ppxscal/embedding_network huggingface dataset:
The Horus location determination system
Authors: Moustafa Youssef, Ashok Agrawala
Venue: Wireless Networks (2008)

We present the design and implementation of the Horus WLAN location determination system. The design of the Horus system aims at satisfying two goals: high accuracy and low computational requirements. The Horus system identifies different causes for the wireless channel variations and addresses them to achieve its high accuracy. It uses location-clustering techniques to reduce the computational requirements of the algorithm. The lightweight Horus algorithm helps in supporting a larger number of users by running the algorithm at the clients. We discuss the different components of the Horus system and evaluate its performance on two testbeds. Our results show that the Horus system achieves its goal. It has an error of less than 0.6 meter on the average and its computational requirements are more than an order of magnitude better than other WLAN location determination systems. Moreover, the techniques developed in the context of the Horus system are general and can be applied to other WLAN location determination systems to enhance their accuracy. We also report lessons learned from experimenting with the Horus system and provide directions for future work.
A fast algorithm for optimally increasing the edge-connectivity
Authors: D. Naor, D. Gusfield, C. Martel
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

An undirected, unweighted graph G=(V, E with n nodes, m edges, and connectivity lambda ) is considered. Given an input parameter delta , the edge augmentation problem is to find the smallest set of edges to add to G so that its edge-connectivity is increased by delta . A solution to this problem that runs in time O( delta /sup 2/nm+nF(n)), where F(n) is the time to perform one maximum flow on G, is given. The solution gives the optimal augmentation for every delta ', 1
The assumed light direction for perceiving shape from shading
Authors: James P. O'Shea, Martin S. Banks, Maneesh Agrawala
Venue: Proceedings of the 5th symposium on Applied perception in graphics and visualization (2008)

Recovering 3D shape from shading is an ill-posed problem that the visual system can solve only by making use of additional information such as the position of the light source. Previous research has shown that people tend to assume light is above and slightly to the left of the object [Sun and Perona 1998]. We present a study to investigate whether the visual system also assumes the angle between the light direction and the viewing direction. We conducted a shape perception experiment in which subjects estimated surface orientation on smooth, virtual 3D shapes displayed monocularly using local Lambertian shading without cast shadows. We varied the angle between the viewing direction and the light direction within a range +/- 66 deg (above/below), and subjects indicated local surface orientation by rotating a gauge figure to appear normal to the surface [Koenderink et al. 1992]. Observer settings were more accurate and precise when the light was positioned above rather than below the viewpoint. Additionally, errors were minimized when the angle between the light direction and the viewing direction was 20--30 deg. Measurements of surface slant and tilt error support this result. These findings confirm the light-from-above prior and provide evidence that the angle between the viewing direction and the light direction is assumed to be 20--30 deg above the viewpoint.
Generating targeted queries for database testing
Authors: Chaitanya Mishra, Nick Koudas, Calisto Zuzarte
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Tools for generating test queries for databases do not explicitly take into account the actual data in the database. As a consequence, such tools cannot guarantee suitable coverage of test cases commonly required for database testing. In this paper, we investigate the problem of generating queries that satisfy cardinality constraints on intermediate subexpressions when executed on a given test database. Such queries are required to test the performance of a database system under different operating conditions. We formally analyze this problem, quantify its difficulty and follow up this analysis with a description of a practical algorithm which utilizes sampling and space pruning techniques to quickly generate test queries that have desired properties. We present the results of an experimental evaluation of our approach as implemented in an open source data manager, demonstrating the utility of our proposal.
Comparing software metrics tools
Authors: Rüdiger Lincke, Jonas Lundberg, Welf Löwe
Venue: Proceedings of the 2008 international symposium on Software testing and analysis (2008)

