Abstract: Renewable natural fibres such as oil palm, flax, and
pineapple leaf can be utilized to obtain new high performance
polymer materials. The reuse of waste natural fibres as reinforcement
for polymer is a sustainable option to the environment. However, due
to its high hydroxyl content of cellulose, natural fibres are
susceptible to absorb water that affects the composite mechanical
properties adversely. Research found that Nano materials such as
Nano Silica Carbide (n-SiC) and Nano Clay can be added into the
polymer composite to overcome this problem by enhancing its
mechanical properties in wet condition. The addition of Nano
material improves the tensile and wear properties, flexural stressstrain
behaviour, fracture toughness, and fracture strength of polymer
natural composites in wet and dry conditions.
Abstract: The use of wind energy for electricity generation is
growing rapidly across the world and in Portugal. However, the
geographical characteristics of the country along with the average
wind regime and with the environmental restrictions imposed to these
projects create limitations to the exploit of the onshore wind
resource. The best onshore wind spots are already committed and the
possibility of offshore wind farms in the Portuguese cost is now
being considered. This paper aims to make a contribution to the
evaluation of offshore wind power projects in Portugal. The technical
restrictions are addressed and the strategic, environmental and
financial interest of the project is analysed from the private company
and public points of view. The results suggest that additional support
schemes are required to ensure private investors interest for these
projects. Assuming an approach of direct substitution of energy
sources for electricity generation, the avoided CO2 equivalent
emissions for an offshore wind power project were quantified. Based
on the conclusions, future research is proposed to address the
environmental and social impacts of these projects.
Abstract: In this paper, we first give the representation of the general solution of the following inverse eigenvalue problem (IEP): Given X ∈ Rn×p and a diagonal matrix Λ ∈ Rp×p, find nontrivial real-valued symmetric arrow-head matrices A and B such that AXΛ = BX. We then consider an optimal approximation problem: Given real-valued symmetric arrow-head matrices A, ˜ B˜ ∈ Rn×n, find (A, ˆ Bˆ) ∈ SE such that Aˆ − A˜2 + Bˆ − B˜2 = min(A,B)∈SE (A−A˜2 +B −B˜2), where SE is the solution set of IEP. We show that the optimal approximation solution (A, ˆ Bˆ) is unique and derive an explicit formula for it.
Abstract: Microstrip antennas are conformable to planar and
nonplanar surfaces, simple and inexpensive to fabricate using modern
printed-circuit technology. Circular polarization of low-profile
microstrip patch with high bandwidth is achieved in this research
through the use of a three-cross-arms branch-line coupler with
sequential rotated arrays, another low-profile antenna of hollow
cylinder is also proposed and the function of reconnaissance with
microstrip antenna on Mini UAV (unmanned aerial vehicle) are
evaluated in practical flight test.
Abstract: Repeated additions of the unfertilized bacteria led to
increase the activity of Nitrogen-fixing bacteria in the root zone with
drip irrigation system compared to traditional manual vaccination to
increase the proportion of Nitrogen from 29% to 64%, and the
efficiency of adding Nitrogen fertilizer did not exceed 9.5% while
dropped to 4%, due to the amount of fertilizer added was not exceed
20kg N/h, and the second was the existence of a large amount of
available Nitrogen in the soil by fixation, while the efficiency of
irrigation system between 2.08 to 2.26 kg/m3.
Abstract: the current study presents a modeling framework to determine the torsion strength of an induction hardened splined shaft by considering geometry and material aspects with the aim to optimize the static torsion strength by selection of spline geometry and hardness depth. Six different spline geometries and seven different hardness profiles including non-hardened and throughhardened shafts have been considered. The results reveal that the torque that causes initial yielding of the induction hardened splined shaft is strongly dependent on the hardness depth and the geometry of the spline teeth. Guidelines for selection of the appropriate hardness depth and spline geometry are given such that an optimum static torsion strength of the component can be achieved.
Abstract: This paper presents the adaptive control scheme
with sliding mode compensator for vibration control problem
in the presence of disturbance. The dynamic model of the
flexible cantilever beam using finite element modeling is
derived. The adaptive control with sliding mode compensator
using output feedback for output tracking is developed to
reject the external disturbance, and to improve the tracking
performance. Satisfactory simulation results verify that the
effectiveness of adaptive control scheme with sliding mode
compensator.
Abstract: This paper presents the experimental results of
comparison between leakage currents and discharge currents. The leakage currents were obtained on polluted porcelain insulator.
