ppxscal/embedding_network huggingface dataset:
On arbitrarily varying Markov source coding and hypothesis LAO testing by non-informed statistician
Authors: Evgueni Haroutunian, Naira Grigoryan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

Two problems concerning arbitrarily varying stationary Markov source (AVMS), namely, the binary hypothesis testing and the source coding problems are solved. First, we consider a logarithmically asymptotically optimal (LAO) hypothesis testing (HT) for distributions of AVMS. The asymptotic behavior of the second type error probability exponent is investigated in function of the first type error probability exponent, as the number of observations tends to infinity. In the problem of AVMS coding, the E-optimal rate function R(E) (the minimum rate R of the source sequences compression when the decoding error probability is less than exp{-NE}, (E > 0) and its inverse reliability function E(R) are obtained from the corresponding HT result.
Identifying fusion events in fluorescence microscopy images
Authors: W. J. Godinez, M. Lampe, S. Wörz, R. Eils, B. Müller, K. Rohr
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

We are investigating the dynamical relationships exhibited by virus particles via fluorescence time-lapse microscopy. To obtain a quantitative description of each particle over time, these objects are tracked. To derive an explicit characterization of each particle as well as to identify interesting transient behaviors, the intensity over time of each particle needs to be analyzed. We have developed an approach based on hybrid stochastic systems for identifying behaviors of interest. We employ a hybrid particle filter for estimating the behavior of individual particles. The approach has been successfully applied to particles tracked in synthetic image sequences as well as in real image sequences displaying HIV-1 particles.
Tandem coding and cryptography on wiretap channels: EXIT chart analysis
Authors: Willie K. Harrison, Steven W. McLaughlin
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Traditional cryptography assumes an eavesdropper receives an error-free copy of the transmitted ciphertext. Wyner's wiretap channel model recognizes that at the physical layer both the intended receiver and the passive eavesdropper inevitably receive an error-prone version of the transmitted message which must be corrected prior to decryption. This paper considers the implications of using both channel and cryptographic codes under the wiretap channel model in a way that enhances the information-theoretic security for the friendly parties by keeping the information transfer to the eavesdropper small. We consider a secret-key cryptographic system with a linear feedback shift register (LFSR)-based keystream generator and observe the mutual information between an LFSR-generated sequence and the received noise-corrupted ciphertext sequence under a known-plaintext scenario. The effectiveness of a noniterative fast correlation attack, which reduces the search time in a brute-force attack, is shown to be correlated with this mutual information. For an iterative fast correlation attack on this cryptographic system, it is shown that an EXIT chart and mutual information are very good predictors of decoding success and failure by a passive eavesdropper.
Performance of random routing on grid-based sensor networks
Authors: Dulanjalie C. Dhanapala, Anura P. Jayasumana, Qi Han
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Random routing protocols in sensor networks forward packets to randomly selected neighbors. These packets are agents carrying information about events, or queries seeking such information. We derive the probability of a packet visiting a given node in a given step as well as the rendezvous probability of agents and queries within a specific number of hops at a given node(s) in a 2-D grid-based sensor network. The utility of the model is demonstrated by determining the protocol parameters to optimize performance of rumor routing protocol under different constraints, e.g., to evaluate the number of queries and agents to maximize the probability of rendezvous for a given amount of energy. Monte Carlo simulations are used to validate the model. The closed form exact solution presented, unlike existing models relying on asymptotic behavior, is applicable to small and medium-scale networks as well. An upper bound is provided for the case where the packet is not sent back to its immediate forwarding node. Simulation results indicate that the model is a good approximation even for sparse arrays with 75 % of the nodes. The model can be used to set parameters and optimize performance of several classes of random routing protocols.
Traffic adaptive active period control with adaptive backoff window for cluster-based IEEE 802.15.4 wireless sensor networks
Authors: Kazuo Mori, Katsuhiro Naito, Hideo Kobayashi
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

This paper proposes an adaptive 2-level active period control method with adaptive backoff window based on traffic load in each cluster for cluster-based wireless sensor networks (WSNs) employing IEEE 802.15.4 medium access control (MAC) protocol under temporal and geographical non-uniform traffic distribution. The proposed method consists of three elements: cluster level active period control, network level active period control, and adaptive backoff window control. In the cluster level control, cluster heads autonomously control their active period length in the superframe defined by a personal area network (PAN) coordinator. The PAN coordinator manages the superframe structure for the whole network in the network level control. In the adaptive backoff window control, the backoff window size is determined according to the length of current active period. The results evaluated by computer simulation show that the proposed method can improve the energy efficiency for the cluster-based WSNs with geographical non-uniform traffic distribution in addition to the improvement of the transmission performance.
Candidate bit based bit-flipping decoding algorithm for LDPC codes
Authors: Guiqiang Dong, Yanan Li, Ningde Xie, Tong Zhang, Huaping Liu
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

