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Purpose: This paper aims to efficiently find the number and optimal placement of BTSs in the coverage area such that the implementation cost is minimized, while the user's traffic in the corresponding area and the channel interference constraints are satisfied. Design/methodology/approach: An integer linear mathematical model has been proposed to assign all customer points to transceiver-based stations. The objective function has been assumed to minimize fixed costs while considering a penalty for reducing interference. An optimization solver has been applied to solve the model. Findings: The proposed mathematical model was compared to another existing model in the literature from three points of view: coverage cost, construction costs, and running time. The results indicated that the proposed model has the appropriate efficiency to find solutions to real practical problems. In more detail, the proposed model succeeded to find solutions with less coverage or construction cost in a shorter time, compared with the model in literature, which has been referred to as the SSH model in the paper. However, there have been some samples in which the SSH model overtakes the proposed model in one or two mentioned aspects for comparison. Research limitations/implications: The limitation of this study is that the channel model was considered based on the simple free space path loss model, while the real channel model based on the environmental effects can be suggested for future work. Another important issue is that for BTS localization design, knowing the status of the real environment leads to the proper design in such networks. Social/practical implications: BTS localization is the most important issue in mobile networks' design. In a practical situation, there is not any software available to design a mobile network in the corresponding coverage area. Therefore, this paper can help communication engineers to implement the proposed approach in a real environment. Originality/value: In this paper, the problem of the optimal location of transceiver-based stations (BTS) in different models in the coverage area has been addressed such that the implementation cost is minimized, while the user's traffic in the corresponding area and the channel interference constraints are satisfied. This has not been considered in the literature. Any of the existing models focus on one aspect to optimize, such as maximizing the coverage, minimizing the interference, and minimizing coverage or construction costs. The novelties of the proposed model are twofold: i) two goals were considered in the objective function, i.e., minimizing construction costs and minimizing interference. Since interference with full coverage is unavoidable, the model added a penalty to the objective function to reduce the interference as much as possible; and ii) it was assumed that there is more than one single type BTS, any of which has different power, radius, and capacity. This makes the model more real and indeed more complicated to solve. [ABSTRACT FROM AUTHOR]

In recent decades, the evolution and advancement of automotive technology have played a crucial role in enhancing the safety and security of drivers and passengers. One prominent technology that significantly contributes to vehicle safety is the Anti-lock Braking System (ABS), which notably improves safety during braking, reduces braking distances, and enhances vehicle control across various road surface conditions. This paper introduces an innovative real-time algorithm aimed at improving the performance of ABS systems, leveraging practical data instead of complex mathematical modeling. Unlike traditional modeling approaches that rely on half car model and dynamic tire simulations, this study utilizes actual wheel data to develop and optimize the algorithms. This approach enhances the sensitivity and adaptability of the algorithm to real-world road changes and varying operational conditions. Furthermore, the method effectively addresses and analyzes the phenomena of Jump and Split, which have not been specifically tackled in other studies. Validated through both analytical and empirical models, this approach provides high accuracy in estimating acceleration in scenarios where accelerometer sensors are unavailable. It offers precise responses under varying braking conditions. Simulation results of the algorithm using practical test data indicate that it achieves approximately 49.1% faster detection times compared to other algorithms, offering significant advantages such as reduced braking distances and lower computational costs. [ABSTRACT FROM AUTHOR]

