ppxscal/embedding_network huggingface dataset:
A general framework for certifying garbage collectors and their mutators
Authors: Andrew McCreight, Zhong Shao, Chunxiao Lin, Long Li
Venue: ACM SIGPLAN Notices (2007)

Garbage-collected languages such as Java and C# are becoming more and more widely used in both high-end software and real-time embedded applications. The correctness of the GC implementation is essential to the reliability and security of a large portion of the world's mission-critical software. Unfortunately, garbage collectors--especially incremental and concurrent ones--are extremely hard to implement correctly. In this paper, we present a new uniform approach to verifying the safety of both a mutator and its garbage collector in Hoare-style logic. We define a formal garbage collector interface general enough to reason about a variety of algorithms while allowing the mutator to ignore implementation-specific details of the collector. Our approach supports collectors that require read and write barriers. We have used our approach to mechanically verify assembly implementations of mark-sweep, copying and incremental copying GCs in Coq, as well as sample mutator programs that can be linked with any of the GCs to produce a fully-verified garbage-collected program. Our work provides a foundation for reasoning about complex mutator-collector interaction and makes an important advance toward building fully certified production-quality GCs.
Non-redundant data clustering
Authors: David Gondek, Thomas Hofmann
Venue: Knowledge and Information Systems (2007)

Data clustering is a popular approach for automatically finding classes, concepts, or groups of patterns. In practice, this discovery process should avoid redundancies with existing knowledge about class structures or groupings, and reveal novel, previously unknown aspects of the data. In order to deal with this problem, we present an extension of the information bottleneck framework, called coordinated conditional information bottleneck, which takes negative relevance information into account by maximizing a conditional mutual information score subject to constraints. Algorithmically, one can apply an alternating optimization scheme that can be used in conjunction with different types of numeric and non-numeric attributes. We discuss extensions of the technique to the tasks of semi-supervised classification and enumeration of successive non-redundant clusterings. We present experimental results for applications in text mining and computer vision.
Evolving mach 3.0 to a migrating thread model
Authors: Bryan Ford, Jay Lepreau
Venue: Proceedings of the USENIX Winter 1994 Technical Conference on USENIX Winter 1994 Technical Conference (1994)

We have modified Mach 3.0 to treat cross-domain remote procedure call (RPC) as a single entity, instead of a sequence of message passing operations. With RPC thus elevated, we improved the transfer of control during RPC by changing the thread model. Like most operating systems, Mach views threads as statically associated with a single task, with two threads involved in an RPC. An alternate model is that of migrating threads, in which, during RPC, a single thread abstraction moves between tasks with the logical flow of control, and "server" code is passively executed. We have compatibly replaced Mach's static threads with migrating threads, in an attempt to isolate this aspect of operating system design and implementation. The key element of our design is a decoupling of the thread abstraction into the execution context and the schedulable thread of control, consisting of a chain of contexts. A key element of our implementation is that threads are now "based" in the kernel, and temporarily make excursions into tasks via upcalls. The new system provides more precisely defined semantics for thread manipulation and additional control operations, allows scheduling and accounting attributes to follow threads, simplifies kernel code, and improves RPC performance. We have retained the old thread and IPC interfaces for backwards compatibility, with no changes required to existing client programs and only a minimal change to servers, as demonstrated by a functional Unix single server and clients. The logical complexity along the critical RPC path has been reduced by a factor of nine. Local RPC, doing normal marshaling, has sped up by factors of 1.7-3.4. We conclude that a migrating-thread model is superior to a static model, that kernel-visible RPC is a prerequisite for this improvement, and that it is feasible to improve existing operating systems in this manner.
Performance portability on EARTH: a case study across several parallel architectures
Authors: Weirong Zhu, Yanwei Niu, Guang R. Gao
Venue: Cluster Computing (2007)

Due to the increase of the diversity of parallel architectures, and the increasing development time for parallel applications, performance portability has become one of the major considerations when designing the next generation of parallel program execution models, APIs, and runtime system software. This paper analyzes both code portability and performance portability of parallel programs for fine-grained multi-threaded execution and architecture models. We concentrate on one particular event-driven fine-grained multi-threaded execution model--EARTH, and discuss several design considerations of the EARTH model and runtime system that contribute to the performance portability of parallel applications. We believe that these are important issues for future high end computing system software design. Four representative benchmarks were conducted on several different parallel architectures, including two clusters listed in the 23rd supercomputer TOP500 list. The results demonstrate that EARTH based programs can achieve robust performance portability across the selected hardware platforms without any code modification or tuning.
Application of simultaneous decoding algorithms to automatic transcription of known and unknown words
Authors: Jianxiong Wu
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 02 (1999)

