ppxscal/embedding_network huggingface dataset:
Efficient product sampling using hierarchical thresholding
Authors: Fabrice Rousselle, Petrik Clarberg, Luc Leblanc, Victor Ostromoukhov, Pierre Poulin
Venue: The Visual Computer: International Journal of Computer Graphics (2008)

We present an efficient method for importance sampling the product of multiple functions. Our algorithm computes a quick approximation of the product on the fly, based on hierarchical representations of the local maxima and averages of the individual terms. Samples are generated by exploiting the hierarchical properties of many low-discrepancy sequences, and thresholded against the estimated product. We evaluate direct illumination by sampling the triple product of environment map lighting, surface reflectance, and a visibility function estimated per pixel. Our results show considerable noise reduction compared to existing state-of-the-art methods using only the product of lighting and BRDF.
Gröbner bases for public key cryptography
Authors: Massimo Caboara, Fabrizio Caruso, Carlo Traverso
Venue: Proceedings of the twenty-first international symposium on Symbolic and algebraic computation (2008)

Up to now, any attempt to use Gröbner bases in the design of public key cryptosystems has failed, as anticipated by a classical paper of B. Barkee et al.; we show why, and show that the only residual hope is to use binomial ideals, i.e. lattices. We propose two lattice-based cryptosystems that will show the usefulness of multivariate polynomial algebra and Grobner bases in the construction of public key cryptosystems. The first one tries to revive two cryptosystems Polly Cracker and GGH, that have been considered broken, through a hybrid; the second one improves a cryptosystem (NTRU) that only has heuristic and challenged evidence of security, providing evidence that the extension cannot be broken with some of the standard lattice tools that can be used to break some reduced form of NTRU. Because of the bounds on length, we only sketch the construction of these two cryptosystems, and leave many details of the construction of private and public keys, of the proofs and of the security considerations to forthcoming technical papers.
The motion of impostors
Authors: Adam Goinski, Slawomir Nikiel
Venue: Machine Graphics Vision International Journal (2007)

We describe a method that brings to life impostor-based environments. In a typical scene, supporting objects are rendered as two-dimensional texture maps always facing the camera. Billboards reduce complexity of objects to high extent. In such a representation, spatial properties of depicted objects are lost. Billboards are usually motionless in order to compress the video memory space. In our technique, we introduce 2.5D morphing with respect to the memory footprint. Minimum two textures are required to animate the billboard. Moreover, the whole process is automated and exploits a programmable GPU. As a result, the main application overhead is reduced. The method is designed for vegetation modeling, but can be easily extended to far- and middle-distance shots of humans.
Distributed construction of bounded-degree low-interference spanners of low weight
Authors: Mirela Damian, Nagesh Javali
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

We propose a new low-interference topology for wireless ad hoc networks modeled by Quasi Unit Disk Graphs (qUDGs). Our topology combines two existing structures, the relaxed Greedy structure developed by Damian, Pandit and Pemmaraju, and the low-interference structure developed by Burkhart, von Rickenbach, Wattenhofer and Zollinger. Our main contribution is showing that, when applied on a qUDG G = (V, E), this new structure inherits most properties of the two underlying structures: (a) it is a t(1+ε) spanner of G, for any t > 1 and ε > 0, (ii) it has optimal interference among all t-spanners for G, (iii) it has O(1) maximum degree, (iv) its total weight is within a factor of O(log n) of the weight of a minimum spanning tree for V, and (v) it can be implemented efficiently in O(log n) rounds of communication.
An intelligent fitting room using multi-camera perception
Authors: Wei Zhang, Takashi Matsumoto, Juan Liu, Maurice Chu, Bo Begole
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2008)

In this paper, we describe the architecture of the vision system for the Responsive Mirror, a novel system for retail fitting rooms that enables online social fashion comparisons in physical stores based on multi-camera perception. This vision system provides implicitly controlled real-time interaction for "self" and "social" clothing comparisons by automatically tracking user's motion as she tries on clothes. We describe the key components of the motion-tracking and clothes-recognition systems and evaluate their effectiveness against images collected during a previous user study and a dataset of images representing content from a social fashion network.
Improving Availability of Mobile Code Systems by Decoupling Interaction from Mobility
Authors: Koukoumpetsos K., Antonopoulos N., Zhang K., Exarchakos G.
Venue: Proceedings of the Seventh International Conference on Networking (2008)

