• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.171-172
• /
• 2008

We propose the sensor networks middleware based on publish/subscribe model for adaptive service to client. Publish/subscribe middleware make capability of sensor to data through the advertisement message. Based on capability of sensor, Publish/subscribe middleware adaptively service to client. And client make a collection of information that it require. Therefore middleware service more effectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.12
• /
• pp.5877-5897
• /
• 2018

With the popularity of mobile networks and smartphones, geo-textual publish/subscribe messaging has attracted wide attention. Different from the traditional publish/subscribe format, geo-textual data is published and subscribed in the form of dynamic data flow in the mobile network. The difference creates more requirements for efficiency and flexibility. However, most of the existing Top-k geo-textual publish/subscribe schemes have the following deficiencies: (1) All publications have to be scored for each subscription, which is not efficient enough. (2) A user should take time to set a threshold for each subscription, which is not flexible enough. Therefore, we propose an efficient and flexible Top-k geo-textual publish/subscribe scheme. First, our scheme groups publish and subscribe based on text classification. Thus, only a few parts of related publications should be scored for each subscription, which significantly enhances efficiency. Second, our scheme proposes an adaptive publish/subscribe matching algorithm. The algorithm does not require the user to set a threshold. It can adaptively return Top-k results to the user for each subscription, which significantly enhances flexibility. Finally, theoretical analysis and experimental evaluation verify the efficiency and effectiveness of our scheme.

• Journal of Korea Multimedia Society
• /
• v.24 no.8
• /
• pp.1101-1113
• /
• 2021

The rapid growth of sense-and-respond applications and the emerging cloud computing model present a new challenge: providing publish/subscribe middleware as a scalable and elastic cloud service. The publish/subscribe interaction model is a promising solution for scalable data dissemination over wide-area networks. In addition, there have been some work on the publish/subscribe messaging paradigm that guarantees reliability and availability in the face of node and link failures. These publish/subscribe systems are commonly used in information-centric networks and edge-fog-cloud infrastructures for IoT. The IoT has an edge-fog cloud infrastructure to efficiently process massive amounts of sensing data collected from the surrounding environment. In this paper. we propose a quorum-based hierarchical fault-tolerant publish/subscribe systems (QHFPS) to enable reliable delivery of messages in the presence of link and node failures. The QHFPS efficiently distributes IoT messages to the publish/subscribe brokers in fog overlay layers on the basis of proposing extended stepped grid (xS-grid) quorum for providing tolerance when faced with node failures and network partitions. We evaluate the performance of QHFPS in three aspects: number of transmitted Pub/Sub messages, average subscription delay, and subscritpion delivery rate with an analytical model.

• The KIPS Transactions:PartA
• /
• v.18A no.5
• /
• pp.181-192
• /
• 2011

Information superiority is an essential factor in modern warfare and it can be archived by efficient information exchange between systems. Various computing systems are installed on the today's navy vessels. However, it is hard to improve interoperability and efficiency of information exchange since the configurations of installed systems are varying. The military standard and commercial standard are mix-used between systems. In this paper, we propose an information exchange architecture based on Pub/Sub model as a communication middleware to improve interoperability as well as enhancing scalability. We also propose a novel tree matching algorithm to improve a performance of PubSub broker. In the proposed algorithm, each tree nodes have information about predicates of subscription that can reduce event matching time. The performance evaluation results show our proposed algorithm reduces time for matching predicates compare with other algorithms.

• Journal of IKEEE
• /
• v.19 no.3
• /
• pp.327-334
• /
• 2015

Various types of middle-ware were created for integration between legacy systems and newly built systems. RPC(Remote Procedure Call), MOM(Message Oriented Middle-ware) and TM(Transaction processing Monitor) are the typical types of middle-ware. One of the most known MOM type middle-ware is PS(Publish/Subscribe). PS enables to create a system which has low coupling and high scalability. But PS based systems also have low cohesiveness. On the contrary, RPC has high cohesiveness but also has high coupling. This paper proposed design and implementation of hybrid model which offset disadvantages of RPC and PS.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2020.07a
• /
• pp.77-80
• /
• 2020

In this paper, we analyze and compare the performance of different publish and subscribe protocols in the real application environment. This paper provides a horizontal comparison of current publish/subscribe protocols in terms of security, throughput, and delay performance. Thanks to the use of lightweight frameworks, the MQTT protocol has demonstrated excellent performance in terms of delay performance. However, the AMQP protocol has more advantages in security and throughput. Although the REST/HTTP protocol has the worst delay performance, it is excellent in terms of compatibility because it is based on the HTTP protocol.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.10
• /
• pp.11-22
• /
• 2009

For a wireless ad-hoc network, event routing algorithm of the publish/subscribe system is especially important for the performance of the system because of the dynamic characteristic and constraint network of its own. In this paper, we propose a new hybrid event routing algorithm. TopSim for efficient publish/subscribe system on the wireless ad-hoc network by extending the ShopParent algorithm by considering not only network overheads to choose a Parent of the publish/subscribe tree, but also topic similarity which is closeness of subscriptions. Our evaluation shows our proposed TopSim performs better for the case where a new joining node subscribed to the multiple topics and there is a node among Parent candidate nodes who subscribe to the ones in the list of multiple topics (related topics).

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06a
• /
• pp.202-203
• /
• 2007

• Journal of IKEEE
• /
• v.25 no.2
• /
• pp.291-301
• /
• 2021

OPC UA at the control and field level does not provide enough performance to replace the field bus. The OPC Foundation aims for a real-time and connection-less mechanism, and has added the OPC UA publish-subscribe model, a new specification that supports broker functions such as MQTT and AMQP, as the OPC UA Part 14 standard. This paper is about a gateway for interoperability between OPC UA publisher with the addition of OPC UA Part14 standard and DDS subscribers. Raspberry Pi 4 is used for the gateway proposed in this paper, and OpenDDS, an open source, is used for DDS. OPC UA publish-subscribe module used A-Open62541 publish-subscribe module, which additionally implements functions not provided by the corresponding source based on Open62541 publish-subscribe open source.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.11a
• /
• pp.801-804
• /
• 2007

실 시간적인 데이터의 수집과 더불어 수집한 데이터의 실 시간적인 전송을 기반으로 정보를 보다 폭넓게 활용할 수 있는 환경을 제공하기 위해 시스템에서 자동적으로 정보를 배포해주는 Publish/Subscribe 시스템에 대한 요구가 증대되고 있다. 이러한 pub/sub 시스템은 사용자의 요구사항을 미리 저장, 이를 이용하여 수집되는 정보와 사용자의 요구와 사용자를 찾아 배포해주는 방법을 사용하는데, 이때, 일치 여부를 확인하는 매칭 과정에서의 많은 자원과 시간의 소모가 문제점으로 대두되고 있다. 따라서, 논문에서는 보다 효율적으로 데이터와 범위를 이용하여 나타내는 사용자의 요구를 매칭하는 방법을 제공하는 CGIM 알고리즘을 제안하였다.