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Journal of Biomedical Science and Engineering 2012年第2期5卷 63-74页

作者： Maryam Ahmadi amir homayoon jafari Department of Biomedical Engineering Tehran University Tehran Iran Young Researcher Club Central Tehran Branch Islamic Azad University Tehran Iran

In recent decades, due to the increasing risk of diabetes, the measurement and control of the blood sugar is of great importance. In typeI diabetes, because of the lack of insulin secretion, the cells cannot absorb glucose, and thus have a low level of glucose. To control blood glucose, the insulin must be injected to the body. In fact, the injection must be in a completely controlled environment. If the level of the insulin exceeds the physiological limits, it may cause death. This paper presents an online approach to control the blood glucose level using a nonlinear model predictive control. This method, maintains the level of blood glucose concentration within a normal range. Thus, the blood glucose level is measured in each minute and predicted for the next time interval. If that is not in the normal range, amount of the insulin which must be injected will be determined. The proposed control approach includes important features such as model uncertainties and prevents acute decrease in the blood glucose level, and instability. In order to assess performance of the proposed controller, computer simulations have been carried out in Matlab/Simulink. Simulation results will reveal the effectiveness of the proposed nonlinear model predictive controller in adjusting the blood glucose level by injecting required insulin. So if the nutrition of the person decreases instantly, the hypoglycemia does not happen.

关键词： Diabetes Delay of Insulin-Glucose Regulatory System Blood Glucose Level Nonlinear Model Predictive Control

Assessing the impact of climate change on agricultural production in central Afghanistan

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Regional Sustainability 2024年第3期5卷 12-23页

作者： homayoon RAOUFI Hamidreza jafari Wakil Ahmad SARHADI Esmail SALEHI Department of Environmental Planning Management and HealthSafetyand EnvironmentFaculty of EnvironmentUniversity of TehranTehran14174-66191Iran Faculty of Agriculture University of KunduzKunduz3502Afghanistan Faculty of Agriculture University of KabulKabul1001Afghanistan

Afghanistan has faced extreme climatic crises such as drought,rising temperature,and scarce precipitation,and these crises will likely worsen in the *** in crop yield can affect food security in Afghanistan,where the majority of population and economy are completely dependent on *** study assessed the interaction between climate change and crop yield in Kabul of Afghanistan during the reference(1990–2020)and future(2025–2100)*** data(1990–2020)were collected from four meteorological stations and three local organizations,and wheat yield data(1990–2020)were acquired from the United States Agriculture *** during the reference period(1990–2020)were used for the validation and calibration of the statistical downscaling models such as the Statistical Downscaling Model(SDSM)and Long Ashton Research Station Weather Generator(LARS-WG).Furthermore,the auto-regression model was used for trend *** results showed that an increase in the average annual temperature of 2.15℃,2.89℃,and 4.13℃will lead to a reduction in the wheat yield of 9.14%,10.20%,and 12.00%under Representative Concentration Pathway(RCP)2.6,RCP4.5,and RCP8.5 during the future period(2025–2100),***,an increase in the annual maximum temperature of 1.79℃,2.48℃,and 3.74℃also causes a significant reduction in the wheat yield of 2.60%,3.60%,and 10.50%under RCP2.6,RCP4.5,and RCP8.5,***,an increase in the annual minimum temperature of 2.98℃,2.23℃,and 4.30℃can result in an increase in the wheat yield of 6.50%,4.80%,and 9.30%under RCP2.6,RCP4.5,and RCP8.5,*** to the SDSM,the decrease of the average monthly precipitation of 4.34%,4.10%,and 5.13%results in a decrease in the wheat yield of 2.60%,2.36%,and 3.18%under RCP2.6,RCP4.5,and RCP8.5,*** study suggests that adaptation strategies can be applied to minimize the consequences of climate change on agricultural production.

