Abstract: This paper proposes a single relay selection scheme in
cooperative communication. Decode-and-forward scheme is
considered when a source node wants to cooperate with a single relay
for data transmission. To use the proposed single relay selection
scheme, the source node makes a little different pattern signal which is
not complex pattern and broadcasts it. The proposed scheme does not
require the channel state information between the source node and
candidates of the relay during the relay selection. Therefore, it is able
to be used in many fields.
Abstract: In broadcasting and cellular system, a cooperative
scheme is proposed for the improvement of performance of bit error
rate. Up to date, the coverage of broadcasting system coexists with the
coverage of cellular system. Therefore each user in a cellular coverage
is frequently involved in a broadcasting coverage. The proposed
cooperative scheme is derived from the shared areas. The users receive
signals from both broadcasting station and cellular station. The
proposed scheme selects a cellular base station of a worse channel to
achieve better performance of bit error rate in cooperation. The
performance of the proposed scheme is evaluated in fading channel.
Abstract: In this research, copper borates are synthesized by the
reaction of copper sulfate pentahydrate (CuSO4.5H2O) and
tincalconite (Na2O4B7.10H2O). The experimental parameters are
selected as 80oC reaction temperature and 60 of reaction time. The
effect of mole ratio of CuSO4.5H2O to Na2O4B7.5H2O is studied. For
the identification analyses X-Ray Diffraction (XRD) and Fourier
Transform Infrared Spectroscopy (FT-IR) techniques are used. At the
end of the experiments, synthesized copper borate is matched with
the powder diffraction file of “00-001-0472” [Cu(BO2)2] and
characteristic vibrations between B and O atoms are seen. The proper
crystals are obtained at the mole ratio of 3:1. This study showed that
simplified synthesis process is suitable for the production of copper
borate minerals.
Abstract: Reconfigurable antennas represent a recent innovation in antenna design that changes from classical fixed-form, fixed function antennas to modifiable structures that can be adapted to fit the requirements of a time varying system.
The ability to control the operating band of an antenna system can have many useful applications. Systems that operate in an acquire-and-track configuration would see a benefit from active bandwidth control. In such systems a wide band search mode is first employed to find a desired signal then a narrow band track mode is used to follow only that signal. Utilizing active antenna bandwidth control, a single antenna would function for both the wide band and narrow band configurations providing the rejection of unwanted signals with the antenna hardware. This ability to move a portion of the RF filtering out of the receiver and onto the antenna itself will also aid in reducing the complexity of the often expensive RF processing subsystems.
Abstract: In this research, the capability of neural networks in
modeling and learning complicated and nonlinear relations has been
used to develop a model for the prediction of changes in the diameter
of bubbles in pool boiling distilled water. The input parameters used
in the development of this network include element temperature, heat
flux, and retention time of bubbles. The test data obtained from the
experiment of the pool boiling of distilled water, and the
measurement of the bubbles form on the cylindrical element. The
model was developed based on training algorithm, which is
typologically of back-propagation type. Considering the correlation
coefficient obtained from this model is 0.9633. This shows that this
model can be trusted for the simulation and modeling of the size of
bubble and thermal transfer of boiling.
Abstract: Cubic equations of state like Redlich–Kwong (RK)
EOS have been proved to be very reliable tools in the prediction of
phase behavior. Despite their good performance in compositional
calculations, they usually suffer from weaknesses in the predictions
of saturated liquid density. In this research, RK equation was
modified. The result of this study show that modified equation has
good agreement with experimental data.
Abstract: A two-dimensional linear wave-body interaction problem can be solved using a desingularized integral method by placing free surface Rankine sources over calm water surface and satisfying boundary conditions at prescribed collocation points on the
calm water surface. A new free-surface Rankine source distribution scheme, determined by the intersection points of free surface and body surface, is developed to reduce numerical computation cost. Associated with this, a new treatment is given to the intersection point. The present scheme results are in good agreement with traditional numerical results and measurements.
Abstract: In this research, the TRACE/PARCS model of
Lungmen ABWR has been developed for verification of ultimate
response guideline (URG) efficiency. This ultimate measure was
named as DIVing plan, abbreviated from system depressurization,
water injection and containment venting. The simulation initial
condition is 100% rated power/100% rated core flow. This research
focuses on the estimation of the time when the fuel might be damaged
with no water injection by using TRACE/PARCS first. Then, the
effect of the reactor core isolation system (RCIC), control
depressurization and ac-independent water addition system (ACIWA),
which can provide the injection with 950 gpm are also estimated for
the station blackout (SBO) transient.
