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P.amiripour, M.bijanzadeh, M.rostamy-Malkhalifeh, M.najafi, Volume 1, Issue 1 (10-2011)
Abstract
Learning disability (LD) is common problem in present world. Teachers and parents seek
the newest instructional methods always. In this research, LD students in particular dyscalculia
students are considered at elementary level. Assistive technology (AT) as assistive tools are designed
and constructed to help LD students. One of tools of AT is software. The aim of this study is to
introduce and design new mathematical software. Via quasi-experimental method, two basic addition
and subtraction operations are taught through mathematical software with its special features for LD
students at elementary level. Then findings are analyzed thereby ANOVA and sheffe tests. The results
indicated that this technology has effect on the performance of these students and also, it is studied
that the effect of using AT (Math Explorer software) on increasing ability of mathematical problem
solving for dyscalculia students do not follow gender that is there is not significant difference between
favorite performance of girl and boy LD students.
Keywords: Learning Disabled Students, Dyscalculia Students, Assistive Technology, Math Explorer,
Ability.
R. Shahverdi, F. Rezai Balf, A. Ebrahimnejhad, M. Hatefi, Volume 1, Issue 1 (10-2011)
Abstract
Technique of Data Envelopment Analysis (DEA) involves methods conducted for desirable
objective management of Decision Making Unit (DMU) that is same increasing of efficiency level.
Data envelopment analysis furthermore determines the efficiency level, provides situation, removes
inefficiency with evaluated benchmarking information. In this paper the use of the improvement
Least-Distance measure with relation previous model by coplanar DMU, is proposed for
computational dissipation at assess distance on these interior combinations, for determination the
shortest projection from a considered unit to the strongly efficient production frontier. Therefore locate
nearest path to improvement efficiency the evaluated DMU.
Keywords: Data Envelopment Analysis, Least Distance, Coplanar DMU, Benchmarking.
H. Azizi, R. Jahed, Volume 1, Issue 1 (10-2011)
Abstract
The performances of decision-making units (DMUs) can be evaluated from two different
points of view optimistic and pessimistic and accordingly, two different efficiencies can be calculated
for each DMU: the best relative efficiency and the worst relative efficiency. In the conventional
methods of data envelopment analysis (DEA), only the best relative efficiency is evaluated. It is
argued here that both efficiencies must be considered simultaneously, and any approach that considers
only one of them will be biased. In this paper, it is proposed that to integrate both efficiencies in the
form of an interval evaluates the overall performance of each DMU. To this end, a virtual DMU is
used called the ideal DMU. The new DEA models with upper and lower bounds on efficiency are
called the bounded DEA models. A numerical example is presented to illustrate the application of the
proposed DEA models.
Keywords: Data Envelopment Analysis (DEA), Optimistic and Pessimistic Efficiencies, Bounded
DEA Models, Efficiency Interval.
T. Allahviranloo, N. Mikaeilvand, F. Hoseinzadeh Lotfi, . Fallah Jelodar, Volume 1, Issue 1 (10-2011)
Abstract
As can be seen from the definition of extended operations on fuzzy numbers, subtraction
and division of fuzzy numbers are not the inverse operations to addition and multiplication . Hence,
to solve the fuzzy equations or a fuzzy system of linear equations analytically, we must use methods
without using inverse operators. In this paper, a novel method to find the solutions in which 0 is not
the inner point of supports, of fully fuzzy linear systems (shown as FFLS ) is proposed, if they exist
by an analytic approach. The system's parameters were splitted into two groups of nonpositive and
nonnegative by solving a multi objective linear programming problem, MOLP , and employing an
embedding method to transform n× n FFLS to 2n× 2n parametric form linear system and hence,
transforming operations on fuzzy numbers to operations on functions. And finally, numerical
examples are used to illustrate this approach.
Keywords: Fuzzy Numbers, Fully Fuzzy Linear System, Systems of Fuzzy Linear Equations,
Embedding Method, Splitting Method.
B. Maleki Vishkaei, M. Ebrahimnezhad Moghadam Rashti, Volume 1, Issue 1 (10-2011)
Abstract
The required storage space and the material handing cost in a warehouse hinge on the
storage implementation decision. Effects of storage area reduction on order picking and storage space
cost are incorporated. Moreover, merchandises which are in the same shape and can be stored beside
each other easily or goods that don't cause any danger like causing a fire if be in touch with each other,
can be stored in one class together. In this paper first a multi-objective class based storage model is
presented in which two objectives are considered one is the sum of storage space cost and handing
cost and the other is the quantitative objective "efficiency of storing products in one class". The
demand rates and the second objective are evaluated with linguistic values. Fuzzy dynamic approach
will be used to solve the proposed model considering an illustrative example to clarify it.
