Abstract: Electro Chemical Discharge Machining (ECDM) is an
emerging hybrid machining process used in precision machining of hard and brittle non-conducting materials. The present paper gives a
critical review on materials machined by ECDM under the prevailing machining conditions; capability indicators of the process are
reported. Some results obtained while performing experiments in micro-channeling on soda lime glass using ECDM are also presented. In these experiments, Tool Wear (TW) and Material Removal (MR)
were studied using design of experiments and L–4 orthogonal array. Experimental results showed that the applied voltage was the most influencing parameter in both MR and TW studies. Field
emission scanning electron microscopy (FESEM) results obtained on the microchannels confirmed the presence of micro-cracks, primarily responsible for MR. Chemical etching was also seen along the edges.
The Energy dispersive spectroscopy (EDS) results were used to detect the elements present in the debris and specimens.
Abstract: Innovation is being view from four areas of
innovation, product, service, technology, and marketing. Whereas
customer loyalty is composed of customer expectation, perceived
quality, perceived value, corporate image, customer satisfaction,
customer trust/confidence, customer commitment, customer
complaint, and customer loyalty. This study aimed to investigate the
influence of innovation factors to customer loyalty to GSM in the
telecom companies where use of products and services. Structural
Equation Modeling (SEM) using to analyze innovation factors. It was
found the factor of innovation have significant influence on customer
loyalty.
Abstract: Inter-organizational Workflow (IOW) is commonly
used to support the collaboration between heterogeneous and
distributed business processes of different autonomous organizations
in order to achieve a common goal. E-government is considered as an
application field of IOW. The coordination of the different
organizations is the fundamental problem in IOW and remains the
major cause of failure in e-government projects. In this paper, we
introduce a new coordination model for IOW that improves the
collaboration between government administrations and that respects
IOW requirements applied to e-government. For this purpose, we
adopt a Multi-Agent approach, which deals more easily with interorganizational
digital government characteristics: distribution,
heterogeneity and autonomy. Our model integrates also different
technologies to deal with the semantic and technologic
interoperability. Moreover, it conserves the existing systems of
government administrations by offering a distributed coordination
based on interfaces communication. This is especially applied in
developing countries, where administrations are not necessary
equipped with workflow systems. The use of our coordination
techniques allows an easier migration for an e-government solution
and with a lower cost. To illustrate the applicability of the proposed
model, we present a case study of an identity card creation in Tunisia.
Abstract: In this paper, a PSO-based approach is proposed to
derive a digital controller for redesigned digital systems having an interval plant based on resemblance of the extremal gain/phase
margins. By combining the interval plant and a controller as an interval system, extremal GM/PM associated with the loop transfer function
can be obtained. The design problem is then formulated as an optimization problem of an aggregated error function revealing the deviation on the extremal GM/PM between the redesigned digital
system and its continuous counterpart, and subsequently optimized by
a proposed PSO to obtain an optimal set of parameters for the digital controller. Computer simulations have shown that frequency
responses of the redesigned digital system having an interval plant bare a better resemblance to its continuous-time counter part by the incorporation of a PSO-derived digital controller in comparison to those obtained using existing open-loop discretization methods.
Abstract: In the present study Schwertmannite (an iron oxide
hydroxide) is selected as an adsorbent for defluoridation of water.
The adsorbent was prepared by wet chemical process and was
characterized by SEM, XRD and BET. The fluoride adsorption
efficiency of the prepared adsorbent was determined with respect to
contact time, initial fluoride concentration, adsorbent dose and pH of
the solution. The batch adsorption data revealed that the fluoride
adsorption efficiency was highly influenced by the studied factors.
Equilibrium was attained within one hour of contact time indicating
fast kinetics and the adsorption data followed pseudo second order
kinetic model. Equilibrium isotherm data fitted to both Langmuir and
Freundlich isotherm models for a concentration range of 5-30 mg/L.
The adsorption system followed Langmuir isotherm model with
maximum adsorption capacity of 11.3 mg/g. The high adsorption
capacity of Schwertmannite points towards the potential of this
adsorbent for fluoride removal from aqueous medium.
Abstract: The purpose of the study is to determine the primary mathematics student teachers- views related to use instructional technology tools in course of the learning process and to reveal how the sample presentations towards different mathematical concepts affect their views. This is a qualitative study involving twelve mathematics students from a public university. The data gathered from two semi-structural interviews. The first one was realized in the beginning of the study. After that the representations prepared by the researchers were showed to the participants. These representations contain animations, Geometer-s Sketchpad activities, video-clips, spreadsheets, and power-point presentations. The last interview was realized at the end of these representations. The data from the interviews and content analyses were transcribed and read and reread to explore the major themes. Findings revealed that the views of the students changed in this process and they believed that the instructional technology tools should be used in their classroom.
