Publication Date: 2002
Journal of Global Optimization (09255001)24(1)pp. 79-88
The Network Design Problem has been studied extensively and in many of these models the cost is assumed to be a concave function of the loads on the links. In this paper we investigate under which conditions this is indeed the case for the communication networks. The result is presented as a theorem, the Concavity Theorem, and a list of conditions that can easily be verified. It is also shown how the theorem can be extended to other applications, like in the area of road transportation.
Darvizeh m., M.,
Darvizeh a., A.,
Ansari, R.,
Sharma c.b., Publication Date: 2004
Composite Structures (0263-8223)63(1)pp. 69-74
Due to the importance of buckling analysis of composite structures in various industrial applications a comparative study of buckling behavior of composite plates is presented here. Mathematical modelling developed in the present work for generally laminated plates is based on generalized differential quadrature rule (GDQR) and R-R method. To show the ability and robustness of the mathematical modeling in handling buckling analysis, results obtained using GDQR and R-R are compared with each other and also with some available results based on experimental and analytical works. The efficiency and reliability of the GDQR in comparison with R-R method on the buckling behavior is also discussed. © 2003 Elsevier Ltd. All rights reserved.
Publication Date: 2004
International Journal of Quality and Reliability Management (0265671X)21(7)pp. 731-746
In almost all of the existing resources of failure mode and effect analysis (FMEA), "severity" is being determined from the designers' point of view, not from the customers' side. In this paper, a new approach is proposed to enhance FMEA capabilities through its integration with Kano model. This evolves the current approaches for determination of severity and "risk priority number" (RPN) through classifying severities according to customers' perceptions. It supports the nonlinear relationship between frequency and severity of failure. Also a new index called "correction ratio" (Cr) is proposed to assess the corrective actions in FMEA. The findings of a short case study highlight the gap between managers and customers in prioritising a set of failures and the difference between RPN and Cr prioritisations, caused by target failure frequencies. The proposed approach enables managers/designers to prevent failures at early stages of design, based on customers who have not experienced their products/services yet. © Emerald Group Publishing Limited.
Publication Date: 2004
Linear Algebra and Its Applications (00243795)390(1-3)pp. 345-355
Let R be a non-commutative ring. The commuting graph of R denoted by Λ (R), is a graph with vertex set R \ Z(R), and two distinct vertices a and b are adjacent if ab = ba. In this paper we investigate some properties of Λ(R), whenever R is a finite semisimple ring. For any finite field F, we obtain minimum degree, maximum degree and clique number of Λ(M n (F)). Also it is shown that for any two finite semisimple rings R and S, if Λ(R) ≃ Λ(S), then there are commutative semisimple rings R1 and S1 and semisimple ring T such that R ≃T × R1, S ≃ T × S1 and |R1| = |S1|. © 2004 Elsevier Inc. All rights reserved.
Afshani, P.,
Ghandehari, M.,
Ghandehari, M.,
Hatami h., H.,
Tusserkani, R.,
Zhu, X. Publication Date: 2005
Journal of Graph Theory (03649024)49(4)pp. 325-335
This paper proves that if G is a graph (parallel edges allowed) of maximum degree 3, then χc′(G) ≤ 11/3 provided that G does not contain H1 or H2 as a subgraph, where H1 and H2 are obtained by subdividing one edge of K23 (the graph with three parallel edges between two vertices) and K4, respectively. As χc′(H1) = χ c′(H2) = 4, our result implies that there is no graph G with 11/3 < χc′(G) < 4. It also implies that if G is a 2-edge connected cubic graph, then χc′(G) ≤ 11/3. © 2005 Wiley Periodicals, inc.
Publication Date: 2005
Discrete Mathematics (0012365X)293(1-3)pp. 121-127
A critical set in an n×n array is a set C of given entries, such that there exists a unique extension of C to an n×n Latin square and no proper subset of C has this property. For a Latin square L, scs(L) denotes the size of the smallest critical set of L, and scs(n) is the minimum of scs(L) over all Latin squares L of order n. We find an upper bound for the number of partial Latin squares of size k and prove thatn2-(e+o(1))n10/6≤maxscs(L)≤n2- π2n9/6.This improves on a result of Cavenagh (Ph.D. Thesis, The University of Queensland, 2003) and disproves one of his conjectures. Also it improves the previously known lower bound for the size of the largest critical set of any Latin square of order n. © 2005 Elsevier B.V. All rights reserved.
