Abstract: The material selection problem is concerned with the
determination of the right material for a certain product to optimize
certain performance indices in that product such as mass, energy
density, and power-to-weight ratio. This paper is concerned about
optimizing the selection of the manufacturing process along with the
material used in the product under performance indices and
availability constraints. In this paper, the material selection problem
is formulated using binary programming and solved by genetic
algorithm. The objective function of the model is to minimize the
total manufacturing cost under performance indices and material and
manufacturing process availability constraints.
Abstract: Hydrologic models are increasingly used as tools to
predict stormwater quantity and quality from urban catchments.
However, due to a range of practical issues, most models produce
gross errors in simulating complex hydraulic and hydrologic systems.
Difficulty in finding a robust approach for model calibration is one of
the main issues. Though automatic calibration techniques are
available, they are rarely used in common commercial hydraulic and
hydrologic modelling software e.g. MIKE URBAN. This is partly
due to the need for a large number of parameters and large datasets in
the calibration process. To overcome this practical issue, a
framework for automatic calibration of a hydrologic model was
developed in R platform and presented in this paper. The model was
developed based on the time-area conceptualization. Four calibration
parameters, including initial loss, reduction factor, time of
concentration and time-lag were considered as the primary set of
parameters. Using these parameters, automatic calibration was
performed using Approximate Bayesian Computation (ABC). ABC is
a simulation-based technique for performing Bayesian inference
when the likelihood is intractable or computationally expensive to
compute. To test the performance and usefulness, the technique was
used to simulate three small catchments in Gold Coast. For
comparison, simulation outcomes from the same three catchments
using commercial modelling software, MIKE URBAN were used.
The graphical comparison shows strong agreement of MIKE URBAN
result within the upper and lower 95% credible intervals of posterior
predictions as obtained via ABC. Statistical validation for posterior
predictions of runoff result using coefficient of determination (CD),
root mean square error (RMSE) and maximum error (ME) was found
reasonable for three study catchments. The main benefit of using
ABC over MIKE URBAN is that ABC provides a posterior
distribution for runoff flow prediction, and therefore associated
uncertainty in predictions can be obtained. In contrast, MIKE
URBAN just provides a point estimate. Based on the results of the
analysis, it appears as though ABC the developed framework
performs well for automatic calibration.
Abstract: MicroRNAs are small non-coding RNA found in
many different species. They play crucial roles in cancer such as
biological processes of apoptosis and proliferation. The identification
of microRNA-target genes can be an essential first step towards to
reveal the role of microRNA in various cancer types. In this paper,
we predict miRNA-target genes for lung cancer by integrating
prediction scores from miRanda and PITA algorithms used as a
feature vector of miRNA-target interaction. Then, machine-learning
algorithms were implemented for making a final prediction. The
approach developed in this study should be of value for future studies
into understanding the role of miRNAs in molecular mechanisms
enabling lung cancer formation.
Abstract: An experiment to verify the relationships between
physiological indexes of an e-learner and the presence or absence of an
operation during e-learning is described. Electroencephalogram
(EEG), hemoencephalography (HEG), skin conductance (SC), and
blood volume pulse (BVP) values were measured while participants
performed experimental learning tasks. The results show that there are
significant differences between the SC values when reading with
clicking on learning materials and the SC values when reading without
clicking, and between the HEG ratio when reading (with and without
clicking) and the HEG ratio when resting for four of five participants.
We conclude that the SC signals can be used to estimate whether or not
a learner is performing an active task and that the HEG ratios can be
used to estimate whether a learner is learning.
Abstract: This paper presents an analysis study on the impacts
of the changes of the capacitor banks, the loss of a transformer, and
the installation of distributed generation on the voltage total harmonic
distortion and harmonic resonance. The study is applied in a real
system in Oman, Sohar Industrial Port–C Substation Network.
Frequency scan method and Fourier series analysis method are used
with the help of EDSA software. Moreover, the results are compared
with limits specified by national Oman distribution code.
Abstract: Liquid storage tanks have become widespread during the recent decades due to their extensive usage. Analysis of liquid containing tanks is known to be complex due to hydrodynamic force exerted on tank which makes the analysis a complex one. The objective of this research is to carry out analysis of liquid domain along with structural interaction for various geometries of circular tanks considering seismic effects. An attempt has been made to determine hydrodynamic pressure distribution on the tank wall considering impulsive and convective components of liquid mass. To get a better picture, a comparative study of Draft IS 1893 Part 2, ACI 350.3 and Eurocode 8 for Circular Shaped Tank has been performed. Further, the differences in the magnitude of shear and moment at base as obtained from static (IS 3370 IV) and dynamic (Draft IS 1892 Part 2) analysis of ground supported circular tank highlight the need for us to mature from the old code to a newer code, which is more accurate and reliable.
