The body freedom flutter phenomenon is one of the aeroelastic instabilities that occurs due to the coupling of the aeroelastic bending mode of the wing with the short-period mode in the flight dynamics of the aircraft. By using the aeroservoelastic model and applying closed loop control, this phenomenon can be suppressed in the operating conditions of the aircraft and the velocity of this event can be increased. The simplest model aircraft capable of displaying this instability includes the flexible wing and the planar flight dynamics model. For this purpose, the wing structure is modeled using the Euler-Bernoulli beam and, the theory of minimum variable state is used to model unstable aerodynamics to make the conditions suitable for modeling the system in state space. In the control section, the elevator is used as the control surface and LQR theory with Kalman filter is used to body freedom flutter suppression. Finally, the effect of adding a closed loop control to increase the body freedom flutter velocity and the limitations of this work are studied.

Introduction: An important variable in investigation of agility during puberty is the age of reaching peak high velocity, which like other agility indicators is under the effect of different factors such as physical condition and type. The purpose of present research was to examine relationship between somatotype and peak high velocity (PHV) among Iranian 7-10 years old boys.Methods: Participants were 313 7-10 year-old members of Basij talent identification centers in all Iran's provinces. Somatotype data were calculated using Heath-Cartr instruction and PHV was measured using Mirwald formula and were analyzed using Pearson correlation and multiple regressions.Results: Results of pearson correlation showed that PHV had a positive correlation with ectomorphy and negative correlation with endomrphy and mesomorphy. Total correlation between PHV and somatotype was 0.50 which explained 25% of PHV variance. Results of regression analysis showed ectomrphy and endomorphy were significant predictors of PHV but msomrphy was not a significant predictor of PHV.Conclusion: Endomorphy had a smaller part in predicting the PHV age, but mesomorphy was not a strong predictor, Moreover, ectomorphy following endomrophy had a strong predicting power. Studies in this area suggest that those who have greater ectomorphic characteristics are less agile and the physiologic requisites for their puberty develop later in their bodies. Therefore poor sport performance of ectomorphic children may result from their distance to PHV age so coaches and instructors should consider this measurement and somatotype.

Integrating advantages of layer based and tomography velocity model building methods could partially resolve some of the problems in seismic imaging. This integration resulted to introduction of the hybrid tomography methods which try to overcome the problem of handling large velocity contrast by tomography methods. In this study, the velocity model building strategy in the hybrid gridded tomography method was modified to reduce the effect of velocity contrast in depth seismic imaging. The proposed strategy then was applied on a seismic data from a complex geological structures and results depicted that the hybrid gridded tomography, with the presented strategy could be used as an alternative to conventional velocity model building. SummaryThe hybrid gridded velocity model uses the concept of soft and hard regions and boundaries in the initial velocity model. In this approach, regions with anomaly velocity values are defined as hard regions and the rest of the media is considered as soft media. The contacts between regions with low uncertainty in position are defined as hard boundary and experience minimum changes in updating steps. Whilst region contacts with high uncertainty in position are considered as soft boundaries. IntroductionThese boundaries vary in position during velocity model updating. These regions and boundaries are simultaneously and separately updated in each model updating sequence. Updating of hard regions doesn’ t disturb soft regions updating results and vice versa. In the proposed strategy, the conventional velocity model is obtained to be used for defining large velocity contrasts. Afterwards soft and hard regions are simultaneously updated by gridded tomography method. Hard boundaries face small variation in place while soft boundaries might largely vary in location. After sufficient iteration, sharp boundaries are smoothed and finalized in location and together with velocity values. Methodology and ApproachesIn the proposed approach, the seismic imaging with velocity model obtained in each iteration was changed from pre-stack depth migration to post stack depth migration. The selected seismic data contains a large salt dome with surrounding dipping layers, faults and an unconformity beside the salt. Through the hybrid velocity model building, top boundary and the body of salt dome were considered as hard regions. Bottom of the salt was considered as soft boundary. Results and ConclusionsResult of applying the proposed strategy showed that this method could handle large lateral velocity contract in depth imaging. Therefore, depth imaging by the final hybrid velocity model obtain seismic image with more accuracy in positioning of seismic reflectors and body of geological structures in comparison to images obtained by conventional velocity modelling.