Darvizeh m., M.,
Haftchenari h., ,
Darvizeh a., A.,
Ansari, R.,
Alijani a., Publication Date: 2005
WSEAS Transactions on Information Science and Applications (17900832)2(8)pp. 1195-1201
In this study a composite cylindrical shell is loaded under a steady-state axisymmetric voltage and analyzed using a semi-analytical finite element method. An attempt has been made to define a critical buckling voltage for a single layer cylindrical composite shell under a clamped-clamped boundary condition at different fiber orientation and length to radius ratios. The voltage to cause instability is derived from fundamental equations of the piezoelectric constitutive relations. Critical buckling voltage applied to a cylindrical composite shell can be determined by employing a piezoelectric actuator.
Publication Date: 2006
Total Quality Management and Business Excellence (14783363)17(5)pp. 567-587
Since customers are not all created equal, it could not be overemphasised that a precise knowledge of Customer Requirements (CR) holds the key to business success. This paper offers Customer Requirements Segmentation (CRS) as a novel technique for categorizing CR with precision. CRS involves three different types of segmentation according to: service encounters or the service provided within each service encounter (CRS-I); customers' characteristics, e.g. age, gender, etc (CRS-II); and prioritized CR importance (CRS-III). Starting with a comprehensive list of Service Quality Dimensions (SQD), the CRS-I, II and IIIs will successively emerge. Although Quality Function Deployment (QFD) has been widely used in analysing and eventually delivering what the customers want, its implementation has not always been effective. CRS would help overcome some of the major difficulties in QFD implementation which are particularly acute in the Service Sector, namely: in ascertaining the ambiguities in the voice of the customer (VoC); in handling large houses of quality (HoQ); and in resolving conflicts among different variety of CR. A case study on using CRS to analyse the service encounter at the front desk of a four-star hotel will be presented in order to demonstrate CRS in action. The implications of the findings are discussed in detail.
Publication Date: 2006
Iranian Journal of Science and Technology, Transaction A: Science (10286276)30(3)pp. 315-323
The problem of finding the minimum cost multi-commodity flow in an undirected and complete network is studied when the link costs are piecewise linear and convex. The arc-path model and overflow model are presented to formulate the problem. The results suggest that the new overflow model outperforms the classical arc-path model for this problem. The classical revised simplex, Frank and Wolf and a heuristic method are compared for the problem. © Shiraz University.
Darvizeh m., M.,
Haftchenari h., ,
Darvizeh a., A.,
Ansari, R.,
Sharma c.b., Publication Date: 2006
Composite Structures (0263-8223)74(4)pp. 495-502
A calculation of overall dynamic response of thin orthotropic cylindrical shells is presented. Due to the obvious importance of the effects of transverse shear deformation and rotary inertia, these terms are included in the analysis. The exact method is modified to predict the dynamic behavior of an orthotropic circular cylindrical shell. The modal forms are assumed to have the axial dependence in the form of a simple Fourier series. By using the present modified exact analysis various aspects such as influence of boundary conditions, changes in shell geometrical parameters, changes in the directions of orthotropy, etc., on the frequencies, mode shapes and modal forces are studied. Analytical results are shown to be in good agreement with some available experimental and theoretical results. © 2005 Elsevier Ltd. All rights reserved.
Publication Date: 2007
Health Information Management Journal (18333575)36(2)pp. 37-42
Strategies for improving the patient discharge process have a beneficial effect on many hospital activities. The main objective of this research was to analyse the discharge process at Kashani Hospital in Esfahan, Iran in the fall of 2004. This study took the form of a case study in which data were collected by questionnaire, observation and checklist. SPSS and Operations Research (O.R.) methods were used to analyse data. The results showed that the average time for patients to complete the discharge process was 4.93 hours. The hospital personnel involved identified the main factors affecting average waiting time as patients' financial problems and distance between different wards. The longest hospital stay was 5.7 days in the Neurology ward. Findings showed there was a queue in completing medical records at the nursing and medical equipment stations.
