An Evolutionary Approach to Design Practical µ Synthesis Controllers

Ali Lari,Alireza Khosravi 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.1

This paper proposes an evolutionary approach to solve µ synthesis problem. The goal is to achieve low order, practical µ synthesis controllers without any order reduction. In the proposed approach µ synthesis problem is solved as a constraint optimization problem in which robust stability and robust performance based on µ analysis are considered as the constraint and the cost function respectively. In order to solve the optimization problem an improved particle swarm optimization (PSO) is chosen to find the required coefficients of a structure-specified controller. The performance and robustness of the proposed controller are investigated by an uncertain mass-damper-spring system and is compared with the D-K iteration controller (the conventional solution to µ synthesis problem). Simulation results demonstrate the advantages of the proposed controller in terms of simple structure and robustness against plant perturbations and disturbances in comparison with D-K iteration controller.

Structural instability of carbon nanotubes embedded in viscoelastic medium and subjected to distributed tangential load

Mohammad Ali Kazemi-Lari,Esmaeal Ghavanloo,S. Ahmad Fazelzadeh 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.7

In this paper, the nonlocal Euler-Bernoulli beam model is used to predict the static and dynamic structural instability of carbon nanotubes (CNTs) subjected to a distributed tangential compressive load. The CNT is considered to be embedded in a Kelvin-Voigt viscoelastic medium. Equation of motion and boundary conditions are obtained using the extended Hamilton’s principle and the extended Galerkin’s method is applied in order to transform the resulting equations into a general eigenvalue problem. The derived equations are validated by comparing the results achieved from the new derivations with existing solutions in literature. Effects of several experimentally interesting boundary conditions are considered on the stability characteristics of the CNT. Moreover, the influences of small scale parameter and material properties of the surrounding viscoelastic medium on the stability boundaries are examined.

Psychometric Analysis of a Persian Version of the European Organization for Research and Treatment of Cancer OG25 Quality of Life Questionnaire in Oesophagogastric Cancer Patients

Hesari, Ali Esmaeili,Lari, Mohsen Asadi,Shandiz, Fatemeh Homai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Health-related quality of life (HRQL) is a fundamental outcome in oncology patients and quality of life (QOL) assessment requires clinically relevant questionnaires. The purpose of this study was translation and definition of measurement properties and the clinical validity of Quality of Life Questionnaire (QLQ)-OG25 module in Persian patients with oesophagus, oesophagogastric junction (OGJ) or gastric cancers. Materials and Methods: The translation procedure followed European Organization for Research and Treatment of Cancer (EORTC) guidelines. Both EORTC QLQ-OG25 and a core questionnaire (EORTC QLQ-C30) were administered to patients with oesophagus (150), OG junction (93) and gastric (32) cancer undergoing multi-modal treatments. Convergent and discriminant validity, Cronbach's alpha coefficient and known-groups comparisons were used to examine reliability and validity. Results: In all, 275 patients (mean age 62 years) completed both questionnaires. Compliance rate was high and the questionnaire module was well accepted. We found good reliability for multi-item subscales of QLQ-OG25 (Cronbach's alpha coefficients 0.76-0.89). About 73% had TNM staging and scales distinguished between clinically distinct groups of patients. However, patients in palliative group experienced compromised functional status and worse treatment-associated symptoms than those in the potentially curative group. Test-retest scores were consistent. Multi-trait scaling analysis demonstrated good convergent and discriminant validity. Conclusions: Overall, the Persian version of QLQ-OG25 demonstrated psychometric and clinical validity that supports its application as a supplement to the original tool (EORTC QLQ-C30) when assessing HRQL in patients with upper-gastrointestinal (GI) cancer both in curative and palliative phases.

The Impact of Management on the Operational Efficiency of Listed Companies in Tehran Stock Exchange

Mahmoud Lari Dashtbayaz,Shaban Mohammadi,Ali Shirzad 국제융합경영학회 2015 융합경영연구 Vol.3 No.4

This study examined the relationship between working capital management and performance of listed companies Stock Exchange in Tehran. A total of 40 companies from the cement industry for the period 2007 to 2010 of which only 25 were selected for this study had the condition. In order to achieve the objectives, this study surveys the exploration of correlation regression analysis and used the curve obtained, the regression equation. To test the hypothesis, quantitative analysis was used as a method. The results showed a negative relationship between the variables of working capital management and the company's performance and the only variable cash conversion cycle did not show a significant relationship. There is often a negative correlation between the variables studied. This study is based on five assumptions impact of working capital management on corporate profitability is examined. Therefore, the results suggest that the variables in working capital (average collection of receivables, average inventory turnover period, the average net debt and average transaction cycle) and net operating profit is significant negative correlation Net cash conversion cycle and only illustrates the relationship is not significant. Thus, it showed that in debt collection and debt payment period, the turnover of inventory and net trade cycle to reduce the profitability of companies will increase.

