• 제목/요약/키워드: region truncation

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The protein truncation caused by fusion of PEP-1 peptide and protective roles of transduced PEP-1-MsrA in skin cells

  • Lee, Tae-Hyung;Choi, Seung-Hee;Kim, Hwa-Young
    • BMB Reports
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    • v.44 no.4
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    • pp.256-261
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    • 2011
  • PEP-1 peptide has been used for transduction of native protein into mammalian cells. This work describes the findings that the fusion of PEP-1 to target proteins led to protein truncation likely in a non-protein-specific manner. Approximately 75% of PEP-1-MsrA fusion protein was truncated in the N-terminal region of MsrA between Lys-27 and Val-28 during expression in Escherichia coli and purification. This large protein truncation was also observed in another PEP-1 fused protein, PEP-1-MsrB2, in the N-terminal region of MsrB2. The full-length PEP-1-MsrA protein was rapidly transduced into keratinocyte cells within 15 min. The transduced PEP-1-MsrA was functionally active and could protect skin cells against oxidative stress- and ultraviolet radiation-induced cell death. Collectively, our data demonstrated the protective roles of MsrA in skin cells and, moreover, may raise a concern of protein truncation caused by fusion of PEP-1 about the general use of this peptide for protein transduction.

Improved GRS80 Gravimetric Geoid in the South Korea Region (KGM93) (개선된 남한지역의 GRS80 중력지오이드 모델 (KGM93))

  • 조규전;이영진;조봉환
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.61-68
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    • 1994
  • Neglecting distant zones in the computation of geoidal heights using Stokes'formula give rise to some truncation errors. The GRS80 Korean Gravimetric geoid Model 1993(KGM93) of the South Korea region was implemented, in this paper, using a combination of satellite-derived GEM-T2 gravity and terrestrial gravity data. A spherical cap size of 30 degree is used on the integration and the truncation error is compensated to the free-air geoid. The results of this study show that the accuracy of the KGM93-C has one meter level.

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Damage detection using finite element model updating with an improved optimization algorithm

  • Xu, Yalan;Qian, Yu;Song, Gangbing;Guo, Kongming
    • Steel and Composite Structures
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    • v.19 no.1
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    • pp.191-208
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    • 2015
  • The sensitivity-based finite element model updating method has received increasing attention in damage detection of structures based on measured modal parameters. Finding an optimization technique with high efficiency and fast convergence is one of the key issues for model updating-based damage detection. A new simple and computationally efficient optimization algorithm is proposed and applied to damage detection by using finite element model updating. The proposed method combines the Gauss-Newton method with region truncation of each iterative step, in which not only the constraints are introduced instead of penalty functions, but also the searching steps are restricted in a controlled region. The developed algorithm is illustrated by a numerically simulated 25-bar truss structure, and the results have been compared and verified with those obtained from the trust region method. In order to investigate the reliability of the proposed method in damage detection of structures, the influence of the uncertainties coming from measured modal parameters on the statistical characteristics of detection result is investigated by Monte-Carlo simulation, and the probability of damage detection is estimated using the probabilistic method.

Adaptive Truncation technique for Constrained Multi-Objective Optimization

  • Zhang, Lei;Bi, Xiaojun;Wang, Yanjiao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.11
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    • pp.5489-5511
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    • 2019
  • The performance of evolutionary algorithms can be seriously weakened when constraints limit the feasible region of the search space. In this paper we present a constrained multi-objective optimization algorithm based on adaptive ε-truncation (ε-T-CMOA) to further improve distribution and convergence of the obtained solutions. First of all, as a novel constraint handling technique, ε-truncation technique keeps an effective balance between feasible solutions and infeasible solutions by permitting some excellent infeasible solutions with good objective value and low constraint violation to take part in the evolution, so diversity is improved, and convergence is also coordinated. Next, an exponential variation is introduced after differential mutation and crossover to boost the local exploitation ability. At last, the improved crowding density method only selects some Pareto solutions and near solutions to join in calculation, thus it can evaluate the distribution more accurately. The comparative results with other state-of-the-art algorithms show that ε-T-CMOA is more diverse than the other algorithms and it gains better in terms of convergence in some extent.

