ppxscal/embedding_network huggingface dataset:
Composing Interoperable Ground Systems
Authors: Judy Kerner, Craig A. Lee, Geri Chaudhri
Venue: Proceedings of the Sixth International IEEE Conference on Commercial-off-the-Shelf (COTS)-Based Software Systems (2007)

Many organizations are composing ground systems from existing components, whether legacy or COTS, and have been wrestling with the need for interoperability of the resulting systems. The growing emphasis on ground system participation in net-centric systemsof- systems highlights the issues involved. Developers and acquirers of ground systems, as well as the academic researchers who develop related technologies, need to understand the challenges and solutions raised by this environment. The Ground System Architectures Workshop (GSAW) series has had a number of presentations that have touched on these concerns, and a panel at ICCBSS04 explored some related issues.
A security model for full-text file system search in multi-user environments
Authors: Stefan Büttcher, Charles L. A. Clarke
Venue: Proceedings of the 4th conference on USENIX Conference on File and Storage Technologies - Volume 4 (2005)

Most desktop search systems maintain per-user indices to keep track of file contents. In a multi-user environment, this is not a viable solution, because the same file has to be indexed many times, once for every user that may access the file, causing both space and performance problems. Having a single system-wide index for all users, on the other hand, allows for efficient indexing but requires special security mechanisms to guarantee that the search results do not violate any file permissions. We present a security model for full-text file system search, based on the UNIX security model, and discuss two possible implementations of the model. We show that the first implementation, based on a postprocessing approach, allows an arbitrary user to obtain information about the content of files for which he does not have read permission. The second implementation does not share this problem. We give an experimental performance evaluation for both implementations and point out query optimization opportunities for the second one.
Concurrency Control Based on Subject and Purpose Concepts
Authors: Tomoya Enokido, Naohiro Hayashibara, Makoto Takizawa
Venue: Proceedings of the 11th IEEE International Workshop on Future Trends of Distributed Computing Systems (2007)

A subject doing a job function plays a role in an enterprise. In the role-based access control model, a role is a set of access rights. A subject granted a role can issue an access request in the role. In addition, objects are required to be consistent even if multiple transactions concurrently manipulate an object in a conflicting way. Here, a subject playing more significant roles should take the object prior to another subject. First, we discuss which roles are more significant than other roles in terms of types of methods. Next, we define which subject is moresignificant in terms of significancy of roles and authorization relations. A method issued by a more significant subject should be performed before another conflicting method issued by a less significant subject in the subject-oriented (SO) view. A transaction issued by a subject is associated with a subset of roles granted to the subject, which is named purpose. A method with a more significant purpose should be performed before another method with a less significant purpose in the purpose-oriented (PO) view. In this paper, we discuss how conflicting methods are ordered in a unique SO and PO (SPO) view. We discuss an SPO scheduler where multiple conflicting transactions are serializable in the SPO view. We evaluate the SPO scheduler compared with the traditional two-phase locking protocol in terms of throughput.
Adaptive Influence Distance Algorithm for Contouring Bus-Based Power System Data
Authors: David O. Savageau, Thomas J. Overbye
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

One viable option for the visualization of bus-based power system data is contouring. As contouring research progresses, more computationally efficient methods must be developed. A new algorithm presented here uses the concept of creating a unique influence distance for each bus. The distance is based on the closest g number of buses, instead of previous methods that use the same influence distance for each bus. The improvement in speed, along with the overall accuracy and pictorial quality of the images produced by this algorithm are examined in this paper.
Front Inside Cover [blank]
Venue: Proceedings of the High Performance Interconnects, 2004. on Proceedings. 12th Annual IEEE Symposium (2004)

IEEE 802.11 wireless LAN technology is mainly used as an access network within corporate enterprises. All the WLAN access points are eventually connected to a wired backbone to reach the Internet or enterprise computing resources. We aim to expand WLAN into an enterprise-scale backbone network technology by developing a multichannel wireless mesh network architecture called Hyacinth. Hyacinth equips each node with multiple IEEE 802.11a/b NICs and supports distributed channel assignment/routing to increase the overall network throughput. We present the results of a detailed performance evaluation study on the multichannel mesh networking aspect of Hyacinth, based on both NS-2 simulations and empirical measurements collected from a 9-node Hyacinth prototype testbed. A key result of this study is that equipping each node of a Hyacinth network with just 3 NICs can increase the total network bandwidth by a factor of 6 to 7, as compared with single-channel wireless mesh network architecture. 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
Two spatio-temporal decorrelation learning algorithms and their application to multichannel blind deconvolution
Authors: S. Choi
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 02 (1999)

