ppxscal/embedding_network huggingface dataset:
Linear receiver based high-rate space-time block codes
Authors: Wei Zhang, Jinhong Yuan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Recently several STBC designs were proposed for MIMO systems with linear receivers. In this paper, we propose a new design of high-rate STBC with linear receivers. Compared to the overlapped Alamouti code (OAC) recently proposed by Shang and Xia, the new STBC has a higher symbol rate without guarantee of achieving full diversity. To achieve the same rate, the new STBC has only a half of the block length (code delay) of the OAC. Simulation results show that in comparison with some existing codes for a given rate the proposed STBC can give a better outage probability performance.
Automated segmentation of retinal layers in OCT imaging and derived ophthalmic measures
Authors: Florence Rossant, Itebeddine Ghorbel, Isabelle Bloch, Michel Paques, Sarah Tick
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

This paper proposes an automated method for the segmentation of eight retinal layers in high resolution OCT images. It has been evaluated based on comparison with manual segmentation performed by five different experts. The method has been successfully applied on a database of 72 images. Quantitative measures are then derived as an aid to ophthalmic diagnosis. A good agreement with measures derived from manual segmentation is obtained which allows us to use the proposed method for retinal variability studies.
Efficient balancing of q-ary sequences with parallel decoding
Authors: Theo G. Swart, Jos H. Weber
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Balancing of q-ary sequences, using a generalization of Knuth's efficient parallel balancing scheme, is considered. It is shown that the new general scheme is as simple as the original binary scheme, which lends itself to parallel decoding of the balanced sequences.
Index coded repetition-based MAC in vehicular ad-hoc networks
Authors: Behnam Hassanabadi, Le Zhang, Shahrokh Valaee
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

In this paper we propose a new class of repetition-based MAC protocols for Vehicular Ad-hoc Networks. The design can be used for safety applications and position information dissemination. An erasure broadcast channel is considered in which several vehicles are in a cluster and each vehicle attempts to send its own safety message to all other vehicles. A distributed feedback mechanism has been introduced to propagate the network transmission and reception information throughout the network. Based on the feedback information, a packet coding algorithm, inspired by index coding, is proposed to efficiently reduce the number of transmissions and contentions. Simulations show that the proposed protocol yields a greater average probability of successful transmission.
Performance and power consumption modeling for green COTS software router
Authors: Raffaele Bolla, Roberto Bruschi, Andrea Ranieri
Venue: Proceedings of the First international conference on COMmunication Systems And NETworks (2009)

We consider a new generation of COTS Software Routers (SRs), able to effectively exploit multi-Core/CPU HW platforms. Our main objective is to analyze, to evaluate and to model the impact of power saving mechanisms, generally included in today's COTS processors, on the SR behavior and networking performance. To this purpose, we tried to understand and to separately characterize the roles of both HW and SW layers through a large set of internal and external experimental measures, obtained with a heterogeneous set of HW platforms and SR setups. Moreover, starting from this detailed measure analysis, we propose a simple model, able to represent the SR performance with a high accuracy level in terms of packet throughput and related power consumption. The proposed model can be effectively applied inside "green optimization" mechanisms to minimize power consumption, while maintaining a certain SR performance target.
Direct splitting and merging of 2-D DCT in the DCT domain
Authors: Yuh-Jue Chuang, Ja-Ling Wu
Venue: Digital Signal Processing (2004)

An efficient method for splitting an 8x8 2-D DCT block into four 4x4, two 8x4 (or 4x8) 2-D DCT blocks is presented in this paper. The reverse direction (the ''merge'' case) also can be realized by inverse transposing the given matrix operations in the ''split'' case. The computational complexity of the proposed methods is lower than that of the direct approach and other known efficient converting approaches. Due to its efficiency, the proposed DCT splitter/merger will play an important role in realizing the transcoding between the latest video coding standard, AVC/H.264, and the older ones, such as MPEG-1, MPEG-2, and MPEG-4 part 2.
Existence and construction of capacity-achieving network codes for distributed storage
Authors: Yunnan Wu
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

