ppxscal/embedding_network huggingface dataset:
Wireless secrecy in cellular systems with infrastructure-aided cooperation
Authors: Petar Popovski, Osvaldo Simeone
Venue: IEEE Transactions on Information Forensics and Security (2009)

In cellular systems, confidentiality of uplink transmission with respect to eavesdropping terminals can be ensured by creating intentional interference via scheduling of concurrent downlink transmissions. In this paper, this basic idea is explored from an information-theoretic standpoint by focusing on a two-cell scenario where the involved base stations (BSs) are connected via a finite-capacity backbone link. A number of transmission strategies are considered that aim at improving uplink confidentiality under constraints on the downlink rate that acts as an interfering signal. The strategies differ mainly in the way the backbone link is exploited by the cooperating downlink to the uplink-operated BSs. Achievable rates are derived for both the Gaussian (unfaded) and the fading cases, under different assumptions on the channel state information available at different nodes. Numerical results are also provided to corroborate the analysis. Extensions to scenarios with more than two cells are briefly discussed as well. Overall, the analysis reveals that a combination of scheduling and base-station cooperation is a promising means to improve transmission confidentiality in cellular systems.
Unified modeling of service logic with user interfaces
Authors: Frank Alexander Kraemer, Surya Bahadur Kathayat, Rolv Bræk
Venue: Proceeding of the first international workshop on Model driven service engineering and data quality and security (2009)

We describe a method based on UML activities for the unified specification of collaborative service behavior and local user interfaces. The method enables a model-driven development process, which eectively combines the need to express service collaborations involving several components with the need to provide detailed operations for user interfaces. Our service models use activities as the primary building blocks that encapsulate self-contained functionalities. We show, how a complete distributed system can be decomposed into such building blocks, and how this decomposition leads to a natural separation of user interface concerns from service collaboration concerns, and how they may be combined with our event-driven composition mechanisms based on activity parameter nodes. We illustrate our method with a case study of a situated collaborative learning service.
The capacity of epidemic routing in vehicular networks
Authors: Joon Yoo, Sunwoong Choi, Chong-kwon Kim
Venue: IEEE Communications Letters (2009)

In this letter, we present an analytic framework to evaluate the capacity of epidemic routing in vehicular networks. Using this analytic model, we derive the upper and lower-bound of end-to-end delay in epidemic routing. Our analytic results reveal that epidemic routing achieves maximum diversity gain over unicast routing when the vehicular network is partially connected, which is in contrast to the expectation that epidemic routing performs better in disconnected networks. We validate the accuracy of our model through simulations.
Towards the definition of requirements for mixed fact and opinion question answering systems
Authors: Alexandra Balahur, Estér Boldrini, Andrés Montoyo, Patricio Martínez-Barco
Venue: Proceeding of the 1st international CIKM workshop on Topic-sentiment analysis for mass opinion (2009)

The growth of the Social Web led to the birth of new textual genres such as blogs, forums or reviews. Such data sources are extremely relevant because texts pertaining to these categories approach a wide range of topics and are written by people with different social backgrounds. As a consequence, they represent a rich resource that can be exploited to carry out different types of analyses by a whole diversity of entities (potential customers, companies, public figures, political parties, etc.). For this research we created a collection of factoid and opinion questions in Spanish, with the purpose of comparing the performance of an open domain and an opinion QA system. Furthermore, we carried out two separate evaluations for each one of them and thoroughly analysed the results in order to understand the reasons for the problematic cases, thus being able to infer the features that an effective QA system for opinions should have. Our conclusion is that this task requires the use of specialised resources, whose creation for languages other than English is highly necessary.
Modeling of energy storage unit installed in on-site generation facility
Authors: Luis T. Youn, Koung Hee Leem
Venue: Proceedings of the IASTED Asian Conference on Modelling and Simulation (2007)

Under the utility deregulation utility customers can operate on-site generation facilities in parallel with a local utility grid to minimize their energy expenses. The energy storage units can be added into these facilities to further reduce energy costs. This paper studies the mathematical model for the optimal operation of an energy storage unit installed in an on-site generation facility. The proposed model has been developed so that it can be incorporated in the stochastic production costing model that uses the modified Gaussian distribution of a load and a binomial distribution of on-site generation and utility
Comparing categories among geographic ontologies
Authors: Marinos Kavouras, Margarita Kokla, Eleni Tomai
Venue: Computers Geosciences (2005)

