Thermal Comfort
Abdullah. N. Olimat; Ahmed Al-Salaymeh; Ayman Al-Maaitah
Abstract
Experimental analysis of thermal properties of phase change material was conducted using DCS and TG apparatus. Moderate rang of temperature of phase change material was selected and experimentally investigated. Measurement of melting and solidification temperature at several heating rate are carried ...
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Experimental analysis of thermal properties of phase change material was conducted using DCS and TG apparatus. Moderate rang of temperature of phase change material was selected and experimentally investigated. Measurement of melting and solidification temperature at several heating rate are carried out. Furthermore, the stability and thermal decomposition of the selected phase change material are also investigated. Experiment demonstrates clearly the phase change material effect in melting and solidification. The lab test with DSC and TG proves that the catalogue data of the Plus ICE H190 PCM is reasonable to be used for thermal storage devices with great deal of consistency. In general, results showed that the utilization of phase change material in thermal storage is feasible to store and extract heat at constant temperature in the range between 170oC to 200oC which has many applications in engineering and industry.
Elaheh Maghsoudi; Hadi Shirouyehzad; Arash Shahin
Volume 2, Issue 3 , September 2015, , Pages 195-203
Abstract
Uncertainly and change in the business environment has been a major topic in conducting research for long time. It seems that to recognize and classify the factors affecting organizational agility, need to specify the amount of their importance, because of knowing agility helps managers for better performance ...
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Uncertainly and change in the business environment has been a major topic in conducting research for long time. It seems that to recognize and classify the factors affecting organizational agility, need to specify the amount of their importance, because of knowing agility helps managers for better performance and success of their company. The purpose of this research is assessment and priority of drivers and capabilities agility that influence in performance of project based organization. The research data are collected through questionnaire and the research methodology is based on Topsis technique. Result of the study shows that between agility capabilities competency and between agility drivers change in competition basis have the most influence in performance of the organization.
Decision analysis and methods
Elham Ebrahimi; Mohammad Reza Fathi; Seyed Mohammad Sobhani
Abstract
Multiple criteria decision-making (MCDM) is well known nowadays as a methodology in which a set of techniques are integrated to evaluate a set of alternatives with specified criteria for the purpose of selecting or ranking. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is ...
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Multiple criteria decision-making (MCDM) is well known nowadays as a methodology in which a set of techniques are integrated to evaluate a set of alternatives with specified criteria for the purpose of selecting or ranking. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is well-established methodology frequently considered in MCDM analyses. TOPSIS has a sound logic that represents the rationale of human choice and is a scalar value simultaneously taking into account both the best and worst alternatives. Moreover, it has a simple computation process that could be easily programmed and finally it has the ability to rank alternatives on attributes to be visualized on a polyhedron, in at least two dimensions. Despite the advantages of this method, the process of ranking alternative according to related criteria may need more consideration. Typically, there are contributions in this article. First, a new similarity measure has been introduced followed by a modification applied to TOPSIS analyses. Second, the modified similarity technique was subsequently extended in the fuzzy context to cope with the uncertainty inherently existing in human judgments. A numerical example of the personnel selection was presented to demonstrate the possible application of the proposed method in human resource management. The outcome of applying fuzzy similarity method showed a significant distinction in ranking alternatives compered to TOPSIS method. Therefore, the modification is sound to be a proper solution.
Ganjar Sidik Gandara; Riko Muri; Humiras Hardi Purba
Abstract
The purpose of this research is to make the right design in improving the service of selling formaldehyde products in the Chemical Industry according to customer requirements by implementing Quality Function Deployment. Complying on customer satisfaction is important in the competitive global market, ...