Abstract: In this paper the intelligent control of full automatic car wash using a programmable logic controller (PLC) has been investigated and designed to do all steps of carwashing. The Intelligent control of full automatic carwash has the ability to identify and profile the geometrical dimensions of the vehicle chassis. Vehicle dimension identification is an important point in this control system to adjust the washing brushes position and time duration. The study also tries to design a control set for simulating and building the automatic carwash. The main purpose of the simulation is to develop criteria for designing and building this type of carwash in actual size to overcome challenges of automation. The results of this research indicate that the proposed method in process control not only increases productivity, speed, accuracy and safety but also reduce the time and cost of washing based on dynamic model of the vehicle. A laboratory prototype based on an advanced intelligent control has been built to study the validity of the design and simulation which it’s appropriate performance confirms the validity of this study.
Abstract: An experimental investigation has been carried out to study the cooling of a hot horizontal Stainless Steel surface of 3 mm thickness, which has 800±10 C initial temperature. A round water jet of 22 ± 1 oC temperature was injected over the hot surface through straight tube type nozzles of 2.5- 4.8 mm diameter and 250 mm length. The experiments were performed for the jet exit to target surface spacing of 4 times of jet diameter and jet Reynolds number of 5000 -24000. The effect of change in jet Reynolds number on the surface quenching has been investigated form the stagnation point to 16 mm spatial location.
Abstract: This study is conducted to investigate the disparity of between learning styles and cognitive abilities specifically in Vocational Education. Felder and Silverman Learning Styles Model (FSLSM) was applied to measure the students’ learning styles while the content in Building Construction Subject consists; knowledge, skills and problem solving were taken into account in constructing the elements of cognitive abilities. Building Construction is one of the vocational courses offered in Vocational Education structure. There are four dimension of learning styles proposed by Felder and Silverman intended to capture student learning preferences with regards to processing either active or reflective, perception based on sensing or intuitive, input of information used visual or verbal and understanding information represent with sequential or global learner. Felder-Solomon Learning Styles Index was developed based on FSLSM and the questions were used to identify what type of student learning preferences. The index consists 44 item-questions characterize for learning styles dimension in FSLSM. The achievement test was developed to determine the students’ cognitive abilities. The quantitative data was analyzed in descriptive and inferential statistic involving Multivariate Analysis of Variance (MANOVA). The study discovered students are tending to be visual learners and each type of learner having significant difference whereas cognitive abilities there are different finding for each type of learners in knowledge, skills and problem solving. This study concludes the gap between type of learner and the cognitive abilities in few illustrations and it explained how the connecting made. The finding may help teachers to facilitate students more effectively and to boost the student’s cognitive abilities.
Abstract: Progressive collapse of buildings typically occurs
when abnormal loading conditions cause local damages, which leads
to a chain reaction of failure and ultimately catastrophic collapse. The
tie force (TF) method is one of the main design approaches for
progressive collapse. As the TF method is a simplified method, further
investigations on the reliability of the method is necessary. This study
aims to develop an improved TF method to design the cross wall
structures for progressive collapse. To this end, the pullout behavior of
strands in grout was firstly analyzed; and then, by considering the tie
force-slip relationship in the friction stage together with the catenary
action mechanism, a comprehensive analytical method was developed.
The reliability of this approach is verified by the experimental results
of concrete block pullout tests and full scale floor-to-floor joints tests
undertaken by Portland Cement Association (PCA). Discrepancies in
the tie force between the analytical results and codified specifications
have suggested the deficiency of TF method, hence an improved
model based on the analytical results has been proposed to address this
concern.
Abstract: This paper was prepared to see the perceptions of online lectures regarding collaborative learning, in terms of how lecturers view online collaborative learning in the higher learning institution. The purpose of this study was conducted to determine the perceptions of online lectures about collaborative learning, especially how lecturers see online collaborative learning in the university. Adult learning education enhance collaborative learning culture with the target of involving learners in the learning process to make teaching and learning more effective and open at the university. This will finally make students learning that will assist each other. It is also to cut down the pressure of loneliness and isolation might felt among adult learners. Their ways in collaborative online was also determined. In this paper, researchers collect data using questionnaires instruments. The collected data were analyzed and interpreted. By analyzing the data, researchers report the results according the proof taken from the respondents. Results from the study, it is not only dependent on the lecturer but also a student to shape a good collaborative learning practice. Rational concepts and pattern to achieve these targets be clear right from the beginning and may be good seen by a number of proposals submitted and include how the higher learning institution has trained with ongoing lectures online. Advantages of online collaborative learning show that lecturers should be trained effectively. Studies have seen that the lecturer aware of online collaborative learning. This positive attitude will encourage the higher learning institution to continue to give the knowledge and skills required.
Abstract: This study aims to determine change in optimal locations of dual trailing-edge flaps for various thrust coefficient to solidity (Ct /σ) ratios of helicopter to achieve minimum hub vibration levels, with low penalty in terms of required trailing-edge flap control power. Polynomial response functions are used to approximate hub vibration and flap power objective functions. Single objective and multiobjective optimization is carried with the objective of minimizing hub vibration and flap power. The optimization result shows that the inboard flap location at low Ct /σ ratio move farther from the baseline value and at high Ct /σ ratio move towards the root of the blade for minimizing hub vibration.