Abstract: Future space vehicles will require the use of non-toxic, cryogenic propellants, because of the performance advantages over the toxic hypergolic propellants and also because of the environmental and handling concerns. A prototypical capillary flow liquid acquisition device (LAD) for cryogenic propellants was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations with different submersion depths of the LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel, including horizontally and vertically submersions of the LAD channel assembly at normal gravity environment was conducted. Gravity effects on the flow field in LAD channel are inspected and analyzed through comparing the simulations.
Abstract: Ensemble learning algorithms such as AdaBoost and
Bagging have been in active research and shown improvements in
classification results for several benchmarking data sets with mainly
decision trees as their base classifiers. In this paper we experiment to
apply these Meta learning techniques with classifiers such as random
forests, neural networks and support vector machines. The data sets
are from MAGIC, a Cherenkov telescope experiment. The task is to
classify gamma signals from overwhelmingly hadron and muon
signals representing a rare class classification problem. We compare
the individual classifiers with their ensemble counterparts and
discuss the results. WEKA a wonderful tool for machine learning has
been used for making the experiments.
Abstract: This paper presents the applicability of artificial
neural networks for 24 hour ahead solar power generation forecasting
of a 20 kW photovoltaic system, the developed forecasting is suitable
for a reliable Microgrid energy management. In total four neural
networks were proposed, namely: multi-layred perceptron, radial
basis function, recurrent and a neural network ensemble consisting in
ensemble of bagged networks. Forecasting reliability of the proposed
neural networks was carried out in terms forecasting error
performance basing on statistical and graphical methods. The
experimental results showed that all the proposed networks achieved
an acceptable forecasting accuracy. In term of comparison the neural
network ensemble gives the highest precision forecasting comparing
to the conventional networks. In fact, each network of the ensemble
over-fits to some extent and leads to a diversity which enhances the
noise tolerance and the forecasting generalization performance
comparing to the conventional networks.
Abstract: Within the collaborative research center 666 a new
product development approach and the innovative manufacturing
method of linear flow splitting are being developed. So far the design process is supported by 3D-CAD models utilizing User Defined
Features in standard CAD-Systems. This paper now presents new
functions for generating 3D-models of integral sheet metal products with bifurcations using Siemens PLM NX 6. The emphasis is placed
on design and semi-automated insertion of User Defined Features.
Therefore User Defined Features for both, linear flow splitting
and its derivative linear bend splitting, were developed. In order to facilitate the modeling process, an application was developed
that guides through the insertion process. Its usability and dialog layout adapt known standard features. The work presented here has
significant implications on the quality, accurateness and efficiency of the product generation process of sheet metal products with higher
order bifurcations.
Abstract: Online news websites are one of the main and wide areas of Mass Media. Since the nineties several Jordanian newspapers were introduced to the World Wide Web to reach various and large numbers of audiances. Examples of these newspapers that have online version are Al-Rai, Ad-Dustor and AlGhad. Other pure online news websites include Ammon and Rum. The main aim of this study is to evaluate online newspaper websites using two assessment measures; usability and web content. This aim is achieved by using a questionnaire based evaluation which is based on the definition of usability and web content in the ISO document as the standard number 9241-part 11. The results are obtained based on 204 audiences- responses. The results of the research showed that the usability factor is relatively good for all Jordanian online newspapers whereas the web content factor is moderate.
Abstract: The emergence of information technology has
resulted in an ever-increasing demand to use computers for the
efficient management and dissemination of information. Keeping in
view the strong need of farmers to collect important and updated
information for interactive, flexible and quick decision-making, a
model of Decision Support System for Farm Management is
developed. The paper discusses the use of Internet technology for the
farmers to take decisions. A model is developed for the farmers to
access online interactive and flexible information for their farm
management. The workflow of the model is presented highlighting
the information transfer between different modules.
Abstract: Water leakage is a serious problem in the maintenance of a waterworks facility. Monitoring the water flow rate is one way to locate leakage. However, conventional flowmeters such as the wet-type flowmeter and the clamp-on type ultrasonic flowmeter require additional construction for their installation and are therefore quite expensive. This paper proposes a novel estimation system for the flow rate in a water pipeline, which employs a vibration sensor. This assembly can be attached to any water pipeline without the need for additional high-cost construction. The vibration sensor is designed based on a condenser microphone. This sensor detects vibration caused by water flowing through a pipeline. It is possible to estimate the water flow rate by measuring the amplitude of the output signal from the vibration sensor. We confirmed the validity of the proposed sensing system experimentally.
Abstract: The objective of this research is to examine the shear thinning behaviour of mixing flow of non-Newtonian fluid like toothpaste in the dissolution container with rotating stirrer. The problem under investigation is related to the chemical industry. Mixing of fluid is performed in a cylindrical container with rotating stirrer, where stirrer is eccentrically placed on the lid of the container. For the simulation purpose the associated motion of the fluid is considered as revolving of the container, with stick stirrer. For numerical prediction, a time-stepping finite element algorithm in a cylindrical polar coordinate system is adopted based on semi-implicit Taylor-Galerkin/pressure-correction scheme. Numerical solutions are obtained for non-Newtonian fluids employing power law model. Variations with power law index have been analysed, with respect to the flow structure and pressure drop.
