Computer Engineering Commons^™

Ict For Poverty Alleviation In Pacific Island Nations: Study Of Icts4d In Fiji, Deogratias Harorimana, Opeti Rokotuinivono, Emali Sewale, Fane Salaiwai, Marica Naulu, Evangelin Roy

Dr Deogratias Harorimana

ICT for Poverty Alleviation in Pacific Island Nations: Study of ICTs4D in Fiji There has been a vague and little knowledge on the role or potential of Information and Communications Technologies (ICTs) in relation to addressing poverty in Fiji. This may be probably due to the newness of the technology in the South Pacific Region as a whole but also probably due to the fact that only 9.7% of the current Fiji 931,000 populations are internet users (ITC Figures 2011). This paper reports on finding how ICTs is contributing towards poverty alleviation in Fiji. On the basis of reviewed best …

Application Of Structured Light Imaging For High Resolution Mapping Of Underwater Archaeological Sites, Chris Roman, Gabrielle Inglis, James Rutter

Christopher N. Roman

This paper presents results from recent work using structured light laser profile imaging to create high resolution bathymetric maps of underwater archaeological sites. Documenting the texture and structure of submerged sites is a difficult task and many applicable acoustic and photographic mapping techniques have recently emerged. This effort was completed to evaluate laser profile imaging in comparison to stereo imaging and high frequency multibeam mapping. A ROV mounted camera and inclined 532 nm sheet laser were used to create profiles of the bottom that were then merged into maps using platform navigation data. These initial results show very promising resolution …

Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, Duane Robinson, Tadeusz A. Wysocki, V. Smith, K. Popovski

Dr Duane Robinson

Incorporation of radio controller units into heavy equipment used in the electricity industry provides numerous advantages including: improved electrical isolation between plant and operator, ability to incorporate an additional remote operator, and reductions in vehicle wiring and hydraulic hoses for equipment control. However, secure operation of vehicles and plant incorporating radio control rely on establishing suitable levels of immunity to possible radio frequency interference. Interference levels in close proximity to high voltage power lines are of special concern to the electricity industry. This paper reports on a preliminary investigation into quantifying the levels of background radio interference at such locations …

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Christopher N. Roman

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …

The 2005 Chios Ancient Shipwreck Survey: New Methods For Underwater Archaeology, Brendan P. Foley, Katerina Dellaporta, Dimitris Sakellariou, Brian S. Bingham, Richard Camilli, Ryan M. Eustice, Dionysis Evagelistis, Vicki Lynn Ferrini, Kostas Katsaros, Dimitris Kourkoumelis, Aggelos Mallios, Paraskevi Micha, David A. Mindell, Christopher Roman, Hanumant Singh, David S. Switzer, Theotokis Theodoulou

Christopher N. Roman

In 2005 a Greek and American interdisciplinary team investigated two ship wrecks off the coast of Chios dating to the 4th-century B.C. and the 2nd/lst century. The project pioneered archaeological methods of precision acoustic, digital image, and chemical survey using an autonomous underwater vehicle (AUV) and in-situ sensors, increasing the speed of data acquisition while decreasing costs. The AUV recorded data revealing the physical dimensions, age, cargo, and preservation of the wrecks. The earlier wreck contained more than 350 amphoras, predominantly of Chian type, while the Hellenistic wreck contained about 40 Dressel 1C amphoras. Molecular biological analysis of two amphoras …

Performance Of Java Middleware - Java Rmi, Jaxrpc, And Corba, N. A. B. Gray

Associate Professor Neil Gray

Developers of distributed Java systems can now choose among Java-RMI, CORBA, and Web-Service (JAXRPC) middleware technologies. Performance is one factor that has to be considered in choosing the appropriate technology for a particular application. The results presented in this paper show that the nature of response data has a greater impact on relative performance than has been allowed for in most previous studies. Relative performances of the technologies as measured on simple requests and responses are not representative of the behaviour that can be expected in practical applications.

