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Problem: The concept of urban public art and its emergence in the public sphere is one of the most important factors in strengthening and accelerating the process of the creative city. Street music as an urban public art, is an influential event in urban communities that seeks to improve the quality of social life, strengthen collective memories, increase the level of vitality and dynamism of the city and achieve creative urban development.
Target: The authors try to redefine the importance and significance of the urban public arts event in urban spaces, identify the feasibility of performing street music in social environments. The green corridor of Shahrchai and the Khayyam Jonubi sidewalk of Urmia city have been studied.
Method: In this regard, in the present study, information has been collected with the aim of application and descriptive-analytical nature and by using documentary-library methods, questionnaire and interview tools. The statistical population and sample size consist of two groups of experts, thinkers and university professors and active members of street music, which includes 60 samples including stratified or group sampling method. For quantitative analysis, the methods of Kolmogorov-Smirnov, Spearman Correlation, Swara and Cocoso have been used. 
Result: According to the findings, the social, cultural and environmental dimensions and the indicators of "possibility of live music performance" and "quality of environmental design" have gained the highest and lowest levels of importance, respectively. Also, the green corridor of Shahrchai has more favorable conditions than the performance of urban Public arts (street music) compared to the Khayyam Jonubi sidewalk of Urmia.               

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In this paper, we used a non-singular backstepping terminal sliding mode control approach to the unmanned aerial vehicle (quadrotor). In the first step, the governing dynamical equations were obtained based on the quadrotor considering all the effective parameters. The controller objective is limited to obtaining proper tracking of the desired positions (x, y, z) and the yaw angle (ψ), as well as maintaining the stability of the roll and pitch angles despite the presence of external disturbances. Controlling methods require complete information about system states that may be limited in practice. Even if all system conditions are available, it is interfered by noise, and also large number of applier sensors to measure states, makes the entire system more complex and costly. For this purpose, the Extended Kalman Filter (EKF) has been used as an observer. The extended Kalman filter is used as a speed observer and estimator of external disturbances such as wind force. Therefore, the use of a controller-observer is suggested to estimate the effects of external disturbances in order to compensate for them. The design method is based on the stability of Lyapunov. Simulation results show the promising performance and suitability of the observer-controller.

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Attention to entrepreneurship has been vital in recent years. Most researchers in this field are looking for why and how to spread entrepreneurial behavior in society and acknowledge that this is an effective factor in economic advancement. Research in this area is sparse and limited. The present study, based on scientometric method and content analysis of documents, examines studies in this field in order to provide a conceptual model by sorting out researches. The statistical population of the study includes all the documents provided in the Scopus database with 666 documents (like articles, books, etc.) until 2019, which evaluated by bibexcle software and VOSviewer. The results are divided into four areas: the first part of individual and cultural factors such as "gender, age, risk-taking, independence, experience, awareness, belief in self-efficacy, self-control, mental norms, entrepreneurial attitude", The second part includes environmental factors such as "entrepreneurial and dynamic environment, enabling, family supportive, and social supportive environment", the third part deal with economic factors such as "individual and social financial resources" and the fourth part is on institutional and legal factors such as legal, supportive laws and supporting institutions issues.