Background & Aims: Every organization has an identity that is based on organizational culture. Organizations, like individuals, have personality, which is called the culture of that organization. Accordingly, the purpose of this study is to investigate the components of organizational culture in medical universities and present a conceptual model using the Delphi technique. Methods: To conduct the research, semi-structured interviews with 15 experts, including university professors in the field of organizational culture at Lorestan University of Medical Sciences and the Delphi method were used. In this paper, three basic steps of qualitative methods included; Open coding, axial coding, and selective coding and then the validity of the extracted codes was checked by Delphi method. Results: The findings showed that in the case of creating and forming friendly groups in universities of medical sciences in order to improve relations and proper cooperation in terms of presenting ideas, opinions and also solving problems, it creates a favorable organizational culture in universities. Medical science will be.in this section, the survey has been conducted in several stages to reach the consensus of the experts for the components. The components identified in the qualitative phase were presented to 15 experts in the form of a closed questionnaire. Then the average answers were calculated using Excel software. The purpose of the Delphi method is to reach the most reliable group agreement of experts on a specific issue, which is done by using questionnaires and asking experts' opinions, repeatedly, according to their feedback. This process continues until the average numbers become stable enough. In this research, the minimum average value of the answers is 3.5 and the difference of opinion for the Delphi averages is 1 (the lowest number in the response spectrum). If the average response is less than 3.5 or the amount of disagreement is greater than 1, the corresponding component will be removed. In the first stage of Delphi, the identified components were presented to the experts in the form of a 5-option Delphi questionnaire, and the average answers were calculated. At this stage, the average answers given for the components of risk acceptance, the importance of work to satisfy personal needs, personal influence, the effort to participate in the public-private sector, and creating an atmosphere without fear and intimidation were less than 3.5, and therefore this component were removed from the process. Kendall's coefficient of agreement in the first stage was equal to 0.569, which shows that the experts' agreement in this stage is average. In the second stage of Delphi, the Delphi questionnaire was again provided to the experts and the average answers and also the average difference with the previous stage were calculated. At this stage, the average difference in all identified components is less than 1, but the average components of voluntary coordination and voluntary presence of people to carry out assigned tasks, sensitivity to the needs, desires and personal problems of organization members, creating a communication network and alliance with Good people, the independence of employees and team members for how to do work and design a happy and stimulating work environment was less than 3.5. Therefore, these components were also removed from the process and the third round of Delphi was conducted. Kendall's coefficient was 0.590 in the second stage, which shows that the experts' agreement in this stage is average. In the third round, the average difference in all components is below 1, and also the average of all identified components is higher than 3.5. Also, Kendall's coefficient was obtained in the third stage equal to 0.690, which shows that the level of agreement of the experts in this stage is almost high. Therefore, all the indicators that entered the third round of Delphi were evaluated according to experts and therefore these indicators were approved. According to the results obtained from the Delphi method, finally 8 main components and 54 secondary components were identified. According to the number of experts, the content validity index of CVR is confirmed. Also, the Cronbach's alpha coefficient in all components is above 0.7, which shows the acceptable reliability of the components questionnaire. Conclusion: The purpose of the current research was to analyze the components of organizational culture in universities of medical sciences using the Delphi technique. Based on the results, 8 main components and 64 sub-components were identified as organizational culture components in medical sciences universities. First, the questionnaire made by the researcher and the answer package was provided to the experts. Then it was done by Delphi method in three rounds until we reached the agreement of the experts for the components. In the first round, 5 sub-components and in the second round, 5 other sub-components were removed from the study process. Kendall's coefficient in the first and second rounds is 0.569 and 0.590, respectively, which shows that the experts' agreement in these two rounds is average. In the third round, the average difference in all components was below 1 and also the average of all identified components was higher than 3.5. Kendall's coefficient was also obtained at 0.690 in the third stage, which shows that the level of agreement of the experts in this stage was almost high. Therefore, all the indicators that entered the third round of Delphi were evaluated and approved by experts. Therefore, in the end, 8 main components and 54 sub-components were identified. According to the results of this study, the components of organizational culture in Lorestan University of Medical Sciences include shared responsibility; team orientation; The main result; desirable communication pattern; adaptability; governance and leadership; The emphasis is on details and ideation and individual creativity. Based on the results obtained, it can be said that in universities of medical sciences, the factors that define the organizational culture of the university are joint responsibility and cooperation among the members of the organization, attention to teamwork, correct communication., friendly and favorable among the members of the organization, accuracy in the results and considering it important, adapting the members of the organization to the conditions and problems created, the presence of a competent and capable manager in the university, emphasizing the details of the problems of the university and trying to provide a solution for it. It is a collective and team form, as well as expression of creativity and ideas by all members of the university. If groups are formed in a friendly manner in universities of medical sciences to create cooperation and proper relationships to solve problems and also to present ideas and opinions, a favorable organizational culture will be implemented in universities of medical sciences. Therefore, it is suggested that the universities of medical sciences of the country pay attention to teamwork and cooperation among the members of the organization so that they can use the opinions and ideas of all people. If all employees have a sense of responsibility in the university and adapt themselves to the conditions, it can be said that an organizational culture has been implemented in the university. The requirement for this is to pay attention to the details available in the university as well as the results obtained from the cooperation of the members of the organization. [ABSTRACT FROM AUTHOR]

