Hash Embeddings for Efficient Word Representations

We present hash embeddings, an efficient method for representing words in a continuous vector form. A hash embedding may be seen as an interpolation between a standard word embedding and a word embedding created using a random hash function (the hashing trick). In hash embeddings each token is represented by $k$ $d$-dimensional embeddings vectors and one $k$ dimensional weight vector. The final $d$ dimensional representation of the token is the product of the two. Rather than fitting the embedding vectors for each token these are selected by the hashing trick from a shared pool of $B$ embedding vectors. Our experiments show that hash embeddings can easily deal with huge vocabularies consisting of millions of tokens. When using a hash embedding there is no need to create a dictionary before training nor to perform any kind of vocabulary pruning after training. We show that models trained using hash embeddings exhibit at least the same level of performance as models trained using regular embeddings across a wide range of tasks. Furthermore, the number of parameters needed by such an embedding is only a fraction of what is required by a regular embedding. Since standard embeddings and embeddings constructed using the hashing trick are actually just special cases of a hash embedding, hash embeddings can be considered an extension and improvement over the existing regular embedding types

Teaching Tolerance in Public Education: Organizing the Exposure to Religious and Life-Stance Diversity

The purpose of this article is to discuss how pupils’ exposure to religious and life-stance diversity should be organized through the formal curriculum of public education in order to best foster tolerance. The article examines two proposals: the Integrated French model and the Norwegian religious education model. In view of normative considerations and considerations of effectiveness, it argues that although each model has its merits, they are both problematic because they in different ways fail to adequately balance the need for relevant exposure to religious and life-stance diversity with sufficient neutrality. By taking the Norwegian model as a point of departure, the article concludes by proposing two improvements - one calling for a sufficiently neutral value basis, and the other for a more mindful use of educational methods

Studies of nucleon form factors with 12 GeV CEBAF and SuperBigBite

The elastic electromagnetic form factors are among the most fundamental quantities that describe the ground-state structure of the proton and neutron. Precision data of the form factors over a wide kinematical range provide a powerful test of current theories of hadron structure. A number of experiments aiming to measure the electric and magnetic elastic form factors of the neutron, G{sub E}{sup n} and G{sub M}{sup n}, and proton, G{sub E}{sup p}, at very high momentum transfer, up to the range of Q{sup 2} = 10-14 (GeV/c){sup 2}, are planned to be carried out with the future 11 GeV electron beam of the upgraded CEBAF at Jefferson Lab. These experiments will determine the nucleon form factors with unprecedented precision to Q{sup 2}-values up to three times higher than those of existing data. We review the approved proposals and the conceptual design of a new spectrometer, SuperBigBite, that will be used in these and other future experiments at Jefferson Lab

Steady state stress distribution and force transmissibility of a rotating disk of variable thickness

The governing equations of the transverse vibration of a spinning disk of varying thickness are derived and solved using numerical integration techniques. A clamped-free rotating annular disk driven at the outer edge with sinusoidally varying force is considered for analysis. Representative graphs showing the stress distribution and the frequency dependence of the force transmissibility of the disk are presented. Results obtained in this paper are compared as applicable to results of previous investigations

A Comparison of Model-based and Design-based Impact Evaluations of Interventions in Developing Countries

We argue that non-experimental impact estimators will continue to be needed for evaluations of interventions in developing countries as social experiments, for various reasons, will never be the most preferred approach. In a survey of four studies that empirically compare the performance of experimental and non-experimental impact estimates using data from development interventions, we show that the preferred non-experimental estimators are unbiased. We try to explain the reasons why the non-experimental estimators perform better in the context of development interventions than American job-market interventions. We also use the survey as a source for suggestions for implementation and assessment of non-experimental impact evaluations. Our main suggestion is to be more careful and precise in the formulation of the statistical model for the assignment into the program and also to use the assignment information for model-based systematic sampling.Development, impact, non-experimental, social experiment, within-study