• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2004.11a
• /
• pp.166-169
• /
• 2004

In the International Code of Practice for dosimetry TRS-398 published by International Atomic Energy Agency(IAEA), water equivalency plastic phantom may be used under certain circumstances for electron beam dosimetry for beam quality E0${\leq}$ 10 MeV. In this study, Palstic Water$^{TM}$ and Virtual Water$^{TM}$ were evaluated in order to determine fluence scaling factor hpl. Plastic phantom was evaluated for five electron energy from 6 MeV to 20 MeV. From the measured data of Palstic Water$^{TM}$, the fluence scaling factor hpl was found to be average 0.9964 and Virtual Water$^{TM}$ fluence scaling factor was 1.0156.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.7
• /
• pp.57-65
• /
• 2002

In this paper, a 2.5V 10-bit 300MSPS CMOS D/A Converter is described. The architecture of the D/A Converter is based on a current steering 8+2 segmented type, which reduces non-linearity error and other secondary effects. In order to achieve a high performance D/A Converter, a novel current cell with a low spurious deglitchnig circuit and a novel inverse thermomeer decoder are proposed. To verify the performance, it is integrated with $0.25{\mu}m$ CMOS 1-poly 5-metal technology. The effective chip area is $1.56mm^2$ and power consumption is about 84mW at 2.5V power supply. The simulation and experimental results show that the glitch energy is 0.9pVsec at fs=100MHz, 15pVsec at fs=300MHz in worst case, respectively. Further, both of INL and DNL are within ${\pm}$1.5LSB, and the SFDR is about 45dB when sampling, frequency, is 300MHz and output frequency is 1MHz.

• Journal of Korean Vacuum Science & Technology
• /
• v.6 no.2
• /
• pp.97-100
• /
• 2002

NaEr(WO$_4$)$_2$ is a new laser material. The planar optical waveguide was formed in NaEr(WO$_4$)$_2$ crystal by 2.6 MeV He$^{+}$ ion implantation at doses of 1.0-1.5 $\times$ 10$^{16}$ ions/cm$^2$ at room temperature. The effective refractive indices of the dark modes were measured using the prism coupling method. foul n modes and five TM modes were observed in the waveguide. The refractive index profiles were analyzed using the reflectivity calculation method (RCM). The influence of heat treatment at moderate temperature on the refractive index profiles of the waveguide was also investigated. We used the TRIM'98 (Transport of ton in Matter) code to simulate the damage profile in the NaEr(WO$_4$) crystal by 2.6 MeV He$^{+}$ion implantation which is helpful for a better understanding of the waveguide formation.ion.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.3
• /
• pp.123-137
• /
• 1998

The finite deformation with self contact problem of C. V. joint boots is analysed by using the implicit finite element code ABAQUS/Standard. It is shown that analysis results have a good agreement with experimental ones to the degree of maximum rotation angle. As an application of design modification, the effects of thickness change of the rounded part of boot model on the bending and the contact situation of deformed geometry are investigated. In this paper, the effect of the design modification in the end on the leakage is examined using 2-D finite element simulation. To solve the leakage problem of grease, the length of the small end is enlarged. From this study, it is confirmed that we can save the cost and time by applying FEM techniques to analyze and design the boot model.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.59 no.2
• /
• pp.238-244
• /
• 2010

In this paper, we studied electrical characteristics of internal converter type of LED lamps for road and street lighting. We surveyed electro-technical regulations and KS(Korean industrial standards) about LED luminairs. Waveforms of voltage and current, thermal distributions, insulation resistances between live parts and exposed conductive parts, and flame test of cover of LED lamps were experimented and analyzed. In regulations, insulation resistance between live conductors and exposed conductive parts should be greater than $0.2M{\Omega}$ in case nominal voltage of wiring is 220V. In KS codes, the value of insulation resistance should be greater than $2M{\Omega}$ while applying DC 500V or DC 100V. In the result of this study, waveforms of primary voltage and current were distorted. There was difference in waveforms of secondary voltage and current according to composition of converter. Mostly, insulation resistances were measured high more than regulation and code value but some measured points were measured badly($0.0M{\Omega}$). Cover of LED lamps was ignited easily. We expect that the results of this study would be helpful for revision of regulations and national codes for the electrical safety of LED road and street lighting.

