• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.133-139
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• 2007

Future MEMS systems will be composed of larger varieties of devices with very different functionality such as electronics, mechanics, optics and bio-chemistry. Integration technology of heterogeneous devices must be developed. This article first deals with the current development trend of new fabrication technologies; those include self-assembling of parts over a large area, wafer-scale encapsulation by wafer-bonding, nano imprinting, and roll-to-roll printing. In the latter half of the article, the concept towards the heterogeneous integration of devices and functionality into micro/nano systems is described. The key idea is to combine the conventional top-down technologies and the novel bottom-up technologies for building nano systems. A simple example is the carbon nano tube interconnection that is grown in the via-hole of a VLSI chip. In the laboratory level, the position-specific self-assembly of nano parts on a DNA template was demonstrated through hybridization of probe DNA segments attached to the parts. Also, bio molecular motors were incorporated in a micro fluidic system and utilized as a nano actuator for transporting objects in the channel.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권9호
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• pp.503-509
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• 1999

This paper proposes a new speed and tension control algorithm for multi-span continuous strip processing line. In this algorithm the speed reference of each roll is adjusted to make the output force follow the load balance reference using an outer loop controller in cascade. Using the information of the output force of the adjacent roll, it is shown that the strip tension between two rolls can be controlled as the desired value without tension sensor. An experimental set-up which consists of 4 driven and 3 measuring rolls is designed and built for the multi-span speed and tension control. The experimental result reveals conspicuous improvement of tension control performance by the proposed algorithm comparing to the conventional tension feedback controller.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.419-422
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• 2008

It is most important to design the roll pass in shape rolling process. However, roll pass design has been accomplished by experience and intuition of a skilled engineer up to now. And it has being produced throughout a lot of trial and error. Thus, in this study, we tried to analysis the rolling process of H-beam by using FEM program for the quantitative evaluation of the plastic deformation. It could be predicted that rolling load, torque, shape of cross section and distribution of effective strain each pass by the analysis of rolling from break down mill(2 Hi rolling) to finishing rolling(Universal rolling) considering the heat transfer.

• 한국재료학회지
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• 제17권10호
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• pp.521-525
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• 2007

The microstructure and mechanical properties of an oxygen free copper processed by accumulative roll bonding(ARB) at low strain rate were studied. The copper sheets were highly strained up to an equivalent strain of ${\sim}6.4$ by ARB process at ambient temperature. The strain rate of the copper during the ARB was $2.6sec^{-1}$. The microstructure and mechanical properties of the ARB-processed copper were compared to those of the specimens processed by ARB at relatively high strain rate ($37sec^{-1}$). The microstructure and mechanical properties of the copper with ARB process was very similar to each other despite of some differences in recovery.

• 산업경영시스템학회지
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• 제18권35호
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• pp.47-52
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• 1995

The aim of this paper is to suggest the cutting stock problems which are two-dimensional in form, but can be treated as the optimization methods for one-dimensional cutting stock problem by exploiting the length requirement of the products. The solution method consists of two stages. The first calculates the number of roll pieces of each size. Next, 1-dimensional cutting stock model is set up. One heuristic method to calculate the number of each roll is suggested. The trim loss minization criteria are used to design the objective function. This model can be solved by the conventional cutting stock procedures based on enumerating the possible cutting patterns.

• ETRI Journal
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• 제46권4호
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• pp.716-726
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• 2024

An ultrawide stopband lowpass filter is reported using three stepped impedance resonators with high selectivity. The filter extends the stopband frequency range and attenuation, and two quarter-wave open stubs and three circular ground slots are introduced. The lumped and distributed equivalent models are derived and analyzed. The corresponding results are validated experimentally in a fabricated prototype. The prototype lowpass filter has a 3 dB cutoff frequency (f_c) of 2.9 GHz, and the stopband is extended up to 35 GHz (12.07f_c), with an attenuation level better than 20 dB throughout. The passband-to-stopband transition (3 dB-20 dB) bandwidth is 0.18 GHz, and the roll-off factor is 135 dB/GHz at 30 dB. The insertion loss is 0.3 dB at 1.6 GHz. The normalized circuit size of the proposed filter with respect to the guided wavelength is 0.04.

• 한국초지조사료학회지
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• 제5권2호
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• pp.116-120
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• 1985

Roll bale silage조제시(調製時) 밀봉지연(密封遲延)이 silage 품질(品質)과 소화율(消化率)에 미치는 영양(影響)에 대한 본(本) 시험(試驗)에서의 결과(結果)는 다음과 같다. 1. Roll bale silage의 내부온도(內部溫度)는 대조구(對照區)에서 $26{\sim}28^{\circ}C$였으나, 밀봉지연구(密封遲延區)에서는 밀봉(密封)을 늦게 함에 따라 열(熱)이 발생(發生)하여 roll bale내(內)의 온도(溫度)가 $55^{\circ}C$까지 상승하였다. 2. 밀봉지연구(密封遲延區)에서 유산함량(乳酸含量)은 현저하게 감소하였으며, $NH_3-N/T-N$함량(含量)은 증가하는 경향을 보였다. 일반성분(一般成分)에서는 밀봉지연구(密封遲延區)의 ADIN/T-N, 섬유질(纖維質) 및 lignin함량(含量)이 증가하였다. 3 . 단백질소화율(蛋白質消化率)에서는 밀봉지연구(密封遲延區)가 대조구(對照區)보다 낮았으나, 섬유질소화율(纖維質消化率)에서는 대조구(對照區)보다 높았다. 4. 제(第)1위내(胃內) pH는 밀봉지연구(密封遲延區)가 낮았으며, $NH_3-N$농도(濃度)에서는 별댜른 차이가 없었다. 총(總)VFA 농도(濃度)에서는 밀봉지연구(密封遲延區)가 낮았으나 총(總)VFA 함량중(含量中) 초산(酢酸)비율은 밀봉지연구(密封遲延區)가 높았다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 춘계학술대회논문
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• pp.101-109
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• 1996

Mini-mill process which is one of the new steel -marking technologies to be able to produce the hot rolled coils by thin slab caster of ISP(In-Line Strip Production) type, will be completed in the Kwangyang Steel Works of POSCO in August, 1996, SEt-Up Model of finishing mill which consists of 5 stands is the most basic and essential in mini-mill plant. Therefore, the simulation program of Finishing-mill Set-Up model were developed in this research , using new temeprature prediction model, roll gap model and rolling physical model. Using the developed FSU program , pass schedules to produce the strips with target strip thickness of 1.8mm, 2.0mm, 2.3mm, 2.7mm an d3.0mm were also determined respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.305-308
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• 2003

We fabricated a flexible ferroelectric liquid crystal (FLC) device containing polymer walls and networks which fix plastic film substrates. The device using 100-${\mu}m$-thick substrates could be bent in a radius of 7mm without disordering the FLC alignment. When sandwiched between polarizers a roll-up display with high-speed grayscale capability for moving-image displays was created.

• 산업기술연구
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• 제8권
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• pp.31-35
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• 1988

To predict the airloads on helicopter rotors in hover, the doublet panel method of the first order is applied. For this simulation, the rotor blade is divided into many panels both in spanwise and in chordwise direction, and Kocurek-Tangler's prescribed wake with roll-up process is taken for determing wake geometry and then represented by vortex lattice. To abtain more physically realistic calculation of induced velocity, the vortex core model is adopted and the compressibility effect is considered by Karman-Tsien rule.