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The purpose of this research is to make the right design in improving the service of selling formaldehyde products in the Chemical Industry according to customer requirements by implementing Quality Function Deployment. Complying on customer satisfaction is important in the competitive global market, which can be realized by innovation and quality fulfillment. Innovation and quality are not only about fulfilling product specifications, but also whether the product is marketable. Furthermore, as the show of average sales formaldehyde product in the last 3 years is 71.6% of a target whereas the formaldehyde market share is very large. It is important to develop sales services of products to meet customer needs. Quality Function Deployment (QFD) is a tool that can translate the customer needs to obtain a technical response in complying with the customer’s satisfaction. Method of this research uses customer satisfaction survey form, the data was collected through a field survey with questionnaires. The market survey generates 9 critical points of the services in selling products. House of quality (HOQ) was developed and analyzed to describe the relationship between customer expectations and technical responses. The overall analysis suggests three priorities of technical responses of a design concept to take into account in the service development. Priority as an action plan is additional hunting line for customer - Marketing and Sales (23%), provide schedule regular meeting with customer - include related department (15%), and shipment schedule to increase On-Time Delivery (OTD) from 80% to 95% through collaborating with external transportation company (14%). Finally, Quality Function Deployment (QFD) is implementing for increasing sales formaldehyde products through customer satisfaction.
Fuzzy optimization
Hamiden Abdelwahed Khalifa
Abstract
In this paper, a Multi-Criteria De Novo Linear Programming (F- MDNLP) problem has been developed under consideration of the ambiguity of parameters. These fuzzy parameters are characterized by fuzzy numbers. A fuzzy goal programming approach is applied for the corresponding multi-criteria De Novo linear ...
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In this paper, a Multi-Criteria De Novo Linear Programming (F- MDNLP) problem has been developed under consideration of the ambiguity of parameters. These fuzzy parameters are characterized by fuzzy numbers. A fuzzy goal programming approach is applied for the corresponding multi-criteria De Novo linear programming (MDNLP) problem by defining suitable membership functions and aspiration levels. The advantage of the approach is that the decision maker's role is only the specification of the level and hence evaluate the efficient solution for limitation of his/ her incomplete knowledge about the problem domain. A numerical example is given for illustration.
Hadi Shirouyehzad; Seyyedeh Athar Mousavirad; Seyed Mojtaba Sajadi
Volume 1, Issue 4 , October 2014, , Pages 259-270
Abstract
Timetabling is one of the most difficult issues in the world; this is a combinatory optimization issue and it has been proven that it is a NP-Hard issue.University Courses Timetabling is very important especially for the exams and courses. The manual solving of the Timetabling needs a broad domain of ...
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Timetabling is one of the most difficult issues in the world; this is a combinatory optimization issue and it has been proven that it is a NP-Hard issue.University Courses Timetabling is very important especially for the exams and courses. The manual solving of the Timetabling needs a broad domain of sources and time to create an applicable schedule with minimum interference in the curriculum and Professor's program is not easy. Different mathematical models and algorithms have been presented for this issue but each strategy considers different limitations according to its environment and factors. Timetabling is different for different university courses Timetabling. In this study a new multi objective mathematical model with new objective functions and new constrains has been presented for university courses timetabling. The present study tries to consider most restrictions for a training center. Finally the validity of the proposed model has been surveyed by a small numerical example and its solving by LINGO11 software shows that this model can satisfy all goals and limitations.
Heuristics and Metaheuristics Algorithms
Hadi Roshan; Masoumeh Afsharinezhad
Abstract
Data analytics allows companies mining the patterns and trends in their customers data to implement more effective market segmentation strategies, then customize promotional offers, allocate marketing resources efficiently, and improve customer relationship management. However the implementation of such ...
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Data analytics allows companies mining the patterns and trends in their customers data to implement more effective market segmentation strategies, then customize promotional offers, allocate marketing resources efficiently, and improve customer relationship management. However the implementation of such strategies often hampered by limited budgets and the ever-changing priorities and goals of marketing campaigns. So, This paper suggests and demonstrates the novel approach dividing a broad target market into subsets of consumers who have common needs, interests, and priorities, and then designing and implementing strategies to target them to achieve profit maximization. Therefore, the aims of this study are twofold, first, is to use historical data (such as purchased items and the associative monetary expenses), the proposed model identifies customer segments based on Firefly Algorithm (FA). Second, is the identification of the most profitable segment according to the RFM model (recency, frequency and monetary). In this article real marketing data are used to illustrate the proposed approach.
