West Virginia University

Displaying 1-28 of 28 results

  • White Papers // Jul 2012

    Optimization of a Finite Frequency-Hopping Ad Hoc Network in Nakagami Fading

    This paper considers the analysis and optimization of a frequency-hopping ad hoc network with a finite number of mobiles and finite spatial extent. The mobiles communicate using coded Continuous-Phase Frequency-Shift Keying (CPFSK) modulation. The performance of the system is a function of the number of hopping channels, the rate of...

    Provided By West Virginia University

  • White Papers // Jul 2012

    Analysis and Optimization of a Frequency-Hopping Ad Hoc Network in Rayleigh Fading

    This paper proposes a new method for optimizing frequency-hopping ad hoc networks in the presence of Rayleigh fading. It is assumed that the system uses a capacity-approaching code (e.g., turbo or LDPC) and non-coherent binary Continuous-Phase Frequency-Shift Keying (CPFSK) modulation. By using transmission capacity as the performance metric, the number...

    Provided By West Virginia University

  • White Papers // Jul 2012

    Guard Zones and the Near-Far Problem in DS-CDMA Ad Hoc Networks

    The central issue in Direct-Sequence Code-Division Multiple-Access (DS-CDMA) ad hoc networks is the prevention of a near-far problem. This paper considers two types of guard zones that may be used to control the near-far problem: a fundamental exclusion zone and an additional CSMA guard zone that may be established by...

    Provided By West Virginia University

  • White Papers // May 2012

    Distributed Parameter Estimation in Wireless Sensor Networks Using Fused Local Observations

    This paper is to reliably estimate a vector of unknown deterministic parameters associated with an underlying function at a fusion center of a wireless sensor network based on its noisy samples made at distributed local sensors. A set of noisy samples of a deterministic function characterized by a finite set...

    Provided By West Virginia University

  • White Papers // Mar 2012

    Fairness and Stability Analysis of Congestion Control Schemes in Vehicular Ad-Hoc Networks

    Cooperative Vehicle Safety (CVS) systems operate based on broadcast of vehicle position and safety information to neighboring cars. The communication medium of CVS is a vehicular ad-hoc network. One of the main challenges in large scale deployment of CVS systems is the issue of scalability. To address the scalability problem,...

    Provided By West Virginia University

  • White Papers // Feb 2012

    Physical-Layer Network Coding Using FSK Modulation Under Frequency Offset

    Physical-layer network coding is a protocol capable of increasing throughput over conventional relaying in the two-way relay channel, but is sensitive to phase and frequency offsets among transmitted signals. Modulation techniques which require no phase synchronization such as non-coherent FSK can compensate for phase offset, however, the relay receiver must...

    Provided By West Virginia University

  • White Papers // Aug 2011

    A Framework for Quality-Based Biometric Classifier Selection

    Multi-biometric systems fuse the evidence (e.g., match scores) pertaining to multiple biometric modalities or classifiers. Most score-level fusion schemes discussed in the literature require the processing (i.e., feature extraction and matching) of every modality prior to invoking the fusion scheme. This paper presents a framework for dynamic classifier selection and...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Face Recognition for Look-Alikes: A Preliminary Study

    One of the major challenges of face recognition is to design a feature extractor and matcher that reduces the intra-class variations and increases the inter-class variations. The feature extraction algorithm has to be robust enough to extract similar features for a particular subject despite variations in quality, pose, illumination, expression,...

    Provided By West Virginia University

  • White Papers // Aug 2011

    On Co-Training Online Biometric Classifiers

    In an operational biometric verification system, changes in biometric data over a period of time can affect the classification accuracy. Online learning has been used for updating the classifier decision boundary. However, this requires labeled data that is only available during new enrollments. This paper presents a biometric classifier update...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Noncoherent Digital Network Coding Using Multi-Tone CPFSK Modulation

    Digital network coding is a relaying technique that increases throughput in two-way relay networks. In contrast with analog network coding, which relays received analog signals plus noise, digital network coding relays digital code-words. The digital code-words are created by demodulation, channel decoding, and re-encoding at the relay. By using FSK...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Improving DVB-S2 Performance Through Constellation Shaping and Iterative Demapping

    Because it is widely supported by Commercial-Off-The-Shelf (COTS) technology, the DVB-S2 waveform standard has become an attractive solution for military communication links. The waveform uses a combination of Amplitude-Phase-Shift Keying (APSK) modulation and Low-Density Parity-Check (LDPC) codes. Typical DVB-S2 implementations select signals from the APSK signal set with uniform probability....

