ppxscal/embedding_network huggingface dataset:
Motion Competition: A Variational Approach to Piecewise Parametric Motion Segmentation
Authors: Daniel Cremers, Stefano Soatto
Venue: International Journal of Computer Vision (2005)

We present a novel variational approach for segmenting the image plane into a set of regions of parametric motion on the basis of two consecutive frames from an image sequence. Our model is based on a conditional probability for the spatio-temporal image gradient, given a particular velocity model, and on a geometric prior on the estimated motion field favoring motion boundaries of minimal length.Exploiting the Bayesian framework, we derive a cost functional which depends on parametric motion models for each of a set of regions and on the boundary separating these regions. The resulting functional can be interpreted as an extension of the Mumford-Shah functional from intensity segmentation to motion segmentation. In contrast to most alternative approaches, the problems of segmentation and motion estimation are jointly solved by continuous minimization of a single functional. Minimizing this functional with respect to its dynamic variables results in an eigenvalue problem for the motion parameters and in a gradient descent evolution for the motion discontinuity set.We propose two different representations of this motion boundary: an explicit spline-based implementation which can be applied to the motion-based tracking of a single moving object, and an implicit multiphase level set implementation which allows for the segmentation of an arbitrary number of multiply connected moving objects.Numerical results both for simulated ground truth experiments and for real-world sequences demonstrate the capacity of our approach to segment objects based exclusively on their relative motion.
Shape and texture preserved non-photorealistic rendering: Research Articles
Authors: Haitao Wang, Jian J. Zhang, Stan Z. Li, Yangsheng Wang
Venue: Computer Animation and Virtual Worlds (2004)

Two approaches, image-space and object-space, exist for non-photorealistic rendering (NPR). The object-space approach has an advantage that it is able to access the 3D shape information of the scene with a 3D model. In this paper, we present a non-stroke based image-space technique that has the strength similar to that of the object-space approach, but without involving explicit 3D models. The basic idea is to factorise the Lambertian model to obtain the shape and texture information implicitly contained in the image. We also develop a specific anisotropic low-pass image filter, which can smooth an image without blurring important features. With the developed techniques, we present two NPR styles, the sketching style and the painting style. Although our work does not aim to mimic any specific existing art form, the sketching style can generate effects similar to those of the pen-and-ink and the painting style is able to produce the colour permeating effects of watercolour. Copyright &copy; 2004 John Wiley & Sons, Ltd.
Main effects screening: a distributed continuous quality assurance process for monitoring performance degradation in evolving software systems
Authors: Cemal Yilmaz, Arvind S. Krishna, Atif Memon, Adam Porter, Douglas C. Schmidt, Aniruddha Gokhale, Balachandran Natarajan
Venue: Proceedings of the 27th international conference on Software engineering (2005)

Developers of highly configurable performance-intensive software systems often use a type of in-house performance-oriented "regression testing" to ensure that their modifications have not adversely affected their software's performance across its large configuration space. Unfortunately, time and resource constraints often limit developers to in-house testing of a small number of configurations and unreliable extrapolation from these results to the entire configuration space, which allows many performance bottlenecks and sources of QoS degradation to escape detection until systems are fielded. To improve performance assessment of evolving systems across large configuration spaces, we have developed a distributed continuous quality assurance (DCQA) process called main effects screening that uses in-the-field resources to execute formally designed experiments to help reduce the configuration space, thereby allowing developers to perform more targeted in-house QA. We have evaluated this process via several feasibility studies on several large, widely-used performance-intensive software systems. Our results indicate that main effects screening can detect key sources of performance degradation in large-scale systems with significantly less effort than conventional techniques.
Optimizing NANOS OpenMP for the IBM Cyclops Multithreaded Architecture
Authors: David Rodenas, Xavier Martorell, Eduard Ayguade, Jesus Labarta, George Almasi, Calin Cascaval, Jose Castanos, Jose Moreira
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

In this paper, we present two approaches to improve the execution of OpenMP applications on the IBM Cyclops multithreaded architecture. Both solutions are independent and they are focused to obtain better performance through a better management of the cache locality. The first solution is based on software modifications to the OpenMP runtime library to balance stack accesses across all data caches. The second solution is a small hardware modification to change the data cache mapping behavior, with the same goal. Both solutions help parallel applications to improve scalability and obtain better performance in this kind of architectures. In fact, they could also be applied to future multi-core processors. We have executed (using simulation) some of the NAS benchmarks to prove these proposals. They show how, with small changes in both the software and the hardware, we achieve very good scalability in parallel applications. Our results also show that standard execution environments oriented to multiprocessor architectures can be easily adapted to exploit multithreaded processors.
Nonblocking memory management support for dynamic-sized data structures
Authors: Maurice Herlihy, Victor Luchangco, Paul Martin, Mark Moir
Venue: ACM Transactions on Computer Systems (TOCS) (2005)

