• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.1
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• pp.42-45
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• 1986

This paper introduces novel functionally integrated logic elements which are conceptuallized for large scale integrated circuits. Efforts are made to minimize the gate size as well as to reduce the operational voltage, without sacrificing the speed performance of the gates. The process used was a rather conventional collector diffusion isolation(CDI) process. New gate structures are formed by merging several transistors of a gate in the silicon substrate. Thested elements are CML(Current Mode Logic) and EECL (Emitter-to-Emitter Coupled Logic)gates. The obtained experimental results are power-delay product of 6~11pJ and delay time/gate of 1.6~1.8 ns, confirming the possibility of these novel gate structures as a VLSI-candidate.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1434-1436
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• 1995

We designed and fabricated a highly sensitive magnetotransistor which employes the emitter region as a Hall plate for inducing Hall voltage across the emitter. The Hall voltage modulates the emitter basic junction bias on both sides of the emitter so that a large collector current difference is resulted. The specially designed $p^+$ ring around the emitter enhances accumulation of drifted electrons in the emitter and thus the Hall voltage. A relative sensitivity of 240/tesla is measured by operating the device in the saturation mode.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.924-931
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• 2011

This paper deal with maximum span calculation technique for 350km/h high speed catenary system. Considers a geometric interaction, possible maximum span length is between two pole. Wind condition and the train current collector is moving even to being pantograph does not escape while operating. Uses like this justice and possible maximum span length is follow next condition. (i) Operating range of pantograph fan head, (ii) The wind velocity which assumes from system, (iii) Width in pantograph from operation height moving, (iv) Type of processing Catenary system, specially tensile strength of overhead contact wire and messenger wire etc. When accurately calculates the maximum permission span, the dropper between of overhead contact wire and messenger wire and must consider the correlation.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2287-2290
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• 2003

The electrical characteristics of power devices such as BJT (Bipolar Junction Transistor), and MOSFET (Metal Oxide Field Effect Transistor), etc, are altered due to impinging photon radiation and temperature in the nuclear or the space environment. In this paper, BJT and MOSFET are the two devices subjected to ${\gamma}$ radiation. In the case of BJT, the current gain (${\beta}$) and the collector to Emiter breakdown voltage ($V_{CEO}$) are the two main parameters considered. When it was subjected to ${\gamma}$ rays, the ${\beta}$ decreases as the dose level increases, whereas, $V_{CEO}$ gradually increases as the dose level increases. In the case of MOSFET, the threshold voltage is decreasing as the dose level increases. Here it has been observed the decent rate is an increasing function of the threshold voltage. The on-resistance does not change with respect to the dose. Both the devices recover back the original specification after the annealing is finished. No permanent damage has been occurred.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.335-340
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• 2018

Transition metal oxide materials have attracted widespread attention as Li-ion battery electrode materials owing to their high theoretical capacity and good Li storage capability, in addition to various nanostructured materials. Here, we fabricated a CoO Li-ion battery in which Co nanoparticles (NPs) are deposited into a current collector through electrophoretic deposition (EPD) without binding and conductive agents, enabling us to focus on the intrinsic electrochemical properties of CoO during the conversion reaction. Through optimized Co NP synthesis and electrophoretic deposition (EPD), CoO Li-ion battery with 630 mAh/g was fabricated with high cycle stability, which can potentially be used as a test platform for a fundamental understanding of conversion reaction.

• Journal of the Korean Ceramic Society
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• v.45 no.8
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• pp.493-496
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• 2008

Composite electrodes consisting of $CoMnO_2$ and carbon nanofibers(vapor grown carbon nanofiber, VGCF) with high electrical conducivity($CoMnO_2$/VGCF) were prepared on a porous nickel foam substrate as a current collector and their supercapacitive properties were investigated using cyclic voltammetry in 1 M KOH aqueous solution. The $CoMnO_2$/VGCF electrode exhibited high specific capacitance value of 630 F/g at 5 mV/s and excellent capacitance retention of 95% after $10^4$ cycles, indicating that the used VGCF played the important roles in reducing the interfacial resistance in the composite electrode to improve supercapacitive performance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2049_2050
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• 2009

본 연구에서는 수소 연료전지의 엔드플레이트와 외부 연결 부분의 금속을 진동시험기를 이용하여 접촉저항을 측정하였다. 수소 연료전지의 집접판에서의 전류밀도의 변화와 온도 분포의 변화를 비교해 볼 수 있었으며, 접촉저항을 측정 할 수 있었다. 진동시험기는 5~50 Hz의 범위까지 설계하였으며 진동에 대한 접촉저항의 변화도 확인 할 수 있었다.

• Current Research on Agriculture and Life Sciences
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• v.33 no.1
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• pp.15-18
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• 2015

Zein/Poria cocos extract nanofibers were prepared based on the electrospinning of aqueous solutions with different Poria cocos extract concentrations (0, 5, 10, and 15 wt.%). The electrospinning parameters, including the polymer contents, voltage, and tip-to-collector distance (TCD), were optimized for the fabrication process. The resulting electrospun materials were all characterized using field-emission scanningelectron microscopy (FE-SEM). The diameters of the electrospun zein nanofibers were found to increase when increasing the zein concentration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.753-756
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• 2001

This research made a study of MnO$_2$electrode for supercapacitor with a diffuser (Polyvinyl alcohol). Manganese dioxide was used as active material. We tried to increase specific surface area by adding PVA. Manganese dioxide was synthesized by a sol-gel method using fumaric acid and oxalic acid in low temperature with high yield. Therefore, We prepared Manganese dioxide powder. This powder was used by active materials. The electrode was made by a mixture of active material, ketjen-black which is a large specific surface area, and PVdF-co-HFP as binder agent with using Nickel mesh as current collector. Here we reported on the synthesis and electrochemical performance of a enhanced material. All active materials have been submitted to X-ray diffraction and Scanning electron microscopy.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.40-47
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• 1998

This paper report sthe design, fabrication and characterization of an AlGaAs/GaAs HBT (heterojunction bipolar transistor) with an air-bridge isolation structure which is made to improve high frequency characteristics for the application to the mobile communication system in the next genration. We found that the size, shape and structure of HBT have an effect on the high frequency operation. The measured dc and ac characteristics of the four type HBTs were compared and analyzed. An E-type HBT with an air-bridge structure by undercut etching exhibited .beta.=56, $V_{off-set}$ = 0.3 V, B $V_{CEO}$=7.0V with $f_{T}$=40 GHz and $f_{max}$=45GHz at a collector current density of 7.1*10$^{4}$ A/c $m^{2}$.>.