234 research outputs found
How Scale Affects Structure in Java Programs
Many internal software metrics and external quality attributes of Java
programs correlate strongly with program size. This knowledge has been used
pervasively in quantitative studies of software through practices such as
normalization on size metrics. This paper reports size-related super- and
sublinear effects that have not been known before. Findings obtained on a very
large collection of Java programs -- 30,911 projects hosted at Google Code as
of Summer 2011 -- unveils how certain characteristics of programs vary
disproportionately with program size, sometimes even non-monotonically. Many of
the specific parameters of nonlinear relations are reported. This result gives
further insights for the differences of "programming in the small" vs.
"programming in the large." The reported findings carry important consequences
for OO software metrics, and software research in general: metrics that have
been known to correlate with size can now be properly normalized so that all
the information that is left in them is size-independent.Comment: ACM Conference on Object-Oriented Programming, Systems, Languages and
Applications (OOPSLA), October 2015. (Preprint
Constraint programming for type inference in flexible model-driven engineering
Domain experts typically have detailed knowledge of the concepts that are used in their domain; however they often lack the technical skills needed to translate that knowledge into model-driven engineering (MDE) idioms and technologies. Flexible or bottom-up modelling has been introduced to assist with the involvement of domain experts by promoting the use of simple drawing tools. In traditional MDE the engineering process starts with the definition of a metamodel which is used for the instantiation of models. In bottom-up MDE example models are defined at the beginning, letting the domain experts and language engineers focus on expressing the concepts rather than spending time on technical details of the metamodelling infrastructure. The metamodel is then created manually or inferred automatically. The flexibility that bottom-up MDE offers comes with the cost of having nodes in the example models left untyped. As a result, concepts that might be important for the definition of the domain will be ignored while the example models cannot be adequately re-used in future iterations of the language definition process. In this paper, we propose a novel approach that assists in the inference of the types of untyped model elements using Constraint Programming. We evaluate the proposed approach in a number of example models to identify the performance of the prediction mechanism and the benefits it offers. The reduction in the effort needed to complete the missing types reaches up to 91.45% compared to the scenario where the language engineers had to identify and complete the types without guidance
A parser generator system to handle complete syntax
To define a language completely, it is necessary to define both its syntax and semantics. If these definitions are in a suitable form, the parser and code-generator of a compiler, respectively, can be generated from them. This thesis addresses the problem of syntax definition and automatic parser generation
Assessing the Relationship Between Cognitive Control and Weight Control.
Obesity is a complex phenomenon with multiple causes, potentially including cognitive factors. Theories of cognition and obesity have typically focused on executive functions, broadly defined, and findings have been somewhat inconsistent across studies. Here we focus on a new hypothesis about one potential core cognitive issue in obesity: cognitive control difficulties. The central idea motivating this research is that efficient cognitive control is critical to effective weight control. Specifically, vulnerability in the capacity to resist distraction during demanding cognitive tasks may be related to weight regulation difficulties. Moreover, such vulnerability may be specific to situations requiring control over food-related distraction. Here we assess cognitive control in working memory and sustained attention by examining resistance to task-intrinsic distraction in working memory tasks, and task-extrinsic distraction in sustained attention tasks. In particular, we use a modified item-recognition working memory task (the recent-probes task), as well as list-based directed ignoring and directed forgetting tasks to assess the removal of task-intrinsic distraction from working memory. We use signal-detection vigilance tasks with and without distraction to assess the control of sustained attention in the presence of task-extrinsic distraction. We find that overweight/obese participants demonstrate specific cognitive control vulnerability in resisting different types of distraction, in the contexts of managing the contents of working memory and maintaining focused attention. Specifically, overweight/obese individuals show increased food-related semantic interference from task-intrinsic information in working memory relative to lean controls, increased food-related proactive interference from task-intrinsic information in working memory relative to food-neutral proactive interference, and poorer performance in the presence of task-extrinsic distraction in sustained attention. However, the content-specificity of these effects varied. In the working memory domain, interference was only increased when overweight/obese participants were required to control distraction from food-related information. Conversely, in the sustained attention domain, there was no evidence of such content-specificity. Results concerning other weight-related variables such as dieting and restrained eating are also considered, though the results concerning these variables were less consistent. Taken together, these findings suggest a relationship between cognitive control in the form of resistance to distraction and weight regulation, though the causal direction of this relationship remains unclear.PhDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/109056/1/lossher_1.pd
Enveloping Sophisticated Tools into Process-Centered Environments
We present a tool integration strategy based on enveloping pre-existing tools without source code modifications or recompilation, and without assuming an extension language, application programming interface, or any other special capabilities on the part of the tool. This Black Box enveloping (or wrapping) idea has existed for a long time, but was previously restricted to relatively simple tools. We describe the design and implementation of, and experimentation with, a new Black Box enveloping facility intended for sophisticated tools --- with particular concern for the emerging class of groupware applications
Integrating independent components with on-demand remodularization
This paper proposes language concepts that facilitate the separation of an application into independent reusable building blocks and the integration of pre-build generic software components into applications that have been developed by third party vendors. A key element of our approach are on-demand remodularizations, meaning that the abstractions and vocabulary of an existing code base are translated into the vocabulary understood by a set of components that are connected by a common collaboration interface. This general concept allows us to mix-and-match remodularizations and components on demand
Motor Neuron Disease Register for England, Wales and Northern Ireland-an analysis of incidence in England.
