Data-Oblivious Stream Productivity

We are concerned with demonstrating productivity of specifications of infinite streams of data, based on orthogonal rewrite rules. In general, this property is undecidable, but for restricted formats computable sufficient conditions can be obtained. The usual analysis disregards the identity of data, thus leading to approaches that we call data-oblivious. We present a method that is provably optimal among all such data-oblivious approaches. This means that in order to improve on the algorithm in this paper one has to proceed in a data-aware fashion

Economische gevolgen van de PKB Waddenzee in de Kop van Noord-Holland. Een beoordeling van het ECORYS-NEI rapport, 2003.

In deze notitie van de Rijksuniversiteit Groningen is het fundament van de conclusies van het ECORYS-NEI rapport “Sociaal-economisch perspectief voor Waddenzeegemeenten in Kop van Noord-Holland - Den Helder, Texel, Wieringen, Anna Palowna” beoordeeld. De Waddenvereniging heeft de Rijksuniversiteit Groningen hierom gevraagd. Het nauwkeurig lezen van het rapport is door de RUG als belangrijkste onderzoeksinstrument gebruikt; nauwkeurig lezen tegen de achtergrond van bestaande algemene en wetenschappelijke kennis over enerzijds de Nederlandse economie en anderzijds economische evaluatie methoden. De belangrijkste conclusie van het ECORYS-NEI rapport, namelijk dat er door de beperkingen van PKB 1993 en de PKB 2001 in het jaar 2015 binnen de vier gemeenten in de Kop van Noord-Holland een totaal van 4234 arbeidsplaatsen minder zullen zijn dan in de situatie zonder PKB’s, blijkt vrijwel zonder fundament. Slechts voor 111 arbeidsplaatsen is sprake van een verantwoorde, zij het maximale, schatting. Het gaat hierbij dan om drie projecten c.q. sectoren: windmolens aan het wad, visserij en recreatie. Verreweg het best geslaagde deel van het rapport is het zes pagina’s tellende Hoofdstuk 5. Dit hoofdstuk identificeert specifieke kansrijke economische ontwikkelingen in de Kop van Noord-Holland in het licht van enerzijds de ontwikkelingen rond de Waddenzee, en anderzijds de duurzame ambities van de regio. De lijst met kansen en mogelijkheden kan een goede inspiratiebron zijn voor verschillende partijen die op zoek zijn naar vruchtbare of niet strijdige combinaties van ecologie en economie

A portfolio of natural places:Using a participatory GIS tool to compare the appreciation and use of green spaces inside and outside urban areas by urban residents

Green space at different distances is important for the wellbeing of urban dwellers. However, since these different types of green space are, for the most part, investigated in separate studies, it is difficult to disentangle how the use and appreciation of nearby and more distant nature by urban dwellers is related. To address this issue, we conduct an analysis in which we directly compare the appreciation and use of green spaces at four different spatial levels: neighbourhood, region, national, and world level, for urban residents in the Netherlands, Germany and Denmark. For this we use a quantitative, internet-based, participatory GIS method. The relationship between the use of local and more distant green spaces by urban dwellers has generally been addressed in terms of compensation. Our results indicate that this relationship can also be viewed in a complementary way. Urban residents appear to have a 'portfolio of natural places'. This portfolio consists of favourite places nearby that are rated lower but visited quite often, and natural places that they find highly attractive but are located farther away and visited less often. Local favourite places offer basic access to green and nature while other more distant natural places offer a larger variety of qualities and recreational possibilities. Results also indicate that, in order to meet the needs of urban residents, more than the immediate urban context needs to be considered in urban planning. (C) 2016 Elsevier B.V. All rights reserved