This paper proposes simultaneous decoding using multiple utterances to derive one or more allophonic transcriptions for each word. Three possible simultaneous decoding algorithms, namely the N-best-based algorithm, the forward-backward-based algorithm and the word-network-based algorithm, are outlined. The proposed word-network-based algorithm can incrementally decode a transcription from any number of training utterances. Speech recognition experiments for both known and unknown word vocabularies show up to 16% reduction in word error rate when simultaneously decoded allophonic transcriptions are added to the recognition dictionaries. This result holds even for dictionaries originally transcribed by expert phoneticians.
An Image Metric-Based ATR Performance Prediction Testbed
Authors: Scott K. Ralph, John Irvine, Magnus Snorrason, Steve Vanstone
Venue: Proceedings of the 35th Applied Imagery and Pattern Recognition Workshop (2006)

Automatic target detection (ATD) systems process imagery to detect and locate targets in imagery in support of a variety of military missions. Accurate prediction of ATD performance would assist in system design and trade stud-ies, collection management, and mission planning. A need exists for ATD performance prediction based exclusively on information available from the imagery and its associated metadata. We present a predictor based on image measures quantifying the intrinsic ATD difficulty on an image. The modeling effort consists of two phases: a learn-ing phase, where image measures are computed for a set of test images, the ATD performance is measured, and a prediction model is developed; and a second phase to test and validate performance prediction. The learning phase produces a mapping, valid across various ATR algorithms, which is even applicable when no image truth is avail-able (e.g., when evaluating denied area imagery). The testbed has plug-in capability to allow rapid evaluation of new ATR algorithms. The image measures employed in the model include: statistics derived from a constant false alarm rate (CFAR) processor, the Power Spectrum Signature, and others. We present a performance predictor using a trained classifier ATD that was constructed using GENIE, a tool developed at Los Alamos National Laboratory. The paper concludes with a discussion of future research.
The spoofer project: inferring the extent of source address filtering on the internet
Authors: Robert Beverly, Steven Bauer
Venue: Proceedings of the Steps to Reducing Unwanted Traffic on the Internet on Steps to Reducing Unwanted Traffic on the Internet Workshop (2005)

Forging, or "spoofing," the source addresses of IP packets provides malicious parties with anonymity and novel attack vectors. Spoofing-based attacks complicate network operator's defense techniques; tracing spoofing remains a difficult and largely manual process. More sophisticated next generation distributed denial of service (DDoS) attacks may test filtering policies and adaptively attempt to forge source addresses. To understand the current state of network filtering, this paper presents an Internet-wide active measurement spoofing project. Clients in our study attempt to send carefully crafted UDP packets designed to infer filtering policies. When filtering of valid packets is in place we determine the filtering granularity by performing adjacent netblock scanning. Our results are the first to quantify the extent and nature of filtering and the ability to spoof on the Internet. We find that approximately one-quarter of the observed addresses, netblocks and autonomous systems (AS) permit full or partial spoofing. Projecting this number to the entire Internet, an approximation we show is reasonable, yields over 360 million addresses and 4,600 ASes from which spoofing is possible. Our findings suggest that a large portion of the Internet is vulnerable to spoofing and concerted attacks employing spoofing remain a serious concern.
New Ferroelectrics for Naval SONAR and Modeling of Nanoscale Ferroelectric Nonvolatile Memory Materials
Authors: Alexie M. Kolpak, Ilya Grinberg, Andrew M., Shawn T. Brown
Venue: Proceedings of the HPCMP Users Group Conference (2006)

Using quantum-mechanical simulations, we have computationally investigated new materials for use in Naval Sound Navigation and Ranging (SONAR). At the nanoscale, our quantum-mechanical studies show that ferroelectricity and the resultant favorable properties are stable at dimensions much smaller than previously thought. We have demonstrated that charge compensation by molecular adsorbates is more efficient than by traditional metal electrodes. This enables even a single molecular electrode to stabilize full-strength ferroelectricity in ultra-thin films and nanowires. We also report successful porting and performance tuning of our computer codes to the CRAY XT3 platform.
Assessing Robustness of Web-Services Infrastructures
Authors: Marco Vieira, Nuno Laranjeiro, Henrique Madeira
Venue: Proceedings of the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (2007)

