ppxscal/embedding_network huggingface dataset:
Prototype implementation of two efficient low-complexity digital predistortion algorithms
Authors: Ernst Aschbacher, Mei Yen Cheong, Peter Brunmayr, Markus Rupp, Timo I. Laakso
Venue: EURASIP Journal on Advances in Signal Processing (2008)

Predistortion (PD) lineariser for microwave power amplifiers (PAs) is an important topic of research. With larger and larger bandwidth as it appears today in modern WiMax standards as well as in multichannel base stations for 3GPP standards, the relatively simple nonlinear effect of a PA becomes a complex memory-including function, severely distorting the output signal. In this contribution, two digital PD algorithms are investigated for the linearisation of microwave PAs in mobile communications. The first one is an efficient and low-complexity algorithm based on a memoryless model, called the simplicial canonical piecewise linear (SCPWL) function that describes the static nonlinear characteristic of the PA. The second algorithm is more general, approximating the pre-inverse filter of a nonlinear PA iteratively using a Volterra model. The first simpler algorithm is suitable for compensation of amplitude compression and amplitude-to-phase conversion, for example, in mobile units with relatively small bandwidths. The second algorithm can be used to linearise PAs operating with larger bandwidths, thus exhibiting memory effects, for example, in multichannel base stations. A measurement testbed which includes a transmitter-receiver chain with a microwave PA is built for testing and prototyping of the proposed PD algorithms. In the testing phase, the PD algorithms are implemented using MATLAB (floating-point representation) and tested in record-and-playback mode. The iterative PD algorithm is then implemented on a Field Programmable Gate Array (FPGA) using fixed-point representation. The FPGA implementation allows the pre-inverse filter to be tested in a real-time mode. Measurement results show excellent linearisation capabilities of both the proposed algorithms in terms of adjacent channel power suppression. It is also shown that the fixed-point FPGA implementation of the iterative algorithm performs as well as the floating-point implementation.
Design of Environment Monitoring System for Aquaculture Farms
Authors: Soonhee Han, Youngman Kang, Kyehwa Park, Moonsuk Jang
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

Recently, for an efficient and safe production process of the aquaculture products, there exists repeated request for an environment monitoring system to efficiently measure and monitor aquaculture farms environment. Considering aquaculture farms' humid and spacious environment, the monitoring system is preferred to have a wireless data transmission capability. To automatically collect the environmental data and transmit the data to the server, a specially designed device with a proper data display feature is required. In this paper, we design and describe the monitoring system that measures and monitors the aquaculture farm's environment. Also, the Sensor Data Logger, the core part of the system, is detailed in its implementation. The monitoring system offers ubiquitous access to the measured data either from the internet or the mobile phones.
3D Environment Modeling and its Application to Human Robot Interaction
Authors: Kyeong-Won Jeon, Jeongseok Ki, Yong-Moo Kwon, Hanseok Ko
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

This paper presents the robotic security service with interaction between human and robot. First, this paper addresses the concept of virtual URS. Second, this paper proposes an algorithm for 3D Environment Modeling for interacting with human and robot. Third, the system architecture for interaction service is described considering the platform of PC, PDA and Mobile phone. Then, this paper introduces a case of interaction service on Web and mobile phone.
A Self-Scheduling Model for NASA Swarm-Based Exploration Missions Using ASSL
Authors: Emil Vassev, Mike Hinchey, Joey Paquet
Venue: Proceedings of the Fifth IEEE Workshop on Engineering of Autonomic and Autonomous Systems (2008)

This article presents our research towards a self-scheduling mechanism for the NASA swarm-based exploration missions. By its virtue, ANTS (Autonomous Nano Technology Swarm) is considered to be an autonomic system with autonomic behavior that constitutes a self-scheduling mechanism, thus allowing task distribution on the fly with no human intervention. The goal of this work is to investigate a possible self-scheduling mechanism for ANTS, in accordance with the system and environmental conditions. In this paper, a formal task-scheduling approach is presented, and the ANTS self-scheduling behavior is modeled and specified with ASSL (Autonomic System Specification Language), where the group and individual tasks are structured in the fashion of TAFT (Time Aware Fault-Tolerant). TAFT is a recently devised approach that applies tolerance to timing violations.
On the power of 2-way probabilistic finite state automata
Authors: C. Dwork, L. Stockmeyer
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

