본 연구는 대형공간을 대상으로 시선추적 실험을 실시하고, 성별에 나타난 동공의 주시특성을 분석하였다. 시선추적 실험 시간의 흐름에서 생겨나는 동공변화를 분석함으로써 성별 주시행태를 객관적이면서도 과학적으로 분석할 수 있는 틀을 제시했다. 나아가 동공의 크기가 안정적으로 변하는 시간과 성별에 따른 차이를 정리하였는데 성별에 따른 시지각 정보 획득 시간의 특성을 발견할 수 있었으며 여자가 남자보다 1~2초 정도 늦게 관심과 흥미요소를 시각정보로서 받아들이기 시작한 것을 알 수 있었다. 초기 ｢1초→2초｣에서 남자는 도약, 여자는 고정에서 동공크기가 확대되었다. 또한 고정 주시에 국한하여 성별 변화율을 보면 9초를 전환점으로 해서 9초 이하 시간에서는 여자가, 9초 이후 시간에서는 남자의 동공크기가 더 커졌다. 즉 1-8초 시간에서는 여자가, 10-15초 범위에서는 남자가 상대적으로 더 큰 동공확대를 통해 시지각 정보를 획득한 것으로 보인다. 하지만 주시시간의 시간의 변화에 따라 여자의 동공크기가 더 크게 확대된 것에서부터 여자의 경우가 일정 시간이 경과한 후에는 관심이나 흥미가 있는 요소를 더 많이 주시하려는 움직임이 활발했다.

OBJECTIVES: The objective of this study is to detect road cavities using multi-channel 3D ground penetrating radar (GPR) tests owned by the Seoul Metropolitan Government. METHODS: Ground-penetrating radar tests were conducted on 204 road-cavity test sections, and the GPR signal patterns were analyzed to classify signal shape, amplitude, and phase change. RESULTS : The shapes of the GPR signals of road-cavity sections were circular or ellipsoidal in the plane image of the 3D GPR results. However, in the longitudinal or transverse direction, the signals showed mostly unsymmetrical (or symmetrical in some cases) parabolic shapes. The amplitude of the GPR signals reflected from road cavities was stronger than that from other media. No particular pattern of the amplitude was found because of nonuniform medium and utilities nearby. In many cases where road cavities extended to the bottom of the asphalt concrete layer, the signal phase was reversed. However, no reversed signal was found in subbase, subgrade, or deeper locations. CONCLUSIONS: For detecting road cavities, the results of the GPR signal-pattern analysis can be applied. In general, GPR signals on road cavity-sections had unsymmetrical hyperbolic shape, relatively stronger amplitude, and reversed phase. Owing to the uncertainties of underground materials, utilities, and road cavities, GPR signal interpretation was difficult. To perform quantitative analysis for road cavity detection, additional GPR tests and signal pattern analysis need to be conducted.

PURPOSES : The objective of this study is to determine the optimal frequency of ground penetrating radar (GPR) testing for detecting the voids under the pavement. METHODS : In order to determine the optimal frequency of GPR testing for void detection, a full-scale test section was constructed to simulate the actual size of voids under the pavement. Voids of various sizes were created by inserting styrofoam at varying depths under the pavement. Subsequently, 250-, 500-, and 800-MHz ground-coupled GPR testing was conducted in the test section and the resulting GPR signals were recorded. The change in the amplitude of these signals was evaluated by varying the GPR frequency, void size, and void depth. The optimum frequency was determined from the amplitude of the signals. RESULTS: The capacity of GPR to detect voids under the pavement was evaluated by using three different ground-coupled GPR frequencies. In the case of the B-scan GPR data, a parabolic shape occurred in the vicinity of the voids. The maximum GPR amplitude in the A-scan data was used to quantitatively determine the void-detection capacity. CONCLUSIONS: The 250-MHz GPR testing enabled the detection of 10 out of 12 simulated voids, whereas the 500-MHz testing allowed the detection of only five. Furthermore, the amplitude of GPR detection associated with 250-MHz testing is significantly higher than that of 500-MHz testing. This indicates that 250-MHz GPR testing is well-suited for the detection of voids located at depths ranging from 0.5~2.0 m. Testing at frequencies lower than 250 MHz is recommended for void detection at depths greater than 2 m.