A novel hard-decision decoding algorithm for low-density parity-check (LDPC) codes is proposed in this paper. This algorithm employs the correlation information among the column vectors of the parity-check matrix and syndrome vector for decoding. It does not require soft information, and has low decoding complexity. Simulation results show that the proposed decoding algorithm could provide an effective tradeoff between error performance and decoding complexity.
Weight distributions of multi-edge type LDPC codes
Authors: Kenta Kasai, Tomoharu Awano, David Declercq, Charly Poulliat, Kohichi Sakaniwa
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

For a (λ(x), ρ(x)) standard irregular LDPC code ensemble, the growth rate of the average weight distribution for small relative weight ω is given by log(λ′(0)ρ′(1))ω + O(ω2) in the limit of code length n. If λ′(0)ρ′(1) < 1, there exist exponentially few code words of small linear weight, as n tends to infinity. It is known that the condition coincides with the stability condition of density evolution over the erasure channels with the erasure probability 1. In this paper, we show that this is also the case with multi-edge type LDPC (MET-LDPC) codes. MET-LDPC codes are generalized structured LDPC codes introduced by Richardson and Urbanke. The parameter corresponding λ&prime(0)ρ′(1) appearing in the conditions for MET-LDPC codes is given by the spectral radius of the matrix defined by extended degree distributions.
Virtual movements-based calibration method of ultrasound probe for computer assisted surgery
Authors: J. Chaoui, G. Dardenne, C. Hamitouche, E. Stindel, C. Roux
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Three-dimensional freehand ultrasound has found several clinical applications, such as in Computer Assisted Orthopaedic Surgery CAOS. Since the last decade, the US applications in CAOS allow the surgeon to objectively plan out critical surgical variables, and would result in improved surgical outcomes. A key step of all the freehand ultrasound imaging systems is calibration. This paper is devoted to present a novel concept for freehand ultrasound calibration method which is based on probe movement simulation in virtual environment. This method has significant advantages over all the prior approaches. Our experiments show that the novel method can be captured fairly accurately by a large number of data points generated by only one ultrasound image using the simulation concept. The added advantages are that it is so fast, easy to use, and does not need user intervention, so it is totally automatic.
An adaptive on-demand channel estimation for vehicular ad hoc networks
Authors: Yusun Chang, Myounghwan Lee, John A. Copeland
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Various vehicular communication technologies have been proposed to provide reliable and seamless wireless communications. Short-range vehicular communications can be established using IEEE 802.11p, and the range of these protocols can be extended using mobile multi-hop ad hoc networks. To provide consistent Quality of Service (QoS) with maximum achievable transmission rate, many algorithms assume that the Signal to Noise Ratio (SNR) of the receiver is known, or can be obtained by modifying protocols. In this paper, we present an efficient on-demand adaptive channel estimation technique. Using simple UDP messages without changing protocols, the estimator predicts the SNR with minimum signaling overheads. Extensive experiments in vehicular environments along the I-85 highway and residential areas in Atlanta, Georgia reinforce that the proposed algorithm is efficient and reliable channel estimation technique for next generation wireless mobile networks.
Evaluation of effect of data throughput evolution on mobile station performance
Authors: Yevgeni Koucheryavy, Sanjoy Dass
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

The next generation of wireless phones promises to change consumers services habits - video streaming, video conferencing, DVB-H etc. will be used practically anytime and anywhere in the world. However, it has been observed that the CPU load and the memory usage is increasing significantly with the increasing data rate and at some point the need for higher processing power and memory is quite evident to support higher data rate. This paper investigates the costs for implementation of higher data rate in mobile station in terms of processing power and memory usage.
A framework for mobile applications based on a structured P2P overlay
Authors: Mario Kolberg, Michael Wilson, Martin Blunn, Evan Magill, Peter Burtwistle
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