In a distributed storage system based on erasure coding, when a storage node fails, repairing the erasure code incurs some network traffic. Previous work has characterized the fundamental tradeoff between storage efficiency and repair network bandwidth. This was done via a cut-based analysis on a graph that models the evolution of information flow in the storage system subject to arbitrary sequences of node failures/repairs. This paper presents techniques for constructing network codes that achieve the optimal tradeoff between storage efficiency and repair network bandwidth. The challenge here is that network coding is applied over an unbounded graph with an unbounded number of receivers. It is shown in this paper that optimal codes can be constructed over a finite field whose size depends only on the maximum number of nodes at any instant, but independent of how many failures/repairs can happen. Key to the code construction is a "path-weaving" procedure that leads to an inductive existence proof/code construction.
Noisy-interference sum-rate capacity of parallel Gaussian interference channels
Authors: Xiaohu Shang, Biao Chen, Gerhard Kramer, H. Vincent Poor
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The sum-rate capacity of the parallel Gaussian interference channel is studied. Sufficient conditions are derived in terms of channel coefficients and power constraints such that the sum-rate capacity can be achieved by: 1) independent transmission across sub-channels, and 2) treating interference as noise in each sub-channel. The optimal power allocation is characterized for such parallel channels.
On destructive superposition of shaping pulses in band-limited linear modulation systems
Authors: Makoto Tanahashi, Hideki Ochiai
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We analyze pulse-shaped transmit signals with correlated input sequences in the framework of band-limited liner modulations. These signals are formed by superposition (convolution) of the shaping pulses and may have different amplitude statistics depending on the correlation properties of the input sequences. Hence, even if the sequences have a unit average power in discrete-time domain, the resulting transmit signals exhibit smaller (or larger) average power if there are many destructive (or constructive) superpositions produced by the correlated source. Since such a reduction of average transmit power does not change the amplitude of the underlying discrete-time sequence, one may expect the so-called shaping gain. We comprehensively analyze the shaping gain achieved by the correlation of the input sequences, and show that the use of a pulse shape, which convolves the sequence destructively, is capable of increasing the achievable information rate of the system.
Optoacoustic systems for functional and molecular imaging in clinical and preclinical research
Authors: Alexander A. Oraevsky
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Optoacoustic imaging systems provide a unique opportunity to visualize, with high spatial resolution, the distribution of optical energy in opaque biological tissues and even to visualize the distribution of optically absorbing molecules in tissues. Since hemoglobin of blood is the main tissue chromophore that dominates optical absorption in the nearinfrared spectral range, the optoacoustic imaging is well suitable for visualization of blood distributions associated with various diseases, such as cancer and atherosclerosis. Design of optoacoustic systems for two-dimensional and three-dimensional imaging and their applications in clinical and preclinical oncology will be presented.
Service platform and social networking service based on peer-to-peer networking
Authors: Il-Woo Lee, Ho-Jin Park, Kwang-Roh Park
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

We designed and developed a virtual home platform based on peer-to-peer (P2P) based networking service. Also, we designed a P2P based social networking service method and apparatus capable of appropriately providing a social networking service under P2P environments. This paper proposed a method for easily providing a social networking service, which will be used as an Application Programming Interface (API) on the basis of a universal P2P platform irrelevant to application characteristics.
On financial transmission rights and market power
Authors: Geoffrey Pritchard, Andy Philpott
Venue: Decision Support Systems (2005)

This paper studies financial transmission rights in electricity pool markets with nodal pricing, when these rights are to be allocated by an auction mechanism. A market distribution function approach is used to investigate the effects on electricity offering behaviour when participants hold financial transmission rights, and the implications of this for the auction design are discussed.
Telescoping rounding for suboptimal finite wordlength FIR digital filter design
Authors: Dušan M. Kodek, Marjan Krisper
Venue: Digital Signal Processing (2005)

Rounding of the so-called infinite precision coefficients to their nearest finite wordlength representation is often used for reasons of simplicity. This rounding, however, is typically far from optimal. A significantly better rounding method that uses a technique called telescoping is presented in this paper. Its practical effectiveness in the design of suboptimal finite wordlength filters is demonstrated. It can also be used to speed up the algorithms for optimal finite wordlength FIR filter design.
Error exponent of exclusive-or multiple-access channels
Authors: Jinho Kim, Wayne E. Stark
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We investigate the error exponent of exclusive-or multiple-access channels (XMAC) where the receiver wants to reconstruct the exclusive-or of incoming messages from two transmitters. We consider both the multiple access channel (MAC) strategy and the network coding (NC) strategy. In our analysis, the cutoff rate is used as a performance measure. Assuming a Gaussian XMAC and binary phase-shift keying (BPSK) modulation at each node, we show that the MAC strategy performs better than the NC strategy in the low rate region while the NC strategy performs better in the high rate region.
An intrusion detection system in ad hoc networks: a social network analysis approach
Authors: Wei Wang, Hong Man, Yu Liu
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

