ppxscal/embedding_network huggingface dataset:
Nonlinear prediction of mobile radio channels: measurements and MARS model designs
Authors: T. Ekman
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

The rapid time variation of mobile radio channels is often modeled as a random process with second order moments reflecting vehicle speed, bandwidth and the scattering environment. These statistics typically show that there is little room for prediction of channel properties such as received power or complex taps of the impulse response coefficients, at least when linear predictor structures are considered. We use mutual information estimation to measure statistical dependencies in sequences of wideband mobile radio channel data and find significant nonlinear dependencies, far exceeding the linear component. Based on these upper limits for the predictability of channel evolution over time intervals up to 30 ms ahead, we develop practical nonlinear predictor systems using multivariate adaptive regression splines (MARS). We demonstrate computationally efficient schemes that increase the prediction horizon beyond 10 ms, compared to less than 4 ms with linear predictors at comparable prediction gains.
Distributed Functional Compression through Graph Coloring
Authors: Vishal Doshi, Devavrat Shah, Muriel Medard, Sidharth Jaggi
Venue: Proceedings of the 2007 Data Compression Conference (2007)

We consider the distributed computation of a function of random sources with minimal communication. Specifically, given two discrete memoryless sources, X and Y , a receiver wishes to compute f(X, Y ) based on (encoded) information sent from X and Y in a distributed manner. A special case, f(X, Y ) = (X, Y ), is the classical question of distributed source coding considered by Slepian and Wolf (1973). Orlitsky and Roche (2001) considered a somewhat restricted setup when Y is available as side information at the receiver. They characterized the minimal rate at which X needs to transmit data to the receiver as the conditional graph entropy of the characteristic graph of X based on f. In our recent work (2006), we further established that this minimal rate can be achieved by means of graph coloring and distributed source coding (e.g. Slepian-Wolf coding). This characterization allows for the separation between "function coding" and "correlation coding." In this paper, we consider a more general setup where X and Y are both encoded (separately). This is a significantly harder setup for which to give a single-letter characterization for the complete rate region. We find that under a certain condition on the support set of X and Y (called the zigzag condition), it is possible to characterize the rate region based on graph colorings at X and Y separately. That is, any achievable pair of rates can be realized by means of first coloring graphs at X and Y separately (function coding) and then using Slepian-Wolf coding for these colors (correlation coding). We also obtain a single-letter characterization of the minimal joint rate. Finally, we provide simulation results based on graph coloring to establish the rate gains on real sequences.
DSSS-Based Flow Marking Technique for Invisible Traceback
Authors: Wei Yu, Xinwen Fu, Steve Graham, Dong Xuan, Wei Zhao
Venue: Proceedings of the 2007 IEEE Symposium on Security and Privacy (2007)

Law enforcement agencies need the ability to conduct electronic surveillance to combat crime, terrorism, or other malicious activities exploiting the Internet. However, the proliferation of anonymous communication systems on the Internet has posed significant challenges to providing such traceback capability. In this paper, we develop a new class of flow marking technique for invisible traceback based on Direct Sequence Spread Spectrum (DSSS), utilizing a Pseudo-Noise (PN) code. By interfering with a sender's traffic and marginally varying its rate, an investigator can embed a secret spread spectrum signal into the sender's traffic. The embedded signal is carried along with the traffic from the sender to the receiver, so the investigator can recognize the corresponding communication relationship, tracing the messages despite the use of anonymous networks. The secret PN code makes it difficult for others to detect the presence of such embedded signals, so the traceback, while available to investigators is, effectively invisible. We demonstrate a practical flow marking system which requires no training, and can achieve both high detection and low false positive rates. Using a combination of analytical modeling, simulations, and experiments on Tor (a popular Internet anonymous communication system), we demonstrate the effectiveness of the DSSS-based flow marking technique.
Resource control for java database extensions
Authors: Grzegorz Czajkowski, Tobias Mayr, Praveen Seshadri, Thorsten von Eicken
Venue: Proceedings of the 5th conference on USENIX Conference on Object-Oriented Technologies & Systems - Volume 5 (1999)

