28,438 research outputs found
Bose-Einstein Condensation with Entangled Order Parameter
We propose a practically accessible non-mean-field ground state of
Bose-Einstein condensation (BEC), which occurs in an interspecies two-particle
entangled state, and is thus described by an entangled order parameter. A
suitably defined entanglement entropy is used as the characterization of the
non-mean-field nature, and is found to persist in a wide parameter regime. The
interspecies entanglement leads to novel interference terms in the dynamical
equations governing the single particle orbital wavefunctions. Experimental
feasibility and several methods of probe are discussed. We urge the study of
multi-channel scattering between different species of atoms.Comment: V1: 5 pages, 4 figures. Accepted by Phys. Rev. Lett.; V2: A couple of
very minor typos corrected, publishe
Benefit Evaluation of the Country of Origin Labeling in Taiwan: Results from Auction Experiment
This research is aimed at investigating the consumer’s preference for food produced in Taiwan and the economic benefits for the country of origin labeling. The study uses both experimental auction and contingent valuation method (CVM) to investigate factors that affect the consumer’s willingness to pay (WTP) for products under country-of-origin labeling (COOL). Experimental auctions of Taiwan and China preserved olives as well as Taiwan, China and Vietnam oolong teas were conducted using the Vickrey’s second price sealed bid auction. For CVM, the study used the double-bounded dichotomous choice method in which we started assuming the same base price for all products in the first question and then varied the prices in the second CV question. The products not chosen in the first question were offered with a discount in a range from 10% to 50% in the following question. Based on auction data, the Tobit model shows that the estimated premiums are 58.1%, 78.15% and 98.13% for Taiwan products over their alternatives of China olives, China oolong tea, and Vietnam oolong tea, respectively. Based on the CVM, the estimated premiums for Taiwan over China olives from a Logit model is 67%, and the premiums for Taiwan produced oolong tea should lie between 50% to an unknown upper bound over China and Vietnam alternatives as the Multinomial Logit model cannot be successfully estimated due to too few choice switches with discounted prices. The study thus demonstrates the superiority of the experimental auction over the CVM in eliciting the WTP for foods produced in Taiwan. The study concludes that enacting a COOL law would increase economic benefits to consumers in Taiwan, and at the same time, placing the imported products in the level playing field.country-of-origin labeling, experimental auction, Tobit model, contingent valuation method, logit model, multinomial logit model, willingness to pay, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Q13, D12.,
Algebraic independence of arithmetic gamma values and Carlitz zeta values
We consider the values at proper fractions of the arithmetic gamma function
and the values at positive integers of the zeta function for F_q[theta] and
provide complete algebraic independence results for them.Comment: 15 page
Computer Assisted Language Learning Based on Corpora and Natural Language Processing : The Experience of Project CANDLE
This paper describes Project CANDLE, an ongoing 3-year project which uses various corpora and NLP technologies to construct an online English learning environment for learners in Taiwan. This report focuses on the interim results obtained in the first eighteen months. First, an English-Chinese parallel corpus, Sinorama, was used as the main course material for reading, writing, and culture-based learning courses. Second, an online bilingual concordancer, TotalRecall, and a collocation reference tool, TANGO, were developed based on Sinorama and other corpora. Third, many online lessons, including extensive reading, verb-noun collocations, and vocabulary, were designed to be used alone or together with TotalRecall and TANGO. Fourth, an online collocation check program, MUST, was developed for detecting V-N miscollocation and suggesting adequate collocates in student’s writings based on the hypothesis of L1 interference and the database of BNC and the bilingual Sinorama Corpus. Other computational scaffoldings are under development. It is hoped that this project will help intermediate learners in Taiwan enhance their English proficiency with effective pedagogical approaches and versatile language reference tools
Modern CFD applications for the design of a reacting shear layer facility
The RPLUS2D code, capable of calculating high speed reacting flows, was adopted to design a compressible shear layer facility. In order to create reacting shear layers at high convective Mach numbers, hot air streams at supersonic speeds, rendered by converging-diverging nozzles, must be provided. A finite rate chemistry model is used to simulate the nozzle flows. Results are compared with one-dimensional solutions at chemical equilibrium. Additionally, a two equation turbulence model with compressibility effects was successfully incorporated with the RPLUS code. The model was applied to simulate a supersonic shear layer. Preliminary results show favorable comparisons with the experimental data
Deconfined fractional electric charges in graphene at high magnetic fields
The resistance at the charge neutral (Dirac) point was shown by Checkelsky et
al in Phys. Rev. B 79, 115434 (2009) to diverge upon the application of a
strong magnetic field normal to graphene. We argue that this divergence is the
signature for a Kekule instability of graphene, which is induced by the
magnetic field. We show that the strong magnetic field does not remove the zero
modes that bind a fraction of the electron around vortices in the Kekule
dimerization pattern, and that quenched disorder present in the system makes it
energetically possible to separate the fractional charges. These findings,
altogether, indicate that graphene can sustain deconfined fractionalized
electrons.Comment: 11 pages, 2 figure
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