Alleviating the Impact of Coincidental Correctness on the Effectiveness of SFL by Clustering Test Cases

2014 ◽  
Author(s):  
Li Weishi ◽  
Xiaoguang Mao
Keyword(s):  
Test Cases ◽  
Clustering Test ◽  
The Impact

scholarly journals Implications of some early Jewish sources for estimates of earthquake hazardin the Holy Land

2009 ◽  
Vol 47 (2-3) ◽  
Author(s):  
I. Karcz
Keyword(s):  
Dead Sea ◽  
Archaeological Sites ◽  
Test Cases ◽  
Holy Land ◽  
Cultural Centers ◽  
The Past ◽  
Mediterranean Countries ◽  
Fertile Ground ◽  
Seismic Origin ◽  
The Impact

For the past two millennia the Holy Land was under the yoke of successive invaders and oppressors, not a fertile ground for growth of historiographic traditions. Consequently, earthquake cataloguers had to rely largely on chronicles and texts written at distant administrative and cultural centers of the day, where earthquake destruction suffered by a culturally and economically depressed province may have been overshadowed by damage in more important parts of the empire. On this assumption, and aided by an implicit notion that the lands bounded by the Dead Sea Rift and Anatolian Fault systems are seismically contiguous, early cataloguers often extended the impact of earthquakes documented in nearby East Mediterranean countries to the Holy Land. Once published, such reports of supposed destructive intensities in Israel were used by Judaic scholars and archaeologists to date poorly defined, often metaphoric, literary seismic echoes, and to justify assigning seismic origin to equivocal signs of damage, asymmetry, or abandonment at archaeological sites of corresponding age. The spread of damage and intensity portraits are therefore enhanced and distorted, and so is their application in palaeoseismic analysis. Four test cases are presented, illustrating the use and misuse of local Judaic sources in identifying destructive intensities supposedly generated in the Holy Land by earthquakes of 92 B.C., 64 B.C. and 31 B.C., and in postulating a regional seismic catastrophe in 749 A.D..

Analysis of VDM++ in Regression Test Suite

2015 ◽  
pp. 382-417
Author(s):  
Zahid Hussain Qaisar ◽  
Farooq Ahmad
Keyword(s):  
Software Development ◽  
Software Testing ◽  
Maintenance Phase ◽  
Vital Role ◽  
Regression Testing ◽  
Test Suite ◽  
Test Cases ◽  
To Come ◽  
The Impact ◽  
Development Methods

Regression testing is important activity during the maintenance phase. An important work during maintenance of the software is to find impact of change. One of the essential attributes of Software is change i.e. quality software is more vulnerable to change and provide facilitation and ease for developer to do required changes. Modification plays vital role in the software development so it is highly important to find the impact of that modification or to identify the change in the software. In software testing that issue gets more attention because after change we have to identify impact of change and have to keenly observe what has happened or what will happen after that particular change that we have made or going to make in software. After change software testing team has to modify its testing strategy and have to come across with new test cases to efficiently perform the testing activity during the software development Regression testing is performed when the software is already tested and now some change is made to it. Important thing is to adjust those tests which were generated in the previous testing processes of the software. This study will present an approach by analyzing VDM (Vienna Development Methods) to find impact of change which will describe that how we can find the change and can analyze the change in the software i.e. impact of change that has been made in software. This approach will fulfill the purpose of classifying the test cases from original test suite into three classes obsolete, re-testable, and reusable test cases. This technique will not only classify the original test cases but will also generate new test cases required for the purpose of regression testing.

