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Adaptive Science & Technology, 2009. ICAST 2009. 2nd International Conference on

Date 14-16 Jan. 2009

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Displaying Results 1 - 25 of 69
  • [Title page]

    Page(s): i - ix
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    Freely Available from IEEE
  • Multi-objective optimization for a helicopter pilot using genetic algorithms

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (386 KB) |  | HTML iconHTML  

    This work aims to develop an artificial intelligence for a helicopter pilot. That is, a system that learns to fly a helicopter the way a human pilot would. It draws on the benefits of using inverse simulation and genetic algorithms to model systems similar to human process. The goal is to define tasks for the helicopter and have the pilot find control settings that carry out those tasks. The inverse simulation technique generates the control inputs required for a desired set of motion outputs. Genetic algorithms (GA) generate feasible solutions to the inverse problem in which the helicopter's trajectory is defined as a set of way-points. The continuous controls encoding method was implemented in flying a longitudinal acceleration/deceleration maneuver. The helicopter pilot was formulated as a multi-optimization problem with four objectives imposed as penalties. The work proposed an optimization approach termed maxPenalty, which compared and returned the biggest of the four penalties. The GA attempts to maximize the fitness and while minimizing the pilot workload. The work shows some aspects of the GA-produced flight that are human-like, and the fact that humans do not move along precise trajectories. View full abstract»

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  • New three-input XOR and XNOR gates based on Generalized Threshold Gates using RTDs

    Page(s): 9 - 13
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    In this paper by utilizing a new concept for designing logic gates based on MOBILE, we have presented new three-input XOR and XNOR gates which were based on generalized threshold gate (GTG) topology. The proposed gates use fewer elements count in comparison with other implementations which utilize MOBILE as a main part. The correct operation of XOR and XNOR gates were confirmed by using HSPICE simulator. View full abstract»

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  • Using business process modelling to reduce the effects of requirements changes in software projects

    Page(s): 14 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (399 KB) |  | HTML iconHTML  

    Requests for changes to software systems have a potential damaging effect on software projects and the life span of software. Changes can not be avoided since it seems impossible to produce complete, correct and stable requirements. Late requests for deep, structural software changes are particularly harmful. We present an approach for early detection of evolutionary changes of software requirements, especially deep structural changes that have implications for the software architecture. The approach is based on using business process modelling (BPM) as a tool to increase the level of understanding of the problem domain in early stages. This enables the system stakeholders to identify and prevent certain types of changes earlier in the development process than what is usual with most commonly used development methods. We present a possible taxonomy of changes to help managing the different types of changes that are most important for our purpose. View full abstract»

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  • Wave probabilistic functions in quantum informatics

    Page(s): 20 - 25
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    The paper presents the theory of wave probabilistic models together with their features that represent basic principles of quantum informatics. These features are mathematically described and the illustrative examples are shown to demonstrate the possible applications of the presented theory. The proposed methodology represents the original approach which comes from defined mathematical assumptions like single-valuedness, resonance principle, etc. From these simple assumptions a lot of principle of quantum informatics can be derived like quantization principle, spin, entanglement, etc. View full abstract»

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  • Residue-to-binary converters for the moduli set {22n+1-1,22n,2n-1}

    Page(s): 26 - 33
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB) |  | HTML iconHTML  

    In this paper, we propose two memoryless converters for the moduli set {22n+1 -1,22n,2n -1}. First, we propose a novel reverse converter, which is purely adder based, using the traditional Chinese remainder theorem (CRT). Second, due to the fact that the proposed CRT based structure does not cover the entire dynamic range, a second converter, which covers the entire dynamic range based on mixed radix conversion (MRC), is proposed. The CRT based converter outperforms the MRC based converter both in terms of area and delay. In comparison with related best known state of the art converters, they are all outperformed by the proposed CRT based scheme in terms of both area cost and conversion delay. The theoretical evaluation is supported by the experimental results, which are estimated on a Standard Cell 0.13-¿m CMOS technology. These experimental results indicate that, on average, for the same dynamic range, the proposed CRT based converter achieves about 23% delay reduction with more than 3% area reduction, when compared to the existing state of the art MRC based converter. Additionally, the proposed CRT based converter is about 6% faster with about 4% area reduction when compared with the existing CRT based converter. View full abstract»

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  • A simple self-timed implementation of a priority queue for dictionary search problems

    Page(s): 34 - 39
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    This paper describes a sparse priority queue suitable for reporting the results from a sequence database search, using a self-timed protocol. The prioritization is simplified through an insertion sort scheme with no greater/less than logic. The resulting implementation promises to be compact, fast, and suitable for the specified application area. The architectural design has been validated on a prototype platform with Altera Cyclone II field programmable gate array (FPGA). View full abstract»

