• The Journal of Information Technology and Database
• /
• v.3 no.2
• /
• pp.3-24
• /
• 1996

In this paper a data replicator scheme with a distributed join architecture is suggested with its cost functions and the performance results. The contribution of this scheme is not only minimizing the number of base relation locks in distributed database tables but also reducing the remote transmission amount remarkably, which will be able to embellish the distributed databse system practical. The differential files that are derived from the active log of the DBMS are mainly forcing the scheme to reduce the number of base relation locks. The amount of transportation between relevant sites could be curtailed by the tuple reduction procedures. Then we prescribe an algorithm of data replicator with its cost function and show the performance results compared with the semi-join scheme in their distributed environments.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06c
• /
• pp.336-340
• /
• 2007

We envisage that grid computing environments allow us to implement distributed data mining services, that is, those applications which analyze large sets of geographically distributed databases and information using the computational power and resources of a grid environment. This paper describes an experimental framework towards such a distributed data mining approach, including design considerations and a prototype implementation. Based on the "Knowledge Grid" architecture suggested by Cannataro et al., we identify four major components - user node, broker node, data node, and computation node - and define their individual roles. For implementing the prototype, we have investigated methods for utilizing distributed resources within a grid computing environment, e.g., communication and coordination among the various resources available.

• Korean Journal of Computational Design and Engineering
• /
• v.5 no.1
• /
• pp.12-22
• /
• 2000

Network and Internet technology opens up another domain for building future CAD/CAM environment. The environment will be global, network-centric, and spatially distributed. In this paper, we present an approach for network-centric feature-based modeling in a distributed design environment. The presented approach combines the current feature-based modeling technique with distributed computing and communication technology for supporting product modeling and collaborative design activities over the network. The approach is implemented in a client/server architecture, in which Web-enabled feature modeling clients, neutral feature model server, and other applications communicate with one another via a standard communication protocol. The paper discusses how the neutral feature model supports multiple views and maintains naming consistency between geometric entities of the server and clients. Moreover, it explains how to minimize the network delay between the server and client according to incremental feature modeling operations.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2531-2533
• /
• 2002

In this paper, we evaluate feasibility of an object-oriented method in a distributed real-time control environment through the prediction of delay expected. We adopt CAN as the distributed network and the application layer of the CAN is composed of client/server communication model of COM and surroundings for the support of real-time capability of the COM. Mathematical models formalizing delays which are predicted to invoke in the COM architecture are proposed. Sensors and actuators which are widely used in distributed network-based systems are represented by COM objects in this paper. It is expected that the mathematical models can be used to protect distributed network-based systems from violation of real-time features by the COM.

• Journal of the Korea Society for Simulation
• /
• v.9 no.4
• /
• pp.25-40
• /
• 2000

The cost of simulation modeling, the expertise required, and the pains of starting a new each time are impediments to more wide spread adoption of simulation technology. In addition, one of the most critical problems in the field of computer simulation today is the lack of published models and physical objects within the World Wide Web (WWW) allowing such distribution. From the viewpoint of WWW as distributed model repositories, it can be assumed that very many simulation models exist on the web. This paper is based on the premise that WWW is a distributed repository. Design Pattern, web-oriented technology like Java and CORBA, which are especially to cope with distributed objects, are introduced and discussed in detail for integration of simulation model. In this paper an architecture of model integration is proposed, which presents the whole procedure of model integration and how the Internet technologies are connected in. The central focus of this research is on the technical realization of integrating simulation models as distributed objects

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.8A
• /
• pp.1144-1152
• /
• 2000

In order to guarantee the user-requested quality-of-service(QoS) and keep the network utilization at maximum it is required to manage the network performance continuously after the network installation. The performance management function should provide the useful information for the network expansion and the capacity reallocation in the future. Currently the TINA provides the specification of the management function of configuration management connection management and fault management ; but the management function of performance management and security management are not well-defined yet. In this paper we propose a TINA-based performance management architecture for the efficient performance management of the heterogeneous networks or NEs with TMN and SNMP management functions. And we examine the proposed architecture into the ATM network (with SNMP and TMN) monitoring. The proposed architecture is based on the distributed processing architecture and the concept the TMN perfo mance management. The proposed architecture have been designed and implemented in multiprocess and multithread structure.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.5
• /
• pp.303-310
• /
• 2017

