ppxscal/embedding_network huggingface dataset:
Elastic block ciphers
Authors: Angelos Keromytis
Venue:  (2006)

Standard block ciphers are designed around one or a small number of block sizes. From both a practical and a theoretical perspective, the question of how to efficiently support a range of block sizes is of interest. In applications, the length of the data to be encrypted is often not a multiple of the supported block size. This results in the use of plaintext-padding schemes that impose computational and space overheads. Furthermore, a variable-length block cipher ideally provides a variable-length pseudorandom permutation and strong pseudorandom permutation, which are theoretical counterparts of practical block ciphers and correspond to ideal properties for a block cipher. The focus of my research is the design and analysis of a method for creating variable-length block ciphers from existing fixed-length block ciphers. As the heart of the method, I introduce the concept of an elastic block cipher, which refers to stretching the supported block size of a block cipher to any length up to twice the original block size while incurring a computational workload that is proportional to the block size. I create a structure, referred to as the elastic network, that uses the round function from any existing block cipher in a manner that allows the properties of the round function to be maintained and results in the security of the elastic version of a block cipher being directly related to that of the original version. By forming a reduction between the elastic and original versions, I prove that the elastic version of a cipher is secure against round-key recovery attacks if the original cipher is secure against such attacks. I illustrate the method by creating elastic versions of four existing block ciphers. In addition, the elastic network provides a new primitive structure for use in symmetric-key cipher design. It allows for the creation of variable-length pseudorandom permutations and strong pseudorandom permutations in the range of b to 2b bits from round functions that are independently chosen pseudorandom permutations on b bits.
Rewrite-Based Decision Procedures
Authors: Maria Paola Bonacina, Mnacho Echenim
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2007)

The rewrite-based approach to satisfiability modulo theories consists of using generic theorem-proving strategies for first-order logic with equality. If one can prove that an inference system generates finitely many clauses from the presentation T of a theory and a finite set of ground unit clauses, then any fair strategy based on that system can be used as a T -satisfiability procedure. In this paper, we introduce a set of sufficient conditions to generalize the entire framework of rewrite-based T-satisfiability procedures to rewrite-based T-decision procedures. These conditions, collectively termed subterm-inactivity, will allow us to obtain rewrite-based T-decision procedures for several theories, namely those of equality with uninterpreted functions, arrays with or without extensionality and two of its extensions, finite sets with extensionality and recursive data structures.
An objectbase schema evolution approach to Windows NT security
Authors: K. Barker, Raj Jayaplan, R. Peters
Venue: Proceedings of the 4th conference on USENIX Windows Systems Symposium - Volume 4 (2000)

The current security model for the Windows NT operating system is powerful and offers many valuable features. The User Manager provided by Windows NT is the primary method for the provision of security maintenance. Unfortunately, this tool does not offer several features that would make the end-user's task more intuitive. This paper demonstrates a new technique to support the security on a Windows NT platform. Our system supports at least the following features: (1) An object-oriented hierarchy, so roles and groups can be supported in a more automated way. (2) A more intuitive user interface so the administrative errors are less likely to be problematic. (3) Simplified security management on a Windows NT platform. (4) Avoids unnecessary creation of objects (users / group) and redundant granting / revoking of privileges. This paper discusses a new security model that has these features in addition to those currently available on Windows NT.
Floorplanning in Modern FPGAs
Authors: Pritha Banerjee, Susmita Sur-Kolay, Arijit Bishnu
Venue: Proceedings of the 20th International Conference on VLSI Design held jointly with 6th International Conference: Embedded Systems (2007)

State-of-the-art FPGA architectures have millions of gates in CLBs, Block RAMs, and Multiplier blocks which can host fairly large designs. While their physical design calls for floorplanning, the traditional algorithm for ASIC do not suffice. In this paper, we have proposed an algorithm for unified floorplan topology generation and sizing for recent heterogeneous FPGAs. Experimental results on a set of benchmark circuits show that our three step floorplan generation method can produce feasible solutions very fast with 45% improvement in total half perimeter wirelength compared to the very few previous approaches.
Optimum transform coding of imagery
Authors: G. P. Abousleman
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

A system is presented for transform coding of imagery. Specifically, the system uses the 2-D discrete cosine transform (DCT) in conjunction with adaptive classification, entropy-constrained trellis-coded quantization, optimal rate allocation, and adaptive arithmetic encoding. Adaptive classification, side rate reduction, and rate allocation strategies are discussed. Entropy-constrained codebooks are designed using a modified version of the generalized Lloyd algorithm. This entropy-constrained DCT-based system is shown to achieve outstanding coding performance as compared to other DCT-based systems.
Optimal DMT transceivers over fading channels
Authors: Yuan-Pei Lin
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 03 (1999)

