• Title/Summary/Keyword: reverse profile

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A Study on the Design of Diesel Engine Cam Profile (디젤엔진용 캠의 형상 설계에 관한 연구)

  • Lee, Wan-Ha;Song, Hwa-Seop;Hong, Jun-Hee
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.3
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    • pp.104-110
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    • 2006
  • It is a study on the design of a cam profile for diesel engine SOHC. It is used a reverse engineering method without the usual copy processing. It draws up the contour data from an actual cam and processes by CNC. The profile of the cam is reappeared to be up to operational specifications that are the opening and shutting time, lift, speed and acceleration of the inhalation and escape valves. While the cam operating, the noise and vibration are occurred by the sudden change of speed. The new design of cam profile is suitable fur the valve operations to be smooth. We propose the design method of a cam profile far the reappearance of an actual cam. It is proved to be the propriety about the design of the cam profile through the processing, measurement, and comparison of the cam profile.

THE STRUCTURE OF THE MANDIBULAR CONDYLE IN THE PANORAMIC RADIOGRAPH (파노라마방사선 사진에서의 하악과두구조)

  • Choi Soon-Chul
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.20 no.2
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    • pp.163-167
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    • 1990
  • The author has evaluated the panoramic image of the mandibular condyle according to its horizontal condylar angle (0˚, 10˚, 20°, 30°, 40°) and mandibular position (standard, 25㎜ forward and reverse position). The results were as follows: 1. The larger the horizontal condylar angle was, the larger the horizontal magnification was in all positions. 2. In case of small horizontal condylar angle, profile view could be obtained in 25㎜ forward and reverse position. 3. In case of large horizontal condylar angle, profile view could not be obtained in any positions.

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Development of an Internal Measurement System for the Footwear using Laser Sensor (레이저 센서를 이용한 신발 내측 측정장치 개발)

  • 이지용;김민주;이승수;박재덕;전언찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.281-284
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    • 2004
  • This paper presents studies on the development of an internal measurement system for the footwear using laser sensor. The measurement system gains to the height of the profile at internal footwear. It accomplishes the 3-axises control which uses ball screws, L-M guides and stepping motors. It is used a laser sensor at the measurement of the distance, and Labview is used for the control and the measurement. We can get the profile through reverse engineering for the LAST. The data of profile is fixed a heigh of the LAST. Then, we try to verify as compare the profile with one which is collected by Internal measurement system..

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Tunnel Reverse Engineering Using Terrestrial LiDAR (지상LiDAR를 이용한 터널의 Reverse Engineering)

  • Cho, Hyung Sig;Sohn, Hong Gyoo;Kim, Jong Suk;Lee, Suk Kun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6D
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    • pp.931-936
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    • 2008
  • Surveying by using terrestrial LiDAR(Light Detection And Ranging) is more rapid than by using total station which enables tunnel section profile surveying to be done in suitable time and minimize centerline error, occurrence of overcut and undercut. Therefore, utilization of terrestrial LiDAR has increased more and more in section profile survey and measurement field Moreover, studies of terrestrial LiDAR for accurate and efficient utilization is now ongoing vigorously. Average end area formula, which was generally used to calculate overcut and undercut, was compared with existing methods such as total station survey and photogrammetry. However, there are no criteria of spacing distance for calculating overcut and undercut through terrestrial LiDAR surveying which can acquire 3D information of whole tunnel. This research performed reverse engineering to decide optimal spacing distance when surveying tunnel section profile by comparing whole tunnel volume and tunnel volume in difference spacing distance. This result was utilized to produce CAD drawing for the test tunnel site where there is no design drawings. In addition to this, efficiency of LiDAR and accuracy of CAD drawing was compared with targetless total station surveying of tunnel section profile. Finally, error analysis of target coordinate's accuracy and incidence angle was done in order to verify the accuracy of terrestrial LiDAR technology.

Study of Reverse Design for an Axial Turbine Blade Profile and Design Parameters for Designing Blade Geometry (축류형 터빈 익형의 역설계 및 형상설계를 위한 설계변수에 관한 연구)

  • Cho, Soo-Yong;Oh, Koon-Sup;Choi, Bum-Seog
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.2 s.7
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    • pp.7-14
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    • 2000
  • For a given axial turbine blade, reverse design method is developed to improve blade efficiency, optimize blade profile, or repair parts etc. In this process, design parameters for designing axial turbine blade are induced. The induced design parameters are as follows; ellipse at leading edge, radios of trailing edge, axial chord, tangential chord, wedge angle at the inlet, and unguided turning angle. Suction and pressure surfaces of turbine blade are described by cubic polynomials. Two sample blades we chosen and their blade profiles are measured at the mean radius. Values of design parameters for sample blades are obtained by the reverse design method. Re-designed blade profiles using calculated design parameters are compared with the measured data, and they show good agreement. So, the developed design method could be applied to design general turbine blades. Various blade shapes are designed, and they show that designed blade profiles can be adjusted by controlling design parameters.