Abstract: Social networks have recently gained a growing
interest on the web. Traditional formalisms for representing social
networks are static and suffer from the lack of semantics. In this
paper, we will show how semantic web technologies can be used to
model social data. The SemTemp ontology aligns and extends
existing ontologies such as FOAF, SIOC, SKOS and OWL-Time to
provide a temporal and semantically rich description of social data.
We also present a modeling scenario to illustrate how our ontology
can be used to model social networks.
Abstract: In recent years, a wide variety of applications are developed with Support Vector Machines -SVM- methods and Artificial Neural Networks -ANN-. In general, these methods depend on intrusion knowledge databases such as KDD99, ISCX, and CAIDA among others. New classes of detectors are generated by machine learning techniques, trained and tested over network databases. Thereafter, detectors are employed to detect anomalies in network communication scenarios according to user’s connections behavior. The first detector based on training dataset is deployed in different real-world networks with mobile and non-mobile devices to analyze the performance and accuracy over static detection. The vulnerabilities are based on previous work in telemedicine apps that were developed on the research group. This paper presents the differences on detections results between some network scenarios by applying traditional detectors deployed with artificial neural networks and support vector machines.
Abstract: Electric field is an important fundamental concept in
electrostatics. In high-school, generally Thai students have already
learned about definition of electric field, electric field due to a point
charge, and superposition of electric fields due to multiple-point
charges. Those are the prerequisite basic knowledge students holding
before entrancing universities. In the first-year university level,
students will be quickly revised those basic knowledge and will be
then introduced to a more complicated topic—electric field due to
continuous charged distributions. We initially found that our
freshman students, who were from the Faculty of Science and
enrolled in the introductory physic course (SCPY 158), often
seriously struggled with the basic physics concepts—superposition of
electric fields and inverse square law and mathematics being relevant
to this topic. These also then resulted on students’ understanding of
advanced topics within the course such as Gauss's law, electric
potential difference, and capacitance. Therefore, it is very important
to determine students' understanding of electric field due to
continuous charged distributions. The open-ended question about
sketching net electric field vectors from a uniformly charged
insulating rod was administered to 260 freshman science students as
pre- and post-tests. All of their responses were analyzed and
classified into five levels of understandings. To get deep
understanding of each level, 30 students were interviewed toward
their individual responses. The pre-test result found was that about
90% of students had incorrect understanding. Even after completing
the lectures, there were only 26.5% of them could provide correct
responses. Up to 50% had confusions and irrelevant ideas. The result
implies that teaching methods in Thai high schools may be
problematic. In addition for our benefit, these students’ alternative
conceptions identified could be used as a guideline for developing the
instructional method currently used in the course especially for
teaching electrostatics.
Abstract: In order to understand whether there is a better than the
learning function of learning methods and improve the CAD Courses
for enterprise’s design human resource development, this research is
applied in learning practical learning computer graphics software. In
this study, Revit building information model for learning content,
design of two different modes of learning curriculum to learning,
learning functions, respectively, and project learning. Via a post-test,
questionnaires and student interviews, etc., to study the effectiveness
of a comparative analysis of two different modes of learning. Students
participate in a period of three weeks after a total of nine-hour course,
and finally written and hands-on test. In addition, fill in the
questionnaire response by the student learning, a total of fifteen
questionnaire title, problem type into the base operating software,
application software and software-based concept features three
directions. In addition to the questionnaire, and participants were
invited to two different learning methods to conduct interviews to
learn more about learning students the idea of two different modes.
The study found that the ad hoc short-term courses in learning, better
learning outcomes. On the other hand, functional style for the whole
course students are more satisfied, and the ad hoc style student is
difficult to accept the ad hoc style of learning.
