Mohammad Mirabi; Mohammad Reza Zare Banadkouki
Abstract
selecting an efficient project portfolio among available projects is a vital decision for any project manager. The main questions are which projects can have more long-term benefits for managers or organizations. Due to the complexity of this field of research, today so many approaches are developed ...
Read More
selecting an efficient project portfolio among available projects is a vital decision for any project manager. The main questions are which projects can have more long-term benefits for managers or organizations. Due to the complexity of this field of research, today so many approaches are developed for project selection. Calculation time and the quality of results are two main criteria that almost all researchers have considered on them. In this research, a new hybrid genetic algorithm with new heuristic mutation and cross-over is developed to choose a good portfolio of available projects. The presented algorithm is fast and effective to reach a good result in a reasonable time. Finding a good point to start as an initial population and using a good operator a heuristic mutation and cross-over are the main points of our algorithm. To check the quality of results we compare the developed algorithms with some recent ones in the literature and comparison studies and statistical calculation demonstrate the efficiency of the new genetic algorithm to select a good portfolio.
P. Jeyanthi; T. Saratha Devi
Abstract
An injective map f : E(G) → {±1, ±2, · · · , ±q} is said to be an edge pair sum labeling of a graph G(p, q) if the induced vertex function f*: V (G) → Z − {0} defined by f*(v) = (Sigma e∈Ev) f (e) is one-one, where Ev denotes the set of edges in G that are incident with a vetex v and f*(V ...
Read More
An injective map f : E(G) → {±1, ±2, · · · , ±q} is said to be an edge pair sum labeling of a graph G(p, q) if the induced vertex function f*: V (G) → Z − {0} defined by f*(v) = (Sigma e∈Ev) f (e) is one-one, where Ev denotes the set of edges in G that are incident with a vetex v and f*(V (G)) is either of the form {±k1, ±k2, · · · , ±kp/2} or {±k1, ±k2, · · · , ±k(p−1)/2} U {k(p+1)/2} according as p is even
or odd. A graph which admits edge pair sum labeling is called an edge pair sum graph. In this paper we exhibit some spider graph.
I. Mohammadi; Dara Moazzami
Abstract
We consider online scheduling of jobs with speci c release time on m identical machines. Each job has a weight and a size; the goal is maximizing total weight of completed jobs. At release time of a job it must immediately be scheduled on a machine or it will be rejected. It is also allowed during execution ...
Read More
We consider online scheduling of jobs with speci c release time on m identical machines. Each job has a weight and a size; the goal is maximizing total weight of completed jobs. At release time of a job it must immediately be scheduled on a machine or it will be rejected. It is also allowed during execution of a job to preempt it; however, it will be lost and only weight of completed jobs contribute on pro t of the algorithm. In this paper we study D-benevolent instances which is a wide and standard class and we give a new algorithm, that admits (2m + 4)-competitive ratio. It is almost half of the previous known upper bound for this problem.
Zahraa Marzeh; Maryam Tahmasbi; Narges Mirehi
Abstract
In many industrial and non-industrial applications, it is necessary to identify the largest inscribed rectangle in a certain shape. The problem is studied for convex and non-convex polygons. Another criterion is the direction of the rectangle: axis aligned or general. In this paper a heuristic algorithm ...
Read More
In many industrial and non-industrial applications, it is necessary to identify the largest inscribed rectangle in a certain shape. The problem is studied for convex and non-convex polygons. Another criterion is the direction of the rectangle: axis aligned or general. In this paper a heuristic algorithm is presented for finding the largest axis aligned inscribed rectangle in a general polygon. Comparing with stare of the art, the rectangles resulted from our algorithm have bigger area. We also proposed an approach to use the algorithm for finding a rectangle with general direction.
G. Marimuthu; S. Stalin Kumar
Abstract
An H-magic labeling in a H-decomposable graph G is a bijection f : V (G) ∪ E(G) → {1, 2, ..., p + q} such that for every copy H in the decomposition, ∑νεV (H) f(v) + ∑νεE (H) f(e) is constant. f is said to be H-E-super magic if f(E(G)) = ...
