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# [Proceedings] Singapore ICCS/ISITA 92

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Displaying Results 1 - 25 of 295
• ### Carrier synchronization under Doppler shift of the nongeostationary satellite communication systems

Publication Year: 1992, Page(s):466 - 470 vol.2
Cited by:  Papers (4)
| | PDF (395 KB)

The satellite communication systems with low-altitude nongeostationary orbits have many valuable features; however, the signals suffer the effects of Doppler shift whose value and drift rate are very large compared with those in the systems with geostationary or highly elliptical orbits. The paper discusses the effects of this Doppler shift in the low-altitude orbital satellite communication syste... View full abstract»

• ### Communications on the Move. Singapore. ICCS/ISITA '92(Cat. No.92TH0479-6)

Publication Year: 1992
| PDF (44 KB)
• ### Performance analysis of an ATM multiplexer with different classes of bursty sources

Publication Year: 1992, Page(s):167 - 172 vol.1
Cited by:  Papers (2)
| | PDF (380 KB)

An ATM multiplexer with different classes of bursty sources is considered for evaluation of the effects of bursty traffic variations on its performance. A discrete-time Markov chain model is developed to obtain cell loss probability both for the whole set of sources and for each class. Calculations carried out for the particular case of two classes, with a first class behaving as declared at call ... View full abstract»

• ### Conference authentication and key distribution service in the RHODOS distribution system

Publication Year: 1992, Page(s):284 - 289 vol.1
Cited by:  Papers (1)
| | PDF (489 KB)

The paper reports on the development of a conference authentication and key distribution service for distributed systems. The authors demonstrate that it is possible to develop such a service as an integral part of the RHODOS distributed operating system, subject to some requirements and extensions to the original Koyama-Ohta system. The basic RHODOS requirement is that users cannot be trusted, an... View full abstract»

• ### Utilizing multiple UIO sequences and segment overlap to shorten test sequences

Publication Year: 1992, Page(s):1291 - 1296 vol.3
| | PDF (412 KB)

This paper presents two new approaches for communication protocols modeled as Finite State Machines. Two of the most important factors for shortening test sequences, viz, multiple unique I/O sequences and segment overlap, are used . The first approach does not verify the uniqueness of UIO sequences of states, but the second approach does. Miller and Paul's (1991) approach derives the shortest test... View full abstract»

• ### A collision resolution algorithm for a finite user model

Publication Year: 1992, Page(s):1297 - 1301 vol.3
| | PDF (248 KB)

The authors consider that initial collision multiplicity or the number of active users at the beginning of the collision resolution epoch is known, and obtain an optimal collision resolution algorithm. They then assume that the probability distribution over the initial states is given, suggest a sub-optimal algorithm and compare its performance with that of the optimal algorithm. The dynamic progr... View full abstract»

• ### Chaotic numbers

Publication Year: 1992, Page(s):50 - 52 vol.1
Cited by:  Papers (3)  |  Patents (2)
| | PDF (144 KB)

A generation of random and pseudorandom numbers with good statistical properties is one of the most important subjects of modern communication and simulation. The author discusses the possibility of generating random and pseudorandom numbers in the area of the strange attractor of the tent map. To estimate basic properties of generated numbers four measures are used: the value of Lyapunov exponent... View full abstract»

• ### Object oriented methodology for switching software reuse

Publication Year: 1992, Page(s):178 - 182 vol.1
Cited by:  Patents (1)
| | PDF (280 KB)

An overview of reuse methods for switching software is given, and an object oriented model is derived. Some formal definitions are given to support this OO method. Object oriented SDL and CHILL are used to promote specification and implementation reuse. A supporting environment for reuse is also developed to make the best use of reusable objects View full abstract»

• ### Connectionless data service by means of metropolitan area networks in Europe

Publication Year: 1992, Page(s):691 - 694 vol.2
| | PDF (248 KB)

