• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.181-181
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• 2010

RF magnetron sputtering을 이용하여 RF power 및 공정 압력에 따라 ZnO 박막을 유리기판 위에 제작하고 구조적, 광학적, 전기적 특성을 조사하였다. 박막 증착 조건의 초기 압력은 $1.0{\times}10^{-6}\;Torr$, 증착온도는 상온으로 고정하였으며 기판은 Corning 1737 유리 기판을 사용하였다. 공정 변수로 RF파워는 25W, 50W, 75W, 100W로 변화시키고, 증착 압력은 20m, 100m, 200m 300mTorr로 변화시켰다. 유리기판 위에 증착된 모든 ZnO 박막에서 (002) 면의 우선배향성이 관찰되었고 RF power가 50 W와 75W 에서 좋은 결정성을 나타내었다. 공정조건별로 제작된 모든 ZnO박막에서 85% 이상의 투과율을 나타내었으며, 증착압력이 증가함에 따라 광학적인 밴드 갭이 증가하였다. Hall 측정 결과 모든 샘플에서 n타입 특성이 확인되으며, 75W와 300mTorr일 때 전기비저항 $3.56\;{\times}\;10^{+1}\;{\Omega}cm$, 전하의 농도 $2.8\;{\times}\;10^{17}cm^{-3}$, 이동도 $0.613\;cm^2V^{-1}s^{-1}$로 반도체 활성층으로 가장 적합한 전기적 특성을 얻었다. RF 파워가 증가하고, 증착압력이 증가할 수록 ZnO 박막 특성이 좋아지는 경향성을 확인하였다.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.325-334
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• 2007

In order to increase the promotion of multimedia processing techniques in MPEG standard, MPEG Multimedia Middleware (M3W) which supports middleware interface for multimedia processing is set up. In this paper, multimedia protection and management service interfaces based on MPEG Multimedia Middleware (M3W) are introduced. The service interfaces are based on component models of M3W and support normative IPMP messages. The proposed interfaces are composed of Tool interfaces and Trust management interfaces: Tool interfaces provide the functionality supporting terminal and tool based on the governed decoder model and Trust management interfaces provide the supporting functionality such as license managing and authentication required in DRM devices. As an application of the proposed interfaces, a JAVA based player simulator is shown. The proposed interfaces can be easily implemented under various device and application environments as an ISO/IEC 23004-2 standard middleware platform.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1837-1844
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• 2009

In this paper, the circuit of 2 variable ternary adder and multiplier circuit using current mode CMOS are implemented. The presented ternary adder circuit and multiplier circuit using current mode CMOS are driven the voltage levels. We show the characteristics of operation for these circuits simulated by HSpice. These circuits are simulated under $0.18{\mu}m$ CMOS standard technology, $5{\mu}A$ unit current in $0.54{\mu}m/0.18{\mu}m$ ratio of NMOS length and width, and $0.54{\mu}m/0.18{\mu}m$ ratio of PMOS length and width, and 2.5V VDD voltage, MOS model Level 47 using HSpice. The simulation results show the satisfying current characteristics. The simulation results of current mode ternary adder circuit and multiplier circuit show the propagation delay time $1.2{\mu}s$, operating speed 300KHz, and consumer power 1.08mW.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.9
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• pp.13-19
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• 1999

This paper describes a design of an 8-bit 100KSPS 1mW CMOS A/D Converter. Using a novel systematic offset cancellation technique, we reduce the systematic offset voltage of operational amplifiers. Further, a new Gain amplifier is proposed. The proposed A/D Converter is fabricated with a $0.6{\mu}m$ single-poly triple-metal n-well CMOS technology. INL and DNL is within ${\pm}1LSB$, and SNR is about 43dB at the sampling frequency of 100KHz. The power consumption is $980{\mu}W$ at +3V power supply.

• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.39-50
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• 2011

This study was conducted to analyze the thermal behavior of a PHC energy pi1e system in saturated soil conditions, various seasonal and flow-speed conditions during 100 hours of operation through numerical analysis. The examination was a1so conducted with a single pile as well as with group pils. For the operation of 100 hours, the average heat exchange rate appeared 55 W/m, 47 W/m during winter and summer respectively. An increase in flow-speed was associated with a rise in the heat exchange rate. And thermal behavior analysis results during winter season show that thermal efficiency has increased when there are more free thermal planes. For the operation in group pile as 3D and 5D pile spacing (D: pile diameter), average heat exchange rate increased as pile spacing grows. Compared with the heat exchange rate of single pile, thermal exchange efficiency of group pile decreased by 89% (for 3D spacing) and 93% (for 5D spacing).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.5
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• pp.311-316
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• 2013

In this study, the wave energy potential (WEP) was evaluated using the wave data measured at nine stations along the Korean east coast and compared with the results of previous studies. Along the Korean east coast, seasonal variations in the WEP were around 6.4 kW/m in winter and 1.2 kW/m in summer, greater than spatial variations of 2.5~4.3 kW/m. In most stations, the wave power during June to July were shown to be smallest. The estimated annual average WEP was greatest in the Mukho and Jukbyeon stations located in the middle of the Korean east coast at around 4.3 kW/m, and smallest in the Jinha station at around 2.5 kW/m. The results found using the previous hindcast data showed WEP having a tendency to decrease from south to north. However, in this study, the WEP showed a tendency of being greatest in the middle of the Korean east coast and decreasing in both north and south directions.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.77-82
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• 2010

