Abstract: The paper focuses on the distance laboratory
organisation for training the electrical engineering staff and students
in the fields of electrical drive and power electronics. To support
online knowledge acquisition and professional enhancement, new
challenges in remote education based on an active learning approach
with self-assessment have been emerged by the authors. Following
the literature review and explanation of the improved assessment
methodology, the concept and technological basis of the labs
arrangement are presented. To decrease the gap between the distance
study of the up-to-date equipment and other educational activities in
electrical engineering, the improvements in the following-up the
learners’ progress and feedback composition are introduced. An
authoring methodology that helps to personalise knowledge
acquisition and enlarge Web-based possibilities is described.
Educational management based on self-assessment is discussed.
Abstract: Test automation allows performing difficult and time
consuming manual software testing tasks efficiently, quickly and
repeatedly. However, development and maintenance of automated
tests is expensive, so it needs a proper prioritization what to automate
first. This paper describes a simple yet efficient approach for such
prioritization of test cases based on the effort needed for both manual
execution and software test automation. The suggested approach is
very flexible because it allows working with a variety of assessment
methods, and adding or removing new candidates at any time. The
theoretical ideas presented in this article have been successfully
applied in real world situations in several software companies by the
authors and their colleagues including testing of real estate websites,
cryptographic and authentication solutions, OSGi-based middleware
framework that has been applied in various systems for smart homes,
connected cars, production plants, sensors, home appliances, car head
units and engine control units (ECU), vending machines, medical
devices, industry equipment and other devices that either contain or
are connected to an embedded service gateway.
Abstract: In this paper, we introduce a flexible box erecting
machine (BEM) that swiftly and automatically transforms cardboard
into a three dimensional box. Recently, the parcel service and
home-shopping industries have grown rapidly, and there is an
increasing need for various box types to ship various products.
However, workers cannot fold thousands of boxes manually in a day.
As such, automatic BEMs are garnering greater attention. This study
takes equipment operation into consideration as well as mechanical
improvements in order to design a BEM that is able to outperform its
conventional counterparts. We analyzed six dispatching rules – First In
First Out (FIFO), Shortest Processing Time (SPT), Earliest Due Date
(EDD), Setup Avoidance, EDD + SPT, and EDD + Setup Avoidance –
to determine which one was most suitable for BEM operation.
Consequently, SPT and Setup Avoidance were found to be the most
critical rules, followed by EDD + Setup Avoidance, EDD + SPT,
EDD, and FIFO. This hierarchy was valid for both our conventional
BEM and our new flexible BEM from the viewpoint of processing
time. We believe that this research can contribute to flexible BEM
management, which has the potential to increase productivity and
convenience.
Abstract: Production fluids are transported from the platform to
tankers or process facilities through transfer pipelines. Water being
one of the heavier phases tends to settle at the bottom of pipelines
especially at low flow velocities and this has adverse consequences
for pipeline integrity. On restart after a shutdown, this could result in
corrosion and issues for process equipment, thus the need to have the
heavier liquid dispersed into the flowing lighter fluid. This study
looked at the flow regime of low water cut and low flow velocity oil
and water flow using conductive film thickness probes in a large
diameter 4-inch pipe to obtain oil and water interface height and the
interface structural velocity. A wide range of 0.1–1.0 m/s oil and
water mixture velocities was investigated for 0.5–5% water cut. Two
fluid model predictions were used to compare with the experimental
results.
Abstract: The post-rain puddles problem that occurs in the first
yard of Prambanan Temple are often disturbing visitor activity. A
poodle layer and a drainage system had ever built to avoid such a
problem, but puddles still did not stop appearing after rain.
Permeability parameter needs to be determined by using a simpler
procedure to find exact method of solution. The instrument modelling
was proposed according to the development of field permeability
testing instrument. This experiment used a proposed Constant
Discharge method. Constant Discharge method used a tube poured
with constant water flow from unsaturated until saturated soil
condition. Volumetric water content (θ) were monitored by soil
moisture measurement device. The results were correlations between
k and θ which were drawn by numerical approach from Van
Genutchen model. Parameters θr optimum value obtained from the
test was at very dry soil. Coefficient of permeability with a density of
19.8 kN/m3 for unsaturated conditions was in range of 3 x 10-6
cm/sec (Sr=68%) until 9.98 x 10-4 cm/sec (Sr=82%). The equipment
and testing procedure developed in this research was quite effective,
simple and easy to be implemented on determining field soil
permeability coefficient value of sandy soil. Using constant discharge
method in proposed permeability test, value of permeability
coefficient under unsaturated condition can be obtained without
establish soil water characteristic curve.