Several European countries are trialling metropolitan area network (MAN) equipment. The MAN implements connectionless data services based on or derived from SMDS (switched multimegabit data services), as defined by Bellcore. The paper gives background on the service, the technology and its evolution towards ATM. A few applications in Europe are presented View full abstract»

• ### Reed-Solomon coded FSK SCM system with distributing LO in local loop in the presence of laser phase noise

Publication Year: 1992, Page(s):1033 - 1037 vol.3
| | PDF (300 KB)

In coherent optical subcarrier multiplexing systems, the performance degradation of the system due to the phase noise of lasers restricts the maximum numbers of stations and channels that the system can serve. The effects are analyzed in terms of carrier-to-noise ratio penalty. The effects of Reed-Solomon coding are also analyzed. It is shown that the numbers of channels and stations can be increa... View full abstract»

• ### A fast Viterbi decoding using the information of most-frequency symbol of convolutional code

Publication Year: 1992, Page(s):1302 - 1306 vol.3
| | PDF (276 KB)

A fast viterbi decoding is proposed and its error performance on additive white Gaussian noise channels analyzed. The frequency of each symbol of received sequence is counted and a reduction of add-compare-select operations is implemented by using the most-frequent symbol View full abstract»

• ### Optimal code for discrete memoryless source with average fidelity criterion

Publication Year: 1992, Page(s):53 - 57 vol.1
| | PDF (252 KB)

Another proof of source coding theorem with average fidelity criterion for discrete memoryless sources is presented by showing certain properties of an asymptotically optimal code. It is shown that the optimal code can be obtained as a constant composition code with probability 1-∈. It also proved that the variance of distortion converges to 0 with increase of the block length when the obtain... View full abstract»

• ### Loss performance analysis of an ATM multiplexer

Publication Year: 1992, Page(s):173 - 176 vol.1
| | PDF (144 KB)

The performance of an ATM statistical multiplexer is studied using an input traffic model which is the superposition of several switched determined processes (SDP). The discrete-time queue with this superposition for its input process was analyzed using the mini-slot method. The expression for loss probability was derived and the numerical results were given. The results obtained can be used for A... View full abstract»

• ### Exact and approximate mean throughput models of the FDDI MAC Asymmetric systems

Publication Year: 1992, Page(s):695 - 699 vol.2
| | PDF (248 KB)

The authors develop several simple iterative algorithms to obtain the approximate mean throughput of an asymmetric FDDI network. Although the methods presented are also applicable to symmetric networks (a symmetric network is just a special case of an asymmetric one), they provide only approximate estimates. Consequently, their practical use lie in estimating the mean throughput of asymmetric syst... View full abstract»

• ### Test sequence generation for protocol conformance testing

Publication Year: 1992, Page(s):204 - 208 vol.1
| | PDF (264 KB)

Generating test sequences automatically from a specification has been the most difficult and time-consuming work in the field of protocol conformance testing, especially taking into account both the data flow portion and the control flow portion of implementation under test (IUT). The authors present a method to generate test sequences based on the model called the normal extended finite-state mac... View full abstract»

• ### Optimal digital filter design with pole-zero sensitivity minimization

Publication Year: 1992, Page(s):765 - 769 vol.2
| | PDF (280 KB)

The authors define a global pole-zero sensitivity measure and then formulate the main problem to be dealt with. They derive the expressions for pole and zero sensitivity functions. The classical pole and zero sensitivity measures are discussed. The main results are to characterize all the optimal similarity transformations that transform any initial realization into those realizations which have e... View full abstract»

• ### Performance of code division multiple-access techniques in optical fibre networks

Publication Year: 1992, Page(s):1038 - 1042 vol.3
| | PDF (320 KB)

The performance of such multi-user systems under two common coding formats-optical orthogonal and prime sequence codes-is investigated. The method used is an extremely accurate modified Monte Carlo technique View full abstract»