Read More
An H-magic labeling in a H-decomposable graph G is a bijection f : V (G) ∪ E(G) → {1, 2, ..., p + q} such that for every copy H in the decomposition, ∑νεV (H) f(v) + ∑νεE (H) f(e) is constant. f is said to be H-E-super magic if f(E(G)) = {1, 2, · · · , q}. A family of subgraphs H1,H2, · · · ,Hh of G is a mixed cycle-decomposition of G if every subgraph Hi is isomorphic to some cycle Ck, for k ≥ 3, E(Hi) ∩ E(Hj) = ∅ for i ≠ j and ∪hi=1E(Hi) = E(G). In this paper, we prove that K2m,2n is mixed cycle-E-super magic decomposable where m ≥ 2, n ≥ 3, with the help of the results found in [1].
Christian Barrientos; Sarah M Minion
Abstract
Graceful labelings use a prominent place among difference vertex labelings. In this work we present new families of graceful graphs all of them obtained applying a general substitution result. This substitution is applied here to replace some paths with some trees with a more complex structures. Two ...
Read More
Graceful labelings use a prominent place among difference vertex labelings. In this work we present new families of graceful graphs all of them obtained applying a general substitution result. This substitution is applied here to replace some paths with some trees with a more complex structures. Two caterpillars with the same size are said to be \textit{analogous} if thelarger stable sets, in both caterpillars, have the same cardinality. We studythe conditions that allow us to replace, within a gracefully labeled graph,some snakes (or paths) by analogous caterpillars, to produce a new gracefulgraph. We present five families of graphs where this replacement isfeasible, generalizing in this way some existing results: subdivided trees, first attachment trees, path-like trees, two-point union of paths, and armed crowns.
R. Ponraj; Rajpal Singh; S. Sathish Narayanan
Abstract
Let G be a (p, q) graph. Let f : V (G) → {1, 2, . . . , k} be a map. For each edge uv, assign the label gcd (f(u), f(v)). f is called k-prime cordial labeling of G if |vf (i) − vf (j)| ≤ 1, i, j ∈ {1, 2, . . . , k} and |ef (0) − ef (1)| ≤ 1 where vf (x) denotes the number ...
Read More
Let G be a (p, q) graph. Let f : V (G) → {1, 2, . . . , k} be a map. For each edge uv, assign the label gcd (f(u), f(v)). f is called k-prime cordial labeling of G if |vf (i) − vf (j)| ≤ 1, i, j ∈ {1, 2, . . . , k} and |ef (0) − ef (1)| ≤ 1 where vf (x) denotes the number of vertices labeled with x, ef (1) and ef (0) respectively denote the number of edges labeled with 1 and not labeled with 1. A graph with a k-prime cordial labeling is called a k-prime cordial graph. In this paper we investigate 3- prime cordial labeling behavior of union of a 3-prime cordial graph and a path Pn.
Hui Min Meng; HongJin Wang; NianMin Yao; ShunYi Cheng
Abstract
PCIP\underline{ }Tree is a Parallelized memory Confidentiality and Integrity Protection technology (PCIP) method that pre-diffuses and encrypts the data stored in off-chip counter value for confidentiality and integrity protection of data, adding redundant checking data to the protection data block to ...
Read More
PCIP\underline{ }Tree is a Parallelized memory Confidentiality and Integrity Protection technology (PCIP) method that pre-diffuses and encrypts the data stored in off-chip counter value for confidentiality and integrity protection of data, adding redundant checking data to the protection data block to ensure the integrity and confidentiality of the memory data. Then use the Simple Scalar tool to run 10 processors (SPEC2000) benchmark programs to simulation test. The result shows that the PCIP\underline{ }Tree method is greatly improved the running efficiency and the efficiency of encryption methods to compare with the Parallelized Encryption and Integrity Checking Engine (PE-ICE) method, at the same time, through the redundant data to check data integrity is better than using complex Hash algorithm to calculate the checking value and reduce system delay, reduce storage overhead chip, and ensure the real-time encryption and checking.