Asymptotic Data Rates Of Receive-Diversity Systems With Mmse Estimation And Interferers At Correlated Locations, Siddhartan Govindasamy

Siddhartan Govindasamy

An asymptotic technique is presented to characterize the bits/symbol achievable on a representative wireless link in a spatially distributed network with active interferers at correlated positions, N receive diversity branches, and linear Minimum-Mean-Square-Error (MMSE) receivers. The models analyzed include analogs to Matern type I and type II networks. It is found that for our network models, with large N, the correlation between interferer positions does not significantly influence the bits/symbol resulting in simple approximations for the data rates achievable in such networks with moderately large numbers of diversity branches.

Comments On "A Practical (T, N) Threshold Proxy Signature Scheme Based On The Rsa Cryptosystem", Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Dr Guilin Wang

In a (t, n) threshold proxy signature scheme based on RSA, any t or more proxy signers can cooperatively generate a proxy signature while t-1 or fewer of them can't do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers. In this article, we discuss the implementation and comparison of some threshold proxy signature schemes that are based on the RSA cryptosystem. Comparison is done on the basis of time complexity, space complexity and communication overhead. We compare the performance of four schemes: Hwang et al., Wen et …

Proxy Signature Scheme With Multiple Original Signers For Wireless E-Commerce Applications, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Dr Guilin Wang

In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. We propose an efficient and secure proxy signature scheme with multiple original signers. Our scheme is suitable for wireless electronic commerce applications, since the overheads of computation and communication are low. As an example, we present an electronic air ticket booking scheme for wireless customers.

On The Effect Of Adjacent Sector Multiple Access Interference On Space Time Spreading Systems, Peter Vial, Ibrahim Raad, Tadeusz A. Wysocki

Dr Peter Vial

Space Time Spreading systems are proposed as a method to enhance communications between the Base Station (BS) and Mobile Station (MS) by using multiple transmit antennas at the Base Station. This provides a form of transmit diversity when there are more than one transmitting antennas. Space Time Spreading systems have been shown to be efficient in their use of the limited number of orthogonal spreading sequences and to provide a diversity gain, which in the case of two transmitter antennas at the BS and one receiving antenna at the MS, is of order two. The paper looks at the effect …

Direct Sequence Modified Time Hopping Ppm Over Ultra Wideband S-V Channel, Peter Vial, Beata Wysocki, Tadeusz Wysocki

Dr Peter Vial

A three position Pulse Position Modulation (PPM) scheme is proposed for a Direct Sequence Time Hopping Ultra Wideband wireless communication system. The channel is based on the Saleh-Valenzuela model. We show that by adapting the Space Time Spreading technique to use three pulse positions in a single input single output system representing -2,0,2 an improvement in Bit Error Rate is achieved compared to sending the same bits using two pulse positions only. In addition, the bit access rate is doubled as two bits can be successfully sent in the same time using our proposed system.

Non-Optimal Receiver For Space Time Spreading Across A Time Hopping Over Ultra Wideband Ppm, Peter Vial, Beata Wysocki, Tadeusz Wysocki

Dr Peter Vial

A novel non-optimal chip based technique is proposed to use two antennas to transmit data across a Direct Sequence Time Hopping Ultra Wideband dual antenna wireless communication system to a single receiver. The spread data is sent over the independent channels using the Space Time Spreading technique to encode the chips which are sent on each antenna simultaneously. A hard decision is made at each chip of the spreading code received based on the known Channel State Information which Pulse Position Modulated signal was received from each antenna. The paper shows that by adapting the Space Time Spreading technique to …

An Ultra Wide Band Simulator Using Matlab/Simulink, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki

Dr Peter Vial

Ultra Wide Band (UWB) is a promising technology for sensor networks, broadband wireless data access and location finding applications. This study outlines the development and validation of a single transmitter and receiver system across the multipath channel proposed by Saleh-Valenzuela. We have designed and tested a UWB simulator using MATLAB’s Simulink in combination with the Real Time Workshop(RTW) Tool box for Simulink using the Fixed Step Discrete Solvers of RTW which is required to produce executable simulations on multiple computers (both Linux and Microsoft based devices). This paper outlines the basic design and modules chosen for the simulation and compares …