Hamidreza Panjehfouladgaran; Nima Bahiraie
Volume 1, Issue 5 , December 2014, , Pages 320-328
Abstract
Environmental issues and globalization pushed companies to be more environmentally conscious and socially responsible. Recently, term of sustainability has been extended in various aspects like manufacturing processes to respond to mentioned concern. Moreover, numerous industries and companies applied ...
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Environmental issues and globalization pushed companies to be more environmentally conscious and socially responsible. Recently, term of sustainability has been extended in various aspects like manufacturing processes to respond to mentioned concern. Moreover, numerous industries and companies applied sustainable supply chain to achieve more advantageous economically as well as environmentally. Many factors exist, that play significant role in SSCM strategies implementation. These critical success factors receive more attention from various angles of management in recent years and help managers to increase competitive advantage and reach to the company’s goals. Identification and investigation of CSFs in SSCM is so important to realize the sustainability. Some of these factors are common between two dimensions and some of them are mutual among all three main dimensions in triple line bottom in sustainability. In this paper, related literature around critical success factors in supply chain is explained and some of the factors are introduced. Then role of interaction between critical success factors and sustainability criteria are discussed.
Engineering Optimization
Suresh Aluvihara; Jagath K. Premachandra
Abstract
Crude oil is an energy resource that mostly composed with hydrocarbons and trace corrosive compounds as well found some cruxes in the petroleum refining industry because of the vast applications of the different types of metals. There were expected to investigate the effect of two different types of ...
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Crude oil is an energy resource that mostly composed with hydrocarbons and trace corrosive compounds as well found some cruxes in the petroleum refining industry because of the vast applications of the different types of metals. There were expected to investigate the effect of two different types of crude oils on the corrosion of seven types of selected ferrous metals in the pertinent research. The concerned corrosive properties of both crude oils were tested by standard methods and instruments also the chemical compositions of selected ferrous metals were tested. The corrosion rates of a series of similar size prepared metal coupons were tested after limited immersion time periods as three trials in crude oils by the weight loss method since aiding the microscopic analysis to identify the corrosion compounds. Apart from those speculations the decayed metallic elemental mounts from the metals into crude oils and the reductions of the initial hardness of metal coupons were tested. The obligatory results showed the relatively higher corrosion rates from carbon steels, relatively lower corrosion rates from stainless steels in both crude oils, formation of FeS in most of observations, decay of ferrous and copper into crude oils from some metals and slight reductions of the initial hardness of metal coupons due to the formation of the corrosion on the metal surfaces.
Reza Darvishinia; Hossein Ebrahimzadeh Shermeh; Samira Barzkar
Abstract
The present study aims at suggesting a model for intelligent investment, through enabling us to be Autoregressive Integrated Moving Average of ARIMA and seasonal coefficient. In this study, the researcher uses seasonal fluctuation Model. The previous trend of time series, related to the companies for ...
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The present study aims at suggesting a model for intelligent investment, through enabling us to be Autoregressive Integrated Moving Average of ARIMA and seasonal coefficient. In this study, the researcher uses seasonal fluctuation Model. The previous trend of time series, related to the companies for a period of 11 years, from 2006 to 2017, was carried out based on seasonal data. Then the researcher predicted the final price based on moving average method. In the next stage, the proportion of real final price and predicted the final price is calculated regarding each period. Then, the seasonal coefficient average is calculated for similar seasons. In the final stage, the value of a prediction, for a given period, is calculated when moving average method is multiplied by a seasonal coefficient average. As a result, seasonal coefficient of a given stock is derived.
Data Envelopment Analysis, DEA
Reza Fallahnejad; Sanaz Asadi Rahmati; Kayvan Moradipour
Abstract
To evaluate the performance and estimate the efficiency of Decision-Making Units (DMUs) in Data Envelopment Analysis (DEA), the available data are used. These data are usually divided into two categories of inputs and outputs based on their natures. If the price data is also available for inputs, it ...
