• Title/Summary/Keyword: Focusing Technique

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Optimization of Optics Design for 3D Laser Scanner (3차원 부품 레이저 용접용 스캐너 광학 최적설계)

  • Choi, Hae Woon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.96-101
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    • 2020
  • In this paper, we present the results of our research to perform 3D laser scanning functions by adding a focusing lens to a conventional 2D laser scanner. For the optical design, the ray-tracing technique was used along with a total of four lenses as the variable incident focusing lens, the collimating lens, and the F-Theta lens. As design variables, the curvature of the incident focusing lens (Lens #1) was assumed to be us, l mm and sumed mm, and the incident angles were set at 0cidenus, l. In addition, the distance between the focusing lens and the collimating lens was set to vary from 5 mm to 15 mm. When the incident focal length was varied from 5 mm to 15 mm, the exit focal length was calculated to vary from 67.5 mm to 56.8 mm for the lens with R = 100 mm and from 108.5 mm to 99.0 mm for the lens with R = 150 mm. When the incident angle was 0°, the focal aberration was only slightly observable at 10㎛ in both the x- and y-direction. At 7.5° was the focal aberration of approximately 20~50㎛ was measured at 20㎛. To investigate the chromatic aberration of the designed optical device, the distortion of the focus was observed when the 550 nm beam was simulated on lens designed for a 980 nm wavelength.

Spatial Characteristics by Application of Contemporary Interior Space with Folding Technique (폴딩 기법이 나타나는 현대 실내공간의 용도별 공간 특성)

  • Lim, Jong-Soo;Kim, Jin-Woo
    • Korean Institute of Interior Design Journal
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    • v.26 no.6
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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.

Development of MRI Scanning Technique that is Comfortable for Patients with Anxiety Disorder

  • Cho, Moo-Seong;Cho, Jae-Hwan;Chang, Yong-Min;Cho, Yong-Ho;Zeon, Seok-Kil;Dong, Kyung-Rae;Chung, Woon-Kwan;Lee, Hae-Kag;Kim, Hyun-Ju;Bae, Jae-Young;Ahn, Jae-Ouk;Lee, Sang-Jeong
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.350-362
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    • 2011
  • The principal objective of this study was to develop a scanning technique that helps patients reduce their anxiety and relax their physical tension in the MRI system. The study targeted 10 healthy persons with no medical history of anxiety disorder in the past and with no current clinically diagnosed anxiety disorder, as well as 10 patients who were currently experiencing an anxiety disorder during the MRI scanning. The focusing board assembly was self-manufactured to conduct a clinical experiment via MRI scans. As a method to confirm the efficacy of the experiment, the bio meter was used to measure brainwaves from the study targets that were divided into the normal person group (A), who felt no anxiety in the MRI system and the experimental group, (B) who did experience anxiety in the MRI system. The two groups were compared between the cases in which the focusing board assembly was used and not used after measurements were conducted using the model MRI system and the bio meter. According to the comparison and analysis results, low measurements of the ${\alpha}$ wave indicate highly effective relaxation of tension. In the normal person group, the ${\alpha}$ wave measurement showed almost no difference between cases in which the focusing board assembly was used and cases in which it was not used. In the experimental group, the $\acute{a}$ wave measurements were lower in cases in which the focusing board assembly was used than in cases in which the focusing board assembly was not used; this was indicative of a profound relaxation effect.

Development of the Advanced NDI Technique Using an Alternating Current : the Evaluation of surface crack and blind surface crack and the detection of defects in a field component (교류전류를 이용한 새로운 비파괴탐상법의 개발;표면결함과 이면결함의 평가 및 실기 부재의 결함 검출)

  • Kim. H.;Lim, J.K.
    • Journal of Welding and Joining
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    • v.13 no.2
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    • pp.42-52
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    • 1995
  • In the evaluation of aging degradation on the structural materials based on the fracture mechanics, the detection and size prediction of defect are very important. Aiming at nondestructive detection and size prediction ol defect with high accuracy and resolution, therefore, an lnduced Current Focusing Potential Drop(ICFPD) technique has been developed. The principle of this technique is to induce a focusing current at an exploratory region by an induction wire flowing an alternating current(AC) that is a constant ampere and frequency. Defects are assessed with the potential drops that are measured the induced current on the surface of metallic material by the potential pick-up pins. In this study, the lCFPD technique was applied for evaluating the location and size of the surface crack and blind crack made in plate specimens, and also for detecting the defects existing in valve, a field component, that were developed by SCC etc. during the service. The results of this present study show that surface crack and blind crack are able to defect with potential drop. these cracks are distinguished with the distribution of potential drop, and the crack depths can be estimated with each normalized potential drop that are parameters estimating the depth of each type crack. In the field component, the defects estimated by experiment result correspond with those in the cutting face of the measuring point within a higher sensitivity.

