Abstract: Orthogonal Frequency Division Multiplexing
(OFDM) has been used in many advanced wireless communication
systems due to its high spectral efficiency and robustness to
frequency selective fading channels. However, the major concern
with OFDM system is the high peak-to-average power ratio (PAPR)
of the transmitted signal. Some of the popular techniques used for
PAPR reduction in OFDM system are conventional partial transmit
sequences (CPTS) and clipping. In this paper, a parallel
combination/hybrid scheme of PAPR reduction using clipping and
CPTS algorithms is proposed. The proposed method intelligently
applies both the algorithms in order to reduce both PAPR as well as
computational complexity. The proposed scheme slightly degrades
bit error rate (BER) performance due to clipping operation and it can
be reduced by selecting an appropriate value of the clipping ratio
(CR). The simulation results show that the proposed algorithm
achieves significant PAPR reduction with much reduced
computational complexity.
Abstract: Concrete is an essential building material which is
widely used in construction industry all over the world due to its
compressible strength. Curing of concrete plays a vital role in
durability and other performance necessities. Improper curing can
affect the concrete performance and durability easily. When areas
like scarcity of water, structures is not accessible by humans external
curing cannot be performed, so we opt for internal curing. Internal
curing (or) self curing plays a major role in developing the concrete
pore structure and microstructure. The concept of internal curing is to
enhance the hydration process to maintain the temperature uniformly.
The evaporation of water in the concrete is reduced by self curing
agent (Super Absorbing Polymer – SAP) there by increasing the
water retention capacity of the concrete. The research work was
carried out to reduce water, which is prime material used for concrete
in the construction industry. Concrete curing plays a major role in
developing hydration process. Concept of self curing will reduce the
evaporation of water from concrete. Self curing will increase water
retention capacity as compared to the conventional concrete. Proper
self curing (or) internal curing increases the strength, durability and
performance of concrete. Super absorbing Polymer (SAP) used as
internal curing agent. In this study 0.2% to 0.4% of SAP was varied
in different grade of high strength concrete. In the experiment
replacement of cement by silica fumes with 5%, 10% and 15% are
studied. It is found that replacement of silica fumes by 10 % gives
more strength and durability when compared to others.
Abstract: In language learning, second language learners as well
as Native speakers commit errors in their attempt to achieve
competence in the target language. The realm of collocation has to do
with meaning relation between lexical items. In all human language,
there is a kind of ‘natural order’ in which words are arranged or relate
to one another in sentences so much so that when a word occurs in a
given context, the related or naturally co-occurring word will
automatically come to the mind. It becomes an error, therefore, if
students inappropriately pair or arrange such ‘naturally’ co–occurring
lexical items in a text. It has been observed that most of the second
language learners in this research group commit collocation errors. A
study of this kind is very significant as it gives insight into the kinds
of errors committed by learners. This will help the language teacher
to be able to identify the sources and causes of such errors as well as
correct them thereby guiding, helping and leading the learners
towards achieving some level of competence in the language. The
aim of the study is to understand the nature of these errors as
stumbling blocks to effective essay writing. The objective of the
study is to identify the errors, analyze their structural compositions so
as to determine whether there are similarities between students in this
regard and to find out whether there are patterns to these kinds of
errors which will enable the researcher to understand their sources
and causes. As a descriptive research, the researcher samples some
nine hundred essays collected from three hundred undergraduate
learners of English as a second language in the Federal College of
Education, Kano, North- West Nigeria, i.e. three essays per each
student. The essays which were given on three different lecture times
were of similar thematic preoccupations (i.e. same topics) and length
(i.e. same number of words). The essays were written during the
lecture hour at three different lecture occasions. The errors were
identified in a systematic manner whereby errors so identified were
recorded only once even if they occur severally in students’ essays.
The data was collated using percentages in which the identified
numbers of occurrences were converted accordingly in percentages.
The findings from the study indicate that there are similarities as well
as regular and repeated errors which provided a pattern. Based on the
pattern identified, the conclusion is that students’ collocation errors
are attributable to poor teaching and learning which resulted in wrong
generalization of rules.
