Moslem Nilchi,; Mohammadesmaeil Fadaeinejad; Seyyed Hossein Razavi-Hajiagha; Ahmad Badri
Abstract
Looking at the economic definition of efficiency as optimal use of resources to produce possible maximum output, it can be understood the importance of this concept in management systems. Basically, Managers are trying to meet the satisfaction of all their stakeholders by optimally utilize of their resources ...
Read More
Looking at the economic definition of efficiency as optimal use of resources to produce possible maximum output, it can be understood the importance of this concept in management systems. Basically, Managers are trying to meet the satisfaction of all their stakeholders by optimally utilize of their resources to produce outputs. Due to high cost of holding money this point has more importance to the banking industry in Iran. In this paper, by looking at the structure of bank activities in Iran, a model with five different parts is provided that depicts the flow of affairs in banks. A mathematical model based on data envelopment analysis is presented to evaluate the efficiency of proposed structure and by using fuzzy approach, a method has been proposed to solve it. The results of applying the proposed model to 210 branches of one bank show that despite relative acceptable efficiency in resource attracting, and management, the efficiency of service, resource allocation and profitability parts are facing with important problem
Majid Hooshmandi Maher; Maghsoud Amiri
Abstract
In most industries the cost of raw materials and product components constitutes almost 60% percent of a product cost (in some industries up to 80%). In this condition، proper sourcing can play a key role in an organization's efficiency and effectiveness، because it has a direct effect on cost reduction، ...
Read More
In most industries the cost of raw materials and product components constitutes almost 60% percent of a product cost (in some industries up to 80%). In this condition، proper sourcing can play a key role in an organization's efficiency and effectiveness، because it has a direct effect on cost reduction، profitability and flexibility of a company. In this paper، to determine the optimal order quantity, multi supplier،multi product and during several periods، shortage and surplus،incremental discounts، multi objective and multi criteria nature of the problem، uncertainty in demand، lead time، fixed order cost، supplier quality level and every period budget are being considered. To incorporate the effective criteria in mathematical model، analytic network process approach has been used. After developing the robust multi objective mixed integer programming، a numerical example is presented. Finally, the results and suggestions for future studies are presented
Ahmad Jafarnejad; Mehrdad Yasaei
Volume 12, Issue 33 , July 2015, , Pages 75-96
Abstract
Due to the changes in production and market conditions, companies are facing many pressures. One of the ways of confronting with these pressures is the concept of supply chain and increasing its flexibility to satisfy different needs of customers. Despite the importance of supply chain flexibility, lack ...
Read More
Due to the changes in production and market conditions, companies are facing many pressures. One of the ways of confronting with these pressures is the concept of supply chain and increasing its flexibility to satisfy different needs of customers. Despite the importance of supply chain flexibility, lack of appropriate analytical models to explain the relationship between the flexibility in a system and the performance of overall system is still recognized. Therefore, in this study a mathematical model of supply chain flexibility has been presented. This research is applied and of the descriptive research types. This study is done in two phases; dimensions detection and modeling. Identified dimensions in the first phase are labor flexibility, machine flexibility, routing and process flexibility. They are important dimensions for assess each three levels; provide, produce and assemble the entire supply chain. The result of the second phase was the design of a mathematical model for each three levels, separately, but dependent on other levels by objective function. Their limitations are defined by identified dimensions in the first phase. .
Faezeh Asadian Ardakani; Ali Morovati Sharifabadi
Volume 10, Issue 26 , January 2012, , Pages 75-94
Abstract
One of the solutions for solving cutting stock problem in differentindustries, such as sheet metal, lumber, glass, paper and textile, isapplying ,Particle Swarm Optimization to minimize the waste ofrawmaterials. This article is intended to solve two-dimensional cuttingproblem. In these problems, larger ...