P2P applications are increasingly popular. Unlike traditional client-server applications they do not require central server resources. This makes them less costly to host and maintain. While there have been a large number of P2P applications developed for PC based systems, there are only very few for mobile appliances, such as mobile phones or networked PDAs. Furthermore, there are even fewer applications which operate successfully on the public mobile data network (GPRS, 3G), rather than WiFi. This is largely due to the difficulties posed by the restrictive data access to mobile devices (NATs, Firewalls by the network operators) and traditionally high charges for data communications. Recently, the latter point has been virtually removed by the introduction of flat-rate data packages by the operators. This paper (and demo) present a framework and applications based on a structured P2P overlay network which can successfully operate on the public data network.
Optimal quantization of random measurements in compressed sensing
Authors: John Z. Sun, Vivek K. Goyal
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Quantization is an important but often ignored consideration in discussions about compressed sensing. This paper studies the design of quantizers for random measurements of sparse signals that are optimal with respect to mean-squared error of the lasso reconstruction. We utilize recent results in high-resolution functional scalar quantization and homotopy continuation to approximate the optimal quantizer. Experimental results compare this quantizer to other practical designs and show a noticeable improvement in the operational distortion-rate performance.
BLINK: securing information to the last connection
Authors: Scott Craver, Yu Chen, Hao Chen, Jun Yu, Idris M. Atakli
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Robust cryptography provides confidentiality and integrity for information transferred between peers. However, the decrypted plaintext in the memory of a receivers' computer is vulnerable--both to surveillance at the endpoints, and users who choose to forward confidential information. In this paper, we proposed a novel scheme called BLINK, which uses a reconfigurable hardware based decoder which operates on the link between a computer and its display. It moves the decryption outside the computer, preventing plaintext stealing, forwarding, screen capture and printing. Currently we are implementing the BLINK scheme on top of Altera FPGA board with Digital Visual Interface (DVI) ports, the correctness, effectiveness, and the performance will be evaluated through experiment.
3D joint Markov-Gibbs model for segmenting the blood vessels from MRA
Authors: Ayman El-Baz, Georgy Gimel'farb, Vedant Kumar, Robert Falk, Mohamed Abo El-Ghar
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

New techniques for more accurate segmentation of a 3D cerebrovascular system from time-of-flight (TOF) magnetic resonance angiography (MRA) data are proposed. In this paper, we describe TOF-MRA images and desired maps of regions (blood vessels and the other brain tissues) by a joint Markov-Gibbs random field model (MGRF) of independent image signals and interdependent region labels but focus on most accurate model identification. To better specify region borders, each empirical distribution of signals is precisely approximated by a Linear Combination of Discrete Gaussians (LCDG) with positive and negative components. We modify a conventional Expectation-Maximization (EM) algorithm to deal with the LCDG and develop a sequential EM-based technique to get an initial LCDG-approximation for the modified EM algorithm. The initial segmentation based on the LCDG-models is then iteratively refined using a GMRF model with analytically estimated potentials. To validate the accuracy of our algorithm, a special 3D geometrical phantom motivated by statistical analysis of the MRA-TOF data is designed. Experiments with both the phantom and 50 real data sets confirm high accuracy of the proposed approach.
Design of low correlation zone sequence sets of period kN
Authors: Jin-Ho Chung, Kyeongcheol Yang
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

In this paper we present a method to construct low correlation zone (LCZ) sequence sets of period kN for some integers k and N which are relatively prime. We construct kN- periodic LCZ sequences by combining an N-periodic sequence having good autocorrelation with a k × k Hadamard matrix. We also give some examples of our construction, which are optimal or nearly optimal with respect to the Tang-Fan-Matsufuji bound. Our construction gives flexible parameters in the sense of period and LCZ size.
Secrecy capacity region of the Gaussian multi-receiver wiretap channel
Authors: Ersen Ekrem, Sennur Ulukus
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We consider the Gaussian multi-receiver wiretap channel and evaluate its secrecy capacity region. This evaluation requires the identification of underlying auxiliary random variables. For this purpose, we first visit the converse proof of the scalar Gaussian broadcast channel, and show that this proof cannot be extended to this secrecy context. The failure of this extension comes from the insufficiency of the entropy-power inequality to resolve the ambiguity regarding the auxiliary random variables. Instead, we provide two converse proofs. The first one uses the alternative representation of the mutual information as an integration of the minimum-mean-square-error (MMSE) along with the properties of the MMSE. The second one uses the relationship between the differential entropy and the Fisher information via the de Bruin identity along with the properties of the Fisher information.
Segmentation of anatomo-functional 3D post mortem data using a MRI-based 3D digital atlas: transgenic mouse brains study
Authors: J. Lebenberg, A.-S. Hérard, A. Dubois, M. Dhenain, P. Hantraye, V. Frouin, T. Delzescaux
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Many analyses in neurosciences are carried out on histological and autoradiographic datasets and performed by manually drawing regions of interest on these 2D post mortem data. Such task being time-consuming, we propose an automated segmentation strategy to analyze 3D post mortem brain images. This method is based on the co-registration of a MRIbased 3D digital atlas on 3D-reconstructed post mortem data. We first deformed the original MRI on post mortem volumes. We then applied deformation parameters to warp the digital atlas. The method was tested on APP/PS1 mouse models of Alzheimer's disease and PS1 control littermates. Its reliability was qualitatively evaluated and a quantitative assessment was performed by comparing atlas and manual segmentations. Our results show this approach is promising to investigate at organ scale post mortem mouse datasets faster and in a more robust manner than with classical methods.
A broadcasting method for suppressing hidden terminals effect on IEEE 802.11 DCF
Authors: Tetsuya Shigeyasu, Hiroshi Matsuno, Norihiko Morinaga
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