Background & Aims: Cancer is one of the great human challenges in all countries, both advanced and developing. Cancer treatment management can include surgery, chemotherapy, or radiation therapy (1). Radiation therapy is done in two ways: Teletherapy and Brachytherapy. Brachytherapy involves the use of radiation sources to treat cancer by irradiating cancerous tissue from within the patient’s body (2). But the dose and how to use this method has always been questionable for researchers. Therefore, this study creates a new fuzzy approach to high-dose brachytherapy by optimizing the distribution of double roughness based on dosimetric criteria. The use of fuzzy logic itself has increased the accuracy of the mathematical model of the problem. This fuzzy model is a new study and innovation used in this paper. Due to the fuzzy nature of this method and its limitations, it is considered fuzzy. This makes the method more accurate and includes parameters such as the patient’s physical ability and age in the problem, which in itself increases the accuracy of the method for each patient. As a result, the obtained answer is improved and the executive program of brachytherapy method is more accurate. Methods: In the present study, the dose prescribed for an organ was evaluated by dosimetric indices listed in Table 1 (18). For the present study, data from 20 patients in the age range of 50 to 74 and mean age 62 years with a wide range of prostate volume between 23 and 103 cubic centimeters, and for the treatment of prostate cancer by brachytherapy from the Academic Medical Center (AMC, Amsterdam, the Netherlands) had participated. To compare brachytherapy programs with high interstitial dose, the dose rate was calculated with 192Ir beam with a radiation dose of 13 Gy, according to the standard protocol TG-43. To begin with, computed tomography (CT) scans or magnetic resonance imaging (MRI) were taken from the patients pelvis, and entered into the treatment planning software for use in treatment planning sessions. BT treatment planners and specialists then determined the input catheters, target volumes, and OARs obtained from the medical images. Depending on the size and exact location of the target volumes, between 14 and 20 catheters entered the patient’s body, reaching the target volumes. After designing and approving an acceptable treatment plan, the catheters inserted into the patient’s body were connected to a retractor 4 that controls the movement of the radiation source. After the treatment program, the source was returned to the retractor (8, 14). Then, an integer program model with fuzzy constraints was proposed for programming on high-dose brachytherapy. The description of infrastructures, parameters and variables in this model are in Table 2 (15 ). Finally, the dosimeter index is equal to the sum of all the index variables, as it turned out: The proposed model is a correct programming model called IP. In general, three evolutionary algorithms (EP), (GA) and (ES) were used in this research. The algorithms stopped after creating 20 generations of desirable answers and the best answer of each generation was determined on the chart as a point. The resulting set of answers were connected in the form of graphs, which are used to analyze the results. Each point on the graph identifies the best answer from each of the generations generated by the respective algorithms. These three algorithms were performed independently for each patient and the obtained answers were identified as dots on the chart. The graph obtained for each patient indicates the capability of each of these algorithms. Results: According to this study, each of the three algorithms (EP), (GA) and (ES) are each run independently for each of the patients with prostate cancer. At first, the genetic algorithm showed the ability to get closer to the desired answer sooner, but as the optimization process continues, the rate of convergence to the desired answer decreases, so if the time parameter is very important, the genetic algorithm can be useful. Especially for patients whose prostate volume was larger than other patients. In patients 15, 12, 8 and 9, due to their younger age than other patients and better physical condition, as well as prostate volume less than 80 ml, they had much more promising results than other patients. In contrast, for patients 4 and 19 with an age of over 70, the results were not as favorable as for other patients. The * sign in the table indicates that there is no answer through that patient-specific algorithm that covers 95 or even more of the tumor volume. Therefore, according to Table 2, it can be concluded that the best algorithm that can be considered for the case where the shortest time to reach the target coverage above 95% is the genetic algorithm. According to Table 2, it can be concluded that the best algorithm that can be considered for the case where the shortest time to reach the target coverage above 95% is the genetic algorithm. Therefore, according to Table 3, the ES algorithm has better answers than the other two algorithms for the case in which the largest volume of the tumor is covered. According to the results, the ES algorithm has obtained the best results for patients under 60 years of age and normal prostate volume. Conclusion: According to the obtained results, it can be stated that whether the main goal is the maximum coverage or the goal is the shortest possible time to reach the coverage above 95%, the best algorithm that can get a good answer for each patient is the evolutionary strategy algorithm. [ABSTRACT FROM AUTHOR]

Background and Aim: The aim of this study was to present a conceptual model of spiritual well-being in prevention of substance abuse in adolescent. Materials and Methods: The present study was done with a qualitative metasynthesis with systematic review of the studies present in the foreign and Iranian journals about spiritual well-being and the role of them in prevention of substance abuse in adolescents. The population of this study consisted of noninterventional archive studies that were done during 1986 -2016 in Oxford Journal, Science Direct, Wiley Online Library, Taylor&Francis, ProQuest, Springer, Iranmedex, Irandoc, SID and Magiran. Keywords were including of spiritual well-being, spirituality, prevention of substance abuse and adolescents. Ethical Considerations: This study with ethics code 8797/1129 has been approved by Farabi Campus of University of Tehran. Findings: After reviewing and evaluating the quality of the research, eventually 73 papers and theses included 8 Persian articles, 65 English papers including 11 theses and 54 articles were found and dissertations and finally conceptual model based on fisher (1998) theory's, wree presented. On this ground, subcategory of spiritual well-being was consisted of three theme of relationship with others, relationship with self and relationship with God. Each of them consisted of two subtheme of psychological health (interpersonal and intimate) and psychological well-being(interpersonal and intimate). Conclusion: The results showed that spiritual well-being influenced on multiple dimensions of adolescent psychological health and well-being and prevention of adolescent substance abuse from this way. [ABSTRACT FROM AUTHOR]

