http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Dynamic response of layered hyperbolic cooling tower considering the effects of support inclinations
Asadzadeh, Esmaeil,Alam, Mehtab,Asadzadeh, Sahebali Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6
Cooling tower is analyzed as an assembly of layered nonlinear shell elements. Geometric representation of the shell is enabled through layered nonlinear shell elements to define the different layers of reinforcements and concrete by considering the material nonlinearity of each layer for the cooling tower shell. Modal analysis using Ritz vector analysis and nonlinear time history analysis by direct integration method have been carried out to study the effects of the inclination of the supporting columns of the cooling tower shell on its dynamic characteristics. The cooling tower is supported by I-type columns and ${\Lambda}$-type columns supports having the different inclination angles. Relevant comparisons of the dynamic response of the structural system at the base level (at the junction of the column and shell), throat level and at the top of the tower have been made. Dynamic response of the cooling tower is found to be significantly sensitive to the change of the inclination of the supporting columns. It is also found that the stiffness of the structure system increases with increase in inclination angle of the supporting columns, resulting in decrease of the period of the structural system. The participation of the stiffness of the tower in structural response of the cooling tower is fund to be dependent of the change in the inclination angle and even in the types of the supporting columns.
Dynamic response of layered hyperbolic cooling tower considering the effects of support inclinations
Esmaeil Asadzadeh,Mehtab Alam,Sahebali Asadzadeh 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6
Cooling tower is analyzed as an assembly of layered nonlinear shell elements. Geometric representation of the shell is enabled through layered nonlinear shell elements to define the different layers of reinforcements and concrete by considering the material nonlinearity of each layer for the cooling tower shell. Modal analysis using Ritz vector analysis and nonlinear time history analysis by direct integration method have been carried out to study the effects of the inclination of the supporting columns of the cooling tower shell on its dynamic characteristics. The cooling tower is supported by I-type columns and ᴧ-type columns supports having the different inclination angles. Relevant comparisons of the dynamic response of the structural system at the base level (at the junction of the column and shell), throat level and at the top of the tower have been made. Dynamic response of the cooling tower is found to be significantly sensitive to the change of the inclination of the supporting columns. It is also found that the stiffness of the structure system increases with increase in inclination angle of the supporting columns, resulting in decrease of the period of the structural system. The participation of the stiffness of the tower in structural response of the cooling tower is fund to be dependent of the change in the inclination angle and even in the types of the supporting columns.
Asadzadeh, Babak,Golshannavaz, Sajjad The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.5
In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.
Babak Asadzadeh,Sajjad Golshannavaz 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.5
In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.
Norouzinia, M.,Asadzadeh, H.,Shalmani, H. Mohaghegh,Al Dulaimi, D.,Zali, M.R. Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11
Background and Aim: Gastric cancer is the second most common cancer worldwide. In this study the clinical and histological features of gastric cancer in the cardia and distal stomach were evaluated. Method: Proximal and distal gastric cancer diagnosed and treated in eight provinces of Iran from 2010-2011 were reviewed in all collected cases. The age standardized incident rates were calculated and tumor location and histological type were recorded. Results: The age-standardized incidence rate for the eight centers was 40.6 per 100,000 populations per year with an upper and lower range of 22.1 and 102.4 per 100,000 population per year. Thirty four percent of the tumors were located in the cardia, 3% in fundus, and 63% in the distal stomach. In 7 provinces the prevalence of distal tumors was significantly greater than proximal tumors (p=0.006). A significant relationship was observed between diffuse form of gastric cancer and distal gastric tumors (p=0.007) and between poor tumor differentiation and distal gastric tumors (p<0.001). Conclusions: the result of this study shows that distal gastric cancer is more common than proximal gastric cancer in Iran.
Fatemeh Shaterian Mohamadi,Hassan Asadzadeh 서울대학교 교육연구소 2012 Asia Pacific Education Review Vol.13 No.3
The purpose of this study is to test the mediating role of teachers' self-efficacy beliefs in the relationship between sources of efficacy information and students achievement. For achieving this aim, this study suggests two alternative models, tested by Structural equation modeling (SEM) technique. In the first model, sources of efficacy information and teachers' sense of self-efficacy independently influenced student achievement. In second model, we examined a dependent 2-factor model, consisting of: (a) antecedent variable: sources of efficacy information, (b) mediator variable: teachers' sense of self-efficacy, and (c) criterion variable: student's achievement. Among 284 teachers who participated in this study, Sources of the Self-Efficacy Inventory (SOSI) and Teachers' Sense of Efficacy Scale (TSES) were distributed. Findings of this study indicated that between two suggested models, the dependent model showed the best overall fit to the data. In this model, teachers' self-efficacy had mediational role between sources of teachers' self-efficacy and student's achievement.
Survival of Colorectal Cancer in the Presence of Competing-Risks - Modeling by Weibull Distribution
Baghestani, Ahmad Reza,Daneshvar, Tahoura,Pourhoseingholi, Mohamad Amin,Asadzadeh, Hamid Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3
Background: Colorectal cancer (CRC) is the commonest malignancy in the lower gastrointestinal tract in both men and women. It is the third leading cause of cancer-dependent death in the world. In Iran the incidence of colorectal cancer has increased during the last 25 years. Materials and Methods: In this article we analyzed the survival of 447 colorectal patients of Taleghani hospital in Tehran using parametric competing-risks models. The cancers of these patients were diagnosed during 1985 - 2012 and followed up to 2013. The purpose was to assess the association between survival of patients with colorectal cancer in the presence of competing-risks and prognostic factors using parametric models. The analysis was carried out using R software version 3.0.2. Results: The prognostic variables included in the model were age at diagnosis, tumour site, body mass index and sex. The effect of age at diagnosis and body mass index on survival time was statistically significant. The median survival for Iranian patients with colorectal cancer is about 20 years. Conclusions: Survival function based on Weibull model compared with Kaplan-Meier survival function is smooth. Iranian data suggest a younger age distribution compared to Western reports for CRC.