• ### On M-route flows in a network

Publication Year: 1992, Page(s):1386 - 1390 vol.3
Cited by:  Papers (1)
| | PDF (244 KB)

In a flow network an m-F-ring, which corresponds to an m-route channel in a communication network, is defined. An m-route flow between two vertices is the sum of m- F-rings between them, and its value is defined to be the sum of values of those m-F-rings. The m-route capacity of a cut is also defined. The authors show... View full abstract»

• ### A technique for correcting the effects of camera shake

Publication Year: 1992, Page(s):644 - 648 vol.2
| | PDF (324 KB)

A major concern in security systems is the frequency of false alarms occurring. False alarms reduce the confidence in the system's ability to detect intruders and are extremely expensive in terms of handling costs. One of the main causes of false alarms is camera shake due to wind movement, or vibrations affecting the post on which the camera mount is located. The authors describe the method devel... View full abstract»

• ### A new concept for simplified Viterbi detection

Publication Year: 1992, Page(s):1307 - 1311 vol.3
Cited by:  Papers (1)  |  Patents (2)
| | PDF (256 KB)

The proposed detection method uses different metrics for comparing any two extended paths at detection time K: paths joining a common state at the detection time are compared via a metric which is equivalent to the Viterbi algorithm; paths emerging from a common state at time K-1 are compared via a modified metric View full abstract»

• ### Aperiodic autocorrelation properties of perfect polyphase sequences

Publication Year: 1992, Page(s):1232 - 1234 vol.3
Cited by:  Papers (3)  |  Patents (1)
| | PDF (124 KB)

Perfect polyphase sequences find applications in radar and synchronisation systems. The authors compute exactly the asymptotic (N→∞) peak-to-side-peak ratios of the original Frank and Zadoff-Chu sequences, which shed light on the meaning of the numerical parameters reported by Antweiler and Bomer (Electron. Lett. vol.26, p.2068-70 of 1990) View full abstract»

• ### A universal coding scheme based on minimizing minimax redundancy for sources with an unknown model

Publication Year: 1992, Page(s):58 - 62 vol.1
| | PDF (288 KB)

The author describes the construction of a universal code for minimizing L.D. Davisson's minimax redundancy in a range where the true model and stochastic parameters are unknown. Minimax redundancy is defined as the maximum difference between the expected per-symbol code length and the per-symbol source entropy in the source range. A universal coding scheme is formulated in terms of the weight fun... View full abstract»

• ### Image coding using fractal parameters

Publication Year: 1992, Page(s):97 - 101 vol.1
| | PDF (264 KB)

A fractal based image coding method is discussed. The regions of an image are classified into two categories using fractal parameters. The regions, categorized not have to preserve the waveform of the image' are encoded using only fractal parameters. The other one categorized `have to preserve the waveform of the image' are encoded using any former waveform coding method (DCT, VQ, etc.). Some of ... View full abstract»

• ### Exact and approximate mean throughput models of the FDDI MAC-. Symmetric systems

Publication Year: 1992, Page(s):700 - 704 vol.2
Cited by:  Papers (1)
| | PDF (256 KB)

The authors present an alternative method for computing the exact mean throughput of a symmetric FDDI network with both synchronous and asynchronous data streams. The approach they have taken is simple in that it only requires mean value estimates and can be computed readily. Closed form solutions for the exact mean throughput and token rotation times of a single priority symmetric network are der... View full abstract»

• ### Formal specification of fault management system using O-Estelle

Publication Year: 1992, Page(s):199 - 203 vol.1
| | PDF (284 KB)

The authors discuss the formal description of a real time application, viz a fault management system (FMS) for the OSI environment, using O-Estelle. O-Estelle is an object oriented specification language that has been proposed by the authors for describing real time applications (Prabhakaran and Ragahvan, 1990). O-Estelle is an Estelle based language with extended features. A distributed FMS is a ... View full abstract»