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Load deformation characteristics of shallow suspension footbridge with reverse profiled pre-tensioned cables

  • Huang, Ming-Hui;Thambiratnam, David P.;Perera, Nimal J.
    • Structural Engineering and Mechanics
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    • v.21 no.4
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    • pp.375-392
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    • 2005
  • Cable supported structures offer an elegant and economical solution for bridging over long spans with resultant low material content and ease of construction. In this paper, a model of shallow cable supported footbridge with reverse profiled pre-tensioned cables is treated and its load deformation characteristics under different quasi-static loads are investigated. Effects of important parameters such as cable sag and pre-tension are also studied. Numerical results performed on a 3D model show that structural stiffness of this bridge (model) depends not only on the cable sag and cross sectional areas of the cables, but also on the pre-tension in the reverse profiled cables. The tension in the top supporting cables can be adjusted to a high level by the pre-tension in the reverse profiled bottom cables, with the total horizontal force in the bridge structure remaining reasonably constant. It is also evident that pre-tensioned horizontally profiled cables can greatly increase the lateral horizontal stiffness and suppress the lateral horizontal deflection induced by eccentric vertical loads.

Tool Mark Removal Method of Aspherical Glass tens Mold by Reverse-rotational Eccentric Motion (역회전 편심 운동 방식에 의한 비구면 유리렌즈 금형의 공구마크 제거 방법에 관한 연구)

  • Lee, H.C.;Kim, J.U.;Kang, H.H.;Kim, D.S.
    • Transactions of Materials Processing
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    • v.18 no.2
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    • pp.172-176
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    • 2009
  • In this paper, new aspherical surface polishing mechanism is suggested to polish aspherical glass lens mold by both airbag polishing tool and reverse-rotational eccentric motion. Up to now, conventional aspherical lens polishing method by the small tool polishing uses the aspherical surface profile and the trajectory of the polishing tool is also controlled. However, full contact concept by airbag polishing tool and no position control make the easy polishing setup and does not need aspherical design profile. An aspherical lens polishing machine was made for this study and a tool mark removal experiment fur the fine-grounded lens mold was successfully performed.

Corrective machining Algorithm for Improving the Motion Accuracy of Hydrostatic Table (유정압테이블의 정밀도향상을 위한 수정가공 알고리즘)

  • 박천홍;이찬홍;이후상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.380-384
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    • 1997
  • For improving the motion accuracy of hydrostatic table, corrective machining algorithm is proposed in this paper. The algorithm consists of three main processes. Reverse analysis is performed firstly to estimate rail profile from measured linear and angular motion error, in the algorithm. For the next step, correctwe machining information is decided as referring to the estimating rail profile. Finally, motion errors on correctively machined rail are analized by using motion error analysls method proposed in the previous paper. These processes can be rtcrated if the analized motion errors are worse than target accuracy. In order to verify the validity of the algorithm theoretically, motion errors by the estimated rail after corrective machining are compared with motion errors by true rail assumed as the measured value. Estimated motion errors show good agreement with assumed values, and it is confirmed that the algorithm IS effective to acquire the corrective machming information to improve the accuracy of hydrostatic table.

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Reverse Takotsubo cardiomyopathy with left bundle branch block after anesthesia induction in a patient with subarachnoid hemorrhage: a case report

  • Choi, Eun Kyung;Kim, Jong-Hoon;Kim, Minhyun
    • Journal of Yeungnam Medical Science
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    • v.39 no.2
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    • pp.172-177
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    • 2022
  • Takotsubo or reverse Takotsubo cardiomyopathy is a well-known cardiac complication of subarachnoid hemorrhage (SAH) that shows transient left ventricular wall motion abnormalities with electrocardiogram (ECG) changes. ST change followed by T inversion is a common ECG finding complicated with these disorders, left bundle branch block (LBBB) may be a potential ECG pattern which is seen. In this case, we describe the clinical profile and outcomes of a patient with LBBB and reverse Takotsubo cardiomyopathy after anesthetic induction, which was scheduled as an emergent external ventricular drainage after SAH. This is the first report of an LBBB pattern in reverse Takotsubo cardiomyopathy.

Strength prediction of steady laminar fluid with normal velocity distribution: A simplified truncation technique

  • Mohamed A. Khadimallah;Muzamal Hussain;Elimam Ali;Abdelouahed Tounsi
    • Advances in concrete construction
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    • v.15 no.5
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    • pp.313-319
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    • 2023
  • In this paper, the analytic solution has been found by using truncation approach. With the help of suitable substitution, different physical parameters are yielded in their non-dimensional form. The governing boundary layer partial differential equations are reduced to a set of ordinary ones by using appropriate similarity transformations. The velocity profile across the domain have also been taken into account. The effect normal velocity profiles buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. It is found that the normal velocity profiles rise with the buoyancy parameter and for the slip parameter. It is observed that the normal velocity profile decreases with the increase of shrinking parameter. The reverse behiour is found for the Casson fluid parameter. The results are numerically computed, analyzed and discussed. For the efficiency of present model, the results are compared with earlier investigations.