Resource availability in pervasive environments is restricted by many either mobility- and/or security-related factors. Multi-agent systems deployed in such environments would have to rely on a potentially low number of hosts allowing and supporting the arrival and execution of foreign code. To address this issue, this paper proposes to decouple interaction of executing programs and services from the actual software mobility pattern used to realize this interaction. The proposed system (MoDeS – Mobility Decision System) dynamically decides on the best mobility method to implement a series of software interactions while satisfying the appropriate software constraints. The system takes as input an interaction plan and produces the corresponding mobility plan. A series of simulations were performed on single- and multi-hop scenarios which showed that MoDeS can significantly increase the availability of software interactions even in highly constraint environments.
Characterization of the Thai hostgraph
Authors: Kulwadee Somboonviwat, Masashi Toyoda, Shinji Suzuki, Masaru Kitsuregawa
Venue: Proceedings of the 2nd international conference on Ubiquitous information management and communication (2008)

The Web of a country or the national Web is a set of web pages related to a specific country. Understanding in the graph structure of the national Web provides invaluable insights for the development of algorithms and localized search services targeting for a specific country. Many empirical studies on the graph structure of the national Webs have been done at the level of individual web pages. However, in reality, the Web information is being organized into a hierarchically nested structure, called a domain name system. The domain name based hierarchical structure adds the intermediate levels of entities and administrative control to the Web. To better understand the characteristics and ecology of the national Web, it is necessary to also understand its graph structure at a more abstract level. In this paper we put our attention to the graph structure of the Web at the level of interconnection between hosts in the Thai Web. The hostgraph is a directed graph with a node corresponding to a host and a directed weighted edge corresponding to the number of links between a pair of hosts. We report various graphical properties of the Thai hostgraph based on a snapshot of the Thai Web obtained in January 2007. For each empirical result, we carefully interpret its implications and discuss how to put it into practical use. We also give an example application of the hostgraph i.e. mining web community from the Thai hostgraph.
The working scientist and the realities of data curation: a qualitative study addressing attitudes and needs
Authors: Megan Winget
Venue: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries (2008)

This poster describes a nascent ethnographic study to examine working scientists' attitudes and perform a needs assessment regarding data collection, representation, and dissemination in terms of cyberinfrastructure initiatives.
Integrated InGaAsP MQW Mach-Zehnder modulator
Authors: D. A. May-Arrioja, P. LiKamWa, I. Shubin, P. K. L. Yu
Venue: Microelectronics Journal (2008)

We demonstrate the use of an area selective zinc in-diffusion process as a simple and efficient technique for the fabrication of integrated photonic devices. By controlling the profile of the diffusion front and the zinc depth the insertion losses of the devices can be minimized. Using this technique an integrated 1x2 Mach-Zehnder analog modulator was fabricated. Our experimental results demonstrate that the modulator exhibits excellent linearity for both TE and TM polarizations over a wavelength range of 40nm. The measured on-chip losses in the order of 3dB are obtained, which is significantly lower compared to the use of isolation trenches.
Strategic planning for the computer science security of banking organizations, companies and government
Authors: Jorge Alberto Ruiz-Vanoye, Ocotlan Díaz-Parra, Ismael Rafael Ponce-Medellín, Alejandro Fuentes-Penna, Juan Carlos Olivares-Rojas
Venue: Proceedings of the 2nd WSEAS International Conference on Computer Engineering and Applications (2008)

The necessity of the companies and organizations to adapt the technological and computer science change takes to formulated key questions: What type of Computer science Security needs my company, financial organization, or government? My financial organization counts with aspects of computer science security in the correct areas? What new tools of computer science security exist? What strategies of security we must follow? In this paper we show a methodology for strategic planning for the computer science security of Banks, Companies and Government, cradle in the concepts of strategic administration of enterprise politics, which tries to give answers to the questions before mentioned.
Why is Security a Software Issue?
Authors: Julia Allen
Venue: The EDP Audit, Control, and Security Newsletter (2007)

Software is everywhere. It runs your car. It controls your cell phone. It's how you access your bank's financial services, receive electricity and natural gas, and fly from coast to coast (McGraw, 2006). Many products, services, and capabilities within both the public and private sectors are highly dependent on software to handle the sensitive and high-value data on which people's privacy, livelihoods, health, and very lives depend. National security-and by extension citizens' personal safety-relies on complex, interconnected, software-intensive information systems-systems that in many cases use the uncontrolled Internet or Internet-exposed private networks as their means for communicating and transporting information.
Extending moodle for collaborative learning
Authors: Francesco Di Cerbo, Gabriella Dodero, Giancarlo Succi
Venue: ACM SIGCSE Bulletin (2008)

In this demo, we present novel features added to the Moodle Learning Management System to achieve collaborative learning
Novel Universal Filter Using Only Two Current Active Elements
Authors: Jan Jerabek, Kamil Vrba
Venue: Proceedings of the Third International Conference on Systems (2008)