Abstract: Excessive vibration means increased wear, increased
repair efforts, bad product selection & quality and high energy
consumption. This may be sometimes experienced by cavitation or
suction/discharge recirculation which could occur only when net
positive suction head available NPSHA drops below the net positive
suction head required NPSHR. Cavitation can cause axial surging, if it
is excessive, will damage mechanical seals, bearings, possibly other
pump components frequently, and shorten the life of the impeller.
Efforts have been made to explain Suction Energy (SE), Specific
Speed (Ns), Suction Specific Speed (Nss), NPSHA, NPSHR & their
significance, possible reasons of cavitation /internal recirculation, its
diagnostics and remedial measures to arrest and prevent cavitation in
this paper. A case study is presented by the author highlighting that
the root cause of unwanted noise and vibration is due to cavitation,
caused by high specific speeds or inadequate net- positive suction
head available which results in damages to material surfaces of
impeller & suction bells and degradation of machine performance, its
capacity and efficiency too. Author strongly recommends revisiting
the technical specifications of CW pumps to provide sufficient NPSH
margin ratios >1.5, for future projects and Nss be limited to 8500 -
9000 for cavitation free operation.
Abstract: The most crucial aspect that is closely related to vocabulary and the one that needs to be emphasized and investigated more than it has been up until now, is the ability to combine words that co-occur frequently in the language. Pedagogically, collocation is one of the error-provoking aspects in foreign language learning. This is indicative of the dire need to provide L2 learners with tools to help them improve their collocational knowledge. This paper pinpoints the role that collocations play in the English language. Furthermore, it presents pedagogical implications for ESL/EFL learners.
Abstract: The simulation in wind tunnel is used thoroughly to model real situations of drainages of air. Besides the automotive industry, a great number of applications can be numbered: dispersion of pollutant, studies of pedestrians’ comfort, and dispersion of particles. This work had the objective of visualizing the characteristics aerodynamics of two automobiles in different ways. To accomplish that drainage of air a fan that generated a speed exists (measured with anemometer of hot thread) of 4,1m/s and 4,95m/s. To visualize the path of the air through the cars, in the wind tunnel, smoke was used, obtained with it burns of vegetable oil. For “to do smoke” vegetable oil was used, that was burned for a tension of 20V generated by a thread of 2,5mm. The cars were placed inside of the wind tunnel with the drainage of “air-smoke” and photographed, registering like this the path lines around them, in the 3 different speeds.
Abstract: A combined heat and power (CHP) system is an efficient and clean way to generate power (electricity). Heat produced by the CHP system can be used for water and space heating. The CHP system which uses hydrogen as fuel produces zero carbon emission. Its’ efficiency can reach more than 80% whereas that of a traditional power station can only reach up to 50% because much of the thermal energy is wasted. The other advantages of CHP systems include that they can decentralize energy generation, improve energy security and sustainability, and significantly reduce the energy cost to the users. This paper presents the economic benefits of using a CHP system in the domestic environment. For this analysis, natural gas is considered as potential fuel as the hydrogen fuel cell based CHP systems are rarely used. UK government incentives for CHP systems are also considered as the added benefit. Results show that CHP requires a significant initial investment in returns it can reduce the annual energy bill significantly. Results show that an investment may be paid back in 7 years. After the back period, CHP can run for about 3 years as most of the CHP manufacturers provide 10 year warranty.
Abstract: Geological structure formed by volcanic activities shows polymorphic characteristics due to repeated cooling and hardening of lava. The Jeju region is showing polymorphic characteristics in which clinker layers are irregularly distributed along with vesicular basalt due to volcanic activities. Accordingly, resident damages and environmental disputes occur frequently in the Jeju region due to blasting. The purpose of this study is to develop a blast vibration equation considering the polymorphic characteristics of basaltic ground in Jeju. The blast vibration equation consists of a functional formula of the blasting vibration constant K that changes according to ground characteristics, and attenuation index n. The case study results in Jeju showed that if there are clinker layers, attenuation index n showed a distribution of -1.32~-1.81, whereas if there are no clinker layers, n was -2.79. Moreover, if there are no clinker layers, the frequency of blast vibration showed a high frequency band from 30Hz to 100Hz, while in rocks with clinker layers it showed a low frequency band from 10Hz to 20Hz.
