ppxscal/embedding_network huggingface dataset:
Systematic constructions of zero-correlation zone sequences
Authors: Ching-Wei Chen, Yen-Cheng Liu, Yu T. Su
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Sequences with desired autocorrelation (AC) and cross-correlation (CC) properties are often needed in many communication and radar system applications. In a multipath fading channel with a known delay spread bound, one needs a family of sequences that meets these desired correlation requirements only for those correlation lags that lie within a window called zero-correlation zone. This paper presents two classes of new systematic approaches-a transform domain method and a direct (time domain) synthesis method-for generating zero-correlation zone (ZCZ) sequences. The former approach generates sequence families that achieve the upper bounds on the family size and the zero-correlation zone width for a given sequence period. The latter unifies many existing construction methods and both provide more flexibilities in producing new families of sequences. We also suggest a modulation operation that is capable of transforming nonconstant modulus sequences into polyphase sequences.
Properties of Savitzky--Golay digital differentiators
Authors: Jianwen Luo, Kui Ying, Ping He, Jing Bai
Venue: Digital Signal Processing (2005)

The Savitzky-Golay (SG) filters are generally used for smoothing and differentiation in many fields. The properties of the SG smoothing filters have been well studied. However, the properties of the SG differentiation filters or SG digital differentiators (SGDD, for the first order differentiation) are not developed well somehow, although they have been widely used. In the paper, the properties of the SGDD are discussed in detail. The effects of the SGDD on a noise-free single Gaussian line and a noise-free Gaussian doublet are studied via simulation. The results indicate that the contrast and resolution loss of the SGDD depends on the ratio of the width of signal derivative and filter length. The linear SGDD is not preferable for preserving small details of signal derivative from this study. The cubic and quintic SGDD with the choice of appropriate filter length are recommended in order to maintain the resolution of signal derivative.
Remote AppBus: enabling seamless access to short term memory on mobile devices
Authors: N. Narasimhan, C. Janssen, M. Pearce
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Richer communication, computational and content-handling capabilities on mobile devices are driving the adoption of more interactive and collaborative applications. These motivate a need for data-sharing paradigms that are flexible, efficient and lightweight - but also accessible across the different applications that may be involved in an ongoing user task. Our AppBus framework provides a unique "short term memory" facility for mobile devices, facilitating such data-sharing across co-resident applications. With the Remote AppBus extension, we make this facility accessible in a consistent manner across address spaces on a device, and potentially across devices. In this paper, we describe the design and implementation of Remote AppBus, and discuss its utility in enabling task collaboration on device, and in facilitating task continuity across devices. We conclude with a look at related efforts, challenges and future directions for the research.
On the totally asynchronous interference channel with single-user receivers
Authors: Eduard Calvo, Javier R. Fonollosa, Josep Vidal
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The performance characterization of decentralized wireless networks with uncoordinated sender-destination pairs motivates the study of the totally asynchronous interference channel with single-user receivers. Since this channel is not information stable, its capacity region is determined resorting to information density, although more amenable single-letter inner and outer bounds are provided as well. Aiming at numerical evaluation of the achievable rates, we subsequently concentrate on the inner bound for the Gaussian case. We show that taking Gaussian inputs is not the best choice in general and derive analytical conditions under which other input distributions may be optimal. Essentially, these conditions require the channel to be interference-limited. Finally, the existence of such non-Gaussian distributions with superior performance is validated numerically in different scenarios.
New sequence families with zero or low correlation zone via interleaving techniques
Authors: Honggang Hu, Guang Gong
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Sequence families with zero or low correlation zone can be used in the quasi-synchronous code-division multiple-access (QS-CDMA) communication systems. Interleaving techniques are very useful for sequence design. In this paper, we present a general construction of sequence families with zero or low correlation zone using interleaving techniques and complex Hadamard matrices. The component sequences are perfect or ideal two-level. In two cases, we construct the shift sequences: 1) P|L; 2) P is even, and L ≡ P/2 (mod P). The conditions are derived under which the new construction is optimal. Some examples are also given to specify the new construction.
A framework for organizing the space of decision problems with application to solving subjective, context-dependent problems
Authors: Yoram Reich, Adi Kapeliuk
Venue: Decision Support Systems (2005)

