Naser Shams Gharneh - Academia.edu (original) (raw)
Papers by Naser Shams Gharneh
Energy and Buildings, Feb 1, 2013
This paper presents a method to determine the optimum capacity of distributed generation technolo... more This paper presents a method to determine the optimum capacity of distributed generation technologies for buildings. The Combined Heat and Power (CHP) unit has both absorption and electric chiller for cooling loads, and a supplementary boiler for heating loads. The demand is uncertain in the model. The underlying uncertainty is modeled using probabilistic theory. In this method, the expected value of the objective function is evaluated using numerical approaches. A simulation based optimization method is presented which can estimate the cost of system operation and find the appropriate design by means of stochastic programming. The effect of minimum economic turn-down of the facilities is also discussed in this paper. The optimum capacity of distributed generation technologies has a great effect on the cost of the building. Therefore, the proposed method is applied for a hospital in Iran as a case study. The results show that the optimum capacities of CHP and absorption chiller decreases and the capacities of the electric chiller and boiler rise by an increase in demand uncertainty. In addition, the appropriate minimum economic turn-down of facilities has a considerable effect on the overall system cost.
Energy, 2012
ABSTRACT This paper presents a robust optimization method to determine the optimum capacity of di... more ABSTRACT This paper presents a robust optimization method to determine the optimum capacity of distributed generation technologies for buildings in the face of uncertain energy demand. The model presents capacity requirements of energy system that is almost optimal for different realizations of the uncertain demand. By adjusting the penalty and degree of solution robustness parameters, the trade-off between optimality and feasibility is analyzed. The optimization is carried out on three related criteria, economical, primary energy saving, and environmental performance as a multi-objective optimization.The optimum capacity of distributed generation technologies has a great effect on the performance indicators of the building. In order to show this effect, the proposed method is applied to a hospital in Iran as a case study. It is assumed that the Combined Heat and Power (CHP) unit has both absorption and electric chiller for cooling loads, and a supplementary boiler for heating loads. In addition to them, thermal storages and renewable technologies are an option. The results show that by taking into account more solution and model robustness, the capacities of CHP and absorption chiller are increasing until they reach to their respective capacities in the solution of high scenario, while the capacities of others are decreasing. Furthermore, recommended values for the penalty and degree of solution robustness parameters are presented.
The South African Journal of Industrial Engineering, 2011
This paper proposes a fuzzy forecasting problem to forecast the Alabama University enrolment data... more This paper proposes a fuzzy forecasting problem to forecast the Alabama University enrolment dataset. A novel simulated annealing heuristic algorithm is used to promote the accuracy of forecasting. The algorithm enjoys two new neighbourhood search operators called 'subtitle' and 'adjust'. A Taguchi method is also used as an optimisation technique to tune the different parameters and operators of the proposed model comprehensively. The experimental results show that the proposed model is more accurate than existing models.
State evaluation of universities is important for administrators to serve as a basis for performa... more State evaluation of universities is important for administrators to serve as a basis for performance monitoring, policy formulations and distribution of funds. In this paper, a formal methodology was proposed to build a rational basis for evaluation and ranking of Iranian state run universities. In the rst step, the entropy method from MCDM is applied and tested using real data from 47 state universities. Poor results of entropy led to the development of a new nonlinear programming formulation. This new model was then reduced to an interactive linear programming formulation in order to solve the problem. Real data is used to test and validate our methodology.
