Developing a Representative Soil Response Model

2020 ◽  
Author(s):  
Ryan Phillips ◽  
Michael Martens
Keyword(s):  
Numerical Modelling ◽  
Field Test ◽  
Test Procedure ◽  
Testing Procedure ◽  
Testing System ◽  
Response Model ◽  
Response Curves ◽  
Soil Response ◽  
Definition Of ◽  
Initial Results

Abstract A testing procedure and methodology has been developed to provide more realistic pipe-soil response curves which account for differing soil types, pipe and trench geometries and backfill conditions. Such curves increase the reliability of the pipe-soil interaction analyses, and help to reduce overall conservatism in definition of springs for pipe-soil interaction. Pipe-soil spring response is now generally determined by geotechnical engineering estimation of the soil properties which are used as inputs to simple pipe-soil interaction guidelines. A new dual axis field test procedure, including equipment and interpretative methodology has been developed to directly measure soil response curves for bearing and shear interactions. A numerical modelling protocol interprets these measurements to directly assess pipe-soil spring responses, rather than relying on simplified guidelines. This paper includes the field and laboratory testing and associated numerical modelling used in the development of the pipe-soil spring response process, as well as the initial results of trials with the new dual axis testing system. The next step for this initiative will be the development of a database of field test data, from which significant advancements can be made to further improve pipe spring recommendations.

A North American Perspective on Service Life and Durability of Concrete Bridges

2018 ◽  
Author(s):  
Neil A. Cumming
Keyword(s):  
Service Life ◽  
Numerical Modelling ◽  
North American ◽  
Concrete Bridges ◽  
Formal Service ◽  
Historical Materials ◽  
American Perspective ◽  
Definition Of ◽  
Further Development ◽  
Empirical Methodology

This paper describes the author’s views on durability and service life of concrete bridges in North America, considering the past, present and future. Historical materials and practices have resulted in disappointing durability and service life that does not meet modern expectations. In recent years formal service life analysis and prediction has been implemented as part of the design process for major projects, typically involving numerical modelling of time to corrosion, and mitigation or avoidance of other forms of deterioration by empirical methodology. These efforts are, however, hampered by a lack of an accepted service life design standard which is adapted to North American practice and materials. Work is under way to answer this need. In the future, further development is needed to provide a better match between expectations and reality, a more practical definition of “service life”, validation of design features implemented to mitigate or avoid deterioration for which there are no available time-based models, and improved validation of numerical modelling parameters that describe exposure conditions and material resistances.

Nominal Response Model Is Useful for Scoring Multiple-Choice Situational Judgment Tests

2018 ◽  
Vol 23 (2) ◽  
pp. 342-366 ◽  
Author(s):  
Jiyun Zu ◽  
Patrick C. Kyllonen
Keyword(s):  
Multiple Choice ◽  
Test Theory ◽  
Parameter Estimates ◽  
Response Model ◽  
Scoring Methods ◽  
Response Curves ◽  
Situational Judgment ◽  
Situational Judgment Tests ◽  
Nominal Response Model ◽  
Nominal Response

We evaluated the use of the nominal response model (NRM) to score multiple-choice (also known as “select the best option”) situational judgment tests (SJTs). Using data from two large studies, we compared the reliability and correlations of NRM scores with those from various classical and item response theory (IRT) scoring methods. The SJTs measured emotional management (Study 1) and teamwork and collaboration (Study 2). In Study 1 the NRM scoring method was shown to be superior in reliability and in yielding higher correlations with external measures to three classical test theory–based and four other IRT-based methods. In Study 2, only slight differences between scoring methods were observed. An explanation for the discrepancy in findings is that in cases where item keys are ambiguous (as in Study 1), the NRM accommodates that ambiguity, but in cases where item keys are clear (as in Study 2), different methods provide interchangeable scores. We characterize ambiguous and clear keys using category response curves based on parameter estimates of the NRM and discuss the relationships between our findings and those from the wisdom-of-the-crowd literature.

The Study of Motor Winding Testing System for Inter-Turn with 30kV

2013 ◽  
Vol 278-280 ◽  
pp. 831-834 ◽  
Author(s):  
Xiao Sun ◽  
Hao Zhou ◽  
Xiang Jiang Lu ◽  
Yong Yang
Keyword(s):  
Data Collection ◽  
Real Time ◽  
Field Test ◽  
Performance Indicators ◽  
Testing System ◽  
Time Data ◽  
Process Data ◽  
Real Time Data ◽  
Long Time ◽  
Factory Testing

This paper designed a motor winding testing system, it can do the dielectric withstand voltage test of inter-turn under 30kV.The system can communicate effectively between PC and machine, by using the PC's powerful capacity of process data and PLC's better stability and the Labview's convenient UI. So the system has real-time data collection, preservation, analysis and other characteristics. This system is able to achieve factory testing and type testing of the motor windings facilitating. Various performance indicators were stable and reliable by field test during a long time.

