ppxscal/embedding_network huggingface dataset:
Space-time modeling of traffic flow
Authors: Yiannis Kamarianakis, Poulicos Prastacos
Venue: Computers Geosciences (2005)

This paper discusses the application of space-time autoregressive integrated moving average (STARIMA) methodology for representing traffic flow patterns. Traffic flow data are in the form of spatial time series and are collected at specific locations at constant intervals of time. Important spatial characteristics of the space-time process are incorporated in the STARIMA model through the use of weighting matrices estimated on the basis of the distances among the various locations where data are collected. These matrices distinguish the space-time approach from the vector autoregressive moving average (VARMA) methodology and enable the model builders to control the number of the parameters that have to be estimated. The proposed models can be used for short-term forecasting of space-time stationary traffic-flow processes and for assessing the impact of traffic-flow changes on other parts of the network. The three-stage iterative space-time model building procedure is illustrated using 7.5min average traffic flow data for a set of 25 loop-detectors located at roads that direct to the centre of the city of Athens, Greece. Data for two months with different traffic-flow characteristics are modelled in order to determine the stability of the parameter estimation.
Cloud Computing: Will Commodity Services Benefit Users Long Term?
Authors: H. Gilbert Miller, John Veiga
Venue: IT Professional (2009)

The attention the IT community has given cloud computing recently rivals that given to American Idol judges by the public. This magazine alone dedicated its March/April 2009 issue and significant other space throughout the year to the topic. The introduction to IT Professional's March/April issue asked whether cloud computing offers anything different; after a review of both the basics and the challenges, the authors respond to that question.
Patent claim decomposition for improved information extraction
Authors: Peter Parapatics, Michael Dittenbach
Venue: Proceeding of the 2nd international workshop on Patent information retrieval (2009)

In several application domains research in natural language processing and information extraction has spawned valuable tools that support humans in structuring, aggregating and managing large amounts of information available as text. Patent claims, although subject to a number of rigid constraints and therefore forced into foreseeable structures, are written in a language even good parsing algorithms tend to fail miserably at. This is primarily caused by long and complex sentences that are a concatenation of a multitude of descriptive elements. We present an approach to split patent claims into several parts in order to improve parsing performance for further automatic processing.
Exact error probability analysis of rectangular QAM for single-and multichannel reception in Nakagami-m fading channels
Authors: Amine Maaref, Sonia Aïssa
Venue: IEEE Transactions on Communications (2009)

In this contribution, we derive exact closed-form expressions for the average symbol error probability (SEP) of arbitrary rectangular quadrature amplitude modulation (QAM) for single- and multichannel diversity reception over independent but not-necessarily identically distributed Nakagami-m fading channels. The diversity branches may hence exhibit identical or distinctive power levels and their associated Nakagami indexes need not be the same. Our work extends previous results pertaining to nondiversity reception of M-ary rectangular QAM over Rayleigh fading channels and multichannel reception of M- ary square QAM over Nakagami-m fading channels. For a given number L of diversity branches and a corresponding set of arbitrary real-valued Nakagami indexes not less than 1/2, our SEP results are expressed in terms of Gauss's hypergeometric function 2F1 and Lauricella's multivariate hypergeometric function FD(L) of L variables, both of which can be efficiently evaluated using standard numerical softwares.
Primary network cognition with spatial diversity signature
Authors: Dae-Young Seol, Tae-Won Yune, Gi-Hong Im
Venue: IEEE Communications Letters (2009)

The identification of primary networks improves efficiency in dynamic spectrum access. We propose a spatial diversity signature for the primary signal detection, which exploits the structure of space-time or space-frequency codeword based on Alamouti scheme. The signature pattern informs the secondary user which network transmits the primary signal and enables to maintain an experiential database for each primary network. The proposed scheme provides reliable detection and network identification performance over frequency-selective fading channels in low signal-to-noise ratio regimes, without sacrificing the data rate of primary system.
A pocket computer program for normal values of selected lung function tests in children and young adults
Authors: Jacques Sahakian
Venue: Computers in Biology and Medicine (1981)

Assessment of selected pulmonary functions can supply objective data useful for the overall management of respiratory problems in children. Determination of peak expiratory flow, FEV"1, FVC, and MMEF are readily available in most hospitals, and in the offices of an increasing number of general practitioners and paediatricians. Modern equipments output patient's performance as a percentage of the average expected but confidence limits are lacking and the programmed norms for children are inadequate. This article describes the use of a pocket computer for a quick display of the above parameters based on recently published prediction formulae.
Multidimensional binary indexing for neighbourhood calculations in spatial partition trees
Authors: José Poveda, Michael Gould
Venue: Computers Geosciences (2005)

