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: Considering the challenges of short product life cycles
and growing variant diversity, cost minimization and manufacturing
flexibility increasingly gain importance to maintain a competitive
edge in today’s global and dynamic markets. In this context, an
aerodynamic part feeding system for high-speed industrial assembly
applications has been developed at the Institute of Production
Systems and Logistics (IFA), Leibniz Universitaet Hannover. The
aerodynamic part feeding system outperforms conventional systems
with respect to its process safety, reliability, and operating speed. In
this paper, a multi-objective optimisation of the aerodynamic feeding
system regarding the orientation rate, the feeding velocity, and the
required nozzle pressure is presented.
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: Poverty alleviation is one of the most difficult
challenges facing third world countries in their development efforts.
Evidences in Nigeria showed that the number of those in poverty has
continued to increase. This paper is aimed at analyzing the
performance of poverty alleviation measures undertaken by
successive administrations in Nigeria with a view to addressing the
quagmire. The study identified the whole gamut of factors that served
as stumbling blocks to the implementation of each of the strategies
and recommended the involvement of local people in the
identification and design of projects so that sufficient participation
could be achieved.
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: Finding the optimal 3D path of an aerial vehicle under
flight mechanics constraints is a major challenge, especially when
the algorithm has to produce real time results in flight. Kinematics
models and Pythagorian Hodograph curves have been widely used
in mobile robotics to solve this problematic. The level of difficulty
is mainly driven by the number of constraints to be saturated at the
same time while minimizing the total length of the path. In this paper,
we suggest a pragmatic algorithm capable of saturating at the same
time most of dimensioning helicopter 3D trajectories’ constraints
like: curvature, curvature derivative, torsion, torsion derivative, climb
angle, climb angle derivative, positions. The trajectories generation
algorithm is able to generate versatile complex 3D motion primitives
feasible by a helicopter with parameterization of the curvature and the
climb angle. An upper ”motion primitives’ concatenation” algorithm
is presented based. In this article we introduce a new way of designing
three-dimensional trajectories based on what we call the ”Dubins
gliding symmetry conjecture”. This extremely performing algorithm
will be soon integrated to a real-time decisional system dealing with
inflight safety issues.
Abstract: Wireless networks are built upon the open shared
medium which makes easy for attackers to conduct malicious
activities. Jamming is one of the most serious security threats to
information economy and it must be dealt efficiently. Jammer
prevents legitimate data to reach the receiver side and also it
seriously degrades the network performance. The objective of this
paper is to provide a general overview of jamming in wireless
network. It covers relevant works, different jamming techniques,
various types of jammers and typical prevention techniques.
Challenges associated with comparing several anti-jamming
techniques are also highlighted.
Abstract: The present research aimed at studying the awareness
and attitudes of teachers towards inclusive education. The sample
consisted of 60 teachers, teaching in the primary section (1st – 4th) of
regular schools affiliated to the SSC board in Mumbai. Sample was
selected by Multi-stage cluster sampling technique. A semi-structured
self-constructed interview schedule and a self-constructed attitude
scale was used to study the awareness of teachers about disability and
Inclusive education, and their attitudes towards inclusive education
respectively. Themes were extracted from the interview data and
quantitative data was analyzed using SPSS package. Results revealed
that teachers had some amount of awareness but an inadequate
amount of information on disabilities and inclusive education.
Disability to most (37) teachers meant “an inability to do something”.
The difference between disability and handicap was stated by most as
former being cognitive while handicap being physical in nature. With
regard to Inclusive education, a large number (46) stated that they
were unaware of the term and did not know what it meant. Majority
(52) of them perceived maximum challenges for themselves in an
inclusive set up, and emphasized on the role of teacher training
courses in the area of providing knowledge (49) and training in
teaching methodology (53). Although, 83.3% of teachers held a
moderately positive attitude towards inclusive education, a large
percentage (61.6%) of participants felt that being in inclusive set up
would be very challenging for both children with special needs and
without special needs. Though, most (49) of the teachers stated that
children with special needs should be educated in regular classroom
but they further clarified that only those should be in a regular
classroom who have physical impairments of mild or moderate
degree.
