• Title/Summary/Keyword: 학부(學部)

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A Study on the Fraud Detection in an Online Second-hand Market by Using Topic Modeling and Machine Learning (토픽 모델링과 머신 러닝 방법을 이용한 온라인 C2C 중고거래 시장에서의 사기 탐지 연구)

  • Dongwoo Lee;Jinyoung Min
    • Information Systems Review
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    • v.23 no.4
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    • pp.45-67
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    • 2021
  • As the transaction volume of the C2C second-hand market is growing, the number of frauds, which intend to earn unfair gains by sending products different from specified ones or not sending them to buyers, is also increasing. This study explores the model that can identify frauds in the online C2C second-hand market by examining the postings for transactions. For this goal, this study collected 145,536 field data from actual C2C second-hand market. Then, the model is built with the characteristics from postings such as the topic and the linguistic characteristics of the product description, and the characteristics of products, postings, sellers, and transactions. The constructed model is then trained by the machine learning algorithm XGBoost. The final analysis results show that fraudulent postings have less information, which is also less specific, fewer nouns and images, a higher ratio of the number and white space, and a shorter length than genuine postings do. Also, while the genuine postings are focused on the product information for nouns, delivery information for verbs, and actions for adjectives, the fraudulent postings did not show those characteristics. This study shows that the various features can be extracted from postings written in C2C second-hand transactions and be used to construct an effective model for frauds. The proposed model can be also considered and applied for the other C2C platforms. Overall, the model proposed in this study can be expected to have positive effects on suppressing and preventing fraudulent behavior in online C2C markets.

The Influencing Factors and Moderating Factors on Intention to Continuously Use Car-Hailing Mobility Service (차량호출 모빌리티 서비스 지속이용의도의 영향요인 및 조절요인 연구)

  • Ae Ri Lee
    • Information Systems Review
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    • v.23 no.4
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    • pp.103-125
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    • 2021
  • Mobility services are rapidly developing along with information and communication technology (ICT) innovation. Recently, the on-demand mobility platform market is growing, and an environment is provided in which users can call services more conveniently and check the connection status in real time using smartphones. This study investigates the current status of users' perceptions and experiences of car-hailing mobility services such as KAKAO Taxi and UT Taxi, and it analyzes the factors affecting the intention to continuously use the car-hailing service, focusing on environmental and instrumental benefits and trust in driver and platform. In particular, this study examines whether the significance of the relationship between influencing factors and continuous use intention could vary depending on the degree of innovativeness and ICT utilization. The results of this study showed that perceived benefits (environmental benefits and convenience and economic instrumental benefits) and trust in driver had significant effects on increasing trust in platform. It was analyzed that the higher the trust in platform, the higher the intention to continuously use the car-hailing service. Furthermore, the influence of perceived environmental benefits and economic benefits on the trust in platform was different depending on the degree of individual innovativeness, and the influence of convenience and economic benefits on the trust in platform varied depending on the degree of ICT utilization. Referring to the results of this study, mobility service providers can better understand the current status of users' perceptions and trust for car-hailing services, and implement service promotion strategies suitable for individual characteristics.

The Differential Impacts of Temporary Aberration on Online Review Consumption and Generation (온라인 리뷰 소비 및 생성에 대한 일시적 이상 현상의 차등 효과)

  • Junyeong Lee;Hyungjin Lukas Kim
    • Information Systems Review
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    • v.23 no.3
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    • pp.127-158
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    • 2021
  • Many online travel agencies (OTAs) provide average ratings and time-relevant information or the most recently posted reviews regarding hotels to satisfy customers. To identify these two factors' relative influence on behavioral decision-making processes, we conducted two studies: (1) an experimental research design to explore the relative influence of the two on online review consumption and (2) an empirical approach to examine their relative impact on online review generation. The results show that when review posters observe an inconsistency between average ratings and recent reviews, they tend to deviate from the recent reviews regardless of the overall direction (reactance behavior). Meanwhile, review consumers tend to conform to the opinions presented in recent reviews (herding behavior). Additionally, in both cases, the effects are amplified in case of a negative aberration. Based on the findings, this study provides theoretical and practical implications regarding the relative influences of average rating and recently posted reviews and their different impacts on online review consumption and generation.