While object-relational database servers can be extended with user-defined functions (UDFs), the security of the server may be compromised by these extensions. The use of Java to implement the UDFs is promising because it addresses some security concerns. However, it still permits interference between different users through the uncontrolled consumption of resources. In this paper, we explore the use of a Java resource management mechanism (JRes) to monitor resource consumption and enforce usage constraints. JRes enhances the security of the database server in the presence of extensions allowing for (i) detection and neutralization of denial-of-service attacks aimed at resource monopolization, (ii) monitoring resource consumption which enables precise billing of users relying on UDFs, and (iii) obtaining feedback that can be used for adaptive query optimization. The feedback can be utilized either by the UDFs themselves or by the database system to dynamically modify the query execution plan. Both models have been prototyped in the Cornell Predator database system. We describe the implementation techniques, and present experiments that demonstrate the effects of the adaptive behavior facilitated by JRes. We conclude that, minimally, a database system supporting extensions should have a built-in resource monitoring and controlling mechanism. Moreover, in order to fully exploit information provided by the resource control mechanisms, both the query optimizer and the UDFs themselves should have access to this information.
Background initialization with a new robust statistical approach
Authors: Hanzi Wang, D. Suter
Venue: Proceedings of the 14th International Conference on Computer Communications and Networks (2005)

Initializing a background model requires robust statistical methods as the task should be robust against random occurrences of foreground objects, as well as against general image noise. The median has been employed for the problem of background initialization. However, the median has only a breakdown point of 50%. In this paper, we propose a new robust method which can tolerate more than 50% of noise and foreground pixels in the background initialization process. We compare our new method with five others and give quantitative evaluations on background initialization. Experiments show that the proposed method achieves very promising results in background initialization.
Building Anti-Phishing Browser Plug-Ins: An Experience Report
Authors: Thomas Raffetseder, Engin Kirda, Christopher Kruegel
Venue: Proceedings of the 29th International Conference on Software Engineering Workshops (2007)

Phishing is an online identity theft that aims to steal sensitive information such as user names, passwords, and credit card numbers. Although phishing is a simple social engineering attack, it has proven to be surprisingly effective. Hence, the number of phishing scams is continuing to grow, and the costs of the resulting damages is increasing. Researchers as well as the IT industry have identified the urgent need for anti-phishing solutions and recently, a number of solutions to mitigate phishing attacks have been proposed. Several of these approaches are browser plugins. In 2005, we implemented a Firefox anti-phishing browser plug-in called AntiPhish. After releasing AntiPhish, we decided to port it to the Microsoft Internet Explorer (IE) browser. Supporting IE was important because a majority of Internet users are accessing the web with this browser. Our initial expectation at the beginning of the project was that porting a browser plug-in that is written for Firefox to IE could not be too difficult; after all, browser plug-ins are conceptually similar. However, creating an anti-phishing browser plug-in for the IE proved to be much more challenging than expected. In this paper, we report on our experience in implementing anti-phishing (i.e., security) browser plug-ins and summarize five lessons we learned from our undertaking.
Fractal modelling for pattern recognition via artificial neural networks
Authors: M. E. Kirlangic
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

In this study, it is aimed to use fractal modelling parameters for electromyography (EMG) pattern recognition, and to compare EMG pattern recognition performances of the fractal and autoregressive (AR) models. For this purpose, EMG signals from biceps brachii and forearm muscles during ten different movements of the arm and the hand are acquired from a twenty four years old male subject. These signals are modelled with both AR and fractal modelling approaches, and these models are studied for pattern recognition purposes via artificial neural networks. The results indicate that the contraction factor in fractal modelling can be used as a criterion for pattern recognition. However, the AR model parameters yield better results. As a further approach, the contraction factors obtained from fractal modelling are modelled as the outcome of an AR process and these AR model coefficients are also studied for EMG pattern recognition.
Objective measures for speech quality assessment in wireless communications
Authors: A. Bayya, M. Vis
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 01 (1996)

Automatic assessment of speech quality is one of the most important problems in mobile communication. The primary goal of this article is to find an objective measure that accurately predicts user acceptance of speech signals recorded under varying noise conditions and channel impairments as well as signals subjected to various noise suppression/signal enhancement techniques. We report some preliminary results on correlation studies between several output-based/input-output-based objective measures and subjective scores. We propose to use these results to design a non-linear model for predicting the subjective quality using several simple objective measures.
An Interpreter for Framed Tempura and Its Application
Authors: Yongtao Ma, Zhenhua Duan, Xiaobing Wang, Xiaoxiao Yang
Venue: Proceedings of the First Joint IEEE/IFIP Symposium on Theoretical Aspects of Software Engineering (2007)

This paper discusses the implementation mechanism and its application of an interpreter for a framed temporal logic programming language called Framed Tempura. Firstly, the basic approach based on the normal form is presented. Then, the structure of the interpreter is illustrated and each of its modules is explained. The work flow of the reduction of programs is given in detail. In particular, the implementation approaches of several important new constructs including frame, await, projection, pointer are presented. As an application, the interpreter is used as a simulator of service models of OWL-S for the Web service composition.
An optimal broadcasting protocol for mobile video-on-demand
Authors: Regant Y. S. Hung, H. F. Ting
Venue: Proceedings of the thirteenth Australasian symposium on Theory of computing - Volume 65 (2007)

