ppxscal/embedding_network huggingface dataset:
A practical method for computing SAR satellite revisit times: application to RADARSAT-1 and ENVISAT
Authors: A. J. E. Smith
Venue: International Journal of Remote Sensing (2007)

Many geoscience applications of space-borne Synthetic Aperture Radar (SAR) imagery require knowledge of the revisit time of the satellite at a location. In this paper, a practical method is presented for computing the revisit times of SAR satellites at any location on Earth. The method is based on the use of maps that give the number of imaging tracks, i.e. the number of satellite ground tracks from which a location can be imaged. With these maps and some basic equations, the revisit time of a SAR satellite or an arbitrary constellation of SAR satellites can be computed easily. As such, the presented method offers an alternative to computer programs that may not be available to everyone and often are tailored to the use of specific satellites. As an illustration of the method, maps with the number of imaging tracks have been computed for RADARSAT-1 and ENVISAT and their ease of use is shown by means of an example.
Mapping visualization on-demand onto a virtual globe: an appealing complement to browser-based navigation
Authors: Romain Vuillemot, Béatrice Rumpler
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

Current browser-based navigation is a universal and powerful tool, but lacks of three useful features: overview of the global website structure, efficient history browsing and an alternative to link-link navigation. By combining Visualization on-demand (Vizod) with an interactive virtual globe, we tackled these issues by means of multi-resolutions maps displayed according to user's interactions and preferences. We provided in this way a contextual hypertext navigation, each page being assigned locations and links on top a a virtual map. We built up and performed experiments of a prototype providing a smooth, appealing and promising complement to browser-based navigation.
The complexity and approximation of fixing numerical attributes in databases under integrity constraints
Authors: Leopoldo Bertossi, Loreto Bravo, Enrico Franconi, Andrei Lopatenko
Venue: Information Systems (2008)

Consistent query answering is the problem of characterizing and computing the semantically correct answers to queries from a database that may not satisfy certain integrity constraints. Consistent answers are characterized as those answers that are invariant under all minimally repaired versions of the original database. We study the problem of repairing databases with respect to denial constraints by fixing integer numerical values taken by attributes. We introduce a quantitative definition of database repair, and investigate the complexity of several decision and optimization problems. Among them, Database Repair Problem (DRP): deciding the existence of repairs within a given distance to the original instance, and CQA: deciding consistency of answers to simple and aggregate conjunctive queries under different semantics. We provide sharp complexity bounds, identifying relevant tractable and intractable cases. We also develop approximation algorithms for the latter. Among other results, we establish: (a) The @D"2^P-hardness of CQA. (b) That DRP is MAXSNP-hard, but has a good approximation. (c) The intractability of CQA for aggregate queries for one database atom denials (plus built-ins), and also that it has a good approximation.
A Scripting Approach for Workflow of Agents
Authors: Guo-Ming Fang, Zeng-Wei Hong, Jim-Min Lin
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

Agents could be applied on workflow system to provide automation and coordination of business process. However, multi-agent systems may be developed on an agent platform. The mental states of agents may be implemented in program codes relevant to the platform. The internal workflow of agents could be planed by using a script-like approach. By this way, users could command the agents to do task for them with less addressing on the implementation of agent codes. Therefore, a scripting approach is proposed in this paper for the internal workflow of mobile agents. All the work done by agents is abstracted to a task-level. The script could be used to handle the service access, the flow control and the cooperation among agents.
SCV: Structure and Constant Value based Binary Diffing
Authors: Heewan Park, Seokwoo Choi, Sunae Seo, Taisook Han
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

Binary diffing is a method to find differences in similar binary executables such as two different versions of security patches. Diffing methods using flow information detect control flow changes very fast, but they cannot track constant value changes. We present a binary diffing tool named SCV which utilizes both structure and value information. SCV summarizes structure and constant value information from disassembled code, and matches the summaries to find differences. By analyzing a Microsoft Windows security patch KB938827, we showed that SCV found necessary differences caused by constant value changes whichthe state-of-the-art binary diffing tool BinDiff failed to find.
PlasmoGF
Authors: Xiang Xu, Jinyu Wu, Jian Xiao, Yi Tan, Qiyu Bao, Fangqing Zhao, Xiaokun Li
Venue: Bioinformatics (2008)

