An Improved Ant Colony Algorithm for the Optimization of Skeletal Structures by the Proposed Sampling Search Space Method

Designing space is dramatically enlarged with optimization of structures based on ACO, regard to increasing section’s list. This problem decreases the speed of optimization in order to reach to optimum point and also increases local optimum probability, because determining suitable cross section process for each design variable in ACO depends on number of members in the list of section. Therefore, this paper by using partitioning the design space tries to decrease the probability of achieving local optimum during the process of structures optimum design by ACO and to increase the speed of convergence. In this regard, the list of section is divided to specific number of subsets inspired by meshing process in finite element. Then a member of each subset (in three case, maximum, middle and minimum of cross section) is defined as a representative of subset in a new list. Optimization process starts based on the new lit of section (global search). After specific number of repetitions, optimum design range for each variable will be determined. Afterward, variable section list is defined for each design variable related to result of previous step of process and based on subset of related variable. Finally, optimization process is continued based on the new list of section for each design variable to the end of process (local search). Proposal is studied in three cases and compared with common method in ACO and standard optimization examples in skeletal structures are used. Results show an increase in accuracy and speed of optimization according to cross section middle method (Case 2)

Clustering Elements of Truss Structures for Damage Identification by CBO

The number of structural elements plays a significant role in detecting damage location and severity; such methods have sometimes failed to provide correct solutions due to the entrapment of damage detection algorithms in the local optimum. To resolve this problem, this study proposed the simultaneous use of mathematical and statistical methods to narrow down the search space. To this end, a two-step damage detection method was proposed. In the first step, the structural elements were initially divided into different clusters using the k-means method. Subsequently, the possibly damaged elements of each cluster were identified. In the second step, the elements selected in the first step were placed in a new set, and a process was applied to identify their respective damage location and severity. Thus, the proposed method reduced the search space as well as the possibility of entrapment in the local optimum. Other advantages of the proposed method include the use of fewer dynamic properties. Accordingly, by narrowing down the search space and the dimensions of the system for governing equations, the proposed method could significantly increase the chance of obtaining favorable results in structures with many elements and those with few vibration modes. A meta-heuristic method, called the colliding bodies optimization (CBO), was used in the proposed damage detection optimization algorithm. The optimization problem was based on the modal strain energy equations. According to the results, the proposed method was able to detect the location and severity of damage, even at its slightest percentage

Optimal Design of Steel Towers Using a Multi-Metaheuristic Based Search Method

In meta-heuristic algorithms, the problem of parameter tuning is one of the most important issues that can be highly time consuming. To overcome this difficulty, a number of researchers have improved the performance of their methods by enhancement and hybridization with other algorithms. In the present paper efforts are made to search design space simultaneously by the Multi Metaheuristic based Search Method (MMSM). In the proposed method, optimization process is performed by dividing the initial population into five subsets so-called islands. An improved multi-metaheuristic method is then employed. After a certain number of repetitions (migration intervals), some percent of the island’s best members are transferred into another island (migration) and replaced by the members of low fitnesses. In the migration phase, the target island is chosen randomly. Examples of large design spaces are utilized to investigate the efficiency of the proposed method. For this purpose, steel are optimized utilizing the proposed method. The results indicate improvements in the available responses

Rationale and Design of a Registry in a Referral and Educational Medical Center in Tehran, Iran: Sina Hospital Covid-19 Registry (SHCo-19R)

Coronavirus disease 2019 (Covid-19) is caused by the novel coronavirus resulting in a highly contagious respiratory tract infection with an increased risk of acute respiratory distress syndrome (ARDS), which was first seen in Wuhan, China. Thus far, this virus has spread to many countries worldwide, including Iran. Multiple studies have assessed disease characteristics, viral genetics, and complications of Covid-19 in the Chinese population. However, there is limited data regarding patient characteristics and outcomes of infected cases outside of China. Besides, risk factors of adverse outcomes are poorly identified in different populations. Due to limited data in the Iranian population affected by the virus, we aimed to design a registry of patients with Covid-19 at Sina Hospital in Tehran, Iran [Sina Hospital Covid-19 Registry (SHCo-19R)] in this regard, to assess patient characteristics, imaging features, laboratory findings, management strategies, and adverse outcomes of Iranian patients with Covid-19 and their differences with other populations

