• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.370-371
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• 2007

To investigate the ZnO thin films which are interested in the next generation of short wavelength LEDs and Lasers and UV photodetector with p-type inversion layer, the ZnO thin films were deposited by. RF sputtering system. Substrate temperature and work pressure is $100^{\circ}C$ and 15 mTorr, respectively, and the purity of ZnO target is 5N. The ZnO thin films were deposited at $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, and $400^{\circ}C$. For sample deposited at $300^{\circ}C$, we observed full width at half maximum (FWHM) of 0.240 and good surface morphology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.276-277
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• 2005

본 연구에서는 MCP법을 이용하여 Bi2212 초전도 튜브를 제작하고 공정 변수에 따른 초전도 튜브의 전기적 특성을 평가하였다. 초전도 분말은 $1100^{\circ}C$에서 용융하여 $300\sim500^{\circ}C$로 예열된 몰드 내에 주입하였으며 몰드는 1000 RPM으로 회전시켰다 제작된 초전도 튜브는 $840^{\circ}C$ 의 $O_2$ 분위기에서 72시간 열처리 하였다. SEM과 XRD 분석결과 튜브는 약 $40{\mu}m$의 크기를 갖는 Bi2212 초전도 상이 일정한 방향성을 갖으며 XRD 분석 결과 튜브 바깥부문에 Bi2201상이 존재하였다. 전기적 특성은 몰드 회전 속도가 증가할수록, 튜브의 두께가 증가할수록, 길이가 감소할수록 높은 $I_c$ 값을 나타내었으며, 이때 50 mm$\times$70 mm$\times$2.5 mm, 1000 RPM의 튜브에서 전기적 특성은 $I_c$=890 A, $T_c$= 80 K의 값을 나타내었다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.8
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• pp.426-432
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• 2004

This paper presents a systematic approach of measurement, modeling and analysis of grounding system impedance in the field of lightning protection system and intelligent power equipments. The measurement and analysis system of ground impedance is based on a computer aided technique. The magnitude and phase of ground impedance were determined by the novel measurement and analysis using the revised fall-of-potential method. The ground impedances of the ground rod of 50 m long are considerably dependent on the frequency. The ground impedance is mainly resistive in the frequency range of 3-20 kHz. At higher frequencies, the reactive components of the ground impedances are no longer negligible and the inductance of the ground rod was found to be the core factor deciding the ground impedance. Although the steady-state ground resistance of the ground rod of 50 m was less than that of the ground rod of 10 m, the ground impedances of the ground rod of 50 m over the frequency range of more than 60 kHz were much greater than those of the ground rod of 10 m. Furthermore, the equivalent circuit model based on the measured data was proposed. and the calculated results were in approximately agreement with the measured data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.104-112
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• 2008

In modern war information system development makes battlefield materialize, and combat factors can maximize combat power exhibition as that apply synchronization. Information system is the core of combat power operation under NCW(Network centric Warfare). This paper proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of information system at the theater joint fire operation in NCW environment. This methodology applied the rule of Newton's second law $F=(m{\Delta}{\upsilon})/t{\Rightarrow}(M{\upsilon}I)/T$) Details factor in combat power evaluation is as following. (1) M : Network power; (2) v : Movement velocity; (3) I : Information superiority; (4) T : C2(command and control) time. We applied this methodology to the "JFOS-K(Joint Fire Operating System-Korea) in Joint Chief of Staff" in the real military affair section.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.8
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• pp.468-474
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• 2009

Ground water source heat pump system is the oldest one of the ground source heat pump systems. Despite of this, little formal design information has been available until recently. The important design parameters for open system are the identification of optimum ground water flow, heat exchanger selection and well pump. In this study, the capacity of 50 RT system of two well type ground water heat pump system was used. As a result, static water level was -7 m and the level during the heating operation was -32 m, cooling operation was -40 m. The initial static water level recovered within 48 hrs. The temperature of ground water is $15.6^{\circ}C$ for heating season and $16.2^{\circ}C$ for cooling season and does not depend on the outdoor temperature. Operation efficiency of the system shows that, COP 3.1 for heating and COP 4.2 for cooling.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.273-280
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• 2014