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  • Optical orthogonal codes over wavelength division multiplexing in passive optical network communication system and its performance analysis

    Page(s): 40 - 44
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    The paper presents a generalized analytical model of error probability in passive optical network (PON) in which optical orthogonal codes (OOC) and (dense) wavelength division multiplexing (WDM) have been considered. Low cost deployment of these networks is determined by several parameters characterizing this system such as optic transmitters with a relatively large spectrum. The distance between the wavelengths used at the transmitters, the code length, the code weight and the correlation values are taken into account in the formulation of a user communication link performance. This work evaluates the relationship between a network using OOC and WDM parameters in crosstalk situation. Simulations results are provided to validate the model and prove the practical significance of the approach. View full abstract»

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  • Survivability strategies in optical networks

    Page(s): 45 - 51
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (178 KB) |  | HTML iconHTML  

    Recent advances in fiber optics technology have enabled extremely high-speed transport of different forms of data, on multiple wavelengths of an optical fiber, using dense wavelength division multiplexing (DWDM). It has now become possible to deploy high-speed, multi-service networks using DWDM technology. As the amount of traffic carried has increased, any single failure can be catastrophic. Survivability becomes indispensable in such networks. Therefore, it is imperative to design networks that can quickly and efficiently recover from failures. Most research to date in survivable optical network design and operation focuses on single link failures, however, the occurrence of multiple-link failures are not uncommon in networks today. View full abstract»

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  • Telecommunications & information technology network management; challenges in acquisition, design and systems development

    Page(s): 52 - 57
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    Recent phenomenal growth in broadband technology, coupled with the need for organizations to stay competitive, requires a corresponding comprehensive understanding of new and advanced technologies. In this regard, new challenges have arisen with respect to mastering the intricacies related to acquisition, design, systems development and methodologies needed to manage these complex technologies. More than ever before network administrators are required to integrate and manage heterogeneous systems and a variety of applications effectively and efficiently. This paper proposes a systematic approach to tackling these challenges. It outlines an effective strategy and methodology for designing a mature industrial-based commercially available product that will provide satisfactory solutions. View full abstract»

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  • Evaluation of popular VoIP services

    Page(s): 58 - 63
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    The dominance of multimedia applications has increased with the emergence of high speed data networks. Among the multimedia applications, VoIP has placed itself in a strong position. However, the market is dominated by a number of VoIP applications with different architectural and protocol layouts. Therefore, analysis and comparison is necessary to understand their behavior and to define the QoS of these applications. This paper analyzes various performance aspects, points out the observed weaknesses, strengths and user expectations of VoIP applications. We focus on analyzing the application performance using holistic manner. Our focus is mainly concentrated on three widely used VoIP applications: Skype, GTalk, and Gizmo. Our analysis observed that, each the application has good performance figure under some criteria. However, no application has shown good performance under all criteria. In addition, current VoIP applications lack interconnection, inter-operability, flexibility, and integration with other services. View full abstract»

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  • MobiNET: A framework for supporting Java mobile application developers through contextual inquiry

    Page(s): 64 - 67
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    From a developing world perspective, mobile phone is the primary technology for the majority of people and will be for the foreseeable future. It will be their connection to the internet, their communication tool, school book, vaccination report, photo album and many other things. Despite this reality, relatively few mobile applications exist. However, a tool to support the programming of mobile applications can significantly impact and improve programmer's productivity and software quality. In this paper, we develop a concept for a mobile tooling framework that extends the Netbeans integrated development environment (IDE) for mobile programming. Mobile Tools for Netbeans (MobiNET) design would support the development of mobile applications for various mobile phones. We evaluate Netbeans as a development took and drawing from insights gained in interviews with mobile software developers, conceptualize MobiNET. A working prototype is discussed and evaluated. View full abstract»

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  • Model design of non-volatile SRAM based on Magnetic Tunnel Junction

    Page(s): 68 - 72
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    Recently there has been considerable interest in MTJ based MRAM because of its promising characteristics exhibiting high non-volatility combined with high density and radiation hardness as well as nondestructive readout (NDRO), very high radiation tolerance higher write/erase endurance compared to the FRAMs, and virtually unlimited power-off storage capability. This paper presents the design of static random access memory (SRAM) cell followed by MTJ that makes SRAM cell non-volatile, in which the output of SRAM cell having logic state 0 and 1 changes the direction of the moment of the free magnetic layer which is used for the information storage in MTJ device. View full abstract»

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  • Networked virtual and remote laboratories for research collaboration in natural sciences and engineering

