• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.229-231
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• 2002

본 논문에서는 실시간 시스템인 전화 교환기에서 운영되는 C언어 기반 분산 처리시스템인 uniORB 상에서 이벤트 전송을 담당하는 서비스인 Event Service의 기능을 보완하고 다양한 이벤트의 타입과 필터링 기능, QoS를 제공하는 Notification Service에 대한 실시간 버전의 설계 및 구현을 하였다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3340-3349
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• 1999

Supporting object group on distributed object system give merits such as load balancing, fault tolerance and high availability. In this paper, we describe a CORBA ORB that has been designed to support object group based on active replication. The ORB supports the operational model in which it uses the IIOP for communication between client and server and total ordered multicast protocol for consistency control among group members. And through extension of ORB, it provides functions required for support of object group. Since it provides transparency of object replication, the ORB is interoperable with the existing CORBA products. It make possible for existing server application to be easily extended to application supporting object group as adding interface functions which should be used for building applications is minimized. A prototype is implemented, and performance of the replicated object group is tested and compared with a single object invocation.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.66-72
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• 2007

In this study, we would like to report the analysis of COMS(Communication, Ocean & Meterological Satellite) MI2U(Meteo-Imager Interface Unit) ORB (On Board Reconfiguration) verification test. MI2U is one of equipment integrated on COMS and in charge of TM/TC function and Power Supply function of MI(Meteo-Imager). COMS, an geo-stationary satellite, is a multi-functional satellite accommodation two observation payloads and one communication payload.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.184-186
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• 2000

임베디드 시스템에서의 응용 개발 기술들은 주로 임베디드 장치에 종속적인 것들로 CPU, 다양한 입력장치, 네트워크, 디스플레이, 사용자 인터페이스에 따라 개별적으로 소프트웨어 및 서버스들을 개발하는 방식으로, 소프트웨어의 내용과 복잡도의 증가에 따른 개발의 어려움이 증가하는 구조이다. 또한 네트워크를 기반으로 한 임베디드 시스템에서 이기종간의 상호운영이 가능한 서비스의 개발이 큰 문제가 되고 있다. 본 논문에서는 자바 기반의 임베디드 ORB를 설계한다. 설계한 ORB는 임베디드 OS 환경에 자바 비추얼 머신 상에서 동작 하므로 다양한 임베디드 시스템에서 별도의 코스 변환이나 수정 없이 이용할 수 있는 표준화된 API를 제공하며 모듈화를 통해 기능의 확장과 축소가 가능한 구조를 가진다. 또한 minimumCORBA 사양을 준수 함으로서 기존의 CORBA 서비스나 제품들과 상호 운영성을 유지한다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.629-631
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• 1999

최근의 분산처리 기술은 이질적인 분산환경에서의 상호 운용성을 보장하는 시스템통합 기술을 중심으로 발전해 나가고 있다. 이러한 환경을 제공하는 대표적 분산 미들웨어인 OMG CORBA는 현재 많은 산업체와 연구기관에서 구현하여 상용화하거나 연구용으로 제공하고 있다. 그러나 하나의 제품에서 개발된 CORBA 응용 프로그램을 다른 제품에서 이식에 필요한 코드 수정 없이 바로 사용할 수 없는 문제점을 보이고 있어 OMG에서 CORBA를 통해 성취하려고 하는 중요한 목표인 이식성과 상호운용성을 보장하지 못하고 있다. 본 논문은 Java 언어 매핑을 지원하는 ORB를 대상으로 위 문제의 해결에 필요한 CORBA 규격 준수 시험을 수행하는 ORB 기능 시험에 대하여 기술한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.189-198
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• 2019

In recent years, visual-inertial odometry(VIO) algorithms have been extensively studied for the indoor/urban environments because it is more robust to dynamic scenes and environment changes. In this paper, we propose loosely coupled(LC) VIO algorithm that utilizes the velocity vectors from both visual odometry(VO) and inertial measurement unit(IMU) as a filter measurement of Extended Kalman filter. Our approach improves the estimation performance of a filter without adding extra sensors while maintaining simple integration framework, which treats VO as a black box. For the VO algorithm, we employed a fundamental part of the ORB-SLAM, which uses ORB features. We performed an outdoor experiment using an RGB-D camera to evaluate the accuracy of the presented algorithm. Also, we evaluated our algorithm with the public dataset to compare with other visual navigation systems.

