Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2004

Florida Institute of Technology

Articles 1 - 25 of 25

Full-Text Articles in Engineering

Using A Reply Path And Handshaking Protocol To Allow For Incentives With Mix-Net Servers, Timothy J. Atkinson, Marius C. Silaghi Nov 2004

Using A Reply Path And Handshaking Protocol To Allow For Incentives With Mix-Net Servers, Timothy J. Atkinson, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Sending a message to a destination anonymously so that the destination cannot figure out who the originator was, and ensuring that the message reaches the destination untampered with, can be a difficult problem. Chaum's mix-net solves this problem but offers little motivation for a person to set up a mix-net server. This paper discusses a method that not only allows monetary payments as an incentive to create a public mix-net server, but also provides some fraud detection at the time a message is being sent. Also compared with other methods, the method described here can be considered reasonable from the …

Go to article

Joint Source-Channel Decoding For Mpeg-2 Video Transmission, Liuguo Yin, Weigang Chen, Jianhua Lu, Chang Wen Chen Oct 2004

Joint Source-Channel Decoding For Mpeg-2 Video Transmission, Liuguo Yin, Weigang Chen, Jianhua Lu, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Joint source-channel coding schemes have been proven to be effective ways for reliable multimedia communications. In this paper, a joint source-channel decoding (JSCD) scheme that combines the hidden Markov source (HMS) estimation and low-density parity-check (LDPC) coding is proposed for the standard MPEG-2 video transmission. The LDPC code of the proposed scheme has a near-Shannon-limit error-correcting capability, while the HMS estimator may accurately extract the residual redundancy within the MPEG-2 video stream without any prior information. Furthermore, with a joint iterative decoding algorithm, the estimated source redundancy may be well exploited by the LDPC decoder, and the channel decoding feedback …

Go to article

Multiple Wavelet-Tree-Based Image Coding And Robust Transmission, Lei Cao, Chang Wen Chen Oct 2004

Multiple Wavelet-Tree-Based Image Coding And Robust Transmission, Lei Cao, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

In this paper, we present techniques based on multiple wavelet-tree coding for robust image transmission. The algorithm of set partitioning in hierarchical trees (SPIHT) is a state-of-the-art technique for image compression. This variable length coding (VLC) technique, however, is extremely sensitive to channel errors. To improve the error resilience capability and in the meantime to keep the high source coding efficiency through VLC, we propose to encode each wavelet tree or a group of wavelet trees using SPIHT algorithm independently. Instead of encoding the entire image as one bitstream, multiple bitstreams are generated. Therefore, error propagation is limited within individual …

Go to article

Layered Unequal Loss Protection For Image Transmission Over Packet Loss Channels With Delay Constraints, Jianfei Cai, Xiangjun Li, Chang Wen Chen Oct 2004

Layered Unequal Loss Protection For Image Transmission Over Packet Loss Channels With Delay Constraints, Jianfei Cai, Xiangjun Li, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

In the case of high bit rate image transmission or having lots of packets, the FEC (forward error correction) encoding and decoding processes in the ULP (unequal loss protection) based schemes should be applied to individual packet groups instead of all the packets in order to avoid long processing delay. In this paper, we propose a layered ULP (L-ULP) scheme for fast and efficient FEC allocations among different packet groups and also within each packet group. The numerical results show that the proposed L-ULP scheme is quite promising for fast image transmission over packet loss networks.

Go to article

Multiple-Description Image Coding With Distributed Source Coding And Side Information, Min Wu, Anthony Vetro, Chang Wen Chen Oct 2004

Multiple-Description Image Coding With Distributed Source Coding And Side Information, Min Wu, Anthony Vetro, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Multiple description coding (MDC) is a source coding technique that involves coding the source information into multiple descriptions. When these descriptions are transmitted over different channels in packet network or error-prone wireless environment, graceful degradation can be achieved even if part of descriptions are not received by the receiver. When MDC is applied to wavelet subband based image coding, it is possible to introduce correlation between the descriptions in each subband. In this paper, we consider using such a correlation as well as potentially error corrupted description as side information in the decoding to formulate the MDC decoding as a …