Abstract: E-government has been adopted and used by many governments/countries around the world including Ghana to provide citizens and businesses with more accurate, real-time, and high quality services and information. The objective of this paper is to present an overview of the Government of Ghana’s (GoG) adoption and implement of e-government and its usage by the Ministries, Departments and its agencies (MDAs) as well as other public sector institutions to deliver efficient public service to the general public i.e. citizens, business etc. Government implementation of e-government focused on facilitating effective delivery of government service to the public and ultimately to provide efficient government-wide electronic means of sharing information and knowledge through a network infrastructure developed to connect all major towns and cities, Ministries, Departments and Agencies and other public sector organizations in Ghana. One aim for the Government of Ghana use of ICT in public administration is to improve productivity in government administration and service by facilitating exchange of information to enable better interaction and coordination of work among MDAs, citizens and private businesses. The study was prepared using secondary sources of data from government policy documents, national and international published reports, journal articles, and web sources. This study indicates that through the e-government initiative, currently citizens and businesses can access and pay for services such as renewal of driving license, business registration, payment of taxes, acquisition of marriage and birth certificates as well as application for passport through the GoG electronic service (eservice) and electronic payment (epay) portal. Further, this study shows that there is enormous commitment from GoG to adopt and implement e-government as a tool not only to transform the business of government but also to bring efficiency in public services delivered by the MDAs. To ascertain this, a further study need to be carried out to determine if the use of e-government has brought about the anticipated improvements and efficiency in service delivery of MDAs and other state institutions in Ghana.
Abstract: Energy has a prominent role for development of
nations. Countries which have energy resources also have strategic
power in the international trade of energy since it is essential for all
stages of production in the economy. Thus, it is important for
countries to analyze the weaknesses and strength of the system. On
the other side, international trade is one of the fields that are analyzed
as a complex network via network analysis. Complex network is one
of the tools to analyze complex systems with heterogeneous agents
and interaction between them. A complex network consists of nodes
and the interactions between these nodes. Total properties which
emerge as a result of these interactions are distinct from the sum of
small parts (more or less) in complex systems. Thus, standard
approaches to international trade are superficial to analyze these
systems. Network analysis provides a new approach to analyze
international trade as a network. In this network, countries constitute
nodes and trade relations (export or import) constitute edges. It
becomes possible to analyze international trade network in terms of
high degree indicators which are specific to complex networks such
as connectivity, clustering, assortativity/disassortativity, centrality,
etc. In this analysis, international trade of crude oil and coal which
are types of fossil fuel has been analyzed from 2005 to 2014 via
network analysis. First, it has been analyzed in terms of some
topological parameters such as density, transitivity, clustering etc.
Afterwards, fitness to Pareto distribution has been analyzed via
Kolmogorov-Smirnov test. Finally, weighted HITS algorithm has
been applied to the data as a centrality measure to determine the real
prominence of countries in these trade networks. Weighted HITS
algorithm is a strong tool to analyze the network by ranking countries
with regards to prominence of their trade partners. We have
calculated both an export centrality and an import centrality by
applying w-HITS algorithm to the data. As a result, impacts of the
trading countries have been presented in terms of high-degree
indicators.
Abstract: This paper explored the challenges faced by the
management of a Ghanaian state enterprise in managing conflicts and
disturbances associated with its attempt to implement new work
practices to enhance its capability to operate as a commercial entity.
The purpose was to understand the extent to which organizational
involvement, consistency and adaptability influence employees’
consumption of new work practices in transforming the
organization’s organizational activity system. Using selfadministered
questionnaires, data were collected from one hundred
and eighty (180) employees and analyzed using both descriptive and
inferential statistics. The results showed that constraints in
organizational involvement and adaptability prevented the positive
consumption of new work practices by employees in the
organization. It is also found that the organization’s employees failed
to consume the new practices being implemented, because they
perceived the process as non-involving, and as such, did not
encourage the development of employee capability, empowerment,
and teamwork. The study concluded that the failure of the
organization’s management to create opportunities for organizational
learning constrained its ability to get employees consume the new
work practices, which situation could have facilitated the
organization’s capabilities of operating as a commercial entity.
