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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Amirkabir (Journal of Science and Technology)
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی:
- انتشار مقاله: 08-07-1396
- نویسندگان: B. VAHIDI,M.R. BANK TAVAKOLI,S.H. HOSSEINIAN
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Operation and Automation in Power Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: reliability,Multi-objective optimization,Reconfiguration,Powe loss,Multi-objective grasshopper optimization algorithm
- چکیده: بازآرایی شبکه یک روش بهینهسازی غیرخطی جهت محاسبه ساختار شعاعی بهینه است و برای کاهش تلفات توان و بهبود شاخص قابلیت اطمینان با لحاظ کردن یکسری محدودیتها در شبکه بکار میرود. در این مقاله چارچوب چندهدفه برای بازآرایی شبکه بهینه با توابع هدف کاهش تلفات توان و بهبود شاخص قابلیت اطمینان ارائه شده است. این مسئله بهینهسازی با الگوریتم بهینهسازی چند هدفه ملخ (MOGOA) که یکی از ابزارهای بهینهسازی پیشرفته است، حل شده است. برای حل یک مسئله بهینهسازی، الگوریتم پیشنهادی به صورت ریاضی رفتار ملخها را شبیهسازی میکند. ضریب تغییرات الگوریتم ملخ برای تعادل اکتشاف و بهرهبرداری، به MOGOAکمک میکند تا تقریبی دقیق از بهینهسازی را پیدا کند. کارایی روش پیشنهادی در سیستمهای توزیع 33 شینه و 69 شینه بررسی و تایید شده است. نتایج بهینهسازی استفاده شده دارای راه حل بهتری در مقایسه با الگوریتمهای قبلی است.
- چکیده انگلیسی: Network reconfiguration is a nonlinear optimization procedure which calculates a radial structure to optimize the power losses and improve the network reliability index while meeting practical constraints. In this paper, a multi-objective framework is proposed for optimal network reconfiguration with the objective functions of minimization of power losses and improvement of reliability index. The optimization problem is solved by multi-objective grasshopper optimization algorithm (MOGOA) which is one of the most modern heuristic optimization tools. To solve an optimization problem, the suggested algorithm mathematically mimics and formulates the behavior of grasshopper swarms. The modifying comfort zone coefficient needs grasshoppers to balance exploration and exploitation, which helps the MOGOA to find an exact approximation of global optimization and not trapped in local optima. The efficiency of the suggested technique is approved regarding the 33-bus and 69-bus test systems. Optimization results expressed that the suggested technique not only presents the intensified exploration ability but also has a better solution compared with previous algorithms.
- انتشار مقاله: 15-12-1397
- نویسندگان: M.A. Tavakoli Ghazi Jahani,P. Nazarian,A. Safari,M.R. Haghifam
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Operation and Automation in Power Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: reliability,Multi-objective optimization,Reconfiguration,Powe loss,Multi-objective grasshopper optimization algorithm
- چکیده: بازآرایی شبکه یک روش بهینهسازی غیرخطی جهت محاسبه ساختار شعاعی بهینه است و برای کاهش تلفات توان و بهبود شاخص قابلیت اطمینان با لحاظ کردن یکسری محدودیتها در شبکه بکار میرود. در این مقاله چارچوب چندهدفه برای بازآرایی شبکه بهینه با توابع هدف کاهش تلفات توان و بهبود شاخص قابلیت اطمینان ارائه شده است. این مسئله بهینهسازی با الگوریتم بهینهسازی چند هدفه ملخ (MOGOA) که یکی از ابزارهای بهینهسازی پیشرفته است، حل شده است. برای حل یک مسئله بهینهسازی، الگوریتم پیشنهادی به صورت ریاضی رفتار ملخها را شبیهسازی میکند. ضریب تغییرات الگوریتم ملخ برای تعادل اکتشاف و بهرهبرداری، به MOGOAکمک میکند تا تقریبی دقیق از بهینهسازی را پیدا کند. کارایی روش پیشنهادی در سیستمهای توزیع 33 شینه و 69 شینه بررسی و تایید شده است. نتایج بهینهسازی استفاده شده دارای راه حل بهتری در مقایسه با الگوریتمهای قبلی است.