Determining the velocity distribution -as a key parameter for estimating other hydraulic parameters- has been always of interest. Velocity distribution in the inner region of the flow (y<0.2D where y is the vertical distance from the bed and D is the flow depth) is well described by the logarithmic law. However, this law deviates from the experimental data in the outer region (y>0.2D). The log-Wake law is among the most accepted laws for determining the velocity distribution in wide open channels. The law modifies the logarithmic law by adding a Wake function; but in the case of narrow open channels, it deviates from the measured data near the free surface. Distribution profile derived by the log-Wake law depicts the velocity which increases monotonically with increase of the distance from the bed. Thus, it is not capable to show the negative gradient of velocity near the free surface which happens in narrow open channels. In narrow open channels, the three dimensional structure of the flow and the transport momentum from the side walls to the central zone -due to strong secondary currents- will cause the maximum velocity to occur below the water surface. This is called velocity-dip phenomenon which -for the first time- is reported more than a century ago. Since that time, numerous investigations have been conducted by many researchers in order to propose new models; not only for describing the dip phenomenon and negative gradient of velocity near the free surface, but also to predict the position of the maximum velocity accurately and to converge the experimental data throughout the whole flow depth.This paper introduces an analytical model based on Reynolds Averaged Navier Stokes (RANS) equations and an eddy viscosity distribution, to estimate velocity distribution in turbulent fully-developed flows. The proposed model is suitable for both narrow and wide open channels and is capable of predicting the dip phenomenon. The numerical results are verified with experimental data measured in several rectangular lab channels and data collected from an actual sewer channel. Since the proposed equation for velocity distribution is dependent on Coles Wake parameter (Π), the effect of this parameter has been studied on the level of accuracy and description of velocity profile as well as prediction of dip phenomenon and location of maximum velocity. Many researchers have proposed different values for Coles Wake parameter. Thus, seemingly there is no universal constant value for this parameter. In this study, the value of Coles Wake parameter is proposed using data from different channels, based on the least error calculated in predicting the velocity profiles by the proposed model. The results show that the profiles derived by the model agreeably match with experimental data, and predict the velocity-dip phenomenon. The model also contains few errors in comparison with the data measured in the channels. This shows a high level of accuracy in defining velocity distribution profile of the flow. The value of Coles Wake parameter estimated for channel-sewer is less than that for lab channels.

In this paper, position control of a dual manipulator system for transporting a common payload is considered. In this regard, a centralized controller is designed for a reduced model developed based on a singularly perturbed formulation (SPF) which reduces the differential-algebraic dynamic equations of the system to a set of ordinary differential equations. In this approach, the controller does not rely on solving nonlinear algebraic constraints and is more applicable to real-time implementation. At the same time, a linear observer is designed to estimate the joint velocities which leads to elimination of velocity sensors and prevents noise injection into the system which may degrade the system performance. Finally, stability of the system is proved by using Lyapunov theorem. Simulation results illustrate the effectiveness of the proposed method.

