• Membrane Journal
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• v.26 no.2
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• pp.152-158
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• 2016

The Chlor-alkali (CA) membrane cell is a major electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. The CA membrane process has been attracted in the industries, since it has relatively low energy consumption when compared with other CA processes. The key component in CA process is perfluorinated sulfonic acid ionomer membranes, which provide ion-selectivity and barrier properties to produced gases. Unfortunately, there is limited information to determine which factors should be satisfied for CA applications. In this study, the influences of PFSA membranes on CA performances are disclosed. They include ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.159-165
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• 2021

A fin channel with a fin width of 20 nm and a gradually increased source/drain extension regions are fabricated on a bulk silicon wafer by using a three-dimensional selective oxidation. The detailed process steps to fabricate the proposed fin channel are explained. We are demonstrating their preliminary characteristics and properties compared with those of the conventional fin field effect transistor device (FinFET) and the bulk FinFET device via three-dimensional device simulation. Compared to control devices, the three-dimensional selective oxidation fin channel MOSFET shows a higher linear transconductance, larger drive current, and lower series resistance with nearly the same scaling-down characteristics.

• Archives of design research
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• v.19 no.2 s.64
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• pp.251-260
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• 2006

Rapid development of electronic technology has made it possible to perform various function. But this technology made it increase it's complexity. Therefore, It was important to identify usability problem in interface design. The quality of interface to promote the efficient interaction should be evaluated with regard to users' cognitive characteristics. So, in this paper, washing machine, that is one of the most useful electronic home application was studied menu structure on interface and it's operational states transition. At first, an cognitive menu structure is identified with users' conceptual similarity of the main function of washing machine. Then three washing machines was selected to compare with the cognitive menu structure. And, we were analyzed how operational state of the washing machine was transfered. As a result, we can be revealed that menu operational method based on the cognitive structure was consistent with the user's preferred operational method during the experimental tasks and the users and designers had a different knowledge of an it's function structure. These results will be useful to design the washing machine interface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2551-2556
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• 2009

The principal operation of a ring laser gyroscope depends on the phase difference for the counter-propagating waves within a closed path. The reflection mirrors mounted on the resonator block form the traveling waves. Thus, the dimension accuracy of resonator block influences the traveling path of beam. In order to maintain the stable optical beam path in the ring resonator, the piezo-driven moveable mirror is adopted for the path length control under the thermal expansion or mechanical strain of resonator block. This paper presents the mathematical description of the elastic behavior of piezo-driven mirror. This description can be applied for the concept design of piezo-driven mirror.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.39-45
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• 2011

This paper proposes a low power current-steering 10-bit DAC selecting clock enable signal. The proposed DAC reduces the clock power by cutting the clock signal to the current-source cells in wihich the data will not be changed. The proposed DAC was implemented using a 0.13${\mu}m$ CMOS process with $V_{DD}=1.2V$. Its core area is 0.21$mm^2$. It consumes 4.46mW at 1MHz signal frequency and 200MHz sampling rate. The clock power is reduced to 30.9% and 36.2% of a conventional DAC at 1.25MHz and 10MHz signal frequencies, respectively. The measured SFDRs are 72.8dB and 56.1dB at 1MHz and 50MHz signal frequencies, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1327-1334
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• 2012

This study shows the conformance-based design results of a fourth-order dynamic actuator showing a performance variation caused by variation in the components as well as aero-induced disturbances. The actuator comprises a BLDC motor, spur gear and worm gear assembly, and canard. The actuator performance was evaluated by using time-variant angle information of the canard. Based on the response surface models, critical system variables were screened using F-tests, and then, the performance was approximated as a function of the variables because it is difficult to determine the performance of a high-order dynamic system as a function of system variables through analytical approaches. In this study, the conformance of uncertain performance to the specification was defined as a probability measure. The design variables obtained by optimizing the measure can provide actuator performance conforming to the specifications considered, even though there is a variation in both the components and the aero-induced disturbances.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.104-110
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• 2021