In this paper, the mathematical modeling, construction, control, and implementation of a onedegree- of-freedom cube dynamic system with a reaction wheel actuator will be discussed. The innovation of this paper is the implementation of the proportional-integral-derivative controller on the experimental system of one degree of freedom with a reaction wheel. First, equations of system are expressed, then the system is analyzed in time and frequency domain. Then, the proportional-integral-derivative controller will be designed and implemented on the constructed system. The system response is compared in six steps for different control gains. The control gains of the best answer are proportional gain of -20, integral gain of -30 and derivative gain of 3- in system theory answers it has 1 degree of superiority and in experimental answer it has 7 degrees of overshoot. The steady-state error is zero for both experimental and theoretical system. The rise time of the simulation theory is 10 time steps, each time step is equal to 0.001 seconds, and the experimental response of the system is 10 time steps. The simulation session time is 180 time steps and the experimental response is 100 time steps. In the next step, the stability of the control designed with the selected gains from the previous step is tested by inserting the perturbation, and the system is stabilized by 4 degrees overshoot. By changing the angle of the bottom plane, the response will have 3 degrees overshoot, but the system will remain stable. The control results show that the constructed system is well stable and appropriate time responses have been obtained. [ABSTRACT FROM AUTHOR]

In this paper, a gas pipeline model with leakage is presented. This model does not need to evaluate the characteristics of downstream equipment and does not rely on sophisticated numerical methods. Changes in the flow variables can be accurately predicted by the model. In this model, a new similarity-based approach is proposed between the pipeline and the electrical circuit, in which a circuit equivalent to a specific structure is used to simulate the leakage pipeline. This new approach can be used to assess leakage losses and guide pipeline operation as well as to help detect leaks. We know that many mathematical expressions have been formulated to describe the flow in a pipeline by leakage, but it is not easy to solve. However, the mathematical model of a leaky pipeline can also be developed with this method. This model is validated using data from a real gas pipeline. The simulation results are in good agreement with the experimental results which confirm the validity of the model and the validity and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

Computer-aided process planning is one of the challenges for researchers to achieve computer-integrated manufacturing, and setup planning is the core of the CAPP system. Based on the literature survey, it has been observed that researchers use different methods for setup planning, and there is a lack of mathematical models in their methods. However, the mathematical model is necessary to implement and develop the setup planning method. Therefore, in this paper, the permutation-based setup planning was selected to determine the setups, and then the setup planning rules were cast into the mathematical model. Finally, the mathematical model is implemented and evaluated in MATLAB software to ensure the accuracy of this model. [ABSTRACT FROM AUTHOR]

In this paper an analytical approach for determining load distribution in single-column multi-bolt composite joints that contain nonlinear behavior is presented. Load distribution can be computed by the writing of governing equation of motion. This method is a closed form solution and includes a combination of spring-based and nonlinear behavior of materials theories. In this method, ideal bolted joint is similar to spring-mass system. Exerted load on each bolt and its displacement can be computed by using this method and analysis of governing equilibrium equation of system. In this paper, after the presentation of this method, load distribution in single- column multi-bolt composite joints is investigated, and curves of load changes versus displacement changes are plotted with linear and nonlinear behavior of material for determining nonlinear behavior effects of material on load distribution. The achieved results via suggested solution indicate that displacement increases about 2.5-5 percent in comparison with results of linear method. Due to manufacturing tolerances, bolt--hole clearances can vary within allowable limits and fits. Therefore, effect of bolt hole-clearance on the composite joints with linear and nonlinear property was investigated. [ABSTRACT FROM AUTHOR]