Abstract: The paper discusses the problem of load transport
using farm tractors and road tractor units. This type of carriage of
goods is often done with farm vehicles. The tests were performed
with the PEMS equipment (Portable Emission Measurement System)
under actual traffic conditions. The vehicles carried a load of 20000
kg. This research method is one of the most desired because it
provides reliable information on the actual vehicle emissions and fuel
consumption (carbon balance method). For the tests, a route was
selected that simulated a trip from a small town to a food-processing
facility located in a city. The analysis of the obtained results gave a
clear answer as to what vehicles need to be used for carriage of this
type of cargo in terms of exhaust emissions and fuel consumption.
Abstract: The paper is focused to the evaluation railway tracks
in the Slovakia by using Multi-Criteria method. Evaluation of railway
tracks has important impacts for the assessment of investment in
technical equipment. Evaluation of railway tracks also has an
important impact for the allocation of marshalling yards. Marshalling
yards are in transport model as centers for the operation assigned
catchment area. This model is one of the effective ways to meet the
development strategy of the European Community's railways. By
applying this model in practice, a transport company can guarantee a
higher quality of service and then expect an increase in performance.
The model is also applicable to other rail networks. This model
supplements a theoretical problem of train formation problem of new
ways of looking at evaluation of factors affecting the organization of
wagon flows.
Abstract: This paper focuses on the orbit avoidance strategy of
the optical remote sensing satellite. The optical remote sensing
satellite, moving along the Sun-synchronous orbit, is equipped with
laser warning equipment to alert CCD camera from laser attacks. This
paper explores the strategy of satellite avoidance to protect the CCD
camera and also the satellite. The satellite could evasive to several
target points in the orbital coordinates of virtual satellite. The so-called
virtual satellite is a passive vehicle which superposes the satellite at the
initial stage of avoidance. The target points share the consistent cycle
time and the same semi-major axis with the virtual satellite, which
ensures the properties of the satellite’s Sun-synchronous orbit remain
unchanged. Moreover, to further strengthen the avoidance capability
of satellite, it can perform multi-target-points avoid maneuvers. On
occasions of fulfilling the satellite orbit tasks, the orbit can be restored
back to virtual satellite through orbit maneuvers. There into, the avoid
maneuvers adopts pulse guidance. In addition, the fuel consumption is
optimized. The avoidance strategy discussed in this article is
applicable to optical remote sensing satellite when it is encountered
with hostile attack of space-based laser anti-satellite.
Abstract: Temperature regulating system by gaseous nitrogen is
of importance to the space environment simulator, which keeps the
shrouds in the temperature range from -150°C to +150°C. Liquid
nitrogen spray equipment is one of the most critical parts in the
temperature regulating system by gaseous nitrogen. Y type jet
atomizer and internal mixing atomizer of the liquid nitrogen spray
equipment are studied in this paper, 2D/3D atomizer model was
established and grid division was conducted respectively by the
software of Catia and ICEM. Based on the above preparation,
numerical simulation on the spraying process of the atomizer by
FLUENT is performed. Using air and water as the medium,
comparison between the tests and numerical simulation was conducted
and the results of two ways match well. Hence, it can be conclude that
this atomizer model can be applied in the numerical simulation of
liquid nitrogen spray equipment.
Abstract: The aim of optimization of store management is not
only designing the situation of store management itself including its
equipment, technology and operation. In optimization of store
management we need to consider also synchronizing of
technological, transport, store and service operations throughout the
whole process of logistic chain in such a way that a natural flow of
material from provider to consumer will be achieved the shortest
possible way, in the shortest possible time in requested quality and
quantity and with minimum costs. The paper deals with the
application of the queuing theory for optimization of warehouse
processes. The first part refers to common information about the
problematic of warehousing and using mathematical methods for
logistics chains optimization. The second part refers to preparing a
model of a warehouse within queuing theory. The conclusion of the
paper includes two examples of using queuing theory in praxis.
Abstract: This study presents a kinematic positioning approach
that uses a global positioning system (GPS) buoy for precise ocean
surface monitoring. The GPS buoy data from the two experiments are
processed using an accurate, medium-range differential kinematic
technique. In each case, the data from a nearby coastal site are
collected at a high rate (1 Hz) for more than 24 hours, and
measurements are conducted in neighboring tidal stations to verify
the estimated sea surface heights. The GPS buoy kinematic
coordinates are estimated using epoch-wise pre-elimination and a
backward substitution algorithm. Test results show that centimeterlevel
accuracy can be successfully achieved in determining sea
surface height using the proposed technique. The centimeter-level
agreement between the two methods also suggests the possibility of
using this inexpensive and more flexible GPS buoy equipment to
enhance (or even replace) current tidal gauge stations.
