• 제목/요약/키워드: field of view

검색결과 2,396건 처리시간 0.036초

정전형 8중극 비점수차 보정기가 내장된 극초소형 마이크로컬럼의 구조 설계 연구 (Study on the Structural Design of an Ultra-miniaturized Microcolumn with a Built-in Electrostatic Octupole Stigmator)

  • 오태식
    • 반도체디스플레이기술학회지
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    • 제22권3호
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    • pp.52-61
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    • 2023
  • We designed a novel ultra-miniaturized microcolumn structure having an stigmator to significantly improve throughput per unit time, which is the biggest disadvantage of microcolumns. We adopted the structure of the stigmator in the form of an electrostatic octupole electrode, and used an electrostatic quadrupole deflector with a relatively simple structure considering the increase in wiring due to the introduction of the stigmator. We have dramatically reduced the effect of astigmatism that occurs when the electron beam probe is scanned to the periphery of the target by introducing the stigmator between the control electrode and the deflector. As our numerical analysis simulation results, the field of view obtained as a result of this study is about 46.3% improved compared to our previous study, and the electron beam probe size of less than 10 nm was achieved in the entire field of view.

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한계변형률 개념을 활용한 터널안전성 평가 (Tunnel Safety Assessment by using the Concept of the Critical Strain in the Ground)

  • 박시현;박성근
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.571-576
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    • 2010
  • In this study, an application method of critical strains concept for tunnels' safety by using the values of measured displacements which are obtained in the field is discussed. The aim is to: (1) study on the engineering meanings of critical strains concept by reviewing the previous researches and application examples with measured displacement values; (2) study on the engineering reasonability of critical strains concept with the view point of a tunnel engineering and a geotechnical engineering; (3) study on the features of ground deformation due to tunneling and reciprocal relation between total displacement and measured displacement; (4) evaluate a tunnel safety by using domestic measurements collected in the field; and (5) re-evaluate the control criteria which were previously used in the field, with the view point of critical strains concept. Consequently, it was confirmed that critical strains in the ground has a reasonability and a possibility of unified or common concept with the view point of a tunnel engineering.

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Impact Angle Control Guidance Synthesis for Evasive Maneuver against Intercept Missile

  • Yogaswara, Y.H.;Hong, Seong-Min;Tahk, Min-Jea;Shin, Hyo-Sang
    • International Journal of Aeronautical and Space Sciences
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    • 제18권4호
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    • pp.719-728
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    • 2017
  • This paper proposes a synthesis of new guidance law to generate an evasive maneuver against enemy's missile interception while considering its impact angle, acceleration, and field-of-view constraints. The first component of the synthesis is a new function of repulsive Artificial Potential Field to generate the evasive maneuver as a real-time dynamic obstacle avoidance. The terminal impact angle and terminal acceleration constraints compliance are based on Time-to-Go Polynomial Guidance as the second component. The last component is the Logarithmic Barrier Function to satisfy the field-of-view limitation constraint by compensating the excessive total acceleration command. These three components are synthesized into a new guidance law, which involves three design parameter gains. Parameter study and numerical simulations are delivered to demonstrate the performance of the proposed repulsive function and guidance law. Finally, the guidance law simulations effectively achieve the zero terminal miss distance, while satisfying an evasive maneuver against intercept missile, considering impact angle, acceleration, and field-of-view limitation constraints simultaneously.

Chimera 격자기법을 이용한 Car-like body 주위 유동장 및 공력소음 해석 (Analysis of flow and aeroacoustic field around a car-like body with Chimera grid technique)

  • 안민기;박원규;홍성훈
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1998년도 춘계 학술대회논문집
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    • pp.99-109
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    • 1998
  • This paper describes the analysis of flow and aeroacoustic field around a car-like body. The governing equations, 3-D unsteady incompressible Navier-Stokes equations, are solved with the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror, After the flow field analysis has been converged, the aerodynamic noise analysis of the side-view mirror has been performed by solving Ffowcs Williams and Hawkings equation. From the present numerical simulation, the A- and C-pillar vortex are evidently shown and the aerodynamic noise level induced by the side-view mirror is predicted to about 100dB.

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LabVIEW 기반의 가스터빈 데이터 취득 시스템 (Gas Turbine Data Acquisition System based on LabVIEW)

  • 강필순;차동진;정재화;서석빈;안달홍
    • 한국정보통신학회논문지
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    • 제10권6호
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    • pp.1082-1087
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    • 2006
  • 본 논문에서는 LabVIEW 기반의 가스터빈 데이터 취득 및 모니터링 시스템을 제안한다. C-Tune DAS로 명명된 실시간 모니터링 시스템은 가스터빈의 유지/보수시 실시간 동작을 분석하는데 중요한 역할을 담당한다. LabVIEW 소프트웨어는 고유 기능별로 데이터 취득부, 데이터 분석 및 표시부, 데이터 저장부로 구성된다. 데이터 취득부를 통해 PMS 서버와 두 대의 cFP로부터 데이터를 취득한다. 복합화력 발전소의 상용 가스터빈에 적용하여 개발된 모니터링 시스템의 타당성을 검증한다.

