ppxscal/embedding_network huggingface dataset:
Bees algorithm for interference suppression of linear antenna arrays by controlling the phase-only and both the amplitude and phase
Authors: K. Guney, M. Onay
Venue: Expert Systems with Applications: An International Journal (2010)

In this paper, bees algorithm (BA) has been used for null steering in the antenna radiation pattern by controlling the phase-only and the complex weights (both the amplitude and phase) of the array elements. The BA is an optimization algorithm inspired by the behavior of the honey bees to find the optimal way of harvesting food resources around the hive. Simulation results for Chebyshev patterns with the imposed single, multiple and broad nulls are given to show the effectiveness of the proposed method. The sensitivity of the nulling patterns due to small variations of the element phases is also investigated.
Animating recursion as an aid to instruction
Authors: Derek Wilcocks, Ian Sanders
Venue: Computers Education (1994)

This paper presents a method for overcoming one of the most difficult problems in teaching programming to first-year university students, namely recursion. It is established that what is required to understand recursion is an abstracted mental model of recursive flow of control. The model which is deemed most suitable for the purposes of this research is the copies model of recursion. In this model recursive instantiations are seen as copies of the recursive function. In order to present this model to students, a program (as opposed to data or algorithm) animator is employed. This animator takes any Pascal program containing a recursive function and presents the student with a dynamic copies model of the recursive function.
Effects of channel estimation error on array processing based QO-STBC coded OFDM systems
Authors: Haixia Zhang, Dongfeng Yuan, Hsiao-Hwa Chen, Josef A. Nossek
Venue: IEEE Communications Letters (2009)

This letter addresses the issues on performance degradation caused by channel estimation error of quasi-orthogonal space-time block (QO-STBC) coded OFDM systems employing array processing decoder. The Least Square (LS) channel estimator is employed to obtain the required channel state information (CSI). Taking mean square error (MSE) as a performance metric, we evaluate the performance of the LS estimator in MIMO-OFDM systems over frequency selective channels, and its impact on symbol error rate (SER) using both analysis and simulations.
Differential reduction to the pole
Authors: G. R. J. Cooper, D. R. Cowan
Venue: Computers Geosciences (2005)

Due to the dipolar nature of the geomagnetic field, magnetic anomalies located anywhere other than at the magnetic poles are asymmetric even when the magnetic source distribution is symmetrical. This complicates interpretation. Pole reduction (RTP) takes the anomaly, as measured at any latitude, and transforms it into that which would have been measured if the body had been laid at the magnetic pole i.e. the area where the field inclination is vertical and the anomalies from symmetrical bodies are symmetrical. The algorithm is usually applied in the frequency domain which has the advantage of being computationally fast, but the disadvantage of restricting the application of the algorithm to regions possessed of constant geomagnetic inclination and declination. Various frequency domain algorithms have been devised to solve this problem, but all have problems of one form or another. A simple algorithm for RTP is suggested here that employs a Taylor series expansion in the space domain (other work has used the Taylor series expansion approach in the frequency domain). The algorithm is demonstrated on synthetic data and on aeromagnetic data from the Northern Territory, Australia.
Authentication Based on Signaling Token Piggybacking
Authors: Qiwei Jin, Tianjing Xu
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 01 (2009)

In order to solve the question of identify of H.323 video conferencing system, this paper presents an authentication mechanism based on signaling token piggybacking. The mechanism is an authentication scheme based on public key, and can divide into two parts: public key registration and check of the identity which happens in the establishment of conference. This paper expatiates the authentication mechanism based on signaling token piggybacking, analyzes in theory and in experimental comparison, and verifies the conclusion that the authentication based on signaling token piggybacking performs rapidly and costs little time to achieve authentication and ensure the system safe.
The design and application of a web-based self- and peer-assessment system
Authors: Yao-Ting Sung, Kuo-En Chang, Shen-Kuan Chiou, Huei-Tse Hou
Venue: Computers Education (2005)

This study describes the web-based self- and peer-assessments system, or the Web-SPA, which has been shown to provide teachers with a flexible interface with which to arrange various self- and peer-assessment procedures. Secondly, this study examines the effects of the application of the progressively focused self- and peer-assessment (PFSPA) procedures that are made available with the Web-SPA. In an evaluative study with 76 third-graders (14 or 15 years old) of junior school, it has been found that the upon completion of the PFSPA activities, the students demonstrate greater objectivity in their self-assessment scores; it has also been shown that significant consistency is found between the students' self- and peer-assessments results and that the assessment results of teachers. Furthermore, the quality of the students' works improved after the assessment activities.
A comparison of two object-oriented programming environments for novices
Authors: Stelios Xinogalos, Maya Satratzemi, Vassilios Dagdilelis
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