Yousef Shafahi; Shahaboddin Kermanshahi
Hossein Shahi; Aghil Yousefikoma; Ali Reza Mehrabian
Abstract
A solution to the problem of identification and control of smart structures is presented in this paper. Smart structures with build-in sensors and actuators can actively and adaptively change their physical geometry and properties. As a particular example, a representative dynamic model of a typical ...
Read More
A solution to the problem of identification and control of smart structures is presented in this paper. Smart structures with build-in sensors and actuators can actively and adaptively change their physical geometry and properties. As a particular example, a representative dynamic model of a typical fighter vertical tail, identified as the smart fin, is considered. Piezoelectric patches, which are mounted on the vertical tail, are employed as actuator in the model. The Frequency Response Function (FRF) of the smart fin is obtained from experiment. The corresponding transfer function is then derived using classic system identification (ID) techniques, using MATLAB® system identification toolbox, which is verified with the experimental data. The model obtained using system ID is then used to tune an optimal PID controller to reduce the vibration of the smart structure. To this end, several cost functions are defined and optimized by a genetic algorithm. Next, the obtained controllers are compared with each other and a suitable one is chosen as the system’s controller. Finally, It is shown in simulations that the designed controller is able to reduce the vibration of the smart fin very well.
Seyyed Khatiboleslam Sadr Nejad; Fateme Asjodi
Abstract
Vanadium is distributed widely and scarcely (150 ppm) on the earth. Its major applications are in steelmaking, dye-production and catalyst-fabrication industries. With the ever-increasing demand for this metal, secondary resource-exploitation of such waste materials as spent catalysts is recommended. ...
Read More
Vanadium is distributed widely and scarcely (150 ppm) on the earth. Its major applications are in steelmaking, dye-production and catalyst-fabrication industries. With the ever-increasing demand for this metal, secondary resource-exploitation of such waste materials as spent catalysts is recommended. Many reactions are involved in vanadium-extraction from these resources. Since roasting in comparison with other reactions is too slow, its investigation is crucial for vanadium revitalization. This paper focuses on sodium-carbonate roasting of vanadium oxide and brings about both process kinetics and the governing rate equations. Experiments are carried out at isothermal conditions with different molar ratios of vanadium oxide to sodium carbonate species (1:1, 3:1 and 6:1). Prevailing mechanism and the activation energies of the roasting steps are determined by application of shrinking core model to the pertaining two-phase reaction.
Nasrin Mohammadbeygi; Ali Haghighi Asl; Faramarz Hormozi
Abstract
Cinnamon is the bark the cinnamomi cassia that exhibits many medical properties such as anti-cancer effect and anti-diabetic effect. Moreover, because of its antioxidant activity; it can be used in food industries. Many studies have already reported biological and chemical properties of the cinnamon ...
Read More
Cinnamon is the bark the cinnamomi cassia that exhibits many medical properties such as anti-cancer effect and anti-diabetic effect. Moreover, because of its antioxidant activity; it can be used in food industries. Many studies have already reported biological and chemical properties of the cinnamon extracted essential oil such as their antimicrobial, antifungal, antimosquito, free radical scavenging activity, antioxidant and antipathogenic properties. In this article, the result of treatments for extraction cinnamon oil with high quality or in the other words with higher percentage of cinnamon aldehyde in different thermal powers, different solvent ratios and different solvent pH have been done. For extraction of the essential oil, the water distillation in atmospheric pressure was used. All the essential oils were analyzed with GC and in the same conditions. According to the results the cinnamon oil is not sensitive to the heat power, the best solvent ratio to cinnamon bark is 25 to 1 and the best water pH is 4.11.