Presenting the dynamic model of football in Qatar: The role of hosting the 2022 FIFA World Cup

The current study aimed to present a dynamic football model in Qatar, concentrating on the role of hosting the 2022 FIFA World Cup. It was practical in terms of purpose and qualitative in terms of strategy. The qualitative research method was based on grounded theory, applying the Strauss-Corbin approach. The sample consisted of 22 football experts selected through purposeful sampling. These individuals represented various roles within the Qatar Stars League during the 2021-2022 football season, including coaches, referees, athletes, heads and managers of football clubs, and veterans. The main categories obtained in this research included causal conditions, contextual conditions, and intervening conditions. Finally, the dynamic model of Qatar football was presented after determining the desired model, process/interactions, consequences, and relationships between the elements. The development of new media and technology also profoundly impacted football club-media relations, as clubs recognized the importance of external communications and the demand for instant information. In general, media, technology, and investment play an important role in shaping the dynamics of the football league in Qatar, driving growth and influencing organizational strategies

Presenting the dynamic model of football in Qatar: The role of hosting the 2022 FIFA World Cup

The current study aimed to present a dynamic football model in Qatar, concentrating on the role of hosting the 2022 FIFA World Cup. It was practical in terms of purpose and qualitative in terms of strategy. The qualitative research method was based on grounded theory, applying the Strauss-Corbin approach. The sample consisted of 22 football experts selected through purposeful sampling. These individuals represented various roles within the Qatar Stars League during the 2021-2022 football season, including coaches, referees, athletes, heads and managers of football clubs, and veterans. The main categories obtained in this research included causal conditions, contextual conditions, and intervening conditions. Finally, the dynamic model of Qatar football was presented after determining the desired model, process/interactions, consequences, and relationships between the elements. The development of new media and technology also profoundly impacted football club-media relations, as clubs recognized the importance of external communications and the demand for instant information. In general, media, technology, and investment play an important role in shaping the dynamics of the football league in Qatar, driving growth and influencing organizational strategies

Protective effect of green tea extract on the deltamethrin-induced toxicity in mice testis: An experimental study

Background: Deltamethrin (DM) is one of the environmental factors that can have destructive effects on the male fertility. Green tea (GT) as a medicinal herb, has antioxidant property. Objective: The present study investigated the protective role of GT extract in improving the harmful effects of DM on the testis. Materials and Methods: In this experimental study, 35 adult male mice (25–30 gr) were divided in to five groups (n = 7/each). The control group received only normal saline. Sham received 0.2 ml corn oil. Green tea group received only GT of 150 mg/kg. bw; deltamethrin group received the DM at a dose of 0.6 mg/kg. bw; GT + DM received both GT and DM. The effect of GT was assessed by measuring oxidative stress markers, sperm parameters, histological and immunohistochemical analysis. Results: The results showed that the count and motility of spermatozoa, testosterone, and Malondialdehyde significantly decreased (p < 0.001) and the abnormal spermatozoa increased (p < 0.001) in DM group compared to control group. Moreover, enhanced caspase-3expression and apoptosis were observed in DM-treated mice compared to control group. Histologically, DM with a degenerative effect on testicular tissue reduced the spermatogenesis progenitor cells. The epithelial height and the diameter of the seminiferous tubules were also reduced in the DM group. Treatment with GT in the DM-treated mice significantly improved these changes. Conclusion: With these findings, it was concluded that the GT treatment with antioxidant activity and anti-apoptotic property could protect the testicular injury induced by DM