• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1157-1169
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• 2021

The disaster recovery refers to policies and procedures to ensure continuity of services and minimize loss of resources and finances in case of emergency situations such as natural disasters. In particular, the disaster recovery method by the cloud service provider has advantages such as management flexibility, high availability, and cost effectiveness. However, this method has a dependency on a service provider and has a structural limitation in which a user cannot be involved in personal data. In this paper, we propose a protocol using proxy re-encryption for data confidentiality by removing dependency on service providers by backing up user data using blockchain and distributed storage. The proposed method is implemented in Ethereum and IPFS environments, and presents the performance and cost required for backup and recovery operations.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.251-260
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• 2022

Despite the development of technology and the increase in the spread of smart speakers, user satisfaction keeps decreasing due to conversational errors. This study aims to examine the effect of the self-repair strategy on user experience in the context of conversational agents of smart speakers. Scenarios were designed based on error situations, and participants were divided into two groups by task criticality. The results revealed that the agent's self-repair strategy has a negative effect on trust and perceived ease of use compared with performance without error. It also influenced adoption intention through interaction with task criticality. This study is significant in that it empirically investigated the effects of the self-repair strategy and the user experience factors related to the actual acceptance of the self-repair strategy.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.17-24
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• 2022

Lora, a non-band network technology of the long-distance wireless standard LPWAN standard, uses ABP and OTTA methods and AES-128-based encryption algorithm (shared key) for internal terminal authentication and integrity verification. Lora's recent firmware tampering vulnerability and shared-key encryption algorithm structure make it difficult to defend against MITM attacks. In this study, the consensus algorithm(PBFT) is applied to the Lora network to enhance safety. It performs authentication and PBFT block chain creation by searching for node groups using the GPS module. As a result of the performance analysis, we established a new Lora trust network and proved that the latency of the consensus algorithm was improved. This study is a 4th industry convergence study and is intended to help improve the security technology of Lora devices in the future.

• Information Systems Review
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• v.22 no.1
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• pp.1-16
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• 2020

Blockchain is emerging as a technology that can build trust between users participating in the system. As interest of Blockchain has increased, previous studies have mainly focused on cryptocurrency and application methods related to Blockchain technology. On the other hand, the studies on the stable implementation of Blockchain were rarely conducted. Typically, uncle block in the Blockchain plays an important role in the stable implementation of the Blockhain system, but no study was conducted on this. Drawing on this recognition, this study attempts to predict the uncle block of Blockchain using machine learning method, Blockchain information, and macro-economic factors. The results of artificial neural network and support vector machine analysis, Blockchain information and macro-economic factors contributed to the prediction of uncle block of Blockchain. In addition, artificial neural network using only Blockchain information provided the best performance for predicting the occurrence of uncle block. This study suggests ways to lead and contribute to Blockchain research in information systems filed.

• Knowledge Management Research
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• v.23 no.4
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• pp.275-294
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• 2022

In recent years, with the continuous integrative development of e-commerce and social media, social commerce, as a trust-centered social transaction mode, has become an important performance form of e-commerce. The good experience of online community and abundant user-generated content (UGC) attract more and more users and businesses to participate in the community contribution. In this context, the cost of accessing information is continuously decreasing, which not only makes the purchase process more concise and efficient, but also greatly increases the possibility of consumers' impulsive consumption. However, there are very few empirical studies on the internal influencing mechanism of consumers' impulsive consumption based on the characteristics of UGC for social commerce. In view of this, based on S-O-R model, this study constructs a model of consumers' impulsive consumption in the context of social commerce from the characteristics of UGC, with perceived risk as the mediating variable and tie strength as the moderating variable. The results show that content authenticity, content usefulness, and content valence of UGC have significant negative impacts on consumers' risk perception in the process of purchase decision-making, and consumers' perceived risk has a significant negative impact on consumers' impulsive consumption. Meanwhile, the tie strength between UGC producer and UGC receiver plays a moderating role between content usefulness and perceived risk, as well as between perceived risk and impulsive consumption. Finally, combined with the above findings, this study provides effective suggestions for relevant participants in social commerce in terms of business management.

