scholarly journals The property changes of ammunition elements due to the exploitation time

2015 ◽  
Vol 36 (1) ◽  
pp. 91-104
Author(s):  
Dariusz Ampuła
Keyword(s):  
Gamma Distribution ◽  
Research Methodology ◽  
Probability Distributions ◽  
Test Results ◽  
Normal Distributions ◽  
Standard Normal ◽  
Evaluation Module ◽  
Property Changes ◽  
Two Parameters ◽  
The Way

Abstract The way carry out of analysis concerning correctness working of evaluation module proposed in functioning research methodology, chosen features elements of artillery fuses was presented in the article. Probability distributions of the aptitude time of tested ammunition elements were applied for verification of undertaken post diagnostic decisions. The analysis of test results chosen fuses elements, based on the standard normal distributions were executed, further the graphic interpretations of these distributions were made. A measurement of the strength of resistance decline of the side-bolt spring was chosen for the analysis, as a way of checking MG-37 and MG-57 fuse types features. Furthermore, the author presents an illustrative comparison of normal distributions, which confirms that post diagnostic decisions had been undertaken correctly. The graphic interpretations of analyzed test results of MG-37 fuse elements type were executed by means of two-parameters gamma distribution in the comparison. Concise conclusions confirming the correctness of functioning of evaluation module in the research methodology were introduced at the end of the article.

scholarly journals Forecasting Long-Lead Rainfall Probability with Application to Australia’s Northeastern Coast

2010 ◽  
Vol 49 (7) ◽  
pp. 1443-1453 ◽  
Author(s):  
Allan J. Clarke ◽  
Stephen Van Gorder ◽  
Yvette Everingham
Keyword(s):  
Gamma Distribution ◽  
El Niño ◽  
El Nino ◽  
Probability Distributions ◽  
Error Distribution ◽  
Rainfall Distribution ◽  
The North ◽  
Two Parameters ◽  
Relationship Of ◽  
Northeastern Coast

Abstract The authors develop a method for the long-lead forecasting of El Niño–influenced rainfall probability and illustrate it using the economically important prediction, from the beginning of the year, of September–November (SON) rainfall in the coastal sugarcane producing region of Australia’s northeastern coast. The method is based on two probability distributions. One is the Gaussian error distribution of the long-lead prediction of the El Niño index Niño-3.4 by the Clarke and Van Gorder forecast method. The other is the relationship of the rainfall distribution to the Niño-3.4 index. The rainfall distribution can be approximated by a gamma distribution whose two parameters depend on Niño-3.4. To predict the rainfall at, say, the Tully Sugar, Ltd., mill on the north Queensland coast in SON 2009, the June–August (JJA) value of Niño-3.4 is predicted and then 1000 possible “observed” JJA Niño-3.4 values calculated from the error distribution. Each one of these observed Niño-3.4 values is then used, with the Niño-3.4-dependent gamma distribution for that location, to calculate 1000 possible SON rainfall totals. The result is one million possible SON rainfalls. A histogram of these rainfalls is the required probability distribution for the rainfall at that location predicted from the beginning of the year. Cross-validated predictions suggest that the method is successful.

Yarning as protected space: relational accountability in research

2021 ◽  
pp. 117718012098615
Author(s):  
Stuart Barlo ◽  
William (Bill) Edgar Boyd ◽  
Margaret Hughes ◽  
Shawn Wilson ◽  
Alessandro Pelizzon
Keyword(s):  
Research Methodology ◽  
Personal Experience ◽  
Indigenous Research ◽  
Indigenous Australian ◽  
Australian Context ◽  
Data History ◽  
Research Relationships ◽  
Relational Accountability ◽  
Relational Process ◽  
The Way

In this article, we open up Yarning as a fundamentally relational methodology. We discuss key relationships involved in Indigenous research, including with participants, Country, Ancestors, data, history, and Knowledge. We argue that the principles and protocols associated with the deepest layers of yarning in an Indigenous Australian context create a protected space which supports the researcher to develop and maintain accountability in each of these research relationships. Protection and relational accountability in turn contribute to research which is trustworthy and has integrity. Woven throughout the article are excerpts of a yarn in which the first author reflects on his personal experience of this research methodology. We hope this device serves to demonstrate the way yarning as a relational process of communication helps to bring out deeper reflection and analysis and invoke accountability in all of our research relationships.