The Evaluation of the Difference of the SUV Caused by DFOV Change in PET/CT (PET/CT 검사에서 확대된 표시시야가 표준섭취계수에 미치는 영향 평가)

  • Kwak, In-Suk;Lee, Hyuk;Choi, Sung-Wook;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.2
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    • pp.13-20
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    • 2011
  • Purpose: The limited FOV(Field of View) of CT (Computed Tomography) can cause truncation artifact at external DFOV (Display Field of View) in PET/CT image. In our study, we measured the difference of SUV and compared the influence affecting to the image reconstructed with the extended DFOV. Materials and Methods: NEMA 1994 PET Phantom was filled with $^{18}F$(FDG) of 5.3 kBq/mL and placed at the center of FOV. Phantom images were acquired through emission scan. Shift the phantom's location to the external edge of DFOV and images were acquired with same method. All of acquired data through each experiment were reconstructed with same method, DFOV was applied 50 cm and 70 cm respectively. Then ROI was set up on the emission image, performed the comparative analysis SUV. In the clinical test, patient group shown truncation artifact was selected. ROI was set up at the liver of patient's image and performed the comparative analysis SUV according to the change of DFOV. Results: The pixel size was increase from 3.91 mm to 5.47 mm according to the DFOV increment in the centered location phantom study. When extended DFOV was applied, $_{max}SUV$ of ROI was decreased from 1.49 to 1.35. In case of shifted the center of phantom location study, $_{max}SUV$ was decreased from 1.30 to 1.20. The $_{max}SUV$ was 1.51 at the truncated region in the extended DFOV. The difference of the $_{max}SUV$ was 25.9% higher at the outside of the truncated region than inside. When the extended DFOV was applied, $_{max}SUV$ was decreased from 3.38 to 3.13. Conclusion: When the extended DFOV was applied, $_{max}SUV$ decreasing phenomenon can cause pixel to pixel noise by increasing of pixel size. In this reason, $_{max}SUV$ was underestimated. Therefore, We should consider the underestimation of quantitative result in the whole image plane in case of patient study applied extended DFOV protocol. Consequently, the result of the quantitative analysis may show more higher than inside at the truncated region.

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Aerodynamic Analysis Based on the Truncation Ratio of Guided-Weapon Nose Using CFD (전산유체역학을 이용한 유도무기 선두부 절단 비율에 대한 공력해석)

  • Jeong, Kiyeon;Kang, Dong-Gi;Lee, Daeyeon;Noh, Gyeongho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.4
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    • pp.245-255
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    • 2019
  • This paper describes on aerodynamic analysis based on the truncation rate of guided-weapon nose using computational fluid dynamics. The shape to perform the analysis is only the body of the guided weapon and the diameter to length ratio is 10.7. Three nose shapes were selected and hemisphere, 25% and 50% truncation were compared. For the accurate CFD analysis of the body, the grid method and the analytical method were selected and verified using NASA wind tunnel test data. For the three nose shapes, the drag analysis for the flight Mach number is 6~20% different. This difference was analyzed by the pressure distribution from nose to base.

Time harmonic analysis of dam-foundation systems by perfectly matched layers

  • Khazaee, Adib;Lotfi, Vahid
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.349-364
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    • 2014
  • Perfectly matched layers are employed in time harmonic analysis of dam-foundation systems. The Lysmer boundary condition at the truncation boundary of the PML region has been incorporated in the formulation of the dam-foundation FE model (including PML). The PML medium is defined in a way that the formulation of the system can be transformed into time domain. Numerical experiments show that applying Lysmer boundary conditions at the truncation boundary of the PML area reduces the computational cost and make the PML approach a more efficient technique for the analysis of dam-foundation systems.