    Provided By West Virginia University

  • White Papers // Jul 2011

    Simultaneous Latent Fingerprint Recognition

    Simultaneous latent fingerprints are clusters of friction ridge impressions deposited concurrently in a crime scene. The analysis of these impressions is a complex task to infer individualization, exclusion or categorize as inconclusive. The problem is further compounded when distinctive features in each latent fingerprint in the cluster are of varying...

    Provided By West Virginia University

  • White Papers // Apr 2011

    Quality Assessment Based Denoising to Improve Face Recognition Performance

    A probe face image may contain noise due to environmental conditions, incorrect use of sensors or transmission error. The performance of face recognition severely depletes when the probe image is contaminated with noise. Denoising techniques can improve recognition performance, provided the correct parameters are used. In this paper, a parameter...

    Provided By West Virginia University

  • White Papers // Mar 2011

    Channel-Aware Distributed Classification in Wireless Sensor Networks Using Binary Local Decisions

    This paper considers the problem of distributed multi-hypothesis classification in the context of wireless sensor networks. The goal is to reliably classify an underlying hypothesis at a fusion center using simple localized decisions at individual sensors. The fusion-center classification must be performed despite the presence of faults in both local...

    Provided By West Virginia University

  • White Papers // Mar 2011

    Constellation Shaping for Communication Channels With Quantized Outputs

    This paper considers a technique to maximize the mutual information between the channel input and channel output of an AWGN channel when the input is chosen from a fixed signal constellation and the output is quantized by a uniform scalar quantizer. The goal is to jointly optimize the input distribution...

    Provided By West Virginia University

  • White Papers // Jan 2011

    Evolutionary Granular Approach for Recognizing Faces Altered Due to Plastic Surgery

    Recognizing faces with altered appearances is a challenging task and is only now beginning to be addressed by researchers. The paper presents an evolutionary granular approach for matching face images that have been altered by plastic surgery procedures. The algorithm extracts discriminating information from non-disjoint face granules obtained at different...

    Provided By West Virginia University

  • White Papers // Jan 2011

    A Reconfigurable Distributed Multiagent System Optimized for Scalability

    This paper proposes a novel solution for optimizing the size and communication overhead of a distributed multiagent system without compromising the performance. The proposed approach addresses the challenges of scalability especially when the multiagent system is large. A modified spectral clustering technique is used to partition a large network into...

    Provided By West Virginia University

  • White Papers // Jan 2011

    Performance Evaluation of Hop-Based Range-Free Localization Methods in Wireless Sensor Networks

    Knowledge of nodes' locations is an important requirement for many applications in Wireless Sensor Networks. In the hop-based range-free localization methods, anchors broadcast the localization messages including a hop count value to the entire network. Each node receives this message and calculates its own distance with anchor in hops and...

    Provided By West Virginia University

  • White Papers // Sep 2010

    Recovery And Reinvestment Act Spending At The State Level: Keynesian Stimulus Or Distributive Politics?

    The authors examine the US state-level pattern of American Recovery and Reinvestment Act (ARRA) spending. They relate spending to Keynesian determinants of countercyclical policy, congressional power and dominance, and presidential electoral vote importance. They find that the ARRA is, in practice, poorly-designed countercyclical stimulus. After controlling for political variables, coefficients...

    Provided By West Virginia University

  • White Papers // Jul 2010

    Institutions, Capital, And Growth

    The international development community has encouraged investment in physical and human capital as a precursor to economic progress. Recent evidence shows, however, that increases in capital do not always lead to increases in output. The authors develop a growth model where the allocation and productivity of capital depends on a...

    Provided By West Virginia University

  • White Papers // Jan 2010

    Quality-Based Fusion for Multichannel Iris Recognition

    The authors propose a quality-based fusion scheme for improving the recognition accuracy using color iris images characterized by three spectral channels - Red, Green and Blue. In the proposed method, quality scores are employed to select two channels of a color iris image which are fused at the image level...

    Provided By West Virginia University

  • White Papers // Jan 2010

    Biometric Classifier Update Using Online Learning: A Case Study in Near Infrared Face Verification

    The performance of large-scale biometric system deteriorates over time as new individuals are continually enrolled. To maintain a high-level of performance, the classifier has to be retrained offline in batch mode using both the existing and new data. The process of retraining can be computationally expensive and time-consuming. This paper...

