ppxscal/embedding_network huggingface dataset:
Linear-complexity models for wireless MAC-to-MAC channels
Authors: Syed Ali Khayam, Hayder Radha
Venue: Wireless Networks (2005)

Wireless local area networks suffer from frequent bit-errors that result in Medium Access Control (MAC) layer packet drops. Bandwidth and media quality constraints of real-time applications necessitate analysis and modeling at the "MAC-to-MAC wireless channel". In this paper, we propose and evaluate stochastic models for the 802.11b MAC-to-MAC bit-error process. We propose an Entropy Normalized Kullback-Leibler (ENK) measure to accurately evaluate the performance of the models. We employ this measure to demonstrate that the traditional full-state Markov chains of order-10 and order-9 are required for accurate representation of the channel at 2 and 5.5 Mbps, respectively. However, the complexity of this modeling paradigm increases exponentially with respect to the order. For many real-time and non-real-time applications, which require (or could benefit significantly from) accurate modeling, the high complexity of full-state high-order Markov models makes them impractical or virtually ineffective. Thus, we propose two new linear-complexity models, which we refer to as the short-term energy model (SEM) and the zero-crossing model (ZCM). These models, which constitute the most important contribution of this paper, constrain the complexity to increase linearly with the model order. We illustrate that the linear-complexity models, while yielding orders of magnitude reduction in complexity, provide a performance comparable to that of the exponential complexity full-state models. Within the linear-complexity context, we illustrate that the zero-crossing model perform better than its short-term energy counterpart. Finally, for varying window sizes and due to its low complexity, we show that the zero-crossing model can be adapted in real-time. Such an adaptive model provides accurate channel modeling and characterization for rate adaptive applications.
Energy Efficient Fractional Coverage Schemes for Low Cost Wireless Sensor Networks
Authors: Mao YE, Edward CHAN, Guihai CHEN, Jie WU
Venue: Proceedings of the 26th IEEE International ConferenceWorkshops on Distributed Computing Systems (2006)

An effective approach for energy conservation in wireless sensor networks is scheduling sleep intervals for extraneous nodes, while the remaining nodes stay active to provide continuous service. Depending on different types of applications, the network lifetime may be much more critical than covering the entire monitored area at every data reporting round. This paper presents a competition based distributed scheme called FCS to address the fractional coverage problem in wireless sensor networks with tiny, lowcost sensors. Through localized, energy-aware competition, the proposed scheme achieves the desired fractional coverage with a minimum number of active sensors. By taking account of both residual battery energy and recent reporting latency, an enhanced version of FCS which uses a novel competition metric to constrain the maximum reporting latency throughout the network is also proposed. These two schemes also contain the desirable property that it can be extended easily to handle the more general k-coverage problem.
Simulation of Fluid Dynamics and Interactions
Authors: Enhua Wu, Hongbin Zhu, Xuehui Liu, Youquan Liu
Venue: Proceedings of the 2006 International Conference on Cyberworlds (2006)

Through interaction with surroundings, the fluids may change their properties such as shapes, temperature vastly, and the same would happen to the surroundings simultaneously. On the other hand, different surroundings characterize different interactions, and may change the shapes and motions of the fluids in different ways. Therefore, it is of importance in physically-based simulation of fluids to build physically correct models to represent the varying interactions between fluids and the environments. In this paper, we will make a simple summation on the interactions, and in particular focus on those most interesting to us, and model them with various physical solutions. In some of the methods, advantage is taken with the Graphics Processing Unit (GPU) to achieve real-time computation for medial-scale simulation.
Designing the virtual campus as a virtual world
Authors: Mary Lou Maher
Venue: Proceedings of the 1999 conference on Computer support for collaborative learning (1999)

Virtual Worlds are networked environments that look like the physical world, and create a sense of place for the person communicating, navigating, and doing things in the virtual world. Virtual worlds have traditionally been developed as games, in fact, most virtual worlds today are games. A virtual campus has been developed in the Architecture Faculty at the University of Sydney that is based on some of the concepts of virtual worlds. The virtual campus is a place on the internet where students can go to take courses, meet with academic staff, and communicate with other students. The development of the virtual campus has been influenced by research in design science and is based on the conceptual metaphor of architectural design. The design of the virtual campus is considered at three levels: the implementation level, the representation level, and the interface level. Identifying these levels provides a basis for the design of virtual worlds for professional and educational environments. The consideration of the representation level results in a consistent use of a conceptual metaphor so that a person in the virtual campus can make use of the facilities in an intuitive manner.
New fast inverse QR least squares adaptive algorithms
Authors: A. A. Rontogiannis, S. Theodoridis
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1995. on International Conference - Volume 02 (1995)