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To evaluate the performance and estimate the efficiency of Decision-Making Units (DMUs) in Data Envelopment Analysis (DEA), the available data are used. These data are usually divided into two categories of inputs and outputs based on their natures. If the price data is also available for inputs, it is necessary to calculate another type of the efficiency called Cost Efficiency (CE). Since the efficiency of units in such a framework is depended on the both quantities of inputs and outputs and also the prices of inputs, it is important to find the sources of cost inefficiency related to each of the factors and plans to address them. In this paper, we intend to present a new decomposition of CE and observed cost versus optimal cost, which are raised from each of the factors involved in the cost inefficiency, in a non-competitive pricing environment which the input price vector for different DMUs can be different. Moreover, for the first time, in parallel with using the PPS based on input and output quantities and introducing some cost inefficiency factors related to this set, we will introduce new sets called price and cost production sets that the first is based on the prices of inputs and output factors, and the second is based on the optimal vectors of inputs and prices obtained from two previous PPS, and then we will introduce other factors of cost inefficiency in the sets. Accordingly, new decomposition for cost inefficiencies will be presented. Also, in the previous analyzes, congestion inefficiency has not been considered as one of the important factors in cost inefficiency. In this study, we also intend to consider the impact of this factor on CE.
Case studies in industry and services
Robert S Keyser; Parisa Pooyan
Abstract
In a lean production environment, reduced setup times can lead to many benefits, including reduced lead times. Previous research has primarily relied on the SMED methodology and mathematical modeling to reduce setup times at machine centers – and both are very useful techniques. We use the Soft ...
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In a lean production environment, reduced setup times can lead to many benefits, including reduced lead times. Previous research has primarily relied on the SMED methodology and mathematical modeling to reduce setup times at machine centers – and both are very useful techniques. We use the Soft Systems Methodology, combined with the Seven Tools of Quality, to provide a structured, illustrative means for diagnosing production and quality issues. A baseline average setup time was established by which future setup times would be compared. The intervention included brainstorming sessions between management and the converting center work crew that disclosed many reasons for increased setup times, some of which were under management’s control. Our findings resulted in a 24% reduction in average setup times and a 62% reduction in the moving range at a bottleneck machine center in the corrugated box industry.
Data Envelopment Analysis, DEA
Mahnaz Maghbouli; Fatemeh Moradi
Abstract
Emotional Intelligence (EQ) is considered as an alternative issue in both fields of psychology and education. Studies that have been conducted in this area illustrate the role of EQ and its components in different aspects of one's life such as academic achievement, occupation, and social relationships. ...
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Emotional Intelligence (EQ) is considered as an alternative issue in both fields of psychology and education. Studies that have been conducted in this area illustrate the role of EQ and its components in different aspects of one's life such as academic achievement, occupation, and social relationships. Turning to a view to academic performance measurement, mathematics is considered as a science which can promote the learners' ability in order to respond to the ups and downs of every individual’s life. Most of the previous papers have investigated the relationship between EQ and mathematical Performance. The main feature of those studies were focusing on statistical analysis. To deal with this issue, this study proposes an alternative procedure not only is interested in employing non parametric models, such as Data Envelopment Analysis (DEA), but also provides the statistical analysis to assess the questioned relation. The proposed procedure can serve as an evaluation tool for educational policy and students ‘promotion. To do so, eighty-one individuals have been selected among Islamic Azad University (Yadegar-e-Imam Khomeini (RAH) branch) engineering students with simple random during the first midterm of academic year 2019-2020. Distributing a standard EQ questionnaire of Bradberry and Greaves [18] reveals EQ and its four components’ scores. The average of three completed math scores have presented mathematical performance quantity. The results of DEA point out no specific pattern between EQ and mathematical performance. The study also reveals that statistical analysis show a similar trend as efficiency analysis method did.
