Abstract: We consider the problem of stabilization of an unstable
heat equation in a 2-D, 3-D and generally n-D domain by deriving a
generalized backstepping boundary control design methodology. To
stabilize the systems, we design boundary backstepping controllers
inspired by the 1-D unstable heat equation stabilization procedure.
We assume that one side of the boundary is hinged and the other
side is controlled for each direction of the domain. Thus, controllers
act on two boundaries for 2-D domain, three boundaries for 3-D
domain and ”n” boundaries for n-D domain. The main idea of the
design is to derive ”n” controllers for each of the dimensions by
using ”n” kernel functions. Thus, we obtain ”n” controllers for the
”n” dimensional case. We use a transformation to change the system
into an exponentially stable ”n” dimensional heat equation. The
transformation used in this paper is a generalized Volterra/Fredholm
type with ”n” kernel functions for n-D domain instead of the one
kernel function of 1-D design.
Abstract: In this study, we have collected cases with adipocere
formation, which were from the South Delhi region (average room
temperature 27-390C) and autopsied at our centre. Details of the
circumstances of the death, cause and time of death, surrounding
environment and demographic profile of the deceased were taken into
account. Total 16 cases were included in this study. Adipocere
formation was predominantly present over cheeks, shoulder, breast,
flanks, buttocks, and thighs. Out of 16, 11 cases were found in a dry
atmosphere, 5 cases were brought from the water. There were 5 cases
in which adipocere formation was seen in less than 2 days, and
among them, in 1 case, as early as one day. This study showed that
adipocere formation can be seen as early as 1 day in a hot and humid
environment.
Abstract: Modelling of building processes of a multimodal
freight transportation support information system is discussed based
on modern CASE technologies. Functional efficiencies of ports in
the eastern part of the Black Sea are analyzed taking into account
their ecological, seasonal, resource usage parameters. By resources,
we mean capacities of berths, cranes, automotive transport, as well as
work crews and neighbouring airports. For the purpose of designing
database of computer support system for Managerial (Logistics)
function, using Object-Role Modeling (ORM) tool (NORMA–Natural ORM Architecture) is proposed, after which Entity
Relationship Model (ERM) is generated in automated process.
Software is developed based on Process-Oriented and Service-Oriented architecture, in Visual Studio.NET environment.
Abstract: In the last decade the emergence of new social needs
as an effect of the economic crisis has stimulated the flourishing of
business endeavours characterised by explicit social goals. Social
start-ups, social enterprises or Corporate Social Responsibility
operations carried out by traditional companies are quintessential
examples in this regard. This paper analyses these kinds of initiatives
in order to discover the main characteristics of social business models
and to provide insights to social entrepreneurs for developing or
improving their strategies. The research is conducted through the
integration of literature review and case study analysis and, thanks to
the recognition of the importance of both profits and social impacts
as the key success factors for a social business model, proposes a
framework for identifying indicators suitable for measuring the social
impacts generated.
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: The study investigated efficiency cassava peel carbon
and Zinc Chloride activated cassava peel carbon at 1:3, 2:3 and 1:1
activation levels in the removal of nitrates from oxidized cassava
processing wastewater. Results showed that the CPC and CPAC were
effective in adsorption of nitrates. A summary of results from the
study revealed that CPAC at 1:3 exhibited the highest initial
decontamination (69.5% after 2 hrs) while CPAC at 1:1 activation
ratio showed a slower initial decontamination rate. The CPC &
CPAC exhibited Langmuir Rα values of 0.15, 0.11, 0.09, and 0.07 for
the 0:1, 1:3, 2:3 and 1:1 confirming its suitability as adsorption
material.
Abstract: In this paper, various methods of providing restricted
earth fault protection are discussed. The proper operation of high and
low impedance Restricted Earth Fault (REF) protection for various
applications has been discussed. The maloperation of a relay due to
improper placement of CTs has been identified and a simple/unique
solution has been proposed in this work with a case study. Moreover,
it is found that the proper placement of CT in high impedance method
will provide the same result with reduced CT. This methodology has
been successfully implemented in Al Takreer refinery for a 2000
KVA transformer. The outcome of the paper may be included in
IEEEC37.91 standard to give the proper guidance for protection
engineers to sort out the issues related to mal functioning of REF
relays.
Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: Financial inclusion has become a crucially important
factor in debates on economic inequality posing challenges to the
financial systems of countries around the world. Nowadays
governments and banks are concerned about creating products that
allow access to wide sectors of the population. The creation of
banking products by the financial sector for people with low incomes
tends to lead to improvements in the quality of life of vulnerable parts
of the population. In countries with notable social and economic
inequalities, financial inclusion is a key aspect for equitable
economic growth. This study is based on the case of Colombia, which is a country
with a strong record of economic growth over the past decade.