Teaching Object Oriented Programming (OOP) to novices is quite problematic. In order to overcome the difficulties various teaching approaches have been proposed. In this paper, we present our findings regarding two teaching approaches based on two different environments: (i) teaching with the Educational Programming Environment of BlueJ; (ii) teaching with the Programming Microworld of objectKarel. The presented results are based on students' answers to a questionnaire that was given to students at the last lesson of the two studies, and refer exclusively to the comprehension of the most basic concepts of OOP: objects and classes. The analysis of the results shows that the combined use of the two environments seems to constitute a better didactic strategy from just using one of the two environments.
Study on the Diversity of E-Commerce Ecosystem and an Example
Authors: Xinjian Li, Qihua Liu, Jingjing Xie
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

Ecosystem theories have been applied in several domains. As the E-Commerce is a kind of business, we can use the business ecosystem theory in the researches of E-Commerce. However, the researches on E-Commerce ecosystem are far beyond mature, which only in the stage of metaphor. This paper builds the framework of E-Commerce ecosystem, which puts up a foundation for the future researches. Then the framework of an ecological characteristic-diversity has been built, which introduces the researching content and aspects of diversity in E-Commerce ecosystem. At the same time, the evolution of E-Commerce ecosystem has been described on the basis of complex systems.
Generating data quality rules and integration into ETL process
Authors: Jasna Rodic, Mirta Baranovic
Venue: Proceeding of the ACM twelfth international workshop on Data warehousing and OLAP (2009)

Many data quality projects are integrated into data warehouse projects without enough time allocated for the data quality part, which leads to a need for a quicker data quality process implementation that can be easily adopted as the first stage of data warehouse implementation. We will see that many data quality rules can be implemented in a similar way, and thus generated based on metadata tables that store information about the rules. These generated rules are then used to check data in designated tables and mark erroneous records, or to do certain updates of invalid data. We will also store information about the rules violations in order to provide analysis of such data. This could give a significant insight into our source systems. Entire data quality process will be integrated into ETL process in order to achieve load of data warehouse that is as automated, as correct and as quick as possible. Only small number of records would be left for manual inspection and reprocessing.
Research on Secure Digital Content Distribution for Peer to Peer E-commerce Applications
Authors: Xi Chen, Shiguo Lian
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 01 (2009)

To resolve network congestion and other problems in electronic commerce (e-commerce) applications, such as digital content distribution in e-commerce, the e-commerce applications distributed systems based on the traditional paradigm are nowadays replaced by peer-to-peer (P2P) systems. Peer to peer technology has a lot of advantages for e-commerce applications especially in digital content distribution field. For commerce applications, the security and P2P rights management become more and more urgent. New schemas and solutions for P2P e-commerce applications' security and right management, which are expected to function automatically or semi-automatically, should be proposed. In this paper, a secure digital content distribution scheme is presented, which can trace illegal distributors in Peer to Peer e-commerce applications. In this scheme, the encrypted content is decrypted into different copy under the control of a fingerprint and encryption key at the peer side. Thus, each decrypted media copy contains unique information that identifies the peer. For the decryption operation and fingerprint embedding operation are combined together, which avoids the leakage of clear media content. Additionally, these operations are implemented by the peer, which makes the scheme compliant with existing Peer to Peer Digital Rights Management (DRM) systems and very proper for P2P digital content distribution e-commerce applications, performance evaluation is also included.
A New Fractal Watermarking Scheme Based on Image Normalization
Authors: Xi-kui Miao, Jin-guang Sun, Yu-han Zhang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

Geometric attacks are the challenging problems for most image watermarking today. Such attacks are very simple to implement, yet they can defeat most of the existing watermarking algorithms without causing serious perceptual image distortion. In the paper, a new fractal watermarking scheme robust to geometric attacks is proposed based on image normalization and fractal coding. Firstly, the geometrically invariant space is constructed by using image normalization. Then, a significant region is obtained from the normalized image by utilizing the invariant centroid theory. Finally, the watermark is embedded into the self-similar blocks DCT transformed of the significant region by fractal. Experimental results show that the scheme is not only invisible and robust to common signals processing such as median filtering, sharpening, noise adding, JPEG compression, etc, but also robust to the geometric attacks such as affine transform, local geometric distortion, etc.
Efficient approach for incremental Vietnamese document clustering
Authors: Tu Anh Nguyen Hoang, Kiem Hoang
Venue: Proceeding of the eleventh international workshop on Web information and data management (2009)

