used as basic data for the guidelines for fair trade between pharmaceutical companies and medical institutions. In addition, it is expected that the study will have significance in that it examined sustainability through transactions with buyers from the viewpoint of suppliers.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.77-83
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• 2021

The dependency on technology has increased with the increase in population. Technology plays a crucial role in facilitating, organizing and securing people's life nowadays. The Internet has penetrated every face of present-day lifestyles. Yet another ubiquitous use of digital technology today is evident in transferring money and speeding cross border payments that are done through digital transactions. This paper investigates transferring money and data through banks and companies by using the Blockchain concept through decentralized distributed system. The present research also peruses several contexts in which this technology has already been implemented successfully and demonstrates the advantages of replacing the paper money with digital money. Using cryptocurrency will facilitate people's life by reducing time, securing the process of money transfer, and increasing data integrity. The primary benefit of this content analysis is that it addresses an innovative subject, in a new light and using timely recent research references drawn from 2018-2020. Thus, our study is a contemporary and conclusive source for all present and future endeavours being undertaken in the domain of using blockchain for e-transactions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.264-284
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• 2021

As the next-generation network architecture, software-defined networking (SDN) has great potential. But how to forward data packets safely is a big challenge today. In SDN, packets are transferred according to flow rules which are made and delivered by the controller. Once flow rules are modified, the packets might be redirected or dropped. According to related research, we believe that the key to forward data flows safely is keeping the consistency of flow rules. However, existing solutions place little emphasis on the safety of flow rules. After summarizing the shortcomings of the existing solutions, we propose FRChain to ensure the security of SDN data forwarding. FRChain is a novel scheme that uses blockchain to secure flow rules in SDN and to detect compromised nodes in the network when the proportion of malicious nodes is less than one-third. The scheme places the flow strategies into blockchain in form of transactions. Once an unmatched flow rule is detected, the system will issue the problem by initiating a vote and possible attacks will be deduced based on the results. To simulate the scheme, we utilize BigchainDB, which has good performance in data processing, to handle transactions. The experimental results show that the scheme is feasible, and the additional overhead for network performance and system performance is less than similar solutions. Overall, FRChain can detect suspicious behaviors and deduce malicious nodes to keep the consistency of flow rules in SDN.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.111-118
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• 2021

Banking systems are sensitive to data privacy since users' data, if not well protected, may be used to perform fake transactions. Blockchains, public and private, are frequently used in such systems thanks to their efficiency and high security. Public blockchains fail to fully protect users' data, despite their power in the accuracy of the transactions. The private blockchain is better used to protect the privacy of the sensitive data. They are not open and they apply authorization to login into the blockchain. However, they have a lower security compared to public blockchain. We propose in this paper a hybrid public-private architecture that profits from network virtualization. The main novelty of this proposal is the use of network virtualization that helps to reduce the complexity and efficiency of the computations. Simulations have been conducted to evaluate the performance of the proposed solution. Findings prove the efficiency of the scheme in reducing complexity and enhancing data privacy by guarantee high security. The contribution conducted by this proposal is that the results are verified by the centralized controller that ensures a correct validation of the resulted blockchains. In addition, computation complexity is to be reduced by profiting from the cooperation performed by the virtual agents.

• ETRI Journal
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• 제40권1호
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• pp.111-121
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• 2018

To find the emerging patterns (EPs) in streaming transaction data, the streaming is first divided into some time windows containing a number of transactions. Itemsets are generated from transactions in each window, and then the emergence of itemsets is evaluated between two windows. In the tilted-time windows model (TTWM), it is assumed that people need support data with finer accuracy from the most recent windows, while accepting coarser accuracy from older windows. Therefore, a limited array's elements are used to maintain all support data in a way that condenses old windows by merging them inside one element. The capacity of elements that accommodates the windows inside is modeled using a particular number sequence. However, in a stream, as new data arrives, the current array updating mechanisms lead to many null elements in the array and cause data incompleteness and inaccuracy problems. Two models derived from TTWM, logarithmic TTWM and Fibonacci windows model, also inherit the same problems. This article proposes a novel push-front Fibonacci windows model as a solution, and experiments are conducted to demonstrate its superiority in finding more EPs compared to other models.

