Search Result

10693

Results Found

Relevance

Filter

Newest

Filter

Most Viewed

Filter

Most Downloaded

Filter

Most Cited

Filter

Pages Count

1070

Go To Page

Search Results/Filters    

Filters

Year

Banks




Expert Group











Full-Text


Issue Info: 
  • Year: 

    1394
  • Volume: 

    1
Measures: 
  • Views: 

    6021
  • Downloads: 

    0
Abstract: 

لطفا برای مشاهده چکیده به متن کامل (PDF) مراجعه فرمایید.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 6021

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0
Issue Info: 
  • Year: 

    1394
  • Volume: 

    46
Measures: 
  • Views: 

    2719
  • Downloads: 

    0
Abstract: 

لطفا برای مشاهده چکیده به متن کامل (pdf) مراجعه فرمایید.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 2719

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0
Issue Info: 
  • Year: 

    2013
  • Volume: 

    2
  • Issue: 

    1
  • Pages: 

    9-16
Measures: 
  • Citations: 

    0
  • Views: 

    699
  • Downloads: 

    157
Abstract: 

A set S of vertices in a graph G is a dominating set if every vertex of V-S is adjacent to some vertex in S. The domination number g (G) is the minimum cardinality of a dominating set in G. The annihilation number a (G) is the largest integer k such that the sum of the first k terms of the non-decreasing degree sequence of G is at most the number of edges in G. In this paper, we show that for any tree T of order n³2, g (T)£3a (T)+2/4, and we characterize the trees achieving this bound.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 699

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 157 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2019
  • Volume: 

    12
  • Issue: 

    45
  • Pages: 

    151-166
Measures: 
  • Citations: 

    0
  • Views: 

    751
  • Downloads: 

    0
Abstract: 

Decimal numbers are one of the most important and useful topics in mathematical education. However, students have trouble with decimal numbers. One way to investigate the reason of difficulty in working decimals for the students is through error analysis. Diagnosis of errors in procedural skills is difficult because of their unstable nature. This study investigates the diagnosis of procedural errors in students’ decimals addition and subtraction performance, by proposing and evaluating a probability-based approach using Bayesian networks. This approach assumes a causal network relating hypothesized decimals addition and subtraction errors to the observed test items. This study is practical and quantitative. The population of this study included all the sixth-grade students of Birjand city in academic year 2017 – 2018. A sample consisted of 407 students was selected through multi-stage sampling method. Network performance was evaluated by two types of testing situations: using binary data (scored as correct or incorrect) and diagnostic use of wrong answers by a multi-choice test. Results showed Bayesian network with binary data had poor performance in errors diagnosis but diagnostic use of students’ wrong answers improved network performance. The Kappa agreement rate for the Bayesian network with wrong answers reached above 90%. Our results suggest that reliable diagnosis of errors can be achieved by using a Bayesian network framework with students’ wrong answers.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 751

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

ALIKHANI S. | SOLTANI N.

Issue Info: 
  • Year: 

    2018
  • Volume: 

    9
  • Issue: 

    4
  • Pages: 

    289-299
Measures: 
  • Citations: 

    0
  • Views: 

    690
  • Downloads: 

    161
Abstract: 

Let 􀜩 = (􀜸 , 􀜧 ) be a simple connected graph. A matching 􀜯 in a graph 􀜩 is a collection of edges of 􀜩 such that no two edges from 􀜯 share a vertex. A matching 􀜯 is maximal if it cannot be extended to a larger matching in 􀜩 . The cardinality of any smallest maximal matching in 􀜩 is the saturation number of 􀜩 and is denoted by 􀝏 (􀜩 ). In this paper we study the saturation number of the corona product of two specific graphs. We also consider some graphs with certain constructions that are of importance in chemistry and study their saturation number.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 690

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 161 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    1399
  • Volume: 

    6
  • Issue: 

    1
  • Pages: 

    39-46
Measures: 
  • Citations: 

    0
  • Views: 

    310
  • Downloads: 

    0
Abstract: 

در سال 2015، حاجی ابوالحسن و علیشاهی عددهای تناوبی گراف ها را به عنوان یک کران پایین برای عدد رنگی گراف ها معرفی کردند. اثبات ارائه شده به وسیله ی آن ها مبتنی برلم تاکر (معادل ترکیبیاتی قضیه بورسوک-اولام) است که یک نتیجه در ترکیبیات توپولوژیکی است. در این مقاله یک اثبات کاملاً ترکیبیاتی برای این قضیه از علیشاهی و حاجی ابوالحسن ارائه می شود.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 310

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Author(s): 

DEHGARDI N.

Issue Info: 
  • Year: 

    2019
  • Volume: 

    5
  • Issue: 

    17
  • Pages: 

    115-120
Measures: 
  • Citations: 

    0
  • Views: 

    571
  • Downloads: 

    0
Abstract: 

A edge 2-rainbow dominating function (E2RDF) of a graph G is a function f from the edge set E(G) to the set of all subsets of the set {1, 2} such that for any edge. . . . . . . . . . . . . . . . . . . . . . .

