Abstract: Security can be defined as the degree of resistance to, or protection from harm. It applies to any vulnerable and valuable assets, such as persons, dwellings, communities, nations or organizations. Cybercrime is any crime committed or facilitated via the Internet. It is any criminal activity involving computers and networks. It can range from fraud to unsolicited emails (spam). It includes the distant theft of government or corporate secrets through criminal trespass into remote systems around the globe. Nigeria like any other nations of the world is currently having her own share of the menace that has been used even as tools by terrorists. This paper is an attempt at presenting cyber security as an issue that requires a coordinated national response. It also acknowledges and advocates the key roles to be played by stakeholders and the importance of forging strong partnerships to prevent and tackle cybercrime in Nigeria.
Abstract: Advance in techniques of image and video processing has enabled the development of intelligent video surveillance systems. This study was aimed to automatically detect moving human objects and to analyze events of dual human interaction in a surveillance scene. Our system was developed in four major steps: image preprocessing, human object detection, human object tracking, and motion trajectory analysis. The adaptive background subtraction and image processing techniques were used to detect and track moving human objects. To solve the occlusion problem during the interaction, the Kalman filter was used to retain a complete trajectory for each human object. Finally, the motion trajectory analysis was developed to distinguish between the interaction and non-interaction events based on derivatives of trajectories related to the speed of the moving objects. Using a database of 60 video sequences, our system could achieve the classification accuracy of 80% in interaction events and 95% in non-interaction events, respectively. In summary, we have explored the idea to investigate a system for the automatic classification of events for interaction and non-interaction events using surveillance cameras. Ultimately, this system could be incorporated in an intelligent surveillance system for the detection and/or classification of abnormal or criminal events (e.g., theft, snatch, fighting, etc.).
Abstract: This study will examine how the therapeutic factors
(therapeutic catharsis-seeking and game-efficacy of the game player)
and self-construal factors (independent and interdependent
self-construal of the game player) as well as social capital factors
(bonding and bridging social capital of the game player) affect
aggression in the game. Results show that both therapeutic
catharsis-seeking and game self-efficacy are particularly important to
the players since they cause the game players’ aggressive tendencies to
be greatly diminished. Independent self-construal reduces the level of
the players’ aggression. Interestingly enough, the bonding social
capital enhances the level of the players’ aggression, while individuals
with bridging social capital did not show any significant effects. The
results and implications will be discussed herein.
Abstract: Distributed applications deployed on LEO satellites
and ground stations require substantial communication between
different members in a constellation to overcome the earth
coverage barriers imposed by GEOs. Applications running on LEO
constellations suffer the earth line-of-sight blockage effect. They
need adequate lab testing before launching to space. We propose
a scalable cloud-based network simulation framework to simulate
problems created by the earth line-of-sight blockage. The framework
utilized cloud IaaS virtual machines to simulate LEO satellites
and ground stations distributed software. A factorial ANOVA
statistical analysis is conducted to measure simulator overhead on
overall communication performance. The results showed a very low
simulator communication overhead. Consequently, the simulation
framework is proposed as a candidate for testing LEO constellations
with distributed software in the lab before space launch.
Abstract: Complex lifting entry was selected for precise landing
performance during the Mars Science Laboratory entry. This study
aims to develop the three-dimensional numerical method for precise
computation and the surface panel method for rapid engineering
prediction. Detailed flow field analysis for Mars exploration mission
was performed by carrying on a series of fully three-dimensional
Navier-Stokes computations. The static aerodynamic performance was
then discussed, including the surface pressure, lift and drag coefficient,
lift-to-drag ratio with the numerical and engineering method.
Computation results shown that the shock layer is thin because of
lower effective specific heat ratio, and that calculated results from both
methods agree well with each other, and is consistent with the
reference data. Aerodynamic performance analysis shows that CG
location determines trim characteristics and pitch stability, and certain
radially and axially shift of the CG location can alter the capsule lifting
entry performance, which is of vital significance for the aerodynamic
configuration design and inner instrument layout of the Mars entry
capsule.