بيماري هلندي، بيماري شناخته شده اي در عرصه اقتصاد ميباشد. این بیماری يک مفهوم اقتصادي است که تل... more بيماري هلندي، بيماري شناخته شده اي در عرصه اقتصاد ميباشد. این بیماری يک مفهوم اقتصادي است که تلاش مي‌کند تا رابطه بين بهره برداري بي‌رويه از منابع طبيعي و رکود در بخش صنعت را توضيح دهد. به یاد می آورم چگونگی شکل گیری اندیشه نخست تالیف این کتاب را که لزوم توجه مجدد و ویژه به این مقوله را به علت تلاقی چندین مولفه در عرصه اقتصاد، سیاست گذاری نادرست، رکود اقتصادی تورمی، نوسانات شدید قیمت نفت و فقدان یک نگاه همه جانبه نگر و علمی به چالشهای مذکور و مشاهده شواهد بروز مجدد بیماری هلندی در اقتصاد ایران دو چندان می نمود. از نظر مولفین دليل توجه بسیار زیاد به پديده بيماري هلندي اين است که پس از پايان دوره رونق اقتصادي حاصل از درآمدهاي بادآورده نفتي، روند تعديل اقتصادي ايجاد شده در شرايط رونق صادراتي، در جهت معکوس عمل نميکند. گسترش مجدد بخش غيرنفتي و قابل تجارت در صورتي که بازار سرمايه و زير بناها تخريب شده باشند، با مشکل مواجه و ورود به بازارهاي صادراتي نيز مشکل خواهد بود، زيرا مابقي کشورها تا آن زمان، بازارهاي رها شده در دوران رونق را به تسخير خود درآوردهاند. کتاب مذکور، بیماری هلندی در اقتصاد ایران را از هشت منظر و نشانه (۱٫ بررسي ارتباط نرخ ارز واقعي و قيمت نفت؛ ۲٫ بررسي ارتباط نرخ ارز واقعي و قيمت کالاهاي قابل تجارت و غير قابل تجارت؛ ۳٫ بررسي ارتباط نرخ ارز واقعي و بهره وري نيروي کار و سرمايه در بخش هاي مختلف اقتصادي؛ ۴٫ بررسي ارتباط ارزش افزوده بخش هاي مختلف اقتصاد با ارزش افزوده بخش نفت؛ ۵٫ بررسي ارتباط قيمت نفت واقعي و توليد ناخالص داخلي؛ ۶٫ بررسي ارتباط قيمت نفت و واردات؛ ۷٫ بررسي ارتباط قيمت نفت و صادرات؛ ۸٫ بررسي ارتباط قيمت نفت و کسري بودجه دولت) مورد بررسي و تجزيه و تحليل قرار ميدهد و پس از طرح مدلهاي تحلیلی رياضي اين بيماري و اثبات بروز مجدد این بیماری در اقتصاد کشور، با استفاده از تهديدها، نقاط ضعف و اهداف پيش رو و بکارگيري استراتژي WT نسبت به ارائه چهار استراتژي اصلی به منظور برون رفت یا کاهش مشکلات ناشی از بیماری مذکور (۱٫ انضباط مالي، ۲٫ کاهش ارزش پول، ۳٫ رعايت عدالت بين النسلي و ۴٫ مديريت بهينه ذخائر ارزي) و چند استراتژی فرعی که به بهبود اين بيماري و توسعه اقتصادي کشور کمک مي‌کند؛ اقدام مينمايد. This research is looking for a conceptual understanding of Dutch Disease mechanism, its effects on important economic variables, proving it occurs, conscious response mechanism for minimizing that’s effect in IRAN economy. The results show after rising oil prices in 1999, the real effective exchange rate (REER) has been appreciated and it is cause of real currency appreciation, weakening of tradable sector particularly industry and consolidation of non-tradable sector particularly building. During this period we can see depreciation of domestic manufacturer’s competency, non oil GDP, non oil export share and appreciation of import and government deficit. The econometrics results show all independent variable (Oil price, Productivity index, Terms of trade and Government deficit) are highly significant determinants of real effective exchange rate (dependent variable) movements. In particular, a 10% rise of the international oil price brings about a real effective exchange rate appreciation of about 2.3%, an upturn in Iran productivity leads to a real appreciation of 4.7%, and an increase in budget deficit produces a real appreciation of 0.4%. A 10% increase in Iran relative prices of manufactures results in a real depreciation of 5.6%. All variables have the expected signs. This research has tried to control Dutch disease with five major strategies. A) Government respect to fiscal discipline to deal with the resource curse, currency instability, financial instability and cyclical policy. B) Currency deprecation with budget surpluses with avoiding governmental expansionary policies. C) Good banking system policy for loan. D) Intergenerational justice’s strategy. E) Oil Fund strategy.
