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In this paper, we propose algorithms for computing Walsh-Hadamard transform with arbitrary K-sparse support. When K is sublinear in the dimension N of the time-domain signal, the algorithms achieve vanishing error probability as K increases without bound and involve sublinear computational complexity. Specifically, under the noiseless setting, an algorithm based on random hashing and successive cancellation...
Private information retrieval scheme for coded data storage is considered in this paper. We focus on the case where the size of each data record is large and hence only the download cost (but not the upload cost for transmitting retrieval queries) is of interest. We prove that the tradeoff between storage cost and retrieval/download cost depends on the number of data records in the system. We propose...
We investigate compressibility of the dimension of positive semidefinite matrices while approximately preserving their pairwise inner products. This can either be regarded as compression of positive semidefinite factorizations of nonnegative matrices or (if the matrices are subject to additional normalization constraints) as compression of quantum models. We derive both lower and upper bounds on compressibility...
Energy saving is one of the most investigated problems in wireless networks. In this paper, we introduce two homology based algorithms: a simulated annealing one and a robust one. These algorithms optimize the energy consumption at network level while maintaining the maximal coverage. By using simplicial homology, the complex geometrical calculation of the coverage is reduced to simple matrix computation...
The objective of this paper is to investigate the plausibility of applying Epoch-Era Analysis (EEA) as a systems engineering technique to evaluate whether an offshore subsea construction vessel (OSCV) can deliver sustained value to stakeholders over time in a complex, uncertain and changing technological, operational and commercial context. Additionally, the article discusses how to evaluate and interpret...
Today's tape storage systems are widely used as a low-cost solution for data backup and archiving for the rapidly growing amount of digital information produced in various fields. Following the Information Storage Industry Consortium (INSIC) Roadmap [1], tape cartridge capacity continues to scale by doubling the capacity every two years. Developments in read channel technology are expected to play...
Spatially-Coupled LDPC (SC-LDPC) codes have been recently shown to be very efficient for transmissions over nonergodic channels, in particular over block-fading channels [1]. In fact, it is possible to design a SC-LDPC code with any given code diversity [2]. In this work, we investigate the performance of SC-LDPC codes over block-fading channels, assuming a mismatch (or offset) between the first bit...
This paper analyzes the robustness of Low Density Parity Check (LDPC) encoders on faulty hardware. The faulty hardware effect on the encoder is represented by an error model at the XOR gate level. We review the existing LDPC encoding solutions [1], [2] and the code constructions [3]–[5] that guarantee low encoding complexity. For each of the existing solutions [1]–[5], we provide the analytic expression...
The task of Simultaneous Localization and Mapping (SLAM) is regularly performed in network spaces consisting of a set of corridors connecting locations in the space. Empirical research has demonstrated that such spaces generally exhibit common structural properties relating to aspects such as corridor length. Consequently there exists potential to improve performance through the placement of priors...
Adaptive filters for hands-free telephone systems need an adaptation control which locks or slows down the adaptation process during double talk periods. In this contribution a block adaptive filter algorithm working in the frequency domain which combines a significant reduced numerical complexity with the same tacking abilities as the NLMS algorithm is presented. Moreover we control the stepfactor...
A new lower bound is derived for the level of performance achieved by a given feedback compensator with a plant that is not known completely. The bound involves quantities reflecting the performance of the controller with a nominal model of the plant, quantities that can be computed from a finite number of frequency response samples of the unknown plant, and quantities related to the complexity (in...
We establish a connection between two well developed research areas, robust control and planning systems. The discount factors used in Markov Decision Process (MDP) models of time-critical planning are derivable from frequency domain concepts of performance and uncertainty used in robust control. The controls framework makes it possible to move beyond merely justifying the discount factor towards...
We consider ill-posed linear inverse problems involving the estimation of structured sparse signals. When the sensing matrix has i.i.d. standard normal entries, there is a full-fledged theory on the sample complexity and robustness properties. In this work, we propose a way of making use of this theory to get good bounds for the i.i.d. Bernoulli ensemble. We first provide a deterministic relation...
This paper presents fast algorithms for line and circle detection based on inverted gradient hash maps (IGHM). Inverted indices are a common technique for storing a map from content of a dataset to its locations in the dataset. Hash maps are typically used to implement associative arrays and reduce search times in large datasets. In this paper, a hash map is used to store an inverted index of image...
We propose a set of novel audio features for classifying the style of classical music. The features rely on statistical measures based on a chroma feature representation of the audio data and describe the tonal complexity of the music, independently from the orchestration or timbre of the music. To analyze this property, we use a dataset containing piano and orchestral music from four general historical...
Query optimizers depend heavily on statistics representing column distributions to create efficient query plans. In many cases, though, statistics are outdated or non-existent, and the process of refreshing statistics is very expensive, especially for ad-hoc workloads on ever bigger data. This results in suboptimal plans that severely hurt performance. The main problem is that any decision, once made...
We consider the problem of designing robust controllers for uncertain spatially-varying interconnected systems distributed in one spatial dimension. Previous work has shown that the matrix structure of such systems can be exploited to allow fast analysis and design of centralized controllers with simple distributed implementations, and this paper seeks to extend these techniques to robust analysis...
We present a low-complex blind interference reduction scheme embedded in the receiver to enhance correlative data detection. The key element is a statistically controlled adaptive nonlinearity prior to correlation. This add-on feature guaranties reliable communication between network-nodes in any type of noise and/or interference. Additionally the concept provides accurate position measurements to...
The characteristics of smart grids introduce robust control techniques as more powerful and suitable control tools for control synthesis/analysis problems in these grids. However, there are some important challenges in application of robust control theorems in new power systems. Here, two main challenges are discussed and probable solutions are given to fill the existing gap between the power of robust...
Existing public transportation networks are usually regarded as being static with respect to their topology. However, in fast growing cities, new lines are added, sometimes focusing only on the demand, without regard to overall efficiency of the system. In this work we propose the application of techniques from evolutionary computation. The aim here is to improve the efficiency of public transportation...
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