ppxscal/embedding_network huggingface dataset:
Combining beamforming and space-time coding using noisy quantized feedback
Authors: Siavash Ekbatani, Hamid Jafarkhani
Venue: IEEE Transactions on Communications (2009)

The goal of combining beamforming and space-time coding is to obtain full-diversity order and to provide additional received power (array gain) compared to conventional space-time codes. In this work, a class of code constellations is proposed, called generalized partly orthogonal designs (PODs) and both high-rate and low-rate feedback information is incorporated with possible feedback errors. A binary symmetric channel (BSC) model characterizes feedback errors. Two cases are studied: first, when the BSC bit error probability is known a priori to the transmission ends, and second, when it is not known exactly. Based on a minimum pairwise error probability (PEP) design criterion, we design a channel optimized vector quantizer (COVQ) for feedback information and a precoder matrix codebook to adjust the transmission codewords. The attractive property of our combining scheme is that it converges to conventional space-time coding with low-rate and erroneous feedback and to directional beamforming with high-rate and error-free feedback. This scheme also shows desirable robustness against feedback channel modeling mismatch.
On the cumulative distribution function of quadratic-form receivers over generalized fading channels with tone interference
Authors: Marco Di Renzo, Fabio Graziosi, Fortunato Santucci
Venue: IEEE Transactions on Communications (2009)

In this paper, we develop a general and unified framework for estimating the Cumulative Distribution Function (CDF) of "quadratic-form" receivers. The expression of the CDF that we finally achieve takes on the form of a single integral with finite limits and integrand composed of elementary functions, which can be readily integrated using standard techniques. In particular, the specific contribution of this manuscript is twofold: i) we present a comprehensive framework for the analysis of multi-channel reception systems using either non-coherent or differentially-coherent detectors, diversity systems with practical (i.e., noisy) channel estimators, and Transmitted-Reference (TR) receiver architectures working in frequency-selective fading channels, and ii) we show that the framework can be efficiently used for performance assessment of wireless systems over generalized fading channels and, under mild assumptions, over generalized fading channels further impaired by in-band multi-tone interference.
Research of Massive Internet Text Data Real-Time Loading and Index System
Authors: WeiHong Han, Yan Jia, ShuQiang Yang
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

With rapid development of the Internet and communication technology, massive text data has been accumulated in Internet, including text data on network pages, emails, instant messengers and etc. Requirements on increasing data volume, real-time data-loading and creating text indexes pose enormous challenges to data-loading techniques. This paper presents a data loading system in real time, Text-loader that is used in ITSR (Internet Text Data Real-time Storage and Retrieval System). Text-loader consists of an efficient algorithm for bulk data loading and exchange partition mechanism, increasing text index creation algorithm, optimized parallelism, and guidelines for system tuning. Performance studies show the positive effects of these techniques with loading speed of every Cluster, increasing from 220 million records per day to 1.2 billion per day, and achieving the top loading speed of 6TB data when 10 Clusters are in parallel. This framework offers a promising approach for loading other large and complex text databases.
An Image Indexing and Retrieval Model Using Reasoning Services
Authors: Suihua Wang, Ailing Zhao
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

This paper uses content-based image retrieval technology and presents a reasoning-based image semantic indexing and retrieval approach, which could bridge the gap between complex structure of shapes and the extracted low-level features of images. It starts with image features extraction as other content-based image retrieval approaches do. Then applies structured knowledge representation methods to index, classify and recognize objects automatically according to the structured and semantic attributes of them. Syntactic and semantic descriptions of this indexing and retrieval model and some reasoning services involved in the issue are also analyzed and discussed. Finally, a simple semantic indexing and retrieval model framework of this method has been presented.
Digital Oil Field Data Management Based on Data Grid
Authors: Man Yuan, Xiaoli Guo, Rui He, Jianping Hu
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

With the development of Internet and computation technique, many areas begin to process their own area data more accurately. Especially, oil field area involves many disciplinary area data, such as physical geography disciplinary, geological disciplinary, reservoir engineering disciplinary and so on, data from simple character type to complex bulk data volume type. How to effectively manage these distributed data is always a hot potato for the oil field companies, recently, many oil companies begin to construct their own data center, however, only some topic data for research is stored in data center, it does not implement real uniform data management. Data grid technique is proposed for solving these issues, it regards data management issues as service management, and it solves data management issues puzzled people. According to these facts, a digital oil field framework based on data grid technique is proposed. We think this framework is able to solve oil field data management issues and provide all kinds of users with interested data.
Application of GIS to spatial analysis of mesofault populations
Authors: Mauro Alberti
Venue: Computers Geosciences (2005)