In recent years, empirical literature used widely GARCH models to characterize crude oil price vo... more In recent years, empirical literature used widely GARCH models to characterize crude oil price volatility. Because this augmenting attention, six univariate GARCH models and two methods of estimation the parameters for forecasting oil price volatility are examined in this paper. Based on obtained results, the best method for forecasting crude oil price volatility of Brent market is determined. All the examined models in this paper belong to the univariate time series family. The four years out-of-sample volatility forecasts of the GARCH models are evaluated using the superior predictive ability test with more loss functions. The results show that GARCH (1,1) can outperform all of the other models for the crude oil price of Brent market across different loss functions. Four different measures are used to evaluate the forecasting accuracy of the models. Also two methods of estimation the parameters of GARCH models are compared for forecasting oil price volatility. The results suggest ...
Revista de Investigaciones Universidad del Quindío, 2021
This paper examines the relationship between the volume of transactions and macroeconomic variabl... more This paper examines the relationship between the volume of transactions and macroeconomic variables on the Tehran Stock Exchange. We are collect data for variables such as liquidity, inflation, exchange rate, the total value of imports and GDP for ten years period of 2009-2019. For analysis of data, have been used regression analytical method and ordinary least squares method (OLS) model. The results indicate that there are relationships between the macroeconomic variables of liquidity, inflation rate, and GDP with the volume of transactions. Therefore, the relationship between the volume of transactions with liquidity and GDP is positive and significant and with inflation is negative.
Journal of Industrial and Systems Engineering, 2017
The use of GARCH models to characterize crude oil price volatility is widely observed in the empi... more The use of GARCH models to characterize crude oil price volatility is widely observed in the empirical literature. In this paper the efficiency of six univariate GARCH models and two methods of estimation the parameters for forecasting oil price volatility are examined and the best method for forecasting crude oil price volatility of Brent market is determined. All the examined models in this paperbelong to the univariate time series family. This article investigates and compares the efficiency of volatility models for crude oil markets. The four years out-of-sample volatility forecasts of the GARCH models are evaluated using the superior predictive ability test with more loss function. The results find that GARCH (1,1) model can outperform all of the other models for the crude oil price of Brent market across different loss functions. Four different measures are used to evaluate the forecasting accuracy of the models. Then, two methods of estimation the parameters of GARCH models, ...
Water supply, 2020
Water management and preventing water shortage require accurate planning with attention to the im... more Water management and preventing water shortage require accurate planning with attention to the importance of urban water. The problems ahead include the increase in demand and reduction in water supply resources due to factors that cause uncertainties and the high cost of water supply infrastructures. Most studies in urban water management consider only a single criterion. However, in this research, two objective functions, namely cost minimization and per capita water consumption maximization, were used simultaneously. A portfolio approach based on the balance of water supply and demand was developed taking uncertainty into account. Then, the problem was solved using a hybrid robust–stochastic optimization approach. The results showed the selected supply augmentation and demand management options in each stage under dry, normal, and wet year scenarios.
Since the introduction of Fuzzy Time Series (FTS), many publications have appeared in the literat... more Since the introduction of Fuzzy Time Series (FTS), many publications have appeared in the literature to improve the performance of the basic model proposed by Song and Chissom. A significant challenge to use fuzzy time series in forecasting is the proper partitioning of the universe of discourse. It is well-known that partitioning the space affects the performance of FTS to a great extent. The main purpose of this paper is to propose a procedure based on Simulated Annealing (SA) to partition the space. This procedure is examined on the well-known data related to enrolments of University of Alabama. The results show that the proposed approach outperforms other publications in the literature.
Lecture Notes in Operations Research
Journal of Advanced Transportation
Public transport is amongst critical infrastructures in modern cities, especially megacities, hom... more Public transport is amongst critical infrastructures in modern cities, especially megacities, home to millions of people. The reliability of these systems is highly crucial for both citizens and service providers. If service providers overlook system reliability, a considerable amount of expenses will be wasted. Several factors such as vehicle failure, accident, lack of budget weather factors, and traffic congestion cause unreliability, among which vehicle failure plays a prominent role. The brake system is the most vulnerable and vital component of a public transportation bus. Brake reliability depends on driver’s expertise, component quality, passenger loading, line situation, etc. Driver’s expertise and components’ quality are the most important factors for brake system reliability. This study aims to implement a hybrid machine learning and optimization model to minimize the total investment and reliability-related costs in a bus rapid transit (BRT) system. A regression analysis ...
