Abstract: This paper presents a new algorithm for the channel estimation of the OFDM system based on a pilot signal for the new generation of high data rate communication systems. In orthogonal frequency division multiplexing (OFDM) systems over fast-varying fading channels, channel estimation and tracking is generally carried out by transmitting known pilot symbols in given positions of the frequency-time grid. In this paper, we propose to derive an improved algorithm based on the calculation of the mean and the variance of the adjacent pilot signals for a specific distribution of the pilot signals in the OFDM frequency-time grid then calculating of the entire unknown channel coefficients from the equation of the mean and the variance. Simulation results shows that the performance of the OFDM system increase as the length of the channel increase where the accuracy of the estimated channel will be increased using this low complexity algorithm, also the number of the pilot signal needed to be inserted in the OFDM signal will be reduced which lead to increase in the throughput of the signal over the OFDM system in compared with other type of the distribution such as Comb type and Block type channel estimation.
Abstract: The technique of inducing micro ecosystem
restoration is one of aquatic ecology engineering methods used to
retrieve the polluted water. Batch scale study, pilot plant study, and
field study were carried out to observe the eutrophication using the
Inducing Ecology Restorative Symbiosis Agent (IERSA) consisting
mainly degraded products by using lactobacillus, saccharomycete,
and phycomycete. The results obtained from the experiments of the
batch scale and pilot plant study allowed us to development the
parameters for the field study. A pond, 5 m to the outlet of a lake,
with an area of 500 m2 and depth of 0.6-1.2 m containing about 500
tons of water was selected as a model. After the treatment with 10
mg IERSA/L water twice a week for 70 days, the micro restoration
mechanisms consisted of three stages (i.e., restoration, impact
maintenance, and ecology recovery experiment after impact). The
COD, TN, TKN, and chlorophyll a were reduced significantly in the
first week. Although the unexpected heavy rain and contaminate
from sewage system might slow the ecology restoration. However,
the self-cleaning function continued and the chlorophyll a reduced
for 50% in one month. In the 4th week, amoeba, paramecium, rotifer,
and red wriggle worm reappeared, and the number of fish flies
appeared up to1000 fish fries/m3. Those results proved that inducing
restorative mechanism can be applied to improve the eutrophication
and to control the growth of algae in the lakes by gaining the selfcleaning
through inducing and competition of microbes. The
situation for growth of fishes also can reach an excellent result due to
the improvement of water quality.
Abstract: The development of entrepreneurial competences of
farmers has been pointed out as a necessary condition for the
modernization of land in facing the phenomenon of globalization.
However, the educational processes involved in such a development
have been studied little, especially in emerging economies. This
research aims to enlighten some of the critical issues behind the early
stages of the transformation of farmers into entrepreneurs, through in
depth interviews with farmers, entrepreneurial promoters and public
officials participating in a public pilot project in Mexico. Although
major impacts were expected only in the long run, important positive
changes in the mind set of farmers and other participants were found
in early stages of the intervention. Apparently, the farmers started a
process of becoming more conscious about the importance of
preserving the aquiferous resources, as well as more market and
entrepreneurial oriented.
Abstract: The paper gives the pilot results of the project that is
oriented on the use of data mining techniques and knowledge
discoveries from production systems through them. They have been
used in the management of these systems. The simulation models of
manufacturing systems have been developed to obtain the necessary
data about production. The authors have developed the way of
storing data obtained from the simulation models in the data
warehouse. Data mining model has been created by using specific
methods and selected techniques for defined problems of production
system management. The new knowledge has been applied to
production management system. Gained knowledge has been tested
on simulation models of the production system. An important benefit
of the project has been proposal of the new methodology. This
methodology is focused on data mining from the databases that store
operational data about the production process.
Abstract: PARADIGMA (PARticipative Approach to DIsease
Global Management) is a pilot project which aims to develop and
demonstrate an Internet based reference framework to share scientific
resources and findings in the treatment of major diseases.