Impact of 0.35 T Magnetic Field on Dose Calculation for Non-small Cell Lung Cancer Stereotactic Radiotherapy Plans

  • Jaeman Son;Sung Young Lee;Chang Heon Choi;Jong Min Park;Jung-in Kim
    • Journal of Radiation Protection and Research
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    • 제48권3호
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    • pp.117-123
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    • 2023
  • Background: We investigated the impact of 0.35 T magnetic field on dose calculation for non-small cell lung cancer (NSCLC) stereotactic ablative radiotherapy (SABR) in the ViewRay system (ViewRay Inc.), which features a simultaneous use of magnetic resonance imaging (MRI) to guide radiotherapy for an improved targeting of tumors. Materials and Methods: Here, we present a comprehensive analysis of the effects induced by the 0.35 T magnetic field on various characteristics of SABR plans including the plan qualities and dose calculation for the planning target volume, organs at risk, and outer/inner shells. Therefore, two SABR plans were set up, one with a 0.35 T magnetic field applied during radiotherapy and another in the absence of the field. The dosimetric parameters were calculated in both cases, and the plan quality indices were evaluated using a Monte Carlo algorithm based on a treatment planning system. Results and Discussion: Our findings showed no significant impact on dose calculation under the 0.35 T magnetic field for all analyzed parameters. Nonetheless, a significant enhancement in the dose was calculated on the skin surrounding the tumor when the 0.35 T magnetic field was applied during the radiotherapy. This was attributed to the electron return effect, which results from the deviation of the electrons ejected from tissues upon radiation due to Lorentz forces. These returned electrons re-enter the tissues, causing a local dose increase in the calculated dose. Conclusion: The present study highlights the impact of the 0.35 T magnetic field used for MRI in the ViewRay system for NSCLC SABR treatment, especially on the skin surrounding the tumors.

KODISA Academic Journal Strategy: Synopsis in 2016 and Vistas of the Future

  • Hwang, Hee-Joong;Youn, Myoung-Kil
    • 유통과학연구
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    • 제14권4호
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    • pp.5-11
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    • 2016
  • Purpose - The Education Ministry has plans to select top 10 percent academic journals among the domestic registration journals in NRF(National Research Foundation of Korea), and designate them as outstanding academic journals. To reflect this trend, KODISA has set its sights on paper publication rate and citation index with pushing forward globalism. First, this study will arrange the process of globalism and the current state of paper submission, and propose the direction of improvement in academic journals through understanding the characteristics of each major field. Research design, data, and methodology - KODISA has preceeded in examining and publishing research papers related to distribution field through indirectly or stimulating academic advancement. KODISA covers the whole fields in social science as well as in business administration and economics that associated with distribution field not limiting only within the range of distribution field. That is, the new subject that contributes to the progress in distribution field with original research can be a priority criteria in KODISA journal publication. Results - The major fields in papers published in KODISA can be categorized broadly as distribution field with economic and business administration point of view. Therefore, the distribution field with economic point of view includes the issues such as regulations, system, industry, market environment, distribution system, trade, and macroeconomics, etc. The business administration point of view in distribution includes distribution strategy, distribution organization, and distribution channel from the perspectives of the firm, etc. Conclusions - The aim of KODISA in 2020 is to be a global academic journal as SCI level of each journal in KODISA, JDS(Registration journal), IJIDB(Registration candidate), EAJBM(Registration candidate), JAFEB(Cabell's Registration journal). The KODISA journals have already settled as the largest academic society and journals of Korea in 2016 currently from humanities and social sciences area by the most gross in publication circulation, volumes, and types. Hereafter, KODISA will focus on the improvement for the objective indicators such as Impact Factor and Centrality index as qualitative growth as well as quantitative expansion. By doing so, KODISA will be a forum for developmental academic debate with attracting the world's greatest scholars' papers. Furthermore, they will be recognized journals and grow as the first-rate academic journals inside and outside of Korea.

Optical Performance Measurement of the MATS Satellite

  • Park, Woojin;Hammar, Arvid;Lee, Sunwoo;Chang, Seunghyuk;Pak, Soojong
    • 천문학회보
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    • 제43권1호
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    • pp.49.1-49.1
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    • 2018
  • The MATS (Mesosphere Airglow/Aerosol Tomography Spectroscopy) satellite is the next Swedish science microsatellite. We report optical performance test results of the limb telescope, which is the major payload. This telescope is designed with "linear astigmatism-free" (LAF) off-axis optical system in order to have high optical performance across the wide field of view. We measured Modulation Transfer Function (MTF) and Encircled Energy Diameter (EED) of the limb telescope. Full field imaging tests show expected results without linear astigmatism across the full field of view ($5.67^{\circ}{\times}0.91^{\circ}$). Since the amount of stray light is from the earth and the sun, we also simulated and measured the stray light in the field image.

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Multiple Vision Based Micromanipulation System for 3D-Shaped Micro Parts Assembly

  • Lee, Seok-Joo;Park, Gwi-Tae;Kim, Kyunghwan;Kim, Deok-Ho;Park, Jong-Oh
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.103.5-103
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    • 2001
  • This paper presents a visual feedback system that controls a micromanipulator using multiple microscopic vision information. The micromanipulation stations basically have optical microscope. However the single field-of-view of optical microscope essentially limits the workspace of the micromanipulator and low dept-of-field makes it difficult to handle 3D-shaped micro objects. The system consists of a stereoscopic microscope, three CCD cameras, the micromanipulator and personal computer. The use of stereoscopic microscope which has long working distance and high depth-of-field with selective field-of-view improves the recognizability of 3D-shaped micro objects and provides a method for overcoming several essential limitations in micromanipulation. Thus, visual feedback information is very important in handling micro objects for overcoming those limitations and provides a mean for the ...

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