ppxscal/embedding_network huggingface dataset:
Failure-aware checkpointing in fine-grained cycle sharing systems
Authors: Xiaojuan Ren, Rudolf Eigenmann, Saurabh Bagchi
Venue: Proceedings of the 16th international symposium on High performance distributed computing (2007)

Fine-Grained Cycle Sharing (FGCS) systems aim at utilizing the large amountof idle computational resources available on the Internet. Such systems allow guest jobs to run on a host if they do not significantly impact the local users of the host. Since the hosts are typically provided voluntarily, their availability fluctuates greatly. To provide fault tolerance to guest jobs without adding significant computational overhead, we propose failure-aware checkpointing techniques that apply the knowledge of resource availability to select checkpoint repositories and to determine checkpoint intervals. We present the schemes of selecting reliable and efficient repositories from the non-dedicated hosts that contribute their disk storage. These schemes are formulated as 0/1 programming problems to optimize the network overhead of transferring checkpoints and the work lost due to unavailability of a storage host when needed to recover a guest job. We determine the checkpoint interval by comparing the cost of checkpointing immediately and the cost of delaying that to a later time, which is a function of the resource availability. We evaluate these techniques on an FGCS system called iShare, using trace-based simulation. The results show that they achieve better application performance than the prevalent methods which use checkpointing with a fixed periodicity on dedicated checkpoint servers.
Faculty teaching practices and perceptions of institutional attitudes toward teaching at eight engineering schools
Authors: R. M. Felder
Venue: Proceedings of the 28th Annual Frontiers in Education - Volume 01 (1998)

All engineering faculty members in the eight universities that comprise the SUCCEED Coalition were surveyed about their use of a variety of instructional methods and their perceptions about attitudes toward teaching on their campuses. The results provide a unique snapshot of engineering education at a transitional moment in its history. The same survey will be administered two years and four years from now. The results should provide an indication of the degree to which the SUCCEED faculty development program is meeting its objectives, which are to promote facility adoption of proven instructional methods and materials and to improve institutional support for effective teaching.
Bridging the host-network divide: survey, taxonomy, and solution
Authors: Glenn A. Fink, Vyas Duggirala, Ricardo Correa, Chris North
Venue: Proceedings of the 20th conference on Large Installation System Administration (2006)

This paper presents a new direction in security awareness tools for system administration-the Host-Network (HoNe) Visualizer. Our requirements for the HoNe Visualizer come from needs system administrators expressed in interviews, from reviewing the literature, and from conducting usability studies with prototypes. We present a tool taxonomy that serves as a framework for our literature review, and we use the taxonomy to show what is missing in the administrator's arsenal. Then we unveil our tool and its supporting infrastructure that we believe will fill the empty niche. We found that most security tools provide either an internal view of a host or an external view of traffic on a network. Our interviewees revealed how they must construct a mental end-to-end view from separate tools that individually give an incomplete view, expending valuable time and mental effort. Because of limitations designed into TCP/IP [RFC-791, RFC-793], no tool can effectively correlate host and network data into an end-to-end view without kernel modifications. Currently, no other visualization exists to support end-to-end analysis. But HoNe's infrastructure overcomes TCP/IP's limitations bridging the network and transport layers in the network stack and making end-to-end correlation possible. The capstone is the HoNe Visualizer that amplifies the users' cognitive power and reduces their mental workload by illustrating the correlated data graphically. Users said HoNe would be particularly good for discovering day-zero exploits. Our usability study revealed that users performed better on intrusion detection tasks using our visualization than with tools they were accustomed to using regardless of their experience level.
Idea Storming Cube: A Game-based System to Support Creative Thinking
Authors: Chun-Chieh HUANG, Tsai-Yen LI, Hao-Chuan WANG, Chun-Yen CHANG
Venue: Proceedings of the The First IEEE International Workshop on Digital Game and Intelligent Toy Enhanced Learning (2007)

This paper describes a collaborative game-based creativity support system, Idea Storming Cube, in support of creative thinking. It aims to make people form a creative and perspective-shift thinking habit. The system acquires knowledge from domain expert, user inputs history, and individuals in the current brainstorming group, and then provides user-, goal- and contextsensitive supports. Comparing to classic tutoring systems, it focuses more on stimulating divergent thinking. The system can be put into the Basic Mode or the Idea Generation Mode in order to support different gaming objectives. A case study for preliminary evaluation of the proposed HCI tool for collaborative idea generation is also reported in this paper.
2007 Special Issue: Environmentally adaptive acoustic transmission loss prediction in turbulent and nonturbulent atmospheres
Authors: Gordon Wichern, Mahmood R. Azimi-Sadjadi, Michael Mungiole
Venue: Neural Networks (2007)

