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Resistance literature, a type of political literature that comes with the popular resistance against tyranny and aggression description, as elemental efficient, pays Bydargry and justice. Analyzing the different aspects of this type of literature, the development of research in the field, particularly since the Islamic Revolution was on.In the field of literature, lasting until the end of 1390 more than 400 original research that the quality and quantity of resistance literature, and not marginal issues that have been detected, but despite little growth management, there are obstacles in the way of researching this area.In this study, the research deviations stability in the pathology literature and removing barriers, attempts to answer this question is that:
Which management deviations ranging from fallacy and confiscation of literature in the field of sustainability have been there? The distortions of what literary trends or challenges in this area have created a false?have created a false?

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- Natural convection heat transfer in a square cavity induced by heated plate is investigated using the lattice Boltzmann method. A suitable forcing term is represented in the Boltzmann equation. With the representation, the Navier-Stokes equation can be derived from the lattice Boltzmann equation through the Chapman-Enskog expansion. Top and bottom of the cavity are adiabatic; the two vertical walls of the cavity have constant temperatures lower than the plate’s temperature. The flow is assumed to be two-dimensional. Air is chosen as a working fluid (Pr=0.71). The study is performed for different values of Grashof number ranging from 103 to 105 for different aspect ratios and position of heated plate. The effect of the position and aspect ratio of heated plate on heat transfer are discussed. With increase of the Grashof number, heat transfer rate is increased in both vertical and horizontal position of the plate. The obtained results of the lattice Boltzmann method are validated with those presented in the literature.

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It’s well known that today’s organizationsens counter the national, regional and international dynamic and complex changes.The survival and development of all organizations require to provide some new methods, alternatives, innovations (new products and services)processes and so on. Since Corporate entrepreneurship involves promoting the entrepreneurial behaviors in an organization, therefore, the organizations have to consider the "corporate entrepreneurship" as a critical success factor. In this paper, the authors atlempted to recognize the corporate entrepreneurship obstacles. Thus, organizational culture, supervision and control, attention to short & long term profits and the ways of giving rewards were studied. The obtained results based on the statistical analysis showed that the conservative organization al culture, close supervision and control, attention to short term profits, and giving unappropriate rewards are the fundamental obstacles of corporate entrepreneurship.

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This paper presents a parameterization method to optimal trajectory planning and dynamic obstacle avoidance for Omni-directional robots. The aim of trajectory planning is minimizing a quadratic cost function while a maximum limitation on velocity and acceleration of robot is considered. First, we parameterize the trajectory using polynomial functions with unknown coefficients which transforms trajectory planning to an optimization problem. Then we use a novel method to solving the optimization problem and obtaining the unknown parameters. Finally, the efficiency of proposed approach is confirmed by simulation.  

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Nanotechnology has been shown to have promising roles in the development of various industries including the agricultural sector. The primary purpose of this study was to investigate the researchers’ attitude and the obstacle hampering the development of nanotechnology in the agricultural sector of Iran. The population of this study consisted of researchers in national research centers/institutes (N= 187) during the biennium, 2009-2010. Proportional stratified random sampling was used for sample selection in the study (123). A questionnaire was developed and its validity was evaluated by a panel that consisted of the experts in the Nanotechnology Committee of the Ministry of Agriculture, Iran, and the faculty members of Tarbiat Modares University. A pilot test was conducted to determine the reliability of the questionnaire and Cronbach Alpha coefficient was confirmed for the scales of the questionnaire (α= 0.92). The results of this study showed that the respondents’ attitude toward the significance of nanotechnology was in the range of adequate to excellent level (92%, accumulatively). On the other hand, among the 37 obstacle variables investigated, 5 factors were found to account for 69.89% of the variance of obstacle variables. These included budget hindrance, instructional difficulties, management problems, research problems, and relative-informative hardships.

