• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5446-5463
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• 2019

Parallel computing system components should be harmonized, and this harmonization is kept existent using synchronization time. Synchronization time affects the system in two ways. First, if we have too little synchronization time, some tasks face the problem of harmonization, as they need appropriate time to update and synchronize with the system. Second, if we allocate a large amount of time, stall system created. Random allocation of synchronization time for parallel systems slows down not only the booting time of the system but also the execution time of each application involved in the system. This paper presents a simulator used to test and allocate appropriate synchronization time for distributed and parallel heterogeneous systems. The simulator creates the parallel and heterogeneous system to be evaluated, and lets the user vary the synchronization time to optimize the booting time. NS3-cGEM5 simulator in this paper is formed by HLA-RTI federation integration of the two independent architecture and network simulators - NS3 and cGEM5. Therefore, nodes created on these simulators need synchronizations for harmonized system performance. We tested and allocated the appropriate synchronization time for our sample parallel system composed of one x86 server and three ARM clients.

• KIISE Transactions on Computing Practices
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• v.21 no.6
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• pp.436-441
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• 2015

There are many types of clustering algorithms such as centroid, hierarchical, or density-based methods. Each algorithm has unique data grouping principles, which creates different varieties of clusters. Ordering Points To Identify the Clustering Structure (OPTICS) is a well-known density-based algorithm to analyze arbitrary shaped and varying density clusters, but the obtained clusters only correlate loosely. Hierarchical agglomerative clustering (HAC) reveals a hierarchical structure of clusters, but is unable to clearly find non-convex shaped clusters. In this paper, we provide a novel hierarchy generation framework and application which can aid users by combining the advantages of the two clustering methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.457-460
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• 2007

Recently, Network companies have introduced security solutions to protect the network from intrusions, attacks and viruses but the network has still weakness and vulnerability. It is time to bring more stable and reliable authentication system that would meet the Internet user's need. In this study, Current broadband networks don't have hierarchic and stable authentication solutions. And so, an integrated and hierarchic system is needed to provide a various kinds of application services.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.447-451
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• 2010

Monitoring and analyzing the status of smart objects, the ubiquitous smart monitoring system provides several information such as user-state index, service states and system operation among the services in real time. It also provides self-optimization and self-management for enhancing the performance of services. In order to expand the application scope of this real-time monitoring system, it is indispensible to process huge amount of stream data. In this paper, we propose a load balancing scheme to solve the overload of the monitoring agents. Our proposed scheme reduces deadline miss ratio of entire data by more than 80%.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.69-76
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• 2009

Self healing systems are considered as cognation-enabled sub form of fault tolerance system. But our experiments that we report in this paper show that self healing systems can be used for performance optimization, configuration management, access control management and bunch of other functions. The exponential complexity that results from interaction between autonomic systems and users (software and human users) has hindered the deployment and user of intelligent systems for a while now. We show that if that exceptional complexity is converted into self-growing knowledge (policies in our case), can make up for initial development cost of building an intelligent system. In this paper, we report the application of AHSEN (Autonomic Healing-based Self management Engine) to in OKKAM Project infrastructure backbone cluster that mimics the web service based architecture of u-Zone gateway infrastructure. The 'blind' load division on per-request bases is not optimal for distributed and performance hungry infrastructure such as OKKAM. The approach adopted assesses the active threads on the virtual machine and does resource estimates for active processes. The availability of a certain server is represented through worker modules at load server. Our simulation results on the OKKAM infrastructure show that the self healing significantly improves the performance and clearly demarcates the logical ambiguities in contemporary designs of self healing infrastructures proposed for large scale computing infrastructures.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.10
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• pp.1-7
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• 1999

As our society turns into the information age we ate witnessing increased productivity by employing electronic document management replacing the traditional paper-based document management and by various application programs using the intranet technology This paper describes design and implementation of an electronic document management system in intranet environment. The user and general administration systems made use of Internet Explorer 4.0 and the related technology therefore it solved the problems of client systems, which were largely dependent on hardware platform. The server and the scan station systems, which require proprietary device driver, were implemented client/server system based on TCP/IP. The jukebox system managing storage of vast amount of data was built by API supporting standard SCSI-ll. The GUI of the jukebox module was employed Motif to enhance the compatibility and ease of use.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.10
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• pp.75-80
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• 1999

Multimedia synchronization model for distributed, continuous or discrete media that was guaranteed high quality of service is requited in developing multimedia application software. In this paper we have specific object controller which is called dynamic key media that is changed by user event generation. This becomes media whose event occurrence and periods can't be predicted. For event occurrence not only audio but also text and image can be chosen for key media and performs its role. Object controller transfers information for next transition. The proposed model offers high qualify of services by permitting maximum allowed jitter and skew in playout time and verified its effectiveness by simulation.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.246-252
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• 2020

Facial recognition is a biometric technology that is used in various fields such as user authentication and identification of human characteristics. Face recognition applications are practically used in various fields, but very few applications have been developed to improve the factory work environment. We implemented applications that uses face recognition to identify a specific employee in a factory .work environment and provide customized information for each employee. Factory workers need documents describing the work in order to do their assigned work. Factory managers can use our application to register documents needed for each worker, and workers can view the documents assigned to them. Each worker is identified using face recognition, and by tracking the worker's face during work, it is possible to know that the worker is in the workplace. In addition, as a mobile app for workers is provided, workers can view the contents using a tablet, and we have defined a simple communication protocol to exchange information between our applications. We demonstrated the applications in a factory work environment and found several improvements were required for practical use. We expect these results can be used to improve factory work environments.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.260-271
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• 2020

Smartphones provide blind users with screenreader as an accessibility tool. However, blind users often experience difficulties accessing online shopping malls via smartphones due to their inconsistent and image-based layouts. To enable screenreader users to get access to the detailed information about products while they are shopping online, we have developed BarrierFreeShop, an accessible mobile shopping application for people with visual impairments. BarrierFreeShop has three accessibility features: (1) layout automation, (2) review summarization, and (3) optical character recognition. We conducted a user study with 80 participants with visual impairments where they were asked to use BarrierFreeShop for a month. The findings revealed the effectiveness of our app in terms of speed and post interview feedback. We have also discovered typical shopping experiences that participants had during the test. This research suggests that computer vision technologies can improve accessibility issues in online shopping malls. In addition, we have confirmed that extracting contents from images help people with visual impairments to get better access to product information.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.595-601
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• 2010

Desktop virtualization technology running on the local computing system in the process of resource depletion or degradation, such as upgrading the system to solve problems and manage critical information and systems must be protected. In addition, a virtualized environment by constructing a convenient stand-virtualized infrastructure and user space, and security from external attack or internal flaw or a problem, even if the service fails to respond quickly and should help to recover. In this paper, a comprehensive virtualization technology based on the client's desktop virtualization technology elements needed to find a local computing environment more comfortable and stable in the proposed new virtualization technologies.