ppxscal/embedding_network huggingface dataset:
The zeta function of a periodic-finite-type shift
Authors: Akiko Manada, Navin Kashyap
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

The class of periodic-finite-type shifts (PFT's) is a class of sofic shifts that strictly includes the class of shifts of finite type (SFT's), and the zeta function of a PFT is a generating function for the number of periodic sequences in the shift. In this paper, we derive a useful formula for the zeta function of a PFT. This formula allows the zeta function of a PFT to be computed more efficiently than the specialization of a formula known for a generic sofic shift.
Spectral analysis of nonuniformly spaced data using least square method
Authors: Jinhwan Koh, Tapan K. Sarkar
Venue: Digital Signal Processing (2005)

The current study investigates an unevenly spaced spectrum using a least square method. The well known Lomb periodogram approach has many benefits, yet it cannot resolve positive and negative frequencies. Using a modified scheme, positive and negative frequencies were discerned without losing any of the benefits of a Lomb periodogram. One of the properties of the periodogram approach is the relationship between the coefficients, i.e., the Hilbert transformation pair. By utilizing this property, the processing time was reduced by half.
A uniform way of reasoning about array-based computation in radar: Algebraically connecting the hardware/software boundary
Authors: Lenore R. Mullin
Venue: Digital Signal Processing (2005)

Embedded software processing requirements will exceed 1 trillion operations per second in the 2005-2010 time frame. Consequently, efficient use of processors and memory, at all levels, is essential. In many defense environments, e.g., radar, as well as medical and other real-time embedded systems, operations are primarily array-based. Although languages support high level, monolithic, array based computation through classes, functions, templates (C++), and grammars (Fortran 95, ZPL), limited optimizations occur to eliminate array valued temporaries, which for embedded real time systems, is enormous. Without an underlying theory of arrays, e.g., an algebra and index calculus, it is difficult, if not impossible to provide such optimizations. This paper presents a Mathematics of Arrays and Psi Calculus. Together they are used to reason about array based computation in radar; the algorithm, decomposition, mapping to processors and memory, performance.
Capacity achieving codes from randomness conductors
Authors: Mahdi Cheraghchi
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We give a general framework for construction of small ensembles of capacity achieving linear codes for a wide range of (not necessarily memoryless) discrete symmetric channels, and in particular, the binary erasure and symmetric channels. The main tool used in our constructions is the notion of randomness extractors and lossless condensers that are regarded as central tools in theoretical computer science. Same as random codes, the resulting ensembles preserve their capacity achieving properties under any change of basis. Our methods can potentially lead to polynomial-sized ensembles; however, using known explicit constructions of randomness conductors we obtain specific ensembles whose size is as small as quasipolynomial in the block length. By applying our construction to Justesen's concatenation scheme (Justesen, 1972) we obtain explicit capacity achieving codes for BEC (resp., BSC) with almost linear time encoding and almost linear time (resp., quadratic time) decoding and exponentially small error probability. The explicit code for BEC is defined and capacity achieving for every block length.
Advancing biological imaging with multi-spectral optoacoustic tomography (MSOT)
Authors: V. Ntziachristos
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Multi-spectral optoacoustic tomography (MSOT) is an imaging method that can resolve fluroch-romes and other reporter molecules with high sensitivity and specificity deep inside live animals and tissues. The method can penetrate for several millimeters to centimeters in tissues and offers resolutions in the 30-100 micron range. We discuss advance with technical implementation and in-vivo imaging applications ranging from mesoscopic imaging of drosophila and adult zebrafish to imaging various cellular functions in mice. MSOT comes with significant potential to shift the paradigm of biological imaging and become a method of choice in basic and drug discovery and in several clinical applications.
A collector overlay architecture for fault diagnosis in access networks
Authors: Mukundan Venkataraman, Shamik Sengupta, Mainak Chatterjee, Raja Neogi
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

