ppxscal/embedding_network huggingface dataset:
Keeping Denial-of-Service Attackers in the Dark
Authors: Gal Badishi, Amir Herzberg, Idit Keidar
Venue: IEEE Transactions on Dependable and Secure Computing (2007)

We consider the problem of overcoming (Distributed) Denial of Service (DoS) attacks by realistic adversariesthat have knowledge of their attack' s successfulness, e.g., by observing service performance degradation,or by eavesdropping on messages or parts thereof. A solution for this problem in a high-speed networkenvironment necessitates lightweight mechanisms for differentiating between valid traffic and the attacker'spackets. The main challenge in presenting such a solution is to exploit existing packet filtering mechanismsin a way that allows fast processing of packets, but is complex enough so that the attacker cannot efficientlycraft packets that pass the filters. We show a protocol that mitigates DoS attacks by adversaries that caneavesdrop and (with some delay) adapt their attacks accordingly. The protocol uses only available, efficientpacket filtering mechanisms based mainly on addresses and port numbers. Our protocol avoids the use of fixedports, and instead performs 'pseudo-random port hopping' . We model the underlying packet-filtering servicesand define measures for the capabilities of the adversary and for the success rate of the protocol. Using these,we provide a novel rigorous analysis of the impact of DoS on an end-to-end protocol, and show that ourprotocol provides effective DoS prevention for realistic attack and deployment scenarios.
Clear P2P IPTV Live Streaming System for Set-Top Box Clients
Authors: Chenjie Zhu, Dejian Ye
Venue: Proceedings of the 7th IEEE International Conference on Computer and Information Technology (2007)

IPTV (Internet Protocol Television) live streaming systems with client-sever based content delivery infrastructures face scalability problems due to their high requirement at server hardware configuration and network bandwidth. This paper presents a P2P based live streaming system-"Clear Live", which tries to achieve better scalability than client-server based system. While current popular P2P IPTV systems support only PC client, our system supports both STB (Set-top Box) client and PC client. "Clear Live" is designed according to meet the requirements of STB client and IPTV services. Evaluation results demonstrate that "Clear Live" can provide high quality live streaming service to a vast number of clients with relatively low cost.
Multidimensional Histogram Equalization and Modification
Authors: A. J. McCollum, W. F. Clocksin
Venue: Proceedings of the 14th International Conference on Image Analysis and Processing (2007)

We describe an approach toward multidimensional histogram equalization for the enhancement of color and multispectral images, based on the histogram explosion algorithm. A development from first principles is presented. We show that in, the multidimensional case, one-dimensional histogram equalization becomes a scalar multiplication of a vector quantity. An image noise reduction scheme is devised using a model of multispectral noise behaviour that is analogous to the behaviour of local spatial noise. Practical results are presented indicating that the method reveals subtle image features and respects the tone of the originals more consistently than earlier methods.
Use of motion field warping to generate cardiac images
Authors: Gang Gao, Paul Cockshott
Venue: Crossroads (2007)

In this study, we developed an algorithmic method to analyze late contrast-enhanced (CE) magnetic resonance (MR) images, revealing the so-called hibernating myocardium. The algorithm is based on an efficient and robust image registration algorithm. Using our method, we are able to integrate the static late CE MR image with its corresponding cardiac cine MR images, constructing cardiac motion CE MR images, which are referred to as cardiac cine CE MR images. This method appears promising as an improved cardiac viability assessment tool
Towards the PIDβ Control of Heat Diffusion Systems
Authors: Isabel S. Jesus, J. A. Tenreiro Machado, Ramiro S. Barbosa, E. S. Solteiro Pires
Venue: Proceedings of the Seventh International Conference on Intelligent Systems Design and Applications (2007)

In this work we study a heat diffusion system on a frac- tional calculus perspective. Several fractional PID tuning methodologies are investigated and compared. The simu- lations demonstrate the good performance of the proposed fractional algorithm.
Tutorial: Data Structures, Types, and Abstractions
Authors: K. S. Shankar
Venue: Computer (1980)