Conventional dynamic memory management methods interact poorly with lock-free synchronization. In this article, we introduce novel techniques that allow lock-free data structures to allocate and free memory dynamically using any thread-safe memory management library. Our mechanisms are lock-free in the sense that they do not allow a thread to be prevented from allocating or freeing memory by the failure or delay of other threads. We demonstrate the utility of these techniques by showing how to modify the lock-free FIFO queue implementation of Michael and Scott to free unneeded memory. We give experimental results that show that the overhead introduced by such modifications is moderate, and is negligible under low contention.
A Typology of Real-Time Validations in Web-Based Surveys
Authors: Andy Peytchev, Scott Crawford
Venue: Social Science Computer Review (2005)

One area in computer-assisted self-interviewing (CASI) where methodological and empirical research have not caught up with technological advancements is real-time validation of respondent input. Some of the literature on computer-assisted interviewing and postsurvey editing is pertinent yet far insufficient--the largest component that could not be deduced being the respondent interaction. This leads to the employment or avoidance of validations by current practitioners based on untested assumptions. This article presents a model that breaks down the different elements in survey validation by type of computation, implementation, and interaction with the respondent. The purpose is twofold: to describe what possibilities exist in validations for web-based surveys and to present a framework in which systematic research could be conducted to evaluate the impact of validations on survey costs and errors. Relevant findings from prior literature are discussed in this context.
First steps towards organic computing systems: monitoring an adaptive protocol stack with a fuzzy classifier system
Authors: Thorsten Schöler, Christian Müller-Schloer
Venue: Proceedings of the 2nd conference on Computing frontiers (2005)

Protocol stacks for small devices like mobile phones have to fulfill multiple functions in different environments. This has lead to highly complex solutions with alternative stacks. It is more economical to construct new stacks from building blocks on the fly depending on the current requirements. Such an adaptive architecture is an example of an organic computing system. In this paper we show how a proposed monitoring architecture for adaptive protocol stacks fits into the observer/controller pattern of organic computing. The protocol stack framework and the observer/controller pattern are briefly described. Subsequently the observer/controller pattern is mapped onto the framework architecture. Two implementations for monitoring agents are described, a finite state machine solution and a fuzzy classifier approach. The fuzzy classifier system is described in detail. It is shown that a finite state machine and a standard Markovian classifier system can be generalised into a non-Markovian learning classifier system, combining the advantages of both parents
Telephone speech recognition via the combination of knowledge sources in a segmental speech model
Authors: László Tóth, András Kocsor, Gábor Gosztolya
Venue: Acta Cybernetica (2004)

The currently dominant speech recognition methodology, Hidden Markov Modeling, treats speech as a stochastic random process with very simple mathematical properties. The simplistic assumptions of the model, and especially that of the independence of the observation vectors have been criticized by many in the literature, and alternative solutions have been proposed. One such alternative is segmental modeling, and the OASIS recognizer we have been working on in the recent years belongs to this category. In this paper we go one step further and suggest that we should consider speech recognition as a knowledge source combination problem. We offer a generalized algorithmic framework for this approach and show that both hidden Markov and segmental modeling are a special case of this decoding scheme. In the second part of the paper we describe the current components of the OASIS system and evaluate its performance on a very difficult recognition task, the phonetically balanced sentences of the MTBA Hungarian Telephone Speech Database. Our results show that OASIS outperforms a traditional HMM system in phoneme classification and achieves practically the same recognition scores at the sentence level.
A Caratheodory-Fejer Approach to Dynamic Appearance Modeling
Authors: Hwasup Lim, Octavia I. Camps, Mario Sznaier
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 1 - Volume 01 (2005)

This paper presents a technique to learn dynamic appearance models from a small number of training frames. Under this framework, dynamic appearance is modelled as an unknown operator that satisfies certain interpolation conditions and that can be efficiently identified using very little a priori information with off the shelf software. The advantages of the proposed method are illustrated with several examples where the leaned dynamics accurately predict the appearance of the targets preventing tracking failures due to occlusion or clutter.
Parallel Algorithm for Multiple Genome Alignment on the Grid Environment
Authors: Nova Ahmed, Yi Pan, Art Vandenberg, Yuzhong Sun
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 13 - Volume 14 (2005)