Developing Decision Support Systems (DSS) is a difficult task, prone to errors and susceptible to colossal failures. In order to alleviate this difficulty and its consequences, we propose a framework for organizing the space of decision problems based on problem characteristics. This organization classifies decision problems into classes that exhibit intra-class similarity. We show how classifying a new decision problem into one of the existing classes provides assistance in designing the DSS for the new problem. The classification could be based simply on problem characteristics or on the structure of the problem-solution relationships. We further show that a DSS whose goal is to support the development of DSS can be developed with the assistance of related DSS. The framework we propose could best serve researchers and practitioners if the reporting of DSS projects would follow the structure presented in this paper. In this way, additional data would be accumulated and would be available for refining the classification of the space of DSS. This in turn, would improve the support for building new DSS.
Bounds and capacity results for the cognitive Z-interference channel
Authors: Nan Liu, Ivana Maric, Andrea J. Goldsmith, Shlomo Shamai
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We study the discrete memoryless Z-interference channel (ZIC) where the transmitter of the pair that suffers from interference is cognitive. We first provide upper and lower bounds on the capacity of this channel. We then show that, when the channel of the transmitter-receiver pair that does not face interference is noiseless, the two bounds coincide and therefore define the capacity region. The obtained results imply that, unlike in the Gaussian cognitive ZIC, in the considered channel superposition encoding at the non-cognitive transmitter as well as Gel'fand-Pinsker encoding at the cognitive transmitter are needed in order to minimize the impact of interference. As a byproduct of the obtained capacity region, we obtain the capacity result for a generalized Gel'fand-Pinsker problem.
On the interplay between Shannon's information measures and reliability criteria
Authors: Siu-Wai Ho
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

In the literature, different reliability criteria are used in different coding theorems. Weak secrecy and strong secrecy are frequently used in information-theoretic security problems and their implications in terms of the average symbol error probability and block error probability of the adversary are studied in this paper. In particular, strong secrecy always ensures that the adversary has maximum error probability but it is too difficult to be satisfied for a serial source. Weak secrecy can ensure the maximum error probability if the source is stationary and memoryless. In the second part of this paper, the relation among different reliability criteria for source or channel coding are shown. With this result, the channel coding theorem for discrete memoryless channel is generalized with a strong reliability criterion for the direct part and a weak reliability criterion for the converse part.
Analyzing human centric data for sharing mobile internet with social buddies
Authors: Siva Gurumurthy, Aura Ganz
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

We propose a middleware called BuddyShare to automatically form an overlay group of nearby friends' mobile phones to collaboratively download data by sharing mobile internet. This system is hypothetical in nature and only work on certain assumptions such as: 1) frequent availability of friends' phone nearby, 2) Sufficient social trust among physically close users to share internet and 3) sufficient social networking information available in phones. In order to validate these hypotheses, we collected human centric dataset of cellular phone users of university environment to study the user behavior. In this paper, we present certain social and proximity behaviors of these users that validate these hypotheses and show the practical feasibility of a BuddyShare system. We also study the usefulness of BuddyShare by virtually leveraging it on this user network, which concludes around three times scaling in download rate on average.
Opt-in detection based on call detail records
Authors: Huiqi Zhang, Ram Dantu
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Opt-in phone calls or emails refer to promotional phone calls or emails that have been requested by the people receiving them. In this paper we propose a model based on dynamic sliding windows to detect opt-in phone calls based on mobile phone call detail records. This work is useful for detecting unwanted calls (e.g., spam) and commercial purposes. For validation of our results, we used actual call logs of 100 users collected at MIT by the Reality Mining Project group for a period of 8 months. The experimental results show that our model achieves good performance with 91% accuracy.
Message passing in distributed wireless networks
Authors: Vaneet Aggarwal, Youjian Liu, Ashutosh Sabharwal
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