• Journal of the Korean School Mathematics Society
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• v.17 no.4
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• pp.717-746
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• 2014

The study aimed to explore how to improve mathematical thinking through metacognitive learning by stressing metacognitive abilities as a core strategy to increase mathematical creativity and problem-solving abilities. Theoretical exploration was followed by an analysis of correlations between metacognitive abilities and various ways of mathematical thinking. Various metacognitive teaching and learning methods used by many teachers at school were integrated for sharing. Also, the methods of learning application and assessment of metacognitive thinking were explored. The results are as follows: First, metacognitive abilities were positively related to 'reasoning, communication, creative problem solving and commitment' with direct and indirect effects on mathematical thinking. Second, various megacognitive ability-applied teaching and learning methods had positive impacts on definitive areas such as 'anxiety over Mathematics, self-efficacy, learning habit, interest, confidence and trust' as well as cognitive areas such as 'learning performance, reasoning, problem solving, metacognitive ability, communication and expression', which is a result applicable to top, middle and low-performance students at primary and secondary education facilities. Third, 'metacognitive activities, metaproblem-solving process, personal strength and weakness management project, metacognitive notes, observation tables and metacognitive checklists' for metacognitive learning were suggested as alternatives to performance assessment covering problem-solving and thinking processes. Various metacognitive learning methods helped to improve creative and systemic problem solving and increase mathematical thinking. They did not only imitate uniform problem-solving methods suggested by a teacher but also induced direct experiences of mathematical thinking as well as adjustment and control of the thinking process. The study will help teachers recognize the importance of metacognition, devise and apply teaching or learning models for their teaching environments, improving students' metacognitive ability as well as mathematical and creative thinking.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.211-218
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• 2020

This study compared and analyzed the efficiency of the research results of the convergence research project operated by the National Science and Technology Research Council and the general research project carried out by the Government-funded research institute and proposed measures to enhance the efficiency of the operation and management of convergence research. Research data were collected from 21 government-funded research institutes through an information disclosure claim and DEA analysis was conducted for efficiency assessment. The SCI papers of convergence research showed high efficiency, and the patent registration and technology transfer sector showed high efficiency of general research projects. This indicates that convergence research projects for securing lead and original technologies are highly efficient, but their performance is low due to lack of participation by businesses in terms of the utilization of derived technologies, and more companies' participation and opportunities are needed for practical use of convergence research results. Through the analysis of efficiency of convergence research project performance, this study provided policy and guidance for R&D planning for rational investment of limited manpower and research costs. Further, future research on identifying efficiency is proposed depending on the type of technology subject to convergence research as a method for managing convergence research.

• The Korean Journal of Financial Management
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• v.25 no.1
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• pp.51-84
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• 2008

We investigate the signaling effect of repurchase preceding new equity issue using Korean data. In a short time span, firms announce stock repurchases and equity offerings. The proximity of two events in Korean firms indicates that those are not independent of each other. In this paper, we test the signaling effect of repurchase on equity offerings on the two measures. One is announcement effect, which is measured as CAR(0, +2). The other is the effectiveness which is measured as CAR(0, +30) because the price movement during this window influences on the price of new issues. Previous studies that stock repurchase convey positive signal to equity offerings-Billet and Xue(2004) and Jung(2004)-construct sample without the limit of time interval between two events. This causes the unclear relation between those because of the long time interval. In this study we consider only samples of being within one year each other to reduce this problem and clarify the signal of repurchase on equity offerings. Korean firms are allowed to repurchase own shares with two different method. One is direct repurchase as same as open market repurchase. The other is stock stabilization fund and stock trust fund which trust company or bank buy and sell their shares on the behalf of firms. Generally, the striking different characteristic between direct repurchase and indirect repurchase is following. Direct repurchase is applied by more strict regulation than indirect repurchase. Therefore, the direct repurchase is more informative signal to the equity offering than the indirect repurchase. We construct two sample firms- firms with direct repurchase preceding-equity offerings and indirect repurchase-preceding equity offering, and one control firms-equity offerings only firms-to investigate the announcement effect and the effectiveness of repurchases. Our findings are as follows. Direct repurchase favorably affect the price of new issues favorably. CAR(0, +2) of firms with direct repurchase is not different from that of equity offerings only firms but CAR(0, +30) is higher than that of equity offerings only firms. For firms with indirect repurchase and equity offerings, Both the announcement effect and the effectiveness does not exist. Jung(2004) suggest the possibilities of how indirect stock repurchase can be regarded as one of unfair trading practices on based on the survey results that financial managers of some of KSE listed firms have been asked of their opinion on the likelihood of the stock repurchase being used in unfair trading. This is not objective empirical evidence but opinion of financial managers. To investigate whether firms announce false signal before equity offerings to boost the price of new issues, we calculate the long-run performance following equity offerings. If firms have announced repurchase to boost the price of new issues intentionally, they would undergo the severe underperformance. The empirical results do not show the severer underperformance of both sample firms than equity offerings only firms. The suggestion of false signaling of repurchase preceding equity offerings is not supported by our evidence.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.27-38
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• 2015