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In order to utilize robots for industrial tasks, designing a suitable path is necessary.Executing the path by the robot in the presence of obstacles, makes the path planning task a difficult one. In addition, path planning is a time consuming task and needs expertise to define certain path for each industrial job. In this paper, uses Jerk-minimum method, B-Spline curves, via-point, and obstacle avoidance algorithm to automatically generate a suitable and safe path for a simulated 7 degrees of freedom industrial manipulator.A user determines via-points for robot trajectory using a Kinect sensor,then a combination of Jerk-minimum method, B-Spline curves, a path is generated. This path is checked by an obstacle avoidance algorithm,and a final path is generated. The obstacle avoidance algorithm uses the inverse kinematic equation of the robot to modify the robot trajectory. One of the advantages of the proposed method is both to facilitate trajectory planning for the user and to create a smooth trajectory for the robotic arm.

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This paper deals with the collision-free path planning of planar parallel robot by avoiding mechanical interferences and obstacle within the workspace. For this purpose, an Artificial Potential Field approach is developed. As the main contribution of this paper, In order to circumvent the local minima problem of the potential fields, a novel approach is proposed which is a combination of Potential Field approach, Fuzzy Logic and also a novel algorithm consisting of Following Obstacle as well as Virtual Obstacle methods, as a hybrid method. Moreover, the inverse kinematic problem of the 3-RRR planar parallel robot is analyzed and then the aforementioned hybrid method is applied to this mechanism in singular-free case. It is worth mentioning that, in this paper, all the probable collisions, i.e., the collision between the mechanism and the obstacles and also among the links, are taken into accounts. Two general cases have been considered in collision-free path planning simulation; the first case considered a mobile robot in several workspaces and the second one was assigned to the 3-RRR planar parallel robot path planning. Results of the simulations, which are implemented in C programming language for the sake of real-time purposes. reveal that for the both cases, the newly proposed hybrid path planning method is efficient enough for the mobile robot, or the end-effector of the planar parallel robot to reach the goal without colliding with the obstacles.

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     vindication have been presented, which are mainly considered as some significant tools for the defendant and, by their assistance, the verdict may be issued in his/her favor. However, none of the concepts mentioned in the Civil Procedure Law have not been well defined and separated from each other. In one comparative survey with jurisprudence in France and Arab countries, it was distinguished that obstacles of trial from the separated objections in cases which, because of the existence of the obstacle, the claim basically is not actionable, issuing the order of not auditing the claim has been predicted and proposed. Sometimes, because of the existence of the trial obstacle, there would be no need for the defense of the defendant in the nature of a claim and issuance of the abatement of action. Therefore, it is better that the legislator separates this way of defense in the law of our country as a method of defending the objections in order to reduce the number of the propounded  claims to the courts predominantly.                     Conceptual
*  Corresponding Author 's Email: hamid.derakhshannia@yahoo.com

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This paper investigates the leader-follower formation control problem of nonholonomic mobile robots based on backstepping technique composed with the bio-inspired neurodynamics while avoiding collision with obstacles. Kinematics model of robot and nonholonomic constraint are introduced and formation control scheme is formed based on backstepping technique. In order to solve velocity jump in backstepping kinematics model, the bio-inspired neurodynamic approach is used. In most of the previous studies, researches are used separation-bearing approach and also supposed that desired separation and bearing are constant. In this paper this assumption is relaxed and desired separation and bearing are considered to be time varying. Error dynamics equations are derived and a new controller is proposed. Also an auxiliary reference angular velocity control law is proposed to guarantee global asymptotic stability of the followers and local asymptotic stability of the entire formation according to direct method of Lyapunov. A common example of changing the formation is obstacle avoidance, when an obstacle is located within a follower path and is not in its leader path. Time varying functions for desired separation and bearing are chosen and the new controller is developed with its proof of stability. Simulations results reveal that each follower robot can track its real time leader employing the proposed kinematic controller while avoiding obstacles. Furthermore control inputs at the start moment and also while avoiding obstacles, do not contain impractical jumps and are reasonable thanks to integrating bio-inspired neurodynamic with backstepping technique.

