ppxscal/embedding_network huggingface dataset:
Location-dependent information appliances for the home
Authors: Kathryn Elliot, Mark Watson, Carman Neustaedter, Saul Greenberg
Venue: Proceedings of Graphics Interface 2007 (2007)

Ethnographic studies of the home revealed the fundamental roles that physical locations and context play in how household members understand and manage conventional information. Yet we also know that digital information is becoming increasingly important to households. The problem is that this digital information is almost always tied to traditional computer displays, which inhibits its incorporation into household routines. Our solution, location-dependent information appliances, exploit both home location and context (as articulated in ethnographic studies) to enhance the role of ambient displays in the home setting; these displays provide home occupants with both background awareness of an information source and foreground methods to gain further details if desired. The novel aspect is that home occupants assign particular information to locations within a home in a way that makes sense to them. As a device is moved to a particular home location, information is automatically mapped to that device along with hints on how it should be displayed.
Variable ordering for taylor expansion diagrams
Authors: D. Gomez-Prado, Q. Ren, S. Askar, M. Ciesielski, E. Boutillon
Venue: Proceedings of the High-Level Design Validation and Test Workshop, 2004. Ninth IEEE International (2004)

This paper presents an algorithm for variable ordering for Taylor Expansion Diagrams (TEDs). First we prove that the function implemented by the TED is independent of the order of its variables, and then that swapping of two adjacent variables in a TED is a local permutation similar to that in BDD. These two properties allow us to construct an algorithm to swap variables locally without affecting the entire TED. The proposed algorithm can be used to perform dynamic reordering, such as sifting or window permutation. We also propose a static ordering that can help reduce the permutation space and speed up the search of an optimal variable order for TEDs.
The design and analysis of graphical passwords
Authors: Ian Jermyn, Alain Mayer, Fabian Monrose, Michael K. Reiter, Aviel D. Rubin
Venue: Proceedings of the 8th conference on USENIX Security Symposium - Volume 8 (1999)

In this paper we propose and evaluate new graphical password schemes that exploit features of graphical input displays to achieve better security than text-based passwords. Graphical input devices enable the user to decouple the position of inputs from the temporal order in which those inputs occur, and we show that this decoupling can be used to generate password schemes with substantially larger (memorable) password spaces. In order to evaluate the security of one of our schemes, we devise a novel way to capture a subset of the "memorable" passwords that, we believe, is itself a contribution. In this work we are primarily motivated by devices such as personal digital assistants (PDAs) that offer graphical input capabilities via a stylus, and we describe our prototype implementation of one of our password schemes on such a PDA, namely the Palm PilotTM.
Fundamental limitation of frequency domain blind source separation for convolutive mixture of speech
Authors: S. Araki
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

Despite several recent proposals to achieve blind source separation (BSS) for realistic acoustic signals, separation performance is still not good enough. In particular, when the length of impulse response is long, performance is highly limited. We show it is useless to be constrained by the condition, P /spl Lt/ T, where T is the frame size of FFT and P is the length of room impulse response. From our experiments. a frame size of 256 or 512 (32 or 64 ms at a sampling frequency of 8 kHz) is best even for the long room reverberation of T/sub R/ = 150 and 300 ms. We also clarified the reason for poor performance of BSS in a long reverberant environment, finding that separation is achieved chiefly for the sound from the direction of jammers because BSS cannot calculate the inverse of the room transfer function both for the target and jammer signals.
Minimally redundant parallel implementation of digital filters and vector scaling
Authors: K. Muhammad
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

We present a computation reduction technique which can be used to obtain multiplierless implementations of digital filters without altering their frequency response. The ideas presented are also directly applicable to multiplication of vectors by scalars. The main idea is to expand computation space and reorder computation to maximize computation sharing. It is shown that the reordering problem can be formulated using a graph in which vertices represent coefficients and edges represent resources required in a computation involving the coefficient. The multiplierless solution is obtained by solving a set cover problem on the vertices in the graph. A simple polynomial run time algorithm based on a greedy approach is presented and it is shown that even for large filters (/spl ges/600 taps) less than 1 adder per coefficient can be obtained using the presented methodology.
Quantum Chaos in Billiards
Authors: Arnd Backer
Venue: Computing in Science and Engineering (2007)

An important class of systems billiards can show a wide variety of dynamical behavior. Using tools developed in Python, researchers can interactively study the complexity of these dynamics. Such behavior is directly reflected in properties of the corresponding quantum systems, such as eigenvalue statistics or the structure of eigenfunctions.
Quasi-inverses of schema mappings
Authors: Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wang-Chiew Tan
Venue: Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2007)

