• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.285-290
• /
• 2011

For developing acoustic window, transmission loss in accordance with incident angle was calculated and compared with measurement results. In design stage, the material choice of acoustic window is very important because the material is parameter of transmission loss and structural strength. In order to analyze the effect of material properties on transmission loss, the parametric studies were carried out and the results were discussed in this paper.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.10
• /
• pp.890-896
• /
• 2011

For developing acoustic window, transmission loss in accordance with incident angle was calculated and compared with measurement results. In design stage, the material choice of acoustic window is very important because the material is one of main parameters of transmission loss and structural strength. In order to analyze the effect of material properties on transmission loss, the parametric studies were carried out and the results were discussed in this paper. And, to verify the design specification of acoustic window, measurement was carried out and the results were compared and analyzed.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.54 no.1
• /
• pp.25-30
• /
• 2005

An accurate digital distance relaying algorithm which is immune to mutual coupling effect and reactance effect of the fault resistance and the load current for the line faults in 765kV untransposed transmission lines is proposed. The algorithm can estimate adaptively the impedance to a fault point independent of the fault resistance. To compensate the magnitude and phase of the apparent impedance, this algorithm uses the angle of an impedance deviation vector. The impedance correction algorithm for phase-to-ground fault and phase-to-phase short fault use a voltage equation at fault point to compensate the fault current at fault point. A series of tests using EMTP output data in a 765kV untransposed transmission lines have proved the accuracy and effectiveness of the proposed algorithm.

• Journal of the Optical Society of Korea
• /
• v.12 no.4
• /
• pp.244-248
• /
• 2008

We have evaluated the performance of strain-chirped fiber Bragg grating (FBG) based tunable dispersion compensator in a 40 Gb/s transmission link. In our proposed compensator, the value of dispersion could be changed from -353 ps/nm to -962 ps/nm by adjusting the rotation angle of the metal beam on which the FBG was mounted. In order to evaluate the effect of ripples in reflectivity and variations in passband of the FBG based dispersion compensator, transmission performance has been measured with our tunable dispersion compensator. Error-free transmission of a 40 Gb/s non-return-to-zero (NRZ) signal over conventional single-mode fiber (SMF) was achieved.

• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.2
• /
• pp.15-18
• /
• 2001

The Mo/si multilayer for EUV lithography was deposited using magnetron sputtering system. The multilayers were characterized using the cross-sectional transmission electron microscope (TEM) and low/high angle X-ray diffraction (XRD). The microstructure of Mo and Si was highly textured structure and amorphous, respectively. The well-defined low angle XRD peaks implies a well-defined multilayer structure. The interfacial layer of Mo-on-Si was thicker than Si-on-Mo interfacial layer.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.627-629
• /
• 2004

V type suspension string sets prevent instabilities from swing motion by the horizontal angle and by wind pressure. These installation conditions are controled mainly 3 items - normal swing angle by horizontal angle of line, unusual swing angle by strong wind, minimum vertical loads. We calculated and analysed that factors for the 765kV transmission line condition. And we were tested swing characteristics of V-string sets in real size test situation. So, we find to installation condition for the V type suspension string sets. This results will be used to design of V type suspension string set and to decision of the installation condition.

• Journal of the Korean Solar Energy Society
• /
• v.28 no.2
• /
• pp.58-63
• /
• 2008

This study has analysed power output characteristics of transparent thin-film PV module depending on incidence angle and azimuth. The experiment results showed power outputs of transparent thin-film PV module applied to full-scale mock up model on slope of $90^{\circ},\;30^{\circ},\;0^{\circ}$ to the south. The simulation results was evaluated power outputs of transparent thin-film PV module depending on incidence angle and azimuth after calibrating the experimental and computed data. As a result. the best power output performance of transparent thin-film PV module was obtained at slope of $30^{\circ}$ to the south, producing the annual power output of 977kWh/kWp. The annual power output data demonstrated that the PV module with a slope of $30^{\circ}$ could produce a 68 % higher power output than that with a slope of $90^{\circ}$ with respect to the inclined slope of the module, Furthermore, the PV module facing south showed a 22 % higher power output than that facing to the east in terms of the angle of the azimuth, Specipically. the varying power output with incidence angle of PV module can be resulted from the influence of incidence angle modifier of glass on PV module. That is, the solar energy transmission can be reduced as an increase of incidence angle of PV module. Therefore, when the inclined slope of the PV module was over $70^{\circ}$ there was a significant reduction of power output, and this was caused by the decrease of solar energy transmission in the transparent thin-film PV module.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.8
• /
• pp.412-417
• /
• 2000

TV ghost interference can be described as passive interference by the conducting part of transmission lines. In order to survey this interference from large-sized overhead EHV (extra high voltage) transmission line, TV reception quality was measured in the vicinity of that before and after construction. Instrumentation system was composed of ghost analyzer, TV received field intensity meter, VHF/UHF antennas, TV monitor and so on. The system is installed inside the vehicle. TV field intensity and PDUR (Perceived Desired wave to Undersired wave Ratio) are measured to evaluate TV ghost by using the system and vehicle. As the results, the useful data, which can be used to evaluate the effect of TV ghost interference from transmission lines could be obtained. In this paper, it is shown that the range of TV ghost interference from transmission lines can vary according to the frequency of TV electromagnetic wave, an incidence angle to the line and the other conditiions. At present, we are making efforts to establish a PDUR guideline for transmission lines.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.7 no.2
• /
• pp.91-100
• /
• 2011

Free viewpoint TV can provide multi-angle view point images for viewer needs. In the real world, But all angle view point images can not be captured by camera. Only a few any angle view point images are captured by each camera. Group of the captured images is called multi-view image. Therefore free viewpoint TV wants to production of virtual sub angle view point images form captured any angle view point images. Interpolation methods are known of this problem general solution. To product interpolated view point image of correct angle need to depth image of multi-view image. Unfortunately, multi-view video including depth image is necessary to develop a new compression encoding technique for storage and transmission because of a huge amount of data. Layered depth image is an efficient representation method of multi-view video data. This method makes a data structure that is synthesis of multi-view color and depth image. This paper proposed enhanced compression method using layered depth image representation and H.264/AVC video coding technology. In experimental results, confirmed high compression performance and good quality reconstructed image.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.11 s.114
• /
• pp.1040-1049
• /
• 2006

A design method for minimizing transmission loss of a broadband right-angle transition from a coaxial cable to a microstrip line is presented. The right-angle transition has been widely used where printed circuit applications need to be fed from behind the ground plane using coaxial line. To obtain the minimized transmission loss over the whole operating frequency range of the transition, design parameters such as ground aperture and probe diameters, ground aperture offset, and stub length are optimized using a commercial electromagnetic simulation software. Results are presented for the optimum right-angle transition from an SMA connector to a microstrip line on common reinforced 0.787 mm thick PTFE substrates. Measurements of a fabricated transition show that reflection coefficient is less than -22 dB and insertion loss is less than 0.45 dB over $0.05{\sim}20GHz$.