ppxscal/embedding_network huggingface dataset:
Queues in DOCSIS cable modem networks
Authors: J. Lambert, B. Van Houdt, C. Blondia
Venue: Computers and Operations Research (2008)

In this paper we determine the optimal fraction c^* of the uplink channel capacity that should be dedicated to the contention channel in a DOCSIS cable network in order to minimize its mean response time. For this purpose, we have developed an open queueing network with a non-standard form of blocking consisting of tens to hundreds of nodes. The network contains several types of customers that enter the network at various points according to a Markovian arrival process with marked customers. One of the main building blocks of the model exists in capturing the behavior of the conflict resolution algorithm by means of a single processor sharing queue. To assess the performance characteristics of this open queueing network we rely on an advanced decomposition technique that is specifically designed to deal with the Markovian nature of the arrival pattern. Several simulations are run to confirm the accuracy of the decomposition technique. We also explore the impact of a variety of systems parameters, e.g., the number of cable modems, the initial backoff window size, the correlation structure of the arrival process, the mean packet sizes, etc., on the optimal fraction c^*.
On the Fundamental Limits of Topology Control in&#x00a0;Ad&#x00a0;Hoc Networks
Authors: Andr&#x00e1;s Farag&#x00f3;
Venue: Algorithmica (2007)

We prove two results that provide new fundamental limits for topology control in large ad hoc and sensor networks. First, we show that it remains true under very general conditions that the maximum expected node degree must grow to infinity at least logarithmically if we want to maintain asymptotic connectivity. This has been known so far only for much more special models than ours. Building on this result, we prove a new fundamental limit regarding link dynamics, which means the worst case length ratio of the longest and shortest link adjacent to the same node. We prove that if link dynamics remains bounded, then no topology control algorithm can keep a large network connected with high probability. Moreover, bounded link dynamics prevents connectivity in the limit without any a priori assumption on node degrees or transmission ranges. Our results hold in a model that is much more general than the frequently used assumption of uniformly distributed nodes in a regularly shaped planar domain. Our more abstract setting also aims at finding (hopefully) more robust and elegant proofs that have less dependence on the special geometry. Since link dynamics is expected to be bounded in practice, the results strenghten the theoretical basis for the argument that a very large ad hoc or sensor network is unable to maintain connectivity if it has a flat, random organization without additional structure.
Scaling of program fitness spaces
Authors: William B. Langdon
Venue: Evolutionary Computation (1999)

We investigate the distribution of fitness of programs concentrating on those represented as parse trees and, particularly, how such distributions scale with respect to changes in the size of the programs. By using a combination of enumeration and Monte Carlo sampling on a large number of problems from three very different areas, we suggest that, in general, once some minimum size threshold has been exceeded, the distribution of performance is approximately independent of program length. We proof this for both linear programs and simple side effect free parse trees. We give the density of solutions to the parity problems in program trees which are composed of XOR building blocks. Limited experiments with programs including side effects and iteration suggest a similar result may also hold for this wider class of programs.
Architectural Optimizations for Text to Speech Synthesis in Embedded Systems
Authors: S. Dey, M. Kedia, A. Basu
Venue: Proceedings of the 2007 Asia and South Pacific Design Automation Conference (2007)

The increasing processing power of embedded devices have created the scope for certain applications that could previously be executed in desktop environments only, to migrate into handheld platforms. An important feature of the computing systems of modern times is their support for applications that interact with the user by synthesizing natural speech output. Such applications deliver state of the art performance in desktop environments. However, the real-time performance of such applications in handheld platforms with on-line incoming text streams have not been explored till date. In this work, the performance of a text to speech synthesis application is evaluated on embedded processor architectures and modifications in the underlying hardware platform are proposed for real time performance improvement of the concerned application.
An inexpensive method to shield wireless devices during hardware forensic investigation in a laboratory setting
Authors: Lawrence W. Hill
Venue: Proceedings of the 8th ACM SIGITE conference on Information technology education (2007)