We present and compare two different spatio-temporal decorrelation learning algorithms for updating the weights of a linear feedforward network with FIR synapses (MIMO FIR filter). Both standard gradient and the natural gradient are employed to derive the spatio-temporal decorrelation algorithms. These two algorithms are applied to multichannel blind deconvolution task and their performance is compared. The rigorous derivation of algorithms and computer simulation results are presented.
mhz: anatomy of a micro-benchmark
Authors: Carl Staelin, Larry McVoy
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1998)

Mhz is a portable ANSI/C program that determines the processor clock speed in a platform independent way. It measures the execution time of several different C expressions and finds the greatest common divisor to determine the duration of a single clock tick. Mhz can be used by anyone who wants or needs to know the processor clock speed. In large installations it is often easier to experimentally determine the clock speed of a given machine than to keep track of each computer. For example, a platform-independent database system optimizer may use the clock speed while calculating the performance tradeoffs of various optimization techniques. To run the benchmark long enough for timing to be accurate, mhz executes each expression in a loop. To minimize the loop overhead the expression is repeated a hundred times. Unfortunately, repetition enables many hardware and compiler optimizations that can have surprising effects on the experimental results. While writing mhz, much of the intellectual effort went into the design of expressions that minimize the opportunities for compiler and hardware optimization. Mhz utilizes lmbench 2.0's new timing harness, which manages the benchmarking process. The harness automatically adjusts the benchmark to minimize run time while preserving accuracy, determines the necessary timing duration to get accurate results from the system clock, and measures and accounts for both loop overhead and measurement overhead. It is used throughout lmbench 2.0 and can be used to measure the performance of other applications.
Self-Adjusting Scheduling: An On-Line Optimization Technique for Locality Management and Load Balancing
Authors: Babak Hamidzadeh, David J. Lilja
Venue: Proceedings of the 1994 International Conference on Parallel Processing - Volume 02 (1994)

Techniques for scheduling parallel tasks on to the processors of a multiprocessor architecture must tradeoff three interrelated factors: 1) scheduling and synchronization costs, 2) load balancing, and 3) memory locality. Current scheduling techniques typically consider only one or two of these three factors at a time. We propose a novel Self- Adjusting Scheduling (SAS) algorithm that addresses all three factors simultaneously. This algorithm dedicates a single processor to execute an on-line branch-and-bound algorithm to search for partial schedules concurrent with the execution of tasks previously assigned to the remaining processors. This overlapped scheduling and execution, along with self-adjustment of duration of partial scheduling periods reduces scheduling and synchronization costs significantly. To satisfy the load-balancing and locality management, SAS introduces a unified cost model that accounts for both of these factors simultaneously. We compare the simulated performance of SAS with the Affinity Scheduling algorithm (AFS). The results of our experiments demonstrate that the potential loss of performance caused by dedicating a processor to scheduling is outweighed by the higher performance produced by SAS's dynamically adjusted schedules, even in systems with a small number of processors. SAS is a general on-line optimization technique that can be applied to a variety of dynamic scheduling problems.
SimICS/sun4m: a virtual workstation
Authors: Peter S. Magnusson, Fredrik Dahlgren, Håkan Grahn, Magnus Karlsson, Fredrik Larsson, Fredrik Lundholm, Andreas Moestedt, Jim Nilsson, Per Stenström, Bengt Werner
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1998)

