168 research outputs found
Linking throughput and output legitimacy in Swiss forest policy implementation
This is the author accepted manuscript. The final version is available from Springer via the DOI in this record.Policy scholars typically assume that implementing actors follow democratically decided rules
in linear, predictable ways. However, this assumption does not factor in the operational
challenges and multiple accountability relations facing policy implementers in contemporary,
hybrid policy implementation settings. Shifting the focus to throughput (governance process)
and output legitimacy (results), this paper explores how throughput dimensions affect the
implementation of policy outputs. We study a hybrid policy – the Swiss Forest Policy 2020 –
in a federalist, multi-level implementation setting. We find that accountability dilemmas have
negative consequences for output implementation, particularly when professionalism clashes
with rules. Accountability dilemmas are exacerbated by policy incoherence and interact with
policy ambiguity. High issue salience can compensate for the negative effects of these factors.
The role of implementing organizations in democratic countries goes beyond rule following:
accountability relations and other throughput dimensions crucially affect output legitimacy
Fast quasi-centroid molecular dynamics for water and ice
We describe how the fast quasi-centroid molecular dynamics (f-QCMD) method
can be applied to condensed phase systems by approximating the quasi-centroid
potential of mean force as a sum of inter- and intra-molecular corrections to
the classical interaction potential. The corrections are found by using a
regularised iterative Boltzmann inversion procedure to recover the inter- and
intra-molecular quasi-centroid distribution functions obtained from a path
integral molecular dynamics simulation. The resulting methodology is found to
give good agreement with a previously published QCMD dipole absorption spectrum
for liquid water, and satisfactory agreement for ice. It also gives good
agreement with spectra from a recent implementation of CMD that uses a
pre-computed elevated temperature potential of mean force. Modern centroid
molecular dynamics methods therefore appear to be reaching a consensus
regarding the impact of nuclear quantum effects on the vibrational spectra of
water and ice.Comment: 10 pages, 4 figures, plus supplementary information and toc figur
Vibrational strong coupling in liquid water from cavity molecular dynamics
We assess the cavity molecular dynamics method for the calculation of
vibrational polariton spectra, using liquid water as a specific example. We
begin by disputing a recent suggestion that nuclear quantum effects may lead to
a broadening of polariton bands, finding instead that they merely result in
anharmonic red shifts in the polariton frequencies. We go on to show that our
simulated cavity spectra can be reproduced to graphical accuracy with a
harmonic model that uses just the cavity-free spectrum and the geometry of the
cavity as input. We end by showing that this harmonic model can be combined
with the experimental cavity-free spectrum to give results in good agreement
with optical cavity measurements. Since the input to our harmonic model is
equivalent to the input to the transfer matrix method of applied optics, we
conclude that cavity molecular dynamics cannot provide any more insight into
the effect of vibrational strong coupling on the absorption spectrum than this
transfer matrix method, which is already widely used by experimentalists to
corroborate their cavity results.Comment: 10 pages, 5 figure
Scrap your boilerplate with object algebras
htmlabstractTraversing complex Abstract Syntax Trees (ASTs) typically requires large amounts of tedious boilerplate code. For many operations most of the code simply walks the structure, and only a small portion of the code implements the functional- ity that motivated the traversal in the first place. This paper presents a type-safe Java framework called Shy that removes much of this boilerplate code. In Shy Object Algebras are used to describe complex and extensible AST structures. Using Java annotations Shy generates generic boilerplate code for various types of traversals. For a concrete traversal, users of Shy can then inherit from the generated code and over- ride only the interesting cases. Consequently, the amount of code that users need to write is significantly smaller. Moreover, traversals using the Shy framework are also much more structure shy, becoming more adaptive to future changes or extensions to the AST structure. To prove the effectiveness of the approach, we applied Shy in the implementation of a domain-specific questionnaire language. Our results show that for a large number of traversals there was a significant reduction in the amount of user-defined code
Understanding Design Patterns Density with Aspects: A Case Study in JHotDraw using AspectJ
International audienceDesign patterns offer solutions to common engineering prob- lems in programs [1]. In particular, they shape the evolution of program elements. However, their implementations tend to vanish in the code: thus it is hard to spot them and to understand their impact. The prob- lem becomes even more difficult with a "high density of pattern": then the program becomes easy to evolve in the direction allowed by patterns but hard to change [2]. Aspect languages offer new means to modular- ize elements. Implementations of object-oriented design patterns with AspectJ have been proposed [3]. We aim at testing the scalability of such solutions in the JHotDraw framework. We first explore the impact of density on pattern implementation. We show how AspectJ helps to reduce this impact. This unveils the principles of aspects and AspectJ to control pattern density