Wireless devices have become prolific in society today. Unfortunately, this paradigm is increasingly useful by criminals during the execution of their illegal actions. A cellular telephone is used as the example in this paper. Our students are taught how to obtain vital information from the phone, for example, by downloading internal files (numbers-called lists, for example) onto an external computer. As the phone is transported to the laboratory, it will be handed-off from one cell site to another, as it would normally operate while roaming. As these hand-offs occur, files in the phone, as well as radio settings, adapt to the new cell sites. When the phone arrives at the laboratory, it has been altered. If in its powered-down state during confiscation at the crime scene, as soon as it is powered-on in the laboratory, it will associate, or connect, to the local cell site in that area, and again its contents will change. To be useful in the classroom, a low-cost method is needed to shield the phone from association with a cellular system. Shielding boxes are available commercially that provide the necessary shielding that preserves the pre-investigation state of the phone. However, these boxes, sometimes incorrectly referred to as, "Faraday shields (or cages)," are prohibitively expensive in the context of classroom use. It is very beneficial for the students in our forensics courses to be exposed to these issues, and provide them the opportunity to use such a shielding environment in hands-on exploratory laboratory experiences. A homemade unit, completely shielded, with appropriate power and data line filtering is discussed in detail. It can be constructed in any minimal shop with standard hand tools where almost all materials are obtained from a local home improvement center, with only a handful of special electrical components needed. The theory underlying its requirements is explained in terms understandable by non-engineering personnel. The shielding box will be shown to provide adequate shielding for cellular telephones from nearby cell sites.
The Value Gap Model: Value-Based Requirements Elicitation
Authors: Sang Won Lim, Taek Lee, Sangsoo Kim, Hoh Peter In
Venue: Proceedings of the 7th IEEE International Conference on Computer and Information Technology (2007)

The User requirements of many web-based services are dynamically and continuously changing even during the service time itself. For that reason, web service companies always keep trying to satisfy users' needs from the market. Requirements elicitation, among the processes in requirements engineering, is a process requiring high costs and time. Thus, a company planning to conduct the process wants to catch the points users don't satisfy in their needs by taking advantage of an effective process of requirements elicitation. In this paper, we propose value based requirements elicitation, so called, the Value Gap Model aiming to clarify need selection and focus on key factors to a requirements engineer who should take into account the value on behalf of users. To do that, the process, at first, recognizes a value gap between the value users currently have and the value a system understand as users' one, and then it figures out the components that a requirements engineer has to select and focus on in his or her requirements elicitation process. In order to focus on and invest effectively the resources of elicitation process, the proposed process finds the part where most of users feel unsatisfying so that it eventually elicits the valuable requirements from users.
Bio-inspired context gathering in loosely coupled computing environments
Authors: Carsten Jacob, David Linner, Stephan Steglich, Ilja Radusch
Venue: Proceedings of the 1st international conference on Bio inspired models of network, information and computing systems (2006)

Context-awareness is a key requirement of human-centric computing systems. Applications may ease user interaction or even anticipate the behavior of the user when utilizing information about the current context. The pervasive provision of context data represents a major challenge in this scope. For that reason we introduce an approach for gathering, disseminating, and interpreting context data in dynamic, highly distributed systems, which are mostly disconnected from central networking infrastructures. On the one hand we describe architectural consideration addressing functional elements and their organization in the computing environment. On the other hand we incorporate a model for request-driven context gathering and a biologically-inspired approach for weighting, storing and forwarding context data. The conceptual considerations are complemented with a description of our first efforts in realizing our approach on top of a peer-to-peer framework.
A Model for Control Structures for Artificial Intelligence Programming Languages
Authors: D. G. Bobrow
Venue: IEEE Transactions on Computers (1976)

Newer programming languages for artificial intelligence extend the class of available control regimes beyond simple hierarchical control. In so doing, a key issue is using a model that clearly exhibits the relation between modules, processes, access environments, and control environments. This paper presents a model which is applicable to diverse languages and presents a set of control primitives which provide a concise basis on which one can define almost all known regimes of control.
The Xerox 1200 Computer Printing System
Authors: J. N. Mitchell
Venue: Computer (1975)

Recent trends toward off-line printing have served to encourage serious development of off-line non-impact computer printer systems. For such systems, the combination of electrophotography and computer output printing is a natural candidate, not only because of the advantages which can be realized in the areas of flexibility, image quality, and speed, but also because of various other enhancement features which can be implemented. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Modelling and querying sensor databases
Authors: Jose-Luis Zechinelli-Martini, Ilian Elias-Morales
Venue: Proceedings of the Eighth Mexican International Conference on Current Trends in Computer Science (2007)

