• Title/Summary/Keyword: slicing

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X-ray diffraction analysis on sapphire wafers with surface treatments in chemical-mechanical polishing process (사파이어 웨이퍼 연마공정에서의 표면처리효과에 대한 X-선 회절분석)

  • 김근주;고재천
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.5
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    • pp.218-223
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    • 2001
  • The chemical-mechanical polishing process was carried out for 2"-dia. sapphire wafer grown by horizontalBridgman method on the urethane lapping pad with the silica sol. The polished wafer shows the full-width at halfmaximum of 200~400 arcsec in double-crystal X-ray diffraction, indicating that the slicing, grinding and lapping processes before the polishing process affected the crystalline structural property of the wafer surface by the mechanical residual stress. For the inclusion of surface treatments after chemical-mechanical polishing such as the thermal annealing at the temperature of $1,200^{\circ}C$for 4 hrs. and chemical etching, the crystalline quality was sigdicantly enhanced with the reduced full-width at half maximum up to 8.3 arcsec.arcsec.

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Visualization for Digesting a High Volume of the Biomedical Literature

  • Lee, Chang-Su;Park, Jin-Ah;Park, Jong-C.
    • Bioinformatics and Biosystems
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    • v.1 no.1
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    • pp.51-60
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    • 2006
  • The paradigm in biology is currently changing from that of conducting hypothesis-driven individual experiments to that of utilizing the results of a massive data analysis with appropriate computational tools. We present LayMap, an implemented visualization system that helps the user to deal with a high volume of the biomedical literature such as MEDLINE, through the layered maps that are constructed on the results of an information extraction system. LayMap also utilizes filtering and granularity for an enhanced view of the results. Since a biomedical information extraction system gives rise to a focused and effective way of slicing up the data space, the combined use of LayMap with such an information extraction system can help the user to navigate the data space in a speedy and guided manner. As a case study, we have applied the system to datasets of journal abstracts on 'MAPK pathway' and 'bufalin' from MEDLINE. With the proposed visualization, we have successfully rediscovered pathway maps of a reasonable quality for ERK, p38 and JNK. Furthermore, with respect to bufalin, we were able to identify the potentially interesting relation between the Chinese medicine Chan su and apoptosis with a high level of detail.

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Delineation Of Coastal Features And Relative Turbidity Levels In The Mid West Sea Of Korea Using Landsat Imagery

  • Youn, Oong Koo;Lee, Byung Don;Kwak, Hi-Sang
    • 한국해양학회지
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    • v.11 no.1
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    • pp.9-17
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    • 1976
  • Multispectral scanner data collected by LANDSAT-1 over the mid West Sea of Korea were analyzed and interpreted for delineation of coastal features and turbidity distribution patterns during different portions of the tidal cycle. Imagery from two successful LANDSAT-1 overpasses of the area in October 1972 and in October 1973 had been used to prepare schematic maps of coastal features and turbidity distributions. Color composite imagery of LANDSAT MSS 4, 5 and 7 gave the best representation of shorelines, coastlines and tidal flats. MSS 5 imagery was most effective in differentiating relative turbidity levels through density slicing techniques. Referring to the tidal power development of Garolim Bay, the basin area measurements assuming dyke construction at the bay entrance, have been carried out on the coastal reature maps comiled from LANDSAT imagery, and those results were correlated with existing data. General areal patterns of surface turbidity distribution in the study area revealed close similarity with bathymetry of the area. Synoptic circulation patterns were also well discriminated from the LANDSAT imagery using the suspended sediment as a tracer.

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Calculation of Rotation Angle of the Linear Hotwire Cutting System for VLM-s (VLM-S용 선형열선절단기의 회전각 계산)

  • Lee, Sang-Ho;An, Dong-Gyu;Yang, Dong-Yeol;Dong Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.2
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    • pp.87-94
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    • 2002
  • Most of Rapid Prototyping (RP) process adopt a solid Computer Aided Design (CAD) model, slicing into thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successive1y deposited and at the same time, bonded onto the previous layers; the stacked layers form a physical part of the model. The objective of this study is to develop a method for calculating the rotation angle ($$\theta$_x, $\theta$_y$) of hotwire of the cutting system in the three-dimensional space for the Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-S). In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes. such as a screw, an extruded cross, and free surface bodies such as miniatures of the monkey(a figure of Sonokong), were made using the data obtained form the method.