A New Grid Multi-Scroll Chaotic System and the Simulation Based on Labview

2012 ◽  
Vol 538-541 ◽  
pp. 2666-2669
Author(s):  
Yong Huang
Keyword(s):  
Chaotic System ◽  
Chaotic Attractor ◽  
Step Function ◽  
Simulation System ◽  
Unstable System ◽  
Simulation Based ◽  
Two Parameters ◽  
The Way

In order to get the grid Multi-Scroll in the two directions, based on a simple unstable system, the way of the combination of the translational transform and step function was put forward to make the scrolls extending in the x and y directions in this paper. The quantity of scrolls can be controlled by two parameters N and M. A simulation system was designed with Labview to simulate grid Multi-Scroll chaotic system, it demonstrates the existence of grid Multi-Scroll chaotic attractor.

scholarly journals Study on Metakaolin Impact on Concrete Performance of Resisting Complex Ions Corrosion

2021 ◽  
Vol 8 ◽  
Author(s):  
Chen Xupeng ◽  
Sun Zhuowen ◽  
Pang Jianyong
Keyword(s):  
Physical Property ◽  
Similar Amount ◽  
Concrete Durability ◽  
Test Results ◽  
Micro Structure ◽  
Complex Ions ◽  
Cyclic Corrosion ◽  
Property Changes ◽  
Micro Morphology ◽  
Composition Changes

The main purpose of this study is to determine the metakaolin (MK) impacts on the concrete durability when the concrete is subjected to joint corrosion of SO42−,Mg2+ and, Cl−. Four groups of concrete test samples, which contained different MK contents, were designed and tested in order to see their physical property changes and macro-morphology differences during the cyclic corrosion process. And a series of approaches, including XRD, FTIR, SEM, and EDS, were applied to study the concrete phase composition changes and the micro-morphology features of all groups. According to the test results, when reaching 20 cycles, the concrete sample with 10% MK showed the best concrete physical properties; when reaching 120 cycles, the concrete with 5% MK content showed the best durability, produced similar amount of corrosion products to ordinary concrete, and presented relatively compacted micro-structure and small internal porosity. Mg2+ actually has a great impact on metakaolin. The corrosion product quantity increased significantly when MK admixture reached 15%. Due to the great number of produced M-S-H, the corrosive ions damaged the concrete for a second time, leading to serious aggregate peeling-off, powder surface of test samples, and porous micro-structure.

scholarly journals Effect of Temperature on the Tribological Properties of Selected Thermoplastic Materials Cooperating with Aluminium Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7318
Author(s):  
Anita Ptak ◽  
Paula Taciak ◽  
Wojciech Wieleba
Keyword(s):  
Aluminium Alloy ◽  
Contact Pressure ◽  
Tribological Properties ◽  
Polymer Materials ◽  
Effect Of Temperature ◽  
Test Results ◽  
Friction Process ◽  
Before And After ◽  
Pin On Disc ◽  
Two Parameters

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.

The Application of the Smirnov Test in the Homogeneity Test for Non-Normal Distribution Temperature Series

2012 ◽  
Vol 516-517 ◽  
pp. 530-535
Author(s):  
Xin Jie Deng ◽  
Yang Sheng You ◽  
Yan Ying Chen ◽  
Xue Mei Yang
Keyword(s):  
Normal Distribution ◽  
Classical Method ◽  
Temperature Series ◽  
Homogeneity Test ◽  
Test Results ◽  
Standard Normal Homogeneity Test ◽  
Standard Normal ◽  
Better Than ◽  
Smirnov Test

The homogeneity test is the first stage to revise the climate records. Its accuracy will directly affect the follow-up work. The classic method SNHT (Standard Normal Homogeneity Test) can only be applied in climatic sequences obey normal distribution, but lots of non-normality climate sequences need to be examined. In this paper, the Smirnov Test was introduced to test the homogeneity of the temperature series, which is a classical method for distribution test, and it can apply for the temperature sequences obey any distribution. The homogeneity test results by testing Chongqing Municipality's temperature sequences show that: the Smirnov Test is better than SNHT

Benfordʼs Law Geometry

Benford's Law ◽  
2015 ◽  
Author(s):  
Lawrence Leemis
Keyword(s):  
Empirical Data ◽  
Probability Distributions ◽  
Benford’S Law ◽  
Data Sets ◽  
Normal Distributions ◽  
Benford's Law ◽  
Using Data