Abstract: The effectiveness of microchannels in enhancing heat
transfer has been demonstrated in the semiconductor industry. In
order to tap the microscale heat transfer effects into macro
geometries, overcoming the cost and technological constraints,
microscale passages were created in macro geometries machined
using conventional fabrication methods. A cylindrical insert was
placed within a pipe, and geometrical profiles were created on the
outer surface of the insert to enhance heat transfer under steady-state
single-phase liquid flow conditions. However, while heat transfer
coefficient values of above 10 kW/m2·K were achieved, the heat
transfer enhancement was accompanied by undesirable pressure drop
increment. Therefore, this study aims to address the high pressure
drop issue using Constructal theory, a universal design law for both
animate and inanimate systems. Two designs based on Constructal theory were developed to study
the effectiveness of Constructal features in reducing the pressure drop
increment as compared to parallel channels, which are commonly
found in microchannel fabrication. The hydrodynamic and heat
transfer performance for the Tree insert and Constructal fin (Cfin)
insert were studied using experimental methods, and the underlying
mechanisms were substantiated by numerical results. In technical
terms, the objective is to achieve at least comparable increment in
both heat transfer coefficient and pressure drop, if not higher
increment in the former parameter. Results show that the Tree insert improved the heat transfer
performance by more than 16 percent at low flow rates, as compared
to the Tree-parallel insert. However, the heat transfer enhancement
reduced to less than 5 percent at high Reynolds numbers. On the
other hand, the pressure drop increment stayed almost constant at 20
percent. This suggests that the Tree insert has better heat transfer
performance in the low Reynolds number region. More importantly,
the Cfin insert displayed improved heat transfer performance along
with favourable hydrodynamic performance, as compared to Cfinparallel
insert, at all flow rates in this study. At 2 L/min, the
enhancement of heat transfer was more than 30 percent, with 20
percent pressure drop increment, as compared to Cfin-parallel insert.
Furthermore, comparable increment in both heat transfer coefficient
and pressure drop was observed at 8 L/min. In other words, the Cfin
insert successfully achieved the objective of this study. Analysis of the results suggests that bifurcation of flows is
effective in reducing the increment in pressure drop relative to heat
transfer enhancement. Optimising the geometries of the Constructal
fins is therefore the potential future study in achieving a bigger stride
in energy efficiency at much lower costs.
Abstract: Flue gas desulfurization gypsum (FGD) is a waste
material arouse from coal power plants. Hydroxyapatite (HAP) is a
biomaterial with porous structure. In this study, FGD gypsum which
retrieved from coal power plant in Turkey was characterized and
HAP particles which can be used as an adsorbent in wastewater
treatment application were synthesized from the FGD gypsum. The
raw materials are characterized by using X Ray Diffraction (XRD)
and Fourier transform infrared spectroscopy (FT-IR) techniques and
produced HAP are characterized by using XRD. As a result, HAP
particles were synthesized at the molar ratio of 5:10, 5:15, 5:20, 5:24,
at room temperature, in alkaline medium (pH=11) and in 1 hour-reaction
time. Among these conditions, 5:20 had the best result.
Abstract: The objective of this research is to mitigate and prevent
the alkali silica reactivity (ASR) in highway construction projects.
ASR is a deleterious reaction initiated when the silica content of the
aggregate reacts with alkali hydroxides in cement in the presence of
relatively high moisture content. The ASR results in the formation of
an expansive white colored gel-like material which forms the
destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the
State of Arkansas were mixed and mortar bars were poured according
to the ASTM specifications. Mortar bars expansion was measured
versus time and aggregates with potential ASR problems were
detected. Different types of supplementary cementitious materials
(SCMs) were used in remixing mortar bars with highly reactive
aggregates. Length changes for remixed bars proved that different
types of SCMs can be successfully used in reducing the expansive
effect of ASR. SCMs percentage by weight is highly dependent on
the SCM type. The result of this study will help avoiding future
losses due to ASR cracking in construction project and reduce the
maintenance, repair, and replacement budgets required for highways
network.
Abstract: Digital technologies offer many opportunities in the
design and implementation of brand communication and advertising.
Augmented reality (AR) is an innovative technology in marketing
communication that focuses on the fact that virtual interaction with a
product ad offers additional value to consumers. AR enables
consumers to obtain (almost) real product experiences by the way of
virtual information even before the purchase of a certain product.
Aim of AR applications in relation with advertising is in-depth
examination of product characteristics to enhance product knowledge
as well as brand knowledge. Interactive design of advertising
provides observers with an intense examination of a specific
advertising message and therefore leads to better brand knowledge.
The elaboration likelihood model and the central route to persuasion
strongly support this argumentation. Nevertheless, AR in brand
communication is still in an initial stage and therefore scientific
findings about the impact of AR on information processing and brand
attitude are rare. The aim of this paper is to empirically investigate
the potential of AR applications in combination with traditional print
advertising. To that effect an experimental design with different
levels of interactivity is built to measure the impact of interactivity of
an ad on different variables o advertising effectiveness.
