support vector regression (svr)
در نشریات گروه فنی و مهندسی-
Support Vector Machines (SVMs) are a valuable tool in the food industry due to their ability to handle complex, nonlinear relationships between variables, even with limited datasets, high-dimensional data, and noisy data. This makes SVMs well-suited for applications such as food quality and safety assessment, sensory evaluation, process optimization, and food authentication. Accordingly, a new approach is introduced to predict different features of a traditional yogurt drink, also called doogh. The proposed model combines the principles of Support Vector Regression with fuzzy logic to handle uncertainty and approximate complex relationships between inputs (retentate, xanthan, and shelf-life) and target variables including viscosity, syneresis, color values, and total acceptability. The implemented approach is particularly useful when dealing with problems where the relationships are not easily captured by traditional mathematical models due to their non-linearity or imprecision. Also, it mitigates the limitations of data availability. The predictive ability of the proposed model has been evaluated in terms of MSE, R2, RMSE, and MAE when adding different noise levels. Additionally, the conditions necessary to attain optimized metric values have been found. At the optimum point, the viscosity, syneresis, L*, a*, b* and total acceptability are 19.70 mPa.s, 11.30%, 97.04, -1.43, 8.13, and 5.00, respectively. Besides, the findings indicate that samples containing 0.8% retentate, 0.4% xanthan, and a 31-day shelf-life exhibit the highest viscosity, while those with 0.6% retentate, 0.4% xanthan, and a 31-day shelf-life show the lowest syneresis. Moreover, samples with 0.7% retentate, 0.2% xanthan, and a 13-day shelf-life demonstrate the highest total acceptability.Keywords: Doogh, Fuzzy Theory, Support Vector Regression (SVR), Syneresis, Uncertainty
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در این مقاله، هدف توسعه مدل هایی داده محور برای پیش بینی حداکثر نشست سطح زمین (Smax) ناشی از استخراج زغال سنگ به روش جبهه کار طویل است؛ پدیده ای که از چالش های اساسی مهندسی معدن محسوب می شود و پیش بینی آن می تواند در کاهش خسارات اعمالی به سازه های سطحی و زیرسطحی مجاور و ارتقاء ایمنی عملیات معدنی موثر باشد. بدین منظور، 46 دسته داده معتبر از مطالعات پیشین شامل سه پارامتر کلیدی ضخامت لایه زغال سنگ (hs)، عمق روباره (H) و عرض پهنه استخراجی (Lw) گردآوری شد.در ادامه، یک مدل پیش بینی کننده ترکیبی مبتنی بر رگرسیون ماشین بردار پشتیبان (SVR) که با الگوریتم فراابتکاری عقاب طلایی (GEO) بهینه سازی شده است توسعه یافت. به منظور ارزیابی عملکرد این مدل، یک مدل مقایسه ای نیز بر پایه رگرسیون چندمتغیره غیرخطی (NLMR) توسعه داده شد. برای ارزیابی تعمیم پذیری و پایداری مدل SVR-GEO، از تکنیک اعتبارسنجی متقابل5-بخشی استفاده شد. عملکرد مدل های پیشنهادی در مراحل آموزش و تست با بهره گیری از دیاگرام تیلور، منحنی مشخصه خطای رگرسیون (REC) و شش شاخص آماری شامل ضریب تعیین (R²)، شمول واریانس (VAF)، a20، جذر میانگین مربعات خطا (RMSE)، میانگین قدرمطلق خطا (MAE) و میانگین درصد خطای مطلق (MAPE) مورد ارزیابی و مقایسه با شش رابطه تجربی رایج قرار گرفت. نتایج بدست آمده از دیاگرام تیلور و منحنی مشخصه خطای رگرسیون (REC) حاکی از آن است که مدل SVR-GEO در هر دو مرحله آموزش و تست عملکرد به مراتب بهتری نسبت به مدل NLMR و روابط تجربی دارد. همچنین، نتایج بدست آمده براساس شاخص های آماری نشان داد که مدل SVR-GEO دارای بالاترین دقت و کمترین میزان خطا نسبت به مدل NLMR و روابط تجربی است؛ به طوری که مقادیر شاخص های R²، VAF، a20، RMSE، MAE و MAPE این مدل به ترتیب در مرحله آموزش 0.988، 98.8%، 0.946، 0.134، 0.053 و 5.7% و در مرحله تست 0.942، 93.9%، 0.778، 0.292، 0.235 و 19.7% بدست آمد. در نهایت، نتایج تحلیل حساسیت نشان داد که ضخامت لایه زغال سنگ (hs) بیشترین تاثیر را بر Smax دارد و پس از آن، عرض پهنه (Lw) و عمق روباره (H) در اولویت قرار دارند. بنابراین، مدل پیشنهادی SVR-GEO می تواند به عنوان ابزاری دقیق، مطمئن و کارآمد برای پیش بینی Smax در پروژه های معدنی به روش جبهه کار طویل مورد استفاده قرار گیرد.