System level simulators allow computer architects and system software designers to recreate an accurate and complete replica of the program behavior of a target system, regardless of the availability, existence, or instrumentation support of such a system. Applications include evaluation of architectural design alternatives as well as software engineering tasks such as traditional debugging and performance tuning. We present an implementation of a simulator acting as a virtual workstation fully compatible with the sun4m architecture from Sun Microsystems. Built using the system-level SPARC V8 simulator SimICS, SimICS/sun4m models one or more SPARC V8 processors, supports user-developed modules for data cache and instruction cache simulation and execution profiling of all code, and provides a symbolic and performance debugging environment for operating systems. SimICS/sun4m can boot unmodified operating systems, including Linux 2.0.30 and Solaris 2.6, directly from snapshots of disk partitions. To support essentially arbitrary code, we implemented binary-compatible simulators for several devices, including SCSI, console, interrupt, timers, EEPROM, and Ethernet. The Ethernet simulation hooks into the host and allows the virtual workstation to appear on the local network with full services available (NFS, NIS, rsh, etc). Ethernet and console traffic can be recorded for future playback. The performance of SimICS/sun4m is sufficient to run realistic workloads, such as the database benchmark TPC-D, scaling factor 1/100, or an interactive network application such as Mozilla. The slowdown in relation to native hardware is in the range of 25 to 75 (measured using SPECint95). We also demonstrate some applications, including modeling an 8-processor sun4m version (which does not exist), modeling future memory hierarchies, and debugging an operating system.
GAMoSe: An Accurate Monitoring Service For Grid Applications
Authors: Thomas Ropars, Emmanuel Jeanvoine, Christine Morin
Venue: Proceedings of the Sixth International Symposium on Parallel and Distributed Computing (2007)

Monitoring distributed applications executed on a computational Grid is challenging since they are ex- ecuted on several heterogeneous nodes belonging to dif- ferent administrative domains. An application moni- toring service should provide users and administrators with useful and dependable data on the applications ex- ecuted on the Grid. We present in this paper a grid application monitoring service designed to handle high availability and scalability issues. The service supplies information on application state, on failures and on re- source consumption. A set of transparent monitoring mechanisms are used according to grid node nature to effectively monitor the applications. Experiments on the Grid'5000 testbed show that the service provides dependable information with a minimal cost on Grid performances.
UBC: an efficient unified I/O and memory caching subsystem for NetBSD
Authors: Chuck Silvers
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

This paper introduces UBC ("Unified Buffer Cache"), a design for unifying the filesystem and virtual memory caches of file data, thereby providing increased system performance. In this paper we discuss both the traditional BSD caching interfaces and new UBC interfaces, concentrating on the design decisions that were made as the design progressed. We also discuss the designs used by other operating systems to solve the same problems that UBC solves, with emphasis on the practical implications of the differences between these designs. This project is still in progress, and once completed will be part of a future release of NetBSD.
The context of engineering: a SUCCEED course at Georgia Tech
Authors: B. Sinclair, W. R. Callen, D. Morton
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

In the early part of January 1993, engineers and historians at Georgia Tech joined together to draft a proposal to SUCCEED, a national engineering education coalition funded by the National Science Foundation. This novel collaboration of academics who do not usually work together imagined an experimental course that would integrate humanities and engineering education in order to provide a broad context for understanding the role of engineering and the engineering profession in modern society. Primarily aimed at beginning students in electrical engineering, this pilot project would develop a set of modular units, each one of which incorporate materials on engineering design or on issues related to engineering professionalism, and which would link that information to economic, political or social considerations. In this fashion, the creative work of engineers, past and present, could be analyzed both in terms of technical detail and in terms of the human context in which engineering always takes place. The course was presented at Georgia Tech for the first time in the Spring Quarter of 1995, and it will be repeated in the Winter Quarter of 1996. We present a progress report that describes the planning, organization and objectives of the course, and that concludes with some observations on the work yet to be done in order to make the course materials we have developed usable by others.
Building Tomorrow's Information Assurance Workforce through Experiential Learning
Authors: David Dellacca, Connie Justice
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

The Department of Computer and Information Technology (CIT) at Indiana University Purdue University Indianapolis (IUPUI) has built a comprehensive and experience-based learning environment. Students coming to the department seeking knowledge and skills in the areas of networking and security are exposed to traditional learning methodologies focusing on terms, concepts and history of the subject matter. In addition to this, students gain practical knowledge and capture experience-based lessons in the field of networking and security. Through class work and outside projects students are given opportunities to gain valuable and relevant hands-on experience designing, implementing, and managing live network environments for the department, other on-campus groups, and ultimately for groups outside of the university. This experience-based teaching methodology not only addresses the challenges of preparing future technologists in an ever-changing field, but also arms students with the experience that many employers are seeking. This article discusses the growth, benefits, challenges, and future goals of the networking and security tra cks of classes offered at IUPUI in the CIT Department.
Side effects are not sufficient to authenticate software
Authors: Umesh Shankar, Monica Chew, J. D. Tygar
Venue: Proceedings of the 13th conference on USENIX Security Symposium - Volume 13 (2004)