Understanding data structures, types, and abstractions not only is important in modularizing a software system but also leads to increased system clarity and reliability.
Creativity support tools: accelerating discovery and innovation
Authors: Ben Shneiderman
Venue: Communications of the ACM (2007)

How can designers of programming interfaces, interactive tools, and rich social environments enable more people to be more creative more often?
Writer identification of Chinese handwriting documents using hidden Markov tree model
Authors: Zhenyu He, Xinge You, Yuan Yan Tang
Venue: Pattern Recognition (2008)

Handwriting-based writer identification, a branch of biometrics, is an active research topic in pattern recognition. Since most existing methods and models aim to on-line and/or text-dependent writer identification, it is necessary to propose new methods for off-line, text-independent writer identification. At present, two-dimensional Gabor model is widely acknowledged as an effective and classic method for off-line, text-independent handwriting identification, while it still suffers from some inherent shortcomings, such as the excessive calculational cost. In this paper, we present a novel method based on hidden Markov tree (HMT) model in wavelet domain for off-line, text-independent writer identification of Chinese handwriting documents. Our experiments show this HMT method, compared with two-dimensional Gabor model, not only achieves better identification results but also greatly reduces the elapsed time on computation.
Fures trifuresque: a case study of class-wide academic fraud in online education
Authors: Andrew Vahid Moshirnia
Venue: Proceedings of the sixth conference on IASTED International Conference Web-Based Education - Volume 2 (2007)

Academic fraud is widespread in secondary education. While several studies have focused on the causes of cheating within the traditional, face-to-face learning environment, few studies examine academic fraud in online learning. Those few studies of online academic fraud focus on plagiarism detection and prevention. This paper presents a case study of academic fraud in an online Latin class. Subjects were interviewed in an attempt to identify the factors which encourage cheating within online learning environments, the methods by which students commit academic fraud, and student attitudes towards cheating. A clearer understanding of academic fraud in distance programs will allow educators to better design their courses.
B72-4 Expanding Use of Computers in the 70' Technology-Markets  Needs  Technology
Authors: E. C. Joseph
Venue: IEEE Transactions on Computers (1972)

This worthwhile book is addressed to the computer user, but has much to offer others interested in computers for the 70's. It contains 13 separately authored papers from the Seventh Informatics, Inc. Symposium on Information Processing. In Isaac L. Auerbach's contribution, there is a statement that summarizes the general tone of the total book, namely, In the past, we have been over-optimistic in short-term forecasts of our accomplishments and, on the other hand, have grossly underestimated long-term accomplishments, particularly regarding the growth and application areas of the computer industry. Considering the nature of our technology, I feel that our crystal ball will be just as cloudy in the 1970's as it has been in the past two decades.
2007 Special Issue: Consciousness CLEARS the mind
Authors: Stephen Grossberg
Venue: Neural Networks (2007)

A full understanding of consciousness requires that we identify the brain processes from which conscious experiences emerge. What are these processes, and what is their utility in supporting successful adaptive behaviors? Adaptive Resonance Theory (ART) predicted a functional link between processes of Consciousness, Learning, Expectation, Attention, Resonance and Synchrony (CLEARS), including the prediction that ''all conscious states are resonant states''. This connection clarifies how brain dynamics enable a behaving individual to autonomously adapt in real time to a rapidly changing world. The present article reviews theoretical considerations that predicted these functional links, how they work, and some of the rapidly growing body of behavioral and brain data that have provided support for these predictions. The article also summarizes ART models that predict functional roles for identified cells in laminar thalamocortical circuits, including the six layered neocortical circuits and their interactions with specific primary and higher-order specific thalamic nuclei and nonspecific nuclei. These predictions include explanations of how slow perceptual learning can occur without conscious awareness, and why oscillation frequencies in the lower layers of neocortex are sometimes slower beta oscillations, rather than the higher-frequency gamma oscillations that occur more frequently in superficial cortical layers. ART traces these properties to the existence of intracortical feedback loops, and to reset mechanisms whereby thalamocortical mismatches use circuits such as the one from specific thalamic nuclei to nonspecific thalamic nuclei and then to layer 4 of neocortical areas via layers 1-to-5-to-6-to-4.
Document Content Inventory and Retrieval
Authors: H. Baird, M. Moll
Venue: Proceedings of the Ninth International Conference on Document Analysis and Recognition - Volume 01 (2007)

