• Progress in Medical Physics
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• v.1 no.1
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• pp.61-68
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• 1990

We have designed the calculation model(AMC method) of electron output for the cut-out fieldsand studied the influence of shielding block size. The output of electron was measured in the water phantom at dmax, for 20 $\times$ 20cm$^2$ cone size electron beams from CL/1800 linear accelerator(Varian, USA), Which generates the energy of 6, 9, 12, 15 and 18MeV electron beams. The shielding blocks were rectangular or squre shaped, low melting point alloy. We can predict the output from the arbitrarily rectangular shaped block within 1% error. by using the AMC method, which considers the contribution of the collimator(block) scatter and the phantom scatter.

• Journal of Sensor Science and Technology
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• v.21 no.6
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• pp.408-412
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• 2012

An in-line dispersive delay line (DDL) demands low and controllable reflectivity of the reflectors, especially if the surface acoustic wave (SAW) propagates all the way along the reflecting structure. The metal reflectors are usually too strong and introduce too much attenuation in such a device. The proposed solution of this problem is to spatially separate the acoustic channels for different frequencies with the help of Fan-shaped Transducers (FIDT) and to use narrow open metal reflectors to reduce reflectivity. Special arrangement of FIDT is performed to use 180-deg. reflection of the SAW. Narrow open metal strips with a metallisation ratio of the order of 20% are used as reflectors with small and controllable reflectivity. Reflectivity of such strips is estimated both theoretically and experimentally. Experimental performance of the proposed DDL is presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1230-1235
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• 2017

We studied surface texture-etching of glass substrate by using reactive ion etching process with various working pressure (0.7~9.0 mT). With the increase in the pressure, a haze parameter, which means diffusive transmittance/total transmittance, was increased in overall wavelength regions, as measured by spectrophotometer. Also, atomic force microscopy (AFM) study also showed that the surface topography transformed from V-shaped, keen surface to U-shaped, flattened surface, which is beneficial for nanocrystalline silicon semiconductor growth with suppressing defective crack formation. The texture-etched ZnO:Al combined with textured glass exhibited pronounced haze properties that showed 60~90 % in overall spectral wavelength regions. This promising optical properties of double textured, transparent conducting substrate can be widely applied in silicon thin film photovoltaics and other optoelectronic devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.595-599
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• 2003

We have studied the phase transition to look for molecular structure by using several different techniques for new banana-shaped liquid crystals shown in Fig. 1. Based on the similarities to recently observed fluro-contaning materials (switching involves layer structure rearrangement, increasing threshold with increasing temperature) for HC sample (where x is H), we assume that the phase C has a triclinic symmetry corresponding to the double tilted $smC_G$ Phase. The observation that the polarization peak appears at lower field ($E_o{\sim}15V/{\mu}m$) than the amplitude of the threshold ($E_{th}$) can be explained assuming a field induced $SmC_G$ - SmCP (or SmAP) transition at $E_{th}$

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.167-168
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• 1998

The purpose of this study is to verify the biomechanical characteristics of the custom-made(our) pedicle screws which are designed the different types of shape, pitch, and profile. The results of experiments for our pedicle screw were summarized. 1) The screw of larger outer diameter showed greater holding strength. 2) The holding strength of cylindrical shaped screw was superior to that of conical shaped screw. 3) The holding strength of buttress shape of thread profile showed superior to that of V-shape. 4) The pull out and holding strength of our pedicle screws was superior to that of commercialized screw (Diapason and CD) which is widely used.

• Bulletin of the Society of Naval Architects of Korea
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• v.19 no.1
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• pp.15-22
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• 1982

The effects of the forebody geometry of ships on the response function of wave loads are investigated by numerical calculations based on a strip method. For the vertical wave loads both shearing forces and bending moments, the V-shaped bow gives greater responses than the U-shaped one in regular oblique waves. These results have been clarified by the vector diagram of all static and dynamic components contributing to the resultant wave bending moment. In the present evaluation the phase relation among the components plays an important role. And the effect of the forebody geometry on lateral wave loads seems to be negligible from the result of the present investigation.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2233-2235
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• 2000

We present the characteristics of microwave and mechanical behavior for the electrostatically actuated z-shaped laterally driven micriomachined CPW SPST(Single Pole Single Throw) Switch, which is for the application of the microwave communication systems. In this paper, we have aimed to maintain advantages. such as low insertion loss and low power consumption that the previously developed RF MEMS Switch has and minimize also stiction problem. enhance the microwave characteristics by etching of substrate beneath the switch, realize the pull-in voltage of below 30V. The optimized design parameters of the MEMS Switch can be selected by the analysis of the mechanical behavior and the use of ANSYS simulation method.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.229-234
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• 2007

Microscale heat transfer and microfluidics have become increasingly important to overcome some very complex engineering challenges. The use of very small passages to gain heat transfer enhancement is a well documented method for achieving high heat flux dissipation. As the passage size is decreased, the heat transfer performance increases but the pressure drop increases sharply when the passage size is reduced. In this study, the performance evaluation of micro plated heat exchangers under the counter flows with straight, V-shaped and Y-shaped channel are carried out.

• Animal cells and systems
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• v.14 no.3
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• pp.221-224
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• 2010

A new and rare perlid stonefly, Togoperla thinhi n. sp., is described from male and female adults and egg specimens from tropical central Vietnam. The male adult of T. thinhi n. sp. can be distinguished from other congeners by the distinct head markings, bilobed processes on the posterior margin of the abdominal tergum V, and S-shaped aedeagus. The female adult has a long and tongue-shaped subgenital plate on the abdominal sternum VIII, which extends to the posterior margin of the abdominal sternum IX. A male key to the Vietnamese species of Togoperla is provided. The finding of this new species provides evidence of an extension of the geographical distribution of Togoperla to tropical mainland Southeast Asia.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.178-186
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• 2021

The wave power extraction by multiple Wave Energy Converters (WECs) deployed in a Y-shaped Water Channel Resonator (WCR) has been investigated. A WCR consists of a long water channel, and a V-shaped wave guider installed at the entrance of a water channel. If the period of the incident waves coincides with the natural periods of the fluid in a WCR, resonance occurs, as a result, the internal fluid in a WCR is greatly amplified. To estimate the wave power by multiple WECs placed at the antinodal points in a WCR, the heave motion response, time-averaged power, and capture width ratio were calculated for several design parameters. Also, the systematic model tests were conducted in a 2D wave tank. The numerical results are in good agreement with the experimental data. It was verified that a WCR helps the WECs to produce electricity more effectively by amplifying the wave energy in a WCR.