This paper presents a GIS approach to spatial analysis of fault populations. Coherence between fault moment tensors, a concept borrowed from the geophysical works of Kagan and Knopoff [1985a. Geophysical Journal of the Royal Astronomical Society 81(2), 429-444; 1985b. Geophysical Journal of the Royal Astronomical Society 83(3), 637-656], is the parameter used for quantifying the degree of similarity between faults. Fault datasets from various structural sites can be imported into a GIS software such as ArcView(R); using a series of customized GIS tools, data can then be checked and their spatial dependence may be investigated. This customization may be used to investigate the distribution of coherence values based on fault types (i.e. normal, left-lateral, etc.) and/or on the distance between faults. The analysis of a natural dataset reveals that, depending on the movement type, faults can display different coherence distributions with increasing distance ranges, and in some cases also a cyclic behavior. These findings can help reconstruct the history and understand the kinematic significance of fault populations.
Decoupling data dissemination from mobile Sink's trajectory in wireless sensor networks
Authors: Aline C. Viana, Artur Ziviani, Roy Friedman
Venue: IEEE Communications Letters (2009)

We propose an efficient proactive data dissemination approach that allows a mobile sink to effectively gather a representative view of a monitored region covered by n sensor nodes by visiting any m nodes, where m ≪ n. Moreover, the proposed strategy allows the mobile sink to follow any trajectory through the deployment region, thus decoupling the data dissemination management from the mobile sink's trajectory.
Symbol-based processing with balanced subcarrier performance for MIMO-OFDM systems
Authors: Yinman Lee, Yun-Jung Hsieh, Hong-Wei Shieh
Venue: IEEE Communications Letters (2009)

Recently, symbol-based beamforming/combining has been introduced for OFDM systems with multiple transmit and receive antennas [1]. Despite the complexity reduction, the resultant SNR values of different subcarriers are often not balanced, and it limits the system performance. In this letter, we propose to use the max-min criterion to overcome the problem. Simulation results show that the error-rate performance of the proposed symbol-based processing scheme can be improved as compared with that of the conventional one.
Testing process performance based on capability index Cpk with critical values
Authors: W. L. Pearn, P. C. Lin
Venue: Computers and Industrial Engineering (2004)

Process capability index C"p"k has been widely used in the manufacturing industry as a process performance measure. In this paper, we investigate the natural estimator of the index C"p"k, and show that under the assumption of normality its distribution can be expressed as a mixture of the chi-square and the normal distributions. We also implement the theory of hypothesis testing using the natural estimator of C"p"k, and provide efficient Maple programs to calculate the p-values as well as the critical values for various values of @a-risk, capability requirements, and sample sizes. The behavior of the p-values and critical values as functions of the distribution parameters are investigated to obtain tight critical values for reliable testing. Based on the test, we develop a simple and practical procedure for in-plant applications. The practitioners can use the proposed procedure to determine whether their process meets the preset capability requirement, and make reliable decisions.
WADA service: an extension of DICOM WADO service
Authors: George V. Koutelakis, Dimitrios K. Lymberopoulos
Venue: IEEE Transactions on Information Technology in Biomedicine (2009)

The Web Access to Digital Imaging and Communication in Medicine (DICOM) Persistent Objects (WADO) service is standardized as the Web extension to DICOM. This paper analyzes the operational specifications of the WADO service and extends its access capability to the whole DICOM hierarchy (patient, study, series, and object). The proposed Web Access to DICOM Archives (WADA) service, as opposed to WADO, also includes an extrainternal query mechanism and support of medical reports submission. A pilot implementation of WADA as software components and their integration into a three-tier architecture are also presented. Advanced security mechanisms are augmented to ensure communication encryption, user identification, and access restriction to data according to user roles. The proposed service is a simple approach, and can be embedded in any system managing medical images and reports. WADA can also be integrated into the Cross-Enterprise Document Sharing--Imaging (XDS-I) standard, which is considered to be the most likely future standard for medical imaging exchange.
A cross-layer framework for multi-layer-video multicast with QoS requirements in multirate wireless networks
Authors: Qinghe Du, Xi Zhang
Venue: IEEE Communications Letters (2009)

We propose a cross-layer framework for efficient multi-layer-video multicast with rate adaptation and quality-of-service (QoS) requirements in multirate wireless networks. We employ time division multiple access at the physical layer to transmit different video layers' data. The multicast sender then dynamically regulates the transmission rate and time-slot allocation based on the channel state information (CSI) and loss QoS requirements imposed by upper protocol layers. Under our proposed cross-layer framework, we first design a rate adaptation algorithm to fulfill the diverse loss QoS requirements for all video layers while achieving high multicast throughput. We then develop a time-slot allocation scheme which synchronizes data transmission across different video layers. Also conducted are simulation results to validate and evaluate our designed adaptive multicasting schemes under the proposed cross-layer framework.
Designing high-speed adders in power-constrained environments
Authors: Fabio Frustaci, Marco Lanuzza, Paolo Zicari, Stefania Perri, Pasquale Corsonello
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