In distributed wireless networks, nodes often do not know the topology (network size, connectivity and the channel gains) of the network. Thus, they cannot compute their own maximum transmission rate and appropriate transmission scheme. In this paper, we address the inter-related problems of learning the network and the associated best achievable rates. To make progress, we will focus on K-user deterministic interference networks. First, we propose a message passing algorithm which allows nodes to incrementally learn the network topology. In each round of message passing, nodes forward what they believe is the new information to their neighbors and thus the network topology information trickles via broadcasts. Next, we consider two special examples of Z-channel and double-Z interference network and determine the sum-rate points with incomplete network information at different nodes. We show that the sum-rate point can in fact be achieved with less than full information at all the nodes but in general, less network information implies reduced set of achievable rates. In order to analyze the performance of a double-Z interference network with limited information, we find the capacity region of a deterministic double-Z interference network with full information, which is of independent interest.
A combined surface and volumetric approach for registration of patient specific models into left atrial cardiac ablation procedures
Authors: M. E. Rettmann, D. R. Holmes, C. Dalegrave, C. Stanton, S. B. Johnson, D. L. Packer, R. A. Robb
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Accurate visualization and targeting of specific anatomic locations are key components for successful treatment in catheter based cardiac ablation therapy. In order to augment visualization tools such as bi-plane fluoroscopy and real-time ultrasound, recent work has focussed on registering detailed, patient-specific models into the procedure. Surface based techniques are a popular approach, however, challenges include sensitivity to both the number and as well as locations of selected surface points, thereby making registration accuracy dependent on operator experience as well as patient anatomy. In this work, we propose a new technique for registering preoperative models into patient space by combining a surface based method with a volumetric based approach. The volumetric approach utilizes points from the continuously tracked catheter which is sampled at a rate of five times per second. The technique is tested using data from a canine experiment with five ground truth fiducial markers. The combined registration technique has smaller mean errors for all fiducial markers as compared to using a surface based technique alone. The combined surface and volumetric approach is also more robust to surface point selection, thereby decreasing the sensitivity of point selection on the registration result.
Performance evaluation of opportunistic round robin scheduling for V -BLAST users over MIMO channels
Authors: Samir AI-Ghadhban
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

In this paper, we compare and evaluate several opportunistic round robin (ORR) scheduling for V-BLAST users over uplink MIMO channels. Each user spatially multiplexes his data over multiple transmit antennas. This spatial multiplexing scheme provides high data rates while multi-user diversity obtained from scheduling improves the performance of the uplink system. The opportunistic round robin scheduler Is totally fair and it allows all users to access the channel. In the same time it captures part of the available multiuser diversity. The main results of this study show the performance gains of using ORR compared to RR scheduling. In addition, we compare the performance to the greedy and proportional fair algorithms in term of BER and supported capacity at different number of users.
Towards a test cases generation method for security policies
Authors: Ryma Abbassi, Sihem Guemara EL Fatmi
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Security Policy specification and testing constitute two fundamental challenges in the development of secure communication systems since they can ensure that a security policy is correctly enforced. Model checking techniques can be used to do such task. Given a system modeling and a test criterion, the model checker can generate a counterexample from which test cases can be deduced. To address the previous challenges, we propose in this paper, a framework to specify a security policy and to test its implementation. This framework is characterized as follows: (1) the security policy enforcement is specified through a new modeling language, S-Promela, (2) the test criteria are expressed by the use of a temporal logic LTL and (3) the test cases are generated by a classical model checking technique.
Packing and covering properties of subspace codes
Authors: Maximilien Gadouleau, Zhiyuan Yan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

Codes in the projective space over a finite field, referred to as subspace codes, and in particular codes in the Grassmannians, referred to as constant-dimension codes (CDCs), have been proposed for error control in random network coding. In this paper, we study the packing and covering properties of subspace codes, which can be used with the subspace metric or the injection metric. We first determine some fundamental geometric properties of the projective space. Using these results, we derive bounds on the cardinalities of packing and covering subspace codes, and determine the asymptotic rate of optimal packing and optimal covering subspace codes for both metrics. We thus show that optimal packing CDCs are asymptotically optimal packing subspace codes for both metrics. However, optimal covering CDCs can be used to construct asymptotically optimal covering subspace codes only for the injection metric.
Combinatorial data reduction algorithm and its applications to biometric verification
Authors: Vladimir B. Balakirsky, Anahit R. Ghazaryan, A. J. Han Vinck
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We present a combinatorial algorithm for transformation of long input binary strings to short codewords called the passwords. Having received the password and another long binary string, the decoder has to decide whether it can be considered as a corrupted version of the input string or not. In the presented examples, the length of strings is 10 Kbytes, the code rate has the order of magnitude 10-4, the decision about the closeness of strings has to be made if the Hamming distance is less than 4096, and the decoding error probabilities that can be attained by the algorithm have the order of magnitude 2-17. The algorithm is derived on the basis of random coding arguments and the proposed probabilistic data reduction scheme, which show that an efficient authentication can be organized with the use of passwords having much smaller length than the length of the original data.
Achievable rates and capacity for Gaussian relay channels with correlated noises
Authors: Jinhua Jiang, Andrea Goldsmith, Shuguang Cui
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