Abstract: Device-to-device (D2D) communication is considered a
promising technique to provide wireless peer-to-peer communication
services. Due to increasing demand on mobile services, available
spectrum for radio frequency (RF) based communications becomes
scarce. Recently, visible light communications (VLC) has evolved
as a high speed wireless data transmission technology for indoor
environments with abundant available bandwidth. In this paper,
a novel VLC based D2D communication that provides wireless
peer-to-peer communication is proposed. Potential low operating
power devices for an efficient D2D communication over increasing
distance of separation between devices is analyzed. Optical repeaters
(OR) are also proposed to enhance the performance in an environment
where direct D2D communications yield degraded performance.
Simulation results show that VLC plays an important role in
providing efficient D2D communication up to a distance of 1 m
between devices. It is also found that the OR significantly improves
the coverage distance up to 3.5 m.
Abstract: In this paper, a desiccant solar unit for air
conditioning and desalination is presented first. Secondly, a dynamic
modelling study of the desiccant wheel is developed. After that, a
simulation study and an experimental investigation of the behaviour
of desiccant wheel are developed. The experimental investigation is
done in the chamber of commerce in Freiburg-Germany. Indeed, the
variations of calculated and measured temperatures and specific
humidity of dehumidified and rejected air are presented where a good
agreement is found when comparing the model predictions with
experimental data under the considered range of operating conditions.
Finally, the study of the compartments of desalination and water
condensation shows that the unit can produce an acceptable quantity
of water at the same time of the air conditioning operation.
Abstract: In military aviation, the use of flight simulators has proliferated recently in order to train fifth generation fighter pilots. With these simulators, pilots can carry out real-time flights resulting in seeing their faults and can perform emergency drills prior to real flights. Since we cannot risk losing the aircraft and the pilot himself/herself in the flight training process, flight simulators are of great importance to adapt the fighter pilots competently to real flights aboard the fifth generation aircraft. The real flights are impossible to simulate thoroughly on the ground. To some extent, the fixed-based simulators may assist the pilot to steer aircraft technically and visually but flight simulators can’t trick the pilot’s vestibular, sensory, and perceptual systems without motion platforms. This paper discusses the benefits of motion simulators for fifth generation fighter pilots’ training in preference to the fixed-based counterparts by analyzing their pros and cons.
Abstract: The tribological test with Pin-On-Disc configuration
measures friction and wear properties in dry or lubricated sliding
surfaces of a variety of materials and coatings. Polymeric matrix
composites loaded with mineral filler were used, 1%, 3%, 10%, 30%,
and 50% mass percentage of filler, to reduce the material cost by
using mineral tailings. Using a pin-on-disc tribometer to quantify
coefficient of friction and wear resistance of the specimens. The
parameters known to performing the test were 300 rpm rotation,
normal load of 16N and duration of 33.5 minutes. The composite
with 10% mineral filler performed better, considering that the wear
resistance was good when compared to the other compositions and an
average low coefficient of friction, in the order of μ ≤ 0.15.
Abstract: The combination of the properties of graphene oxide
(OG) and PVDF homopolymer makes their combined composite
materials as multifunctional systems with great potential. Knowledge
of the molecular structure is essential for better use. In this work, the
degradation of PVDF polymer exposed to gamma irradiation in
oxygen atmosphere in high dose rate has been studied and compared
to degradation of PVDF/OG composites. The samples were irradiated
with a Co-60 source at constant dose rate, with doses ranging from
100 kGy to 1,000 kGy. In FTIR data shown that the formation of
oxidation products was at the both samples with formation of
carbonyl and hydroxyl groups amongst the most prevalent products
in the pure PVDF samples. In the other hand, the composites samples
exhibit less presence of degradation products with predominant
formation of carbonyl groups, these results also seen in the UV-Vis
analysis. The results show that the samples of composites may have
greater resistance to the irradiation process, since they have less
degradation products than pure PVDF samples seen by spectroscopic
techniques.
Abstract: Fe-2%Mn-0.5%Si-0.2C steel was welded and corroded
at 600, 700 and 800oC for 20 h in 1 atm of N2/H2S/H2O-mixed gas in
order to characterize the high-temperature corrosion behavior of the
welded joint. Corrosion proceeded fast and almost linearly. It
increased with an increase in the corrosion temperature. H2S formed
FeS owing to sulfur released from H2S. The scales were fragile and
nonadherent.