An environmentally adaptive system for prediction of acoustic transmission loss (TL) in the atmosphere is developed in this paper. This system uses several back propagation neural network predictors, each corresponding to a specific environmental condition. The outputs of the expert predictors are combined using a fuzzy confidence measure and a nonlinear fusion system. Using this prediction methodology the computational intractability of traditional acoustic model-based approaches is eliminated. The proposed TL prediction system is tested on two synthetic acoustic data sets for a wide range of geometrical, source and environmental conditions including both nonturbulent and turbulent atmospheres. Test results of the system showed root mean square (RMS) errors of 1.84 dB for the nonturbulent and 1.36 dB for the turbulent conditions, respectively, which are acceptable levels for near real-time performance. Additionally, the environmentally adaptive system demonstrated improved TL prediction accuracy at high frequencies and large values of horizontal separation between source and receiver.
Extended data formatting using Sfio
Authors: Glenn S. Fowler, David G. Korn, Kiem-Phong Vo
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

The ANSI-C Standard defines Stdio as the I/O library for C programs. Despite its ubiquitous use, Stdio has well-documented deficiencies in various areas including data formatting. The Sfio library provides an alternative to Stdio with improved functionality, robustness and performance. In particular, Sfio extends the data formatting functions so that applications can deal with arbitrary scalar objects, avoid unsafe operations and even define their own conversion patterns. This paper discusses these formatting enhancements
Integrated scientific workflow management for the Emulab network testbed
Authors: Eric Eide, Leigh Stoller, Tim Stack, Juliana Freire, Jay Lepreau
Venue: Proceedings of the annual conference on USENIX '06 Annual Technical Conference (2006)

The main forces that shaped current network testbeds were the needs for realism and scale. Now that several testbeds support large and complex experiments, management of experimentation processes and results has become more difficult and a barrier to high-quality systems research. The popularity of network testbeds means that new tools for managing experiment workflows, addressing the ready-made base of testbed users, can have important and significant impacts. We are now evolving Emulab, our large and popular network testbed, to support experiments that are organized around scientific workflows. This paper summarizes the opportunities in this area, the new approaches we are taking, our implementation in progress, and the challenges in adapting scientific workflow concepts for testbed-based research. With our system, we expect to demonstrate that a network testbed with integrated scientific workflow management can be an important tool to aid research in networking and distributed systems.
Interactive presentation: Boosting SER test for RF transceivers by simple DSP technique
Authors: Jerzy Dabrowski, Rashad Ramzan
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

The paper presents a new technique of symbol error rate test (SER) for RF transceivers. A simple DSP algorithm implemented at the receiver baseband is introduced in terms of constellation correction, which is usually used to compensate for IQ imbalance. The test is oriented at detection of impairments in gain and noise figure in a transceiver frontend. The proposed approach is shown to enhance the sensitivity of a traditional SER test to the limits of its counterpart, the error vector magnitude (EVM) test. Its advantage over EVM is in simple implementation, lower DSP overhead and the ability of achieving a larger dynamic range of the test response. Also the test time is saved compared to a traditional SER test. The technique is validated by a simulation model of a Wi-Fi transceiver implemented in Matlab&trade;.
Rendering anti-aliased line segments
Authors: K.-H. Wong, X. Ouyang, C.-W. Lim, T.-S. Tan
Venue: Proceedings of the Computer Graphics International 2005 (2005)

Bridging the modeling and rendering gap between the existing triangle and point primitives, we explore the use of line segments as a new primitive to represent and render 3D models. Our main contribution extends the anti-aliasing theory in texture mapping to anti-aliased line segment rendering, and presents an approximation algorithm to render high quality anti-aliased opaque and transparent line segments in 3D models. This antialiasing technique is empirically validated by building a software pipeline to render models of any combination of the three types of modeling primitives: triangles, line segments and points. Our experiment shows that models comprising line segments are generally more efficient and effective for high quality rendering as compared to their corresponding pure point models.
Fully Distributed Active and Passive Task Management for Grid Computing
Authors: Alain Bui, Olivier Flauzac, Cyril Rabat
Venue: Proceedings of the Sixth International Symposium on Parallel and Distributed Computing (2007)

The task management is a key point in grid applications and can highly influence their efficiency. There are many solutions that we can classify according to their centralization degree: fully centralized, semi-distributed and fully distributed. A fully distributed approach leaves the nodes in charge of the scheduling: the schedule is performed thanks to the local view of the system. Such a local treatment reduces the communication cost but it must not impact on the computational power devoted to applications. This kind of solution seems to be more scalable and flexible than a centralized one, especially in a highly volatile environment like peer-to-peer networks. In this article, we propose two fully distributed solutions for the task management based on random walks. We choose to maximize the computational power of nodes by reducing the maintenance cost of an underling structure (a spanning structure). So, it reduces the number of control message exchanges that is a critical point in networks with a low bandwidth or in which the energy of nodes must be saved. We analyze two methods called passive and active and we present some simulation results.
Medium access control protocols for cognitive radio based multi-hop wireless networks
Authors: Ravi Prakash
Venue:  (2006)