Read More
One of the solutions for solving cutting stock problem in differentindustries, such as sheet metal, lumber, glass, paper and textile, isapplying ,Particle Swarm Optimization to minimize the waste ofrawmaterials. This article is intended to solve two-dimensional cuttingproblem. In these problems, larger rectangular plates, divided intosmaller rectangularsegments, aim to minimizing the number of usedplates or the waste of plates by considering demand. In this articlePSO is used. To enhance the efficiency of algorithm, and preventingoverlap in cutting problem, the CUL algorithm is used. In order toinvestigate the results of algorithm, new software has been designed.This software has two ways for solving the problem. First, it ends upwith optimized cutting pattern considering the number and dimensionof segments and, length and width of main plate. Also, there is apossibility to give different width to software, in this case, thesoftware gives the user the optimum cutting pattern and optimumlength of main plate in addition to optimum width
Kaveh Khalili Damghani; Mohammad TaghaviFard; Kiaras Karbaschi
Abstract
The main goal of this paper is to evaluate the relative efficiency of each level of customer services in MELLI bank branches. A three stage process is defined as consecutive results of service provision to the customers. This process consists of sub-process such as customer expectations, customer satisfaction, ...
Read More
The main goal of this paper is to evaluate the relative efficiency of each level of customer services in MELLI bank branches. A three stage process is defined as consecutive results of service provision to the customers. This process consists of sub-process such as customer expectations, customer satisfaction, and customer loyalty. A hybrid method based on Multi-criteria Satisfaction Analysis (MUSA) and network Data Envelopment Analysis (DEA) is proposed to evaluate the relative efficiency of 30 branches. In this way, first the customer satisfaction was measured through a direct questionnaire based on customers perceptions analysis and quantified using MUSA method. Then, the customer satisfaction scores and the other important evaluating criteria such as number of employees, average evaluation scores of staff, operating costs, the amount of deposits, total credit facilities, the number of new checking accounts, expectations and customer loyalty were considered in DEA model as inputs and outputs. A three-stage DEA model was used to evaluate the efficiency of bank branches. The proposed DEA model was based on multipliers perspective, output-oriented with constant return to scale. The proposed three-stage DEA model quantified and assessed the efficiency of customer expectations, customer satisfactions, and customer loyalties in branches. The results showed that the mean relative efficiency of selected branches in three sub-processes namely customer satisfaction, operational results and customer loyalty were 83%, 94%, and 90%, respectively. The mean efficiency of the overall process is 89%.And four branches (about 13% of sample) were placed on efficient frontier for all sub-processes. Based on research findings, the branches which have been efficient in customer expectations were also efficient in other sub-processes and the main process.
A. Azar; M. Fadaei
Volume 2, Issue 4 , March 2004, , Pages 75-99
Abstract
Management is one of the basic foundations of administration in developed countries. Since suitable combination of available factors and resources coordination and relation between them and finally due attention to lots of real restrictions are vital to increasing efficiency and productivity. In recent ...
Read More
Management is one of the basic foundations of administration in developed countries. Since suitable combination of available factors and resources coordination and relation between them and finally due attention to lots of real restrictions are vital to increasing efficiency and productivity. In recent years requirement to considering and analysis of relationships and interactions between different elements has resulted in inventing new methods. These methods and techniques have enabled managers to make effective decisions based on accurate information.
This paper surveys the extent to which managers of manufacturing industries are aware about MS techniques and exploits them in practice. For this aim we selected some of the most famous and applicable MS techniques. Then industrial managers view about these techniques and application of them was asked by the means of a questionnaire. In this questionnaire degree of applying and reasons for not applying these methods in important organizational decisions were also surveyed. Degree of awareness and applying these methods in different industries was recognized. Relationship between these two variables and other relevant elements was assessed in the next stage.
Finally degree of applying MS techniques in different managerial decisions and reasons for not applying them were ranked based on average ranks obtained from sample.
Fattah Sahrifzadeh; Mahmood Sharifi
Volume 5, Issue 14 , December 2006, , Pages 75-110
Abstract
This research was conducted to evaluate goal-achievement level of science and technology parks and research centers in Iran. Today technology change and development, have led to significant move and innovation in all aspects of our lives to the point, it has remarkably impacted our welfare and life.
In ...