Underwater robots operating in constrained underwater environment have requirements for software systems. Firstly, it is necessary to provide reusable common software components for hardware interface of sensors and actuators that are frequently used in underwater robots. Secondly, it is required to support distributed execution environment on multiple embedded controllers. Thirdly, it is need to implement a monitoring system capable of high-speed and large-data transmission for underwater robots operating in an environment where it is difficult to check the robot status. For these requirements, we have designed the layered architecture pattern and applied several design patterns to enhance the reusability and the maintainability of software components, In addition, we overlaid the broker architecture pattern to support distributed execution environments. Finally, we implemented the underwater robot software system using ROS framework based on the software architecture design. In order to evaluate the performance of the implemented software system, we performed an experiment to measure the response time between components and the transmission rate of the monitoring data, and obtained the results satisfying the required performance.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.1124-1128
• /
• 2005

In this paper, a plan-coordination architecture is proposed for multi-agent control in the fractal manufacturing system (FrMS). A fractal in FrMS is a set of distributed agents whose goal can be achieved through cooperation, coordination, and negotiation with other agents. Since each agent in the FrMS generates, achieves, and modifies its own plan fragments autonomously during the coordination process with other agents, it is necessary to develop a systematic methodology for the achievement of global plan in the manufacturing system. The heterarchical structure of the FrMS provides a compromised plan-coordination approach, it compromise a centralized plan-generation/execution (which mainly focuses on the maximization of throughput) with a distributed one (which focuses on the autonomy of each module and flexibility of the whole system). Plan-coordinators in lower level fractal independently generate plan fragments according to the global plan of higher level fractal, and plan-coordinators in higher level fractal mediate/coordinate the plan fragments to enhance the global performance of the system. This paper assumes that generation method of the plan fragments and the negotiation policy of the fractal is achieved by a simple process, and we mainly focuses on the information exchanging and distributed decision making process to coordinate the combinations of plan fragments within a limited exchange of information.

• Journal of KIISE:Information Networking
• /
• v.27 no.1
• /
• pp.1-11
• /
• 2000

Recently, the explosive popularity of Internet gave birth to researches on Distributed Virtual Environments(DVE). They aim at providing a shared application data environment at realtime for users participating in the same application session across Internet. As more users join the session, and as more multimedia data are shared, because of network resource limitation, it is more difficult to maintain the quality of DVE, such as users' satisfaction level. Previous works mainly tried to solve the scalability, synchronization and data transport issues at the application level, with limited success. We suggest a new network centric solution, that consists of a novel network architecture and protocols upon which any large-scale DVE application can be easily developed. The performance of the proposed scheme, called GAIA, is verified by simulation.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2002.05a
• /
• pp.61-65
• /
• 2002

These days, in order to satisfy the complex and various demands of the customers, the telecommunication networks must provide rapid and flexible services, with the support of efficient service and network management systems. To satisfy these requirements, many objects for management have been released to manage network services and elements. But there are no efficient ways to manage these newly managed objects in object-oriented software. Therefore, we study several problems, when a subsystem using object-oriented technique is implemented. The first problem is that interface works between realized application programs using its technique. The second problem is that reusability of internal managed objects is difficult. In this paper, we will point out some problems and to solve these problems, we have proposed the Object Management System (OMS) architecture, which supports a transparent interface between object-oriented applications and the distributed data repositories. Also in order to manage efficient business objects stored in the different repositories, we suggest a method for integrating dynamic information resources in heterogeneous and distributed network environments. Finally, we applied OMS to TINA(Telecommunication Information Network Architecture) domain, implemented OMS, and verified it with SMV(Symbolic Model Verifier) which is model checking technology.