• Journal of information and communication convergence engineering
• /
• v.10 no.1
• /
• pp.71-77
• /
• 2012

This study examines the factors influencing internet protocol television (IPTV) usage intention. Using Davis's technology acceptance model (TAM) and DeLone and McLean's model of information system success, this study investigates the effects of information system quality (information quality, system quality, and service quality) and media quality on IPTV use in terms of perceived usefulness, perceived ease of use, and usage intention. We examined the proposed model by employing structural equation modeling and survey data from 222 IPTV users. The results indicate that information quality, service quality, and media quality had significant effects on perceived usefulness and that information quality and media quality had significant effects on perceived ease of use. However, system quality had no effect on perceived usefulness or perceived ease of use. In addition, perceived ease of use influenced perceived usefulness, and perceived usefulness and perceived ease of use influenced IPTV usage intention. Further, the stability and reliability of IPTV services encouraged IPTV use, and successful IPTV services showed high media quality.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.4
• /
• pp.1223-1247
• /
• 2012

The need for securing Wireless Sensor Networks (WSNs) is essential especially in mission critical fields such as military and medical applications. Security techniques that are used to secure any network depend on the security requirements that should be achieved to protect the network from different types of attacks. Furthermore, the characteristics of wireless networks should be taken into consideration when applying security techniques to these networks. In this paper, energy efficient Security Model for Tree-based Routing protocols (SMTR) is proposed. In SMTR, different attacks that could face any tree-based routing protocol in WSNs are studied to design a security reference model that achieves authentication and data integrity using either Message Authentication Code (MAC) or Digital Signature (DS) techniques. The SMTR communication and processing costs are mathematically analyzed. Moreover, SMTR evaluation is performed by firstly, evaluating several MAC and DS techniques by applying them to tree-based routing protocol and assess their efficiency in terms of their power requirements. Secondly, the results of this assessment are utilized to evaluate SMTR phases in terms of energy saving, packet delivery success ratio and network life time.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2005.11a
• /
• pp.461-470
• /
• 2005

A dynamic supply chain that is composed of many different companies with different rent roles and interests allows free joining and secession. Buyers place orders simultaneously and manufacturers should compete each other for the orders. The purpose of our paper is how to find the optimal formation of supply chain ill a global viewpoint while allowing each member company to pursue his local goal The dynamic nature of supply chain formation causes the variation of cost depending on how many orders a manufacturer would accept. We propose a multi-agent based negotiation protocol that efficiently leads to the formation of optimal supply chain without giving up maximization of the individual profit in multi-agent environment of the make-to-order industry. The goal of the negotiation is to form a supply chain to minimize the overall sum of manufacturers' manufacturing cost, and earliness cost and tardiness cost based on SET model. We compare the negotiation protocol with Branch & Bound method. Finally, the validity and performance of buyer's negotiation has been tested experimentally.

• Journal of the Semiconductor & Display Technology
• /
• v.18 no.4
• /
• pp.40-45
• /
• 2019

The smart factory has developed with the help of several technologies such as automation, artificial intelligence, big data, smart sensors and communication protocols. The Internet of things(IOT) among communication protocols has become the key factor for the seamless integration of various manufacturing equipment. Therefore, it is important that the IOT cooperate with the standards of communication protocols proposed by the SEMI in the semiconductor industry. In this paper, we suggest a novel reference model of the communication protocols for semiconductor equipment by introducing an IOT service layer. With the IOT service layer, we can use the functions and the additional services provided by the IOT standards that give the inter-operability between factory machines and host computers. We implement the standard of the communication protocols for semiconductor equipment with the IOT service layer by using ns3 simulator. It concludes that it is necessary to provide the platform for the IOT service layer to deploy efficiently the proposed reference model of the communication protocols.

• Journal of Drive and Control
• /
• v.19 no.2
• /
• pp.36-44
• /
• 2022

Hydrogen energy as an alternative source of energy has been receiving tremendous support around the world, and research is being actively conducted accordingly. However, most of the studies focus on hydrogen storage tanks and only are few studies on interpreting the hydrogen filling system itself. In this study, with reference to SAE J2601, a hydrogen fueling protocol, a simulation model was developed that can confirm the behavior of the vehicle's internal tank during hydrogen fueling. With respect to factors such as fuel supply temperature, ambient temperature, and pressure increase rate, the developed model can check the change of temperature and pressure in the tank and the state of hydrogen charging during hydrogen fueling. The validity of the developed simulation model was confirmed by comparing the simulation results with the experimental results presented in SAE J2601.