The multiple genome sequence alignment problem falls in the domain of problems that can be parallelized to address large sequence lengths. Although there is communication required for the computation of the aligned sequences, the proper distribution can reduce the overall problem to a set of tasks to be solved independently and then merged. A parallel algorithm for the alignment of multiple genome sequences is described. The algorithm is experimentally evaluated in a distributed Grid environment that provides very scalable and low cost computation performance. The Grid environment is evaluated with respect to a traditional cluster environment and results are compared to evaluate the effectiveness of a Grid environment for large computational biology.
Minimal path broadcast networks
Venue: Networks (2004)

Broadcasting is the communication process whereby a message that is initially known by one site becomes known to all sites of a network. Messages are transmitted by calls from senders to sets of receivers. In path broadcasting, a site can call nonneighboring sites over paths in the network. A call occupies all sites and edges on the path followed by the call; thus, any calls made concurrently must be vertex-disjoint. We discuss the design of sparse networks that allow path broadcasting to be completed in minimum time under three different path broadcast models. &copy; 2004 Wiley Periodicals, Inc.
Software Testing (2nd Edition)
Authors: Ron Patton
Venue:  (2005)

Software Testing, Second Edition provides practical insight into the world of software testing and quality assurance. Learn how to find problems in any computer program, how to plan an effective test approach and how to tell when software is ready for release. Updated from the previous edition in 2000 to include a chapter that specifically deals with testing software for security bugs, the processes and techniques used throughout the book are timeless. This book is an excellent investment if you want to better understand what your Software Test team does or you want to write better software.
A simple movement time model for scrolling
Authors: Tue Haste Andersen
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

A model for movement time for scrolling is developed and verified experimentally. It is hypothesized that the maximum scroll speed is a constant at which the target can be perceived when scrolling over the screen. In an experiment where distance to target and target width were varied, it was found that movement time did not follow Fitts' law. Rather, it was linearly dependent on the distance to the target, suggesting a constant maximum scrolling speed. We hypothesize that the same relationship between movement time and target distance apply to other computer interaction tasks where the position of the target is not known ahead of time, and the data in which the target is sought is not ordered.
Use of video in user interfaces that require non-linguistic cues
Authors: Sam Racine, Rachel Nilsson
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

This case study describes the creation of a user interface for a self-service kiosk that collects biographic and biometric data from non-English-speaking individuals who are unfamiliar with American/Western culture, with little formal education, and little-to-no experience with computers. The users were also completely unfamiliar with the task and in a very stressful environment. Therefore, unlike most commercial software interfaces that "tell" users how to complete a task by relying on entry fields labels and controls, or use language to provide context for tasks, we need to "show" users how to interact with interface. The goals for our user interface are similar to the goals of arcade video game machines that use a short demonstration video, without words, to draw the viewer's attention, create an expectation in the viewer of what is to come, and demonstrate the task to the viewer. User testing found that demonstration videos could meet these requirements.
Influence of Spherical Radiation Pattern Measurement Uncertainty on Handset Performance Measures
Authors: Jesper Ødum Nielsen, Gert Frølund Pedersen
Venue: Wireless Personal Communications: An International Journal (2005)

An important characteristic of a mobile handset is its ability to receive and transmit power. One way to characterize the performance of a handset in this respect is to use measurements of the spherical radiation pattern from which the total radiated power (TRP), total isotropic sensitivity (TIS), and mean effective gain (MEG) can be computed. Often this kind of measurements are made with a phantom head next to the handsets in order to simulate the influence of a real user. The measured radiation patterns are only expected to be repeatable if the same setup is used, i.e., the same phantom and the same mounting of the handset on the phantom. In this work the influence of mounting errors on the TRP, TIS, and MEG is investigated. Knowledge about the error due to incorrect mounting is necessary in determining requirements for both the mounting accuracy as well as for other parts of the measurement system that may introduce errors in standardized performance measurements. Radiation patterns of six handsets have been measured while they were mounted at various offsets from the reference position defined by the Cellular Telecommunications Internet Association (CTIA) certification. The change in the performance measures are investigated for both the GSM-900 and the GSM-1800 band. Despite the deliberately large deviations from the reference position, the changes in TRP and TIS are generally within ±0.5 dB with a maximum of about 1.4 dB. For the MEG values the results depend on the orientation of the handset with respect to the environment. Standard deviations up to about 0.5 dB and a maximum deviation of about 1.6 dB were found.
Martial arts in artificial reality
Authors: Perttu Hämäläinen, Tommi Ilmonen, Johanna Höysniemi, Mikko Lindholm, Ari Nykänen
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2005)