Optimal Receiver For Space Time Spreading Across A Time Hopping Ppm Over Ultra Wideband Saleh-Valenzuela Mimo Channel, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki

Dr Peter Vial

This paper outlines a technique which can use multiple transmit antennas to send more than one binary bit using the same number of transmit antennas over a single transmission. It uses Ultra Wideband orthogonal pulse position modulation to achieve this, with the receiver employing a Rake receiver and a Maximum Ratio Combiner optimal detector. This is done over a Space Time Spreading Time Hopping Ultra Wideband Pulse Position Modulation system assuming a rich multipath Saleh-Valenzuela MIMO channel model. Simulation results indicate that a significant gain can be achieved compared with other proposed schemes utilising multiple transmit antennas for Ultra Wide …

A Study Of Umts Turbo Codes Across Space Time Spreading Channel With The Case Of M = 1 And M = 2, Ibrahim S. Raad, Peter Vial, Tadeusz A. Wysocki

Dr Peter Vial

The study presented in this paper is that of Universal Mobile Telecommunications Systems (UMTS) Turbo Codes across Space Time Spreading channel with one transmitter antenna, one receiver (m = 1) and two transmitter antennas and one receiver (m = 2) to see to what extent the bit error rate (BER) can be improved. Using the Max-log decoding algorithm and 12 iterations it is shown in the simulation results that an extra 5 dB is achievable.

Generalized Williamson And Wallis-Whiteman Constructions For Improved Square Order-8 Cois Stbc, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah A. Spence

Dr Le Chung Tran

Constructions of square, maximum rate Complex Orthogonal Space-Time Block Codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols equally disperse through transmit antennas. Those codes, referred to as the improved square CO STBCs, have the advantages that …

Orthogonal Spreading Sequences Constructed Using Hall’S Difference Set, Jennifer Seberry, Le Chung Tran, Yejing Wang, Beata Wysocki, Tadeusz Wysocki, Ying Zhao

Dr Le Chung Tran

In the paper we propose a new set of orthogonal spreading sequences based on the Hadamard matrix of order 32 constructed using the Hall difference set. The proposed sequences are characterised by low peaks in the aperiodic cross-correlation functions and have also good aperiodic auto-correlation properties.

Two Complex Orthogonal Space-Time Codes For Eight Transmit Antennas, Le Chung Tran, J. Seberry, Yejing Wang, B. J. Wysocki, T. A. Wysocki, Tianbing Xia, Ying Zhao

Dr Le Chung Tran

Two new constructions of complex orthogonal space-time block codes of order 8 based on the theory of amicable orthogonal designs are presented and their performance compared with that of the standard code of order 8. These new codes are suitable for multi-modulation schemes where the performance can be sacrificed for a higher throughput.

A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Radio Channels, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins

Dr Le Chung Tran

Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied in case of spatial correlation, such as with antenna arrays in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division Multiplexing (OFDM) systems. …

Multi-Modulation Schemes To Increase The Rate Of Space-Time Block Codes In Rayleigh Fading Channels, Le Chung Tran, Tadeusz A. Wysocki, Jennifer Seberry, Alfred Mertins

Dr Le Chung Tran

he paper examines multi-modulation schemes (MMSs) to increase the rate of our two new Complex Orthogonal Designs (CODS) proposed for eight transmit antennas, namely C₁ and C₂, corresponding to the Amicable Orthogonal Designs (AODs) (~l,l,Z,Z:l,l,Z~) and (8:1,1,1,~1,1,1,4), respectively. In addition, the optimal inter-symbol power allocation in the proposed codes in single modulation as well BS in MMSs in flat Rayleigh fading channels is considered. It turns out that, in some modulation schemes, equal power transmission pure each symbol time slot is not only optimal from the technical point of view, but also optimal in terms of achieving …

A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins

Dr Le Chung Tran

Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied in case of spatial correlation, such as with antenna arrays in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division Multiplexing (OFDM) systems. …

Combinatorial Constructions Of 3- And 4-Secure Codes, Yeijing Wang, Jennifer Seberry, Beata J. Wysocki, Tadeusz A. Wysocki, Willy Susilo, Tianbing Xia, Ying Zhao, Le Chung Tran

Professor Willy Susilo

In this paper, 3- and 4-secure codes are constructed from combinatorial designs. Both constant weight and non-constant weight codes are shown.