- چکیده انگلیسی: Network reconfiguration is a nonlinear optimization procedure which calculates a radial structure to optimize the power losses and improve the network reliability index while meeting practical constraints. In this paper, a multi-objective framework is proposed for optimal network reconfiguration with the objective functions of minimization of power losses and improvement of reliability index. The optimization problem is solved by multi-objective grasshopper optimization algorithm (MOGOA) which is one of the most modern heuristic optimization tools. To solve an optimization problem, the suggested algorithm mathematically mimics and formulates the behavior of grasshopper swarms. The modifying comfort zone coefficient needs grasshoppers to balance exploration and exploitation, which helps the MOGOA to find an exact approximation of global optimization and not trapped in local optima. The efficiency of the suggested technique is approved regarding the 33-bus and 69-bus test systems. Optimization results expressed that the suggested technique not only presents the intensified exploration ability but also has a better solution compared with previous algorithms.
- انتشار مقاله: 15-12-1397
- نویسندگان: M.A. Tavakoli Ghazi Jahani,P. Nazarian,A. Safari,M.R. Haghifam
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Mining and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: Sustainable Development,Eastern Alborz coal mines,Environmental Impact Assessment (EIA),Phillips mathematical model
- چکیده:
- چکیده انگلیسی: Environmental impact assessment (EIA) has led to the dominance of planners on the natural environment of the regions, providing the possibility of continuously monitoring and controlling the status quo by management staff. In this regard, a new semi-quantitative model is presented for the EIA of the Eastern Alborz Coal Mining complex using the matrix method, and determining the corresponding impacting factors and environmental components. For this purpose, the expert opinions are used to gather the preliminary data and score the parameters involved. The effect of each impacting factor involved on each environmental component is determined by quantifying the qualitative comments. According to the results obtained, the components air quality, human health and safety, and ecology and soil of the area undergo the most environmental damages from the mining activities. Then the EIA results obtained are used to assess the sustainability of the complex using the Phillips mathematical model. The results obtained indicate that the sustainability of this complex is weak, and, therefore, the preventive environmental measures with a preference must be recommended to reduce the environmental damages to its components.
- انتشار مقاله: 08-11-1393
- نویسندگان: M. Ataei,E. Tajvidi Asr,R. Khalokakaie,K. Ghanbari,M. R. Tavakoli Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Mining and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: Dissolved Nitrogen Pre-Dispersed Solvent Extraction (DNPDSE) Contractor,Pre-Dispersed Solvent Extraction (PDSE) Contractor,Colloidal Aphrons (CAs),Metal Extraction,Performance Study
- چکیده:
- چکیده انگلیسی: Efforts to increase the mass transfer coefficient, enhance the contact area, and decrease the power input of contractors have given risen to the development of the pre-dispersed solvent extraction (PDSE) contactor and the devise of the new dissolved nitrogen PDSE (DNPDSE) contactors. The studies conducted after the design of the new contactor to determine the working conditions for its suitable performance (2.5-3.5 bar pressure, 0.1 L/min sparger flow rate, and 1.5 L of the aqueous phase) showed that for all the evaluated conditions (i.e. the pressure, polyaphron type, and dilution percentage), the recovery in the DNPDSE contactor was higher than that in the PDSE one. In addition, pictures of the performance modes of the two contactor indicated the presence of the organic phase in the form of colloidal gas aphrons (CGAs) in the DNPDSE contactor and of polyaphron aggregations in the PDSE one. This is a good reason for the increased copper recovery in the DNPDSE contactor. The best recovery for the extraction process in the DNPDSE contactor was achieved using the anionic polyaphron of sodium dodecylbenzene sulphonate (NaDBS) with five-fold dilution at 3.5 bar.
- انتشار مقاله: 08-02-1393
- نویسندگان: M. R. Tavakoli Mohammadi,Seyed M. J. Koleini,M. Abdollahy
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Electrical and Computer Engineering Innovations (JECEI)
- نوع مقاله: Journal Article
- کلمات کلیدی: Ka Band,CMOS power amplifier,Distributed structure,Doherty power amplifier,Power divider
- چکیده:
- چکیده انگلیسی: Background and Objectives: In this paper, a new design strategy was proposed in order to enhance bandwidth and efficiency of power amplifier.
