An empirical investigation of software reliability indicators

University of Technology, Sydney. Faculty of Engineering and Information Technology.This thesis investigates how individuals and organisations, without technical skills, might determine the reliability of open source software given the increased use of such software. Software reliability is normally indicated by the growth and subsequent decline of defects in the software. A notable observation is that reliability growth models require a definitive stabilisation phase during which testing can reveal the growth and decline of defects as the indication of the increase in reliability of software. However, there is not necessarily a definitive stabilisation phase in the open source software development. More importantly, the presence or absence of the stabilisation phase is an attribute of a software development method and is not restricted to open source software. When software is developed without a definitive stabilisation phase, reliability growth models are not applicable because the conditions for their validity have not been achieved. Consequently, this thesis looks for alternative information based on tests to aid decision-making about software acquisition. Data was collected by conducting semi-structured interviews from 29 participants who were currently engaged in software development. The information of tests; coverage, sufficiency and rigours of tests concerns the testing that has been performed on the software product and gives expectations on how well the software product has been tested

Open Source, Agile and Reliability Measures

As open source and agile development do work in some circumstances, particularly with regard to shorter and more frequent release policy, we wonder whether the defect profile (reliability growth) found in the open-source projects so far is typical of open-source software development or of software developed iteratively and incrementally. To investigate this, we examined an open source web testing tool developed by an agile leading company. The results of this analysis indicate two findings. First, it supports the tentative findings that iteratively developed software does not exhibit a standard reliability growth in the defect modeling, and second, somewhat surprisingly that the defect density is reducing, as a sign of improving in quality yet the normal measure of software reliability are not useful

Reliability growth of open source software using defect analysis

We examine two active and popular open source products to observe whether or not open source software has a different defect arrival rate than software developed in-house. The evaluation used two common models of reliability growth models; concave and S-shaped and this analysis shows that open source has a different profile of defect arrival. Further investigation indicated that low level design instability is a possible explanation of the different defect growth profile. © 2008 IEEE

A comparison of the reliability growth of open source and in-House software

As commercial developers have established processes to assure software quality, open source software depends largely on community usage and defect reporting to achieve some level of quality. Thus, quality of open source software may vary. We examined defects reported in two active and popular open source software projects and an in-house project. The results of this analysis indicate that the reliability growth of each is quite distinct and that the defect profile of open source software appears to be a consequence of the open source software development method itself. © 2008 IEEE

Hepatoprotective potential of glyceryl trinitrate against chemically induced oxidative stress and hepatic injury in rats

Glyceryl trinitrate (GTN) has been used widely as a potent vasodilator to treat heart conditions, such as angina pectoris and chronic heart failure. This study aims to elucidate the effect of exogenous nitric oxide (NO) administration, using GTN, on carbon tetrachloride (CCl4)-induced oxidative stress and liver injury in rats. The results obtained demonstrated that NO generated by the administration of GTN affords protection against CCl4-induced oxidative stress and liver injury. Administration of CCl4 resulted in a significant (p < 0.001) increase in lipid peroxidation and tissue damage markers (aspartate and alanine transaminase and lactate dehydrogenase) release in serum. Parallel to these changes, CCl4 also caused downregulation of antioxidant enzymes including glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST), and several fold induction in γ-glutamyl transpeptidase (GGT) activity. Subsequent administration of GTN resulted in significant (p < 0.001) recovery of GSH-metabolizing enzymes in a dose-dependent manner. Further, administration of NO inhibitor, NG-nitro-l-arginine methyl ester (l-NAME), exacerbated CCl4-induced oxidative tissue injury. Overall, the study suggests that GTN might suppress oxidant-induced tissue injury and hepatotoxicity in rats

An In-Depth Analysis on Efficiency and Vulnerabilities on a Cloud-Based Searchable Symmetric Encryption Solution

Searchable Symmetric Encryption (SSE) has come to be as an integral cryptographic approach in a world where digital privacy is essential. The capacity to search through encrypted data whilst maintaining its integrity meets the most important demand for security and confidentiality in a society that is increasingly dependent on cloud-based services and data storage. SSE offers efficient processing of queries over encrypted datasets, allowing entities to comply with data privacy rules while preserving database usability. Our research goes into this need, concentrating on the development and thorough testing of an SSE system based on Curtmola’s architecture and employing Advanced Encryption Standard (AES) in Cypher Block Chaining (CBC) mode. A primary goal of the research is to conduct a thorough evaluation of the security and performance of the system. In order to assess search performance, a variety of database settings were extensively tested, and the system's security was tested by simulating intricate threat scenarios such as count attacks and leakage abuse. The efficiency of operation and cryptographic robustness of the SSE system are critically examined by these reviews

Test adequacy assessment using test-defect coverage analytic model

Software testing is an essential activity in software development process that has been widely used as a means of achieving software reliability and quality. The emergence of incremental development in its various forms required a different approach to determining the readiness of the software for release. This approach needs to determine how reliable the software is likely to be based on planned tests, not defect growth and decline as typically shown in reliability growth models. A combination of information from a number of sources into an easily understood dashboard is expected to provide both qualitative and quantitative analyses of test and defect coverage properties. Hence, Test-Defect Coverage Analytic Model (TDCAM) is proposed which combines test and defect coverage information presented in a dashboard to help deciding whether there are enough tests planned. A case study has been conducted to demonstrate the usage of the proposed model. The visual representations and results gained from the case study show the benefits of TDCAM in assisting practitioners making informed test adequacy-related decisions