Go to article

Multiple Description Coding Based On Multiple-Bitstream Wavelet Zero-Tree Image Compression, Daewon Song, Chang Wen Chen, Lei Cao Oct 2004

Multiple Description Coding Based On Multiple-Bitstream Wavelet Zero-Tree Image Compression, Daewon Song, Chang Wen Chen, Lei Cao

Electrical Engineering and Computer Science Faculty Publications

Multiple description coding (MDC) is a well-known robust data compression algorithm designed to minimize the distortion caused by data loss in packet-based communication systems. Several MDC schemes for transmitting wavelet compressed images have been developed. However, these MDC schemes cannot be adopted for digital mobile wireless applications where both packet loss and bit error are present, because individual description in these MDC schemes usually does not have adequate error resilience capability to combat the bit error in transmission. In this paper, we propose an algorithm to achieve robust communication over error prone transmission channels with both packet loss and bit …

Go to article

Improving Arithmetic Circuits For Solving Constraint Satisfaction And Optimization Problems, Marius C. Silaghi Oct 2004

Improving Arithmetic Circuits For Solving Constraint Satisfaction And Optimization Problems, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

In the recent years we have proposed a set of secure multiparty computations for solving distributed constraint satisfaction and optimization problems, with applications to areas like distributed scheduling, configurations, team-making, and auctions. Some of the newest versions were based on an arithmetic circuit for selecting a random element out of the elements with a given value in a (secret) array. Here we show how to improve that arithmetic circuit by a factor of at least 4. The improvement is based on an optimization of the functions and on the usage of CSP solvers to exploit public constraints.

Go to article

Incentive Auctions And Stable Marriages Problems Solved With Bn=2c-Privacy Of Human Preferences, Marius C. Silaghi Jul 2004

Incentive Auctions And Stable Marriages Problems Solved With Bn=2c-Privacy Of Human Preferences, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Incentive auctions let several participants to cooperate for clearing a set of offers and requests, ensuring that each participant cannot do better than by inputting his true utility. This increases the social welfare by efficient allocations, and is proven to have similar outcomes as the tradition English Auctions. The desk-mates (stable matchings) problem comes from the need of placing students in pairs of two for working in projects or seating in two-seats desks. The stable marriages problem consists of finding matches of a man and a woman out of two sets of men, respectively women. Each of the persons in …

Go to article

A Suite Of Secure Multi-Party Computation Algorithms For Solving Distributed Constraint Satisfaction And Optimization Problems, Marius C. Silaghi Jul 2004

A Suite Of Secure Multi-Party Computation Algorithms For Solving Distributed Constraint Satisfaction And Optimization Problems, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Privacy requirements can be modeled within the distributed constraint satisfaction framework, where the constraints are secrets of the participants. In [20] we introduced a first technique allowing agents to solve distributed constraint problems (DisCSPs), without revealing anything and without trusting each other or some server. The first technique we propose now, MPC-DisCSP2, is a dm times improvement for m variables of domain size d. A second technique we propose, MPC-DisCSP3, has a similar complexity as MPD-DisCSP2, a little slower in the worst case, but guarantees that the returned solutions are picked according to a uniform distribution over the total set …

Go to article

Robust Image Transmission Based On Wavelet Tree Coding, Error Resilient Entropy Coding, And Error Concealment, Lei Cao, Chang Wen Chen Jul 2004

Robust Image Transmission Based On Wavelet Tree Coding, Error Resilient Entropy Coding, And Error Concealment, Lei Cao, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

A scheme with three key components including wavelet tree coding, error resilient entropy coding (EREC), and error concealment is proposed for robust image coding and transmission over noisy channels. First, we individually encode the spatial-orientation trees in the wavelet domain using the algorithm of set partitioning in hierarchical trees (SPIHT). Error propagation is thus limited because multiple independent bit streams are generated. Meanwhile, a high source coding efficiency is also preserved because the self-similarity property in each wavelet tree remains intact. Next, we use EREC to reorganize these variable-length bit streams into fixed-length data slots before multiplexing and transmission. Therefore, …

Go to article

Identifying Variable-Length Meaningful Phrases With Correlation Functions, Hyoung-Rae Kim, Philip K. Chan Jun 2004

