• 제목/요약/키워드: projection geometry

검색결과 80건 처리시간 0.021초

Wave plate 습분제거기의 형상 변경을 통한 성능 개선 (Performance improvement of wave plate mist eliminator through geometry modification)

  • 노정훈;조민철;이승종
    • 한국입자에어로졸학회지
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    • 제18권4호
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    • pp.97-107
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    • 2022
  • The geometry of popular wave plate type mist eliminator for the wet flue gas desulfurization process was improved, fabricated, and experimentally evaluated. A Mist eliminator is a type of inertial particle collector which collection efficiency is proportional to the velocity of the gas phase. However, as the amount of re-entrainment is also proportional to the gas phase velocity, there is a limitation for the gas phase flow rate. Re-entrainment is one of the most important issues in a mist eliminator and is likely to occur as the input of the liquid phase and flow rate of the gas phase increase. In order to resolve this problem, the projection angle of the improved mist eliminator is set to 30° from the conventional one while maintaining the cross-section. With low flow rate conditions, the modified mist eliminator showed a similar pressure drop and overall collection efficiency. However, with conditions in which re-entrainment is obviously occurring, the modified mist eliminator showed better performance in draining droplets than the conventional one. As a result, the modified mist eliminator showed higher overall collection efficiency.

2차원 유체- 구조물-지반 상호작용해석 전산프로그램 (A Computer Program for 2-D Fluid-Structure-Soil Interaction Analysis)

  • 김재민
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.427-434
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    • 2000
  • This paper presents a computer program for a 2-D fluid-structure-soil interaction analysis. With this computer program the fluid can be modeled by a spurious free 4-node displacement-based fluid element which uses rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and near field soil are discretized by the standard finite elements while the unbounded far field soil are discretized by the standard finite elements while the unbounded far field soil is represented by the frequency dependent dynamic infinite elements. Sine this method models directly the fluid-structure-soil system it can be applied to the dynamci analysis of 2-D liquid storage structure with complex geometry. For the purpose of verification dynamic analyses for tanks on a rigid foundation and on compliant embankment are carried out. Comparison of the present results with those by ANSYS program shows good agreement.

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2차원 유체-구조뭍-지반계의 지진응답해석 (Earthquake Response Analysis for 2-D Fluid-Structure-Soil Systems)

  • 윤정방;장수혁;김재민;홍선기
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
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    • pp.289-296
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    • 2000
  • This paper presents a method of seismic analysis for a 2-D fluid-structure-soil interaction systems. With this method, the fluid can be modeled by spurious free 4-node displacement-based fluid elements which use rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and the near-field soil are discretized by the standard 2-D finite elements, while the unbounded far-field soil is represented by the dynamic infinite elements in the frequency domain. Since this method directly models the fluid-structure-soil interaction systems, it can be applied to the dynamic analysis of a 2-D liquid storage structure with complex geometry. Finally, results of seismic analyses are presented for a spent fuel storage tank embedded in a layered half-space and a massive concrete dam on a layered half-space.

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Critical Review of Current Trends in ASIC Writing and Layout Analysis

  • Vikram, Abhishek;Agarwal, Vineeta
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권2호
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    • pp.236-250
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    • 2016
  • Electrical Designs for Application Specific Integrated Circuits (ASIC) has undergone a change recently with the advent of the sub-wavelength lithography. The optical projection with 193 nm wavelength has been further extended with the use of immersion and other techniques. The competing trends for printing smaller design features have been discussed in this paper with the discussion of the electrical layout analysis to find unfriendly design features. The early knowledge of the unfriendly design features allows remedial actions in time for better yield on the wafer. There are existing standard design qualification criteria being used in the design and fabrication community, but they seem to be insufficient to guarantee defect free designs. This paper proposes an integrated approach for screening the layout with multiple aspects: layout geometry based, graphical analysis and process model based verification. The results have been discussed with few example design features from the 28nm design layout.