• The Journal of the Korea Contents Association
• /
• v.6 no.2
• /
• pp.17-26
• /
• 2006

SIP(Session Initiation Protocol)-based centralized conference service model has advantage of easiness in conference management and service as compared to other models. However when media server which is one of the components of conference server is included in the conference server, this model shows disadvantage of high server work load with increasing numbers of conferences and participants. In this paper, to improve this problem, we have suggested and implemented a new conference service model in which an UA(User Agent) who first make the conference acts as a media server instead of conventional conference server and, the conference server with conference event package takes only part of management of the conference and its participants. Therefore, many more conferences can be held and managed compared to the conventional centralized conference service model because load of the conference server decreases in our suggested model md, furthermore the participants needs only make SIP call connections to the UA who first make the conference for establishing media session.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8940-8947
• /
• 2015

Mixed-model assembly line has been widely used in automotive assembly industry to quickly respond the diverse product demands. But, this model can lead to part confusion, which is a source for assembly errors when parts are physically interchangeable in a mixed-model assembly line. With the recent application of new technologies such as radio frequency identification (RFID) and ZigBee wireless sensor network (WSN) to the assembly process, real-time information has become available in this manufacturing systems through IT infrastructures. At first, this paper presents an RFID application for assembly processes, specifically, for a mixed-model assembly line. Thus, to ensure that parts be picked accurately, each cockpit module on the assembly line is attached with a RFID tag and the tag is scanned using a RFID reader and recognizes the vehicle, and each part of the cockpit module is attached with a barcode and the barcode is scanned by a barcode reader and each part is identified correctly for the vehicle. Second, this paper presents a ZigBee wireless sensor network (WSN) protocol-based application for a reconfigurable mixed-model assembly line of cockpit module to reduce the assembly errors and the cost of the change/reconfiguration on the assembly lines due to the various orders and new models from the motor company, avoiding the wiring efforts and inconvenience by wiring between the several RFID devices and the IT server system. Finally, we presents the operation results for several years using this RFID/ZigBee wireless sensor network (WSN) protocol-based cockpit module assembly line.

• Journal of Digital Convergence
• /
• v.12 no.8
• /
• pp.229-234
• /
• 2014

Vehicular electronic communication system has continued to develop in favor of high performance and user convenience with the evolution of auto industry. Yet, due to the nature of communication system, concerns over intruder attacks in transmission sections have been raised with a need for safe and secure communication being valued. Any successful intruder attacks on vehicular operation and control systems as well as on visual equipment could result in serious safety and privacy problems. Thus, research has focused on hardware-based security and secure communication protocols. This paper proposed a safe and secure vehicular communication protocol, used the formal verification tool, Casper/FDR to test the security of the proposed protocol against different types of intruder attacks, and verified that the proposed protocol was secure and ended without problems.

• Journal of Digital Convergence
• /
• v.10 no.10
• /
• pp.325-332
• /
• 2012

Due to its communication vulnerability resulting in a range of problems, e.g. eavesdropping, information exposure, traffic analysis and spoofing, RFID system becomes the target of attackers. Accordingly, many investigators have proposed various protocols to the extent of theorem proving or verification as the implementation is challenging. This paper thus proposes a safe RFID security protocol using public keys, session keys, hashes, XORs, and random numbers. Timestamps and hashes are applied to the most vulnerable section between readers and tags to detect attacks in attack signals with time difference. Also, to prevent tag information from being exposed in the last session, hash operation is adopted before communication. Finally, in this paper, we designed a RFID security protocol using public and session keys applicable to real systems and verified the security of the proposed protocol with a differentiated formal verification technique.

• Journal of the Korea Convergence Society
• /
• v.7 no.4
• /
• pp.25-32
• /
• 2016

When using reliable multicast protocol over air links, the multicast packets lost in the air link cause the initiation of retransmission request packets and the implosion of retransmission packets, which deteriorate multicast session performance. This paper proposes on the efficient reliable multicast mechanism in wireless networks utilizing the Agents. In this paper we show the design of a retransmission agent which improves the performance of reliable multicast sessions in wireless network. The main idea is to cache reliable multicast packets at the base station and perform local retransmissions across the wireless link. MATLAB has been used to simulate and to get performance results for signaling overhead and processing delay through the comparison of the proposed agent model to the Multicast File Transfer Protocol. It has been proven from the simulation results that the proxy module make pass trials shorter in Multicast File Transfer Protocol.