S. S. Hashemin, Volume 1, Issue 1 (10-2011)
Abstract
This paper discusses that the fuzzy metagraphs can be used as a tool for scheduling and
control of fuzzy projects. Often, available resources for executing projects may be limited. It is
assumed the resources required to accomplish each activity of project (metagraph edges) is renewable.
One of the common methods for scheduling projects is using the min-slack. So, first, the forward and
backward computations for deterministic metagraphs are described. Then, assuming that the
completion time of activities are positive trapezoidal fuzzy numbers, the forward and backward
computations are generalized for fuzzy metagraphs. Consequently, completion time of project, earliest
and latest time of start and end of activities and floating time of them are obtained as fuzzy numbers.
Also, critical activities and critical paths are defined. Then, for scheduling, by using the selected
ranking method, the activities of project (metagraph edges) based on min-slack ascending were
ordered. Through some numerical examples, calculation steps and the results are illustrated.
R. Eslami, M. Khoveyni, Volume 1, Issue 1 (10-2011)
Abstract
The purpose of this study is to utilize a new method for ranking extreme efficient decision
making units (DMUs) based upon the omission of these efficient DMUs from reference set of
inefficient and non-extreme efficient DMUs in data envelopment analysis (DEA) models with constant
and variable returns to scale. In this method, an L2- norm is used and it is believed that it doesn't have
any existing problems of such methods. Finally, two numerical examples for illustration and
comparing the proposed method with other ranking approaches are presented.
Keywords: Data Envelopment Analysis (DEA), Ranking, Efficiency.
M. M. Movahedi, S. Y. Abtahi,, M. Motamedi, Volume 1, Issue 1 (10-2011)
Abstract
Efficiency measurement is critical for industries where firms do not face strong competition,
as we cannot rely on the market to discipline the firms' efficiency. Railway is a typical example. At the
same time the fact that railway produces multiple outputs using the common set of inputs calls for a
delicate and sophisticated treatment in measuring the efficiencies. In this article, the DEA method is
used to determine RAI (RahAhan Iran) efficiency comparison with other countries. The scale
efficiency rate of RAI was calculated and showed the percentage of 0.564. Finally, by analyzing this
performance, a suitability in inputs and outputs for reaching the efficiency boundary was resulted.
M. Bamenimoghadam, N. Najmi Sarooghi, Volume 1, Issue 2 (11-2011)
Abstract
Today, quality improvement and cost reduction are key factors for achieving business
success, growth and position. One of the primary tools for quality improvement and cost reduction in
online activities of statistical process control is control charts. As the need for monitoring several
correlated quality characteristics is extensively growing, the use of multivariate control charts
becomes more popular. Among these, the control chart is the most popular due to many
advantages. In this paper, the variable sampling scheme is studied to increase the power of the fixed
sampling rate (
)
control chart to show small shifts. In this study, one of the parameters of
control chart, e.g., the sample size, vary between three values, depending on the most recent
value.
The design of
control chart with three variable sample sizes (
3
) from the statistical and
economic perspective has been investigated, when the shift in the process mean does not occur at the
beginning but at some random time in the future. Therefore, the Markov Chain approach used to
develop the cost function. Then, the genetic algorithm (
GA
) is applied to search for the optimal values
of the parameters of the
3
control chart. Finally, numerical comparisons among
and
3
schemes are made and discussed.
Keywords:
Multivariate T
2
Control Chart with Three Variable Sample Sizes (3VSS), Small Shifts,
Markov Chain, Genetic Algorithm.
R. Ramezanian, M. Gorji Ashtiani , Volume 1, Issue 2 (11-2011)
Abstract
In this paper, there are two competitors in a planar market. The first competitor, called,
the leader, opens new facilities. After that, the second competitor, the follower, reacts to the leader’s
action and opens r new facilities. The leader and the follower have got some facilities in advance in
this market. The optimal locations for leader and follower are chosen among predefined candidate
locations. In this paper, it is assumed that the demand is inelastic. Considering the huff model,
customers share their demand among all facilities, probabilistically. The leader’s objective function is
the maximization of its market share after the follower’s new facilities entry. The leader and follower
problems are solved via an exact solution method.
Keywords: Competitive Location, Leader-Follower, Huff-Type, Market Share.
