ppxscal/embedding_network huggingface dataset:
Joint ML timing and phase estimation in OFDM systems using the EM algorithm
Authors: E. Panagirci
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

In this paper, a computationally efficient algorithm is presented for joint maximum likelihood (ML) timing and carrier phase estimation of OFDM systems employing M-PSK modulation scheme with additive Gaussian noise, based on the expectation-maximization (EM) algorithm. A nondata-aided (NDA) scheme is considered for the joint timing and phase synchronizer which maximizes the low SNR limit of the likelihood function averaged over the M-PSK signal constellation. For this, an EM algorithm is derived which estimates the timing offset and the phase rotations of each subcarrier iteratively and which converges to the true ML estimation of the unknown timing and phase. It is shown that the algorithm becomes independent of the signal-to-noise ratio for both low and high SNR cases. The algorithm is applied to the QPSK modulated OFDM systems and it is concluded that for SNR values greater than 10 dB the convergence is achieved in first iteration and for SNR values less than 10 dB, at most in three iterations. It is also concluded that the convergence is independent of the initial starting points.
Feature Subset Selection on Multivariate Time Series with Extremely Large Spatial Features
Authors: Hyunjin Yoon, Cyrus Shahabi
Venue: Proceedings of the Sixth IEEE International Conference on Data Mining - Workshops (2006)

Several spatio-temporal data collected in many applications, such as fMRI data in medical applications, can be represented as a Multivariate Time Series (MTS) matrix with m rows (capturing the spatial features) and n columns (capturing the temporal observations). Any data mining task such as clustering or classification on MTS datasets are usually hindered by the large size (i.e., dimensions) of these MTS items. In order to reduce the dimensions without losing the useful discriminative features of the dataset, feature selection techniques are usually preferred by domain experts since the relation of the selected subset of features to the originally acquired features is maintained. In this paper, we propose a new feature selection technique for MTS datasets where their spatial features (i.e., number of rows) are much larger than their temporal observations (i.e., number of columns), or m /ge n. Our approach is based on Principal Component Analysis, Recursive Feature Elimination and Support Vector Machines. Our empirical results on real-world datasets show that our technique significantly outperforms the closest competitor technique.
An Enterprise Messaging Middleware for Mobile Services
Authors: Brahim Medjahed, David Carver
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems Workshops (2007)

In this paper, we introduce a messaging middleware for enterprise services in wireless environments. The proposed middleware enables seamless integration between mobile devices/users and enterprise services. Mobile users send their requests to the enterprise system which replies by sending back the requests' results to the mobile user. We adopt object-oriented analysis methods to provide for in-depth description and analysis of the messaging middleware.
Pseudorandom Bits for Constant-Depth Circuits with Few Arbitrary Symmetric Gates
Authors: Emanuele Viola
Venue: SIAM Journal on Computing (2006)

We exhibit an explicitly computable pseudorandom generator stretching $l$ bits into $m(l) = l^{\Omega(\log l)}$ bits that look random to constant-depth circuits of size $m(l)$ with $\log m(l)$ arbitrary symmetric gates (e.g., PARITY, MAJORITY). This improves on a generator by Luby, Velickovic, and Wigderson [Proceedings of the Second Israel Symposium on Theory of Computing Systems, 1993, pp. 18-24] that achieves the same stretch but fools only circuits of depth 2 with one arbitrary symmetric gate at the top. Our generator fools a strictly richer class of circuits than Nisan&rsquo;s generator for constant-depth circuits (but Nisan&rsquo;s generator has a much bigger stretch) [Combinatorica, 11 (1991), pp. 63-70]. In particular, we conclude that every function computable by uniform $\poly(n)$-size probabilistic constant-depth circuits with $O(\log n)$ arbitrary symmetric gates is in $\mathit{TIME}(2^{n^{o(1)}})$. This seems to be the richest probabilistic circuit class known to admit a subexponential derandomization. Our generator is obtained by constructing an explicit function $f : \zo^n \to \zo$ that is very hard on average for constant-depth circuits of size $s(n) = n^{\Omega(\log n)}$ with $\log s(n)$ arbitrary symmetric gates, and plugging it into the Nisan-Wigderson pseudorandom generator construction [J. Comput. System Sci., 49 (1994), pp. 149-167]. The proof of the average-case hardness of this function is a modification of arguments by Razborov and Wigderson [Inform. Process. Lett., 45 (1993), pp. 303-307] and Hansen and Miltersen [Proceedings of the 29th International Symposium on Mathematical Foundations of Computer Science, Lecture Notes in Comput. Sci. 3153, Springer-Verlag, Berlin, 2004, pp. 334-345] and combines Ha&ring;stad&rsquo;s switching lemma [Computational Limitations of Small-Depth Circuits, MIT Press, Cambridge, MA, 1987] with a multiparty communication complexity lower bound by Babai, Nisan, and Szegedy [J. Comput. System Sci., 45 (1992), pp. 204-232].
On Resources Allocation in Binary n-Cube Network Systems
Authors: Nian-Feng Tzeng, Gui-Liang Feng
Venue: Proceedings of the 1993 International Conference on Parallel Processing - Volume 02 (1993)