We investigate the Gaussian relay channel where the additive noises at the relay and destination are correlated. We obtain achievable rates for the compress-and-forward and decode-and-forward relaying strategies, and compare them to each other and to the capacity upper bound. We show that neither scheme is uniformly best over all channel gains and correlation coefficients. We also derive specific relationships between the channel gains and noise correlations for which one of these schemes is capacity-achieving, thereby increasing the class of relay channels for which capacity is known.
StemCerts-2: pairs of X.509 v3 certificates for greater security, flexibility and convenience
Authors: Giovanni Chiola, Paolo Gasti
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

We introduce the notion of StemCerts, a digital certificate scheme that allows the user to modify some fields of a digital certificate while keeping it valid. The owner can modify a StemCert in a limited and controlled fashion without interacting with the Certification Authority which issued it. By modifying her identity, the user can achieve "pseudonymous anonymity" - but the CA can still associate a certificate to its owner - and/or handle temporary or permanent address changes. Modifying the expiry date allows the user to transform her certificate into a set of "one time" certificates, thus alleviating the need for revocation lists. We developed two proof-of-concept implementations for this new scheme. The first one was based on Chameleon Hash functions, while the second one was based on the use of two chained, standard X.509 v3 certificates. We also present experimental data collected from the prototype implementations that show how the second prototype can easily be adopted in real environments, possibly exploiting smartcard technology.
Design of multi-edge type bilayer-expurgated LDPC codes
Authors: Marwan H. Azmi, Jinhong Yuan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

This paper presents a new bilayer-expurgated LDPC (BE-LDPC) code design for decode-and-forward relay system. The code design is based on the multi-edge type LOPC (MET-LDPC) code structure. The lower and upper graphs edges of the BE-LDPC codes are represented via different edge types. We call the codes as multi-edge type bilayer-expurgated LDPC (MET-BE-LDPC) codes. We derive the relationship between the lower and the overall graphs of the MET-BE-LDPC codes using the multi-edge type multinomials. This relationship acts as a constraint in optimizing the MET-BE-LDPC codes under the density evolution. We apply the differential evolution algorithm to search for the best MET-BE-LDPC codes. Applying the proposed methodology, two MET-BE-LDPC codes are designed. The codes perform asymptotically within 0.08474-0.5087 dB from the theoretical limits. Finally, we demonstrate that the proposed methodology can be used to design the BE-LDPC codes at a larger source-to-relay and source-to-destination SNR differences.
Design of network codes for multiple-user multiple-relay wireless networks
Authors: Ming Xiao, Mikael Skoglund
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We investigate the design of network codes for multiple-user multiple-relay (MUMR) wireless networks. In the networks, multiple (M ≥ 2) users have independent information to be transmitted to a common base station (BS), with the help of N (N ≥ 2) relays. The networks consist of independent quasistatic fading channels. We investigate such networks in terms of outage probabilities (to measure asymptotic performance), and propose network codes with linearly independent global encoding kernels for all possible source-relay channel situations (outage or not) to achieve asymptotic optimality. We compare the performance of proposed finite -field network coding (FFNC) and superposition coding (real-domain network coding) in the relays. The results show that proposed FFNC has better performance than superposition coding in high rate regions.
ODF reconstruction in Q-ball imaging with solid angle consideration
Authors: Iman Aganj, Christophe Lenglet, Guillermo Sapiro
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Q-ball imaging (QBI) is a high angular resolution diffusion imaging (HARDI) technique which has been proven very successful in resolving multiple intravoxel fiber orientations in MR images. The standard computation of the orientation distribution function (ODF, the probability of diffusion in a given direction) from q-ball uses linear radial projection, neglecting the change in the volume element along the ray, thereby resulting in distributions different from the true ODFs. For instance, they are not normalized or as sharp as expected, and generally require post-processing, such as sharpening or spherical deconvolution. In this paper, we consider the mathematically correct definition of the ODF and derive a closed-form expression for it in QBI. The derived ODF is dimensionless and normalized, and can be efficiently computed from q-ball acquisition protocols. We describe our proposed method and demonstrate its significantly improved performance on artificial data and real HARDI volumes.