This paper shows that existing software metric tools interpret and implement the definitions of object-oriented software metrics differently. This delivers tool-dependent metrics results and has even implications on the results of analyses based on these metrics results. In short, the metrics-based assessment of a software system and measures taken to improve its design differ considerably from tool to tool. To support our case, we conducted an experiment with a number of commercial and free metrics tools. We calculated metrics values using the same set of standard metrics for three software systems of different sizes. Measurements show that, for the same software system and metrics, the metrics values are tool depended. We also defined a (simple) software quality model for "maintainability" based on the metrics selected. It defines a ranking of the classes that are most critical wrt. maintainability. Measurements show that even the ranking of classes in a software system is metrics tool dependent.
Expert clustering of hydraulic-geotechnical control parameters of rubble mound breakwaters using rough sets theory
Authors: Gh. A. Montazer, H. Gh. Pour Khatir Reza Sabzevari
Venue: Proceedings of the 5th WSEAS International Conference on Computational Intelligence, Man-Machine Systems and Cybernetics (2006)

The problem of how various parameters of sea and soil affect the hydraulic and geotechnical aspects of breakwaters and the way these parameters must be controlled stably despite of undesired environmental factors is a challenging task in Hydraulics Engineering. The most popular solution for this problem is based on forming an information table whose entities have been extracted from empirical experiments and then try to find the relations between the affecting parameters and affected elements. In this paper, a new expert method based on the notions of Rough Sets Theory (RST) has been developed to solve this problem. Also, this development method has been applied to the problem of clustering the hydraulic-geotechnical control parameters of a real rubble mound breakwater and then the results and advantages of this approach have been explained and discussed.
Understanding iDTV in a developing country and designing a T-gov application prototype
Authors: Lara Schibelsky, Godoy Piccolo, Maria Cecília, Calani Baranauskas
Venue: Proceedings of the 7th ACM conference on Designing interactive systems (2008)

TV is an artifact present in 90% of Brazilian homes and it is the main source of information for a major part of the population. The moment of definition and consolidation of an interactive digital TV technology in Brazil provides us with a unique opportunity to cope with the digital divide issues. Making sure that iDTV contents and devices are flexible enough so that people are able to perceive, understand and interact with them is an essential requirement for the democratization of information via TV broadcasting. This paper investigates the basis for setting an interactive digital TV in Brazil by analyzing the Brazilian scenario and by proposing recommendations for the design of accessible user interfaces for iDTV applications; this basis is illustrated with the design of ciT-goV, a t-gov application prototype.
A real-time inventory decision system using Western Electric run rules and ARMA control chart
Authors: Jui-Chang Cheng, Chao-Yu Chou
Venue: Expert Systems with Applications: An International Journal (2008)

Inventory management is an important area of production control. In 1999, Pfohl et al. [Pfohl, H.-C., Cullmann, O., & Stolzle, W. (1999). Inventory management with statistical process control: Simulation and evaluation. Journal of Business Logistics, 20, 101-120] developed a real-time inventory decision support system by using the individual control charts for monitoring the inventory level (i.e., stock quantity) and the market demand, in which a series of decision rules are provided to help the inventory manager to determine the time and the quantity to order. In the present paper, a real-time inventory decision system is proposed by incorporating Western Electric run rules into the decision rules of the system. Since the data of demand sometimes present a pattern of time series (i.e., autocorrelation may exist in the data of demand), in the proposed decision system the ARMA control chart is employed to monitor the market demand and the individual control chart is used to monitor the inventory level. A simulation study is conducted to investigate the effects of demand pattern and autocorrelation on the proposed inventory decision system and to verify the effectiveness of the system. The index ''service level'' is selected as the key indicator for the system performance. Based on the results of the simulation study, it is shown that the performance of the proposed inventory decision system is quite consistent with service level always greater than 90% for various demand patterns.
Fault Diagnosis of Discretely Controlled Continuous Systems by Means of Discrete-Event Models
Authors: Jan Lunze
Venue: Discrete Event Dynamic Systems (2008)