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Effect of Stepwise Communication Education Program using SBAR among Nursing Students: Focusing on Scenarios and Nursing Case-based Role Playing (간호대학생의 SBAR를 이용한 단계별 의사소통 교육프로그램의 효과: 시나리오와 간호사례기반 역할극을 중심으로)

  • Noh, Yoon Goo;Lee, Insook
    • The Journal of Korean Academic Society of Nursing Education
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    • v.24 no.2
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    • pp.115-126
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    • 2018
  • Purpose: This study intends to examine the effects of a stepwise communication education program among nursing college students, focusing on scenarios and nursing case-based role playing. Methods: The study design was a one-group repeated measure ANOVA. Participants were 27 nursing students in practice. Students participated in 5-week stepwise communication education program using SBAR; including 1 week of lecture education, 4 weeks of scenarios and nursing case-based role playing. The data were collected at each level of the education process: pre-education, after 1 week of lectures, and after completion of scenarios and nursing case-based role playing. Repeated measures ANOVA was used to determine changes in SBAR technique knowledge and communication self-efficacy. Results: The stepwise communication education program using SBAR was effective in increasing SBAR technique knowledge, and communication self-efficacy. The lecture-based education was effective only in the area of SBAR technique knowledge and its subscale, attitudes towards SBAR. However, scenarios and nursing case-based role playing was broadly effective across communication self-efficacy, SBAR technique knowledge, and its subscale, knowledge of the SBAR. Conclusion: Based on this study, we propose that it is necessary to confirm the effect of long-term SBAR communication education using scenarios and nursing case-based role playing in nursing students' practice.

Effect of Board Independence on Performance: Interaction Effect with CEO's Firm Specific Experience (이사회의 독립성이 기업성과에 미치는 영향 : CEO의 기업 내 경력과의 상호작용효과에 대한 연구)

  • Yoo, Jae-Wook;Kim, Kwang-Soo
    • Management & Information Systems Review
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    • v.24
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    • pp.1-24
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    • 2008
  • This paper examines the direct effects of board independence and also its interaction effects with CEO's firm specific experience on firm performance. The findings in an hierarchial regression analysis of multiyear sample of computer hardware companies indicate that independent, outsider directors are beneficial to firms' performance when CEO has high-level of firm specific experience whereas it is harmful when CEO has low-level of firm specific experience. However, separating the positions of board chair and chief executive officer that has been used as another means for increasing board independence does not influence to firms' performance. These findings imply that researchers in corporate governance should reconsider the relative weight placed on directors' monitoring and assistance role. Rather than focusing predominantly on directors' willingness or ability to control executives, in future research scholars should yield more productive results by focusing on the assistance directors provide in bringing valued resources to the CEOs and in serving as a source of advice and counsel especially for CEO's improvement of management technique. In addition, they should pay more attention on identifying intervening processes between board and firm performance in order to provide optimal governance mechanisms and configurations to practitioners.

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Reconstructing Flaw Image Using Dataset of Full Matrix Capture Technique (Full Matrix Capture 데이터를 이용한 균열 영상화)

  • Lee, Tae-Hun;Kim, Yong-Sik;Lee, Jeong-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.37 no.1
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    • pp.13-20
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    • 2017
  • A conventional phased array ultrasonic system offers the ability to steer an ultrasonic beam by applying independent time delays of individual elements in the array and produce an ultrasonic image. In contrast, full matrix capture (FMC) is a data acquisition process that collects a complete matrix of A-scans from every possible independent transmit-receive combination in a phased array transducer and makes it possible to reconstruct various images that cannot be produced by conventional phased array with the post processing as well as images equivalent to a conventional phased array image. In this paper, a basic algorithm based on the LLL mode total focusing method (TFM) that can image crack type flaws is described. And this technique was applied to reconstruct flaw images from the FMC dataset obtained from the experiments and ultrasonic simulation.

