Abstract: There are a variety of reference current identification
methods, for the shunt active power filter (SAPF), such as the
instantaneous active and reactive power, the instantaneous active and
reactive current and the synchronous detection method are evaluated
and compared under ideal, non sinusoidal and unbalanced voltage
conditions. The SAPF performances, for the investigated
identification methods, are tested for a non linear load. The
simulation results, using Matlab Power System Blockset Toolbox
from a complete structure, are presented and discussed.
Abstract: Powder metallurgy (P/M) is the only economic way to
produce porous parts/products. P/M can produce near net shape parts
hence reduces wastage of raw material and energy, avoids various
machining operations. The most vital use of P/M is in production of
metallic filters and self lubricating bush bearings and siding surfaces.
The porosity of the part can be controlled by varying compaction
pressure, sintering temperature and composition of metal powder
mix. The present work is aimed for experimental analysis of friction
and wear properties of self lubricating copper and tin bush bearing.
Experimental results confirm that wear rate of sintered component
is lesser for components having 10% tin by weight percentage. Wear
rate increases for high tin percentage (experimented for 20% tin and
30% tin) at same sintering temperature. Experimental results also
confirms that wear rate of sintered component is also dependent on
sintering temperature, soaking period, composition of the preform,
compacting pressure, powder particle shape and size.
Interfacial friction between die and punch, between inter powder
particles, between die face and powder particle depends on
compaction pressure, powder particle size and shape, size and shape
of component which decides size & shape of die & punch, material of
die & punch and material of powder particles.
Abstract: The purpose of this work is examining the multiproduct
multi-stage in a battery production line. To improve the
performances of an assembly production line by determine the
efficiency of each workstation. Data collected from every
workstation. The data are throughput rate, number of operator, and
number of parts that arrive and leaves during part processing. Data
for the number of parts that arrives and leaves are collected at least at
the amount of ten samples to make the data is possible to be analyzed
by Chi-Squared Goodness Test and queuing theory. Measures of this
model served as the comparison with the standard data available in
the company. Validation of the task time value resulted by comparing
it with the task time value based on the company database. Some
performance factors for the multi-product multi-stage in a battery
production line in this work are shown.
The efficiency in each workstation was also shown. Total
production time to produce each part can be determined by adding
the total task time in each workstation. To reduce the queuing time
and increase the efficiency based on the analysis any probably
improvement should be done. One probably action is by increasing
the number of operators how manually operate this workstation.
Abstract: Many problems in science and engineering field require
the solution of shifted linear systems with multiple right hand
sides and multiple shifts. To solve such systems efficiently, the
implicitly restarted global GMRES algorithm is extended in this
paper. However, the shift invariant property could no longer hold over
the augmented global Krylov subspace due to adding the harmonic
Ritz matrices. To remedy this situation, we enforce the collinearity
condition on the shifted system and propose shift implicitly restarted
global GMRES. The new method not only improves the convergence
but also has a potential to simultaneously compute approximate
solution for the shifted systems using only as many matrix vector
multiplications as the solution of the seed system requires. In
addition, some numerical experiments also confirm the effectiveness
of our method.
Abstract: This research work is concerned with the life cycle
assessment (LCA) of an expressway, as well as its infrastructure, in
Thailand. The life cycle of an expressway encompasses the raw
material acquisition phase, the construction phase, the use or service
phase, the rehabilitation phase, and finally the demolition and
disposal phase. The LCA in this research was carried out using CML
baseline 2000 and in accordance with the ISO 14040 standard. A
functional unit refers to transportation of one person over one
kilometer of a 3-lane expressway with a 50-year lifetime. This
research has revealed that the construction phase produced the largest
proportion of the environmental impact (81.46%), followed by the
service, rehabilitation, demolition and disposal phases and
transportation at 11.97%, 3.72% 0.33% and 2.52%, respectively. For
the expressway under study, the total carbon footprint over its
lifetime is equivalent to 245,639 tons CO2-eq per 1 kilometer
functional unit, with the phases of construction, service,
rehabilitation, demolition and disposal and transportation
contributing 153,690; 73,773; 3693, 755 and 13,728 tons CO2-eq,
respectively. The findings could be adopted as a benchmark against
which the environmental impacts of future similar projects can be
measured.
