• Title/Summary/Keyword: Reverse Analysis

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Optimal Design of PV Module with Bypass Diode to Reduce Degradation due to Reverse Excess Current

  • Jung, Tae-Hee;Kang, Gi-Hwan;Ahn, Hyung-Keun
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.5
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    • pp.279-283
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    • 2014
  • In this paper, we present an economical and practical standard to install a bypass diode in a thin-film PV module. This method helps to reduce heat generation and to prevent module degradation due to excess current from reverse bias. The experimental results confirm that for different numbers of solar cells, there is a relation between the excess reverse current and the degradation of solar cells in a-Si:H modules. The optimal number of solar cells that can be connected per bypass diode could be obtained through an analysis of the results to effectively suppress the degradation and to reduce the heat generated by the module. This technique could be expanded for use in high power crystalline Si PV modules.

Application of Reverse Engineering on Sheet Metal Forming Analysis (Reverse Engineering 기술의 판재 성형 해석에의 응용)

  • Han S. S.;Kim D. J.
    • Transactions of Materials Processing
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    • v.14 no.4 s.76
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    • pp.303-309
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    • 2005
  • Reverse Engineering 기술을 이용하여 금형 형상을 측정하고 이를 이용하여 자동차 주요 대형 성형 부품에 대하여 유한 요소 성형 해석을 수행하여 성형 인자들의 영향에 대하여 분석한 결과 다음과 같은 결론을 얻었다. (1) Reverse Engineering 기술의 사용은 대형 자동차 성형 부품에 대하여 성형 해석을 위한 금형 CAD 데이터를 확보하는데 유용함을 알 수 있었다. 그러나 보다 적극적으로 사용되기 위해서는 곡면 생성의 시간 단축과 제품 면에 발생한 주름에 의한 형상 차이 등의 문제를 해결하여야 할 과제가 남아 있다. (2) 성형 해석을 위하여 자동차 외판 부품 Trunk lid outer에 대하여 성형 해석을 수행 결과 부픔의 성형성에 영향을 주지 않는 한도 내에서 r값과 n 값이 낮은 소재를 사용하는 것이 부품의 형상 동결성을 확보하는데 유리한 것을 알 수 있었다. (3) 판재 성형 부품에 대한 적절한 소재의 재질 선정 방법으로서 유한 요소 해석이 매우 유용한 것을 알 수 있었다.

Structural analysis of $Al_{x}Ga_{1-x}As/In_{y}Ga_{1-y}$As P-HEMTs reverse engineering (Reverse Engineering을 이용한 $Al_{x}Ga_{1-x}As/In_{y}Ga_{1-y}$As P-HEMTs의 구조적 분석)

  • 김병헌;황광철;안형근;한득영
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.255-258
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    • 2001
  • In this paper, DC and small signal characteristics with different physical parameters are expected for p-HEMTs (Pseudomorphic High Electron Mobility Transistors) with different temperatures ranging from 300K to 623K which are widely used for a low noise and/or ultra high frequency device. A device of 0.2$\times$200 ${\mu}{\textrm}{m}$$^2$dimension having very low noise has been chosen to extract the experimental data. Theoretical prediction has been obtained using a simulaor(HELENA) which needs experimental input data extracted from reverse engineering process. From the results, relation between structural parameters and temperature dependency of electrical characteristics are qualitatively explained to use in the design of descrete and integrated circuits to guarantee the optimal operation of the system.

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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.

Object-oriented Concept Learning using Reverse-engineering Method Based on XNA Game Development Environment (XNA기반 게임 개발 환경에서 역공학 방법을 이용한 객체지향 개념 학습)

  • Choi, Young-Mee;Choo, Moon-Won;Yoon, Tae-Bok
    • Journal of Digital Contents Society
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    • v.10 no.1
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    • pp.45-54
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    • 2009
  • This paper proposes object-oriented learning method of using reverse-engineering based on game development environment. The game has advantages such as interest and enjoyment. Also, the reverse analysis of game help us understand the technique to be used in game. Through this process, we introduce learning method enabling us to actively understand object-oriented concept. Thus, the proposed method describes case learning based on XNA game development environment, and presents a scenario according to role of teacher and learner.

