180520 How Robust Are Canonical Experimental Economics Results?

Title:
How Robust Are Canonical Experimental Economics Results?

Speaker:
林伯軒 (Po-Hsuan Lin)

Time:

*注意：本週演講往後調整到週日 (US) / 週一 (TW)

05/20 (Sun.) 6 pm PDT, 7 pm MDT, 8 pm CDT, 9 pm EDT
05/21 (Mon.) 9 am Taiwan

Keywords:
Economics, Experimental Economics, Experimental Methodology

Abstract:
Conventional wisdom suggests that experimental results due to other regarding preferences may vary greatly across cultures, while results that concern markets institutions will remain constant. However, existing data that supports such conclusion is sparse; it is often cost-prohibitive and not pragmatic to run the same experiment across a large number of countries. Thus, we are either left to compare results of slight variations of designs across many countries or the same design across very few countries. Our paper provides an alternative. Utilizing data from MobLab educational platform, we are able to examine data from 10 different countries to test whether the players’ behavior is consistent with theoretical prediction across different countries. We focus on results of identical experiments of the well-known Ultimatum Game and Double Auction.

Results generally support conventional wisdom. In ultimatum game data, we note a significant country heterogeneity in proposer offers but not responders' behavior. We also note subtle effects of 50/50 offers on responder's behavior both in response and decision time previously not reported in studies with smaller sample time. In the double auction, we find little differences in “mean error deviation”, “Smith’s alpha”, and “efficiency”, three commonly calculated measures of market convergence.

180512 The Evaluation of Alternative Exposure Metrics for Traffic-related Air Pollutant Exposure in North Carolina

Title:
The Evaluation of Alternative Exposure Metrics for Traffic-related Air Pollutant Exposure in North Carolina

Speaker:
張世穎 (Shih-Ying Chang)

Time:

*注意：本週演講時間略有調整

05/12 (Sat.) 2 pm PDT, 3 pm MDT, 4 pm CDT, 5 pm EDT
05/13 (Sun.) 5 am Taiwan

Keywords:
Environmental science, Air pollution, Exposure assessment, Air quality modeling, Environmental health, Indoor air quality

Abstract:
Human exposure to air pollution in many studies is represented by ambient concentrations from space-time kriging of observed values. Space-time kriging techniques based on a limited number of ambient monitors may fail to capture the concentration from local sources. Further, because people spend more time indoors, using ambient concentration to represent exposure may cause error. To quantify the associated exposure error, we computed a series of six different hourly-based exposure metrics at 16,095 Census blocks of three Counties in North Carolina for CO, NOx, PM2.5, and elemental carbon (EC) during 2012. These metrics include ambient background concentration from space-time ordinary kriging (STOK), ambient on-road concentration from the Research LINE source dispersion model (R-LINE), a hybrid concentration combining STOK and R-LINE, and their associated indoor concentrations from an indoor infiltration mass balance model. Using a hybrid-based indoor concentration as the standard, the comparison showed that outdoor STOK metrics yielded large error at both population (67% to 93%) and individual level (average bias between (10% to 95%). For pollutants with significant contribution from on-road emission (EC and NOx), the on-road based indoor metric performs the best at the population level (error less than 52%). At the individual level, however, the STOK-based indoor concentration performs the best (average bias below 30%). For PM2.5, due to the relatively low contribution from on-road emission (7%), STOK-based indoor metric performs the best at both population (error below 40%) and individual level (error below 25%). The results of the study will help future epidemiology studies to select appropriate exposure metric and reduce potential bias in exposure characterization.

180505 Strong Low-Frequency Squeezed Light from Dual-Seeded Four-Wave Mixing

Title:
Strong Low-Frequency Squeezed Light from Dual-Seeded Four-Wave Mixing

Speaker:
吳孟昌 (Meng-Chang Wu)

Time:

*注意：本週演講時間略有調整

05/05 (Sat.) 6 pm PDT, 7 pm MDT, 8 pm CDT, 9 pm EDT
05/06 (Sun.) 9 am Taiwan

Keywords:
Physics, Quantum physics, Quantum measurement, Four-wave mixing

  為配合本研究發表時程，本次錄影將延遲至年底上傳

Abstract:
Quantum correlated twin beams generate entanglement that can be used as a resource for quantum information processing and quantum communication. Furthermore, intensity-difference squeezing at low-frequencies has applications such as quantum calibration of large area photodiodes. One way to generate these twin beams is by performing four-wave mixing (4WM) in a hot rubidium vapor. In previous experiments, the imbalanced power between the seeded probe beam and the conjugate beam limited the squeezing to frequencies above a few kilohertz. Here, by locking our diode laser via polarization spectroscopy and utilizing a “dual-seed” technique, we achieve intensity difference squeezing at frequencies as low as 10 Hz.