Discretely controlled continuous systems consist of continuous plants whose operation mode is switched by a feedback controller. Fault diagnosis has to use the measured switching sequence and the measured continuous movement to detect and identify faults. In order to get the diagnostic algorithm with the least possible complexity, the kind of measurement information and the granularity of the model have to be chosen in accordance with the faults to be detected. The paper presents five diagnostic methods in a uniform way, which differ with respect to the model and the measurement information used. From the hybrid model of discretely controlled continuous systems, four more abstract representations are derived, which have the form of embedded maps, semi-Markov processes, timed automata and nondeterministic automata. The validity of the diagnostic result is ensured by the claim that the models should be complete and, hence, consistent with all the input-output sequences of the discretely controlled system in the appropriate fault case. In this way a hierarchy of models and of diagnostic results is obtained. The methods are illustrated by an example.
Software Studies: A Lexicon (Leonardo Books)
Authors: Matthew Fuller, Matthew Fuller
Venue:  (2008)

This collection of short expository, critical, and speculative texts offers a field guide to the cultural, political, social, and aesthetic impact of software. Computing and digital media are essential to the way we work and live, and much has been said about their influence. But the very material of software has often been left invisible. In Software Studies, computer scientists, artists, designers, cultural theorists, programmers, and others from a range of disciplines each take on a key topic in the understanding of software and the work that surrounds it. These include algorithms; logical structures; ways of thinking and doing that leak out of the domain of logic and into everyday life; the value and aesthetic judgments built into computing; programming's own subcultures; and the tightly formulated building blocks that work to make, name, multiply, control, and interweave reality. The growing importance of software requires a new kind of cultural theory that can understand the politics of pixels or the poetry of a loop and engage in the microanalysis of everyday digital objects. The contributors to Software Studies are both literate in computing (and involved in some way in the production of software) and active in making and theorizing culture. Software Studies offers not only studies of software but proposes an agenda for a discipline that sees software as an object of study from new perspectives. Contributors: Alison Adam, Wilfried Hou Je Bek, Morten Breinbjerg, Ted Byfield, Wendy Hui Kyong Chun, Geoff Cox, Florian Cramer, Cecile Crutzen, Marco Deseriis, Ron Eglash, Matthew Fuller, Andrew Goffey, Steve Goodman, Olga Goriunova, Graham Harwood, Friedrich Kittler, Erna Kotkamp, Joasia Krysa, Adrian Mackenzie, Lev Manovich, Michael Mateas, Nick Montfort, Michael Murtaugh, Jussi Parikka, Sren Pold, Derek Robinson, Warren Sack, Grzesiek Sedek, Alexei Shulgin, Matti Tedre, Adrian Ward, Richard Wright, Simon Yuill.
Speeding up dynamic programming
Authors: D. Eppstein, Z. Galil, R. Giancarlo
Venue: Proceedings of the 29th Annual Symposium on Foundations of Computer Science (1988)

A number of important computational problems in molecular biology, geology, speech recognition, and other areas can be expressed as recurrences which have typically been solved with dynamic programming. By using more sophisticated data structures, and by taking advantage of further structure from the applications, the authors speed up the computation of several of these recurrences by one or two orders of magnitude. The algorithms used are simple and practical.
MGFs for Rayleigh Random Variables
Authors: Christopher S. Withers, Saralees Nadarajah
Venue: Wireless Personal Communications: An International Journal (2008)

Expressions are given for the moment generating functions of the Rayleigh and generalized Rayleigh distributions.
On the use of complementary spectral features for speaker recognition
Authors: Danoush Hosseinzadeh, Sridhar Krishnan
Venue: EURASIP Journal on Advances in Signal Processing (2008)