Abstract: For the last decade, researchers have started to focus
their interest on Multicast Group Key Management Framework. The
central research challenge is secure and efficient group key
distribution. The present paper is based on the Bit model based
Secure Multicast Group key distribution scheme using the most
popular absolute encoder output type code named Gray Code. The
focus is of two folds. The first fold deals with the reduction of
computation complexity which is achieved in our scheme by
performing fewer multiplication operations during the key updating
process. To optimize the number of multiplication operations, an
O(1) time algorithm to multiply two N-bit binary numbers which
could be used in an N x N bit-model of reconfigurable mesh is used
in this proposed work. The second fold aims at reducing the amount
of information stored in the Group Center and group members while
performing the update operation in the key content. Comparative
analysis to illustrate the performance of various key distribution
schemes is shown in this paper and it has been observed that this
proposed algorithm reduces the computation and storage complexity
significantly. Our proposed algorithm is suitable for high
performance computing environment.
Abstract: Liver segmentation from medical images poses more
challenges than analogous segmentations of other organs. This
contribution introduces a liver segmentation method from a series of
computer tomography images. Overall, we present a novel method for
segmenting liver by coupling density matching with shape priors.
Density matching signifies a tracking method which operates via
maximizing the Bhattacharyya similarity measure between the
photometric distribution from an estimated image region and a model
photometric distribution. Density matching controls the direction of
the evolution process and slows down the evolving contour in regions
with weak edges. The shape prior improves the robustness of density
matching and discourages the evolving contour from exceeding liver’s
boundaries at regions with weak boundaries. The model is
implemented using a modified distance regularized level set (DRLS)
model. The experimental results show that the method achieves a
satisfactory result. By comparing with the original DRLS model, it is
evident that the proposed model herein is more effective in addressing
the over segmentation problem. Finally, we gauge our performance of
our model against matrices comprising of accuracy, sensitivity, and
specificity.
Abstract: Routing in adhoc networks is a challenge as nodes are
mobile, and links are constantly created and broken. Present ondemand
adhoc routing algorithms initiate route discovery after a path
breaks, incurring significant cost to detect disconnection and
establish a new route. Specifically, when a path is about to be broken,
the source is warned of the likelihood of a disconnection. The source
then initiates path discovery early, avoiding disconnection totally. A
path is considered about to break when link availability decreases.
This study modifies Adhoc On-demand Multipath Distance Vector
routing (AOMDV) so that route handoff occurs through link
availability estimation.
Abstract: Fading noise degrades the performance of cellular
communication, most notably in femto- and pico-cells in 3G and 4G
systems. When the wireless channel consists of a small number of
scattering paths, the statistics of fading noise is not analytically
tractable and poses a serious challenge to developing closed
canonical forms that can be analysed and used in the design of
efficient and optimal receivers. In this context, noise is multiplicative
and is referred to as stochastically local fading. In many analytical
investigation of multiplicative noise, the exponential or Gamma
statistics are invoked. More recent advances by the author of this
paper utilized a Poisson modulated-weighted generalized Laguerre
polynomials with controlling parameters and uncorrelated noise
assumptions. In this paper, we investigate the statistics of multidiversity
stochastically local area fading channel when the channel
consists of randomly distributed Rayleigh and Rician scattering
centers with a coherent Nakagami-distributed line of sight component
and an underlying doubly stochastic Poisson process driven by a
lognormal intensity. These combined statistics form a unifying triply
stochastic filtered marked Poisson point process model.