کلید واژگان: روش جبهه کار طویل، حداکثر نشست سطح زمین، رگرسیون ماشین بردار پشتیبان، الگوریتم فراابتکاری عقاب طلایی، رگرسیون چندمتغیره غیرخطیThis study aims to develop accurate data-driven models for predicting the maximum ground surface subsidence (Smax) induced by longwall coal mining, one of the key challenges in mining engineering. Accurate prediction of Smax is crucial for minimizing damage to surface and subsurface structures and enhancing operational safety. A total of 46 datasets from literature, involving three influential parameters including coal seam thickness (hs), depth of cover (H), and panel width (Lw), were collected. Two predictive models were developed: a support vector regression (SVR) model optimized using the Golden Eagle Optimization (GEO) algorithm (SVR-GEO), and a nonlinear multivariate regression model (NLMR). The generalization ability of SVR-GEO was validated using 5-fold cross-validation. Models’ performance in both training and testing phases was evaluated using Taylor diagrams, regression error characteristic (REC) curves, and six statistical indices (R², VAF, a20, RMSE, MAE, and MAPE), and compared against six empirical equations. Results showed that SVR-GEO outperformed both NLMR and empirical models, achieving R² values of 0.988 (training) and 0.942 (testing). Sensitivity analysis revealed that coal seam thickness (hs) had the greatest impact on Smax, followed by panel width (LW) and depth of cover (H). The SVR-GEO model is proposed as a robust and reliable tool for predicting Smax in longwall mining projects.Keywords: Longwall Mining, Maximum Ground Surface Subsidence, Support Vector Regression (SVR), Golden Eagle Ptimizer (GEO), Nonlinear Multivariate Regression (NLMR)
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The application of dynamic and continuous time series has drawn attention due to the complexities of the rainfall-runoff process and the simplification of multiple regression and static methods. On the other hand, forecasting river flow is one of the main topics in flood control. This paper reports the results of applying the SWAT hydrological model to analyze the rainfall-runoff relationship for a 6-year period in the Kahir catchment basin, Sistan and Baluchistan province. The model output was calibrated by the SUF12 optimizer algorithm, and the data entered the model again. Then, the model output was used to forecast future periods using Support Vector Regression (SVR) and essential codes in MATLAB. The acceptable results of the SVR model regarding data prediction can be used as another method to estimate parameters and inputs.Keywords: SWAT hydrological model, Support Vector Regression (SVR), Time-series forecast, Kahir River
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Journal of Electrical and Computer Engineering Innovations, Volume:10 Issue: 2, Summer-Autumn 2022, PP 447 -462Background and ObjectivesStock markets have a key role in the economic situation of the countries. Thus one of the major methods of flourishing the economy can be getting people to invest their money in the stock market. For this purpose, reducing the risk of investment can persuade people to trust the market and invest. Hence, Productive tools for predicting the future of the stock market have an undeniable effect on investors and traders’ profit.MethodsIn this research, a two-stage method has been introduced to predict the next week's index value of the market, and the Tehran Stock Exchange Market has been selected as a case study. In the first stage of the proposed method, a novel clustering method has been used to divide the data points of the training dataset into different groups and in the second phase