Abstract: Due to the determination of the pollution status of
fresh resources in the Egyptian territorial waters is very important for
public health; this study was carried out to reveal the levels of heavy
metals in the shellfish and their environment and its relation to the
highly developed industrial activities in those areas. A total of 100
shellfish samples from the Rosetta, Edku, El-Maadiya, Abo-Kir and
El-Max coasts [10 crustaceans (shrimp) and 10 mollusks (oysters)]
were randomly collected from each coast. Additionally, 10 samples
from both the water and the sediment were collected from each coast.
Each collected sample was analyzed for cadmium, chromium,
copper, lead and zinc residues using a Perkin Elmer atomic
absorption spectrophotometer (AAS). The results showed that the
levels of heavy metals were higher in the water and sediment from
Abo-Kir. The heavy metal levels decreased successively for the
Rosetta, Edku, El-Maadiya, and El-Max coasts, and the
concentrations of heavy metals, except copper and zinc, in shellfish
exhibited the same pattern. For the concentration of heavy metals in
shellfish tissue, the highest was zinc and the concentrations decreased
successively for copper, lead, chromium and cadmium for all coasts,
except the Abo-Kir coast, where the chromium level was highest and
the other metals decreased successively for zinc, copper, lead and
cadmium. In Rosetta, chromium was higher only in the mollusks,
while the level of this metal was lower in the crustaceans; this trend
was observed at the Edku, El-Maadiya and El-Max coasts as well.
Herein, we discuss the importance of such contamination for public
health and the sources of shellfish contamination with heavy metals.
We suggest measures to minimize and prevent these pollutants in the
aquatic environment and, furthermore, how to protect humans from
excessive intake.
Abstract: Frequency stability of microgrids under islanded
operation attracts particular attention recently. A new cooperative
frequency control strategy based on centralized multi-agent system
(CMAS) is proposed in this study. Based on this strategy, agents sent
data and furthermore each component has its own to center operating
decisions (MGCC).After deciding on the information, they are
returned. Frequency control strategies include primary and secondary
frequency control and disposal of multi-stage load in which this study
will also provide a method and algorithm for load shedding. This
could also be a big problem for the performance of micro-grid in
times of disaster. The simulation results show the promising
performance of the proposed structure of the controller based on
multi agent systems.
Abstract: In this work, a Multi-Level Artificial Bee Colony
(called MLABC) for optimizing numerical test functions is presented.
In MLABC, two species are used. The first species employs n
colonies where each of them optimizes the complete solution vector.
The cooperation between these colonies is carried out by exchanging
information through a leader colony, which contains a set of elite
bees. The second species uses a cooperative approach in which the
complete solution vector is divided to k sub-vectors, and each of
these sub-vectors is optimized by a colony. The cooperation between
these colonies is carried out by compiling sub-vectors into the
complete solution vector. Finally, the cooperation between two
species is obtained by exchanging information. The proposed
algorithm is tested on a set of well-known test functions. The results
show that MLABC algorithm provides efficiency and robustness to
solve numerical functions.
Abstract: This paper proposes the designing direct adaptive
neural controller to apply for a class of a nonlinear pendulum
dynamic system. The radial basis function (RBF) neural adaptive
controller is robust in presence of external and internal uncertainties.
Both the effectiveness of the controller and robustness against
disturbances are importance of this paper. The simulation results
show the promising performance of the proposed controller.
Abstract: The use of mobile phones is growing tremendously all
over the world. In Tanzania there are a number of operators licensed
by Tanzania Communications Regulatory Authority (TCRA) aiming
at attracting customers into their networks. So far
telecommunications market competition has been very stiff. Various
measures are being taken by mobile operators to survive in the
market. Such measure include introducing of different air time
bundles on daily, weekly and monthly at lower tariffs. Other
measures include the introduction of normal tariff, tourist package
and one network. Despite of all these strategies, there is a dynamic
competition in the market which needs to be explored. Some
influences which attract customers to choose a certain mobile
operator are of particular interest. This paper is investigating if the
network effects and Quality of Services (QoS) influence mobile
customers in selection of their mobile network operators. Seventy
seven students from high learning institutions in Dodoma
Municipality in Tanzania participated in responding to prepared
questionnaires. The data was analyzed using Statistical Package for
Social Science (SPSS) Software. The results indicate that, network
coverage does influence customers in selection of mobile operators.