Evaluation Research on the Crane Failure Prediction based on Machine Learning

Mekatronika ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Wang Yan ◽  
HouJun Lu ◽  
Chun Sern Choong
Keyword(s):  
Machine Learning ◽  
Evaluation Research ◽  
Failure Prediction ◽  
Support Vector ◽  
Test Cases ◽  
Failure Data ◽  
Maintenance Decision ◽  
Percent Accuracy ◽  
The Impact

It is difficult to spot failures in port machinery and equipment, and maintaining such systems is even more complex. Maintenance such modifications in a reasonable time  is a tough challenge since each change might have an endless number of test cases run. It's critical to have a risk assessment of the impact of such maintenance fixes. In the software engineering community, there has been a considerable amount of study on failure prediction. Regrettably, there is little evidence of their application in day-to-day software development in port machinery and equipment. In this paper, we propose an unsupervised machine learning (k-means clustering) method for categorising cranes for maintenance and use a machine learning pipeline to solve the classification of crane failure data. The crane's maintenance decision data demonstrates the method's effectiveness. It was demonstrated that the Linear Support Vector Machine could give a superior classification accuracy of crane maintenance prediction with a 100 percent accuracy in train set and 94.5 percent accuracy in test set.

Numerical Analysis of Dilution Holes Deterioration Impacting the Performance of a V2500 Combustor

2020 ◽  
Author(s):  
Marco Konle ◽  
Ludovic de Guillebon ◽  
Lukas Schäflein
Keyword(s):  
Film Cooling ◽  
Operation Time ◽  
Test Cases ◽  
Air Jets ◽  
Individual Variations ◽  
Wide Range ◽  
Aero Engine ◽  
High Level ◽  
The Impact ◽  
Combustor Liner

Abstract In aero engine combustors, dilution air jets are used to additionally tailor the temperature field, the emissions, and the turbine inlet profile. These jets are entering the combustion chamber at different axial and circumferential locations through dedicated holes in the combustor liners. By deterioration, the diameters of these holes can significantly change over operation time. To evaluate the impact of such deterioration in the MRO context, the authors created a numerical model of a V2500 aero engine combustor and analyzed the impact. The data of dilution holes deterioration is based on the nominal design according the engine manual and the deviation measured for three engine combustors during maintenance inspection. The processes inside an aero engine combustor are very complex. To achieve most reliable information, a multi-physics approach was chosen for this evaluation. Validated in the past with a wide range of different academic test cases as well as industrial combustor test rigs, the evaluation allows conclusive analyses of the described deterioration. Back-to-back comparisons of individual variations reveals the most significant dilution holes row and give information about potential local shifts in combustor liner heat loads as well as in the exit profiles. Especially the distortion of the film cooling by the local interaction with the dilution jets could be observed. Since the deterioration of the dilution holes measured for the three combustors inspected is very small compared to the nominal design, the authors payed a lot of attention also on analyzing the model sensitivity. Increasing the spatial resolution, the plausibility of the numerical results were checked by analyzing the flow splits and the dilution jets penetration. The final step was the variation of the dilution holes individually and combined and the evaluation of resulting temperature distribution at the combustor liners and changes in the exit profile. Due to the fact that a multi-physics solver developed in the framework of OpenFOAM could be used, the authors could do these quite intensive CFD studies highly parallelized and, thus, in an acceptable time. The scalability of the solver reported already in former publications could be shown also in this application to the real engine combustor with a high level of complexity.

Optimized Shroud Design for Axial Turbine Aerodynamic Performance

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
L. Porreca ◽  
A. I. Kalfas ◽  
R. S. Abhari
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Cases ◽  
Axial Turbine ◽  
Significant Difference ◽  
Flow Field Analysis ◽  
The Impact ◽  
Partial Shroud