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In this paper, kinematic and dynamic model of planar cable-driven parallel robots are introduced in general form which are verified for a constrained cable-driven parallel robot in Sim-mechanics. Path planning based on artificial potential field approach is considered to prevent collision between dynamic obstacle, end-effector and cables in order to achieve collision-free path. As well as to reduce energy consumption, cable tension constraints have been involved in optimization of path planning. This method is proposed to control a cable robot. Therefore, obstacles are distributed randomly in order to have a complex environment. By this way, cable tension constraint is studied as one of the most crucial challenges for cable driven robots. Moreover, Fmincon function of Matlab is applied in order to take into account the required constraints and maintain the limits for cables tension. The latter leads to solve the redundancy resolution which is a definite asset in controlling a cable-driven parallel robot. Finally, a four-cables driven parallel robot is controlled by using the so-called computed torque method for tracking the desired and optimized path. The method is explained and obtained results indicate the efficiency of the proposed approach.

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This is the main question was how the combination of primary and secondary obstacles facing spatial planning? For this purpose, were used of the Delphi technique and AHP. Findings show that is highlighted at the primary and secondary obstacles, the role of administrative and structural obstacles among the six obstacle studied (Economical, geographic and territorial, political and security, Research, Social and Cultural and the Administration - Structural). For example, among the 60 sub-obstacle studied, were at first to fourth place Ignore to land use planning by managers during management changes with final weight (0.109), lack of coordination between responsible organizations for land use planning in the preparation implementation and monitoring with final weight (0.078), lack of clear strategy in trustee organizations to implementation of proposed scenarios projects in preparation of weak regulatory foundations with final weight (0.061) and weaknesses of of the regulatory bodies final weight 0.055. Among the other primary and secondary obstacles has been an economic barrier of the preference.    

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In this article, mixing in the combined electroosmotic/pressure driven flows of non-Newtonian fluid in a microchannel with rectangular obstacles and non-homogeneous ζ-potential has been studied numerically. The non-Newtonian behavior of the fluid is considered for the flow field using power law rule. Also, the nonlinear Poisson-Boltzmann equation is used to model the distribution of ions across the channel and the electric potential. Numerical solutions of coupled equations of momentum, electric field and concentration field are performed by means of finite element method. In this study, the effects of various parameters such as pressure gradient, rheological behavior of the fluid and the geometrical and physical parameters of obstacles on the mixing quality are investigated. The results indicate that applying adverse pressure gradient to the flow, the dilatant behavior of the fluid, as well as the height of barriers, are highly effective in the enhancement of the mixing quality within the microchannel. It is found that for microchannels with heterogeneous ζ-potential, increasing the length of obstacles significantly increases the mixing efficiency while for the microchannels with homogeneous ζ-potential, barrier length has a slight effect on mixing efficiency.

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In this paper, according to flight devices categories, advantages and features of quadrotors and its performances are investigated. Then, the main challenges in quadrotors control and stability in the presence of obstacles have been considered in such a way that the system crosses the maximum number of obstacles in the best distance and time. For this purpose, the equations of motion of the system are derived and a controller for command tracking is designed without obstacles based on sliding mode method. The simulation results of the controller performances are given in the paper. In continuous, trajectory planning for crossing the system from the obstacles in alternative positions is presented and the quadrotor with the designed control system are simulated using the designed trajectory. The preference of the proposed trajectory planning is that the system can cross the number of obstacles in alternative positions in minimum time and using fewer sensors. Because of free shape of designing method and alternative initial velocity, the proposed method are applicable for piecewise trajectories. As a result of considering the drag force, the proposed approach is more successful in the various problems.

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This paper presents a new method based on machine vision for mobile robots to detect and avoid obstacles in unknown environments. One of the challenges of mobile robots trajectory control in unknown environments is that their obstacle avoidance system to be designed robust to material and shape of the obstacle. In this research a mobile robot equipped with a camera is designed and fabricated. Also an algorithm is proposed and implemented on the robot in order to detect obstacles by image processing and to control the robot trajectory. Three color laser pointers are mounted on the robot with certain angles that emit beams to the ground at ahead of the robot. The received images from camera contain these colored points that their coordinates are determined by image processing. Then position of any possible obstacle is detected using the proposed algorithm and the robot is commanded to avoid obstacles by changing its path. These obstacles can be static or dynamic. Our experimental results show that the proposed method, with a high reliability, has the ability to detect and avoid obstacles with any shape and material whereas other similar methods had restrictions in this regard.