The recognition power of two-way probabilistic finite-state automata (2PFAs) is studied. It is shown that any 2PFA recognizing a nonregular language must use exponential expected time infinitely often. The power of interactive proof systems (IPSs) where the verifier is a 2PFA is also investigated. It is shown that (1) IPSs in which the verifier uses private randomization are strictly more powerful than IPSs in which the random choices of the verifier are made public to the prover. (2) IPSs in which the verifier uses public randomization are strictly more powerful than 2PFAs alone, that is, without a prover; (3) every language accepted by some deterministic Turing machine in exponential time can be accepted by some IPS. Other results concern IPSs with 2PFA verifiers that run in polynomial expected time.
A Simulation Study of Common Mobility Models for Opportunistic Networks
Authors: Muhammad Abdulla, Robert Simon
Venue: Proceedings of the 41st Annual Simulation Symposium (anss-41 2008) (2008)

Understanding mobility characteristics is important for the design and analysis of routing schemes for mobile ad hoc networks (MANETs). This is especially true for mobile opportunistic networks where node mobility is utilized to achieve message delivery. In this paper, we study the properties of common mobility models. Specifically, we study inter-contact times of mobile nodes in Random Waypoint and Random Direction mobility models under opportunistic network settings. We also introduce a modified Random Waypoint model with hot-spots to study its mobility properties. Through extensive simulation study, we provide simulation results for mobility properties of Random Waypoint and Random Direction models. Further, our modified Random Waypoint with hot-spots model is also found to show an approximate power-law and exponential inter-contact time dichotomy found in real-world mobility traces as described in recent literature.
Redundancy Analysis and a Distributed Self-Organization Protocol for Fault-Tolerant Wireless Sensor Networks
Authors: Yi Zou, Krishnendu Chakrabarty
Venue: International Journal of Distributed Sensor Networks (2007)

Sensor nodes in a distributed sensor network can fail due to a variety of reasons, e.g., harsh environmental conditions, sabotage, battery failure, and component wear-out. Since many wireless sensor networks are intended to operate in an unattended manner after deployment, failing nodes cannot be replaced or repaired during field operation. Therefore, by designing the network to be fault-tolerant, we can ensure that a wireless sensor network can perform its surveillance and tracking tasks even when some nodes in the network fail. In this paper, we describe a fault-tolerant self-organization scheme that designates a set of backup nodes to replace failed nodes and maintain a backbone for coverage and communication. The proposed scheme does not require a centralized server for monitoring node failures and for designating backup nodes to replace failed nodes. It operates in a fully distributed manner and it requires only localized communication. This scheme has been implemented on top of an energy-efficient self-organization technique for sensor networks. The proposed fault-tolerance-node selection procedure can tolerate a large number of node failures using only localized communication, without losing either sensing coverage or communication connectivity.
Specified precision polynomial root isolation is in NC
Authors: C. A. Neff
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

Given a polynomial p(z) od degree n with integer coefficients, whose absolute values are bounded above by 2/sup m/, and a specified integer mu , it is shown that the problem of determining all roots of p with error less than 2/sup - mu / is in the parallel complexity class NC. To do this, an algorithm that runs on at most POLY(n+m+ mu ) processors with a parallel time complexity of O(log/sup 3/(n+m+ mu )) is constructed. This algorithm extends the algorithm of M. Ben-Or et al. (SIAM J. Comput., vol.17, p.1081-92, 1988) by removing the severe restriction that all the roots of p(z) should be real.
Robotics Today: The Good, Bad, and Ugly
Authors: Noel Sharkey
Venue: Proceedings of the 15th Annual IEEE International Conference and Workshop on the Engineering of Computer Based Systems (2008)

Although robots and robot fantasies have existed in some form for over two millennia, we are only beginning to see their predicted benefits come to fruition in our world of rapidly developing cheap technologies. Robots are now entering our homes for domestic service; they are harvesting our fruit, making our cars, milking our cows, performing surgery, and nursing us. Yet despite the long lead in, we are surprisingly unprepared for the consequences. No proper guidelines have been set in place for the influx of autonomous machines. Governments have been more concerned with issues such as the possibility of robots having legal rights than with the pressing ethical problem on our doorsteps. Work has already begun on robot carers for our aging populations and for minding our children. More worryingly, robots are integral to the US $230bn future combat systems project, a massive plan to develop unmanned vehicles that can strike from the air, under the sea and on land. South Korea and Israel are deploying armed robot border guards and China, Singapore and the UK are among those making increasing use of military robots. Uglier yet, the military technologies are coming back to haunt civilian world with increased use in policing and surveillance. This talk aims to provoke wider discussion of the new developments and their ethical implications.
On iterative intelligent medical search
Authors: Gang Luo, Chunqiang Tang
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

