Graph Theory Approach to Detect Examinees Involved in Test Collusion

2021 ◽  
pp. 014662162110139
Author(s):  
Dmitry I. Belov ◽  
James A. Wollack
Keyword(s):  
Graph Theory ◽  
Simulated Data ◽  
Connected Components ◽  
Theory Approach ◽  
Important Special Case ◽  
Similarity Indices ◽  
Different Types ◽  
Different Response ◽  
Special Case ◽  
Practical Recommendations

Test collusion (TC) is sharing of test materials or answers to test questions before or during the test (important special case of TC is item preknowledge). Because of potentially large advantages for examinees involved, TC poses a serious threat to the validity of score interpretations. The proposed approach applies graph theory methodology to response similarity analyses for identifying groups of examinees involved in TC without using any knowledge about parts of test that were affected by TC. The approach supports different response similarity indices (specific to a particular type of TC) and different types of groups (connected components, cliques, or near-cliques). A comparison with an up-to-date method using real and simulated data is presented. Possible extensions and practical recommendations are given.

scholarly journals On the number of excursion sets of planar Gaussian fields

2020 ◽  
Vol 178 (3-4) ◽  
pp. 655-698
Author(s):  
Dmitry Beliaev ◽  
Michael McAuley ◽  
Stephen Muirhead
Keyword(s):  
Plane Wave ◽  
Lower Bounds ◽  
Upper And Lower Bounds ◽  
Gaussian Fields ◽  
Important Special Case ◽  
Level Densities ◽  
Excursion Sets ◽  
Nodal Set ◽  
Different Types ◽  
Special Case

Abstract The Nazarov–Sodin constant describes the average number of nodal set components of smooth Gaussian fields on large scales. We generalise this to a functional describing the corresponding number of level set components for arbitrary levels. Using results from Morse theory, we express this functional as an integral over the level densities of different types of critical points, and as a result deduce the absolute continuity of the functional as the level varies. We further give upper and lower bounds showing that the functional is at least bimodal for certain isotropic fields, including the important special case of the random plane wave.

The Arabic Origins of English and Indo-European “Definite Articles”: A Radical Linguistic Theory Approach

2016 ◽  
Vol 4 (6) ◽  
pp. 26
Author(s):  
Zaidan Ali Jassem
Keyword(s):  
Comparative Method ◽  
Linguistic Theory ◽  
General Level ◽  
Theory Approach ◽  
Tree Model ◽  
Linguistic Change ◽  
European Languages ◽  
The Family ◽  
Different Types ◽  
Definite Articles

This paper traces the Arabic origins or cognates of the “definite articles” in English and Indo-European languages from a radical linguistic (or lexical root) theory perspective. The data comprises the definite articles in English, German, French, Spanish, Portuguese, Italian, Romanian, Latin, Greek, Macedonian, Russian, Polish, Sanskrit, Hindi, Bengali, Persian, and Arabic. The results clearly indicate that five different types of such articles emerged in the data, all of which have true Arabic cognates with the same or similar forms and meanings, whose differences are due to natural and plausible causes and different routes of linguistic change, especially lexical, semantic, or morphological shift. Therefore, the results support the adequacy of the radical linguistic theory according to which, unlike the Family Tree Model or Comparative Method, Arabic, English, German, French, Latin, Greek, and Sanskrit not only belong to the same language family, renamed Eurabian or Urban family, but also are dialects of the same language, with Arabic being their origin all because only it shares the whole cognates with them all and because it has a huge phonetic, morphological, grammatical, and lexical variety. They also manifest fundamental flaws and grave drawbacks which plague English and Indo-European lexicography for ignoring Arabic as an ultimate ancestor and progenitor not only in the treatment of the topic at hand but in all others in general. On a more general level, they also show that there is a radical language from which all human languages stemmed and which has been preserved almost intact in Arabic, thus being the most conservative and productive language