Read More
This research was conducted to evaluate goal-achievement level of science and technology parks and research centers in Iran. Today technology change and development, have led to significant move and innovation in all aspects of our lives to the point, it has remarkably impacted our welfare and life.
In other words, one of the most effective planning tools in the area of national and international technical and scientific development is establishing connection between industrial and scientific centers to improve its status and standing. Establishing such sound relationship can effectively lead to industrial and scientific developments. In Iran special attention has recently been paid to this issue. Nowadays, Ministries of Sciences, Technology and Researches, Information and Technology, and Mines and Industry and other related organizations have attempted to perform active role in establishing these centers and scientific parks to meet their goals and missions. Testing hypotheses and concluding our research findings indicate that activities of these institutions lead to improving Knowledge - based growth and competitive power and technological .entrepreneur ship through Knowledge-based economy.
Ali Saeedi; Ommolbanin Dadar
Volume 6, Issue 16 , June 2007, , Pages 75-97
Abstract
One of the most important function of financial markets and especially stock exchanges is facilitating, accelerating and cost reduction in conversion of financial asset into cash and vice versa.
Turnover velocity is the ability to buy and sell considerable amount of securities, quickly and with very ...
Read More
One of the most important function of financial markets and especially stock exchanges is facilitating, accelerating and cost reduction in conversion of financial asset into cash and vice versa.
Turnover velocity is the ability to buy and sell considerable amount of securities, quickly and with very little price effect. This feature has been defined for the market as a whole (Such as WFE calculate for its members monthly and yearly) and for individual securities as well.
In this research liquidity index is defined as the ratio of the number of shares transacted and total number of issued shares. The relationship between stock liquidity index at time t and its 6 lags is tested among 242 Tehran Stock Exchange (TSE) listed companies during four years (2005 to 2008) in panel data. The stationarity of data is also approved by unit root test. The significant relation between stock liquidity at time t and 6 previous lags is approved, besides, significant relation between Amihud liquidity index and the ratio which be applied in this research is approved. But model's R Squared is not high enough to be a good model for forecasting.
Hasan Ghasemi; Seyed Mohammad A’arabi; NabiAllah Dehghan
Volume 6, Issue 17 , September 2007, , Pages 75-105
Abstract
This paper is consequence of field survey that is done for studying the effect of alignment between international marketing strategy and organizational contextual dimensions and international marketing subsystems on export performance of engineering and technical services firms.
The statistical population ...
Read More
This paper is consequence of field survey that is done for studying the effect of alignment between international marketing strategy and organizational contextual dimensions and international marketing subsystems on export performance of engineering and technical services firms.
The statistical population is engineering and technical services exporter firms that is selected 41 firms as statistical sample by judgment sampling of nonprobability sampling methods. This sample covers 95 percent of Iranian engineering and technical services export. The results illustrate the internal and external alignment variables affect export performance of engineering and technical services firms, separately and mutually. Also, the results show that the effect of internal alignment is more than the effect of external alignment. In addition, the research quantitative model come from multiple stepwise regression analysis displays that the portion of internal alignment variable in predicting export performance is .225, but the portion of external alignment variable is .162 that this result appreciated the more effect of internal alignment on firms export performance.
Hossein Rahmanseresht; Mitra Safaeian
Volume 9, Issue 22 , September 2011, , Pages 75-104
Abstract
Industry competitiveness has positive impact on productivity and public wealth. In this research, we try to draw a proper competitiveness model for Iranian manufacturing industries through recognizing influential factors. We reviewed 23 manufacturing industries in Iran from 1373 to 1386. The result shows ...
Read More
Industry competitiveness has positive impact on productivity and public wealth. In this research, we try to draw a proper competitiveness model for Iranian manufacturing industries through recognizing influential factors. We reviewed 23 manufacturing industries in Iran from 1373 to 1386. The result shows that “Industry size” is the most important factor among others that impact on competitiveness of manufacturing industries in Iran. “Labor productivity” has low impact on Industry competitiveness. Besides, government has a central role on competitiveness success in Iranian manufacturing industries.