Solmaz Babakan; Mehdi Zare; Hossein Memarian
Abstract
Natural hazards are among destructive agents that annually take thousands of lives and impose devastating damages in Iran. Spotting such a high risk areas can help reducing the amount of their probable risk. A 1:500000 liquefaction and landslide hazard zonation map developed for the southern shoreline ...
Read More
Natural hazards are among destructive agents that annually take thousands of lives and impose devastating damages in Iran. Spotting such a high risk areas can help reducing the amount of their probable risk. A 1:500000 liquefaction and landslide hazard zonation map developed for the southern shoreline of the Caspian Sea. This geotechnical hazard map divides the study area to 15 hazard classes (five and three hazard classes for liquefaction and landslide respectively). Removing negative factors affects the landslide hazard map, using effect analysis and reevaluating the accuracy of hazard map, increased the map accuracy by 93.5%. Based on the compiled geotechnical hazard map, about 30% of the study area is prone to low sliding and high liquefaction hazards.
Mohammad Mehdi Montazer Rahmati; Seyyed Jaber Safdari; Hossein Akhgari
Abstract
Holdup was measured at various frequencies, amplitudes, continuous and dispersed phase flow rates for binary systems in a pulsed plate column capable of providing samples at various heights. The binary systems was so selected as to cover a wide spectrum of interfacial tensions. Dispersed phase holdup ...
Read More
Holdup was measured at various frequencies, amplitudes, continuous and dispersed phase flow rates for binary systems in a pulsed plate column capable of providing samples at various heights. The binary systems was so selected as to cover a wide spectrum of interfacial tensions. Dispersed phase holdup was found to increase with height in a logarithmic fashion at conditions away from the flooding point and to become almost invariant with height near flooding conditions. The interfacial tension of the binary system has a large effect on the dispersed phase holdup. In systems having low interfacial tension, a small increase in any of the parameters can increase the holdup significantly and lead to flooding. In systems having high interfacial tension, on the other hand, variations in system parameters do not affect system performance significantly.
Sajjad Haghir Chehreh Ghani; Ali Asghar Khodayari; Mohammad Farough Hosseini
Abdorreza Safari; Yahyallah Tavakkoli
Abstract
The problem of downward continuation of the gravity field from the Earth’s surface to the reference ellipsoid arises from the fact that the solution to the boundary value problem for geoid determination without applying Stokes formula is sought in terms of the disturbing potential on the ellipsoid ...
Read More
The problem of downward continuation of the gravity field from the Earth’s surface to the reference ellipsoid arises from the fact that the solution to the boundary value problem for geoid determination without applying Stokes formula is sought in terms of the disturbing potential on the ellipsoid but the gravity observations are only available on the Earth’s surface. Downward continuation is achieved via Abel-Poisson integral and its derivatives. Before solving downward continuation problem it should be checked the solvability of the problem. The solvability of the problem is guarantied if Picard condition is satisfied. The topic of this paper is the study of solvability of downward continuation problem via Picard condition.
Mohammad Reza Ghasemi; Akbar Azadi
Abstract
One of the major purposes of optimization in civil engineering is to perform a suitable design for the structure. This goal has to fulfill technical criteria and contain the minimum economical costs. Building frames are of the most customary civil engineering structures. Therefore, optimization of these ...
Read More
One of the major purposes of optimization in civil engineering is to perform a suitable design for the structure. This goal has to fulfill technical criteria and contain the minimum economical costs. Building frames are of the most customary civil engineering structures. Therefore, optimization of these types of structures could be of a great concern from the economical viewpoints. One of the current obstacles in such optimization problems is the local convergence debility. Thus, using means of tackling this problem seems necessary. Genetic Algorithm which is one of the optimization methods inspired by nature, has overcome this problem. In order to solve such problems, genetic algorithm needs a multiple analyses of structures. Therefore, in this study attempts were made to introduce and embed new formulae into a newly developed program to handle new techniques for selection and mutation as genetic operations. As for the aspects of application, the introduced techniques were inspected and investigated in the optimization of some planar and special braced steel frames. The outcome through comparisons proclaimed a considerable decrease in numbers of analyses as well as significant increases in the speed of convergence.