Abstract: Sub-Saharan Africa is described as the second fastest
growing in mobile phone penetration in the world more than in the
United States or the European Union. Mobile phones have been used
to provide a lot of opportunities to improve people’s lives in the
region such as in banking, marketing, entertainment, and paying for
various bills such as water, TV, and electricity. However, the
potential of mobile phones to enhance teaching and learning has not
been explored. This study presents an experience of developing and
delivering SMS based quiz questions used to assess mastery of
subject content knowledge of science and mathematics secondary
school teachers in Tanzania. The SMS quizzes were used as a follow
up support mechanism to 500 teachers who participated in a project
to upgrade subject content knowledge of teachers in science and
mathematics subjects in Tanzania. Quizzes of 10-15 questions were
sent to teachers each week for 8 weeks and the results were analyzed
using SPSS. Results show that teachers who participated in chemistry
and biology subjects have better performance compared to those who
participated in mathematics and physics subjects. Teachers reported
some challenges that led to poor performance, This research has
several practical implications for those who are implementing or
planning to use mobile phones in teaching and learning especially in
rural secondary schools in sub-Saharan Africa.
Abstract: Synchrophasor technology is fast being deployed in
electric power grids all over the world and is fast changing the way
the grids are managed. This trend is to continue until the entire
power grids are fully connected so they can be monitored and
controlled in real-time. Much achievement has been made in the
synchrophasor technology development and deployment, and there
are still much more to be achieved. For instance, real-time power
grid control and protection potentials of synchrophasor are yet to be
explored. It is of necessity that researchers keep in view the various
challenges that still need to be overcome in expanding the frontiers
of synchrophasor technology. This paper outlines the major
challenges that should be dealt with in order to achieve the goal of
total power grid visualization, monitoring, and control using
synchrophasor technology.
Abstract: The liberalisation of the education industry has
exposed the institute of higher learning (IHL) in Malaysia to the
financial challenges. Without good financial standing, public
institution will rely on the government funding. Ostensibly, this
contradicts with the government’s aspiration to make universities
self-sufficient. With stiff competition from private institutes of higher
learning, IHL need to be prepared at the forefront level. The
corporate identity itself is the entrance to the world of higher learning
and it is in this uniqueness, it will be able to distinguish itself from
competitors. This paper examined the perception of the stakeholders
at one of the public universities in the east coast region in Malaysia
on the perceived reputation and how the university communicate its
preparedness for self-sustainability through corporate identity. The
findings indicated while the stakeholders embraced the challenges in
facing the stiff competition and struggling market conditions, most of
them felt the university should put more efforts in mobilising the
corporate identity to its constituencies.
Abstract: At a global level, water stewardship, water stress and
water security are crucial factors in tourism planning and
development considerations. Challenges associated with water is of
particular concern to the Maldives as there is limited availability of
freshwater, high dependency on desalinated water, and high unit cost
associated with desalinating water. While the Maldives is promoted
as an example of sustainable tourism, a key sustainability challenge
facing tourism dependent communities is the efficient use and
management of available water resources. A water crisis event in the
capital island of Maldives highlighted how precarious water related
issues are in this tourism dependent destination. Applying
netnography, the focus of this working paper is to present community
perceptions of how government policies addressed Malé Water and
Sewerage Company (MWSC) water crisis event.
Abstract: Foundation differential settlement and supported
structure tilting are an occasionally occurred engineering problem.
This may be caused by overloading, changes in ground soil properties
or unsupported nearby excavations. Engineering thinking points
directly toward the logic solution for such problem by uplifting the
settled side. This can be achieved with deep foundation elements
such as micro-piles and macro-piles™, jacked piers, and helical piers,
jet grouted mortar columns, compaction grout columns, cement
grouting or with chemical grouting, or traditional pit underpinning
with concrete and mortar. Although, some of these techniques offer
economic, fast and low noise solutions, many of them are quite the
contrary. For tilted structures, with the limited inclination, it may be much
easier to cause a balancing settlement on the less-settlement side
which shall be done carefully in a proper rate. This principal has been
applied in Leaning Tower of Pisa stabilization with soil extraction
from the ground surface. In this research, the authors attempt to
introduce a new solution with a different point of view. So, the
micro-tunneling technique is presented in here as an intended ground
deformation cause. In general, micro-tunneling is expected to induce
limited ground deformations. Thus, the researchers propose to apply
the technique to form small size ground unsupported holes to produce
the target deformations. This shall be done in four phases: 1.