Schema mappings are high-level specifications that describe the relationship between two database schemas. Two operators on schema mappings, namely the composition operator and the inverse operator, are regarded as especially important. Progress on the study of the inverse operator was not made until very recently, as even finding the exact semantics of this operator turned out to be a fairly delicate task. Furthermore, this notion is rather restrictive, since it is rare that a schema mapping possesses an inverse. In this paper, we introduce and study the notion of a quasi-inverse of a schema mapping. This notion is a principled relaxation of the notion of an inverse of a schema mapping; intuitively, it is obtained from the notion of an inverse by not differentiating between instances that are equivalent for data-exchange purposes. For schema mappings specified by source-to-target tuple-generating dependencies (s-t tgds), we give a necessary and sufficient combinatorial condition for the existence of a quasi-inverse, and then use this condition to obtain both positive and negative results about the existence of quasi-inverses. In particular, we show that every LAV (local-as-view) schema mappinghas a quasi-inverse, but that there are schema mappings specified by full s-t tgds that have no quasi-inverse. After this, we study the language needed to express quasi-inverses of schema mappings specifiedby s-t tgds, and we obtain a complete characterization. We also characterize the language needed to express inverses of schema mappings, and thereby solve a problem left open in the earlier study of the inverse operator. Finally, we show that quasi-inverses can be used in many cases to recover the data that was exported by the original schemamapping when performing data exchange.
Image interpolation using wavelet based hidden Markov trees
Authors: K. Kinebuchi
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

Hidden Markov trees in the wavelet domain are capable of accurately modeling the statistical behavior of real world signals by exploiting relationships between coefficients in different scales. The model is used to interpolate images by predicting coefficients at finer scales. Various optimizations and post-processing steps are also investigated to determine their effect on the performance of the interpolation. The interpolation algorithm was found to produce noticeably sharper images with PSNR values which outperform many other interpolation techniques on a variety of images.
TinyPEDS: Tiny persistent encrypted data storage in asynchronous wireless sensor networks
Authors: Joao Girao, Dirk Westhoff, Einar Mykletun, Toshinori Araki
Venue: Ad Hoc Networks (2007)

In wireless sensor networks there is a need to securely store monitored data in a distributed way whenever it is either not desired or simply not possible to transmit regional volatile information to an authorised recipient in real-time. In particular, for wireless sensor network applications with an asynchronous character, the wireless sensor network itself needs to store the monitored data. Since nodes may disappear over time, a replicated and read-protected, but yet space- and energy-efficient, data storage is mandatory. In this work we provide and analyse an approach for a tiny Persistent Encrypted Data Storage (tinyPEDS) of the environmental fingerprint for asynchronous wireless sensor networks. Even if parts of the network are exhausted, restoring rules ensure that, with a high probability, environmental information from past is still available.
Estimation and Evaluation of Common Cause Failures
Authors: J. Borcsok, S. Schaefer, E. Ugljesa
Venue: Proceedings of the Second International Conference on Systems (2007)

Success of many modern applications is highly dependent on the correct functioning of complex computer based systems. In some cases, failures in these systems may cause serious consequences in terms of loss of human life. Systems in which failure could endanger human life are termed safetycritical. The SIS (Safety Instrumented System) should be designed to meet the required safety integrity level as defined in the safety requirement specification (safety requirement allocation). Moreover, the SIS design should be performed in a way that minimizes the potential for common mode or common cause failures (CCF). A CCF occurs when a single fault result in the corresponding failure of multiple components. Thus, CCFs can result in the SIS failing to function when there is a process demand. Consequently, CCFs have to be identified during the design process and the potential impact on the SIS functionality have to be understood. This paper gives details about the estimation and evaluation of common failures and assesses a 1oo2 system. It is a survey paper that presents the newest developments in common cause failure analysis.
Aeneas: real-time performance evaluation approach for distributed programs with reliability-constrains
Authors: Hai Jin, Yunfa Li, Zongfen Han, Hao Wu, Weizhong Qiang
Venue: Cluster Computing (2007)

A novel approach, called Aeneas, which is based on the execution state of distributed programs, is proposed in this paper. It is for the real-time performance analysis of distributed programs with reliability-constrains. In Aeneas, there are two important factors, the available data files and the transmission paths of each available data file. Some algorithms are designed to find all the transmission paths of each data file needed while the program executes, count the transmission time for each transmission path, then get the aggregate expression of transmission time, calculate the fastest response time and the slowest response time of distributed programs with reliability-constrains. In order to justify the feasibility and the availability of this approach, a series of experiments have been done. The results show that it is feasible and efficient to evaluate the real-time performance for distributed software with reliability-constrains.
Application Resource Demand Phase Analysis and Prediction in Support of Dynamic Resource Provisioning
Authors: Jian Zhang, Mazin Yousif, Robert Carpenter, Renato J. Figueiredo
Venue: Proceedings of the Fourth International Conference on Autonomic Computing (2007)