We introduce systematic approaches to resource allocation in a cube system so that each non resource node is connected with one resource copy and that the allocation performance measure of interest is optimized.
An Agent Infrastructure for Distributed Simulations over HLA and a Case Study Using Unmanned Aerial Vehicles
Authors: F. Cicirelli, A. Furfaro, A. Giordano, L. Nigro
Venue: Proceedings of the 40th Annual Simulation Symposium (2007)

This paper proposes an agent infrastructure (Theatre) centered on Java for distributed simulations over HLA/RTI. The architecture rests on actors (agents) as the basic building blocks. Actors have a public message interface and encapsulate a state of local variables and a behavior patterned as a finite state machine. Actors interact to one another by asynchronous message passing. At the system level, theatres are used as the execution platforms for actors. Theatres naturally map on to HLA federates. Actors can migrate between theatres for configuration or load-balancing concerns. The paper introduces Theatre and shows its application to a complex simulation model based on unmanned aerial vehicles (UAVs). The case study is an open agent-based distributed model where mobile agents follow communication patterns established at runtime.
LagOver: Latency Gradated Overlays
Authors: Anwitaman Datta, Ion Stoica, Mike Franklin
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems (2007)

We propose a new genre of overlay network for disseminating information from popular but resource constrained sources. We call this communication primitive as Latency Gradated Overlay, where information consumers selforganize themselves according to their individual resource constraints and the latency they are willing to tolerate in receiving the information from the source. Such a communication primitive finds immediate use in applications like RSS feeds aggregation. We propose heuristic algorithms to construct LagOver based on preferably some partial knowledge of the network at users (no knowledge slows the construction process) but no global coordination. The algorithms are evaluated based on simulations and show good characteristics including convergence, satisfying peers' latency and bandwidth constraints even in presence of moderately high membership dynamics. There are two points worth noting. First, optimizing jointly for latency and capacity (i.e., placing nodes that have free capacity close to the source) as long as latency constraint of other nodes are not violated performs better than optimizing for latency only. The joint optimization strategy has faster convergence of the LagOver network, and can deal with adversarial workloads that optimization of only latency can not deal with. Secondly, somewhat counter-intuitively, in order to do the aforementioned joint optimization, it is sufficient to find random nodes based on only the latency constraint, since even if the capacity of individual nodes is saturated it does not matter since the LagOver network can potentially be reconfigured.
Overcoming workstation scheduling problems in a real-time audio tool
Authors: Isidor Kouvelas, Vicky Hardman
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1997)

The recent interest in multimedia conferencing is a result of the incorporation of cheap audio and video hard-ware in today's workstations, and also as a result of the development of a global infrastructure capable of supporting multimedia traffic - the Mbone. Audio quality is impaired by packet loss and variable delay in the network, and by lack of support for real-time applications in today's general purpose workstations. A considerable amount of research effort has focused on solving the network side of the problem by providing packet loss robustness techniques, and network conscious adaptive applications. Effort to solve the operating system induced problems has concentrated on kernel modifications. This paper presents an architecture for a real-time audio media agent that copes with the problems presented by the UNIX operating system at the application level. The mechanism produces a continuous audio signal, despite the variable allocation of processing time a real-time application is given under UNIX. Continuity of audio is ensured during scheduling hiccups by using the buffering capabilities of workstation audio devices drivers. Our solution also tries to restrict the amount of audio stored in the device buffers to a minimum, to reduce the perceived end-to-end delay of the audio signal. A comparison between the method presented here (adaptive cushion algorithm), and that used by all other audio tools shows substantial reductions in both the average end-to-end delay, and the audio sample loss caused by the operating system.
A group-theoretical model of the formal neuron
Authors: G. M. Alakoz, A. A. Salomatov
Venue: Automation and Remote Control (2007)

A group-theoretical model of the formal neuron which allows one to design optimally the neural computers over a finite set of the integer variations of the weight and threshold vectors was constructed and examined. This model creates the preconditions for direct mapping of the problems of the user of neural computer onto the quantum processes of the nanoelectronic systems whose fundamental characteristics are defined and described by the symmetry groups.
Measuring Knowledge Management Projects: Fitting the Mosaic Pieces Together
Authors: Alton Y. K. Chua, Dion Goh
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