2차원 유체-구조물-지반계의 지진응답해석 (Earthquake Response Analysis for 2-D Fluid-Structure-Soil Systems)

  • 윤정방;장수혁;김재민
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.132-137
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    • 2001
  • This paper presents a method of seismic analysis for a 2-D fluid-structure-soil interaction systems. With this method, the fluid can be modeled by spurious free 4-node displacement-based fluid elements which use rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and the near-field soil are discretized by the standard 2-D finite elements, while the unbounded far-field soil is represented by the dynamic infinite elements in the frequency domain. Since this method directly models the fluid-structure-soil interaction systems, it can be applied to the dynamic analysis of a 2-D liquid storage structure with complex geometry. Finally, results of seismic analyses are presented for a spent fuel storage tank embedded in a layered half-space and a massive concrete dam on a layered half-space.

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Neural Network를 이용한 고무 타이어의 돌출 문자 인식 (Raised characters rocognition of rubber tires using neural network)

  • 김경민;박중조;김민기;박귀태
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.864-869
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    • 1993
  • This paper presents the problem of automatically recognizing embossed or molded characters which are raised from the side wall on rubber tire. In the tire image objects have approximately the same gray-value as the background and because of the tire geometry, illumination of the surface is nonhomogenous. Therefore it is difficult to recognize the raised tire character. In this paper, for describing the process of processing three steps have been proposed: 1) MIN & MAX smoothing operation filter, 2) edge detection algorithm using modified laplacian operator, 3) noise rejection. Afterwards, segmentation is done to attain characters from tire image by projection method. The recognition of the characters in the segmented image is carried out by using multilayered neural network, which is insensitive to the noise.

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UV-LED를 이용한 광조형 장치 개발 (Development of Stereolithography Apparatus by using UV-LED)

  • 윤해룡;고태조;김호찬
    • 한국기계가공학회지
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    • 제13권2호
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    • pp.15-20
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    • 2014
  • The stereolithography(SL) process is a type of fabrication technology which relies on photopolymerization. It has a relatively simple fabrication process and a resolution of several tens of ${\mu}m$. Recently, SL technology has been applied to various areas, such as bioengineering and MEMS devices, due to the development of advanced materials. This technologycan be divided intothe scanning(SSL) and projection (PSL) types. In this paper, in stereolithography, parts are fabricated by curing photopolymeric resins with light. The application of stereolithography can now include fabricated parts. This process, called stereolithography, can fabricate parts by taking into account theirdegrees of geometry complexity. In particular, UV-LED stereolithography can perform quite rapid fabrication in which specific cross-sections are cured upon exposure to light.

Selective laser melted titanium implants: a new technique for the reconstruction of extensive zygomatic complex defects

  • Rotaru, Horatiu;Schumacher, Ralf;Kim, Seong-Gon;Dinu, Cristian
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제37권
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    • pp.1.1-1.6
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    • 2015
  • The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

ESTIMATION OF PEDESTRIAN FLOW SPEED IN SURVEILLANCE VIDEOS

  • Lee, Gwang-Gook;Ka, Kee-Hwan;Kim, Whoi-Yul
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.330-333
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    • 2009
  • This paper proposes a method to estimate the flow speed of pedestrians in surveillance videos. In the proposed method, the average moving speed of pedestrians is measured by estimating the size of real-world motion from the observed motion vectors. For this purpose, pixel-to-meter conversion factors are calculated from camera geometry. Also, the height information, which is missing because of camera projection, is predicted statistically from simulation experiments. Compared to the previous works for flow speed estimation, our method can be applied to various camera views because it separates scene parameters explicitly. Experiments are performed on both simulation image sequences and real video. In the experiments on simulation videos, the proposed method estimated the flow speed with average error of about 0.1m/s. The proposed method also showed a promising result for the real video.

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유클리드 카메라 보정을 하지 않는 비디오 기반 증강현실 (Video-Based Augmented Reality without Euclidean Camera Calibration)

  • 서용덕
    • 한국컴퓨터그래픽스학회논문지
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    • 제9권3호
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    • pp.15-21
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    • 2003
  • An algorithm is developed for augmenting a real video with virtual graphics objects without computing Euclidean information. Real motion of the camera is obtained in affine space by a direct linear method using image matches. Then, virtual camera is provided by determining the locations of four basis points in two input images as initialization process. The four pairs of 2D location and its 3D affine coordinates provide Euclidean orthographic projection camera through the whole video sequence. Our method has the capability of generating views of objects shaded by virtual light sources, because we can make use of all the functions of the graphics library written on the basis of Euclidean geometry. Our novel formulation and experimental results with real video sequences are presented.

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