• Journal of Internet Computing and Services
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• v.3 no.1
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• pp.81-90
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• 2002

Large-scale distributed applications based on Internet and client/server applications have to deal with series of problems. Load balancing, unpredictable communication delays, and networking failures can be the example of the series of problems. Therefore. sophisticated applications such as teleconferencing, video-on-demand, and concurrent software engineering require an abstracted group communication, CORBA does not address these paradigms adequately. It mainly deals with point-to-point communication and does not support the development of reliable applications that include predictable behavior in distributed systems. In this paper, we present our design, implementation and performance analysis of the group communication using the CORBA-ORB. JAVA-RML and Socket based on distributed computing Performance analysis will be estimated latency-lime according to object increment, in case of group communication using ORB of CORBA the average is 14.5172msec, in case of group communication using RMI of Java the average is 21.4085msec, in case of group communication using socket the average is becoming 18.0714msec. Each group communication using multicast and UDP can be estimated 0.2735msec and 0.2157msec. The performance of the CORBA-ORB group communication is increased because of the increased object by the result of this research. This study can be applied to the fault-tolerant client/server system, group-ware. text retrieval system, and financial information systems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.30-42
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• 2022

Due to the increase in construction of tunnels, the burdens of maintenance works for tunnel structures have been increasing in Korea. In addition, the increase of traffic volume and aging of materials also threatens the safety of tunnel facilities, therefore, maintenance costs are expected to increase significantly in the future. Accordingly, automated condition assessment technologies like image-based tunnel scanning system for inspection and diagnosis of tunnel facilities have been proposed. For image-based tunnel scanning system, it is key to create a planar image through stitching of multiple images captured by tunnel scanning system. In this study, performance of feature-based stitching algorithms suitable for stitching tunnel scanning images was evaluated. In order to find a suitable algorithm SIFT, ORB, and BRISK are compared. The performance of the proposed algorithm was determined by the number of feature extraction, calculation speed, accuracy of feature matching, and image stitching result. As for stitching performance, SIFT algorithm was the best in all parts of tunnel image. ORB and BRISK also showed satisfactory performance and short calculation time. SIFT can be used to generate precise planar images. ORB and BRISK also showed satisfactory stitching results, confirming the possibility of being used when real-time stitching is required.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.11
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• pp.40-49
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• 2009

HAO is a ORB engine to support the logic-based CORBA development environments in FPGA. In this papers, in order to support the logic component developments with HAO, we proposes the translation rule from IDL to VHDL, and the generation of skeleton logic code following the rule. It enables to guarantee the interoperability between the components in distributed multi processor environments includes the general purpose processor and FPGAs, and to improve the performance through the usage of logic-circuit.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1675-1689
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• 2000

We present CReMeS a CORBA-compliant design and implementation of a new real-time communication service. It provides for efficient predictable and scalable communication between information producers and consumers. The CReMeS architecture is based on MidART's Real-Time Channel-based Reflective Memory (RT-CRM) abstraction. This architecture supports the separation of QoS specification between producer and consumer of data and employs a user-level scheduling scheme for communicating real-time tasks. These help us achieve end-to-end predictability and allows our service to scale. The CReMeS architecture provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer. Thus it can run on non real-time Off-The-Shelf ORBs enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition an application designer can select whether to use an out-of-band channel or the ORB GIOP/IIOP for data communication. This permits a trade-off between performance predictability and reliability. Experimental results demonstrate that our architecture can achieve better performance and predictability than a real-time implementation of the CORBA Even Service when the out-of-band channel is employed for data communication it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.