    Provided By West Virginia University

  • White Papers // Nov 2009

    Combining Mean Reversion And Momentum Trading Strategies In Foreign Exchange Markets

    The literature on equity markets documents the existence of mean reversion and momentum phenomena. Researchers in foreign exchange markets find that foreign exchange rates also display behaviors akin to momentum and mean reversion. This paper implements a trading strategy combining mean reversion and momentum in foreign exchange markets. The strategy...

    Provided By West Virginia University

  • White Papers // Nov 2009

    Reconsidering The Role Of Capital Accumulation For International Specialization Across Industries

    The Heckscher-Ohlin-Vanek (HOV) model allows us to analyze whether countries specialize in particular subsets of industries as they accumulate production factors. Davis and Weinstein (2001) provided evidence that global data supports the HOV model when production techniques are modified to reflect countries' capital abundances. However, once factor trades are measured...

    Provided By West Virginia University

  • White Papers // Oct 2009

    Context Switching Algorithm for Selective Multibiometric Fusion

    This paper presents a multimodal biometric fusion algorithm that supports biometric image quality and case-based context switching approach for selecting appropriate constituent unimodal traits and fusion algorithms. Depending on the quality of input samples, the pro-posed algorithm intelligently selects appropriate fusion algorithm for optimal performance. Experiments and correlation analysis on...

    Provided By West Virginia University

  • White Papers // Oct 2009

    A New Biometric Modality Based on Conjunctival Vasculature

    A new biometric indicator based on the patterns of conjunctival vasculature is proposed. Conjunctival vessels can be observed on the visible part of the sclera that is exposed to the outside world. These vessels demonstrate rich and specific details in visible light, and can be easily photographed using a regular...

    Provided By West Virginia University

  • White Papers // Jun 2009

    A Coding Scheme for Indexing Multimodal Biometric Databases

    In biometric identification systems, the identity associated with the input data is determined by comparing it against every entry in the database. This exhaustive matching process increases the response time of the system and, potentially, the rate of erroneous identification. A method that narrows the list of potential identities will...

    Provided By West Virginia University

  • White Papers // Mar 2009

    Multibiometric Systems: Overview, Case Studies and Open Issues

    Information fusion refers to the reconciliation of evidence presented by multiple sources of information in order to generate a decision. In the context of biometrics, evidence reconciliation plays a pivotal role in enhancing the recognition accuracy of human authentication systems and is referred to as multibiometrics. Multibiometric systems combine the...

    Provided By West Virginia University

  • White Papers // Oct 2009

    A New Biometric Modality Based on Conjunctival Vasculature

    A new biometric indicator based on the patterns of conjunctival vasculature is proposed. Conjunctival vessels can be observed on the visible part of the sclera that is exposed to the outside world. These vessels demonstrate rich and specific details in visible light, and can be easily photographed using a regular...

    Provided By West Virginia University

  • White Papers // Mar 2009

    Multibiometric Systems: Overview, Case Studies and Open Issues

    Information fusion refers to the reconciliation of evidence presented by multiple sources of information in order to generate a decision. In the context of biometrics, evidence reconciliation plays a pivotal role in enhancing the recognition accuracy of human authentication systems and is referred to as multibiometrics. Multibiometric systems combine the...

    Provided By West Virginia University

  • White Papers // Jun 2009

    A Coding Scheme for Indexing Multimodal Biometric Databases

    In biometric identification systems, the identity associated with the input data is determined by comparing it against every entry in the database. This exhaustive matching process increases the response time of the system and, potentially, the rate of erroneous identification. A method that narrows the list of potential identities will...

    Provided By West Virginia University

  • White Papers // Jul 2012

    Optimization of a Finite Frequency-Hopping Ad Hoc Network in Nakagami Fading

    This paper considers the analysis and optimization of a frequency-hopping ad hoc network with a finite number of mobiles and finite spatial extent. The mobiles communicate using coded Continuous-Phase Frequency-Shift Keying (CPFSK) modulation. The performance of the system is a function of the number of hopping channels, the rate of...

    Provided By West Virginia University

  • White Papers // Jul 2012

    Guard Zones and the Near-Far Problem in DS-CDMA Ad Hoc Networks

    The central issue in Direct-Sequence Code-Division Multiple-Access (DS-CDMA) ad hoc networks is the prevention of a near-far problem. This paper considers two types of guard zones that may be used to control the near-far problem: a fundamental exclusion zone and an additional CSMA guard zone that may be established by...

    Provided By West Virginia University

  • White Papers // Jul 2012

    Analysis and Optimization of a Frequency-Hopping Ad Hoc Network in Rayleigh Fading

    This paper proposes a new method for optimizing frequency-hopping ad hoc networks in the presence of Rayleigh fading. It is assumed that the system uses a capacity-approaching code (e.g., turbo or LDPC) and non-coherent binary Continuous-Phase Frequency-Shift Keying (CPFSK) modulation. By using transmission capacity as the performance metric, the number...

