• ETRI Journal
• /
• v.25 no.1
• /
• pp.34-40
• /
• 2003

This paper considers a TMN-based management system for the management of public ATM switching networks using a four-level hierarchical structure consisting of one network management system, several element management systems, and several agent-ATM switch pairs. Using Jackson's queuing model, we analyze the effects of one TMN command on the performance of the component ATM switch in processing local calls. The TMN command considered is the permanent virtual call connection. We analyze four performance measures of ATM switches- utilization, mean queue length and mean waiting time for the processor directly interfacing with the subscriber lines and trunks, and the call setup delay of the ATM switch- and compare the results with those from Jackson's queuing model.

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.12
• /
• pp.984-990
• /
• 2005

The aim of this paper is to investigate a control framework for mobile robots, operating in shared environment with humans. The Intelligent Space (iSpace) can sense the whole space and evaluate the situations in the space by distributing sensors. The mobile agents serve the inhabitants in the space utilizes the evaluated information by iSpace. The iSpace evaluates the situations in the space and learns the walking behavior of the inhabitants. The human intelligence manifests in the space as a behavior, as a response to the situation in the space. The iSpace learns the behavior and applies to mobile agent motion planning and control. This paper introduces the application of fuzzy-neural network to describe the obstacle avoidance behavior teamed from humans. Simulation results are introduced to demonstrate the efficiency of this method.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.361-363
• /
• 2004

무선 센서 네트워크(WSN: Wireless Sensor Network) 환경에서 보안성을 확보하기 위하여, 센서 노드간에 전송된 메시지를 암호화하고 인증하는 것이 중요하다. 암호화와 인증을 위해 사용되는 키는 통신 노드 사이에 합의되어야 한다. 그러나 자원의 제약성 때문에, 일반적인 네트워크에서 많이 사용되는 Diffie-Hellman이나 공개키 기반 키 협의 방법은 WSN 환경에 적합하지 않다. 많은 노드에 비밀키를 사전에 정적으로 분배하는 것은 대용량의 메모리와 계산 능력을 요구하고, 네트워크 환경이 커짐에 따라 이들의 요구량이 급증하기 때문이다. 따라서 이러한 사전 키 분배 문제를 해결하기 위하여, 본 논문은 계층적인 사전 키 분배 방법을 제시한다. 제안된 방법은 기존 방법론과 비교하여 센서 노드간의 공유키가 존재 할 가능성을 증가시켜, 통신 채널을 쉽게 형성할 수 있도록 하였다. 또한 외부 공격자의 위협에 대비하여 q-composite 이론을 적용하여, 보안성을 강화시켰다.

• Knowledge Management Research
• /
• v.16 no.3
• /
• pp.81-102
• /
• 2015

With the rapid development of digital media, there has been a huge change in a way of communication, a process of information diffusion and a role of traditional media. Not like mass media, social media enables users to generate and tap into the opinions of a larger world. From that reason, social media is impacting marketing strategies. However, still social media marketing researches just focus on case study, analysis of users motivation or analysis of power user's usage pattern. Word-of-mouth has always been important especially in marketing area. In social media, word-of-mouth depends on each user that's why this research focuses on individual user's activity in SNS. I defined 4 factors (produce, diffusion, network size, activity of network size enlarge) that are effect on activity and verified hypothesis by multiple regression analysis, hierarchical regression analysis and moderated multiple regression.

• Journal of Korea Multimedia Society
• /
• v.21 no.8
• /
• pp.960-968
• /
• 2018

The mobile visual search service uses a query image to acquire linkage information through pre-constructed DB search. From the standpoint of this purpose, it would be more useful if you could perform a search on a web-based keyword search system instead of a pre-built DB search. In this paper, we propose a representative query extraction algorithm to be used as a keyword on a web-based search system. To do this, we use image classification labels generated by the CNN (Convolutional Neural Network) algorithm based on Deep Learning, which has a remarkable performance in image recognition. In the query extraction algorithm, dictionary meaningful words are extracted using Wikipedia, and hierarchical categories are constructed using WordNet. The performance of the proposed algorithm is evaluated by measuring the system response time.

• The Journal of the Korea Contents Association
• /
• v.1 no.1
• /
• pp.118-129
• /
• 2001

This paper investigates the previous research results on communication and server technologies for networked virtual environments and presents several new technologies to improve performance. Specially, a hierarchical client-server network topology to support numerous clients are presented and a dead-reckoning algorithm considering network latency to provide clients with fair service is also presented. Finally, several examples to confirm the proposed technologies are introduced.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.5
• /
• pp.521-530
• /
• 1989

Broadband ATM(Asynchronous Transfer Mode) networking techniques based on lightwave technology and high speed integrated circuits appear to be the choice of transport technology for broadband ISDN. Among other problems, the issue of video transport over broadband packet(ATM) networks still requries further investigation. In this paper, the problems of transporting video signals over a broaband packet network are investigated together with possible solutions. In particular, clock recovery packet loss compensation and transport technique based on hierarchical video coding scheme are described in detail. This would allow efficient bandwidth sharing and minimum degradation in video quality.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.32B no.1
• /
• pp.171-179
• /
• 1995

In many continuous speech recognition systems, phoneme is used as a basic recognition unit However, the coarticulation generated among neighboring phonemes makes difficult to recognize phonemes consistently. This paper proposes allophone as an alternative recognition unit. We have classified each phoneme into three different allophone groups by the location of phoneme within a syllable. For a recognition algorithm, time-delay neural network(TDNN) has been designed. To recognize all Korean allophones, TDNNs are constructed in modular fashion according to acoustic-phonetic features (e.g. voiced/unvoiced, the location of phoneme within a word). Each TDNN is trained independently, and then they are integrated hierarchically into a whole speech recognition system. In this study, we have experimented Korean plosives with phoneme-based recognition system and allophone-based recognition system. Experimental results show that allophone-based recognition is much less affected by the coarticulation.

• Journal of information and communication convergence engineering
• /
• v.8 no.5
• /
• pp.549-553
• /
• 2010

Lim et al. proposed a Hybrid Group Key Management scheme for Hierarchical Self-Organizing Sensor Network in 2008 to provide a secure way to pass down the group key for cluster-based communication. This paper presents two practical attacks on the scheme proposed by Lim et al. by tampering sensor nodes of a cluster to recover necessary secret keys and by exploiting the IDS employed by the scheme. The first attack enables a long-term but slow data fabrication while other attack causes more severe DoS on the access to cluster sensor nodes.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.7
• /
• pp.101-108
• /
• 1998

In this paper, after we got to realized FDNN (fuzzy decision neural network) applied the quantization triangularity fuzzy function to DBNN(decision based neural network) of a hierarchical structure for image process, we could esign hardware of the realized FDNN. Also it is normalized the standard image and the input image as the same size. We are applied DWW algorithm which selected the closest value with finding similarity of an interval image by this distance to FDNN. So we could calulated in terms of distance to weight of pixel which composed two image and eliminated the nise of image, minimized the lost of information, obtained the optimal information. It is designed hardware of high speed weighted FDNN using COMPASS tool. Aslo, the total circuit is realized as gates of 61,000 and could show to superiority of FDNN using the simulation.