Profiling the execution phases of an application can lead to optimizing the utilization of the underlying resources. This is the thrust of this paper, which presents a novel system-level application resource demand phase analysis and prediction prototype to support on-demand resource provisioning. The phase profile learned from historical runs is used to classify and predict phase behavior using a set of algorithms based on clustering. The process takes into consid- eration application's resource consumption patterns, pricing schedules defined by the resource provider, and penalties associated with Service-Level Agreement (SLA) violations.
An Experimental Comparison of Event Driven and Multi-Threaded Sensor Node Operating Systems
Authors: Cormac Duffy, Utz Roedig, John Herbert, Cormac Sreenan
Venue: Proceedings of the Fifth IEEE International Conference on Pervasive Computing and Communications Workshops (2007)

Two different operating system types are currently considered for sensor networks: event driven and multi-threaded. This paper compares the two well-known operating systems TinyOS (event driven) and MANTIS (multi-threaded) regarding their memory usage, power consumption and processing capabilities. TinyOS and MANTIS are both ported to the DSYS25 sensor platform. Both operating systems are used to execute the same sensor network application and the aforementioned parameters of interest are measured. The results presented in this paper show for which set of applications each operating system is preferable.
Minimum-energy LDPC decoder for real-time mobile application
Authors: Weihuang Wang, Gwan Choi
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This paper presents a low-power real-time decoder that provides constant-time processing of each frame using dynamic voltage and frequency scaling. The design uses known capacity-approaching low-density parity-check(LDPC) code to contain data over fading channels. Real-time applications require guaranteed data rates. While conventional fixed-number of decoding-iteration schemes are not energy efficient for mobile devices, the proposed heuristic scheme pre-analyzes each received data frame to estimate the maximum number of necessary iterations for frame convergence. The results are then used to dynamically adjust decoder frequency. Energy use is then reduced appropriately by adjusting power supply voltage to minimum necessary for the given frequency. The resulting design provides a judicious trade-off between power consumption and error level.
Optical CDMA Serial Interference Cancellation: First Cancellation Stage
Authors: E. I. Babekir, N. Elfadel, A. Mohammed, A. A. Aziz, N. M. Saad
Venue: Proceedings of the International Multi-Conference on Computing in the Global Information Technology (2007)

Multiple access interference (MAI) is a primary concern in optical coded division multiple access (OCDMA). To alleviate this issue, first cancellation stage of an optical serial interference cancellation (O-SIC) can be employed. In this paper, we investigate the effect of optical serial interference cancellation for the first cancellation stage on bit error rate (BER). We compare the first cancellation stage with the conventional correlation method by utilizing different threshold values with the various length and different number of users. We have successfully shown that the optical serial interference cancellation yields a better performance than the conventional correlation method by choosing the optimum value in the first cancellation stage. We provide the results of computer simulations showing the BER improvement when the first cancellation stage of optical serial interference cancellation (OPSIC) is used over the cancellation technique. The comparisons are done for several numbers of users.
Interactive presentation: RECOPS: reconfiguring programmable devices for military hardware electronics
Authors: Philippe Manet, Daniel Maufroid, Leonardo Tosi, Marco Di Ciano, Olivier Mulertt, Yves Gabriel, Jean-Didier Legat, Denis Aulagnier, Christian Gamrat, Raffaele Liberati, Vincenzo La Barba
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This paper presents the RECOPS project that aims to study the use of reconfiguration in military applications. The project explores the new potentials and possibilities offered by reconfigurable components like FPGA. It identifies specificities related to the use of this technology in military applications and proposes solutions to support them. Specific techniques like dynamic reconfiguration or high speed serial I/Os are also covered. The paper gives a description of the project and then presents preliminary results on the advantages and impacts of using reconfiguration in military applications. It also gives a synthetic view of the needs and challenges that need to face this technology to be integrated in professional and military electronics applications. They are based on a study made over a broad range of seven demonstrators covering most of the fields of military applications.
2-1/2D texture mapping: real-time perceptual surface roughening
Authors: Sylvia C. Pont, Pradeep Sen, Pat Hanrahan
Venue: Proceedings of the 4th symposium on Applied perception in graphics and visualization (2007)