Hamed Rahmani; Morteza Moosakhani; Gholamreza Memarzade Tehran; Karamollah Daneshfard; Abolfazl Kazemi
Abstract
Referring to a variety of media and news headlines, we can figure out the increase in the phenomenon of corruption in the country. One of the applied mechanisms by international organizations like international transparency and global bank is applying Governance Model to combat against Corruption. There ...
Read More
Referring to a variety of media and news headlines, we can figure out the increase in the phenomenon of corruption in the country. One of the applied mechanisms by international organizations like international transparency and global bank is applying Governance Model to combat against Corruption. There are different theories about good governance and the most controversial one is the mechanism of social control. In this theory, an appropriate model for governance in government systems is the combination of police power (force), exchange and persuasion in a variety of organizations. The aim of this study is to identify this combination in different organizations to combat against corruption. The present study is a developed research kind that has utilized Fuzzy Inference System for identification the mixture of three forces. For constructing fuzzy rules in the present study, we have applied mixed method of Shannon entropy and Delphi analysis. Shannon entropy has been used for analyzing the coefficients of the components of corruption in the organizations and as an "if" part of the rules, furthermore Delphi analysis has been applied for analysis of the combination of the social control or as a "then" part of the rules. The results of the study were applied as an " if and then" rules for analyzing six areas of a model. The three areas, related to Grand Corruption, included law enforcement agencies, financial and normative as well as three other areas related to Petty Corruption including law enforcement organizations, financial and normative. These procedures were applied in Fuzzy Inference System and the results have been analyzed
Volume 11, Issue 30 , October 2014, , Pages 77-97
Abstract
Due to the sharp rise of the information technology (IT), the amount of datastored in databases is dramatically on the rise. Analyzing the stored data andconverting it to information and knowledge which is applicable in organizationsrequires powerful instruments. As with other economic sectors, recognizing ...
Read More
Due to the sharp rise of the information technology (IT), the amount of datastored in databases is dramatically on the rise. Analyzing the stored data andconverting it to information and knowledge which is applicable in organizationsrequires powerful instruments. As with other economic sectors, recognizing andattracting low-risk and profitable customers are of high significance for insuranceindustry. Car insurance is one of the most important insurance brancheswhich accounts for a great deal of portfolio of insurance industry. Risk segmentationof policyholders on the basis of observable features can help insurancecompanies to reduce loss, raise the rate of insurance coverage, and prevent themfrom making an inappropriate choice in the insurance market. In this study, thesegmentation of comprehensive car insurance customers on the basis of risk wasselected through self-organizing map and K-means. At first, the effective factorson the risk of policyholders are identified. Then, the insurance policyholders aresegmented using the proposed SOM and K-means. Customers’ characteristicsin every cluster are identified. Finally, the two methods compared with eachother. The advantages and disadvantages of them illustrated
Reza Abasi; Jamshid Salehi Sadaghiani; Maghsoud Amiri
Volume 13, Issue 38 , October 2015, , Pages 79-98
Abstract
There are several different factors in industrial processes, which may have an impact on final product specifications. In this paper, the nonlinear multi-objective mathematical modeling for the 5 qualitative characteristics of polyethylene terephthalate (PET) as one of the most widely used products in ...
Read More
There are several different factors in industrial processes, which may have an impact on final product specifications. In this paper, the nonlinear multi-objective mathematical modeling for the 5 qualitative characteristics of polyethylene terephthalate (PET) as one of the most widely used products in petrochemical industry is done by 9 Key parameters affecting the production process. For this purpose, Response Surface Methodology that is the combination of experiments design and statistical tests is applied along with Artificial Neural Network and Metaheuristic algorithms.
Reza Alikhani; Mahmoud Saremi
Abstract
The scheduling of preventive maintenance and replacement is one of the crucial issues in the literature of system reliability and maintenance engineering. The importance of this issue is more evident in series system in which by stopping a component the whole system will stop. However, the quest of the ...