We present a binary array encoding (location arrays) of the nodes in a spatial partition tree representing spaces of dimension k. This framework facilitates tree traversal for optimizing access speed, and also supports simplified calculation of the neighbourhood of a subinterval of a particular partition. After defining the encoding we present a neighbour determination algorithm which extends work carried out by Samet, Goodchild and others on quadtrees, of particular interest when managing large data volumes during real-time terrain flyovers. The primary extension is that the encoding and the neighbour determination algorithm extend to arbitrary dimensions beyond the 2-d quadtree case.
Mathematical model for low-rate DoS attacks against application servers
Authors: Gabriel Maciá-Fernández, Jesús E. Díaz-Verdejo, Pedro García-Teodoro
Venue: IEEE Transactions on Information Forensics and Security (2009)

In recent years, variants of denial of service (DoS) attacks that use low-rate traffic have been proposed, including the Shrew attack, reduction of quality attacks, and low-rate DoS attacks against application servers (LoRDAS). All of these are flooding attacks that take advantage of vulnerability in the victims for reducing the rate of the traffic. Although their implications and impact have been comprehensively studied, mainly by means of simulation, there is a need for mathematical models by which the behaviour of these sometimes complex processes can be described. In this paper, we propose a mathematical model for the LoRDAS attack. This model allows us to evaluate its performance by relating it to the configuration parameters of the attack and the dynamics of network and victim. The model is validated by comparing the performance values given against those obtained from a simulated environment. In addition, some applicability issues for the model are contributed, together with interpretation guidelines to the model's behaviour. Finally, experience of the model enables us to make some recommendations for the challenging task of building defense techniques against this attack.
Area-efficient ESD-transient detection circuit with smaller capacitance for on-chip power-rail ESD protection in CMOS ICs
Authors: Shih-Hung Chen, Ming-Dou Ker
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

The RC-based power-rail electrostatic-discharge (ESD) clamp circuit with big field-effect transistor (BigFET) layout style in the main ESD clamp n-channel metal-oxide-semiconductor (NMOS) transistor was widely used to enhance the ESD robustness of a CMOS IC fabricated in advanced CMOS processes. To further reduce the occupied layout area of the RC in the power-rail ESD clamp circuit, a new ESD-transient detection circuit realized with smaller capacitance has been proposed and verified in a 0.13-µm CMOS process. From the experimental results, the power-rail ESD clamp circuit with the new proposed ESD-transient detection circuit can achieve a long-enough turn-on duration and higher ESD robustness under ESD stress condition, as well as better immunity against mistrigger and latch-on event under the fast-power-on condition.
Study on the Pedestrian Network Model Oriented to Pedestrian Navigation
Authors: Yuefeng Liu, Ting Liu, Min Lu, Huabo Sun
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

Walking is one of the most elementary traffic modes nowadays. The more frequently the road network changes, the more urgent the desire of pedestrian navigation becomes. To realize pedestrian navigation, pedestrian network model must be established first. In this paper, we propose the rules how to build pedestrian network, and description of the logic model and attribute. Based on these theories, we also propose the means of connecting the pedestrian network with public transport network and vehicle network.
Use of airborne LiDAR and aerial photography in the estimation of individual tree heights in forestry
Authors: Juan C. Suárez, Carlos Ontiveros, Steve Smith, Stewart Snape
Venue: Computers Geosciences (2005)

This paper describes the use of aerial photography and airborne LiDAR to estimate individual tree heights in forest stands. The advantages and disadvantages in the use of LiDAR systems are revised and a data fusion analysis with digital aerial photography is proposed. An example of the use of these techniques in a forested area in Scotland is presented. An algorithm has been developed to extract a high-resolution digital terrain model of the bare ground. This provided a tree canopy model as the difference between the laser first pulse and the model of the underlying terrain. Information about individual trees was obtained by image segmentation and classification. This analysis provided a good method of estimating individual tree canopies and heights.
Digital image source coder forensics via intrinsic fingerprints
Authors: W. Sabrina Lin, Steven K. Tjoa, H. Vicky Zhao, K. J. Ray Liu
Venue: IEEE Transactions on Information Forensics and Security (2009)

