• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.79-85
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• 2013

In SIP(Session Initiation Protocol) environment, the presence server should process SIP SUBSCRIBE request messages including multiple presence resources addresses from users, and also precess massive notification messages from the subscribed presence resources. The load of the presence server increases as number of users increase, and it limits system extendability. Therefore a new multiple presence servers architecture has been suggested in this research. In this architecture presence servers can be added dynamically and each server's load can be controlled effectively as number of users increase. Each presence server can monitor current load status of entire presence system by using presence event notification package which newly has been suggested in this paper. When a particular presence server's load increases over predefined limit, the presence service processing is distributed by selecting a server which has the smallest load, or by generating a new server dynamically. In this system the overall load of the entire system can be controlled optimally and extendability of the system can be increased. For this purpose a new presence event notification package and presence information data format have been suggested. The performance of the proposed system has been evaluated by experiments. They shows 44.3% increase in SUBSCRIBE message processing time, and 43.1% increase in Notification message processing time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.547-553
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• 2019

Presence server should process massive SIP subscription request messages and massive presence event notifications from presence resources in real time. Therefore multiple servers architecture is needed for presence service system. In this paper, an architecture of multiple servers presence service system using SIP based CCMP control messages for lowering presence server load level has been presented. In this system, each presence server exchanges current load status using CCMP control messages, and total system load according to variance of users number and amount of presence resources has been effectively distributed processed. The CCMP control messages has been optimally designed to control presence servers, and exchange procedures of these control messages between presence servers has been also presented and the performance of the proposed multiple servers presence service system has been analysed by experiments. The result shows that average presence subscription processing time reduced from 40.8% to 69.2% and average presence notification processing time reduced from 29.4% to 62.7%.

• Electronics and Telecommunications Trends
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• v.20 no.5 s.95
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• pp.127-138
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• 2005

메신저로 대표되는 IMPP 서비스의 핵심 기술로 프레즌스 프로토콜이 필요하며, SIP기반 프레즌스 프로토콜에 대한 표준화 작업이 IETF SIMPLE WG에서 진행중에 있다. 이러한 프레즌스 서비스는 앞으로 인터넷상에서 핵심 통신 기술로 사용되어 프레즌스기반 통합된 서비스가 많이 등장하리라 예상된다. 그러나, SIP 기반 프레즌스 서비스에서 간단한 상태 정보 등의 변화를 전달하기 위하여 전달되는 프레즌스 메시지 트래픽의 양이 상당히 많은 것이 문제점으로 대두되었다. 이는 대역폭이 제한된 무선 환경의 경우 특히 많은 문제를 야기한다. 따라서, 본 고에서는 SIP 기반 프레즌스 프로토콜 관련 표준화 현황을 통한 기본 개념을 살펴보고 프레즌스 메시지 트래픽을 줄이기 위한 다양한 방법들에 대한 최근 표준화 동향을 살펴보고자 한다.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.34-41
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• 2007

The presence service which provides user's presence information by subscription and notification is one of SIP(session initiation protocol) extension services, and it is used importantly in VoIP(Voice over IP) and Instant Messaging service. In this paper, we propose a new method in which users can combine and control presence service and call processing services in various ways by extending call processing language, and only changed parts of the presence information are published instead of full presence information document. Each user registers full presence information document with his own call processing script during the first publication to a presence server. The presence server executes these call processing scripts, so it can provide various services with combination of presence service and call processing services during the presence subscriptions and notifications. Afterwards, users publish only changed parts of the presence information and the presence server notify only these changed parts to watchers. Therefore the efficiency of the overall system can be improved. The performance of our proposed model is evaluated by experiments.

• Smart Media Journal
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• v.13 no.1
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• pp.76-85
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• 2024

This study examined the Presence experience, resulting effects, and re-viewing intentions of visitors to experiential exhibition content. For this purpose a survey was conducted targeting 246 visitors to experiential exhibition content based on Hyecho's travel story and SilkRoad cultural heritage. As a result of the survey, understanding and interest in the content material and similar exhibition viewing experience did not affect Presence experience. In addition the higher the Presence experience of exhibition content, the greater the awareness and emotion that is the effect of Presence. And among the effects of Presence, emotion had a positive effect on revisiting intentions. Therefore, it was confirmed that future experiential exhibition contents require planning, production, and exhibition that allow users to experience Presence.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.67-73
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• 2010