Publication Date: 2007
International Journal of Quality and Reliability Management (0265671X)24(7)pp. 753-770
Purpose - The purpose of this paper is to enhance understanding of corporate governance (CG) in delivering excellence in corporate social responsibility (CSR). Design/methodology/approach - The paper demonstrates models of CG and the associated elements affecting CSR. It addresses the integration of CSR into management systems through a framework as a process-based management system and studies the role of leadership style for socially responsible organizations. The paper develops a comprehensive questionnaire that enables organizations to audit their commitment to environment and social responsibility. Findings - The paper reflects that CG encompasses different internal and external factors, by which management of organizations are influenced. This is also compatible with the new corporate community models, in which investors, the public, customers, employees and associated corporations have a mutual impact on management. The leadership style is also found to play an important role in socially responsible organizations. In this respect, transformational leader seems to be more effective, compared with manager and transactional leader. The paper suggests that organizations should audit their CG capabilities towards CSR, based on a proposed questionnaire in order to drive excellence in CSR. Originality/value - The paper provides a comprehensive study to help understand key elements of CG and CSR and proposes a new questionnaire to organizations for assessing how far they are able to move towards socially responsible organizations. © Emerald Group Publishing Limited.
Haftchenari h., ,
Darvizeh m., M.,
Darvizeh a., A.,
Ansari, R.,
Sharma c.b., Publication Date: 2007
Composite Structures (0263-8223)78(2)pp. 292-298
Free vibration analysis of composite cylindrical shells with different boundary conditions is presented in this paper using differential quadrature method (DQM). Equations of motion are derived based on first order shear deformation theory taking the effects of shear deformation and rotary inertia terms into account. By applying the differential quadrature formulation and the required modified relationships for implementing the different boundary conditions, equations of motion of a circular cylindrical shell are transformed into a set of algebraic equations. By solving this algebraic system natural frequencies of circular cylindrical shells made of fibrous composite materials with different fibre angles are evaluated. The results thus obtained are then compared with some available results and a good agreement is observed. In all the cases studied here efficiency, ease and usefulness of the DQM are well illustrated. © 2005 Elsevier Ltd. All rights reserved.
Publication Date: 2007
Social Behavior and Personality (11796391)35(6)pp. 803-818
Previous research has not been conclusive as to whether people prefer different or identical allocation principles in distributions of positive and negative outcomes. Thus, in this study, the question of whether or not group goal accounts for preferred allocation of positive and negative outcomes was posed. As hypothesized for division of surpluses, the results showed that relationship-oriented goals predicted preferences for equality, whereas performanceoriented goals predicted preferences for equity. Moreover, the results were the same for allocation of deficits. This suggests that people implicitly have different orientations, or goals, in mind in group situations that similarly influence the way they prefer to allocate positive and negative outcomes. The results also showed that participants allocating deficits deviated to a larger extent from the allocation principles than did participants allocating surpluses. © Society for Personality Research (Inc.).
Publication Date: 2007
International Journal of Productivity and Performance Management (17410401)56(3)pp. 226-240
Purpose - The purpose of this paper is to provide an integrated approach that prioritizes organizational key performance indicators (KPIs) in terms of the criteria of SMART (Specific, Measurable, Attainable, Realistic, Time-sensitive) goal setting. Design/methodology/approach - The research was carried out using the analytical hierarchy process (AHP) technique as the basis for pairwise comparisons of SMART criteria, considering each KPI. Findings - A new approach is outlined, encompassing step-by-step guidelines for decision makers to conduct the prioritization process of SMART KPIs. The results of the case study highlight the applicability of the proposed approach and the calculation process for prioritizing KPIs. Research limitations/implications - The rating scales used in the AHP analysis are conceptual; although it identifies which dimensions require improvement, the proposed approach does not provide guidance on an appropriate action plan to address deficiencies; another limitation is that the framework adopted only the SERVQUAL service dimensions. Originality/value - This paper gives a novel approach for prioritization of KPIs. The proposed approach has a holistic mechanism; it could empower decision-making teams; it is capable of enhancing advanced quality engineering approaches; and provides great opportunities for future research. © Emerald Group Publishing Limited.