This paper presents and approach for modelling and querying sensor databases for implementing continuous information systems. Our approach defines query processing strategies that exploit as much as possible the computing and energy capacities of sensors. We introduce the concept of broker for representing and associating querying capacities to sensors, so that query processing can be done by making sensors cooperate in order to retrieve data. The paper discusses also implementation issues based on the TinyDB platform.
Modeling Real-time Garbage Collection Cost
Authors: Wei Fu, Carl Hauser
Venue: Proceedings of the 13th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (2007)

Given the major advantages of productivity and safety, the use of garbage collection (GC) in real-time systems has gained increasing attention. Guaranteeing garbage collection activities' worst-case execution time (WCET) is necessary for a real-time system to perform scheduling and schedulability analysis. This paper describes a detailed GC cost model for incremental mark-and-sweep GC exemplified by a modified Boehm-Demers-Weiser (BDW) collector. The GC cost model computes the WCET for garbage collection in terms of (1) the performance of collector operations and (2) the garbage collection load offered by a real-time task. Separating these aspects is a step along the road to an engineering approach to garbage collection in real-time systems, allowing prediction of system behavior from knowledge of component behavior and environmental specifications. The model incorporates the cost of write barriers that are needed to support incremental GC. To be useful for real-time systems, a model's predicted WCET must be no less than the actual WCET. However, unreasonably large overestimates are also problematic as they may lead to the incorrect conclusion that the application cannot be feasibly scheduled. A pessimism metric assesses the degree to which the model's predictions exceed the measured worst-case cost in particular instances.
The perceptions towards mobile services: an empirical analysis of the role of use facilitators
Authors: Timo Koivumäki, Annu Ristola, Manne Kesti
Venue: Personal and Ubiquitous Computing (2008)

The adoption patterns for new technology such as mobile services are essential to understand for developing them further. Hence, it is important to study how willing people are to try new mobile services and do variables, which facilitate the use of the services have an effect on the consumers' perceptions of the services and their adoption readiness. This study analyses how the familiarity of mobile devices, the time the services are initially used and users' technology skills affect the initial mobile service usage experience and the likelihood of continuous usage. The results show that the duration of the use does not effect consumers' perceptions about mobile services, but familiarity of the device and user skills have an impact on the perceptions of the services.
Arbitrated time-to-first spike CMOS image sensor with on-chip histogram equalization
Authors: Chen Shoushun, Amine Bermak
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2007)

This paper presents a time-to-first spike (TFS) and address event representation (AER)-based CMOS vision sensor performing image capture and on-chip histogram equalization (HE). The pixel values are read-out using an asynchronous handshaking type of read-out, while the HE processing is carried out using simple and yet robust digital timer occupying a very small silicon area (0.1 × 0.6 mm2). Low-power operation (10 nA per pixel) is achieved since the pixels are only allowed to switch once per frame. Once the pixel is acknowledged, it is granted access to the bus and then forced into a stand-by mode until the next frame cycle starts again. Timing errors inherent in AER-type of imagers are reduced using a number of novel techniques such as fair and fast arbitration using toggled priority (TP), higher-radix, and pipelined arbitration. A verilog simulator was developed in order to simulate the effect of timing errors encountered in AER-based imagers. A prototype chip was implemented in AMIS 0.35µm process with a silicon area of 3.1 × 3.2 mm2. Successful operation of the prototype is illustrated through experimental measurements.
Improvement of Data Grid's Performance by Combining Job Scheduling with Dynamic Replication Strategy
Authors: Nhan Nguyen Dang, Soonwook Hwang, Sang Boem Lim
Venue: Proceedings of the Sixth International Conference on Grid and Cooperative Computing (2007)

Dealing with a large amount of data makes the requirement for efficient data accesses more critical in Data Grid. Through improving performance of data replication, job execution cost is reduced. In this paper, we proposed a new strategy of replication based on organizing the data in Data Grid based on its property. Particularly, we organized the data into several data categories that it belongs to and this categorization helps improving data replication placement strategy. In addition, the paper also introduces Dataset Scheduler which helps optimize obtaining input data for job. The performance studies are conducted using simulation tool and prove the improvement of scheduling performance over current approaches.
Second-order optimal array receivers for synchronization of BPSK, MSK, and GMSK signals corrupted by noncircular interferences
Authors: Pascal Chevalier, François Pipon, François Delaveau
Venue: EURASIP Journal on Advances in Signal Processing (2007)