Dependence of High Affinity Binding of Epidermal Growth Factor on Receptor Cytoplasmic Domain (Receptor Cytoplasmic 영역에 의존하는 EGF의 고친화성 결합)

  • 강용호
    • KSBB Journal
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    • v.7 no.3
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    • pp.201-208
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    • 1992
  • Cell surface binding of epidermal growth factor(EGF) to EGF receptors was studied for a series of site-directed receptor mutants transfected into B82 mouse fibroblasts. Scatchard plots for truncation mutant receptors significantly lost nonlinearity for truncations below residue 1022. Transient plots of dissociation kinetics exhibited biphasic behavior for all receptor types, but the fraction of receptor in slow-dissociating form was reduced by an order of magnitude for the truncation mutants below residue 1022. Comparison of dissociation kinetics between control cells and cells treated with Triton X-100 revealed no significant variation for the slow-dissociating receptor form, but a noticeable variation was observed for the fast-dissociating receptor form when EGF receptors were truncated below residue 991. These results suggest that high affinity of EGF binding at cell surface depend on the EGF receptor cytoplasmic region.

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A New Tailored Sinc Pulse and Its Use for Multiband Pulse Design

  • Park, Jinil;Park, Jang-Yeon
    • Investigative Magnetic Resonance Imaging
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    • v.20 no.1
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    • pp.27-35
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    • 2016
  • Purpose: Among RF pulses, a sinc pulse is typically used for slice selection due to its frequency-selective feature. When a sinc pulse is implemented in practice, it needs to be apodized to avoid truncation artifacts at the expense of broadening the transition region of the excited-band profile. Here a sinc pulse tailored by a new apodization function is proposed that produces a sharper transition region with well suppression of truncation artifacts in comparison with conventional tailored sinc pulses. A multiband pulse designed using this newly apodized sinc pulse is also suggested inheriting the better performance of the newly apodized sinc pulse. Materials and Methods: A new apodization function is introduced to taper a sinc pulse, playing a role to slightly shift the first zero-crossing of a tailored sinc pulse from the peak of the main lobe and thereby producing a narrower bandwidth as well as a sharper pass-band in the excitation profile. The newly apodized sinc pulse was also utilized to design a multiband pulse which inherits the performance of its constituent. Performances of the proposed sinc pulse and the multiband pulse generated with it were demonstrated by Bloch simulation and phantom imaging. Results: In both simulations and experiments, the newly apodized sinc pulse yielded a narrower bandwidth and a sharper transition of the pass-band profile with a desirable degree of side-lobe suppression than the commonly used Hanning-windowed sinc pulse. The multiband pulse designed using the newly apodized sinc pulse also showed the better performance in multi-slice excitation than the one designed with the Hanning-windowed sinc pulse. Conclusion: The new tailored sinc pulse proposed here provides a better performance in slice (or slab) selection than conventional tailored sinc pulses. Thanks to the availability of analytical expression, it can also be utilized for multiband pulse design with great flexibility and readiness in implementation, transferring its better performance.

Discrete controller order reduction with the closed-loop performance guaranteed (폐루프시스템의 성능을 보장하는 이산제어기 차수축소)

  • 오도창;정은태;박홍배
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.3
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    • pp.24-32
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    • 1997
  • This paper is on a discrete controller order reduction with the closed-loop stability and performance guaranteed. to achieve this, after finding the solutionsof two lyapunov inequalities and balancing the full order controller system, we find the reudced order controlers using the balanced truncation (BT) and the balanced singular perturbation approximation (BSPA). When the solutions of the two lyapunov inequalities exist, it is shown that the resulting controllers guarantee the closed-loop stability, and .inf.-norm error bounds are derived for the closed-loop performance region for the BT and in low frequency region for the BSPA. Finally, a numerical example is given to illustrate the validity of the proposed method.

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