Abstract: Virtual Assembly (VA) is one of the key technologies
in advanced manufacturing field. It is a promising application of
virtual reality in design and manufacturing field. It has drawn much
interest from industries and research institutes in the last two decades.
This paper describes a process for integrating an interactive Virtual
Reality-based assembly simulation of a digital mockup with the
CAD/CAM infrastructure. The necessary hardware and software
preconditions for the process are explained so that it can easily be
adopted by non VR experts. The article outlines how assembly
simulation can improve the CAD/CAM procedures and structures;
how CAD model preparations have to be carried out and which
virtual environment requirements have to be fulfilled. The issue of
data transfer is also explained in the paper. The other challenges and
requirements like anti-aliasing and collision detection have also been
explained. Finally, a VA simulation has been carried out for a ball
valve assembly and a car door assembly with the help of Vizard
virtual reality toolkit in a semi-immersive environment and their
performance analysis has been done on different workstations to
evaluate the importance of graphical processing unit (GPU) in the
field of VA.
Abstract: The effect of teaching method on learning
assistance Dunn Review .The study, to compare the effects of
collaboration on teaching mathematics learning courses, including
writing, science, experimental girl students by other methods of
teaching basic first paid and the amount of learning students
methods have been trained to cooperate with other students with
other traditional methods have been trained to compare. The
survey on 100 students in Tehran that using random sampling ¬
cluster of girl students between the first primary selections was
performed. Considering the topic of semi-experimental research
methods used to practice the necessary information by
questionnaire, examination questions by the researcher, in
collaboration with teachers and view authority in this field and
related courses that teach these must have been collected.
Research samples to test and control groups were divided.
Experimental group and control group collaboration using
traditional methods of mathematics courses, including writing and
experimental sciences were trained. Research results using
statistical methods T is obtained in two independent groups show
that, through training assistance will lead to positive results and
student learning in comparison with traditional methods, will
increase also led to collaboration methods increase skills to solve
math lesson practice, better understanding and increased skill
level of students in practical lessons such as science and has been
writing.
Abstract: In the open space of decision support system the
mental impression of a manager-s decision has been the subject of
large importance than the ordinary famous one, when helped by
decision support system. Much of this study is an attempt to realize
the relation of decision support system usage and decision outcomes
that governs the system. For example, several researchers have
proposed so many different models to analyze the linkage between
decision support system processes and results of decision making.
This study draws the important relation of manager-s mental
approach with the use of decision support system. The findings of
this paper are theoretical attempts to provide Decision Support
System (DSS) in a way to exhibit and promote the learning in semi
structured area. The proposed model shows the points of one-s
learning improvements and maintains a theoretical approach in order
to explore the DSS contribution in enhancing the decision forming
and governing the system.
Abstract: This study proposes a novel recommender system to
provide the advertisements of context-aware services. Our proposed
model is designed to apply a modified collaborative filtering (CF)
algorithm with regard to the several dimensions for the personalization
of mobile devices – location, time and the user-s needs type. In
particular, we employ a classification rule to understand user-s needs
type using a decision tree algorithm. In addition, we collect primary
data from the mobile phone users and apply them to the proposed
model to validate its effectiveness. Experimental results show that the
proposed system makes more accurate and satisfactory advertisements
than comparative systems.
Abstract: In this paper we propose, a Lagrangian method to solve unsteady gas equation which is a nonlinear ordinary differential equation on semi-infnite interval. This approach is based on Modified generalized Laguerre functions. This method reduces the solution of this problem to the solution of a system of algebraic equations. We also compare this work with some other numerical results. The findings show that the present solution is highly accurate.
Abstract: This paper analyses the unsteady, two-dimensional
stagnation point flow of an incompressible viscous fluid over a flat
sheet when the flow is started impulsively from rest and at the same
time, the sheet is suddenly stretched in its own plane with a velocity
proportional to the distance from the stagnation point. The partial
differential equations governing the laminar boundary layer forced
convection flow are non-dimensionalised using semi-similar
transformations and then solved numerically using an implicit finitedifference
scheme known as the Keller-box method. Results
pertaining to the flow and heat transfer characteristics are computed
for all dimensionless time, uniformly valid in the whole spatial region
without any numerical difficulties. Analytical solutions are also
obtained for both small and large times, respectively representing the
initial unsteady and final steady state flow and heat transfer.
Numerical results indicate that the velocity ratio parameter is found
to have a significant effect on skin friction and heat transfer rate at
the surface. Furthermore, it is exposed that there is a smooth
transition from the initial unsteady state flow (small time solution) to
the final steady state (large time solution).