The Automatic Determination of the Optimal Build-Direction in Rapid Prototyping (고속적층조형법에서 최적 적층방향의 자동결정)

  • 채희창
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.04a
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    • pp.150-155
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    • 1997
  • Rapid Prototyping(RP) is the technique which is used to make prototypes or functional parts directly using the 3-D solid data. Before building the prototype, several processes such as transfering 3D data from CAD system(STL) determination of build-direction, adding support structure and slicing are required. Among the above processes. determination of build-direction is the target of this study. The build direction is determined by many factors according to the objective of the user, like part accuracy, number of support structure, build time, amount of trapped volume, etc, But it is not easy to determine the build-direction because there are many factors and some factors have dependent properties with one another. So, in this study the part accuracy, the number of support structures and build time are considered as the main factor to determine the optimal build-direction. To determine the optimal build-direction for increasing part accuracy, sum of projected area which caused stairstepping effect was considered. The less the projected area is the better part accuracy is About the optimal build-direction to minimize the amount of support structure, sum of projected area of facets that require support structures was considered. About the build time, we considered the minimum height of part we intended. About the build time, we considered the minimun height of part we intended to make.

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Behavior of Laterally Damaged Prestressed Concrete Bridge Girders Repaired with CFRP Laminates Under Static and Fatigue Loading

  • ElSafty, Adel;Graeff, Matthew K.;Fallaha, Sam
    • International Journal of Concrete Structures and Materials
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    • v.8 no.1
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    • pp.43-59
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    • 2014
  • Many bridges are subject to lateral damage for their girders due to impact by over-height vehicles collision. In this study, the optimum configurations of carbon fiber reinforced polymers (CFRP) laminates were investigated to repair the laterally damaged prestressed concrete (PS) bridge girders. Experimental and analytical investigations were conducted to study the flexural behavior of 13 half-scale AASHTO type II PS girders under both static and fatigue loading. Lateral impact damage due to vehicle collision was simulated by sawing through the concrete of the bottom flange and slicing through one of the prestressing strands. The damaged concrete was repaired and CFRP systems (longitudinal soffit laminates and evenly spaced transverse U-wraps) were applied to restore the original flexural capacity and mitigate debonding of soffit CFRP longitudinal laminates. In addition to the static load tests for ten girders, three more girders were tested under fatigue loading cycles to investigate the behavior under simulated traffic conditions. Measurements of the applied load, the deflection at five different locations, strains along the cross-section height at mid-span, and multiple strains longitudinally along the bottom soffit were recorded. The study investigated and recommended the proper CFRP repair design in terms of the CFRP longitudinal layers and U-wrapping spacing to obtain flexural capacity improvement and desired failure modes for the repaired girders. Test results showed that with proper detailing, CFRP systems can be designed to restore the lost flexural capacity, sustain the fatigue load cycles, and maintain the desired failure mode.

Generating Cartesian Tool Paths for Machining Sculptured Surfaces from 3D Measurement Data (3차원 측정자료부터 자유곡면의 가공을 위한 공구경로생성)

  • Ko, Byung-Chul;Kim, Kwang-Soo
    • Journal of Korean Institute of Industrial Engineers
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    • v.19 no.3
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    • pp.123-137
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    • 1993
  • In this paper, an integrated approach is proposed to generate gouging-free Cartesian tool paths for machining sculptured surfaces from 3D measurement data. The integrated CAD/CAM system consists of two modules : offset surface module an Carteian tool path module. The offset surface module generates an offset surface of an object from its 3D measurement data, using an offsetting method and a surface fitting method. The offsetting is based on the idea that the envelope of an inversed tool generates an offset surface without self-intersection as the center of the inversed tool moves along on the surface of an object. The surface-fitting is the process of constructing a compact representation to model the surface of an object based on a fairly large number of data points. The resulting offset surtace is a composite Bezier surface without self-intersection. When an appropriate tool-approach direction is selected, the tool path module generates the Cartesian tool paths while the deviation of the tool paths from the surface stays within the user-specified tolerance. The tool path module is a two-step process. The first step adaptively subdivides the offset surface into subpatches until the thickness of each subpatch is small enough to satisfy the user-defined tolerance. The second step generates the Cartesian tool paths by calculating the intersection of the slicing planes and the adaptively subdivided subpatches. This tool path generation approach generates the gouging-free Cartesian CL tool paths, and optimizes the cutter movements by minimizing the number of interpolated points.