Web-services are supported by a complex software infrastructure that must provide a robust service to the client applications. This practical experience report presents a practical approach for the evaluation of the robustness of web-services infrastructures. A set of robustness tests (i.e., invalid web-services call parameters) is applied during web-services execution in order to reveal possible robustness problems in the web-services code and in the application server infrastructure. The approach is illustrated using two different implementations of the web-services specified by the TPC-App performance benchmark running on top of the JBoss application server. The proposed approach is generic and can be used to evaluate the robustness of web-services implementations (relevant for programmers) and application server infrastructures (relevant for administrators and system integrators).
XTP as a transport protocol for distributed parallel processing
Authors: W. Timothy Strayer, Michael J. Lewis, Raymond E. Cline,  Jr.
Venue: Proceedings of the High-Speed Networking Symposium on USENIX 1994 High-Speed Networking Symposium (1994)

The Xpress Transfer Protocol (XTP) is a flexible transport layer protocol designed to provide efficient service without dictating the communication paradigm or the delivery characteristics that qualify the paradigm. XTP provides the tools to build communication services appropriate to the application. Current data delivery solutions for many popular cluster computing environments use TCP and UDP. We examine TCP, UDP, and XTP with respect to the communication characteristics typical of parallel applications. We perform measurements of end-to-end latency for several paradigms important to cluster computing. An implementation of XTP is shown to be comparable to TCP in end-to-end latency on preestablished connections, and does better for paradigms where connections must be constructed on the fly.
MOSIX: how Linux clusters solve real world problems
Authors: Steve McClure, Richard Wheeler
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

As the complexity of software increases, the size of the software tends to increase as well, which incurs longer compilation and build cycles. In this paper, the authors present one example of how clusters of Linux systems, using the MOSIX extensions for load monitoring and remote execution, were used to eliminate a performance bottleneck and to reduce the cost of building software. We present a discussion of our original software development cluster, an analysis of the performance issues in that cluster, and the development and modifications done to MOSIX and Linux in order to produce a solution to our problem. We finish by presenting future developments that will enhance our cluster.
Institutionalizing curriculum change: a SUCCEED case history
Authors: M. Hoit, M. Ohland
Venue: Proceedings of the Frontiers in Education Conference on 1995. Proceedings., 1995 vol 1. - Volume 01 (1995)

A freshman interdisciplinary laboratory class was recently adopted as a permanent course in the engineering curriculum at the University of Florida. This class is one of the projects developed under the Southeastern University and College Coalition for Engineering Education (SUCCEED). This class replaced the standard one-hour-per-week introductory freshman lecture. The class rotates 14 groups of 20 students each through weekly three-hour laboratory sessions in 11 engineering disciplines. Each discipline's lab exposes the students to hands-on experiments representing concepts related to the discipline's specialty. This paper discusses the efforts required to take an experimental course and make it a permanent one. Included are statistics which indicate that women experience significantly improved retention through the new course and minority retention is raised to the level of the general population.
Building an HPC Ecosystem in Europe
Authors: Kimmo Koski
Venue: Proceedings of the Sixth International Symposium on Parallel and Distributed Computing (2007)

During 2006 there has been intense work in Europe in order to increase European competitiveness in highend computing and grid collaboration. Various new activities have been started in addition to the existing European grid projects, such as EGEE and DEISA. High- Performance Computing in Europe Taskforce (HET) has drafted a strategy for European HPC Ecosystem with a focus in enabling European centers with a computing capability beyond petaflop. Collaboration of the various National Grid Initiatives, European Grid Initiative (EGI), has been planned with a focus on transparent interoperability between national cluster environments. European Strategy Forum for Research Infrastructures (ESFRI) has published a roadmap with 35 major new experiments, all requiring data management capabilities and many of them in addition high end computing. Integration of activities and tight collaboration between the various European initiatives is essential in order to manage the growing complexity.
Deniable File System--Application of Deniable Storage to Protection of Private Keys
Authors: Bartosz Oler, Imed El Fray
Venue: Proceedings of the 6th International Conference on Computer Information Systems and Industrial Management Applications (2007)