In addition, this paper proposes further research in some areas
especially where the study came up with different findings from what
the theory has in place.
Abstract: Applied industrial engineering is concerned with
imparting employable skills to improve the productivity for current
situation of products and services. The purpose of this case study is to
present the results of an initial research study conducted to identify
the desired professional characteristics of an industrial engineer with
an undergraduate degree and the emerging topic areas that should be
incorporated into the curriculum to prepare industrial engineering
(IE) graduates for the future workforce. Conclusions and
recommendations for applied industrial engineering syllabus have
been gathered and reported below. A two-pronged approach was
taken which included a method of benchmarking by comparing the
applied industrial engineering curricula of various universities and an
industry survey to identify job market requirements. This
methodology produced an analysis of the changing nature of
industrial engineering from learning to practical education. A
curriculum study for engineering is a relatively unexplored area of
research in the Middle East, much less for applied industrial
engineering. This work is an effort to bridge the gap between
theoretical study in the classroom and the real world work
applications in the industrial and service sectors.
Abstract: Dissimilar joining of Titanium and Aluminum thin
sheets has potential applications in aerospace and automobile
industry which can reduce weight and cost and improve strength,
corrosion resistance and high temperature properties. However
successful welding of Titanium/Aluminium sheets is of challenge due
to differences in physical, chemical and metallurgical properties
between the two. This paper describes research results of Laser Beam
Welding (LBW) of Ti/Al thin sheets in which many researchers have
recently performed and critically reviewed from different
perspectives. Also some of notable works in the field of laser welding
with changes in mechanical properties, crack propagation, diffusion
behavior, chemical potential, interfacial reaction and the
microstructure are reported.
Abstract: Artificial Immune Systems (AIS), inspired by the
human immune system, are algorithms and mechanisms which are
self-adaptive and self-learning classifiers capable of recognizing and
classifying by learning, long-term memory and association. Unlike
other human system inspired techniques like genetic algorithms and
neural networks, AIS includes a range of algorithms modeling on
different immune mechanism of the body. In this paper, a mechanism
of a human immune system based on apoptosis is adopted to build an
Intrusion Detection System (IDS) to protect computer networks.
Features are selected from network traffic using Fisher Score. Based
on the selected features, the record/connection is classified as either
an attack or normal traffic by the proposed methodology. Simulation
results demonstrates that the proposed AIS based on apoptosis
performs better than existing AIS for intrusion detection.
Abstract: The primary purpose of this paper is to explain the
impact of successful classroom management on the academic
achievements of students, the importance of positive relationship
between teacher and students, among students, between teacher and
parents. Effective communication plays an important role to
encourage students study hard and learn materials which are covered
by the teacher in the class. Friendly relationships among students
other than their preferred friends help them to have team working and
be socialized. In addition, a well-organized classroom arrangement
enhances students learning. As the consequence of successful
classroom management students should feel responsibility and need
to feel it. The one who is responsible to provide a comfortable
environment and help students learn is the manager of the classroom
who is named Teacher.
Abstract: Wireless sensor network is vulnerable to a wide range
of attacks. Recover secrecy after compromise, to develop technique
that can detect intrusions and able to resilient networks that isolates
the point(s) of intrusion while maintaining network connectivity for
other legitimate users. To define new security metrics to evaluate
collaborative intrusion resilience protocol, by leveraging the sensor
mobility that allows compromised sensors to recover secure state
after compromise. This is obtained with very low overhead and in a
fully distributed fashion using extensive simulations support our
findings.
Abstract: In today’s era, it is no news that organizations should
demonstrate honest conduct as well as ethical administration.
Therefore, the concept of corporate social responsibility
(subsequently CSR) has created its tag upon the company’s focal
point as well as marketing communications, and will continue in the
future. The importance of CSR has increased in the last decade, and
this concept has attracted global attention. The notion of CSR has
strategic significance for many organizations. However, businesses
are not adapting the activities of CSR that benefit to all of its
stakeholders (including society). The main reason is the practitioners
are unfortunately unable to comprehend its importance; and
therefore, the activities of the CSR are so detached from the business
activities. Hence, it is required to develop an understanding that the
activities of CSR are not only beneficial for the society but it also
benefit to business. This paper focuses on the concept of strategic
CSR, and develops a theoretical framework that will help
practitioners to filter and chose the activities of CSR that are strategic
in nature.
