ppxscal/embedding_network huggingface dataset:
High resolution spatio-temporal water vapour mapping using GPS and MERIS observations
Authors: Roderick Lindenbergh, Maxim Keshin, Hans van der Marel, Ramon Hanssen
Venue: International Journal of Remote Sensing (2008)

Improved knowledge of atmospheric water vapour and its temporal and spatial variability is of great scientific interest for climate research and weather prediction. Moreover, the availability of fine resolution water vapour maps is expected to reduce significant errors in applications using the Global Positioning System, GPS, or radar interferometry. Several methods exist to estimate water vapour using satellite systems. Combining radiances as measured in two spectral bands of the Medium Resolution Imaging Spectrometer (MERIS) results in an Integrated Water Vapor (IWV) product with high spatial resolution, up to 300 m, but a limited temporal resolution of about three days, in case of cloud free conditions. On the other hand, IWV estimates can be derived from the zenith total delays as observed by continuous GPS networks. The GPS IWV estimates have a higher temporal resolution of typically 1 hour, but, even in Western Europe, inter-station distances are at least tenths of kilometres. Here we describe how to obtain IWV products with high spatio-temporal resolution by combining GPS and MERIS IWV estimates. For this purpose an analysis is made of MERIS and GPS based IWV data, retrieved at the same day over Western Europe. A variance-covariance analysis is performed and is subsequently applied to produce time series of combined high-resolution water vapour maps using Kriging. The research presented here is a first step towards near real-time fine resolution water vapour products.
Rose: compressed, log-structured replication
Authors: Russell Sears, Mark Callaghan, Eric Brewer
Venue: Proceedings of the VLDB Endowment (2008)

Rose is a database storage engine for high-throughput replication. It targets seek-limited, write-intensive transaction processing workloads that perform near real-time decision support and analytical processing queries. Rose uses log structured merge (LSM) trees to create full database replicas using purely sequential I/O, allowing it to provide orders of magnitude more write throughput than B-tree based replicas. Also, LSM-trees cannot become fragmented and provide fast, predictable index scans. Rose's write performance relies on replicas' ability to perform writes without looking up old values. LSM-tree lookups have performance comparable to B-tree lookups. If Rose read each value that it updated then its write throughput would also be comparable to a B-tree. Although we target replication, Rose provides high write throughput to any application that updates tuples without reading existing data, such as append-only, streaming and versioning databases. We introduce a page compression format that takes advantage of LSM-tree's sequential, sorted data layout. It increases replication throughput by reducing sequential I/O, and enables efficient tree lookups by supporting small page sizes and doubling as an index of the values it stores. Any scheme that can compress data in a single pass and provide random access to compressed values could be used by Rose. Replication environments have multiple readers but only one writer. This allows Rose to provide atomicity, consistency and isolation to concurrent transactions without resorting to rollback, blocking index requests or interfering with maintenance tasks. Rose avoids random I/O during replication and scans, leaving more I/O capacity for queries than existing systems, and providing scalable, real-time replication of seek-bound workloads. Analytical models and experiments show that Rose provides orders of magnitude greater replication bandwidth over larger databases than conventional techniques.
Control for stability and positivity of 2-D linear discrete-time systems
Authors: Mohammed Alfidi, Abdelaziz Hmamed
Venue: WSEAS Transactions on Systems and Control (2007)

This paper investigate the stabilizability of 2-D linear discrete-time systems described by the Roesser model with closed-loop positivity. Necessary and sufficient condition for the existence of desired state-feedback controllers guaranteeing the resultant closed-loop system to be asymptotically stable and positive is obtained. The synthesis of state-feedback controllers, including the requirement of positiveness of the controllers and its extension to uncertain plants are solved in terms of Linear Matrix Inequalities (LMIs) which can be easily verifies by using standard numerical software. Numerical examples are provided to illustrate the proposed conditions.
Implementation and comparison of contemporary data clustering techniques for a multi-compressor system: a case study
Authors: Gursewak S. Brar, Yadwinder S. Brar, Yaduvir Singh
Venue: WSEAS Transactions on Systems and Control (2007)