Abstract: In this paper we propose a computer-aided solution
with Genetic Algorithms in order to reduce the drafting of reports:
FMEA analysis and Control Plan required in the manufacture of the
product launch and improved knowledge development teams for
future projects. The solution allows to the design team to introduce
data entry required to FMEA. The actual analysis is performed using
Genetic Algorithms to find optimum between RPN risk factor and
cost of production. A feature of Genetic Algorithms is that they are
used as a means of finding solutions for multi criteria optimization
problems. In our case, along with three specific FMEA risk factors is
considered and reduce production cost. Analysis tool will generate
final reports for all FMEA processes. The data obtained in FMEA
reports are automatically integrated with other entered parameters in
Control Plan. Implementation of the solution is in the form of an
application running in an intranet on two servers: one containing
analysis and plan generation engine and the other containing the
database where the initial parameters and results are stored. The
results can then be used as starting solutions in the synthesis of other
projects. The solution was applied to welding processes, laser cutting
and bending to manufacture chassis for buses. Advantages of the
solution are efficient elaboration of documents in the current project
by automatically generating reports FMEA and Control Plan using
multiple criteria optimization of production and build a solid
knowledge base for future projects. The solution which we propose is
a cheap alternative to other solutions on the market using Open
Source tools in implementation.
Abstract: Knowledge of bone mechanical properties is important
for bone substitutes design and fabrication, and more efficient
prostheses development. The aim of this study is to characterize the
viscoelastic behavior of bone specimens, through stress relaxation
and fatigue tests performed to trabecular bone samples from bovine
femoral heads. Relaxation tests consisted on preloading the samples
at five different magnitudes and evaluate them for 1020 seconds,
adjusting the results to a KWW mathematical model. Fatigue tests
consisted of 700 load cycles and analyze their status at the end of the
tests. As a conclusion we have that between relaxation stress and
each preload there is linear relation and for samples with initial
Young´s modulus greater than 1.5 GPa showed no effects due fatigue
test loading cycles.
Abstract: In this paper, we are interested in the problem of
finding similar images in a large database. For this purpose we
propose a new algorithm based on a combination of the 2-D
histogram intersection in the HSV space and statistical moments. The
proposed histogram is based on a 3x3 window and not only on the
intensity of the pixel. This approach overcome the drawback of the
conventional 1-D histogram which is ignoring the spatial distribution
of pixels in the image, while the statistical moments are used to
escape the effects of the discretisation of the color space which is
intrinsic to the use of histograms. We compare the performance of
our new algorithm to various methods of the state of the art and we
show that it has several advantages. It is fast, consumes little memory
and requires no learning. To validate our results, we apply this
algorithm to search for similar images in different image databases.
Abstract: Biomass briquette gasification is regarded as a
promising route for efficient briquette use in energy generation, fuels
and other useful chemicals. However, previous research has been
focused on briquette gasification in fixed bed gasifiers such as
updraft and downdraft gasifiers. Fluidised bed gasifier has the
potential to be effectively sized to medium or large scale. This study
investigated the use of fuel briquettes produced from blends of rice
husks and corn cobs biomass, in a bubbling fluidised bed gasifier.
The study adopted a combination of numerical equations and Aspen
Plus simulation software, to predict the product gas (syngas)
composition base on briquette density and biomass composition
(blend ratio of rice husks to corn cobs). The Aspen Plus model was
based on an experimentally validated model from the literature. The
results based on a briquette size 32 mm diameter and relaxed density
range of 500 to 650kg/m3, indicated that fluidisation air required in
the gasifier increased with increase in briquette density, and the
fluidisation air showed to be the controlling factor compared with the
actual air required for gasification of the biomass briquettes. The
mass flowrate of CO2 in the predicted syngas composition increased
with an increase in air flow, in the gasifier, while CO decreased and
H2 was almost constant. The ratio of H2 to CO for various blends of
rice husks and corn cobs did not significantly change at the designed
process air, but a significant difference of 1.0 was observed between
10/90 and 90/10 % blend of rice husks and corn cobs.
Abstract: This study was aimed to investigate the machining
stability of a spindle tool with different preloaded amount. To this end,
the vibration tests were conducted on the spindle unit with different
preload to assess the dynamic characteristics and machining stability
of the milling machine. Current results demonstrate that the tool tip
frequency response characteristics and the machining stabilities in X
and Y direction are affected to change due to the different preload of
spindle bearings. As found from the results, a high preloaded spindle
tool shows higher limited cutting depth at mid position, while a spindle
with low preload shows a higher limited depth. This indicates that the
machining stability of a milling machine is affected to vary by the
spindle unit when it was assembled with different bearing preload.