Publication Date: 2008
Scientia Iranica (23453605)15(5)pp. 652-660
In this paper, a new approach to formulate a class of scheduling problems is introduced, which can be applied to many other discrete problems with complicated structures. The concept of graph circular coloring is applied to develop a model for the special case of an open shop scheduling problem. In this problem, there are some independent jobs to be processed in a shop with dedicated renewable resources. Each job consists of several tasks with no precedence restriction. Each task is processed without preemption. The processing time of the tasks is given. Processing each task requires using some multiple specified types of resource, while no more than one task can use each resource, simultaneously. Some tasks can be shared by more than one job and the process may be repeated more than once. The objective is to develop a schedule which yields the minimal makespan length of all jobs, as well as the number of cycles. The model is first developed for cases when the processing time of each task is one unit and, then, it is generalized by relaxing this restriction. In both cases, a circular coloring formulation is shown in comparison with traditional formulation (single process execution) results in an improved makespan and also the required information regarding the optimum number of cycles to repeat the process. © Sharif University of Technology, October 2008.
Publication Date: 2008
International Journal of Six Sigma and Competitive Advantage (14792753)4(1)pp. 48-59
Design for Six Sigma (DFSS) is a powerful approach for designing products, processes and services to meet the needs and expectations of the customer while driving down quality costs. It involves the utilisation of powerful and useful statistical tools to predict and improve quality before building prototypes. This paper attempts to study DFSS and the associated experiences of world-class companies. For this purpose, DFSS methodologies are introduced and compared with Six Sigma methodology. The DFSS process is demonstrated and some examples of world-class companies are presented. Finally, some implementation obstacles are addressed and the DFSS training programme is described and emphasised. The findings imply that the methodologies for DFSS are enormous and companies employ different methodologies. Also, it has been found that the role of project leaders is essential for the success of projects and the training programme offered in DFSS should be flexible. Copyright © 2008, Inderscience Publishers.
Publication Date: 2008
International Journal of Information Science and Management (20088310)6(2)pp. 79-98
This study aims at providing an explanation of Electronic Human Resource Management (E-HRM) and introducing its activities and tools. Furthermore, we investigate the effect of various independent variables such as job satisfaction, professional commitment, organizational commitment... on the effectiveness of HRM as a dependent variable. For this purpose, by cluster sampling from Iranian HR managers, 110 of them were chosen to participate in this study. Then, research hypotheses were examined by deploying multiple linear regressions to the data gathered from specially designed questionnaire. Findings indicate that E-HRM tools are rarely used, however, according to the experts' judgment if they are used, they would have a positive effect on the HRM output in Iranian organization. Finally, a model for assessing the effectiveness of HRM was proposed.
Publication Date: 2008
Communications in Computer and Information Science (18650929)12pp. 288-296
Security is very often mentioned as one of the preconditions for the faster growth of e-commerce. Without a secure and reliable internet, customer will continue to be reluctant to provide confidential information online, such as credit card number. Moreover, organizations of all types and sizes around the world rely heavily on technologies of electronic commerce (e-commerce) for conducting their day-to-day business transaction. Providing organizations with a secure e-commerce environment is a major issue and challenging one especially in Middle Eastern countries. Without secure e-commerce, it is almost impossible to take advantage of the opportunities offered by e-commerce technologies. E-commerce can create opportunities for small entrepreneurs in Middle Eastern countries. This requires removing infrastructure blockages in telecommunications and logistics alongside the governance of e-commerce with policies on consumer protection, security of transactions, privacy of records and intellectual property. In this paper, we will explore the legal implications of e-commerce security governance by establishing who is responsible for ensuring compliance with this discipline, demonstrating the value to be derived from information security governance, the methodology of applying information security governance, and liability for non-compliance with this discipline. Our main focus will be on analyzing the importance and implication of e-commerce security governance in developing countries. © Springer-Verlag Berlin Heidelberg 2008.