This paper seeks to develop an integrated perspective on knowledge management (KM) project measurement. Based on a review of the existing literature, a theoretical framework which identifies four distinct measurement elements, namely, activities, knowledge assets, organizational processes and business benefits is proposed. Using this framework, an empirical study on KM measurement was conducted among six Singapore Civil Service agencies. It was found that most KM projects were driven top-down, technology-focused and had some form of milestones specified along their development stage. Additionally, all four measurement elements identified in the theoretical framework could be found across the measurement schemes used in the public agencies. Two implications can be drawn from the findings. One, the context under which a KM project is conceived should be carefully considered when specifying indicators for measurement. Two, to balance among the needs of all stakeholders, the use of all four measurement elements to measure a KM project is advocated.
Range search on multidimensional uncertain data
Authors: Yufei Tao, Xiaokui Xiao, Reynold Cheng
Venue: ACM Transactions on Database Systems (TODS) (2007)

In an uncertain database, every object o is associated with a probability density function, which describes the likelihood that o appears at each position in a multidimensional workspace. This article studies two types of range retrieval fundamental to many analytical tasks. Specifically, a nonfuzzy query returns all the objects that appear in a search region rq with at least a certain probability tq. On the other hand, given an uncertain object q, fuzzy search retrieves the set of objects that are within distance &epsiv;q from q with no less than probability tq. The core of our methodology is a novel concept of &ldquo;probabilistically constrained rectangle&rdquo;, which permits effective pruning/validation of nonqualifying/qualifying data. We develop a new index structure called the U-tree for minimizing the query overhead. Our algorithmic findings are accompanied with a thorough theoretical analysis, which reveals valuable insight into the problem characteristics, and mathematically confirms the efficiency of our solutions. We verify the effectiveness of the proposed techniques with extensive experiments.
Feedback on Collaborative Skills in Remote Studio Design
Authors: Gina Turner, Michael F. Schober
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

The study reported here examines how feedback affects remote collaborative brainstorming and product design in a studio setting. 10 teams of 4 students at the Parsons School of Design met remotely via a chatroom interface for three 30- minute sessions to design a T-shirt. Team members who proposed ideas were rated as better collaborators, and team members who critiqued ideas without offering alternatives were rated as poor collaborators. This was also reflected in team members' word use, as measured by Pennebaker & Francis' Linguistic Inquiry and Word Count too; for example, team members who used more affect words were rated as poorer collaborators. A case study of one team suggests that the ideas proposed by team members rated as the best collaborators may be most likely to survive. Peer feedback can affect remote studio design discussion in ways comparable to what is found in other settings, despite task differences.
Modified Word Recognition System--New Performance
Authors: Marek Tabedzki, Khalid Saeed
Venue: Proceedings of the 6th International Conference on Computer Information Systems and Industrial Management Applications (2007)

This paper presents a hybrid system for word recognition. It is based on a modification to the view-based approach presented in authors' previous works. The algorithm is based on recognizing the whole words without separating them into letters. The characteristic vectors taken from both top and bottom views of the image are processed with the method of Töeplitz matrices. The obtained series of minimal eigenvalues is used for classification. The procedure of classification involves arrays of Neural Networks. Each network in the array is responsible for detecting one class. The results of the experiments on a set of common English words are presented.
Learning of neural network parameters using a fuzzy genetic algorithm
Authors: S. H. Ling, H. K. Lam, F. H. F. Leung, P. K. S. Tam
Venue: Proceedings of the Evolutionary Computation on 2002. CEC '02. Proceedings of the 2002 Congress - Volume 02 (2002)

This paper presents the learning of neural network parameters using a fuzzy genetic algorithm (GA). The proposed fuzzy GA is modified from the traditional GA with arithmetic crossover and non-uniform mutation. By introducing modified genetic operations, it will be shown that the performance of the proposed fuzzy GA are better than the traditional GA based on some benchmark test functions. Using the fuzzy GA, the parameters of the neural networks can be tuned. An application example on sunspot forecasting is given to show the merits of the proposed fuzzy GA.
Multimedia courseware for teaching dynamic concepts: assessment of student learning
Authors: C. E. Hmelo, E. Y. Lunken, K. Gramoll, I. Yusuf
Venue: Proceedings of the Frontiers in Education Conference on 1995. Proceedings., 1995 vol 1. - Volume 01 (1995)

The rise of multimedia has spurred the development of innovative packages for educational use. But what are students learning? To make the best use of this technology, we need to examine how it can enhance student learning. This makes issues of assessment very important. Multimedia is particularly powerful in engineering education for allowing students to visualize various dynamic physical phenomena, such as vibrations. We discuss the assessment of learning for those students who use the GT-VIBS multimedia package and case study to learn about engineering vibrations. We also performed evaluation of the software. We accomplished this by conducting an experiment in which students who use a multimedia tutorial module or an engineering case study were compared to students who read text. We present some of our preliminary results.
Semantic Web Services in Corporate Memories
Authors: Moussa Lo, Fabien Gandon
Venue: Proceedings of the Second International Conference on Internet and Web Applications and Services (2007)

