Abstract: An antenna apparatus includes: a parabolic reflector; a dielectric support pedestal; a sub-reflector connected to an upper part of the dielectric support pedestal; and a waveguide connected to a lower part of the dielectric support pedestal, wherein the parabolic reflector has a curved surface in which a ratio of a focal length to a diameter is greater than a preset value, and at least one corrugation configured to suppress a cross polarization is formed in a region of the dielectric support pedestal.

Abstract: An underwater vehicle having a hovering system using a tube type launcher. The underwater vehicle includes a streamlined body and a hovering system connected to a rear of the streamlined body to generate a kinetic force of the streamlined body. The hovering system includes an extension shaft extended to be connected to the rear, a connection assembly connected to the rear through the extension shaft, and an auxiliary propeller assembly connected to the connection assembly.

Abstract: An underwater vehicle having a hovering system using a tube type launcher. The underwater vehicle includes a streamlined body and a hovering system connected to a rear of the streamlined body to generate a kinetic force of the streamlined body. The hovering system includes an extension shaft extended to be connected to the rear, a connection assembly connected to the rear through the extension shaft, and an auxiliary propeller assembly connected to the connection assembly.

Abstract: Disclosed is a discrete event simulation method using Matlap object-oriented programming (OOP). The method of simulating a discrete event comprising a plurality of models and a root coordinator, comprises: the root coordinator's managing time schedules of the models; the root coordinator's calling a model function based on the time schedules; and the models' transmitting external input events to each other when the model function is called, based on a coupling structure of the models, wherein when the plurality of models transmit the external input events to each other, the external input events are transmitted as an input parameter of the model function.