Abstract: This paper presents a study on Proportional Resonant
(PR) current control with additional PR harmonic compensators for
Grid Connected Photovoltaic (PV) Inverters. Both simulation and
experimental results will be presented. Testing was carried out on a
3kW Grid-Connected PV Inverter which was designed and
constructed for this research.
Abstract: Curcuma longa L. (Zingiberaceae), commonly known
as turmeric, has a long history of traditional uses for culinary
purposes as a spice and a food colorant. The present study aimed to
document the ethnobotanical knowledge about Curcuma longa, and
to assess the variation in the herbalists’ experience in Northeastern
Algeria. Data were collected using semi-structured questionnaires
and direct interviews with 30 herbalists. Ethnobotanical indices,
including the fidelity level (FL%), the relative frequency citation
(RFC), and use value (UV) were determined by quantitative methods.
Diversity in the level of knowledge was analyzed using univariate,
non-parametric, and multivariate statistical methods. Three main
categories of uses were recorded for C. longa: for food, for medicine,
and for cosmetic purposes. As a medicine, turmeric was used for the
treatment of gastrointestinal, dermatological, and hepatic diseases.
Medicinal and food uses were correlated with both forms of
preparation (rhizome and powder). The age group did not influence
the use. Multivariate analyses showed a significant variation in
traditional knowledge, associated with the use value, origin, quality,
and efficacy of the drug. The findings suggested that the geographical
origin of C. longa affected the use in Algeria.
Abstract: The use of information and communication
technologies such as computers, mobile phones and the Internet is
becoming prevalent in today’s world; and it is facilitating access to a
vast amount of data, services and applications for the improvement of
people’s lives. However, this prevalence of ICTs is hampered by the
problem of low income levels in developing countries to the point
where people cannot timeously replace or repair their ICT devices
when damaged or lost; and this problem serves as a motivation for
this study whose aim is to examine the perceptions of teachers on the
reliability of cellphones when used for teaching and learning
purposes. The research objectives unfolding this aim are of two
types: Objectives on the selection and design of theories and models,
and objectives on the empirical testing of these theories and models.
The first type of objectives is achieved using content analysis in an
extensive literature survey: and the second type of objectives is
achieved through a survey of high school teachers from the ILembe
and UMgungundlovu districts in the KwaZulu-Natal province of
South Africa. Data collected from this questionnaire based survey is
analysed in SPSS using descriptive statistics and Pearson correlations
after checking the reliability and validity of the questionnaires. The
main hypothesis driving this study is that there is a relationship
between the demographics and the attribution identity of teachers on
one hand, and their perceptions on the reliability of cellphones on the
other hand, as suggested by existing literature; except that attribution
identities are considered in this study under three angles: intention,
knowledge and ability, and action. The results of this study confirm
that the perceptions of teachers on the reliability of cellphones for
teaching and learning are affected by the school location of these
teachers, and by their perceptions on learners’ cellphones usage
intentions and actual use.
Abstract: Self-service technologies (SSTs) make an important
contribution to the daily life of people nowadays. However, the
introduction of SST does not lead to its usage. Thereby, this paper
was an attempt on discovery of the most preferred SST in the
customers’ point of view. To fulfill this aim, the Analytical Hierarchy
Process (AHP) was applied based on Saaty’s questionnaire which
was administered to the customers of e-banking services located in
Golestan providence, northern Iran. This study used qualitative
factors in association with the intention of consumers’ usage of SSTs
to rank three SSTs: ATM, mobile banking and internet banking. The
results showed that mobile banking get the highest weight in
consumers’ point of view. This research can be useful both for
managers and service providers and also for customers who intend to
use e-banking.