Hossein Shokouhmand; Javad Rostami
Abstract
In this paper conjugated heat transfer in thermal entrance region through the sinusoidal wavy channel has been investigated. The fluid flow is assumed to be laminar, steady state, incompressible, and hydrodynamically fully developed. A constant heat flux is assumed to be applied on the outer edge of ...
Read More
In this paper conjugated heat transfer in thermal entrance region through the sinusoidal wavy channel has been investigated. The fluid flow is assumed to be laminar, steady state, incompressible, and hydrodynamically fully developed. A constant heat flux is assumed to be applied on the outer edge of the channel wall. In this study the governing equations including continuity, momentum and energy are solved numerically by a finite volume method (SIMPLE). The flow field for different Reynolds numbers has been obtained using this flow field, pressure loss and skin friction coefficient have been calculated. Also temperature field in both solid and fluid for wide range of effective parameters in conjugated heat transfer such as Peclet number, solid-fluid conductivity ratio and solid thicknesses have been investigated. From the obtained numerical results for thermal field effects of conjugated heat transfer characteristics on fluid mean bulk temperature, solid-fluid interface temperature, solid-fluid interface heat flux and Nusselt number have been calculated. The obtained results have been compared with available numerical and experimental data and a good agreement is achieved.
Shirin Malihi; Hamid Ebadi; Farshid Farnoud Ahmadi; Mehdi Maboudi
Abstract
An important issue in implementation of a GIS system is preparation of data to be entered in GIS. To produce spatial data for GIS using photogrammetric techniques, conventional method is to apply photogrammetric and GIS systems individually (off-line procedure).
This approach is costly, time consuming ...
Read More
An important issue in implementation of a GIS system is preparation of data to be entered in GIS. To produce spatial data for GIS using photogrammetric techniques, conventional method is to apply photogrammetric and GIS systems individually (off-line procedure).
This approach is costly, time consuming and somehow unreliable due to the fact that 3D photogrammetric model is not available at the time of GIS data structuring, To overcome these problems, editing and structuring of spatial data can be carried out simultaneously during feature digitization.
Feature digitizing from photogrammetric models can be performed in an interface CAD environment by real time integration of photogrammetric and CAD systems. Based on this approach, generated data can be saved with standard structure and format defined by CAD environments (e.g., Micro Station)and directly used for GIS without further editing. In this paper, design and development of a software package called Object oriented CAD-Based Photogrammetric System (OCBPS2, version 2) which integrates Photomod and Micro Station systems in an object oriented way, is described. This system carries out real time structuring and editing of spatial data for class of road features by controlling logical relations among road class features and other features.
Vahid Azizi; Hossein Memarian; Arash Khosravi
Abstract
Numerous parameters influence bit selection process, which considering all them is not normally feasible. Existing methods use limited number of these parameters to choose a suitable bit for a specific drilling condition. One of the widely used methods is cost per foot. Specific energy and drilling strength ...
Read More
Numerous parameters influence bit selection process, which considering all them is not normally feasible. Existing methods use limited number of these parameters to choose a suitable bit for a specific drilling condition. One of the widely used methods is cost per foot. Specific energy and drilling strength are another methods currently used for bit selection. Different methods of bit selection and bit lifetime estimation were tested on a gas field, in southern Iran. Although cost per foot method is most widely used, present study showed that similar bits may have different cost per foot in different wells, rock formations or drilling conditions. Therefore, where geological and geothechnical conditions widely vary in a single formation, this method cannot be used alone for bit selection. The specific energy method was also found to have some deficiencies as it is highly dependent on drilling parameters. The outcome of using existing formula for predicting unconfined compressive strength from petrophysical data of oil and gas wells is in fact drilling resistance, which is a very rough estimate of unconfined compressive strength. On the other hand, the drilling strength method, using Young's Modulus and clay content, showed to have rewarding results on the studied field. This method, if used together with cost per foot method, will give better results. The present study also showed that the results derived from the drilling strength method should be modified according to drilling parameters.