The paper presents two new, closely related adaptive algorithms for LS system identification. The starting point for the derivation of the algorithms is the inverse Cholesky factor of the data correlation matrix, obtained via a QR decomposition (QRD). Both are of O(p) computational complexity with p being the order of the system. The first algorithm is a fixed order QRD scheme with enhanced parallelism. The second is a lattice type algorithm based on Givens rotations, with lower complexity compared to previously derived ones.
Symptom Database Builder for Autonomic Computing
Authors: Sampath K. Chilukuri, Kalpana Doraisamy
Venue: Proceedings of the International Conference on Autonomic and Autonomous Systems (2006)

Companies in the software development business accumulate an enormous amount of data, generated through their test and support teams. This data could be in the form of defect records and their resolutions, queries or responses to the customers. This data may be classified as problem data, and contains information that can be used for proactive problem diagnosis and resolution. However, in real situation it is rarely reused, as the data is populated in 'human' (communication language) and lacks structured information to be effectively used by IT management tools. IBM Log and Trace Analyzer for Autonomic Computing (LTA) [1, 7] is one tool that helps IT administrators and support personnel in easy problem diagnosis through its Symptom Database. A symptom database is a collection of XML files adhering to a schema and contains records of incident and problem indications that could arise in the operation of the software or hardware infrastructure. For every symptom, the Symptom Database also contains the cause of the problem and a recommended solution for the problem. Typically the Symptom Database is created by the development teams from the scratch; however we have found that the unstructured data collected by the support and the test teams can also be processed using various natural language processing and unstructured information processing algorithms to build symptom databases.
Issues of law for software agents within virtual environments
Authors: Woodrow Barfield
Venue: Presence: Teleoperators and Virtual Environments (2005)

A software agent is a computer program that operates within computing environments. The owners of software agents may instruct their agents to roam the networks, access desired information by exchanging data with other agents or people, and handle business and personal transactions. As the interactions between software agents and humans become more frequent, it is relevant to ask whether there are any issues of law that may guide their interactions and conduct. For example, as the agents become more intelligent and autonomous, who will be responsible for the mistakes that software agents make? Will software agents be allowed to contract with humans and with each other, and if so will such contracts be enforceable? And, will software agents have standing to sue and be sued? While there are a host of legal issues associated with software agents operating within virtual environments, the main issue addressed in this paper is whether software agents should be granted the legal rights associated with personhood. After discussing basic characteristics of software agents, and personhood in general, the paper concludes by outlining three possible scenarios that could represent the legal status of software agents in the future; these include the current status quo of property, the status of an indentured servant, and the status and associated rights of legal personhood.
Consistent Query Answering By Minimal-Size Repairs
Authors: Andrei Lopatenko, Leopoldo Bertossi
Venue: Proceedings of the 17th International Conference on Database and Expert Systems Applications (2006)

A database D may be inconsistent wrt a given set IC of integrity constraints. Consistent Query Answering is the problem of computing from D the answers to a query that are consistent wrt IC . Consistent answers have been characterized as those that are invariant under certain minimal forms of restoration of the consistency of the database. In this paper we investigate algorithmic and complexity theoretic issues of CQA under database repairs that minimally depart -wrt the cardinality of the symmetric difference- from the original database. Research on this kind of repairs had been suggested in the literature, but no systematic study had been done. Here we obtain first tight complexity bounds.
Thresholds for virus spread on networks
Authors: Moez Draief, Ayalvadi Ganesh, Laurent Massoulié
Venue: Proceedings of the 1st international conference on Performance evaluation methodolgies and tools (2006)

We study how the spread of computer viruses, worms, and other self-replicating malware is affected by the logical topology of the network over which they propagate. We consider a model in which each host can be in one of 3 possible states - susceptible, infected or removed (cured, and no longer susceptible to infection). We characterise how the size of the population that eventually becomes infected depends on the network topology. Specifically, we show that if the ratio of cure to infection rates is larger than the spectral radius of the graph, and the initial infected population is small, then the final infected population is also small in a sense that can be made precise. Conversely, if this ratio is smaller than the spectral radius, then we show in some graph models of practical interest (including power law random graphs) that the final infected population is large. These results yield insights into what the critical parameters are in determining virus spread in networks.A category with the (minimum) three required fields
Event sequence mining to develop profiles for computer forensic investigation purposes
Authors: Tamas Abraham
Venue: Proceedings of the 2006 Australasian workshops on Grid computing and e-research - Volume 54 (2006)