Abstract: Drying behavior of blanched sweet potato in a cabinet
dryer using different five air temperatures (40-80°C) and ten sweet
potato varieties sliced to 5mm thickness were investigated. The
drying data were fitted to eight models. The Modified Henderson and
Pabis model gave the best fit to the experimental moisture ratio data
obtained during the drying of all the varieties while Newton (Lewis)
and Wang and Singh models gave the least fit. The values of Deff
obtained for Bophelo variety (1.27 x 10-9 to 1.77 x 10-9 m2/s) was
the least while that of S191 (1.93 x 10-9 to 2.47 x 10-9 m2/s) was the
highest which indicates that moisture diffusivity in sweet potato is
affected by the genetic factor. Activation energy values ranged from
0.27-6.54 kJ/mol. The lower activation energy indicates that drying
of sweet potato slices requires less energy and is hence a cost and
energy saving method. The drying behavior of blanched sweet potato
was investigated in a cabinet dryer. Drying time decreased
considerably with increase in hot air temperature. Out of the eight
models fitted, the Modified Henderson and Pabis model gave the best
fit to the experimental moisture ratio data on all the varieties while
Newton, Wang and Singh models gave the least. The lower activation
energy (0.27 - 6.54 kJ/mol) obtained indicates that drying of sweet
potato slices requires less energy and is hence a cost and energy
saving method.
Abstract: This paper is drawn from a wider study of the
management of gender, age and disability diversity in the banking
sector in the Kingdom of Saudi Arabia (KSA), which aims to develop
a framework for diversity management (DM) in this sector. The
paper focuses on the management of disability diversity. The purpose
of the paper is to assist in understanding disability DM in the banking
sector in KSA and to make suggestions for its enhancement. Hence, it
contributes to filling a research gap, as there is a dearth of literature
on disability DM, in KSA in general, and in the banking sector
specifically.
Discrimination against people with disabilities is a social issue that
has not been entirely overcome in any society. However, in KSA,
Islam informs almost every aspect of daily life including work, and
Islam is against discrimination. Hence, in KSA, there are regulations
to accommodate people with disabilities; however, employers are still
free not to hire job applicants with disabilities specifically because of
their condition. Indeed, disabled people are almost entirely absent
from the labour market.
There are 12 Saudi-owned or part-Saudi-owned banks in KSA and
two managers from each of these were interviewed, making a total of
24. The interviews aimed to investigate empirically the understanding
of managers in the banking sector in KSA of diversity management,
including disability DM, in the banking sector. The interview data
were analysed using thematic analysis. Two interviewees stated that
banks used the employment of people with disabilities to enhance
their corporate image, while five expressed the opinion that disabled
employees could contribute to the bank provided they did not have to
deal with customers face-to-face. Nine of the interviewees perceived
that disabled employees could be of value to the bank for their own
sake, not only in ‘behind the scenes’ roles. Another two interviewees
mentioned that employing disabled people could be part of the bank’s
community service programme and one thought it would be part of
the bank’s Saudisation efforts. The remaining five interviewees did
not know how disabled people could contribute to the bank.
The findings show that disability DM in the banking sector in
KSA is a relatively new concept, and is not yet well understood. In
the light of the findings, in order to achieve the purpose of the paper,
the following suggestions were made for the enhancement of
disability DM in the banking sector in KSA. A change in attitudes
towards disabled people is necessary. Such a change in the workplace
can only be achieved if a top-down approach is taken to the
integration of disabled people. Hence, it is suggested that
management and employees follow a course in disability awareness.
Further, a diversity officer in the HR department could enhance the
integration of disabled people into the banking workforce. It is also
suggested that greater government support is required through closely
monitored and enforced anti-discrimination legislation. Moreover,
flexible working arrangements such as part-time work would
facilitate the employment of disabled people and benefit other groups
of employees.
Abstract: We introduced an all-optical multicasting
characteristics with wavelength conversion based on a novel
all-optical triode using negative feedback semiconductor optical
amplifier. This study was demonstrated with a transfer speed of 10
Gb/s to a non-return zero 231-1 pseudorandom bit sequence system.