The Factors Influencing Value Awareness of Personalized Service and Intention to Use Smart Home: An Analysis of Differences between "Generation MZ" and "Generation X and Baby Boomers" (스마트홈 개인화 서비스에 대한 가치 인식 및 사용의도에의 영향 요인: "MZ세대"와 "X세대 및 베이비붐 세대" 간 차이 분석)

  • Sang-Keul Lee;Ae Ri Lee
    • Information Systems Review
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    • v.23 no.3
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    • pp.201-223
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    • 2021
  • Smart home is an advanced Internet of Things (IoT) service that enhances the convenience of human daily life and improves the quality of life at home. Recently, with the emergence of smart home products and services to which artificial intelligence (AI) technology is applied, interest in smart home is increasing. To gain a competitive edge in the smart home market, companies are providing "personalized service" to users, which is a key service that can promote smart home use. This study investigates the factors affecting the value awareness of personalized service and intention to use smart home. This research focuses on four-dimensional motivated innovativeness (cognitive, functional, hedonic, and social innovativeness) and privacy risk awareness as key factors that influence the value awareness of personalized service of smart home. In particular, this study conducts a comparative analysis between the generation MZ (young people in late teens to 30s), who are showing socially differentiated characteristics, and the generation X and baby boomers in 40s to 50s or older. Based on the analysis results, this study derives the distinctive characteristics of generation MZ that are different from the older generation, and provides academic and practical implications for expanding the use of smart home services.

Chart-based Stock Price Prediction by Combing Variation Autoencoder and Attention Mechanisms (변이형 오토인코더와 어텐션 메커니즘을 결합한 차트기반 주가 예측)

  • Sanghyun Bae;Byounggu Choi
    • Information Systems Review
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    • v.23 no.1
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    • pp.23-43
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    • 2021
  • Recently, many studies have been conducted to increase the accuracy of stock price prediction by analyzing candlestick charts using artificial intelligence techniques. However, these studies failed to consider the time-series characteristics of candlestick charts and to take into account the emotional state of market participants in data learning for stock price prediction. In order to overcome these limitations, this study produced input data by combining volatility index and candlestick charts to consider the emotional state of market participants, and used the data as input for a new method proposed on the basis of combining variantion autoencoder (VAE) and attention mechanisms for considering the time-series characteristics of candlestick chart. Fifty firms were randomly selected from the S&P 500 index and their stock prices were predicted to evaluate the performance of the method compared with existing ones such as convolutional neural network (CNN) or long-short term memory (LSTM). The results indicated the method proposed in this study showed superior performance compared to the existing ones. This study implied that the accuracy of stock price prediction could be improved by considering the emotional state of market participants and the time-series characteristics of the candlestick chart.

Conductive Performance of Mortar Containing Fe-Activated Biochar (Fe에 의해 활성화된 목질계 바이오차를 혼입한 모르타르의 전도성능)

  • Jin-Seok Woo;Ai-Hua Jin;Won-Chang Choi;Soo-Yeon Seo;Hyun-Do Yun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.2
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    • pp.27-34
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    • 2024
  • This study was conducted to examine the feasibility of using Fe-activated wood-derived biochar as a conductive filler for manufacturing cement-based strain sensor. To evaluate the compressive and electrical properties of cement composite with 3% Fe-activated biochar, three cubic specimens of size 50 x 50 x 50mm3 and three prismatic cement-based sensors of size 40 x 40 x 80mm3 were prepared respectively. The four-probe method of electrical resistance measurement was used for cement-based sensors. For cement-based sensors with FE-activated biochar, the conductive performance such as electrical resistance and impedance under different water content and repeated compression was investigated. Results showed that the fractional changes in the DC electrical resistivity of cement-based sensors increase with increasing time and the maximum fractional changes in the resistivity decrease with increasing the moisture contents during 900s. At moisture content of 7.5% range, the conductive performance of cement composite including 3% Fe-activated biochar as a conductive filler showed the most stable, while the strain detection ability tended to decrease somewhat as the repeated compressive stress increased between repeated compressive strain and fractional change in resistivity (FCR).

What's Different about Fake Review? (조작된 리뷰(Fake Review)는 무엇이 다른가?)

  • Jung Won Lee;Cheol Park
    • Information Systems Review
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    • v.23 no.1
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    • pp.45-68
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    • 2021
  • As the influence of online reviews on consumer decision-making increases, concerns about review manipulation are also increasing. Fake reviews or review manipulations are emerging as an important problem by posting untrue reviews in order to increase sales volume, causing the consumer's reverse choice, and acting at a high cost to the society as a whole. Most of the related prior studies have focused on predicting review manipulation through data mining methods, and research from a consumer perspective is insufficient. However, since the possibility of manipulation of reviews perceived by consumers can affect the usefulness of reviews, it can provide important implications for online word-of-mouth management regardless of whether it is false or not. Therefore, in this study, we analyzed whether there is a difference between the review evaluated by the consumer as being manipulated and the general review, and verified whether the manipulated review negatively affects the review usefulness. For empirical analysis, 34,711 online book reviews on the LibraryThing website were analyzed using multilevel logistic regression analysis and Poisson regression analysis. As a result of the analysis, it was found that there were differences in product level, reviewer level, and review level factors between reviews that consumers perceived as being manipulated and reviews that were not. In addition, manipulated reviews have been shown to negatively affect review usefulness.