Amyotrophic lateral sclerosis (ALS) has a reported incidence of 1-2/100,000 person-years. It is estimated that there are 5000 people with ALS in the UK at any one time; however, the true figure and geographical distribution, are unknown. In this study, we describe the establishment of a population register for England, Wales, and Northern Ireland and report-estimated incidence. Methods: People with a diagnosis of ALS given by a consultant neurologist and whose postcode of residence is within England, Wales, or Northern Ireland were eligible. The catchment area was based on six data contributors that had been participating since 2016. All centres included in this analysis were in England, and therefore Wales and Northern Ireland are not included in this report. Crude age- and sex-specific incidence rates were estimated using population census records for the relevant postcodes from Office of National Statistics census data. These rates were standardized to the UK population structure using direct standardization. Results: There were 232 people in the database with a date of diagnosis between 2017 and 2018, when missing data were imputed there were an estimated 287-301 people. The denominator population of the catchment area is 7,251,845 according to 2011 UK census data. Age- and sex-adjusted incidence for complete cases was 1.61/100,000 person-years (95% confidence interval 1.58, 1.63), and for imputed datasets was 2.072/100,000 person-years (95% CI 2.072, 2.073). Discussion: We found incidence in this previously unreported area of the UK to be similar to other published estimates. As the MND Register for England, Wales, and Northern Ireland grows we will update incidence estimates and report on further analyses
The impact of age on genetic testing decisions in amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a heterogeneous neurodegenerative syndrome. In up to 20% of cases, a family history is observed. Although Mendelian disease gene variants are found in apparently sporadic ALS, genetic testing is usually restricted to those with a family history or younger patients with sporadic disease. With the advent of therapies targeting genetic ALS, it is important that everyone treatable is identified. We therefore sought to determine the probability of a clinically actionable ALS genetic test result by age of onset, globally, but using the UK as an exemplar. Blood-derived DNA was sequenced for ALS genes, and the probability of a clinically actionable genetic test result estimated. For a UK subset, age- and sex-specific population incidence rates were used to determine the number of such results missed by restricting testing by age of onset according to UK's National Genomic Test Directory criteria. There were 6274 people with sporadic ALS, 1551 from the UK. The proportion with a clinically actionable genetic test result ranged between 0.21 [95% confidence interval (CI) 0.18-0.25] in the youngest age group to 0.15 (95% CI 0.13-0.17) in the oldest age group for a full gene panel. For the UK, the equivalent proportions were 0.23 (95% CI 0.13-0.33) in the youngest age group to 0.17 (95% CI 0.13-0.21) in the oldest age group. By limiting testing in those without a family history to people with onset below 40 years, 115 of 117 (98% of all, 95% CI 96%-101%) clinically actionable test results were missed. There is a significant probability of a clinically actionable genetic test result in people with apparently sporadic ALS at all ages. Although some countries limit testing by age, doing so results in a significant number of missed pathogenic test results. Age of onset and family history should not be a barrier to genetic testing in ALS.</p
Aspect-Oriented Programming for Dynamic Web Service Monitoring and Selection
Abstract. In Service-Oriented Application Development, applications are composed by selecting and integrating third-party web services. To avoid hardwiring concrete services in client applications we introduced in previous work the Web Services Management Layer (WSML) and suggested a redirection mechanism based on Aspect Oriented Programming (AOP). Even though this mechanism enables hot swapping between semantically equivalent services based on their availability, this is not enough to create applications that are driven by business requirements. In this paper we introduce a more advanced selection mechanism that allows dynamic switching between services based on business driven requirements that can change over time. Choosing a service may be done based on cost, presence on approved partners list, as well as binding support, quality of service classifications, historical performance and proximity. We introduce a modular monitoring mechanism that is able to observe these criteria and trigger a more advanced service selection procedure. We show how the AOP language JAsCo with its dynamically pluggable aspects is well suited to achieve this. 1
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