Numerous attempts have been made to generate semantic ''mappings'' between different ontologies, or create aligned/integrated ones. An essential step towards their success is the ability to compare the categories involved. This paper introduces a systematic methodology for comparing categories met in geographic ontologies. The methodology explores/extracts semantic information provided by categories' definitions. The first step towards this goal is the recognition of syntactic and lexical patterns in definitions, which help to identify (a) semantic properties such as purpose, location, cover, and (b) semantic relations such as hypernym, part of, has-parts, etc. At the second step, a similarity measure among categories is applied, in order to explore how (the) extracted properties and relations interrelate. This framework enables us to (a) better understand the impact of context in cross-ontology ''mappings'', (b) evaluate the ''quality'' of definitions as to whether they respect mere ontological aspects (such as unambiguous taxonomies), and (c) deal more effectively with the problem of semantic translation among geographic ontologies.
Fair resource sharing for cooperative relay networks using Nash bargaining solutions
Authors: Guopeng Zhang, Hailin Zhang, Liqiang Zhao, Wei Wang, Li Cong
Venue: IEEE Communications Letters (2009)

This letter considers the problem of resource sharing between two selfish nodes in cooperative relay networks. In our system, each node can act as a source as well as a potential relay, and both nodes are willing to achieve an optimal signal-to-noise ratio (SNR) increase by adjusting their power levels for cooperative relaying. We formulate this problem as a two-person bargaining game, and use the Nash bargaining solution (NBS) to achieve a win-win strategy for both nodes. Simulation results indicate the NBS resource sharing is fair in that the degree of cooperation of a node only depends on how much contribution its partner can make to its SNR increase.
Research on Reliable Transport Technology of Tubular Distribution Mobile Wireless Sensor Network
Authors: Zhang Lejun, Zhang Jianpei, Guo Lin, Huang Hua, Yang Yongtian, Sun Pengfei
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

This paper presents a reliable transport technology of tubular distribution Mobile Wireless Sensor Network (MWSN). The combination of GPRS and distance measurement location algorithm is presented to precisely locate sensor nodes. Connection handoff is put forward to support the reliable transport technology. Cluster Node Selection Algorithm and Connection Handoff Node Selection Algorithm are proposed to dynamically arrange the nodes in MWSN. The method is transparent to the sensor node so can be used to many fields.
The design of distributed real-time video analytic system
Authors: Tao Yu, Baoyao Zhou, Qinghu Li, Rui Liu, Weihong Wang, Cheng Chang
Venue: Proceeding of the first international workshop on Cloud data management (2009)

Video has become an indispensable carrier of information and requires extremely computation expensive analysis to understand high level semantics. The computational difficulties in extracting embedded information and bridging the semantic gap present the major challenges in interoperability, scalability and real-time response of video analytic systems. In this paper, we propose a distributed scalable infrastructure VAP (Video Analytic Platform) for supporting real-time video stream analysis. In VAP, the application requirements are represented as a Directed Acrylic Graph (DAG), where nodes stand for video analysis computation modules and links show data flow and dependencies between nodes. VAP leverages UIMA (Unstructured Information Management Architecture) framework as the data flow control engine and multiple commodity databases as the storage and computation resources. The actual executions of video analysis computation modules have been pushed down into database engines to minimize the data movement cost. We initially choose video surveillance in retail store as a representative application domain. As a case study, a prototype system has been developed to achieve fundamental functions of real-time video surveillance, including video capture/store, human detection/tracking and customer shopping trajectory analysis.
Performance analysis of Fridrich-Goljan self-embedding authentication method
Authors: Gabriel Domínguez-Conde, Pedro Comesaña, Fernando Pérez-González
Venue: IEEE Transactions on Information Forensics and Security (2009)

This paper analyzes the performance of the image authentication method based on robust hashing proposed by J. Fridrich and M. Goljan. In this method, both the embedder and the detector generate the watermark from a perceptual digest of the image. Therefore, an accurate performance analysis requires assessing the relation between noise and hash bit errors. Our approach first derives the probability of hash bit error due to watermark embedding and/or the attack, and then uses such probability to derive the probabilities of false positive and false negative.
Asymptotic performance analysis of amplify-and-forward cooperative networks in a Nakagami-m fading environment
Authors: Behrouz Maham, Are Hjørungnes
Venue: IEEE Communications Letters (2009)

This letter analyzes the performance of repetition-based cooperative wireless networks using amplify-and forward relaying. The network consists of a source, R parallel relays, and a destination, and the channel coefficients are distributed as independent, non-identical, Nakagami-m. The approximated average symbol error rate (SER) is investigated. For sufficiently large SNR, this letter derives a close-form average SER when m is an integer. The simplicity of the asymptotic results provides valuable insights into the performance of cooperative networks and suggests means of optimizing them. We also use simulation to verify the analytical results. Results show that the derived error rates are tight approximations particularly at medium and high SNR.
Users' Privacy Issues with E-learning in Library2.0
Authors: Deng Xiaozhao, Ruan Jianhai
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