This paper gives the implementation and deployment of fuzzy clustering algorithm applied to a process control data along with its comparison to various other clustering algorithms. In this paper, the analysis is carried out for the data as obtained from a multi-compressor system based on the factor of keeping the maximum weighted square error at the minimum level. Also, this paper consists of an algorithm, which groups the data according to fuzzy clustering, considering the intermediate values between zero and one. The paper also outlines the comparison among other clustering algorithms on the basis of various validation parameters there by telling us the importance of fuzzy clustering, which considers all the ambiguity in data to be a part of n-clusters, giving an extra attribute of membership function.
A complete analyze of using shift registers in cryptosystems for grade 4, 8 and 16 irreducible polynomials
Authors: Mirella Amelia Mioc
Venue: WSEAS Transactions on Computers (2008)

A Linear Feedback Shift Register (LFSR) is always the kernel of any digital system based on pseudorandom bits sequences and is frequently used in cryptosystems, in codes for errors detecting, in wireless system communication. The Advanced Encryption System (Rijndael) is based on using a grade 8 irreducible polynomials in a Galois Field. For a better understanding this study contains aspects of functioning for Linear Feedback Shift Register and Multiple Input-Output Shift Register (MISR) using grade 4, 8 and 16 irreducible polynomials. This experiment shows that the Linear Feed-back Shift Register and Multiple Input-Output Shift Register have the same function. The conclusion of this paper is that for grade 8 and 16 irreducible polynomials the weights are calculated with a formula discovered in this work.
Capacity and performance analysis of space-time block codes in Rayleigh fading channels
Authors: A. S. Hiwale, A. A. Ghatol
Venue: WSEAS TRANSACTIONS on COMMUNICATIONS (2007)

Multi-Antenna systems are expected to play very important role in future multimedia wireless communication systems. Such systems are predicted to provide tremendous improvement in spectrum utilization. In this paper we consider the capacity analysis of Multiple-Input Multiple-Output (MIMO) systems. Space-Time coding schemes are the practical signal design techniques to realize the information theoretic capacity limits of MIMO systems. Here the orthogonal space-time block codes are considered for the capacity and error probability analysis of MIMO systems as a case study. The numerical and simulation results obtained using MATLAB are presented for the Multi-antenna system channel capacity and bit-error probability in Rayleigh fading channels.
Tools for analyzing intelligent agent systems
Authors: Tibor Bosse, Dung N. Lam, K. Suzanne Barber
Venue: Web Intelligence and Agent Systems (2008)

When developing sophisticated multi-agent systems whose behaviors include collaboration, negotiation, and conflict resolution, analyzing and (empirically) verifying agent system behavior is a challenging task. To aid the developer in such tasks, this paper presents an approach that combines two software engineering tools - the Tracer Tool and the TTL Checker, which together record agent activities as execution traces and verify that the traces satisfy specified properties. The objective of the combined tool is to aid the user in redesigning, debugging, and maintaining the agent system. The Tracer Tool ensures that the user's comprehension of the system behavior is accurate with respect to the execution traces and provides explanations of anomalous behavior, which can be detected as a failed behavioral property by the TTL Checker. The integrated approach has been applied to an agent-based system designed to coordinate unmanned aerial vehicles.
Evaluation of global land cover data sets over the tundra-taiga transition zone in northernmost Finland
Authors: J. Heiskanen
Venue: International Journal of Remote Sensing (2008)