In this paper, we present how to use graph model for clustering Vietnamese document incrementally. Graph based model allows us to model completely the structure of not only each document but also the whole collection of documents. The graph structure is easily updated when there is a new document. When building the graph incrementally we can identify representative subgraph features, which are later used for calculating hybrid pair-wise document similarity. These subgraph features make clustering process less sensitive to the Vietnamese word segmentation step. Based on the hybrid similarity measure, the documents are groups into clusters on-the-fly without any assumptions on the number of clusters and without retrieving previous documents.
Generalized eigen-combining algorithm for adaptive array systems in a co-channel interference environment
Authors: Seungheon Hyeon, Seungwon Choi
Venue: IEEE Communications Letters (2009)

This paper presents a generalized eigen-combining algorithm for an adaptive array system that provides a diversity gain in angular spread, and a maximum signal-to-interference ratio (SIR) in the presence of strong interference. The proposed technique generates the maximum ratio of signal components distributed in the spatial channel subspace using channel bases that span the signal subspace and nullify the interference. Through extensive computer simulations, it is shown that the proposed algorithm represents a breakthrough in preventing performance saturation caused by strong co-channel interference.
An Extended Subsampling Based Reversible Data Hiding Method
Authors: Xiao Yi Yu, Aiming Wang
Venue: Proceedings of the 2009 International Conference on Multimedia Information Networking and Security - Volume 02 (2009)

An improved reversible data hiding scheme, which can restore the original image completely after data extraction, is presented in this paper. The method is an extended subsampling reversible data hiding method. Compared with the previous method, the proposed method has much more room for data hiding. The data hiding capacity is much higher than the previous method while the visual distortion keep the same as the previous method. Experimental results show that the proposed algorithm provides high embedding capacity while keeping the distortions low
Towards an open architecture for vector GIS
Authors: Robert I. Dunfey, Bruce M. Gittings, James K. Batcheller
Venue: Computers Geosciences (2006)

A range of open source software tools are now available to the Geographical Information Systems (GIS) analyst. However these tools are not necessarily interoperable and rarely significantly interoperable with proprietary systems. The open architectures, which have been developed for web-oriented systems, together with those proposed by the Open Geospatial Consortium (OGC), suggest that an open GIS architecture could be developed as an alternative to proprietary systems. The architecture would use open source components to store, translate, analyse, render and visualise GI data and would escape many of the problems of monolithic systems. Particularly what is proposed permits the loose coupling of any number of components and data stores in a manner that is both open and flexible. This paper proposes such an architecture and focuses on determining the suitability of Scalable Vector Graphics (SVG), an open vector-oriented eXtensible Markup Language (XML) grammar, as a significant component of such architecture. SVG is shown as an effective means of rendering GI data, not least because of its compatibility with the WC3 Document Object Model (DOM), permitting GIS-specific client tools to be written and transmitted to the web browser along with the SVG pages. While realising that the technology is in its infancy, the conclusion reached is that SVG currently provides a powerful solution and has enormous future potential.
Optimization of a multi-response problem in Taguchi's dynamic system
Authors: Kun-Lin Hsieh, Lee-Ing Tong, Hung-Pin Chiu, Hsin-Ya Yeh
Venue: Computers and Industrial Engineering (2005)

Taguchi method was known as an off-line quality control methodology to be used in many industries. Until now, most applications only focus on optimizing a single-response in a static system. Furthermore, due to the increasing complexity of the product design, more than one quality characteristic must be considered simultaneously to improve the production quality. Therefore, there are several studies to address the multi-response problem. In order to satisfy the requirements of the production's design, optimization of a dynamic system been mentioned by Taguchi has received more attentions in the recent years. Hence, optimizing a multi-response problem in a dynamic system becomes an important issue to address the quality improvement. This study proposes a procedure utilizing the statistic regression analysis and desirability function to optimize the multi-response problem with Taguchi's dynamic system consideration. Firstly, the regression analysis is employed to screen out the control factors significantly affecting the quality variation, and the adjustment factors significantly affecting the sensitivity of a Taguchi's dynamic system. Then, the desirability function will be applied to optimize such a multi-response problem. Finally, the effectiveness of the proposed procedure will be demonstrated by an example of a biological reduction of ethyl acetoacetate process experiment project at the Union Chemical Laboratories of the Industrial Technology Research Institute in Taiwan.
Adapting to changing expectations: Post-graduate students' experience of an e-learning tax program
Authors: Elmarie Engelbrecht
Venue: Computers Education (2005)