The Effects of Live Commerce and Show Host Features on Consumers' Likelihood of Impulse Buying: A Scenario-Based Experiment (라이브 커머스 및 쇼호스트 특성이 소비자의 충동구매가능성에 미치는 영향: 시나리오 기반 실험연구)

  • Nakyeong Kim;Sung-Byung Yang;Sang-Hyeak Yoon
    • Information Systems Review
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    • v.24 no.4
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    • pp.77-96
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    • 2022
  • Live commerce has recently received substantial attention due to the spread of the non-face-to-face consumption culture driven by the COVID-19 pandemic. Live commerce has a higher purchase conversion rate than other forms of commerce. Accordingly, the likelihood of impulse buying in a live commerce environment is expected to be high. However, there is a shortage of research on consumer impulse buying in the live commerce environment. This study designs a scenario-based experiment using the integrated model of consumption impulse formation and enactment. Through this method, this study validates the influence of the characteristics of live commerce (i.e., vicarious experience and real-time interaction) on consumers' likelihood of impulse buying and further examines the moderating role of a live commerce host feature (i.e., professionalism) in these relationships. The results of this study confirm that both vicarious experience and real-time interaction have a positive effect on consumers' likelihood of impulse buying and that professionalism strengthens the impact of vicarious experience on the likelihood of impulse buying. This study's scenario-based experimental design is meaningful because it analyzes the likelihood of impulse buying in the context of live commerce shopping. Additionally, it provides live commerce service and platform providers with practical insights into how to maximize profits and operate services more efficiently.

Analysis of Research Trends Related to drug Repositioning Based on Machine Learning (머신러닝 기반의 신약 재창출 관련 연구 동향 분석)

  • So Yeon Yoo;Gyoo Gun Lim
    • Information Systems Review
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    • v.24 no.1
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    • pp.21-37
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    • 2022
  • Drug repositioning, one of the methods of developing new drugs, is a useful way to discover new indications by allowing drugs that have already been approved for use in people to be used for other purposes. Recently, with the development of machine learning technology, the case of analyzing vast amounts of biological information and using it to develop new drugs is increasing. The use of machine learning technology to drug repositioning will help quickly find effective treatments. Currently, the world is having a difficult time due to a new disease caused by coronavirus (COVID-19), a severe acute respiratory syndrome. Drug repositioning that repurposes drugsthat have already been clinically approved could be an alternative to therapeutics to treat COVID-19 patients. This study intends to examine research trends in the field of drug repositioning using machine learning techniques. In Pub Med, a total of 4,821 papers were collected with the keyword 'Drug Repositioning'using the web scraping technique. After data preprocessing, frequency analysis, LDA-based topic modeling, random forest classification analysis, and prediction performance evaluation were performed on 4,419 papers. Associated words were analyzed based on the Word2vec model, and after reducing the PCA dimension, K-Means clustered to generate labels, and then the structured organization of the literature was visualized using the t-SNE algorithm. Hierarchical clustering was applied to the LDA results and visualized as a heat map. This study identified the research topics related to drug repositioning, and presented a method to derive and visualize meaningful topics from a large amount of literature using a machine learning algorithm. It is expected that it will help to be used as basic data for establishing research or development strategies in the field of drug repositioning in the future.

A Design of Authentication Mechanism for Secure Communication in Smart Factory Environments (스마트 팩토리 환경에서 안전한 통신을 위한 인증 메커니즘 설계)

  • Joong-oh Park
    • Journal of Industrial Convergence
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    • v.22 no.4
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    • pp.1-9
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    • 2024
  • Smart factories represent production facilities where cutting-edge information and communication technologies are fused with manufacturing processes, reflecting rapid advancements and changes in the global manufacturing sector. They capitalize on the integration of robotics and automation, the Internet of Things (IoT), and the convergence of artificial intelligence technologies to maximize production efficiency in various manufacturing environments. However, the smart factory environment is prone to security threats and vulnerabilities due to various attack techniques. When security threats occur in smart factories, they can lead to financial losses, damage to corporate reputation, and even human casualties, necessitating an appropriate security response. Therefore, this paper proposes a security authentication mechanism for safe communication in the smart factory environment. The components of the proposed authentication mechanism include smart devices, an internal operation management system, an authentication system, and a cloud storage server. The smart device registration process, authentication procedure, and the detailed design of anomaly detection and update procedures were meticulously developed. And the safety of the proposed authentication mechanism was analyzed, and through performance analysis with existing authentication mechanisms, we confirmed an efficiency improvement of approximately 8%. Additionally, this paper presents directions for future research on lightweight protocols and security strategies for the application of the proposed technology, aiming to enhance security.