for each cluster’s data, a hybrid regression method (HHO-SVR) has been trained to detect the patterns hidden in each group. For unknown samples, after determining their cluster, the corresponding trained regression model estimates the target value. In the hybrid regression method, HHO is hired to select the best feature subset and also to tune the parameters of SVR.ResultsThe experimental results show the high accuracy of the proposed method in predicting the market index value of the next week. Also, the comparisons made with other metaheuristics indicate the superiority of HHO over other metaheuristics in solving such a hard and complex optimization problem. Using the historical information of the last 20 days, our method has achieved 99% accuracy in predicting the market index of the next 7 days while PSO, MVO, GSA, IPO, linear regression and fine-tuned SVR has achieved 67%, 98%, 38%, 4%, 5.6% and 98 % accuracy respectively.Conclusionin this research we have tried to forecast the market index of the next m (from 1 to 7) days using the historical data of the past n (from 10 to 100) days. The experiments showed that increasing the number of days (n), used to create the dataset, will not necessarily improve the performance of the method.Keywords: Tehran Stock Market, Harris Hawks Optimization (HHO), Support Vector Regression (SVR), APSO-Clustering, Metaheuristics
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از منظر تنوع زیستی، جزایر مرجانی مانند جنگل های استوایی، متنوع ترین اکوسیستم های جهان و شاخصی از سلامت اکوسیستم محسوب می شوند اما اکثر این جزایر به دلیل تحولات توریستی و نیز تاثیرات تغییر آب وهوا رو به نابودی اند.توانایی شناسایی و ارزیابی سلامت مرجان ها با استفاده از تصاویر ماهواره ای شیوه ای مقرون به صرفه و موثر است. با توجه به اثرگذاری دمای سطح آب بر روی سلامت و توزیع رجان ها، با استفاده از الگوریتم هایی به رابطه ی بین آن ها و سلامت مرجان های منطقه مورد مطالعه که در این مقاله جزیره مرجانی هرون استرالیا می باشد، پرداخته شده است. در این مطالعه با استفاده از تصاویر لندست-8 و به دست آوردن بازتابش باندها، ویژگی ها و شاخص های طیفی مهم مرتبط با آب و صخره های مرجانی مانند: NDVI, NDWI, FAI, AWEI, SWI,MNDWI,GRVI توسط محققین و با استفاده از روش رگرسیون بردار پشتیبان (SVR) و بدست آوردن پارامترهای کرنل آن، به مدل سازی وضعیت سلامت صخره های مرجانی پرداخته شده است. در این مقاله از الگوریتم های تکاملی مثل الگوریتم ژنتیک (GA) و الگوریتم انتخاب ویژگی ترتیبی جلویی(SFS) برای رسیدن به انتخاب ویژگی مطلوب و مدل سازی بهینه و طبقه بندی سلامت مرجان ها استفاده شده است.در این مقاله با استفاده از روش رگرسیون بردار پشتیبان در حالت کلی به 0.591RMSE= و0.979=R2 رسیدیم و در حالت پیشنهادی(GA-SVR) به 0.53RMSE= و0.983 =R2 رسیدیم که بیانگر عملکرد خوب این مدل بهینه می-باشد.کلید واژگان: شاخص های طیفی، وضعیت سلامت، SVR، جزیره هرون استرالیا، تصاویر لندست-8، انتخاب ویژگیCoral reef communities face unprecedented pressures at local, regional and global scales as a consequence of climate change and anthropogenic disturbance. Remote sensing, from satellites or aircraft, is possibly the only means to measure the effects of such stresses at appropriately large spatial scales. Coral reefs are indicators of environmental, climate and sea surface change which shows the reefs damages. For this purpose, an algorithm that includes relation between those variables was used. Australia’s Heron reef island is considered to be studied. In order to modeling the coral reef health condition by support vector regression (SVR), water and coral important spectral indexes and features was found using landsat-8. From this method, the SVR is achieved the high performance for modeling the statistical problem .In this study we used genetic algorithm (GA) and sequential feature selection (SFS) for selecting suitable features in order to estimate model. The results for the testing data in this area of best model is [RMSE= 0.53 and R² =0.983] that show the high SVR performance.Keywords: Coral reef, Heron reef island, support vector regression (SVR) , spectral indexes, genetic algorithm, landsat-8