In the last 150 year, most destructive earthquakes of Kopeh Dagh occurred near Quchan. These earthquakes caused large damages to Quchan (Tchalenko, 1975; Ambraseys and Melville, 1982). The Kopeh Dagh zone accommodates a motion, by a combination of slip-partitioning in the NW, thrust faulting in the SE, and anticlockwise block rotation in the Central Kopeh Dagh (Hollingsworth et al.2006, 2008). The system of NNW–SSE right-lateral strike-slip faults in the Bakharden–Quchan fault zone between Bojnurd and Quchan is one of the most prominent structural and topographic features of the central Kopeh Dagh (Hollingsworth et al., 2006). The Kopeh Dagh is made up of a sequence of mostly conformable and complete Mesozoic–Tertiary sedimentary rocks (Stocklin, 1968; Berberian, 1976). The Kopeh Dagh form a linear intracontinental fold and thrust belt trending NW–SE between the stable Turkmenistan platform and Central Iran (Hollingsworth et al., 2006). Shortening in Iran accommodates the northward motion of the Arabian shield into Eurasia. Recent GPS measurements (McClusky et al., 2003; Vernant et al., 2004) indicate that Arabia moves approximately northwards, with respect to Eurasia, at ~ 23 mma−1 at the longitude of the Kopeh Dagh. The Kopeh Dagh fold belt as a part of Alpine-Himalayan mountain belt in western Asia, constitutes the north-eastern border of the Iranian plateau and lies on the south-western margin of the Turan (Turkmenistan) continental crust, forming its epi-Hercynian (Early Kimmerian) cover (Berberian, 1981; Nabavi, 1983).In this study, the Double-Difference earthquake location algorithm was applied to the relocation of a large set of seismic events that occurred in Quchan region and recorded by Quchan and Mashhad seismic networks affiliated with the Iranian Seismological Center (IRSC) during the period from 1996 to 2012. The study area extends from 35.5°N to 39°N and 56°E to 60.5°E and is located in the Kopeh Dagh major seism otectonic province. The purpose of this study is to improve earthquakes location by using Double-Difference method developed by Felix Wald hauser and William Ellsworth (2000). Relative earthquake location methods can locate earthquakes with higher accuracy by removing effects due to unmodeled velocity structure. HypoDD program determines relative locations within clusters using the Double-Difference algorithm. In order to estimate capability of Double-Difference technique in the area, we performed synthetic tests by which four datasets, each including 10 synthetic earthquakes, were considered along the Kashafrud, Quchan, Binalud and Robat-e-Qarabil faults. The single event method by hypo71 program was applied to determine initial locations. Then, Double-Difference technique by hypoDD program was used for relocating the events. The results showed significant decrease in errors using Double-Difference technique. By using the synthetic tests, capability of Double-Difference algorithm was demonstrated. Then, by putting constraints on primary data, a number of 2516 earthquakes, recorded by Quchan and Mashhad's seismic networks from 1996 to 2012, were chosen to be relocated by the latest version of hypoDD program using the Double-Difference algorithm and Mehraban’s 3D velocity model (2012). The distribution of the events in the central part of the Kashafrud fault shows that the fault is dipping northeast and the occurrence of earthquakes at different depths can be the representation of a high-angle thrust fault and the activity in the entire fault plane of this reverse fault. According to the relocation of the earthquakes and the cross sections in the north of the Shandiz-Sangbast and the west of the Quchan faults, the existence of seismic activities can represent hidden fault activity. The linearity of earthquakes to the south of Baghan-Garmab fault can be also the representation of the continuation of seismic activity in this fault, though the surface trace of this activity is not visible in the geologic maps. In the present study, the average RMS is 0.27 s in the initial locating and reaches to 0.09 s in the relocation by hypoDD using the 3D velocity model. The average of the relative horizontal and vertical uncertainties stood at 686 m and 721 m for relative relocation. The relocation using a 3D model could improve the depth distribution of earthquakes, which is more accurate than initial location. This means that it reveals the concentration of the events between the depths of 5 to 23 km. As for the constraints imposed on the initial data, we considered a minimum depth of 3 km, but the Double-Difference relocation of earthquakes using the 3D model shows that 73 earthquakes occur at depth less than 3 km with least errors.

In this paper, an approximate solution of required velocity with final position constraint is derived using a piecewise linear gravity assumption for elliptical earth model. In this approach, the total flight time is divided into several time intervals and the gravitational acceleration is assumed to be linear at each interval. The solution gives an explicit relation in terms of the current position vector, desired final position and flight time in three dimensions. The accuracy and computational burden of the method are obtained numerically in terms of the number of time intervals, and compared with linearized solution and Zarchan's iterative algorithm. Numerical solution shows that the present method has better accuracy than the two mentioned approaches with the same computational burden up to a range angle of 18 deg for minimum energy trajectory in an elliptical earth model. The presented method can be extended for two or multi-body problem and also for the computation of sensitivity matrix of required velocity.

Velocity analysis is an important part of seismic data processing steps. The stacking velocity can be calculated by the Normal-Incident-Point (NIP) wave and the emergence angle، which are attributes of Common-Reflection-Surface (CRS) stack method. But the NIP-wave is impressed by the Normal wave of the CRS attribute. The Common-Diffraction-Surface (CDS) stack is introduced by developing the CRS method. The model-based CDS attributes can be calculated by ray tracing on smooth velocity model with minor accuracy. As in model-based CDS method، the NIP-wave is not affected by N-wave. Hence، the calculated stacking velocity is more accurate and more reliable. Here، it is proposed by us to apply the model-based CDS on a range of constant velocity model several times. In this way، the coherence and stacking velocity sections are produced for each time. In addition، the production of coherence and stacking velocity sections allows us to select the stacking velocity with high coherence. Finally، the propose method on a synthetic model with five layers has been applied and the results of stacking velocity obtained by CRS have been compared with the results obtained from model-based CDS method. The results show a great improvement in accuracy of stacking velocity calculated with CDS attributes.