The advance of wireless and mobile technology introduces a new type of Video-on-Demand (VOD) systems, namely the mobile VOD systems, that provide VOD services to mobile clients. It is a challenge to design broadcasting protocols for such systems because of the following special requirements: (1) fixed maximum bandwidth requirement: the maximum bandwidth required for broadcasting a video should be fixed and independent of the number of requests, (2) load adaptivity: the total bandwidth should be dependent on the number of requests; the fewer the requests the smaller the total bandwidth usage, and (3) clients sensitivity: the system should be able to support clients with a wide range of heterogeneous capabilities. In the literature, there are some partial solutions that give protocols meeting one or two of the above requirements. In this paper, we give the first protocol that meets all of the three requirements. The performance of our protocol is optimal up to a small constant factor.
Low-cost protection for SER upsets and silicon defects
Authors: Mojtaba Mehrara, Mona Attariyan, Smitha Shyam, Kypros Constantinides, Valeria Bertacco, Todd Austin
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

Extreme transistor scaling trends in silicon technology are soon to reach a point where manufactured systems will suffer from limited device reliability and severely reduced life-time, due to early transistor failures, gate oxide wear-out, manufacturing defects, and radiation-induced soft errors (SER). In this paper we present a low-cost technique to harden a microprocessor pipeline and caches against these reliability threats. Our approach utilizes online built-in self-test (BIST) and microarchitectural checkpointing to detect, diagnose and recover the computation impaired by silicon defects or SER events. The approach works by periodically testing the processor to determine if the system is broken. If so, we reconfigure the processor to avoid using the broken component. A similar mechanism is used to detect SER, faults, with the difference that recovery is implemented by re-execution. By utilizing low-cost techniques to address defects and SER, we keep protection costs significantly lower than traditional fault-tolerance approaches while providing high levels of coverage for a wide range of faults. Using detailed gate-level simulation, we find that our approach provides 95% and 99% coverage for silicon defects and SER events, respectively, with only a 14% area overhead.
TORBA: trading contracts for CORBA
Authors: Raphaël Marvie, Philippe Merle, Jean-Marc Geib, Sylvain Leblanc
Venue: Proceedings of the 6th conference on USENIX Conference on Object-Oriented Technologies and Systems - Volume 6 (2001)

Trading is a key function in the context of distributed applications: It allows runtime discovering of available resources. In order to standardize this function, the Open Distributed Processing (ODP) and Object Management Group (OMG) have specified a trading service for CORBA objects: The CosTrading. This specification has two main drawbacks: First, this service is complex to use from applications and second, it does not offer type checking of trading requests at compilation time. Both are discussed in this paper. The main goal of our Trader Oriented Request Broker Architecture (TORBA) is to provide a trading framework and its associated tools, which tend to offer typed trading operations that are simple to use from applications and checked at compilation time. In that, we define the concept of Trading Contracts, written with the TORBA Definition Language (TDL). Such contracts are then compiled to generate trading proxies offering simple-to-use interfaces. These interfaces completely hide the complexity of the ODP/OMG CosTrading APIs. In the meantime, TDL contracts could be dynamically used through a generic graphical console exploiting a contract repository. The example used in this paper, clearly states the advantages brought by the TDL trading contracts: type checking at compilation time, simple to use, and providing a powerful framework for CORBA object trading.
The All-or-Nothing Anti-Theft Policy--Theft Protection for Pervasive Computing
Authors: Jakob Illeborg Pagter, Michael Ostergaard Pedersen
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 01 (2007)

In many application scenarios for pervasive computing, theft is a serious security threat. In this paper we present the All-Or-Nothing anti-theft policy aimed at providing theft protection for pervasive computing. The overall idea behind the All-Or-Nothing anti-theft policy is to chain devices together in friendly networks so that any device will only work when it can see all of its friends. Thus a thief will have to keep the network of friendly devices together even if he only desires to steal one of the devices. Otherwise the device will not work. We provide a detailed security policy, present the required cryptographic protocols, provide three different applications, and finally we document that the policy is suitable for implementation on typical pervasive computing devices.
A teaching strategy for physics learning in a Chinese military academy environment
Authors: Tien-Hsing Yang
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

The objective of this study is to conduct two different teaching methods, expository method and Peer's instruction method, on two sessions and to assess the effectiveness of two teaching methods, and also to compare the physics background of the ROC naval cadets with those of USA college students. Preliminarily we find the Peer instruction method is a better way to improve the physics concepts. ROC cadets are on the verge of understanding physics. Also the strict limitation imposed by the military environment on the cadet's life plays a critical role in our teaching strategy.
Implementation of smart antenna base station with a novel searcher and tracker for CDMA 2000 1X
Authors: Yoonjee Kim, Heungjae Im, Jaehong Park, Hwanseog Bahk, Jonghun Kim, Seungwon Choi
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 01 (2002)