Summary: Malaria, one of the world's most common diseases, is caused by the intracellular protozoan parasite known as Plasmodium. Recently, with the arrival of several malaria parasite genomes, we established an integrated system named PlasmoGF for comparative genomics and phylogenetic analysis of Plasmodium gene families. Gene families were clustered using the Markov Cluster algorithm implemented in TribeMCL program and could be searched using keywords, gene-family information, domain composition, Gene Ontology and BLAST. Moreover, a number of useful bioinformatics tools were implemented to facilitate the analysis of these putative Plasmodium gene families, including gene retrieval, annotation, sequence alignment, phylogeny construction and visualization. In the current version, PlasmoGF contained 8980 sets of gene families derived from six malaria parasite genomes: Plasmodium. falciparum, P. berghei, P. knowlesi, P. chabaudi, P. vivax and P. yoelii. The availability of such a highly integrated system would be of great interest for the community of researchers working on malaria parasite phylogenomics. Availability: PlasmoGF is freely available at http://bioinformatics.zj.cn/pgf/ Contact:xiaokunli@163.net; baoqy@genomics.org.cn; fuz3@psu.edu
Customizing computation accelerators for extensible multi-issue processors with effective optimization techniques
Authors: Ya-shuai Lü, Li Shen, Li-bo Huang, Zhi-ying Wang, Nong Xiao
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

Compared with single-issue general purpose processors (GPPs), extensible multi-issue/VLIW processors can exploit instruction-level parallelism, which are more suitable for computation intensive tasks. Moreover, they offer the ability of customizing computation accelerators for an application domain. In this paper, we present an automated methodology that customizes computation accelerators for the multi-issue/VLIW extensible processors, where several techniques are also proposed to optimize the design of an accelerator.
The Design of Bionic Joints: A Lesson from Synovial Joints
Authors: Zhao Danpu, Wu Dan, Yi Qiang, Nie Chenghui, Chen Ken, Xu Leon, Salo Antti, Wang Xia
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 02 (2008)

The new form factor is one of the important drivers for future electronic devices. In nature, there are many form factors with evolution process that are elegant and adaptive. In this paper, we explore the characteristics of arthrosis, with the focus on the difference between the arthrosis and machine joints. Then three types of joints are introduced, which are simulated from body arthrosis. With the analyses of the structure and motion track of these joints, the strongpoint of such joints is introduced.
The application of fluid mobility modelling in wireless cellular networks
Authors: Ronan J. Skehill, Sean McGrath
Venue: Mobile Information Systems (2007)

Mobility models, synthetic or trace, try to accurately model the movement of a single user or a group of users. Models can be used in simulators and emulators to investigate the consequences of mobility on new protocols or network management techniques. A limitation with current trace mobility models is they are based on empirical data which are limited to specific network types and environments. Limitations with synthetic models are that they are complex, computationally heavy, and lack realism. To address these issue a new approach needs to be taken. One such approach is the use of fluid mechanics and transport theory to represent user mobility. A model based on viscous free irrotational fluid mechanics with empirical data from pedestrian and vehicular studies provide a means of creating realistic group movement characteristics with smooth non random trajectories and smooth continuous velocity. The model is used in an example to provide boundary crossing rates for users in a cellular network and optimising the size of cellular location areas.
An Exploration of Power-Law in Use-Relation of Java Software Systems
Authors: Makoto Ichii, Makoto Matsushita, Katsuro Inoue
Venue: Proceedings of the 19th Australian Conference on Software Engineering (2008)

A software component graph, where a node represents a component and an edge represents a use-relation between components, is widely used for analysis methods of software engineering. It is said that a graph is characterized by its degree distribution. In this paper, we investigate software component graphs composed of Java classes, to seek whether the degree distribution follows so-called the power-law, which is a fundamental characteristic of various kinds of graphs in different fields. We found that the in-degree distribution follows the power-law and the out-degree distribution does not follow the power-law. In a software component graph with about 180 thousand components, just a few of the components have more than ten thousand in-degrees while most of the components have only one or zero in-degree.
Fast Simulation of Realistic Trees
Authors: Jason P. Weber
Venue: IEEE Computer Graphics and Applications (2008)

By leveraging research in cloth dynamics and building from established mathematical algorithms, the proposed process realistically drives detailed vegetation with minimal computation. A method of dimensionally separate semi-implicit solvers allows quick reaction to not only simple force fields, such as wind and gravity, but also hard collisions against solid obstacles.
Throughput-delay tradeoff in small and sparse mobile ad hoc networks
Authors: Swapnil Bhatia, Radim Bartoš, Kevin Ma
Venue: ACM SIGMOBILE Mobile Computing and Communications Review (2008)

This paper takes the first step in characterizing the throughput-delay tradeoff for small and sparse MANETs which have many practical applications. We find that as the MANET becomes sparser, throughput decreases and delay increases, as expected. If relaying is disabled then the throughput and delay depend on the size of the area of operation. While relaying does increase throughput, the single packet relaying strategy worsens the delay for small MANETs in the Grossglauser traffic model. Greedy relaying overcomes this worsening without trading throughput, but only for rapidly mixing mobility. Unlike in dense networks, local broadcasting does not provide any significant benefit. Packet repetition does decrease delay, but only at the expense of reduced throughput. Our results are useful in practical underwater MANETs which are typically small and sparse.
A proposal for managing ASI fabrics
Authors: Antonio Robles-Gómez, Aurelio Bermúdez, Rafael Casado, Francisco J. Quiles, Tor Skeie, José Duato
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2008)

