Abstract: Asymmetric incremental sheet forming (AISF) could significantly reduce costs incurred by the fabrication of complex industrial components with a minimal environmental impact. The AISF experiments were carried out on commercially pure titanium (Ti-Gr2), Timetal (15-3-3-3) alloy, and Ti-6Al-4V (Ti-Gr5) alloy. A special testing geometry was used to characterize the titanium alloys properties from the point of view of the forming zone and titanium structure effect. The structure and properties of the materials were assessed by means of metallographic analyses and microhardness measurements.The highest differences in the parameters assessed as a function of the sampling zone were observed in the case of alpha-phase Ti-Gr2at the expense of the most substantial sheet thinning occurrence. A springback causes a smaller stored deformation in Timetal (β alloy) resulting in less pronounced microstructure refinement and microhardness increase. Ti-6Al-4V alloy exhibited early failure due to its poor formability at ambient temperature.
Abstract: This article is concerned with the determination of the static interaction of a vertically loaded rigid circular disc embedded at the interface of a horizontal layer sandwiched in between two different transversely isotropic half-spaces called as tri-material full-space. The axes of symmetry of different regions are assumed to be normal to the horizontal interfaces and parallel to the movement direction. With the use of a potential function method, and by implementing Hankel integral transforms in the radial direction, the government partial differential equation for the solely scalar potential function is transformed to an ordinary 4th order differential equation, and the mixed boundary conditions are transformed into a pair of integral equations called dual integral equations, which can be reduced to a Fredholm integral equation of the second kind, which is solved analytically. Then, the displacements and stresses are given in the form of improper line integrals, which is due to inverse Hankel integral transforms. It is shown that the present solutions are in exact agreement with the existing solutions for a homogeneous full-space with transversely isotropic material. To confirm the accuracy of the numerical evaluation of the integrals involved, the numerical results are compared with the solutions exists for the homogeneous full-space. Then, some different cases with different degrees of material anisotropy are compared to portray the effect of degree of anisotropy.
Abstract: As internet continues to expand its usage with an
enormous number of applications, cyber-threats have significantly
increased accordingly. Thus, accurate detection of malicious traffic in
a timely manner is a critical concern in today’s Internet for security.
One approach for intrusion detection is to use Machine Learning (ML)
techniques. Several methods based on ML algorithms have been
introduced over the past years, but they are largely limited in terms of
detection accuracy and/or time and space complexity to run. In this
work, we present a novel method for intrusion detection that
incorporates a set of supervised learning algorithms. The proposed
technique provides high accuracy and outperforms existing techniques
that simply utilizes a single learning method. In addition, our
technique relies on partial flow information (rather than full
information) for detection, and thus, it is light-weight and desirable for
online operations with the property of early identification. With the
mid-Atlantic CCDC intrusion dataset publicly available, we show that
our proposed technique yields a high degree of detection rate over 99%
with a very low false alarm rate (0.4%).
Abstract: Numerical study of heat transfer and fluid flow over vertical double forward facing step were presented. The k-w model with finite volume method was employed to solve continuity, momentum, and energy equations. Different step heights were adopted for range of Reynolds number varied from 10000 to 40000, and range of temperature varied from 310K to 340 K. The straight side of duct is insulated while the side of double forward facing step is heated. The result shows augmentation of heat transfer due to the recirculation region created after and before steps. Effect of step length and Reynolds number observed on increase of local Nusselt number particularly at recirculation regions. Contour of streamline velocity is plotted to show recirculation regions after and before steps. Numerical simulation in this paper done by used ANSYS FLUENT 14.
Abstract: Analyzing classroom assessments is one of the responsibilities of the teacher. It aims improving teacher’s instruction and assessment as well as student learning. The present study investigated factors that might explain variation in teachers’ practices regarding analysis of classroom assessments. The factors considered in the investigation included gender, in-service assessment training, teaching load, teaching experience, knowledge in assessment, attitude towards quantitative aspects of assessment, and self-perceived competence in analyzing assessments. Participants were 246 in-service teachers in Oman. Results of a stepwise multiple linear regression analysis revealed that self-perceived competence was the only significant factor explaining the variance in teachers’ analysis of assessments. Implications for research and practice are discussed.