关键词： Climate change Wheat yield Food security Representative Concentration Pathway(RCP) Afghanistan

Respiratory complications of propofol,sevoflurane,and dexmedetomidine anesthesia for fiberoptic bronchoscopy in children aged 1 month to 3 years:a randomized trial

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南方医科大学学报 2024年第9期44卷 1631-1636页

作者： amir Shafa Mohammad Montasery Sedighe Shahhosseini Majid Keivanfar Asieh Maghami Mehr Mahtab Ebrahim Babaei Mohammad jafari Department of Anesthesiology Anesthesiology and Critical Care Research Center Department of Pediatrics Isfahan University of Medical SciencesIsfahanIran Department of Statistics Yazd UniversityYazdIran Departments of Obstetrics and Gynecology Shahrekord University of Medical SciencesShahrekordIran

Objective To evaluate the effect of propofol,sevoflurane,and dexmedetomidine on respiratory complications inchildren undergoing fiberoptic bronchoscopy(FOB).Methods This double-blind randomized clinical trial was conductedamong 120 children aged 1 month to 3 years undergoing *** patients were randomized into 3 groups(n=40)foranesthesia induction with sevoflurane inhalation,1 mg/kg propofol,or 1μg/kg dexmedetomidine before bronchoscopy,andthe changes in hemodynamic parameters,sedation level,and respiratory complications during and after the procedure *** The patients'heart rate during bronchoscopy was significantly lower and the mean arterial blood pressuresignificantly higher in dexmedetomidine group than in sevoflurane and propofol groups(P<0.05).Cough duringbronchoscopy did not occur in any of the cases in propofol group,while the highest frequency of cough was recorded indexmedetomidine *** incidence of laryngospasm in the propofol group(12.5%)was significantly lower than those insevoflurane and dexmedetomidine groups(30%and 32.5%,respectively)(P<0.05).Conclusion Sevoflurane and propofol aresafe and suitable for anesthesia induction in children below 3 years of age undergoing diagnostic FOB and can achieve bettersedative effect and lower the incidences of cough and respiratory complications as compared with dexmedetomidine.

关键词： fiberoptic bronchoscopy propofol sevoflurane dexmedetomidine children

Crowdsourcing-Based Framework for Teaching Quality Evaluation and Feedback Using Linguistic 2-Tuple

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Computers, Materials & Continua 2018年第10期57卷 81-96页

作者： Tiejun Wang Tao Wu amir homayoon Ashrafzadeh Jia He Department of Computer Science Chengdu University of Information and TechnologyChengdu610025China. CSIT Department School of ScienceRMIT UniversityMelbourne3058Australia.

Crowdsourcing is widely used in various fields to collect goods and services from large *** teaching quality by collecting feedback from experts or students after class is not only delayed but also not *** this paper,we present a crowdsourcing-based framework to evaluate teaching quality in the classroom using a weighted average operator to aggregate information from students’questionnaires described by linguistic 2-tuple *** we define crowd grade based on similarity degree to distinguish contribution from different students and minimize the abnormal students’impact on the *** crowd grade would be updated at the end of each feedback so it can guarantee the evaluation ***,a simulated case is shown to illustrate how to apply this framework to assess teaching quality in the ***,we developed a prototype and carried out some experiments on a series of real questionnaires and two sets of modified *** results show that teachers can locate the weak points of teaching and furthermore to identify the abnormal students to improve the teaching ***,our approach provides a strong tolerance for the abnormal student to make the evaluation more accurate.

关键词： Teaching quality evaluation crowdsourcing linguistic 2-tuple group decision making

A Novel Metaheuristic Algorithm: The Team Competition and Cooperation Optimization Algorithm

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Computers, Materials & Continua 2022年第11期73卷 2879-2896页

作者： Tao Wu Xinyu Wu Jingjue Chen Xi Chen amir homayoon Ashrafzadeh School of Computer Science Chengdu University of Information TechnologyChengdu610225China School of Computer Science and Engineering Southwest Minzu UniversityChengdu610041China CSIT Department School of ScienceRMIT UniversityMelbourne3058Australia

Metaheuristic algorithm is a generalization of heuristic algorithm that can be applied to almost all optimization *** optimization problems,metaheuristic algorithm is one of the methods to find its optimal solution or approximate solution under limited *** of the existing metaheuristic algorithms are designed for serial ***,existing algorithms still have a lot of room for improvement in convergence speed,robustness,and *** address these issues,this paper proposes an easily parallelizable metaheuristic optimization algorithm called team competition and cooperation optimization(TCCO)inspired by the process of human team cooperation and *** proposed algorithm attempts to mathematically model human team cooperation and competition to promote the optimization process and find an approximate solution as close as possible to the optimal solution under limited *** order to evaluate the performance of the proposed algorithm,this paper compares the solution accuracy and convergence speed of the TCCO algorithm with the Grasshopper Optimization Algorithm(GOA),Seagull Optimization Algorithm(SOA),Whale Optimization Algorithm(WOA)and Sparrow Search Algorithm(SSA).Experiment results of 30 test functions commonly used in the optimization field indicate that,compared with these current advanced metaheuristic algorithms,TCCO has strong competitiveness in both solution accuracy and convergence speed.

