ppxscal/embedding_network huggingface dataset:
The covering number for some Mercer kernel Hilbert spaces
Authors: Sheng Baohuai, Wang Jianli, Li Ping
Venue: Journal of Complexity (2008)

In the present paper, we investigate the estimates for the covering number of a ball in a Mercer kernel Hilbert space on [0,1]. Let P"l(x) be the Legendre orthogonal polynomial of order l, a"l>0 be real numbers satisfying @?"l"="0^+^~la"l
An Automated Approach for Writing Alloy Specifications Using Instances
Authors: Sarfraz Khurshid, Muhammad Zubair Malik, Engin Uzuncaova
Venue: Proceedings of the Second International Symposium on Leveraging Applications of Formal Methods, Verification and Validation (2006)

We present aDeryaft, a novel technique for automating the writing of specifications in Alloy---a first-order relational logic with transitive closure. Alloy is particularly suitable for specifying structural properties of software, and has steadily been gaining popularity due to the rapid feedback that its SAT-based analyzer provides fully automatically. Alloy users however, still have to manually write specifications in a declarative language and use a paradigm that is different from the commonly used imperative programming paradigm. aDeryaft assists Alloy users in writing their specifications by providing a novel specification-writing approach, which is particularly tailored to users, such as engineers or practitioners inindustry, who may not have much prior experience or proficiency inAlloy or similar logics. The user constructs by hand a few small concrete instances that represent the constraints of the software structure they want to specify. aDeryaft then fully automatically generates an executable Alloy specification, which represents the constraints that summarize the given structures. The generated specification is fully executable. For example, the Alloy Analyzer can use it to systematically enumerate a large number of concrete instances that satisfy the same constraints as the given instances. Indeed, a user may use aDeryaft to generate partial specifications while the user writes the rest of the specification by hand. To efficiently generate Alloy specifications, aDeryaft exploits the relational basis of Alloy and formulates graph properties that are likely to hold for the given instances. It then checks the properties for these instances and translates the valid properties into Alloy constraints, which it outputs as an Alloy specification. We illustrate aDeryaft's constraint generation on a variety of commonly used data structures.
Non-monotonic modelling from initial requirements: a proposal and comparison with monotonic modelling methods
Authors: Jelena Marincic, Angelika Mader, Hanno Wupper, Roel Wieringa
Venue: Proceedings of the 3rd international workshop on Applications and advances of problem frames (2008)

Researchers make a significant effort to develop new modelling languages and tools. However, they spend less effort developing methods for constructing models using these languages and tools. We are developing a method for building an embedded system model for formal verification. Our method provides guidelines to build a model and to construct a correctness argument. We start from a high-level formula stating that a plant (a device that performs a task) and its control should satisfy requirements. As our knowledge about the system grows, we refine this formula and the model gradually, in a stepwise non-monotonic process, until we have a description that can be formally verified. In this paper we explain our method on a simple example and compare it briefly with two other methods: requirements progression and the goal-oriented KAOS approach. The requirements progression is an extension of a problem frames approach. The KAOS method is also based on problem frames, but introduces new concepts for describing a system.
Mining Medical Databases with Modified Gini Index Classification
Authors: Quocnam Tran
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

Decision tree classification is a common method used in data mining. It has been used for predicting medical diagnoses. Among data mining methods for classification, decision trees have several advantages such as they are simple to understand and interpret; they are able to handle both numerical and categorical attributes. However, it is well-known that when Gini index is used for classification, the method biases multivalued attributes. In addition to having difficulty when the number of classes is large, the method also tends to favor tests that result in equal-sized partitions and purity in all partitions.In this paper, we modify the Gini-based decision tree method. To overcome the known problems, we normalize the Gini indexes by taking into account information about the splitting status of all attributes. Instead of using the Gini index for attribute selection as usual, we use ratios of Gini indexes and their splitting values in order to reduce the biases. We report our experiments with several benchmark medical data bases. Comparisons between our method and other known classification algorithms are provided.
Generalising multiple capture-recapture to non-uniform sample sizes
Authors: Paul Thomas
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

Algorithms in distributed information retrieval often rely on accurate knowledge of the size of a collection. The "multiple capture-recapture" method of Shokouhi et al. is one of the more reliable algorithms for determining collection size, but it relies on samples with a uniform number of documents. Such uniform samples are often hard to obtain in a working system. A simple generalisation of multiple capture-recapture does not rely on uniform sample sizes. Simulations show it is as accurate as the original method even when sample sizes vary considerably, making it a useful technique in real tools.
Perceptually adaptive joint deringing - deblocking filtering for scalable video coding
Authors: Shuai Wan, Marta Mrak, Ebroul Izquierdo
Venue: Proceedings of the 2nd international conference on Mobile multimedia communications (2006)