On automatic class insertion with overloading
Also published in Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (OOPSLA)International audienceSeveral algorithms [Cas92, MS89, Run92, DDHL94a, DDHL95, GMM95] have been proposed to automatically insert a class into an inheritance hierarchy. But actual hierarchies all include overriden and overloaded properties that these algorithms handle either very partially or not at all. Partially handled means handled provided there is a separate given function f able to compare overloaded properties [DDHL95, GMM95].In this paper, we describe a new version of our algorithm (named Ares) which handles automatic class insertion more efficiently using such a function f. Although impossible to fully define, this function can be computed for a number of well defined cases of overloading and overriding. We give a classification of such cases and describe the computation process for a well-defined set of nontrivial cases.The algorithm preserves these important properties:- preservation of the maximal factorization of properties- preservation of the underlying structure (Galois lattice) of the input hierarchy- conservation of relevant classes of the input hierarchy with their properties
Synthesizing Iterators from Abstraction Functions
A technique for synthesizing iterators from declarative abstraction functions written in a relational logic specification language is described. The logic includes a transitive closure operator that makes it convenient for expressing reachability queries on linked data structures. Some optimizations, including tuple elimination, iterator flattening, and traversal state reduction, are used to improve performance of the generated iterators.
A case study demonstrates that most of the iterators in the widely used JDK Collections classes can be replaced with code synthesized from declarative abstraction functions. These synthesized iterators perform competitively with the hand-written originals.
In a user study the synthesized iterators always passed more test cases than the hand-written ones, were almost always as efficient, usually took less programmer effort, and were the qualitative preference of all participants who provided free-form comments
Scrap your boilerplate with object algebras
International audienceTraversing complex Abstract Syntax Trees (ASTs) typically requires large amounts of tedious boilerplate code. For many operations most of the code simply walks the structure, and only a small portion of the code implements the functional- ity that motivated the traversal in the first place. This paper presents a type-safe Java framework called Shy that removes much of this boilerplate code. In Shy Object Algebras are used to describe complex and extensible AST structures. Using Java annotations Shy generates generic boilerplate code for various types of traversals. For a concrete traversal, users of Shy can then inherit from the generated code and over- ride only the interesting cases. Consequently, the amount of code that users need to write is significantly smaller. Moreover, traversals using the Shy framework are also much more structure shy, becoming more adaptive to future changes or extensions to the AST structure. To prove the effectiveness of the approach, we applied Shy in the implementation of a domain-specific questionnaire language. Our results show that for a large number of traversals there was a significant reduction in the amount of user-defined code
Real-time pollen identification using holographic imaging and fluorescence measurements
Over the past few years, a diverse range of automatic real-time instruments has been developed to respond to the needs of end users in terms of information about atmospheric bioaerosols. One of them, the SwisensPoleno Jupiter, is an airflow cytometer used for operational automatic bioaerosol monitoring. The instrument records holographic images and fluorescence information for single aerosol particles, which can be used for identification of several aerosol types, in particular different pollen taxa. To improve the pollen identification algorithm applied to the SwisensPoleno Jupiter and currently based only on the holography data, we explore the impact of merging fluorescence spectra measurements with holographic images. We demonstrate, using measurements of aerosolised pollen, that combining information from these two sources results in a considerable improvement in the classification performance compared to using only a single source (balanced accuracy of 0.992 vs. 0.968 and 0.878). This increase in performance can be ascribed to the fact that often classes which are difficult to resolve using holography alone can be well identified using fluorescence and vice versa. We also present a detailed statistical analysis of the features of the pollen grains that are measured and provide a robust, physically based insight into the algorithm's identification process. The results are expected to have a direct impact on operational pollen identification models, particularly improving the recognition of taxa responsible for respiratory allergies.</p
- …