PARADIGMA defines and disseminates a common methodology and
optimised protocols (Clinical Pathways) to support service functions
directed to patients and individuals on matters like prevention, posthospitalisation
support and awareness. PARADIGMA will provide a
platform of information services - user oriented and optimised
against social, cultural and technological constraints - supporting the
Health Care Global System of the Euro-Mediterranean Community
in a continuous improvement process.
Abstract: Dedicated Short Range Communication (DSRC) is a
key enabling technology for the next generation of
communication-based safety applications. One of the important
problems for DSRC deployment is maintaining high performance
under heavy channel load. Many studies focus on congestion control
mechanisms for simulating hundreds of physical radios deployed on
vehicles. The U.S. department of transportation-s (DOT) Intelligent
Transportation Systems (ITS) division has a plan to chosen prototype
on-board devices capable of transmitting basic “Here I am" safety
messages to other vehicles. The devices will be used in an IntelliDrive
safety pilot deployment of up to 3,000 vehicles. It is hard to log the
information of 3,000 vehicles. In this paper we present the designs and
issues related to the DSRC Radio Testbed under heavy channel load.
The details not only include the architecture of DSRC Radio Testbed,
but also describe how the Radio Interfere System is used to help for
emulating the congestion radio environment.
Abstract: Self-directed learning (SDL) was developed initially
for adult learning. Guglielmino constructed a scale to measure SDL.
Recent researchers have applied this concept to children. Although
there are sufficient theoretical evidences to present the possibility of
applying this concept to children, empirical evidences were not
provided. This study aimed to examine the quality of SDL and
construct a scale to measure SDL among young children. A modified
scale of Guglielmino-s scale was constructed and piloted with 183
subjects of age 9. Findings suggest that the qualities of SDL in young
ages are apparently congruent with that of adults.
Abstract: Currently, there is no database or local norms for the
physical performance of Malaysian rugby players. This database or
norms are vital for Malaysian-s sports development as programs can
be setup to improve the current status. This pilot study was
conducted to evaluate the status of our semi professional rugby
players. The rugby players were randomly selected from the
Malaysian National team and several clubs in the Klang valley, Kuala
Lumpur Malaysia. 54 male rugby players (Age: 24.41 ± 4.06 years)
were selected for this pilot study. Height, bodyweight, percentage
body fat and body mass index (BMI) and several other physical tests
were performed. Results from the BLEEP test revealed an average of
level 9, shuttle 2 for the players. Interestingly, forwards were taller,
heavier, and had lower maximal aerobic power than backs in the
same team. In conclusion, the physical characteristics of the rugby
players were much lower when compared to international players
from other countries. From this pilot study, the physical performance
of the Malaysian team must be improved in order to further develop
the sports.
Abstract: The research investigates the “impact of VLE on mathematical concepts acquisition of the special education needs (SENs) students at KS4 secondary education sector" in England. The overall aim of the study is to establish possible areas of difficulties to approach for above or below knowledge standard requirements for KS4 students in the acquisition and validation of basic mathematical concepts. A teaching period, in which virtual learning environment (Fronter) was used to emphasise different mathematical perception and symbolic representation was carried out and task based survey conducted to 20 special education needs students [14 actually took part]. The result shows that students were able to process information and consider images, objects and numbers within the VLE at early stages of acquisition process. They were also able to carry out perceptual tasks but with limiting process of different quotient, thus they need teacher-s guidance to connect them to symbolic representations and sometimes coach them through. The pilot study further indicates that VLE curriculum approaches for students were minutely aligned with mathematics teaching which does not emphasise the integration of VLE into the existing curriculum and current teaching practice. There was also poor alignment of vision regarding the use of VLE in realisation of the objectives of teaching mathematics by the management. On the part of teacher training, not much was done to develop teacher-s skills in the technical and pedagogical aspects of VLE that is in-use at the school. The classroom observation confirmed teaching practice will find a reliance on VLE as an enhancer of mathematical skills, providing interaction and personalisation of learning to SEN students.