Ebrahim Rahimpour; Vahid Rashtchi; Esma'eel Mashhadi Rezapour
Amir Pirouz Ghale; Majid Sanaye Pasand; Hamed Asadi
Abstract
Power system blackouts have become a serious problem for electric utilities especially in recent years. Different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. To counteract each form of system instability, special algorithms have ...
Read More
Power system blackouts have become a serious problem for electric utilities especially in recent years. Different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. To counteract each form of system instability, special algorithms have been designed in the protection system, e.g. Under Frequency Load Shedding (UFLS) and Under Voltage Load Shedding (UVLS) schemes. One of the major weaknesses of these algorithms is that combination of different forms of instability is not considered in their design, while any one form of instability may not occur in its pure form. This is particularly true in highly stressed systems and for cascading events. This paper presents an adaptive algorithm to combine UVLS and UFLS schemes. The purpose of this method is to enhance the flexibility of under frequency relays and increase the security of power system during large disturbances by improving system voltage stability margins. In the proposed algorithm, loads with greater voltage decay are shed sooner. In this way, locations of load shedding become dependent to the location of disturbance and voltage stability margins of the system are enhanced. Indeed, load shedding is performed faster for severe events accompanying large voltage or frequency declines. Using this load shedding method, faster reactions could be obtained for major system failures. This way, system blackouts could be better controlled. Performance of the proposed method is compared with the conventional UFLS method. In this paper, dynamic model of the Khorasan HV network of Iran national grid is used for simulation. This network includes 75 high voltage 400 kV and 132 kV buses with about 2700 MW of generation. Performance of the schemes has been evaluated using dynamic simulations as well as the P-V curves, and reactive power margins for a number of events. Simulation results show that conventional UFLS algorithm will not necessarily result in acceptable voltage stability margins for the system following a disturbance. Meanwhile, the proposed algorithm improves voltage stability margins. The proposed algorithm is suitable for saving system stability after occurrence of major system disturbances.
Farzad Parsa; Abdorreza Sarvghad Moghaddam
Abstract
An experimental study is conducted on three ½ scales, single-story, single-bay, frame specimens. The first specimen was a reinforced concrete frame with solid-brick infill. The second specimen was a reinforced concrete frame with hollow clay perforated-brick infill. The last specimen was a reinforced ...
Read More
An experimental study is conducted on three ½ scales, single-story, single-bay, frame specimens. The first specimen was a reinforced concrete frame with solid-brick infill. The second specimen was a reinforced concrete frame with hollow clay perforated-brick infill. The last specimen was a reinforced concrete frame without any infill. These three specimens were tested by pseudostatic method. Different response parameters are investigated and results are compared with those resulted from analytical approach. The results of the experimental and analytical studies indicate that use of masonry infill increases the lateral stiffness of the reinforced concrete frame. The increase in the stiffness is almost the same for both types of infill considered in this study. Use of masonry infill also increases the ultimate strength of the reinforced concrete frame. However, the strength of the frame in the case of hollow clay-block decays much faster in compare with frame infilled with solid clay-bricks because of a faster rate of failure in hollow blocks. Using masonry infill increases the energy dissipation capability of the reinforced concrete frame. In the case of frame with solid clay-bricks infill, a much more uniform distribution of damages is observed in columns. Comparisons with analytical approach show that analytical method provides a good estimation of initial stiffness of solid-brick infill but its estimations of initial stiffness of perforated-brick infill and inelastic response of both types of masonry infill frames are not in good agreement with the experimental results.
Amir Ta'ebi; Hamid Ghoddousi
Reza Khalili; Mehdi Shirazi; Ahmad Salahi