Hadi Shirouyehzad; Mohammad Mehdi Tavakoli; Mostafa Badakhshian
Volume 3, 1(4) , December 2016, , Pages 49-57
Abstract
One of the most important issues in modern societies is to provide better services and evaluation of provided services. Service organizations are always looking to increase their level of customer satisfaction. In this context, Service quality and service quality gaps analysis are taken into account. ...
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One of the most important issues in modern societies is to provide better services and evaluation of provided services. Service organizations are always looking to increase their level of customer satisfaction. In this context, Service quality and service quality gaps analysis are taken into account. In this paper a method developed for ranking service organization based on the services quality approach and multi attribute decision making tools. In this method, options are organizations and the indicators are service quality gaps. However, other than gaps the perception of service quality is considered as a separate indicator. The weight of indicators are calculated by paired comparisons tools and experts panel results. Linear assignment method is used to rank the options. The developed method is used to rank seven hotels in city of Isfahan. The results show that the implemented method ranked the Abbasi hotel as first and Kosar hotel as last in the ranking.
Risk management
Hadi Faghihmaleki
Abstract
If in the event of a critical incident, by eliminating a structural element, a comprehensive damage occurs, such a phenomenon is called progressive collapse. At the moment of explosion, redistribute the carried load by members of damaged structural element or the adjacent members may Lead to excessive ...
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If in the event of a critical incident, by eliminating a structural element, a comprehensive damage occurs, such a phenomenon is called progressive collapse. At the moment of explosion, redistribute the carried load by members of damaged structural element or the adjacent members may Lead to excessive tension or exceed the load capacity of the other members of that damage is the result of diffusion. To study the phenomenon of progressive collapse and structural robustness index under blast loading, four types of structures with RC moment frame with shear walls in four, seven, twelve, and fourteen story level, which all of them have the same plan, have been considered. In the above-mentioned buildings, Some structural elements have been removed and the impact of these scenarios on the dynamic behavior of structures during the explosion has been examined. In this study, the potential and capacity structures against the progressive collapse and the failure modes using local dynamic analysis of the explosion has been determined. Also, robustness structural Index has been evaluated. So the analysis to find the most likely failure mode for development improvement purposes, it is possible that could result in structures with higher reliability in a seismic zone.
Decision analysis and methods
Ali Montazeri; Javid Jouzdani
Abstract
Understanding financial literacy and knowing the financial skills that an investor can invest in Tehran Stock Exchange are very important in order to reduce investor's concerns and worries. Hence, investment companies that invest on behalf of their stockholders can reduce these concerns and worries. ...
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Understanding financial literacy and knowing the financial skills that an investor can invest in Tehran Stock Exchange are very important in order to reduce investor's concerns and worries. Hence, investment companies that invest on behalf of their stockholders can reduce these concerns and worries. Therefore, the advertising activities of these companies are important in attracting investors, as well as providing company activities, etc. In this paper, the appropriate criteria and desired advertising activities that are obtained by financial literacy for investment companies, which are invested in Tehran Stock Exchange, are outlined. These advertising activities are ranked by using the step-by-step approach of analytic network process which is a multi-criteria decision-making method. According to its results, advertising activities using TV has the most weight among other advertising activities. This indicates that the use of television for advertising in company investments in Tehran Stock Exchange will be very influential. Also, social networks are ranked second, and in the end, two activities of billboards and magazines with a very small difference are placed in the fifth and sixth rankings. These two advertising activities have less effect than other ones in Tehran Stock Exchange investment companies.
Quality Control
Hernadewita Hernadewita; Mahefud Ismail; Mohamad Nurdin; Lien Kusumah
Abstract
Quality control is an important thing that must be done by the company to minimize defective products. The company can analyze product defects by using the Six Sigma method, by formulating Define, Measure, Analyze, Improve, and Control (DMAIC) that occurs. PT. XYZ as a large company that prints magazines ...
