• Title/Summary/Keyword: Reverse-engineering

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Selection and Allocation of Point Data with Wavelet Transform in Reverse Engineering (역공학에서 웨이브렛 변황을 이용한 점 데이터의 선택과 할당)

  • Ko, Tae-Jo;Kim, Hee-Sool
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.9
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    • pp.158-165
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    • 2000
  • Reverse engineering is reproducing products by directly extracting geometric information from physical objects such as clay model wooden mock-up etc. The fundamental work in the reverse engineering is to acquire the geometric data for modeling the objects. This research proposes a novel method for data acquisition aiming at unmanned fast and precise measurement. This is come true by the sensor fusion with CCD camera using structured light beam and touch trigger sensor. The vision system provides global information of the objects data. In this case the number of data and position allocation for touch sensor is critical in terms of the productivity since the number of vision data is very huge. So we applied wavelet transform to reduce the number of data and to allocate the position of the touch probe. The simulated and experimental results show this method is good enough for data reduction.

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Comparison of Dynamic Operation Performance of LNG Reliquefaction Processes based on Reverse Brayton Cycle and Claude Cycle (Reverse Brayton 사이클과 Claude 사이클 기반 LNG 재액화 공정의 동특성 운전성능 비교)

  • Shin, Young-Gy;Seo, Jung-A;Lee, Yoon-Pyo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.12
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    • pp.775-780
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    • 2008
  • A dynamic model to simulate LNG reliquefaction process has been developed. The model was applied to two candidate cycles for LNG reliquefaction process, which are Reverse Brayton and Claude cycles. The simulation was intended to simulate the pilot plant under construction for operation of the two cycles and evaluate their feasibility. According to the simulation results, both satisfy control requirements for safe operation of brazed aluminum plate-fin type heat exchangers. In view of energy consumption, the Reverse Brayton cycle is more efficient than the Claude cycle. The latter has an expansion valve in addition to the common facilities sharing with the Reverse Brayton cycle. The expansion valve is a main cause to the efficiency loss. It generates a significant amount of entropy associated with its throttling and increases circulation flow rates of the refrigerant and power consumption caused by its leaking resulting in lowered pressure ratio. It is concluded that the Reverse Brayton cycle is more efficient and simpler in control and construction than the Claude cycle.

A Study on the Selection of Highly Flexible Blanket for Reverse Offset Printing (Reverse Offset Printing용 고신축성 Blanket 재료 선정에 관한 연구)

  • Shin, Seunghang;Kim, Seok;Cho, Young Tae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.5
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    • pp.121-127
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    • 2021
  • Reverse offset printing is considering as an emerging technology for printed electronics owing to its environmentally friendliness and cost-effectiveness. In reverse offset printing, selecting the materials for cliché and blanket is critical because of its minimum resolution, registration errors, aspect ratio of reliefs, pattern area, and reusability. Various materials such as silicon, quartz, glass, electroplated nickel plates, and imprinted polymers on rigid substrates can be used for the reverse offset printing of cliché. However, when new structures are designed for specific applications, new clichés need to re-fabricated each time employing multiple time-consuming and costly processes. Therefore, by modifying the blanket materials containing the printing ink, several new structures can be easily created using the same cliché. In this study, we investigated various elastomeric materials and evaluated their applicability for designing a highly stretchable blanket with controlled elastic deformation to implement tunable reverse offset printing.

Application of Sequence Diagrams to the Reverse Engineering Process of the ESf-ccs

  • Hasan, Md. Mehedi;Elakrat, Mohamed;Mayaka, Joyce;Jung, Jae Cheon
    • Journal of the Korean Society of Systems Engineering
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    • v.15 no.1
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    • pp.1-8
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    • 2019
  • Reverse engineering involves examining a system or component so as to comprehend its structure, functionality, and operation. Creation of a system model in reverse engineering can serve several purposes: test generation, change impact analysis, and the creation of a new or modified system. When attempting to reverse engineering a system, often the most readily accessible information is the system description, which does not readily lend itself to use in Model Based System Engineering (MBSE). Therefore, it is necessary to be able to transform this description into a diagram, which clearly depicts the behavior of the system as well as the interaction between components. This study demonstrates how sequence diagrams can be extracted from the systems description. Using MBSE software, the sequence diagrams for the Engineered Safety Features Component Control System (ESF-CCS) of the Nuclear Power Plant are created. Sequence diagrams are chosen because they are a means of representing the systems behavior and the interaction between components. In addition, from these diagrams, the system's functional requirements can be elicited. These diagrams then serve as the baseline of the reverse engineering process and multiple system views are subsequently be created from them, thus speeding up the development process. In addition, the use of MBSE ensures that any additional information obtained from auxiliary sources can then be input into the system model, ensuring data consistency.