Conceptual design optimization of spacecraft systems is a complex and multidisciplinary process. In this case evaluation of the objective functions relies heavily on running iterative simulation models and analysis codes between various subsystems (such as structures, payload, electrical power supply, attitude determination and control, communication, command and data handling). The conventional sequential optimization approaches to such a complex design problem is time consuming and does not guarantee to achieve the best compromise among the various competing coupled subsystems, and may even lead to non-optimal design. In addition, the design search space can be multi-modal, non-convex with multiple local minima and hence it is time consuming or difficult to rapidly evaluate trade-offs between various subsystems (disciplines). To address these issues, in this paper an efficient surrogate (response surface) model-based multidisciplinary spacecraft systems design optimization technique with discrete and continuous design variables is presented. The methodology is based on the utilization of genetic algorithms (GA) for both system level and discipline level as an optimizer. Surrogate-modeling as an efficient tool is also used to decrease computational cost in discipline (subsystem) level within a collaborative optimization (CO) framework. Results obtained in this study show that the method introduced in this paper provides an effective way of improving computational efficiency of a complex space system design such as conceptual design optimization of a spacecraft. [ABSTRACT FROM AUTHOR]

Background Transparency has long been a basic principle for the management of public organizations and is usually considered a powerful tool to achieve desirable social goals, including strengthening accountability and reducing corruption. Objective The current research aims to develop a model for institutionalization of transparency culture in Lorestan University of Medical Sciences (LUMS) and assess the relationships between its components. Methods This is a mixed-method (exploratory sequential) study. In the qualitative phase using the content analysis method, the participants included university faculty members and senior managers of LUMS. A researcher-made questionnaire tool was used to collect information, and the interpretive structural modelling method was used to analyze and rank the components. Results Based on the results, 18 factors were identified as the main factors of the model for institutionalization of transparency culture in LUMS, which were organizational agility, change management, the rule of law, trust and confidence, clear accountability, cultural infrastructure, knowledge management, effectiveness and efficiency of processes, regulatory quality, participatory management, justice orientation, cognitive skills, adaptation and tolerance, reduced administrative corruption, improved community satisfaction, transformation and improvement of the administrative system, meritocracy, and employee satisfaction. Among these factors, the reduced administrative corruption and employee satisfaction had the greatest effect on institutionalizing the culture of transparency in LUMS. Conclusion The most important factors for institutionalizing the culture of transparency in LUMS are the reduction of administrative corruption and the satisfaction of human resources. Therefore, it is important to pay attention to these factors in institutionalizing the culture of transparency. [ABSTRACT FROM AUTHOR]

In the present paper, cooling performance of a hybrid system of air underground channel and direct evaporative cooler to provide cooling load for residential spaces was investigated in summer and its performance evaluation was studied for Tehran, Iran. The study was performed on the hottest day of the year in Tehran, which has a hot and dry condition. At first, mathematical modeling of the hybrid system components was developed, then by using the mathematical modeling, outlet air temperature distribution of any component of the proposed hybrid system was calculated. The obtained results imply that air temperature drops about 10°C in underground air channel and 6°C in direct evaporative cooler. According to the obtained temperatures and thermal comfort zone, it was found that the hybrid system is able to provide, on the hottest days of the year, thermal comfort for the residental occupants in Tehran. Then, by calculating the system efficiency, it was found that the efficiency is more than 1 which indicates high performance of the hybrid system. Eventually, by comparing the efficiency of the hybrid system and direct evaporative cooler it was found that efficiency of the hybrid system is 45 percent more than direct evaporative cooler. Also the system efficiency is higher than conventional mechanical systems efficiency and it is eco-friendly because the system is passive. Thus according to the present work, the proposed hybrid cooling system could be a suitable alternative for conventional HVAC systems. [ABSTRACT FROM AUTHOR]

In this paper, effect of advanced yield criteria including BBC2003, Yld2004 and BBC2008 are studied using Swift hardening law on determination of limit strains based on Marciniak-- Kuczynski (M-K), Swift's diffuse necking and Hill's localized necking models. These models are used to assess the formability prediction of orthotropic AA2090-T3 and AA6111-T4 sheets. The Portevin-Le Chatelier effect on formability of AA5182-O sheet is also studied. The sensitivity of Marciniak--Kuczynski model to the initial imperfection factor is investigated and the effect of this parameter on prediction of forming limit diagram has been shown. Study of the effect of yield criteria exponent on formability shows the higher exponents which are recommended for FCC metals have higher forming limits in comparison with lower exponents adopted to BCC metals. The effects of strain hardening coefficient and anisotropy are studied too. The results show that the increase of strain hardening exponent improves the formability, while the PLC effect and increase of anisotropy coefficient reduce it. Experimental results show better conformity with M-K model at the right side of FLD and with Hill's localized necking model at its left side. [ABSTRACT FROM AUTHOR]