The most popular features for speaker recognition are Mel frequency cepstral coefficients (MFCCs) and linear prediction cepstral coefficients (LPCCs). These features are used extensively because they characterize the vocal tract configuration which is known to be highly speaker-dependent. In this work, several features are introduced that can characterize the vocal system in order to complement the traditional features and produce better speaker recognition models. The spectral centroid (SC), spectral bandwidth (SBW), spectral band energy (SBE), spectral crest factor (SCF), spectral flatness measure (SFM), Shannon entropy (SE), and Renyi entropy (RE) were utilized for this purpose. This work demonstrates that these features are robust in noisy conditions by simulating some common distortions that are found in the speakers' environment and a typical telephone channel. Babble noise, additive white Gaussian noise (AWGN), and a bandpass channel with 1 dB of ripple were used to simulate these noisy conditions. The results show significant improvements in classification performance for all noise conditions when these features were used to complement the MFCC and ΔMFCC features. In particular, the SC and SCF improved performance in almost all noise conditions within the examined SNR range (10-40 dB). For example, in cases where there was only one source of distortion, classification improvements of up to 8% and 10% were achieved under babble noise and AWGN, respectively, using the SCF feature.
Cooperating coscheduling: a coscheduling proposal aimed at non-dedicated heterongeneous NOWs
Authors: Francesc Giné, Francesc Solsona, Mauricio Hanzich, Porfidio Hernández, Emilio Luque
Venue: Journal of Computer Science and Technology (2007)

Implicit coscheduling techniques applied to non-dedicated homogeneous Networks Of Workstations (NOWs) have shown they can perform well when many local users compete with a single parallel job. Implicit coscheduling deals with minimizing the communication waiting time of parallel processes by identifying the processes in need of coscheduling through gathering and analyzing implicit runtime information, basically communication events. Unfortunately, implicit coscheduling techniques do not guarantee the performance of local and parallel jobs, when the number of parallel jobs competing against each other is increased. Thus, a low efficiency use of the idle computational resources is achieved. In order to solve these problems, a new technique, named Cooperating CoScheduling (CCS), is presented in this work. Unlike traditional implicit coscheduling techniques, under CCS, each node takes its scheduling decisions from the occurrence of local events, basically communication, memory, Input/Output and CPU, together with foreign events received from cooperating nodes. This allows CCS to provide a social contract based on reserving a percentage of CPU and memory resources to ensure the progress of parallel jobs without disturbing the local users, while coscheduling of communicating tasks is ensured. Besides, the CCS algorithm uses status information from the cooperating nodes to balance the resources across the cluster when necessary. Experimental results in a non-dedicated heterogeneous NOW reveal that CCS allows the idle resources to be exploited efficiently, thus obtaining a satisfactory speedup and provoking an overhead that is imperceptible to the local user.
A 4-Gbps Uncompressed Wireless HD A/V Transceiver Chipset
Authors: Jeffrey M. Gilbert, Chinh H. Doan, Sohrab Emami, C. Bernard Shung
Venue: IEEE Micro (2008)

Wireless transmission of uncompressed lossless HD video provides higher image quality with lower latency and cost than compressed-content transmission. However, it requires data rates of about 4 Gbps for 1080p resolution, exceeding the capabilities of existing wireless technologies. Using the 60-GHz band as detailed by the Wireless HD specification, SiBEAM's chipset makes such data rates economically achievable.
Economic-based Incentive Schemes for Dynamic Data Management in Mobile P2P Computing
Authors: Sanjay Kumar Madria, Anirban Mondal
Venue: Proceedings of the The Ninth International Conference on Mobile Data Management (2008)