A Case Study of The Reverse Logistics Considering An Environment (환경을 고려한 역물류시스템의 사례 연구)

  • 김현수;한대희;이인철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.66
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    • pp.69-77
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    • 2001
  • The management of return flows induced by the various forms of reuse of products and materials in industrial production processes has received growing attention throughout this decade. As one of the developing countries in the world trade market, we have to apply the reverse logistics system considering an environment seriously, and to implement reverse logistics activities abreast with the forward logistics system of a companies. Therefore, the objective of this study was to discuss what the reverse logistics system of Environmentally Conscious Logistics Systems(ECLS) is by introducing a case study.

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On the ill - condition of reverse process from structural dynamic response data (구조계의 동적응답을 이용한 역해석에서의 악조건)

  • 양경택
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.390-397
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    • 1998
  • An approach to identifying input forces is proposed using measured structural dynamic responses and its analytical model. The identification of input forces is a reverse process and ill-conditioned problem. Its solution is unstable and generally case dependent. In this paper, the ill-condition is described considering characteristic matrix which is defined by reduced dynamic stiffness matrix. Special attention is focused on the condition number of a characteristic matrix used in the solution algorithm of this reverse process. Simple example is presented in support of the ill-condition of a reverse process.

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A Study on Application of Reverse Engineering using Modified B-spline approximation (수정 B-spline 근사를 통한 역공학 적용에 관한 연구)

  • Hwang Jong Dae;Jung Jong-Yun;Jung Yoon Gyo
    • Proceedings of the Society of Korea Industrial and System Engineering Conference
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    • 2002.05a
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    • pp.473-478
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    • 2002
  • Reverse Engineering is to find CAD model through measured data of a physical model which is not available in CAD model. The measured data are obtained from measuring with Coordinate Measuring Machine or Laser Scanner This paper introduces efficient methods of reconstruction through the application of the Reverse Engineering using Modified B-spline approximation.

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Decompilation-Preventive Java Runtime Environment by Dynamic Reconfigurable Security Module (재구성 가능한 보안 모듈을 이용한 역컴파일 방지 Java 실행 환경)

  • Kim, Sung-Eun;Yoo, Hyuck
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.10a
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    • pp.309-312
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    • 2006
  • 현재의 네트워크화 된 환경에서 Reverse Engineering 방지의 중요성은 높아지고 있다. 특히 Java의 경우 Reverse Engineering에 의한 위험성에 더욱 노출되어 있다. 본 논문에서는 이러한 환경에서 Reverse Engineering 방지에 대한 기존의 연구에 대하여 검토하고, Java 바이트 코드의 암호화를 통한 방어 기법으로서 동적 인스트루멘테이션을 이용한 재구성이 가능한 새로운 Java 실행 환경을 제안하였다. 이를 통하여 보다 신뢰성 있는 모바일 에이전트 환경을 구축할 수 있을 것이다.

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Analysis of Master Dimensional Shape Error Rate According to Reverse Engineering Technique (역설계 방법에 의한 시편 치수 형상의 오차율 분석)

  • Jung, Hyun-Suk;Park, Su-Jung;Yoo, Joong-Hak
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.5
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    • pp.393-399
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    • 2016
  • In this study, an experiment was conducted using a 3D scanner, commonly used in reverse engineering techniques, and the newly introduced CT measuring machine. The hole, width, and angle of specimens having various shapes were designated, the error rates in dimensional modelling generated during scanning with each device were compared, and the models were printed using a 3D printer. A secondary comparative analysis of the two printed specimens was conducted; the causes of dimension errors that occur during the printing process after scanning with each device and the differences associated with variation in shape were also analyzed. Based on the analysis results, the featured shape for each scanning application method and issues to consider in reverse engineering were presented, and the use of the CT measuring machine was recommended as a method to minimize error rates in dimensions and ensure efficient reverse engineering.

Reverse Engineering for Sculptured Surfaces by Using NURBS Approximation (역공학(Reverse Engineering)을 위한 자유곡면 형상의 NURBS Approximation)

  • Cho, Jae-Hyung;Cho, Myung-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.8
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    • pp.108-115
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    • 2002
  • In measuring step for reverse engineering of sculptured surfaces, computer vision system is used to simplify the complicated surface by boundary edge detection method that minimizes the measuring error. The measured data by Coordinate measuring machine is clouded data points of surfaces which is segmented surface using image process. In this research, the measured data is approximated as NURBS surfaces by new suggested algorithm. The position and number of control points, selection of parametric values and compensation of weight factors are proposed. Finally, surface model is simulated and improved resulting performance is obtained.