Detecting and preventing incidents with obstacles is a challenging problem. Most of the common obstacle detection techniques are currently sensor-based. Mobile robots like Small Unmanned Aerial Vehicles (UAVs) are not able to carry obstacle detection sensors such as radar; therefore, vision-based methods are considered, which can be divided into stereo and mono techniques. Mono methods are classified into two groups: Foreground-background separation, and brain-inspired methods. Brain-inspired methods are highly efficient in obstacle detection. A recent research in this field has focused on matching the Scale- Invariant Feature Transform (SIFT) points along with SIFT size-ratio factor and area-ratio of convex hulls in two consecutive frames to detect obstacles. However, this method is not able to distinguish between near and far obstacles nor the obstacles in a complex environment and, thus, is sensitive to wrong matched points. This paper aims to solve the aforementioned problems through using the distance-ratio of matched points. Then, every point is investigated for distinguishing between far and near obstacles. The results demonstrated the high efficiency of the proposed method in complex environments. The least achieved accuracy of the algorithm was 60.0%, and the overall accuracy was 79.0%.

In this everchanging world, any policy - makersand expertshave been focused on the problems of employment and it"s complexities. It is obvious that the frame of country"s youth population and increasing work inquiries, requires more attention to this phenomenon. The fact is that, in due to change in traditional economies, in providing imployment and generating production, some temporary industrial projects, are not efficient. In other words, in today"s country situations, which have been most affected by external elements, to decfease the problem of unemployment, the new job opportunities should be defined and introduced to the society. In this paper, the focus woutd be on analysing the infrastructure obstacles facing the problems of country"s unemployment. Finally, with more attention to the different economic sectors with high potential, educational system and production development, the ways that can get rid of this crisis, will be presented.

Bushehr is one of the famous and historical ports. it has an important place in economy politics history and sailing of Iran and Persian gulf. in duration of Afsharieh Zandieh Qajar and even initial Pahlavi Bushehr port was not the largest port in Sothern iran but also considered as the most important and famous ports of Persian gulf. Near about 20 consulates from different countriesare located in the region. In 19 th century economy of Bushehr was basedon Business and commercial sailing. In crease in Bushehr commercial sailing in 19 th century resulted in forming a powerful commercial societythere in a way that great businessmen and capital owners migrated from different parts of iran and resded in bushehr. Despite of this prominent historical place in second half of 20th century bushehr dropped behind and left its place to rivals. As the moment it is considerd as the second class ports in Persian gulf. this research aims at exploring historical obstacles in development of bushehrand consequently the key question would be as: what are the historical obstaclers in deveploment of busheh? The main hypothesis in this study is weakness and degeneration of bushehr commercial society along with some other factores which ended in bushehr decline part. Obviously other factores will be also be studied in this research. Results show that bushrhr development dependes on resolving historical obstacles.

Hydraulic structures in some cases, cause to produce obstacles in path of the flow that create oscillating vortices in downstream of the obstacles. Vortices produce oscillating forces to the obstacle that are harmful for the stability of structure. In recent years this phenomenon is used to create clean energy. In this study, oscillation of an obstacle in the presence of a fixed obstacle at the upstream was examined. The experiments on triangular block were carried out under varying discharge and different upstream distances. The main objective of this study was to investigate the effect of parameters of velocity and upstream obstacle distance on the oscillation frequency. Using dimensional analysis, the dimensionless parameters of Strouhal number, Reynolds number and ratio of distance to diameter were obtained. The charts of the relationship of the Reynolds number and also the ratio of distance to diameter vs. the Strouhal numbers were plotted. Finally, a new relationship was presented using data analysis and spss20 software to estimate the Strouhal number. Verifying the proposed relation, confirmed a fairly good prediction of this relation.

Introduction: Regarding the role of research in developing and improving a better culture, society and economics, 95% to 97% world finance in research belongs to developed countries while only 3%-5% to developing countries. Although the universities as the major organizations are to do research works, it seems that there are some problems to bring this true. We tried to find out if a load of teaching hours could work as an obstacle to "research" or not.Methods: 413 academic staff from Hamadan, Kermanshah, Booshehr and Ahwaz universities was randomly selected in this descriptive research. Content validity and reliability were examined before approaching research. The data was collected through a questionnaire and analyzed.Results: The most teaching hours was in Ahwaz (11.59 hours) and the least was in Booshehr (5.32 hours). Reseach works was the most in Booshehr (96.8%), and the least in Hamadan (84.2%). 26.4% from Ahwaz, 17.8% from Kermanshah, Hamadan 47.8%, Booshehr 22.6%, agreed on the following obstacles: a) Intensive clinical education, b) Intensive teaching hours, c) Strong authoritical preference for clinical matters than to research work.Conclusion: A very significant correlation among the teachers views was not seen, but all of them agreed on intensivity of clinical education as am obstacle to do "research".

The aim of this study was to determine whether previous trajectory plans reused in aiming targets with obstacles sometimes emerge in the way. For this purpose, in two experiments, right hand position of voluntary male students (N=55, 18-22 years) was measured in conditions that presence of obstacle in sequential trails was changed (randomly, in first experiment; predictable sequences in second experiment) by using potentiometer encoders located at the manipulandum joints. In first experiment, ANOV A results showed that trajectories when no obstacles were present had more start angel (motor planning index) if obstacle had recently appeared than if obstacles had not recently appeared (p<0.001). In the second experiment, from the similarity (F<1) between start angel of groups (predictable sequence groups with and without instruction; random pattern group) concluded that not only trajectory perseveration effect was not the result of sequential expectancy, but also this effect was related to trajectory planning. In general, we inferenced that control of sequential obstacle avoidance movements depended on previous movements and that in the motor planning, optimization of computational costs of trajectory formation preferred by minimal biomechanical costs of effectors.

In this paper, an algorithm to detect obstacles surrounding an autonomous vehicle and the method usedto navigate this vehicle on the road were studied. For this purpose, road was divided into cells in lateraland longitudinal directions. The assumption was that some special tools specify the cells positions andthen full and empty-cell corresponding matrix was generated. In this matrix, full cells were displayedwith digit 1 and empty cells are displayed with digit 0. In the next step, by analyzing the matrix inMATLAB®, the vehicle was navigated. In this analysis, first, the position of the vehicle and theobstacles were identified. Then, based on the road conditions and the obstacles positions, requiredorders to move the vehicle were determined. If a lane change is needed, according to the road’scurvature and the distance between the vehicle and the obstacle, appropriate path for the vehicle will bechosen. In this paper, for the first time in autonomous vehicle navigations, the road was considered as a1 and 0 matrix. In this method, the road matrix was updated over time and provides the possibility ofanalyzing the vehicle’s movement. In addition, the algorithm used to solve the problem is very simple.

Eyes play a vital role in our life. Usually, all of us have seen the visually impaired people and know the problems that they face in their daily life. In order to detect the obstacles, blind people use sticks when they are walking but this instrument just can help them find objects on the ground. Obstacle detection is a field of effort that has led to vast progress in primary safety systems and in the primary-secondary safety systems interaction. Obstacle detector for the blind is an automated device for blind people. The main objective of this device is to make easy the walking environment for blind people. In this paper, a device is made which help the blind people by assisting through an android application. First, the device is made and then its performance is tested in three demanding conditions, for instance, normal, windy, and rainy conditions. The device shows a satisfactory level of accuracy in the three conditions. It helps the user to hear the distance and the location in an automated human voice.