• فهرس المقالات Optimisation

      • حرية الوصول المقاله

        1 - Isogeometric Analysis for Topology Optimisation of Two Dimensional Planar and Laminated Composite Plate Continuum Structures
        K.N.V Chandrasekhar V Bhikshma N Rakesh N Swapnareddy C Rakesh
        Isogeometric analysis is the recent development in the field of engineering analysis with high performance computing and greater precision. This current research has opened a new door in the field of structural optimisation. The main focus of this research study is to p أکثر
        Isogeometric analysis is the recent development in the field of engineering analysis with high performance computing and greater precision. This current research has opened a new door in the field of structural optimisation. The main focus of this research study is to perform topology optimisation of continuum structures in civil engineering using Isogeometric analysis. The continuum structures analysed here in this study are reinforced concrete, steel and laminated composite plates. Reinforced concrete is a rational union of concrete and steel. Topology optimisation of reinforced concrete structures is an emerging area of study to determine the optimal layout of material in the concrete domain. Laminated structures are made of several layers of material and bonded to achieve high stiffness and low weight to strength ratio. The deformed shape at the optimal state can be determined with topology optimisation of laminated composites. The formulation for composite plates is done using kirchoff thin plate theory without any shear contribution. B-splines are used to model the geometry. The objective is to optimise the energy of the structure and optimality criteria is used to calculate the newer values of relative densities. First order sensitivity analysis is performed to determine the newer values of objective function. The code is written in MatLab® and a few problems have been solved with different domains. The results are verified and have shown a good agreement with those in the literature. تفاصيل المقالة
      • حرية الوصول المقاله

        2 - بهبود بهره‌وری سیستم توزیع با استفاده از بهینه‌سازی چندهدفه انواع منابع تولید پراکنده و جبران ساز استاتیک توزیع
        مسعود علیلو سجاد سعدی سعید زمانیان جواد غلامی شهاب مشاری
        جایابی و ظرفیت یابی بهینه واحدهای تولید پراکنده و جبران سازهای مدرن تاثیر مستقیمی بر روی کارایی این ادوات در سیستم توزیع دارد. به همین دلیل، در این مقاله، بهینه سازی همزمان مکان و اندازه انواع منابع تولید پراکنده و جبران ساز استاتیک سنکرون در سیستم های توزیع مورد مطال أکثر
        جایابی و ظرفیت یابی بهینه واحدهای تولید پراکنده و جبران سازهای مدرن تاثیر مستقیمی بر روی کارایی این ادوات در سیستم توزیع دارد. به همین دلیل، در این مقاله، بهینه سازی همزمان مکان و اندازه انواع منابع تولید پراکنده و جبران ساز استاتیک سنکرون در سیستم های توزیع مورد مطالعه قرار گرفته است. جهت نزدیک تر کردن نتایج به شرایط واقعی تر بهره برداری، از یک مدل بار غیرخطی که ترکیبی از الگوری مصرف روزانه و بار متغیر به ولتاژ و فرکانس است، استفاده می شود. میکروتوربین، توربین بادی، پنل فتوولتائیک و پیل سوختی به عنوان منابع تولید پراکنده در نظر گرفته می شوند. توابع هدف مسئله ترکیبی از شاخص های فنی و زیست محیطی هستند. از الگوریتم بهینه سازی چندهدفه وال برای بهینه سازی توابع هدف و تشکیل صفحه بهینه پارتو استفاده می شود. پس از اجرای الگوریتم چندهدفه، از روش تحلیل سلسله مراتبی برای انتخاب بهترین ذره از صفحه پارتو که معادل با بهینه ترین مکان و اندازه ادوات است، استفاده می شود. در نهایت، روش پیشنهادی در سیستم های توزیع استاندارد 69 شینه IEEE و واقعی 101 شینه خوی- ایران مورد ارزیابی قرار می گیرد. نتایج شبیه سازی نشان دهنده کارایی مناسب روش پیشنهادی در جایابی و ظرفیت یابی بهینه ادوات و بهبود شاخص های سیستم توزیع هستند. تفاصيل المقالة
      • حرية الوصول المقاله

        3 - Optimisation of assembly scheduling in VCIM systems using genetic algorithm
        Son Duy Dao Kazem Abhary Romeo Marian
        Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the app أکثر
        Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is quite different from one in traditional production systems because of the difference in the working principles of the two systems. In this article, the assembly scheduling problem in VCIM systems is modeled and then an integrated approach based on genetic algorithm (GA) is proposed to search for a global optimised solution to the problem. Because of dynamic nature of the scheduling problem, a novel GA with unique chromosome representation and modified genetic operations is developed herein. Robustness of the proposed approach is verified by a numerical example. تفاصيل المقالة
      • حرية الوصول المقاله

        4 - Emergency department resource optimisation for improved performance: a review
        Kazi Badrul Ahsan M. R. Alam Doug Gordon Morel M. A . Karim
        Emergency departments (EDs) have been becoming increasingly congested due to the combined impacts of growing demand, access block and increased clinical capability of the EDs. This congestion has known to have adverse impacts on the performance of the healthcare service أکثر
        Emergency departments (EDs) have been becoming increasingly congested due to the combined impacts of growing demand, access block and increased clinical capability of the EDs. This congestion has known to have adverse impacts on the performance of the healthcare services. Attempts to overcome with this challenge have focussed largely on the demand management and the application of system wide process targets such as the “four-hour rule” intended to deal with access blocks. In addition, EDs have introduced various strategies such as “fast tracking”, “enhanced triage” and new models of care such as introducing nurse practitioners aimed at improving throughput. However, most of these practices require additional resources. Some researchers attempted to optimise the resources using various optimisation models to ensure best utilisation of resources to improve patient flow. However, not all modelling approaches are suitable for all situations and there is no critical review of optimisation models used in hospital EDs. The aim of this article is to review various analytical models utilised to optimise ED resources for improved patient flow and highlight benefits and limitations of these models. A range of modelling techniques including agent-based modelling and simulation, discrete-event simulation, queuing models, simulation optimisation and mathematical modelling have been reviewed. The analysis revealed that every modelling approach and optimisation technique has some advantages and disadvantages and their application is also guided by the objectives. The complexity, interrelationships and variability of ED-related variables make the application of standard modelling techniques difficult. However, these models can be used to identify sources of flow obstruction and to identify areas where investments in additional resources are likely to have most benefit. تفاصيل المقالة