To prevent subscriber churn, network service providers of VoD, SDV and IPTV have a pressing need to pro-actively detect, isolate and fix outages within an access network. Network induced degradations prove to be detrimental for streaming applications. This typically leads to a poor quality of experience (QoE) for subscribers. By monitoring key functional points of the access network for traces of degradation, service providers can devise mechanisms to mitigate the problem. In this work we propose a hierarchy of exporters, collectors and ANCON (ANalysis and CONtrol) nodes that can semiautonomously monitor, detect and isolate impairments within an access network. Exporters on the data plane gather and disseminate statistics for individual subnets, which are streamed onto "collector" nodes on an orthogonal plane. Collector nodes aggregate traffic from various exporters, and stream them onto the root of the tree (ANCON). With an even placement of exporters, root cause analysis can now take the granularity of loss rates or delay rates in individual segments or subnets of an access network. As an extension to our architecture, we show that the overlay can support instrumentations of quality evaluation for streaming video. As an example, we use a simple MOS model that is in part an extension of the ITU-T Erlang model to predict the quality of a video stream much before it reaches the end user. Extensive simulations are presented to justify the design choices made in the process.
Generalized concatenation for quantum codes
Authors: Markus Grassl, Peter W. Shorz, Bei Zeng
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

We show how good quantum error-correcting codes can be constructed using generalized concatenation. The inner codes are quantum codes, the outer codes can be linear or nonlinear classical codes. Many new good codes are found, including both stabilizer codes as well as so-called nonadditive codes.
Binary causal-adversary channels
Authors: M. Langberg, S. Jaggi, B. K. Dey
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

In this work we consider the communication of information in the presence of a causal adversarial jammer. In the setting under study, a sender wishes to communicate a message to a receiver by transmitting a codeword x = (x1, . . . , xn) bit-by-bit over a communication channel. The adversarial jammer can view the transmitted bits xi one at a time, and can change up to a p-fraction of them. However, the decisions of the jammer must be made in an online or causal manner. Namely, for each bit xi the jammer's decision on whether to corrupt it or not (and on how to change it) must depend only on xj for j ≤ i. This is in contrast to the "classical" adversarial jammer which may base its decisions on its complete knowledge of x. We present a non-trivial upper bound on the amount of information that can be communicated. We show that the achievable rate can be asymptotically no greater than min{1 - H(p), (1 - 4p)+}. Here H(.) is the binary entropy function, and (1 - 4p)+ equals 1 - 4p for p ≤ 0.25, and 0 otherwise.
On the design of medium access control for multi-Gbps wireless networks in 60-GHz bands
Authors: Chun-Ting Chou
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

New applications such as high-definition (HD) video streaming are driving the data rate of wireless links from hundreds of Mbps to multi Gbps. Among a few technologies that can provide such high rates, transmission in 60-GHz bands is considered as a very promising solution. In this paper, we identify key design challenges of wireless transmission in 60-GHz bands from the perspective of medium access control (MAC) design. Ecma TC-48 MAC Protocol is used as a case study to show how these challenges are addressed in a practical and efficient manner.
Influence in a large society: interplay between information dynamics and network structure
Authors: Lara Dolecek, Devavrat Shah
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Motivated by the recent emergence of large online social networks, we seek to understand the effects the underlying social network (graph) structure and the information dynamics have on the creation of influence of an individual. We examine a natural model for information dynamics under two important temporal scales: a first impression setting and a long- term or equilibrated setting. We obtain a characterization of relevant network structures under these temporal aspects, thereby allowing us to formalize the existence of influential agents. Specifically, we find that the existence of an influential agent corresponds to: (a) strictly positive information theoretic capacity over an infinite-sized noisy broadcast tree network in the first impression case, and (b) positive recurrent property of an appropriate (countable state space) Markov chain in the long-term case. As an application of our results, we evaluate the parameter space of the popular "small world" network model to identify when the network structure supports the existence of influential agents.
Effects of mobility in hierarchical mobile ad hoc networks
Authors: Pratap S. Prasad, Prathima Agrawal, Krishna M. Sivalingam
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

In this paper, we study the effects of mobility on network parameters in hierarchical ad hoc networks. Several mobility models have been designed and studied to mimic the behavior of real world mobility in networks. They have been successful in modeling the movement of mobile nodes in simulations. However, in this work, we show that several mobility models fall short of extending the same result to hierarchical networks. Most mobility models can only predict the movement of nodes in a single cell or cluster. When mobile nodes start moving into adjacent clusters, the time required for handoff and other protocol overhead issues alter the throughput. This leads to drastic drop in throughput and increased latency in packet delivery. Also, commonly used routing protocols do not adequately support handling high mobility and frequent route discovery issues. We evaluate the performances of various routing protocols and mobility models in a highly mobile hierarchical ad hoc network using NS2 simulation.
Challenges in future broadband radio access, co-operative communications and self-organising networks
Authors: M. Latva-aho
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Despite of great improvements in e.g. mobile cellular networks during the past decade, the changes in the future may be even more dramatic. Several enabling basic technological barriers seem to become solved in the near future. This will potentially cause dramatic changes the way commercial wireless networks will function and deliver services for users. In this paper, an overview of critical enabling technologies which are foreseen to change the future wireless networking is given. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Triangulation in decision support systems: Algorithms for product design
Authors: P.V. (Sundar) Balakrishnan, Varghese S. Jacob
Venue: Decision Support Systems (1995)