Abstract: We have experimentally demonstrated bright-dark
pulses in a nonlinear polarization rotation (NPR) based mode-locked
Erbium-doped fiber laser (EDFL) with a long cavity configuration.
Bright–dark pulses could be achieved when the laser works in the
passively mode-locking regime and the net group velocity dispersion
is quite anomalous. The EDFL starts to generate a bright pulse train
with degenerated dark pulse at the mode-locking threshold pump
power of 35.09 mW by manipulating the polarization states of the
laser oscillation modes using a polarization controller (PC). A split
bright–dark pulse is generated when further increasing the pump
power up to 37.95 mW. Stable bright pulses with no obvious
evidence of a dark pulse can also be generated when further adjusting
PC and increasing the pump power up to 52.19 mW. At higher pump
power of 54.96 mW, a new form of bright-dark pulse emission was
successfully identified with the repetition rate of 29 kHz. The bright
and dark pulses have a duration of 795.5 ns and 640 ns, respectively.
Abstract: City shrinkage is one of the thorny problems that many
European cities have to face with nowadays. It is mainly expressed as
the decrease of population in these cities. Eastern Germany is one of
the pioneers of European shrinking cities with long shrinking history.
The paper selects one representative shrinking city Halle (Saale) in
eastern Germany as research objective, collecting and investigating
nearly 20 years (1993-2010) municipal data after the reunification of
Germany. These data based on five dimensions, which are
demographic, economic, social, spatial and environmental and total 16
eligible variables. Factor Analysis is used to deal with these variables
in order to assess the most important factors affecting shrinking Halle.
The results show that there are three main factors determine the
shrinkage of Halle, respectively named “demographical and
economical factor”, “social stability factor”, and “city vitality factor”.
The three factors act at different time period of Halle’s shrinkage: from
1993 to 1997 the demographical and economical factor played an
important role; from 1997 to 2004 the social stability factor is
significant to city shrinkage; since 2005 city vitality factor determines
the shrinkage of Halle. In recent years, the shrinkage in Halle mitigates
that shows the sign of growing population. Thus the city Halle should
focus on attaching more importance on the city vitality factor to
prevent the city from shrinkage. Meanwhile, the city should possess a
positive perspective to shift the growth-oriented development to tap
the potential of shrinking cities. This method is expected to apply to
further research and other shrinking cities
Abstract: The objective of this study was to determine effect of
dietary essential oil (EO) compounds, which contained
cinnamaldehyde, eugenol, peppermint, coriander, cumin, lemongrass,
and an organic carrier on feed intake, milk composition, and rumen
fermentation of dairy cows during heat exposure. Thirty-two Holstein
cows (days in milk= 60 ± 5) were assigned to one of two treatment
groups: a Control and EO fed. The experiment lasted 28 days. Dry
matter intake (DMI) was measured daily while and milk production
was measured weekly. Our result showed that DMI and milk yield
was decreased (P < 0.01) in control cows relative to EO cows.
Furthermore, supplementation with EO was associated with a
decrease in the molar proportion of propionate (P < 0.05) and
increase (P < 0.05) in acetate to propionate ratio. In conclusion, EO
supplementations in diets can be useful nutritional modification to
alleviate for the decrease DMI and milk production during heat
exposure in lactating dairy cows.
Abstract: In this paper, the influence of upstream structures on the flow patternaround and inside the wind-catcher is experimentally investigated by smoke flow visualization techniques. Wind-catchers are an important part of natural ventilation in residential buildings or public places such as shopping centers, libraries, etc. Wind-catchers might be also used in places of high urban densities; hence their potential to provide natural ventilation is dependent on the presence of upstream structures. In this study, the two-sided wind-catcher model was based on a real wind-catcher observed in the city of Yazd, Iran. The present study focuses on the flow patterns around and inside the isolated two-sided wind-catcher, and on a two-sided wind-catcher in the presence of an upstream structure. The results show that the presence of an upstream structure influences the airflow pattern force and direction. Placing a high upstream structure reverses the airflow direction inside the wind-catcher.