This article examines why policy ideas emerging during crises sometimes become institutionalised while in other cases they remain unimplemented. We argue that policy responsiveness is shaped by unequal instrumental and structural power across first-tier and second-tier citizens. In South Korea, this hierarchy reflected institutional legacies of developmental citizenship, which accorded privileged status to workers in conglomerates and manufacturing production networks. Using a comparative analysis of employment insurance reforms during the 1997 Financial Crisis and the COVID-19 pandemic, we find that policy expansion occurred when crises severely affected first-tier citizens, which include export-oriented conglomerates, their integrated subcontractors, and the workers employed therein. By contrast, proposals during COVID-19 largely remained unfulfilled, as the most impacted groups, including the self-employed and non-standard workers, occupied a marginal position. This unequal responsiveness can be interpreted through a three-gap mechanism – structural presence, representation, and political participation – underscoring that the institutionalisation of policy ideas is contingent on historically embedded power structures.

Based on practical requirements, this paper presents the design, fabrication, and experimental validation of a Ka-band wideband two-dimensional (2D) phased array antenna with 45° slant polarization. The array integrates a polarizer with 28 six-element metallic Vivaldi linear sub-arrays. To the best of the authors’ knowledge, no previous work has reported the engineering implementation of a polarizer-integrated 2D phased array at Ka-band, as existing studies are limited to single elements or one-dimensional arrays. Measured results show that the array achieves an active Voltage Standing Wave Ratio (VSWR) below 2.6 over 32–40 GHz, with a gain exceeding 25.5 dBi. It supports wide-angle scanning up to ±50° in the azimuth plane and ±30° in the elevation plane, with a scan loss not exceeding 3 dB across the entire scanning range. Furthermore, the amplitude difference between horizontal and vertical polarization components remains within 2.9 dB throughout the scanning range, confirming desirable slant polarization characteristics.

Understanding trends in height and body mass index (BMI), along with trajectories of weight status, is crucial to identifying the optimal timing for intervention. The objective of this study was to describe trends in height and BMI among children and adolescents and identify the trajectory of weight status over time. This was a longitudinal study with data collected annually (2013-2020). A total of 41,325 students aged 5 to 18 from 47 schools participated in the study, and a subsample of 11,535 participants with at least five BMI measurements was used for the analyses. Mixed-effects analysis showed significant increases in height over the years for boys (0.19 cm, standard error 0.01, P<0.001) and girls (0.15cm, standard error 0.01, P<0.001). Regarding BMI, an increasing trend over the years was also found in boys (0.04 kg/m2, standard error 0.01, P<0.001) and girls (0.04 kg/m², standard error 0.01, P<0.001). Analyzing weight status trajectories, three groups were identified: consistently normal weight (males 63.7%, females 64.5%), increasingly overweight (males 21.8%, females 20.7%), and increasingly obese (males 14.5%, females 14.8%). We conclude that in adolescence, height was below expected, indicating that children are not reaching their maximum growth potential. Furthermore, the identification of increasing trajectories of overweight and obesity, starting in childhood, emphasizes the progressive nature of excessive weight gain before adulthood. These findings highlight the early onset of nutritional deviations in this population, suggesting the need for interventions to promote healthy weight as children transition into adolescence to mitigate future health risks.