Data-driven dynamic logic (D3L) is very efficient when low-power constraints are mandatory. Unfortunately, this advantage is typically obtained at the expense of speed performances. This paper presents a novel technique to realize D3L parallel prefix tree adders without significantly compromising speed performance. When applied to a 64-bit Kogge-Stone adder realized with 90-nm complementary metal-oxide-semiconductor (CMOS) technology, the proposed technique leads to an energy-delay product that is 29% and 21% lower than its standard domino logic and conventional D3L counterparts, respectively. It also shows a worst case delay tbat is 10% lower than that of the D3L approach and only 5% higher than that of the conventional domino logic.
Steganalysis Based on Artificial Immune System
Authors: Dawei Wei, Shishu Zhang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

A new steganalysis method based on immune is proposed in this paper. By analyzing the theory of immune, the steganalysis based on Artificial Immune System is devised, described in detail and realized. The results of experiment show, the new method can detect the feature space parted by un-continuous boundaries, which is more effective than conventional classifiers such as FLD. Moreover, it's an intelligent technique and able to sense some unknown steganographic algorithms.
Stochastic simulation of large grids using free and public domain software
Authors: S. de Bruin, A. J. W. de Wit
Venue: Computers Geosciences (2005)

This paper proposes a tiled map procedure enabling sequential indicator simulation on grids consisting of several tens of millions of cells, without putting excessive memory requirements. Spatial continuity across map tiles is handled by conditioning adjacent tiles on their shared boundaries. Tiles across the area can be characterized by dissimilar models of spatial continuity (semi-variograms) thus relieving the requirement of a global stationarity decision. Additionally, the approach provides a simple mechanism for reseeding the pseudo random number generator. Implementation of the algorithm involved small modifications to a GSLIB program and Bash and awk scripting. The software was stable on several platforms, including 32-bit systems with a 4Gb memory addressing limit. In an experiment we simulated 25 realizations of a 11,274x13,000 grid representing local uncertainty in the Dutch land cover at 25m resolution. With the objective of mimicking the typical absence of well-distributed hard reference data, the simulations were only conditioned on local prior class probabilities and semi-variograms. Output was evaluated on the basis of reproduction of target levels of (1) cover type proportions, (2) overall class label accuracy and (3) spatially averaged local Shannon entropy. As expected, the realized statistics differed significantly from the target levels. However, the differences were consistent over the borders and the insides of map tiles. Thus, they did not result from the tiled map procedure but rather should be attributed to the used semi-conditional sequential indicator simulator. The current implementation can easily be adapted to accept other simulation algorithms.
Individual and pair behavior in learning problem in school education
Authors: Kazuhiro Shin-ike
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

In Japan most students take many courses in a classroom where more than forty students participate, and they learn many kinds of subjects individually. On the other hand, in a couple of courses such as an experiment and PBL (Problem-Based Learning), students make some groups and learn subjects collaboratively. In collaborative learning, an excellent learner belonging to a group teaches other learners, and the learning effect may improve better than individual learning, because new knowledge is provided through communication. But it is said that in group learning, some groups enhance the learning effect, and others do not. In this paper, we examine factors in enhancing the learning effect of pairs of college students who take a course. First of all, each student takes Synthetic Personality Inventory (SPI) test to investigate personalities and capabilities, and solves ten kinds of learning problems. Next, the students are divided into pair groups in order to solve some learning problems collaboratively. An analysis of this experiment shows which pairs can improve the learning effect or not. This research will be very useful to analyze the learning process in collaborative learning of pairs of students in school education.
Improving power-delay performance of ultra-law-power subthreshold SCL circuits
Authors: Armin Tajalli, Massimo Alioto, Yusuf Leblebici
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

This brief presents a technique for improving the power-delay performance of subthreshold source-coupled logic (SCL) circuits. Based on the proposed approach, a source-follower buffer stage is used at the output of each SCL stage. Analytical results confirmed by measurements in 0.18-µm CMOS technology show an improvement by a factor of as high as 2.4 in power-delay product (PDP). It is also shown that the proposed technique can be used for implementing subthreshold ultra-low power SCL logic gates with a better power and area efficiency, compared to the traditional SCL subthreshold circuits. An optimized approach is proposed to improve the power efficiency of ultra-low power STSCL library cells.
Design criteria of two-hop based wireless networks with non-regenerative relays in arbitrary fading channels
Authors: Stefano Savazzi, Umberto Spagnolini
Venue: IEEE Transactions on Communications (2009)