1891 Eruption Of Foerstner Volcano (Pantelleria, Sicily): Insights Into The Vent Structure Of Basaltic Balloon Eruptions, J. Kelly, S. Carey, K. Croff-Bell, C. Roman, M. Rosi, M. Marani, M. Pistolesi, E. Baker

Christopher N. Roman

AGU session number V21A-2750.

Casting A Wider Net, Lynn Stein

Lynn Andrea Stein

This article is a book review of Mung Chiang's book Networked Life: 20 Questions and Answers. In this text intended for both classroom and online learning, Chiang uses questions about our online lives to explore the technology and computer science behind the Internet, wireless, and Web industries.

The Legal Challenges Of Networked Robotics: From The Safety Intelligence Perspective, Yueh-Hsuan Weng, Sophie T.H. Zhao

Yueh-Hsuan Weng

At The Tone, The Time Will Be... Unknown – A Perspective On The Evolution Of Time In Telecommunications, Robert Iannucci

Robert A Iannucci

No abstract provided.

A Pipeline For Structured Light Bathymetric Mapping, Gabrielle Inglis, Clara Smart, J. Vaughn, Chris Roman

Christopher N. Roman

This paper details a methodology for using structured light laser imaging to create high resolution bathymetric maps of the sea floor. The system includes a pair of stereo cameras and an inclined 532nm sheet laser mounted to a remotely operated vehicle (ROV). While a structured light system generally requires a single camera, a stereo vision set up is used here for in-situ calibration of the laser system geometry by triangulating points on the laser line. This allows for quick calibration at the survey site and does not require precise jigs or a controlled environment. A batch procedure to extract the …

How Can Pacific Island Economies Benefits From The Advent Of Ict’S – Review Of Best Practices In Education, Deogratias Harorimana Sr

Dr Deogratias Harorimana

This paper explored implementation and use of information and communication technologies in Fiji, in order to gain insight into recent government initiatives to introduce computers and other ICTs for the community of Fiji. The focus of this paper in that it provided the framework for an in-depth exploration of e-learning centers around the country and the benefits from the advent of ICT’s in e-learning community centers in Fiji. Areas concentrated on are outcome of ICT’s in formal education to students and community as a whole in areas of agriculture, health, environment and infrastructure etc. The research sought understanding from the …

Efficient Delay And Energy Based Routing In Cognitive Radio Ad Hoc Networks, Rana Asif Rehman, Muhammad Sher, Muhammad Khalil Afzal

Rana Asif Rehman

Cognitive radio ad hoc networks (CRAHNs) are multi-hop, dynamic and self-configurable networks, which can communicate without any infrastructure support. Most of the research in CRAHNs has been already carried out on physical and media access control layers, but without effective routing protocols we cannot take full advantage of CRAHNs. In this paper, we discuss the problems in already proposed routing protocols for cognitive radio networks and proposed a novel protocol: Delay and Energy based Spectrum Aware Routing Protocol (DESAR), which consider both delay and energy for the computation of efficient path between source and destination. Simulation results show that DESAR …

Wispernet: Anti-Jamming For Wireless Sensor Networks, Miroslav Pajic, Rahul Mangharam

Rahul Mangharam

Resilience to electromagnetic jamming and its avoidance are difficult problems. It is often both hard to distinguish malicious jamming from congestion in the broadcast regime and a challenge to conceal the activity patterns of the legitimate communication protocol from the jammer. In the context of energy-constrained wireless sensor networks, nodes are scheduled to maximize the common sleep duration and coordinate communication to extend their battery life. This results in well-defined communication patterns with possibly predictable intervals of activity that are easily detected and jammed by a statistical jammer. We present an anti-jamming protocol for sensor networks which eliminates spatio-temporal patterns …