• Title/Summary/Keyword: Reverse-engineering

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A Study on the Appropriateness of Virtual Machine for Reverse Engineering (역공학을 위한 가상머신의 적합성에 대한 연구)

  • Oh, Seokhyung;Chang, Byoungchun;Ro, Yunsik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.6
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    • pp.31-38
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    • 2014
  • The purpose of this study is to make virtual machine using a 3D modeller to perform reverse engineering. Through the intuitive designer's ability, approximated model of the object is created and used to extract the data and NC tool path. The extracted data make approximated curve by using NURBS curve fitting. And the curve is used to remodel. From these series of process, the final reverse engineering data of the objects can be obtained. Two conclusions are drawn from this study. First, initial deviation of the intuitive model is one of the important factors that determine the number of repetitions of the experiment. Due to the characteristic of intuitive curve, after a certain number of repetitions the average deviation increase and radiate rather than decrease.

Point Data Reduction in Reverse Engineering by Delaunay Triangulation (역공학에서의 Delaunay 삼각형 분할에 의한 점 데이터 감소)

  • Lee, Seok-Hui;Heo, Seong-Min;Kim, Ho-Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1246-1252
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models for the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model and the generation of manufacturing data like STL file. A laser scanner has a great potential to get geometrical data of a model for its fast measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points. A new approach to remove point data with Delaunay triangulation is introduced to deal with problems during reverse engineering process. This approach can be used to reduce a number of measuring data from laser scanner within tolerance, thus it can avoid the time for handling point data during modelling process and the time for verifying and slicing STL model during RP process.

Investigation on reverse flow characteristics in U-tubes under two-phase natural circulation

  • Chu, Xi;Li, Mingrui;Chen, Wenzhen;Hao, Jianli
    • Nuclear Engineering and Technology
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    • v.52 no.5
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    • pp.889-896
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    • 2020
  • The vertically inverted U-tube steam generator (UTSG) is widely used in the pressurized water reactor (PWR). The reverse flow behavior generally exists in some U-tubes of a steam generator (SG) under both single- and two-phase natural circulations (NCs). The behavior increases the flow resistance in the primary loop and reduces the heat transfer in the SG. As a consequence, the NC ability as well as the inherent safety of nuclear reactors is faced with severe challenges. The theoretical models for calculating single- and two-phase flow pressure drops in U-tubes are developed and validated in this paper. The two-phase reverse flow characteristics in two types of SGs are investigated base on the theoretical models, and the effects of the U-tube height, bending radius, inlet steam quality and primary side pressure on the behavior are analyzed. The conclusions may provide some promising references for SG optimization to reduce the disadvantageous behavior. It is also of significance to improve the NC ability and ensure the PWR safety during some accidents.

A Comparative Study of Feature Extraction Algorithm for unKnown Protocol Classification (비공개 프로토콜 분류를 위한 특징 추출 알고리즘 비교 연구)

  • Jung, YoungGiu;Jeong, Chang-Min
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.5
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    • pp.251-255
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    • 2019
  • On today, Protocol reverse-engineering technique can be used to extract the specification of an unknown protocol. However, there is no standardized method, and in most cases, the extracting process is executed manually or semi-automatically. If the information about the structure of an unknown protocol could be acquired in advance, it would be easy to conduct reverse engineering. the feature extraction is an important step in unknown protocol classification. However, in this paper, we present a comparison several feature extraction techniques and suggests a method of feature extraction algorithm for recognizing unknown protocol. In order to verify the performance of the proposed system, we performed the training using eight open protocols to evaluate the performance using unknown data.

Database Reverse Engineering Using Master Data in Microservice Architecture (마스터 데이터를 활용한 마이크로 서비스 아키텍처에서의 데이터베이스 리버스 엔지니어링)

  • Shin, Kwang-chul;Lee, Choon Y.
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.5
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    • pp.523-532
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    • 2019
  • Microservice architecture focuses on dividing it into small and lightweight services to build for the purpose of performing very close business functions. So it tends to concentrate only on agility, productivity, reliability, and ease of deployment of software development. Microservice architecture considers database as just a file or storage for storing and extracting data, emphasizing that data quality can be sacrificed for convenience and scalability of software development. Database reverse engineering for understanding database structure and data semantics is needed for data utilization for business decision making. However, it is difficult that reverse database engineering is applied in microservice architecture that neglects data quality. This study proposes database reverse engineering method that utilizes master data to restore the conceptual data model as a solution. The proposed method is applied to the return service database implemented by microservice architecture and verified its applicability.

Signal Analysis of Motor Current for End Point Detection in the Chemical Mechanical Polishing of Shallow Trench Isolation with Reverse Moat Structure

  • Park, Chang-Jun;Kim, Sang-Yong;Seo, Yong-Jin
    • KIEE International Transactions on Electrophysics and Applications
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    • v.2C no.5
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    • pp.262-267
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    • 2002
  • In this paper, we first studied the factors affecting the motor current (MC) signal, which was strongly affected by the systematic hardware noises depending on polishing such as pad conditioning and arm oscillation of platen and recipe, head motor. Next, we studied the end point detection (EPD) for the chemical mechanical polishing (CMP) process of shallow trench isolation (STI) with reverse moat structure. The MC signal showed a high amplitude peak in the fore part caused by the reverse meal. pattern. We also found that the EP could not be detected properly and reproducibly due to the pad conditioning effect, especially when conventional low selectivity slurry was used. Even when there was no pad conditioning effect, the EPD method could not be applied, since the measured end points were always the same due to the characteristics of the reverse moat structure with an open nitride layer.

Reverse annealing of boron doped polycrystalline silicon

  • Hong, Won-Eui;Ro, Jae-Sang
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.140-140
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    • 2010
  • Non-mass analyzed ion shower doping (ISD) technique with a bucket-type ion source or mass-analyzed ion implantation with a ribbon beam-type has been used for source/drain doping, for LDD (lightly-doped-drain) formation, and for channel doping in fabrication of low-temperature poly-Si thin-film transistors (LTPS-TFT's). We reported an abnormal activation behavior in boron doped poly-Si where reverse annealing, the loss of electrically active boron concentration, was found in the temperature ranges between $400^{\circ}C$ and $650^{\circ}C$ using isochronal furnace annealing. We also reported reverse annealing behavior of sequential lateral solidification (SLS) poly-Si using isothermal rapid thermal annealing (RTA). We report here the importance of implantation conditions on the dopant activation. Through-doping conditions with higher energies and doses were intentionally chosen to understand reverse annealing behavior. We observed that the implantation condition plays a critical role on dopant activation. We found a certain implantation condition with which the sheet resistance is not changed at all upon activation annealing.

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SMLD: Enhanced MIMO-Signal Detection for Wireless MIMO Communication Receivers

  • Baek, Myung-Sun;Woo, Mi-Ae;Lim, Jae-Hyuck;You, Young-Hwan;Song, Hyoung-Kyu
    • ETRI Journal
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    • v.29 no.2
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    • pp.240-242
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    • 2007
  • This letter proposes a simplified maximum likelihood detection (SMLD) scheme to improve the detection performance of multiple-input multiple-output receivers. The SMLD detects V streams according to the first detected V sub-streams. Through an ML test, the most probable stream is selected. Moreover, to detect the layer with the worst post-detection SNR accurately, reverse ordering is applied to the SMLD. Simulation results show that the performance of the Vertical Bell Laboratories layered space-time (V-BLAST) system can be improved by adopting the SMLD technique. In the case of reverse ordering, the SMLD can achieve a similar ML performance with significant reduction in computational complexity.

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