Recent development in multimedia processing and network technologies has facilitated the distribution and sharing of multimedia through networks, and increased the security demands of multimedia contents. Traditional image content protection schemes use extrinsic approaches, such as watermarking or fingerprinting. However, under many circumstances, extrinsic content protection is not possible. Therefore, there is great interest in developing forensic tools via intrinsic fingerprints to solve these problems. Source coding is a common step of natural image acquisition, so in this paper, we focus on the fundamental research on digital image source coder forensics via intrinsic fingerprints. First, we investigate the unique intrinsic fingerprint of many popular image source encoders, including transform-based coding (both discrete cosine transform and discrete wavelet transform based), subband coding, differential image coding, and also block processing as the traces of evidence. Based on the intrinsic fingerprint of image source encoders, we construct an image source coding forensic detector that identifies which source encoder is applied, what the coding parameters are along with confidence measures of the result. Our simulation results show that the proposed system provides trustworthy performance: for most test cases, the probability of detecting the correct source encoder is over 90%.
Hierarchical Fast Clustering Method for fMRI Feature Reconstruction
Authors: Xiaomin Li, Wei Lin, Shuanghua Huang
Venue: Proceedings of the 2009 Second International Symposium on Knowledge Acquisition and Modeling - Volume 01 (2009)

In order to solve the feature reconstruction problem of fMRI time series, hierarchical fast clustering method (HFCM) is proposed. The reconstruction of features can be thought as finding the task-related region of interest (ROI) in the human brain fMRI in order to eliminate information redundary. HFCM takes advantage of optimizing the hierarchical structure and tuning weights of different kind of distances. Comparing with the existing reconstruction methods, e.g. K-means and t-test, HFCM saves more than 62% running time, on condition of ensuring the precision of task-related estimating.
LSP partial spatial-protection in MPLS over WDM optical networks
Authors: Qin Zheng, Mohan Gurusamy
Venue: IEEE Transactions on Communications (2009)

We consider Label Switched Path (LSP) protection for connections with various protection grade requirements in multi-protocol label switching (MPLS) over wavelength division multiplexing (WDM) optical networks. In full protection, bandwidth needs to be reserved for the backup LSP to protect the failure of any fiber along the primary LSP. In this paper, we study the problem of partial spatial-protection (PSP) where bandwidth is reserved for the backup LSP to protect the failure of a subset of fibers traversed by the primary LSP to satisfy the specified protection grade. We formulate the optimal LSP PSP problem as an ILP and identify three suboptimal problems. For each suboptimal problem, an exhaustive search algorithm and a heuristic are developed. We analyze the probability that a connection can be restored upon a fiber failure and find that it is higher than or equal to the protection grade specified. We also develop a failure recovery protocol which specifies recovery operations upon failure and determines whether a connection can be recovered if the failed fiber is one of its unprotected fibers. Through extensive simulation experiments, we demonstrated that the proposed LSP PSP algorithms perform better than shared LSP protection in blocking probability and resource efficiency.
Asymptotic spectral behavior of spectrally precoded OFDM signal with arbitrary input statistics
Authors: Hao-Ming Chen, Char-Dir Chung
Venue: IEEE Communications Letters (2009)

In this letter, we study the asymptotic spectral behavior of the spectrally precoded orthogonal frequency-division multiplexing (SP-OFDM) signal with arbitrary input statistics. It is shown that all constraints and spectral precoders previously developed for SP-OFDM with independent and identically distributed and zero-mean data provide fast decaying spectral sidelobes for SP-OFDM with arbitrary input statistics.
A cognitive tool for teaching the addition/subtraction of common fractions: a model of affordances
Authors: Siu Cheung Kong, Lam For Kwok
Venue: Computers Education (2005)

The aim of this research is to devise a cognitive tool for meeting the diverse needs of learners for comprehending new procedural knowledge. A model of affordances on teaching fraction equivalence for developing procedural knowledge for adding/subtracting fractions with unlike denominators was derived from the results of a case study of an initial prototype of a graphical partitioning model. Offering affordances in our model makes available profitable spaces for learners to interact in ways that meet their needs. This model of affordances was evaluated by a pre-test-post-test control group design to study the performance of the experimental group in learning with the model. Results of the study indicated that the model afforded learners, with various abilities for learning, knowledge of fraction equivalence. The key for mediating the generation of procedural knowledge for adding/subtracting fractions with unlike denominators in working with our cognitive tool was the concept of fraction equivalence and the capability of computing this.
Channel-based detection of Sybil attacks in wireless networks
Authors: Liang Xiao, Larry J. Greenstein, Narayan B. Mandayam, Wade Trappe
Venue: IEEE Transactions on Information Forensics and Security (2009)