Performa Broiler dengan Pemberian Jamu Kombinasi Jahe, Kunyit, dan Temulawak

Jamu dapat diberikan sebagai feed additive untuk meningkatkan performa dan kesehatan broiler. Penelitian bertujuan menentukan konsentrasi optimal pemberian jamu kombinasi jahe, kunyit, dan temulawak yang dapat meningkatkan performa broiler, pengaruh jamu terhadap fungsi organ dan cita rasa daging ayam broiler. Sebanyak 96 ekor ayam galur Cobb dibagi menjadi 4 kelompok perlakuan, yaitu konsentrasi jamu 0%, 0,25%, 0,5%, dan 0,75% masing-masing dengan 2 kelompok ulangan. Pemberian jamu dimulai pada hari ke-20 sampai hari ke-36 dengan cara mencampur serbuk ke dalam air minum. Peubah yang diamati terdiri atas konsumsi pakan, konsumsi minum, bobot akhir, pertambahan bobot badan, Feed Conversion Ratio (FCR), indeks performa (IP), mortalitas, profil organ, dan karakteristik organoleptik daging. Hasil menunjukkan jamu dengan konsentrasi 0,25% dapat meningkatkan bobot akhir, pertambahan bobot badan, dan bobot karkas, tetapi tidak menunjukkan pengaruh terhadap konsumsi pakan, konsumsi minum, FCR, IP, dan cita rasa daging. Selain itu, mortalitas dapat ditekan pada konsentrasi jamu 0,25% dan 0,5%. Jamu kombinasi jahe, kunyit, dan temulawak dapat meningkatkan performa dan kesehatan broiler

High-levelexpression of functional recombinant human coagulation factor VII in insect cells

Abstract: Recombinant coagulation factor VII (FVII) is used as a potential therapeutic intervention in hemophilia patients who produce antibodies against the coagulation factors. Mammalian cell lines provide low levels of expression, however, the Spodoptera frugiperda Sf9 cell line and baculovirus expression system are powerful systems for high-level expression of recombinant proteins, but due to the lack of endogenous vitamin K-dependent carboxylase, expression of functional FVII using this system is impossible. In the present study, we report a simple but versatile method to overcome the defect for high-level expression of the functional recombinant coagulation FVII in Sf9 cells. This method involves simultaneous expression of both human γ-carboxylase (hGC) and human FVII genes in the host. It may be possible to express other vitamin K-dependent coagulation factors using this method in the future. Keywords: Baculovirus; γ-carboxylase; Coagulation FVII; Factor VII; Insect cel

Long-term halocarbon observations from a coastal and an inland site in Sabah, Malaysian Borneo

Abstract. Short-lived halocarbons are believed to have important sources in the tropics, where rapid vertical transport could provide a significant source to the stratosphere. In this study, quasi-continuous measurements of short-lived halocarbons are reported for two tropical sites in Sabah (Malaysian Borneo), one coastal and one inland (rainforest). We present the observations for C2Cl4, CHBr3, CH2Br2* (actually ~80% CH2Br2 and ~20% CHBrCl2) and CH3I from November 2008 to January 2010 made using our μDirac gas chromatographs with electron capture detection (GC-ECD). We focus on the first 15 months of observations, showing over one annual cycle for each compound and therefore adding significantly to the few limited-duration observational studies that have been conducted thus far in southeast Asia. The main feature in the C2Cl4 behaviour at both sites is its annual cycle, with the winter months being influenced by northerly flow with higher concentrations, typical of the Northern Hemisphere, and with the summer months influenced by southerly flow and lower concentrations representative of the Southern Hemisphere. No such clear annual cycle is seen for CHBr3, CH2Br2* or CH3I. The baseline values for CHBr3 and CH2Br2* are similar at the coastal (overall median: CHBr3 1.7 ppt, CH2Br2* 1.4 ppt) and inland sites (CHBr3 1.6 ppt, CH2Br2* 1.1 ppt), but periods with elevated values are seen at the coast (overall 95th percentile: CHBr3 4.4 ppt, CH2Br2ast 1.9 ppt), presumably resulting from the stronger influence of coastal emissions. Overall median bromine values from [CHBr3 × 3] + [CH2Br2* × 2] are 8.0 ppt at the coast and 6.8 ppt inland. The median values reported here are largely consistent with other limited tropical data and imply that southeast Asia generally is not, as has been suggested, a hot spot for emissions of these compounds. These baseline values are consistent with the most recent emissions found for southeast Asia using the p-TOMCAT (Toulouse Off-line Model of Chemistry And Transport) model. CH3I, which is only observed at the coastal site, is the shortest-lived compound measured in this study, and the observed atmospheric variations reflect this, with high variability throughout the study period. This work was supported by a NERC consortium grant to the OP3 team, by NCAS, by the European Commission through the SCOUT-O3 project (505390-GOCE-CF2004) and by NERC western Pacific grant number NE/F020341/1 and NERC CAST grant number NE/J006246/1. L. M. O’Brien and M. J. Ashfold thank NERC for research studentships. A. D. Robinson acknowledges NERC for their support through small grant project NE/D008085/1. N. R. P. Harris is supported by a NERC Advanced Research Fellowship. We thank the Sabah Foundation, Danum Valley Field Centre and the Royal Society (Glen Reynolds) for field site support. The research leading to these results has received funding from the European Union’s Seventh Framework Programme FP7/2007–2013 under grant agreement no. 226224 – SHIVA. We thank David Oram and Stephen Humphrey at UEA for their assistance in checking the calibration of our Aculife cylinder in May 2009. This is paper number 626 of the Royal Society’s South East Asian Rainforest Research Programme.This is the final published version. It first appeared at http://www.atmos-chem-phys.net/14/8369/2014/acp-14-8369-2014.html