ppxscal/embedding_network huggingface dataset:
Program-counter-based pattern classification in buffer caching
Authors: Chris Gniady, Ali R. Butt, Y. Charlie Hu
Venue: Proceedings of the 6th conference on Symposium on Opearting Systems Design & Implementation - Volume 6 (2004)

Program-counter-based (PC-based) prediction techniques have been shown to be highly effective and are widely used in computer architecture design. In this paper, we explore the opportunity and viability of applying PC-based prediction to operating systems design, in particular, to optimize buffer caching. We propose a Program-Counterbased Classification (PCC) technique for use in pattern-based buffer caching that allows the operating system to correlate the I/O operations with the program context in which they are issued via the program counters of the call instructions that trigger the I/O requests. This correlation allows the operating system to classify I/O access pattern on a per-PC basis which achieves significantly better accuracy than previous per-file or per-application classification techniques. PCC also performs classification more quickly as per-PC pattern just needs to be learned once. We evaluate PCC via trace-driven simulations and an implementation in Linux, and compare it to UBM, a state-of-the-art pattern-based buffer replacement scheme. The performance improvements are substantial: the hit ratio improves by as much as 29.3% (with an average of 13.8%), and the execution time is reduced by as much as 29.0% (with an average of 13.7%).
Global predicate monitoring applied for control of parallel irregular computations
Authors: J. Borkowski, D. Kopanski, M. Tudruj
Venue: Proceedings of the 15th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (2007)

Many computational problems have irregular data/control characteristics, which make programs difficult to be efficiently implemented in parallel systems. Due to irregular character of code or data, even division of work between processors at application startup is frequently impossible. Runtime optimization is possible, but it requires a constant exchange of control information and/or data during runtime is required. A novel parallel application control method is proposed in the paper. It is based on application global state monitoring for runtime irregular application control. The method provides a ready-to-use control infrastructure, which can be conveniently applied by a programmer. Both suitability and efficiency of the proposed control method are discussed in the paper based on two selected numerical applications: adaptive integration and branch and bound search. The presented experimental results were obtained with PS-GRADE graphical parallel design system, which embeds the proposed control method. The results confirm the efficiency of control based on global predicates in irregular computations.
Reducing startup latency in web and desktop applications
Authors: Dennis Lee, Jean-Loup Baer, Brian Bershad, Tom Anderson
Venue: Proceedings of the 3rd conference on USENIX Windows NT Symposium - Volume 3 (1999)

Application startup latency has become a performance problem for both desktop applications and web applications. In this paper, we show that much of the latency experienced during application startup can be avoided by more efficiently packing application code pages. To take advantage of more efficient packing, we describe the implementation of demand paging for web applications. Finally, we show that combining demand paging with code reordering can improve application startup latency by more than 58%.
Sequential estimation of random parameters under model uncertainty
Authors: P. M. Djuric
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

In many signal processing problems, the estimation of random parameters must be carried out sequentially and under model uncertainty. In the paper, a Bayesian approach is proposed for solving this problem, which is based on sequential updating of the posterior distribution of the desired parameters. It is shown that under a certain general set of conditions, the posterior of the unknown parameters is a mixture density. Since the computation of the solution becomes very intensive as the number of data (records) grows, a numerical procedure is proposed based on the sequential importance sampling scheme. Its number of computations per new data record is constant, and the procedure can easily be implemented in parallel.
Introduction
Authors: Michael Zyda
Venue: Communications of the ACM (2007)

The same technology that makes interactive 3D games so entertaining in the physical action domain is just as effective in education, training, and other more serious applications.
A Deep-Space Trail Forecast Method Based on the Enlargement of Field of View
Authors: Qiulei Han, Zhijun Yao, Ming Zhu
Venue: Proceedings of the 16th International Conference on Artificial Reality and Telexistence--Workshops (2006)

During the procedure of target tracing, lots of stars will cross the field of view. These stars will disturb the procedure and, the precision of system will be degraded. At the same time, because the optical surveillance system is limited by environment, the targets are often covered by clouds. The above situations will seriously degrade the system's robustness, and once the target is disappeared, the traditional system can't track the target again. Traditional forecast methods merely use coder information, so the precision is low. In order to upgrade the precision, we combine the coder information and the missdistance to forecast the next frame target position. The method is based on field range enlargement. Proved by practical experiments, this method can effectively improve the robustness of the target tracking system.
A multidimensional irregular sampling algorithm and applications
Authors: J. J. Benedetto
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