This multi-wavelength converter device can simultaneously provide
three channels of output signal with the support of non-inverted and
inverted conversion. We studied that an all-optical multicasting and
wavelength conversion accomplishing cross gain modulation is
effective in a semiconductor optical amplifier which is effective to
provide an inverted conversion thus negative feedback. The
relationship of received power of back to back signal and output
signals with wavelength 1535 nm, 1540 nm, 1545 nm, 1550 nm, and
1555 nm with bit error rate was investigated. It was reported that the
output signal wavelengths were successfully converted and modulated
with a power penalty of less than 8.7 dB, which the highest is 8.6 dB
while the lowest is 4.4 dB. It was proved that all-optical multicasting
and wavelength conversion using an optical triode with a negative
feedback by three channels at the same time at a speed of 10 Gb/s is a
promising device for the new wavelength conversion technology.
Abstract: GRF, Growth regulating factor, genes encode a novel
class of plant-specific transcription factors. The GRF proteins play a
role in the regulation of cell numbers in young and growing tissues
and may act as transcription activations in growth and development
of plants. Identification of GRF genes and their expression are
important in plants to performance of the growth and development of
various organs. In this study, to better understanding the structural
and functional differences of GRFs family, 45 GRF proteins
sequences in A. thaliana, Z. mays, O. sativa, B. napus, B. rapa, H.
vulgare and S. bicolor, have been collected and analyzed through
bioinformatics data mining. As a result, in secondary structure of
GRFs, the number of alpha helices was more than beta sheets and in
all of them QLQ domains were completely in the biggest alpha helix.
In all GRFs, QLQ and WRC domains were completely protected
except in AtGRF9. These proteins have no trans-membrane domain
and due to have nuclear localization signals act in nuclear and they
are component of unstable proteins in the test tube.
Abstract: Many quality models have been used to measure egovernment
portals quality. However, the absence of an international
consensus for e-government portals quality models results in many
differences in terms of quality attributes and measures. The aim of
this paper is to compare and analyze the existing e-government
quality models proposed in literature (those that are based on ISO
standards and those that are not) in order to propose guidelines to
build a good and useful e-government portals quality model. Our
findings show that, there is no e-government portal quality model
based on the new international standard ISO 25010. Besides that, the
quality models are not based on a best practice model to allow
agencies to both; measure e-government portals quality and identify
missing best practices for those portals.
Abstract: In the second decade of the XXI century the role of
tourism destination attractiveness is becoming increasingly important
for destination management. Competition in tourism market moves
from ordinary service quality to provision of unforgettable emotional
experience for tourists. The main purpose of the present study is to
identify the perception of the tourism destinations based on the
number of factors related to its tourist attractiveness.
The content analysis method was used to analyze the on-line
tourist feedback data immensely available in Social Media and in
travel related sites. The collected data made it possible to procure the
information which is necessary to understand the perceived
attractiveness of the destinations and key destination appeal factors
that are important for Russian leisure travelers.
Results of the present study demonstrate key attractiveness factors
or destination ‘properties’ that were unveiled as the most important
for Russian leisure tourists. The study targeted five main Spanish
tourism destinations that initially were determined by in-depth
interview with a number of Russian nationals who had visited Spain
at least once.
The research results can be useful for Spanish Tourism
Organization Representation office in Russia as well as for the other
national tourism organizations in order to promote their respective
destinations for Russian travelers focusing on main attractiveness
factors identified in this study.
Abstract: This paper presents the electromagnetic interference
(EMI) shielding effectiveness of rice husk and carbon nanotubes
(RHCNTs) composites in the X-band region (8.2-12.4 GHz). The
difference weight ratio of carbon nanotubes (CNTs) were mix with
the rice husk. The rectangular waveguide technique was used to
measure the complex permittivity of the RHCNTs composites
materials. The complex permittivity is represented in terms of both
the real and imaginary parts of permittivity in X-band frequency. The
conductivity of RHCNTs shows increasing when the ratio of CNTs
mixture increases. The composites materials were simulated using
Computer Simulation Technology (CST) Microwave Studio
simulation software. The shielding effectiveness of RHCNTs and
pure rice husk was compared. The highest EMI SE of 30 dB is
obtained for RHCNTs composites of 10 wt % CNTs with 10mm
thickness.