The remote sensing-based continental to global scale land cover data sets provide several land cover depictions over the circumpolar tundra-taiga transition zone. The aim of this study was to evaluate three data sets in northernmost Finland: the Global Land Cover 2000 Northern Eurasia map (GLC2000-NE), the MODIS global land cover map (MODIS-IGBP) and the tree cover layer of the MODIS vegetation continuous fields product (MODIS-VCF). The data sets were first compared both visually and statistically to biotope inventory data including tree cover, height, species composition and shrub cover information as continuous variables. The agreement with reference data was poor because the classifications do not correspond to the class descriptions. The MODIS-VCF tree cover overestimates the tree cover in the low values and underestimates it in the high values. The agreement was relatively good when the global data sets were aggregated to a forest-non-forest level and compared to the Finnish CORINE Land Cover 2000 map over a larger area. However, the inaccurate mapping of the deciduous broadleaf forests and mires reduced the agreement at the forest-non-forest level. The vegetation transitions are difficult to map using low-resolution satellite data and further improvements to the land cover characterization over the tundra-taiga transition zone are required.
Throughput-oriented MAC for mobile ad hoc networks: A game-theoretic approach
Authors: Fan Wang, Ossama Younis, Marwan Krunz
Venue: Ad Hoc Networks (2009)

The conservative nature of the 802.11 channel access scheme has instigated extensive research whose goal is to improve the spatial reuse and/or energy consumption of a mobile ad hoc network. Transmission power control (TPC) was shown to be effective in achieving this goal. Despite their demonstrated performance gains, previously proposed power-controlled channel access protocols often incur extra hardware cost (e.g., require multiple transceivers). Furthermore, they do not fully exploit the potential of power control due to the heuristic nature of power allocation. In this paper, we propose a distributed, single-channel MAC protocol (GMAC) that is inspired by game theory. In GMAC, each transmitter computes a utility function that maximizes the link's achievable throughput. The utility function includes a pricing factor that accounts for energy consumption. GMAC allows multiple potential transmitters to contend through an admission phase that enables them to determine the transmission powers that achieve the Nash equilibrium (NE). Simulation results indicate that GMAC significantly improves the network throughput over the 802.11 scheme and over another single-channel power-controlled MAC protocol (POWMAC). These gains are achieved at no extra energy cost. Our results also indicate that GMAC performs best under high node densities and large data packet sizes.
Differential symbolic execution
Authors: Suzette Person, Matthew B. Dwyer, Sebastian Elbaum, Corina S. Pǎsǎreanu
Venue: Proceedings of the 16th ACM SIGSOFT International Symposium on Foundations of software engineering (2008)

Detecting and characterizing the effects of software changes is a fundamental component of software maintenance. Version differencing information can be used to perform version merging, infer change characteristics, produce program documentation, and guide program re-validation. Existing techniques for characterizing code changes, however, are imprecise leading to unnecessary maintenance efforts. In this paper, we introduce a novel extension and application of symbolic execution techniques that computes a precise behavioral characterization of a program change. This technique, which we call differential symbolic execution (DSE), exploits the fact that program versions are largely similar to reduce cost and improve the quality of analysis results. We define the foundational concepts of DSE, describe cost-effective tool support for DSE, and illustrate its potential benefit through an exploratory study that considers version histories of two Java code bases.
Manipulating trigonometric expressions encodedthrough electro-tactile signals
Authors: Tatiana G. Evreinova
Venue: Proceedings of the 10th international conference on Multimodal interfaces (2008)

Visually challenged pupils and students need special developmental tools. To facilitate their skills acquisition in math, different game-like techniques have been implemented. Along with Braille, the electro-tactile patterns (eTPs) can be used to deliver mathematical content to the visually challenged user. The goal of this work was to continue an exploration on non-visual manipulating mathematics. The eTPs denoting four trigonometric functions and their seven arguments (angles) were shaped with designed electro-tactile unit. Matching software application was used to facilitate the learning process of the eTPs. The permutation puzzle game was employed to improve the perceptual skills of the players in manipulating the trigonometric functions and their arguments encoded. The performance of 8 subjects was investigated and discussed. The experimental findings confirmed the possibility of the use of the eTPs for communicating different kinds of math content.
Interactive source registration in community-oriented information integration
Authors: Yannis Katsis, Alin Deutsch, Yannis Papakonstantinou
Venue: Proceedings of the VLDB Endowment (2008)

