Bulk Viscosity of Interacting Hadrons

We show that first approximations to the bulk viscosity $\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\eta_v$ on the factor $(\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.Comment: 4 pages, 1 figure, Contribution to Quark Matter 2009, Knoxville, Tennessee, US

Constrained speaker linking

In this paper we study speaker linking (a.k.a.\ partitioning) given constraints of the distribution of speaker identities over speech recordings. Specifically, we show that the intractable partitioning problem becomes tractable when the constraints pre-partition the data in smaller cliques with non-overlapping speakers. The surprisingly common case where speakers in telephone conversations are known, but the assignment of channels to identities is unspecified, is treated in a Bayesian way. We show that for the Dutch CGN database, where this channel assignment task is at hand, a lightweight speaker recognition system can quite effectively solve the channel assignment problem, with 93% of the cliques solved. We further show that the posterior distribution over channel assignment configurations is well calibrated.Comment: Submitted to Interspeech 2014, some typos fixe

Creating a Dutch testbed to evaluate the retrieval from textual databases

This paper describes the first large-scale evaluation of information retrieval systems using Dutch documents and queries. We describe in detail the characteristics of the Dutch test data, which is part of the official CLEF multilingual texttual database, and give an overview of the experimental results of companies and research institutions that participated in the first official Dutch CLEF experiments. Judging from these experiments, the handling of language-specific issues of Dutch, like for instance simple morphology and compound nouns, significantly improves the performance of information retrieval systems in many cases. Careful examination of the test collection shows that it serves as a reliable tool for the evaluation of information retrieval systems in the future

Dutch AG-MEMOD model; A tool to analyse the agri-food sector

Agricultural policies in the European Union (EU) have a history of continuous reform. AG-MEMOD, acronym for Agricultural sector in the Member states and EU: econometric modelling for projections and analysis of EU policies on agriculture, forestry and the environment, provides a system for analysing the impact of policy changes across the EU. Teams from each EU member state have developed models for the specific agri-food sector in their own country, which were reviewed by experts. Country-specific differences with regard to the operation of the agri-food sector and how each responds to external influences such as EU policies and world market prices have been carefully modelled. Not only CAP policy variables, but also economic and biophysical variables have been inserted. As all country models were built on a common format, they could be combined and run as an overall system for the EU. Hence, AG-MEMOD is able to analyse the impact of policy changes on individual member states, in all their diversity, as well as on the EU as a whole. This report describes the construction of the Dutch agri-food sector within the AG-MEMOD framework and summarises the specification, estimation and testing procedures applied to build the Dutch model. An application of the model is provided for a sugar policy reform. Although there is scope for improvements, the current model version can already produce reasonable projections for agricultural commodities in the Netherlands.Agricultural and Food Policy,

IMPORTANCE OF CAP REFORMS FOR THE DUTCH AGRICULTURAL SECTOR IN 2000-2020

Since 2000, the two important reforms of The EU Common Agricultural Policy (CAP) took place. The Agenda 2000 Berlin Agreement of March 1999 aimed to increase EU agriculture market orientation and focuses on the grain, oilseed, dairy and the beef sectors. It reduced intervention prices in these sectors and lowered the set-aside requirements for crops and by implementation of non-crop specific compensatory payments. The core of The Luxembourg Agreement from June 2003 was an acceleration of decoupling of farm support initiated by the Agenda 2000 complementary payment. It introduces a system of direct payments (known as single payment scheme - SPS), which are no longer linked to the production (decoupling). This CAP reform also includes commodity specific measures, especially in dairy sector. The Luxemburg Agreement links the direct payments to farmers with farm management practices which maintain environmental and other requirements set at EU and national levels (‘Cross-compliance’). The goal of this paper is twofold. First, we investigate the impact of the CAP reform on the Dutch agricultural sector in 2004 – 2007; second we examine effects of possible future CAP reform decision on the Dutch agriculture till 2020. The study is based on the AGMEMOD econometric model developed within the framework of projects financed by the European Commission. It reflects a sectoral, dynamic, partial equilibrium model, which takes into account the national specificities and is built up of models for the Member States of the EU27. The foundation for AGMEMOD is laid in the establishment of country model templates, which must achieve compatibility of the models to be built and the communality of data. The most important differences between the national models are macroeconomic assumptions, components of policies under the CAP and SAPS (in respect with the new Member States) and assumptions on the impact of direct payments on agricultural production (degree of decoupling). On the country level, commodity templates must encapsulate the modeling system to be used. Many components of these templates are based on the information and guidelines delivered by Hanrahan (2001), but then adapted to country-specific conditions. At least, they must contain issues on market and policy description, flow charts, key market and specification of the functional forms of the commodity model. The AGMEMOD model covers all important CAP commodities: grains, oilseeds, potatoes, sugar and sugar beets, livestock products, milk and dairy products. We will investigate the CAP impact on the Dutch agriculture by mean of policy simulations with the Dutch AGMEMOD model. To isolate policy effect in the historical period 2000 - 2007, counterfactual simulations for 2000 - 2007 will be run. To simulate the response of the Dutch agriculture on different policy changes in 2008 - 2020, the no-policy change baseline scenario will be developed and several policy experiments will be conducted: milk quota abolition, biofuel directive implementation and animal premiums decoupling. To indentify the policy effects the policy scenarios will be compared with the baseline.CAP, CAP Reform, Dutch agriculture, Agricultural and Food Policy, Research Methods/ Statistical Methods, Q10, Q18,