Methods: To realize the introduced design strategy, a power amplifier was designed using TSMC CMOS 0.18um technology for operating in the Ka band, i.e. the frequency range of 26.5-40GHz. To design the power amplifier, first a power divider (PD) with a very wide bandwidth, i.e. 1-40GHz, was designed to cover the whole Ka band. The designed Doherty power amplifier consisted of two different amplification paths called main and auxiliary. To amplify the signal in each of the two pathways, a cascade distributed power amplifier was used. The main reason for combining the distributed structure and cascade structure was to increase the gain and linearity of the power amplifier.
Results: Measurements results for designed power divider are in good agreement with simulations results. The simulation results for the introduced structure of power amplifier indicated that the gain of proposed power amplifier at the frequency of 26-35GHz was more than 30dB. The diagram of return loss at the input and output of power amplifier in the whole Ka band was less than -8dB. The maximum Power Added Efficiency (PAE) of the designed power amplifier was 80%. The output p 1dB of the introduced structure was 36dB, and the output power of power amplifier was 36dBm. Finally, the IP3 value of power amplifier was about 17dB.
Conclusion: The strategy presented in this paper is based on usage of Doherty and distributed structures and a new wideband power divider to benefit from their advantages simultaneously.
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======================================================================================================- انتشار مقاله: 18-12-1397
- نویسندگان: M. Mirzajani Darestani,M. Tavakoli,P. Amiri
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: tatement of Problem: Oral premedication used to reduce the anxiety in patients undergoing dental treatment. Passion flower has been used as a sedative that can control the dental anxiety.Purpose: This study determines the efficacy of Passion flower, in reducing anxiety during the dental procedures.Material and Methods: In this randomized- one sided blind clinical trial, 63 patients, with moderate, high and severe anxiety(according to VAS score) in need of periodontal treatment were randomly divided into 3 groups of 21.The first group was given the drop Passion flower drop and the second group were given the drop of placebo and the third group; neither drug nor placebo were given (negative control group). Results were analyzed by Chi Square, Variance Analysis, Tucky and Paired-T using SPSS software.Results: Mean anxiety level prior to the drug administration was 12.09±2.42 for the Passion flower group, 12.00±2.66 for the placebo group and 11.66±2.39 for the negative control group. After premedication, these values were: 8.47±2.58 for the Passion flower group, 10.52±2.11 for the placebo group and 11.23±2.34 for the negative control group. These results demonstrated a significant difference (p< 0.0001) in the anxiety levels before and after the Passion flower administration in the Passion flower group and also between the Passion flower group and the other two groups.Conclusion: Results indicated that administration of Passion flower, as a premedication, is significantly effective in reducing the anxiety. Since this study is a pioneer on the subject, further trials with greater number of subjects are required to confirm our results.
- انتشار مقاله: 15-05-1392
- نویسندگان: N. Kaviani,M. Tavakoli,MR. Tabanmehr,RA. Havaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: posterior teeth,Successful periodontal therapies,Delphitechnique
- چکیده:
- چکیده انگلیسی: Statement of Problem: Periodontists use different criteria to assess the success of periodontal treatments so that there is no consistent approach regarding the important parameters to be used for successful treatment. Purpose: The aim of this study was to determine success criteria of periodontal treatment using Delphi method based on the experience of expert panel of periodontists. Materials and Method: In this cross-sectional study using Delphi method, 15 periodontitists in Iran determined the level of importance of attachment level, probing depth, furcation involvement, mobility, plaque, inflammation and patient satisfaction following periodontal treatment of the posterior teeth in a patient with moderate to severe chronic periodontitis. The periodontists were questioned concerning the relative importance of each outcome measure, a minimally acceptable level for success for each criterion and the length of time for these parameters to remain stable. Results: Following two rounds of Delphi surveys, the periodontists considered the attachment level, bone loss and plaque to be a ''very important'' parameter for successful periodontal treatment. Probing depth, furcation involvement, inflammation, function, esthetics, mobility and patient satisfaction were considered to be" important" factors for successful periodontal treatment. The panelists agreed that a minimal of 1mm attachment gain, 1mm reduction in probing depth, Glickman grade I furcation involvement, Miller degree I mobility, and no change in the bone level are acceptable outcomes following 1 year of treatment. Finally, the periodontists considered that 1 year results of treatment should remain stable for a minimum of 5 years. Conclusion: These studies suggest that Delphi method is a practical approach which can establish minimal standards for successful therapy of the posterior teeth based on the opinions of expert periodontists.