This paper presents a comprehensive study of the effect of shroud design in axial turbine aerodynamics. Experimental measurements and numerical simulations have been conducted on three different test cases with identical blade geometry and tip clearances but different shroud designs. The first and second test cases are representative of a full shroud and a nonaxisymmetric partial shroud geometry while the third test case uses an optimized partial shroud. Partial shrouds are sometimes used in industrial application in order to benefit from the advantage of shrouded configuration, as well as reduce mechanical stress on the blades. However, the optimal compromise between mechanical considerations and aerodynamic performances is still an open issue due to the resulting highly three-dimensional unsteady flow field. Aerodynamic performance is measured in a low-speed axial turbine facility and shows that there are clear differences between the test cases. In addition, steady and time resolved measurements are performed together with computational analysis in order to improve the understanding of the effect of the shroud geometry on the flow field and to quantify the sources of the resultant additional losses. The flow field analysis shows that the effect of the shroud geometry is significant from 60% blade height span to the tip. Tip leakage vortex in the first rotor is originated in the partial shroud test cases while the full shroud case presents only a weak indigenous tip passage vortex. This results in a significant difference in the secondary flow development in the following second stator with associated losses that varies by about 1% in this row. The analysis shows that the modified partial shroud design has improved considerably the aerodynamic efficiency by about 0.6% by keeping almost unchanged the overall weight of this component, and thus blade root stresses. The work, therefore, presents a comprehensive flow field analysis and shows the impact of the shroud geometry in the aerodynamic performance.

Application of Reliability Based Design and Assessment to Maintenance and Protection Decisions for Natural Gas Pipelines

2010 ◽  
Author(s):  
Maher Nessim ◽  
Howard Yue ◽  
Joe Zhou
Keyword(s):  
Public Awareness ◽  
Test Cases ◽  
Natural Gas Pipelines ◽  
Reliability Based Design ◽  
Wide Range ◽  
Awareness Programs ◽  
Detailed Assessment ◽  
Pipeline Failure ◽  
The Impact ◽  
Practical Implications

This paper describes a detailed assessment that was carried out to investigate the practical implications of using the Reliability Based Design and Assessment (RBDA) methodology, as described in Annex O of CSA Z662, as a basis for evaluating existing pipelines and making decisions on maintenance planning and damage prevention strategies. Two key pipeline failure threats are addressed, namely corrosion and equipment impact. The assessment was based on a number of test cases covering a wide range of diameters, grades, pressures, location classes and corrosion severities. The reliability levels associated with these cases were calculated as a function of time and compared to the reliability targets. Cases that did not meet the targets were re-analyzed with increasingly enhanced maintenance measures until the targets were met. Maintenance actions considered included higher maintenance frequencies and more stringent repair criteria for corrosion, and enhancements to such parameters as right-of-way patrol frequency and condition, public awareness programs and dig notification response for equipment impact. The results demonstrate that the reliability targets can be met through the implementation of reasonable and practical maintenance measures for the cases considered. The impact of using RBDA on the expected failure rates is discussed. In addition, the diameter and class ranges of pipelines requiring enhanced maintenance over the current norm are identified.

ComboRT: A New Approach for Generating Regression Test Cases for Evolving Programs

2016 ◽  
Vol 26 (06) ◽  
pp. 1001-1026 ◽  
Author(s):  
Xiaobing Sun ◽  
Xin Peng ◽  
Hareton Leung ◽  
Bin Li
Keyword(s):  
Impact Factor ◽  
Regression Testing ◽  
Software Systems ◽  
Test Case ◽  
Test Cases ◽  
Test Case Selection ◽  
Case Selection ◽  
Testing Techniques ◽  
The Impact ◽  
Ranked List

Regression testing is essential to ensure software quality during software evolution. Two widely-used regression testing techniques, test case selection and prioritization, are used to maximize the value of the continuously enlarging test suite. However, few works consider both these two techniques together, which decreases the usefulness of the independently studied techniques in practice. In the presence of changes during program evolution, regression testing is usually conducted by selecting the test cases that cover the impact results of the changes. It seldom considers the false-positives in the information covered. Hence, the effectiveness of such regression testing techniques is decreased. In this paper, we propose an approach, ComboRT, which combines test case selection and prioritization together to directly generate a ranked list of test cases. It is based on the impact results predicted by the change impact analysis (CIA) technique, FCA–CIA, which generates a ranked list of impacted methods. Test cases which cover these impacted methods are included in the new test suite. As each method predicted by FCA–CIA is assigned with an impact factor value corresponding to the probability of this method to be impacted, test cases are then ordered according to the impact factor values of the impacted methods. Empirical studies on four Java based software systems demonstrate that ComboRT can be effectively used for regression testing in object-oriented Java-based software systems during their evolution.