The measurement of hydrodynamic loads on submerged bodies is one of the main uses of water tunnels. Due to the limitations of the water tunnel, an accurate force balance is necessary. This paper describes the design, fabrication and calibration of a new six-component force moment balance system for measuring the forces and moments acting on the model, in static and dynamic water tunnel testing. A balanced team performed many areas for designing balance system such as structural design, balance technology, design of calibration mechanism, balance calibration etc. A six-component balance is able to measure the three elements of force and three components of moment simultaneously and instantly on cavitating and non- cavitating models in a water tunnel. The concept used in the balance design is the bending beam and the strain gage principle. The electrical signals are proportional to the forces applied to the model. By considering the relationship between the applied force and the balance's output signal and by using the calibration models, the forces and moments exerted on the model in the water tunnel can be measured directly. To calibrate multi component balance, a new six-degree of freedom calibration rig is designed and constructed. The system is designed based on applicability of formal experimental design techniques, using gravity for balance loading and balance position and alignment relative to gravity. The six-component balance was calibrated using this rig. The standard error between the measured values and the values obtained from calibration model less than 0.1 percent of maximum loading was achieved. [ABSTRACT FROM AUTHOR]

In this article, a novel intelligent online tip-over avoidance algorithm is presented considering the interactions between the mobile base and manipulator arm. To this end, the newly suggested dynamic stability margin measure named Moment-Height-Stability (MHS) is adopted. Additionally, a function representing the increment of postural stability margin metric is defined based on MHS. The system dynamic equilibrium is then enhanced using a fuzzy logic approach. The response of the suggested method of this paper is compared with that of a previously Force-Angle based proposed method considering a planar mobile manipulator. First, the dynamics of the robot is derived using Newton-Euler method via MAPLE 16 and is verified through the model provided in SimMechanics toolbox of Simulink. The efficiency of the suggested method is illustrated in comparison to the previous one on a destabilizing robot path. Besides, the performance of the proposed method of the present study is investigated in the presence of external disturbances. The obtained simulation results reveal the effectiveness of the performance of the suggested technique for stability improvement of wheeled mobile manipulators, once unexpected disturbing situations are encountered. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of constructional elements on the biomechanical behavior of desert locust hind wing. First, the microstructure of the insect wing is investigated using scanning electron microscope. The results of the scanning electron microscopy are used to develop finite element models of the wing with different constructional elements. The presented models are studied under the inertial and aerodynamic loads applied during flight and the obtained stresses and displacements are assessed. The results show that longitudinal veins, longitudinal and cross veins, corrugations, corrugations and longitudinal veins and finally a combination of corrugations and longitudinal and cross veins cause, on average, a 4, 25.75, 4.34, 184.54, 768.5 times decrease of the achieved principal stresses in comparison with a wing without the mentioned constructional elements. Constructional elements of the locust wing play an important role to stablize the pattern of stress distribution in the wing during flight. Further, the existence of the mentioned constructional elements causes a decrease in the variation of the stress within a stroke-cycle. In addition, it is shown that the inertia and aerodynamic forces have less effect on the wing deformation than the elastic ones. The results of this research may be helpful in the development of lightweight structures with high strength. [ABSTRACT FROM AUTHOR]

Cortical bone milling is used in orthopedic surgeries such as knee replacement, otological, spinal cord, and hip replacement. The cutting forces created by the cutting tool during cortical bone milling in order to control the wear of the tool as well as applying allowable force to the bone to prevent fracture should be controlled. In this paper, the effective parameters in the bone milling including cutting speed, feed rate, cutting depth and tool diameter has been investigated using the response surface method in order to predict the cutting forces. In this method, a second-order linear regression equation can be presented in order to predict the behavior of the bone milling process precisely. Also, Sobel’s sensitivity analysis method was used to study the effect of input parameters on the behavior of cutting force. In this research, the behavior of different input parameters and the effect of their interactions on the machining force has been evaluated and analyzed. The components of cutting force were measured and investigated in three directions of feed, perpendicular to the feed and perpendicular to the bone surface. The results show that the mathematical model governing the problem has a proper function within the range of the defined parameters and it can provide a good prediction of force behavior. The minimum cutting force can be achieved in a rotational speed of 1500 rpm, feed of 12 mm/min, tool diameter of 2 mm, and cutting depth of 0.2 mm. Also, about the sensitivity of the force behavior based on the input parameters variation in the range of experiments, the greatest effect was related to the cutting depth with 36.3% of the effect, and feed rate with 28.4% of the effect, the diameter of the tool with 27.5% of the effect and the rotational speed with 7.8% of the effect. [ABSTRACT FROM AUTHOR]