We present our experiment in integrating semantic web services in the existing corporate semantic web server architecture we use to implement corporate memories. We rely on a semantic web search engine, to provide a semantic registry and automatically discover and invoke corporate applications wrapped into semantically annotated web services. Using rules we also demonstrate how to compose the web services with queries on the knowledge stored in the corporate memory to automatically populate the service inputs.
Workflow Flexibility: The Forlorn Promise
Authors: Hajo A. Reijers
Venue: Proceedings of the 15th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (2006)

It is argued in this position paper that a workflow management system is potentially a powerful solution to bring more flexibility to the management of business processes. At the same time, the technical difficulties of integrating such systems in a business environment prevent this advantage to materialize up to this day.
Scalable Video By Software
Authors: J. A. Nicholls
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 04 (1996)

An error concealment scheme for Motion Picture Experts Group (MPEG) video networking is proposed. During video transmission, video packet loss occurs in the presence of network congestion and buffer overflow. This phenomenon of packet loss transforms into single or multiple macroblock loss in the decoding process, which can severely degrade the viewing quality. The new method differs from the conventional concealment by its exploitation of temporal redundancies in a large scale. In many applications where there is significant camera motion (e.g., remote surveillance), the evolution from frame to frame can be well described by the affine motion. The motion estimation is carried out by registering images within a multiresolution pyramid. The global motion is estimated in the lowest resolution level, and is then used to update and refine the local motion. The local motion is further refined iteratively at higher resolution levels. An affine transform is used to extract translation, scaling and rotation parameters.
Fast n-D Fourier-Heisenberg-Weyl transforms
Authors: V. Labunets
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

In this work we study the harmonic analysis of functions on the n-D Heisenberg groups H over the Galois field GF(p) for generating Gabor atoms. Analogous to the Fourier transform, the expansion of functions on the basis of irreducible complex matrix representations of the Heisenberg group defines the generalized Fourier transform on this group, or, simply, the Fourier-Heisenberg transform. The fast algorithms for the n-D Fourier transforms on the Heisenberg and affine groups are developed in this paper. A general method of computing the Gabor distribution and wavelet transform based on the fast Fourier-Heisenberg-Weyl transform is also presented.
Compression for Low Power Consumption in Battery-powered Handsets
Authors: Mayumi Kato, Chia-Tien Dan Lo
Venue: Proceedings of the 2007 Data Compression Conference (2007)

Java has been introduced to the mobile/wireless handsets and Java enabled handsets are now prevalent in the market, showing their successful launch. A variety of attractive services have been developed and promise a lot of fun to our daily lives, which are however targeted to the high end products that are very expensive. We focus on economic types with similar performance to the high end products. Memory compression is a key technique to achieve the goal and is integrated into a Java runtime environment.
Observing intermediate structures in a parallel lazy functional language
Authors: Alberto de la Encina, Luis Llana, Fernando Rubio, Mercedes Hidalgo-Herrero
Venue: Proceedings of the 9th ACM SIGPLAN international conference on Principles and practice of declarative programming (2007)

Due to the use of higher-order functions and laziness, debugging lazy functional programs is not a trivial task. Fortunately, several debuggers have appeared during the last years. However, the difficulty of the debugging process is increased when considering parallel extensions of lazy functional languages. Thus, it is necessary not only to develop practical debuggers, but also to provide a clear semantic environment to understand what the debuggers should do. In this paper we present a formal framework for debugging two different parallel extensions of the lazy functional language Haskell. In order to do that, we define an operational semantics model which allows us to deal with side-effects and parallelism. By doing so, we provide a formalization of a parallel debugger we have already implemented by extending the sequential debugger Hood.
A memory reduction scheme for multi-channel echo canceller implementation
Authors: C. Y. Choo
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

One of the critical resources of the multi-channel echo canceller is the memory that stores both tapped delay lines of voice data and filter tap coefficients. A simple variable-length/run-length coding scheme for reducing coefficient memory for multi-channel echo cancellers is proposed. We also describe the corresponding memory system architecture. Simulations based on a bit-accurate Matlab model show that the proposed scheme is effective.
A rote extractor with edit distance-based generalisation and multi-corpora precision calculation
Authors: Enrique Alfonseca, Pablo Castells, Manabu Okumura, Maria Ruiz-Casado
Venue: Proceedings of the COLING/ACL on Main conference poster sessions (2006)

In this paper, we describe a rote extractor that learns patterns for finding semantic relationships in unrestricted text, with new procedures for pattern generalization and scoring. These include the use of part-of-speech tags to guide the generalization, Named Entity categories inside the patterns, an edit-distance-based pattern generalization algorithm, and a pattern accuracy calculation procedure based on evaluating the patterns on several test corpora. In an evaluation with 14 entities, the system attains a precision higher than 50% for half of the relationships considered.