Guided Unfoldings for Finding Loops in Standard Term Rewriting

In this paper, we reconsider the unfolding-based technique that we have introduced previously for detecting loops in standard term rewriting. We improve it by guiding the unfolding process, using distinguished positions in the rewrite rules. This results in a depth-first computation of the unfoldings, whereas the original technique was breadth-first. We have implemented this new approach in our tool NTI and compared it to the previous one on a bunch of rewrite systems. The results we get are promising (better times, more successful proofs).Comment: Pre-proceedings paper presented at the 28th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2018), Frankfurt am Main, Germany, 4-6 September 2018 (arXiv:1808.03326

Pedagogies of Optimism: Teaching to ‘look forward’ in activating welfare programmes in the Netherlands

In the context of the Dutch welfare state, precarisation entails particular pedagogies: citizens are taught how to feel about being insecure through the techniques of (1) accepting; (2) controlling; and (3) imagining. Welfare activation thus focuses on teaching citizens to accept their precarious position, to embrace it and to prepare for its continuation while remaining optimistic about its discontinuation. Perhaps cruelly, then, the state teaches citizens to develop optimism towards certain imagined futures while at the same time acknowledging the unattainability of these futures. Importantly, case managers in Dutch welfare offices are often precarious themselves too, making the affective labour they perform both difficult and essential for themselves. Contemporary activation and workfare programmes are therefore best understood as characterised by insecurity and precarisation on both the receiving and the providing end of state–citizen encounters

DARIS : a low-frequency distributed aperture array for radio astronomy in space

The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, space research such as space weather tomography, are also areas of scientific interest. \ud \ud Due to ionospheric scintillation (below 30MHz) and its opaqueness (below 15MHz), earth-bound radio astronomy observations in these bands are either severely limited in sensitivity and spatial resolution or entirely impossible. A radio telescope in space obviously would not be hampered by the Earth's ionosphere. In the past, several (limited) studies have been conducted to explore possibilities for such an array in space. These studies considered aperture synthesis arrays in space, at the back-side of the Moon, or a satellite constellation operating in a coherent mode. \u

A Suzuki Coupling Based Route to 2,2'-Bis(2-indenyl)biphenyl Derivatives

Because of the promising performance in olefin polymerization of 2,2'-bis(2-indenyldiyl)biphenyl zirconium dichloride, we developed a new and broadly applicable route to 2,2'-bis(2-indenyl)biphenyl derivatives. Reaction of the known 2,2'-diiodobiphenyl with the new 2-indenyl boronic acid did not result in the desired 2,2'-bis(2-indenyl)biphenyl (10); instead an isomer thereof, (spiro-1,1-(2,2'-biphenyl)-2-(2-indenyl)indane), was obtained. It was found that compound 10 could be made via a palladium-catalyzed reaction of 2,2-biphenyldiboronic acid with 2-bromoindene under standard Suzuki reaction conditions. However, the yield of this reaction was low at low palladium catalyst loadings, due to a competitive hydrolysis reaction of 2,2-biphenyldiboronic acid. HTE techniques were used to find an economically viable protocol. Thus, use of the commercially available 1.0 molar solution of (n-Bu)4NOH in methanol with cosolvent toluene led to precipitation of the pure product in a fast and clean reaction, using only 0.7 mol % (0.35 mol % per C-C) of the expensive palladium catalyst.

Efficient optimization of the dual-index policy using Markov chains

3We consider the inventory control of a single product in one location with two supply sources facing stochastic demand. A premium is paid for each product ordered from the faster `emergency' supply source. Unsatistfied emand is backordered and ordering decisions are made periodically. The optimal control policy for this system is known to be complex. For this reason we study a type of base-stock policy known as the dual-index policy (DIP) as control mechanism for this inventory system. Under this policy ordering decisions are based on a regular and an emergency inventory position and their corresponding order-up-to-levels. Previous work on this policy assumes deterministic lead times and uses simulation to and their optimal order-up-to levels. We provide an alternate proof for the result that separates the optimization of the DIP in two one-dimensional problems. An insight from this proof allows us to generalize the model to accommodate stochastic regular lead times and provide an approximate evaluation method based on limiting results so that optimization can be done without simulation. An extensive numerical study shows that this approach yields excellent results for deterministic lead times and good results for stochastic lead times

Analysis of the EMBRACE aperture array antenna by the characteristic Basis Function Method

This paper describes the use of the Characteristic Basis Function Method for the simulation of large phased array antennas for radio astronomy. It will be shown how the antenna effective area and the receiver noise temperature depend on array size. Also the receiving sensitivity Aeff /T sys normalised with respect to the physical area of the array will be shown for different array sizes and scan angles

Residential satisfaction close to highways: The impact of accessibility, nuisances and highway adjustment projects

In this paper we focus on gaining insight into the residential satisfaction of households near highways, based on survey data collected among 1,225 respondents in the Netherlands living within 1,000 meters from a highway. Ordinal regression was used to study the impact of highway externalities on residential satisfaction. Moreover, we gained first insights into the reactions of people on highway adjustment projects, by studying people’s expectations towards residential satisfaction as a consequence of the project with use of a multinomial logistic regression analysis. On average, 85 percent of respondents reported being satisfied with living near a highway. Regarding explanatory characteristics, subjective evaluations of air and noise nuisance and of accessibility are of comparable importance and seem to outperform objective exposure calculations or distance from the highway or access lane in explaining residential satisfaction. Moreover highway interest is directly reflected in a higher satisfaction. However, other factors such as neighborhood design, traffic safety and social cohesion are important as well. People react differently to highway adjustment plans, negative expectations being highly driven by current negative feelings towards nuisance, and positive expectations by personal interest in accessibility and a positive attitude towards cars. An important implication could be the notion that exposure is not the same as perceived nuisance, which may give reason to be cautious when making transportation planning decisions based solely on calculations. In addition, the finding that other (neighborhood) factors are also very important in explaining residential satisfaction is interesting when thinking about compensating for the negative effects of a highway in the neighborhood. Also, the results regarding reactions to an announced highway adjustment project might be used to better adjust the planning process to the characteristics of the residents in the area. Further research is necessary to deepen the results, for example through the addition of other road project locations, interviews and longitudinal data

Digital technology and the conservation of nature.

Digital technology is changing nature conservation in increasingly profound ways. We describe this impact and its significance through the concept of 'digital conservation', which we found to comprise five pivotal dimensions: data on nature, data on people, data integration and analysis, communication and experience, and participatory governance. Examining digital innovation in nature conservation and addressing how its development, implementation and diffusion may be steered, we warn against hypes, techno-fix thinking, good news narratives and unverified assumptions. We identify a need for rigorous evaluation, more comprehensive consideration of social exclusion, frameworks for regulation and increased multi-sector as well as multi-discipline awareness and cooperation. Along the way, digital technology may best be reconceptualised by conservationists from something that is either good or bad, to a dual-faced force in need of guidance.RCUKThis is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s13280-015-0705-