Application of one or more micro-tunnels, regarding the existing
differential settlement value, under the raised side of the tilted
structure. 2. For each individual tunnel, the lining shall be pulled out
from both sides (from jacking and receiving shafts) in the slow rate.
3. If required, according to calculations and site records, an additional
surface load can be applied on the raised foundation side. 4. Finally, a
strengthening soil grouting shall be applied for stabilization after
adjustment. A finite element based numerical model is presented to simulate
the proposed construction phases for different tunneling positions and
tunnels group. For each case, the surface settlements are calculated
and induced plasticity points are checked. These results show the
impact of the suggested procedure on the tilted structure and its
feasibility. Comparing results also show the importance of the
position selection and tunnels group gradual effect. Thus, a new
engineering solution is presented to one of the structural and
geotechnical engineering challenges.
Abstract: The education sector is constantly faced with rapid
changes in technologies in terms of ensuring that the curriculum is up
to date and in terms of making sure that students are aware of these
technological changes. This challenge can be seen as the motivation
for this study, which is to examine the factors affecting computing
students’ awareness of the latest Information Technologies (ICTs).
The aim of this study is divided into two sub-objectives which are:
the selection of relevant theories and the design of a conceptual
model to support it as well as the empirical testing of the designed
model. The first objective is achieved by a review of existing
literature on technology adoption theories and models. The second
objective is achieved using a survey of computing students in the four
universities of the KwaZulu-Natal province of South Africa. Data
collected from this survey is analyzed using Statistical package for
the Social Science (SPSS) using descriptive statistics, ANOVA and
Pearson correlations. The main hypothesis of this study is that there is
a relationship between the demographics and the prior conditions of
the computing students and their awareness of general ICT trends and
of Digital Switch Over (DSO) a new technology which involves the
change from analog to digital television broadcasting in order to
achieve improved spectrum efficiency. The prior conditions of the
computing students that were considered in this study are students’
perceived exposure to career guidance and students’ perceived
curriculum currency. The results of this study confirm that gender,
ethnicity, and high school computing course affect students’
perceived curriculum currency while high school location affects
students’ awareness of DSO. The results of this study also confirm
that there is a relationship between students prior conditions and their
awareness of general ICT trends and DSO in particular.
Abstract: Radio Frequency Identification (RFID) has become a
key technology in the emerging concept of Internet of Things (IoT).
Naturally, business applications would require the deployment of
various RFID systems developed by different vendors that use
different data formats and structures. This heterogeneity poses a
challenge in developing real-life IoT systems with RFID, as
integration is becoming very complex and challenging. Semantic
integration is a key approach to deal with this challenge. To do so,
ontology for RFID systems need to be developed in order to
annotated semantically RFID systems, and hence, facilitate their
integration. Accordingly, in this paper, we propose ontology for
RFID systems. The proposed ontology can be used to semantically
enrich RFID systems, and hence, improve their usage and reasoning.
Abstract: As computing technology advances, smartphone
applications can assist student learning in a pervasive way. For
example, the idea of using mobile apps for the PA Common Trees,
Pests, Pathogens, in the field as a reference tool allows middle school
students to learn about trees and associated pests/pathogens without
bringing a textbook. While working on the development of three heterogeneous mobile
apps, we ran into numerous challenges. Both the traditional waterfall
model and the more modern agile methodologies failed in practice.
The waterfall model emphasizes the planning of the duration for each
phase. When the duration of each phase is not consistent with the
availability of developers, the waterfall model cannot be employed.
When applying Agile Methodologies, we cannot maintain the high
frequency of the iterative development review process, known as
‘sprints’. In this paper, we discuss the challenges and solutions. We
propose a hybrid model known as the Relay Race Methodology to
reflect the concept of racing and relaying during the process of
software development in practice. Based on the development project,
we observe that the modeling of the relay race transition between any
two phases is manifested naturally. Thus, we claim that the RRM
model can provide a de fecto rather than a de jure basis for the core
concept in the software development model. In this paper, the background of the project is introduced first.
Then, the challenges are pointed out followed by our solutions.
Finally, the experiences learned and the future works are presented.