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Full-Text Articles in Information Security
A Probabilistic Approach To Fault Diagnosis In Linear Lightwave Networks, Robert H. Deng, A. A. Lazar, W. Wang
A Probabilistic Approach To Fault Diagnosis In Linear Lightwave Networks, Robert H. Deng, A. A. Lazar, W. Wang
Research Collection School Of Computing and Information Systems
The application of probabilistic reasoning to fault diagnosis in linear lightwave networks (LLNs) is investigated. The LLN inference model is represented by a Bayesian network (or causal network). An inference algorithm is proposed that is capable of conducting fault diagnosis (inference) with incomplete evidence and on an interactive basis. Two belief updating algorithms are presented which are used by the inference algorithm for performing fault diagnosis. The first belief updating algorithm is a simplified version of the one proposed by Pearl (1988) for singly connected inference models. The second belief updating algorithm applies to multiply connected inference models and is …
An Adaptive Coding Scheme With Code Combining For Mobile Radio Systems, Robert H. Deng, Huafei Zhou
An Adaptive Coding Scheme With Code Combining For Mobile Radio Systems, Robert H. Deng, Huafei Zhou
Research Collection School Of Computing and Information Systems
The authors propose and study an adaptive error-control coding scheme for binary digital FM (BFM) mobile radio transmission. The scheme employs code combining through packet retransmissions. The number of transmissions of a packet is in proportion to the channel fading/noise levels, which is in contrast to time diversity techniques where a fixed number of repetitions of a data packet is performed even in the absence of channel errors. Furthermore, the receiver uses received signal envelopes as channel state information, which significantly improves the throughput and bit error rate (BER) performance. Performance of the proposed scheme is analyzed for frequency-flat Rayleigh …
Hybrid Arq Schemes For Point-To-Multipoint Communications Over Nonstationary Broadcast Channels, Robert H. Deng
Hybrid Arq Schemes For Point-To-Multipoint Communications Over Nonstationary Broadcast Channels, Robert H. Deng
Research Collection School Of Computing and Information Systems
Hybrid automatic-repeat-request (ARQ) error control schemes make use of both error detection and error correction in order to achieve high throughput and low undetected error probabilities on two way channels. Two hybrid ARQ schemes, termed hybrid go-back-N (HGB- N) and hybrid selective-repeat (HSR), are proposed for point-to-multipoint communications over broadcast channels. Both schemes incorporate a concatenated code for error correction and error detection. The performance study of the hybrid schemes is based on a two-state Markov model of a burst noise channel. An analytic solution is derived for the throughput efficiency of the HSR scheme, while approximations and computer simulation …
Performance Analysis Of Two Bridged Csma/Cd Networks, C. C. Ko, W. C. Wang, J. L. Du, Robert H. Deng, K. M. Lye
Performance Analysis Of Two Bridged Csma/Cd Networks, C. C. Ko, W. C. Wang, J. L. Du, Robert H. Deng, K. M. Lye
Research Collection School Of Computing and Information Systems
This paper analyses the performance of two non-persistent CSMA/CD LANs linked by a bridge. The main function of the bridge is to buffer all internet work packets and forward them across networks to their destinations. From establishing and solving the main equations governing the behaviour of the bridged networks, the effects of design parameters such as the bridge buffer size and re-transmission back off delay on the performance of the system are studied. It is shown that if these parameters are chosen properly, better throughput and delay performance can be obtained, when compared with an equivalent CSMA/CD network without using …
Performance Analysis Of Interconnected Lans With Server/Client Configuration, Jiangling Du, Robert H. Deng, Chi Chung Ko
Performance Analysis Of Interconnected Lans With Server/Client Configuration, Jiangling Du, Robert H. Deng, Chi Chung Ko
Research Collection School Of Computing and Information Systems
In this paper, we study the end-to-end performance of interconnected local area networks (LAN) with server/client configuration. The system uses bridges to connect two token-ring LANs through a high-speed communication link. A server station located on one LAN receives requests from client-stations on the same LAN as well as on the remote LAN, processes the requests, and returns responses to the client-stations. The end-to-end connections of the interconnected network are modelled as single-chain and multiple-chain closed queueing systems, which are solved by an iterative algorithm based on the MVA (mean value analysis) method. The performance examples are shown in terms …
Performance Of A Token-Passing System With Batch Arrivals And Its Application To File Transfers, Robert H. Deng, Xuanyu Zhang, Kuan Tase Huang
Performance Of A Token-Passing System With Batch Arrivals And Its Application To File Transfers, Robert H. Deng, Xuanyu Zhang, Kuan Tase Huang
Research Collection School Of Computing and Information Systems
This paper investigates the performance of token-passing systems with limited service and Poisson arrivals. For pure Poisson arrivals, the Laplace-Stieltjes Transform (LST) of an approximate customer/packet waiting time distribution is derived and expressed as a functional equation, from which the approximate mean and variance of waiting time are obtained; for batch Poisson arrivals, an approximate mean of waiting time is derived. Mean waiting time approximations are compared against both simulation results and other results presented in the literature; the variance approximation is evaluated by comparing it to simulation results only, since no other results on variance have been reported so …
Development Of A Classification System For Computer Viruses In The Ibm Pc Environment Using The Dos Operating System, Hugh R. Browne
Development Of A Classification System For Computer Viruses In The Ibm Pc Environment Using The Dos Operating System, Hugh R. Browne
Theses : Honours
The threat to computers worldwide from computer viruses is increasing as new viruses and variants proliferate. Availability of virus construction tools to facilitate 'customised' virus production and wider use of more sophisticated means of evading detection, such as encryption, polymorphic transformation and memory resident 'stealth' techniques increase this problem. Some viruses employ methods to guard against their own eradication from an infected computer, whilst other viruses adopt measures to prevent disassembly of the virus for examination and analysis. Growth in computer numbers and connectivity provide a growing pool of candidate hosts for infection. Standardised and flexible systems for classification and …