Abstract: Off-grid Photovoltaic (PV) systems are empowering
technology in underdeveloped countries like Ethiopia where many
people live far away from the modern world. Where there is
relatively low energy consumption, providing energy from grid
systems is not commercially cost-effective. As a result, significant
people groups worldwide stay without access to electricity. One
remote village in northern Ethiopia was selected by the United
Nations for a pilot project to improve its living conditions. As part of
this comprehensive project, an intelligent charge controller circuit for
Off-grid PV systems was designed for the clinic in that village. In
this paper, design aspects of an intelligent charge controller unit and
its load driver circuits are discussed for an efficient utilization of PVbased
supply systems.
Abstract: More and more governments around the world are
introducing e-government as a means of reducing costs, improving
services, saving time and increasing effectiveness and efficiency in
the public sector Therefore e-government has been identified as one
of the top priorities for Saudi government and all its agencies.
However, the adoption of e-government is facing many challenges
and barriers such as technological, cultural, organizational, and social
issues which must be considered and treated carefully by any
government contemplating its adoption. This paper reports on a pilot
study amongst online (e-ready) citizens to identify the challenges and
barriers that affect the adoption of e-government services especially
from their perspective in Saudi society. Based on the analysis of data
collected from an online survey the researcher was able to identify
some of the important barriers and challenges from the e-ready
citizen perspective. As a result, this study has generated a list of
possible strategies to move towards successful adoption of egovernment
services in Saudi Arabia.
Abstract: Cyclic delay diversity (CDD) is a simple technique to
intentionally increase frequency selectivity of channels for orthogonal
frequency division multiplexing (OFDM).This paper proposes a residual
carrier frequency offset (RFO) estimation scheme for OFDMbased
broadcasting system using CDD. In order to improve the RFO
estimation, this paper addresses a decision scheme of the amount of
cyclic delay and pilot pattern used to estimate the RFO. By computer
simulation, the proposed estimator is shown to benefit form propoerly
chosen delay parameter and perform robustly.
Abstract: In the present study, a heterogeneous and
homogeneous gas flow dispersion model for simulation and
optimisation of a large-scale catalytic slurry reactor for the direct
synthesis of dimethyl ether (DME) from syngas and CO2, using a
churn-turbulent regime was developed. In the heterogeneous gas flow
model the gas phase was distributed into two bubble phases: small
and large, however in the homogeneous one, the gas phase was
distributed into only one large bubble phase. The results indicated
that the heterogeneous gas flow model was in more agreement with
experimental pilot plant data than the homogeneous one.
Abstract: The present study conducted experimental investigation on combustion and emission characteristics of compression ignition engine using diesel as pilot fuel and methane, hydrogen and methane/hydrogen mixture as gaseous fuels at 1800 rev min-1. The effect of gaseous fuel on peak cylinder pressure and heat release is modest at low to medium loads. At high load, the high combustion temperature and high quantity of pilot fuel contribute to better combustion efficiency for all kinds of gaseous fuels and increases the peak cylinder pressure. Enrichment of hydrogen in methane gradually increases the peak cylinder pressure. The brake thermal efficiency increases with higher hydrogen fraction at lower loads. Hydrogen addition in methane contributed to a proportional reduction of CO/CO2/HC emission without penalty of NOx. For particulate emission, methane and hydrogen, could both suppress the particle emission. 30% hydrogen fraction in methane is observed to be best in reducing the particulate emission.
Abstract: All the available algorithms for blind estimation namely constant modulus algorithm (CMA), Decision-Directed Algorithm (DDA/DFE) suffer from the problem of convergence to local minima. Also, if the channel drifts considerably, any DDA looses track of the channel. So, their usage is limited in varying channel conditions. The primary limitation in such cases is the requirement of certain overhead bits in the transmit framework which leads to wasteful use of the bandwidth. Also such arrangements fail to use channel state information (CSI) which is an important aid in improving the quality of reception. In this work, the main objective is to reduce the overhead imposed by the pilot symbols, which in effect reduces the system throughput. Also we formulate an arrangement based on certain dynamic Artificial Neural Network (ANN) topologies which not only contributes towards the lowering of the overhead but also facilitates the use of the CSI. A 2×2 Multiple Input Multiple Output (MIMO) system is simulated and the performance variation with different channel estimation schemes are evaluated. A new semi blind approach based on dynamic ANN is proposed for channel tracking in varying channel conditions and the performance is compared with perfectly known CSI and least square (LS) based estimation.