Abstract: Students of Higher Education Technical School of
Professional Studies in Novi Sad follow the subject ‘Maintenance of
Electric Power Equipment’ at the Electrotechnical Department. This
paper presents educational plan and program of the subject
Maintenance of Electric Power Equipment. The course deals with the
problems of preventive and investing maintenance of transformer
stations (TS), performing and maintenance of grounding of TS and
pillars, as well as tracing and detection the location of the cables
failure. There is a special elaborated subject concerning the safe work
conditions for the electrician during network maintenance, as well as
the basics of making and keeping technical documentation of the
equipment.
Abstract: The shielding ability of a shielding cavity with an
aperture will be greatly degraded at resonance frequencies, and the
resonance modes and frequencies are affected by aperture resonances
and aperture-cavity coupling, which are closely related with aperture
sizes. The equivalent circuit method and numerical method of
Transmission Line Matrix (TLM) are used to analyze the effects of
aperture resonances and aperture-cavity coupling on the
electromagnetic resonances of a cavity with an aperture in this paper.
Both analytical and numerical results show that the resonance modes
of a shielding cavity with an aperture consist of cavity resonance
modes and aperture resonance modes, and the resonance frequencies
will shift with the change of the aperture sizes because of the aperture
resonances and aperture-cavity coupling. Variation rules of
electromagnetic resonances with aperture sizes for a cavity with an
aperture are given, which will be useful for design of shielding
cavities.
Abstract: A teeming set of doctors that graduated from various
universities within and outside Nigeria with the hope of practicing in
the country, has their hope shattered because of poor financing, lack
of medical equipments and a very weak healthcare systems. Such
hydra headed challenges, allows room for quackery which
increasingly contributes to the cause of mortality in Nigeria. With a
view of reversing the challenges of healthcare delivery and financing
in Nigeria, African Health Market for Equity (AHME), a project
funded by the Bill and Melinda Gates foundation [With contribution
from Department For International Development (DFID)] and
currently implemented in three African Countries (Nigeria, Kenya
and Ghana) over a Five (5) year period supports the healthcare sector
via Medical credit fund (MCF). The study examines the impact of
credit policy and medical credit funding on Nigerian health market.
Ordinary least square analysis, correlation and granger causality tests
were employed to measure the extent to which the Nigerian
healthcare market has been influenced. Medical credit fund
significantly and positively influenced average monthly turnover of
private healthcare providers and Commercial bank’s lending rate had
a weak relationship with access to credit/approved loans (13.46%).
The programme has so far made 13.91% progress, which is very
poor, considering the minimum targeted private health care providers
(437.6) and expected number of loan approvals (180.4) for the two
years. Medical credit policy in Nigeria should be revised to include
private healthcare providers in rural area for more positive impact
and increased returns. Good brand advert and sensitization of the
programme to stakeholders and health pressure group, and an
extension of the programme beyond five years is necessary to better
address the issues raised in the study.
Abstract: Current transformers are an integral part of power
system because it provides a proportional safe amount of current for
protection and measurement applications. However, when the power
system experiences an abnormal situation leading to huge current
flow, then this huge current is proportionally injected to the
protection and metering circuit. Since the protection and metering
equipment’s are designed to withstand only certain amount of current
with respect to time, these high currents pose a risk to man and
equipment. Therefore, during such instances, the CT saturation
characteristics have a huge influence on the safety of both man and
equipment and on the reliability of the protection and metering
system. This paper shows the effect of burden on the Accuracy Limiting
factor/ Instrument security factor of current transformers and the
change in saturation characteristics of the CT’s. The response of the
CT to varying levels of overcurrent at different connected burden will
be captured using the data acquisition software LabVIEW. Analysis
is done on the real time data gathered using LabVIEW. Variation of
current transformer saturation characteristics with changes in burden
will be discussed.
Abstract: In most existing buildings in hot climate, cooling
loads lead to high primary energy consumption and consequently
high CO2 emissions. These can be substantially decreased with
integrated renewable energy systems. Kuwait is characterized by its
dry hot long summer and short warm winter. Kuwait receives annual
total radiation more than 5280 MJ/m2 with approximately 3347 h of
sunshine. Solar energy systems consist of PV modules and parabolic
trough collectors are considered to satisfy electricity consumption,
domestic water heating, and cooling loads of an existing building.
This paper presents the results of an extensive program of energy
conservation and energy generation using integrated photovoltaic
(PV) modules and Parabolic Trough Collectors (PTC). The program
conducted on an existing institutional building intending to convert it
into a Net-Zero Energy Building (NZEB) or near net Zero Energy
Building (nNZEB). The program consists of two phases; the first
phase is concerned with energy auditing and energy conservation
measures at minimum cost and the second phase considers the
installation of photovoltaic modules and parabolic trough collectors.