Abstract: In order to retrieve images efficiently from a large
database, a unique method integrating color and texture features
using genetic programming has been proposed. Opponent color
histogram which gives shadow, shade, and light intensity invariant
property is employed in the proposed framework for extracting color
features. For texture feature extraction, fast discrete curvelet
transform which captures more orientation information at different
scales is incorporated to represent curved like edges. The recent
scenario in the issues of image retrieval is to reduce the semantic gap
between user’s preference and low level features. To address this
concern, genetic algorithm combined with relevance feedback is
embedded to reduce semantic gap and retrieve user’s preference
images. Extensive and comparative experiments have been conducted
to evaluate proposed framework for content based image retrieval on
two databases, i.e., COIL-100 and Corel-1000. Experimental results
clearly show that the proposed system surpassed other existing
systems in terms of precision and recall. The proposed work achieves
highest performance with average precision of 88.2% on COIL-100
and 76.3% on Corel, the average recall of 69.9% on COIL and 76.3%
on Corel. Thus, the experimental results confirm that the proposed
content based image retrieval system architecture attains better
solution for image retrieval.
Abstract: In this paper, a modified Wilkinson power divider for
GSM application is presented. The quarter–wavelength microstrip
lines in the conventional Wilkinson power divider (WPD) are
replaced by one-eighth wavelength transmission line. Wilkinson
power divider is designed using λ/4 and λ/8 transmission line. It has
the operating frequency of 915 MHz which is used in the GSM
standard. The proposed Wilkinson Power Divider is designed using
the simulation tool Advanced Design System. The results of λ/8
transmission line are very close to the results of λ/4 transmission line.
The isolation loss of λ/8 transmission line is improved by introducing
a capacitor between the output ports. The proposed Wilkinson power
divider has the best return loss of greater than -10 dB and isolation
loss of -15.25 dB. The λ/8 transmission line Wilkinson power divider
has the reduced size of 53.9 percentages than λ/4 transmission line
WPD. The proposed design has simple structure, better isolation loss
and good insertion loss.
Abstract: The early-stage damage detection in offshore
structures requires continuous structural health monitoring and for the
large area the position of sensors will also plays an important role in
the efficient damage detection. Determining the dynamic behavior of
offshore structures requires dense deployment of sensors. The wired
Structural Health Monitoring (SHM) systems are highly expensive
and always needs larger installation space to deploy. Wireless sensor
networks can enhance the SHM system by deployment of scalable
sensor network, which consumes lesser space. This paper presents the
results of wireless sensor network based Structural Health Monitoring
method applied to a scaled experimental model of offshore structure
that underwent wave loading. This method determines the
serviceability of the offshore structure which is subjected to various
environment loads. Wired and wireless sensors were installed in the
model and the response of the scaled BLSRP model under wave
loading was recorded. The wireless system discussed in this study is
the Raspberry pi board with Arm V6 processor which is programmed
to transmit the data acquired by the sensor to the server using Wi-Fi
adapter, the data is then hosted in the webpage. The data acquired
from the wireless and wired SHM systems were compared and the
design of the wireless system is verified.
Abstract: The paper focuses on the distance laboratory
organisation for training the electrical engineering staff and students
in the fields of electrical drive and power electronics. To support
online knowledge acquisition and professional enhancement, new
challenges in remote education based on an active learning approach
with self-assessment have been emerged by the authors. Following
the literature review and explanation of the improved assessment
methodology, the concept and technological basis of the labs
arrangement are presented. To decrease the gap between the distance
study of the up-to-date equipment and other educational activities in
electrical engineering, the improvements in the following-up the
learners’ progress and feedback composition are introduced. An
authoring methodology that helps to personalise knowledge
acquisition and enlarge Web-based possibilities is described.
Educational management based on self-assessment is discussed.
Abstract: This paper presents the experimental results of 11 kV
and 33 kV silicon composite insulators under artificial salt and urea
polluted conditions. The tests were carried out under different
seasons like summer, winter, and monsoon. The artificial pollution is
prepared by properly dissolving the salt and urea in the water. The
prepared salt and urea pollutions are sprayed on the insulators and
dried up for sufficiently large time. The process is continued until a
uniform layer is formed on the surface of insulator. For each insulator
rating, four samples were tested. The maximum leakage current and
breakdown voltage were measured. From experimental data,
performance of test specimen is evaluated by comparing breakdown
voltage and leakage current during different seasons when exposed to
salt and urea polluted conditions. From these results the performance
of the insulators can be predicted when they are installed in
industrial, agricultural, and coastal areas. The experimental tests were
carried out in the High Voltage laboratory using two stage cascade
transformer having the rating of 1000 kVA, 500 kV.
