• Title/Summary/Keyword: GCV

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GLOBAL GENERALIZED CROSS VALIDATION IN THE PRECONDITIONED GL-LSQR

  • Chung, Seiyoung;Oh, SeYoung;Kwon, SunJoo
    • Journal of the Chungcheong Mathematical Society
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    • v.32 no.1
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    • pp.149-156
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    • 2019
  • This paper present the global generalized cross validation as the appropriate choice of the regularization parameter in the preconditioned Gl-LSQR method in solving image deblurring problems. The regularization parameter, chosen from the global generalized cross validation, with preconditioned Gl-LSQR method can give better reconstructions of the true image than other parameters considered in this study.

MULTI-PARAMETER TIKHONOV REGULARIZATION PROBLEM WITH MULTIPLE RIGHT HAND SIDES

  • Oh, SeYoung;Kwon, SunJoo
    • Journal of the Chungcheong Mathematical Society
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    • v.33 no.4
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    • pp.505-516
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    • 2020
  • This study shows that image deblurring problems can be transformed into the multi-parameter Tikhonov type with multiple right hand sides. Also, this paper proposes the extension of the global generalized cross validation to obtain an appropriate choice of the regularization parameters for this problem. The experimental results of using the preconditioned Gl-CGLS algorithm were analyzed.

Expression and Antigenicity of Replicase Protein from Snow Mountain-Like Caliciviruses, Korean Isolates (한국형 사람 Calicivirus Replicase 단백의 발현 및 항원성 평가)

  • Chang, Mi-Yoon;Yang, Jai-Myung;Kim, Kyung-Hee
    • The Journal of Korean Society of Virology
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    • v.27 no.2
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    • pp.151-160
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    • 1997
  • In view of the potential of replicase protein as a diagnostic reagent for human caliciviruses (HuCVs), we have cloned and over-expressed this gene from the Snow Mountain-like Korean strains in Escherichia coli as a fusion protein with glutathione S-transferase (GST), and described the preliminary antigenic characterization of the recombinant products. Each 470bp fragment corresponding to highly conserved region of RNA-dependent RNA polymerase was generated by RT-PCR from stools of two diarrheal children, cloned in pMOSBlue T-vector, and subcloned between the EcoRI and SalI restriction sites of pGEX-4T-3, a GST gene fusion vector, yielding $pGCV_{pol}$. This construct expressed a Snow Mountain-like HuCV replicase under the control of the IPTG-inducible tac promoter. An extract prepared by sonication of the E. coli cell inclusion bodies bearing $pGCV_{pol}$ products was purified and analyzed by SDS-PAGE. After Coomassie blue staining, it was shown that the recombinant replicase migrated on the gels with an approximate molecular mass of 46.5 kDa, that was subsequently cleaved into a 26 kDa GST fragment and a 20.5 kDa replicase protein upon digestion with thrombin protease. The replicase was recognized on immunoblotting with the sera from symptomatic children with the HuCV-associated diarrhea but not by asymptomatic sera from adults. The results presented the first biological activity of individually expressed HuCV replicase subunit and provided important reagents for diagnosis of HuCV infection.

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Effect of Immune System on Retrovirus-Mediated Herpes Simplex Virus Thymidine Kinase Gene Therapy (면역체계가 Retroviral Vector로 이입한 Herpes Simplex Virus Thymidine Kinase 유전자치료에 미치는 영향)

  • Park, Jae-Yong;Joo, So-Young;Chang, Hee-Jin;Son, Ji-Woong;Kim, Kwan-Young;Kim, Keong-Seok;Kim, Chang-Ho;Park, Jae-Ho;Lee, Jong-Ki;Jung, Tae-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.2
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    • pp.229-240
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    • 1999
  • Background: The impact of the immune response on cancer gene therapy using viral vectors to deliver a "suicide gene" is currently unclear. A vigrous immune response targeted at viral proteins or transgene may enhance the efficacy of tumor destruction and even augment responses to tumor antigens. These responses may involve the release of cytokines and stimulation of tumor specific cytotoxic T-lymphocytes that enhance therapeutic efficacy. On the other hand, a vigorous rapid cellular immune response may destroy cells expressing the therapeutic gene and attenuate the response to therapy. Furthermore, development of neutralizing antibody responses may prevent readministration of virus, a potentially significant limitation. Evaluating the significance of these limitations in animal models and developing solutions are therefore of obvious importance. Methods: After retroviral transduction of mouse mesothelioma cell line(AB12) with Herpes Simplex Virus thymidine kinase (HSVtk) gene in vitro, subcutaneous flank tumors were established. To study the effect of intact immune system on efficacy of tumor erradication, the ability of the HSVtk/ganciclovir system to inhibit tumor growth was compared among normal Balb/c mice, immunodeficient Balb/c-nude and SCID mice, and Balb/c mice immunosuppressed with cyclosporin. Results: Ganciclovir treatment resulted in greater inhibition of tumor growth in Balb/c mice compared with immunodeficient Balb/c-nude mice and SCID mice(in immunodeficient mice, there were no growth inhibition by ganciclovir treatment). Ganciclovir treatment resulted in greater inhibition of tumor growth in noncyclosporin (CSA) treated Balb/c mice compared with CSA treated Balb/c mice. On day 8, mean ganciclovir-treated tumor volume were 65% of control tumor volume in Balb/c mice versus 77% control tumor volume in CSA-treated Balb/c mice. This effect was still evident during therapy (day 11 and 13). On day 13, non-CSA treated tumor volume was 35% of control tumor volume versus 60% of control tumor volume in CSA treated Balb/c mice. Duration of expression of HSVtk was not affected by the immunosuppression with CSA. Conclusion: These results indicate that the immune responses against retrovirally transduced cells enhance the efficacy of the HSVtk/ganciclovir system. These findings have important implications for clinical trials using currently available retrovirus vectors as well as for future vector design.