Abstract: Recently, there have been a lot of earthquakes in Japan.
It is necessary to promote seismic isolation devices for buildings. The
devices have been hardly diffused in attached houses, because the
devices are very expensive. We should develop a low-cost seismic
isolation device for detached houses. We suggested a new seismic
isolation device which uses a two-layer circular tube as a unit. If
hysteresis is produced in the two-layer circular tube under lateral
compression load, we think that the two-layer circular tube can have
energy absorbing capacity. It is necessary to contact the outer layer
and the inner layer to produce hysteresis. We have previously reported
how the inner layer comes in contact with the outer layer from a
perspective of analysis used mechanics of materials. We have clarified
that the inner layer comes in contact with the outer layer under a lateral
compression load. In this paper, we explored contact area between the
outer layer and the inner layer under a lateral compression load by
using FEA. We think that changing the inner layer’s thickness is
effective in increase the contact area. In order to change the inner
layer’s thickness, we changed the shape of the inner layer. As a result,
the contact area changes depending on the inner layer’s thickness.
Additionally, we experimented to check whether hysteresis occurs in
fact. As a consequence, we can reveal hysteresis in the two-layer
circular tube under the condition.
Abstract: In new energy development, wind power has boomed.
It is due to the proliferation of wind parks and their operation in
supplying the national electric grid with low cost and clean resources.
Hence, there is an increased need to establish a proactive
maintenance for wind turbine machines based on remote control and
monitoring. That is necessary with a real-time wireless connection in
offshore or inaccessible locations while the wired method has many
flaws. The objective of this strategy is to prolong wind turbine
lifetime and to increase productivity. The hardware of a remote
control and monitoring system for wind turbine parks is designed. It
takes advantage of GPRS or Wi-Max wireless module to collect data
measurements from different wind machine sensors through IP based
multi-hop communication. Computer simulations with Proteus ISIS
and OPNET software tools have been conducted to evaluate the
performance of the studied system. Study findings show that the
designed device is suitable for application in a wind park.
Abstract: This paper presents reliability indices evaluation of the
rotor core magnetization of the induction motor operated as a self
excited induction generator by using probability distribution approach
and Monte Carlo simulation. Parallel capacitors with calculated
minimum capacitive value across the terminals of the induction motor
operated as a SEIG with unregulated shaft speed have been connected
during the experimental study. A three phase, 4 poles, 50Hz, 5.5 hp,
12.3A, 230V induction motor coupled with DC Shunt Motor was
tested in the electrical machine laboratory with variable reactive loads.
Based on this experimental study, it is possible to choose a reliable
induction machines operated as a SEIG for unregulated renewable
energy application in remote area or where grid is not available.
Failure density function, cumulative failure distribution function,
survivor function, hazard model, probability of success and
probability of failure for reliability evaluation of the three phase
induction motor operating as a SEIG have been presented graphically
in this paper.
Abstract: Different services based on different switching
techniques in wireless networks leads to drastic changes in the
properties of network traffic. Because of these diversities in services,
network traffic is expected to undergo qualitative and quantitative
variations. Hence, assumption of traffic characteristics and the
prediction of network events become more complex for the wireless
networks. In this paper, the traffic characteristics have been studied
by collecting traces from the mobile switching centre (MSC). The
traces include initiation and termination time, originating node, home
station id, foreign station id. Traffic parameters namely, call interarrival
and holding times were estimated statistically. The results
show that call inter-arrival and distribution time in this wireless
network is heavy-tailed and follow gamma distributions. They are
asymptotically long-range dependent. It is also found that the call
holding times are best fitted with lognormal distribution. Based on
these observations, an analytical model for performance estimation is
also proposed.