A novel selective oxidation process has been developed for low source/drain (S/D) series resistance of the fin channel metal oxide semiconductor field effect transistor (MOSFET). Using this technique, the selective oxidation fin-channel MOSFET (SoxFET) has the gate-all-around structure and gradually enhanced S/D extension regions. The SoxFET demonstrated over 70% reduction in S/D series resistance compared to the control device. Moreover, it was found that the SoxFET behaved better in performance, not only a higher drive current but also higher transconductances with suppressing subthreshold swing and drain induced barrier lowering (DIBL) characteristics, than the control device. The saturation current, threshold voltage, peak linear transconductance, peak saturation transconductance, subthreshold swing, and DIBL for the fabricated SoxFET are 305 ㎂/㎛, 0.33 V, 13.5 𝜇S, 76.4 𝜇S, 78 mV/dec, and 62 mV/V, respectively.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.88-89
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• 1996

투과증발 시스템은 막 분리 기술의 일종으로 액체 혼합물 중의 한 성분에 대해 친화적인 비다공성 막을 사용하여 그 성분을 선택적으로 투과시켜 혼합물을 분리하는 기술이다. 투과증발 시스템에서는 Feed가 비교적 높은 온도에서 액상 형태로 막의 Feed side에 공급되어 막을 투과한 물질(Permeate)은 Permeate side에서 기화된 후 냉각기로부터 공급되는 Cold brine에 의하여 응축되며, 이는 투과증발막 투과 구동력이 각 성분의 증기압 차이기 때문에 이를 크게 유지하기 위함이다. 현재 투과증발 시스템이 상업적으로 적용되고 있는 공정은 유기물 탈수 공정으로, 이 공정에서는 물에 대한 용해도 및 투과 속도가 우수한 친수성 막을 이용하여 유기물과 물의 혼합물로부터 물을 제거하여 유기물을 농축하며, 대표적인 유기물은 에탄올, Isopropyl alcohol(IPA), 아세톤, MIBK, Ethyl acetate, THF 등의 중성 유기물이다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.1-11
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• 2009

In this paper, a new 1 kW power amplifier with high efficiency and high stability in a RF generator is designed and fabricated for plasma applications. The efficiency of power amplifier is improved by using class-E amplifier that consists of one push-pull MOSFET and high current drive IC instead of class-C amplifier composed of several single ended MOSFET. Switchable damper that allows selecting three different modes of amplifiers for considering efficiency and stability is added into the amplifier for plasma applications. Stable region of an early electronic discharge section is extended to VSWR of 4.5:1 compared to conventional VSWR of 3.8:1 through using switchable damper. The dimension of the amplifier is also reduced to 30 % of conventional amplifier. The 80 % efficiency of power amplifier with switchable damper is obtained the output power of 1 kW in operating frequency of 13.56 MHz. In comparison of conventional power amplifier for plasma applications, 13 % efficiency is improved.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.411-412
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• 2016

최근 퍼스널 모빌리티에 대한 관심과 수요가 증대됨에 따라 전기에너지를 구동원으로 하는 소형 이동형 제품을 생활속에서 쉽게 접할 수 있게 되었다. 이러한 퍼스널 모빌리티 제품은 자이로센서 기술이 접복된 바퀴가 하나인 외발 전동휠과 세그웨이류의 제품, 전동퀵보드, 전동스쿠터 등 다양한 제품이 출시되고 있다. 또한 이들 제품의 구동전원은 대부분 리튬이차전지가 사용되고 있다. 본 논문에서는 충전과 방전을 반복하는 다셀이 직렬로 구성된 리튬 이차전지 배터리팩에서 발생되는 셀간 편차와 이로 인해 배터리팩의 전체적인 효율성이 저하되는 것을 방지하는 셀 밸런싱에 관한 기술로 과거 완속형의 표준충전에 적합한 1단 밸런싱의 문제점을 보완하기 위해 표준충전과 급속충전을 임의로 선택하여 사용하는 경우에도 정상적인 셀 밸런싱 수행은 물론 빠른 셀 밸런싱을 수행하기 위한 기법에 대해 살펴보았다.