• فهرست مقالات Multi-objective particle swarm optimization

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        1 - Optimal Locations on Timoshenko Beam with PZT S/A for Suppressing 2Dof Vibration Based on LQR-MOPSO
        M Hasanlu A Bagheri
        Neutralization of external stimuli in dynamic systems has the major role in health, life, and function of the system. Today, dynamic systems are exposed to unpredicted factors. If the factors are not considered, it will lead to irreparable damages in energy consumption چکیده کامل
        Neutralization of external stimuli in dynamic systems has the major role in health, life, and function of the system. Today, dynamic systems are exposed to unpredicted factors. If the factors are not considered, it will lead to irreparable damages in energy consumption and manufacturing systems. Continuous systems such as beams, plates, shells, and panels that have many applications in different industries as the main body of a dynamic system are no exceptions for the damages, but paying attention to the primary design of model the automatic control against disturbances has highly met the objectives of designers and also has saved much of current costs. Beam structure has many applications in constructing blades of gas and wind turbines and robots. When it is exposed to external loads, it will have displacements in different directions. Now, it is the control approach that prevents from many vibrations by designing an automated system. In this study, a cantilever beam has been modeled by finite element and Timoshenko Theory. Using piezoelectric as sensor and actuator, it controls the beam under vibration by LQR controller. Now, in order to increase controllability of the system and reduce the costs, there are only spots of the beam where most displacement occurs. By controlling the spots and applying force on them, it has the most effect on the beam. By multi-objective particle swarm optimization or MOPSO algorithm, the best weighting matrices coefficients of LQR controller are determined due to sensor and actuator displacement or the beam vibration is controlled by doing a control loop. پرونده مقاله
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        2 - A new two-phase approach to the portfolio optimization problem based on the prediction of stock price trends
        Hamid Reza Yousefzade Amin Karrabi Aghileh Heydari
        Forming a portfolio of different stocks instead of buying a particular type of stock can reduce the potential loss of investing in the stock market. Although forming a portfolio based solely on past data is the main theme of various researches in this field, considering چکیده کامل
        Forming a portfolio of different stocks instead of buying a particular type of stock can reduce the potential loss of investing in the stock market. Although forming a portfolio based solely on past data is the main theme of various researches in this field, considering a portfolio of different stocks regardless of their future return can reduce the profits of investment. The aim of this paper is to introduce a new two-phase approach to forming an optimal portfolio using the predicted stock trend pat-tern. In the first phase, we use the Hurst exponent as a filter to identify stable stocks and then, we use a meta-heuristic algorithm such as the support vector regression algorithm to predict stable stock price trends. In the next phase, according to the predicted price trend of each stock having a positive return, we start arranging the portfolio based on the type of stock and the percentage of allocated capacity of the total portfolio to that stock. To this end, we use the multi-objective particle swarm optimization algorithm to determine the optimal portfolios as well as the optimal weights corresponding to each stock. The sample, which was selected using the systematic removal method, consists of active firms listed on the Tehran Stock Ex-change from 2018 to 2020. Experimental results, obtained from a portfolio based on the prediction of stock price trends, indicate that our suggested approach outperforms the retrospective approaches in approximating the actual efficient frontier of the problem, in terms of both diversity and convergence. پرونده مقاله
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        3 - Modelling and optimization of a tri-objective Transportation-Location-Routing Problem considering route reliability: using MOGWO, MOPSO, MOWCA and NSGA-II
        Fariba Maadanpour Safari Farhad Etebari Adel Pourghader Chobar
        In this research, a tri-objective mathematical model is proposed for the Transportation-Location-Routing problem. The model considers a three-echelon supply chain and aims to minimize total costs, maximize the minimum reliability of the traveled routes and establish a w چکیده کامل
        In this research, a tri-objective mathematical model is proposed for the Transportation-Location-Routing problem. The model considers a three-echelon supply chain and aims to minimize total costs, maximize the minimum reliability of the traveled routes and establish a well-balanced set of routes. In order to solve the proposed model, four metaheuristic algorithms, including Multi-Objective Grey Wolf Optimizer (MOGWO), Multi-Objective Water Cycle Algorithm (MOWCA), Multi-objective Particle Swarm Optimization (MOPSO) and Non-Dominated Sorting Genetic Algorithm- II (NSGA-II) are developed. The performance of the algorithms is evaluated by solving various test problems in small, medium, and large scale. Four performance measures, including Diversity, Hypervolume, Number of Non-dominated Solutions, and CPU-Time, are considered to evaluate the effectiveness of the algorithms. In the end, the superior algorithm is determined by Technique for Order of Preference by Similarity to Ideal Solution method. پرونده مقاله
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        4 - مسیریابی شبکه های حسگر بی سیم با استفاده از خوشه بندی مبتنی بر الگوریتم بهینه سازی ازدحام ذرات چندهدفه
        سید رضا نبوی نفیسه اوسطی عراقی جواد اکبری ترکستانی
        در سال های اخیر، با گسترش کاربردهای شبکه های حسگر بی سیم، بهره‌برداری از این نوع شبکه ها به منظور رسیدگی بر محیط و تحلیل داده های جمع آوری شده از محیط های خاص و متنوع بسیار رواج یافته است. شبکه های حسگر بی سیم با توجه به سهولت پیکربندی و عدم نیاز به تجهیزات گران چکیده کامل
        در سال های اخیر، با گسترش کاربردهای شبکه های حسگر بی سیم، بهره‌برداری از این نوع شبکه ها به منظور رسیدگی بر محیط و تحلیل داده های جمع آوری شده از محیط های خاص و متنوع بسیار رواج یافته است. شبکه های حسگر بی سیم با توجه به سهولت پیکربندی و عدم نیاز به تجهیزات گران قیمت، یکی از بهترین گزینه ها برای جمع آوری داده ها از محیط هستند. انرژی گره های حسگر در شبکه های حسگر بی سیم محدود است که با توجه به عدم وجود منبع شارژ ثابت یکی از چالش های اساسی است که با آن مواجه می‌شویم. از آن جایی که بیشترین مقدار انرژی گره ها در طی انتقال داده ها اتلاف می شود، گره ای که بیشتر از بقیه به انتقال داده ها بپردازد و یا بسته های داده ای را در فواصل طولانی انتقال دهد، انرژی آن زودتر از بقیه به اتمام می رسد. با اتمام انرژی یک حسگر در شبکه ممکن است در روند کار شبکه اختلال ایجاد شود. بنابراین، با توجه به توپولوژی پویا و طبیعت توزیع‌شده شبکه‌های حسگر بی‌سیم، طراحی پروتکل‌های انرژی کارآمد برای مسیریابی یکی از چالش‌های اصلی است. ازاین‌رو در این مقاله پروتکل مسیریابی آگاه از انرژی براساس الگوریتم بهینه سازی ازدحام ذرات چندهدفه ارائه شده است. در رویکرد پیشنهادی تابع شایستگی الگوریتم بهینه سازی ازدحام ذرات برای انتخاب گره سرخوشه بهینه براساس هدف های کیفیت خدمات شامل انرژی باقیمانده، کیفیت پیوند، تأخیر انتها به انتها و نرخ تحویل استفاده شده است. نتایج شبیه سازی نشان می دهد روش پیشنهادی با توجه به ایجاد توازن در اهداف معیارهای کیفیت خدمات، نسبت به سایر روش های موجود اتلاف انرژی کمتر و طول عمر بیشتری دارد. پرونده مقاله