关键词： Optimization metaheuristic algorithm

Detailed seismic risk analysis of electrical substation equipment using a reliability based approach

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 495-511页

作者： amir Ghahremani Baghmisheh Milad Khodaei Ali Zare Feiz Abadi homayoon E.Estekanchi Department of Civil Engineering University of British ColumbiaVancouver V6T 2B8Canada Department of Civil Engineering University of TabrizTabriz 51666Iran Department of Civil Engineering Sharif University of TechnologyTehran 11155-9313Iran

This paper proposes a risk analysis framework for substation structures based on reliability *** though several risk assessment approaches have been developed for buildings,detailed risk analysis procedures for infrastructure components have been lacking in prior *** proposed framework is showcased by its application to a system of interconnected structures at a power substation in *** element models of structures are developed and validated in accordance with previous *** uncertainties in the material,mass,and geometric properties of structures are described by random variables that are input to the finite element *** artificial ground motion model is employed to comprehensively consider uncertainty in ground *** Carlo sampling is subsequently conducted on the library of probabilistic *** analysis resulted in the loss distribution in the life cycle of ***,the loss associated with six earthquake scenarios having specific magnitudes and return periods is *** application provides insight into the most vulnerable equipment in the considered ***,introduced risk measures can guide stakeholders to make risk-based decisions to optimize design or prioritize a retrofit of infrastructure components under conditions of uncertainty.

关键词： seismic risk reliability analysis infrastructure components loss estimation uncertainty

Effect of extrusion process on microstructure and mechanical and corrosion properties of biodegradable Mg-5Zn-1.5Y magnesium alloy

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International Journal of Minerals,Metallurgy and Materials 2022年第3期29卷 490-502页

作者： Hassan jafari amir Houshang Mojiri Tehrani Mojiri Tehrani Mahsa Heydari Materials Engineering Department Faculty of Materials Engineering and Interdisciplinary ScienceShahid Rajaee Teacher Training University16785-136 TehranIran

The effect of extrusion temperature and ratio on the microstructure, hardness, compression, and corrosion behavior of Mg-5Zn-1.5Y alloy were analyzed in this study. The microstructural observations revealed that the cast alloy consists of α-Mg grains, and Mg3Zn6Y and Mg3Zn3Y2 intermetallic compounds, mostly located on the α-Mg grain boundaries. Extruded alloy at higher temperatures showed coarser grain microstructures, whereas those extruded at higher ratios contained finer ones, although more dynamic recrystalized grains with lower intermetallics were measured at both conditions. Combined conditions of the lower temperature (340°C) and higher ratio (1:11.5) provided higher compressive strengths. However, no significant hardness improvement was achieved. The extrusion process could decrease the corrosion rate of the cast alloy in simulated body fluid for over 80% due to primarily the refined microstructure. The extrusion temperature showed a more pronounced effect on corrosion resistance compared to the extrusion ratio, and the higher the extrusion temperature, the higher the corrosion resistance.

关键词： magnesium alloy biodegradable extrusion microstructure mechanical properties corrosion

A Novel Quantum-Behaved Particle Swarm Optimization Algorithm

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Computers, Materials & Continua 2020年第5期63卷 873-890页

作者： Tao Wu Lei Xie Xi Chen amir homayoon Ashrafzadeh Shu Zhang School of Computer Science Chengdu University of Information TechnologyChengdu610225China School of Computer Science and Technology Southwest Minzu UniversityChengdu610041China CSIT Department School of ScienceRMIT UniversityMelbourne3058Australia Department of Emergency Medicine West China HospitalSichuan UniversityChengdu610041China

The efficient management of ambulance routing for emergency requests is vital to save lives when a disaster ***-behaved Particle Swarm Optimization(QPSO)algorithm is a kind of metaheuristic algorithms applied to deal with the problem of *** paper analyzed the motion pattern of particles in a square potential well,given the position equation of the particles by solving the Schrödinger equation and proposed the Binary Correlation QPSO Algorithm Based on Square Potential Well(BC-QSPSO).In this novel algorithm,the intrinsic cognitive link between particles’experience information and group sharing information was created by using normal Copula *** that,the control parameters chosen strategy gives through ***,the simulation results of the test functions show that the improved algorithms outperform the original QPSO algorithm and due to the error gradient information will not be over utilized in square potential well,the particles are easy to jump out of the local optimum,the BC-QSPSO is more suitable to solve the functions with correlative variables.

