• ETRI Journal
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• v.24 no.5
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• pp.381-390
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• 2002

We analyze the performance of a telecommunications management network (TMN) system using models of networks of queues, Jackson's theorem, and simulation. TMN systems for managing public asynchronous transfer mode (ATM) networks generally have a four-level hierarchical structure consisting of a network management system, a few element management systems (EMSs), and several pairs of agents and ATM switches. We construct a Jackson's queuing network and present formulae to calculate its performance measures: distributions of queue lengths and waiting times, mean message response time, and maximum throughput. We perform a numerical analysis and a simulation analysis and compare the results.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.3
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• pp.360-365
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• 1999

TMN에 기초한 망 관리 시스템은 관리자/관리대행자 패러다임으로 역할이 분류되며 관리자는 관리대행자를 통해 관리 객체의 집합체인 관리정보베이스(MIB)에 접근할수 있다. CMIP 질의는 관리 정보 트리 상에서 관리 행위가 이루어질 관리객체를 선별하기 위하여 Scope 와 Filter를 이용한다. 본 논문에서는 관계형 데이터베이스를 이용하여 관리 정보베이스를 구축시 이러한 질의를 한번의 데이터 베이스 스캔으로 처리할 수 있도록 관리 객체의 " Distinguished Name"을 이용하여 MIT를 형성하고 SQL의 LIKE 연산자를 이용하여 Scope를 만족하는 노드를 찾는 방안을 제시한다. 이러한 방법은 부모자식 관계를 이용하여MIT를 표현하고자 결합 연산에 의해 Scope를 처리하는 일반적인 방법에비하여 성능이 우수함을 보였다. 관리자와 관리 대행자간의 교신을 위하여 IODE 8.0 CMIP프로토콜 스택을 이용하였고 ASN.1인코딩을 위하여 Pepsy컴파일러를 사용하였다.일러를 사용하였다.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.597-600
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• 1999

TMN5 used to test the performance of H.263 is a DCT-based H.263 which DCT is used as transform coding, but DWT is used instead of DCT and adaptive quantizer of being appropriate to DWT is designed in this paper while the structure of TMN5 is maintained. DWT-based H.263, which is proposed in this paper, is excellent in transplantation of the existing system and can improve frame rate by transmitting more Frame. Also, the average PSNR, objective quality of image, has been lost at degree of average 0.35㏈ in luminance signals, but has been improved over a average of 2㏈ in chrominance signals. Subjective quality of image has been improved as blocking effect, which has seriously occurred in DCT based H.263, is diminished. DWT-based H.263 can. therefore. advance video quality of image comparing with the existing ways.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.1
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• pp.122-133
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• 1999

OSI 망 관리는 TMN의 하부 구조로 채택됨에 따라서 앞으로 더욱 많이 쓰일 것으로 기대된다. OSI 망관리는 관리자-대리인 모델을 기본으로 하는데 , 관리 시스템(관리자 역할) 보다 관리대상 시스템(대리인 역할)이 더 중요한 역할을 수행하는 특징을 가진다. 기존의 관리대상 시스템들은 많은 관리 객체들을 대상으로 하는 CMIS 연산 요구를 받았을 때, 관리 객체들을 순차적으로 처리하기 때문에 빠른 응답시간을 보장할 수 없었다. 본논문에서는 CMIS 연산을 효율적으로 처리하는 관리대상 시스템을 위한 다중 쓰레드 기반의 프로세스 구조를 제안한다. 제안된 시스템은 OSIMIS TMN플랫폼을 이용해서 솔라리스 운영체계에서 구현되었다. 제안된 시스템의 성능을 측정해본결과, 관리대상 시스템 내부의 망 자원들을 관리할 때는 성능이 그리 좋지 않았으나 , 시스템 외부의 망 자원들을 관리 할 때는 뛰어난 성능을 보였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.842-847
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• 2004