This paper presents a performance analysis of smart antenna BTS (base-station transceiver subsystem) for the frame error rate (FER) and detection probability in PN-code acquisition, which provides a tremendous increase in communication capacity.
A Jitter Attenuating Timing Chain
Authors: Suwen Yang, Mark R. Greenstreet, Jihong Ren
Venue: Proceedings of the 13th IEEE International Symposium on Asynchronous Circuits and Systems (2007)

A long chain of inverters and wire segments will amplify clock jitter and drop timing pulses due to intersymbol interference. We present a jitter attenuating buffer based on surfing techniques. Our buffer circuit consists of a few inverters with variable output strength that implement a simple, low-gain DLL. Chains of these surfing buffers attenuate jitter making them well suited for source-synchronous interfaces. Furthermore, our chains can be used to reliably transmit handshaking signals and support sliding-window protocols to improve the throughput of asynchronous communication.
Time delay estimation in unknown spatially uncorrelated Gaussian noises using higher-order statistics
Authors: Yong Wu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

Bispectrum methods have been proposed for non-Gaussian signal time delay estimation (TDE) problem. When the signal is non-Gaussian and additive noises are spatially uncorrelated Gaussian, the bispectrum methods are outperformed by generalized cross-correlation (GCC) methods. This problem is addressed in this paper and new methods are proposed to improve the TDE performance. The new methods exploit the higher-order statistics characteristics of the signals and formulate weighting functions to improve the time delay estimation. Computer simulation results show that the new methods outperform both the GCC and the bispectrum methods.
Knowledge Acquisition through Computer-Based Training: Histology of the Skin in Basic Medical Education
Authors: Josef Smolle, Gilbert Reibnegger
Venue: Proceedings of the Twentieth IEEE International Symposium on Computer-Based Medical Systems (2007)

In 2002, the medical university of Graz launched an e-learning program to support face-to- face teaching and to facilitate blended learning. Computer-based training, which provides branching tutorial programs with elaborate feedback, is widely used in pre-clinical and clinical years. In the present study, we examined the potential of computer-based training for facilitating the acquisition of explicit knowledge in a pre-clinical topic. Content analysis of essays prepared by 42 students before and after computer-based training showed a highly significant increase in knowledge (21 +- 10 hits compared to 54 +- 28; t-test for paired values: t = 8.41, p \le 0.001). Furthermore, there was a significant correlation between essay content on one hand and the scoring in computer-based training on the other. Our study shows that computer-based training does not only drill the response to particular frames, but significantly supports knowledge acquisition in an undergraduate medical setting.
Using performance reflection in systems software
Authors: Robert Fowler, Alan Cox, Sameh Elnikety, Willy Zwaenepoel
Venue: Proceedings of the 9th conference on Hot Topics in Operating Systems - Volume 9 (2003)

We argue that systems software can exploit hard-ware instrumentation mechanisms, such as performance monitoring counters in modern processors, along with general system statistics to reactively modify its behavior to achieve better performance. In this paper we outline our approach of using these instrumentation mechanisms to estimate productivity and overhead metrics while running user applications. At the kernel level, we speculate that the scheduler can exploit these metrics to improve system performance. At the application level, we show that applications can use these metrics as well as application-specific productivity metrics to reactively tune their performance. We give several examples of using reflection at the kernel level (e.g., scheduling to improve memory hierarchy performance) and at the application level (e.g., server throttling).
Designing and prototyping interactive fluid dynamics exhibits for the Carnegie Science Center: an undergraduate team project experience
Authors: S. Finger
Venue: Proceedings of the Frontiers in Education Conference,1997. on 27th Annual Conference. Teaching and Learning in an Era of Change. - Volume 01 (1997)

This paper describes a team project experience at Carnegie Mellon University in which undergraduate students designed and prototyped interactive exhibits to teach principles of fluid dynamics. The client for the exhibits was the Carnegie Science Center (CSC) in Pittsburgh. The CSC promotes science awareness, focusing primarily on stimulating science appreciation in pre-teenagers through interactive exhibits that create an intuitive understanding of scientific principles. The students participating in this project first researched basic child development concepts, child motivation techniques, and the science museum's practices. Then students conducted brainstorming sessions to identify fluid dynamics principles and to create a list of design criteria for the exhibits. Twelve exhibit ideas were selected and presented to the CSC from which six were chosen to further analyze, design and prototype.