R. Ramezanian, M. Saidi-Mehrabad, D. Rahmani, Volume 1, Issue 2 (11-2011)
Abstract
Flow shop scheduling problem with missing operations is studied in this paper. Missing
operations assumption refers to the fact that at least one job does not visit one machine in the
production process. A mixed-binary integer programming model has been presented for this problem
to minimize the makespan. The genetic algorithm (GA) and tabu search (TS) are used to deal with the
optimization problem. According to computational experiments on data sets, it is suggested that GA is
a more appropriate method to solve this problem. GA can reach good-quality solutions in short
computational time, and can be used to solve large scale problems effectively.
Keywords: Flow Shop Scheduling, Missing Operation, Mixed-Binary Integer Programming, Genetic
Algorithm, Tabu Search.
N. Najafli, B. Farnoushfar, M. Nasiri, B. Minaei, Volume 1, Issue 2 (11-2011)
Abstract
Risk management is one of the most prominent concepts which has recently been brought
into sharp focus regarding security issues in computer networks. Scientifically speaking, risk in the
field of network security is a generalized matter leading the organization to the provision of
resolutions which target resources and profits of the organization. This paper has discussed what
methods are to be adopted with respect to identification and classification of risk assessment and
evaluation of computer networks using data mining. The proposed method uses support vector
machine to generate and analyze results of risk evaluation. Considering available resources in the
organization, the tasks performed by means of this method are of high accuracy therefore, results are
hereby in accordance with theories of management and security and based on resources and
organizational profits depending on adjustable parameters as inputs. Outcomes of this study can be
implemented in a dynamically real-time defensive system.
Keywords: Risk Management, Risk Evaluation Model, Network Vulnerability, Data Mining, Support
Vector machine.
M. Nasiri, L. Sadat Taghavi, B. Minaee, Volume 1, Issue 2 (11-2011)
Abstract
Abstract as a single objective one. Measures like support, confidence and other interestingness criteria which
are used for evaluating a rule, can be thought of as different objectives of association rule mining
problem. Support count is the number of records, which satisfies all the conditions that exist in the
rule. This objective represents the accuracy of the rules extracted from the database. Confidence
represents the proportion of records for which the prediction of the rule (or model in the case of a
complete classification) is correct, and it is one of the most widely quoted measures of quality,
especially in the context of complete classification. Interestingness measures how much interesting the
rule is. Using these three measures as the objectives of rule mining problem, this article uses a
Simulated Annealing algorithm to extract some useful and interesting rules from any Market-basket
type databases. The experimental results show that the algorithm may be suitable for large and noisy
datasets but don’t stay in local minimum.
Keywords: Simulated Annealing, Numeric Association Rule Mining.
M.najafi, P.aminpour, M. Rostamy-Malkhalifeh, Volume 1, Issue 2 (11-2011)
Abstract
Blind students have limitations that their teachers have to apply efficient educational
methods for them. Since mathematics concepts are abstract for blind students and they cannot
understand these concepts deeply, this research has tried that used and introduced cooperative learning
method for this reason. Blind students have high listening capacity then cooperative learning method
can promote other their capacities. Through quasi-experimental method, 40 girl blind students are
chosen at third grade of elementary level. Basic mathematical operations are taught via cited method.
The results of T-tests indicated that cooperative learning can be positive effect on solving capacity of
blind students for basic mathematical concepts.
Keywords: Blind, Mathematical Concepts, Cooperative Learning Method, Teaching.
M. Ebrahimnezhad, B. Maleki Vishkaei, H. R. Pasandideh, J. Safari , Volume 1, Issue 2 (11-2011)
Abstract
This paper proposes a new mathematical model for multi-objective redundancy allocation
problem (RAP) without component mixing in each subsystem when the redundancy strategy can be
chosen for individual subsystems. Majority of the mathematical model for the multi-objective
redundancy allocation problems (MORAP) assume that the redundancy strategy for each subsystem is
predetermined and fixed. In general, active redundancy has received more attention in the past.
However, in practice both active and cold-standby redundancies may be used within a particular
system design and the choice of the redundancy strategy becomes an additional decision variable. The
proposed model for MORAP simultaneously maximizes the reliability and the net profit of the system.
And finally, to clarify the proposed mathematical model a numerical example will be solved.
Keywords: Redundancy Allocation Problem, Serial-Parallel System, Redundancy Strategies,
MORAP.