Abstract: The results of the study on the project evaluation to
develop the competencies, capabilities, and skills in repairing
computers of people in Jompluak Local Municipality, Bang Khonthi
District, Samut Songkram Province showed that the overall result
was good (4.33). When considering on each aspect, it was found that
the highest one was on process evaluation (4.60) followed by product
evaluation (4.50) and the least one was on feeding factor (3.97).
When considering in details, it was found that: 1) the context aspect
was high (4.23) with the highest item on the arrangement of the
training situation (4.67) followed by the appropriateness of the target
(4.30) and the least aspect was on the project cooperation (3.73). 2)
The evaluation of average overall primary factor or feeding factor
showed high value (4.23) while the highest aspect was on the
capability of the trainers (4.47) followed by the suitable venue (4.33)
while the least aspect was on the insufficient budget (3.47). 3) The
average result of process evaluation was very high (4.60). The
highest aspect was on the follow-op supervision (4.70) followed by
responsibility of each project staffs (4.50) while the least aspect was
on the present situation and the problems of the community (4.40). 4)
The overall result of the product evaluation was very high (4.50). The
highest aspect was on the diversity of the activities and the
community integration (4.67) followed by project target achievement
(4.63) while the least aspect was on continuation and regularity of the
activities (4.33). The trainees reported high satisfaction on the project
management at very high level (43.33%) while 40% reported high
level and 16.67% reported moderate level. Suggestions for the project
were on the additional number of the computer sets (37.78%)
followed by longer training period especially on computer skills
(43.48%).
Abstract: In this paper a novel method for the detection of
clipping in speech signals is described. It is shown that the new
method has better performance than known clipping detection
methods, is easy to implement, and is robust to changes in signal
amplitude, size of data, etc. Statistical simulation results are
presented.
Abstract: Steam reforming is industrially important as it is
incorporated in several major chemical processes including the
production of ammonia, methanol, hydrogen and ox alcohols. Due to
the strongly endothermic nature of the process, a large amount of heat
is supplied by fuel burning (commonly natural gas) in the furnace
chamber. Reaction conversions, tube catalyst life, energy
consumption and CO2 emission represent the principal factors
affecting the performance of this unit and are directly influenced by
the high operating temperatures and pressures.
This study presents a simulation of the performance of the
reforming of methane in a primary reformer, through a developed
empirical relation which enables to investigate the effects of
operating parameters such as the pressure, temperature, steam to
carbon ratio on the production of hydrogen, as well as the fraction of
non converted methane.
It appears from this analysis that the exit temperature Te, the
operating pressure as well the steam to carbon ratio has an important
effect on the reforming of methane.
Abstract: A thin gold metal layer was deposited on the top of
silicon oxide films containing embedded Si nanocrystals (Si-nc). The
sample was annealed in a gas containing nitrogen, and subsequently
characterized by photoluminescence. We obtained 3-fold
enhancement of photon emission from the Si-nc embedded in silicon
dioxide covered with a Gold layer as compared with an uncovered
sample. We attribute this enhancement to the increase of the
spontaneous emission rate caused by the coupling of the Si-nc
emitters with the surface plasmons (SP). The evolution of PL
emission with laser irradiated time was also collected from covered
samples, and compared to that from uncovered samples. In an
uncovered sample, the PL intensity decreases with time,
approximately with two decay constants. Although the decrease of
the initial PL intensity associated with the increase of sample
temperature under CW pumping is still observed in samples covered
with a gold layer, this film significantly contributes to reduce the
permanent deterioration of the PL intensity. The resistance to
degradation of light-emitting silicon nanocrystals can be increased by
SP coupling to suppress the permanent deterioration. Controlling the
permanent photodeterioration can allow to perform a reliable optical
gain measurement.
Abstract: The outstanding mechanical properties of Carbon
nanotubes (CNTs) have generated great interest for their potential as
reinforcements in high performance cementitious composites. The
main challenge in research is the proper dispersion of carbon
nanotubes in the cement matrix. The present work discusses the role
of dispersion of multiwalled carbon nanotubes (MWCNTs) on the
compressive strength characteristics of hydrated Portland IS 1489
cement paste. Cement-MWCNT composites with different mixing
techniques were prepared by adding 0.2% (by weight) of MWCNTs
to Portland IS 1489 cement. Rectangle specimens of size
approximately 40mm × 40mm ×160mm were prepared and curing of
samples was done for 7, 14, 28 and 35days. An appreciable increase
in compressive strength with both techniques; mixture of MWCNTs
with cement in powder form and mixture of MWCNTs with cement
in hydrated form 7 to 28 days of curing time for all the samples was
observed.