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Quality control is an important thing that must be done by the company to minimize defective products. The company can analyze product defects by using the Six Sigma method, by formulating Define, Measure, Analyze, Improve, and Control (DMAIC) that occurs. PT. XYZ as a large company that prints magazines often faces the problem of quality defects in its printouts, resulting in the cost losses due to production defects every year is not small, as a result of not being sold. The Six Sigma method is an approach method to help control the quality of production. This study conducts to determine the level of sigma from the current production process, the types of defects that are a priority to be addressed, and the causes of disability. From the results of the study, the sigma value of current production is 3.6 or DPMO of 15919.63613. The type of defect that occurs is blurred by 59%, does not register at 29% and paper cut by 12%. To achieve Six Sigma it is necessary to take corrective steps using the results of the analysis.
Other
Aniekan Essienubong Ikpe; Akanu-Ibiam Effiong Ndon; Promise Joseph Etim
Abstract
The R3 (Reduce, Reuse, Recycle) system of waste management specified by Environmental Protection Agency’s (EPA) waste management framework is the pathway to sustainable environment. This system which is practiced in advanced countries is given little or no preference in Nigeria where open waste ...
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The R3 (Reduce, Reuse, Recycle) system of waste management specified by Environmental Protection Agency’s (EPA) waste management framework is the pathway to sustainable environment. This system which is practiced in advanced countries is given little or no preference in Nigeria where open waste dumping is mostly practiced. Questionnaire based survey was employed to determine the awareness of the effects of open waste dumping by individuals. A physical survey was carried out to assess the risks posed by open waste dumping on the physical environment and health of individuals. Findings from the questionnaire-based survey indicated that many individuals are aware of the risks posed by open waste dumping system but have little or no knowledge of the R3 waste management standard for proper waste management. The physical survey pointed out that open waste dumping leads to infrastructural dilapidation and environmental degradation from drainage blockage and flooding. The findings also revealed that open waste dumping is responsible for outbreak of diseases such as Cholera, Diarrhoea, Malaria, Tetanus, Lassa fever, Typhoid and Yellow fever, Hookworm, and other parasite infestation as well as the promotion of fecal contamination of the hands, food and water that may result in fecal-oral transmission diseases. Hence, this method of waste management is responsible for water pollution, land pollution and the emission of obnoxious odour and also aid climate change and global warming through the release of Green House Gases (GHGs). From the risk evaluation carried out, simple and effective processes and technologies must be employed to aid the R3 practice for domestic recycling of specific waste.
Computational modelling
Anisul Islam; Md. Mashrur Islam; Nadim Mahmud
Abstract
Spur gears are the most well-known kind of gears used in hybrid vehicle’s power transmission. They have straight teeth and are mounted on parallel shafts. In some cases, many spur gears are utilized without a moment's delay to make huge rigging decreases. In this paper how stress creates on a spur ...
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Spur gears are the most well-known kind of gears used in hybrid vehicle’s power transmission. They have straight teeth and are mounted on parallel shafts. In some cases, many spur gears are utilized without a moment's delay to make huge rigging decreases. In this paper how stress creates on a spur equip under various conditions and conditions and reenactments of a rigging system (two spur gears) is assessed by Ansys workbench. For this static, the structural and dynamic analysis modeling is utilized. A couple of spurs equip tooth in real life is by and large subjected to two sorts of cyclic stress: Contact stress and twisting stress including bowing fatigue. The two stresses may not accomplish their greatest esteems at a similar purpose of contact fatigue. These sorts of failure can be limited by analysis of the issue amid the outline organize and making appropriate tooth surface profile with legitimate assembling strategies.
Data Envelopment Analysis, DEA
Rita de Fátima Muniz; Wagner Bandeira Andriola; Sheila Maria Maria Muniz; Antônio Clécio Fontelles Thomaz
Abstract
The present article deals with the application of the Data Envelopment Analysis (DEA) methodology to identify the most weighty factors that are associated with student performance on large-scale assessments, amongst them, the permanent assessment system for basic education "SPAECE" test. The DEA Slacks-Based-Measure ...