Traditional wireless communication networks use a static allocation of the frequency spectrum: individual applications are assigned fixed bands within the spectrum. It has been observed that this static allocation results in inefficient utilization of the spectrum bandwidth. The scarcity of the spectrum for new applications coupled with the under-utilization of a significant portion of the spectrum is driving the shift from a static to a dynamic allotment of the spectrum. Cognitive Radio (CR) technology provides a way to efficiently utilize the frequency spectrum by enabling wireless devices to adapt dynamically to the locally available spectrum and to each others' capabilities. Cognitive radios are capable of switching between wide range of frequency bands. The CR-enabled devices can either form a stand-alone multi-hop wireless network or form a multi-hop wireless backbone network that can connect different types of devices together. In this work, we address the Medium Access Control (MAC) sub-layer issues in CR-based multi-hop wireless networks. The number of channels available and the channel identities vary from one node to another within the CR network. This is in contrast to the existing use of multiple channels where all the nodes have the same set of channels available (for example in IEEE 802.11 networks). In this work, we classify the CR-based networks into eight categories based on the following three characteristics: (i) Number of transceivers at nodes, (ii) Presence/absence of a global common control channel, and (iii) Presence/lack of synchronization. We present MAC sub-layer solutions for three of eight system models and derive solutions for the four other system models. The solutions presented in this work are evaluated by conducting extensive simulation experiments.
Hands-on science for grades K-5: an industry, school, university collaboration
Authors: N. Streim, J. Horwitz, T. Pica, J. Abel
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

The Penn-Merck Collaborative for the Enhancement of Science Education is a five year teacher enhancement program that uses a multifaceted approach to make science a fundamental, exciting and successful part of the education of urban, minority elementary school children. The Penn-Merck Collaborative brings together Merck and Co., the world's largest pharmaceutical company, 25 elementary schools in Philadelphia, the nation's fifth largest city, and their neighbor, the University of Pennsylvania, a major research university. Multiple, additional partnerships within this broad collaborative work together in a program of mutual benefit and support. The program addresses four aspects of science education: hands on science in the classroom; integrated science and language arts curricula; teacher leadership in science education; and pursuit of science careers by children from under represented groups. To focus these efforts, teams of teachers participate in a thirteen month cycle of activities, comprised of a year long graduate seminar framed by two summer institutes. Their work is guided by University faculty and master classroom teachers, supported through activities designed by undergraduate engineering students, and enhanced through interaction with Merck scientists and engineers. This approach not only broadens teachers' knowledge of science concepts and instructional strategies, but also forms the basis for their role as change agents and mentors for other teachers at their schools.
Increasing the functionality of finite element based surgical suturing simulators
Authors: George M. Turkiyyah
Venue:  (2006)

Despite the potential of surgical and suturing simulators to provide immersive virtual environments for patient-specific preoperative procedure rehearsal, as well as training of medical professionals, current simulators do not yet exhibit the necessary realistic, real-time ingredients to achieve these goals. First generation open surgical suturing simulators lack the necessary components to make them useful instructional aides. Key missing components include: bi-manual manipulation, soft-tissue cutting, skin repositioning, skin undermining, and the ability to place multiple types of sutures. The goal of this research is to increase the functionality of an open surgical suturing simulator by allowing users to perform bi-manual manipulation, soft-tissue cutting and skin undermining. To achieve these goals, a finite element based surgical simulation platform was developed to demonstrate the feasibility of these tasks. Tool-tissue interaction, closure of a predefined cut path and adherence of skin elements to subcutaneous tissue elements are all modeled through the use of displacement constraints. It is the release of these displacement constraints that allows the user to cut soft-tissue along a predefined path and separate skin from the underlying tissue. Addition of a displacement constraint upon tool-model collision allows the user to manipulate the soft-tissue based on the type of virtual tool being used. The addition of displacement constraints to a system of equilibrium equations creates a 2 &times; 2 block system; solution of this block system introduces the Schur complement, S, of the coefficient matrix. During user interaction, displacement constraints are dynamically added and removed from the system of equations, which directly affects the Schur complement and any product based on S. In order to interactively solve this system of equations, low-rank updates are used to incrementally update the Schur complement and its inverse, which allows for real-time updates of the model displacements and haptic reaction forces. Timing tests and image comparisons show the methods developed in this research are capable of interactively capturing accurate tissue response for problems of modest size during soft-tissue cutting and skin undermining. This also is the first haptic demonstration of bi-manual tissue manipulation and skin undermining in a finite element based surgical simulation environment.
File system logging versus clustering: a performance comparison
Authors: Margo Seltzer, Keith A. Smith, Hari Balakrishnan, Jacqueline Chang, Sara McMains, Venkata Padmanabhan
Venue: Proceedings of the USENIX 1995 Technical Conference Proceedings on USENIX 1995 Technical Conference Proceedings (1995)

