• 한국정밀공학회지
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• 제28권7호
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• pp.821-826
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• 2011

This paper deals with an analysis of dynamic mechanism for the industrial two-step folding automatic door. A nonlinear equation of motion was derived in terms of folding angle to estimate driving forces. Based on this dynamic behavior, time taken during the door's opening well as their velocities were controlled so that the operating conditions can be obtained for the purpose of design. The stiffness of twisting spring was also investigated when the automatic door closed, because a dangerous accident takes place from the door's free falling. The current research will be a very useful tool in the near future for the dynamic analysis for the multi-step folding automatic door.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.591-594
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• 1988

A three-step heuristic algorithm for PLA column folding and row folding of column-folded PLA is presented, which is significantly faster than the earlier works and provides nearly optimal results. The three steps are i) min-cut partition of vertices in the column (or row) intersection graph, ii) determination of products' order using Fiduccia's min-net cut algorithm, and iii) head-tail pairing for column folding, while some heuristics are proposed for deciding row folding pairs. The time complexity of this algorithm is O($n^{2}$log n) compared to the O($n^{3}$) - O($n^{4}$) of the earlier works.$^[2][3][9]$ For a test PLA with 23 inputs, 19 outputs and 52 products, the number of column folding pairs obtained using this algorithm is 20 which is optimal, as compared to 17 in a previous work.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.626-628
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• 2004

This paper describes an 8-bit CMOS folding A/D converter for set-top box. Modular low-power, high-speed CMOS A/D converter for embedded systems aims at design techniques for low-power, high-speed A/D converter processed by the standard CMOS technology. The time-interleaved A/D converter or flash A/D converter are not suitable for the low-power applications. The two-step or multi-step flash A/D converters need a high-speed SHA, which represents a tough task in high-speed analog circuit design. On the other hand, the folding A/D converter is suitable for the low-power, high-speed applications(Embedded system). The simulation results illustrate a conversion rate of 40MSamples/s and a Power dissipation of 80mW(only analog block) at 2.5V supply voltage.

• 한국실내디자인학회논문집
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• 제26권6호
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• pp.42-52
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• 2017

In this modern world of drastic change, folding architecture was an alternative that offered a novel architectural insight. Today, the folding technique is being used above and beyond architecture, spreading to fashion, lighting, medicine, etc. Especially in the interior space design field, the folding technique is in the limelight as an alternative to create an original space for modern society. However, research and experiments into folding mainly remains at philosophical interpretation or architectural examples, and even these were mostly before the 2000s. Therefore, the present study determined it necessary to look deeply into the post-2000s folding technique focusing on interior space. In this paper, 33 cases of indoor space where folding technique appears are derived, and classified them again by use. The folding technique which was the first step of Sophia Vyzoviti's experiment on her book, "Folding Architecture" was extracted and used as the framework. We summarizes the range of application of folding techniques (interior space in general, floor, wall, ceiling, etc.) and major folding techniques by combining photographs, drawings, and descriptions of the works of the architects. This paper summarizes the characteristics of the space described comprehensively, and draws out the spatial characteristics of the modern interior space where the folding technique appears.

• 한국철도학회논문집
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• 제17권2호
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• pp.87-93
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• 2014

국내에서 운행중인 프랑스 알스톰에서 도입된 고속철도차량인 KTX의 승강문 접이식 발판이 유럽 표준 규격인 EN14752를 따르고 있으나 접이식 스텝 동작 시 발판 형성 폭이 200mm가 되어 국내 20세에서 60세의 발평균 사이즈인 253mm에 미치지 못하고 있다. 신체구조 상 신체 하중은 발 뒤축에 대부분 걸리므로 현재의 발판은 승하차 시 전도나 미끄러짐이 발생 할 수 있는 위험이 존재하고 있으며, 실제 발생을 하고 있다. 이에 기존 차량 조건 내에서 발판의 폭을 확대하여 스텝 개념설계(안)의 구조해석을 수행하고 이의 안전성을 검토하였다.