    Page(s): 73 - 77
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    Based on the BW-eLabs platform, the goal of the NETLABS is the development of a software infrastructure, allowing for the interlinking and integration of experimental superstructures and simulations, as well as the software used for evaluation and archiving of data. In addition, a role- and rights-based model is developed, allowing access to experiments or measured data. The necessary components are integrated in the 3D Wonderland engine. View full abstract»

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  • Development of a policy framework to enable beneficial use of ICTs for national and community objectives

    Page(s): 78 - 85
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB) |  | HTML iconHTML  

    This paper provides insight in how existing ICT for Development (ICT4D) paradigms are becoming less successful in meeting the ICT needs of disadvantaged communities. In addition it shows that the call for a new paradigm incorporating existing economic activities within these communities is surfacing. The main research question discusses what policy framework enables beneficial use of ICTs on both a national and communal level. The paper does so by researching recent literature to combine the advantages of both the national and communal approach and by using Egypt as a case study to derive components of a framework and to construct a new framework policy to improve Egypt's governance approach to social project development. It is concluded that such a combination is possible. Furthermore, a new framework is presented that incorporates a governance approach to social project development and that supports the aim of ICT4D to economically advantage the people it was originally designed for. View full abstract»

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  • Designing ultra low power Wireless Sensor Network with TCP/IP link

    Page(s): 86 - 91
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    In this paper, a brief description of a low cost wireless sensor network (WSN) node, which is designed using ultra low power based MSP430 and Nordic nRF24L01, has been given. This network works at 2.4 GHz frequency in ISM band. We have also described a biomedical wireless sensor network (BWSN) comprising of ECG (electrocardiogram) sensor that communicates wirelessly through the smart wireless modules with the patients to control device for monitoring and external communication. To get added features and flexibility in the field of biomedical instrumentation, we have connected the wireless sensor network to GSM/GPRS to make the patient's data available globally. This architecture fulfils the requirements of low power, compact size and self-organization with TCP/IP link. View full abstract»

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  • Reducing the VoIP packet overhead in UMTS air interface

    Page(s): 92 - 98
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    Despite the continuous growth of data services, telephony is still the main source of revenue for the third generation mobile systems operators, particularly in the case of UMTS systems already deployed in the world. Considering the increasing utilization of VoIP (voice over IP), it is important to adequate the UMTS systems to this technology, in order to maximize the efficiency of transmission over the air interface. This paper considers a new contribution in this direction, based on the reduction of VoIP packet overhead, aiming to lower power consumption during a typical conversation. It is well known the advantages of HSPA systems for VoIP transmission, but at this moment there are only a few networks commercially available using this technology. View full abstract»

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  • Route discovery in wireless mobile ad hoc networks with adjusted probabilistic flooding

    Page(s): 99 - 109
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    Message flooding has been extensively used in wireless mobile ad hoc networks for activities such as route and resource discovery. This can potentially lead to high channel contention, causing redundant retransmissions and thus excessive packet collisions in the network. Such a phenomenon has been shown to greatly increase the network communication overhead and end-to-end delay. In this paper, we propose a probabilistic method of flooding that adjusts the forwarding probability at a node using its local topological characteristics. Our simulation analysis reveals that equipping a routing protocol with the proposed adjusted probabilistic flooding for route discovery can result in a significant reduction of routing control overhead while achieving good throughput. View full abstract»

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  • Tracking a Sycophant Wireless Sensor Network for its seamless integration to mobile Wireless Sensor Networks

    Page(s): 110 - 116
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    In this paper we introduce our novel concept of sycophant wireless sensors (SWS) which is a static ecto-parasitic clandestine sensor network mounted incognito on a mobile agent using only the agent's mobility without intervention. SWS networks not only communicate with each other through mobile WSN but also cooperate with them to form a global hybrid wireless sensor network (WSN). Our work develops the SLAM methodology integrating the different type of mobilities of SWS networks and mobile WSN's where the units of the latter network need also to track SWS besides cooperating and maintaining connectivity between the different SWS networks to form a seamless hybrid sensor network. This paper focuses on that latter issue. Demonstrative results are provided on the experimental setup including performance analysis of the methodology which also is conducted in simulation besides the hardware implementation for an elaborate sensitivity analysis to system parameters. View full abstract»

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  • Dynamic stability enhancement using Particle Swarm Optimization Power System Stabilizer

    Page(s): 117 - 119
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    In this paper the dynamics of a single machine connected to infinite bus power system is analyzed. Such analysis requires a certain level of system modeling. The main system components models are the synchronous machine, excitation system and the Power System Stabilizer. The Matlab/Simulink is used as a programming tool to analyze the system performance. According to the system performance a proper design for the Power System Stabilizer (PSS) using Particle Swarm Optimization (PSO) is carried out. Then the designed PSS is implemented in the model and the dynamic system response is analyzed. Since the simulation results without the PSS showed unacceptable system response, the system response with the PSS has improved and the PSS succeeded to stabilize an unstable system. View full abstract»

