What good are strong specifications?

Abstract—Experience with lightweight formal methods suggests that programmers are willing to write specification if it brings tangible benefits to their usual development activities. This paper considers stronger specifications and studies whether they can be deployed as an incremental practice that brings additional benefits without being unacceptably expensive. We introduce a methodology that extends Design by Contract to write strong specifications of functional properties in the form of preconditions, postconditions, and invariants. The methodology aims at being palatable to developers who are not fluent in formal techniques but are comfortable with writing simple specifications. We evaluate the cost and the benefits of using strong specifications by applying the methodology to testing data structure implementations written in Eiffel and C#. In our extensive experiments, testing against strong specifications detects twice as many bugs as standard contracts, with a reasonable overhead in terms of annotation burden and runtime performance while testing. In the wide spectrum of formal techniques for software quality, testing against strong specifications lies in a “sweet spot ” with a favorable benefit to effort ratio. I

Enhancing SDO/HMI images using deep learning

The Helioseismic and Magnetic Imager (HMI) provides continuum images and magnetograms with a cadence better than one per minute. It has been continuously observing the Sun 24 hours a day for the past 7 years. The obvious trade-off between full disk observations and spatial resolution makes HMI not enough to analyze the smallest-scale events in the solar atmosphere. Our aim is to develop a new method to enhance HMI data, simultaneously deconvolving and super-resolving images and magnetograms. The resulting images will mimic observations with a diffraction-limited telescope twice the diameter of HMI. Our method, which we call Enhance, is based on two deep fully convolutional neural networks that input patches of HMI observations and output deconvolved and super-resolved data. The neural networks are trained on synthetic data obtained from simulations of the emergence of solar active regions. We have obtained deconvolved and supper-resolved HMI images. To solve this ill-defined problem with infinite solutions we have used a neural network approach to add prior information from the simulations. We test Enhance against Hinode data that has been degraded to a 28 cm diameter telescope showing very good consistency. The code is open source.Comment: 13 pages, 10 figures. Accepted for publication in Astronomy & Astrophysic

Outcomes from Collaborative provision audit: use of the Academic Infrastructure

"This paper is based on a review of the outcomes of the 30 Collaborative provision audits for institutions in England and Northern Ireland published between May 2005 and March 2007. The paper considers the use of the Academic Infrastructure in the management of collaborative provision during the period. The Academic Infrastructure is a set of nationally agreed reference points which give all institutions a shared starting point for setting, describing and assuring the quality and standards of their higher education provision." - Page 1

The Crescent Student Newspaper, April 22, 2005

Student newspaper of George Fox University.https://digitalcommons.georgefox.edu/the_crescent/2285/thumbnail.jp

On Systematic Design of Protectors for Employing OTS Items

Off-the-shelf (OTS) components are increasingly used in application areas with stringent dependability requirements. Component wrapping is a well known structuring technique used in many areas. We propose a general approach to developing protective wrappers that assist in integrating OTS items with a focus on the overall system dependability. The wrappers are viewed as redundant software used to detect errors or suspicious activity and to execute appropriate recovery when possible; wrapper development is considered as a part of system integration activities. Wrappers are to be rigorously specified and executed at run time as a means of protecting OTS items against faults in the rest of the system, and the system against the OTS item's faults. Possible symptoms of erroneous behaviour to be detected by a protective wrapper and possible actions to be undertaken in response are listed and discussed. The information required for wrapper development is provided by traceability analysis. Possible approaches to implementing “protectors” in the standard current component technologies are briefly outline

Inflation dynamics with labour market matching: assessing alternative specifications

This paper reviews recent approaches to modeling the labour market and assesses their implications for inflation dynamics through both their effect on marginal cost and on price-setting behaviour. In a search and matching environment, we consider the following modeling setups: right-to-manage bargaining vs. efficient bargaining, wage stickiness in new and existing matches, interactions at the firm level between price and wage-setting, alternative forms of hiring frictions, search on-the-job and endogenous job separation. We find that most specifications imply too little real rigidity and, so, too volatile inflation. Models with wage stickiness and right-to-manage bargaining or with firm-specific labour emerge as the most promising candidates. JEL Classification: E31, E32, E24, J64business cycle, Inflation Dynamics, labour market, real rigidities