Abstract: Liquefaction is a phenomenon in which the strength
and stiffness of a soil is reduced by earthquake shaking or other rapid
cyclic loading. Liquefaction and related phenomena have been
responsible for huge amounts of damage in historical earthquakes
around the world.
Modeling of soil behavior is the main step in soil liquefaction
prediction process. Nowadays, several constitutive models for sand
have been presented. Nevertheless, only some of them can satisfy this
mechanism. One of the most useful models in this term is
UBCSAND model. In this research, the capability of this model is
considered by using PLAXIS software. The real data of superstition
hills earthquake 1987 in the Imperial Valley was used. The results of
the simulation have shown resembling trend of the UBC3D-PLM
model.
Abstract: An effort for the detection of damages in the
reinforcement bars of reinforced concrete members using PZTs is
presented. The damage can be the result of excessive elongation of
the steel bar due to steel yielding or due to local steel corrosion. In
both cases the damage is simulated by considering reduced diameter
of the rebar along the damaged part of its length. An integration
approach based on both electromechanical admittance methodology
and guided wave propagation technique is used to evaluate the
artificial damage on the examined longitudinal steel bar. Two
actuator PZTs and a sensor PZT are considered to be bonded on the
examined steel bar. The admittance of the Sensor PZT is calculated
using COMSOL 3.4a. Fast Furrier Transformation for a better
evaluation of the results is employed. An effort for the quantification
of the damage detection using the root mean square deviation
(RMSD) between the healthy condition and damage state of the
sensor PZT is attempted. The numerical value of the RSMD yields a
level for the difference between the healthy and the damaged
admittance computation indicating this way the presence of damage
in the structure. Experimental measurements are also presented.
Abstract: Determination of optimal parameters of a passive
control system device is the primary objective of this study.
Expanding upon the use of control devices in wind and earthquake
hazard reduction has led to development of various control systems.
The advantage of non-linearity characteristics in a passive control
device and the optimal control method using LQR algorithm are
explained in this study. Finally, this paper introduces a simple
approach to determine optimum parameters of a nonlinear viscous
damper for vibration control of structures. A MATLAB program is
used to produce the dynamic motion of the structure considering the
stiffness matrix of the SDOF frame and the non-linear damping
effect. This study concluded that the proposed system (variable
damping system) has better performance in system response control
than a linear damping system. Also, according to the energy
dissipation graph, the total energy loss is greater in non-linear
damping system than other systems.
Abstract: The advantage of using non-linear passive damping
system in vibration control of two adjacent structures is investigated
under their base excitation. The base excitation is El Centro
earthquake record acceleration. The damping system is considered as
an optimum and effective non-linear viscous damper that is
connected between two adjacent structures. A MATLAB program is
developed to produce the stiffness and damping matrices and to
determine a time history analysis of the dynamic motion of the
system. One structure is assumed to be flexible while the other has a
rule as laterally supporting structure with rigid frames. The response
of the structure has been calculated and the non-linear damping
coefficient is determined using optimum LQR algorithm in an
optimum vibration control system. The non-linear parameter of
damping system is estimated and it has shown a significant advantage
of application of this system device for vibration control of two
adjacent tall building.
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: 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 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: 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: The paper presents an analysis of the innovation performance of small and medium-sized furniture enterprises in Bulgaria, accounting for over 97% of the companies in the sector. It contains advanced features of innovation in enterprises, specific features of the furniture industry in Bulgaria and analysis of the results of studies on the topic. The results from studies of three successive periods - 2006-2008; 2008-2010; 2010-2012, during which were studied 594 small and medium-sized furniture enterprises. There are commonly used in the EU definitions and indicators (European Commission, OECD, Oslo Manual), which allows for the comparability of results.
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: The pipe taper thread measurement and uncertainty
normally used the four-wire probe according to the JIS B 0262.
Besides, according to the EA-10/10 standard, the pipe thread could be
measured using the three-wire probe. This research proposed to use
the three-wire probe measuring the pitch diameter of the pipe taper
thread. The measuring accessory component was designed and made,
then, assembled to one side of the ULM 828 CiM machine.