A new perceptually adaptive joint deringing - deblocking filtering method for wavelet based scalable video coding is proposed. The proposed approach is specially designed to deal with the artifacts inherent to video transmission over very low-bit-rate channels, wireless channel for example. A structure based on in-loop filtering is designed to decode scalable coded video considering the update step in motion compensated temporal filtering. Since ringing and blocking artifacts are visually disturbing, the characteristics of the human visual system (HVS) are considered in the underlying bilateral filtering. In the proposed approach, the filter strength is adjusted according to the perceptual distortion by integrating the HVS models of luminance masking, activity masking and temporal masking. Consequently, a different filtering strength is applied to areas with different perceptual sensitivity in terms of the HVS. A comparative evaluation using conventional loop filtering structure and bilateral filter was conducted. The experimental assessment demonstrates a superior performance of the proposed adaptive filtering, providing substantial and consistent better objective and subjective quality.
The State of Executable Real-Time Specification Languages and the Need for Advancements
Authors: Amir A. Khwaja, Joseph E. Urban
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

Several real-time executable software specification languages and techniques exist. However, there are aspects among these languages that are preventing these languages from being widely accepted and adopted. The paper identifies three key areas contributing to this non-acceptability. The paper also suggests future directions and advancements needed in the identified areas.
Some Aspects of Thermal and Radiation Flows Modelling in Buildings Using Modelica
Authors: Anton Sodja, Borut Zupancic
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

Efficient use of energy in buildings is very important. Special attention is given to the use of passive energy resources as the costs for heating and cooling can be significantly reduced and living conditions at the same time improved. Modelling of thermal and radiant flows and illumination is very important in this area and so many models with different aims and complexity were developed in the past. Traditional models have a significant lack of object orientation which represents an important disadvantage, because it is difficult or sometimes even impossible to reuse model components. This paper deals with some activities about a simulator which models thermal and radiation flows in buildings. It was originally developed in Matlab/Simulink environment. With the reimplementation in object-oriented Dymola Modelica environment the quality of simulator was significantly improved in different aspects. However, since distribution of radiation flows is mostly geometrical problem, the reusability is not gained implicitly by using Modelica as it is when using models described by DAE. Additional efforts were needed to make components fully reusable. The proposed solutions significantly increased the possibilities for more complicated building structures modelling.
Why Predicting Outliers in Software is a Good Thing to Do!
Authors: Norm Schneidewind, Mike Hinchey
Venue: Proceedings of the 13th IEEE International Conference on on Engineering of Complex Computer Systems (2008)

A software reliability model is used to predict outliers, that is, values that significantly depart from the expected or mean values. In contrast with most projects that cleanse outliers from their databases because their presence distorts results, we tend to like outliers because by predicting them, we can help ensure safety in critical systems. We use the Space Shuttle failure data to make predictions of whether reliability goals are met if outliers should occur during test or the operational mission. In addition, prospective Shuttle software releases are analyzed to detect possible anomalous behavior that would call for re-inspection of the software to bring it into conformance with reliability specifications.
A high-performance operating system for structured concurrent programs
Authors: Luc Bläser
Venue: Proceedings of the 4th workshop on Programming languages and operating systems (2007)

With the advent of multi-processor machines, the time has definitively come to use new programming models that offer an improved support of concurrency. While various interesting new models have been recently presented for concurrent and structured programming, no appropriate runtime systems currently exists. Therefore, we have developed our own new operating system which has been particularly optimized for high-performance execution of such programs.
Mapping evapotranspiration in the Indus Basin using ASTER data
Authors: A. Sarwar, R. Bill
Venue: International Journal of Remote Sensing (2007)

