• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.323-330
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• 2002

Recently, the existing embedded real-time operating systems(RTOSs) are being developed in terms of various modified versions in every application fields. Major characteristics and difference of these OSs lie in their distinct development of mechanisms which can be used in various environment and task-scheduling function which can control time-limited contingencies. In this paper, we design and implement round/robin scheduling algorithm based on time-sharing with equal-priority for multiple tasks which are provided preemptive and priority task allocation function in $\mu{C/OS-II}$ version 2.03. We propose the most important event-ready list structure in $\mu{C/OS-II}$; kernel, and provide the running result for multiple tasks with equal priority for the proposed structure.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.87-93
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• 2003

Data Replication makes distributed system and database system improved in availability and performance. But it is difficult to keep strict consistency in data update. Existing algorithms keep strict consistency, but have problems of cost a great deal and delay time. It is to introduce hybrid update propagation algorithm which permits eager update for original copy and propagates lazy update for other copies. Hybrid update propagation algorithm also permits group update in ownership. This algorithm menages replica version in order to control group update consistency. Consistency and performance is improved by combining eager update and lazy update with group ownership. Simulation shows improvement of transaction throughput and response time depending on application and execution environment.

• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1436-1443
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• 2010

In vocabulary recognition system has it's bad points of processing vocabulary unseen triphone and then no got distribution of confidence measure by cannot normalization. According to this problem to improve suggested VCOR(Version Control for Out-of Rejection) system by out-of vocabulary rejection algorithm use vocabulary management optimization and then phone data search support. In VCOR system to provide vocabulary information efficiently offering for user's vocabulary information using extend facet classification that improved for vocabulary measure management function offering accuracy of recognition for vocabulary. In this paper proposed system performance as a result of represent vocabulary dependence recognition rate of 97.56%, vocabulary independence recognition rate of 96.23%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.236-240
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• 2004

We have implemented image monitoring system on PXA255 processor based embedded board that is ported QT/Embedded 2.3.7 version. User is able to monitor camera's capture image for widely separated host PC at client PXA255 board target board by ethernet communication method. And we designed PCI interface card that control motor for camera's Pan & Tilt. Bitmap format's images of $320\times{240}$ size are displayed on PXA255 board's TFT-LCD and User is able to monitor wanted position's image by touch screen input method.

• Journal of the Korea Society of Computer and Information
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• v.8 no.2
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• pp.16-23
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• 2003

In most organizations, the relational DBMS was used for store and manage XML documents due to the pre-established relational DBMS. But, relational DBMS has some problems. They has the possibilities of informational loses in the process of mapping the structure of XML documents to RDB, and they require expensive cost to reflect all XML properties. Thus, this paper was intended to design and implement XML document management system which utilize O2 DBMS-object oriented DBMS in order to overcome the existing problem and reflect all XML Properties. The XML document management system purposed in this thesis has multiple function, such as the library service function for XML documents-check-in/check-out, versioning, user access management-, dynamic indexing and retrieval, and publishing function using style sheet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1915-1925
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• 1998

The switching system software is large scale, real-time multi-task system which requires high reliability. The reliability assessment of large-scale software is very important for the success of software development project. For this raeson, the software quality measurement is much more important. In this paper, we have learned about the software reliability, metho of the analysis of failure data and estimation of software quality. To estimate the software reliability, using the failure data found during of the system test. We apply the two software reliability growth models, named Goel-Okumoto(G-O) and S-shaped model, to estimate the software reliability. Also, we compared with the results and we reviewed fully not only development cycle but validation and verification of the test data, for each software versions. This paper presents a software reliability model that suitale the software development project and the activeity of quality control for the switching system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.717-720
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• 2004

Jini is a middle ware supposed in Sun Microsystems. The goal of lil is the establishment of dynamic distributed system, which can share information and control of other Jini technology-enabled services or devices in the same Jini system. Jini is one of the best middleware together UPnP and HAVi. Hone network security, soch as privacy protection, crime prevention, and etc, is very important. So Jini 2.0 adds security mechanism in 11. 2003. This paper describes the analysis of Jini 2.0 security mechanism, and home network security.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.957-968
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• 2021

To improve the data on reliability of the onshore fish farm water quality monitoring system and operate the system efficiently, the water quality data of the onshore seawater fish farms which are progressing test operation, and the marine environmental information network(Wando tidal station) were compared and analyzed. Furthermore, data validation, data range filters, and data displacement checks were applied to analyze the data in a way that eliminates the data errors in water quality monitoring systems and increases the reliability of measurement data.

• Annual Conference of KIPS
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• 2022.05a
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• pp.252-255
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• 2022

기존 블록체인 기술을 활용해 새로운 비즈니스 모델을 개발 및 투자하려는 기업들의 관심이 높아지고 있으나, 낮은 확장성으로 인해 기존 블록체인 기술만으로는 시장에서 활용되기 어렵다. 블록체인의 낮은 확장성을 해결하기 위해 검증된 참여자만 참여하는 프라이빗 블록체인과 프라이빗 블록체인 고속화를 위한 관련 연구가 같이 진행되고 있다. 삼성의 넥스레저는 하이퍼레저 패브릭의 다중 버전 동시성 제어(MVCC) 충돌로 인한 낮은 TPS 문제를 해결하기 위해 Accelerator를 추가하여 고속화를 진행하였다. 하지만 모든 트랜잭션을 수집하여 처리하는 방식인 Accelerator는 중앙화로 인해 악의적인 공격 타깃이 되어 단일 장애 지점 문제가 발생할 수 있으며, 공격으로 인해 위조되거나 분실된 데이터는 검증 없이 블록체인 블록에 반영되고, 한번 반영된 데이터는 수정이 어렵다. 본 논문에서는 이와 같이 프라이빗 블록체인 고속화 상황에서 발생할 수 있는 단일 장애 지점 문제를 해결하기 위해 CMT와 사기증명 기반의 고속화 하이퍼레저 패브릭 시스템을 제안했으며, 제안한 시스템을 구축하고 성능 테스트를 통해 CMT 하이퍼레저 패브릭 시스템 성능이 99.58% 유지됨과 사기증명이 가능함을 확인하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.623-634
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• 2003

In this paper, we propose a collaborative multimedia authoring system. Our authoring system represents a multimedia presentation in a 3D coordinate system. One axis represents the traditional timeline information (T-zone), and the other two axes represent spatial coordinates (XY-zone). Our system represents a visual media objects as a 3D parallelepipeds and audio media objects as cylinders. This interface allows for simultaneous authoring and manipulation of both the temporal and the spatial aspects of a presentation. Using our system, users can design multimedia presentations collaboratively in the unified spatio-temporal space while freely traversing the spatial domain and the temporal domain without changing the context of authoring. In addition, we suggest an efficient mechanism of concurrency control for shared objects generated by our collaborative writing system. The mechanism is mainly based on the user awareness, the multiple versions, and the access permission of shared objects. Our concurrency control mechanism is designed to keep data consistency by minimizing the collision due to the delay or the failure of network communication and to allow maximum responsiveness for users using optimistic concurrency control. Also, the mechanism maximize the responsiveness by refining the locking granularity and applying different concurrency control mechanisms to each.