Nevertheless, corruption, unemployment, and poverty contribute to
uncertainty regarding the country’s future growth prospects. This study wants to explain the situation of financial exclusion and
financial inclusion with respect to the Colombian case. Financial
inclusion is going to be studied from the perspective of social
innovation.
Abstract: This paper describes a subarray based low
computational design method of multiuser massive multiple
input multiple output (MIMO) system. In our previous works, use of
large array is assumed only in transmitter, but this study considers
the case both of transmitter and receiver sides are equipped with
large array antennas. For this aim, receive arrays are also divided
into several subarrays, and the former proposed method is modified
for the synthesis of a large array from subarrays in both ends.
Through computer simulations, it is verified that the performance
of the proposed method is degraded compared with the original
approach, but it can achieve the improvement in the aspect of
complexity, namely, significant reduction of the computational load
to the practical level.
Abstract: The hydrodynamic and thermal behaviors of fluid
flow in wavy microchannel are investigated numerically. Effects of
Reynolds number on the hydrodynamics and thermal behaviors are
investigated. Three cases of Reynolds number (580, 1244, and 1910)
are adopted in this study. It is found that the separation zone begin
appears when Reynolds number is greater than 1910 at the endsection
of the wave. Also it is found that dimensionless maximum
velocity at the mid-section of the wave decreases and becomes as a
turbulent behavior as Reynolds numbers increases. The maximum
temperature at the center line at the mid-section of the wave increases
as Reynolds number increases until it reaches the turbulent behavior
when Reynolds number is equal or greater than 1244, while this
behavior will be achieved at very high velocities at the end section of
the wave.
Abstract: The need to merge software artifacts seems inherent
to modern software development. Distribution of development over
several teams and breaking tasks into smaller, more manageable
pieces are an effective means to deal with the kind of complexity. In
each case, the separately developed artifacts need to be assembled as
efficiently as possible into a consistent whole in which the parts still
function as described. In addition, earlier changes are introduced into
the life cycle and easier is their management by designers.
Interaction-based specifications such as UML sequence diagrams
have been found effective in this regard. As a result, sequence
diagrams can be used not only for capturing system behaviors but
also for merging changes in order to create a new version. The
objective of this paper is to suggest a new approach to deal with the
problem of software merging at the level of sequence diagrams by
using the concept of dependence analysis that captures, formally, all
mapping, and differences between elements of sequence diagrams
and serves as a key concept to create a new version of sequence
diagram.
Abstract: Ocean current is always available around the
surrounding of SHELL Sabah Water Platform and data are collected
every 10 minutes, 24 hours a day, for a period of 365 days. Due to
low current speed, conventional hydrokinetic power generation is not
feasible, thus leading to the study of low current enabled vortex
induced vibration power generation application. In this case, the
design of a vortex induced vibration application is studied to obtain
an optimum design for the VIV oscillator. Power output is then
determined to study the feasibility of the VIV application in low
current condition.
Abstract: This paper studies a mathematical model based on the
integral equations for dynamic analyzes numerical investigations of a
non-uniform or multi-material composite beam. The beam is
subjected to a sub-tangential follower force and elastic foundation.
The boundary conditions are represented by generalized
parameterized fixations by the linear and rotary springs. A
mathematical formula based on Euler-Bernoulli beam theory is
presented for beams with variable cross-sections. The non-uniform
section introduces non-uniformity in the rigidity and inertia of beams
and consequently, more complicated equilibrium who governs the
equation. Using the boundary element method and radial basis
functions, the equation of motion is reduced to an algebro-differential
system related to internal and boundary unknowns. A generalized
formula for the deflection, the slope, the moment and the shear force
are presented. The free vibration of non-uniform loaded beams is
formulated in a compact matrix form and all needed matrices are
explicitly given. The dynamic stability analysis of slender beam is
illustrated numerically based on the coalescence criterion. A realistic
case related to an industrial chimney is investigated.
Abstract: New and more powerful communications technologies
continue to emerge at a rapid pace and their uses in education are
widespread and the impact remarkable in the developing societies.
This study investigates Mobile Collaboration Learning Technique
(MCLT) on learners’ outcome among students in tertiary institutions
of developing nations (a case of Nigeria students). It examines the
significance of retention achievement scores of students taught using
mobile collaboration and conventional method. The sample consisted
of 120 students using Stratified random sampling method. Five
research questions and hypotheses were formulated, and tested at
0.05 level of significance. A student achievement test (SAT) was
made of 40 items of multiple-choice objective type, developed and
validated for data collection by professionals. The SAT was
administered to students as pre-test and post-test. The data were
analyzed using t-test statistic to test the hypotheses. The result
indicated that students taught using MCLT performed significantly
better than their counterparts using the conventional method of
instruction. Also, there was no significant difference in the post-test
performance scores of male and female students taught using MCLT.
