No abstract

Students' perceptions of their educational environment are positive in Korea. The learning environment should be evaluated by curriculum planners and administrators of medical schools to improve its quality.

In this paper, we present a circularly polarized (CP) composite cavity-backed crossed dipole antenna for global positioning system (GPS) applications. We produce the CP radiation by crossing two dipoles through a 90° phase delay line of a vacant-quarter printed ring, which also has a broadband impedance matching characteristic. Two techniques, insertion of meander lines in the dipole arm and arrowhead-shaped trace at its end, are employed to reduce the sizes of the primary radiation element. The compact radiator is backed by a cavity reflector to achieve a wide CP radiation beamwidth. The proposed antenna exhibits a measured bandwidth of 1.450～1.656 GHz for a voltage standing wave ratio (VSWR) < 2 and 1.555～1.605 GHz for AR < 3-dB. At 1.575 GHz, the antenna has a gain of 7 dBic, a frontto-back ratio of 27 dB, AR of 1.18 dB, and 3-dB AR beamwidths of 130° and 132° in the x-z and y-z planes, respectively.

The clinical, angiographic, histopathologic and operative findings of Oriental patients were similar to those reported in western patients, but the incidence of isolated left main coronary ostial stenosis was higher in the Oriental group. Angiographically definable isolated coronary ostial stenosis may often not be true isolated ostial stenosis.

No abstract