In response to the impact of information and communication technology on traditional business and commerce practices, and the empowerment of individuals by the growth of information available on the Internet, educators are challenged to adapt the curricula and delivery modes of educational programs for knowledge workers, such as tax accountants. Today's tax accountants are expected to be computer and information literate, and are valued for their critical thinking skills based on subject knowledge. This article evaluates the implementation of an e-learning Masters Program in Taxation in South Africa based on the feedback from students. Three criteria are used: the use of technology, the learning design, and flexibility of the tax program. Students reacted positively to the use of technology, but expressed concern about the lack of interaction between students, and between students and teachers. The author argues that the choice of technologies, the outsourcing of teaching services, and the program facilitator's teaching approach emulate the face-to-face tax program and therefore still support a teacher-centered teaching and learning approach. Students and teachers who are used to a traditional teacher-centered teaching and learning approach often measure the quality of a learning experience by the amount of information transmitted by a subject expert. Getting students to take responsibility for their own learning poses a bigger challenge than improving students' computer and information skills. Several recommendations are made to improve e-learning programs that will produce self-directed, lifelong learners who can be productive in an information-based economy.
Finite element modeling of Cr(VI) reduction by Shewanella oneidensis MR-1 employing the dual-enzyme kinetic model
Authors: Md. Akram Hossain, Mahbub Alam, David Yonge, Prashanta Dutta
Venue: Computers Geosciences (2005)

Chromium (VI) (Cr(VI)) contamination of soil and groundwater is considered a major environmental concern. Bioreduction of Cr(VI) to chromium (III) (Cr(III)) can be considered an effective technology in remediating Cr(VI) contaminated sites. Among the Cr(VI) reducing bacteria, Shewanella oneidensis MR-1 (MR-1) is relatively effective. Reduction of Cr(VI) by MR-1 is defined by the dual-enzyme kinetic model. Existing models are not able to simulate bioreduction of Cr(VI) by employing the dual-enzyme kinetic model. The objective of this paper is to present a finite element model capable of simulating bioreduction of Cr(VI) by employing the dual-enzyme kinetic model and compare its prediction with experimental results. The model developed is accurate and can provide oscillation-free results for Peclet number Pn@?20 and Courant number Cn@?1. The model prediction compares well with the experimental results.
All work and no play: Measuring fun, usability, and learning in software for children
Authors: Gavin Sim, Stuart MacFarlane, Janet Read
Venue: Computers Education (2006)

This paper describes an empirical study of fun, usability, and learning in educational software. Twenty five children aged 7 and 8 from an English primary school participated. The study involved three software products that were designed to prepare children for government initiated science tests. Pre and post tests were used to measure the learning effect, and observations and survey methods were used to assess usability and fun. The findings from the study demonstrate that in this instance learning was not correlated with fun or usability, that observed fun and observed usability were correlated, and that children of this age appeared to be able to differentiate between the constructs used to describe software quality. The Fun Sorter appears to be an effective tool for evaluating products with children. The authors discuss the implications of the results, offer some thoughts on designing experiments with children, and propose some ideas for future work.
Analyzing the one dimensional Ising model by probabilistic model checking
Authors: Toshifusa Sekizawa, Tatsuhiro Tsuchiya, Tohru Kikuno, Koichi Takahashi
Venue: Proceedings of the IASTED Asian Conference on Modelling and Simulation (2007)

Probabilistic model checking is an emerging verification technology for probabilistic analysis. It has started being used not only in the computer science field but also in interdisciplinary fields. In this paper, we show that probabilistic model checking allows one to analyze magnetic behaviours of the one dimensional Ising model which describes physical phenomena of magnets. The Ising model consists of elementary microscopic objects called spins and is often statically analyzed using the Metropolis method. Spins are microscopic elements, while the interesting properties to be measured are macroscopic physical quantities such as the energy. To analyze the Ising model with probabilistic model checking, we build labelled Discrete Time Markov Chain (DTMC) models in which states represent spins and macroscopic physical quantities and transitions occur according to the Metropolis method. Two representative physical quantities, energy and magnetization, are focused on. We use PRISM, a probabilistic model checker, to assess these quantities. To this end, we provide specifications expressed in PCTL (Probabilistic real time Computation Tree Logic) to instruct PRISM to compute the quantities.
Development framework for pervasive computing applications
Authors: Václav Slováček, Miroslav Macík, Martin Klíma
Venue: Issue 95 (September 2009) (2009)

Pervasive computing [1] brings the technology closer to the users by enabling the users to use daily-life devices (mobile phones, TVs, touch screen walls, etc.) for controlling their environment and accessing information virtually anywhere. Interacting with such devices does not remind users of classical computers and enables them to more naturally interact with the controlled system, if user interface is designed properly. These devices usually operate in networked environments with every controlling and controlled device connected to a central hub. Bringing easy-to-use applications to such environments faces the challenge of highly heterogeneous, dynamically changing environment and necessity to deploy applications to controlling devices with very different features (display size, input methods, operating systems, etc.).