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This paper aims at proposing an algorithm for collision-free motion planning of two wheeled mobile robots. The proposed approach relies on discrete motion planning, convex optimization and receding horizon control (RHC) concepts. The proposed algorithm is employed for motion planning and control of a mobile robot in order to pass through an unknown environment both in simulation and practical implementation. In this regard, CVX package benefited from the Gurobi solver is employed to solve the optimization problem in the simulation. Moreover, in order to perform a collision-free motion planning, corresponding Robot Operating System (ROS) package with the intended mobile robot is employed to cooperate with the provided motion planner package. The provided package utilizes educational license of Gurobi optimizer solely to speed up solving proposed optimization problem and its built in branch and bound for Mixed Linear Integer Programming (MLIP). In order to keep the linear form of the constraints, a combination of the Velocity Obstacle (VO) in the first horizon and Bug method concept for the rest of the horizons is used. Obtained results show the reliability of this algorithm for safe collision avoidance. The reported results reveal this fact that by considering the maximum velocity of the E-puck, obtained computational time is less than 0.004 sec. in each stage which is fast enough for robot motion planning tasks.

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Turbidity currents account for transporting sediments into reservoirs, seas, and oceans. Therefore, understanding dynamics of these currents for sedimentation and erosion is very important. In this paper, the effects of two obstacles on the behaviour of turbidity currents investigated experimentally. An 11 m long rectangular channel (11 m×0.6 m×1.0 m) with the bottom slope of 0.25% was used to run the experiments and a 3 m3 tank along with a constant head tank were served as the turbid water supplier. Two triangular obstacles were installed at predefined locations from the sluicegate. Then the experiments were carried out and the results compared with those from without obstacle condition. Velocity and concentration profiles at the upstream of first obstacle and between the first and second obstacles are measured by Vectrino at quasi-steady conditions and compared to those of without obstacle conditions showing a significant decrease of velosity in the presence of the two obstacles specially between the two obstacles and also at the downstream of the second obstacle. Fluid volume discharge per unit width and suspended sediment transport rate are calculated based on measured velocity and concentration. Also, the effects of inlet Froud number on the fluid volume discharge per unit width and suspended sediment transport rate was investigated. The results show that presence of obstacles introduces new regions to velocity profiles and two ponds of turbidity currents are formed at the upstream of the first obstacle and between the two obstacles. The hydraulic conditions at these ponds make a suitable condition for the suspended particles to be trapped and hence the sedimentation. Variation of the suspended sediment transport rate and the fluid volume discharge per unit width depend on obstacle location. These parameters at the upstream of the first obstacle are directly in proportion to the inlet Froud number while at the downstream the second obstacle and between the obstacles are inversely proportional. By decreasing the inlet Froud number, the volume discharge per unit width increases at the upstream of the first obstacle wheras, the amount decreases between the obstacles. Also, as the inlet Froud number decreases, the suspended sediment transport rate increases at the the upstream of the first obstacle but the value decreases between the obstacles and downstream of the second obstacle resulting the increase of the trap efficiency. The obstacles become more effective in controlling the turbidity currents when the inlet Froud number decreases. The first obstacle is 1.8 times more effective on reduction of local sedimentation rate than the second obstacle. These parameters at the upstream of the first obstacle are directly in proportion to the inlet Froud number while at the downstream the second obstacle and between the obstacles are inversely proportional. By decreasing the inlet Froud number, the volume discharge per unit width increases at the upstream of the first obstacle wheras, the amount decreases between the obstacles. Also, as the inlet Froud number decreases, the suspended sediment transport rate increases at the the upstream of the first obstacle but the value decreases between the obstacles and downstream of the second obstacle resulting the increase of the trap efficiency. The obstacles become more effective in controlling the turbidity currents when the inlet Froud number decreases. The first obstacle is 1.8 times more effective on reduction of local sedimentation rate than the second obstacle.