TESTING AS A METHOD OF CONTROL AND ASSESSMENT OF THE FORMATION OF COMPETENCIES

2021 ◽  
Vol 23 (1) ◽  
pp. 18-23
Author(s):  
Belalov R.М.
Keyword(s):  
Educational Practice ◽  
Testing System ◽  
Test Results ◽  
Present Stage ◽  
Research Issues ◽  
Test Items ◽  
Wide Range ◽  
Level Of Knowledge ◽  
Definition Of

At the present stage, pedagogical tests are one of the most accessible and developed methods for assessing students' knowledge. Evaluation of the results of global research on testing problems showed that the developers of test items pay special attention to the form and their standardization, the processing of test results and the interpretation of the data obtained, methods of automatic test formation. The goal is to study the possibility of using testing to assess the formation of students' competencies. Materials and methods. Theoretical: a review of psychological and pedagogical literature on research issues, analysis, synthesis, generalization, systematization. Results. Testing characterizes a number of properties, the main of which is the objectivity of the assessment of results, the definition of "gaps" in knowledge. The result of testing is obtaining objective information about the quality of knowledge and skills, determining the sections that are the worst learned by the students. All of the above makes it possible to adjust the course of training. Test control can be external, when the subjects are offered a dichotometric range, which contains both completed and unfulfilled tasks on a wide range of issues. During the testing process, students have the opportunity to independently identify gaps in their own knowledge. The study confirms the possibility of using testing in assessing the formation of students' competencies and ultimately provides an increase in the level of knowledge. Conclusion. At the present stage, the introduction of tests into educational practice is an inevitable process, therefore, efforts should be directed to the development of a theoretical platform for the testing system, which will entail an increase in the efficiency of using tests as a form of control.

scholarly journals Uncertainty of PM10 concentration measurement on the example of an optical measuring device

2018 ◽  
Vol 57 ◽  
pp. 02008 ◽  
Author(s):  
Tomasz Owczarek ◽  
Mariusz Rogulski
Keyword(s):  
Regression Models ◽  
Test Procedure ◽  
Reference Method ◽  
Ambient Air ◽  
Alternative Methods ◽  
Linear Regression Models ◽  
Measuring Device ◽  
Incomplete Knowledge ◽  
Uncertainty Of Measurements ◽  
Definition Of

The interest in the natural environment, in particular the ambient air, has been growing. For this reason, growing interest in measuring of concentration of pollutants in the air. To the reduction of costs and time of obtained results, increasingly are used non-reference, alternative methods and devices. However, it is necessary to ensure equivalence of results obtained by alternative methods with the results of the reference method. One of the equivalence issues is the assessment of the measurements uncertainty of the alternative method in relation to the reference method. This uncertainty is understood as the probability of obtaining a measurement result which differs from the real (reference) result by a predetermined value. Uncertainty can be caused by many reasons: imperfect implementation of the definition of the measurand, incomplete knowledge of the influence of external factors, heterogeneity of the analyzed phenomenon, errors of the measuring device and others. The paper presents methods for testing the uncertainty of measurements used in the study of equivalence and also proposed extending the test procedure with equivalence models, different from the linear regression models.

GENETIC VARIATION IN DIURETIC RESPONSES TO WATER LOADS: DEFINITION OF SOME PARAMETERS OF DIURETIC RESPONSE AND INITIAL RESULTS OF SELECTION FOR THESE PARAMETERS

1965 ◽  
Vol 33 (3) ◽  
pp. 417-428 ◽  
Author(s):  
J. STEWART ◽  
S. G. SPICKETT
Keyword(s):  
Genetic Variation ◽  
Disruptive Selection ◽  
Total Output ◽  
Water Load ◽  
Diuretic Response ◽  
Set Up ◽  
Definition Of ◽  
Response To Water ◽  
The Relationship ◽  
Initial Results

SUMMARY Three parameters of the diuretic response to a water load are defined these are: diuretic lag, rate of diuresis and total output/input. A heterogeneous stock of mice was set up using the strains A/Cam, CBA/FaCam, SF/Cam and Peru. Directional selection was made from this stock for rate of diuresis, and total output/input. The initial generations of selection showed positive and significant parent-offspring regressions and hence demonstrated genetic variation in these parameters. Two positive disruptive selection experiments were set up to explore the relationship between diuretic lag at 4 and 8 weeks of age. These experiments show also that there is genetic variation in diuretic lag and that gene manifestation at 4 weeks and at 8 weeks is different. The genetic variation affecting diuretic response to water load is discussed with respect to concepts of 'normal' physiology.

scholarly journals Nonconservative current-induced forces: A physical interpretation

2011 ◽  
Vol 2 ◽  
pp. 727-733 ◽  
Author(s):  
Tchavdar N Todorov ◽  
Daniel Dundas ◽  
Anthony T Paxton ◽  
Andrew P Horsfield
Keyword(s):  
Physical Interpretation ◽  
Current Flow ◽  
Test Procedure ◽  
Electrical Current ◽  
Stimulated Emission ◽  
General Definition ◽  
Noninvasive Test ◽  
Electrical Current Flow ◽  
Definition Of ◽  
A Current

We give a physical interpretation of the recently demonstrated nonconservative nature of interatomic forces in current-carrying nanostructures. We start from the analytical expression for the curl of these forces, and evaluate it for a point defect in a current-carrying system. We obtain a general definition of the capacity of electrical current flow to exert a nonconservative force, and thus do net work around closed paths, by a formal noninvasive test procedure. Second, we show that the gain in atomic kinetic energy over time, generated by nonconservative current-induced forces, is equivalent to the uncompensated stimulated emission of directional phonons. This connection with electron–phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.

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