• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.637-638
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• 2017

The MQTT broker has problems such as packet loss and delay due to degraded network performance according to traffic. However, the MQTT broker does not support a separate interface for traffic measurement, so it can not cope with network degradation. In this paper, we propose a system for traffic measurement of MQTT broker. The proposed system uses the jnetpcap library to measure all traffic to and from the MQTT broker.

• 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 Broadcast Engineering
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• v.3 no.1
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• pp.24-37
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• 1998

This paper presents a new interworking paradigm using service-level interworking functionality for provision of end-to-end interperability in Heterogeneous Network Environments such as ATM network to Internet, Internet to ATM network. PSTN to ATM network, etc. We propose the concept of the Service Interworking Broker. We also propose the functional architecture of the Interworking Broker. The middleMEN is implemented for evaluating the functions of the Interworking Broker

• Journal of KIISE
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• v.43 no.6
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• pp.668-677
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• 2016

The information superiority through effective networking is a core element that accelerates command decision for mission completion. Our military wants to acquire capabilities of effective information sharing with Network-Centric Operational Environment(NCOE) for Network-Centric Warfare (NCW). In this paper, we suggested an information broker for overcoming current limits and maximizing future expandability and possibility of information sharing capacities. The information broker, which is an intermediate layer between users and information providers, provides the functions for mediating and managing information and for ensuring security of the system. We evaluated the consistency of proposed architecture and the implementation of the operational architecture design concept using existing design frameworks.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.89-92
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• 2002

It is important that fault management of devices which is composing network in the next-generation internet environment. It is best method of operating network safely and efficiently. In this paper, we have suggested double message broker architecture to transmit trap messages in web-based fault management system using Java technologies. The double message broker fault management system shows that manager can do its own job efficiently

• Knowledge Management Research
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• v.19 no.4
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• pp.19-37
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• 2018

Knowledge transfer among employees integrates individual knowledge scattered within a firm, thus increases organizational effectiveness. In particular, the role of knowledge broker, which enables knowledge sharing across multiple teams or subunits, is critical for the success of knowledge management. This study classified the types of knowledge broker that facilitates knowledge flows among team, and examined the influences of various intra- and inter-team social networks. Survey responses from 128 employees of four R&D teams were gathered and analyzed using partial least square structural equation modeling. The results of analysis showed that all types of inter-team networks(i.e., emotional closeness network, frequency of interaction network, and perceived expertise network) had significant influences on related knowledge brokerage behaviors. In case of intra-team networks, only the emotional closeness network showed significant influence. These results proved the necessity of managing various types of intra- and inter-team networks to encourage knowledge brokerage behaviors within a firm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.83-93
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• 2003

Differentiated service networks, based on bandwidth broker, perform the control and management of QoS provisioning for the QoS guaranteed services, However, the centralized bandwidth broker model has a scalability problem since it has centralized resource management for the admission control function of all call attempts, Therefore, in this paper, we proposea novel adaptive admission control mechanism according to the attempted call status for enhancing the scalability under the centralized bandwidth broker model in IP differentiated service networks, The proposed mechanism decouples the function of admission control from the bandwidth broker, So, the ingress edge node performs the admission control and the bandwidth broker performs the resource management and QoS provisioning, We also introduce an edge-to-edge path concepts and the ingress edge node performs the admission control under the allocated bandwidth to eachpath. The allocated bandwidth per path adaptively varies according to the status of the attempted calls, This mechanism can significantly reduce the number of communication message between the bandwidth broker and each edge node in the network and increase the bandwidth utilization via adaptable resource allocation, In this paper we study the adaptive admission control operation and show the efficient and extensive improvement through the performance evaluation.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.3
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• pp.133-141
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• 2018

There are increasing interests on smart home systems. However, most of the existing works focus on the functionality itself. In this paper, we propose an extensible smart home system based on low power networking such as CoAP, 6LoWPAN, and Zigbee. The proposed home IoT system consists of Home APP, Home Server, Home Broker, and Power Devices. Each component of the system is connected by the low-power network technologies aforementioned. As the end device, Power Device senses the current consumption of the attached appliance and controls the power to it. Power Device reports the sensing data to Home Server via Home Broker. The Home Broker enhances the scalability of the system. Home Broker extends the service area and the user's services, and it manages the connection of the underlying devices and processes, and transmits data to Home Server from Power Devices. Through the experimental evaluation, we show that the proposed system achieves the design goals such as extensibility and low power networking.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.41-49
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• 2006

Wireless AD-hoc network can construct a network itself without any arbitrator. Therefore, it is difficult to make preparation for disguised assault from an illegal node, and because lots of packets from disguised assault spread over whole network, it influences the network usability and livability. This thesis proposed a safe IPv6 tunnel broker (TB) based on TSP (Tunnel Setup Protocol) to improve safety of the wireless Ad-hoc network, and to solve security problem of a tunnel broker that makes a linkage IPv4 and IPv6. To communicate between client and the tunnel broker, proposed method does not base on HTTP, but S-HTTP (Secure-HTTP) and it uses encryption/decryption to send and receive XML document. Finally, this method encrypts (decrypts) important information by applying IPSec between client and TS (Tunnel Server).

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.6
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• pp.531-537
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• 2005

The Tunnel Broker is to provide dedicated servers and to automatically manage tunnel requests coming from the users. This approach is useful to stimulate the growth of IPv6 interconnected hosts and to provide easy access to their IPv6 networks. However, the existing tunnel broker is vulnerable to attacks of malicious users about network resources and services. Therefore, to solve the secure problem of tunnel broker, this paper presents secure IPv6 tunnel broker based on TSP(Tunnel Setup Protocol). The clients and the tunnel broker are communicated based on SHTTP(Secure HTTP) and the XML message of plain text is converted to XML signature by encryption and decryption. finally, Clients and tunnel server use the IPsec method to protect the important information.