The synchronization and/or time acquisition problem in the presence of interferences has been strongly studied these last two decades, mainly to mitigate the multiple access interferences from other users in DS/CDMA systems. Among the available receivers, only some scarce receivers may also be used in other contexts such as F/TDMA systems. However, these receivers assume implicitly or explicitly circular (or proper) interferences and become suboptimal for noncircular (or improper) interferences. Such interferences are characteristic in particular of radio communication networks using either rectilinear (or monodimensional) modulations such as BPSK modulation or modulation becoming quasirectilinear after a preprocessing such as MSK, GMSK, or OQAM modulations. For this reason, the purpose of this paper is to introduce and to analyze the performance of second-order optimal array receivers for synchronization and/or time acquisition of BPSK, MSK, and GMSK signals corrupted by noncircular interferences. For given performances and in the presence of rectilinear signal and interferences, the proposed receiver allows a reduction of the number of sensors by a factor at least equal to two.
A High Efficiency Approach to Querying Rough Data
Authors: Xinglei Hu, Xiaoguang Hong, Yan Yuan
Venue: Proceedings of the Fourth International Conference on Fuzzy Systems and Knowledge Discovery - Volume 02 (2007)

Any attribute in Rough Relational Database (RRDB) can be multi-valued, and has an indiscernibility relation in its domain. Currently, the research on rough data querying mainly discussed some simple select-querying. That is, selecting the tuples whose attribute's value is equal to a constant from a single table. The main idea of its implementation is to expand the original search conditions according to the indiscernibility relation in attribute's domain. Because the search conditions after being expanded need more calculation, the querying becomes very slow. In this paper, we present a solution called rough data querying based on encoding. Firstly encode the data of multi-valued attribute into the single-valued data according to the indiscernibility relation in attribute's domain, and then execute the querying on the single-valued data despite the indiscernibility relation to make the implementation of rough data querying much simpler and more efficient.
Ariadne: an eclipse-based system for tracking the originality of source code
Authors: L. Luo, D. M. Hao, Z. Tian, Y. B. Dang, B. Hou, P. Malkin, S. X. Yang
Venue: IBM Systems Journal (2007)

In this paper we introduce Ariadne, an Eclipse-based system for tracking the originality of source code in collaborative software development environments in which software reuse is a common practice. We describe its architecture within the Eclipse framework, the originality metadata of which it keeps track, and the history clue-the data structure used to implement the tracking mechanism. We also discuss the implementation of the Ariadne client, the main component of the system, and show how digital signatures are used to validate the integrity of the metadata-handling process. We demonstrate the functions of Ariadne in two typical scenarios: tracking of software bugs and generating originality claims for Certificate of Originality reports. Although our Eclipse-based prototype is designed to handle Java source code, our approach can be extended to other kinds of artifacts.
Incremental wavelet importance sampling for direct illumination
Authors: Hao-da Huang, Yanyun Chen, Xing Tong, Wen-cheng Wang
Venue: Proceedings of the 2007 ACM symposium on Virtual reality software and technology (2007)

Most of existing importance sampling methods for direct illumination exploit importance of illumination and surface BRDF. Without taking the visibility into consideration, they can not adaptively adjust the number of samples for each pixel during the sampling process. As a result, these methods tend to produce images with noise in partially occluded regions. In this paper, we introduce an incremental wavelet importance sampling approach, in which the visibility information is used to determine the number of samples at run time. For this purpose, we present a perceptual-based variance that is computed from visibility of samples. In the sampling process, the Halton sample points are incrementally warped for each pixel until the variance of warped samples converges. We demonstrate that our method is more efficient than existing importance sampling approaches.
Relative Position Estimation Using Airport Image from a Camera of Missile-borne
Authors: Dongxue Yue, Xinsheng Huang, Hongli Tan, Qingwei Yang
Venue: Proceedings of the Fourth International Conference on Image and Graphics (2007)

In vision aided terminal inertial navigation system, the camera always attaches rigidly, or straps down, to the body of missile. Because the pitch angle of the missile usually is not constant and varies with time, the optical axis of the camera is not vertical. Then the rectangular border of the runway stripe in horizontal land plane is projected as trapezoid in the image plane. The weak perspective camera model does not destroy the parallel structure of the runway. Using the parallel structure of the runway, weak perspective image of the runway can be achieved from the perspective image of the missile-borne camera. When the length of the runway is known, based on the error position of the feature points of the runway in perspective image and weak perspective image, an algorithm estimating the relative position of missile to the runway is presented in this paper. Theoretical deduction and the results of simulation experiments demonstrate that the method proposed is feasible and performs well.