    Provided By West Virginia University

  • White Papers // Feb 2012

    Physical-Layer Network Coding Using FSK Modulation Under Frequency Offset

    Physical-layer network coding is a protocol capable of increasing throughput over conventional relaying in the two-way relay channel, but is sensitive to phase and frequency offsets among transmitted signals. Modulation techniques which require no phase synchronization such as non-coherent FSK can compensate for phase offset, however, the relay receiver must...

    Provided By West Virginia University

  • White Papers // May 2012

    Distributed Parameter Estimation in Wireless Sensor Networks Using Fused Local Observations

    This paper is to reliably estimate a vector of unknown deterministic parameters associated with an underlying function at a fusion center of a wireless sensor network based on its noisy samples made at distributed local sensors. A set of noisy samples of a deterministic function characterized by a finite set...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Noncoherent Digital Network Coding Using Multi-Tone CPFSK Modulation

    Digital network coding is a relaying technique that increases throughput in two-way relay networks. In contrast with analog network coding, which relays received analog signals plus noise, digital network coding relays digital code-words. The digital code-words are created by demodulation, channel decoding, and re-encoding at the relay. By using FSK...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Improving DVB-S2 Performance Through Constellation Shaping and Iterative Demapping

    Because it is widely supported by Commercial-Off-The-Shelf (COTS) technology, the DVB-S2 waveform standard has become an attractive solution for military communication links. The waveform uses a combination of Amplitude-Phase-Shift Keying (APSK) modulation and Low-Density Parity-Check (LDPC) codes. Typical DVB-S2 implementations select signals from the APSK signal set with uniform probability....

    Provided By West Virginia University

  • White Papers // Mar 2011

    Channel-Aware Distributed Classification in Wireless Sensor Networks Using Binary Local Decisions

    This paper considers the problem of distributed multi-hypothesis classification in the context of wireless sensor networks. The goal is to reliably classify an underlying hypothesis at a fusion center using simple localized decisions at individual sensors. The fusion-center classification must be performed despite the presence of faults in both local...

    Provided By West Virginia University

  • White Papers // Mar 2011

    Constellation Shaping for Communication Channels With Quantized Outputs

    This paper considers a technique to maximize the mutual information between the channel input and channel output of an AWGN channel when the input is chosen from a fixed signal constellation and the output is quantized by a uniform scalar quantizer. The goal is to jointly optimize the input distribution...

    Provided By West Virginia University

  • White Papers // Mar 2012

    Fairness and Stability Analysis of Congestion Control Schemes in Vehicular Ad-Hoc Networks

    Cooperative Vehicle Safety (CVS) systems operate based on broadcast of vehicle position and safety information to neighboring cars. The communication medium of CVS is a vehicular ad-hoc network. One of the main challenges in large scale deployment of CVS systems is the issue of scalability. To address the scalability problem,...

    Provided By West Virginia University

  • White Papers // Nov 2009

    Combining Mean Reversion And Momentum Trading Strategies In Foreign Exchange Markets

    The literature on equity markets documents the existence of mean reversion and momentum phenomena. Researchers in foreign exchange markets find that foreign exchange rates also display behaviors akin to momentum and mean reversion. This paper implements a trading strategy combining mean reversion and momentum in foreign exchange markets. The strategy...

    Provided By West Virginia University

  • White Papers // Nov 2009

    Reconsidering The Role Of Capital Accumulation For International Specialization Across Industries

    The Heckscher-Ohlin-Vanek (HOV) model allows us to analyze whether countries specialize in particular subsets of industries as they accumulate production factors. Davis and Weinstein (2001) provided evidence that global data supports the HOV model when production techniques are modified to reflect countries' capital abundances. However, once factor trades are measured...

    Provided By West Virginia University

  • White Papers // Sep 2010

    Recovery And Reinvestment Act Spending At The State Level: Keynesian Stimulus Or Distributive Politics?

    The authors examine the US state-level pattern of American Recovery and Reinvestment Act (ARRA) spending. They relate spending to Keynesian determinants of countercyclical policy, congressional power and dominance, and presidential electoral vote importance. They find that the ARRA is, in practice, poorly-designed countercyclical stimulus. After controlling for political variables, coefficients...