Read More
The scheduling of preventive maintenance and replacement is one of the crucial issues in the literature of system reliability and maintenance engineering. The importance of this issue is more evident in series system in which by stopping a component the whole system will stop. However, the quest of the efficient periodicity maintenance for all of component of a system which has antagonistic objectives is not a trivial task. The aim of this paper is to presenting scheduling model of preventive maintenance and replacement for series system by variable and not predetertmined periods and also by applying inflation in the model. The model is designed based on fuzzy multi-objective and integer non-linear programming. Also the proposed model is solved for a case study with numerical example and furthermore, analysis of various senarios, the effects of inflation on the model will be considered. The results show that applying inflation in the model changes not only scheduling for replacement and maintenance, but also affects the effective age of components
kamran faizi
Laya Olfat; Maghsoud Amiri; Ebrahim Teimoury; Fatemeh Ghasemzadeh Gevari
Abstract
In today’s competitive world, supply chain management gains more attention every day. One of the most challenging topics in this field for managers and researchers is supply chain disruption management. When a disruption occurs in an echelon of a multi level supply chain, it may affect other echelon’s ...
Read More
In today’s competitive world, supply chain management gains more attention every day. One of the most challenging topics in this field for managers and researchers is supply chain disruption management. When a disruption occurs in an echelon of a multi level supply chain, it may affect other echelon’s performance in that supply chain as well. The main objective of current research is helping decision makers to choose best supply, production and ordering quantity between echelons so that after disruption occurrence, SC recovers and returns to pre-disruption plan with minimum recovering costs.In this paper, production and retailers disruptions are studied and a mathematical recovery plan is designed with objective function of minimizing total cost of supply chain in the recovery period to help all members of the supply chain in returning to normal situation. The proposed model is solved in MATLAB 2011 by the suggested heuristic method as well as GAMS software. Finally, results of both solvers are compared which shows the applicability of heuristic method
Soheila Khishtandar; Farhad Farzad; Mostafa Zandieh
Volume 8, Issue 20 , March 2011, , Pages 81-99
Abstract
Different inventory control systems try to determine how much and when to order at the least relevant cost while maintaining a desirable service level for customers. In this article, a continuous review stochastic inventory system, with three objectives, is optimized. In this model, contrary to the traditional ...
Read More
Different inventory control systems try to determine how much and when to order at the least relevant cost while maintaining a desirable service level for customers. In this article, a continuous review stochastic inventory system, with three objectives, is optimized. In this model, contrary to the traditional inventory models, customer service is not considered a shortage cost in the objective function. But the frequency of stock out occasions and the number of items stocked out annually are to be minimized. For determining the Pareto optimal set, multi-objective evolutionary algorithms are used. First, NSGA-II, MOGA, VEGA, RWGA are developed. Then some improvements in NSGA-II mechanisms are made and R-NSGA-II is developed. Subsequently, these algorithms are examined for some criteria such as set coverage and spacing, and the best algorithms for each criteria arc presented. The Result shows that R-NSGA-II has good scores for most criteria. Afterwards, Pareto optimal set is ranked using the method of global criteria.
Seyyed Habibollah Tabatabaeian; Seyyed Kamran Bagheri
Volume 1, Issue 2 , October 2003, , Pages 83-99
Abstract
Technological progress has significantly accelerated in recent years. This makes most developing countries unable to keep up with the waves of technology development. On the other hand, there is a wide consensus that technological development has greatly affected the economical, industrial, security ...
Read More
Technological progress has significantly accelerated in recent years. This makes most developing countries unable to keep up with the waves of technology development. On the other hand, there is a wide consensus that technological development has greatly affected the economical, industrial, security and even cultural status of countries and there is no way to be competitive in the era of globalization, unless by acquiring and strengthening local technological capabilities. On the verge of preparation of the 4th development plan of Iranian economy, national policy – makers should focus on technology development and provide its infrastructures and prerequisites as one of their major concerns.
One of the most important conceptual frameworks that have been adopted by policy–makers of developed countries is National Innovation Systems (NIS), which provides comprehensive and coherent perspective in formulation of long – term national development plans. So in this paper, we will try to illuminate the importance of national policy – making in terms of NIS concepts.
