• Title/Summary/Keyword: reverse transformation

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The Reverse Shape Memory Effect in a DO3 CuZnAl Alloy (DO3 CuZnAl 합금에 있어서의 역형상기억효과)

  • Chung, In-Sang;Lee, In-Chul;Park, Jung-Sig;Lee, Soon-Lin
    • Journal of the Korean Society for Heat Treatment
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    • v.3 no.2
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    • pp.1-9
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    • 1990
  • Since the reverse shape memory effect(RSME) was reported in a CuZnAl alloy, further study has been done on the mechanism of this phenomenon and reported that it occurs by the bainitic transformation. But the present authors revealed in the previous work that the RSME in a B2 CuZnAl alloy is not caused by the shear process involved in the bainitic transformation and also that the RSME takes place as the remaining ${\alpha}^{\prime}{_2}$ phase, which is two-step transformed strain induced martensite, is newly transformed into ${\alpha}$ phase. In order to provide further evidence in supporting the facts, thus, more detailed investigations have been carried out in a $DO_3$ CuZnAl alloy.

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A Code Block Cipher Method to Protect Application Programs From Reverse Engineering (응용프로그램 역분석 방지를 위한 코드블록 암호화 방법)

  • Jung, Dong-Woo;Kim, Hyong-Shik;Park, Joong-Gil
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.2
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    • pp.85-96
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    • 2008
  • One of the typical methods to prevent tampering and reverse engineering on executable codes is to encrypt them. This paper proposes a code block cipher method based on key chaining to encrypt the code. The block cipher by key chaining has been known to be inadequate for encrypting the code with control transfer, even though the key chaining has advantage of hiding the keys in blocks and making the individual keys different from block to block. This paper proposes a block transformation and duplication method to apply the block cipher by key chaining to the executable codes with control transfer instructions, and shows the idea works with the MIPS instruction set.

An Efficient Reengineering Process for Legacy System Evolution (레거시 시스템 진화를 위한 효율적 재공학 프로세스)

  • Choi, Il-Woo;Rhew, Sung-Yul
    • The KIPS Transactions:PartD
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    • v.10D no.5
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    • pp.845-858
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    • 2003
  • The various software engineering techniques have been come out in order to cope with the software crisis since 1980's. These days the software Engineering has focused on the process of software development which is the guide for a qualify and productive improvement of software. But, most of the methodologies assume that a new system will be constructed and reused in the future. these do not support how we reuse legacy system's resources and construct a new system efficiently. In this paper, we present an efficient Reengineering Process for legacy system evolutions, RUP+re, which extends and customizes RUP. RUP+re consists of Reverse Engineering Workflow, Transformation Workflow and Evolution Workflow based on Small-h model. We describe RUP+re's workflows with their own detail steps and verify the process through the case study practivally. So, we provide efficient guidelines to the software Reengineering process construction which evolutes the resources of a legacy system.

Projected Image Reconstruction Using Higher Order B-Spline (사영된 영상의 고차원 비-스플라인을 이용한 복원법)

  • Kim Sung-Soo
    • The Journal of the Korea Contents Association
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    • v.5 no.6
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    • pp.97-108
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    • 2005
  • In this paper a method of reconstructing a desired image through the geometrical transformation and the interpolation techniques is presented by comparing different interpolation schemes. Several different interpolation schemes are compared with respect to the amount of error that is the difference between the original and the reverse-projective transformed images. Higher ordered B-spline interpolation turned to be superior to other techniques in reconstructing the image which is desired to be close to the unskewed image as much as possible. In the results, this paper demonstrates that the reverse projection using the higher ordered B-spline interpolation is superior to those conventional interpolation methods, linear, cubic spline for reconstructing image. In experiments, the error decreases as the order of B-spline increases. The proposed technique is useful for various practical and theoretical applications in the area of satellite, medical, and commercial image processing.

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Highly Efficient Electroporation-mediated Transformation into Edible Mushroom Flammulina velutipes

  • Kim, Jong-Kun;Park, Young-Jin;Kong, Won-Sik;Kang, Hee-Wan
    • Mycobiology
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    • v.38 no.4
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    • pp.331-335
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    • 2010
  • In this study, we developed an efficient electroporation-mediated transformation system featuring Flammulina velutipes. The flammutoxin (ftx) gene of F. velutipes was isolated by reverse transcription-PCR. pFTXHg plasmid was constructed using the partial ftx gene (410 bp) along with the hygromycin B phosphotransferase gene (hygB) downstream of the glyceraldehydes-3-phosphate dehydrogenase (gpd) promoter. The plasmid was transformed into protoplasts of monokaryotic strain 4019-20 of F. velutipes by electroporation. High transformation efficiency was obtained with an electric-pulse of 1.25 kV/cm by using 177 transformants/${\mu}g$ of DNA in $1{\times}10^7$ protoplasts. PCR and Southern blot hybridization indicated that a single copy of the plasmid DNA was inserted at different locations in the F. velutipes genome by non-homologous recombination. Therefore, this transformation system could be used as a useful tool for gene function analysis of F. velutipes.