Discrete Fourier transform (DFT) based discrete multitone modulation (DMT) systems have been widely applied to various applications. We study a broader class of DMT systems using more general unitary matrices instead of DFT matrices. For this class we show how to design the optimal DMT systems over fading channels with colored noise. Examples are given to show the improvement over the traditional DFT based DMT system. In addition we introduce a modified DFT based DMT system. The new system has the same complexity but better noise rejection property.
Inapproximability of the Tutte polynomial
Authors: Leslie Ann Goldberg, Mark Jerrum
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

The Tutte polynomial of a graph G is a two-variable polynomial T(G;x,y) that encodes many interesting properties of the graph. We study the complexityof the following problem, for rationals x and y: take as input a graph G, and output a value which is a good approximation to T(G;x,y). We are interested in determining for which points (x,y) there is a fullypolynomial randomised approximation scheme (FPRAS) for T(G;x,y). Our main contribution is a substantial widening of the region known to benon-FPRASable.
A personal naming and directory service for mobile internet users
Authors: Alain Macaire, David Carlier
Venue: Proceedings of the USENIX Workshop on Smartcard Technology on USENIX Workshop on Smartcard Technology (1999)

This paper proposes a new approach for the role of smartcards into distributed and mobile service environments. It is based on the naming and directory service architecture. We present a naming and directory service architecture which is based on a new component we named Personal Naming and Directory Service (PNDS), which is embedded on a smartcard. In section two, after a short introduction, we present PNDS concept and list advantages to have it stored on a smartcard. Section three gives an overview and limits of current smartcards applications for mobile users. Section four presents PNDS features more precisely, and shows how it has been integrated into a federated architecture of naming servers (PNDS has been prototyped using a GemXpresso JavaCard platform). To demonstrate the PNDS concept, an example of a PNDS-based application is presented in section five.
Training set synthesis for entropy-constrained transform vector quantization
Authors: D. Comaniciu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 04 (1996)

This paper introduces the concept of training set synthesis for entropy-constrained transform vector quantization (TSS-ECTVQ). The statistics of actual sets of transform vectors are first approximated using histograms. New sets of vectors-called synthesized training sets-are obtained based upon the estimated parameters-called training set parameters. By employing a fast entropy-constrained algorithm, codebooks are populated from the synthesized training sets for each image being coded. Then, entropy-constrained vector quantization is performed. The training set parameters are sent to the decoder, which obtains the same training sets, and generates codebooks identical to the encoder. Experimental results demonstrate that high quality image coding at low bit rates can be obtained with the proposed TSS-ECTVQ method. In particular, the image Lenna was coded at 0.25 bits/pixel with a PSNR of 32.42 dB.
Tying student work and assessment directly to learning objectives in CS1
Authors: D. J. Neebel
Venue: Proceedings of the Frontiers in Education Conference, 2001. on 31st Annual - Volume 01 (2001)

The general goal for most CS1 courses is that a student be able to develop a simple algorithm to solve a simple problem and then implement that algorithm in a highlevel object-oriented programming language. Many instructors refine the general goal into a set of specific objectives that are loosely related to student work. This paper presents a CS1 course where specific objectives directly relate to assessed work. Because objectives are either met or not met, the number of objectives met determines a student's course grade rather than scores on individually graded assignments and exams. A high course grade requires that the student meet most or all of the objectives.
Automatic generation of embedded communication SW for heterogeneous MPSoC platforms
Authors: Ines Viskic, Samar Abdi, Daniel D. Gajski
Venue: Proceedings of the 2007 ACM SIGPLAN/SIGBED conference on Languages, compilers, and tools for embedded systems (2007)

This paper addresses the problem of long design cycle of MPSoCs communication SW with automatic synthesis. The tool we propose takes as input a transaction level model (TLM) of MPSoC communication and outputs pin and cycle-accurate (PCA) bus drivers that can be linked to the synthesizable PCA model (PCAM). The TL communication is simple since TLM channels abstract away protocol details. PCAM communication, in turn, includes explicit definitions for each signal and pin. However, in most cases the TLMs are not suitable for implementation since they do not reflect the MPSoC platform. Usually the designers simulate (fast) TLMs, then manually implement PCA communication. Our communication SW synthesis transforms TL send and receive functions into platform specific PCAM bus drivers which can be automatically downloaded to the FPGA board. The presented results demonstrate the significant productivity gain achieved with our tool, with no great cost to either code size or system performance.
Locality-aware Connection Management and Rank Assignment forWide-area MPI
Authors: Hideo Saito, Kenjiro Taura
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

