• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.364-373
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• 2015

Purpose: The purpose of this study was to identify the effect of self-efficacy promoting reducing alcohol program on drinking related knowledge, drinking refusal self-efficacy, drinking outcome expectancy and problematic drinking behavior of women college students over 8 scores of AUDIT-K. Methods: Data were collected from 22 students with intervention program in the experimental group and 24 students with no intervention program in the control group and analyzed using ${\chi}^2$, t-test and ANCOVA. Results: The Drinking related knowledge(F=14.33, p<.001) of experimental group was significantly higher than that of control group and the optimistic drinking outcome expectancy(F=18.28, p<.001), and problematic drinking behavior(F=5.57, p=.003) of experimental group were significantly less than those of control group. Conclusion: it is recommended that college students should receive this program to prevent and reduce their drinking behaviors.

• Journal of KIISE:Databases
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• v.30 no.4
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• pp.397-407
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• 2003

Transactions of updating spatial dta with mobile clients are log transactions because a user disconnected from a server surveys real features and updates them. In this environment, it is appropriate to exploit the optimistic approach based on the validation test in order to control the concurrency of transactions. On the contrary, the pessimistic concurrency control scheme makes transactions wait for a long time due to the lock. In this paper, we propose the surrogate transaction model and implement its manager for the S-S-M(Server-Surrogate PC-Mobile Client) structure which is appropriate for updating spatial data in mobile environments. In the S-S-M structure, the mobile client communicates with the server by the surrogate PC. We extend the validation condition in consideration of spatial relationships between spatial objects in this model. We also present the commit protocol where the user of a surrogate PC adjusts objects of the conflicted surrogate transaction to minimize costs for the abortion of the transaction.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.571-582
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• 2009

This paper provides a way to overcome limitations of general collaborative software development tools that completely restrict co-ownership of resources among individuals in a team oriented developmental environment. It also provides a solution for users to co-own resources and at the same time manage version control and collision problems that may occur due to the co-ownership of resources.The cooperative development support tool of developed software uses the conventional optimistic technique but employs the algorithm which is improved to reduce costs and efforts required for solving collision. The collaborative software development tool presented in this paper is made up of the classical client/server structure with the P2P(peer to peer) method which supports information exchange among individuals. This tool is developed based on open source software CVS(Concurrent Version System). Functional efficiency was confirmed by comparing it to the utility of prior existing collaborative software development tools.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.57-69
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• 2022

Purpose : The purpose of this study was to investigate the effect of ankle strengthening exercise combined with sling-assisted gluteus medius strengthening on ankle instability score, and static and dynamic balance ability, muscle strength in adults in their 20s with chronic ankle instability. Methods : Twenty-eight adults in their 20s with chronic ankle instability were recruited. After screening test, they were randomized through R studio program as an experimental group (n=14) to apply an ankle strengthening exercise combined with sling-assisted gluteus medius strengthening and a control group (n=14) to apply ankle strengthening exercise. The intervention lasted two times a week for 6 weeks. To compare the intervention effects, the Cumberland ankle instability tool (CAIT) score, static and dynamic balance ability, and muscle strength of lower extremities were measured. Results : The experimental group showed a significant increase in pre and post-intervention Cumberland ankle instability tool (CAIT) score, static and dynamic balance ability, and muscle strengt (p<.05). The control group showed a significant increase in pre and post-intervention CAIT score, dynamic balance ability, and muscle strength (p<.05). The experimental group showed a significant increase in CAIT score, dynamic balance ability, and muscle strength compared to the control group (p<.05), and showed a high effect size. Conclusions : The results of this study confirmed that ankle strengthening exercise combined with sling-assisted gluteus medius strengthening on people with chronic ankle instability the possibility that it could be effective in improving ankle instability and improving dynamic balance ability, and strength by movement. Although additional research is needed to increase the number of participants due to the small sample size, it is hoped that this study will be an optimistic clinical protocol for people with chronic ankle instability.

• Journal of KIISE:Software and Applications
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• v.26 no.6
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• pp.735-751
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• 1999

클라이언트-서버 DBMS에 대한 기존의 연구는 클라이언트 데이터 캐슁이 캐쉬 일관성 유지에 드는 오버헤드에도 불구하고 시스템의 성능향상에 유용함을 보여주었다 본 논문에서는 시간적 제약을 가지는 실시간 트랜잭션을 처리하는데 있어서도 클라이언트 데이터 캐슁이 실시간 트랜잭션의 마감시간 충족률을 높이는데 유용하다는 것을 보였다. 기존실시간 데이터베이스 시스템에서 동시성 제어 기법과 실시간 트랜잭션 스케쥴링 기법을 통합한 것처럼 , 캐쉬 일관성 유지 및 동시성 제어 기법과 실시간 트랜잭션 스케쥴링 기법을 통합한 낙관적 알고리즘을 제시하고 클라이너트 데이터 캐슁을 지원하지 않는 경우와 그 성능을 비교하였다. 성능 평가 결과데이타의 지역성이 낮은 작업부하에서는 , 클라이언트 캐쉬의 이용으로 인해 마감시간을 어긴 실시간 트랜잭션의 비율 감소가 크지 않았지만(10%이하), 데이터의 지역성이 높은 작업부하에서는 그 감소폭이 컸다. HOTCOLD 작업부하의 경우 클라이언트의 수가 50, 트랜잭션의 데이터 변경률이 20% 일 때 마감시간을 어긴 실시간 트랜잭션의 비율이 약 47%감소하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2913-2921
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• 1994

In SMA(shape memory alloy), the degradation by fatigue is one of the most important problems to be overcome, when SMA is used for robot-actuator material. The actuator is operated repeatitively for long time and its repeating operation develops the fatigue degradation of SMA. The fatigue degradation changes the transformation temperature and deformation behavior and results in inaccurate operation control of robot. Accordingly, the changing behavior of transformation temperature and deformation which results from repeating operation is to be investigated in advance and the scheme to resolve those problems have to be made for the design of actuator. In this study, the fatigue tests were carried out on SMA specimens prepared to have different condition of aging time and pre-strain with the direct-current heating-cooling method, which was a general method of operation in robot actuators. The behavior of transformation temperature and deformation were examined and analyzed in each specimen and the study was performed to establish the optimistic manufacturing condition of SMA against the fatigue degradation.