For a given spiral, a bandwidth B can be chosen and a sequence S can be constructed on the spiral with the property that all finite energy signals having bandwidth B can be reconstructed from sampled values on S. The bandwidth can be expanded as desired, and reconstruction is attained by constructing sampling sets on interleaving spirals. This solves a problem in MRI; and the algorithm can be modified to deal with irregular sampling problems in SAR. The algorithm is a consequence of our theoretical results, which in turn were inspired by seminal work on balayage in the 1960s by Beurling (1966) and Landau (1967). Our results depend on d-dimensional Fourier frames and tiling properties of spectral synthesis sets.
Storage management in large distributed object-based storage systems
Authors: Scott A. Brandt
Venue:  (2006)

Driven by the requirements for extremely high bandwidth and large capacity, storage subsystem architectures are undergoing fundamental changes. The object-based storage model, which repartitions the file system functionalities and offloads the storage management functions to intelligent storage devices, is a promising new model. In this model, Object-based Storage Devices (OSDs) manage their own storage space, provide persistent storage, and export an object interface to the data. With abundant on-board computing power, OSDs are able to provide complex services to facilitate high level system designs. This thesis focuses on the design, performance and functionality of an individual OSD in a large distributed object-based storage system, currently being developed in the Storage Systems Research Center at the University of California, Santa Cruz. Based on the file system workload analysis and the expected object workload studies, I extract unique features of object workloads and design an efficient storage manager, named OBFS, for individual OSDs. OBFS employs variable-sized blocks to optimize disk layouts and improve object throughput. Object metadata and attributes are also laid contiguously together with data, which further improves disk bandwidth utilization. The physical storage space is partitioned into fixed-size regions to organize blocks with different sizes together, which effectively reduces file system fragmentation in the long run. A series of experiments was conducted to evaluate OBFS performance compared with two Linux file systems, Ext2 and XFS. The results show that OBFS successfully limits the file system fragmentation even after long term aging. OBFS demonstrates very good synchronous write performance, exceeding those of Ext2 and XFS by up to 80% on both fresh systems and aged systems. Its asynchronous write performance is about 5% to 10% lower than that of Ext2, but 20% to 30% higher than that of XFS on a lightly used disk. On a heavily used disk, OBFS beats both Ext2 and XFS by 20%. For read operations, the performance of OBFS almost doubles that of Ext2 and is only slightly slower than that of XFS. Overall, OBFS achieves 30% to 40% performance improvements over Ext2 and XFS under expected object workloads, and forms a fundamental building block for larger distributed storage systems.
Contract as a Source of Trust--Commitment in Successful IT Outsourcing Relationship: An Empirical Study
Authors: Jahyun Goo, Kichan Nam
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Existing studies on IT outsourcing have mainly examined partnership factors that influence IT outsourcing effectiveness. This stream of IT outsourcing research has largely ignored how to foster and manage necessary attributes of partner relationships that promote relationship quality, leaving the role of the formal contract in the context of managing outsourcing relationships untouched. This research extends such studies and integrates the extant views that contracts and relational governance function as a complement and that relationship commitment and trust are the key attributes in relational governance impacting on the interorganizational performance. Using service level agreements (SLA) we examine how specific elements of formal contracts help firms to shape their relational attributes such as trust and commitment that leads to the success of IT outsourcing. The results show that the effects of well-structured SLA in managing the relational aspects of IT outsourcing contracts are significant. This paper also provides insight into the development of relational governance through a contractual mechanism in IT outsourcing engagements.
Some QoS Aspects of Multimedia Communication
Authors: Zbigniew Hulicki
Venue: Proceedings of the Fourth European Conference on Universal Multiservice Networks (2007)

The quality of multimedia communication services has been considered in this contribution. Abilities of assuring the proper parameters of network operation have been analysed using a traffic engineering point of view. QoS mechanisms have been shortly discussed, then the QoS evaluation procedure has been described. Finally, various aspects of QoS have been examined using sample applications of multimedia communications. It has been stated that QoS mechanisms can be successfully applied in such services as VoIP and in case of network games the required bandwidth is not a crucial parameter unless users exchange other information.
Distributive Generation Algorithm of Long Range Contact for Remote Spatial-data Access on P2P Delaunay Network
Authors: Masaaki Ohnishi, Shinji Tsuboi, Masao Hirayama, Takayuki Eguchi, Shinichi Ueshima
Venue: Proceedings of the Fifth International Conference on Creating, Connecting and Collaborating through Computing (2007)