The 2-storey building under consideration is the Applied Sciences
Department at the College of Technological Studies, Kuwait. Single
effect lithium bromide water absorption chillers are implemented to
provide air conditioning load to the building. A numerical model is
developed to evaluate the performance of parabolic trough collectors
in Kuwait climate. Transient simulation program (TRNSYS) is
adapted to simulate the performance of different solar system
components. In addition, a numerical model is developed to assess
the environmental impacts of building integrated renewable energy
systems. Results indicate that efficient energy conservation can play
an important role in converting the existing buildings into NZEBs as
it saves a significant portion of annual energy consumption of the
building. The first phase results in an energy conservation of about
28% of the building consumption. In the second phase, the integrated
PV completely covers the lighting and equipment loads of the
building. On the other hand, parabolic trough collectors of optimum
area of 765 m2 can satisfy a significant portion of the cooling load,
i.e about73% of the total building cooling load. The annual avoided
CO2 emission is evaluated at the optimum conditions to assess the
environmental impacts of renewable energy systems. The total annual
avoided CO2 emission is about 680 metric ton/year which confirms
the environmental impacts of these systems in Kuwait.
Abstract: This study was to explore and utilize the fresh rind of
mangosteen Index Colour 5 as an upcoming raw material for the
production of natural dyes. Rind from the fresh mangosteen Index
Colour 5 was utilized to extract the dyes. The established extracts
were experimented on silk fabrics via three types of mordanting and
dyeing procedures; pre-mordanting, simultaneous mordanting and
post-mordanting. As a result, the applications of the freeze-drying
methodology and mechanizable equipment have helped to produce
excellent range of natural colours. Silk fabric treated simultaneously
with mordanting and dyeing with extract dye Index Colour 5
produced a brilliant shade of the red colour and the colour from this
index is also discovered sensitive to light and washing during the
fastness tests. The preliminary evaluation and instrumentation
analysis allowed us to examine whether the application of different
mordanting and dyeing procedures with the same extract samples and
concentrations affected the colours and shades of the fabric samples.
Abstract: The application of cold Radio-Frequency (RF) plasma
in the conservation of cultural heritage became important in the last
decades due to the positive results obtained in decontamination
treatments. This paper presents an equipment especially designed for cold RF
plasma application on paper documents, developed within a research
project. The equipment consists in two modules: the first one is
designed for decontamination and cleaning treatments of any type of
paper supports, while the second one can be used for coating friable
papers with adequate polymers, for protection purposes. All these
operations are carried out in cold radio-frequency plasma, working in
gaseous nitrogen, at low pressure. In order to optimize the equipment parameters ancient paper
samples infested with microorganisms have been treated in nitrogen
plasma and the decontamination effects, as well as changes in surface
properties (color, pH) were assessed. The microbiological analysis
revealed complete decontamination at 6 minutes treatment duration;
only minor modifications of the surface pH were found and the
colorimetric analysis showed a slight yellowing of the support.
Abstract: The paper presents an advanced control system for
tennis ball throwing machines to improve their accuracy according to
the ball impact points. A further advantage of the system is the much
easier calibration process involving the intelligent solution of the
automatic adjustment of the stroking parameters according to the ball
elasticity, the self-calibration, the use of the safety margin at very flat
strokes and the possibility to placing the machine to any position of
the half court. The system applies mathematical methods to
determine the exact ball trajectories and special approximating
processes to access all points on the aimed half court.
Abstract: Expansive soils are often encountered in many parts
of the world, especially in arid and semi-arid fields. Such kind of
soils, generally including active clay minerals in low water content,
enlarge in volume by absorbing the water through the surface and
cause a great harm to the light structures such as channel coating,
roads and airports. The expansive soils were encountered on the path
of Apa-Hotamış conveyance channel belonging to the State
Hydraulic Works in the region of Konya. In the research done in this
area, it is predicted that the soil has a swollen nature and the soil
should be filled with proper granular equipments by digging the
ground to 50-60 cm. In this study, for purpose of helping the other
research to be done in the same area, it is thought that instead of
replacing swollen soil with the granular soil, by stabilizing it with
polypropylene fiber and using it its original place decreases effect of
swelling percent, in this way the cost will be decreased. Therefore,
laboratory tests were conducted to study the effects of polypropylene
fiber on swelling characteristics of expansive soil. Test results
indicated that inclusion of fiber reduced swell percent of expansive
soil. As the fiber content increased, the unconfined compressive
strength was increased. Finally, it can be said that stabilization of
expansive soils with polypropylene fiber is an effective method.