Abstract: Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation by heavy rain.
In this Paper we have studied the heavy rain effects on the aerodynamic efficiency of cambered NACA 64-210 and symmetric
NACA 0012 airfoils. Our results show significant increase in drag and decrease in lift. We used preprocessing software gridgen for creation of geometry and mesh, used fluent as solver and techplot as postprocessor. Discrete phase modeling called DPM is used to model the rain particles using two phase flow approach. The rain particles are assumed to be inert.
Both airfoils showed significant decrease in lift and increase in drag in simulated rain environment. The most significant difference between these two airfoils was the NACA 64-210 more sensitivity than NACA 0012 to liquid water content (LWC). We believe that the results showed in this paper will be useful for the designer of the commercial aircrafts and UAVs, and will be helpful for training of the pilots to control the airplanes in heavy rain.
Abstract: In China, with the rapid urbanization and
industrialization, and highly accelerated economic development have
resulted in degradation of water resource. The water quality
deterioration usual result from eutrophication in most cases, so how to
dispose this type pollution water higher efficiently is an urgent task.
Hower, different with traditional technology, constructed wetlands are
effective treatment systems that can be very useful because they are
simple technology and low operational cost. A pilot-scale treatment
including constructed wetlands was constructed at XingYun Lake,
Yuxi, China, and operated as primary treatment measure before
eutrophic-lake water draining to riverine landscape. Water quality
indices were determined during the experiment, the results indicated
that treatment removal efficiencies were high for Nitrate nitrogen,
Chlorophyll–a and Algae, the final removal efficiency reached to
95.20%, 93.33% and 99.87% respectively, but the removal efficiency
of Total phosphorous and Total nitrogen only reach to 68.83% and
50.00% respectively.
Abstract: Salinity is a measure of the amount of salts in the
water. Total Dissolved Solids (TDS) as salinity parameter are often
determined using laborious and time consuming laboratory tests, but
it may be more appropriate and economical to develop a method
which uses a more simple soil salinity index. Because dissolved ions
increase salinity as well as conductivity, the two measures are
related. The aim of this research was determine of constant
coefficients for predicting of Total Dissolved Solids (TDS) based on
Electrical Conductivity (EC) with Statistics of Correlation
coefficient, Root mean square error, Maximum error, Mean Bias
error, Mean absolute error, Relative error and Coefficient of residual
mass. For this purpose, two experimental areas (S1, S2) of Khuzestan
province-IRAN were selected and four treatments with three
replications by series of double rings were applied. The treatments
were included 25cm, 50cm, 75cm and 100cm water application. The
results showed the values 16.3 & 12.4 were the best constant
coefficients for predicting of Total Dissolved Solids (TDS) based on
EC in Pilot S1 and S2 with correlation coefficient 0.977 & 0.997 and
191.1 & 106.1 Root mean square errors (RMSE) respectively.
Abstract: Qualification of doctoral students- and the candidates for a scientific degree is evaluated by the ability to solve scientific ideas in an innovative way, consequently, being a potential of research and science they play a significant role in the sustainability context of the society. The article deals with the analysis of the results of the pilot project, the aim of which has been to study the structure of doctoral students- research competences in the sustainability context. With the existance of variety of theories on research competence development, their analysis focuses on the attained aim approach. Three competence groups have been identified in this study: informative, communicative and instrumental. Within the study the doctoral students and candidates for a scientific degree (N=64) made their self-assessment of research competences. The study results depict their present research competence development level and its dynamics according to the aim to attain.
Abstract: In this paper we propose the study of a centrifugal pump control system driven by a three-phase induction motor, which is supplied by a PhotoVoltaic PV generator. The system includes solar panel, a DC / DC converter equipped with its MPPT control, a voltage inverter to three-phase Pulse Width Modulation - PWM and a centrifugal pump driven by a three phase induction motor. In order to control the flow of the centrifugal pump, a Direct Torque Control - DTC of the induction machine is used. To illustrate the performances of the control, simulation results are carried out using Matlab/Simulink.