Mathematics
Companies always seek ways to make their professional employees stay with them to reduce extra re... more Companies always seek ways to make their professional employees stay with them to reduce extra recruiting and training costs. Predicting whether a particular employee may leave or not will help the company to make preventive decisions. Unlike physical systems, human resource problems cannot be described by a scientific-analytical formula. Therefore, machine learning approaches are the best tools for this aim. This paper presents a three-stage (pre-processing, processing, post-processing) framework for attrition prediction. An IBM HR dataset is chosen as the case study. Since there are several features in the dataset, the “max-out” feature selection method is proposed for dimension reduction in the pre-processing stage. This method is implemented for the IBM HR dataset. The coefficient of each feature in the logistic regression model shows the importance of the feature in attrition prediction. The results show improvement in the F1-score performance measure due to the “max-out” featu...
Management of Environmental Quality: An International Journal
PurposeTackling the challenges of water scarcity requires comprehensive management according to f... more PurposeTackling the challenges of water scarcity requires comprehensive management according to financial, environmental and social issues. This paper aims to develop a planning approach for systematic decision-making and pay attention to uncertainties in water demand management and supply investment.Design/methodology/approachThis study presents a multiobjective optimization model to manage water resources based on the balance of supply and demand. The objectives of the model include economic, social and environmental (sustainable development) factors. The model achieves an optimal urban water portfolio by using a scenario tree.FindingsThe mathematical goal programming (GP) in a multiobjective optimization model is applied and solved by the branch and bound method. The results indicate the selected supply augmentation and demand management options in each stage for 20 years according to the dry, normal and wetness year scenarios.Practical implicationsThis model is based on a real-w...
Physica A: Statistical Mechanics and its Applications
Energy and Buildings, Feb 1, 2013
This paper presents a method to determine the optimum capacity of distributed generation technolo... more This paper presents a method to determine the optimum capacity of distributed generation technologies for buildings. The Combined Heat and Power (CHP) unit has both absorption and electric chiller for cooling loads, and a supplementary boiler for heating loads. The demand is uncertain in the model. The underlying uncertainty is modeled using probabilistic theory. In this method, the expected value of the objective function is evaluated using numerical approaches. A simulation based optimization method is presented which can estimate the cost of system operation and find the appropriate design by means of stochastic programming. The effect of minimum economic turn-down of the facilities is also discussed in this paper. The optimum capacity of distributed generation technologies has a great effect on the cost of the building. Therefore, the proposed method is applied for a hospital in Iran as a case study. The results show that the optimum capacities of CHP and absorption chiller decreases and the capacities of the electric chiller and boiler rise by an increase in demand uncertainty. In addition, the appropriate minimum economic turn-down of facilities has a considerable effect on the overall system cost.
Energy, 2012
ABSTRACT This paper presents a robust optimization method to determine the optimum capacity of di... more ABSTRACT This paper presents a robust optimization method to determine the optimum capacity of distributed generation technologies for buildings in the face of uncertain energy demand. The model presents capacity requirements of energy system that is almost optimal for different realizations of the uncertain demand. By adjusting the penalty and degree of solution robustness parameters, the trade-off between optimality and feasibility is analyzed. The optimization is carried out on three related criteria, economical, primary energy saving, and environmental performance as a multi-objective optimization.The optimum capacity of distributed generation technologies has a great effect on the performance indicators of the building. In order to show this effect, the proposed method is applied to a hospital in Iran as a case study. It is assumed that the Combined Heat and Power (CHP) unit has both absorption and electric chiller for cooling loads, and a supplementary boiler for heating loads. In addition to them, thermal storages and renewable technologies are an option. The results show that by taking into account more solution and model robustness, the capacities of CHP and absorption chiller are increasing until they reach to their respective capacities in the solution of high scenario, while the capacities of others are decreasing. Furthermore, recommended values for the penalty and degree of solution robustness parameters are presented.