• Bulletin of the Korean Space Science Society
• /
• 2008.10a
• /
• pp.23.2-23.2
• /
• 2008

We presented the accurate absolute dimensions and distances of fifteen main sequence eclipsing binaries. The photometric and spectroscopic solutions of the binary systems were determined by analyzing light curves and radial velocity curves collected from the literature using the Wilson-Devinney computer code. The fifteen double-line spectroscopic binaries consist of nine detached systems; QX Car, AH Cep, CW Cep, ZZ Cep, XY Cet, RX Her, V451 Oph, VV Pyx and V760 Sco, six semi-detached systems; LY Aur, IU Aur, AO Cas, DM Per, V Pup and HU Tau. The temperatures of the binary systems were determined from their colors using the color-temperature calibrations. Then the temperature of each component star were determined using the temperature ratio which was adjusted from the light curves. We estimated the possible Z values and ages for the detached systems by adopting the Y2 (Yonsei-Yale) stellar evolutionary tracks. The derived distances are in good agreement of the Hipparcos distances whose error of parallax is within 10 %. Finally these well-investigated systems will be used as the standard eclipsing binaries.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.29 no.1 s.139
• /
• pp.13-22
• /
• 2005

The purpose of this study is to understand the feature and phenomena of women's costume in Choson dynasty by the approach of semiotics. In order to do so, F Saussure's linguistic symbol theory, C. Peirce's conception on semiology theory and cultural semiology of R. Barthes ware used as tool to analyse traditional women's costumes in $Chos\v{o}n$ dynasty. And I choose basic conceptions based on their semiotic theory. which were langue & parole. dennotation & connotation, paradigm & syntagm, code, and analysed. structure of sign, communication though the non-language. The fashion of the $Chos\v{o}n$ dynasty contains various meaning as sign symbol system and makes the communication possible as it is mentioned above. We nay understand the sign symbol system described in the fashion sign by analysing the structure and meaning operation of sign on the basis of social, political, and idealistic background of the times, to understand the polysemy quality of the fashion.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.799-802
• /
• 2009

We have been studying the next generation of video creation solution based on TVML (TV program Making Language) technology. TVML is a well-known scripting language for computer animation and a TVML Player interprets the script to create video content using real-time 3DCG and synthesized voices. TVML has a long history proposed back in 1996 by NHK, however, the only available Player has been the one made by NHK for years. We have developed a new TVML Player from scratch and named it T2V (Text-To-Vision) Player. Due to the development from scratch, the code is compact, light and fast, and extendable and portable. Moreover, the new T2V Player performs not only a playback of TVML script but also a Text-To-Vision conversion from input written in XML format or just a mere plane text to videos by using 'Text-filter' that can be added as a plug-in of the Player. We plan to make it public as freeware from early 2009 in order to stimulate User-Generated-Content and a various kinds of services running on the Internet and media industry. We think that our T2V Player would be a key technology for upcoming new movement.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.2
• /
• pp.301-309
• /
• 1996

This paper estimates the electric field effect near 765[kV] AC double transmission line with numerical data. The induced voltage and current of a human and car under who kinds of phase arrangement are calculated when each of two objects is insulated or grounded. When the calculated results of the low-reactance and superposition phase arrangement are compared, it is proved that the induced voltage and current of the former are about 30 [%] smaller than that of the latter. The induced current of a human and car are less than 0.5[mA] which is about 10[%] less than that of the American National Standard Code. Also the induced voltage and current of dead lines by other live lines are calculated. Finally the effective number and position of shield wires to reduce the field in ground level are considered. charge simulation method and surface charge method are used to simulate the 2 or 3 dimensional transmission line model respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.3
• /
• pp.1035-1039
• /
• 2010

Activation products generated by photoneutrons in concrete shielding wall around electron linac were estimated for a high energy X-ray container cargo inspection system. Monte carlo code, MCNPX2.5.0 was used for reference system of 9MeV fixed type dual-direction container cargo inspection system installed at major harbors in Korea. Activation products inventory generated by photoneutron (n,$\gamma$) reaction are estimated, and then radiation dose rate is calculated from the results.