Harmfulness of Code Duplication - A Structured Review of the Evidence

Duplication of code has long been thought to decrease changeability of systems, but recently doubts have been expressed whether this is true in general. This is a problem for researchers because it makes the value of research aimed against clones uncertain, and for practitioners as they cannot be sure whether their effort in reducing duplication is well-spent. In this paper we try to shed light on this is-sue by collecting empirical evidence in favor and against the nega-tive effects of duplication on changeability. We go beyond the flat yes/no-question of harmfulness and present an explanatory model to show the mechanisms through which duplication is suspected to affect quality. We aggregate the evidence for each of the causal links in the model. This sheds light on the current state of duplication re-search and helps practitioners choose between the available mitiga-tion strategies

Gold Dreams, Gold Nightmares: The Social Construction of Inflation as Delegitimation Discourse

Using archival data from the four most popular gold investment websites, this study is a content analysis of gold investment enthusiast (\'gold bug\') commentaries over a six-month time period, from November 2007 to April 2008. We examine gold bug discourse as a conspiracy narrative whose central tenet is the criticism of inflationary monetary policy. Gold bugs argue that the continual presence of inflation demonstrates the fundamental flaws of global capitalism and the illegitimacy of the administrative system that operates it. The invocation of inflation is the primary way in which gold bugs forecast economic conditions and the inevitable failure of those who control global monetary policy. Based upon the ontological claim that gold is the only \'true\' store of value, gold bugs posit a sharp rebuke of monetary policy, predicting a drastic increase in the price of gold and a consequent collapse of the world\'s fiat currencies.Content Analysis, Gold, Conspiracy, Inflation, Monetary Policy

Connecting Software Metrics across Versions to Predict Defects

Accurate software defect prediction could help software practitioners allocate test resources to defect-prone modules effectively and efficiently. In the last decades, much effort has been devoted to build accurate defect prediction models, including developing quality defect predictors and modeling techniques. However, current widely used defect predictors such as code metrics and process metrics could not well describe how software modules change over the project evolution, which we believe is important for defect prediction. In order to deal with this problem, in this paper, we propose to use the Historical Version Sequence of Metrics (HVSM) in continuous software versions as defect predictors. Furthermore, we leverage Recurrent Neural Network (RNN), a popular modeling technique, to take HVSM as the input to build software prediction models. The experimental results show that, in most cases, the proposed HVSM-based RNN model has a significantly better effort-aware ranking effectiveness than the commonly used baseline models

Empirical Notes on the Interaction Between Continuous Kernel Fuzzing and Development

Fuzzing has been studied and applied ever since the 1990s. Automated and continuous fuzzing has recently been applied also to open source software projects, including the Linux and BSD kernels. This paper concentrates on the practical aspects of continuous kernel fuzzing in four open source kernels. According to the results, there are over 800 unresolved crashes reported for the four kernels by the syzkaller/syzbot framework. Many of these have been reported relatively long ago. Interestingly, fuzzing-induced bugs have been resolved in the BSD kernels more rapidly. Furthermore, assertions and debug checks, use-after-frees, and general protection faults account for the majority of bug types in the Linux kernel. About 23% of the fixed bugs in the Linux kernel have either went through code review or additional testing. Finally, only code churn provides a weak statistical signal for explaining the associated bug fixing times in the Linux kernel.Comment: The 4th IEEE International Workshop on Reliability and Security Data Analysis (RSDA), 2019 IEEE International Symposium on Software Reliability Engineering Workshops (ISSREW), Berlin, IEE

Use of noninvasive ‘bug-eggs’ to enable comparative inferences on genetic mating system with and without parental information: A study in a cattle egret colony

Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentage allocation tests. Here, we investigate the genetic mating system of the invasive cattle egret using hematophagous insects contained in fake eggs to collect blood from incubating adults in a wild breeding colony. We tested a protocol with a previously unused Neotropical Triatominae, Panstrongylus megistus, obtained blood samples from males and females in 31 nests built on trees, drew blood from 89 nestlings at those nests, and genotyped all samples at 14 microsatellite loci, including six new species-specific loci. We comparatively addressed the performance of parentage allocation versus kinship classification of nestlings to infer the genetic mating system of cattle egrets. In line with previous behavioral observations, we found evidence in support of a non-monogamous genetic mating system, including extra-pair paternity (EPP) and conspecific brood parasitism (CBP). Parentage allocation tests detected a higher percentage of nests with alternative reproductive tactics (EPP: 61.7%; CBP: 64.5%) than the kinship classification method (EPP: 50.0%; CBP: 43.3%). Overall, these results indicate that rates of alternative reproductive tactics inferred in the absence of parental genetic information could be underestimated and should be interpreted with caution. This study highlights the importance of incorporating samples from candidate parents to adequately determine the genetic mating system of a species. We expand knowledge on the reproductive tactics of colonial waterbirds, contributing novel data on the genetic mating system of the cattle egret, valuable for the design of management strategies for this invasive bird.Fil: Miño, Carolina Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Dantas de Souza, Elaine. Universidade Federal do São Carlos; BrasilFil: Moralez-Silva, Emmanuel. Universidade Federal do São Carlos; BrasilFil: Valdes, Talita Alvarenga. Universidade Federal do São Carlos; BrasilFil: Cortiço Corrêa Rodrigues, Vera Lúcia. Superintendencia de Controle de Endemias; BrasilFil: Del Lama, Sílvia Nassif. Universidade Federal do São Carlos; Brasi

US-Europe Differences in Technology-Driven Growth: Quantifying the Role of Education

European economic growth has been weak, compared to the US, since the 80s. In previous work (Krueger and Kumar, 2003), we argued that the European focus on specialized, vocational education might have been effective during the 60s and 70s, but resulted in a growth gap relative to the US during the subsequent information age, when new technologies emerged more rapidly. In this paper, we extend our framework to assess the quantitative importance of education policy, when compared to labor market rigidity and product market regulation, other policy differences more commonly suggested to be responsible for US-Europe differences. A assigns a major role to education policy in explaining US-Europe growth differences.