Probabilistic Assessment of Reliability and Risk Values by Certification Results

2020 ◽  
pp. 52-67
Author(s):  
Vladimir A. Lapin ◽  
Erken S. Aldakhov ◽  
S. D. Aldakhov ◽  
A. B. Ali
Keyword(s):  
Seismic Risk ◽  
Housing Stock ◽  
Seismic Resistance ◽  
Probabilistic Assessment ◽  
Quantitative Estimates ◽  
Different Types ◽  
Reduce Risk ◽  
First Time ◽  
Structural Solutions ◽  
Practical Recommendations

For the first time in Almaty full passport of apartment stock of multiapartment building was carried out. The structure of the housing stock was revealed with the allocation of groups of buildings according to structural solutions and assessment of their seismic resistance. Based on the results of certification, quantitative estimates of failure probability values for different types of buildings were obtained. Formulas for estimation of quantitative value of seismic risk are obtained. The number of deaths in the estimated zem-shakes was estimated. The results of the assessments will be used for practical recommendations to reduce risk and expected losses in possible earthquakes.

ON THE DENSITY OF HAUSDORFF DIMENSIONS OF BOUNDED TYPE CONTINUED FRACTION SETS: THE TEXAN CONJECTURE

2004 ◽  
Vol 04 (01) ◽  
pp. 63-76 ◽  
Author(s):  
OLIVER JENKINSON
Keyword(s):  
Hausdorff Dimension ◽  
Finite Subset ◽  
Continued Fraction ◽  
Cantor Set ◽  
Computational Method ◽  
Accurate Approximation ◽  
Natural Numbers ◽  
Important Special Case ◽  
The One ◽  
Special Case

Given a non-empty finite subset A of the natural numbers, let EA denote the set of irrationals x∈[0,1] whose continued fraction digits lie in A. In general, EA is a Cantor set whose Hausdorff dimension dim (EA) is between 0 and 1. It is shown that the set [Formula: see text] intersects [0,1/2] densely. We then describe a method for accurately computing dimensions dim (EA), and employ it to investigate numerically the way in which [Formula: see text] intersects [1/2,1]. These computations tend to support the conjecture, first formulated independently by Hensley, and by Mauldin & Urbański, that [Formula: see text] is dense in [0,1]. In the important special case A={1,2}, we use our computational method to give an accurate approximation of dim (E{1,2}), improving on the one given in [18].

scholarly journals Vulnerability Assessment of a Large Electrical Grid by New Graph Theory Approach

2018 ◽  
Vol 16 (2) ◽  
pp. 527-535 ◽  
Author(s):  
J. BEYZA ◽  
J. M. Yusta ◽  
G. J. Correa ◽  
H. F. Ruiz
Keyword(s):  
Graph Theory ◽  
Vulnerability Assessment ◽  
Theory Approach ◽  
Electrical Grid

scholarly journals Exploring the full catalytic cycle of rhodium(i)–BINAP-catalysed isomerisation of allylic amines: a graph theory approach for path optimisation

2017 ◽  
Vol 8 (6) ◽  
pp. 4475-4488 ◽  
Author(s):  
Takayoshi Yoshimura ◽  
Satoshi Maeda ◽  
Tetsuya Taketsugu ◽  
Masaya Sawamura ◽  
Keiji Morokuma ◽  
...  
Keyword(s):  
Graph Theory ◽  
Reaction Mechanism ◽  
Catalytic Cycle ◽  
Theory Approach ◽  
Allylic Amines ◽  
Reaction Route ◽  
Reaction Method ◽  
Mapping Strategy ◽  
Global Reaction ◽  
Induced Reaction

The reaction mechanism of the cationic rhodium(i)–BINAP complex catalysed isomerisation of allylic amines was explored using the artificial force induced reaction method with the global reaction route mapping strategy.

scholarly journals Theoretical treatment of tight-binding inhibition of an enzyme. Ribonuclease inhibitor as special case