Abstract: More than 3000 plants of notable phyto-therapeutic
value grow in South Africa; these include Cissampelos capensis,
commonly known in Afrikaans as dawidjie or dawidjiewortel. C.
capensis is the most significant and popular medicinal plant used by
the Khoisan as well as other rural groups in the Western region of
South Africa. Its rhizomes are traditionally used to treat male fertility
problems. Yet, no studies have investigated the effects of this plant or
its extracts on human spermatozoa. Therefore, this study aimed at
investigating the effects of C. capensis rhizome extract (CRE)
fractions on ejaculated human spermatozoa in vitro. Spermatozoa
from a total of 77 semen samples were washed with human tubular
fluid medium supplemented with bovine serum albumin (HTF-BSA)
and incubated for 2 hours with 20 μg/ml progesterone (P4) followed
by incubation with different concentrations (0, 0.05, 0.5, 5, 50, 200
μg/ml) of fractionated CRE (F1=0% MeOH, F2=30% MeOH,
F3=60% MeOH and F4=100% MeOH) for 1.5 hours at 37°C. A
sample without addition of CRE fractions served as control. Samples
were analyzed for sperm motility, reactive oxygen species (ROS),
DNA-fragmentation, acrosome reaction and capacitation. Results
showed that F1 resulted in significantly higher values for ROS,
capacitation and hyper-activation compared to F2, F3, and F4 with
P4-stimulated samples generally having higher values. No significant
effect was found for the other parameters. In conclusion, alkaloids
present in F1 of CRE appear to have triggered sperm intrinsic ROS
production leading to sperm capacitation and acrosome reaction
induced by P4.
Abstract: Steady three-dimensional and two free surface waves
generated by moving bodies are presented, the flow problem to be
simulated is rich in complexity and poses many modeling challenges
because of the existence of breaking waves around the ship hull, and
because of the interaction of the two-phase flow with the turbulent
boundary layer. The results of several simulations are reported. The
first study was performed for NACA0012 of hydrofoil with different
meshes, this section is analyzed at h/c= 1, 0345 for 2D. In the second
simulation a mathematically defined Wigley hull form is used to
investigate the application of a commercial CFD code in prediction of
the total resistance and its components from tangential and normal
forces on the hull wetted surface. The computed resistance and wave
profiles are used to estimate the coefficient of the total resistance for
Wigley hull advancing in calm water under steady conditions. The
commercial CFD software FLUENT version 12 is used for the
computations in the present study. The calculated grid is established
using the code computer GAMBIT 2.3.26. The shear stress k-ωSST
model is used for turbulence modeling and the volume of fluid
technique is employed to simulate the free-surface motion. The
second order upwind scheme is used for discretizing the convection
terms in the momentum transport equations, the Modified HRIC
scheme for VOF discretization. The results obtained compare well
with the experimental data.
Abstract: Whey is the lactose rich by-product of the dairy
industry, having good amount of nutrient reservoir. Most abundant
nutrients are lactose, soluble proteins, lipids and mineral salts.
Disposing of whey by most of milk plants which do not have proper
pre-treatment system is the major issue. As a result of which, there
can be significant loss of potential food and energy source. Thus,
whey has been explored as the substrate for the synthesis of different
value added products such as enzymes. β-galactosidase is one of the
important enzymes and has become the major focus of research due
to its ability to catalyze both hydrolytic as well as
transgalactosylation reaction simultaneously. The enzyme is widely
used in dairy industry as it catalyzes the transformation of lactose to
glucose and galactose, making it suitable for the lactose intolerant
people. The enzyme is intracellular in both bacteria and yeast,
whereas for molds, it has an extracellular location. The present work
was carried to utilize the whey for the production of β-galactosidase
enzyme using both yeast and fungal cultures. The yeast isolate
Kluyveromyces marxianus WIG2 and various fungal strains have
been used in the present study. Different disruption techniques have
also been investigated for the extraction of the enzyme produced
intracellularly from yeast cells. Among the different methods tested
for the disruption of yeast cells, SDS-chloroform showed the
maximum β-galactosidase activity. In case of the tested fungal
cultures, Aureobasidium pullulans NCIM 1050 was observed to be
the maximum extracellular enzyme producer.
Abstract: In this study, the pedestrian simulation VISWALK
integration and application platform ant algorithms written program
made to construct a renovation engineering schedule planning mode.
The use of simulation analysis platform construction site when the user
running the simulation, after calculating the user walks in the case of
construction delays, the ant algorithm to find out the minimum delay
time schedule plan, and add volume and unit area deactivated loss of
business computing, and finally to the owners and users of two
different positions cut considerations pick out the best schedule
planning. To assess and validate its effectiveness, this study
constructed the model imported floor of a shopping mall floor
renovation engineering cases. Verify that the case can be found from
the mode of the proposed project schedule planning program can
effectively reduce the delay time and the user's walking mall loss of
business, the impact of the operation on the renovation engineering
facilities in the building to a minimum.