Inversion of spinning sound fields

A method is presented for the reconstruction of rotating monopole source distributions using acoustic pressures measured on a sideline parallel to the source axis. The method requires no \textit{a priori} assumptions about the source other than that its strength at the frequency of interest vary sinusoidally in azimuth on the source disc so that the radiated acoustic field is composed of a single circumferential mode. When multiple azimuthal modes are present, the acoustic field can be decomposed into azimuthal modes and the method applied to each mode in sequence. The method proceeds in two stages, first finding an intermediate line source derived from the source distribution and then inverting this line source to find the radial variation of source strength. A far-field form of the radiation integrals is derived, showing that the far field pressure is a band-limited Fourier transform of the line source, establishing a limit on the quality of source reconstruction which can be achieved using far-field measurements. The method is applied to simulated data representing wind-tunnel testing of a ducted rotor system (tip Mach number~0.74) and to control of noise from an automotive cooling fan (tip Mach number~0.14), studies which have appeared in the literature of source identification.Comment: Revised version of paper submitted to JASA; five more figures; expanded content with more discussion of error behaviour and relation to Nearfield Acoustical Holograph

Evaluating manifest monotonicity using Bayes factors

The assumption of latent monotonicity in item response theory models for dichotomous data cannot be evaluated directly, but observable consequences such as manifest monotonicity facilitate the assessment of latent monotonicity in real data. Standard methods for evaluating manifest monotonicity typically produce a test statistic that is geared toward falsification, which can only provide indirect support in favor of manifest monotonicity. We propose the use of Bayes factors to quantify the degree of support available in the data in favor of manifest monotonicity or against manifest monotonicity. Through the use of informative hypotheses, this procedure can also be used to determine the support for manifest monotonicity over substantively or statistically relevant alternatives to manifest monotonicity, rendering the procedure highly flexible. The performance of the procedure is evaluated using a simulation study, and the application of the procedure is illustrated using empirical data. Keywords: Bayes factor, essential monotonicity, item response theory, latent monotonicity, manifest monotonicit

Stream Productivity by Outermost Termination

Streams are infinite sequences over a given data type. A stream specification is a set of equations intended to define a stream. A core property is productivity: unfolding the equations produces the intended stream in the limit. In this paper we show that productivity is equivalent to termination with respect to the balanced outermost strategy of a TRS obtained by adding an additional rule. For specifications not involving branching symbols balancedness is obtained for free, by which tools for proving outermost termination can be used to prove productivity fully automatically

Quality assessment of scientific manuscripts in peer review and education

We report a vignette study and a survey to investigate which study characteristics influence quality ratings academics give of articles submitted for publication, and academics and students give of students’ theses. In the vignette study, 800 respondents evaluated the quality of an abstract of studies with small or large sample sizes, showing statistically significant or non-significant results, and containing statistical reporting errors or no errors. In the survey, the same participants rated the importance of 29 manuscript characteristics related to the study’s theory, design, conduct, data analyses, and presentation for assessing either the quality of a manuscript or its publishability (article) or grade (thesis). Results showed that quality ratings were affected by sample sizes but not by statistical significance or the presence of statistical reporting errors in the rated researchvignette. These results suggest that researchers’ assessments of manuscript quality are not responsible for publication bias. Furthermore, academics and students provided highly similar ratings of the importance of different aspects relevant to quality assessment of articles and theses. These results suggest that quality criteria for scientific manuscripts are already adopted by students and are similar for submitted manuscripts and theses

Identifying Citizens' Place Values for Integrated Planning of Road Infrastructure Projects

Projects for road infrastructure and spatial development easily meet public resistance because of a lack of local knowledge of place values by (often non-local) planners. The aim of this study is to explore how insights in place values might improve the local knowledge base for planners of integrated road infrastructure projects and spatial development. We developed, tested and analysed the results from a novel online value-mapping tool called the ‘Place Value Identifier’. The developed method allows us to (i) relate to ‘soft’ valuable places identified by Public Participation GIS as a complement to ‘hard’ land use data, (ii) define Valued yet Unprotected places based on combining ‘hard’ and ‘soft’ values and (iii) illustrate how these insights can be used for integrated planning of road infrastructure projects. The findings of this study show the increased potential of value mapping techniques and illustrate possible resistance areas around road infrastructure planning projects. This knowledge may assist planners in creating and selecting acceptable project alternatives that may invoke high public acceptance