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پیش بینی دقیق نیاز مصرف شبکه برق ماهانه می تواند در برنامه ریزی انرژی موثر باشد و مدیریت صحیح تر مصرف برق را امکان پذیر کند. نیاز مصرف برق ماهانه نشان دهنده گرایش فصلی پیچیده و غیرخطی است یکی از مدل هایی که به طور گسترده برای پیش بینی سری های زمانی غیرخطی استفاده می شود، رگرسیون بردار پشتیبان (SVR) است که در آن باید انتخاب پارامترهای کلیدی و تاثیر تغییرات فصلی درنظر گرفته شود؛ بنابراین ضروری است پارامترهای مدل رگرسیون بردار پشتیبان به صورت مناسب انتخاب شوند و گرایش های غیرخطی و فصلی داده های نیاز مصرف برق تعدیل شوند. روشی که در پژوهش حاضر پیشنهاد می شود، پیوندزدن مدل رگرسیون بردار پشتیبان (SVR) با الگوریتم بهینه سازی مگس میوه (FOA) و تنظیم شاخص فصلی برای پیش بینی نیاز مصرف برق ماهانه است. علاوه براین، به منظور ارزیابی جامع عملکرد پیش بینی مدل ترکیبی، نمونه ای کوچک از نیاز مصرف برق ماهانه ایران و نمونه بزرگی از تولید برق ماهانه ایران برای نشان دادن عملکرد پیش بینی بررسی شده است. همچنین در این پژوهش برتری «مدل ترکیبی رگرسیون بردار پشتیبان با الگوریتم بهینه سازی مگس میوه با تعدیل گرایش های فصلی (SFOASVR)» در مقایسه با سایر مدل های شناخته شده پیش بینی از نظر دقت پیش بینی و کم بودن خطای پیش بینی بررسی شده است. برای این منظور معیارهای ارزیابی ریشه میانگین مربعات خطا (RMSE) و میانگین درصد خطای مطلق (MAPE)، همچنین آزمون ناپارامتری ویلکاکسون صورت می گیرد. براساس نتایج، مدل SFOASVR از سایر مدل های پیش بینی خطای کمتری دارد و درنتیجه گزینه ای مناسب برای کاربردهای پیش بینی نیاز مصرف برق است.کلید واژگان: الگوریتم بهینه سازی مگس میوه (FOA)، تغییرات فصلی، پیش بینی، رگرسیون بردار پشتیبان (SVR)، نیاز مصرف شبکه برقAccurate monthly power demand network forecasting can help to plan the energy and it can handle the correct management of the power consumption. It has been found that the monthly electricity consumption demonstrates a complex nonlinear characteristic and has an obvious seasonal tendency. One of the models that is widely used to predict the nonlinear time series is the support vector regression model (SVR) in which the selection of key parameters and the effect of seasonal changes could be considered. The important issues in this research are to determine the parameters of the support vector regression model optimally, as well as the adjustment of the nonlinear and seasonal trends of the electricity data. The method that is proposed by this study is to hybrid the support vector regression model (SVR) with Fruit fly optimization Algorithm (FOA) and the seasonal index adjustment to forecast the monthly power demand. In addition, in order to evaluate the performance of the hybrid predictive model a small sample of the monthly power demand from Iran and a large sample of Iran monthly electricity production has been used to demonstrate the predictive model performance. This study also evaluates the superiority of the SFOASVR model to the other known predictive methods. In terms of the prediction accuracy, we used the evaluation criteria such as Root Mean Square Error (RMSE) and mean absolute percentage error (MAPE) as well as Wilcoxon's nonparametric statistical test. The results show that the SFOASVR model has less error than the other forecasting models and is superior to the most other models in terms of Wilcoxon test. Therefore, SFOASVR method is an appropriate option for prediction of the power demand.Keywords: Forecast, Power demand network, Seasonal changes, Support Vector Regression (SVR), Fruit fly Optimization Algorithm (FOA)
