eng
Iranian Institute of Industrial Engineering
Journal of Industrial and Systems Engineering
1735-8272
1735-8272
2010-04-01
4
1
1
17
4018
Congestion Pricing: A Parking Queue Model
Richard C. Larson
1
Katsunobu Sasanuma
2
Engineering Systems Division, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA
Heinz College, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 USA
Drivers in urban neighborhoods who patrol streets, seeking inexpensive on-street parking create a significant fraction of measured traffic congestion. The pool of drivers patrolling at any time can be modeled as a queue, where ‘queue service’ is the act of parking in a recently vacated parking space and queue discipline is SIRO – Service In Random Order. We develop a queueing model of such driver behavior, allowing impatient drivers to abandon the queue and to settle for more expensive off-street parking. We then relate the model to the economic theory of congestion pricing, arguing that price differentials between on-street and off-street parking should be reduced in order to reduce traffic congestion. Reducing the number of “patrolling drivers” often can reduce urban road congestion significantly, in some cases as effectively as technologically expensive road pricing schemes that cordon off the center city.
http://www.jise.ir/article_4018_b3602eb0f54ec792f1f7eb7840cdcf91.pdf
Queuing
Traffic
Parking
Markovian model
eng
Iranian Institute of Industrial Engineering
Journal of Industrial and Systems Engineering
1735-8272
1735-8272
2010-04-01
4
1
18
32
4019
Budgetary Constraints and Idle Time Allocation in Common-Cycle Production with non-zero Setup Time
Rasoul Haji
haji@sharif.edu
1
Alireza Haji
ahaji@sharif.edu
2
Ali Ardalan
3
Dept. of Industrial Engineering, Sharif University of Technology, Teharan, Iran
Dept. of Industrial Engineering, Sharif University of Technology, Teharan, Iran
College of Business and Public Administration, Old Dominion University, Virginia 23529
Economic lot size scheduling problem (ELSP) for a multi-product single machine system is a classical problem. This paper considers ELSP with budgetary constraint as an important aspect of such systems. In the real world situations the available funds for investment in inventory is limited. By adopting the common cycle time approach to ELSP, we obtain the optimal common cycle which minimizes the total inventory ordering and holding costs for the case of nonzero setup times. One aspect of the scheduling is to decide what should be the sequence of production runs and how the idle times shall be distributed in the common cycle time. For such a sequencing problem, we consider two cases: a) the common cycle time is given, and b) the common cycle time is a decision variable. In the literature, scheduling rules are introduced for both cases, which assume that the total idle time is located at the end of each cycle. This paper relaxes this assumption and provides: i) a rule to optimize the production sequence and the length of idle times before (or after) producing each item, for both cases (a) and (b), and ii) the optimal common cycle for case (b). The presented rule is interestingly general, simple and easy-to-apply.
http://www.jise.ir/article_4019_17ac6384ec52dded9c646a4c8e6d3227.pdf
ELSP
sequencing
Inventory control
eng
Iranian Institute of Industrial Engineering
Journal of Industrial and Systems Engineering
1735-8272
1735-8272
2010-04-01
4
1
33
46
4020
Contour Crafting Process Plan Optimization Part I: Single-Nozzle Case
Jing Zhang
1
Behrokh Khoshnevis
2
Department of Industrial & Systems Engineering, University of Sothern California, USA
Department of Industrial & Systems Engineering, University of Sothern California, USA
Contour Crafting is an emerging technology that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. The Contour Crafting technology scales up automated additive fabrication from building small industrial parts to constructing buildings. Tool path planning and optimization for Contour Crafting benefit the technology by increasing the efficiency of construction especially for complicated structures. The research reported here has aimed at providing a systematic solution for improving the overall system efficiency and realizing the Contour Crafting technology for building customdesigned houses. In Part-I of this paper, an approach is presented to find the optimal tool path for the single nozzle Contour Crafting system. The model developed incorporates the physical constraints of the technology as well as some practical construction issues. In Part-II several algorithms are presented to find the collision-free tool paths for the multiple-nozzle system based on the algorithm developed for the single nozzle approach.
http://www.jise.ir/article_4020_933aa9953ee6a7acf0f3b91a4c251c55.pdf
Contour crafting
Tool path planning
optimization
eng
Iranian Institute of Industrial Engineering
Journal of Industrial and Systems Engineering
1735-8272
1735-8272
2010-04-01
4
1
47
58
4021
A Two-Phase Robust Estimation of Process Dispersion Using M-estimator
Hamid Shahriari
1
Orod Ahmadi
2
Amir H. Shokouhi
3
Department of Industrial Engineering, K.N. Toosi University of Technology, Tehran, Iran
Department of Industrial Engineering, K.N. Toosi University of Technology, Tehran, Iran
Department of Industrial Engineering, K.N. Toosi University of Technology, Tehran, Iran
Parameter estimation is the first step in constructing any control chart. Most estimators of mean and dispersion are sensitive to the presence of outliers. The data may be contaminated by outliers either locally or globally. The exciting robust estimators deal only with global contamination. In this paper a robust estimator for dispersion is proposed to reduce the effect of local contamination when estimating the parameters. The results have shown that the introduced estimator is more precise in estimating the dispersion when there are outliers within the subgroups. Simulation results indicate that robustness and efficiency of the proposed dispersion estimator is considerably high and its sensitivity to the changes in mean and standard deviation of any subgroup is roughly lower than the other estimators being compared.
http://www.jise.ir/article_4021_1ea1b7cce16a3bf07ce9f7fd2aadc3d0.pdf
Dispersion Estimator
Local Contamination
Global Contamination
Robust
Estimator
M-estimator
Bisquare Function
eng
Iranian Institute of Industrial Engineering
Journal of Industrial and Systems Engineering
1735-8272
1735-8272
2010-04-01
4
1
59
76
4022
The Effect of Gauge Measurement Capability and Dependency Measure of Process Variables on the MCp
Davood Shishebori
1
Ali Zeinal Hamadani
hamadani@cc.iut.ac.ir
2
Department of Industrial Engineering; Isfahan University of Technology; Iran
Department of Industrial Engineering; Isfahan University of Technology; Iran
It has been proved that process capability indices provide very efficient measures of the capability of processes from many different perspectives. These indices have been widely used in the manufacturing industry for measuring process reproduction capability according to manufacturing specifications. In the past few years, univariate capability indices have been introduced and used to characterize process performance, but are comparatively neglected for multivariate processes where multiple dependent characteristics are involved in quality measurement. Also, most of researches related to process capability indices have assumed no gauge measurement errors. Unfortunately, such an assumption does not reflect real situations accurately even with highly sophisticated advanced measuring instruments. Conclusions drawn from process capability analysis are hence unreliable. In this paper, we consider the effect of process variables correlation coefficient on the multivariate process capability index (MCp) for different gauge measurement capabilities. Also, with respect to correlation coefficient and measurement capability we investigate the statistical properties of the estimated MCp. The results indicate that gauge measurement capability has an important role in determining process capability. This factor would increase the effect of correlation coefficient on estimating the process capability, such that for different gauge measurement capabilities, correlation coefficients will change the results of estimating and testing the process capability.
http://www.jise.ir/article_4022_28507418f1472aa715e15c8d149f9714.pdf
Capability analysis
Correlation coefficient
Critical value
Hypothesis testing
Multivariate process
Gauge measurement errors