Modern Internet communities need to integrate and query structured information. Employing current information integration infrastructure, data integration is still a very costly effort, since source registration is performed by a central authority which becomes a bottleneck. We propose the community-based integration paradigm which pushes the source registration task to the independent community members. This creates new challenges caused by each community member's lack of a global overview on how her data interacts with the application queries of the community and the data from other sources. How can the source owner maximize the visibility of her data to existing applications, while minimizing the clean-up and reformatting cost associated with publishing? Does her data contradict (or could it contradict in the future) the data of other sources? We introduce RIDE, a visual registration tool that extends schema mapping interfaces like that of MS Biz Talk Server and IBM's Clio with a suggestion component that guides the source owner in the autonomous registration, assisting her in answering these questions. RIDE's implementation features efficient procedures for deciding various levels of self-reliance of a GLAV-style source registration for contributing answers to an application query and checking potential and definite inconsistency across sources.
Enhanced duckweed detection using bootstrapped SVM classification on medium resolution RGB MODIS imagery
Authors: C. Castillo, I. Chollett, E. Klein
Venue: International Journal of Remote Sensing (2008)

From early 2004, Lake Maracaibo (northwest Venezuela) experienced an unprecedented invasion of duckweed Lemna obscura. Recurrent blooms of the plant in the past 2 years illustrate the need for an automatic monitoring method to follow the plant cover with time and to plan contingency measures. We present an approach that allows the cover of the duckweed to be quantified through the classification of MODIS 250 m RGB composite images available from the internet. The method improves the accuracy of the results of the Support Vector Machine (SVM) algorithm for classification by including a bootstrap step during the training phase. Using only 200 pixels for training (
Outer-loop vectorization: revisited for short SIMD architectures
Authors: Dorit Nuzman, Ayal Zaks
Venue: Proceedings of the 17th international conference on Parallel architectures and compilation techniques (2008)

Vectorization has been an important method of using data-level parallelism to accelerate scientific workloads on vector machines such as Cray for the past three decades. In the last decade it has also proven useful for accelerating multi-media and embedded applications on short SIMD architectures such as MMX, SSE and AltiVec. Most of the focus has been directed at innermost loops, effectively executing their iterations concurrently as much as possible. Outer loop vectorization refers to vectorizing a level of a loop nest other than the innermost, which can be beneficial if the outer loop exhibits greater data-level parallelism and locality than the innermost loop. Outer loop vectorization has traditionally been performed by interchanging an outer-loop with the innermost loop, followed by vectorizing it at the innermost position. A more direct unroll-and-jam approach can be used to vectorize an outer-loop without involving loop interchange, which can be especially suitable for short SIMD architectures. In this paper we revisit the method of outer loop vectorization, paying special attention to properties of modern short SIMD architectures. We show that even though current optimizing compilers for such targets do not apply outer-loop vectorization in general, it can provide significant performance improvements over innermost loop vectorization. Our implementation of direct outer-loop vectorization, available in GCC 4.3, achieves speedup factors of 3.13 and 2.77 on average across a set of benchmarks, compared to 1.53 and 1.39 achieved by innermost loop vectorization, when running on a Cell BE SPU and PowerPC970 processors respectively. Moreover, outer-loop vectorization provides new reuse opportunities that can be vital for such short SIMD architectures, including efficient handling of alignment. We present an optimization tapping such opportunities, capable of further boosting the performance obtained by outer-loop vectorization to achieve average speedup factors of 5.26 and 3.64.
BioBayes
Authors: Vladislav Vyshemirsky, Mark Girolami
Venue: Bioinformatics (2008)