Recent years, computer performance has been significantly increased. As a consequence, data I/O systems have become bottlenecks within systems. To alleviate this problem, Advanced Switching was recently proposed as a new standard for future interconnects. The Advanced Switching specification establishes a fabric management infrastructure, which is in charge of updating the set of fabric paths each time a topological change takes place. The use of source routing and passive switches makes unfeasible the adaptation to this new technology of many existing proposals to handle topological changes in switched interconnection networks. This paper presents a fabric management mechanism for Advanced Switching, but also suitable for other source routing interconnects. Furthermore, the work presents a detailed performance evaluation for this proposal. This evaluation allows us to identify the main drawbacks of the mechanism and to define future improvements.
On Chip Jitter Measurement through a High Accuracy TDC
Authors: Akhil Garg, Prashant Dubey
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

In High speed applications, ratio of total jitter to clock period is critical. It necessitates accurate measurement of Jitter. In this paper we describe an on-chip methodology to measure jitter in time domain, with resolutions up to 0.1ps.
Comparisons of titer estimation methods for multiplexed pneumococcal opsonophagocytic killing assay
Authors: D. Wang, S. -J. Soong
Venue: Computational Statistics Data Analysis (2008)

Titer estimation is one of the major components of immunoassay and vaccine development. A multiplexed in vitro opsonization assay (MOPA) is widely accepted to quantitate Streptococcus pneumococcal antibodies to serotype-specific pneumococcal capsular polysaccharide. Titer estimation of vaccine based on OPA is one important component of standardization of OPA, and the selected statistical method is a factor influencing the accuracy and precision of titer estimation. We evaluated five titer estimation methods for pneumococcal OPA in terms of precision and accuracy using three data sets generated by specifically designed experiments with both an eight-dilution and an eleven-dilution design. The bootstrap resampling technique was also used to determine the performance of the estimation. We concluded that the traditional direct method did not perform as well as the other four methods in terms of precision and accuracy of titer estimation. The Spearman-Karber estimator might be biased upward for OPA titer estimation. The four-parameter logistic model (4PL) method is an alternative choice for OPA titer estimation. The eleven-dilution design provided more information than the eight-dilution design for titer estimation and enhanced precision of estimators. UAB opsotiter, computer software using the statistical language R and Microsoft Excel^(R), was developed to implement OPA titer estimation.
A model transformation tool for performance simulation of complex uml models
Authors: Olivier Constant, Wei Monin, Susanne Graf
Venue: Companion of the 30th international conference on Software engineering (2008)

We present a tool that automatically translates UML2 models of service-oriented systems to models for performance evaluation by a commercial simulator. The strength of our tool lies in its support for complex behaviors, which is made possible by a rich intermediate metamodel with clear operational semantics.
Practical trust management without reputation in peer-to-peer games
Authors: Adam Wierzbicki, Tomasz Kaszuba
Venue: Multiagent and Grid Systems (2007)

The development of complex applications that use the Peer-to-Peer computing model is restrained by security and trust management concerns, despite evident performance benefits. An example of such an application of P2P computing is P2P Massive Multi-user Online Games, where cheating by players is simple without centralized control or specialized trust management mechanisms. The article presents new techniques for trust enforcement that use cryptographic methods and are adapted to the dynamic membership and resources of P2P systems. The proposed approach to trust management differs significantly from previous work in the area that mainly used reputation. The paper describes a comprehensive trust management infrastructure for P2P MMO games that enables to recognize and exclude cheating players while keeping the performance overhead as low as possible. While the architecture requires trusted centralized components (superpeers), their role in trust management is limited to a minimum and the performance gains of using the P2P computing model are preserved. The performance of the proposed trust management architecture is validated by a prototype implementation in an MMO game.
Policy-Based Enforcement of Database Security Configuration through Autonomic Capabilities
Authors: Ghassan Jabbour, Daniel A. Menascé
Venue: Proceedings of the Fourth International Conference on Autonomic and Autonomous Systems (2008)