The South African Journal of Industrial Engineering, 2011
This paper proposes a fuzzy forecasting problem to forecast the Alabama University enrolment data... more This paper proposes a fuzzy forecasting problem to forecast the Alabama University enrolment dataset. A novel simulated annealing heuristic algorithm is used to promote the accuracy of forecasting. The algorithm enjoys two new neighbourhood search operators called 'subtitle' and 'adjust'. A Taguchi method is also used as an optimisation technique to tune the different parameters and operators of the proposed model comprehensively. The experimental results show that the proposed model is more accurate than existing models.
State evaluation of universities is important for administrators to serve as a basis for performa... more State evaluation of universities is important for administrators to serve as a basis for performance monitoring, policy formulations and distribution of funds. In this paper, a formal methodology was proposed to build a rational basis for evaluation and ranking of Iranian state run universities. In the rst step, the entropy method from MCDM is applied and tested using real data from 47 state universities. Poor results of entropy led to the development of a new nonlinear programming formulation. This new model was then reduced to an interactive linear programming formulation in order to solve the problem. Real data is used to test and validate our methodology.
بيماري هلندي، بيماري شناخته شده اي در عرصه اقتصاد ميباشد. این بیماری يک مفهوم اقتصادي است که تل... more بيماري هلندي، بيماري شناخته شده اي در عرصه اقتصاد ميباشد. این بیماری يک مفهوم اقتصادي است که تلاش مي‌کند تا رابطه بين بهره برداري بي‌رويه از منابع طبيعي و رکود در بخش صنعت را توضيح دهد. به یاد می آورم چگونگی شکل گیری اندیشه نخست تالیف این کتاب را که لزوم توجه مجدد و ویژه به این مقوله را به علت تلاقی چندین مولفه در عرصه اقتصاد، سیاست گذاری نادرست، رکود اقتصادی تورمی، نوسانات شدید قیمت نفت و فقدان یک نگاه همه جانبه نگر و علمی به چالشهای مذکور و مشاهده شواهد بروز مجدد بیماری هلندی در اقتصاد ایران دو چندان می نمود. از نظر مولفین دليل توجه بسیار زیاد به پديده بيماري هلندي اين است که پس از پايان دوره رونق اقتصادي حاصل از درآمدهاي بادآورده نفتي، روند تعديل اقتصادي ايجاد شده در شرايط رونق صادراتي، در جهت معکوس عمل نميکند. گسترش مجدد بخش غيرنفتي و قابل تجارت در صورتي که بازار سرمايه و زير بناها تخريب شده باشند، با مشکل مواجه و ورود به بازارهاي صادراتي نيز مشکل خواهد بود، زيرا مابقي کشورها تا آن زمان، بازارهاي رها شده در دوران رونق را به تسخير خود درآوردهاند. کتاب مذکور، بیماری هلندی در اقتصاد ایران را از هشت منظر و نشانه (۱٫ بررسي ارتباط نرخ ارز واقعي و قيمت نفت؛ ۲٫ بررسي ارتباط نرخ ارز واقعي و قيمت کالاهاي قابل تجارت و غير قابل تجارت؛ ۳٫ بررسي ارتباط نرخ ارز واقعي و بهره وري نيروي کار و سرمايه در بخش هاي مختلف اقتصادي؛ ۴٫ بررسي ارتباط ارزش افزوده بخش هاي مختلف اقتصاد با ارزش افزوده بخش نفت؛ ۵٫ بررسي ارتباط قيمت نفت واقعي و توليد ناخالص داخلي؛ ۶٫ بررسي ارتباط قيمت نفت و واردات؛ ۷٫ بررسي ارتباط قيمت نفت و صادرات؛ ۸٫ بررسي ارتباط قيمت نفت و کسري بودجه دولت) مورد بررسي و تجزيه و تحليل قرار ميدهد و پس از طرح مدلهاي تحلیلی رياضي اين بيماري و اثبات بروز مجدد این بیماری در اقتصاد کشور، با استفاده از تهديدها، نقاط ضعف و اهداف پيش رو و بکارگيري استراتژي WT نسبت به ارائه چهار استراتژي اصلی به منظور برون رفت یا کاهش مشکلات ناشی از بیماری مذکور (۱٫ انضباط مالي، ۲٫ کاهش ارزش پول، ۳٫ رعايت عدالت بين النسلي و ۴٫ مديريت بهينه ذخائر ارزي) و چند استراتژی فرعی که به بهبود اين بيماري و توسعه اقتصادي کشور کمک مي‌کند؛ اقدام مينمايد. This research is looking for a conceptual understanding of Dutch Disease mechanism, its effects on important economic variables, proving it occurs, conscious response mechanism for minimizing that’s effect in IRAN economy. The results show after rising oil prices in 1999, the real effective exchange rate (REER) has been appreciated and it is cause of real currency appreciation, weakening of tradable sector particularly industry and consolidation of non-tradable sector particularly building. During this period we can see depreciation of domestic manufacturer’s competency, non oil GDP, non oil export share and appreciation of import and government deficit. The econometrics results show all independent variable (Oil price, Productivity index, Terms of trade and Government deficit) are highly significant determinants of real effective exchange rate (dependent variable) movements. In particular, a 10% rise of the international oil price brings about a real effective exchange rate appreciation of about 2.3%, an upturn in Iran productivity leads to a real appreciation of 4.7%, and an increase in budget deficit produces a real appreciation of 0.4%. A 10% increase in Iran relative prices of manufactures results in a real depreciation of 5.6%. All variables have the expected signs. This research has tried to control Dutch disease with five major strategies. A) Government respect to fiscal discipline to deal with the resource curse, currency instability, financial instability and cyclical policy. B) Currency deprecation with budget surpluses with avoiding governmental expansionary policies. C) Good banking system policy for loan. D) Intergenerational justice’s strategy. E) Oil Fund strategy.