Whereas, the discharge currents were obtained on lightly artificial
polluted porcelain specimen. The conducted measurements were
leakage current or discharge current and applied voltage. The insulator or specimen was in a hermetically sealed chamber, and the
current waveforms were analyzed using FFT.
The result indicated that the leakage current (LC) on low RH condition the fifth harmonic would be visible, and followed by the
seventh harmonic. The insulator had capacitive property. Otherwise,
on 99% relative humidity, the fifth harmonic would also be visible,
and the phase angle reached up to 12.2 degree. Whereas, on discharge current, the third harmonic would be visible, and followed
by fifth harmonic. The third harmonic would increase as pressure reduced. On this condition, the specimen had a non-linear characteristics
Abstract: This study utilizes the panel vector error correction
model (PVECM) to examine the relationship among corruption,
economic growth, and income inequality experienced within ten Asian
countries over the 1995 to 2010 period. According to the empirical
results, we do not support the common perception that corruption
decreases economic growth. On the contrary, we found that corruption
increases economic growth. Meanwhile, an increase in economic
growth will cause an increase in income inequality, although the effect
is insignificant. Similarly, an increase in income inequality will cause
an increase in economic growth but a decrease in corruption, although
the effect is also insignificant.
Abstract: In this work the design and characterization of an optoelectronic automated measurement system it is presented. The optoelectronic devices of this system are an optical transmitter, the optical components and the optical receiver, which were selected for a great precision of the system. The mechanical system allows free displacement of the components as well as the devices that generate the movement. The results, length and profile of the objects are display in Lab View.
Abstract: It is claimed that a new style of urban planning and
policy intertwined with ICT is emerging and urban planning and ICT
policy are no longer considered as separate disciplines. The
interactions between electronic spaces and urban spaces are so
complex and uncertain that confront urban planners and policy makers
with great challenges. However, the assumption about the relationship
between ICT and urban planning is mainly based on North American
and European experiences. In the light of empirical evidence from
Taipei City, this paper shows that this new type of urban planning and
policy intertwined with ICT has existed in Asian city for a decade as
well. Based on these results, this paper further reviews how the Taipei
City government implements this new type of urban ICT planning and
the validity and realism of its underlying assumptions. Finally, it also
explores the extent to which urban ICT planning could promote
positive synergies between physical and electronic developments.
Abstract: Flow-shop scheduling problem (FSP) deals with the
scheduling of a set of jobs that visit a set of machines in the same
order. The FSP is NP-hard, which means that an efficient algorithm
for solving the problem to optimality is unavailable. To meet the
requirements on time and to minimize the make-span performance of
large permutation flow-shop scheduling problems in which there are
sequence dependent setup times on each machine, this paper
develops one hybrid genetic algorithms (HGA). Proposed HGA
apply a modified approach to generate population of initial
chromosomes and also use an improved heuristic called the iterated
swap procedure to improve initial solutions. Also the author uses
three genetic operators to make good new offspring. The results are
compared to some recently developed heuristics and computational
experimental results show that the proposed HGA performs very
competitively with respect to accuracy and efficiency of solution.
Abstract: For positive integer s and t, the Ramsey number R(s, t)
is the least positive integer n such that for every graph G of order n, either G contains Ks as a subgraph or G contains Kt as a subgraph.
We construct the circulant graphs and use them to obtain lower bounds of some small Ramsey numbers.
Abstract: The fluorescent pseudomonad strain R81 is a root
colonizing rhizobacteria which promotes the growth of many plants
by various mechanisms. Its broth containing siderophore (ironchelating
compound) and 2,4- diacetyl phloroglucinol (DAPG) is
used for preparing bioinoculant formulations for agronomical
applications. Glycerol was found to be the best carbon source for
improved biomass production. Splitting of nitrogen source to NH4Cl
and urea had a stabilizing effect on pH during batch cultivation. Ltryptophan
at 0.5 % in the medium increased the siderophore
production to 850 mg/l. During batch cultivation of the strain in a
bioreactor, a maximum of 4 g/l of dry cell mass, 1.8 g/l of
siderophore and 20 mg/l of DAPG was achieved when glycerol was
15 g/l and C/N ratio was maintained at 12.5. In case of intermittent
feeding of fresh medium during fed-batch cultivation, the dry cell
mass was increased to 25 g/l with improved production of DAPG to
70 mg/l.
Abstract: Dengue fever has become a major concern for health
authorities all over the world particularly in the tropical countries.
