• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.238-256
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• 2016

Modern web services have been broadly deployed on the Internet. Most of these services use multi-tier architecture for flexible scaling and software reusability. However, managing the performance of multi-tier web services under dynamic and unpredictable workload, and different resource demands in each tier is a critical problem for a service provider. When offering quality of service assurance with least resource usage costs, web service providers should adopt self-adaptive resource provisioning in each tier. Recently, a number of rule- and model-based approaches have been designed for dynamic resource management in virtualized data centers. This survey investigates the challenges of resource provisioning and provides a competing assessment on the existing approaches. After the evaluation of their benefits and drawbacks, the new research direction to improve the efficiency of resource management and recommendations are introduced.

• Journal of Multimedia Information System
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• v.4 no.2
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• pp.93-98
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• 2017

A new cultivation diary system based on environment sensor data and Web 2.0 with Flex is suggested, to improve the previous system using the subjective data of cultivators. The proposed system is designed by applying an object-oriented model called mini-architecture, in order to enhance the reliability of software as well as promote stability to overall system design. The environment sensor data such as temperature and humidity are used to develop the new reliable diary. Also, an active interface based on Web 2.0 and Android as the user GUI are implemented to maximize the convenience while recording the cultivation diary. The result of the performance evaluation shows that the data from sensors has 99.1% of correlation with that of analogue.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.621-624
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• 2003

Recently, there has been rising concerns to integrate and connect a developed spatial information services without consideration of location in the heterogeneous distributed environment. The Open GIS Consortium provides system architecture model related to open web service for spatial information. This paper discusses the issues related to the web service framework for spatial information services using standards of Open GIS Consortium. In particular, we concentrate upon the WRS that support the runtime discovery and evaluation of resources. The technology for integration of spatial information services is expected to get synergy effect and overcomes limit of individual development of each spatial information technology. Also this system provides the interoperability and the reusability and prevents the duplication development of system.

• Journal of Internet of Things and Convergence
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• v.9 no.3
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• pp.1-6
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• 2023

One of the economical ways to satisfy the quality of service desired by the user in a web service environment is to adjust the size of the object. To this end, this study finds the maximum size of objects that satisfy this constraint when the mean response time is given below an arbitrary threshold for quality of service. It can be inferred that in the steady state of system, the mean response time in the deterministic model by using the round-robin will be the same as that of the queueing model following the general distribution. Based on this, analytical formulas and procedures for finding the maximum object size are obtained. As a service distribution of web traffic, the Pareto distribution is appropriate, so the maximum object size is computed by applying the M/G(Pareto)/1 model and the M/G/1/PS model using exponential distribution as computational experience. Performance evaluation through numerical calculation shows that as the shape parameter in the Pareto distribution increases, the M/G(Pareto)/1 model and M/G/1/PS model have the same maximum object size. The results of this study can be used to environments where objects can be sized for economical web service control.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1708-1727
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• 2021

In the advent of the twenty-first century, human beings began to closely interact with technology. Today, technology is developing, and as a result, the world wide web (www) has a very important place on the Internet and the significant task is fulfilled by Web services. A lot of Web services are available on the Internet and, therefore, it is difficult to find matching Web services among the available Web services. The recommendation systems can help in fixing this problem. In this paper, our observation was based on the recommended method such as the collaborative filtering (CF) technique which faces some failure from the data sparsity and the cold-start problems. To overcome these problems, we first applied an ontology-based clustering and then the k-nearest neighbor (KNN) algorithm for each separate cluster group that effectively increased the data density using the past user interests. Then, user ratings were predicted based on the model-based approach, such as singular value decomposition (SVD) and the predictions used for the recommendation. The evaluation results showed that our proposed approach has a less prediction error rate with high accuracy after analyzing the existing recommendation methods.

• Journal of Information Processing Systems
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• v.5 no.1
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• pp.11-18
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• 2009

As well as providing various APIs for the development of inference engines and storage models, Jena is widely used in the development of systems or tools related with Web ontology management. However, Jena still has several problems with regard to the development of real applications, one of the most important being that its query processing performance is unacceptable. This paper proposes a storage model to improve the query processing performance of the original Jena storage. The proposed storage model semantically classifies OWL elements, and stores an ontology in separately classified tables according to the classification. In particular, the hierarchical knowledge is managed, which can make the processing performance of inferable queries enhanced and stores information. It enhances the query processing performance by using hierarchical knowledge. For this paper an experimental evaluation was conducted, the results of which showed that the proposed storage model provides a improved performance compared with Jena.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.163-168
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• 2002

The road sign in dynamic traffic system is an important element which affects on human cognitive performance on driving. Web-based vision system simulator was developed to examine the cognition time of the road sign in dynamic environment. This experiment was designed in within-subject design with two factors; vehicle speed and the amount of information of the traffic sign. It measured the cognition time of the road sign through two evaluation methods; the subjective test with vision system simulator and computational cognitive model. In these two evaluations of human cognitive performance under the dynamic traffic environment, it demonstrated that subject's cognition time was affected by both the amount of information of traffic sign and driving speed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.779-791
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• 2021

Common web services have been continuously targeted by hackers due to an access control policy that must be allowed to an unspecified number of people. In order to cope with this situation, companies regularly check web vulnerabilities and take measures according to the risk of discovered vulnerabilities. The risk of these web vulnerabilities is calculated through preliminary statistics and self-evaluation of domestic and foreign related organizations. However, unlike static diagnosis such as security setting and source code, web vulnerability check is performed through dynamic diagnosis. Even with the same vulnerability item, various attack results can be derived, and the degree of risk may vary depending on the subject of diagnosis and the environment. In this respect, the predefined risk level may be different from that of the actual vulnerability. In this paper, to improve this point, we present a web vulnerability risk assessment model based on the attack result centering on the cyber kill chain.

• Journal of the Korean Society for information Management
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• v.25 no.4
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• pp.165-184
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• 2008

This study is aiming to develop an evaluation model considering electronic journal's properties and terms of subscription. As the first step to develop an evaluation model, this study analyzed features of electronic journals and various terms of subscription through reviewing literature. Second, it developed the evaluation model for electronic journals by using proper evaluation indicators which were extracted from previous studies on the evaluation journals and considering the terms of ScienceDirect subscription. Third, this evaluation model was applied to the 99 journals in the field of mechanical engineering in ScienceDirect. As a result of the evaluation, it was found out that there were variations in the value of journals between in 2000 and 2007. Some implications regarding e-journal subscription were also added.

• Korean Journal of Health Education and Promotion
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• v.25 no.4
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• pp.83-92
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• 2008

Objectives: This study was to develop and evaluate a web-based multimedia content for the education of hospice volunteers. Methods: The multimedia content was developed based on Baik's teaching and learning structure plan model. The developed program was evaluated by 24 hospice volunteer university students. Results: On main page, there were 4 menu bars that consisted of a lecture guide, cyber lecture, pause and quiz. In the operation of the web based multimedia content, HTML, Java Script, Photoshop and multimedia technology were utilized. There were significant differences in the test scores, before and after using this web-based learning program. After using a web-based learning program, scores of students were much higher. Conclusion: The developed web based program is based on systematic structure and it can provide hospice volunteers with the educational flexibilities and will be help for them to perform the more efficient hospice care.