In SIP(Session Initiation Protocol) environment, the presence event notification operation makes presence service user to recognize presence information status changes of the other party. In conventional method, the user should send each SIP SUBSCRIBE message containing the address of the other party to the presence server. Furthermore each presence subscription requires refresh messages, and the amount of notification messages from the other party becomes large. These facts increases network traffic and the load of presence server. In this paper, to solve these problems a new presence list service has been suggested. It uses a presence list consists of URI of the other party and make it possible to subscribe by using one SUBSCRIBE message. So this method decreases the amount of SUBSCRIBE messages and refresh messages, and it also decreases the amount processing event notification messages from the subscribed the other party. And to increase the efficiency, a presence filtering method which enables to include some parts of selected presence information into the notification message body has been also suggested. The implemented system can reduce SIP message related network traffic and message processing time of the presence server. The performance of this proposed system has been evaluated by experiments, and the results showed decreasing of server processing time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2678-2684
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• 2014

In this paper a new message control method that can reduce server load and network traffic in XMPP/SIP presence service system has been proposed. This presence service system can process both XMPP(Extensible Massaging and Presence Protocol) based presence information and SIP(Session Initiation Protocol) based presence information. A new XMPP stanza architecture with added elements for presence stanza and IQ stanza has been designed, and a new presence information data processing method which can reduce size of SIP notification message and SIP PUBLISH message has been suggested. Furthermore a messages exchanging procedure that can transfer presence information between XMPP domain and SIP domain has been also suggested. The performance of the proposed system has been analysed by simulation.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.587-592
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• 2017

In this paper, we raise a question: what makes presence in artistic works. Presence has been defined as a physiological and emotional feeling which feels that he or she is immerged in a specific artworks when he/she is very interested in the artwork. We design and implemented an abstract media art "The Light" which uses the color, trace, and interactivity of light to measure quantitative presence. Frequency spectrum of light on specific object which we perceive makes color; Motion of light and its impact on object makes shape which perceived in our human visual system; Interactivity or perceived distance between object and observer makes intensity of perception. We experimented our images with subjective survey which includes PQS (presence questionnaire survey) and objective test using brain signals (EEG). From our interactive experimental moving images tested on 30 subject, we conclude that we can make more presence as we interact more with images. Photo-realistic images is just pass-by and it is transformed to abstract images, as we more focused on the images, and the essential components of the abstraction includes color, trace, and interaction with subjects.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.514-520
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• 2018

Presence service provides various information about users such as locations, status of on/offline and network access methods, and number of presence resources required by each users increases largely in mobile environment. Therefore an effective method which can reduce load of presence servers is needed. In this paper, a large scale distributed presence service system which can distribute effectively total presence system load of presence servers using message control session has been presented. This large scale distributed presence service system provides various presence information for massive volumes of users. In this study, a new message control session architecture which can dynamically distribute loads of the presence servers to multiple servers has been presented, and a new presence information data architecture for controlling load of the presence servers has been designed. In this architecture, each presence server can exchange current load level in real time to get variance of the total system load change according to user numbers, and can distribute system load to maintain load level of each server evenly. The performance of the proposed large scale distributed presence service system has been analysed by experiments. The results has been showed that average presence resource subscription processing time reduced from 42.6% to 73.6%, and average presence notification processing time reduced from 37.6% to 64.8%.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.16-20
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• 2007

SIP 기반 프레즌스 서비스는 향후 유비쿼터스 시대의 상황인지형 서비스를 비롯한 다양한 곳에 응용될 수 있는 핵심서비스이다. 또한 프레즌스 서비스는 개인의 프라이버시 문제를 다루기 때문에, 권한관리를 위해 draft로 제시되어 있는 XCAP 기반 기술이 주요 이슈로 대두되고 있다. 그러나, 현재 프레즌스 기반 구조를 활용한 응용서비스 모델이 제시되어 있지 않으며, XCAP 기반 권한관리 기술이 적용된 사례가 나와있지 않다. 본 논문에서는 VoIP에 적용 가능한 프레즌스 서비스 모델을 선정하고, 서비스 개발을 위한 프레즌스 기반구조의 적용방법, XCAP 기반 권한관리 기술의 적용방안을 설계하였다. 본 논문을 통해 중요한 서비스로 인식되면서도 마땅한 서비스가 발굴되지 않은 현실에서, 프레즌스 기반 서비스 개발 및 XCAP 기반 권한관리 기술개발을 위한 참조모델로 활용할 수 있다. 특히, 보안에 민감한 프라이버시 정보를 다루는 프레즌스 서비스 보호를 위해 XCAP 기반기술은 반드시 필요하며, 임의의 응용서비스에 독립적으로 적용할 수 있는 XCAP 기반기술의 특징을 고려하면 더욱 큰 의미를 지닌다.