Abstract: The objectives of this research were to study the management of local towns and to develop a better model of town management according to the Philosophy of Sufficiency Economy. This study utilized qualitative research, field research, as well as documentary research at the same time. A total of 10 local towns or Tambons of Supanburi province, Thailand were selected for an in-depth interview. The findings revealed that the model of local town management according to Philosophy of Sufficient Economy was in a level of “good” and the model of management has the five basic guidelines: 1) ability to manage budget information and keep it up-to-date, 2) ability to decision making according to democracy rules, 3) ability to use check and balance system, 4) ability to control, follow, and evaluation, and 5) ability to allow the general public to participate. In addition, the findings also revealed that the human resource management according to Philosophy of Sufficient Economy includes obeying laws, using proper knowledge, and having integrity in five areas: plan, recruit, select, train, and maintain human resources.
Abstract: The two primary objectives of this research were (1)
to examine the current knowledge and actual circumstance of
agricultural workers about mangosteen product processing; and (2) to
analyze and evaluate ways to develop capacity of mangosteen
product processing. The population of this study was 15,125 people
who work in the agricultural sector, in this context, mangosteen
production, in the eastern part of Thailand that included Chantaburi
Province, Rayong Province, Trad Province and Pracheenburi
Province. The sample size based on Yamane’s calculation with 95%
reliability was therefore 392 samples. Mixed method was employed
included questionnaire and focus group discussion with
Connoisseurship Model used in order to collect quantitative and
qualitative data. Key informants were used in the focus group
including agricultural business owners, academic people in agro food
processing, local academics, local community development staff,
OTOP subcommittee, and representatives of agro processing
industry professional organizations. The study found that the
majority of the respondents agreed with a high level (in five- rating
scale) towards most of variables of knowledge management in agro
food processing. The result of the current knowledge and actual
circumstance of agricultural human resource in an arena of
mangosteen product processing revealed that mostly, the respondents
agreed at a high level to establish 7 variables. The guideline to
developing the body of knowledge in order to enhance the capacity
of the agricultural workers in mangosteen product processing was
delivered in the focus group discussion. The discussion finally
contributed to an idea to produce manuals for mangosteen product
processing methods, with 4 products chosen: (1) mangosteen soap;
(2) mangosteen juice; (3) mangosteen toffee; and (4) mangosteen
preserves or jam.
Abstract: Slab sliding system (SSS) with Coulomb friction
interface between slab and supporting frame is a passive structural
vibration control technology. The system can significantly reduce the
slab acceleration and accompanied lateral force of the frame. At the
same time it is expected to cause the slab displacement magnification
by sliding movement. To obtain the general comprehensive seismic
response of a single story structure, inelastic response spectra were
computed for a large ensemble of ground motions and a practical range
of structural periods and friction coefficient values. It was shown that
long period structures have no trade-off relation between force
reduction and displacement magnification with respect to elastic
response, unlike short period structures. For structures with the
majority of mass in the slab, the displacement magnification value can
be predicted according to simple inelastic displacement relation for
inelastically responding SDOF structures because the system behaves
elastically to a SDOF structure.
Abstract: Mangabeira (Hancornia speciosa Gomes), a native plant in Brazil, is found growing spontaneously in various regions of the country. The high perishability of tropical fruits such as mangaba, causes it to be necessary to use technologies that promote conservation, aiming to increase the shelf life of this fruit and add value. The objective of this study was to compare the mangabas lyophilization curves behaviors with different sizes and maturation stages. The fruits were freeze-dried for a period of approximately 45 hours at lyophilizer Liotop brand, model L -108. It has been considered large the fruits between 38 and 58 mm diameter and small, between 23 and 28 mm diameter and the two states of maturation, intermediate and mature. Large size mangabas drying curves in both states of maturation were linear behavior at all process, while the kinetic drying curves related to small fruits, independent of maturation state, had a typical behavior of drying, with all the well-defined steps. With these results it was noted that the time of lyophilization was suitable for small mangabas, a fact that did not happen with the larger one. This may indicate that the large mangabas require a longer time to freeze until reaches the equilibrium level, as it happens with the small fruits, going to have constant moisture at the end of the process. For both types of fruit were analyzed water activity, acidity, protein, lipid, and vitamin C before and after the process.