Nondestructive Evaluation of 2-Dimensional Surface Crack in Ferromagnetic Metal and Paramagnetic Metal by ICFPD Technique (집중유도형 교류전위차법에 의한 강자성체 및 상자성체의 2차원 표면결함의 비파괴평가)

  • 김훈;장자철웅;정세희
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.5
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    • pp.1202-1210
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    • 1995
  • Aiming at nondestructive evaluation of defect with high accuracy and resolution, ICFPD(Induced Current Focusing Potential Drop) technique was newly developed. This technique can be applied for locating and sizing of defects in components with not only simple shape such as plain surface but also more complex shape and geometry such as curved surface and dissimilar joing. This paper describes the principle of ICFPD technique and also the results of 2-dimensional surface crack in ferromagnetic metal(A508 Cl. III steel) and paramagnetic metal (pure aluminum and stainless 304 steel) measured by this technique. Results are that surface defects in each specimen are detected with the difference of potential drop, and potential drops are distributed a similar shape for each metal and each depth. The normalized potential drop ( $V_{\delta}$2/$^{t}$ / $V_{{\delta} 2}$$^{-1}$) max. in the vicinity of defect is varied with the depth of defect. Therefore, ICFPD technique can be used for the evaluation of defect not only in ferromagnetic metal but also in paramagnetic steel..

The Types and Characteristics of Golden Decoration Technique used in the Chinese Fabrics - Focused on the Fabrics from Dang to Cheong Dynasty Era - (중국 직물에 사용된 금장식기법의 유형과 특성 - 당대${\sim}$청대직물을 중심으로 -)

  • Jang, Hyun-Joo;Ko, Soon-Hee
    • Journal of the Korean Society of Costume
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    • v.57 no.9
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    • pp.1-15
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    • 2007
  • The purpose of this study is to classify the types of and to examine the characteristics of the golden decoration technique used for expressing patterns on the costumes from Dang dynasty to Cheong dynasty era. In order to classify the types of the golden decoration technique and to examine its characteristics, literature review, focusing on documents and records of China, and investigation on the relics from Dang to Cheong Dynasty era were conducted. The types of decoration technique using gold include china JigGeum (brocade technique), InGeum (attaching gold powder and flake technique), GeumSaJaSu (embroidery technique), GeumSaTapestry, mixed technique. Interestingly, it was newly found in this study that embroidery with golden thread was used in the GeumSaTapestry technique and that there were some cases of the mixture of 2-3 gold decoration technique. The GeumSajaSu technique was used the most frequently from Dang dynasty to Yo dynasty era. However, its use had decreased enormously while the use of JigGeum had increased a lot since Geum dynasty era. The mixture of 2-5 techniques was used frequently in JigGeum, GeumSaJaSu, and GeumSaTapestry, but not used in InGeum. Particularly, the mixture technique was the most frequently used in the GeumSaTapestry, which expresses by composition of paintings. All four methods were used the mostly frequently in costumes, while GeumSaJaSu and GeumSaTapestry were generally used for home accessories. InGeum and GeumSaJaSu were used a lot for gaze and leno fabrics such as Sa or Ra, while JigGeum was mostly used for satin weaved fabrics like Dan.

Numerical Evaluation of a Radially Variable Cell Density Strategy for Improving Light-off Performance: Focusing on Light-off Catalyst (자동차용 촉매변환기의 활성화 성능 향상을 위한 횡방향 가변 셀 밀도법의 수치적 평가: 활성화 촉매변환기를 중심으로)

  • 정수진;김우승
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.1
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    • pp.115-124
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    • 2002
  • The optimum design of auto-catalyst needs a good compromise between the pressure drop and flow distribution in the monolith. One of the effective methods to achieve this goal is to use the concept of radially variable cell density. However, there has been no study of evaluating the usefulness of this method on light-off catalyst. We have computationally investigated the effectiveness of variable cell density technique applied to the light-off catalyst using a three-dimensional integrated CFD model. in which transient chemical reacting calculations are involved. Computed results show that variable cell density technique can reduce the accumulated emissions of CO and HC during the early 100sec of FTP cycle by 86.78 and 80.87%, respectively, The effect of air-gap between the monoliths has been also examined. It is found that air-gap has a beneficial effect on reducing pressure drop and cold-start emissions.