• Journal of Environmental Science International
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• v.10 no.3
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• pp.173-178
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• 2001

The aim of this paper is to evaluate users benefit values of theme park using Travel Cost Method with special reference to Woobang Tower Land in Taegu for the estimation of economic values. This research is mainly based on questionnaire survey of 100 users of the theme park. Socio-economic factors such as income, year of education, annual income, age and money(travel cost) are analysed from 5 residential areas of the respondents. Multiple regression analysis was used for the evaluation of annual number of park visitings based on the analysis. The regression model shows NV = $\alpha$+$\beta_1$TC+$\beta_2$INC+$\beta_3$EDU+$\beta_4$AGE (NV : Annual Number of Visitings, TC : Travel Cost, INC : Annual Income, EDU : Years of Education, AGE : Age). Regarding to visitors demand curve based on the equation showed that annual economic values of Woobang Tower Land was estimated as 50billion Korean Won.

• Journal of applied mathematics & informatics
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• v.30 no.1_2
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• pp.101-109
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• 2012

In this paper, we present an algorithm for computing the number of points on the Jacobian varieties of one-dimensional family of genus 3 nonhyperelliptic curves over finite fields. We also provide the explicit formula of the characteristic polynomial of the Frobenius endomorphism of the Jacobian of $C:y^3=x^4+{\alpha}$ over a finite field $\mathbb{F}_p$ with $p{\equiv}1$ (mod 3) and $p{\neq}1$ (mod 4). Moreover, we give some implementation results using Gaudry-Schost method. A 162-bit order is computed in 97 s on a Pentium IV 2.13 GHz computer using our algorithm.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.129-132
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• 2001

This paper presents an efficient method to estimate the maximum SSN (simultaneous switching noise) for ground interconnection networks in CMOS systems using Taylor's series and analyzes the truncation error that has occurred in Taylor's series approximation. We assume that the curve form of noise voltage on ground interconnection networks is linear and derive a polynomial expression to estimate the maximum value of SSN using $\alpha$-power MOS model. The maximum relative error due to the truncation is shown to be under 1.87% through simulations when we approximate the noise expression in the 3rd-order polynomial.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.159-162
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• 2000

The purpose of this study is to develope an accurate procedure for measuring the glass content of fly ash produced by bituminous coal to assist in predicting their behavior in concrete. Quantitative mineralogical compositions of fly ashes were obtained by internal standard method using powder X-ray diffraction analysis. In the X-ray diffraction method, the specimen and standard fluorite were cautiously mixed and pulverized to 22$\mu$m in wet process so as to avoid the prefered orientation of the crystal and microabsorption effect of X-ray. calibration curve were fitted for several references peaks of four phases:$\alpha$-quartz. mullite, magnetite, hematite. The amount of glass was calculated by subtracting the amount of crystal phase and loss on ignition from the total amount. Glass content determined with this method ranged from 66.7 to 75.wt%.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.181-187
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• 2001

This study was carried out to measure the variations of potential and current density with polymers. The results were particularly examined to identify the influences on potential and rate of various factors including temperature and pH. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum current density were designated as the relative polarization sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.149.1-149.1
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• 2011

보현산 천문대의 근적외선 카메라시스템인 KASINICS(KASI Near Infrared Camera System)를 사용하여 다주기 변광성 BL Cam을 관측하였다. BL Cam(${\alpha}=03^h47^m19^s$, ${\delta}=+63^{\circ}22'7"$[J2000.0], V=13.10, ${\Delta}V$=0.33mag)은 광학적 쌍성으로 SX Pheoenics 변광성 중 하나이며 0.03 - 0.08day의 짧은 주기를 갖는 다주기 변광성으로 알려져 있다. 대상 천체의 적외선 관측을 위하여 한국천문연구원에서 개발한 지상 망원경용 근적외선 카메라 시스템 KASINICS를 사용해 J, H, Ks filter로 시계열 관측을 하였다. 대상 천체의 가시광 파장대에서의 관측 자료와 적외선 파장대에서의 관측 자료를 비교 분석함으로써 천체의 외곽층에서 발생하는 상호작용에 대해 알아볼 수 있다.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.393-394
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• 2007

In this study, to minimize the above effect Zinc Oxide(ZnO) thin films on Si(100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as Ar/$O_2$ gas ratios, RF power, substrate temperature, chamber prsssure and target-substrate distance. To analyze a crystallographic properties of the films, ${\Theta}/2{\Theta}$ mode X-ray diffraction, rocking curve and Alpha-step were performed. SAW filters were fabricated to evaluate the feasibility of ZnO thin film as a piezoelectrical materials and the processes of ZnO SAW filters using etch and lift-off were compared.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.324-327
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• 2000

ZnO(Zinc Oxide) thin films were deposited on glass substrate by Facing Targets Sputtering. Facing Targets Sputtering system can deposit thin films in plasma-free situation and change the sputtering conditions in wide range. The characteristics of ZnO thin films deposited at variation of sputtering conditions films thickness, power and substrate temperature were evaluated by XRD(x-ray diffractometer), ${\alpha}$-step (Tencor). The excellently c-axis oriented ZnO thin films were obtained at sputter pressure ImTorr, power 150W, substrate temperature 200$^{\circ}C$. In these conditions, the rocking curve of ZnO thin films deposited on glass was 3.3$^{\circ}$.

• Journal of Korea Foundry Society
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• v.2 no.2
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• pp.2-9
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• 1982

This paper is concerned with the improvement of impact and tensile Properties of spheroidal graphite cast iron of the following duplex matricess which were heat treated in the eutectic transformation temperature range (that is, $({\alpha}+{\gamma})$ coexisting range) ; ferrite-martensite, ferrite-bainite and ferrite-pearlite. The absorbed energy and maximum load was measured by recording the load-deflection curve with instrumented Charpy impact testing machine in the temperature range from $+100^{\circ}C$ to $-196^{\circ}C$. It was found the ferrite-bainite duplex matrix showed the highest toughness among the above matrices in the room temperature and the low temperature range. Comparison of this matrix to ferrite-pearlite matrix(that is, as cast) showed a lowering of $27^{\circ}C$ in the nil-ductility transition temperature (NDT) and a lowering of $40^{\circ}C$ in the ductile-brittle transition temperature (TrE), Which seems to result from the finner dimple pattern observed using miorofractography.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.901-904
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• 2000

In order to investigate the effect of deposition conditions on crystallographic properties of ZnO thin films by Facing Targets Sputtering system which can deposit thin films in plasma-free situation and change the deposition conditions in wide range. The characteristics of zinc oxide thin films on power, inter targets distance, and substrate temperature were investigated by XRD(x-ray diffractometer), alpha-step (Tencor) analyses. The excellently c-axis oriented zinc oxide thin films were obtained at sputter pressure 1mTorr, sputtering current 0.4A, substrate temperature 300$^{\circ}C$, inter target distance 100mm. In these conditions, the rocking curve of zinc oxide thin films deposited on Glass was 3.9$^{\circ}$.