Significant emphasis has been placed recently on the hardening of databases and on regular audits of such systems by independent auditors and certified Information Systems Security Officers (ISSO). Data centers hosting sensitive data and mission-critical systems, especially centers that belong to governmental agencies, have been under tremendous pressure to secure their databases in compliance with several security guidelines. Such requirements mandate that each system passes a strict security scan before it is deemed suitable to go into operational mode and that it be subjected to regular audits thereafter. This in turn has been putting tremendous pressure on database administrators who, in many cases, are already overwhelmed by the tasks of installing, properly maintaining, and configuring their systems in a way that provides optimal performance. However, it is becoming extremely challenging, time consuming, and resource intensive to address security demands under tight budgets and timelines. Therefore, it would be advantageous to implement autonomic features into database systems to address some aspects of this challenge. This paper presents a framework that embeds autonomic capabilities into database systems to provide selfprotection features in case of unauthorized, inadvertent, or intentional change in security parameters. This is achieved by embedding into the database the capability to compare each security configuration parameter change attempt (or request) with an embedded predefined security policy before allowing or rejecting the change. The paper demonstrates how the proposed framework can be implemented in an Oracle 10g Release 2 database.
ForMAAD: A formal method for agent-based application design
Authors: Ahmed Hadj-Kacem, Amira Regayeg, Mohamed Jmaiel
Venue: Web Intelligence and Agent Systems (2007)

This paper has two purposes. First, it defines a formal language, for specifying agent-based applications, that integrates linear temporal logic to the Z notation. This integration offers a language that is expressive enough to cover both individual agent aspects (e.g., knowledge, goals and roles) as well as collective aspects (e.g., cooperation strategy, organization structure and collective behaviour). Second, it proposes a formal methodology for designing agent-based applications using stepwise refinements. The main contribution of our design process consists of a set of methodological principles and hints that help the user to build, in a systematic and incremental way, a verified design starting from abstract requirements. This approach will be illustrated by developing an agent-based solution for the air traffic control problem.
Energy efficient searching in delay-tolerant wireless sensor networks
Authors: Kiran Rachuri, A. Antony Franklin, C. Siva Ram Murthy
Venue: Proceeding of the 1st ACM international workshop on Heterogeneous sensor and actor networks (2008)

In this paper, we consider the problem of information discovery in densely deployed and delay-tolerant Wireless Sensor Network (WSN), where the initiator of search is unaware of the location of target information. We propose Increasing Ray Search (IRS), an energy efficient query resolution or search technique. The basic principle of IRS is to route the search packet along a set of trajectories called rays that maximizes the likelihood of discovering the target information by consuming least amount of energy. The rays are organized such that, if the search packet travels along all these rays, then the entire terrain area will be covered by its transmissions while minimizing the overlap of these transmissions. In this way, only a subset of total sensor nodes transmit the search packet while others listen. We believe that query resolution based on the principles of area coverage provides a new dimension for conquering the scale of WSN. We compare IRS with existing query resolution techniques for unknown target location such as, Expanding Ring Search, Random Walk Search, and Gossip Search. We prove by analysis and simulation that IRS is highly scalable, the energy consumed for searching is independent of node density, and it is much lower than that of existing search techniques under high node density.
Hidden information and actions in multi-hop wireless ad hoc networks
Authors: Xiang-Yang Li, YanWei Wu, Ping Xu, GuiHai Chen, Mo Li
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

For multi-hop ad hoc networks formed by individually owned nodes, the endpoints can only observe whether or not the end-to-end transaction was successful or not, but not the individual actions of intermediate nodes. Consequently, in the absence of properly designed incentive schemes, rational (i.e., selfish) intermediate nodes may choose to forward data packets at a very low priority or simply drop the packets at all, and it could put the blame on the unreliable wireless channel. Using a principal-agent model, we propose several efficient methods that can eliminate the hidden actions under hidden information in multi-hop wireless networks with high probability. We design several algorithmic mechanisms for a number of routing scenarios such that each selfish agent will maximize its utility (i.e., profit) when it truthfully declares its type (i.e., cost and its actions) and it truthfully follows its declared actions. Our simulations show that the payment by our mechanisms is only slightly larger than the actual cost incurred by all intermediate nodes.
A context gathering framework for context-aware mobile solutions
Authors: Anusuriya Devaraju, Simon Hoh, Michael Hartley
Venue: Proceedings of the 4th international conference on mobile technology, applications, and systems and the 1st international symposium on Computer human interaction in mobile technology (2007)

One of the fundamental design issues in context-aware mobile services development is the necessary support for adequately powerful yet efficient querying of the sensory data. This issue argues for research into the creation of a technology-independent, high-level software application programming interface (API) that provides mechanisms for dealing with the heterogeneity of sensors providing raw context data. In this paper, we review approaches in existing context-aware platforms especially those that consider with sensory data acquisition. The review formed the basis for the design and development of the context gathering framework which consists of sensor data model, messaging and communication protocol and software application programming interface. These components form as one of the enabler to support the development of context aware mobile applications.