Based on the findings, the following submissions was made that:
Mobile collaboration system be encouraged in the institutions to
boost knowledge sharing among learners, workshop and training
should be organized to train teachers on the use of this technique,
schools and government should consistently align curriculum
standard to trends of technological dictates and formulate policies
and procedures towards responsible use of MCLT.
Abstract: Radiative heat transfer in participating medium was
carried out using the finite volume method. The radiative transfer
equations are formulated for absorbing and anisotropically scattering
and emitting medium. The solution strategy is discussed and the
conditions for computational stability are conferred. The equations
have been solved for transient radiative medium and transient
radiation incorporated with transient conduction. Results have been
obtained for irradiation and corresponding heat fluxes for both the
cases. The solutions can be used to conclude incident energy and
surface heat flux. Transient solutions were obtained for a slab of heat
conducting in slab and by thermal radiation. The effect of heat
conduction during the transient phase is to partially equalize the
internal temperature distribution. The solution procedure provides
accurate temperature distributions in these regions. A finite volume
procedure with variable space and time increments is used to solve
the transient radiation equation. The medium in the enclosure
absorbs, emits, and anisotropically scatters radiative energy. The
incident radiations and the radiative heat fluxes are presented in
graphical forms. The phase function anisotropy plays a significant
role in the radiation heat transfer when the boundary condition is
non-symmetric.
Abstract: Digital reference service is when a traditional library
reference service is provided electronically. In most cases users do
not get full satisfaction from using digital reference service due to
variety of reasons. This paper discusses the formal specification of
web services applications for digital reference services (WSDRS).
WSDRS is an informal model that claims to reduce the problems of
digital reference services in libraries. It uses web services technology
to provide efficient digital way of satisfying users’ need in the
reference section of libraries. Informal model is in natural language
which is inconsistent and ambiguous that may cause difficulties to the
developers of the system. In order to solve this problem we decided
to convert the informal specifications into formal specifications. This
is supposed to reduce the overall development time and cost. We use
Z language to develop the formal model and verify it with Z/EVES
theorem prover tool.
Abstract: Piezoelectric actuator is treated as RC load when it is
modeled electrically. For some piezoelectric actuator applications,
arbitrary voltage is required to actuate. Especially for unidirectional
arbitrary voltage driving like as sine wave, some special inverter with
circuit that can charge and discharge the capacitive energy can be
used. In this case, the difference between power supply level and the
object voltage level for RC load is varied. Because the control gain is
constant, the controlled output is not uniform according to the voltage
difference. In this paper, for charge and discharge circuit for
unidirectional arbitrary voltage driving for piezoelectric actuator, the
controller gain is controlled according to the voltage difference. With
the proposed simple idea, the load voltage can have controlled
smoothly although the voltage difference is varied. The
appropriateness is proved from the simulation of the proposed circuit.
Abstract: Operation enhancement in an air cooler depends on
rate of heat transfer, and pressure drop. In this paper for a given heat
duty, study of the effects of FPI (Fin Per Inch) and fin type (circular
and hexagonal fins) on heat transfer, and pressure drop in an air
cooler in Iran, Arvand petrochemical. A program in EES
(Engineering Equations Solver) software moreover, Aspen B-JAC
and HTFS+ softwares are used for this purpose to solve governing
equations. At first the simulated results obtained from this program is
compared to the experimental data for two cases of FPI. The effects
of FPI from 3 to 15 over heat transfer (Q) to pressure drop ratio
(Q/Δp ratio). This ratio is one of the main parameters in design, and
simulation heat exchangers. The results show that heat transfer (Q)
and pressure drop increase with increasing FPI steadily, and the Q/Δp
ratio increases to FPI=12 and then decreased gradually to FPI=15,
and Q/Δp ratio is maximum at FPI=12. The FPI value selection
between 8 and 12 obtained as a result to optimum heat transfer to
pressure drop ratio. Also by contrast, between circular and hexagonal
fins results, the Q/Δp ratio of hexagonal fins more than Q/Δp ratio of
circular fins for FPI between 8 and 12 (optimum FPI)
Abstract: This paper proposes a novel heuristic algorithm that aims to determine the best size and location of distributed generators in unbalanced distribution networks. The proposed heuristic algorithm can deal with the planning cases where power loss is to be optimized without violating the system practical constraints. The distributed generation units in the proposed algorithm is modeled as voltage controlled node with the flexibility to be converted to constant power factor node in case of reactive power limit violation. The proposed algorithm is implemented in MATLAB and tested on the IEEE 37 -node feeder. The results obtained show the effectiveness of the proposed algorithm.