We give an analysis of relationships between expected retrieval performance and classification recognition accu- racy in the context of document image content extraction and inventory. By content extraction we mean location and measurement of regions containing handwriting, machine- printed text, photographs, blank space, etc, in documents represented as bilevel, grey-level, or color images. Recent experiments have shown that even modest per-pixel content classification accuracies can support usefully high recall and precision rates (of, e.g., 80 90%) for retrieval queries within document collections seeking pages that contain a given minimum fraction of a certain type of content. In an effort to elucidate this interesting empirical result, we have analyzed the interdependency of classification and re- trieval under a variety of assumptions about the distribution of content types in document image collections. We show that under general conditions we cannot derive precision and recall measures from per-pixel classification measures alone, but we can estimate the expected values of these mea- sures. If however the distribution of content and error rates are uniform across the entire collection, our results suggest, it is possible to predict precision and recall measures from classification accuracy and vice versa.
An Analytical Approach to Performance Analysis of an Asynchronous Web Server
Authors: U. Praphamontripong, S. Gokhale, Aniruddha Gokhale, Jeff Gray
Venue: Simulation (2007)

Concurrency can be implemented in a Web server using synchronous or asynchronous mechanisms provided by the underlying operating system. Compared to the synchronous mechanisms, asynchronous mechanisms are attractive because they provide the benefit of concurrency while alleviating much of the overhead and compleXity of multi-threading. The Proactor pattern in middleware, which encapsulates the asynchronous mechanisms provided by the operating system, can be used to implement a high performance Web server. The performance eXpectations imposed on a Web server make it necessary to analyze its performance prior to deployment. While the performance of a server can be measured after implementation, design-time performance analysis, conducted early in the life cycle, can enable informed configuration and provisioning choices. A model-based approach can be used for such design-time performance analysis. In this paper we present a performance model of the architecture of an asynchronous Web server which uses the Proactor pattern. We discuss the implementation of the performance model using the Stochastic Reward Net (SRN) modeling paradigm. A model decomposition strategy along with its SRN implementation to facilitate the application of the model to practical Web servers is then described. We demonstrate the use of the model to guide key provisioning and configuration decisions with several eXamples.
On the Number of Fanout-Free Functions and Unate Cascade Functions
Authors: T. Sasao
Venue: IEEE Transactions on Computers (1979)

In this correspondence, the number of functions and the number of equivalence classes of functions realized by fanout-free networks and cascades of AND'S, OR'S, and inverters are presented. For fanout-free functions, recursive formulas for TND(n) and fND(n), the number of n-p-n-equivalence classes of n-variable functions and p-equivalence classes of n-variable functions, resp
Concolic testing
Authors: Koushik Sen
Venue: Proceedings of the twenty-second IEEE/ACM international conference on Automated software engineering (2007)