A P2P Delaunay network is a network that connects nodes over 2-dimensional plane by utilizing a well-known geometric structure, a Delaunay triangulation in computational geographically geometry. This structure possesses the property that two adjacent nodes are connected. We have shown its autonomous generation algorithm in P2P settings with a greedy routing among two arbitrary nodes, and also shown the extensibility of the network. By setting Voronoi regions as a node's governing a area, a P2P Delaunay network works as a spatial database, and we can easily embed a range query mechanism over the network, realizing a extensible spatial database in P2P contexts. We aim at the diverse applications in geographical information systems(GIS), virtual collaboration systems, location-aware services, and so on. However, in case a P2P Delaunay network consists of a large number of nodes, its diameter and hop counts between two nodes increase in O(N1/2), which causes a serious communication delay in remote data accesses. Hence, we here propose Long Range Contact(LRC) for a P2P Delaunay network and its distributive generation algorithm. Our LRC is a set of bridges that connect two nodes in O(logN) hops with O(logN) node degree. We present a combination of horizontal/vertical generation algorithm in a collaboration of autonomous nodes, as well as a routing methods that utilizes LRC. We also evaluate both CPU and communication loads in our LRC generation, as well as routing efficiencies of LRC numerically. Finally, we discuss application fields of a P2P Delaunay network with LRC.
Transaction processing in mobile database system
Authors: Vijay Kumar
Venue:  (2006)

Mobile Computing has become a reality thanks to the convergence of two technologies: appearance of powerful portable computers and development of fast reliable wireless networks. Among, applications that are finding their way to the market of Mobile Computing, those that involve data management, hold a prominent position. In past few years there has been tremendous surge of research in the area of data management in mobile computing. However mobile computing as exists today is not fully capable of processing database transactions. This research concentrates on providing transactional support appropriate for mobile computing. Mobile Database System (MDS) is a distributed system that supports mobility during information processing. A new transaction model for MDS is first presented. The scope of traditional transaction properties is expanded by introducing new location property to transaction. Transaction execution could be distributed over multiple components. Some sub transactions would be executed on MU and rest on the servers on wired network. For consistency preserving execution either all subtransactions should commit or all should abort. We propose TCOT (Transaction Commit on Timeout protocol) protocol for MDS. TCOT protocol is based on timeouts and uses lesser number of messages than 2-Phase Commit (2PC), which is commonly used in database systems for fixed networks. We show using detailed simulation study that TCOT performs better than 2PC. Next we propose mechanisms for processing transactions locally at the mobile unit in presence of data broadcast. Broadcast-based data dissemination is likely to be a major mode of information transfer in mobile computing and wireless environment. As these systems evolve, they will be used to run sophisticated applications many of which will involve data whose consistency must be maintained and data updates may originate at mobile client. In pull-based broadcast environment we propose integrated approach to broadcast data scheduling and transaction processing. Our approach aims at reducing tuning time, commit time and number of aborts for the transaction. For push-based environment a new concurrency control mechanism, which uses requires low bandwidth, ensures availability, accommodates the disconnection problem, and is scalable. We did detailed performance study of transaction processing in broadcast environment.
Detection of signal number based on statistics of maximum likelihood
Authors: M. Suzuki
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

This paper presents a novel approach to the problem of detecting the number of signals superimposed in a multichannel time-series, based on the statistics of the maximum likelihood for observation models. The proposed method can be applied to the case of a small number of observation samples available, while conventional methods based on information criteria have difficulties because of asymptotic stochastic properties for the maximum likelihood used in their formulation. When the sample number is large, the proposed method provides high correct rate under lower SNR than the conventional methods. Finally, simulation results are shown to demonstrate the validity of the proposed method.
Distributed Web caching
Authors: M. N. Wijesundara, T. T. Tay
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 02 (2002)

The novel feature in the distributed Web caching system we developed is that every client node could act as a cache server and share its cache with neighboring nodes. We show that within a particular cache, the maximum inter-arrival time between two consecutive requests for a document without a cache miss increases due to distributed Web caching hence reducing the miss rate. We also show that the system always speeds up compared to uncooperative caching.
Secure coprocessors in electronic commerce applications
Authors: Bennet Yee, J. D. Tygar
Venue: Proceedings of the 1st conference on USENIX Workshop on Electronic Commerce - Volume 1 (1995)

Many researchers believe electronic wallets (secure storage devices that maintain account balances) are the solution to electronic commerce challenges. This paper argues for a more powerful model--a secure coprocessor--that can run a small operating system, run application programs, and also keep secure storage for cryptographic keys and balance information. We have built a system called Dyad, on top of a port of the Mach 3.0 microkernel to the IBM Citadel secure coprocessor. This paper describes the abstract architecture of Dyad and a general discussion of secure coprocessor implementations of a variety of electronic commerce applications: • Copy protection for software • Electronic cash (including a critique of proposed solutions for point-of-sale electronic wallet systems) • Electronic contracts • Secure postage
Flaming and thrashing: an examination of tone in electronic mail
Authors: M. A. Dyrud
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 02 (2000)

