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The Characteristic of the Performance of the Bypass Diode with Composition Change of the String in Si-PV Module (결정질 PV 모듈의 string 구성에 따른 바이패스 다이오드 동작 특성)

  • Ji, Yang-Geun;Kong, Ji-Hyun;Kang, Gi-Hwan;Yu, Gwon-Jong;Ahn, Hyung-Gun;Han, Deuk-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2212-2217
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    • 2010
  • Previous studies have been focused on the voltage of Bypass diode and Isc(Short Circuit Current) of the influenced solar cell. The Bypass diode starts working when it gets the reverse applied voltage. Previous studies have only concentrated on Isc of the influenced solar cell and Imp of PV module to explain the bypassing performance. PV module is usually working together with inverter having MPPT(Maximum Power Point Tracking) function for best performance. bypassing point is regulated by MPPT function of inverter. In this paper, simulation results of Bypass diode in PV module have been analyzed to represent the relationship of the bypassing point with the composition of PV module. From the results, the more cells are connected with each string, the earlier bypassing performance happens under the fixed number of strings. As diode groups increase or irradiation decreases, the bypassing performance starts fast.

An elastoplastic bounding surface model for the cyclic undrained behaviour of saturated soft clays

  • Cheng, Xinglei;Wang, Jianhua
    • Geomechanics and Engineering
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    • v.11 no.3
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    • pp.325-343
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    • 2016
  • A total stress-based bounding surface model is developed to predict the undrained behaviour of saturated soft clays under cyclic loads based on the anisotropic hardening modulus field and bounding-surface theories. A new hardening rule is developed based on a new interpolation function of the hardening modulus that has simple mathematic expression and fewer model parameters. The evolution of hardening modulus field is described in the deviatoric stress space. It is assumed that the stress reverse points are the mapping centre points and the mapping centre moves with the variation of loading and unloading paths to describe the cyclic stress-strain hysteresis curve. In addition, by introducing a model parameter that reflects the accumulation rate and level of shear strain to the interpolation function, the cyclic shakedown and failure behaviour of soil elements with different combinations of initial and cyclic stresses can be captured. The methods to determine the model parameters using cyclic triaxial compression tests are also studied. Finally, the cyclic triaxial extension and torsional shear tests are performed. By comparing the predictions with the test results, the model can be used to describe undrained cyclic stress-strain responses of elements with different stress states for the tested clays.

Effect on 4H-SiC Schottky Rectifiers of Ar Discharges Generated in A Planar Inductively Coupled Plasma Source

  • Jung, P.G.;Lim, W.T.;Cho, G.S.;Jeon, M.H.;Lee, J.W.;Nigam, S.;Ren, F.;Chung, G.Y.;Macmillan, M.F.;Pearton, S.J.
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.3 no.1
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    • pp.21-26
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    • 2003
  • 4H-SiC Schottky rectifiers were exposed to pure Ar discharges in a planar coil Inductively Coupled Plasma system, as a function of source power, of chuck power and process pressure. The reverse breakdown voltage ($V_B$) decreased as a result of plasma exposure due to the creation of surface defects associated with the ion bombardment. The magnitude of the decrease was a function of both ion flux and ion energy. The forward turn-on voltage ($V_F$), on-state resistance ($R_{ON}$) and diode ideality factor (n) all increased after plasma exposure. The changes in all of the rectifier parameters were minimized at low power, high pressure plasma conditions.

Stiffness Prediction of Spatially Reinforced Composites (공간적으로 보강된 복합재료의 강성예측)

  • 유재석;장영순;이상의;김천곤
    • Composites Research
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    • v.17 no.5
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    • pp.25-38
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    • 2004
  • In this study, the stiffness of spatially reinforced composites (SRC) are predicted by using superposition of a rod and matrix stiffnesses in an arbitrary direction. To confirm the predicted values, the material properties of SRC are measured. The predicted values from the volume average of stiffness matrix are consistent with the tested values in a rod direction, but are inconsistent in an off-rod direction while reverse is true fur the volume average of compliance matrix. Therefore, the harmony function from superposition of stiffness and compliance matrix is introduced. The predicted values from the harmony function are consistent with the tested values in both the rod and the off-rod directions.