Searching for medical information on the Web has become highly popular, but it remains a challenging task because searchers are often uncertain about their exact medical situations and unfamiliar with medical terminology. To address this challenge, we have built an intelligent medical Web search engine called iMed, which uses medical knowledge and an interactive questionnaire to help searchers form queries. This paper focuses on iMed's iterative search advisor, which integrates medical and linguistic knowledge to help searchers improve search results iteratively. Such an iterative process is common for general Web search, and especially crucial for medical Web search, because searchers often miss desired search results due to their limited medical knowledge and the task's inherent difficulty. iMed's iterative search advisor helps the searcher in several ways. First, relevant symptoms and signs are automatically suggested based on the searcher's description of his situation. Second, instead of taking for granted the searcher's answers to the questions, iMed ranks and recommends alternative answers according to their likelihoods of being the correct answers. Third, related MeSH medical phrases are suggested to help the searcher refine his situation description. We demonstrate the effectiveness of iMed's iterative search advisor by evaluating it using real medical case records and USMLE medical exam questions.
Maximal Causes for Non-linear Component Extraction
Authors: Jörg Lücke, Maneesh Sahani
Venue: The Journal of Machine Learning Research (2008)

We study a generative model in which hidden causes combine competitively to produce observations. Multiple active causes combine to determine the value of an observed variable through a max function, in the place where algorithms such as sparse coding, independent component analysis, or non-negative matrix factorization would use a sum. This max rule can represent a more realistic model of non-linear interaction between basic components in many settings, including acoustic and image data. While exact maximum-likelihood learning of the parameters of this model proves to be intractable, we show that efficient approximations to expectation-maximization (EM) can be found in the case of sparsely active hidden causes. One of these approximations can be formulated as a neural network model with a generalized softmax activation function and Hebbian learning. Thus, we show that learning in recent softmax-like neural networks may be interpreted as approximate maximization of a data likelihood. We use the bars benchmark test to numerically verify our analytical results and to demonstrate the competitiveness of the resulting algorithms. Finally, we show results of learning model parameters to fit acoustic and visual data sets in which max-like component combinations arise naturally.
A Laser Show Device Works in an Open Space for Hearing-Impaired Students
Authors: Toru Takahashi, Miki Namatame, Fusako Kusunoki, Isao Ono, Takao Terano
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

The paper proposes a new pointing device for education of hearing-impaired students. The device: Big Fat Wand (BFW) is developed from a conventional laser show device, however, is modified to a small enough one to be used at out-of-classroom lectures. BFW is connected to a laptop PC, which provides character, symbol images, and/or animations with the device through a conventional one board micro-computer. This paper describes the educational objectives, basic principles, and preliminary experimental results of BFW. We conclude that BFW is a good gear to improve the methodology to educate and educate hearing-impaired students.
Subspace Clustering of High Dimensional Data Streams
Authors: Shuyun Wang, Yingjie Fan, Chenghong Zhang, HeXiang Xu, Xiulan Hao, Yunfa Hu
Venue: Proceedings of the Seventh IEEE/ACIS International Conference on Computer and Information Science (icis 2008) (2008)

In this paper, SOStream, which is a novel algorithm of clustering over high dimensional online data stream is presented, it is based on subspace. SOStream partitions the data space into grids, and maintains a superset of all dense units in an online way. A deterministic lower and upper bound of the selectivity of each maintained units are also given. With the maintained potential dense units, SOStream is capable of discovering the clusters in different subspaces over high dimensional data stream with arbitrary shape. The experimental results on real and synthetic datasets demonstrate the effectivity of the approach.
Performance analysis of a lightweight NEMO implementation for low-end devices
Authors: J. L. Almodovar, A. de la Oliva, C. Lazo Ram, C. Cervelló-Pastor
Venue: Proceedings of the 4th International Conference on Testbeds and research infrastructures for the development of networks & communities (2008)

IETF Network Mobility (NEMO) Basic Support Protocol is an IP mobility management protocol designed to provide seamless IP mobility to complete networks. This protocol is of crucial interest in vehicular mobility and it is being applied in several research projects and initiatives which pretend to incorporate communication support to the transportation system. One of the problems which appear when including NEMO on vehicles is the need of incorporate network infrastructure to the vehicle with its associated cost in terms of money, space etc. On this work we present an implementation of the NEMO protocol specifically designed to run on low end network devices. We also present the performance figures of it running on a reference device, proving that its performance is enough to comply the requirements of vehicular communications.
An overview of video shot clustering and summarization techniques for mobile applications
Authors: Nicola Adami, Sergio Benini, Riccardo Leonardi
Venue: Proceedings of the 2nd international conference on Mobile multimedia communications (2006)

