Abstract: In this paper, approach to incoherent signal detection
in multi-element antenna array are researched and modeled. Two
types of useful signals with unknown wavefront were considered:
first one, deterministic (Barker code), and second one, random
(Gaussian distribution). The derivation of the sufficient statistics took
into account the linearity of the antenna array. The performance
characteristics and detecting curves are modeled and compared for
different useful signals parameters and for different number of
elements of the antenna array. Results of researches in case of some
additional conditions can be applied to a digital communications
systems.
Abstract: We present probabilistic multinomial Dirichlet
classification model for multidimensional data and Gaussian process
priors. Here, we have considered efficient computational method that
can be used to obtain the approximate posteriors for latent variables
and parameters needed to define the multiclass Gaussian process
classification model. We first investigated the process of inducing a
posterior distribution for various parameters and latent function by
using the variational Bayesian approximations and important sampling
method, and next we derived a predictive distribution of latent
function needed to classify new samples. The proposed model is
applied to classify the synthetic multivariate dataset in order to verify
the performance of our model. Experiment result shows that our model
is more accurate than the other approximation methods.
Abstract: This paper introduces a signal monitoring program
developed with a view to helping electrical engineering students get
familiar with sensors with digital output. Because the output of digital
sensors cannot be simply monitored by a measuring instrument such as
an oscilloscope, students tend to have a hard time dealing with digital
sensors. The monitoring program runs on a PC and communicates with
an MCU that reads the output of digital sensors via an asynchronous
communication interface. Receiving the sensor data from the MCU,
the monitoring program shows time and/or frequency domain plots of
the data in real time. In addition, the monitoring program provides a
serial terminal that enables the user to exchange text information with
the MCU while the received data is plotted. The user can easily
observe the output of digital sensors and configure the digital sensors
in real time, which helps students who do not have enough experiences
with digital sensors. Though the monitoring program was programmed
in the Matlab programming language, it runs without the Matlab since
it was compiled as a standalone executable.
Abstract: The use of Computer Aided Design (CAD)
technologies has become pervasive in the Architecture, Engineering
and Construction (AEC) industry. This has led to its inclusion as an
important part of the training module in the curriculum for
Architecture Schools in Nigeria. This paper examines the ethical
questions that arise in the implementation of Computer Aided Design
(CAD) Content of the curriculum for Architectural education. Using
existing literature, it begins this scrutiny from the propriety of
inclusion of CAD into the education of the architect and the
obligations of the different stakeholders in the implementation
process. It also examines the questions raised by the negative use of
computing technologies as well as perceived negative influence of
the use of CAD on design creativity. Survey methodology was
employed to gather data from the Department of Architecture,
Chukwuemeka Odumegwu Ojukwu University Uli, which has been
used as a case study on how the issues raised are being addressed.
The paper draws conclusions on what will make for successful ethical
implementation.
Abstract: Password authentication is one of the widely used
methods to achieve authentication for legal users of computers and
defense against attackers. There are many different ways to
authenticate users of a system and there are many password cracking
methods also developed. This paper proposes how best password
cracking can be performed on a CPU-GPGPU based system. The
main objective of this work is to project how quickly a password can
be cracked with some knowledge about the computer security and
password cracking if sufficient security is not incorporated to the
system.
Abstract: Thermoacoustic refrigerator is a cooling device which
uses the acoustic waves to produce the cooling effect. The aim of this
paper is to explore the experimental and numerical feasibility of a
standing-wave thermoacoustic refrigerator. The effects of the stack
length, position of stack and operating frequency on the cooling
performance are carried out. The circular pore stacks are tested under
the atmospheric pressure. A low-cost loudspeaker is used as an
acoustic driver. The results show that the location of stack installed in
resonator tube has a greater effect on the cooling performance, than
the stack length and operating frequency, respectively. The
temperature difference across the ends of stack can be generated up
to 13.7°C, and the temperature of cold-end is dropped down by 5.3°C
from the ambient temperature.
Abstract: The power electronic components within Electric Vehicles (EV) need to operate in several important modes. Some modes directly influence safety, while others influence vehicle performance. Given the variety of functions and operational modes required of the power electronics, it needs to meet efficiency requirements to minimize power losses. Another challenge in the control and construction of such systems is the ability to support bidirectional power flow. This paper considers the construction, operation, and feasibility of available converters for electric vehicles with feasible configurations of electrical buses and loads. This paper describes logic and control signals for the converters for different operations conditions based on the efficiency and energy usage bases.
Abstract: The aim of the study was to investigate the effect of
Saccharomyces cerevisiae (SC) live yeast culture on microbial
protein supply to small intestine in Kivircik male yearlings when fed
with different ratio of forage and concentrate diets. Four Kivircik
male yearlings with permanent rumen canula were used in the
experiment. The treatments were allocated to a 4x4 Latin square
design. Diet I consisted of 70% alfalfa hay and 30% concentrate, Diet
II consisted of 30% alfalfa hay and 70% concentrate, Diet I and II
were supplemented with a SC. Daily urine was collected and stored at
-20°C until analysis. Calorimetric methods were used for the
determination of urinary allantoin and creatinine levels. The
estimated microbial N supply to small intestine for Diets I, I+SC, II
and II+SC were 2.51, 2.64, 2.95 and 3.43 g N/d respectively.