We present a new video coding technique to tradeoff frame rate and picture quality for low bit rate video coding. We show a model equation for selecting the optimal frame rate from the motion content of the source video. We can determine DCT quantization parameter (QP) using the frame rate and bit rate. For objective video quality measurement we propose a simple and effective error measure for skipped frames. The proposed method enhances the video quality up to 2 ㏈ over the H.263 TMN5 encoder.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.947-950
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• 2001

This paper implements H.263 codec using SIMD(single instruction multiple data) method in real time based on PC. This system uses INS algorithm previously proposed by the authors as motion estimation module. SIMD method is used in DCT, IDCT, quantization, motion estimation, and display module. The developed algorithms are implemented using TMN5. Using the above algorithm, H.263 Codec can communicate more than 15 frames/sec in CIF resolution on a Pentium-IV 1.7GHz computer.

• Information and Communications Magazine
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• v.14 no.5
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• pp.108-119
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• 1997

본 논문은 앞으로 전개될 초고속 통신망이 가지고 있어야 할 서비스 관리 구조에 대해 논 한다. 서비스 관리 구조라 함은 통신망의 고객이 통신망 서비스를 사용할 수 있도록 해주는 통신망 소프트웨어 구조를 칭한다. 현재 서비스 관리는 IN, TMN에서 각각 정의하여 표준화 진행 중이거나 연구 중에 있고, DAVIC에서도 통신망(DAVIC에서는 Delivery System 이라고 함)에서 다루어야 할 서비스 관리의 요구 사항을 작성하였다. 한편 TINA-C에서는 이러한 서비스 관리를 보다 체계적으로 정리하고 있으나 아직 많은 부분의 연구가 필요하다. 한국 통신에서는 초고속 정보통신망(ATM-Highway)을 위한 서비스 관리 구조를 TINA-C의 결과를 기반으로 하여 좀더 체계적으로 정리하여 규격화하고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.411-417
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• 2007

The rate control is an essential component in video coding to provide better quality under given coding constraints, such as channel capacity, frame rates, etc. In general, source data cannot be described as a single distribution in a video coding, hence it can cause an exhaustive approximation problem. It drops a coding efficiency under weak channel environments, such as mobile communications. In this paper, we design a new quantization parameter decision model that is based on a rate-distortion function of generalized Gaussian distribution. In order to adaptively express various source data distribution, we decide a shape parameter by observing a ratio of samples, which have a small value. For experiment, the proposed algorithm is implemented into H.264/AVC video codec, and its performance is compared with that of MPEG-2 TM5, H.263 TMN8 rate control algorithm. As shown in simulation results, the proposed algorithm provides an improved quality rather than previous algorithms and generates the number of bits closed to the target bits.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.63-72
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• 2005

In this paper, we propose the bit-rate control algorithm for the block based image compression like H.263, H.263+ or MPEG-4. The proposed algorithm is designed to identify the quantization parameter set through the Lagrangian optimization technique based on the well-known linear source model. We set the Lagrangian cost function with the rates and distortion calculated from the linear source model. We calculate the quantization parameter set using the Vitervi algorithm to solve the Lagrangian optimization problem considering the Dquant method of H.263 and MPEG-4. The proposed algorithm improves the video quality by up to 1.5 dB compared with the TMN8 scheme, and is more effective in the video sources with dynamic activities than the consistent quality approaches.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2663-2675
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• 1998

The billing manabement techniques for multiple services in the B-ISDN network have been rarely developed. In fact, the management techniques including billing manabement only focus on a single service environment. In this paper, we propose a billing management system architecture for the multiple services in a Broadband access network. The architecture is based in OSI system management infrastruture and TMN Q3 interface to exchange and process the billing information from access node that is an ATM Cross connecter. The system is designed to actively adopt the rapidly changing service environments and B-ISDN network management techniques. Futhermore, this system supports multiple services providers by real-time collector and charging functions for their requirements compared to the previous methodologies tat only use the statistical data.