Most e-mail users have experienced some sort of computerized verbal abuse, ranging from less-than-gentle-reminders to full-blown obscenities. This paper explores tone and language usage in electronic mail. Specifically, it focuses on definitions and characteristics, situations which spawn flaming and thrashing, and ways that hostile tone can affect working relationships. Flaming can be particularly destructive in the educational arena, where relationships tend to be close and intense. In addition, for instructors who use e-mail in the classroom, this paper includes suggestions for maintaining a civil tone and avoiding abusive outbursts. 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
Distributed Graphics Pipelines on the Grid
Authors: Ade J. Fewings, Nigel W. John
Venue: IEEE Distributed Systems Online (2007)

Standard Grid technologies and the Chromium cluster graphics software are the building blocks of jgViz (Java-implemented GridVisualization) a Grid-based, distributed graphics pipeline system. Using the Metacomputing Directory Service to discover availableresources, jgViz schedules the best graphics pipeline available to suit the OpenGL application being run, launches the pipelinecomponents using the Globus Resource Allocation Manager, and monitors performance. Users interact with the system through a GUIimplemented using Java and the Commodity Grid Toolkit, enabling easy access to visualization resources.
Effects of spinal recurrent inhibition on motoneuron short-term synchronization
Authors: Takanori Uchiyama, Uwe Windhorst
Venue: Biological Cybernetics (2007)

Spinal recurrent inhibition linking skeleto- motoneurons (&#x03b1;-MNs) via Renshaw cells (RCs) has been variously proposed to increase or decrease tendencies toward synchronous discharges between &#x03b1;-MNs. This controversy is not easy to settle experimentally in animal or human paradigms because RCs receive, in addition to excitatory input from &#x03b1;-MNs, many other modulating influences which may change their mode of operation. Computer simulations help to artificially isolate the recurrent inhibitory circuit and thus to study its effects on &#x03b1;-MN synchronization under conditions not achievable in natural experiments. We present here such a study which was designed to specifically test the following hypothesis. Since many &#x03b1;-MNs excite any particular Renshaw cell, which in turn inhibits many &#x03b1;-MNs, this convergence&#x2013;divergence pattern establishes a random network whose random discharge patterns inject uncorrelated noise into &#x03b1;-MNs, and this noise counteracts any synchronization potentially arising from other sources, e.g., common inputs (Adam et&#x00a0;al. in Biol Cybern 29:229&#x2013;235, 1978). We investigated the short-term synchronization of &#x03b1;-MNs with two types of excitatory input signals to &#x03b1;-MNs (random and sinusoidally modulated random patterns). The main results showed that, while recurrent inhibitory inputs to different &#x03b1;-MNs were indeed different, recurrent inhibition (1) exerted rather small effects on the modulation of &#x03b1;-MN discharge, (2) tended to increase the short-term synchronization of &#x03b1;-MN discharge, and (3) did not generate secondary peaks in &#x03b1;-MN-&#x03b1;-MN cross-correlograms associated with &#x03b1;-MN rhythmicity.
Workflow adaptation as an autonomic computing problem
Authors: Kevin Lee, Rizos Sakellariou, Norman W. Paton, Alvaro A. A. Fernandes
Venue: Proceedings of the 2nd workshop on Workflows in support of large-scale science (2007)

The performance of long running scientific workflows stands to benefit from adapting to changes in their environment. Autonomic Computing provides methodologies for managing run-time adaptations in managed systems. In this paper, we apply the monitoring, analysis, planning and execution (MAPE) model from autonomic computing to support the runtime modification of workflows with the aim of improving their performance. We systematically identify run-time adaptations and indicate how such behaviours can be captured using the MAPE model from the Autonomic Computing community. By characterising these as autonomic computing problems we make a proposal about how workflow adaptation can be achieved.
Smurf-based Distributed Denial of Service (DDoS) Attack Amplification in Internet
Authors: Sanjeev Kumar
Venue: Proceedings of the Second International Conference on Internet Monitoring and Protection (2007)

The Smurf-based distributed denial of service (DDoS) attack is an amplification attack where the attacker uses unprotected intermediate networks to amplify the attack traffic load and direct it to the victim computer. In this paper, we investigate the factors that contribute to the amplification of the smurf attack traffic and understand the relation among the original attack traffic, intermediate unprotected network and the final amplified attack traffic. We also define a new term called attack amplification factor which represents the degree of amplification that original attack traffic undergoes during its transmission towards the victim computer. It is also shown in this paper that utilizing this attack, it is possible for an attacker to just use a dialup modem and an unprotected intermediary network to exhaust even an ultra high speed optical line such as OC-192 of the victim network.