• Journal of Korea Multimedia Society
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• v.21 no.9
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• pp.1090-1098
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• 2018

MQTT is a lightweight messaging protocol that can be used for low power IoT devices. The MQTT basically uses single MQTT broker to indirectly share message information between publishers and subscribers. This approach has a weakness in regard to traffic overflow, connection fault, security, etc. In this paper, we propose a distributed MQTT broker architecture that solves the problems in single MQTT broker structure. The distributed MQTT broker architecture is expected to support new application services that cannot be supported by a conventional MQTT architecture. We have designed and implemented a distributed MQTT broker architecture based on the RPL protocol that has been widely used for IoT network. The experiment results show that the proposed MQTT broker architecture represents better publishing/subscribing latency and network stability than the conventional MQTT broker architecture.

• Journal of Korea Multimedia Society
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• v.6 no.6
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• pp.1071-1078
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• 2003

SOAP is a protocol used for information exchange in distributed computing environment and SOAP defines mechanisms for message transferring between distributed system and remote procedure call/response process. This SOAP is able to be used independently on operating systems and program languages because it uses only a text-based XML for protocol. Therefor ebXML that is a standard for E-Commerce adopts SOAP for message exchange. In this paper, we developed Message Broker System based on SOAP. By this Message Broker System we can more easily exchange messages for B2B. Accordingly we can manage and integrate a lots of business partners.

• The Journal of Society for e-Business Studies
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• v.2 no.2
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• pp.155-169
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• 1997

The CALS integrated database is a key information technology in which CALS implements an information sharing system to enable digital data transfers for technical and non-technical information in distributed and heterogeneous environments. Such heterogeneously distributed CALS information needs to be systematically incorporated so that it can provide a global data view for CALS users. In this paper, we investigated the technologies of CALS integrated database, and proposed a system prototype to implement an integrated data environment (IDE) utilizing distributed object environments CORBA (Common Object Request Broker Architecture).

• The Journal of Society for e-Business Studies
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• v.5 no.1
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• pp.105-122
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• 2000

Enterprise integration and virtual enterprise are practical visions of industrial information implementations in the information society. In these environments, the distributed and heterogeneous data sources should be exchanged and shared in effective and integrated way. However, the distributed and heterogeneous data sources are managed by independent and heterogeneous computer systems, thus system users and developers are faced difficulties in implementing enterprise integration environments, In this study, we designed and developed a database broker system utilizing a routing broker method to provide transparent location access mechanisms for the distributed and heterogeneous data sources. The proposed mechanism is designed to act as a middle tier between clients and multiple servers, and adopts Java, CORBA, and JDBC as its state-of-the-art techniques.

• 연구논문집
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• s.28
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• pp.239-246
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• 1998

Today’s information technology departments face a dilemma to create a competitive advantage for the organization by developing. deploying, and managing distributed applications that scale across the LAN, WAN, and Internet, while preserving investments in systems. Applications, information. IT organizations are today being asked to build the future, without breaking systems that maintain the current business. A possible answer to this dilemma is the implementation of a multi-tier distributed computing architecture. Multi-tier architecture has the potential to provide better, more timely information across the enterprise at a lower cost than the current combination of PC LAN, two-tier client/server, or mainframe applications that have been developed in most organizations. In this paper, we implement management information system based on distributed object middleware using multi-tier distributed computing architecture. This system uses Microsoft's implementation of DCOM/ActiveX and provides easily accessible web interface to the system users.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.259-268
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• 2004

According to the increasing demand of application software that must be applied to the distributed computing environment, the various tools are proposed to write distributed softwares. But, if using these tools, programmers have to know the usage of each tool requisite for writing distributed softwares. If programmers can write distributed software without additional knowledge, they can get better concentration of the functions of software itself to develop, because it reduces burden for distributed programming. In this paper. we introduce new distributed programming tool, named TORB(Transparent Object Request Broker). With TORB, thanks to programming transparency that is supported by TORB, we can write the distributed software with java more easily. After postprocessing, this software can run in the distributed processing environment that is supported by TORB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.321-323
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• 2016

The current cloud system is not compatible as low interoperability between cloud systems because they build up cloud environments with their own way. For example, users who are using Google's cloud system, it will not be able to use the cloud system of MS (Microsoft). To solve these problems, CSB (Cloud Service Broker) technology appeared, but solves interoperability problems between cloud systems require circumstances to develop and still much research. In this study, in the CSB, which has appeared as a service intermediary technology of heterogeneous distributed cloud environment (Cloud Service Broker) technology, to study authentication system, which is a fundamental problem to be solved of the interoperability of the cloud user.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.10
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• pp.752-760
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• 2009

Emerging peer-to-peer systems benefit from the large amount of resources provided by many peers. However, many peer-to-peer systems or applications suffer from malicious peers and it is not guaranteed that peers are always online. Micropayment systems are accounting and charging mechanism for buying services, so we can apply them to solve these problems. In the past the majority of micropayment system uses a centralized broker but the problem with most existing micropayment system is a heavy load on the broker. For instance, when an owner of the coin is offline, the broker delegates the owner and handles payment messages. It occurs frequently because of characteristic of peer-to-peer system and is another load of the broker. In this paper we introduce DPay, a peer-to-peer micropayment system that uses distributed hash table (DHT) for storing encrypted payment messages and increases scalability and reduces the load of broker by removing downtime protocol. We show the idea of real-time double spending detection in DPay and report the results of several evaluations in order to compare DPay and other payment scheme. In simulation result, the load of broker in DPay is reduced by 30% on average of other previous payment scheme. We expect that DPay can apply various peer-to-peer systems because it provides a real-time double spending detection and stores more secure payment messages.

• 한국공간정보시스템학회:학술대회논문집
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• 1999.06a
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• pp.9-18
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• 1999

지리정보 및 이와 관련된 프로세스의 표준화를 위해서 구성된 OGC에서는 개방형 GIS를 구현하기 위한 방법으로 CORBA, COM, 그리고 SQL의 세 가지를 제시하고 있다. 본 논문에서는 세 가지 구현방안 중 CORBA 구현명세를 바탕으로 하는 분산객체GIS에 대한 구현모델을 제시하고, 제시된 구현모델에 대하여 JAVA와 VisiBroker를 이용하여 서버와 클라이언트 측면에서 구현하는 방안을 제시하고자 한다.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.6
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• pp.145-154
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• 2018

A loosely coupled message broker system is a popular method for integrating distributed software components. Especially, a distributed broker structure with multiple brokers with active-standby or active-active message replicas are used to enhance availability as well as message processing performance. However, there are problems in both active-standby and active-active replica structure. The active-standby has relatively low processing performance and The active-active structure requires a high synchronization overhead. In this paper, we propose an active-active structure of replicas to increase the availability of the brokers without compromising its high fault-tolerancy. In the proposed structure, standby replicas process the requests of the active replicas so that load balancing is achieved without additional brokers, while the distributed coordinators are used for the synchronization process to decrease the overhead. We formulated the overhead incurred when synchronizing messages among replicas, and the formulation was used to support the experiment results. From the experiment, we observed that replicas of the active-active structure show better performance than the active stand-by structure with increasing number of users.