Motivation: There are several levels of uncertainty involved in the mathematical modelling of biochemical systems. There often may be a degree of uncertainty about the values of kinetic parameters, about the general structure of the model and about the behaviour of biochemical species which cannot be observed directly. The methods of Bayesian inference provide a consistent framework for modelling and predicting in these uncertain conditions. We present a software package for applying the Bayesian inferential methodology to problems in systems biology. Results: Described herein is a software package, BioBayes, which provides a framework for Bayesian parameter estimation and evidential model ranking over models of biochemical systems defined using ordinary differential equations. The package is extensible allowing additional modules to be included by developers. There are no other such packages available which provide this functionality. Availability: http://www.dcs.gla.ac.uk/BioBayes/ Contact: vvv@dcs.gla.ac.uk
Inter-context control-flow and data-flow test adequacy criteria for nesC applications
Authors: Zhifeng Lai, S. C. Cheung, W. K. Chan
Venue: Proceedings of the 16th ACM SIGSOFT International Symposium on Foundations of software engineering (2008)

NesC is a programming language for applications that run on top of networked sensor nodes. Such an application mainly uses an interrupt to trigger a sequence of operations, known as contexts, to perform its actions. However, a high degree of inter-context interleaving in an application can cause it to be error-prone. For instance, a context may mistakenly alter another context's data kept at a shared variable. Existing concurrency testing techniques target testing programs written in general-purpose programming languages, where a small scale of inter-context interleaving between program executions may make these techniques inapplicable. We observe that nesC blocks new context interleaving when handling interrupts, and this feature significantly restricts the scale of inter-context interleaving that may occur in a nesC application. This paper models how operations on different contexts may interleave as inter-context flow graphs. Based on these graphs, it proposes two test adequacy criteria, one on inter-context data-flows and another on inter-context control-flows. It evaluates the proposal by a real-life open-source nesC application. The empirical results show that the new criteria detect significantly more failures than their conventional counterparts.
An Efficient Approach to Compose Web Services
Authors: Hongbing Wang, Hui Liu, Xiaohui Guo
Venue: Proceedings of the 2008 IEEE/WIC/ACM International Conference on Web Intelligence and Intelligent Agent Technology - Volume 03 (2008)

An intensive work has been done for designing efficient algorithms for combining a series of Web services. However, existing solutions for Web services composition fail to present a specific method which can guide us to compose multiple services step by step. In this paper, we propose an efficient approach to address this issue. We employ Temporal Logic of Actions (TLA) to describe the behavior of services and design an algorithm to cope with the issue. Furthermore, our approach is a formal one when compared with current solutions based on BPEL, WS-CDL, OWL-S, etc. Besides, the approach can be used to both composition and verification while Petri net based method can not.
Enriched transcription factor binding sites in hypermethylated gene promoters in drug resistant cancer cells
Authors: Meng Li, Hyun-il Henry Paik, Curt Balch, Yoosung Kim, Lang Li, Tim H-M. Huang, Kenneth P. Nephew, Sun Kim
Venue: Bioinformatics (2008)

Motivation: In the human genome, ‘CpG islands’, CG-rich regions located in or near gene promoters, are normally unmethylated. However, in cancer cells, CpG islands frequently gain methylation, resulting in silencing of growth-limiting tumor suppressor genes. To our knowledge, the potential relationship between CpG island hypermethylation, transcription factor (TF) binding in local promoter regions and transcriptional control has not been previously explored in a genome-wide context. Results: In this study, we utilized bioinformatics tools and TF binding site(TFBs) databases to globally analyze sequences methylated in a laboratory model for the development of drug-resistant cancer. Our results demonstrated that four TFBS were enriched in hypermethylated sequences. More interestingly, overrepresentation of these TFBS was observed in hyper-/hypo-methylated sequences where signi.cant changes in methylation levels were observed in drug-resistant cancer cells. In summary, we believe that these.ndings offer a means to further explore the relationship between DNA methylation and gene expression in drug resistance and tumorigenesis. Contact:sunkim2@indiana.edu; knephew@indiana.edu