Background Staff training in organizations is a measure for developing human capital. The pathology of this process needs to be assessed to understand the current situation and solve the challenges and limitations. Objective This study aims to assess the pathology of the training process for the incident command system (ICS) staff of hospitals in Guilan Province using the three-pronged approach. Methods This is a qualitative-quantitative study. The study population in the qualitative phase included experts in the hospital ICS. In the quantitative phase, the study population included all ICS managers and staff in the Guilan Province hospitals (n= 548). The data collection tool was a semi-structured interview in the qualitative phase and a researcher-made questionnaire in the quantitative phase. For data analysis, MAXQDA software, version 2020 was used in the qualitative phase and SPSS software, version 26 was used in the quantitative phase. Results The results in the qualitative phase showed the extraction of 55 open codes, 25 axial codes, and 6 selective codes in the form of three domains of processes, context, and structure. The results in the quantitative phase showed that among all the domains, the process domain-related factors with a percentage of variance (impact) of 0.262 were more harmful than context- and structure-related factors in the training process. Conclusion The pathology assessment based on the three-pronged model is an effective method for determining the training priorities for the hospital ICS staff. The use of this model during a crisis can be an effective step for identifying shortcomings to solve them and take appropriate measures for the ICS staff training. [ABSTRACT FROM AUTHOR]

Contrast Avoidance model claims that the main fear of individuals with generalized anxiety disorder is a negative emotional contrasts (shifts) and they use worry to create and maintain the negative and stable emotional state, so in this way, they could avoid from a negative emotional contrast. On the other hand, being in a negative emotional state, increases the likelihood of experiencing a positive emotional contrast and negative reinforcement due to a positive emotional contrast, maintains the worry process. the aim of present article is to a brief review on the Contrast Avoidance model, review of the studies supporting its tenets, and comparing the Contrast Avoidance model with present models of worry and generalized anxiety disorder. At the end, research suggestions are presented as future direction for this model. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to provide a mathematical model for oil future contracts. The study basis has put on the Schwartz Model (1997), but it is clear that with the small change, it is applicable for Iranian Oil Industry Futures. The Schwartz Model has considered only short jumps in the prices, but with recent oil price volatilities having significant effects on oil properties, it is necessary to include both short and long jumps in the model. According to these conditions, the model designed results in a complicated mathematical problem, which forms a Partial Differential Equation (DPE) having integral terms, and boundary and initial conditions. There is no closed solution for such equation. Thus, it should be solved by numerical methods. In the other hand, there is no access to real data for Iranian Oil Market, so we used a simulation model, but it will be possible to use an applied model in Iranian Oil Industry with real data in the future.

In this work, nonlinear electromagnetic vibration energy harvesting from cantilever beam under base harmonic oscillation is investigated and the effects of electromagnetic parameters on behavior of system are considered. For modeling assumed mode method is used, and beam is modeled according to Timoshenko theory, which includes shear deformation and rotary inertia. In energy harvesting the frequency response of the system is very important because it shows the best areas for energy harvesting and is a good criterion for designing energy harvesters, hence a semi analytical method is used to find simply the amplitude of oscillation in terms of excitation frequency. In this method, at first equations of motion are solved with complex averaging method and the obtained equations are solved using continuation method. For validation, comparison between results obtained from numerical and semi analytical method is given. Also, comparison between linear and nonlinear system, and stability of periodic response and their bifurcations are given. In addition, in order to compare the effect of number of mode shapes and convergence of solution, frequency response of one, two, three modes and four modes cases are compared with each other. [ABSTRACT FROM AUTHOR]

One of the most important devices for absorbing energy of the impact is circular tubes which absorb energy in different modes of plastic deformation. But one of the most important modes of deformation is dynamic progressive buckling caused by the axial collapse. This mode has the most energy absorption. In this study, the behavior of thin walled tubes (with caps) which have a fossa near the end edges of the tube has been investigated in a numerical and experimental way. This is contrary to the previous researches on energy absorption which used the quasi-static form. To carry out experimental tests, a drop hammer machine has been used. In the numerical part, capabilities of Abaqus have been employed. The results show that caps improve energy absorption, thus more energy is absorbed in less length crushing, and the up and down fossa of the tube causes the maximum collapse force to occur with a delay. Also, these absorbers have a linear behavior in absorbing energy with respect to the crushing length and the average collapse force has not been changed by increasing the hammer weight. An experiment was conducted to assess the collisions with the same kinetic energy to study strain rates in four collisions. It was seen that a reduction of 16.9 percent in strain rate increases 2.6 percent of the crushing length. [ABSTRACT FROM AUTHOR]