In this paper we evaluate outage performances of multirelay amplify and forward (AF) transmission over fading channels. We focus on the uplink of a two-hop based network where N (with N ≥ 1) single antenna relay stations (RSs) serve as non-regenerative repeaters for the message transmitted by a single antenna source node (or mobile station MS). Performances are derived at high SNR for arbitrary fading distributions over each cooperative link. In Rayleigh fading the high price of cooperation in terms of signalling (e.g. during MS-to-RSs transmissions and control messages broadcasts) causes a significant loss in spectral efficiency. Instead, provided that the RSs can be strategically positioned to benefit from a channel with marginal diffusive fading component compared to Rayleigh, this paper shows that this loss in efficiency can be significantly alleviated depending on the particular propagation environment. Closed form conditions on the fading statistics for the relayed links are derived to guarantee that collaborative transmission performs as if the MS node would benefit from the same diversity and bandwidth efficiency provided by multi-antenna transmission. The proposed conditions are computed for arbitrary distributed fading for the relays-to-BS link and are specialized for Rice faded RSs-to-BS links.
Artificial neural networks in wave predictions at the west coast of Portugal
Authors: O. Makarynskyy, A. A. Pires-Silva, D. Makarynska, C. Ventura-Soares
Venue: Computers Geosciences (2005)

In coastal and open ocean human activities, there is an increasing demand for accurate estimates of future sea state. In these activities, predictions of wave heights and periods are of particular importance. In this study, two different neural network strategies were employed to forecast significant wave heights and zero-up-crossing wave periods 3, 6, 12 and 24h in advance. In the first approach, eight simple separate neural nets were implemented to simulate every wave parameter over each prediction interval. In the second approach, only two networks provided simultaneous forecasts of these wave parameters for the four prediction intervals. Two independent sets of measurements from a directional wave buoy moored off the Portuguese west coast were used to train and to validate the artificial neural nets. Saliency analysis of the results permitted an optimization of the networks' architectures. The optimal learning algorithm for each case was also determined. The short-term forecasts of the wave parameters verified by actual observations demonstrate the suitability of the artificial neural technique.
Design of joint network-low density parity check codes based on the EXIT charts
Authors: Ying Li, Guanghui Song, Lili Wang
Venue: IEEE Communications Letters (2009)

For the multiple-access relay network where two sources communicate with one destination in the presence of one relay, a practical joint network-low density parity check code is designed to help the relay jointly re-encode the messages from both sources. A bilayer Extrinsic Information Transfer Chart is developed based on which a design methodology is proposed to iteratively improve the degree distribution of the proposed code. Simulations illustrate that the gap between the convergence threshold and the performance of the coding scheme is less than 0.6dB at BER=10-5.
A New GEP Algorithm Based on Multi-phenotype Chromosomes
Authors: Zenghong Wu, Min Yao
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

This paper presents an improved Gene Expression Programming (GEP) algorithm Based on Multi-Phenotype Chromosomes (MPC-GEP). The populations in MPC-GEP are composed of chromosomes with multiple phenotypes. Each multi-gene chromosome corresponds to multiple expression trees. The new algorithm can find the optimal individual in less time than traditional GEP. Finally, experiments on the new algorithm against traditional GEP algorithm are conducted on several benchmark datasets. Results show that MPC-GEP outperforms traditional GEP in function finding in terms of speed.
Transferring e-learning skills between Europe and China: the telepath approach
Authors: Carlos Vaz de Carvalho, Dave Harvey, Allan Hobson, Suiran Yu
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

The Telepath action aims to promote and strengthen the e-learning infrastructure in China, by transferring key ICT (Information and Communication Technologies) skills from Europe into Asia. By linking three well respected universities in China, Portugal and the UK it is planned to develop a cluster of e-learning courses at post-graduate level in an innovative organizational methodology that addresses virtual mobility.
A Scoring Function for Retrieving Photo Sets with Broad Topic Coverage
Authors: Sangjin Lee, Jonghun Park
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

As a storage-unit of user created web objects, the set has become an emerging challenge in the retrieval. Set search requires relevant sets to meet the information need of users, whereas traditional information retrieval focuses on finding relevant web objects. This paper proposes a new approach to measure relevance of sets with respect to a user query by their topic coverage. The main idea of the proposed approach is to prefer the set which covers as many different query-related topics as possible. The problem domain of this paper is photo sets of the Flickr.com, which are collections of photos. The experimental result shows that our algorithm outperforms the previous collection selection algorithm.