Abstract: In the age of globalization, higher education
institutions attempt to equip students with global competence. In
response, most universities have been developing and running various
international programs. However, teacher education has been a
neglected area in this trend. Therefore, in this study, we suggest a
program that offers a dual bachelor’s degree from both universities
located on different countries, focusing on teacher education
institutions with different policies and regulations of teacher education
programs that may become obstacles to designing a dual degree
program. We discuss a possible way to get a dual degree including a
teaching certificate at a specialized college, college of secondary
education. To be specific, this research presents a way to attain two
diplomas from Jeju National University (JNU) in Korea and Boise
State University (BSU) in the U.S. It attempts to build an effective
plan for students to declare simultaneous degrees at both universities.
From the study, we find that it takes about 5 years to fulfill
requirements for the dual degree at the undergraduate level.
Abstract: Recently, ‘play of learning’ becomes important and is
emphasized as a useful learning tool. Therefore, interest in
edutainment contents is growing. Storytelling is considered first as a
method that improves the transmission of information and learner's
interest when planning edutainment contents. In this study, we
designed edutainment contents in the form of an adventure game that
applies the storytelling method. This content provides questions and
items constituted dynamically and reorganized learning contents
through analysis of test results. It allows learners to solve various
questions through effective iterative learning. As a result, the learners
can reach mastery learning.
Abstract: Patients under health treatments that involve long
stays at a hospital or health center (e.g. cancer, organ transplants and
severe burns), tend to get bored or depressed because of the lack of
social interaction with family and friends. Such a situation also
affects the evolution and effectiveness of their treatments. In many
cases, the solution to this problem involves extra challenges, since
many patients need to rest quietly (or remain in bed) to their being
contagious. Considering the weak health condition in which usually
are these kinds, keeping them motivated and quiet represents an
important challenge for nurses and caregivers. This article presents a
mobile ubiquitous game called MagicRace, which allows hospitalized
kinds to interact socially with one another without putting to risk
their sensitive health conditions. The game does not require a
communication infrastructure at the hospital, but instead, it uses a
mobile ad hoc network composed of the handheld devices used by
the kids to play. The usability and performance of this application
was tested in two different sessions. The preliminary results show
that users experienced positive feelings from this experience.
Abstract: This paper gave an attempt in prioritizing information
technologies that organizations should give concentration. The case
study was organizations in the automotive assembly industry in
Thailand. Data were first collected to gather all information
technologies known and used in the automotive assembly industry in
Thailand. Five experts from the industries were surveyed based on
the concept of fuzzy DEMATEL. The information technologies were
categorized into six groups, which were communication, transaction,
planning, organization management, warehouse management, and
transportation. The cause groups of information technologies for each
group were analyzed and presented. Moreover, the relationship
between the used and the significant information technologies was
given. Discussions based on the used information technologies and
the research results are given.
Abstract: This paper proposes a novel e-learning model that is
based on a dynamic formative evaluation. On evaluating the existing
format of e-learning, conditions regarding repetitive learning to
achieve mastery, causes issues for learners to lose tension and become
neglectful of learning. The dynamic formative evaluation proposed is
able to supplement limitation of the existing approaches. Since a
repetitive learning method does not provide a perfect feedback, this
paper puts an emphasis on the dynamic formative evaluation that is
able to maximize learning achievement. Through the dynamic
formative evaluation, the instructor is able to refer to the evaluation
result when making an estimation about the learner. To show the flow
chart of learning, based on the dynamic formative evaluation, the
model proves its effectiveness and validity.
Abstract: Several meteorological parameters were used for the
prediction of monthly average daily global solar radiation on
horizontal using recurrent neural networks (RNNs). Climatological
data and measures, mainly air temperature, humidity, sunshine
duration, and wind speed between 1995 and 2007 were used to design
and validate a feed forward and recurrent neural network based
prediction systems. In this paper we present our reference system
based on a feed-forward multilayer perceptron (MLP) as well as the
proposed approach based on an RNN model. The obtained results
were promising and comparable to those obtained by other existing
empirical and neural models. The experimental results showed the
advantage of RNNs over simple MLPs when we deal with time series
solar radiation predictions based on daily climatological data.