In this study, the water entry problem of a spherical-nose projectile is investigated numerically and experimentally. For the numerical simulations, a three dimensional model of the projectile with six-degree-of-freedom rigid body motion is considered. A Coupled Eulerian-Lagrangian (CEL) method is employed for modeling fluid-structure interactions. Through Eulerian-Lagrangian contact, Eulerian material can interact with Lagrangian elements. Also, an equation of state model describes the hydrodynamic behavior of the material. The numerical results are well compared with the available experimental results of a falling sphere in the literature and also the experiments of the current study. The experiments are performed for a spherical-nose projectile in a water tank equipped with a launching system and a high speed camera. The simulation results such as air cavity shape and the projectile trajectory are compared with the presented experiment data. The good agreement observed between the numerical results and those of the experiments, revealed the accuracy and capability of the proposed numerical algorithm. Also, it has been shown that the pinch-off time is a weak function of impact velocity, however, increasing velocity leads to a linear increase in depth of pinch-off. [ABSTRACT FROM AUTHOR]

This study attempts to numerically investigate the hydro-thermal characteristics of a ferrofluid (water and 4 vol % Fe3O4) in a counter-current horizontal double pipe heat exchanger, which is exposed to a non-uniform transverse magnetic field with different intensities. The magnetic field is generated by an electric current going through a wire located parallel to the inner tube and between two pipes. The single phase model and the control volume technique have been used to study the flow. The effects of magnetic field have been added to momentum equation by applying C++ codes in Ansys Fluent 14. The results show that applying this kind of magnetic field causes kelvin force to be produced perpendicular to the ferrofluid flow, changing axial velocity profile and creating a pair of vortices which leads to an increase in Nusselt number, friction factor and pressure drop. Comparing the enhancement percentage of Nusselt number, friction factor and pressure drop demonstrates that the optimum value of magnetic number for Reff =50 is between Mn=1.33x106 and Mn=2.37x106. So applying non-uniform transverse magnetic field can control the flow of ferrofluid and improve heat transfer process of double pipe heat exchanger. [ABSTRACT FROM AUTHOR]

In this study, the numerical and experimental investigation of the maximum deflection of circular plates under shock wave from the air blast is discussed. Shock wave will be generated by explosion of a spherical charge at different distances from the center of the plate. Two series of tests were designed, in the first series non-uniform shock wave reached the structure, and the second series of shock waves were uniform. The purpose of design and implementation of experiments was to investigate the effect of waves on the deformation behavior and extract semi-empirical model to predict the maximum deflection of the center of the circular plate subjected to uniform and non- uniform normal shock wave. These two models are presented, as a function of the Nurick damage number that summarize the effects of all parameters of explosive material and structures and make them dimensionless. Then for the experimental verification using finite element software LS-DYNA, the numerical simulation of the behavior of plate under free air explosion was performed and the results were compared with experimental results. Results obtained with acceptable margin of error are close to the experimental results. Finally, the results obtained were compared with semi- empirical models of other scholars who have researched this area. [ABSTRACT FROM AUTHOR]

In this article, the effects of important physical and geometrical parameters on free vibration and impact response of three-layer sandwich plate with magneto rheological smart core were investigated. The natural frequencies and structural loss factors for the first four mode shapes and different core thicknesses, magnetic fields and aspect ratios, were obtained. The magneto rheological (MR) material shows different properties when it was subjected to different magnetic fields. The governing equations of motion were obtained using Hamilton's principle. The results were obtained by the systematic analytical solution. Using the two degrees of freedom mass-spring model, the contact force function can be obtained analytically. The obtained natural frequency from Eigen value problem was used for calculating of equivalent mass of the plate in spring mass model. The results show that with systematic variation of magnetic field and with increasing the ratio of core thickness to the plate thickness and also with increasing the ratio of length to the plate thickness, the stiffness, structural loss factor coefficient and maximum contact force can be changed and controlled, respectively. [ABSTRACT FROM AUTHOR]

To investigate understanding and prediction of dynamic fracture behavior of a cracked body, dynamic stress intensity factors (DSIFs) are important parameters. In the present work interaction integral method is presented to compute static and dynamic stress intensity factors for three-dimensional cracks contained in the functionally graded materials (FGMs), and is implemented in conjunction with the finite element method (FEM). By a suitable definition of the auxiliary fields, the interaction integral method, which is not related to derivatives of material properties, can be obtained. For the sake of comparison, center, edge and elliptical cracks in homogeneous and functionally graded materials under static and dynamic loading are considered. Then, material gradation is introduced in an exponential form in the two directions in and normal to the crack plane. Next, the influence of the graded modulus of elasticity on static and dynamic stress intensity factors is investigated. It has been shown that, material gradation has considerable reduction influence on DSIFs of functionally graded material in comparison with homogenous material, while static stress intensity factors can decrease or increase, depending on the direction of gradation material property. [ABSTRACT FROM AUTHOR]