On two paradigms of legal theory and their relationship

H. L. A. Hart thought that a theory of law can be purely descriptive and called his theory a “descriptive sociology”. One of his great contributions to modern legal theory is his emphasis on the internal aspect of social rules. According to him, a theory of law can be built on the basis of the description of the participants’ view without sharing with it. This descriptivism is totally rejected by Dworkin, who propagates a theory that denies a sharp separation between a legal theory and its implications for adjudication. For Dworkin, a legal theory is only possible as a theory with “the internal, participants’ point of view”. Dworkin’s position implies a radicalization of legal theory that will transform the statement of an external point of view to that of an internal one. For Dworkin, the descriptivism bases on the sociological concept of law, which is an “imprecise criterial concept” and is “not sufficiently precise to yield philosophically interesting essential features.”Hart’s position is vulnerable because it takes an impure form of descriptivism that still draws a categorical distinction between fact and norm. This theoretical impurity results from the ambiguity of interpreting the internal aspect of rules. A strategy to rescue the Hart’s project is to radicalize his descriptivism with Luhmann's systems theory. Adapting the systems theoretical distinction between internal and external observation of law with all its implications for the explanation of the legal system and legal communications, Hart’s descriptivism finally attains its pure form, which is not only a distinctive paradigm of legal theory, but also possesses the potentialities to clarify its relationship to the legal theory based on the internal aspect of law

Families of Conformal Fixed Points of N=2 Chern-Simons-Matter Theories

We argue that a large class of N=2 Chern-Simons-matter theories in three dimensions have a continuous family of exact IR fixed points described by suitable quartic superpotentials, based on holomorphy. The entire family exists in the perturbative regime. A nontrivial check is performed by computing the 4-loop beta function of the quartic couplings, in the 't Hooft limit, with a large number of flavors. We find that the 4-loop beta function can only deform the family of 2-loop fixed points, and does not change the dimension of this family. We further present an explicit computation of a perturbative correction to the Zamolodchikov metric on this space of three-dimensional superconformal field theories.Comment: 27 pages, 108 figure

The behavior of real exchange rates: the case of Japan

The study examines the convergence rate of mean reversion by contrasting the estimated half-life of real exchange rate (RER). We employ an extensive monthly consumer price index (CPI)-based product price’s panel for Japan (the U.S. as the num´eraire). We find that the disaggregated RERs are persistent due to the cross-sectional dependence problems. By controlling common correlated effects, the estimated half-life for all goods may fall to as low as 2.54 years, below the consensus view of 3 to 5 years summarized by Rogoff (1996). After correcting the small-sample bias, the estimated half-life of deviations from purchasing power parity (PPP) increase by 1.03 year. Our findings also support that the half-life of mean reversion of RER is about 3.55 years for traded goods, about 0.11 year lower than non-traded goods. We also show that traded goods and non-traded goods perform distinct distributions of persistence

Calculation of secondary electron emission yields from low-energy electron deposition in tungsten surfaces

We present calculations of secondary electron emission (SEE) yields in tungsten as a function of primary electron energies between 50 eV and 1 keV and incidence angles between 0 and 90{\deg}. We conduct a review of the established Monte Carlo methods to simulate multiple electron scattering in solids and select the best suited to study SEE in high-Z metals. We generate secondary electron yield and emission energy functions of the incident energy and angle and fit them to bivariate fitting functions using symbolic regression. We compare the numerical results with experimental data, with good agreement found. Our calculations are the first step towards studying SEE in nanoarchitected surfaces for electric propulsion chamber walls

DeepProbe: Information Directed Sequence Understanding and Chatbot Design via Recurrent Neural Networks

Information extraction and user intention identification are central topics in modern query understanding and recommendation systems. In this paper, we propose DeepProbe, a generic information-directed interaction framework which is built around an attention-based sequence to sequence (seq2seq) recurrent neural network. DeepProbe can rephrase, evaluate, and even actively ask questions, leveraging the generative ability and likelihood estimation made possible by seq2seq models. DeepProbe makes decisions based on a derived uncertainty (entropy) measure conditioned on user inputs, possibly with multiple rounds of interactions. Three applications, namely a rewritter, a relevance scorer and a chatbot for ad recommendation, were built around DeepProbe, with the first two serving as precursory building blocks for the third. We first use the seq2seq model in DeepProbe to rewrite a user query into one of standard query form, which is submitted to an ordinary recommendation system. Secondly, we evaluate DeepProbe's seq2seq model-based relevance scoring. Finally, we build a chatbot prototype capable of making active user interactions, which can ask questions that maximize information gain, allowing for a more efficient user intention idenfication process. We evaluate first two applications by 1) comparing with baselines by BLEU and AUC, and 2) human judge evaluation. Both demonstrate significant improvements compared with current state-of-the-art systems, proving their values as useful tools on their own, and at the same time laying a good foundation for the ongoing chatbot application.Comment: Proceedings of the 23rd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, 201