Publication Date: 2008
TQM Journal (17542731)20(1)pp. 68-86
Purpose - The purpose of this paper is to propose an integrated model of quality function deployment (QFD) and customer relationship management (CRM) for design and delivery processes. Design/methodology/approach - After the literature review, the elements of a CRM business cycle were integrated with different phases in QFD. The proposed model was further developed, based on customer participation in the design and delivery of products/services, as a major stage in CRM in three cases: customer participation in design; delivery; and design and delivery. As a case study, the customer participation in delivery was studied in after-sale services of the Iran Khodro Co., which is the second major carmaker company in Iran. Findings - The results imply that QFD and CRM are complementary approaches and once they are combined, their capabilities are enhanced and managing customer relationship is empowered. According to the case study, personnel monitoring and human resources management (HRM) have been targeted as the first priorities in process parameters and process control characteristics, respectively. Research limitations/implications - Although the developed model involves considerable advantages, due to the different matrixes used for QFD, its use might become time consuming and complicated. Also, gathering information from customers and categorizing them respectively play major roles in effective and strategic CRM. Originality/value - The proposed model provides a means of harnessing the power of the present research innovations and advancements in order to empower customer need assessment, acquisition, development, equity leverage, retention and referrals, as well as prioritization of the features of products/services, processes, and performance indicators, according to the voice of customers. © Emerald Group Publishing Limited.
Publication Date: 2008
International Journal of Process Management and Benchmarking (14606739)2(4)pp. 323-337
A In this paper, an attempt has been made to provide a comprehensive perspective of the integrative approaches and frameworks. For this purpose, the subjects of lean and Six Sigma have been demonstrated separately and compared, and then their integration approaches and frameworks have been studied and discussed. The outcomes imply that integrating lean and Six Sigma creates a win-win situation. The combination of both can provide the philosophy and the effective tools to solve problems and create rapid transformational improvement at lower cost. Potentially, this could increase efficiency and effectiveness, which in turn leads to higher performance. Copyright © 2008 Inderscience Enterprises Ltd.
Publication Date: 2008
Communications in Computer and Information Science (18650929)12pp. 274-287
The purpose of this study is twofold. First, in order to guarantee a coherent discussion about mobile customer relationship management (mCRM), this paper presents a conceptualization of mCRM delineating its unique characteristics because of Among the variety of mobile services, considerable attention has been devoted to mobile marketing and in particular to mobile customer relationship management services. Second, the authors discusses the security risks in mobile computing in different level(user, mobile device, wireless net-work,…) and finally we focus on enterprise mobile security and it’s subgroups with a series of suggestion and solution for improve mobile computing security. © Springer-Verlag Berlin Heidelberg 2008.
Publication Date: 2008
Composite Structures (0263-8223)85(4)pp. 284-292
In this study, a general analytical approach is presented to investigate vibrational behavior of functionally graded shells. Theoretical formulations, based on first order shear deformation shell theory, take into consideration transverse shear deformation and rotary inertia effects. The modal forms are assumed to have the axial dependency in the form of Fourier series whose derivatives are legitimized using Stoke's transformation. Material properties are assumed to be temperature-dependent and graded in the thickness direction according to different volume fraction functions. These functions are assumed to have power-law, sigmoid and exponential distributions. A FGM cylindrical shell made up of a mixture of ceramic and metal is considered. The Influence of some commonly used boundary conditions, the effect of variations of volume fractions and shell geometrical parameters on the vibration characteristics are studied. The results obtained for a number of particular cases show good agreement with those available in the literature. © 2007 Elsevier Ltd. All rights reserved.
