Impact Factor :
1.025
Q1(Year 2015)
ISSN : 1026-3098
e-ISSN : 2345-3605
Published Issues
Estimating Daily Pan Evaporation Using Data Mining Process
2013
Abstract :
This study investigates applicability of data mining process in estimation of daily pan evaporation which is one of the fundamental elements in the hydrological cycle. Firstly, the models were developed by using autoregressive modeling frequently preferred in hydrological studies for Lake Eğirdir in the southern part of Turkey and it was shown suitability of the AR(3) model. Hence, the 1-day, 2-day and 3-day previous daily pan evaporation values of Lake Eğirdir were used to develop the other DM models. The correlation coefficient and root mean square error criteria were used for evaluating the accuracy of the developed models. When the results of developed models were compared to observed pan evaporation according to these criteria, it was determined that the AR(3) model is a little more appropriate to estimate of daily pan evaporation. Consequently, it was shown DM models are useful as they are based on only daily pan evaporation data and not included the meteorological parameters.
Keywords :
pan evaporation; data mining process; Lake Eğirdir
( 1589 Visit ) ( 423 Download )

Investigation of Strong-Motion Duration Consistency in Endurance Time Excitation Functions
2013
Abstract :
Endurance Time (ET) method is a dynamic analysis procedure using intensifying excitation. The ET excitation functions are generated so that structural performance can be assessed at different excitation levels in a single response history analysis. The ET accelerograms which have been generated so far possess response spectra consistency; this means that the duration consistency has not been directly considered. Strong-motion duration can influence the response of structures which have stiffness or strength degrading characteristics. In this paper, several well-known strong-motion duration definitions are studied in the ET method context. Ground motions are scaled to spectral acceleration of code spectrum as well as the ET records; furthermore, the ET records are scaled to have consistent duration compared to real ground motions considering different strong-motion duration definitions. In order to determine which definitions have the highest correlation with structure responses, several SDOF structures which have cyclic deterioratingbehavior in stiffness and strength are subjected to both the ET records and real ground motions. Sincemaximum inter story drift and maximum displacement of a structure subjected to several motions with roughly same acceleration spectra but different motion durations,are approximately identical and in this paper, aim is to pursue the influence ofmotion durationin responses, those indices which are based on energy and accumulative damageare employed. Correlation of each definition with structure responses has been examined by comparing the results of the ET records and real ground motions. Good performance of the ET records in nonlinear region can be deduced due to the high correlation between the results of ET records and real ground motions. This paper provides an approach for considering the duration consistency in ET accelerograms. The efficiency of this approach for current ET accelerograms is aslo investigated.


Keywords :
strong-motion duration, Endurance Time method, degrading material models, intensifying dynamic excitation, damage indices.
( 1866 Visit ) ( 750 Download )

Simulation of Flow Over The Side Weir Using Simulink
2013
Abstract : The present study focuses concept for an elementary discharge coefficient that is related to the discharge flowing through an elementary strip along the side weir length. Simulations of discharge and water depth elevation were done. It is shown that the predicted discharge was agreement with the observed one within an error not exceed 10%. A discharge coefficient was compared with other works, it was increased when side weir installed as an oblique against flow direction.
Keywords : Side weir, Simulation, Simulink, discharge coefficient
( 1417 Visit ) ( 201 Download )

NEURAL NETWORK PREDICTION OF THE ULTIMATE CAPACITY OF SHEAR STUD CONNECTORS ON COMPOSITE BEAMS WITH PROFILED STEEL SHEETING
2013
Abstract : In this paper, the efficiency of different artificial neural networks (ANNs) in predicting the ultimate shear capacity of shear stud connectors is explored. Experimental data involving push-out test specimens of 118 composite beams from an existing database in the literature were used to develop the ANN model. The input parameters affecting the shear capacity were selected as sheeting, stud dimensions, slab dimensions, reinforcement in the slab and concrete compression strength. Each parameter was arranged in an input vector and a corresponding output vector that includes the ultimate shear capacity of composite beams. For the experimental test results, the ANN models were trained and tested using three layered back-propagation methods. The prediction performance of the ANN was obtained. In addition to these, the paper presents a short review of the codes in relation to the design of composite beams. The accuracy of the codes in predicting the ultimate shear capacity of composite beams was also examined in a comparable way by using the same test data. At the end of the study, the effect of the all parameters is also discussed. The study concludes that all ANN models predict the ultimate shear capacity of beams better than codes.
Keywords :
Shear stud; Shear connection; Composite beams; Push-out tests; Artificial neural network
( 1223 Visit ) ( 128 Download )