Kennell and Jamieson [KJ03] recently introduced the Genuinity system for authenticating trusted software on a remote machine without using trusted hardware. Genuinity relies on machine-specific computations, incorporating side effects that cannot be simulated quickly. The system is vulnerable to a novel attack, which we call a substitution attack. We implement a successful attack on Genuinity, and further argue this class of schemes are not only impractical but unlikely to succeed without trusted hardware.
Knowledge-based two-level control of a group of mobile executors
Authors: Jerzy Józefczyk
Venue: Integrated Computer-Aided Engineering (2003)

Two interconnected sub-problems, i.e. scheduling of independent, non-preemptive tasks on unrelated executors as well as motion control of a group of moving executors performing the tasks, which form a two-level manufacturing operation system are investigated. As the performance index of the two-level system the makespan is assumed. For the motion control sub-problem a knowledge based pattern recognition procedure is used. The procedure is treated as a co-ordinator of movements of separate executors and allows avoiding their possible collisions. The knowledge-based pattern recognition problem is solved using the logic-algebraic method. An expert is assumed to be the source of knowledge about collisions, which is given in the form of logic expressions. Two heuristic solution algorithms for the two-level system are presented. The first algorithm ensures the current modification of solutions for the scheduling sub-problem during the control procedure of the two-level system. In the second one the on-line procedure is used, which enables determination of the best solution in the current decision step of the control procedure. Both algorithms are compared via computer simulation and examples of results are presented. A numerical example for both solution algorithms is also given. It concerns the selected process in a discrete manufacturing system.
Coding of digital imagery for transmission over multiple noisy channels
Authors: S. S. Channappayya
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

This paper presents a multiple description image coding scheme that facilitates the transmission of digital imagery over multiple noisy channels. The proposed scheme divides the image into smaller parts that are transmitted over the individual channels of an inverse multiplexing system. The division or splitting is done in such a fashion that it facilitates the interpolation of lost coefficients in the case of one or more channel failures. At the receiver, the image is reconstructed by proper assembly of the data received from each channel. In case of channel failure, the missing coefficients are estimated from the available data with the use of a novel post-processing scheme. For operation over four noisy channels with various bit error probabilities, we investigate the quantitative and subjective performance of the proposed system for the case of multiple channel failures.
The ARS Model: Virtual Learning Communities with P2PAgents on the Grid
Authors: Eric Gouarderes, Yon Dourisboure, Guy Gouarderes, Saber Mansour
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems Workshops (2007)

This paper presents the ARS (Actor-Role-Signature) model designed to easily manage open groups with fluid boundaries in dynamic and rapid changing environment. This work is part of the ELeGI "European Learning Grid infrastructure" project. Using the grid for e-learning can be considered as a major innovation that will boost Internet potential for group collaborative work. The addressed problem is to define a model of MAS to support a new on-line process, the e-Qualification (e-learning qualification), in order to assess both formal and informal learning in virtual learning communities. Agents working in Peer-to- Peer mode, will handle user's e-Portfolios as knowledge prosthesis and exploit e-Qualification processes as aggregation methods to dynamically gather users in working groups, and qualify their knowledge after a training session.
Non-control-data attacks are realistic threats
Authors: Shuo Chen, Jun Xu, Emre C. Sezer, Prachi Gauriar, Ravishankar K. Iyer
Venue: Proceedings of the 14th conference on USENIX Security Symposium - Volume 14 (2005)

Most memory corruption attacks and Internet worms follow a familiar pattern known as the control-data attack. Hence, many defensive techniques are designed to protect program control flow integrity. Although earlier work did suggest the existence of attacks that do not alter control flow, such attacks are generally believed to be rare against real-world software. The key contribution of this paper is to show that non-control-data attacks are realistic. We demonstrate that many real-world applications, including FTP, SSH, Telnet, and HTTP servers, are vulnerable to such attacks. In each case, the generated attack results in a security compromise equivalent to that due to the control-data attack exploiting the same security bug. Non-control-data attacks corrupt a variety of application data including user identity data, configuration data, user input data, and decision-making data. The success of these attacks and the variety of applications and target data suggest that potential attack patterns are diverse. Attackers are currently focused on control-data attacks, but it is clear that when control flow protection techniques shut them down, they have incentives to study and employ non-control-data attacks. This paper emphasizes the importance of future research efforts to address this realistic threat.