In recent years, empirical literature used widely GARCH models to characterize crude oil price vo... more In recent years, empirical literature used widely GARCH models to characterize crude oil price volatility. Because this augmenting attention, six univariate GARCH models and two methods of estimation the parameters for forecasting oil price volatility are examined in this paper. Based on obtained results, the best method for forecasting crude oil price volatility of Brent market is determined. All the examined models in this paper belong to the univariate time series family. The four years out-of-sample volatility forecasts of the GARCH models are evaluated using the superior predictive ability test with more loss functions. The results show that GARCH (1,1) can outperform all of the other models for the crude oil price of Brent market across different loss functions. Four different measures are used to evaluate the forecasting accuracy of the models. Also two methods of estimation the parameters of GARCH models are compared for forecasting oil price volatility. The results suggest ...
Revista de Investigaciones Universidad del Quindío, 2021
This paper examines the relationship between the volume of transactions and macroeconomic variabl... more This paper examines the relationship between the volume of transactions and macroeconomic variables on the Tehran Stock Exchange. We are collect data for variables such as liquidity, inflation, exchange rate, the total value of imports and GDP for ten years period of 2009-2019. For analysis of data, have been used regression analytical method and ordinary least squares method (OLS) model. The results indicate that there are relationships between the macroeconomic variables of liquidity, inflation rate, and GDP with the volume of transactions. Therefore, the relationship between the volume of transactions with liquidity and GDP is positive and significant and with inflation is negative.
Journal of Industrial and Systems Engineering, 2017
The use of GARCH models to characterize crude oil price volatility is widely observed in the empi... more The use of GARCH models to characterize crude oil price volatility is widely observed in the empirical literature. In this paper the efficiency of six univariate GARCH models and two methods of estimation the parameters for forecasting oil price volatility are examined and the best method for forecasting crude oil price volatility of Brent market is determined. All the examined models in this paperbelong to the univariate time series family. This article investigates and compares the efficiency of volatility models for crude oil markets. The four years out-of-sample volatility forecasts of the GARCH models are evaluated using the superior predictive ability test with more loss function. The results find that GARCH (1,1) model can outperform all of the other models for the crude oil price of Brent market across different loss functions. Four different measures are used to evaluate the forecasting accuracy of the models. Then, two methods of estimation the parameters of GARCH models, ...
Water supply, 2020
Water management and preventing water shortage require accurate planning with attention to the im... more Water management and preventing water shortage require accurate planning with attention to the importance of urban water. The problems ahead include the increase in demand and reduction in water supply resources due to factors that cause uncertainties and the high cost of water supply infrastructures. Most studies in urban water management consider only a single criterion. However, in this research, two objective functions, namely cost minimization and per capita water consumption maximization, were used simultaneously. A portfolio approach based on the balance of water supply and demand was developed taking uncertainty into account. Then, the problem was solved using a hybrid robust–stochastic optimization approach. The results showed the selected supply augmentation and demand management options in each stage under dry, normal, and wet year scenarios.