Conventional methods that use point measurements to estimate evapotranspiration are representative only of local areas and cannot be extended to large areas because of heterogeneity of landscape. To overcome this difficulty, remote sensing has proven to be the most suitable approach for large area estimation of evapotranspiration because remote sensing data can provide representative parameters such as radiometric surface temperature, albedo and vegetation index. The heterogeneity is more prominent in the Indus Basin as more than 80% of farmers have land holdings less than 4 ha, and within these holdings, two or three different crops are usually grown. The limitation of most remote sensing based procedures to estimate evapotranspiration is the measurements of large number of crop-specific and climatic parameters, which are not only difficult to obtain but also require considerable field work, equipment and therefore involve much expenditure. The purpose of this study was to present a simple methodology that requires minimum ground observations for estimation of evapotranspiration to test the reliability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for estimation of evapotranspiration in the Indus Basin. The methodology is based on surface energy balance to estimate sensible and latent heat fluxes by combining remotely sensed data from ASTER with common meteorological data. The various components of surface energy balance were computed during satellite overpass and 24-h integrated fluxes were derived for the full ASTER scene acquired over the lower Rechna doab region of the Indus Basin. The surface brightness temperatures were derived from thermal band 13 and NDVI from two VNIR bands of the ASTER. Evapotranspiration values from the maize field in the Indus Basin, as estimated using ASTER data at Shahkot, Jaranwala and Satiana locations, were estimated as 2.05, 2.77 and 2.32 mm day-1, respectively. The estimated evapotranspiration was compared with evapotranspiration computed at three different locations using CROPWAT software and was found to be in close agreement.
The impact of information technology on individual and firm marketing performance
Authors: Robert W. Stone, David J. Good, Lori Baker-Eveleth
Venue: Behaviour & Information Technology (2007)

The perceived impacts of information technology use on firm marketing organization performance are examined. A theoretical model is presented linking organizational and end-user traits, information quality, system/service quality, industry traits, and tasks performed using a system to perceptions of organizational performance impacts through ease of system use, perceived individual performance impacts (i.e. perceived usefulness), attitudes toward using the system, and system use. The empirical examination uses a mail survey of US marketing executives to collect the data. The quantitative technique used is structural equation modeling. The results indicate that measures of organizational traits, individual traits, information quality, system/service quality, and tasks performed using the system impact perceived performance of the marketing organization mediated individual performance impacts (i.e. perceived usefulness), attitudes toward using the system, and system use. Managerial implications and conclusions are presented based upon these results.
Perfectly secure message transmission
Authors: D. Dolev, C. Dwork
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

The problem of perfectly secure communication in a general network in which processors and communication lines may be faulty is studied. Lower bounds are obtained on the connectivity required for successful secure communication. Efficient algorithms that operate with this connectivity and rely on no complexity theoretic assumptions are derived. These are the first algorithms for secure communication in a general network to achieve simultaneously the goals of perfect secrecy, perfect resiliency, and a worst case time which is linear in the diameter of the network.
IPzip: A Stream-Aware IP Compression Algorithm
Authors: Su Chen, Supranamaya Ranjan, Antonio Nucci
Venue: Proceedings of the Data Compression Conference (2008)

This paper proposes IPzip, a comprehensive suite of algorithms for compressing IP network packet headers and payloads. We propose an online algorithm for compressing packets in real-time for efficient transfer and an offline algorithm for efficient storage of the network data. In contrast to related approaches, IPzip achieves better compression by exploiting the correlations exhibited by (i) packets that are similar such as those belonging to the same layer-4 flow or those with the same destination port (inter-packet correlation) and (ii) header fields that are correlated to each other (intra-packet correlation). Since reordering of packets and fields is resource intensive, IPzip generates a near-optimal compression plan in an offline phase. Moreover, we propose a methodology to monitor over time the effectiveness of the compression plan being used and switch to a new compression plan when performance of the current compression plan decreases due to changes in the intrinsic traffic structure. Finally, via trace-driven experiments on network traffic obtained from Tier-1 ISPs, we validate that IPzip achieves better performance compared to related approaches.
Star-factors of tournaments
Authors: Guantao Chen, Xiaoyun Lu, Douglas B. West
Venue: Journal of Graph Theory (1998)

Let Sm denote the m-vertex simple digraph formed by m - 1 edges with a common tail. Let f(m) denote the minimum n such that every n-vertex tournament has a spanning subgraph consisting of n-m disjoint copies of Sm. We prove that m lg m - m lg lg m &le; f(m) &le; 4m2 - 6m for sufficiently large m. &copy; 1998 John Wiley & Sons, Inc. J. Graph Theory 28: 141&ndash;145, 1998
A framework of order evaluation and negotiation for SMMEs in networked manufacturing environments
Authors: B. -H. Zhou, L. Feng Xi, L. -Y. Tao
Venue: International Journal of Computer Integrated Manufacturing (2007)

