arXiv subjects

Do Won Kim

Publications and source records attributed to Do Won Kim.

3 recordsLinked to original sources

arXiv2026

Challenging Partisan Expectations Reduces Political Polarization

Political conversations are often proposed as a remedy for political polarization, yet their effectiveness remains inconsistent. We argue that this inconsistency partly reflects a neglected feature of political contact: the expectations partisans bring to these encounters. We hypothesize that conversations should reduce political polarization the most when they violate the expected link between partisan identity and issue position. We test this hypothesis in a 2x2 experiment in which 1,983 U.S. adults engaged in structured conversations with an AI chatbot whose presented partisan identity and policy stance were independently manipulated. We find that expectation-challenging conversations in which participants talk with a disagreeing ingroup member or an agreeing outgroup member are effective in reducing affective and issue polarization. Although these effects emerge without meaningful shifts in participants' own policy positions, a follow-up survey shows that most effects disappear over one month. Interestingly, these conversations maintain or improve objective measures of deliberation but are experienced as less satisfying by participants. Our findings identify expectation violation as an underexplored depolarization mechanism. Our results also demonstrate the promises and limitations of how conversational AI can serve as a scalable method for experimentally studying interventions to mitigating partisan divides.

cs.SI↗

arXiv2026

Understanding the Gap Between Stated and Revealed Preferences in News Curation: A Study of Young Adult Social Media Users

Social media feed algorithms infer user preferences from their past behaviors. Yet what drives engagement often diverges from what users value. We examine this gap between stated preferences (what users say they prefer) and revealed preferences (what their behavior suggests they prefer) among young adults, a group deeply embedded in algorithmically mediated environments. Using a mixed-methods approach combining surveys and interviews with feed curation activities, we investigate: what gaps exist between stated and revealed preferences; how users make sense of these gaps; what values users believe should guide algorithmic curation; and how systems might reflect those values. Participants often found themselves engaging with low-quality content they did not endorse, despite wanting high-quality information. When asked to curate an ideal social media news feed for a hypothetical persona, participants created feeds they considered more satisfying and higher in quality by prioritizing values such as accuracy and diversity. In doing so, they navigated trade-offs between different values, factoring in social relationships and context surrounding the persona. These findings suggest that feed curation is a socially situated process of judging what should be visible and appropriate in shared information spaces. Based on these insights, we offer design directions for bridging the gap between stated and revealed preferences.

cs.HC↗

arXiv2025

Parallel-plate chambers as radiation-hard detectors for time-based beam diagnostics in carbon-ion radiotherapy

Accurate range verification of carbon ion beams is critical for the precision and safety of charged particle radiotherapy. In this study, we evaluated the feasibility of using a parallel-plate ionization chamber for real-time, time-based diagnostic monitoring of carbon ion beams. The chamber featured a 0.4 mm gas gap defined by metallic electrodes and was filled with carbon dioxide (CO$_2$), a non-polymerizing gas suitable for high-rate applications. Timing precision was assessed via self-correlation analysis, yielding a precision approaching one picosecond for one-second acquisitions under clinically relevant beam conditions. This level of timing accuracy translates to a water-equivalent range uncertainty of approximately 1 mm, which meets the recommended clinical tolerance for carbon ion therapy. Furthermore, the kinetic energy of the beam at the synchrotron extraction point was determined from the measured orbital period, with results consistently within 1 MeV/nucleon of the nominal energy. These findings demonstrate the potential of parallel-plate chambers for precise, real-time energy and range verification in clinical carbon ion beam quality assurance.

physics.med-ph↗