Abstract: The objective in this work is to generate and discuss the stability results of fully-immersed end-milling process with parameters; tool mass m=0.0431kg,tool natural frequency ωn = 5700 rads^-1, damping factor ξ=0.002 and workpiece cutting coefficient C=3.5x10^7 Nm^-7/4. Different no of teeth is considered for the end-milling. Both 1-DOF and 2-DOF chatter models of the system are generated on the basis of non-linear force law. Chatter stability analysis is carried out using a modified form (generalized for both 1-DOF and 2-DOF models) of recently developed method called Full-discretization. The full-immersion three tooth end-milling together with higher toothed end-milling processes has secondary Hopf bifurcation lobes (SHBL’s) that exhibit one turning (minimum) point each. Each of such SHBL is demarcated by its minimum point into two portions; (i) the Lower Spindle Speed Portion (LSSP) in which bifurcations occur in the right half portion of the unit circle centred at the origin of the complex plane and (ii) the Higher Spindle Speed Portion (HSSP) in which bifurcations occur in the left half portion of the unit circle. Comments are made regarding why bifurcation lobes should generally get bigger and more visible with increase in spindle speed and why flip bifurcation lobes (FBL’s) could be invisible in the low-speed stability chart but visible in the high-speed stability chart of the fully-immersed three-tooth miller.
Abstract: This paper presents the results of a study aimed at establishing the temperature distribution during the welding of aluminum alloy plates by Pulsed Current Gas Tungsten Arc Welding (PCGTAW) and Constant Current Gas Tungsten Arc Welding (CCGTAW) processes. Pulsing of the GTA welding current influences the dimensions and solidification rate of the fused zone, it also reduces the weld pool volume hence a narrower bead. In this investigation, the base material considered was aluminum alloy AA 6351 T6, which is finding use in aircraft, automobile and high-speed train components. A finite element analysis was carried out using ANSYS, and the results of the FEA were compared with the experimental results. It is evident from the study that the finite element analysis using ANSYS can be effectively used to model PCGTAW process for finding temperature distribution.
Abstract: Stirred tanks are widely used in all industrial sectors. The need for further studies of the mixing operation and its different aspects comes from the diversity of agitation tools and implemented geometries in addition to the specific characteristics of each application. Viscous fluids are often encountered in industry and they represent the majority of treated cases, as in the polymer sector, food processing, pharmaceuticals and cosmetics. That's why in this paper, we will present a three-dimensional numerical study using the software Fluent, to study the effect of varying the fluid viscosity in a stirred tank with a Rushton turbine. This viscosity variation was performed by adding carboxymethylcellulose (CMC) to the fluid (water) in the vessel. In this work, we studied first the flow generated in the tank with a Rushton turbine. Second, we studied the effect of the fluid viscosity variation on the thermodynamic quantities defining the flow. For this, three viscosities (0.9% CMC, 1.1% CMC and 1.7% CMC) were considered.
Abstract: The author proposes an extension of genetic algorithm (GA) for solving fuzzy-valued optimization problems. In the proposed GA, values in the genotypes are not real numbers but fuzzy numbers. Evolutionary processes in GA are extended so that GA can handle genotype instances with fuzzy numbers. The proposed method is applied to evolving neural networks with fuzzy weights and biases. Experimental results showed that fuzzy neural networks evolved by the fuzzy GA could model hidden target fuzzy functions well despite the fact that no training data was explicitly provided.
Abstract: Wavelet analysis has some strong advantages over Fourier analysis, as it allows a time-frequency domain analysis, allowing optimal resolution and flexibility. As a result, they have been satisfactorily applied in almost all the fields of communication systems including OFDM which is a strong candidate for next generation of wireless technology. In this paper, the performances of wavelet based Multiuser Multiple Input and Multiple Output Orthogonal Frequency Division Multiplexing (MU-MIMO OFDM) systems are analyzed in terms of BER. It has been shown that the wavelet based systems outperform the classical FFT based systems. This analysis also unfolds an interesting result, where wavelet based OFDM system will have a constant error performance using Regularized Channel Inversion (RCI) beamforming for any number of users, and outperforms in all possible scenario in a multiuser environment. An extensive computer simulations show that a PAPR reduction of up to 6.8dB can be obtained with M=64.
Abstract: This paper presents a preliminary attempt to apply classification of time series using meta-clusters in order to improve the quality of regression models. In this case, clustering was performed as a method to obtain subgroups of time series data with normal distribution from the inflow into wastewater treatment plant data, composed of several groups differing by mean value. Two simple algorithms, K-mean and EM, were chosen as a clustering method. The Rand index was used to measure the similarity. After simple meta-clustering, a regression model was performed for each subgroups. The final model was a sum of the subgroups models. The quality of the obtained model was compared with the regression model made using the same explanatory variables, but with no clustering of data. Results were compared using determination coefficient (R2), measure of prediction accuracy- mean absolute percentage error (MAPE) and comparison on a linear chart. Preliminary results allow us to foresee the potential of the presented technique.