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  • Dynamic probabilistic counter-based broadcasting in mobile ad hoc networks

    Page(s): 120 - 127
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (273 KB) |  | HTML iconHTML  

    In Mobile Ad hoc Network (MANETs), flooding is the simplest broadcasting mechanism where each node retransmits every uniquely received packet exactly once. Despite its simplicity it could potentially leads to high redundant retransmissions causing high channel contention and thus excessive packet collisions in the network. This phenomenon referred to as broadcast storm problem has been shown to greatly increase the network communication overhead and end-to-end delay. Numerous probabilistic approaches have been proposed to mitigate the impact of this inherent phenomenon. However, most of these techniques are inadequate in reducing the number of redundant retransmissions while still guaranteeing that all nodes receive the packet. Further, in most cases they use a predetermined forwarding probability value for all nodes in the network which is quite unlikely to be optimal in other network set up. In this paper, we propose a new dynamic probabilistic counter-based broadcast scheme that can dynamically compute the forwarding probability at a node based on its neighbourhood information. Simulation results show that the new broadcast scheme achieves superior performance in terms of retransmitting nodes, collision rate, and end-to-end delay without sacrificing reachability compared to the existing schemes. View full abstract»

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  • Broadband / future generation network services deployment in rural and remote areas

    Page(s): 128 - 132
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    In this paper we provide an overview of current broadband and future generation services and their possible deployment in rural areas on the African continent. We discuss the challenges for deployment. In general Broadband access and the future generation network in rural areas should be increased through any technology, including wireless, wire line and optical. To be economically viable, rural areas need access to health care, government services, educational and business opportunities. It is in our view that in the interim wireless, high-speed Internet can fill the broadband void in rural areas by providing a cost- effective, overall platform for some of the services. View full abstract»

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  • Throughput considerations of cross-talk free single plane self routing switching fabric

    Page(s): 133 - 139
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    Wavelength division multiplexing (DWDM ) based all-optical networks have since become the promising solution to the unprecedented increasing demands for bandwidth. However the continued use of electronic switch architectures/routers serves as bottlenecks solely because of the impairment between switching capability and transmission speeds as the earlier continues to lag quite significantly. In a bid to reduce switch bottlenecks, switch architectures that blend both horizontal expansion and vertical stacking of optical Banyan networks are seen to be the ultimate solution. However the resultant structures (horizontally expanded and vertically stacked switch architectures) are usually quite expensive because of the hardware redundancy required in order to guarantee the minimal to non-blocking property. High quality of service (QoS) consistency may also be compromised due to the presence of crosstalk contributed by the directional couplers (DCs) which themselves are the elementary building blocks of such architectures. In this paper we focus on evaluating the overall delay across such switching architectures. View full abstract»

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  • Optimum mix of ground electrodes and conductive backfills to achieve a low ground resistance

    Page(s): 140 - 145
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    Based on response curves derived from field measurements, optimum number of vertical ground electrodes for grounding electrical installation is determined. On sites where the optimum number of the electrodes cannot reach a target ground resistance, a `critical resistance area concept' with conductive backfills is used. In this study, efficiencies of local conductive backfills for reducing ground resistance are investigated. Results show that application of tyre ashes as a conductive backfills lowers ground resistance to over 80%. It is also shown that the most favourable benefit in the ground resistance improvement is to limit the backfill to four electrodes. View full abstract»

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  • High temperature electronics: R&D challenges and trends in materials, packaging and interconnection technology

    Page(s): 146 - 153
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (131 KB) |  | HTML iconHTML  

    The development of new high temperature electronics (HTE)/systems is the key to achieving high reliability safety critical operations in aerospace, automotive and well-logging applications. Reliability issues associated with the operation of HTE devices have been shown to account for some of the recent aircraft crashes as well as failures of the electronic control Unit in modern vehicles. The reliability of electronic systems is partly dependent on its operating ambient conditions; and reliability generally decreases in harsh operating conditions. The life expectancy of components and systems is known to reduce exponentially as the operating temperature increases; adversely impacting long-term system reliability. As under-bonnet, aerospace and well-logging applications require the direct exposure of sensors to very harsh conditions - these applications demand new HTE systems which can operate reliably in harsh conditions whilst preserving their properties/functions over long operating periods. The packaging and interconnection of the new HTE systems requires better understanding of the complex interactions between HTE system parameters and specific environmental conditions. The paper presents an overview of HTE research, reviews the trends in materials, component packaging and interconnect technology. The paper also outlines the key challenges in HTE research and the outstanding R&D issues. View full abstract»

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