Therefore, this machine could be used to measure and calibrate both
the pipe thread and the pipe taper thread. The equations and the
expanded uncertainty for pitch diameter measurement were
formulated. After the experiment, the results showed that the pipe
taper thread had the pitch diameter equal to 19.165mm and the
expanded uncertainty equal to 1.88µm. Then, the experiment results
were compared to the results from the National Institute of Metrology
Thailand. The equivalence ratio from the comparison showed that
both results were related. Thus, the proposed method of using the
three-wire probe measured the pitch diameter of the pipe taper thread
was acceptable.
Abstract: The main aim of the current work is to examine if 14N
is candidate to be clusterized nuclei or not. In order to check this
attendance, we have measured the angular distributions for 14N ion
beam elastically scattered on 12C target nuclei at different low
energies; 17.5, 21, and 24.5MeV which are close to the Coulomb
barrier energy for 14N+12C nuclear system. Study of various transfer
reactions could provide us with useful information about the
attendance of nuclei to be in a composite form (core + valence). The
experimental data were analyzed using two approaches;
Phenomenological (Optical Potential) and semi-microscopic (Double
Folding Potential). The agreement between the experimental data and
the theoretical predictions is fairly good in the whole angular range.
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.
Abstract: This paper presents a new control scheme to control a brushless doubly fed induction generator (BDFIG) using back-to-back PWM converters for wind power generation. The proposed control scheme is a New Self-Tuning Fuzzy Proportional-Derivative Controller (NSTFPDC). The goal of BDFIG control is to achieve a similar dynamic performance to the doubly fed induction generator (DFIG), exploiting the well-known induction machine vector control philosophy. The performance of NSTFPDC controller has been investigated and compared with the two controllers, called Proportional–Integral (PI) and PD-like Fuzzy Logic controller (PD-like FLC) based BDFIG. The simulation results demonstrate the effectiveness and the robustness of the NSTFPDC controller.
Abstract: Climate considerations are essential dimensions in the assessment of thermal comfort and indoor environments inside Egyptian housing. The primary aim of this paper is to analyze the indoor environment of new housing in the new city of Assiut in the Southern Upper Egypt zone, in order to evaluate its thermal environment and determine the acceptable indoor operative temperatures. The psychrometric charts for ASHRAE Standard 55 and ACS used in this study would facilitate an overall representation of the climate in one of the hottest months in the summer season. This study helps to understand and deal with this problem and work on a passive cooling ventilation strategy in these contexts in future studies. The results that demonstrated the indoor temperature is too high, ranges between 31°C to 40°C in different natural ventilation strategies. This causes the indoor environment to be far from the optimum comfort operative temperature of ACS except when using air conditioners. Finally, this study is considered a base for developing a new system using natural ventilation with passive cooling strategies.
Abstract: Pioneer networked systems assume that connections are reliable, and a faulty operation will be considered in case of losing a connection. Transient connections are typical of mobile devices. Areas of application of data sharing system such as these, lead to the conclusion that network connections may not always be reliable, and that the conventional approaches can be improved. Nigerian commercial banking industry is a critical system whose operation is increasingly becoming dependent on information technology (IT) driven information system. The proposed solution to this problem makes use of a hierarchically clustered network structure which we selected to reflect (as much as possible) the typical organizational structure of the Nigerian commercial banks. Representative transactions such as data updates and replication of the results of such updates were used to simulate the proposed model to show its applicability.
Abstract: Kumasi is Ghana’s second largest and fastest growing city with an annual population growth rate of 5.4 percent. A major result of this phenomenon is a growing sprawl at the fringes of the city. This paper assesses the nature, extent and impact of sprawl on Kumasi and examines urban planning efforts at addressing this phenomenon. Both secondary and empirical data were collected from decentralized government departments of the Kumasi Metropolitan Assembly and residents of some sprawling communities. The study reveals that sprawl in the metropolis is rapidly consuming fringe rural communities. This situation has weakened effective management of the metropolis causing problems such as congestion and conversion of peri-urban land into residential use without ancillary infrastructure and social services. The paper recommends effective and timely planning and provision of services as well as an overall economic development and spatial integration through regional planning as a way of achieving a long term solution to sprawl.