In the paper, the process of universal frequency filter design with single-input and multiple-output current followers is shown. The filter can operate at very high frequencies and with a very low supply voltage, without affecting the signal-to-noise ratio. The filter design starts from an autonomous circuit with general current elements referred to as DOCAs (Dual Output Current Amplifiers). The characteristic equation (CE) of this circuit is successively modified to be capable of controlling some parameters of the designed filter and setting the value of the quality factor independently. The paper also contains verification results of the universal filter characteristics based on a 3rd-order behavioral model of the UCC (Universal Current Conveyor).
On wing-perfect graphs
Authors: Stefan Hougardy
Venue: Journal of Graph Theory (1999)

An edge in a graph G is called a wing if it is one of the two nonincident edges of an induced P4 (a path on four vertices) in G. For a graph G, its wing-graph W (G) is defined as the graph whose vertices are the wings of G, and two vertices in W (G) are connected if the corresponding wings in G belong to the same P4. We will characterize all graphs whose wing-graph is a cycle. This solves a conjecture posed by Hoang [9]. &copy; 1999 John Wiley & Sons, Inc. J Graph Theory 31:51&ndash;66, 1999
Automatic Composition of AADL Models for the Verification of Critical Component-Based Embedded Systems
Authors: Hugues Balp, Étienne Borde, Grégory Haïk, Jean-François Tilman
Venue: Proceedings of the 13th IEEE International Conference on on Engineering of Complex Computer Systems (2008)

Early analysis and verification of a critical embedded system requires a precise platform specific model (PSM) of the whole system. On the other hand, to master the complexity of large complex critical distributed real-time and embedded systems (DRES), a component-oriented approach is adopted, which entails a higher-level of structural modeling. This contribution presents some AADL usage guidelines for component based systems, and details model transformation rules to obtain PSM also in AADL. The approach is based on automatic model composition from component-based architecture diagrams, and allows to take into account separation of concerns in the platform-level system design.
Quality Control Schemes for Industrial Production by Workers' Motion Capture
Authors: Nobuyoshi Sato, Yoshitoshi Murata
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

In quality control of industrial products, it is very important that not only qualities of materials and parts, design, but also a manufacturing work accords to instruction manuals for manufacturing process. Generally, most assembly process such as assembly line and cell production system have processes in everywhere to confirm quality and work in former processes. However, there are some cases that are difficult to be confirmed in later processes. For example, to fix a part by some screws, it is desirable to drive in diagonal order little by little. However, it is not easy to detect in appearance in case of this desirable procedure is violated. Therefore, we are developing a system to improve quality of industrial products. This system deals manufacturing processes as context, and grasp manufacturing process, recognizes context by tracing motions of worker’s arm/hand by using terrestrial magnetism sensors and accelerometers. In this paper, as first step, we show that violation of desirable motion is distinguishable by dividing manufacturing process as context into some fundamental motion, and tracing motions by each context. Also, we discuss on fundamental conditions to introduce the system in actual manufacturing process.
Measuring QoS for GPRS mobile networks
Authors: C. M. Sarraf, L. El-Khazan, T. Zoghby, J. Maksoud, S. El-Asmar, J. Nassif
Venue: Proceedings of the 4th WSEAS International Conference on Telecommunications and Informatics (2005)

By applying a packet radio service to transfer user data between the mobile stations and external networks such as the Internet or enterprise networks; the General Packet Radio Service (GPRS), as a bearer service for GSM Mobile Networks, is supposed to greatly improve the data access of mobile users those external networks. GPRS as a service by itself and as foundation for third generation mobile systems (e.g. UMTS) became an interesting area for study and evaluation mainly in the area of Quality of Services. In this paper, we present a model for GPRS QoS measurements as well as the results of accessibility parameters related to data performance in a life network.
Register allocation by puzzle solving
Authors: Fernando Magno Quintão Pereira, Jens Palsberg
Venue: ACM SIGPLAN Notices (2008)

We show that register allocation can be viewed as solving a collection of puzzles. We model the register file as a puzzle board and the program variables as puzzle pieces; pre-coloring and register aliasing fit in naturally. For architectures such as PowerPC, x86, and StrongARM, we can solve the puzzles in polynomial time, and we have augmented the puzzle solver with a simple heuristic for spilling. For SPEC CPU2000, the compilation time of our implementation is as fast as that of the extended version of linear scan used by LLVM, which is the JIT compiler in the openGL stack of Mac OS 10.5. Our implementation produces x86 code that is of similar quality to the code produced by the slower, state-of-the-art iterated register coalescing of George and Appel with the extensions proposed by Smith, Ramsey, and Holloway in 2004.
Virtual communities of practice: the communication of knowledge across cultural boundaries
Authors: Jo Hanisch, Deborah Churchman
Venue: International Journal of Web Based Communities (2008)