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Bacterial Reverse Mutation Test of 1,2,4-trimethylbenzene (1,2,4-trimethylbenzene의 미생물복귀돌연변이시험)

  • Kim, Soo-Jin;Cho, Hae-Won;Rim, Kyung-Taek;Maeng, Seung-Hee;Kim, Hyeon-Yeong
    • Environmental Analysis Health and Toxicology
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    • v.21 no.4 s.55
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    • pp.317-322
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    • 2006
  • We have investigated the genotoxicity of 1,2,4-trimethylbenzene using Ames reverse mutation test. In Ames reverse mutation test, 1,2,4-trimethylbenzene treatment at the dose of 100, 50, 25, 12.5, $6.25{\mu}g/plate$ did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537 and in Escherichia coli WP2uvrA with and without metabolic activation. These results indicate that 1,2,4-trimethylbenzene has no mutagenic potential under the rendition in this study.

Reverse engineering of data abstractions on fragmented binary code (단편화된 실행파일을 위한 데이터 구조 역공학 기법)

  • Lee, Jong-Hyup
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.3
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    • pp.615-619
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    • 2012
  • Reverse engineering via static analysis is an essential step in software security and it focuses on reconstructing code structures and data abstractions. In particular, reverse engineering of data abstractions is critical to understand software but the previous scheme, VSA, is not suitable for applying to fragmented binaries. This paper proposes an enhanced method through dynamic region assignment.

A Method of Measuring the Plastic Properties of Materials using Spherical Indentation (Spherical Indentation 실험을 이용한 재료 소성 물성치 측정방법)

  • Li, Guanghe;Kang, Yoon-Sik;Xi, Chen;Park, Tae-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.4
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    • pp.353-360
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    • 2010
  • In this paper, an efficient algorithm is established in order to estimate the plastic properties of power-law hardening bulk specimen materials with one simple spherical indentation impression test. This work is based on a new formulation of representative strain and, therefore, compare to the preceding approaches the fitting parameters are significantly reduced. Moreover, the new definition of representative strain endowed more physical meaning to the representative strain. In order to verify the reliability of the reverse analysis, we have studied a broad set of materials whose property ranges cover essentially all engineering metals and alloys. Based on the indentation force-displacement P-${\delta}$ curves obtained from numerical simulations, the characteristics of the indentation response and material elastoplastic properties are bridged via explicit functions. Next, through the procedure of reverse analysis the yield stress and power-law hardening exponent of bulk specimen materials can be determined. Finally, good agreement between the result from reverse analysis and initial input data from experiment can be observed.

Crash FE Analysis of Front Side Assembly of Passenger Cars for Management of Collapse Shape Via Variation of Thickness with Reverse Engineering (승용차용 프론트 사이드 조립체의 박판 두께 조정에 따른 붕괴모드 제어에 관한 역설계적 유한요소 층돌해석)

  • Kim, Yong-Woo;Kim, Jeong-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.2
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    • pp.106-113
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    • 2008
  • The goal of crashworthiness is an optimized vehicle structure that can absorb the crash energy by controlled vehicle deformations while maintaining adequate space so that the residual crash energy can be managed by the restraint systems to minimize crash loads transfer to the vehicle occupants. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on auto-makers and size of vehicles. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of a passenger car to investigate the effect of thickness distribution of the front side assembly on the collapse shape, which is important in the aspect of controlling deformation to maintain adequate space, from the viewpoint of reverse engineering. To do this, we have performed crash FE analysis for the assembly by varying the thickness distribution of the assembly.

Crush FE Analysis of Front Side Assembly of Passenger Cars for Identifying the Roles of Major Parts Influencing on Collapse Mode with Reverse Engineering (승용차 프론트 사이드 조립체 부품의 역할과 붕괴모드에 관한 역설계적 유한요소 충돌해석)

  • Kim, Yong-Woo;Kim, Jeong-Ho;Jeong, Kyung-Shin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.4
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    • pp.33-40
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    • 2007
  • Crashworthiness design is of special interest in automotive industry and in the transportation safety field to ensure the vehicle structural integrity and more importantly the occupant safety in the event of the crash. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on auto-makers and size of vehicles. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of passenger cars to identify the mechanical roles of major parts in relation to collapse modes from the viewpoint of reverse engineering. To do this, we have performed crash FE analysis for the two different assemblies of small car and heavy passenger car and have compared dynamic behaviors of the two.