Identifying Variable-Length Meaningful Phrases With Correlation Functions, Hyoung-Rae Kim, Philip K. Chan

Electrical Engineering and Computer Science Faculty Publications

Finding meaningful phrases in a document has been studied in various information retrieval systems in order to improve the performance. Many previous statistical phrase finding methods had different aim such as document classification. Some are hybridized with statistical and syntactic grammatical methods; others use correlation heuristics between words. We propose a new phrase-finding algorithm that adds correlated words one by one to the phrases found in the previous stage, maintaining high correlation within a phrase. Our results indicate that our algorithm finds more meaningful phrases than an existing algorithm. Furthermore, the previous algorithm could be improved by applying different correlation …

Go to article

Hydrazine/Nitrogen Dioxide Fiber Optic Sensor, Alfred S. Andrawis, Josephine B. Santiago, Rebecca Young, Clayton J. Baum Jun 2004

Hydrazine/Nitrogen Dioxide Fiber Optic Sensor, Alfred S. Andrawis, Josephine B. Santiago, Rebecca Young, Clayton J. Baum

Chemistry and Chemical Engineering Faculty Publications

This paper outlines the development of a dual hydrazine/nitrogen dioxide (HZ/NO2) prototype fiber optic sensor utilizing an acid-base indicator that undergoes color changes depending on which gas is present. Bromothymol blue bromocresol green mixture (1/1) in hydrogel (1/1), produces a blue-green indicator for HZ and/or NO2. The sensor was tested several times over a period of eight weeks and the response was consistent and proved the feasibility of dual HZ/NO2 leak detection. Prototype sensor construction, the hardware, and the software of the electronic interrogator circuitry are briefly explained. The paper presents a summary of sensor response when exposed to 52 …

Go to article

Morpheus: Motif Oriented Representations To Purge Hostile Events From Unlabeled Sequences, Guarav Tandon, Debasis Mitra, Philip K. Chan Jun 2004

Morpheus: Motif Oriented Representations To Purge Hostile Events From Unlabeled Sequences, Guarav Tandon, Debasis Mitra, Philip K. Chan

Electrical Engineering and Computer Science Faculty Publications

Most of the prevalent anomaly detection systems use some training data to build models. These models are then utilized to capture any deviations resulting from possible intrusions. The efficacy of such systems is highly dependent upon a training data set free of attacks. "Clean" or labeled training data is hard to obtain. This paper addresses the very practical issue of refinement of unlabeled data to obtain a clean data set which can then train an online anomaly detection system. Our system, called MORPHEUS, represents a system call sequence using the spatial positions of motifs (subsequences) within the sequence. We also …

Go to article

Synthesis Of Electromagnetic Devices With A Novel Neural Network, Heriberto Jose Delgado, Michael Thursby, Fredric M. Ham Apr 2004

Synthesis Of Electromagnetic Devices With A Novel Neural Network, Heriberto Jose Delgado, Michael Thursby, Fredric M. Ham

Electrical Engineering and Computer Science Faculty Publications

A novel Artificial Neural Network (ANN) is presented, which has been designed for computationally intensive problems, and applied to the optimization of electromagnetic devices such as antennas and microwave devices. The ANN exploits a unique number representation in conjunction with a more standard neural network architecture. An ANN consisting of a hetero-associative memory provided a very efficient method of computing the necessary geometrical values for the devices, when used in conjunction with a new randomization process. The number representation used provides significant insight into this new method of fault-tolerant computing. Further work is needed to evaluate the potential of this …

Go to article

Consistency Restoration In Point And Interval Spatio-Temporal Reasoning, Florent Launay, Debasis Mitra Apr 2004

Consistency Restoration In Point And Interval Spatio-Temporal Reasoning, Florent Launay, Debasis Mitra

Electrical Engineering and Computer Science Faculty Publications

In this work, we first have proposed a technique to define the “causes” of inconsistency on an online point based reasoning constraint network. Second, we introduce an algorithm that proposes the user a minimal set of relations to remove when inconsistencies are detected. We have developed and implemented a battery of algorithms for the purpose of this type of reasoning. Some useful theorems and properties are defined for proving the ‘minimal’ aspect of the algorithm. Finally, we found that our investigation was a polynomially solvable sub problem of the vertex cover problem.