This article discusses various ideas of deniable file systems, their advantages, drawbacks and use as a storage for sensitive data (e.g. private keys for the asymmetric algorithms). Also a design of such a new file system is presented. Its goal is to revive the concept and, in the future, popularize it by merging into Linux.
Application of data acquisition systems in the undergraduate laboratories of mechanical engineering and engineering science
Authors: H. V. Estrada
Venue: Proceedings of the Frontiers in Education Conference,1997. on 27th Annual Conference. Teaching and Learning in an Era of Change. - Volume 01 (1997)

A number of experiments in different areas of mechanical engineering and engineering science at the University of North Carolina at Charlotte, USA, have been revisited to improve the experiments' scope and their educational value for the student. Various experiments are being updated to assist in the ongoing curriculum revision, and to bring in data acquisition methods and protocols into the curriculum. Two cases are presented in this paper to illustrate the benefits and efficiency gained when simple data acquisition programs are included in the curriculum.
Security mechanism independence in ONC RPC
Authors: Mike Eisler, Roland J. Schemers,  III, Raj Srinivasan
Venue: Proceedings of the 6th conference on USENIX Security Symposium, Focusing on Applications of Cryptography - Volume 6 (1996)

Generic Security Services API (GSS-API) [4] provides a framework for security services. It allows source level portability. It allows applications to run independently of the underlying security mechanisms and technologies. To provide security mechanism independence in ONC RPC [1, 2, 3], this paper proposes a new security flavor, RPCSEC_GSS. RPCSEC_GSS incorporates services offered by the GSS-API into ONC RPC. Using the programming interface for the RPCSEC_GSS flavor, ONC RPC applications can specify a GSS-API security mechanism to be used with an RPC session, and also request security services, such as integrity and privacy.
Optimal Power management scheme for Heterogeneous Wireless Sensor Networks: Lifetime Maximization under QoS and Energy Constraints
Authors: Ines Slama, Badii Jouaber, Djamal Zeghlache
Venue: Proceedings of the Third International Conference on Networking and Services (2007)

Wireless Sensor Networks are composed of autonomous interconnected sensing devices. Power limitation is considered as the most significant constraint for sensors. It directly influences the sensors' lifetime and hence the application quality of service. Many studies have been conducted in the field, where different power-based routing and data gathering strategies are proposed. However, most of them are driven for specific applications and for specific network topologies. In this paper, we propose a power-and-QoSbased framework for heterogeneous sensor networks. This framework is formulated as an optimization problem. It aims at maximizing the application lifetime while ensuring acceptable level of quality of service. Moreover, the proposed framework is designed for a general network architecture where both clustered and hierarchical structures can coexist. The framework simultaneously optimizes intra-cluster transmissions and inter-cluster multi-hop routing.
Analysis of echoes in single-image random-dot stereograms
Authors: M. S. K. Lau
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

Three-dimensional depth information of a surface can be encoded in two-dimensional images called single-image random-dot-stereograms or, more widely known, autostereograms. It is achieved by using the correlations of pixels in the horizontal direction. Using the correspondences between pixels in human brains or computer algorithms, surfaces can be reconstructed from autostereograms. However, in some cases, the reconstructed surfaces are not unique because of "echoes". In the presence of echoes, reconstruction of the original surface from an autostereogram cannot be guaranteed since no cue of the original surface is available in autostereograms. The causes of echoes are investigated and conditions for echo-free reconstructions are derived. Based on these conditions, an improved autostereogram generation algorithm is proposed to guarantee echo-free autostereograms. Besides, the surface reconstruction algorithm is modified such that the originally encoded surfaces can always be reconstructed from echo-free autostereograms.
Chunkfs: using divide-and-conquer to improve file system reliability and repair
Authors: Val Henson, Arjan van de Ven, Amit Gud, Zach Brown
Venue: Proceedings of the 2nd conference on Hot Topics in System Dependability - Volume 2 (2006)

The absolute time required to check and repair a file system is increasing because disk capacities are growing faster than disk bandwidth and seek time remains almost unchanged. At the same time, file system repair is becoming more common, because the per-bit error rate of disks is not dropping as fast as the number of bits per disk is growing, resulting in more errors per disk. With existing file systems, a single corrupted metadata block requires the entire file system to be unmounted, checked, and repaired--a process that takes hours or days to complete, during which time the data is completely unavailable. The resulting "fsck time crunch" is already making file systems only a few terabytes in size impractical administrate. We propose chunkfs, which divides on-disk file system data into small, individually repairable fault-isolation domains while preserving normal file system semantics.