Identifying the Crack Nature Using b-Value Acoustic Emission Signal Analysis

Concrete is an important constituent of structures. The strength performance of the concrete decrease due to several factors. Concrete suffers from deterioration at a later stage. Early and constant identification of concrete deterioration is necessary. Nowadays, non-destructive testing (NDT) is widely used especially on continuous real-time monitoring system with minimum labor involvement. It could also be used to discriminate the different types of damage occurring in reinforced concrete (RC) beam and real structure. In this research was monitored by using Acoustic Emission testing and it have several analysis such as RA-value, b-value, intensity signal analysis and historical index. To determine the acoustic emission signals for concrete structures and cracking identification this research using b-value analysis. b-value signals analysis contain useful information about damage mechanisms. A high b-value arises due to a large number of small AE hits, it representing new crack formation and slow crack growth, whereas a low b-value indicates faster or unstable crack growth accompanied by relatively high amplitude AE in large number. Reinforced concrete beams measuring of size 150 mm 250 mm 1500 mm were used during the acoustic emission test. A four-point load test was carried out on specimens until cracking occurred. The signals generated from the equipment were used for the analysis process, and the values are compared to define and summarise type of cracking and cracking processes

Comment on “Football-specific fitness testing: adding value or confirming the evidence?”

The recent point–counter-point exchange arising from the article by Mendez-Villanueva and Buchheit (2013) (Football-specific fitness testing: Adding value or confirming the evidence? Journal of Sports Sciences, 31, 1503–1508) has generated an interesting debate on the real-world utility of fitness testing in professional association football (soccer). In the present authors’ opinion, this exchange could also have been placed more in the context of the physical testing and subsequent benchmark profiling of the youth player within elite academy talent identification and development processes. This point is further strengthened by the current media debate at the time of writing on the development of elite youth football players in England and the Elite Player Performance Plan or EPPP (The Premier League. (2011). Elite Player Performance Plan. London: Author) published by the English Premier League as part of a vision for the future development of youth football in the League and throughout the English professional game. The EPPP recommends the implementation of a national database to enable comparison of Academy player performances against national physical testing “benchmark” profiles. In continuing the above debate, this letter questions the real-world utility and potential pitfalls of nationwide athletic benchmark profiling programmes for elite youth football

Quasi purchasing power parity: Structural change in the Mexican peso/us dollar real exchange rate

This paper analyzes whether the real exchange-rate of the Mexican peso/US dollar revert to a long-run equilibrium value, and whether this value is unique. We use a method for testing stationarity, that allows for an unknown number of structural breaks in the level of the series. Using a long span of annual data covering the period 1925-1994, our results provide evidence favouring long-run Quasi-Purchasing Power Parity. In particular, we find that the real peso/dollar exchange rate has fluctuated stationarily around a 70 year long-run level, perturbed by a series of events, both domestic and external, in or around 1981.

Visualization of the decision criteria in testing statistical hypotheses on programming in R (Rstudio)

Purpose: The case study addresses a development and justification of approaches to visualization of decision criteria in the problems of testing statistical hypotheses for a given distribution law (specifically, checking the distribution normality). Design/Methodology/Approach: The study describes a construction of graphical model that visualizes an application of criteria when testing statistical hypotheses for compliance with a given distribution law. This problem is solved in the language of statistical analysis R in the RStudio environment. Using the standard approach and focusing only on the P-value in relation to the chosen level of significance, the researcher cannot take into account the error of the second kind. However, analyzing the graphical representation of the behavior of the sample under study, one can conclude whether the value of the obtained P-value corresponds to the real assumption that the sample corresponds to a given distribution law. Findings: The research case proposes a new approach to testing statistical hypotheses on the compliance of a sample with a given distribution law, using visualization tools and allowing a researcher having even a little experience with the R language to solve applied problems. Practical implications: The approach does not require an in-depth knowledge of mathematics and programming which can be used by experts in various fields of knowledge to successfully solve applied problems. The text of the article contains working scripts in the language R and graphical illustrations obtained with their help. Originality/Value: The main contribution of this study is to expand the variety of methods for testing statistical hypotheses. The proposed method extends the set of statistical problems successfully solved by means of R.peer-reviewe

Examining Patterns of Bilateral Trade between Australia and Colombia by Using Cointegration Analysis and Error-Correction Models

The main objective of this paper is to understand whether there is a long-term relationship between Australia and Colombian imports by using macroeconomic fundamentals such as the real exchange rate, income, population and openness. We use multivariate cointegration techniques and error correction models along with time-series data (1960-2005). We focus on testing for cointegration in the presence of structural breaks. The findings suggest that the value of Australian imports from Colombia is cointegrated with three economic series: income of both participating countries and the Colombian population. The real value of Colombian imports from Australia is cointegrated with the real bilateral exchange rate and total Colombian world imports. The relationship between the value of bilateral imports and the cointegrated series can be seen as long-running bilateral import elasticities. High coefficients of the cointegrated variables indicate that opportunities exist to improve long-term trade relationships between the two countries.trade, gravity model, Latin America, Australia, cross-sectional data.

SmartUnit: Empirical Evaluations for Automated Unit Testing of Embedded Software in Industry

In this paper, we aim at the automated unit coverage-based testing for embedded software. To achieve the goal, by analyzing the industrial requirements and our previous work on automated unit testing tool CAUT, we rebuild a new tool, SmartUnit, to solve the engineering requirements that take place in our partner companies. SmartUnit is a dynamic symbolic execution implementation, which supports statement, branch, boundary value and MC/DC coverage. SmartUnit has been used to test more than one million lines of code in real projects. For confidentiality motives, we select three in-house real projects for the empirical evaluations. We also carry out our evaluations on two open source database projects, SQLite and PostgreSQL, to test the scalability of our tool since the scale of the embedded software project is mostly not large, 5K-50K lines of code on average. From our experimental results, in general, more than 90% of functions in commercial embedded software achieve 100% statement, branch, MC/DC coverage, more than 80% of functions in SQLite achieve 100% MC/DC coverage, and more than 60% of functions in PostgreSQL achieve 100% MC/DC coverage. Moreover, SmartUnit is able to find the runtime exceptions at the unit testing level. We also have reported exceptions like array index out of bounds and divided-by-zero in SQLite. Furthermore, we analyze the reasons of low coverage in automated unit testing in our setting and give a survey on the situation of manual unit testing with respect to automated unit testing in industry.Comment: In Proceedings of 40th International Conference on Software Engineering: Software Engineering in Practice Track, Gothenburg, Sweden, May 27-June 3, 2018 (ICSE-SEIP '18), 10 page