Concolic testing automates test input generation by combining the concrete and symbolic (concolic) execution of the code under test. Traditional test input generation techniques use either (1) concrete execution or (2) symbolic execution that builds constraints and is followed by a generation of concrete test inputs from these constraints. In contrast, concolic testing tightly couples both concrete and symbolic executions: they run simultaneously, and each gets feedback from the other. We have implemented concolic testing in tools for testing both C and Java programs. We have used the tools to find bugs in several real-world software systems including SGLIB, a popular C data structure library used in a commercial tool, a third-party implementation of the Needham-Schroeder protocol and the TMN protocol, the scheduler of Honeywell's DEOS real-time operating system, and the Sun Microsystems' JDK 1.4 collection framework. In this tutorial, we will describe concolic testing and some of its recent extensions
Practical Patching for Efficient Bandwidth Sharing in VOD Systems
Authors: Kyung-Sook Lee, Sook-Jeong Ha, Ihn-Han Bae
Venue: Proceedings of the 5th ACIS International Conference on Software Engineering Research, Management & Applications (2007)

Recursive Patching recursively shares existing video streams with asynchronous clients for efficient multicast in large-scale video on demand systems. In this paper, we propose Practical Patching that removes unnecessary data included in transition streams of Recursive Patching. Practical Patching dynamically expands ongoing transition streams when a new request actually arrives at the server. Simulation result confirmed that the proposed technique is better than Recursive Patching in terms of service latency and defection rate.
Book Reviews
Venue: Computer (1975)

This is the 21st book of the Macdonald/American Elsevier Computer Monograph series dealing with the theory and practice of computing. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
DTCS: A Dynamic Tree-Based Consistency Scheme of Cooperative Caching in Mobile Ad Hoc Networks
Authors: Gaogang Xie, Zhenyu Li, Jianing Chen, Yifen Wei, Valerie Issarny, Alberto Conte
Venue: Proceedings of the Third IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (2007)

addressed in Mobile Ad Hoc Networks (MANETs). How to keep caching consistency efficiently is a very important issue. In this paper, a Dynamic Tree-based Consistency Scheme of cooperative caching, called DTCS, is proposed to address this issue. The nodes in MANET that host cooperative caches are organized into a ring with Chord as group management protocol. A virtual binary tree, called Chord tree, can be computed from the ring and then be adjusted into a temporary updating tree according to the location and routing information of the MANET nodes when an updating data item appears. The updated data item can be transmitted along the updating tree from the source nodes to the nodes hosting cooperative caches. The updating tree is released once the updated data item has been transmitted so that it is not necessary to keep the tree all time in nodes. The Chord ring is not affected by the dynamic topology due to the moving of nodes, and the updated tree may decreases mismatch with the physical topology. The effect of nodes density, network scale, nodes' mobility, updating data size, signal propagating distance and number of cooperative nodes are analyzed in the simulation experiment. The simulation results also demonstrate the scheme outperforms the Gossip-based multicast protocol for consistency of cooperative caching with less workload, higher success rate of updating and less updating time.
Testing Random Number Generators by Walsh Transform
Authors: Chung-Kwong Yuen
Venue: IEEE Transactions on Computers (1977)

A truly random sequence of numbers has an asymptotically flat Walsh power spectrum. This fact is used to devise a new test for the randomness of the output of random number generators. Because it takes little computing time to obtain the Walsh power spectrum of even very long sequences, generators with large periods can be tested. Some computed examples are shown.
A Convention for Explicit Declaration of Environments and Top-Down Refinement of Data
Authors: E. Towster
Venue: IEEE Transactions on Software Engineering (1979)

Many problems of block structure derive from the remote specification of parts of the local environment. An alternative to block structure is proposed, in which the local environment is described within each program module. Concise environment descriptions are made possible by creating a tree whose terminal nodes are declarations and whose intermediate nodes can represent all of their descendant terminal node declarations. The tree encompasses all of the data used by the program and can thus be thought of as the data structure for the entire program. Each intermediate node of the tree names an abstract data structure that is implemented from the data named in its descendant nodes. Top-down refinement of abstract data structures consists of creating descendant nodes, and terminates when all terminal nodes of the tree have been created. This activity occurs as a normal part of program development, along with the top-down refinement of program modules. The tree can be used in place of a symbol table as a referencing structure for compilation or interpretation. Compilation time wili then increase linearly with the length of the program and the referencing structure can grow dynamically during compilation.
Security License Distribution Mechanism for Rights Delegation Models of Group Distribution between Consumers
Authors: Zonghua Liu, Bohyun Wang, Byungwook Lee, Myung-Mook Han
Venue: Proceedings of the The 2007 International Conference Computational Science and its Applications (2007)