1988 ◽  
Vol 253 (2) ◽  
pp. 517-522 ◽  
Author(s):  
J M Fominaya ◽  
J M García-Segura ◽  
M Ferreras ◽  
J G Gavilanes
Keyword(s):  
Tight Binding ◽  
Theoretical Treatment ◽  
Inhibitor Protein ◽  
Ribonuclease Inhibitor ◽  
Rat Testis ◽  
Binding Inhibition ◽  
Different Types ◽  
Functional Consequences ◽  
Inhibitor System ◽  
Special Case

A general treatment of very tight-binding inhibition is described. It was applied to purified endogenous RNAase inhibitor from rat testis. This treatment discriminates among the different types of inhibition and allows for calculation of the inhibition parameters. When very tight-binding inhibitions are studied at similar molar concentrations of both enzyme and inhibitor, a further approach is required. This is also described and applied to the RNAase inhibitor. A Ki value of 3.2 x 10(-12) M was found for this inhibitor protein. On the basis of this result, it was considered inappropriate to classify this type of inhibitor in terms of competitive or non-competitive, as has been done for such inhibitors so far. Functional consequences of this analysis are discussed for the RNAase-RNAase inhibitor system.

scholarly journals Conserving woodland caribou habitat while maintaining timber yield: a graph theory approach

2016 ◽  
Vol 46 (7) ◽  
pp. 914-923 ◽  
Author(s):  
Jonathan L.W. Ruppert ◽  
Marie-Josée Fortin ◽  
Eldon A. Gunn ◽  
David L. Martell
Keyword(s):  
Graph Theory ◽  
Rangifer Tarandus ◽  
High Volume ◽  
Timber Harvesting ◽  
Optimization Approach ◽  
Theory Approach ◽  
Heuristic Procedure ◽  
Woodland Caribou ◽  
Old Growth ◽  
Old Growth Forest

The fragmentation and loss of old-growth forest has led to the decline of many forest-dwelling species that depend on old-growth forest as habitat. Emblematic of this issue in many areas of the managed boreal forest in Canada is the threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). We develop a methodology to help determine when and how timber can be harvested to best satisfy both industrial timber supply and woodland caribou habitat requirements. To start, we use least-cost paths based on graph theory to determine the configuration of woodland caribou preferred habitat patches. We then developed a heuristic procedure to schedule timber harvesting based on a trade-off between merchantable wood volume and the remaining amount of habitat and its connectivity during a planning cycle. Our heuristic can attain 84% of the potential woodland caribou habitat that would be available in the absence of harvesting at the end of a 100 year planning horizon. Interestingly, this is more than that which is attained by the current plan (50%) and a harvesting plan that targets high volume stands (32%). Our results indicate that our heuristic procedure (i.e., an ecologically tuned optimization approach) may better direct industrial activities to improve old-growth habitat while maintaining specified timber production levels.

The Unified Theory of Tubesheet Design - Part III: Comparison with ASME Method and Case Study

2021 ◽  
Author(s):  
Hong-Song Zhu ◽  
Jinguo Zhai ◽  
Guo-Yan Zhou
Keyword(s):  
Heat Exchangers ◽  
Numerical Comparison ◽  
Unified Theory ◽  
Element Analysis ◽  
Theoretical Comparison ◽  
Comparison Results ◽  
Different Types ◽  
Special Case ◽  
Simplified Mechanical Model

Abstract Based on the unified theory of tubesheet (TS) design for fixed TS heat exchangers (HEX), floating head and U-tube HEX presented in Part I and Part II, theoretical and numerical comparisons with ASME method are performed in this paper as Part III. Theoretical comparison shows that ASME method can be obtained from the special case of the simplified mechanical model of the unified theory. Numerical Comparison results indicate that predictions given by the unified theory agree well with finite element analysis (FEA), while ASME results are not accurate or not correct. Therefore, it is concluded that the unified theory deals with different types of HEX in equal detail with confidence to predict design stresses.

Sign in / Sign up

Export Citation Format

Share Document