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تجدید ساختار در سیستم های قدرت سبب شده است که پیش بینی قیمت انرژی الکتریکی یکی از چالش های مهم در پیش روی شرکت کنندگان بازار برق باشد. پیش بینی دقیق قیمت انرژی الکتریکی می تواند به تولیدکنندگان و مصرف کنندگان کمک نماید تا تصمیم گیری بهتری به منظور افزایش سود خود داشته باشند. در این مقاله با استفاده از اطلاعات مربوط به قیمت و میزان مصرف انرژی در روزهای گذشته، قیمت انرژی الکتریکی برای 24 ساعت آینده پیش بینی می شود. الگوریتم هوشمند پیشنهادی از طریق سه مرحله مهم تحقق می یابد: 1- مرحله پیش پردازش، 2- مرحله انتخاب ویژگی و 3- مرحله پیش بینی. در ابتدا، سیگنال های قیمت مربوط به روزهای گذشته با استفاده از تبدیل موجک تجربی به مودهای مختلفی تجزیه می گردد. سپس در مرحله دوم، روش انتخاب ویژگی مبتنی بر اطلاعات متقابل به منظور بهبود عملکرد ماشین یادگیری بر روی داده های ورودی اعمال می گردد. در مرحله سوم، به منظور پیش بینی قیمت انرژی در ساعات روز پیشرو، رگرسیون بردار پشتیبان با استفاده از ویژگی های برتر انتخاب شده، آموزش داده می شود. عملکرد الگوریتم ارائه شده با استفاده از داده های واقعی مربوط به دو بازار برق (Pennsylvania New-Jersey Maryland (PJM و (Operador del Mercado Ibérico de Energía-Polo Español (OMEL مورد ارزیابی قرار می گیرد.کلید واژگان: پیش بینی قیمت، تبدیل موجک تجربی، رگرسیون بردار پشتیبان، انتخاب ویژگی، اطلاعات متقابلRestructuring in power systems has caused electricity price forecasting became one of the most important challenges facing electricity market participants. The precise electricity price forecasting helps both consumers and producers to make better decision in order to maximize their benefit. In this paper, the historical data of electricity price and energy consumption are utilized for prediction of electricity price for the next 24 hours. The proposed intelligent algorithm is realized through three main steps: 1- preprocessing step, 2- feature selection and 3- forecasting step. At first, the price signal is decomposed to different modes by using Empirical Wavelet Transform (EWT). Afterward, in the second step, the feature selection method based on mutual information is applied on input data to improve the performance of forecasting engine. In the third step, for day-ahead hourly electricity price forecasting, the Support Vector Regression (SVR) is trained by selected features. The performance of the proposed algorithm is evaluated using real data of two electricity markets i.e. Pennsylvania New-Jersey Maryland (PJM) and Operador del Mercado Ibérico de Energía-Polo Español (OMIE).Keywords: Price forecasting, empirical wavelet transform (EWT), support vector regression (SVR), feature selection, mutual information
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Remote sensing image analysis can be carried out at the per-pixel (hard) and sub-pixel (soft) scales. The former refers to the purity of image pixels, while the latter refers to the mixed spectra resulting from all objects composing of the image pixels. The spectral unmixing methods have been developed to decompose mixed spectra. Data-driven unmixing algorithms utilize the reference data called training samples and end-members. The performance of algorithms using training samples can be negatively affected by the curse of dimensionality. This problem is usually observed in the hyperspectral image classification, especially when a low number of training samples, compared to the large number of spectral bands of hyperspectral data, are available. An unmixing method that is not highly impressed by the curse of dimensionality is a promising option. Among all the methods used, Support Vector Machine (SVM) is a more robust algorithm used to overcome this problem. In this work, our aim is to evaluate the capability of a regression mode of SVM, namely Support Vector Regression (SVR), for the sub-pixel classification of alteration zones. As a case study, the Hyperion data for the Sarcheshmeh, Darrehzar, and Sereidun districts is used. The main classification steps rely on 20 field samples taken from the Darrehzar area divided into 12 and 8 samples for training and validation, respectively. The accuracy of the sub-pixel maps obtained demonstrate that SVR can be successfully applied in the curse of dimensional conditions, where the size of the training samples (12) is very low compared to the number of spectral bands (165).Keywords: Hydrothermal Alteration, Hyperspectral Remote Sensing, Soft Classification, Spectral Unmixing, Support Vector Regression (SVR)