This chapter switches from the traditional analysis of Benford's law using data sets to a search for probability distributions that obey Benford's law. It begins by briefly discussing the origins of Benford's law through the independent efforts of Simon Newcomb (1835–1909) and Frank Benford, Jr. (1883–1948), both of whom made their discoveries through empirical data. Although Benford's law applies to a wide variety of data sets, none of the popular parametric distributions, such as the exponential and normal distributions, agree exactly with Benford's law. The chapter thus highlights the failures of several of these well-known probability distributions in conforming to Benford's law, considers what types of probability distributions might produce data that obey Benford's law, and looks at some of the geometry associated with these probability distributions.

scholarly journals Genuine and false pre-consolidation and yield pressures

2019 ◽  
Vol 92 ◽  
pp. 05001 ◽  
Author(s):  
Laurence D Wesley
Keyword(s):  
Measured Data ◽  
Soil Types ◽  
Log P ◽  
Test Results ◽  
Linear Scale ◽  
Consolidation Pressure ◽  
Oedometer Test ◽  
The Way

“It remains a mystery why the international profession still uses the awkward e-log p plots, and the incomplete and useless coefficient Cc which is not even determined from the measured data, but from a constructed line outside the measurements”. These are the words of Nilmar Janbu (1998). This paper does not solve the mystery; what it does is highlight the issue behind the mystery in the hope that the profession will face up to the defects of the log scale. An examination is made of oedometer test results when plotted to both scales. Examples are given for sedimentary and residual clays, and sands. It is shown that the e-logp plot routinely produces graphs from which pre-consolidation pressures or yield pressures can be determined. However, when plotted using an arithmetic (linear) scale, this apparent pre-consolidation or yield pressure is found, in most cases, to disappear. It is a false value created by the way the data are plotted. The paper does not deny that pre-consolidation or yield pressures exist in many soils; it gives examples for each of the soil types listed above. It is recommended that the term “yield pressure” be used in preference to “pre-consolidation pressure”, and that only the use of a linear scale will reveal whether such a pressure exists.

scholarly journals A comparison of three parameter estimation methods of the gamma distribution of annual maximum low flow duration and deficit in the Upper Vistula catchment (Poland)

2018 ◽  
Vol 23 ◽  
pp. 00001
Author(s):  
Katarzyna Baran-Gurgul
Keyword(s):  
Gamma Distribution ◽  
Goodness Of Fit ◽  
Probability Distributions ◽  
Low Flow ◽  
Estimation Methods ◽  
Goodness Of Fit Test ◽  
Flow Duration ◽  
Distribution Parameters ◽  
Anderson Darling ◽  
Parameter Estimation Methods

Based on 30-year 24-hour flow sequences at 69 water gauging stations in the Upper Vistula catchment, it was determined that the probability distributions of the low flow duration and its maximum annual deficit can be described by the gamma distribution with the estimated parameters by the methods: MOM, the method of moments, LMOM, the method of linear moments, and MLE, the method of maximum likelihood. The stationarity of the time series was tested by the Mann-Kendall correlation using the Hamed and Rao variance correction. The low flows were defined by the SPA method, with the limit flow Q70%. The quality of the match was tested by the Anderson-Darling goodness of fit test. This test allowed accepting the gamma distribution in all analysed cases, regardless of the method used to estimate the distribution parameters, since the pv (p-values) values were greater than 5% (over 18% for Tmax and 7.5% for Vmax). The highest pv values for individual water gauging stations, as well as the highest 90% Tmax and Vmax quantiles were noted using LMOM to estimate the gamma distribution parameters. The highest 90% Tmax and Vmax quantiles were observed in the uppermost part of the studied area.

Visual Ethnography as a Research Methodology

2022 ◽  
pp. 18-40
Author(s):  
Candace Kaye
Keyword(s):  
Qualitative Research ◽  
Data Collection ◽  
Research Methodology ◽  
Visual Ethnography ◽  
Research Topics ◽  
Data Collection And Analysis ◽  
The Future ◽  
Investigative Process ◽  
The Way

The chapter presents a rationale for using visual ethnography as part of the methodology in qualitative research and illustrates what visual ethnography methodology is capable of accomplishing when imagery is included in the investigative process. Visual ethnography offers a venue for collecting and analyzing data that would otherwise be inaccessible and positions imagery as an important, rather than a minimal or occasional, choice for use in qualitative research. Topics include contemporary definitions of visual ethnography and its value in qualitative research, historical applications of visual ethnographic theory that influence the way researchers view visual ethnography today, and contemporary uses of visual ethnography in data collection and analysis. Finally, the conclusion explores the future of visual ethnography.

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