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A powerful two-phase lattice Boltzmann model with the ability of modeling high density ratio is applied to simulate a rising bubble striking a porous obstacle. This model is able to simulate immiscible two-phase flow with density ratio of 1000 and result in desirable mass conservation. In present research, a porous obstacle is posed in two-phase flow domain, bounce back and wetting boundary conditions at walls and corners is discussed and showed that after implementation of obstacle boundary conditions, mass conservation of the model is preserved. Accuracy and ability of the model firstly examined by some basic problems. Next, striking of a rising bubble with 1000 density ratio to a porous obstacle is simulated and the effect of contact angle, Eotvos number and porosity ratio in deformation and passing of the bubble from the obstacle is investigated systematically. Different porosity ratios and contact angles, result in different bubble behavior striking the porous obstacle; In low porosity ratios and low contact angles, the bubble remains below the obstacle. At high contact angles, the hydrophobicity of the obstacle surface draws the bubble into the porosities, and the bubble moves to the top of the obstacle and stays on the top surface of the obstacle. In other cases, the bubble completely passes through the obstacle and separates it. Mass conservation error of bubble passing the porous obstacle is of order of 10-11 which is completely desirable.

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Abstact:  Hydrodynamically, there is a complex confrontation among the porous obstacles along the flow path and the fluid is significantly important Existence of obstacles in the flow path causes changes in hydraulics and hydrodynamic parameters of the flow. Among the hydrodynamic parameters that change due to the presence of obstacles in the flow path, we can mention the intensity of flow turbulence. Since turbulence is related to the energy dissipation of flow, it has always been important to study this phenomenon.one of the most important issues of river engineering is The construction of obstacles in the fluid path, especially when these obstacles are built at the river crossing. The results of studying the behavior of fluid around porous obstacles can be used in the design of gabion groins, as well as the construction of gabion obstacles in the flow path, to dissipate flow energy .In this study, the flow structure around porous groins on the side of the canal and porous obstacles in the middle of a straight channel with a fixed bed has been investigated in a laboratory. The ADV  was used to measure three-dimensional velocities and reynolds stresses around the gabion obstacles with different porosity on the side and middle of the channel The obstacles on the side of the canal act as groins and the obstacles in the middle of the canal act as obstacle consuming the energy of the stream. The velocity was measured at 1265 points for groins and it was measured at 1525  points for obstacles located in the middle of the channel .The results showed that the three-dimensional velocity components  decrease with increasing porosity in groins and obstacles. Also, the separation of flow, return flow, ..., is more severe when the obstacles is in the middle of the channel than when the groin is on the side of the channel wall.Also, the effect of porosity percentage on obstacles is much greater and clearer than on groins.And the intensity of turbulence and the extent of the area have the maximum intensity of turbulence in the obstacles in the middle of the canal is more severe than the groins in the side wall. The maximum amount of kinetic energy for obstacles is somewhat larger than for similar groins. However, the maximum turbulence intensity for the obstacles with porosity percentages of 0, 20, 40 and 60 is about 2.95, 2.4, 1.9 and 1.6 times the maximum turbulence intensity in the same groin, which is relatively large. Therefore, it can be understood that the presence of a obstacles in the middle of the channel, although it does not cause much change in flow energy, but the presence of obstacles in the middle causes the current energy dissipation up to about 2 times the current energy dissipation behind the groin.and, the process of reducing the intensity of turbulence is slower at higher porosities. Finally, The width of the zone with more turbulence intensity in the cross section for the obstacles with porosity of 0, 20, 40 and 60% is about 2.3, 2.1, 2 and 1.9 times the range in the same groin, respectively. Which in itself indicates a greater depreciation of the flow behind the obstacle.