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The present article deals with the application of the Data Envelopment Analysis (DEA) methodology to identify the most weighty factors that are associated with student performance on large-scale assessments, amongst them, the permanent assessment system for basic education "SPAECE" test. The DEA Slacks-Based-Measure (SBM) model was used to estimate the relative efficiency of school units in the city of Sobral (CE), one of the most prominent Brazilian counties in the educational scenario. It was evident that the presence of libraries, computer labs, sports courts and rooms for special care in school units constitutes a significant factor associated with the high performance of students, impacting, therefore, school efficiency.
Systems and service modeling and simulation
Aniekan Essienubong Ikpe; Ijeoma Camelita Iluobe; Desmond Iria-evbo Imonitie
Abstract
The aim of this study was to analyze the performance of Omotosho Phase II gas turbine power plant for improved performance. To obtain the required output performance of the gas turbine power plant, operation data from years of 2013 to 2016 was collected from Omotosho Phase II gas turbine power plant ...
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The aim of this study was to analyze the performance of Omotosho Phase II gas turbine power plant for improved performance. To obtain the required output performance of the gas turbine power plant, operation data from years of 2013 to 2016 was collected from Omotosho Phase II gas turbine power plant in Ondo State, Nigeria. ASPEN HYSYS 2016 version was used to create two models, with one representing Omotosho Phase II gas turbine power plant with fogging unit incorporated while the other represented the power plant without fogging unit. The data was fed as input variables into the models in ASPEN HYSYS 2016 version which simulated the power plant process Specific Fuel Consumption (SFC) obtained from the power plant simulation when fogging is not incorporated was 0.199 kg/kwh, whereas, SFC of the plant with fogging was 0.179 kg/kwh. Thermal efficiency of 43.93% was obtained from the result of the simulated power plant with fogging system, whereas, thermal efficiency of 39.39% obtained from the result of the simulated power plant without fogging system. Net power of 131 MW was obtained from the simulation of the power plant with fogging system while net power of 117.46 MW was obtained when the plant operates without fogging system installed. For the compressor work, 82 MW/h was obtained from the simulation of the power plant with fogging system, whereas, 112.11 MW/h was obtained from the simulation of the power plant without fogging system. Furthermore, turbine work of 213 MW/h were obtained from the simulation of the power plant operating with fogging system while turbine work of 229.57 MW/h was obtained from the power plant without fogging system. This indicates that the incorporation of fogging system into Omotosho Phase II gas turbine power plant is economically viable in terms of fuel consumption, efficiency, power requirement, and GHG emissions compared to operation of the power plant without fogging system.
Operations Research
Fouad El-Hosiny; Mohamed Abdeldayem AbdelKhalek; Khaled Selim; Inge Osama
Abstract
An Electro-flotation cell was designed for industrial wastewater treatment. The affecting parameters of the Electro-flotation process such as, pH, initial dye concentration, temperature, current density, current type, ionic strength, stirring speed and number, connection and inter-distance of electrodes ...
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An Electro-flotation cell was designed for industrial wastewater treatment. The affecting parameters of the Electro-flotation process such as, pH, initial dye concentration, temperature, current density, current type, ionic strength, stirring speed and number, connection and inter-distance of electrodes were investigated using a synthetic Acid Red 1 (anionic), Basic Violet 3 (cationic) and Disperse Blue 14 (nonionic) dyes. Two textile wastewater samples were employed for performance evaluation. The maximum removal for all dyes is achieved at pH 7. The AC current and the bipolar electrodes were preferred. The maximum removal was achieved with AC current density of 80 A/m2 at 5 Volts through a bipolar connection of 8 electrode with 2 cm inter-distance. The designed Electro-flotation cell could remove 91.7 – 98.9 % of constituents of textile wastewater samples. The energy consumption was 1.39 Kwh/m3 of the treated wastewater.
Fuzzy optimization
Faranak Mahmoudi; Seyed Hadi Nasseri
Abstract
Today, human decisions are more than ever based on information. But most of this information is not definitive, and in this situation, logical decision making is very difficult based on this uncertainty. Different methods are used to represent this uncertainty, including the fuzzy numbers. The fuzzy ...