A new generalized approach for implementing any homogeneous and non-homogeneous boundary conditions in the generalized di erential quadrature analysis of beams
2013
Abstract : In this paper, a new way of implementing any homogeneous and non homogeneous boundary conditions in the Generalized Di deferential Quadrature (GDQ) analysis of beams is presented. Like analytical methods in the solution of a
di differential equation, this approach governs the general solution of GDQ discrete equations for the di fferential equation of beams by assuming some unknown constants, and satis es the boundary conditions in the general solution. Then, unknown constants are evaluated by solving the resultant algebraic equation system. Thus, the particular solution for the beam equilibrium diff deferential equation is obtained by the GDQ method. As described, this approach satis es the boundary conditions in the general solution, so, it is referred to as SBCGS (Satisfying the Boundary Conditions in the General Solution). The SBCGS approach can satisfy any type of boundary condition exactly at boundary points with high accuracy and can easily be implemented for each type of boundary condition. So, this approach overcomes the drawbacks of previous approaches by its generality and simplicity.
At the end of this paper, a comparison of the SBCGS approach, using the method of substitution of boundary conditions into governing equations (the SBCGE approach), is
made by their accuracy with the analysis of beam equilibrium under lateral loading with combinations of simply supported and clamped boundary conditions. Other boundary
conditions and di erent numbers of mesh point results are also discussed for the SBCGS approach only. The results indicate that although the SBCGS approach is essentially very
similar to some other approaches, like SBCGE, it is an easy and powerful method for implementation of any boundary condition to the GDQ governing equations, and provides
highly accurate results.
Keywords : Generalized dfferential quadrature; SBCGS approach; Beam analysis; General boundary conditions; Non-homogeneous boundary conditions.
( 1358 Visit ) ( 98 Download )

TunnedTTStochastic Directional Search: an Efficient Heuristic for Structural Optimization of Building Frames
2013
Abstract :
Performance of an optimization heuristic highly depends to the method it employs to represent and decompose the search space. A class of optimization methods including swarm intelligence utilize an especial way of decomposing the search space via specified direction states. The present work expands the idea providing a stochastic directional state search with tuned thresholds for selecting every direction state. The proposed meta-heuristic is then utilized for the problem of structural weight minimization in building frames under lateral and gravitational loading using a finite element analyzer. Treating a number of examples from literature, efficiency and effectiveness of the proposed method is shown superior to some other meta-heuristics including an improved particle swarm optimizer


Keywords :
Stochastic Directional Search, Structural Design, Sizing Optimization, Building Frame
( 1233 Visit ) ( 156 Download )

Characteristics of rock mechanics and PDC bit optimization of glutenite formation in the Pearl River Mouth Basin oil fields
2013
Abstract : In order to increase the Rate Of Penetration (ROP) in the glutenite formation of the Pearl River Mouth Basin (PRMB) oil eld, the mineral components of drilling detritus were tested, and laboratory tests of Uniaxial Compressive Strength (UCS), drillability and abrasivity were undertaken. Prediction models of the rock mechanical properties of the glutenite formation with logging data were established. An abrasivity test was done using a modi ed rock drillability tester with micro Polycrystal Diamond Compact (PDC) bits. The bits used in the glutenite formation were discussed to nd out the reason for the low ROP.
According to the properties of the rock mechanics and the bit applications of adjacent wells, structures, such as tooth type, crown pro le, tooth assembly parameters and the hydraulic structure of selected bits, were optimized. A new tiger tooth and an anticollision tooth for the optimized PDC bit were developed to increase shock and wear resistance in glutenite formation. Compared with conventional bits used in glutenite formation, the optimized bit raised footage and ROP by 131% and 48%, respectively. The new method, combined with the properties of rock mechanics, bit application and bit structure, is simple and e ffective to guide the bit design for glutenite formation.
Keywords : Rock mechanics;PDC bit;Glutenite formation;Bit optimization;Pearl River Mouth Basin
( 1603 Visit ) ( 51 Download )