Supplementation of Diets I and II with SC significantly affected the
allantoin levels in μmol/W0.75 (p
Abstract: The transesterification of dimethyl malonate (DMM)
with phenol has been studied in vapour phase over cordierite
honeycomb coated with solid acid catalysts such as ZrO2,
Mo(VI)/ZrO2 and SO42-/ZrO2. The catalytic materials were prepared
honeycomb coated, powder forms, and characterized for their total
surface acidity by NH3-TPD and crystalinity by powder XRD
methods. Phenyl methyl malonate (PMM) and diphenyl malonate
(DPM) were obtained as the reaction products. A good conversion of
DMM (up to 82%) of MPM with 95% selectivity was observed when
the reactions were carried out at a catalyst bed temperature of 200 °C
and flow-rate of 10 mL/h in presence of Mo(VI)/ZrO2 as catalyst.
However, over SO4^2-/ZrO2 catalyst, the yield of DPM was found to be
higher. The results have been interpreted based on the variation of
acidic properties and powder XRD phases of zirconia on
incorporation of Mo(VI) or SO42– ions. Transesterification reactions
were also carried out over powder forms of the catalytic materials
and the yield of the desired phenyl ester products were compared
with that of the HC coated catalytic materials. The solid acids were
found to be reusable when used for at least 5 reaction cycles.
Abstract: In this paper, a robust fault detection and isolation
(FDI) scheme is developed to monitor a multivariable nonlinear
chemical process called the Chylla-Haase polymerization reactor,
when it is under the cascade PI control. The scheme employs a radial
basis function neural network (RBFNN) in an independent mode to
model the process dynamics, and using the weighted sum-squared
prediction error as the residual. The Recursive Orthogonal Least
Squares algorithm (ROLS) is employed to train the model to
overcome the training difficulty of the independent mode of the
network. Then, another RBFNN is used as a fault classifier to isolate
faults from different features involved in the residual vector. Several
actuator and sensor faults are simulated in a nonlinear simulation of
the reactor in Simulink. The scheme is used to detect and isolate the
faults on-line. The simulation results show the effectiveness of the
scheme even the process is subjected to disturbances and
uncertainties including significant changes in the monomer feed rate,
fouling factor, impurity factor, ambient temperature, and
measurement noise. The simulation results are presented to illustrate
the effectiveness and robustness of the proposed method.
Abstract: Durian skin is a newly explores natural fibre
potentially reinforced polyolefin for diverse applications. In this
work, investigation on the effect of coupling agent, maleic anhydride
polypropylene (MAPP) on the mechanical, morphological, and
thermal properties of polypropylene (PP) reinforced with durian skin
fibre (DSF) was conducted. The presence of 30 wt% DSF
significantly reduced the tensile strength of PP-DSF composite.
Interestingly, even though the same trend goes to PP-DSF with the
presence of MAPP, the reduction is only about 4% relative to
unreinforced PP and 18% higher than PP-DSF without MAPP
(untreated composite or UTC). The used of MAPP in treated
composite (TC) also increased the tensile modulus, flexural
properties and degradation temperature. The enhanced mechanical
properties are consistent with good interfacial interaction as
evidenced under scanning electron microscopy.
Abstract: Much of the literature on research design has focused
on research conducted in developed, uni-cultural or primarily English
speaking countries. Studies of qualitative case study research, the
challenges, and prospects have been embedded in Western/Eurocentric
society and social theories. Although there have been some
theoretical studies, few empirical studies have been conducted to
explore the nature of the challenges of qualitative case study in
developing countries. These challenges include accessibility to
organizations, conducting interviews in developing countries,
accessing documents and observing official meetings, language and
cultural challenges, the use of consent forms, issues affecting access
to companies, respondent issues, and data analysis. The author, while
conducting qualitative case study research in Libya, faced all these
issues. The discussion in this paper examines these issues in order to
make a contribution toward the literature in this area.
Abstract: The goal of this paper is to identify the main
differences in the way men and women perceive TV ads. This paper
is based on a research project conducted partly as a review of relevant
papers, which deals with gender influence on the cognitive process
and postmodern perception of advertising. In addition to that,
qualitative research was conducted by means of interviews and
structured questionnaires. Furthermore, data acquired from the
research were used to evaluate our objectives and hypotheses. The
goal of this paper is to compare women's and men's perception of
advertisement. Although women are able to perceive more details
than men, men are more susceptible to sexual appeals in advertising.
Significant differences were also found in the perception of sexual
appeals in the context of gender.