In everyday life, people often encounter situations where their personal interests are at odds with the welfare of a larger collective to which they belong. What seems to be an individually rational choice may later have detrimental effects on the wellbeing of the group. Such conflicts of interest are referred to as social dilemmas (Dawes, 1980). Social dilemmas are formally defined as situations in which (1) individual outcomes for non-cooperative behavior or defection are larger than outcomes for cooperative behavior (favoring the collective interest), regardless of how other members in a collective behave; but (2) if all members adhere to this individually rational behavior, all members will acquire a lower payoff in the end as compared to if all had chosen to cooperate in the first place. © 2008 Springer US.
Publication Date: 2008
Nordic Psychology (19012276)60(3)pp. 209-234
This article provides an overview of some selected aspects of social psychological theory and research on justice in the allocation of social resources. We start with a brief outline of the origins of systematic inquiries of justice in social psychology. Six central issues in social justice theory and research are discerned and discussed (the definition, dimensionality, and criteria of justice, the salience of the justice motive, the importance of justice, the formation of justice judgments, the cognitive and behavioral reactions to injustice, and the cross-cultural generality of justice considerations). A selective overview of recent applications, developments, and areas of interest are also presented, and some avenues for future research are suggested. © 2008 Taylor and Francis Group, LLC.
Publication Date: 2008
International Journal of Productivity and Quality Management (17466474)3(2)pp. 206-222
Today's economic climate characterised by increasing competition and structural turbulence will require a higher combined level of productivity and quality than has been the case in the past. This paper has demonstrated the interlinkages among quality and productivity, and for this purpose, similarities of the two important concepts have been reviewed. Major quality factors, which are the possible sources for poor/high productivity have been introduced, and finally, some advanced models have been presented and developed in which, the direct and indirect relationships between quality and productivity are addressed. This study has also highlighted the fact that improving quality plays a fundamental role in increasing operations productivity in organisations. Copyright © 2008 Inderscience Enterprises Ltd.
Publication Date: 2009
Communications in Computer and Information Science (18650929)45pp. 64-75
Today firms deal to customers with variety attitudes and no limited demands. These attitudes are so multiplicity and changeable in nature. Some of them define from face to face deal and organizations try to evaluation in a good manner, but many attitudes of customers are not measurable by traditional ways. Therefore the companies design their structure according to customers' wants. This designing includes change on organization, mangers thought, personnel skills and e.g. Customer's wants depend on its attitude. Besides attitude of customers has several functions. In this research we survey the extent of vendors notice to the customers attitude in their organizational structure based on the functional theory of attitude. In the next step we will show the effect of that vendor's consideration on trust in e-purchasing. To this reason a questionnaire offered to 210 employees of automobile companies. Population was selected from the central office of four large car factories and the research method was descriptive. Results show the companies have noticeable plans for regarding customer's attitude. Further findings demonstrate the significant relationship between use of a well-designed websites by vendors and improve of one and more customer attitude functions and that has affect on their trust in e-buying. © 2009 Springer Berlin Heidelberg.
Publication Date: 2009
International Journal of Information Science and Management (20088310)7(2)pp. 57-65
Iran's Small and Medium Enterprises (SMEs) have been widely introduced in the market these days. In the emerging trend of electronic data interchange, Iran's political, economical and social issues have been diverted to a more aggressive approach to the world of e-commerce, that despite the shadowing issues of the past, Iran already internalized the promising craft of e-commerce through various IT adoption techniques and skills. In line with this, this study is aimed to the growing emergence on Iran's SMEs and how e-commerce contributes to the success of IT adoption. (Ajdari, 2007). This paper would further identify the ways and reasons how Iran thrived to its current status as a raising e-commerce country (Powers and Carvar, 1990) It's the main responsibility of governmental forces to enable organizational and national forces to gain dynamic control over resources and markets for a better e-Commerce take off (Moor & Benbasat, I996). Also, we will investigate fifty SMEs and surveys along with personal interviews will be conducted to locate findings, reasons, causes and effects in this regard. Study will focus on three main areas of SMEs including organizational, environmental and technological aspects. Results indicate the significant perceived value of government support in SMEs development in Iran (Dearing, 1990).