This article discusses the users' privacy issues when they learn in Libray2.0. The authors classify learners' privacy issues in Library2.0 into four categories: users' personal information, users' seeking behavior privacy, threat from the third party and affiliated links, and leak of users' private documents. In order to protect users' privacy, various privacy-enhancing measures should be adopted. In authors' opinion, privacy protection should not only be approached as a technical concern, but also a social consideration. These measures include privacy protection principle, privacy policy statements, users' anonymity or pseudonymity, technologies methods, and librarians' efforts. Moreover, the authors present that trust is an important concern in e-learning systems in Library2.0. It is of significance for librarians to help users find the appropriate balance between sharing information and protecting privacy. Relevant suggestions are put forward.
Statistics of macrocell-synchronous femtocell-asynchronous users' delays for improved femtocell uplink receiver design
Authors: Ismail Guvenc
Venue: IEEE Communications Letters (2009)

In a typical macrocell network, the mobile users are synchronized to the macrocell base station (mBS), where users further away to the mBS transmit their signals earlier. In such a network, the signals of the macrocell users arrive at a femtocell base station (fBS) asynchronously, which may yield interference problems such as inter-carrier-interference in orthogonal frequency domain multiple access (OFDMA) systems. In this letter, statistics of the arrival times of macrocell-synchronous femtocell-asynchronous mobile users' signals to an fBS is derived (conditioned on the fBS-mBS distance), and its implications on the femtocell uplink receiver design are briefly discussed.
Real-domain decoder for full-rate full-diversity STBC with multidimensional constellations
Authors: Heunchul Lee, Jungho Cho, Jong-kyu Kim, Inkyu Lee
Venue: IEEE Transactions on Communications (2009)

In this letter, we present a new maximum likelihood (ML) decoding algorithm for space time block codes (STBCs) that employ multidimensional constellations. We start with a lattice representation for STBCs which transforms complex channel models into real matrix equations. Based on the lattice representation, we propose a new decoding algorithm for quasi-orthogonal STBCs (QO-STBC) which allows simpleML decoding with performance identical to the conventional ML decoder. Multidimensional rotated constellations are constructed for the QO-STBCs to achieve full diversity. As a consequence, for quasi-orthogonal designs with an arbitrary number of transmit antennas N (N ≥ 4), the proposed decoding scheme achieves full rate and full diversity while reducing the decoding complexity from O(McN/2) to O(McN/4) in a Mc-QAM constellation.
Model of three-tank liquid system with air bubbles in pipes
Authors: Petr Chalupa, Vladimir Bobál
Venue: Proceedings of the IASTED Asian Conference on Modelling and Simulation (2007)

This paper describes the process of development of a mathematical model of three-tank liquid system. The DTS200 Three-Tank-System was used as a real equipment to be modelled. This system consists of three cylindrical water tanks, six valves, two water pumps, pipes and water reservoir. The model based on ideal properties of individual components is relatively simple and is derivation using differential equations is straightforward. But the model proposed in this paper incorporates real properties and behaviour of individual parts. The main difference between ideal three-tank system and this real plant consists in presence of air bubbles in pipes. Flooding the bubbles out leads to dramatic change of plant parameters and thus the system can be considered as multi-model or multi-parametric. The effect of air bubbles is studied static. The proposed model was verified by comparison with the real DTS200 system. Described problems, which occurred during model development, are general and similar problems occur in most model-development processes.
Lyapunov theory-based multilayered neural network
Authors: King Hann Lim, Kah Phooi Seng, Li-Minn Ang, Siew Wen Chin
Venue: IEEE Transactions on Circuits and Systems II: Express Briefs (2009)

This brief presents a Lyapunov theory-based weight adaptation scheme for a multilayered neural network (MLNN) mainly used to classify a multiple-input-multiple-output (MIMO) problem. Initially, the MLNN system is linearized using Taylor series expansion. Then, the weight adaptation scheme is designed based on the Lyapunov stability theory to iteratively update the weight. In the design, the Lyapunov function has to be well selected to construct an energy space with a single global minimum. Hence, the Lyapunov theory-based MLNN acts as a MIMO classifier for face recognition. Analysis and discussion on Lyapunov properties of the proposed classifier are included. The performance of the proposed technique is tested on the Olivetti Research Laboratory database for face classification, and some comparisons with existing conventional techniques are given. Simulation results have revealed that our proposed system achieved better performance.
On the workload and 'phaseload' allocation problems of short reliable production lines with finite buffers
Authors: M. I. Vidalis, C. T. Papadopoulos, C. Heavey
Venue: Computers and Industrial Engineering (2005)