关键词： Ambulance routing problem quantum-behaved particle swarm optimization square potential well convergence

Kinetic studies on extra heavy crude oil upgrading using nanocatalysts by applying CFD techniques

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Chinese Journal of Chemical Engineering 2018年第2期26卷 343-355页

作者： Javad Aminian Dehkordi Arezou jafari Seyyed amir Sabet Fatemeh Karami Faculty of Chemical Engineering Tarbiat Modares UniversityTehranIran Islamic Azad University ShahroodIran

Regarding the growth of global energy consumption and the paucity of light crude oil, extracting and using heavy and extra heavy crude oil has received much more attention, but the application of this kind of oil is complicated due to its very high molecular weight. High viscosity and low flowability complicate the transportation of heavy and extra heavy crude oil. Accordingly, it is essential to reduce the viscosity of heavy and extra heavy crude oil through in-situ operations or immediate actions after extraction to reduce costs. Numerical simulations are influential methods, because they reduce calculation time and costs. In this study, the cracking of extra heavy crude oil using computational fluid dynamics is simulated, and a unique kinetic model is proposed based on experimental procedures to predict the behavior of extra heavy crude oil cracking reaction. Moreover, the hydrodynamics and heat transfer of the system and influence of nanocatalysts and temperature on the upgrading of crude oil are studied. The geometry of a reactor is produced using commercial software, and some experiments are performed to examine the validity and accuracy of the numerical results. The findings reveal that there is a good agreement between the numerical and experimental results. Furthermore, to investigate the main factors affecting the process, sensitivity analysis is adopted. Results show that type of catalyst and concentration of catalyst are the parameters that influence the viscosity reduction of extra heavy crude oil the most. The findings further revealed that when using a 25 nm SiO_2 nanocatalyst, a maximum viscosity reduction of 98.67% is observed at 623 K. Also, a catalyst concentration of 2.28 wt% is best for upgrading extra heavy crude oil. The results obtained through sensitivity analysis, simulation model, and experiments represent effectual information for the design and development of high performance upgrading processes for energy applications.

关键词： Upgrading Extra heavy oil Simulation Nanocatalyst

Halothane hepatitis in Iran:A review of 59 cases

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World Journal of Gastroenterology 2008年第34期14卷 5322-5326页

作者： Payam Eghtesadi-Araghi amir-Ali Sohrabpour homayoon Vahedi Mehdi Saberi-Firoozi Digestive Disease Research Center Shariati HospitalMedical Sciences/University of Tehran Gastroenterology Research Center Shiraz University of Medical Sciences Digestive Disease Research Center Shariati Hospital Medical Sciences/University of Tehran

AIM:To study halothane hepatitis (HH) in Iran and its associated risk factors. METHODS: We retrospectively studied files of all cases diagnosed with HH referred to three referral hospitals and four private centers in Iran from April 1994 to September 2006. Information on age at surgery, gender, medications history, obesity, history of previous exposure, previous reaction to halothane, familial history, type of surgery, perioperative hypoxia or sepsis, morbidity and mortality were recorded and analyzed. RESULTS: A total of 59 cases were identifi ed. Forty- eight (81%) were women. The median age at the time of surgery was 44 years (range, 18 to 80 years). Sixty percent of patients were above 40-year-old. Obesity was observed in 22.2%. Previous history of exposures to halothane was noted in 61% of which 50% had history of post-exposure reaction. Coronary artery bypass graft (CABG), cholecystectomy, and cosmetic surgeries (mainly weight reduction) were the most frequent surgeries. The mortality rate was 12.2%. In patients developing encephalopathy, it was as high as 50%. CONCLUSION: HH remains an important cause of morbidity and mortality in centers still using this anesthetic. However, a large percentage of these casescould have been avoided. To lessen occurrence of further cases of HH, the authors suggest that in female patients having a history of surgery (or delivery) with general anesthesia, the use of halothane should be absolutely avoided. Utilization of proper substitutes in adults’ anesthesia is advocated.

关键词： Anesthesia Inhalation Halothane Hepatitis Drug-Induced