• Journal of Digital Contents Society
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• v.19 no.4
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• pp.661-671
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• 2018

The avoidance tendency of voice call in younger generation facilitates the growth of mobile O2O service that utilizes Messaging. This study adopted and elaborated original concepts of telephone apprehension to apply phone anxiety to O2O. We examined previous researches related to the ubiquity of service quality, communication ability and anxiety, and then conducted a survey to understand the consciousness of mobile O2O service users. The results show that users with high message intimacy and users with poor logicality are afraid of voice calls. The mobile O2O service is considered useful as a means to replace an unstable situation. In this study, we considered individual characteristics of acceptance factor of O2O mobile service technology, and it was a new attempt to expand telephone apprehension characteristic reflecting current situation. In addition, the different results of this research from prior studies that examined the relationships among apprehension, usefulness, and continuous use intentions might be helpful to expand and sophisticate the research area.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.3
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• pp.256-261
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• 2013

The AIS(Automatic Identification System) has been widely used for ship safety at sea over the last 10 years. The AIS traffic load at VDL(VHF Data Link) has been continuously increased. As the traffic load at VDL increases, the quality of AIS service may be deteriorated. In the previous research, the AIS traffic has been analyzed in the major ports of Korea, and its problem due to traffic overload has been suggested. However, no solutions has been given so far. In this paper, the method of autimatically controlling the VDL traffic at AIS base station is represented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1393-1400
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• 2006

This paper optimizes the access probabilities (APs) in a network resource allocation scheme based on access probabilities in order that the waiting time and the blocking probability are minimized under the given constraints, and obtains its performance. In order to optimize APs, an infinite number of balance equations is reduced to a finite number of balance equations by applying Neuts matrix geometric method. And the nonlinear programming problem is converted into a linear programming problem. As a numerical example, the performance measures of waiting time and blocking probability for optimal access probabilities and the maximum utilization under the given constraints are obtained. And it is shown that the scheme with optimal APs gives more performance build-up than the strategy without optimization.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.121-125
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• 2007

This paper proposes automatic generation method of proxy client code to automation of web service selection process through a monitoring agent. The technique of this paper help service consumer to provide source code of proxy client as it bring an attribute value of specific element of WSDL document using template rule. Namely, a XSLT script file provide code frame of dynamic invocation interface model. The automatic code generation technique need to solving starvation status of selection architecture. It is required to creating request HTTP message for every service on the result of search. The created proxy client program code generate dummy message about services. The proposed client code generation method show us a possibility of application in the automatic generation programming domain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2533-2540
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• 2013

In multihop cellular network environments, the mobility of nodes is a major obstacle to find a reliable routing path between a mobile node (MN) and the access node (AN). Therefore, in this paper, we propose a fast and reliable neighbor discovery protocol that enables the fast and reliable neighbor discovery by considering the node mobility in the multihop cellular network. The proposed neighbor discovery protocol inhibits the transmission of unnecessary control messages to quickly find a suitable neighbor node (NN) and performs a priority-based access control to transmit control messages without collision in the order of NN desirable to be selected. Simulation results show that the proposed neighbor discovery protocol can discover the NNs faster than the conventional scheme and select a more reliable relay node although the number of neighbor nodes increases and the node mobility increases.

• The KIPS Transactions:PartB
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• v.18B no.1
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• pp.1-10
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• 2011

Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications, where high capacity and high visual quality are major requirements. This paper presents a new effective multi-round embedding scheme for the differential histogram-based reversible watermarking that satisfies high capacity requirements of the application. The proposed technique exploits the row-column cross scanning to fully utilize the locality of images when multi-round embedding phase to the message inserted image. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, effectiveness of multi-round embedding, and higher visual quality, while maintaining the induced-distortion low.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.55-61
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• 2002

Real-time Internet multi-media services requires fast data transmission, QoS and IP multicast. MARS is proposed to support IP multicast in the ATM Networks based on Internet, and RSVP is proposed to guarantee QoS in the Internet which is originally based on only best-effort service. In this paper, we propose two mechanisms to support IP multicast service involving QoS support over the ATM networks with MARS architecture based on multiple MCSs. In the first mechanism, when an ATM host requests joining into a specific multicast group, the MARS selects a proper MCS among the multiple MCSs to minimize the average time of transfer delay between the sender and the group members. In the second mechanism, when the RSVP reservation message from group member arrive at the MARS, the MARS which can process the RSVP reservation message select again the MCS with using the MCS management table. Finally, we recommend the mechanism to keep the QoS of Internet service and to reduce the processing-overhead between MARS and MCS.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.109-114
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• 2021

As various users increase in a network environment, it is difficult to protect sensitive and confidential information transmitted and received from attackers. Concealing bitwise secret data in an image using the LSB technique can be very vulnerable to attack. To solve this problem, a hybrid method that combines encryption and information hiding is used. Therefore, an effective method for users to securely protect secret messages and implement secret communication is required. A new approach is needed to improve security and imperceptibility to ensure image quality. In this paper, I propose an LSB steganography technique that hides Hangul messages in a cover image based on MSB and LSB. At this time, after separating Hangul into chosung, jungsung and jongsung, the secret message is applied with Exclusive-OR or Exclusive-NOR operation depending on the selected MSB. In addition, the calculated secret data is hidden in the LSB n bits of the cover image converted by Fibonacci technique. PSNR was used to confirm the effectiveness of the applied results. It was confirmed 41.517(dB) which is suitable as an acceptable result.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.137-142
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• 2016

A two-step open system(TOS) was proposed to relay between a healing platform and a repository of personal health documents. TOS was designed by taking into consideration the pubsub service based on large scale connections to monitor a provider's access/request process for health documents in real time. TOS, however, uses WebSocket as a communication protocol in case of pubsub. Given the operational environment of low quality wireless networks for mobile devices that are user terminals in a healing platform, there is a need to add a messaging protocol to support QoS as well as a transmission protocol. As a light messaging protocol optimized for mobile devices, MQTT defines reliable messaging QoS to consider a wireless network situation of low speed/low quality. This study designed an MQTT protocol-based message broker to support QoS in case of large scale connections and pubsub by taking into consideration mobile devices that are user terminals in a healing platform. After designing a model between TOS and MQTT message broker, the study implemented a prototype based on the proposed design and compared it with its counterparts from previous studies based on the performance indicators in a load-test with the MQTT client tool.

• The KIPS Transactions:PartD
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• v.15D no.2
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• pp.235-246
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• 2008

Service-Oriented Architecture (SOA) is emerging as an effective approach for developing applications by dynamically discovering and composing reusable services. Generally, the benefits of SOA are known as low-development cost, high agility, high scalability, business level reuse, etc. However, a representative problem for widely applying SOA is the performance problem. This is caused by the nature of SOA such as service deployment and execution in distributed environment, heterogeneity of service platforms, use of a standard message format, etc. Therefore, performance problem has to be overcome to effectively apply SOA, and service performance has to be measured precisely to analyze where and why the problem has occurred. Prerequisite for this is a definition of a quality model to effectively measure service performance. However, current works on service performance lacks in defining a practical and precise quality model for measuring performance which adequately addresses the execution environment and features of SOA. Hence, in this paper, we define a quality model which includes a set of practical metrics for measuring service performance and an effective technique to measure the value of the proposed metrics. In addition, we apply the metrics for Hotel Reservation Service System (HRSS) to show the practicability and usefulness of the proposed metrics.