The problem of content characterization of video programmes is of great interest because video appeals to large audiences and its efficient distribution over various networks should contribute to widespread usage of multimedia services. In this paper we analyze several techniques proposed in literature for content characterization of video programmes, including movies and sports, that could be helpful for mobile media consumption. In particular we focus our analysis on shot clustering methods and effective video summarization techniques since, in the current video analysis scenario, they facilitate the access to the content and help in quick understanding of the associated semantics. First we consider the shot clustering techniques based on low-level features, using visual, audio and motion information, even combined in a multi-modal fashion. Then we concentrate on summarization techniques, such as static storyboards, dynamic video skimming and the extraction of sport highlights. Discussed summarization methods can be employed in the development of tools that would be greatly useful to most mobile users: in fact these algorithms automatically shorten the original video while preserving most events by highlighting only the important content. The effectiveness of each approach has been analyzed, showing that it mainly depends on the kind of video programme it relates to, and the type of summary or highlights we are focusing on.
A Framework for Proactive Fault Tolerance
Authors: Geoffroy Vallee, Kulathep Charoenpornwattana, Christian Engelmann, Anand Tikotekar, Chokchai Leangsuksun, Thomas Naughton, Stephen L. Scott
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

Fault tolerance is a major concern to guarantee availability of critical services as well as application execution. Traditional approaches for fault tolerance include checkpoint/restart or duplication. However it is also possible to anticipate failures and proactively take action before failures occur in order to minimize failure impact on the system and application execution. This document presents a proactive fault tolerance framework. This framework can use different proactive fault tolerance mechanisms, i.e., migration and pause/unpause.The framework also allows the implementation of new proactive fault tolerance policies thanks to a modular architecture. A first proactive fault tolerance policy has been implemented and preliminary experimentations have been done based on system-level virtualization and compared with results obtained by simulation.
Structured metadata for representation, query and retrieval of behaviour models of virtual products
Authors: T. -L. Sun
Venue: International Journal of Computer Integrated Manufacturing (2007)

Although the interactive three-dimensional visualization and intuitive interface offered by virtual reality (VR) technology are useful at various product development stages, the expensive and time-consuming process required to construct a VR model often hinders the widespread adoption of VR in industry. Fast and low-cost VR model construction is a critical factor for broader acceptance of VR technology in industry. Since many industrial products, e.g. products belonging to the same product family, have similar behaviours, it is reasonable to store the behaviour models of products and reuse them later. Behaviour query and retrieval, however, are not easy because of their complex composing data elements. This paper proposes a metadata-based approach for behaviour representation, query and retrieval. The metadata are designed by identifying the important objects in constructing a VRML-compliant behaviour model and designing representative metadata for these objects. The resulted metadata table captures three types of information: the operation units; the animation and interaction functions applied to the operation units; and the execution logics and sequences of these functions. The metadata table also provides a simple interface for VR programmer to define a query specification. Behaviour model retrieval is done by matching the query table against the metadata tables of existed behaviour models. The proposed metadata-based approach could be integrated with existing VR authoring systems to facilitate fast construction of virtual products.
Wavelet and curvelet moments for image classification: Application to aggregate mixture grading
Authors: Fionn Murtagh, Jean-Luc Starck
Venue: Pattern Recognition Letters (2008)

We show the potential for classifying images of mixtures of aggregate, based themselves on varying, albeit well-defined, sizes and shapes, in order to provide a far more effective approach compared to the classification of individual sizes and shapes. While a dominant (additive, stationary) Gaussian noise component in image data will ensure that wavelet coefficients are of Gaussian distribution, long tailed distributions (symptomatic, for example, of extreme values) may well hold in practice for wavelet coefficients. Energy (second order moment) has often been used for image characterization for image content-based retrieval, and higher order moments may be important also, not least for capturing long tailed distributional behavior. In this work, we assess second, third and fourth order moments of multiresolution transform - wavelet and curvelet transform - coefficients as features. As analysis methodology, taking account of image types, multiresolution transforms, and moments of coefficients in the scales or bands, we use correspondence analysis as well as k-nearest neighbors supervised classification.