This paper presents Kick Ass Kung-Fu, a martial arts game installation where the player fights virtual enemies with kicks and punches as well as acrobatic moves such as cartwheels. Using real-time image processing and computer vision, the video image of the user is embedded inside 3D graphics. Compared to previous work, our system uses a profile view and two displays, which allows an improved view of many martial arts techniques. We also explore exaggerated motion and dynamic slow-motion effects to transform the aesthetic of kung-fu movies into an interactive, embodied experience. The system is described and analyzed based on results from testing the game in a theater, in a television show, and in a user study with 46 martial arts practitioners.
Fast evaluation of bounded slice-line grid
Authors: Song Chen, Xian-Long Hong, She-Qin Dong, Yu-Chun Ma, Chung-Kuan Cheng, Jun Gu
Venue: Journal of Computer Science and Technology (2004)

Bounded Slice-line Grid (BSG) is an elegant representation of block placement, because it is very intuitionistic and has the advantage of handling various placement constraints. However, BSG has attracted little attention because its evaluation is very time-consuming. This paper proposes a simple algorithm independent of the BSG size to evaluate the BSG representation in O(n log log n) time, where n is the number of blocks. In the algorithm, the BSG-rooms are assigned with integral coordinates firstly, and then a linear sorting algorithm is applied on the BSG-rooms where blocks are assigned to compute two block sequences, from which the block placement can be obtained in O(n log log n) time. As a consequence, the evaluation of the BSG is completed in O(n log log n) time, where n is the number of blocks. The proposed algorithm is much faster than the previous graph-based O(n2) algorithm. The experimental results demonstrate the efficiency of the algorithm.
NewsInEssence: a system for domain-independent, real-time news clustering and multi-document summarization
Authors: Dragomir R. Radev, Sasha Blair-Goldensohn, Zhu Zhang, Revathi Sundara Raghavan
Venue: Proceedings of the first international conference on Human language technology research (2001)

NEWSINESSENCE is a system for finding, visualizing and summarizing a topic-based cluster of news stories. In the generic scenario for NEWSINESSENCE, a user selects a single news story from a news Web site. Our system then searches other live sources of news for other stories related to the same event and produces summaries of a subset of the stories that it finds, according to parameters specified by the user.
Applying Security Design Analysis to a service-based system: Research Articles
Authors: Howard Chivers, Martyn Fletcher
Venue: Software&mdash;Practice Experience (2005)

Risk analysis is the only effective way of making value judgments about the need for security. Established analysis methods apply to whole operational systems, taking a necessarily holistic view of security, but this makes them difficult to integrate into the design process for service-based applications, where design and implementation are independent of operational deployment. However, the most costly mistakes occur early in the development lifecycle, and effective security can be difficult to retrofit, motivating the need for early security analysis. This paper describes SeDAn (Security Design Analysis), a security risk analysis framework that is adapted for use in the design phase of service-based systems, and its application to a significant Grid-based project (Distributed Aircraft Maintenance Environment&mdash;DAME). The complete lifecycle of the risk analysis is described, and the effectiveness of the process in identifying design defects validates both the need for, and the effectiveness of, this type of analysis. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Combining multiple clustering systems
Authors: Constantinos Boulis, Mari Ostendorf
Venue: Proceedings of the 8th European Conference on Principles and Practice of Knowledge Discovery in Databases (2004)

Three methods for combining multiple clustering systems are presented and evaluated, focusing on the problem of finding the correspondence between clusters of different systems. In this work, the clusters of individual systems are represented in a common space and their correspondence estimated by either clustering clusters or with Singular Value Decomposition. The approaches are evaluated for the task of topic discovery on three major corpora and eight different clustering algorithms and it is shown experimentally that combination schemes almost always offer gains compared to single systems, but gains from using a combination scheme depend on the underlying clustering systems.
Practical Evaluation of a Radial Soft Hash Algorithm
Authors: F.-X Standaert, F. Lefebvre, G. Rouvroy, B. Macq, J.-J Quisquater, J.-D Legat
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume II - Volume 02 (2005)

This paper presents a practical evaluation of a RADIa1 Soft Hash algorithm, an image hashing technique used for image and visual content authentication.First we evaluate its collision resistance and susceptibility to geometrical deformations and image processing attacks.Second we investigate its actual efficiency on different platforms.Although software implementations allow managing sizes and throughput for most applications, they suffer from some troubles for real time applications such as video and for images in high definition. For these more constrained contexts, we propose hardware implementations.In practice, throughput up to 2^{18} (resp. 2^{26}) pixels/sec are managed in a single SW (resp. HW) implementation.