Modern DRM system not only emphasizes the protection of copyrights, but also aims to support specific business use models for the digital contents. Group distribution is a kind of newer business distribution model that would allow to purchase the digital contents by an group, such as a family or an organization etc. It makes convenient for consumer, but how to use the rights of group flexibly and securely has not been solved yet. In this paper, we propose two kinds of rights delegation models, m2m and m2c for group distribution and also give a formal definition for these models. We propose authenticate method for consumer and personalize Content Encryption Key to detect illegal distribution. Finally, we describe security license distribution mechanism for these models.
Temporal constraints in clinical diagnosis
Authors: E.T. Keravnou
Venue: Journal of Intelligent Fuzzy Systems: Applications in Engineering and Technology (2002)

Time representation and temporal reasoning are of crucial importance to clinical diagnosis. In this paper we present a general model for diagnostic knowledge, the Causal-Temporal-Action (C-T-A) model. This has a central tri-planar structure for the representation, in causal terms, of knowledge on disorders and physiological processes. The central structure is bounded by two other, orthogonal planes that represent temporal constraints and therapeutic actions. These planes function to constrain the existences of the temporal entities residing on the central structure. A major focus of the paper is the temporal constraints plane of the C-T-A model. An abstract structure, the Abstract Temporal Graph (ATG) is proposed for the representation of temporal constraints. Specific cases of the ATG structure encountered in the literature on temporal clinical diagnosis are discussed and algorithms for checking the consistency and satisfiability of temporal constraints are presented. These algorithms are of relevance to the validation of diagnostic knowledge and patient data and the evaluation of diagnostic hypotheses.
Annealing temperature effect on electrical and structural properties of Cu/Au Schottky contacts to n-type GaN
Authors: V. Rajagopal Reddy, P. Koteswara Rao
Venue: Microelectronic Engineering (2008)

Schottky contacts were fabricated on n-type GaN using a Cu/Au metallization scheme, and the electrical and structural properties have been investigated as a function of annealing temperature by current-voltage (I-V), capacitance-voltage (C-V), Auger electron spectroscopy (AES) and X-ray diffraction (XRD) measurements. The extracted Schottky barrier height of the as-deposited contact was found to be 0.69eV (I-V) and 0.77eV (C-V), respectively. However, the Schottky barrier height of the Cu/Au contact slightly increases to 0.77eV (I-V) and 1.18eV (C-V) when the contact was annealed at 300^oC for 1min. It is shown that the Schottky barrier height decreases to 0.73eV (I-V) and 0.99eV (C-V), 0.56eV (I-V) and 0.87eV (C-V) after annealing at 400^oC and 500^oC for 1min in N"2 atmosphere. Norde method was also used to extract the barrier height of Cu/Au contacts and the values are 0.69eV for the as-deposited, 0.76eV at 300^oC, 0.71eV at 400^oC and 0.56eV at 500^oC which are in good agreement with those obtained by the I-V method. Based on Auger electron spectroscopy and X-ray diffraction results, the formation of nitride phases at the Cu/Au/n-GaN interface could be the reason for the degradation of Schottky barrier height upon annealing at 500^oC.
Two comparison theorems of BSDES
Authors: Huang Xiao-Qin, Wang Mian-Sen, Jia Jun-Guo
Venue: Journal of Applied Mathematics and Computing (2007)

In this paper, by the equations of Mao [9] and Peng [5], we use the martingale method to establish the comparison theorems of backward stochastic differential equations (BSDEs). We generalize the results of Cao-Yan [1].