Communities of practice, described as social structures which enable knowledge to be managed by practitioners, are recognised as important to the social fabric of knowledge (Wenger, 2004). As a result of the internationalisation of business and the development of enabling technologies, there has emerged the notion of Virtual (online) Communities of Practice (VCoP), where members make use of Information and Communication Technologies (ICTs) to share stories, knowledge and practices. This new phenomenon raises some issues for the ways knowledge communication occurs at work. Little is known about the application of communities of practice theory in the virtual domain, especially in relation to the communication of knowledge across cultural boundaries. This paper draws on qualitative data from a study of several VCoPs to explore their members' communication and cultural experiences. The findings identify some barriers to sustaining communities of practice in a virtual context, and the issues which exist when organisations intentionally create these communities for specific organisational purposes. These issues include the transition of legitimate peripheral participants to full practising members of the VCoP; cultural diversity in intercultural VCoPs; and the ways in which VCoPs are constructed by management to meet a transient need, rather than allowed to emerge.
A Novel Approach for Robust Control of Single-Link Manipulators with Visco-Elastic Behavior
Authors: Meysam Torabi, Mehran Jahed
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

Overwhelming number of control laws has been studied for control of robot manipulators with rigid links and joints. However, controllers designed under this assumption may not accurately control the manipulator link due to visco-elastic properties that appear in the link behavior. In this study, a novel approach for robust control of a single-link manipulator is presented to force the link to have rigid motions, while it has visco-elastic behavior. In this regard, initially robot dynamics is extracted, followed by the design of four appropriate controllers through the loop-shaping approach. The obtained model is first represented in state space, however later converted to transfer function representation to attain robot characteristic equation. Next, a simple and effective method is applied to reduce the order of the robot manipulator model. The final model is examined in time and frequency domains to show the validation of the order reduction method. In order to locate proper zeros and poles of the controllers, Bode plot is used to change the magnitude curve of the manipulator response as desired. The four special controllers are planned for each of four zones of the frequency response. The results show improvements in five major aspects of the behavior of the manipulator, namely transient response, steady state response, robust stability, command following and noise rejection.
Improving the Dependability of Web Services Integration
Authors: Yuhul Chen, Alexander Romanovsky
Venue: IT Professional (2008)

The WS-Mediator framework employs an off-the-shelf mediator architecture and resilience-explicit computing in pursuit of dependable, dynamic Web services integration.
Dynamic PDE parametric curves
Authors: Xu-Zheng Liu, Xia Cui, Guo-Qin Zheng, Jun-Hai Yong, Jia-Guang Sun
Venue: Journal of Computational and Applied Mathematics (2008)

Dynamic partial differential equation (PDE) parametric curves which can be expressed as a coupled system of two hyperbolic equations are developed. In curve design, dynamic PDE parametric curves can be modified intuitively and are more flexible than ordinary differential equation (ODE) curves. The calculation of dynamic PDE parametric curves must recur to numerical methods and a three-level finite difference scheme is proposed. Approximation and stability properties for the scheme are proved and convergence property is derived. An example of interpolating PDE curves is presented as an application of dynamic PDE parametric curves.
Exact finite approximations of average-cost countable Markov decision processes
Authors: Arie Leizarowitz, Adam Shwartz
Venue: Automatica (Journal of IFAC) (2008)

For a countable-state Markov decision process we introduce an embedding which produces a finite-state Markov decision process. The finite-state embedded process has the same optimal cost, and moreover, it has the same dynamics as the original process when restricting to the approximating set. The embedded process can be used as an approximation which, being finite, is more convenient for computation and implementation.
Spot Me if You Can: Uncovering Spoken Phrases in Encrypted VoIP Conversations
Authors: Charles V. Wright, Lucas Ballard, Scott E. Coull, Fabian Monrose, Gerald M. Masson
Venue: Proceedings of the 2008 IEEE Symposium on Security and Privacy (2008)

Despite the rapid adoption of Voice over IP (VoIP), its security implications are not yet fully understood. Since VoIP calls may traverse untrusted networks, packets should be encrypted to ensure confidentiality. However, we show that when the audio is encoded using variable bit rate codecs, the lengths of encrypted VoIP packets can be used to identify the phrases spoken within a call. Our results indicate that a passive observer can identify phrases from a standard speech corpus within encrypted calls with an average accuracy of 50%, and with accuracy greater than 90% for some phrases. Clearly, such an attack calls into question the efficacy of current VoIP encryption standards. In addition, we examine the impact of various features of the underlying audio on our performance and discuss methods for mitigation.