Mohammad Taghi Taghavifard; Ahmad Nadali
Volume 9, Issue 25 , July 2012, , Pages 85-107
Abstract
This research study aims at using Data Mining and Fuzzy Logicapproaches to classify the credit scoring of banking system applicantsas to cover uncertainties and ambiguity connected with applicantclasses and also variables that affect their behavior.The methodology, according to a standard Data Mining ...
Read More
This research study aims at using Data Mining and Fuzzy Logicapproaches to classify the credit scoring of banking system applicantsas to cover uncertainties and ambiguity connected with applicantclasses and also variables that affect their behavior.The methodology, according to a standard Data Mining process, is tocollect and refine the client data, then those variables which are inlinguistic forms are converted to fuzzy variables under the supervisionof banking experts and final data are modeled using Fuzzy DecisionTree, subsequently. The unfuzzy data are also modeled using the otheralgorithms.The results of the study suggest that as far as client distinctionaccuracy is concerned Fuzzy Decision Tree produces better resultscompared to Traditional Trees, Neural Networks, and statisticalprocedures such as Logistic Regression and Bayesian Network.However, it is not as accurate as Support Vector Machine and GeneticTree. On the other hand, Fuzzy Decision Tree technique has gainedbetter prediction than prediction performance of bank credit scoringexperts.
Mohammad T. Taghavifard; Majid Gheitasi; Farzad Soltani
Volume 3, Issue 11 , December 2005, , Pages 85-113
Abstract
This research paper presents a methodology to assist enterprise decision-makers CDMs) to select from a numbers of processes during the Business Process Reengineering (BPR) according to organizational objectives. For this ...
Read More
This research paper presents a methodology to assist enterprise decision-makers CDMs) to select from a numbers of processes during the Business Process Reengineering (BPR) according to organizational objectives. For this purpose, the proposed methodology utilizes fuzzy QFD technique to convert the qualitative data (DMs' opinion) to quantitative ones and then calculates the effects of each process on the organization objectives and criteria. Then, by using the result of fuzzy QFD, the amount of satisfaction of each process according to each criterion is calculated. By combining this data with other effective variables in BPR projects such as "cost" and "time", a multi-objective goal programming (MOOP) model is formulated and solved to identify the most appropriate business processes. Finally, an example is presented to illustrate how the methodology works. The proposed model was also applied to a public-service organization by considering three main objectives: project quality, project cost, and project time. The achieved results were quite satisfactory and promising.
Seyyed Ali Akbar Afjahe; Reza Sepahvand
Volume 6, Issue 15 , March 2007, , Pages 87-113
Abstract
Introducing strategic human resource management makes human resource management researcher the understood about the relationships between corporate strategy, human capital, human resource strategy and firm performance. One of the key mysterious subjects in this field appears to be understanding of processes ...
Read More
Introducing strategic human resource management makes human resource management researcher the understood about the relationships between corporate strategy, human capital, human resource strategy and firm performance. One of the key mysterious subjects in this field appears to be understanding of processes and mechanisms that human resource management practices influence firm performance through them. It seems that with regard to importance of corporate strategies and their effect on firm performance, coordination between human resource, human capital and organizational strategies is one of the issues that can have significant effect on the relationship between human resource management practices and firm performance.
The main purpose of of this paper is to investigate the effect of the strategic cooperation between human resource, human capital and organizational behavior strategies on the firm performance. Data analysis shows that the firm performance would improve if there were
Coordination between human resource strategy and human capital strategy and organizational behavior strategy and also between human resource strategy and human capital strategy and organizational behavior strategy.
Finally, the results show that strategic coordination between human resource strategy and human capital and organizational behavior have significant effect on the firm performance.
Kaveh Khalili,; Maryam Tajik Khavh
Volume 13, Issue 37 , July 2015, , Pages 91-121
Abstract
Performance of supply chain usually is measured through multiple-criteria. In this paper, an integrated model is proposed to plan a supply chain with three-echelons of supply, production, and distribution considering both logistic costs and service level, concurrently. A mixed-integer linear mathematical ...