Abstract: Nowadays, the rapid development of CAD systems’
programming environments results in the creation of multiple
downstream applications, which are developed and becoming
increasingly available. CAD based manufacturing simulations is
gradually following the same trend. Drilling is the most popular holemaking
process used in a variety of industries. A specially built piece
of software that deals with the drilling kinematics is presented. The
cutting forces are calculated based on the tool geometry, the cutting
conditions and the tool/work-piece materials. The results are verified
by experimental work. Finally, the response surface methodology
(RSM) is applied and mathematical models of the total thrust force
and the thrust force developed because of the main cutting edges are
proposed.
Abstract: Metal thin-walled members have been widely used in
building industry. Usually they are utilized as purlins, girts or ceiling
beams. Due to slenderness of thin-walled cross-sections these
structural members are prone to stability problems (e.g. flexural
buckling, lateral torsional buckling). If buckling is not
constructionally prevented their resistance is limited by buckling
strength. In practice planar members of roof or wall cladding can be
attached to thin-walled members. These elements reduce
displacement of thin-walled members and therefore increase their
buckling strength. If this effect is taken into static assessment more
economical sections of thin-walled members might be utilized and
certain savings of material might be achieved. This paper focuses on
problem of determination of critical load of steel thin-walled beams
with lateral continuous restraint which is crucial for lateral torsional
buckling assessment.
Abstract: This paper addresses a cutting edge method of
business demand forecasting, based on an empirical probability
function when the historical behavior of the data is random.
Additionally, it presents error determination based on the numerical
method technique ‘propagation of errors.’ The methodology was
conducted characterization and process diagnostics demand planning
as part of the production management, then new ways to predict its
value through techniques of probability and to calculate their mistake
investigated, it was tools used numerical methods. All this based on
the behavior of the data. This analysis was determined considering
the specific business circumstances of a company in the sector of
communications, located in the city of Bogota, Colombia. In
conclusion, using this application it was possible to obtain the
adequate stock of the products required by the company to provide its
services, helping the company reduce its service time, increase the
client satisfaction rate, reduce stock which has not been in rotation
for a long time, code its inventory, and plan reorder points for the
replenishment of stock.
Abstract: In order to address construction project requirements
and specifications, scholars and practitioners need to establish
taxonomy according to a scheme that best fits their need. While
existing characterization methods are continuously being improved,
new ones are devised to cover project properties which have not been
previously addressed. One such method, the Project Definition Rating
Index (PDRI), has received limited consideration strictly as a
classification scheme. Developed by the Construction Industry
Institute (CII) in 1996, the PDRI has been refined over the last two
decades as a method for evaluating a project's scope definition
completeness during front-end planning (FEP). The main
contribution of this study is a review of practical project classification
methods, and a discussion of how PDRI can be used to classify
projects based on their readiness in the FEP phase. The proposed
model has been applied to 59 construction projects in Ontario, and
the results are discussed.
Abstract: This paper participates in giving new vision and
explains the learning and acquisition processes of English language
by analyzing a certain context. Five important factors in English
language acquisition and learning are discussed and suitable solutions
are provided. The factors are compared with the learners' linguistic
background at Bisha College of Technology BCT attempting to link
the issues faced by students and the research done on similar
situations. These factors are phonology, age of acquisition,
motivation, psychology and courses of English. These factors are
very important; because they interfere and affect specific learning
processes at BCT context and general English learning situations.
Abstract: This study examines the feasibility of indirect solar
desalination in oil producing countries in the Middle East and North
Africa (MENA) region. It relies on value engineering (VE) and costbenefit
with sensitivity analyses to identify optimal coupling
configurations of desalination and solar energy technologies. A
comparative return on investment was assessed as a function of water
costs for varied plant capacities (25,000 to 75,000 m3/day), project
lifetimes (15 to 25 years), and discount rates (5 to 15%) taking into
consideration water and energy subsidies, land cost as well as
environmental externalities in the form of carbon credit related to
greenhouse gas (GHG) emissions reduction. The results showed
reverse osmosis (RO) coupled with photovoltaic technologies (PVs)
as the most promising configuration, robust across different prices for
Brent oil, discount rates, as well as different project lifetimes.
Environmental externalities and subsidies analysis revealed that a
16% reduction in existing subsidy on water tariffs would ensure
economic viability. Additionally, while land costs affect investment
attractiveness, the viability of RO coupled with PV remains possible
for a land purchase cost