We introduce a social network analysis method as a new approach to build an Intrusion Detection System (SNIDS) in ad hoc networks. The SN-IDS utilizes social relations as metrics-of-interest for anomaly detections, which is different from most traditional IDS approaches. To construct proper social networks, we first investigate ad hoc MAC and network layer data attributes and select relevant social feature sets; then we build up a set of socio-matrices based on these features. Social analysis methods are applied to these matrices to detect suspicious behaviors of mobile nodes. NS-2 simulation results show that this SN-IDS system can effectively detect common attacks with high detection rates and low false positive alarm rates. Furthermore, it has clear advantages over the conventional association rule based data mining IDS in terms of computation and system complexity.
Matching intermediaries for information goods in the presence of direct search: an examination of switching costs and obsolescence of information
Authors: Manish Agrawal, Govind Hariharan, Rajiv Kishore, H. R. Rao
Venue: Decision Support Systems (2005)

This paper investigates patterns of revenues earned by an intermediary that matches buyers and sellers in the presence of direct search markets. We develop a theoretical structure and a computer simulation model of such a marketplace where vendors are horizontally differentiated, and an intermediary matches clients to the optimal vendor for a fee. The model is applicable to information services such as application service providers (ASPs). The contribution of this paper is the identification of scenarios under which intermediaries that match clients and vendors are likely to be profitable considering switching costs and obsolescence of information.
Towards a tree-based taxonomy of anonymous networks
Authors: Douglas Kelly, Richard Raines, Rusty Baldwin, Barry Mullins, Michael Grimaila
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

In the boundless digital world and global society of the Internet, anonymity and privacy are becoming increasingly important issues. Many anonymous networking protocols have been proposed and numerous empirical investigations over these networks analyzed; however, no known taxonomies exist for consumers to quickly and easily identify which anonymity properties are offered by the disparate wired and wireless anonymous networks. This paper proposes a novel tree-based taxonomy (TBT) which allows the consumer to choose a desired classical or state-of-the-art anonymity protocol depending upon their specific network environment and anonymity requirements. The two key anonymity properties of unidentifiability and unlinkability and various network types are explored. This paper highlights the expanding definition of anonymity and aids consumer and researcher classification of state-of-the-art technological privacy-preserving anonymous networks.
In vivo comparison of real-time tracking algorithms for interventional flexible endoscopy
Authors: N. Masson, Fl. Nageotte, Ph. Zanne, M. De Mathelin
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Flexible endoscopes are used in many diagnostic and interventional procedures. Physiological motions may render the physicians task very difficult to perform. Assistance could be achieved by using motorized endoscopes and real-time visual tracking algorithm to automatically follow a selected target. In order to control the motors, one needs to have an accurate estimation of the motion of the target in the endoscopic view, which requires an efficient tracking algorithm. In this paper, we compare existing tracking algorithms on various in vivo targets in order to assess their behavior under different conditions. The study shows that several issues have to be overcome by tracking algorithms in in vivo environment like illumination change and forward/backward motions of the target.
Achievability results for statistical learning under communication constraints
Authors: Maxim Raginsky
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

The problem of statistical learning is to construct an accurate predictor of a random variable as a function of a correlated random variable on the basis of an i.i.d, training sample from their joint distribution. Allowable predictors are constrained to lie in some specified class, and the goal is to approach asymptotically the performance of the best predictor in the class. We consider two settings in which the learning agent only has access to rate-limited descriptions of the training data, and present information-theoretic bounds on the predictor performance achievable in the presence of these communication constraints. Our proofs do not assume any separation structure between compression and learning and rely on a new class of operational criteria specifically tailored to joint design of encoders and learning algorithms in rate-constrained settings.
Opportunistic scheduling in large-scale wireless networks
Authors: Mehdi Ansari Sadrabadi, Alireza Bayesteh, Eytan Modiano
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

In this paper, we consider a distributed one-hop wireless network with n pairs of transmitters and receivers. It is assumed that each transmitter/receiver node is only connected to k receiver/transmitter nodes which are defined as neighboring nodes. The channel between the neighboring nodes is assumed to be Rayleigh fading. The objective is to find the maximum achievable sum-rate of the network in the asymptotic case of n, k → ∞. It is shown that the asymptotic throughput of the system scales as nlogk/k. An opportunistic on-off scheduling is proposed and shown to be asymptotically throughput optimal.
Coset codes for compound multiple access channels with common information
Authors: Hideki Yagi, H. Vincent Poor
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