We applied fundamental perceptual and physico-mathematical studies to a fast method for luminance remapping of 2D texture maps which enhances perceived surface roughness in comparison with conventional 2D texture mapping. The fundamental physical mechanism underlying the method is the fact that texture contrast increases as the incident illumination tends towards grazing for rough matte surfaces, actually "exploding" near the shadow edge [Pont and Koenderink 2005]. A psychophysical study by Ho et al. [Ho et al. 2006] confirmed that human observers use texture contrast as a cue for relief-depth or surface roughness. Thus, 2D texture-mapped objects will appear to have a rougher surface if the texture contrast is increased as a function of the local illumination angle. In particular, we increase the bidirectional texture contrast in close accordance with the contrast gradients measured for real objects with rough surfaces. The method presented works well for random textures of locally-matte surfaces if the original texture does not have a contrast that is too high. This modification is in addition to the usual attenuation of the surface irradiance due to the angle of the incident illumination and the computational costs of the technique are similar to that of conventional diffuse shading. This low cost makes it straightforward to implement the technique with real-time shaders which allow interactive rendering on modern graphics hardware.
Real-time foveation techniques for H.263 video encoding in software
Authors: H. R. Sheikh
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

Video coding techniques employ characteristics of the human visual system (HVS) to achieve high coding efficiency. Lee (2000) and Bovik have exploited foveation, which is a non-uniform resolution representation of an image reflecting the sampling in the retina, for low bit-rate video coding. We develop a fast approximation of the foveation model and demonstrate real-time foveation techniques in the spatial domain and discrete cosine transform (DCT) domain. We incorporate fast DCT domain foveation into the baseline H.263 video encoding standard. We show that DCT-domain foveation requires much lower computational overhead but generates higher bit rates than spatial domain foveation. Our techniques do not require any modifications of the decoder.
Reversible circuit technology mapping from non-reversible specifications
Authors: Zeljko Zilic, Katarzyna Radecka, Ali Kazamiphur
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This paper considers the synthesis of reversible circuits directly from an irreversible specification, with no need for producing a reversible embedding first. We present a feasible methodology for realizing the networks of reversible gates, in a manner that builds on the classical technology mapping. We do not restrict ourselves to the restricted notion of realizing permutation functions, and construct reversible implementations where extraneous signals are efficiently reused for overcoming the inherent fanout limitation.
Successful Broadband Projects in the Public Sector - a Service Innovation Perspective
Authors: Bendik Bygstad, Gjermund Lanestedt, Jyoti Choudrie
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

The development of national broadband infrastructures has been recognized as an important part of the vision of the information society, as well as of the modernization of the public sector. This paper investigates the relationship between broadband dissemination and service innovation in the public sector. We ask, what characterizes successful broadband based service innovation projects in the public sector? The research approach is a quantitative survey in a large public broadband diffusion initiative in Norway The paper offers three conclusions. First, broadband based service innovation is seen as a two-step process; first a technologically oriented project, followed by an organizational implementation. The focus of the project manager should be on the second of the phases, not the first. Second, the engagement of a professional external project manager does not support service innovation. The reason is that the external project manager lacks the necessary local knowledge and alliances with central stakeholders. Third, traditional project management is not well suited to understand and manage service innovation.
Security Analysis of Voice-over-IP Protocols
Authors: Prateek Gupta, Vitaly Shmatikov
Venue: Proceedings of the 20th IEEE Computer Security Foundations Symposium (2007)

The transmission of voice communications as datagram packets over IP networks, commonly known as Voice-over- IP (VoIP) telephony, is rapidly gaining wide acceptance. With private phone conversations being conducted on insecure public networks, security of VoIP communications is increasingly important. We present a structured security analysis of the VoIP protocol stack, which consists of signaling (SIP), session description (SDP), key establishment (SDES, MIKEY, and ZRTP) and secure media transport (SRTP) protocols. Using a combination of manual and tool-supported formal analysis, we uncover several design flaws and attacks, most of which are caused by subtle inconsistencies between the assumptions that protocols at different layers of the VoIP stack make about each other. The most serious attack is a replay attack on SDES, which causes SRTP to repeat the keystream used for media encryption, thus completely breaking transport-layer security. We also demonstrate a man-in-the-middle attack on ZRTP, which allows the attacker to convince the communicating parties that they have lost their shared secret. If they are using VoIP devices without displays and thus cannot execute the "human authentication" procedure, they are forced to communicate insecurely, or not communicate at all, i.e., this becomes a denial of service attack. Finally, we show that the key derivation process used in MIKEY cannot be used to prove security of the derived key in the standard cryptographic model for secure key exchange.