    Provided By West Virginia University

  • White Papers // Jul 2010

    Institutions, Capital, And Growth

    The international development community has encouraged investment in physical and human capital as a precursor to economic progress. Recent evidence shows, however, that increases in capital do not always lead to increases in output. The authors develop a growth model where the allocation and productivity of capital depends on a...

    Provided By West Virginia University

  • White Papers // Jan 2011

    A Reconfigurable Distributed Multiagent System Optimized for Scalability

    This paper proposes a novel solution for optimizing the size and communication overhead of a distributed multiagent system without compromising the performance. The proposed approach addresses the challenges of scalability especially when the multiagent system is large. A modified spectral clustering technique is used to partition a large network into...

    Provided By West Virginia University

  • White Papers // Jan 2011

    Performance Evaluation of Hop-Based Range-Free Localization Methods in Wireless Sensor Networks

    Knowledge of nodes' locations is an important requirement for many applications in Wireless Sensor Networks. In the hop-based range-free localization methods, anchors broadcast the localization messages including a hop count value to the entire network. Each node receives this message and calculates its own distance with anchor in hops and...

    Provided By West Virginia University

  • White Papers // Aug 2011

    On Co-Training Online Biometric Classifiers

    In an operational biometric verification system, changes in biometric data over a period of time can affect the classification accuracy. Online learning has been used for updating the classifier decision boundary. However, this requires labeled data that is only available during new enrollments. This paper presents a biometric classifier update...

    Provided By West Virginia University

  • White Papers // Jul 2011

    Simultaneous Latent Fingerprint Recognition

    Simultaneous latent fingerprints are clusters of friction ridge impressions deposited concurrently in a crime scene. The analysis of these impressions is a complex task to infer individualization, exclusion or categorize as inconclusive. The problem is further compounded when distinctive features in each latent fingerprint in the cluster are of varying...

    Provided By West Virginia University

  • White Papers // Jan 2010

    Biometric Classifier Update Using Online Learning: A Case Study in Near Infrared Face Verification

    The performance of large-scale biometric system deteriorates over time as new individuals are continually enrolled. To maintain a high-level of performance, the classifier has to be retrained offline in batch mode using both the existing and new data. The process of retraining can be computationally expensive and time-consuming. This paper...

    Provided By West Virginia University

  • White Papers // Jan 2010

    Quality-Based Fusion for Multichannel Iris Recognition

    The authors propose a quality-based fusion scheme for improving the recognition accuracy using color iris images characterized by three spectral channels - Red, Green and Blue. In the proposed method, quality scores are employed to select two channels of a color iris image which are fused at the image level...

    Provided By West Virginia University

  • White Papers // Oct 2009

    Context Switching Algorithm for Selective Multibiometric Fusion

    This paper presents a multimodal biometric fusion algorithm that supports biometric image quality and case-based context switching approach for selecting appropriate constituent unimodal traits and fusion algorithms. Depending on the quality of input samples, the pro-posed algorithm intelligently selects appropriate fusion algorithm for optimal performance. Experiments and correlation analysis on...

    Provided By West Virginia University

  • White Papers // Aug 2011

    A Framework for Quality-Based Biometric Classifier Selection

    Multi-biometric systems fuse the evidence (e.g., match scores) pertaining to multiple biometric modalities or classifiers. Most score-level fusion schemes discussed in the literature require the processing (i.e., feature extraction and matching) of every modality prior to invoking the fusion scheme. This paper presents a framework for dynamic classifier selection and...

    Provided By West Virginia University

  • White Papers // Apr 2011

    Quality Assessment Based Denoising to Improve Face Recognition Performance

    A probe face image may contain noise due to environmental conditions, incorrect use of sensors or transmission error. The performance of face recognition severely depletes when the probe image is contaminated with noise. Denoising techniques can improve recognition performance, provided the correct parameters are used. In this paper, a parameter...

    Provided By West Virginia University

  • White Papers // Jan 2011

    Evolutionary Granular Approach for Recognizing Faces Altered Due to Plastic Surgery

    Recognizing faces with altered appearances is a challenging task and is only now beginning to be addressed by researchers. The paper presents an evolutionary granular approach for matching face images that have been altered by plastic surgery procedures. The algorithm extracts discriminating information from non-disjoint face granules obtained at different...

    Provided By West Virginia University

  • White Papers // Aug 2011

    Face Recognition for Look-Alikes: A Preliminary Study

    One of the major challenges of face recognition is to design a feature extractor and matcher that reduces the intra-class variations and increases the inter-class variations. The feature extraction algorithm has to be robust enough to extract similar features for a particular subject despite variations in quality, pose, illumination, expression,...

    Provided By West Virginia University