Finite Element Analysis of NiTi Alloy Tubes with the Superelastic Behavior (초탄성 거동을 고려한 NiTi 합금 튜브의 변형해석)

  • Kang, Woo-Jong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.5
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    • pp.100-106
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    • 2006
  • NiTi alloy known as its shape memory effect also has superelastic characteristic, which makes it possible to be elastic under large deformation. Since the tensile strength of the alloy is very high and density is low compared to carbon steel, it can be applied to lightweight structural design. In order to design structures with shape memory alloy, finite element analysis is used and a constitutive algorithm based on Aurrichio's model is added to LS-DYNA as a user subroutine. Explicit time integration and shell element formulation are used to simulate thin-walled structures. The algorithm uses Drucker-Prager type loading condition to calculate martensite volume fraction during the transformation. The implemented algorithm is verified in uni-axial loading condition and martensite phase transformation can be detected well with the algorithm. In this study, as a energy absorbing structure, thin-walled tube is modeled with finite elements and the deformation behavior is studied. Simulation results has shown that the martensite transformation was generated in loading condition. After plastic deformation reached, the load decreases linearly without reverse martensite transformation.

Image Translation: Verifiable Image Transformation Networks for Face Sketch-Photo and Photo-Sketch (영상변형:얼굴 스케치와 사진간의 증명가능한 영상변형 네트워크)

  • Sung, Thai-Leang;Lee, Hyo-Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.05a
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    • pp.451-454
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    • 2019
  • In this paper, we propose a verifiable image transformation networks to transform face sketch to photo and vice versa. Face sketch-photo is very popular in computer vision applications. It has been used in some specific official departments such as law enforcement and digital entertainment. There are several existing face sketch-photo synthesizing methods that use feed-forward convolution neural networks; however, it is hard to assure whether the results of the methods are well mapped by depending only on loss values or accuracy results alone. In our approach, we use two Resnet encoder-decoder networks as image transformation networks. One is for sketch-photo and another is for photo-sketch. They depend on each other to verify their output results during training. For example, using photo-sketch transformation networks to verify the photo result of sketch-photo by inputting the result to the photo-sketch transformation networks and find loss between the reversed transformed result with ground-truth sketch. Likely, we can verify the sketch result as well in a reverse way. Our networks contain two loss functions such as sketch-photo loss and photo-sketch loss for the basic transformation stages and the other two-loss functions such as sketch-photo verification loss and photo-sketch verification loss for the verification stages. Our experiment results on CUFS dataset achieve reasonable results compared with the state-of-the-art approaches.

Mechanical Behavior of Cu Nanowire under Cyclic Loading (반복하중을 받는 구리 나노 와이어의 기계적 거동)

  • Lee, Sang-Jin;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1784-1787
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    • 2008
  • Molecular dynamics (MD) simulations are used to analyze behavior of copper nanowires under cyclic loading. The embedded atom method (EAM) potential is employed to represent atomic interaction. Cyclic load is applied in two ways (Forward Tension / Reverse Compression and Forward Compression / Reverse Tension). The results show that dislocations are piled up as a result of plastic deformation during alternate tensile and compressive loading. After cyclic loading with a change of direction, yield stress decreases in consequence of the effect by the dislocation pileups. On the other hand, under FC/RT cyclic load, phase transformation represent associated with mechanical twinning. And copper nanowire can return to almost former undeformed condition during tensile loading at 300K.

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The Effect of Harder Second Phase on Mechanical Properties of Compacted/Vermicular Graphite Cast Iron (CV 흑연주철의 기계적 성질에 미치는 경질의 제2상의 영향)

  • Park, Yoon-Woo
    • Journal of Korea Foundry Society
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    • v.19 no.1
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    • pp.84-90
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    • 1999
  • In this study, CV cast iron was reverse transformed to produce harder second phase surrounding graphite nodules, and then the microstructure and related mechanical properties of the reverse transformed CV cast iron were investigated by using optical microscopy and by carrying out hardness, tension and impact test. The formation of hard second phase surrounding graphite nodules increased the hardness in CV cast iron. The marked increase in hardness was resulted from the formation of martensite surrounding graphite nodule. It is expected from these results that the formation of martensite surrounding graphite nodule would improve the wear resistance of CV cast iron. The formation of both martensite and pearlite surrounding graphite nodule improved the tensile properties. Impact properties were decreased with increasing the volume fraction of hard second phase. However, the reduced impact properties could be recovered through phase transformation of martensite into pearlite and sorbite by tempering.

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Immortalization of Swine Umbilical Vein Endothelial Cells with Human Telomerase Reverse Transcriptase

  • Hong, Hai Xia;Zhang, Yan Ming;Xu, Hao;Su, Zheng Yuan;Sun, Pei
    • Molecules and Cells
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    • v.24 no.3
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    • pp.358-363
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    • 2007
  • Swine endothelial cells are commonly used as an in vitro model for studying features of the blood-brain barrier and some hemorrhagic diseases. However, primary cultures of swine cells have finite lifespans. To establish immortalized swine umbilical vein endothelial cells (SUVECs) using human telomerase reverse transcriptase (hTERT), the plasmid pCI-neo-hTERT was transfected into SUVECs by lipofection. Clones were selected for G418 resistance, and positive clones were amplified. One of the clones was cultured for up to 50 passages. Factor VIII-related antigen and CD34 were detected. The immortalized cells shared the properties of normal cells, such as contact inhibition, serum requirement and anchorage dependence. Karyotype analysis revealed that the immortalized cells were in the diploid range. In addition, both in vivo and in vitro assays of tumorigenicity showed no neoplastic transformation. Furthermore, NO, $PGI_2$, and ET-1 concentrations in the transfected cells were normal. These results suggest that the SUVECs immortalized by hTERT retain their original characteristics.