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Studies on Embryo Cryopreservation and Twinning by Embryo Transfer of Korean Native Cattle: III. Culture and Freezing of IVF Bisected Embryos (한우 수정란의 동결보존 및 쌍자생산에 관한 연구 III. 이분 체외수정란의 배양과 동결)

  • 손동수;김일화;이호준;양병철;최선호;이광원;노규진;최상용
    • Journal of Embryo Transfer
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    • v.12 no.2
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    • pp.151-159
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    • 1997
  • In vitro fertilization(IVF) derived morula and blastocyst embryos were bisected by a simple method and cultured in vitro without zona pellucida And also bisected embryos were frozen-thawed and cultured in vitro) to evaluate the survival rate. The results obtained were as follows : The average number of grade I or II immature follicular oocytes recovered by slicing method per ovary was 11.9 from 142 ovaries. Following in vitro fertilization, the rates of cleavage and in vitro development to morula and blatocyst were 61.7 and 32.2% respectively. The successful bisection rate of IVE embryos was 67.51%, and the embryos of blastocyst stage were bisected successfully at significantly(P

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Iterative V-BLAST Decoding Algorithm in the AMC System with a STD Scheme

  • Lee, Keun-Hong;Ryoo, Sang-Jin;Kim, Seo-Gyun;Hwang, In-Tae
    • Journal of information and communication convergence engineering
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    • v.6 no.1
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    • pp.1-5
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    • 2008
  • In this paper, we propose and analyze the AMC (Adaptive Modulation and Coding) system with efficient turbo coded V-BLAST (Vertical-Bell-lab Layered Space-Time) technique. The proposed algorithm adopts extrinsic information from a MAP (Maximum A Posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. Also, we consider the AMC system using the conventional turbo coded V-BLAST technique that simply combines the V-BLAST scheme with the turbo coding scheme. And we compare the proposed decoding algorithm to a conventional V-BLAST decoding algorithm and a ML (Maximum Likelihood) decoding algorithm. In addition, we apply a STD (Selection Transmit Diversity) scheme to the systems for better performance improvement. Results indicate that the proposed systems achieve better throughput performance than the conventional systems over the entire SNR range. In terms of transmission rate performance, the suggested system is close in proximity to the conventional system using the ML decoding algorithm.

Development of Agile SFFS(Solid Freeform Fabrication System) for a Wide Variety of Engineering Materials (다종재료용 쾌속 임의형상가공시스템의 개발)

  • Ko, Min-Kook;Um, Tai-Joon;Joo, Young-Cheol;Kong, Yong-Hae;Chun, In-Gook;Bang, Jae-Cheol;Kim, Seung-Woo
    • Proceedings of the KIEE Conference
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    • 2001.11c
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    • pp.311-314
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    • 2001
  • The objectives of this paper include the development of an agile prototype of SFFS, the $CAFL^{VM}$(Computer Aided fabrication of Lamination for Various Material), which is suitable for the multi-item and small-quantity production and various material fabrication. This paper includes remodeling of the layer slices for the 2D cutting, supplementing information of the layer slices and developing process conditions to fabricate products of various shape. And also includes developing control hardware as well as software by enhancing BOF of the manipulator to 3 degree for the precise 2D cutting. It will generate optimal layer trajectory considering the dynamic characteristics of the laser beam. The system can be used as a competitive agile protype system in terms of various materials, fabrication speed, and accuracy by CAD modeling precise layer slicing, material development, robot path control, and optimization of the support structure.

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