Abstract: Disclosed is a system and method for connection of host behind network address translators. The system includes a server placed in a public network, and a transparent middleware (TMW). The server records the related data between each host and one or more NAT devices. The TMW may be performed in each host. When a first host of a first NAT device tries to establish connection to a second host of a second NAT device, through the server, the TMW looks up a first IP address mapping from the first host to the second NAT device, and a second IP address mapping from the second host to the first NAT device. Accordingly, the TMW accomplishes the support for establishing connection between the first and the second hosts.

Abstract: The invention of a Low-Cost alternating color-pulse digital particle-image velocimetry DPIV (Digital Particle Image Velocimetry) system is proposed. In the proposed system Low-Cost basic equipments are used such as a continuous-wave laser in mixed mode, a CCD (Charge Couple Device) camera, a PMT (Photo-Multiplier Tube), an image-processing card, a PC (personal computer) etc., with an add-on alternating-color planar laser-sheet generating facility to achieve the purpose of DPIV (Digital Particle Image Velocimetry) of planar velocity measurements. With the add-on facility, the laser beam from the continuous-wave laser operated in mixed mode is turned into a planar laser sheet with alternating color at a designated frequency. The CCD (Charge Couple Device) camera captures the alternating-color images of the flow field seeded with small particles.

Abstract: The invention of a Low-Cost alternating color-pulse digital particle-image velocimetry DPIV (Digital Particle Image Velocimetry) system is proposed. In the proposed system Low-Cost basic equipments are used such as a continuous-wave laser in mixed mode, a CCD (Charge Couple Device) camera, a PMT (Photo-Multiplier Tube), an image-processing card, a PC (personal computer) etc., with an add-on alternating-color planar laser-sheet generating facility to achieve the purpose of DPIV (Digital Particle Image Velocimetry) of planar velocity measurements. With the add-on facility, the laser beam from the continuous-wave laser operated in mixed mode is turned into a planar laser sheet with alternating color at a designated frequency. The CCD (Charge Couple Device) camera captures the alternating-color images of the flowfield seeded with small particles. The images are then sent to a personal computer for analysis of the magnitude and direction of the velocity distribution of the flowfield.