Read More
Performance of supply chain usually is measured through multiple-criteria. In this paper, an integrated model is proposed to plan a supply chain with three-echelons of supply, production, and distribution considering both logistic costs and service level, concurrently. A mixed-integer linear mathematical programming model with two objective functions, including minimizing logistic costs, and maximizing service level is developed. Goal programming method is used to solve the proposed multi-objective mathematical programming. Finally a real case study is analyzed in order to check the applicability of proposed model and the solution approach
Mohammad Mahdi Bahrololoum; Mirfeiz Fallahshams; Ghasem Blue
Volume 13, Issue 39 , January 2016, , Pages 91-114
Abstract
In this study, the strategy of effective asset allocation under uncertainty with the capability of risk control, transaction cost reduction and favorable return realization is investigated. In order to implement this strategy and to overcome the shortfalls of classic portfolio optimization models in ...
Read More
In this study, the strategy of effective asset allocation under uncertainty with the capability of risk control, transaction cost reduction and favorable return realization is investigated. In order to implement this strategy and to overcome the shortfalls of classic portfolio optimization models in dealing with uncertainty, the formation of an index fund using a robust approach and considering cardinality constraint became the agenda. Accordingly, in order to solve the index tracking problem, a linear programming model as minimizing the absolute deviation between the expected return of the index fund and that of the benchmark is presented. Considering the dimension of the solution space, a Meta heuristic genetic algorithm was implemented to solve the robust counterpart of the problem. The results of the analysis imply on the selection of 20 stocks as the index fund composition and indicate good performance of the index tracking funds based on criteria such as correlation, root mean square error and the excess return using out of sample data.
ASghar Aghaei; Jamshid Salehi Sadaghiani; Vajholah Ghorbanizadeh; Fatah Mikaeili
Volume 13, Issue 36 , April 2015, , Pages 95-113
Abstract
Today supply chains are working in an environment that are seeking improvement and decreasing costs and applying alternatives and strategies based on this direction. Lean strategy in one them which helps supply chains for elimination of wastes as the main aim. So, this research aims to design a model ...
Read More
Today supply chains are working in an environment that are seeking improvement and decreasing costs and applying alternatives and strategies based on this direction. Lean strategy in one them which helps supply chains for elimination of wastes as the main aim. So, this research aims to design a model for lean supply chain with the emphasis on police environment. This is an analytic-descriptive research from the point of method and practical from the point of end. The statistical population is all managers and specialists of supply chain in Naja and 101 samples were choosed by random sampling. In this research, after designing conceptual model, we applied a researcher made questioner for gathering information and structural equation and PLS software and Friedman test were applied for considering the affections and ranking. The results showed that the dimensions of Naja lean supply chain pattern are as bellow: managerial, production and service, strategic, suppliers and customer orientation
pedram Pourkarim guilani; Mani Sharifi; parham azimi; maghsoud Amiri
Abstract
Due to the high sensitivity in applying of electronic and mechanical equipment, creating any conditions to increase the reliability of a system is always one of the important issues for system designers. Hence, making academic models much closer to the real word applications is very attractive. In the ...
Read More
Due to the high sensitivity in applying of electronic and mechanical equipment, creating any conditions to increase the reliability of a system is always one of the important issues for system designers. Hence, making academic models much closer to the real word applications is very attractive. In the most studies in the reliability area, it is assumed that the failure rates of the system components are constant and have exponential distributions. This distribution and its attractive memory less property provide simple mathematical relationships in order to obtain the system reliability. But in real word problems, considering time-dependent failure rates is more realistic to model processes. It means that, the system components do not fail with a constant rate during the time horizon; but this failure rate changes over the time. One of the most useful statistical distributions in order to model the time-dependent failure rates is the Weibull distribution. This distribution is not a memory less one, so it was impossible to apply simple and explicit mathematical relationships as the same as exponential distributions for the reliability of a system. Therefore, researchers in this field have used simulation technique in these circumstances which is not an exact method to get near-optimum solutions. In this paper, for the first time, it is tried to obtain a mathematical equation to calculate the reliability function of a system with time-dependent components based on Weibull distribution. Also, in order to validate the proposed method, the results compared with exact solution that exists in literature.