Abstract: We have studied the temporal characteristics of
bistable perception of the stimuli of two types: one involves
alterations in a perceived depth and another one has an ambiguous
content. We used the Necker lattice and lines of shadowed circles
ambiguously perceived either as spheres or holes as stimuli of the
first type. The Winson figure (the Eskimo/Indian picture) was a
stimulus of the second type. We have analyzed how often the
reversals occurred (reversal rate) and for how long each of the two
interpretations, or percepts, was observed during one presentation
(stability durations). For all three ambiguous images the reversal rate
and the stability durations had similar values, which provide another
evidence for a significant role of top-down processes in multistable
perception.
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: Global economy today is full of sophistication. All
over the world, business and marketing practices are undergoing
unprecedented transformation. In realization of this fact, the federal
government of Nigeria has put in place a robust transformation
agenda in order to put Nigeria in a better position to be a competitive
player and in the process transform all sectors of its economy. New
technologies, especially the Internet, are the driving force behind this
transformation. However, technology has inadvertently affected the
way businesses are done thus necessitating the acquisition of new
skills. In developing countries like Nigeria, citizens are still battling
with effective application of those technologies. Obviously, students
of business education need to acquire relevant business knowledge to
be able to transit into the world of work on graduation from school
and compete favorably in the labor market. Therefore, effective
utilization of social media by both teachers and students can help
extensively in empowering students with the needed skills. Social
media which is a group of Internet-based applications built on the
ideological foundations of Web 2.0, that allow the creation and
exchange of user generated content, and if incorporated into the
classroom experience may be the needed answer to unemployment
and poverty in Nigeria as beneficiaries can easily connect with
existing and potential enterprises and customers, engage with them
and reinforce mutual business benefits. Challenges and benefits of
social media use in education in Nigeria universities were revealed in
this study.
Abstract: Wind energy is rapidly emerging as the primary
source of electricity in the Philippines, although developing an
accurate wind resource model is difficult. In this study, Weather
Research and Forecasting (WRF) Model, an open source mesoscale
Numerical Weather Prediction (NWP) model, was used to produce a
1-year atmospheric simulation with 4 km resolution on the Ilocos
Region of the Philippines. The WRF output (netCDF) extracts the
annual mean wind speed data using a Python-based Graphical User
Interface. Lastly, wind resource assessment was produced using a
GIS software. Results of the study showed that it is more flexible to
use Python scripts than using other post-processing tools in dealing
with netCDF files. Using WRF Model, Python, and Geographic
Information Systems, a reliable wind resource map is produced.
Abstract: The underutilization of biomass resources in the
Philippines, combined with its growing population and the rise in
fossil fuel prices confirms demand for alternative energy sources. The
goal of this paper is to provide a comparison of MODIS-based and
Landsat-based agricultural land cover maps when used in the
estimation of rice hull’s available energy potential. Biomass resource
assessment was done using mathematical models and remote sensing
techniques employed in a GIS platform.
Abstract: This research work presents the surface
thermodynamics approach to M-TB/HIV-Human sputum
interactions. This involved the use of the Hamaker coefficient
concept as a surface energetics tool in determining the interaction
processes, with the surface interfacial energies explained using van
der Waals concept of particle interactions. The Lifshitz derivation for
van der Waals forces was applied as an alternative to the contact
angle approach which has been widely used in other biological
systems. The methodology involved taking sputum samples from
twenty infected persons and from twenty uninfected persons for
absorbance measurement using a digital Ultraviolet visible
Spectrophotometer. The variables required for the computations with
the Lifshitz formula were derived from the absorbance data. The
Matlab software tools were used in the mathematical analysis of the
data produced from the experiments (absorbance values). The
Hamaker constants and the combined Hamaker coefficients were
obtained using the values of the dielectric constant together with the
Lifshitz Equation. The absolute combined Hamaker coefficients
A132abs and A131abs on both infected and uninfected sputum samples
gave the values of A132abs = 0.21631x10-21Joule for M-TB infected
sputum and Ã132abs = 0.18825x10-21Joule for M-TB/HIV infected
sputum. The significance of this result is the positive value of the
absolute combined Hamaker coefficient which suggests the existence
of net positive van der waals forces demonstrating an attraction
between the bacteria and the macrophage. This however, implies that
infection can occur. It was also shown that in the presence of HIV,
the interaction energy is reduced by 13% conforming adverse effects
observed in HIV patients suffering from tuberculosis.
Abstract: This research aimed to investigate the relationship
between attitude towards marketing mix, brand image and consumer
behavior of the passengers of low-cost airlines service. This study
employed by quantitative research and the questionnaire was used to
collect the data from 400 sampled of the passengers who have ever
used the low-cost airline services based in Bangkok, Thailand. The
descriptive statistics and Pearson’s correlation analysis were used to
analyze data. The research results revealed that the attitude of the marketing mix
of the low-cost airline services including product, price, place,
promotion and process had related to the consumer behavior on the
aspects of duration of service and frequency of service. While, the
brand image of the low cost airline including the characteristics of
organization, service quality and company identity had related to the
consumer behavior on duration of service, frequency of service and
cost of service at the significant statistically acceptable levels.