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Today, human decisions are more than ever based on information. But most of this information is not definitive, and in this situation, logical decision making is very difficult based on this uncertainty. Different methods are used to represent this uncertainty, including the fuzzy numbers. The fuzzy linear programming problem is one of the interesting concepts to be addressed in fuzzy optimization. Fully Fuzzy Linear Programming Problems (FFLP) are issues in which all parameters of the coefficients of the variables in the target functions, the coefficients of the variables in the constraints, the right-hand side of the constraints, and the decision variables in them are fuzzy. In this paper, we show that Definition 2.6 which is used by Ezzati et al. [1], failed to compare any arbitrary triangular fuzzy numbers. We demonstrate that their presented method is not well in general, thus the proposed method finds the fuzzy optimal solution of fully fuzzy linear programming problems by Ezzati et al. [1]. Then a new approach is proposed for solving this FFLP problem. An example is also presented to demonstrate the new method.
Engineering Optimization
Amir Parnianifard; Siti Azfanizam Ahmad; Mohd Khairol Anuar Ariffin; Mohd Idris Shah Ismail
Abstract
Computational complexity and time-consuming iteration of simulation for tuning of Proportional-Integral-Derivative (PID) controller is a common drawback in many types of existing methods. This paper aims to propose a new method for achieving an optimal design for PID gains parameters with the least number ...
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Computational complexity and time-consuming iteration of simulation for tuning of Proportional-Integral-Derivative (PID) controller is a common drawback in many types of existing methods. This paper aims to propose a new method for achieving an optimal design for PID gains parameters with the least number of simulation runs. To achieve this purpose, we combine polynomial regression and Latin Hypercube Sampling (LHS) in order to Design and Analyze of Computer Experiments (DACE). In this method, the LHS is performed three times to design the associated sample points for different usage that includes training sample points to fit polynomial regression as a common surrogate model; validating sample points to scale standardized residuals; grid search sample points for investigating optimal point over whole design space. To show the flexibility and applicability of the proposed method, we serve a numerical case in the tuning of PID controller for linear speed control of Direct Current (DC) motor. Four different polynomial regression fit input/output (I/O) data over separately four model’s performances that includes Integral-Square-Error (ISE), Integral-Absolute-error (IAE), Integral-Time-Square-Error (ITSE), and Integral-Time-Absolute-Error (ITAE). Comparison of the result with two existing approaches such as traditional Zeigler-Nichols method and Taguchi-Gray Relational Analysis (Taguchi-GRA) confirms the reliability and superiority of the proposed method.
Engineering Modeling
Ahmad Almagableh; Mohammad A. Omari; Ahmad. S. Awad
Abstract
A micromechanical model is applied to examine the tensile properties of composite materials filled with multi-wall CNT oriented in in-plane and out-of-plane direction and a quantitative micromechanical model for the mechanical behavior of CNT-composites has been developed. Digimat-MF is used to generate ...
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A micromechanical model is applied to examine the tensile properties of composite materials filled with multi-wall CNT oriented in in-plane and out-of-plane direction and a quantitative micromechanical model for the mechanical behavior of CNT-composites has been developed. Digimat-MF is used to generate a realistic three-dimensional microstructure for the current carbon nanotube/ epoxy composite. The Digimat model simulates a system of aligned carbon nanotubes arranged in-plane and another one having out of plane arrangement of reinforcements. A second model shows a representative volume element for the current nano-composite, in which the carbon nanotubes were simulated as a randomly (fully) dispersed, where all particles have been separated from each other. The predicted mechanical properties are compared with experimental tensile properties of composite materials reinforced with multi-wall CNTs arranged in in-plane and out-of-plane direction. A good agreement between the micromechanical modeling and the experimental part is observed. Results show that the elastic energy stored in -the-through thickness direction reinforced composites is about two times higher than that in the pure polymer.