Go to article

Semi-Automatic Road Extraction From Aerial Images, Somkait Udomhunsakul, Samuel Peter Kozaitis, Uthai Thai Sritheeravirojana Feb 2004

Semi-Automatic Road Extraction From Aerial Images, Somkait Udomhunsakul, Samuel Peter Kozaitis, Uthai Thai Sritheeravirojana

Electrical Engineering and Computer Science Faculty Publications

In this work, we proposed a method to detect roads in aerial imagery. In our approach, we applied the wavelet transform in a multiresolution sense by forming the products of wavelet coefficients at the different scales to locate and identify roads. After detecting possible road pixels, we used a graph searching algorithm to identify roads. We found that our approach leads to an effective method to form the basis of a road extraction approach.

Go to article

On The Implementation Of Swarmlinda? A Linda System Based On Swarm Intelligence (Extended Version), Ahmed Charles, Ronaldo Menezes, Robert Tolksdorf Feb 2004

On The Implementation Of Swarmlinda? A Linda System Based On Swarm Intelligence (Extended Version), Ahmed Charles, Ronaldo Menezes, Robert Tolksdorf

Electrical Engineering and Computer Science Faculty Publications

Natural-forming multi-agent systems (aka Swarms) can grow to enormous sizes and perform seemingly complex tasks without the existence of any centralized control. Their success comes from the fact that agents are simple and the interaction with the environment and neighboring agents is local in nature. In this paper we discuss the implementation of SwarmLinda, a Linda-based system that abstracts Linda concepts in terms of swarm intelligence constructs such as scents and stigmergy. The goal of this implementation is to achieve many characteristics such as scalability, adaptiveness and some level of fault tolerance. This paper describes our initial version of SwarmLinda …

Go to article

A Faster Technique For Distributed Constraint Satisfaction And Optimization With Privacy Enforcement, Marius C. Silaghi Jan 2004

A Faster Technique For Distributed Constraint Satisfaction And Optimization With Privacy Enforcement, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

A problem that received recent attention is the development of negotiation/cooperation techniques for solving naturally distributed problems with privacy requirements. An important amount of research focused on those problems that can be modeled with distributed constraint satisfaction, where the constraints are the secrets of the participants. Distributed AI develops techniques where the agents solve such problems without involving trusted servers. Some of the existing techniques aim for various tradeoffs between complexity and privacy guarantees [MTSY03], some aim only at high efficiency [ZM04], while others aim to offer maximal privacy [Sil03]. While the last mentioned work achieves an important level of …

Go to article

Layered Unequal Loss Protection For Progressive Image Transmission Over Packet Loss Channels, Jianfei Cai, Xiangjun Li, Chang Wen Chen Jan 2004

Layered Unequal Loss Protection For Progressive Image Transmission Over Packet Loss Channels, Jianfei Cai, Xiangjun Li, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

In the past, many schemes have been proposed for progressive image transmission using unequal error protection (UEP) or unequal loss protection (ULP). However, most existing UEP/ULP schemes do not consider the minimum image quality requirement and usually have high computation complexity. In this paper, we propose a layered ULP (L-ULP) scheme for progressive image transmission over packet loss channels, which is able to solve the mentioned problems of existing ULP schemes by smartly choosing the layers. The numerical results show that the proposed L-ULP scheme is quite promising for fast image transmission over packet loss networks.

Go to article

A Half D1 Mpeg-4 Encoder On The Bsp-15 Dsp, Lulin Chen, Zhihai He, Chang Wen Chen, Michael A. Isnardi Jan 2004

A Half D1 Mpeg-4 Encoder On The Bsp-15 Dsp, Lulin Chen, Zhihai He, Chang Wen Chen, Michael A. Isnardi

Electrical Engineering and Computer Science Faculty Publications

In this paper, we present the work on implementation of a half-Dl interlaced MPEG-4 encoder with Equator Technology DSP chip, BSP-15. The BSP-15 DSP consists mainly of a VLIW core, Co-processors, and media I/O interfaces. The encoder utilizes several BSP-15 functional blocks in parallel. In general, the VLIW performs pixel processing that is computationally intensive. The VLx coprocessor completes variable length coding. Further parallelism is obtained by pre-loading data cache and doubling data buffers. Given the DSP processing power and real time requirements, a complexity control scheme is implemented. A frame-level quantization scheme with quality and rate control is employed. …