Recently, Corporate Social Responsibility(CSR) is essential firm activity to establish favorable firm true and sustainability management. However, there has been a controversy over the relationship between CSR and financial performance, also, it has been a little research that investigate relationship between CSR, firm reputation in firm level and firm true, firm loyalty in financial institution. This paper investigate empirically relationship between CSR activities, firm reputation and firm loyalty, moderating effect of firm true on the relationship between CSR activities, firm reputation and firm loyalty. Results were computed using SPSS 20.0 statistical analysis programs. The results are summarized as follows. First, The elements of CSR activities are divided into four factor, such as economic, ethical, consumer protection and environmental responsibilities. In the results of the analyses, consumer protection responsibility, economic reliability and business management skill positive affects the reliability of firm. Second, testing its mediating role, I use the three regression equation models by Baron and Kenny. When the mediator effect of firm true on firm loyalty was represented, the effect of CSR and firm reputation was statistically significant or diminished. Thus, the mediating role of firm true was supported. It means the higher the CSR and corporation reputation activities are, the higher the firm true is, further the higher level of firm true can enhance firm loyalty.

• Journal of Distribution Science
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• v.10 no.12
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• pp.35-43
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• 2012

Purpose - This study analyzes the effects of types of leadership on the employees of Italian restaurants, its efficacy, and organizational citizenship behavior, utilizing a causal assessment model. In this study, independent variables such as the type of leadership perceived in the manager or chef by an Italian restaurant's employees, and its efficacy were parameters, and the organizational citizenship behavior and organizational effectiveness were the variables representing the results in the hypothesis. The study aimed to draw implications by verifying the leadership via efficacy and the impact on organizational citizenship behavior of Italian restaurants. Research design, data, methodology - For the purpose of this analysis, specific questionnaire items were configured according to the theory and efficacy of the study. From a questionnaire used in organizational citizenship behavior comprising 22 questions, six were modified to suit the research purpose of this study. The configured questionnaire comprised 5 parts and 40 items. A Likert (Likert) 5-point scale was utilized to measure responses to the questionnaire items from the employees of an Italian restaurant in Seoul who participated in the survey. For data collection, 400 questionnaires were distributed, and 344 collected. Factor analysis and reliability verification were conducted using SPSS18.0 and AMOS18.0. A covariance structure analysis was conducted to test the research hypotheses. Results - Based on the results of the analyses, the summary and suggested implications of the research are as follows: The covariance structure analysis used to analyze the kind of effect transformational and transactional leadership styles in Italian restaurant employees had on self-efficacy, group-efficacy, and organizational citizenship behavior, indicated that among the characteristics of transformational leadership (such as, idealized influence, inspirational motivation, individual consideration, and intellectual stimulation), idealized influence and individual consideration had a positive influence on self-efficacy. Idealized influence, individual consideration, conditional reward, and management by exception also positively influenced self-efficacy and altruistic and conscientious behavior (organizational citizenship behavior). Conclusions - Results suggest that with regard to self-efficacy and group efficacy, managers in different departments and chefs should provide team members with a vision for the future, increase their confidence in their abilities, and build their trust in the organization. By evaluating employee performance and experiences, management can demonstrate leadership and encourage organizational citizenship behavior through enjoyable, voluntary participation. Transformational and transactional leadership is effective in group processes that include social-exchange relationships, self-efficacy and group efficacy, and organizational citizenship behavior. However, as this research study utilizes only self-reported data, it has several limitations, such as a vulnerability of errors caused by the various experiment types. A significant limitation of this study is the lack of potential for the duplication of results. The covariance structure analysis, however, provides complementation to limit the impact of errors from self-reporting studies. A future study can extend this research by utilizing different data collection methods.