Developing profiles to describe user or system behaviour is a useful technique employed in Computer Forensic investigations. Information found in data obtained by investigators can often be used to establish a view of regular usage patterns which can then be examined for unusual occurrences. This paper describes one such method based on details provided by events found within computer forensic evidence. Events compiled from potentially numerous sources are grouped according to some criteria and frequently occurring event sequences are established. The methodology and techniques to extract and contrast these sequences are then described and discussed along with similar prior work in the same domain.
A Massive Multiplayer Game Framework for Mobile Learning
Authors: Nawaz Mohamudally
Venue: Proceedings of the Fourth IEEE International Workshop on Wireless, Mobile and Ubiquitous Technology in Education (2006)

The recent developments in mobile technology are having a tremendous impact on the instructional designing and learning styles in mobile learning and the way collaboration takes place. Not only technology is shaping the content delivery and other collaborative frameworks but imposing limits on what could be achieved. One factor is the maximum number of users collaborating with each other with an acceptable QoS given a particular mobile network infrastructure. There has been considerable work on suggestions of distributed architectures that could be scalable with the number of users. Most of them are web based and on fixed workstations whereby mobility is completely absent. In this paper we are discussing the roadmap to a massive multiplayer game framework that would enable a large number of mobile learners to interact through an exciting large scale game.
Developing the Framework of Integrated Performance Management System for State-Owned Enterprises in China
Authors: Wang Xindi, Zhang Qingjie
Venue: Proceedings of the IEEE International Conference on e-Business Engineering (2006)

Some challenges were faced in traditional performance management of state-owned enterprises (SOEs) in China, such as more involuted reports, esoteric performance measures, unrealistic plans and budgets, inefficient rewards system etc.. It is necessary and important to integrate performance management. A business model of integrated business performance management is clarified in this paper, which included strategy plan, performance measures, business planning, management reports, organizational alignment and reward systems. A technical framework of integrated business performance management system is discussed, which shows the infrastructure of system design. This paper's results will be benefit to further study of how to improve performance through implementing business performance management system for SOEs.
A New Initial Rotor Position Detection Technology Based on HF Injection and Software PLL
Authors: Shujin Chen, Baozhu Ma, Zhengyun Ran, Fei Guo, Huade Li
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 1 (2006)

In order to improve the start performance of electrical vehicles, a new method used to track the initial rotor position is proposed. ....is method is based on the high-frequency (HF) voltage model and the software phase locked loop (PLL).. After HF voltage signal is injected into motor, the initial rotor position signal is modulated by high-frequency carrier wave, and then a PLL is adopted to track the initial rotor position after the HF current signal was treated with heterodyning. The HF injection method and PLL are introduced in the paper, then the experiments on the rotor position self-sensing during start process are carried out. The performance of this method is demonstrated by a real-time implementation using a digital signal processor (DSP) chip on a permanentmagnet synchronous motor with sinusoidal flux distribution. Theoretic analysis and experiments verify the validity and feasibility of this approach.
Utility-based collaboration among autonomous agents for resource allocation in data centers
Authors: Rajarshi Das, Ian Whalley, Jeffrey O. Kephart
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

Autonomic computing, a proposed solution to the looming complexity crisis in IT, is a realm in which software agents and multi-agent systems can play a critically important role. Conversely, given its importance to a multi-billion dollar industry, it is fair to say that autonomic computing is a killer app for agents. Two years ago, we introduced Unity, an agent-based autonomic data center prototype that demonstrated the virtues of agency in autonomic computing applications. We discuss the road to commercialization of Unity, which entails infusing agent concepts into well-established lines of software and middleware, and discuss experiments that establish the commercial viability of utility-based resource allocation. Furthermore we examine the practicality of framing resource allocation in data centers as a collaboration between two agents, each of which is based on a commercially available product.
Spin injection in double magnetic tunnel junctions: A tight-binding study
Authors: Y. Li
Venue: Microelectronic Engineering (2005)

Spin current injection in double magnetic tunnel junctions is investigated theoretically based on conservation of spin and charge currents. Numerical calculations are performed for spin accumulation, current density and spin polarization in Fe/insulator (I) (semiconductor (S))/Co/I(S)/Fe double junctions using generalized formalism based on the non-equilibrium Green's function, which are implemented with recursive calculation of real space Green's function in tight-binding model in linear response region. It is shown that spin accumulation leads to difference in resistance, depending on the direction of applied bias with respect to the magnetization configuration of the double barrier magnetic tunnel junctions.
Analysis of LIDAR Data Fused with Co-Registered Bands
Authors: Marc Bartels, Hong Wei, James Ferryman
Venue: Proceedings of the IEEE International Conference on Video and Signal Based Surveillance (2006)