- انتشار مقاله: 06-12-1398
- نویسندگان: J. Yaghini,M. Tavakoli,N. Naghsh,A. Moghareh Abed,E. Bateni,A. Nazer
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Research
- نوع مقاله: Journal Article
- کلمات کلیدی: antimicrobial resistance,E. coli,Virulence factors,STEC,Clinical mastitis
- چکیده: هدف از این مطالعه شناسایی ژنهای حدت و مقاومت آنتی بیوتیکی در باکتریهای اشریشیا کولای جدا شده از موارد ورم پستان بالینی در گلههای شیری در ایران میباشد. نمونهگیری از 86 کارتیه التهابی در 8 گاوداری شیری صنعتی در استان البرز طی تابستان 1394 انجام شد. ژنهای حدت STEC با استفاده از مالتیپلکس-پی سی آر مشخص و الگوی مقاومت نسبت به آنتی بیوتیکهای مختلف با استفاده از آنتی بیوگرام تعیین گردید. در بین 60 نمونه اشریشیا کولای جدا شده از نمونههای مورد آزمون، 13 نمونه (6/21%) STEC بود. همچنین ژن stx1 به همراه ژن eaeA در 7 نمونه (8/53%) از جدایههای STEC، ژنهای stx1 و stx2 تنها در یک نمونه (7/7%) از نمونههای مورد آزمایش مشاهده شد. نتایج آنتی بیوگرام حاکی از این است که جدایههای اشریشیا کولای به پنی سیلین، تایلوزین، اکسی تتراسیکلین، اریترومایسین، آمپی سیلین، استرپتومایسین و نئومایسین مقاوم میباشند. با این حال تمام جدایهها نسبت به انروفلوکساسین حساس بودند. بنابراین طبق نتایج تعیین سیستم پایش منظم جهت شناسایی موارد پستان بالینی و وضعیت حساسیت نسبت به آنتی بیوتیکها لازم به نظر میرسد.
- چکیده انگلیسی: The aim of this study was to identify virulence genes and antimicrobial resistance of Escherichia coli isolated from bovine clinical mastitis in dairy herds in Iran. Sampling was done from 86 inflamed quarters of dairy cows in 8 commercial farms of Alborz province, Iran in summer 2015. Shiga toxin-producing E. coli (STEC) virulence genes were detected by multiplex PCR and multi-drug resistance profiles were confirmed using disk diffusion method. Among 60 E. coli isolated from examined samples, 13 (21.6%) of them were STEC. The results of PCR assay showed that eaeA gene was carried by 4 (30.8%) of STEC isolates. Although stx1 in combination with eaeA gene was detected from 7 (53.8%) of STEC isolates, stx1 and stx2 genes were detected from only 1 (7.7%) of the examined samples. The result of the disk diffusion method showed that all E. coli isolates were resistant to penicillin, tylosin, oxytetracycline, erythromycin, ampicillin, streptomycin and neomycin. However all isolates were susceptible to enrofloxacin. Therefore, according to the results establishing a regular monitoring system for identification of cases with clinical mastitis and conducting antibiotic sensitivity tests are recommended.
- انتشار مقاله: 31-05-1395
- نویسندگان: M. Tavakoli,H. Pourtaghi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mathematical Chemistry
- نوع مقاله: Journal Article
- کلمات کلیدی: Distance-balanced graphs,Graph operation
- چکیده:
- چکیده انگلیسی: Distance-balanced graphs are introduced as graphs in which every edge uv has the following property: the number of vertices closer to u than to v is equal to the number of vertices closer to v than to u. Basic properties of these graphs are obtained. In this paper, we study the conditions under which some graph operations produce a distance-balanced graph.
- انتشار مقاله: 02-02-1393
- نویسندگان: M. TAVAKOLI,H. YOUSEFI-AZARI
- مشاهده