Purpose : To verify the skin dose in Tomotherapy-based radiation treatment according to the change in tumor locations, skin dose was measured by using Gafchromic EBT3 film and compared with the planned doses to find out the gap between them. Materials and Methods : In this study, to measure the skin dose, I'm RT Phantom(IBA Dosimetry, Germany) was utilized. After obtaining the 2.5mm CT images, tumor locations and skin dose measuring points were set by using Pinnacle(ver 9.2, Philips Medical System, USA). The tumor location was decided to be 5mm and 10mm away from surface of the phantom and center. Considering the attenuation of a Tomo-couch, we ensured a symmetric placement between the ceiling and floor directions of the phantom. The measuring point of skin doses was set to have 3mm and 5mm thickness from the surface. Measurement was done 3 times. By employing TomoHD(TomoHD treatment system, Tomotherapy Inc., Madison, Wisconsin, USA), we devised Tomotherapy plans, measured 3 times by inserting Gafchromic EBT3 film into the phantom and compared the measurement with the skin dose treatment plans. Results : The skin doses in the upper part of the phantom, when the tumor was located in the center, were found to be 7.53 cGy and 7.25 cGy in 5mm and 3mm respectively. If placed 5mm away from the skin in the ceiling direction, doses were 18.06 cGy and 16.89 cGy; if 10mm away, 20.37 cGy and 18.27 cGy, respectively. The skin doses in the lower part of the phantom, when the tumor was located in the center, recorded 8.82 cGy and 8.29 cGy in 5mm and 3mm, each; if located 5mm away from the lower part skin, 21.69 cGy and 19.78 cGy were respectively recorded; and if 10mm away, 20.48 cGy and 19.57 cGy were recorded. If the tumor was placed in the center, skin doses were found to increase by 3.2~17.1% whereas if the tumor is 5mm away from the ceiling part, the figure decreased to 2.8~9.0%. To the Tomo-couch direction, skin doses showed an average increase of 11% or over, compared to the planned treatment. Conclusion : This study found gaps between planned skin doses and actual doses in the Tomotherapy treatment planning. Especially to the Tomo-cocuh direction, skin doses were found to be larger than the planned doses. Thus, during the treatment of tumors near the Tomo-couch, doses will need to be more accurately calculated and more efforts to verify skin doses will be required as well.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.478-482
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• 1996

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C50) for robotic manipulators to achieve trajectorytracking angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide motion for robotic manipulators. In the proposed scheme, adapation laws are derived from the improved second stability analysis based on the indirect adaptive control theory.l The proposed control scheme is simple in structure, fast in computation, an suitable for implementation of real-time control. Moreover, this scheme does not requre an accurate dynamic modeling, nor values of manipulator paramenters and payload Performance of the adaptive controller is illustrated by exeperimental results for a SCARA robot.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.278-284
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• 2004

In order to determine the bioavailability of c1onazepam, an anxiolytic drug, a simple, rapid and sensitive HPLC analysis was developed in healthy Korean volunteers. The analysis system was validated in specificity, accuracy, precision and linearity. The analysis condition we established was 2.58 min and 5 ng/$m\ell$ in retention time and limit of quantitation of c1onazepam, respectively, using reverse-phase C18 column connected to UV detector. Quantitation was performed at 235 nm wave length with p-hydroxybenzoic acid ethyl ester as internal standard. The method involved a simple extraction. In order to study blood level profiles as a function of time, eight volunteers were enrolled and orally took 6 mg clonazepam once. The blood samples were collected from 0 to 120 h after the drug administration. Mean AUC and Cmax value were 1028.17$\pm$568.165 (ng/$m\ell$$.$hr) and 41.25$\pm$10.82 (ng/$m\ell$), respectively. And mean Tmax and T$_{1}$2/ value were 1.08$\pm$0.42 (hr) and 30.78$\pm$3.26 (hr). From the results we determine the pharmacokinetic characteristics of clonazepam in Korean people using a newly developed and useful HPLC method.

• KSBB Journal
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• v.5 no.2
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• pp.119-124
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• 1990

Phospholipase D catalyzes the phosphatidohydrolysis and transphosphatidylation of phospholipid in the biological systems. In this study we were partially purified phospholipase D from Chinese cabbage and the characterization of the enzyme was carried out in a multistirring batch system bioreactor. The enzyme showed optimum activity at pH ,5.6, highest activity at 37$^{\circ}C$ and Ca2+ is important for the enzyme activity. Optimum concentrations of Ca2+ for phosphatidohydrolysis was 20 mM and for transphosphatidylation was 40 mM, respectively. Some organic solvents such as diethylether, isopropylether and butylacetate were activated the enzyme activity. On the other hand, EDTA, Ba2+, Mn2+ and Zn2+ showed inhibitory effect on the enzyme activity. The base acceptors in transphosphatidylation by the Chinese cabbage phospholipase D were tested. Various poly-and monohydroxy alcohols were found to be active.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1205-1209
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• 2003

We investigated the effects of calcination temperatures on the sintering behaviors and microwave dielectric Properties of (Z $n_{0.8}$M $g_{0.2}$)Ti $O_3$ system. Highly densified samples were obtained at the sintering temperatures below 100$0^{\circ}C$ with additions of 0.45 wt.%B $i_2$ $O_3$ and 0.55 wt.% $V_2$ $O_{5}$. From the examination of the existing phases and microstructures before and after sintering of (Z $n_{0.8}$M $g_{0.2}$)Ti $O_3$ system which is calcined at the various temperatures ranging from 80$0^{\circ}C$ to 100$0^{\circ}C$, it was found that higher Q${\times}$ $f_{o}$ values were obtained when unreacted phases in calcined body were reduced. When calcined at 100$0^{\circ}C$ and sintered at 90$0^{\circ}C$, it consists of hexagonal as. a main phase with uniform microstructure and exhibits Q${\times}$ $f_{o}$ value of 42,000 GHz and dielectric constant of 22. 22. 22.