이수형 교수

An axion dark matter search with the CAPP-8TB haloscope is reported. Our results are sensitive to axion-photon coupling g_{aγγ} down to the QCD axion band over the axion mass range between 6.62 and 6.82 μeV at a 90% confidence level, which is the most sensitive result in the mass range to date.

SUMMARY The effect of a program or treatment may vary according to observed characteristics. In such a setting, it may not only be of interest to determine whether the program or treatment has an effect on some sub‐population defined by these observed characteristics, but also to determine for which sub‐populations, if any, there is an effect. This paper treats this problem as a multiple testing problem in which each null hypothesis in the family of null hypotheses specifies whether the program

Abstract A growing number of papers theoretically study the effects of introducing a preference signaling mechanism. However, the empirical literature has had difficulty proving a basic tenet, namely that an agent has more success when the agent uses a signal. This paper provides evidence based on a field experiment in an online dating market. Participants are randomly endowed with two or eight “virtual roses” that a participant can use for free to signal special interest when asking for a date.

Summary Online dating services have increased in popularity around the world, but a lack of quality data hinders our understanding of their role in family formation. This paper studies the effect of online dating services on marital sorting, using a novel dataset with verified information on people and their spouses. Estimates based on matching techniques suggest that, relative to other spouse search methods, online dating promotes marriages that exhibit weaker sorting along occupation and geogr

Various countries have implemented transfer programs to individuals since the Covid-19 outbreaks. However, the extent to which such transfers alleviate economic recessions is unclear. This paper analyzes a South Korean program, which provided vouchers redeemable only at small local businesses. We find that, due to the program, over 30% of households across all income groups increased their food and overall household spending, but the usage restriction may have affected consumer choice as well as

This paper presents a new estimation method, entitled the asynchronous sampling pulse method (ASPM), for determining velocity in systems with low but variable speeds, and/or with low-resolution encoders. The ASPM forces the estimator procedure to synchronize with the actual encoder pulse input, thus eliminating encoder positioning error independent of target velocity variations. This method is based on using an auxiliary sampling period to measure the time interval between the moment of encoder

We present measurements of the masses and decay widths of the baryonic states ${\mathrm{\ensuremath{\Sigma}}}_{c}(2455{)}^{0/++}$ and ${\mathrm{\ensuremath{\Sigma}}}_{c}(2520{)}^{0/++}$ using a data sample corresponding to an integrated luminosity of $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric-energy collider operating at the $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance. We report the mass differenc

We estimate the causal impact of school and classroom gender composition on achievement. We take advantage of the random assignment of Korean middle school students to single-sex schools, co-educational (coed) schools with single-sex classes, and coed schools with mixed-gender classes. Male students attending single-sex classes within coed schools score 0.10 of a standard deviation below male students in mixed-gender classes, and this achievement gap is entirely accounted for by classroom gender

The large literature on costly signaling and the somewhat scant literature on preference signaling had varying success in showing the effectiveness of signals. We use a field experiment to show that even when everyone can send a signal, signals are free and the only costs are opportunity costs, sending a signal increases the chances of success. In an online dating experiment, participants can attach "virtual roses" to a proposal to signal special interest in another participant. We find that att

This paper examines the implications of online mate search for marriage, using data from a Korean online matchmaking company. Using the estimated marital preferences, I nd that customized recommendations from an online matchmaker and individuals’

Developed East Asian countries import a large number of women from abroad as brides every year, although such cross‐border marriages virtually did not exist 20 years ago. With a theoretical framework and empirical evidence, we argue that developed Asian countries' demand for foreign brides is the consequence of improvement in women's economic status and gender‐discriminative household arrangements that insufficiently incorporate women's improved status in marriage. We offer sets of empirical evi

Marital sorting along education, income and other salient dimensions is well-documented for many countries. Understanding the mechanisms behind such sorting is important because the degree of marital sorting may influence income inequality, intergenerational mobility, and household labor supply, as well as other economic outcomes. Marital sorting is often thought to arise from some combination of people’s preferences and constraints on their choice sets. However, separating these two causes of m