Viscosity and Dynamic Rheological Properties of Job's-tears as a Function of Moisture Content (수분함량에 따른 율무가루의 점도변화 및 동적물성 특성에 관한 연구)

  • Yoon, Won-Byung;Kim, Byung-Yong;Shin, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.29 no.5
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    • pp.932-938
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    • 1997
  • Changes in viscosity and dynamic theological properties of Job's-tears were measured by Bohlin dynamic tester as a function of moisture, and measurement was performed within a linear viscoelastic range. The result of the shear stress vs shear rate of Job's-tears at different moisture contents $(50{\sim}75%)$ was applied to mathematical models and Herschel-Bulkley model showed the highest correlation coefficient. Lower moisture content (55%) produced higher yield stress and consistency index, but lower flow behavior index, whereas higher moisture content showed reverse effects. Job's-tears with $50{\sim}70%$ moisture contents showed a higher storage modulus (G') than loss modulus (G') at all frequencies, showing a higher concentrated polymer characteristics. However, higher moisture content (>75%) showed crossover point between G' and G', and frequency dependency. As the moisture content was increased, the amount of viscoelastic properties such as G', G', complex viscosity decreased during heating, and initial temperature and miximum value of viscoelastic properties shifted to higher temperatures, representing the moisture-dependence of Job's-tears upon theological properties.

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The Function of ArgE Gene in Transgenic Rice Plants

  • Guo, Jia;Seong, Eun-Soo;Cho, Joon-Hyeong;Wang, Myeong-Hyeon
    • Korean Journal of Plant Resources
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    • v.20 no.6
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    • pp.524-529
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    • 2007
  • We carried out to study the function of ArgE in transgenic rice plants, which were confirmed by PCR analysis and hygromycin selection. Transgenic rice plants were with selectable marker gene(HPT) inserted in genome of the rice. Southern analysis with hpt probe confirmed by two restriction enzymes that copy numbers of the selectable gene was introduced into the plant genome. We displayed that the relationship between drought stress and ArgE gene with the overexpressing rice plants. From this result, we observed that the degree of leaves damage has no difference in control and transgenic lines. The total RNAs were extracted from 6 weeks-seedling in normal condition in order to examine their expression levels with ArgE-overexpressed transgenic rice. In particular, expression patterns of genes encoding enzymes involved in abiotic stress, including drought and salt stresses. OsGF14a and OsSalt were investigated by reverse transcription-PCR(RT-PCR). Expression levels of the OsSalt gene decreased significantly in transgenic rice plants compared to control plant. However, ion leakage measurement did not demonstrate any leaves damage change between control and ArgE transgenic plants exposure to mannitol treatment. These results suggest that expression of the ArgE is not involved in tolerance for drought stress in rice but may playa role of signaling networks for salt-induced genes.

Harnessing CRISPR-Cas adaptation for RNA recording and beyond

  • Gyeong-Seok Oh;Seongjin An;Sungchul Kim
    • BMB Reports
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    • v.57 no.1
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    • pp.40-49
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    • 2024
  • Prokaryotes encode clustered regularly interspaced short palindromic repeat (CRISPR) arrays and CRISPR-associated (Cas) genes as an adaptive immune machinery. CRISPR-Cas systems effectively protect hosts from the invasion of foreign enemies, such as bacteriophages and plasmids. During a process called 'adaptation', non-self-nucleic acid fragments are acquired as spacers between repeats in the host CRISPR array, to establish immunological memory. The highly conserved Cas1-Cas2 complexes function as molecular recorders to integrate spacers in a time course manner, which can subsequently be expressed as crRNAs complexed with Cas effector proteins for the RNA-guided interference pathways. In some of the RNA-targeting type III systems, Cas1 proteins are fused with reverse transcriptase (RT), indicating that RT-Cas1-Cas2 complexes can acquire RNA transcripts for spacer acquisition. In this review, we summarize current studies that focus on the molecular structure and function of the RT-fused Cas1-Cas2 integrase, and its potential applications as a directional RNA-recording tool in cells. Furthermore, we highlight outstanding questions for RT-Cas1-Cas2 studies and future directions for RNA-recording CRISPR technologies.