We propose a connection management scheme that limits the number of inter-cluster connections and forwards messages for processes that cannot communicate directly. We also propose a rank assignment scheme that finds rankprocess mappings with low communication overhead by solving the Quadratic Assignment Problem. Our proposed methods perform locality-aware communication optimizations, and do so without tedious manual configuration by obtaining latency and traffic information from a short profiling run of the environment and the application. Using these methods, we implemented a wide-area-enabled MPI library called MC-MPI, and evaluated its performance by running the NAS Parallel Benchmarks on 256 real nodes distributed across 4 clusters. MC-MPI was able to limit the number of process pairs that established connections to just 10% without suffering a performance penalty. Moreover, MC-MPI was able to find rank assignments that resulted in up to 160% better performance than locality-unaware assignments.
Tracking of mobile phone using IMM in CDMA environment
Authors: J. Lee
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

This paper proposes an effective method to localize mobile phones in a CDMA environment. This is to remedy the performance limitation inherent in the traditional localization algorithms, which make use of the present information only. If a Kalman filter is used that includes the previous information of location of a mobile unit, then the location error can be significantly reduced. Since it is difficult to represent the actual movement of a user by only one motion model, better error performance will be shown if an interacting multiple model (IMM) that uses several Kalman filter models is applied in place of just one Kalman filter. Performance analysis of the location error between the Kalman filter and IMM implementations confirm our postulation that the IMM significantly reduces location error.
Using Digital Cameras for Text Input on Mobile Devices
Authors: Frank Siegemund, Muhammad Haroon
Venue: Proceedings of the Fifth IEEE International Conference on Pervasive Computing and Communications (2007)

This paper presents novel text input methods for mobile devices. In particular, it shows how users can capture text from books, newspapers, and other objects by using the digital cameras that are integrated into an increasing number of smartphones. The idea is to select text from a live video stream generated by these digital cameras. Different interaction patterns are discussed that allow users to select text: (1) automatic detection of the word closest to a fixed position on the mobile device's screen, (2) delayed movement of the text selection to improve the precision of the selection procedure, and (3) using the stylus to select words and word groups. The proposed interaction patterns are evaluated based on the results of a user study, and their application is shown in an example scenario. The presented research has practical relevance because it can improve the usability of mobile applications such as online searching.
Enterprise Collaborative Contexts and their Provisioning for Secure Managed Extranets
Authors: Jonathan Chan, Glynn Rogers, Darwin Agahari, David Moreland, John Zic
Venue: Proceedings of the 15th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (2006)

Our research into secure managed extranets was motivated by the requirements of companies (possibly competitors) needing to collaborate on occasion because transient business windows present mutual opportunities. Our contributions towards satisfying these requirements are twofold: (i) we present a service-construct abstraction based on what we term a "Collaborative Context' where authorized participants (e.g. project leaders) have collective provisioning capabilities for the purpose of negotiating and contributing exclusive resources to create a virtual private enterprise, and (ii) we present a realization of the collaborative context as a commercially oriented, on-demand Virtual Private eXtranet Service (VPXS).
Increasing engineering opportunities for K-12 students in south Central Kentucky
Authors: S. S. Wilson
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

Recruiting students is always an important issue for any engineering program. One method of recruiting is to involve K-12 students in hands-on engineering applications. Many K-12 students have no appreciation for the field of engineering and what engineers do. Informing students can be achieved by providing students with the opportunity to experience engineering. Faculty members in the Department of Engineering at Western Kentucky University (WKU) are involved in several means of outreach to the K-12 community such as a high school robot competition, elementary school enrichment programs, junior high student summer programs, and elementary school Saturday programs. These measures will provide students with a concept of the field of engineering and eventually increase enrollment at WKU. 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
Accurate estimation of R-D characteristics for rate control in real-time video encoding
Authors: Junfeng Bai
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