F. Rezai Balf, R. Shahverdi, Volume 1, Issue 2 (11-2011)
Abstract
In data envelopment analysis, anyone can do classification decision units with efficiency
scores. It will be interesting if a method for classification of DMUs without regarding to efficiency
score is obtained. So in this paper, the classification of Decision Making Units (DMUs) is done
according to the additive model without being solved for obtaining scores efficiency. This is because it
is known that the additive model is the simplest non-radial model in DEA. In fact, the classification of
DMUs to a set of efficient, weak efficient, and inefficient units, based upon feasibility concept is done
here. Especially, the models and theorems for this aim are presented.
Keywords: Data Envelopment Analysis, Classification, Decision Making Units.
K. V. Chandratre, K. N. Nandurkar, Volume 1, Issue 3 (12-2011)
Abstract
In today’s economy, manufacturing plants must be able to operate efficiently and respond
quickly to changes in the product mix and demand.[1] Layout design has a significant impact on
manufacturing efficiency. Initially, it was treated as a static decision but due to improvements in
technology, it is possible to rearrange the manufacturing facilities in different scenarios. The Plant
layout affects on the total cost in the industry. Nowadays Dynamic layout is becoming an important
issue. Dynamic layout is the different layout at different time periods to satisfy the needs of industry
due to change in product, or reduced product life cycle, or change in demand. Layout problem is a
quadratic assignment problem, and for larger size problems it becomes impossible to be solved. So, for
solving this problem Meta heuristic algorithms are used. In this paper, Dynamic layout problem is
solved using Genetic algorithm. This Dynamic Problem is restricted up to two-time periods only.
Keywords: Dynamic Layout, Heuristics, Genetic Algorithm.
M. Alinaghian, M. Ghazanfari, A. Salamatbakhsh, N. Norouzi, Volume 1, Issue 3 (12-2011)
Abstract
This paper presents a novel multi-objective mathematical model of a periodic vehicle
routing problem (PVRP) in a competitive situation for obtaining more sales. In such a situation, the
reaching time to customers affects the sale amount therefore, distributors intend to service customers
earlier than other rivals for obtaining the maximum sale. Moreover, a partial driver’s benefit is related
to the amount of their sale thus, the balance of goods based on the vehicles capacity is important. Due
to its complexity, it is so difficult to optimally solve this problem in a reasonable computational time.
Hence, two algorithms are proposed based on multi-objective particle swarm optimization (MOPSO)
and NSGAII algorithm. A comparison of our results with three performance metrics confirms that the
proposed MOPSO is an efficient algorithm for solving the competitive PVRP with a reasonable
computational time.
Keywords: Periodic Vehicle Routing Problem, Competitive Time Windows, Multi Objective
Optimization, MOPSO.
F. Hosseinzadeh Lotfi, N. Ebrahimkhany Ghazy, S. Ebrahimkhany Ghazy, M. Ahadzadeh Namin, Volume 1, Issue 3 (12-2011)
Abstract
Data envelopment analysis (DEA) is a method for recognizing the efficient frontier of
decision making units (DMUs).This paper presents a Context-dependent DEA which uses the interval
inputs and outputs. Context-dependent approach with interval inputs and outputs can consider a set of
DMUs against the special context. Each context shows an efficient frontier including DMUs in
particular levels. The Context-dependent DEA with interval inputs and outputs can measure (i) the
attractiveness when DMUs showing weaker performance are selected as an appraisal context, and (ii)
the interval progress when DMUs showing better performance are selected as the appraisal context.
Keywords: Interval Inputs and Outputs, Context-Dependent Data Envelopment Analysis,
Attractiveness, Progress, Value Judgment.
K. Shahroudi, G. Mohammadi, M. Taleghani, Volume 1, Issue 3 (12-2011)
Abstract
Traditional DEA models ignore the internal process of production systems and are not able
to identify the cause of deficiency in efficiencies measuring. At this research, traditional DEA model
and two-stage DEA model were used to measure the efficiency of Iranian private insurance companies
during 2007-2009. The results indicated that the traditional DEA model is not suitable for such kind of
network systems. In marketing perspective, Melat and Hafez companies were efficient during the
study period. But these two companies are not efficient due to weakness in investment sub-process.
Wilcoxon’s signed-rank test was used to identify the main reason of weakness between efficiency
average of marketing sub-process and investment sub-process with significant level of 0.01. The
results indicated that the investment weakness is the main reason of insurance companies’ deficiencies
during the studied period.
Keywords: Two-Stage DEA, Insurance Industry, Marketing Sub-Process, Investment Sub-Process.
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