Abstract: With advances in solid-state power electronic devices
and microprocessors, various pulse-width-modulation (PWM)
techniques have been developed for industrial applications. This
paper presents the comparison of two different PWM techniques, the
sinusoidal PWM (SPWM) technique and the space-vector PWM
(SVPWM) technique applied to two level VSI for micro grid
applications. These two methods are compared by discussing their
ease of implementation and by analyzing the output harmonic spectra
of various output voltages (line-to-neutral voltages, and line-to-line
voltages) and their total harmonic distortion (THD). The SVPWM
technique in the under-modulation region can increase the
fundamental output voltage by 15.5% over the SPWM technique.
Abstract: Since the emergence of e-Commerce, the world of
business has witnessed a radical shift in the way business activities
are conducted. However, the emergence of m-Commerce has further
pushed the boundaries of virtual commerce revolution. As a result,
there seems to be a growing blur in the distinction between e-
Commerce and m-Commerce. In addition, existing definitions for
both forms of commerce highlight characteristics (e.g. type of device
and activity conducted) that may be applicable to both concepts. The
aim of this paper is to identify the characteristics that help define and
delineate between e- and m- Commerce. The paper concludes that
characteristics of mobility, ubiquity and immediacy provide a clearer
and simpler template to distinguish between e-Commerce and m-
Commerce.
Abstract: In this paper family of multilevel inverter topology
with reduced number of power switches is presented. The proposed
inverter can generate both even and odd level. The proposed topology
is suitable for symmetric structure. The proposed symmetric inverter
results in reduction of power switches, power diode and gate driver
circuits and also it may further minimize the installation area and
cost. To prove the superiority of proposed topology is compared with
conventional topologies. The performance of this symmetric
multilevel inverter has been tested by computer based simulation and
prototype based experimental setup for nine-level inverter is
developed and results are verified.
Abstract: Students’ achievement and motivation in learning
English in Malaysia is a worrying trend as it is lagging behind several
other countries in Asia. Thus, necessary actions have to be taken by
the parties concerned to overcome this problem. The purpose of this
research was to study the effects of drill and practice courseware on
students’ achievement and motivation in learning English language.
A multimedia courseware was developed for this purpose. The
independent variable was the drill and practice courseware while the
dependent variables were the students’ achievement and motivation.
Their achievement was measured using pre-test and post-test scores,
while motivation was measured using a questionnaire. A total of 60
students from three vernacular primary schools in a northern state in
Malaysia were randomly selected in this study. The findings indicate:
(1) a significant difference between the students’ pre-test and posttest
scores after using the courseware, (2) no significant difference in
the achievement score between male and female students after using
the courseware, (3) a significant difference in motivation score
between the female and the male students, and (4) while the female
students scored significantly higher than the male students in the
aspects of relevance, confidence and satisfaction, no significant
difference in terms of attention was observed between them. Overall,
the findings clearly indicate that although the female students are
significantly more motivated than their male students, they are
equally good in terms of achievement after learning from the
courseware. Through this study, the drill and practice courseware is
proven to influence the students’ learning and motivation.
Abstract: Lately, asynchronous discussion forum is integrated in
higher educational institutions as it may increase learning process,
learners’ understanding, achievement and knowledge construction.
The asynchronous discussion forum is used to complement the
traditional, face-to-face learning session in hybrid learning courses.
However, studies have proven that students’ engagement in online
forums is still unconvincing. Thus, the aim of this study is to
investigate the motivating factors and obstacles that affect the
learners’ engagement in asynchronous discussion forum. This study
is carried out in one of the public higher educational institutions in
Malaysia with 18 postgraduate students as samples. The authors have
developed a 40-items questionnaire based on literature review. The
results indicate several factors that have encouraged or limited
students’ engagement in asynchronous discussion forum: (a) the
practices or behaviors of peers, or instructors, (b) the needs for the
discussions, (c) the learners’ personalities, (d) constraints in
continuing the discussion forum, (e) lack of ideas, (f) the level of
thoughts, (g) the level of knowledge construction, (h) technical
problems, (i) time constraints and (j) misunderstanding. This study
suggests some recommendations to increase the students’
engagement in online forums. Finally, based upon the findings, some
implications are proposed for further research.