• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.339-350
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• 2004

A broadcast method in mobile computing environments which have very large client populations solves the problem of low bandwidth. But most of previous proposed concurrency control protocols are restricted to read-only transactions from mobile client. In this paper, we propose the UTSM-ARM method which uses caching and broadcast method, and allows update transactions in mobile client. The UTSM-ARM decides the validation of cache data consistency with the dynamic update pattern ratio of accessed cached data. Also, the timestamps of accessed cached data and transaction in mobile client guarantee the serializable execution of mobile transactions. As a result, UTSM-ARM makes efficiently use of the asymmetric bandwidth of broadcast environment and can Increase the transaction throughput.

• Journal of Korean Philosophical Society
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• v.147
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• pp.261-281
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• 2018

This paper will cover recent discussions on the risks of human being due to the development of artificial intelligence(AI). We will consider AI research as artificial narrow intelligence(ANI), artificial general intelligence(AGI), and artificial super intelligence(ASI). First, we examine the risks of ANI, or weak AI systems. To maximize efficiency, humans will use autonomous AI extensively. At this time, we can predict the risks that can arise by transferring a great deal of authority to autonomous AI and AI's judging and acting without human intervention. Even a sophisticated system, human-made artificial intelligence systems are incomplete, and virus infections or bugs can cause errors. So I think there should be a limit to what I entrust to artificial intelligence. Typically, we do not believe that lethal autonomous weapons systems should be allowed. Strong AI researchers are optimistic about the emergence of artificial general intelligence(AGI) and artificial superintelligence(ASI). Superintelligence is an AI system that surpasses human ability in all respects, so it may act against human interests or harm human beings. So the problem of controlling superintelligence, i.e. control problem is being seriously considered. In this paper, we have outlined how to control superintelligence based on the proposed control schemes. If superintelligence emerges, it is judged that there is no way for humans to completely control superintelligence at this time. But the emergence of superintelligence may be a fictitious assumption. Even in this case, research on control problems is of practical value in setting the direction of future AI research.

• Journal of Korean Academy of Nursing
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• v.29 no.5
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• pp.1155-1166
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• 1999

The purpose of this study was to investigate the residents' opinions about community mental health in the Taegu-Kyungpuk area for the future development of a community mental health program and model appropriate for Korea, The subjects were 152 residents in the Taegu - Kyungpuk area. In July 1999, the data was collected using a convenience sample technique. Mental health status was significantly different for the level of occupational advantage(x$^2$＝15.684, p＜.05) and physical health(x$^2$＝39.262, p＜.000). Factor structure for mental health problems with the percentage of variance was as follows. optimistic view(27.518), dark view(10.758), mastery(6.200), discomfiture(6.101) and life style(5.641). Most of the respondents(92.1%) took the mental health problems seriously. The serious aspects of the mental health problem were found to be epilepsy, mental retardation, neurosis and schizophrenia respectively. Concerning about the view of community mental health, most of the respondents answered that the a C.M.H.C. was ‘useful and urgent’ concerning the need for C.M.H,(77.6%). They answered positively on the utilization of C.M.H.C(75.7% ) and preferred the separately new community mental heath center. A psychiatrist was preferred as the key person in charge(44.1%). If community mental health centers were established in a community health center, they answered that the expected major problem would be quality control of care(44.7%). They preferred the psychiatrist's office as the recommended agency for the insane(44.7%). Opinions of the asylum system were found very negative in respect to psychiatric therapy and humanitarianism. The results of this study will help establish a relevant model for this community as the primary site for a community-based mental health model.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.509-521
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• 2014

The purpose of this study is to find the correlation between elements of resilience and small group activities in the university, and to explore small group activities as a protective and a positive factor in controlling the stress of college students. As the first part of the study, positive roles of resilience to the stress of college students and the elements that promote the efficiency of resilience are analyzed. The study precedent in detail and four elements of resilience are presented as following; optimistic realism, vitality, ability to control emotion, and interpersonal ability, addressing the faith in God is one of the strong positive factors for developing resilience. Then, this study deals with how the four elements of resilience relates to the characteristics of small group activities. In conclusion, this study suggests Christian universities to develop small group activities because they can develop each of the four elements of resilience of college students. Christian universities have a missional duty and the responsibility to help college students experience real happiness in their lives. Therefore, if Christian universities understand the effectiveness of resilience of college students and find out the correlation between resilience and faith, they can help students not only to live a positive life in their generation, but also to experience the authentic happiness.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2310-2326
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• 2000

Client-server DBMS based on a data-shipping model can exploit e1ient resources effectively by allowing inter-transaction caching. However, inter-transaction caching raises the need of transactional cache consistency maintenancetTCCM protocol. since each client is able to cache a portion of the database dynamically. Deferred locking(DL) is a new detection-based TCCM scheme designed on the basis of a primary copy locking algorithm. In DL, a number of lock ,ujuests and a data shipping request are combined into a single message packet to minimize the communication overhead required for consistency checking. Lsing a simulation model. the performance of the prolxlsed scheme is compared with those of two representative detection based schemes, the adaptive optimistic concurrency control and the caching two-phase locking. The performance results indicate that DL improves the overall system throughput with a reasonable transaction abort ratio over other detection - based schemes.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.326-333
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• 2010

The purpose of this study is to find out the effects of tax officials' perceived self-leadership on their empowerment and organization commitment, improve the effectiveness of human resource management of tax organizations, and provide measures for effective organization management. The study results show that the more their self-leadership improves, the more their empowerment improves. Firstly, the reason why their self-leadership has a positive influence on empowerment is that they set their own purpose about their task by themselves, make efforts to achieve the goals, and do their job with optimistic and constructive attitude. Secondly, the study results that their empowerment has a positive influence on organization commitment show that organizational members with high-level empowerment attach significance to their work and it makes their organization commitment high. To maximize organization performance, tax officials should recognize their work's value, meaning, and importance by himself, be equipped with sufficient knowledge for their work, apply their leverage and control in their job, have their self-determination, and improve their organization commitment.