The Log-structured File System (LFS), introduced in 1991 [8], has received much attention for its potential order-of-magnitude improvement in file system performance. Early research results [9] showed that small file performance could scale with processor speed and that cleaning costs could be kept low, allowing LFS to write at an effective bandwidth of 62 to 83% of the maximum. Later work showed that the presence of synchronous disk operations could degrade performance by as much as 62% and that cleaning overhead could become prohibitive in transaction processing workloads, reducing performance by as much as 40% [10]. The same work showed that the addition of clustered reads and writes in the Berkeley Fast File System [6] (FFS) made it competitive with LFS in large-file handling and software development environments as approximated by the Andrew benchmark [4]. These seemingly inconsistent results have caused confusion in the file system research community. This paper presents a detailed performance comparison of the 4.4BSD Log-structured File System and the 4.4BSD Fast File System. Ignoring cleaner overhead, our results show that the order-of-magnitude improvement in performance claimed for LFS applies only to meta-data intensive activities, specifically the creation of files one-kilobyte or less and deletion of files 64 kilobytes or less. For small files, both systems provide comparable read performance, but LFS offers superior performance on writes. For large files (one megabyte and larger), the performance of the two file systems is comparable. When FFS is tuned for writing, its large-file write performance is approximately 15% better than LFS, but its read performance is 25% worse. When FFS is optimized for reading, its large-file read and write performance is comparable to LFS. Both LFS and FFS can suffer performance degradation, due to cleaning and disk fragmentation respectively. We find that active FFS file systems function at approximately 85-95% of their maximum performance after two to three years. We examine LFS cleaner performance in a transaction processing environment and find that cleaner overhead reduces LFS performance by more than 33% when the disk is 50% full.
Stampede RT: Programming Abstractions for Live Streaming Applications
Authors: David Hilley, Umakishore Ramachandran
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems (2007)

We present Stampede^RT, middleware designed to provide a natural programming model appropriate for live streaming applications. Such applications require pervasive access to multiple streaming data sources for distributed online analysis. One motivating example is a distributed robotics application which analyzes live camera feeds for control and planning. Most existing middlewares for streaming data focus on media streams and low-level transport characteristics such as delivery latency and efficient transfer, but do not define a programming model to succinctly express applications that manipulate and analyze the streaming content. StampedeRT provides for straightforward transport and manipulation of temporally-ordered data streams, enabling simple synchronization and correlation of data sources. We present an abstract programming model to support the aforementioned class of applications and then describe a concrete realization of the model as a distributed middleware architecture. We also evaluate our implementation of the architecture and present several motivating applications StampedeRT is designed to support.
A Signaling Architecture for Consumer Oriented Grids Based on Optical Burst Switching
Authors: R. Avo, M. Guerreiro, N. S. C. Correia, M. C. R. Medeiros
Venue: Proceedings of the Third International Conference on Networking and Services (2007)

This paper presents a signaling architecture for consumer oriented photonic Grids. We propose to decrease the end-to-end transmission job delay, by exploring the potential of advanced Grid network architectures based on active Optical Burst Switching and Active Routers. The proposed scheme is discussed in detail and it is shown that conceptually it performs always better than the conventional Just Enough Time (JET) signaling protocol.
Lower bounds for 2-dimensional range counting
Authors: Mihai Patrascu
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

Proving lower bounds for range queries has been an active topic of research since the late 70s, but so far nearly all results have been limited to the (rather restrictive) semigroup model. We consider one of the most basic range problem, orthogonal range counting in two dimensions, and show almost optimal bounds in the group model and the (holy grail) cell-probe model. Specifically, we show the following bounds, which were known in the semigroup model, but are major improvements in the more general models:* In the group and cell-probe models, a static data structure of size n lgO(1) n requires Omega(lg n lglg n) time per query. This is an exponential improvement over previous bounds, and matches known upper bounds.* In the group model, a dynamic data structure takes time Omega((lg n lglg n)2) per operation. This is close to the O(lg2 n) upper bound, where as the previous lower bound was Omega(lg n). Proving such (static and dynamic) bounds in the group model has been regarded as an important challenge at least since [Fredman, JACM 1982] and [Chazelle, FOCS 1986].