Since the introduction of Fuzzy Time Series (FTS), many publications have appeared in the literat... more Since the introduction of Fuzzy Time Series (FTS), many publications have appeared in the literature to improve the performance of the basic model proposed by Song and Chissom. A significant challenge to use fuzzy time series in forecasting is the proper partitioning of the universe of discourse. It is well-known that partitioning the space affects the performance of FTS to a great extent. The main purpose of this paper is to propose a procedure based on Simulated Annealing (SA) to partition the space. This procedure is examined on the well-known data related to enrolments of University of Alabama. The results show that the proposed approach outperforms other publications in the literature.
Lecture Notes in Operations Research
Journal of Advanced Transportation
Public transport is amongst critical infrastructures in modern cities, especially megacities, hom... more Public transport is amongst critical infrastructures in modern cities, especially megacities, home to millions of people. The reliability of these systems is highly crucial for both citizens and service providers. If service providers overlook system reliability, a considerable amount of expenses will be wasted. Several factors such as vehicle failure, accident, lack of budget weather factors, and traffic congestion cause unreliability, among which vehicle failure plays a prominent role. The brake system is the most vulnerable and vital component of a public transportation bus. Brake reliability depends on driver’s expertise, component quality, passenger loading, line situation, etc. Driver’s expertise and components’ quality are the most important factors for brake system reliability. This study aims to implement a hybrid machine learning and optimization model to minimize the total investment and reliability-related costs in a bus rapid transit (BRT) system. A regression analysis ...
Mathematics
Companies always seek ways to make their professional employees stay with them to reduce extra re... more Companies always seek ways to make their professional employees stay with them to reduce extra recruiting and training costs. Predicting whether a particular employee may leave or not will help the company to make preventive decisions. Unlike physical systems, human resource problems cannot be described by a scientific-analytical formula. Therefore, machine learning approaches are the best tools for this aim. This paper presents a three-stage (pre-processing, processing, post-processing) framework for attrition prediction. An IBM HR dataset is chosen as the case study. Since there are several features in the dataset, the “max-out” feature selection method is proposed for dimension reduction in the pre-processing stage. This method is implemented for the IBM HR dataset. The coefficient of each feature in the logistic regression model shows the importance of the feature in attrition prediction. The results show improvement in the F1-score performance measure due to the “max-out” featu...
Management of Environmental Quality: An International Journal
PurposeTackling the challenges of water scarcity requires comprehensive management according to f... more PurposeTackling the challenges of water scarcity requires comprehensive management according to financial, environmental and social issues. This paper aims to develop a planning approach for systematic decision-making and pay attention to uncertainties in water demand management and supply investment.Design/methodology/approachThis study presents a multiobjective optimization model to manage water resources based on the balance of supply and demand. The objectives of the model include economic, social and environmental (sustainable development) factors. The model achieves an optimal urban water portfolio by using a scenario tree.FindingsThe mathematical goal programming (GP) in a multiobjective optimization model is applied and solved by the branch and bound method. The results indicate the selected supply augmentation and demand management options in each stage for 20 years according to the dry, normal and wetness year scenarios.Practical implicationsThis model is based on a real-w...
Physica A: Statistical Mechanics and its Applications
To fulfill a project, there are varieties of organizations cooperating as a supply chain. Being i... more To fulfill a project, there are varieties of organizations cooperating as a supply chain. Being in large numbers and diversity, the supply chain may result in complexity and uncertainty in managing the projects; although it provides the required resources to achieve project objectives. The more a project faces complexity, the higher attention is required to effective management of its inter-organizational relationship model. In the following study, the structure of relations between organizations in two Iranian petrochemical projects is studied and compared. Modeling methods and analysis are based on Social Network Analysis (SNA). After modeling the network structure of each project, the inter-organizational relationships model are analyzed and compared to the ideal model of Iranian National Petrochemical Company (NPC) and the results are presented. Finally some areas for further research are also discussed.