Detection of the Efflux-Mediated Erythromycin Resistance Transposon in Streptococcus pneumoniae

Azadeh Azadegan,Malihe Talebi,Ali Ahmadi,Abdolaziz Rastegar Lari 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.1

Background: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. Methods: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. Results: Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. Conclusion: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.

Trends in gastrointestinal cancer incidence in Iran, 2001-2010:

Mehdi Darabi,Mohsen Asadi Lari,Seyed Abbas Motevalian,Ali Motlagh,Shahram Arsang-Jang,Maryam Karimi Jaberi 한국역학회 2016 Epidemiology and Health Vol.38 No.-

OBJECTIVES: The main purpose of this study was to evaluate changes in the time trends of stomach, colorectal, and esophageal cancer during the past decade in Iran. METHODS: Cancer incidence data for the years 2001 to 2010 were obtained from the cancer registration of the Ministry of Health. All incidence rates were directly age-standardized to the world standard population. In order to identified significant changes in time trends, we performed a joinpoint analysis. The annual percent change (APC) for each segment of the trends was then calculated. RESULTS: The incidence of stomach cancer increased from 4.18 and 2.41 per 100,000 population in men and women, respectively, in 2001 to 17.06 (APC, 16.7%) and 8.85 (APC, 16.2%) per 100,000 population in 2010 for men and women, respectively. The corresponding values for colorectal cancer were 2.12 and 2.00 per 100,000 population for men and women, respectively, in 2001 and 11.28 (APC, 20.0%) and 10.33 (APC, 20.0%) per 100,000 in 2010. For esophageal cancer, the corresponding increase was from 3.25 and 2.10 per 100,000 population in 2001 to 5.57 (APC, 12.0%) and 5.62 (APC, 11.2%) per 100,000 population among men and women, respectively. The incidence increased most rapidly for stomach cancer in men and women aged 80 years and older (APC, 23.7% for men; APC, 18.6% for women), for colorectal cancer in men aged 60 to 69 years (APC, 24.2%) and in women aged 50 to 59 years (APC, 25.1%), and for esophageal cancer in men and women aged 80 years and older (APC, 17.5% for men; APC,15.3% for women) over the period of the study. CONCLUSIONS: The incidence of gastrointestinal cancer significantly increased during the past decade. Therefore, monitoring the trends of cancer incidence can assist efforts for cancer prevention and control.

Spatial Inequalities in the Incidence of Colorectal Cancer and Associated Factors in the Neighborhoods of Tehran, Iran: Bayesian Spatial Models

Kamyar Mansori,Masoud Solaymani-Dodaran,Alireza Mosavi-Jarrahi,Ali Ganbary Motlagh,Masoud Salehi,Alireza Delavari,Mohsen Asadi-Lari 대한예방의학회 2018 Journal of Preventive Medicine and Public Health Vol.51 No.1

Objectives: The aim of this study was to determine the factors associated with the spatial distribution of the incidence of colorectal cancer (CRC) in the neighborhoods of Tehran, Iran using Bayesian spatial models. Methods: This ecological study was implemented in Tehran on the neighborhood level. Socioeconomic variables, risk factors, and health costs were extracted from the Equity Assessment Study conducted in Tehran. The data on CRC incidence were extracted from the Iranian population-based cancer registry. The Besag-York-Mollié (BYM) model was used to identify factors associated with the spatial distribution of CRC incidence. The software programs OpenBUGS version 3.2.3, ArcGIS 10.3, and GeoDa were used for the analysis. Results: The Moran index was statistically significant for all the variables studied (p<0.05). The BYM model showed that having a women head of household (median standardized incidence ratio [SIR], 1.63; 95% confidence interval [CI], 1.06 to 2.53), living in a rental house (median SIR, 0.82; 95% CI, 0.71 to 0.96), not consuming milk daily (median SIR, 0.71; 95% CI, 0.55 to 0.94) and having greater household health expenditures (median SIR, 1.34; 95% CI, 1.06 to 1.68) were associated with a statistically significant elevation in the SIR of CRC. The median (interquartile range) and mean (standard deviation) values of the SIR of CRC, with the inclusion of all the variables studied in the model, were 0.57 (1.01) and 1.05 (1.31), respectively. Conclusions: Inequality was found in the spatial distribution of CRC incidence in Tehran on the neighborhood level. Paying attention to this inequality and the factors associated with it may be useful for resource allocation and developing preventive strategies in atrisk areas.