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The tensile strength (TS) of rocks is an important parameter in the design of a variety of engineering structures such as the surface and underground mines, dam foundations, types of tunnels and excavations, and oil wells. In addition, the physical properties of a rock are intrinsic characteristics, which influence its mechanical behavior at a fundamental level. In this paper, a new approach combining the support vector regression (SVR) with a cultural algorithm (CA) is presented in order to predict TS of rocks from their physical properties. CA is used to determine the optimal value of the SVR controlling the parameters. A dataset including 29 data points was used in this study, in which 20 data points (70%) were considered for constructing the model and the remaining ones (9 data points) were used to evaluate the degree of accuracy and robustness. The results obtained show that the SVR optimized by the CA model can be successfully used to predict TS.Keywords: Tensile Strength (TS) of Rocks, Support Vector Regression (SVR), Cultural Algorithm (CA), Physical Properties
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هدف این پژوهش توصیف یک مدل جدید به نام ترکیب سیستم استنتاج نرو فازی تطبیقی و الگوریتم بهینه سازی ازدحام ذرات برای پیش بینی خوردگی کربن استیل تحت محیط های دریایی متفاوت میباشد. دیتاست استفاده شده برای این پژوهش شامل 5 پارامتر بنام های دما، اکسیژن حل شده، میزان شوری، pH، و پتانسیل اکسایش کاهش به عنوان متغیرهای ورودی سیستم و نرخ خوردگی بعنوان متغیر خروجی میباشد. در مدل هیبریدی، الگوریتم بهینه سازی ازدحام ذرات برای پیدا کردن پارامترهای بهینه سیستم استنتاج نرو فازی تطبیقی بکار گرفته شد تا قدرت عمومی سازی مدل را بهبود ببخشد. میزان کارایی مدل هیبریدی نسبت به نتایج ازمایشی با دو مدل بنام های ترکیب سیستم استنتاج نرو فازی تطبیقی- الگوریتم ژنتیک و مدل ماشین بردار رگرسیون مقایسه شدند. نتایج نشان داد که مدل پیشنهادی خطاهای پیش بینی کمتری نسبت به دو مدل دیگر دارد. در واقع مدل پیشنهادی یک مدل کاربردی و مناسب و قابل اعتماد برای پیش بینی خوردگی کربن استیل در محیط های دریایی متفاوت فراهم می اورد.
کلید واژگان: پیش بینی خوردگی، سیستم استنتاج نرو فازی تطبیقی، الگوریتم بهینه سازی ازدحام ذرات، ماشین بردار رگرسیون، کربن استیلThis research aims to describe a novel model, namely Hybrid Adaptive-Neuro Fuzzy Inference System-Particle Swarm Optimization (ANFIS-PSO), for predicting corrosion rate of 3C steel considering different marine environment factors. In the present research, five parameters (temperature, dissolved oxygen, salinity, pH, and oxidationreduction potential) were used as input variables, with corrosion rate being the only output variable. In the proposed hybrid ANFIS-PSO model, the PSO served as a tool to automatically search for and update optimal parameters for the ANFIS, so as to improve generalizability of the model. Eeffectiveness of the hybrid model was then compared those to two other models, namely Adaptive-Neuro Fuzzy Inference SystemGenetic Algorithm (ANFIS-GA) and Support Vector Regression (SVR) models, by evaluating their results against the same experimental data. The results showed that the proposed hybrid model tends to produce a lower prediction error than those of ANFIS-GA and SVR with the same training and testing datasets. Indeed, the hybrid ANFIS-PSO model provides engineers with an applicable and reliable tool to conduct real-time corrosion prediction of 3C steel considering different marine environment factors.