In the context of enhancing the manufacturing abilities of Chinese small-and medium-sized manufacturing enterprises (SMMEs), the present paper reports on a framework of order evaluation and negotiation of collaborative manufacturing for SMMEs in networked manufacturing environments. First, the background and problem domain are introduced. Then the information required to evaluate and negotiate orders is examined in a collaborative manufacturing process. Based on this information, a framework of order evaluation is built on the profit and due date, and then an order negotiation model framework, combined with an order evaluation model, is also presented. At the same time, a standardized negotiation process is described in more detail. Finally, a case study is presented to illustrate how business-to-business SMMEs evaluate and negotiate an order with a business-to-customer SMME to obtain the best profit-due date trade-off.
P2P-based routing and data management using the virtual cord protocol (VCP)
Authors: Abdalkarim Awad, Reinhard German, Falko Dressler
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

We present Virtual Cord Protocol (VCP), a virtual relative position based routing protocol for sensor networks that also provides methods for data management as known from standard DHT services. Self-organizing and cooperative algorithms are thought to be the optimal solution to overcome the inherent resource limitations in sensor networks. On an abstract level, DHT techniques offer O(1) complexity data lookup. Unfortunately, they usually rely on underlayer routing techniques. The key contributions of VCP are the independence of real location information by relying on relative positions of neighboring nodes, successors and predecessors in the cord are always in their vicinity, and the high scalability because only information about direct neighbors are needed for routing. Furthermore, VCP inherently prevents dead-ends and it is easy to be implemented.
Statistical trust establishment in wireless sensor networks
Authors: Matthew J. Probst, Sneha Kumar Kasera
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 01 (2007)

We present a new distributed approach that establishes reputation-based trust among sensor nodes in order to identify malfunctioning and malicious sensor nodes and minimize their impact on applications. Our method adapts well to the special characteristics of wireless sensor networks, the most important being their resource limitations. Our methodology computes statistical trust and a confidence interval around the trust based on direct and indirect experiences of sensor node behavior. By considering the trust confidence interval, we are able to study the tradeoff between the tightness of the trust confidence interval with the resources used in collecting experiences. Furthermore, our approach allows dynamic scaling of redundancy levels based on the trust relationship between the nodes of a wireless sensor network. Using extensive simulations we demonstrate the benefits of our approach over an approach that uses static redundancy levels in terms of reduced energy consumption and longer life of the network. We also find that high confidence trust can be computed on each node with a relatively small memory overhead and used to determine the level of redundancy operations among nodes in the system.
On critically perfect graphs
Authors: Annegret Wagler
Venue: Journal of Graph Theory (1999)

A perfect graph is critical, if the deletion of any edge results in an imperfect graph. We give examples of such graphs and prove some basic properties. We relate critically perfect graphs to well-known classes of perfect graphs, investigate the structure of the class of critically perfect graphs, and study operations preserving critical perfectness. &copy; 1999 John Wiley & Sons, Inc. J Graph Theory 32: 394&ndash;404, 1999
A versatile policy toolkit supporting run-time policy reconfiguration
Authors: Richard John Anthony
Venue: Cluster Computing (2008)

This paper describes an autonomics development tool which serves as both a powerful and flexible policy-expression language and a policy-based framework that supports the integration and dynamic composition of several autonomic computing techniques including signal processing, automated trend analysis and utility functions. Each of these technologies has specific advantages and applicability to different types of dynamic adaptation. The AGILE platform enables seamless interoperability of the different technologies to each perform various aspects of self-management within a single application. Self-management behaviour is specified using the policy language semantics to bind the various technologies together as required. Since the policy semantics support run-time re-configuration, the self-management architecture is dynamically composable. The policy language and implementation library have integrated support for self-stabilising behaviour, enabling oscillation and other forms of instability to be handled at the policy level with very little effort on the part of the application developer. Example applications are presented to illustrate the integration of different autonomics techniques, and the achievement of dynamic composition.
Silhouette Smoothing for Real-Time Rendering of Mesh Surfaces
Authors: Lu Wang, Changhe Tu, Wenping Wang, Xiangxu Meng, Bin Chan, Dongming Yan
Venue: IEEE Transactions on Visualization and Computer Graphics (2008)

Coarse piecewise linear approximation of surfaces causes undesirable polygonal appearance of silhouettes. We present an efficient method for smoothing the silhouettes of coarse triangle meshes using efficient 3D curve reconstruction and simple local re-meshing. It does not assume the availability of a fine mesh and generates only moderate amount of additional data at run time. Furthermore, polygonal feature edges are also smoothed in a unified framework. Our method is based on a novel interpolation scheme over silhouette triangles and this ensures that smooth silhouettes are faithfully reconstructed and always change continuously with respect to continuous movement of the view point or objects. We speed up computation with GPU assistance to achieve real-time rendering of coarse meshes with the smoothed silhouettes. Experiments show that this method outperforms previous methods for silhouette smoothing.