Data Management in Mobile Peer to Peer (M-P2P) systems needs dynamic data management due to mobility and fragile wireless connection connecting resource constraint devices. Traditional methods of data management and services in mobile P2P environment generally assume all peers to cooperate. Since peer activities in M-P2P are not generally monitored, users assume that they are free to use the resources anyway they like. Under this feeling of freedom, a subset of users (free riders) begins to consume much more resources available on M-P2P than they wish to contribute. In addition, due to the dynamic nature of moving hosts, topology changes very often and traditional schemes fall short in providing reasonable data availability. This becomes much more important in M-P2P where the network communication is generally multi-hop and intermediate peers have to render relay services other than data providers to improve the connectivity. Economic-based incentive schemes have been proposed which may play a better role in inciting free riders to collaborate. The data and service availability can be increased by associating a price with data items and services. In such schemes, peers can bid for better services, intermediate peers can earn incentives by providing relay services and in fact, outgoing peers can lease data items to others to still earn incentives while disconnected. New peers can become data providers by providing hosting services to earn incentives. This tutorial will explore issues involved in managing resources using Economic incentives.
Designing efficient irregular networks for heterogeneous systems-on-chip
Authors: Christian Neeb, Norbert Wehn
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2008)

Networks-on-chip will serve as the central integration platform in future complex systems-on-chip (SoC) designs, composed of a large number of heterogeneous processing resources. Most researchers advocate the use of traditional regular networks like meshes, tori or trees as architectural templates which gained a high popularity in general-purpose parallel computing. However, most SoC platforms are special-purpose tailored to the domain-specific requirements of their application. They are usually built from a large diversity of heterogeneous components which communicate in a very specific, mostly irregular way. In this work, we propose a methodology for the design of customized irregular networks-on-chip, called INoC. We take advantage of a priori knowledge of the communication characteristic of the application to generate an optimized network topology and routing algorithm. We show that customized irregular networks are clearly superior to traditional regular architectures in terms of performance at comparable implementation costs for irregular workloads. Even more, they inherently offer a high degree of scalability and expansibility which allows to adapt the network to an arbitrary number of nodes with a given communication demand. This can normally not be accomplished by traditional approaches.
Performance Comparison of On-Demand and Table Driven Ad Hoc Routing Protocols Using NCTUns
Authors: Khaleel Ur Rahman Khan, Rafi U. Zaman, A. Venugopal Reddy
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

The main aim of any ad-hoc network routing protocol is to meet the challenges of the dynamically changing topology and establish a correct and an efficient communication path between any two nodes with minimum routing overhead and bandwidth consumption. The design problem of such a routing protocol is not simple since an ad hoc environment introduces new challenges that are not present in fixed networks. A number of routing protocols have been proposed for this purpose like Ad Hoc On Demand Distance Vector (AODV), Dynamic Source Routing (DSR), Destination- Sequenced Distance Vector (DSDV). In this paper, we study and compare the performance of the following three routing protocols AODV, DSR and DSDV. NCTUns 4.0 is used to study the relative performance of the routing protocols according to different criteria. The notable point of our analysis is that, it is based on varying number of nodes in the ad hoc network.
Provably Correct Pervasive Computing Environments
Authors: Anand Ranganathan, Roy H. Campbell
Venue: Proceedings of the 2008 Sixth Annual IEEE International Conference on Pervasive Computing and Communications (2008)

The field of pervasive computing has seen a lot of exciting innovations in the past few years. However, there are currently no mechanisms for describing the properties and capabilities of pervasive computing environments in a formal manner. This makes it difficult to prove the correctnesss of a pervasive computing environment, i.e. to verify that the environment satisfies certain desired properties. In this paper, we propose a formal model for describing pervasive computing environments %Active Spaces. Active Spaces are physical spaces that have been enhanced with various computing and communication resources in order to help users perform various kinds of tasks. This model isbased on ambient calculus and the associated ambient logic. The model allows us to state and verify several properties of these environments such as ``anywhere anyhow services'', ``mobility of devices and applications'' and ``context-aware adaptation''. The model allows us to describe the resources present in an environment, the operations that can be performed in the environment, and how users can use the resources in th environment to perform different kinds of activities. As a case study, we shall describe some of the resources and operations supported by the Gaia middleware using this model, and verify an example property of a pervasive computing environment supported by Gaia.