These countries, in particular are experiencing the most worrying
outbreak of dengue fever (DF) and dengue haemorrhagic fever
(DHF). The DF and DHF epidemics, thus, have become the main
causes of hospital admissions and deaths in Malaysia. This paper,
therefore, attempts to examine the environmental factors that may
influence the recent dengue outbreak. The aim of this study is twofold,
firstly is to establish a statistical model to describe the
relationship between the number of dengue cases and a range of
explanatory variables and secondly, to identify the lag operator for
explanatory variables which affect the dengue incidence the most.
The explanatory variables involved include the level of cloud cover,
percentage of relative humidity, amount of rainfall, maximum
temperature, minimum temperature and wind speed. The Poisson and
Negative Binomial regression analyses were used in this study. The
results of the analyses on the 915 observations (daily data taken from
July 2006 to Dec 2008), reveal that the climatic factors comprising of
daily temperature and wind speed were found to significantly
influence the incidence of dengue fever after 2 and 3 weeks of their
occurrences. The effect of humidity, on the other hand, appears to be
significant only after 2 weeks.
Abstract: Technical laboratories are typically considered as
highly hazardous places in the polytechnic institution when
addressing the problems of high incidences and fatality rates. In
conjunction with several topics covered in the technical curricular,
safety and health precaution should be highlighted in order to
connect to few key ideas of being safe. Therefore the assessment of
safety awareness in terms of safety and health about hazardous and
risks at laboratories is needed and has to be incorporated with
technical education and other training programmes. The purpose of
this study was to determine the efficacy of technical laboratory safety
in one of the polytechnics in northern region. The study examined
three related issues that were; the availability of safety material and
equipment, safety practice adopted by technical teachers and
administrator-s safety attitudes in enforcing safety to the students. A
model of efficacy technical laboratory was developed to test the
linear relationship between existing safety material and equipment,
teachers- safety practice and administrators- attitude in enforcing
safety and to identify which of technical laboratory safety issues was
the most pertinent factor to realize safety in technical laboratory.
This was done by analyzing survey-based data sets particularly those
obtained from samples of 210 students in the polytechnic. The
Pearson Correlation was used to measure the association between the
variables and to test the research hypotheses. The result of the study
has found that there was a significant correlation between existing
safety material and equipment, safety practice adopted by teacher
and administrator-s attitude. There was also a significant relationship
between technical laboratory safety and safety practice adopted by
teacher and between technical laboratory safety and administrator
attitude. Hence, safety practice adopted by teacher and administrator
attitude is vital in realizing technical laboratory safety.
Abstract: Space Vector Modulation (SVM) is an optimum Pulse Width Modulation (PWM) technique for an inverter used in a variable frequency drive applications. It is computationally rigorous and hence limits the inverter switching frequency. Increase in switching frequency can be achieved using Neural Network (NN) based SVM, implemented on application specific chips. This paper proposes a neural network based SVM technique for a Voltage Source Inverter (VSI). The network proposed is independent of switching frequency. Different architectures are investigated keeping the total number of neurons constant. The performance of the inverter is compared for various switching frequencies for different architectures of NN based SVM. From the results obtained, the network with minimum resource and appropriate word length is identified. The bit precision required for this application is identified. The network with 8-bit precision is implemented in the IC XCV 400 and the results are presented. The performance of NN based general purpose SVM with higher bit precision is discussed.
Abstract: In the current study we present a system that is
capable to deliver proxy based differentiated service. It will help the
carrier service node to sell a prepaid service to clients and limit the
use to a particular mobile device or devices for a certain time. The
system includes software and hardware architecture for a mobile
device with moderate computational power, and a secure protocol for
communication between it and its carrier service node. On the
carrier service node a proxy runs on a centralized server to be
capable of implementing cryptographic algorithms, while the mobile
device contains a simple embedded processor capable of executing
simple algorithms. One prerequisite is needed for the system to run
efficiently that is a presence of Global Trusted Verification Authority
(GTVA) which is equivalent to certifying authority in IP networks.
This system appears to be of great interest for many commercial
transactions, business to business electronic and mobile commerce,
and military applications.
Abstract: In this paper, many techniques for blind identification of moving average (MA) process are presented. These methods utilize third- and fourth-order cumulants of the noisy observations of the system output. The system is driven by an independent and identically distributed (i.i.d) non-Gaussian sequence that is not observed. Two nonlinear optimization algorithms, namely the Gradient Descent and the Gauss-Newton algorithms are exposed. An algorithm based on the joint-diagonalization of the fourth-order cumulant matrices (FOSI) is also considered, as well as an improved version of the classical C(q, 0, k) algorithm based on the choice of the Best 1-D Slice of fourth-order cumulants. To illustrate the effectiveness of our methods, various simulation examples are presented.