Abstract: Fermentation is well known as an essential process to
develop chocolate flavor in dried cocoa beans. Besides developing
the precursor of cocoa flavor, it also induces the color changes in the
beans. The fermentation process is influenced by various factors such
as planting material, preconditioning of cocoa pod and fermentation
technique. Therefore, this study was conducted to evaluate color of
Malaysian cocoa beans and how the duration of pods storage and
fermentation technique using shallow box will effect on its color
characteristics. There are two factors being studied i.e. duration of
cocoa pod storage (0, 2, 4 and 6 days) and duration of cocoa
fermentation (0, 1, 2, 3, 4 and 5 days). The experiment is arranged in
4 x 6 factorial designs with 24 treatments and arrangement is in a
Completely Randomised Design (CRD). The produced beans are
inspected for color changes under artificial light during cut test and
divided into four groups of color namely fully brown, purple brown,
fully purple and slaty. Cut tests indicated that cocoa beans which are
directly dried without undergone fermentation has the highest slaty
percentage. However, application of pods storage before fermentation
process is found to decrease the slaty percentage. In contrast, the
percentages of fully brown beans start to dominate after two days of
fermentation, especially from four and six days of pods storage batch.
Whereas, almost all batches of cocoa beans have a percentage of fully
purple less than 20%. Interestingly, the percentage of purple brown
beans are scattered in the entire beans batch regardless any specific
trend. Meanwhile, statistical analysis using General Linear Model
showed that the pods storage has a significant effect on the color
characteristic of the Malaysian dried beans compared to fermentation
duration.
Abstract: Energy consumption of a hotel can be a hot topic in
smart city; it is difficult to evaluate the contribution of impact factors
to energy consumption of a hotel. Therefore, grasping the key impact
factors has great effect on the energy saving management of a hotel.
Based on the SPIRTPAT model, we establish the identity with the
impact factors of occupancy rate, unit area of revenue, temperature
factor, unit revenue of energy consumption. In this paper, we use the
LMDI (Logarithmic Mean Divisia Index) to decompose the impact
factors of energy consumption of hotel from Jan. to Dec. in 2001. The
results indicate that the occupancy rate and unit area of revenue are the
main factors that can increase unit area of energy consumption, and the
unit revenue of energy consumption is the main factor to restrain the
growth of unit area of energy consumption. When the energy
consumption of hotel can appear abnormal, the hotel manager can
carry out energy saving management and control according to the
contribution value of impact factors.
Abstract: The focus of this study was to determine the factors associated with the use of substances for sport performance of youth in Lagos state sport. Questionnaire was the instrument used for the study. Descriptive research method was used. The estimated population for the study was 2000 sport men and women. The sample size was 200 respondents for purposive sampling techniques were used. The instrument was validated in it content and constructs value. The instrument was administered with the assistance of the coaches. Same 200 copies administered were returned. The data obtained was analysed using simple percentage and chi-square (x2) for stated hypothesis at 0.05 level of significance. The finding reveal that sport injuries exercise induced and anaphylaxis and asthma and feeling of loss of efficacy associated with alcohol used on sport performance among the users of substances. Alcohol users are recommended to partake in sport like swimming, basketball and volleyball because they have space of time for resting while at play. Government should be fully in charge of the health of sport men and women.
Abstract: In this research, we propose to conduct diagnostic and
predictive analysis about the key factors and consequences of urban
population relocation. To achieve this goal, urban simulation models
extract the urban development trends as land use change patterns from
a variety of data sources. The results are treated as part of urban big
data with other information such as population change and economic
conditions. Multiple data mining methods are deployed on this data to
analyze nonlinear relationships between parameters. The result
determines the driving force of population relocation with respect to
urban sprawl and urban sustainability and their related parameters.
This work sets the stage for developing a comprehensive urban
simulation model for catering to specific questions by targeted users. It
contributes towards achieving sustainability as a whole.