Often complex decision problems requiring decision aids, such as a Decision Support System (DSS), do not have solution procedures that can generate an optimal solution in a realistic time period. This has led to the specification of heuristic solution procedures. However, the quality of the solution obtained using a heuristic in specific instances can be uncertain and may be open to debate. One approach to increase the confidence in the quality of the obtained solution is to use the triangulation approach recommended and often used in the social sciences. Thus, the result obtained with a specific heuristic can be considered 'good' (i.e., close to optimal) if that result is in the ball park of the result obtained through a maximally different method. In other words, using very different solution techniques helps provide benchmarks and thus enables the decision maker to avoid those solutions which are caught in local maxima. Based on this notion we have designed a prototype GENEtic algorithms based decision support SYStem (GENESYS) for the product design problem. The DSS provides three different solution techniques, specifically, complete enumeration (optimal solution) for small problems, heuristic dynamic programming and genetic algorithms, to address the product design problems.
High performance adaptive video services based on bitstream switching for IPTV systems
Authors: Yingnan Zhu, Wei Liu, Lina Dong, Wenjun Zeng, Heather Yu
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

As the Next Generation Network gains increasing attention, IPTV has been recognized as an efficient way to provide key IP multimedia services. Compared to conventional TV services, IPTV is sensitive to the IP network characteristics such as packet loss, delay and jittering. In addition, the potential long delay in channel switching is another significant challenge for IPTV systems. In this paper, to improve the QoS (Quality of Service) and QoE (Quality of Experience), we propose a framework which includes (1) introducing server-side bit-rate adaptation to deal with bandwidth variation; (2) multicasting low bit-rate videos for preview of multi-channel programs and Picture-in-Picture (PiP); and (3) using a two-step P-frame switching mechanism to reduce the delay in channel switching. Our results from a real-world test-bed show that the proposed framework greatly improves the perceived video quality and user experience at the client side.
Random linear network coding for time-division duplexing: queueing analysis
Authors: Daniel E. Lucani, Muriel Médard, Milica Stojanovic
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

We study the performance of random linear network coding for time division duplexing channels with Poisson arrivals. We model the system as a bulk-service queue with variable bulk size. A full characterization for random linear network coding is provided for time division duplexing channels [1] by means of the moment generating function. We present numerical results for the mean number of packets in the queue and consider the effect of the range of allowable bulk sizes. We show that there exists an optimal choice of this range that minimizes the mean number of data packets in the queue.
Using consensus measures for atlas construction
Authors: Liliane Ramus, Grégoire Malandain
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

Atlas-based segmentation has been shown to provide promising results to delineate critical structures for radiotherapy planning. However, it requires to have a reference image with its reference segmentation available. Classical methods used to build an average segmentation can lead to over-segmentation in case of high variability among the manual segmentations. We propose in this paper a consensusbased approach to construct a reference segmentation from a database of manually delineated images. We first compute local consensus measures to estimate a variability map, and then deduct from it a consensus segmentation. Finally, the proposed method is evaluated using a dataset of 64 manually delineated images of the head and neck region.
An approach based on the uncertain LOWG and induced uncertain LOWG operators to group decision making with uncertain multiplicative linguistic preference relations
Authors: Zeshui Xu
Venue: Decision Support Systems (2006)