Effects of evaporation processes and a reduction annealing on thermoelectric properties of the Sb-Te thin films prepared by thermal evaporation have been investigated. The thin film evaporated by using the powders formed by crushing a $Sb_2Te_3$ ingot as an evaporation source exhibited a power factor of $2.71{\times}10^{-4}W/m-K^2$. The thin film processed by evaporation of the mixed powders of Sb and Te as an evaporation source showed a power factor of $0.12{\times}10^{-4}W/m-K^2$. The thin film fabricated by coevaporation of Sb and Te dual evaporation sources possessed a power factor of $0.73{\times}10^{-4}W/m-K^2$. With a reduction annealing at $300^{\circ}C$ for 2 hrs, the power factors of the films evaporated by using the $Sb_2Te_3$ ingot-crushed powders and coevaporated with Sb and Te dual evaporation sources were remarkably improved to $24.1{\times}10^{-4}W/m-K^2$ and $40.2{\times}10^{-4}W/m-K^2$, respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.80-85
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• 2005

Electrochemical control of the metabolic flux of W. kimchii sk10 on glucose and pyruvate was studied. The growing cell of W. kimchii sk10 produced 87.4 mM lactate, 69.3 mM ethanol, and 4.9mM lactate from 83.1mM glucose under oxidation condition of the anode compartment, but 98.9 mM lactate, 84.3mM ethanol, and 0.2 mM acetate were produced from 90.8 mM glucose under reduction condition of the cathode compartment for 24 h, respectively. The resting cell of W. kimchii sk10 produced 15.9 mM lactate and 15.2 mM acetate from 32.1 mM pyruvate under oxidation condition of the anode compartment, and 71.3 mM lactate and 3.8 mM acetate from 79.8mM pyruvate under reduction condition of the cathode compartment. The redox balance (NADH/$NAD^+$) of metabolites electrochemically produced from pyruvate was 1.05 and 18.76 under oxidation and reduction conditions, respectively. On the basis of these results, we suggest that the neutral red (NR) immobilized in bacterial membrane can function as an electron channel for the electron transfer between electrode and cytoplasm without dissipation of membrane potential, and that the bacterial fermentation of W. kimchii sk10 can be shifted to oxidized or reduced pathways by the electrochemical oxidation or reduction, respectively.

• Explosives and Blasting
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• v.9 no.1
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• pp.3-13
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• 1991

The cautious blasting works had been used with emulsion explosion electric M/S delay caps. Drill depth was from 3m to 6m with Crawler Drill ${\phi}70mm$ on the calcalious sand stone (soft -modelate -semi hard Rock). The total numbers of test blast were 88. Scale distance were induced 15.52-60.32. It was applied to propagation Law in blasting vibration as follows. Propagtion Law in Blasting Vibration $V=K(\frac{D}{W^b})^n$ were V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites(m) W : Maximum charge per delay-period of eight milliseconds or more (kg) K : Ground transmission constant, empirically determind on the Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents where the quantity $\frac{D}{W^b}$ is known as the scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagorized in three groups. Cubic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge Per delay Plots of peak particle velocity versus distoance were made on log-log coordinates. The data are grouped by test and P.P.V. The linear grouping of the data permits their representation by an equation of the form ; $V=K(\frac{D}{W^{\frac{1}{3}})^{-n}$ The value of K(41 or 124) and n(1.41 or 1.66) were determined for each set of data by the method of least squores. Statistical tests showed that a common slope, n, could be used for all data of a given components. Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom over loom distance because the frequency is verified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m ------- under l00m ${\cdots\cdots\cdots}{\;}41(D/sqrt[2]{W})^{-1.41}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}A$ Over 100m ${\cdots\cdots\cdots\cdots\cdots}{\;}121(D/sqrt[3]{W})^{-1.66}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}B$ where ; V is peak particle velocity In cm / sec D is distance in m and W, maximLlm charge weight per day in kg K value on the above equation has to be more specified for further understaring about the effect of explosives, Rock strength. And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• Korean Journal of Materials Research
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• v.11 no.6
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• pp.472-476
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• 2001

Type and three-dimensional morphology of carbides precipitated in the X(X= 1.70, 1.92, 2.21, 2.50, 2.86)%C-5%Cr-5%V-5%Mo-5%W-5%Co multi-component white cast iron were investigated using an optical microscope and SEM. The types of carbides precipitated were MC, M$_2$C and M$_{7}$C$_{3}$. Morphology of the MC carbide took three forms, that it petal-like, nodular and coral-like. MC carbide seemed to change its morphology from petal-like through nodular, and finally to coral-like with an increase in carbon content. M7C carbide was classified into lamellar and plate-like type. The lamellar M$_2$C arbide precipitated in the iron with low molybdenum and tungsten contents, and higher contents of both elements in the iron were needed to form the plate-like M$_2$C carbide. The morphology of M$_{7}$C$_{3}$ was rod-like similar to that observed in high chromium white cast iron. However, cobalt does not affect the type and morphology of precipitated carbides.des.