In real-time video communications, the rate control strategies must be utilized to satisfy the end-to-end delay and prevent the encoding buffer from over/underflow. In other words, to acquire the best possible video quality with a minimal quality variation in the playback video, an accurate rate-distortion (R-D) model of the video source is critical in optimizing the bit allocation for video coding. In the paper, an exponential functions based R-D model is proposed for intra-coded frames in video coding. Numerous experiments have consistently shown that the proposed model outperforms other popular R-D models in terms of both the estimation accuracy and computation complexity, making it suitable for rate control in real-time video coding.
NewsCache: a high performance cache implementation for Usenet news
Authors: Thomas Gschwind, Manfred Hauswirth
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1999)

Usenet News is reaching its limits as current traffic strains the available infrastructure. News data volume increases steadily and competition with other Internet services has intensified. Consequently bandwidth requirements are often beyond that provided by typical links and the processing power needed exceeds a single system's capabilities. A rapidly growing number of users, especially attracted by WWW, overloads communication links and makes bandwidth a scarce resource. While an elaborate caching infrastructure was adopted for the WWW, Usenet News still uses most of its originally defined infrastructure. Caching techniques have not yet been adopted on a large scale. We believe that this is due to the lack of efficient cache implementations. In this paper we present a high performance cache server for Usenet News that helps to conserve network bandwidth, computing power, and disk storage and is compatible with the current infrastructure and standards. After a thorough comparison of existing news database formats and replacement strategies we designed and implemented NEWSCACHE to remedy Usenet News bottlenecks. We present an empirical comparison of different cache replacement strategies as well as an evaluation of the use of NEWSCACHE as a news server.
Brain-Computer Interfaces: Where Human and Machine Meet
Authors: Sixto Ortiz Jr.
Venue: Computer (2007)

Several academic and corporate researchers are now working to commercialize brain-computer interface technology, which reads brain activity and translates it into a digital form that computers can understand, process, and convert into actions of some kind.
Assessment and correction of voice quality variabilities in large speech databases for concatenative speech synthesis
Authors: Y. Stylianou
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 01 (1999)

In an effort to increase the naturalness of concatenative speech synthesis, large speech databases may be recorded. While it is desirable to have varied prosodic and spectral characteristics in the database, it is not desirable to have variable voice quality. We present an automatic method for voice quality assessment and correction, whenever necessary, of large speech databases for concatenative speech synthesis. The proposed method is based on the use of a Gaussian mixture model, GMM, to model the acoustic space of the speaker of the database and on autoregressive filters for compensation. An objective method to measure the effectiveness of the database correction based on a likelihood function for the speaker's GMM, is presented as well. Both objective and subjective results show that the proposed method succeeds in detecting voice quality problems and successfully corrects them. Results show a 14.2% improvement of the log-likelihood function after compensation.
Location-aware information access through wireless networks
Authors: Gaetano Borriello
Venue:  (2006)

Location-aware information applications run continuously wherever the user may go and change their behaviors based on the information relevant to their user's current location. Therefore, it is important to provide location-specific information in as many places as possible. This dissertation explores the possibility of taking advantage of the widespread WiFi networks to build a ubiquitous location-aware information system that can support location-aware information applications in wide geographical areas to a large number of people. This dissertation suggests two ways to use the existing WiFi networks for location-aware information systems. One approach is to use the existing WiFi networks as is in a passive way without asking network owners to do anything extra. In this approach, the existing WiFi networks are used for location determination. However, the raw locations generated by the location system that uses the existing WiFi networks need to be translated into more meaningful descriptions of places so that they can be used by applications. The translation step requires the definitions of important places, and the issue is to define important places automatically to minimize the burden on the user. This dissertation proposes a novel algorithm that extracts important places for a user from the user's trace of locations. The algorithm shows that use of time information enhances the performance and the accuracy of place extraction. The other approach is to use the existing WiFi networks actively by encouraging network owners to participate in the system to support a wider range of applications. In this approach, the WiFi networks are used to deliver location-specific information, and WiFi network owners need to open their networks for public use. The issue is to design an architecture that can deliver location-specific information through existing WiFi networks while protecting the network security and the user privacy. This dissertation presents a cell-based grassroots architecture and shows that the broadcast communication model is a viable model for disseminating location-specific information through WiFi networks in this architecture.
An efficient parallel repetition theorem for Arthur-Merlin games
Authors: Rafael Pass, Muthuramakrishnan Venkitasubramaniam
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

We show a parallel-repetition theorem for constant-round Arthur-Merlin Games, using an efficient reduction. As a consequence, we show that parallel repetition reduces the soundness-error at an optimal rate (up to a negligible factor) in constant-round public-coin argument systems, and constant-round public-coinproofs of knowledge. The former of these results resolves an open questionposed by Bellare, Impagliazzo and Naor (FOCS '97).