This paper considers code construction for arbitrary discrete memoryless compound multiple access channels (MACs) with common information. This class of channels includes a MAC with/without common messages or with partially cooperating encoders. A construction method of code ensembles based on coset codes is proposed for these channels. Assuming joint maximum likelihood decoding, the performance of the proposed code ensemble is analyzed by deriving error exponents. A condition is shown such that codes achieve the capacity region on average. The result obtained here reduces to the result of Slepian and Wolf or other conventional works if restricted to a single MAC. A combination of good linear codes gives capacity achieving codes for compound MACs with common messages or with partially cooperating encoders.
Structured superposition for backhaul constrained cellular uplink
Authors: Bobak Nazer, Amichai Sanderovich, Michael Gastpar, Shlomo Shamai
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

In this paper, we demonstrate the advantage of the inherent algebraic structure of lattice codes, for the uplink channel of a cellular deployment. The out-of-cell interference is assumed to be symmetric, as in Wyner's model. We employ a new relaying technique, compute-and-forward, which allows cell-sites to decode equations of the transmitted bits by exploiting the channel interference. However, the standard compute-and-forward technique is penalized whenever the channel coefficients are non-integer. We develop a superposition strategy to mitigate this penalty. By using part of the power towards a private message, we can effectively modify the channel seen by compute-and-forward. We demonstrate that, in certain regimes, this mixed strategy significantly outperforms decode-and-forward, compress-and-forward, and ordinary compute-and-forward.
Ideal structure of the silver code
Authors: Avik Ray, K. Vinodh, G. Rekaya-Ben Othman, P. V. Kuma
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The Silver code has captured a lot of attention in the recent past, because of its nice structure and fast decodability. In their recent paper, Hollanti et al. show that the Silver code forms a subset of the natural order of a particular cyclic division algebra (CDA). In this paper, the algebraic structure of this subset is characterized. It is shown that the Silver code is not an ideal in the natural order but a right ideal generated by two elements in a particular order of this CDA. The exact minimum determinant of the normalized Silver code is computed using the ideal structure of the code. The construction of Silver code is then extended to CDAs over other number fields.
Tissue level segmentation and tracking of biological structures in microscopic images based on density maps
Authors: K. Mosaliganti, A. Gelas, A. Gouaillard, S. Megason
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

During embryogenesis, cells coordinate to form geometric arrangements. These arrangements are initially noticed as stereotypic clumps of cells that further divide to form a rigorous structure with a high density of cells. In this work, we explore density-based segmentation and tracking of cellular structures as observed in microscopy images. Using a new modified form of the Mumford-Shah energy functional, we derived a variational level-set for density-based segmentation. The novelty of the work lies in evolving an initialized contour that represents a salient structure on density maps to automatically generate novel cell structures upon convergence. We validate our methods and show results on confocal ear images of the zebrafish embryo.
On extended Fomey-Kovalev GMD decoding
Authors: Vladimir R. Sidorenko, Anas Chaaban, Christian Senger, Martin Bossert
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

Consider a code C with Hamming distance d. Assume we have a decoder Φ that corrects Ɛ errors and θ erasures if λƐ + θ ≤ d - 1, where a real number 1 < λ ≤ 2 is the tradeoff rate between errors and erasures for this decoder. This holds e.g, for l-punctured Reed-Solomon codes, i.e., codes over the field Fql of length n < q with locators taken from the subfield Fq where l ơ {1, 2, ...} and λ = 1+1/l. We propose an m-trial generalized minimum distance (GMD) decoder based on Φ. Our approach extends results of Forney and Kovalev (obtained for λ = 2) to the whole given range of λ. We consider both fixed erasing and adaptive erasing GMD strategies. For l > 1 the following approximations hold. For the fixed erasing strategy the error correcting radius is ρF ≈ d/2 (1-l-m/2). For the adaptive erasing strategy, ρA ≈ d/2 (1-l-2m) quickly approaches d/2 if l or m grows. The minimum number of decoding trials required to reach an error correcting radius d/2 is mA=1/2 (logld+1). This means that 2 or 3 trials are sufficient to reach ρA = d/2 in many practical cases if l > 1.
Mismatched estimation and relative entropy
Authors: Sergio Verdú
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

A random variable with distribution P is observed in Gaussian noise and is estimated by a minimum meansquare estimator that assumes that the distribution is Q. This paper shows that the integral over all signal-to-noise ratios of the excess mean-square estimation error incurred by the mismatched estimator is twice the relative entropy D(P∥Q). This representation of relative entropy can be generalized to non real-valued random variables, and can be particularized to give a new general representation of mutual information in terms of conditional means. Inspired by the new representation, we also propose a definition of free relative entropy which fills a gap in, and is consistent with, the literature on free probability.