In the past decade, LIght Detection And Ranging (LIDAR) has been recognised by both the commercial and public sector as a reliable and accurate source for land surveying. Object classification in LIDAR data tends towards data fusion by employing additional simultaneously recorded bands. In this paper, a rule-based approach is presented for improving classification accuracy obtained in a supervised Maximum Likelihood classification. Simultaneously recorded co-registered bands are used such as high resolution LIDAR first, last echo and intensity data, aerial and near infra-red photos. Issues regarding feature and class selection and differentiated accuracy assessment are addressed. Furthermore, the individual influence of each band on the classification is investigated. The results show that incorporating additional knowledge and considering contextual relationships among classes is beneficial for improving classification accuracy in fused LIDAR datasets.
Parametric probabilistic routing in sensor networks
Authors: Christopher L. Barrett, Stephan J. Eidenbenz, Lukas Kroc, Madhav Marathe, James P. Smith
Venue: Mobile Networks and Applications (2005)

Motivated by realistic sensor network scenarios that have mis-informed nodes and variable network topologies, we propose an approach to routing that combines the best features of limited-flooding and information-sensitive path-finding protocols into a reliable, low-power method that can make delivery guarantees independent of parameter values or information noise levels. We introduce Parametric Probabilistic Sensor Network Routing Protocols, a family of light-weight and robust multi-path routing protocols for sensor networks in which an intermediate sensor decides to forward a message with a probability that depends on various parameters, such as the distance of the sensor to the destination, the distance of the source sensor to the destination, or the number of hops a packet has already traveled. We propose two protocol variants of this family and compare the new methods to other probabilistic and deterministic protocols, namely constant-probability gossiping, uncontrolled flooding, random wandering, shortest path routing (and a variation), and a load-spreading shortest-path protocol inspired by (Servetto and Barrenechea, 2002). We consider sensor networks where a sensor's knowledge of the local or global information is uncertain (parametrically noised) due to sensor mobility, and investigate the trade-off between robustness of the protocol as measured by quality of service (in particular, successful delivery rate and delivery lag) and use of resources (total network load). Our results for networks with randomly placed nodes and realistic urban networks with varying density show that the multi-path protocols are less sensitive to misinformation, and suggest that in the presence of noisy data, a limited flooding strategy will actually perform better and use fewer resources than an attempted single-path routing strategy, with the Parametric Probabilistic Sensor Network Routing Protocols outperforming other protocols. Our results also suggest that protocols using network information perform better than protocols that do not, even in the presence of strong noise.
Combining Regions and Patches for Object Class Localization
Authors: Caroline Pantofaru, Gyuri Dorko, Cordelia Schmid, Martial Hebert
Venue: Proceedings of the 2006 Conference on Computer Vision and Pattern Recognition Workshop (2006)

We introduce a method for object class detection and localization which combines regions generated by image segmentation with local patches. Region-based descriptors can model and match regular textures reliably, but fail on parts of the object which are textureless. They also cannot repeatably identify interest points on their boundaries. By incorporating information from patch-based descriptors near the regions into a new feature, the Region-based Context Feature (RCF), we can address these issues. We apply Region-based Context Features in a semi-supervised learning framework for object detection and localization. This framework produces object-background segmentation masks of deformable objects. Numerical results are presented for pixel-level performance.
A novel color image hiding scheme using block truncation coding
Authors: Yu-Chen Hu, Min-Hui Lin, Ji-Han Jiang
Venue: Fundamenta Informaticae (2005)

In this paper, a novel color image hiding scheme that is capable of hiding two color secret images into a color host image is proposed. The secret images to be embedded are first compressed by the single bit map block truncation coding. DES encryption is then conducted on the compressed message before the secret image is embedded into the rightmost 3, 2, 3 bits of the R, G, B channels of every pixel in the host image.The experimental results show that our scheme provides an average secret image quality of 29.220 dB. In addition to the improved quality of both host images and retrieved secret images, our scheme further strengthens the protection of the secret images by conducting image compression and DES encryption on the secret image in advance. Therefore, our scheme not only extends the hiding capability of host images, but also is practical and secure.
Innovative and Sustainable Mobile Learning in Africa
Authors: John Traxler, Jenny Leach
Venue: Proceedings of the Fourth IEEE International Workshop on Wireless, Mobile and Ubiquitous Technology in Education (2006)

Mobile learning is gaining ground in the developed countries of Europe, North America and the Pacific Rim. In the dramatically different affordances of sub Saharan Africa, mobile learning is developing in a different direction. This paper brings together accounts of two contrasting initiatives, both of which support in-service teacher training and novel but appropriate blended learning formats, in the region in order to illustrate the differences and the difficulties of mobile learning and in order to explore their potential synergy.