IEEE802.11DCF is widely used wireless LAN standard. But, packet delivery ratio of broadcast transmission is much lower than unicast transmission because the IEEE802.11DCF executes broadcast transmission without RTS/CTS exchange and ACK process. Hence, many protocols have been proposed to improve reliability of the broadcast transmission. Most of these protocols are proposed based on collision recovery policy using ACK signal or NACK signal instead of ACK frame. Then, transmission overhead is increased by retransmission under the condition that network contains some hidden terminals since ACK or NACK signal could not prevent transmission of hidden terminals. This paper proposes a new broadcast protocol based on collision prevention policy using modified RTS/CTS exchange, and clarifies that our proposed protocol achieved highly reliability with computer simulations
Time-division multiplexing for green broadcasting
Authors: Pulkit Grover, Anant Sahai
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The problem of minimizing the total (transmit and decoding) energy required for communicating over a two-receiver Gaussian broadcast channel is investigated. For achieving a specified rate-tuple, joint broadcast schemes (e.g, superposition coding) require smaller transmit energy per-bit than the conceptually simpler time-division multiplexing (TDM) based schemes. However, for short distance communication, the energy expended in the decoding can be comparable to that required in the transmission. Two technical advances are introduced to understand these energy costs: (a) an improvement on the best known outer bounds on the error exponents for the Gaussian broadcast problem, and (b) a finer analysis to have these bounds hold for neighborhood sizes instead of block-lengths. Using these results, it is then shown that in some typical short and moderate distance communication scenarios, time-division multiplexing saves on the decoding energy, thereby likely requiring smaller total energy than any joint broadcasting scheme for achieving the target rate and error probabilities. Further, we observe that TDM outperforms joint schemes by larger margins when the ratio of the distances of the receivers from the transmitter is closer to 1.
Concurrent measurements of the vehicular channel transfer function and the 802.11 received signal strength index
Authors: Haris Kremo, Ivan Šeškar, Predrag Spasojevic
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

This paper describes experiments which study the effects of both a stationary and a moving vehicle on the 22 MHz 802.11b and the 20 MHz 802.11a channel transfer functions. Our setup enables concurrent measurements of: (1) the complex channel transfer function with a Vector Network Analyzer (VNA), and (2) the Received Signal Strength Index (RSSI) obtained using off-the-shelf 802.11 cards. Our results show that, for the case of the stationary channel, the average RSSI is a several dBs away from the channel loss measured by the VNA, even with meticulous calibration of the 802.11 cards. The VNA measurements show that a vehicle moving in an environment resembling a multi-lane highway can cause a change in the magnitude of the transfer function on the order of tens of dB. The results of the RSSI measurements show that changes in RSSI caused by the passing vehicle are in the order of magnitude of the ones measured with the VNA.
Generalized results of transmission capacities for overlaid wireless networks
Authors: Changchuan Yin, Changhai Chen, Tie Liu, Shuguang Cui
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We study the transmission capacities of two coexisting wireless networks (a primary network vs. a secondary network) that operate in the same geographic region and share the same spectrum. The primary (PR) network has a higher priority to access the spectrum without particular considerations for the secondary (SR) network, where the SR network limits its interference to the PR network by carefully controlling its node density. Considering general power-law wireless channels with path-loss exponent α > 2 and small-scale Rayleigh fading, based on the stochastic geometry theory, we derive the transmission capacities for both of the two networks and quantify their tradeoff via asymptotic analysis. Our results show that if the PR network permits a small increase of its outage probability, the sum transmission capacity of the two networks (i.e., the overall spectrum efficiency per unit area) will be boosted significantly over that of a single network, which generalizes our previous result in [1] over a special case of deterministic power-law channel with α = 4.