Serial flow or production lines are modeled as tandem queueing networks and formulated as continuous-time Markov chains to investigate how to maximize throughput or minimize the average work-in-process (WIP) when the total service time and the total number of service phases among the stations are fixed (these are the workload and 'phaseload' allocation problems, respectively). This paper examines both the effect of the kind of service time distribution on the optimal workload allocation in order to maximize throughput or minimize the average WIP of perfectly reliable production lines. The new approach of this work is the differentiation of the number of service phases of the service time distribution which is assumed to be of phase type at all stations of the flow line and the placement of storage space (buffers) between any two successive stations in order to examine the effect of these factors to the form of the optimal workload vector t and the optimal service phase vector ph.
A Novel Reversible Data Hiding Based on Exploiting Modification Direction Algorithm
Authors: Kang-Kang Chen, Jian-Jun Wang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

In this paper, a novel reversible data hiding technique based on exploiting modification direction algorithm is proposed. First, binary secret messages are converted into a sequence of data in a 5-ary notational system. Then two equal gray images are used as cover objects. In accordance with Human Visual System, the secret messages are embedded into each pair of the integer wavelet coefficients of the two gray images. Furthermore, to avoid overflow problem, histogram modification technology is used. Experiment results show that it can obtain 1 bit per pixel (bpp) in many images when the data is embedded in the single-layer. At the same time, each of the two images achieves high capacity while keeping low distortion.
ReLOAD: Real Laboratories Operated at a Distance
Authors: Ben Hanson, Peter Culmer, Justin Gallagher, Kate Page, Elizabeth Read, Andrew Weightman, Martin Levesley
Venue: IEEE Transactions on Learning Technologies (2009)

Remote laboratories are increasingly being developed to provide students with Web-based access to real laboratory experiments. The demonstrable advantages (e.g., increased accessibility) are tempered by concerns that remote access will be substituted for "hands-on” practical work, and reduce interaction between students. We argue that these concerns can be avoided if remote labs are used appropriately, as with any other pedagogical method. We review studies that have made direct comparisons between remote and hands-on labs, and analyze the important similarities and differences by considering the students' physical and psychological experiences. A case study is presented: "ReLOAD”, which has been in operation since 2001 providing remote operation of dynamic experiments in Mechanical Engineering, featuring personalized experiments, immediate automated grading and feedback, and collaborative learning. We present results from online surveys and from focus groups of students' opinions and experiences with hands-on and remote labs. Drawing from this experience, the characteristic properties of remote-access labs are investigated from a pedagogical perspective. We find that many of the differences and similarities between the modalities are controllable factors, to greater or lesser extents, and provide examples of remote labs offering some valuable educational advantages which are not possible with traditional labs.
Symbol timing recovery for CPM with correlated data symbols
Authors: Prashanth Chandran, Erik Perrins
Venue: IEEE Transactions on Communications (2009)

We consider symbol timing recovery for continuous phase modulations (CPMs) with correlated data symbols. A popular example of such a scheme is shaped offset quadrature phase-shift keying (SOQPSK). We propose an extension to an existing non-data-aided (blind) timing error detector (TED) to make it compatible with such modulation schemes. The merits of the modified TED are demonstrated by comparing its performance with and without taking the data correlation into account. As a further modification, we show that a quantization scheme can be used to yield an extremely low-complexity version of the system with only negligible performance losses. The S-curve of the proposed quantized TED is given, which rules out the existence of false lock points. The proposed scheme shows great promise in a wide range of applications due to its low complexity, its lack of false lock points, and its blind nature; such applications include timing recovery for noncoherent detection schemes and false lock detectors.
Why are macros not used? A brief review and an approach for improving training
Authors: Eldad Yechiam
Venue: Computers Education (2006)

Macros are programming scripts that can be generated by recording users' actions. It appears that despite their potential for reducing monotonous work, they are under-used by non-programmers. The present paper reviews the literature on the use of macros. Included is an original study that examines the effect of adding the ''search and replace'' option as an alternative to using macros in a hypothetical task. It is concluded that the problem of not using macros is due, in part, to motivational biases. Motivational biases emerge even after macro training because simpler alternatives that ''compete'' with macros are more attractive to users. These biases can be addressed through the training process. Some training principles for a strategically competitive real-world environment are presented.
An Improved Application MAC Model for Cross-Layer Optimized Wireless Video
Authors: Hai-qing Du, Yixi Liu, Chang Guo, Yong Liu
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

Cross-layer optimization has been recently proposed for improving the performance of real-time video transmission over 802.11 WLAN. In this paper, an improved IEEE 802.11 WLAN analytical model under unsaturated traffic conditions was proposed. It adapts Distributed Coordination Function (DCF) models to handle all the states. Two special states were added for this model, one is the idle state, which means the MAC queue is empty, and the other is D state, which means if the medium is sensed to be unoccupied for a time interval greater than the DIFS, then the station proceeds with the packet transmission. The improved model can be used to assist the cross-layer optimization for real-time wireless transmission though realistically predicting the interactions between layers.