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 571

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2016
  • Volume: 

    16
  • Issue: 

    5
  • Pages: 

    153-159
Measures: 
  • Citations: 

    0
  • Views: 

    803
  • Downloads: 

    0
Abstract: 

Cavity length estimation is important as supercavity condition is generated. The natural cavity length is function of cavity number and is calculated by relations deduced from experimental results which are different from each other and are not driven from analytical approaches. Literature survey shows that correlations based on cavity length in relation with Reynolds and cavity numbers have not been attempted. The purpose of the present work is to estimate analytical based relations for cavity length with respect to mass transfer, continuity and momentum conservation equations. This attempt, which was conducted by order of magnitude method resulted in three relations. The first analytical based relation calculates cavity length versus cavity number. The obtained relation shows that cavity length is proportional to the inverse square root of cavity number. The second analytical relation calculates cavity length with respect to Reynolds number. It shows cavity length has a proportional relation to Reynolds square root. The third analytical relation considers cavity number with respect to Reynolds number. The third relation shows that cavity number has inverse relation to Reynolds number. Unknown coefficients values of the relations are obtained through comparison with the already existed experimental results. These analytical relations which are an appropriate alternative to experimental based relations estimate cavity length with respect to cavity and Reynolds number.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 803

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
Issue Info: 
  • Year: 

    2020
  • Volume: 

    6
  • Issue: 

    1
  • Pages: 

    109-118
Measures: 
  • Citations: 

    0
  • Views: 

    489
  • Downloads: 

    0
Abstract: 

Introduction: The graph is a mathematical model for a discrete set whose members are interlinked in some way. The members of this collection can be the different parts of the earth and the connections between them are bridges that tie them together (like the Konigsberg problem). Graph theory is one of the important issues in discrete mathematics, which studies graphs and modeling issues by them. In 1736, Leonard Euler established the graph theory for solving the Konigsberg Bridge problem. But James Joseph Sylvester was the first to use the word "graph" in 1878 to name these mathematical models. In graph theory, graph coloring is a special case of graph labeling; it is an assignment of labels traditionally called "colors" to elements of a graph subject to certain constraints. In its simplest form, it is a way of coloring the vertices of a graph such that no two adjacent vertices share the same color; this is called a vertex coloring. Similarly, an edge coloring assigns a color to each edge so that no two adjacent edges share the same color, and a face coloring of a planar graph assigns a color to each face or region so that no two faces that share a boundary have the same color. The convention of using colors originates from coloring the countries of a map, where each face is literally colored. Graph coloring enjoys many practical applications as well as theoretical challenges. Beside the classical types of problems, different limitations can also be set on the graph, or on the way a color is assigned, or even on the color itself. It has even reached popularity with the general public in the form of the popular number puzzle Sudoku. Graph coloring is still a very active field of research. This paper is concerned with a specific coloring, say the distinguishing coloring which is originated from a classic elementary problem, Frank Rubin's key problem, which Stan Wagon circulated in the Macalester College problem column: Professor X, who is blind, keeps keys on a circular key ring. Suppose there are a variety of handle shapes available that can be distinguished by touch. Assume that all keys are symmetrical so that a rotation of the key ring about an axis in its plane is undetectable from an examination of a single key. How many shapes does Professor X need to use in order to keep n keys on the ring and still be able to select the proper key by feel? The surprise is that if six or more keys are on the ring, there need only be 2 different handle shapes; but if there are three, four, or five keys on the ring, there must be 3 different handle shapes to distinguish them. The answer to the key problem depends on the shape of the key ring. A labeling of a graph G, ɸ : V(G) → {1, 2, … , r}, is said to be r-distinguishing if no automorphism of G preserves all of the vertex labels. The point of the labels on the vertices is to destroy the symmetries of the graph, that is, to make the automorphism group of the labeled graph trivial. Consequently, we define the distinguishing number of a graph G by D(G)=min {r| G has a labeling that is r-distinguishing}. Similarly, the distinguishing index D′ (G) of a graph G is the least integer d such that G has an edge labeling with d labels that is preserved only by a trivial automorphism. Let G be a connected graph of order n ≥ 3 and let c: E(G) → {1, 2, … , k} be a coloring of the edges of G (where adjacent edges may be colored the same). For each vertex v of G, the color code of v with respect to c is the k-tuple c(v) = (a1, a2, … , ak), where ai is the number of edges incident with v that are colored i (1 ≤ i ≤ k). The coloring c is detectable if distinct vertices have distinct color codes. The detection number det(G) of G is the minimum positive integer k for which G has a detectable k-coloring. Material and methods: We use cycle rank parameter and first consider the case Ψ ≤ and prove that D'(G) ≤ det(G). and then using spanning trees we obtain an upper bound for distinguishing number. Results and discussion: In this paper, we consider the relationship between the distinguishing number and index with the detection number of a graph. In particular, we show that the distinguishing index of a connected graph is at most equal with the detection number, i. e., D'(G) ≤ det(G). Conclusion: The following conclusions were drawn from this research. An upper bound for D(G) by the detection number of its spanning trees. The upper and lower bounds for the distinguishing number by the detection number of a graph. Every detectable coloring is a distinguishing labeling of the edges of a graph. The upper bounds for the distinguishing index by the detection number of a graph.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 489

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesDownload 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesCitation 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic ResourcesRefrence 0
litScript
telegram sharing button
whatsapp sharing button
linkedin sharing button
twitter sharing button
email sharing button
email sharing button
email sharing button
sharethis sharing button