• Journal of KIISE:Information Networking
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• v.28 no.1
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• pp.154-163
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• 2001

인터넷으로 연결된 다수의 참여자를 지원하는 대규모 분산 가상 환경을 위한 확장성 있는 예측 기반 동시성 제어 방법을 제안한다. 예측 기반 동시성 제어 방식은 낙관적(optimistic) 방식과 같이 참여자들에게 실시간 상호 작용 성능을 제공함과 동시에 비관적(pesimistic)방식과 같이 잠금 허가를 받은 사용자에게만 객체 조작을 허용하므로 충돌을 확실히 방지할 수 있다. 본 논문에서는 사용자 수의 증가에 따른 확장성 있는 예측 알고리즘을 위하여 객체 중심 다중 전송그룹을 도입했다. 객체에 관심있는 객체주변의 사용자들만 객체에 할당된 다중 전송 그룹에 소유권 요청 메시지로서의 참여 메시지를 보냄으로써 소유자 후부가 된다. 현재 소유자는 소유자 후보들 중 다음 소유자를 예측한다. 가상 영역내의 모든 사용자 대신 객체의 할당된 다중 전송 그룹에 소유권 요청 메시지로서의 참여 메시를 보냄으로써 소유자 후보가 된다. 현재 소유자는 소유자 후보들 중 다음 소유자를 예측한다. 가상 영역내의 모든 사용자 대신 객체의 다중 전송 그룹에 참여하고 있는 사용자로부터만 소유권 요청 메시지를 받으므로 소유자가 받는 메시지 수는 가상환경의 전체 사용자의 수에 관계없이 상수값을 갖는다. 이는 소유자의 소유권 요청메세지 처리 시간을 줄여 보다 더 정확한 예측을 하고 사용자의 객체 조작 시간 전에 소유권이 전달되도록한다. 제안한 예측 알고리즘은 라이브러리로 구현되어 기존의 가상 환경 시스템에 적용되었고 실험을 통해 제안한 알고리즘이 대규모 가상 환경에서 갖는 효율성과 확장성을 증명한다.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.39-45
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• 1998

In the previous study. the powder casting was attempted as the rapid tooling. The powder casting was the process to cast dry powder into the casting mold transferred from R/P model and infiltrate the liquid binder to solidify the powder. And then, the melted copper was infiltrated to control the shrinkage rate of the final mold Conseqently, the shrinkage rate was under 0.1% through that process. The mechanical characteristic was also excellent. Generally, in the slurry casting, the alumina powder and the water soluble phenol were mainly used. However, the mechanical property of the phenol was not good enough to apply to molds directly. In this study, aluminium powder filled with epoxy is applicated to the slurry casting to solve these problems. The mechanical and thermal properties are better than phenol because the epoxy is the thermosetting resin. We achieved a successful result that the shrinkage rate is shortened about 0.047%. Futhermore, the manufacturing time and cost savings are significant. Finally, we assume that the developing possibility of this process is very optimistic.

• International Journal of Contents
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• v.18 no.1
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• pp.17-26
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• 2022

With the acceleration of urbanization and industrialization, air pollution has become increasingly serious, and the pollution control situation is not optimistic. Climate change has become a major global challenge faced by mankind. To actively respond to climate change, China has proposed carbon peak and carbon neutral goals. However, atmospheric pollutants and meteorological factors that affect air quality are complex and changeable, and the complex relationship and correlation between them must be further clarified. This paper uses China's 2013-2018 high-resolution air pollution reanalysis open data set, as well as statistical methods of the Pearson Correlation Coefficient (PCC) to calculate and visualize the design and analysis of environmental monitoring big data, which is intuitive and it quickly demonstrated the correlation between pollutants and meteorological factors in the temporal and spatial sequence, and provided convenience for environmental management departments to use air quality routine monitoring data to enable dynamic decision-making, and promote global climate governance. The experimental results show that, apart from ozone, which is negatively correlated, the other pollutants are positively correlated; meteorological factors have a greater impact on pollutants, temperature and pollutants are negatively correlated, air pressure is positively correlated, and the correlation between humidity is insignificant. The wind speed has a significant negative correlation with the six pollutants, which has a greater impact on the diffusion of pollutants.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1377-1389
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• 1998

Firm real time transactions on firm real-time database systems arc discarded when they miss their deadlines. as there is no value to completing them after they miss their deadlines. Several approaches that exploit the semantics of firm deadlines to improve the performance of firm real-time database systems have been proposed in the literature. They are based Oil locking or optimistic concurrency controL The performance comparisons of the two approaches differ with svstems load. In this paper. we develop a novel policy termed stop/resume deferred restart policy, and a concurrency control algorithm based on the policy (temled Altcmativc Version Concurrency Contro). When conflicts : due to Pliority) occur our algmithm maintains the immediately restarted VerSlOn as wpll as the stopped version of a transaction in order to use one of the two to meet the firm deadline. At last we show that our policy generates scrializable schedules and show tbat our algorithm performs better than the traditionally used method for wide ranges of the system load for firm deadline transaction.