In this paper, we define the concept of uncertain multiplicative linguistic preference relation, and introduce some operational laws of uncertain multiplicative linguistic variables. We propose some new aggregation operators including the uncertain linguistic geometric mean (ULGM) operator, uncertain linguistic weighted geometric mean (ULWGM) operator, uncertain linguistic ordered weighted geometric (ULOWG) operator, and induced uncertain linguistic ordered weighted geometric (IULOWG) operator. The IULOWG operator is a more general type of aggregation operator, which is based on the ULGM and ULOWG operators. Moreover, based on the ULOWG and IULOWG operators and the formula for the comparison between two uncertain multiplicative linguistic variables, we develop an approach to group decision making with uncertain multiplicative linguistic preference relations, and, finally, an application of the approach to group decision-making problem with uncertain multiplicative linguistic preference relations is pointed out.
A security service protocol for MANETs
Authors: Antonio Vincenzo Taddeo, Alberto Ferrante
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Mobile Ad-hoc Networks are composed of heterogeneous mobile systems. Securing their communications may be difficult due to differences in the supported algorithms and protocols. In this paper we propose a protocol to negotiate security settings for the communications. This protocol aims at minimizing the power consumption and at providing the highest possible security level associated with the communications.
An adaptive opportunistic routing scheme for wireless ad-hoc networks
Authors: A. A. Bhorkar, M. Naghshvar, T. Javidi, B. D. Rao
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

In this paper, an adaptive opportunistic routing scheme for multi-hop wireless ad-hoc networks is proposed. The proposed scheme utilizes a reinforcement learning framework to achieve the optimal performance even in the absence of reliable knowledge about channel statistics and network model. This scheme is shown to be optimal with respect to an expected average per packet cost criterion. The proposed routing scheme jointly addresses the issues of learning and routing in an opportunistic context, where the network structure is characterized by the transmission success probabilities. In particular, this learning framework leads to a stochastic routing scheme which optimally "explores" and "exploits" the opportunities in the network.
Digital IIR filter design for communication systems by discrete-time vector fitting
Authors: Chi-Un Lei, Ngai Wong
Venue: Proceedings of the 16th international conference on Digital Signal Processing (2009)

A recent digital system identification technique, called discrete-time vector fitting (VFz), is extended to two communication system filter design problems. The first one is the complex infinite-impulse-response (IIR) filter design. The second one is the common-denominator MIMO filter design. In the second problem, a combination of VFz and QR decomposition is proposed to reduce the computational complexity. Robustness in finite-precision arithmetic is imposed in both problems via a pole radius constraint. Numerical examples confirm that VFz exhibits fast convergence and produces highly accurate approximants.
Outer bounds for user cooperation
Authors: Ravi Tandon, Sennur Ulukus
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

We obtain a dependence balance based outer bound on the capacity region of the two-user multiple access channel with generalized feedback (MAC-GF). We investigate a Gaussian MAC with user-cooperation (MAC-UC), where each transmitter receives an additive white Gaussian noise corrupted version of the channel input of the other transmitter. For all non-zero values of cooperation noise variances, our outer bound strictly improves upon the cut-set outer bound. Moreover, as the variances of the cooperation noises become large, our outer bound collapses to the capacity region of the Gaussian MAC without cooperation.
Average entropy functions
Authors: Qi Chen, Chen He, Lingge Jiang, Qingchuan Wang
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The closure of the set of entropy functions associated with n discrete variables, Γn*, is a convex cone in (2n - 1)- dimensional space, but its full characterization remains an open problem. In this paper, we map Γn* to an n-dimensional region Φn* by averaging the joint entropies with the same number of variables, and show that the simpler Φn* can be characterized solely by the Shannon-type information inequalities.
Evaluation and comparison of capacities and costs of multihop cellular networks
Authors: Ali Imran, Rahim Tafazolli
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Multihop Cellular Networks (MCN) have emerged as promising solution to cope with the time persistent problem of poor cell edge and indoor coverage offered by Conventional Cellular Networks (CCN). Furthermore, having potential to increase system throughput and performance while decreasing deployment cost, MCN are being envisioned as essential part of future broadband networks. In prospective of these futuristic trends, this paper addresses the dire need to assess different MCN architecture options and quantify the gains they offer in terms of capacity, performance and system cost compared to CCN. As the first standard for MCN i.e. 802.16j is on the way yet, this paper relies on the most well known example of CCN i.e. GSM to demonstrate the concepts in this study and evaluates the realistic capacity and performance of three different architectural options for MCN. These are : 1) MCN without spectrum sharing between Base Station (BS) to Relay stations (RS) and RS to Mobile Station (MS) links. 2) MCN with spectrum sharing between BS-RS and RS-MS links, and 3) MCN without out spectrum sharing while BS's acting as umbrella cells on top of RS's. Results show the MCN, depending on the their configuration, in addition to improved Grade of Service (GoS ) can yield 34% to 170% higher system capacity for a 50 to 67% more system cost compared to an optimised CCN.