• 한국기계가공학회지
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• 제10권4호
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• pp.16-21
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• 2011

This paper described an analysis of dynamic mechanism for the industrial two-step folding automatic door using commercial software packages. Two modeling types of operating on the guide rail, the sliding one and the rolling, were adopted to investigate effects of impact force when the door ascends the guide rail. The magnitude of impact force was found very peaklike large over an initial duration of the door's moving up. The amount of damping coefficient for alleviating this shock was controlled to such a moderate degree that the operating conditions can be obtained for the purpose of design. Moreover the behavior of both dynamic stress and deformation were observed for acquirement of structural reliabilities of the combined guide rail and rolling mechanism. This research will be a very useful tool in the near future for the dynamic analysis of the multi-step folding automatic door.

• 소성∙가공
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• 제16권4호
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• pp.239-243
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• 2007

Superplastic forming/diffusion bonding(SPF/DB) has been widely used in the automotive and aerospace industry since it has great advantages to produce very light and strong components. Finite element method(FEM) is used to model the SPF/DB process of 3-sheet sandwich panel to predict the pressure-time curve and to analyze the process parameters. In order to eliminate defects of the part, a new pressurization scheme is proposed. Contrary to the conventional one-step pressurization, which causes the folding at the DB joint, two-step pressurization can eliminate the folding. Effect of pressurization cycle was investigated by using FE analysis and proper pressurization cycle is proposed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.255-258
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• 1999

This paper describes a 40-Msample/s 10-bit CMOS folding and interpolating analog-to-digital converter (ADC). A new 2-step architecture is proposed. The proposed architecture is composed of a coarse ADC bloch for the 6bits of MSBs and a fine ADC block for the remaining 4bits. The amplified folding analog signals in the coarse ADC are selectively chosen for the fine ADC. In the fine ADC, the bubble errors of the comparators are corrected by using the BGM(binary-gray-mixed) code[1] and extra two comparators are used to correct underflow and overflow errors. The proposed ADC was simulated using CMOS 0.25${\mu}{\textrm}{m}$ parameters and occupies 1.0mm$\times$1.0mm. The power consumption is 48㎽ at 40MS/s with 2.5-V power supply. The INL is under $\pm$2.0LSB and the DNL. is under $\pm$1.0LSB by Matlab simulations.

• 소성∙가공
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• 제8권2호
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• pp.135-142
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• 1999

Tube Process(TP) is one of the processes to produce permanent magnets. Advantage claimed for this process is that it can accmplish both densification and anisotropication in one step forming. This process is distinguished from other processes since it uses deformable tube for densification of powder magnets. TP has, however, difficulties in manufacturing permanent magnets from Nd-Fe-B green powder due to folding resulted from large height reduction and localized densification. Therefore, an adequate preform is necessary to reduce folding resulted from large height reduction and localized densification. Therefore, an adequate preform is necessary to reduce folding, lead magnets into almost desired final shape and get uniform densification. In this paper, preform design for TP is carried out without a deformable tube to investigate the behaviour of magnet sinter-forging. Preform design is accomplished to increase the effective magnet area with a near net shape and uniform densification.

• Bulletin of the Korean Chemical Society
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• 제21권3호
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• pp.281-290
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• 2000

We varied recombination method of fenetic algorithm (GA), i.e., crossover step, to compare efficiency of these methods, and to find more optimum GA method. In one method (A), we select two conformations(parents) to be recombined by systematic combination of lowest energy conformations, and in the other (B), we select them in a ratio proportional to the energy of the conformation. Second variation lies in how to select crossover point. First, we select it randomly(1). Second, we select range of residues where internal energy of the molecule does not vary for more than two residues, select randomly among such regions, and we select either thr first (2a) or the second residue (2b) from the N-terminal side, or the first (2c) or the second residue (2d) from the C-terminal side in the selected region for crossover point. Third, we select longest such hregion, and select such residue(as cases 2) (3a, 3b, 3c or 3d) of the region. These methods were tested in a 2-dimensionl lattice system for 8 different sequences (the same ones used by Unger and Moult., 1993). Results show that compared to Unger and Moult's result(UM) which corresponds to B-1 case, our B-1 case performed similarly in overall. There are many cases where our new methods performed better than UM for some different sequences. When cooling factor affecting higher energy conformation to be accepted in Monte Carlo step was reduced, our B-1 and other cases performed better than UM; we found lower energy conformers, and found same energy conformers in a smaller steps. We discuss importance of cooling factor variation in Monte Carlo simulations of protein folding for different proteins. (A) method tends to find the minimum conformer faster than (B) method, and (3) method is superior or at least equal to (1) method.