Go to article

Effective Quality Analysis For Video Streaming Over Wireless Ad Hoc Network, Zhihai He, Chang Wen Chen Jan 2004

Effective Quality Analysis For Video Streaming Over Wireless Ad Hoc Network, Zhihai He, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Video encoding and streaming over wireless ad hoc network operates under severe conditions, such as time-varying channel characteristics with bursty errors, limit power for data transmission, and dynamic topology of the self-organized network, stringent time delay for packet delivery, etc. Due to the dynamic topology, complex mechanism, and time-varying nature of the wireless ad hoc network, the network system and the streaming service often exhibit unpredictable behaviors. The ultimate goal in the wireless video streaming service is to provide the end user with the best possible video presentation quality. The video streaming quality, often measured by the end-to-end picture distortion, …

Go to article

Collaborative Image Transmission Over Wireless Sensor Networks, Min Wu, Chang Wen Chen Jan 2004

Collaborative Image Transmission Over Wireless Sensor Networks, Min Wu, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

The imaging sensors are able to provide intuitive visual information for quick recognition and decision. However, imaging sensors usually generate vast amount of data. Thus, processing of image data collected in the sensor network for the purpose of energy efficient transmission poses a significant technical challenge. In particular, when a cluster of imaging sensors is activated to track certain moving target, multiple sensors may be collecting similar visual information simultaneously. With correlated image data, we need to intelligently reduce the redundancy among the neighboring sensors so as to minimize the energy for transmission, the primary source of sensor energy consumption. …

Go to article

Evaluation Of The Human Impact Of Password Authentication Practices On Information Security, Deborah Sater Carstens, Pamela R. Mccauley-Bell, Linda C. Malone, Ronald F. Demara Jan 2004

Evaluation Of The Human Impact Of Password Authentication Practices On Information Security, Deborah Sater Carstens, Pamela R. Mccauley-Bell, Linda C. Malone, Ronald F. Demara

Aeronautics Faculty Publications

The research objective was to develop a model for evaluating the human impact that password authentication issues are having on the security of information systems. Through distributing a survey and conducting an experiment, researchers created a model for predicting the vulnerability that a particular set of conditions will have on the likelihood of error in an information system. The survey consisted of over 250 respondents. The experiment consisted of 30 subjects and the analysis utilized a χ2 goodness of fit test. The findings indicate that human error associated with password authentication can be significantly reduced through the use of passwords …

Go to article

Speckle Denoising Using Wavelet Transforms And Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun Jan 2004

Speckle Denoising Using Wavelet Transforms And Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun

Electrical Engineering and Computer Science Faculty Publications

We reduced speckle noise in SAR imagery by retaining only those wavelet coefficients with significant third-order correlation coefficients. These coefficients were generated from the cross-correlation functions of the image and wavelet basis functions. Using this approach, we compared the results between directly applying our denoising method, and first preprocessing by taking the logarithm of an image. In our approach, we examined wavelet coefficients in an environment where the contribution from the second-order moment of the noise had been reduced.

Go to article

Ubiquitous Map-Image Access Through Wireless Overlay Networks, Jianfei Cai, Haijie Huang, Zefeng Ni, Chang Wen Chen Jan 2004

Ubiquitous Map-Image Access Through Wireless Overlay Networks, Jianfei Cai, Haijie Huang, Zefeng Ni, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

With the availability of various wireless link-layer technologies, such as Bluetooth, WLAN and GPRS, in one wireless device, ubiquitous communications can be realized through managing vertical handoff in the environment of wireless overlay networks. In this paper, we propose a vertical handoff management system based on mobile IPv6, which can automatically manage the multiple network interfaces on the mobile device, and make decisions on network interface selection according to the current situation. Moreover, we apply our proposed vertical handoff management with JPEG-2000 codec to the wireless application of map image access. The developed system is able to provide seamless communications, …

Go to article