Learning Relations: An Evaluation of Search Strategies

1993 ◽  
Vol 18 (2-4) ◽  
pp. 221-232
Author(s):  
Cristina Baroglio ◽  
Marco Botta ◽  
Attilio Giordana
Keyword(s):  
Information Gain ◽  
A Priori ◽  
Search Strategies ◽  
Test Cases ◽  
Experimental Conditions ◽  
Description Languages ◽  
The Impact ◽  
Learning Relations ◽  
Learning Data

Inducing concept descriptions in first order logic is inherently a complex task; then, heuristics are needed to keep the problem to manageable size. In this paper we explore the effect of alternative search strategies, including the use of information gain and of a-priori knowledge, on the quality of the acquired relations, intended as the ability to reconstruct the rule used to generate the examples. To this aim, an artificial domain has been created, in which the experimental conditions can be kept under control, the “solulion” of the learning problem is known and a perfect theory is available. Another investigated aspect is the impact of more complex description languages, such as, for instance, including numerical quantifiers. The resultS show that the information gain criterion is too greedy to be useful when the concepts have a complex internal structure; however, this drawback is more or less shared with any purely statistical evaluation criterion. The addition of parts of the available domain theory increases the obtained performance level. Similar results have been previously obtained on a number of real applications and of test-cases taken from standard machine learning data bases.

scholarly journals The impact of test case summaries on bug fixing performance: An empirical investigation

2016 ◽  
Author(s):  
Sebastiano Panichella ◽  
Annibale Panichella ◽  
Moritz Beller ◽  
Andy Zaidman ◽  
Harald C Gall
Keyword(s):  
Test Generation ◽  
Empirical Investigation ◽  
Test Case ◽  
Test Cases ◽  
Minimal Set ◽  
Automated Test Generation ◽  
Structural Coverage ◽  
Manual Testing ◽  
The Cost ◽  
The Impact

Automated test generation tools have been widely investigated with the goal of reducing the cost of testing activities. However, generated tests have been shown not to help developers in detecting and finding more bugs even though they reach higher structural coverage compared to manual testing. The main reason is that generated tests are difficult to understand and maintain. Our paper proposes an approach, coined TestScribe, which automatically generates test case summaries of the portion of code exercised by each individual test, thereby improving understandability. We argue that this approach can complement the current techniques around automated unit test generation or search-based techniques designed to generate a possibly minimal set of test cases. In evaluating our approach we found that (1) developers find twice as many bugs, and (2) test case summaries significantly improve the comprehensibility of test cases, which is considered particularly useful by developers.

scholarly journals Did I make a mistake? Finding the impact of code change on energy regression

2017 ◽  
Author(s):  
Shaiful Alam Chowdhury ◽  
Stephanie Gil ◽  
Stephen Romansky ◽  
Abram Hindle
Keyword(s):  
Energy Consumption ◽  
Model Building ◽  
Continuous Process ◽  
Measurement Data ◽  
Energy Measurement ◽  
Test Cases ◽  
End User ◽  
Energy Models ◽  
Software Energy Consumption ◽  
The Impact

Software energy consumption is a performance related non-functional requirement that complicates building software on mobile devices today. Energy hogging applications are a liability to both the end-user and software developer. Measuring software energy consumption is non-trivial, requiring both equipment and expertise, yet many researchers have found that software energy consumption can be modelled. Prior works have hinted that with more energy measurement data one can make more accurate energy models but this data was expensive to extract because it required energy measurement of running test cases (rare) or time consuming manually written tests. We address these concerns by automatically generating test cases to drive applications undergoing energy measurement. Automatic test generation allows a model to be continuously improved in a model building process whereby applications are extracted, tests are generated, energy is measured and combined with instrumentation to train a grander big-data model of software energy consumption. This continuous process has allowed the authors to generate and extract measurements from hundreds of applications in order to build accurate energy models capable of predicting the energy consumption of applications without end-user energy measurement. We clearly show that models built from more applications reduce energy modelling error.

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