• 한국전자통신학회논문지
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• 제16권5호
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• pp.783-788
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• 2021

스마트제조는 제품기획, 설계, 생산, 품질, 재고, 조달 등 스마트공장 내 제조 프로세스의 정보화, 최적화 및 생산 시스템의 자동화를 ICT기반 스마트 기술로 실현하는 제조 공정으로 정의된다. 본 논문에서는 스마트공장과 스마트제조 시스템의 운영시 발생하는 제조 데이터와 관련된 국내 표준화 동향에 대해 소개한다. 표준화의 범위가 매우 넓기 때문에 스마트공장 및 제조 ICT시스템과 관련된 일반적인 표준화 내용 및 제조 데이터를 거래시 필요한 표준에 관련된 사항을 다룬다. 이를 기반으로 하여 제조 데이터의 활용을 위해 필요한 사항에 대해 논의한다.

• ETRI Journal
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• 제34권4호
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• pp.553-563
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• 2012

Serial peripheral interface (SPI) has been identified as a bottleneck in many wireless sensing systems today. SPI is used almost universally as the physical connection between the microcontroller unit (MCU) and radios, storage devices, and many types of sensors. Virtually all wireless sensor nodes today perform up to twice as many bus transactions as necessary to transfer a given piece of data, as an MCU must serve as the bus master in all transactions. To eliminate this bottleneck, we propose the master-handoff protocol. After the MCU initiates reading from the source slave device and writing to the sink slave device, the MCU as a master becomes a slave, and either the source or the sink slave becomes the temporary master. Experiment results show that this master-handoff technique not only cuts the data transfer time in half, but, more importantly, also enables a superlinear energy reduction.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2007년도 추계학술대회
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• pp.489-498
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• 2007

For better predictions and classifications in customer recommendation, this study proposes an integrative model that efficiently combines the currently-in-use statistical and artificial intelligence models. In particular, by integrating the models such as Association Rule, Frequency Matrix, and Rule Induction, this study suggests an integrative prediction model. The data set for the tests is collected from a convenience store G, which is the number one in its brand in S. Korea. This data set contains sales information on customer transactions from September 1, 2005 to December 7, 2005. About 1,000 transactions are selected for a specific item. Using this data set, it suggests an integrated model predicting whether a customer buys or not buys a specific product for target marketing strategy. The performance of integrated model is compared with that of other models. The results from the experiments show that the performance of integrated model is superior to that of all other models such as Association Rule, Frequency Matrix, and Rule Induction.

• 한국정보과학회논문지:데이타베이스
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• 제30권1호
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• pp.95-107
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• 2003

방송환경은 서버(server)와 클라이언트(client)간 대역폭이 서버에서 클라이언트 쪽으로는 크고 클라이언트에서 서버쪽으로의 대역폭은 상대적으로 많이 작은 비대칭적(asymmetric) 특수한 환경이다. 또한 대부분의 방송 환경 응용 시스템들은 클라이언트 측에서 발생한 주로 주식 데이타, 교통 정보와 새로운 뉴스와 같은 여러 가지 다양한 정보를 검색하는 읽기전용 즉 질의 거래들을 허락한다. 그러나. 기존의 여러가지 동시성 제어 기법들은 이러한 특수성을 고려하지 않음으로써 방송 환경에 적용된 때 거래들의 불필요한 철회를 일으킨다. 이 논문에서는 방송환경에서 질의 거래를 위한 효율적인 동시성 제어 기법을 제안한다. 이 기법은 서버에 의해 관리 유지되고 클라이언트에 의해 읽혀지는 데이타의 상호 일치성과 데이터의 현재성을 만족시키기에 가장 적절한 정확성 검증 기준인 약한 일치성(Weak consistency)을 채택하였다. 또한, 그것을 효율적으로 실행할 수 있도록 직렬화 그래프(serializability graph)를 이용하였다. 그 결과, 전역적 직렬화를 적용할 때 발생되는 질의 거래의 불필요한 철회 및 재시작의 횟수를 줄임으로써 성능향상을 도모하였다.