Keywords: corrosion prediction, Adaptive Neuro-Fuzzy Inference System (ANFIS), Particle Swarm Optimization (PSO), Support Vector Regression (SVR), steel -
International Journal of Optimization in Civil Engineering, Volume:5 Issue: 3, Summer 2015, PP 267 -282Displacements induced by earthquake can be very large and result in severe damage to earth and earth supported structures including embankment dams, road embankments, excavations and retaining walls. It is important, therefore, to be able to predict such displacements. In this paper, a new approach to prediction of earthquake induced displacements of slopes (EIDS) using hybrid support vector regression (SVR) with particle swarm optimization (PSO) is presented. The PSO is combined with the SVR for determining the optimal value of its user-defined parameters. The optimization implementation by the PSO significantly improves the generalization ability of the SVR. In this research, the input data for the EIDS prediction consist of values of geometrical and geotechnical input parameters. As an output, the model estimates the EIDS that can be modeled as a function approximation problem. A dataset that includes 45 data points was applied in current study, while 36 data points (80%) were used for constructing the model and the remainder data points (9 data points) were used for assessment of degree of accuracy and robustness. The results obtained show that the SVR-PSO model can be used successfully for prediction of the EIDS.Keywords: earthquake, support vector regression (SVR), particle swarm optimization (PSO), displacement, slope
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Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. In the current study, two newly developed models called Least Square Support Vector Regression (LSSVR) and Regression Tree (RT) are used. The LSSVR model is based on the constrained optimization method and applies structural risk minimization in order to yield a general optimized result. Also in the RT, data movement is based on laws discovered in the tree. Both models have been applied to the data in the Kashkan watershed. Variables include (a) recorded precipitation values in the Kashkan watershed stations, and (b) outlet discharge values of one and two previous days. Present discharge is considered as output of the two models. Following that, a sensitivity analysis has been carried out on the input features and less important features has been diminished so that both models have provided better prediction on the data. The final results of both models have been compared. It was found that the LSSVR model has better performance. Finally, the results present these models as a suitable models in river flow forecasting.Keywords: Streamflow forecast, artificial intelligence, support vector regression (SVR), Regression tree (RT), Kashkan watershed
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Iranian Journal of Science and Technology Transactions of Mechanical Engineering, Volume:36 Issue: 2, 2012, PP 193 -205Toward green educational building development, windows are important design elements as the source of natural lighting and heating in classrooms. The amount of natural lighting and net heating received by a classroom in a year depends on the school location, weather conditions, as well as the window orientation and size. Schools in Iran consume a considerable amount of energy which is mostly supplied using nonrenewable fossil fuel resources. This energy consumption can be reduced through a well-designed daylighting approach. In this paper, in order to investigate the effects of window characteristics on construction and operational costs of schools, by varying the Window-to-Wall Ratio (WWR) and window orientation, 288 daylighting scenarios are generated for a typical standard classroom in a warm-dry climatic zone in central Iran. The DOE-2 software is utilized to estimate annual gas and electric consumption, for the generated scenarios over a period of 50 years. Considering the operation and construction cost, the best window facing and optimal range of WWR in each orientation is determined for the studied standard classroom. The results of simulated daylighting scenarios are then used to train regression based Support Vector Machines (SVMs) in order to show the feasibility of applying the Support Vector Regression (SVR) as an artificial intelligent system. The obtained results show that SVR as an architectural assistant performs well and the SVR-based predictor can rapidly, easily and accurately predict the operational and construction cost of a classroom just by determining the window size and installation face.Keywords: Window characteristics, energy efficient window, daylighting, classrooms, green educational buildings, support vector regression (SVR)
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