Comparative proteomic analysis of PK-15 cells infected with wild-type strain and its EP0 gene-deleted mutant strain of pseudorabies virus

  • Di Wang;Dongjie Chen;Shengkui Xu;Fang Wei;Hongyuan Zhao
    • Journal of Veterinary Science
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    • v.25 no.4
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    • pp.54.1-54.16
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    • 2024
  • Importance: As one of the main etiologic agents of infectious diseases in pigs, pseudorabies virus (PRV) infections have caused enormous economic losses worldwide. EP0, one of the PRV early proteins (EP) plays a vital role in PRV infections, but the mechanisms are unclear. Objective: This study examined the function of EP0 to provide a direction for its in-depth analysis. Methods: In this study, the EP0-deleted PRV mutant was obtained, and Tandem Mass Tag-based proteomic analysis was used to screen the differentially expressed proteins (DEPs) quantitatively in EP0-deleted PRV- or wild-type PRV-infected porcine kidney 15 cells. Results: This study identified 7,391 DEPs, including 120 and 21 up-regulated and down-regulated DEPs, respectively. Western blot analysis confirmed the changes in the expression of the selected proteins, such as speckled protein 100. Comprehensive analysis revealed 141 DEPs involved in various biological processes and molecular functions, such as transcription regulator activity, biological regulation, and localization. Conclusions and Relevance: These results holistically outlined the functions of EP0 during a PRV infection and might provide a direction for more detailed function studies of EP0 and the stimulation of lytic PRV infections.

A discretization method of the three-dimensional poisson's equation with excellent convergence characteristics (우수한 수렴특성을 갖는 3차원 포아송 방정식의 이산화 방법)

  • 김태한;이은구;김철성
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.8
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    • pp.15-25
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    • 1997
  • The integration method of carier concentrations to redcue the discretization error of th box integratio method used in the discretization of the three-dimensional poisson's equation is presented. The carrier concentration is approximated in the closed form as an exponential function of the linearly varying potential in the element. The presented method is implemented in the three-dimensional poisson's equation solver running under the windows 95. The accuracy and the convergence chaacteristics of the three-dimensional poisson's equation solver are compared with those of DAVINCI for the PN junction diode and the n-MOSFET under the thermal equilibrium and the DC reverse bias. The potential distributions of the simulatied devices from the three-dimensional poisson's equation solver, compared with those of DAVINCI, has a relative error within 2.8%. The average number of iterations needed to obtain the solution of the PN junction diode and the n-MOSFET using the presented method are 11.47 and 11.16 while the those of DAVINCI are 21.73 and 23.0 respectively.

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Material feature representation and identification with composite surfacelets

  • Huang, Wei;Wang, Yan;Rosen, David W.
    • Journal of Computational Design and Engineering
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    • v.3 no.4
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    • pp.370-384
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    • 2016
  • Computer-aided materials design requires new modeling approaches to characterize and represent fine-grained geometric structures and material compositions at multiple scales. Recently, a dual-Rep approach was developed to model materials microstructures based on a new basis function, called surfacelet. As a combination of implicit surface and wavelets, surfacelets can efficiently identify and represent planar, cylindrical, and ellipsoidal geometries in material microstructures and describe the distribution of compositions and properties. In this paper, these primitive surfacelets are extended and composite surfacelets are proposed to model more complex geometries. Composite surfacelets are constructed by Boolean operations on the primitives. The surfacelet transform is applied to match geometric features in three-dimensional images. The composition of the material near the identified features can then be modeled. A cubic surfacelet and a v-joint surfacelet are developed to demonstrate the reverse engineering process of retrieving material compositions from material images.