Experimental study on the mechanical properties of clayey soil under different freezing apparatus temperatures and freeze-thaw cycles
2013
Abstract :
The objective of this study was to investigate the mechanical properties of clayey soil with different moisture contents. Two groups of clayey soil with different moisture contents were prepared as samples. One group of samples was subjected to eleven freeze-thaw cycles under a constant freezing apparatus temperature in an enclosed apparatus. The other group was subjected to one freeze-thaw cycle exposed to a decreasing freezing apparatus temperature in an enclosed apparatus. A series of triaxial compression experiments were conducted on both groups of samples. The first experimental results indicated that the mechanical properties of the clayey soil changed after the freeze-thaw cycles under constant freezing apparatus temperature, and cohesion decreased with an increased number of freeze-thaw cycles and increased moisture content. In addition, the internal friction angle increased with the number of freeze-thaw cycles and decreased with increased moisture content.However, the moisture content of the clayey soil had a greater influence on cohesion than the internal friction angle. Additional experimental group results indicated that the internal friction angle of the clayey soil diminished with a decrease in the freezing apparatus temperature and increased moisture content. Finally, cohesion increased with a decrease in either the freezing apparatus temperature or moisture content.
Keywords :
Freeze-thaw cycles;Moisture content; Cohesion; Internal friction angle; Clayey soil
( 1929 Visit ) ( 1294 Download )

Nonlinear oscillators with rational terms: A new semi-analytical technique
2013
Abstract : This paper presents a new generalization of the standard homotopy analysis approach towards solving nonlinear oscillators equations with rational terms. By using this method, analytical approximations to the frequency of these oscillators and periodic
solutions are calculated. Excellent agreement of the approximate frequencies and periodic
solutions with exact ones is demonstrated and discussed. It is shown that this method is very simple, e ective and convenient for solving nonlinear oscillator problems with rational terms.
Keywords : Nonlinear oscillators;Approximate periodic solution;Homotopy analysis method;Rational elastic terms
( 1384 Visit ) ( 264 Download )

Updated Lagrangian Large Deformation Analysis of Consolidation Settlement with Finite Element Method for a Case Study in Iran
2013
Abstract : Settlement of ne-grained soils is often governed by a consolidation process which involves quite large strains. The classic, one-dimensional consolidation formula is based on the small strain theory, although it is still practically useful. Since strains are relatively large during the consolidation process, the overall behavior of the medium is geometrically nonlinear. In this paper, a coupled consolidation analysis was carried out to predict the consolidation settlement of ground beneath an embankment, as a case study, representing the feasibility of large strain consolidation analysis. A two-dimensional,
updated Lagrangian, large deformation, nite element formulation was employed to simultaneously solve the transient flow and the deformation equations which constitute the coupled consolidation equations. It was followed by the development of a code in the MATLAB environment to solve the required equations, with further application to a case study in Iran. In addition, analyses were performed by one-dimensional conventional methods and compared with the results obtained by the nite element
procedure. Predictions made by large deformation nite element analysis, in comparison to those obtained based on small strain assumptions and conventional methods, appeared
to be more accurate, although the required computational e ort was much higher, owing to frequent recomputation of the sti ness matrix.
Keywords : Consolidation;Large strain;Updated Lagrangianformulation;Finite element;Settlement.
( 1467 Visit ) ( 216 Download )

Reliability-Based Evaluation of Load Factors using Beta Unzipping and Bayesian Methods
2013
Abstract :
In this study, various sources of uncertainty in demand and capacity and their direct and indirect dependencies according to their significant function in performance based earthquake engineering (PBEE), were incorporated proposing a practically new simple procedure. This procedure distinguishes and evaluates collapse probability of elementary mechanisms as well as computes their dependencies utilizing commonly used deterministic computer software through a full probabilistic methodology using β-unzipping and Bayesian methods. This procedure has been benchmarked for a typical 2D reinforced concrete moment frame and reliability index of the structure for the most probable collapse mechanism was obtained within a reliability-based framework. Moreover, the coefficients of dead, live and earthquake loads for a ACI load combination were reevaluated utilizing β-unzipping and Bayesian methods through the proposed procedure and were compared with the code's coefficients. Good compatibility between obtained coefficients and code's ones has been perceived and the probability of collapse, implicitly considered in the code, was revealed. It has been concluded that the coefficients extracted from Bayesian method are closer to the code's ones comparing to those from β-unzipping method; however, requiring less primary computational effort and slight differences between the results, β-unzipping is usually more preferred by evaluators.




Keywords :
Seismic Reliability,Bayesian Method, β-Unzipping, Probabilistic Design Method,Reinforced Concrete Frames,PBEE.
( 1189 Visit ) ( 191 Download )

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Transactions on Civil Engineering
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Transactions on Civil Engineering
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2014
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Transactions on Chemistry and Chemical Engineering
Transactions on Computer Science & Engineering and Electrical Engineering
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Transactions on Nanotechnology
2013
Transactions on Civil Engineering
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Transactions on Chemistry and Chemical Engineering
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