• The Journal of Korean Association of Computer Education
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• v.15 no.2
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• pp.9-18
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• 2012

This study investigated the extraction algorithm fitting for variables of adolescents' computer use type with the sample from KYPS data (3409 in the second grade of the junior high school; 1704 boys and 1705 girls). The results of the decision tree model revealed that : (1) Gender, computer use time, misdeed friends, parent supervision, other agreement of misdeed, parent study expectation, self-control, teacher attachment, and sibling relation were significant for entertainment type. (2) Gender, cyberclub, computer use time, self-belief, online misdeed were significant for relation type. (3) Study enthusiasm, personal study time, optimistic disposition, study and spare time, cyberclub, self-belief, and other people criticism were significant for information type. These results suggest that adolescents' diverse conditions should be considered for using computer more efficiently.

• Journal of KIISE:Software and Applications
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• v.26 no.8
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• pp.974-987
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• 1999

이동 컴퓨팅 환경에서 자주 접근하는 데이터에 대한 캐싱은 무선 채널의 좁은 대역폭에서 경쟁을 줄일 수 있는 유용한 기술이다. 그러나, 트랜잭션 캐시 일관성을 지원하는 전통적인 클라이언트/서버 전략은 클라이언트와 서버간에 많은 양의 통신을 필요로 하기 때문에 이동 클라이언트/서버 컴퓨팅 환경에서는 적절하지 않다. 본 논문에서는 브로드캐스트-기반 캐시 무효화 정책을 사용하면서 트랜잭션 캐시 일관성을 지원하는 OCC-UTS (Optimistic Concurrency Control with Update TimeStamp) 프로토콜을 제안한다. 접근한 데이터에 대한 일관성 검사 및 완료 프로토콜은 캐시 무효화 과정의 내부 과정으로 완전 분산 형태로 효율적으로 구현되며, 일관성 체크의 대부분이 이동 클라이언트에서 수행된다. 또한, 분석 모델에 기반한 성능 비교를 통해, 본 논문에서 제안하는 OCC-UTS 프로토콜이 다른 경쟁 프로토콜보다 높은 트랜잭션 처리율을 얻으며, 데이터 항목을 자주 접근하면 할수록 지역 캐시를 사용하는 OCC-UTS 프로토콜이 더 효율적임을 보인다. 이동 클라이언트의 접속 단절에 대해서는 무효화 브로드캐스트 윈도우를 크게 하여 접속 단절에 적절히 대처할 수 있다.Abstract In a mobile computing environment, caching of frequently accessed data has been shown to be a useful technique for reducing contention on the narrow bandwidth of the wireless channels. However, the traditional client/server strategies for supporting transactional cache consistency that require extensive communications between a client and a server are not appropriate in a mobile client/server computing environment. In this paper, we propose a new protocol, called OCC-UTS (Optimisitic Concurrency Control with Update TimeStamp), to support transactional cache consistency in a mobile client/server computing environment by utilizing the broadcast-based solutions for the problem of invalidating caches. The consistency check on accessed data and the commitment protocol are implemented in a truly distributed fashion as an integral part of cache invalidation process, with most burden of consistency check being downloaded to mobile clients. Also, our experiments based on an analytical model substantiate the basic idea and study the performance characteristics. Experimental results show that OCC-UTS protocol without local cache outperforms other competitor protocol, and the more frequent a mobile client accesses data items the more efficient OCC-UTS protocol with local cache is. With respect to disconnection, the tolerance to disconnection is improved if the invalidation broadcast window size is extended.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.145-153
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• 2014

This study examined the linkage between positive cognitive bias and entrepreneurial intention. Self-enhancement, unrealistic optimism, and illusion of control have been collectively referred as positive cognitive bias. We examined the effects of positive cognitive bias on attitudes toward success and failure. And we also examined the effect of attitudes toward success and failure on entrepreneurial intension. This study investigated these relationships using 240 high school students. The result of analysis indicated that the self-enhancement bias and unrealistic optimism bias had positive effects on attitude toward failure, but it had not any effect on attitude toward success. The illusion of control bias has positive effects on attitude toward success, but it had not any effect on attitude toward failure. The attitudes toward success and failure had positive effect on entrepreneurial intension. Then results of this study suggests that the cognitive biases showed a role of antecedents of attitudes toward success and failure. Finally, this study concluded with a discussion of the implications of the research findings and directions for future research.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.484-493
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• 2001

As real-time database systems are extended to the distributed computing environment, the need to apply the existing real-time concurrency control schemes to the distributed computing environment has been made. In this paper we propose an efficient concurrency control scheme for distributed real-time database system. Our proposed scheme guarantees a transaction to commit at its maximum, reduces the restart of a transaction that is on the prepared commit phase, and minimizes the time of the lock holding. This is because it raises the priority of the transaction that is on the prepared commit phase in the distributed real-time computing environment. In addition, it reduces the waiting time of a transaction that owns borrowed data and improves the performance of the system, as a result of lending the data that the transaction with the raised priority holds. We compare the proposed scheme with DO2PL_PA(Distributed Optimistic Two-Phase Locking) and MIRROR(Managing Isolation in Replicated Real-time Object Repositories) protocol in terms of the arrival rate of transactions, the size of transactions, the write probability of transactions, and the replication degree of data in a firm-deadline real-time database system based on two-phase commit protocol. It is shown through the performance evaluation that our scheme outperforms the existing schemes.