Due to the broadcast nature of the wireless medium, wireless networks are especially vulnerable to Sybil attacks, where a malicious node illegitimately claims a large number of identities and thus depletes system resources. We propose an enhanced physical-layer authentication scheme to detect Sybil attacks, exploiting the spatial variability of radio channels in environments with rich scattering, as is typical in indoor and urban environments. We build a hypothesis test to detect Sybil clients for both wideband and narrowband wireless systems, such as WiFi and WiMax systems. Based on the existing channel estimation mechanisms, our method can be easily implemented with low overhead, either independently or combined with other physical-layer security methods, e.g., spoofing attack detection. The performance of our Sybil detector is verified, via both a propagation modeling software and field measurements using a vector network analyzer, for typical indoor environments. Our evaluation examines numerous combinations of system parameters, including bandwidth, signal power, number of channel estimates, number of total clients, number of Sybil clients, and number of access points. For instance, both the false alarm rate and the miss rate of Sybil attacks are usually below 0.01, with three tones, pilot power of 10 mW, and a system bandwidth of 20 MHz.
A Probe into the Concept of Multimedia
Authors: Song Chunhui, Wu Shulei, Chen Huandong, Zhan Jinmei, Chen Juntao
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

Nowadays the various understanding of the concept of multimedia has a great influence on the study and application of multimedia. In order to improve the understanding of the concept of multimedia, this paper probes into the essential meaning of multimedia through the analysis of its word structure, the internal properties of its concept, historical background of its origin and its essential properties.
Covert Timing Channel with Distribution Matching
Authors: Guangjie Liu, Jiangtao Zhai, Yuewei Dai, Zhiquan Wang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

Network covert channel is a communication fashion that uses the redundancy in network protocols to transfer information. The goal of covert channel is reliably transmit more information undetectably. In this paper, a simple covert timing channel with distribution matching is proposed. The approach processes the network traffic as fixed-length fragment and obtains the histogram of the delays, then uses the binary coding method to embed the message bits. Experimental results show that our method works well.
Convergence analysis of teleoperation systems with unsymmetric time-varying delays
Authors: Chang-Chun Hua, Peter X. Liu
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

This brief addresses the stability problem of a class of teleoperation systems. Compared with previous work, the communication delays are assumed to be both time varying and unsymmetric. We consider the usual case that the master and the slave manipulators are coupled using a proportional-derivative (PD) control strategy. By using a new Lyapunov-Krasovskii functional, we show that the master-slave teleoperation system is asymptotically stable under specific linear matrix inequality (LMI) conditions. With the given PD parameters, the values of allowable maximum time delays can be obtained. Finally, simulations are performed to show the effectiveness of the proposed method.
Perceptual Hash Functions Based on Contourlet Transform and Singular Value Decomposition
Authors: Ting-ting Zhu, Dong-hui Hu, Li-na Wang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

Perceptual image hashing maps an image to a fixed length binary string based on the image's appearance to the human eye, and has applications in content authentication, watermarking and anti-piracy search. In this paper, we present a hash scheme that is robust and secure to non-malicious manipulation and sensitive to the malicious tampering. The algorithm is based on contourlet transform and singular value decomposition. Due to Contourlet is a "true" two dimensional transform representation for images and the singular values of the image are simple and have good stability, we transform image in the contourlet domain and decompose the singular value of low frequency component. The final image hash is obtained by applying binary quantization to the singular value. Experimental result are presented to show the effectiveness of the proposed scheme.
Nutrition Catering System of Hospitals Based on Web Services Integrating Wireless and Wired Network
Authors: Hongzhen Xu, Hua Qin, Maolan Li
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

The web services technology has been emerged as a set of standards for publishing, discovering, and composing independent services in an open network. While the rapid development in wireless communication technologies is greatly changing the way people access and work with information. Mobile computing system based on web services now supports advanced methods for application integration through distributed network computing environments. This paper presents an integration of wireless communication, wired communication and web services technologies to implement a nutrition catering system of hospitals, in which patients can access to the servers and catering ordering functions through both desktop PCs and mobile devices such as Pads over a wired/wireless integrated local area network. To sure the security of the system, the secure web service architecture and some security strategies to ensure mobile communication security are discussed. Web services-based wireless applications on mobile devices provide a means of convenience, improving efficiency and accuracy by saving time, reducing human errors, etc.
Designing smart home interfaces for the elderly
Authors: Zoraida Callejas, Ramón López-Cózar
Venue: Issue 95 (September 2009) (2009)

In this paper we highlight the importance of tailoring the design of dialogue systems to the targeted user group. We propose a human-centered design cycle and report the results from a survey conducted among the intended users of a smart home for the elderly.