Predictors of Colorectal Cancer Survival in Golestan, Iran: A Population-based Study

Mohammad Aryaie,Gholamreza Roshandel,Shahryar Semnani,Mohsen Asadi-Lari,Mohsen Aarabi,Mohammad Ali Vakili,Vahideh Kazemnejhad,Seyed Mehdi Sedaghat,Masoud Solaymani-Dodaran 한국역학회 2013 Epidemiology and Health Vol.35 No.-

OBJECTIVES: We aimed to investigate factors associated with colorectal cancer survival in Golestan, Iran. METHODS: We used a population based cancer registry to recruit study subjects. All patients registered since 2004 were contacted and data were collected using structured questionnaires and trained interviewers. All the existing evidences to determine the stage of the cancer were also collected. The time from first diagnosis to death was compared in patients according to their stage of cancer using the Kaplan-Meir method. A Cox proportional hazard model was built to examine their survival experience by taking into account other covariates. RESULTS: Out of a total of 345 subjects, 227 were traced. Median age of the subjects was 54 and more than 42% were under 50 years old. We found 132 deaths among these patients, 5 of which were non-colorectal related deaths. The median survival time for the entire cohort was 3.56 years. A borderline significant difference in survival experience was detected for ethnicity (log rank test, p=0.053). Using Cox proportional hazard modeling, only cancer stage remained significantly associated with time of death in the final model. CONCLUSIONS: Colorectal cancer occurs at a younger age among people living in Golestan province. A very young age at presentation and what appears to be a high proportion of patients presenting with late stage in this area suggest this population might benefit substantially from early diagnoses by introducing age adapted screening programs.

Spatial Inequalities in the Incidence of Colorectal Cancer and Associated Factors in the Neighborhoods of Tehran, Iran: Bayesian Spatial Models

Mansori, Kamyar,Solaymani-Dodaran, Masoud,Mosavi-Jarrahi, Alireza,Motlagh, Ali Ganbary,Salehi, Masoud,Delavari, Alireza,Asadi-Lari, Mohsen The Korean Society for Preventive Medicine 2018 Journal of Preventive Medicine and Public Health Vol.51 No.1

Objectives: The aim of this study was to determine the factors associated with the spatial distribution of the incidence of colorectal cancer (CRC) in the neighborhoods of Tehran, Iran using Bayesian spatial models. Methods: This ecological study was implemented in Tehran on the neighborhood level. Socioeconomic variables, risk factors, and health costs were extracted from the Equity Assessment Study conducted in Tehran. The data on CRC incidence were extracted from the Iranian population-based cancer registry. The $Besag-York-Molli{\acute{e}}$ (BYM) model was used to identify factors associated with the spatial distribution of CRC incidence. The software programs OpenBUGS version 3.2.3, ArcGIS 10.3, and GeoDa were used for the analysis. Results: The Moran index was statistically significant for all the variables studied (p<0.05). The BYM model showed that having a women head of household (median standardized incidence ratio [SIR], 1.63; 95% confidence interval [CI], 1.06 to 2.53), living in a rental house (median SIR, 0.82; 95% CI, 0.71 to 0.96), not consuming milk daily (median SIR, 0.71; 95% CI, 0.55 to 0.94) and having greater household health expenditures (median SIR, 1.34; 95% CI, 1.06 to 1.68) were associated with a statistically significant elevation in the SIR of CRC. The median (interquartile range) and mean (standard deviation) values of the SIR of CRC, with the inclusion of all the variables studied in the model, were 0.57 (1.01) and 1.05 (1.31), respectively. Conclusions: Inequality was found in the spatial distribution of CRC incidence in Tehran on the neighborhood level. Paying attention to this inequality and the factors associated with it may be useful for resource allocation and developing preventive strategies in at-risk areas.