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PRECONDITIONED GL-CGLS METHOD USING REGULARIZATION PARAMETERS CHOSEN FROM THE GLOBAL GENERALIZED CROSS VALIDATION

  • Oh, SeYoung;Kwon, SunJoo
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.4
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    • pp.675-688
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    • 2014
  • In this paper, we present an efficient way to determine a suitable value of the regularization parameter using the global generalized cross validation and analyze the experimental results from preconditioned global conjugate gradient linear least squares(Gl-CGLS) method in solving image deblurring problems. Preconditioned Gl-CGLS solves general linear systems with multiple right-hand sides. It has been shown in [10] that this method can be effectively applied to image deblurring problems. The regularization parameter, chosen from the global generalized cross validation, with preconditioned Gl-CGLS method can give better reconstructions of the true image than other parameters considered in this study.

Sparse Kernel Regression using IRWLS Procedure

  • Park, Hye-Jung
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.735-744
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    • 2007
  • Support vector machine(SVM) is capable of providing a more complete description of the linear and nonlinear relationships among random variables. In this paper we propose a sparse kernel regression(SKR) to overcome a weak point of SVM, which is, the steep growth of the number of support vectors with increasing the number of training data. The iterative reweighted least squares(IRWLS) procedure is used to solve the optimal problem of SKR with a Laplacian prior. Furthermore, the generalized cross validation(GCV) function is introduced to select the hyper-parameters which affect the performance of SKR. Experimental results are then presented which illustrate the performance of the proposed procedure.

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Acoustic holography for an engine radiation noise using equivalent sources (등가음원을 이용한 엔진 방사 소음의 음향 홀로그래피에 대한 연구)

  • Jeon, In-Youl;Ih, Jeong-Guon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.1101-1106
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    • 2004
  • This study presents the reconstruction of sound field radiated from an automotive engine using equivalent sources. Basic concept of the method presented is to replace the engine noise source with elementary sources of multipoles, e.g., monopoles and dipoles. The so-called Helmholtz equation least-squares (HELS) method can reconstruct the sound radiation fields from spherical geometries in a series expansion of spherical Hankel functions and spherical harmonics. In this paper, multi-Point, multipole equivalent sources are employed to reconstruct the sound field radiated from an automotive engine with a fixed rotation speed. To ensure and improve the accuracy of reconstruction, the spatial filters of multipole coefficients and wave-vectors are adopted for suppressing the adverse effect of high-order multipoles. Optimal filter shapes are designed with regularization parameters minimizing the generalized cross validation (GCV) function between actual and reproduced model. After regeneration of field pressures using the proposed method as many as necessary, the vibro-acoustic field of an engine could be reconstructed by using the BEM-based near-field acoustic holography (NAH) technique in a cost-effective manner.

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The Combining Ability Effects for the Several Quantitative Characters in the Silkworms (Bombyx mori L.) by the Diallel Crosses. (이면교잡 의한 가잠의 몇가지 계량형질의 조합능력분석)

  • Jang, Chang-Sik;Son, Hae-Ryong;Kim, Nak-Sang
    • Journal of Sericultural and Entomological Science
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    • v.28 no.2
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    • pp.28-34
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    • 1986
  • The general combining ability (GCV), the specific combining ability (SCA) and the reciprocal combining ability (RCA) effects wereobtained by 8$\times$8 diallel crosses of the silkworms with four Japanese races and four Chinese races, total eight lines. The result are as follows ; 1. The general combining ability (GVA) effects appeared high significant level in the total and the fifth instar periods (TP, FP), a female and a male cocoon weights (FW, MW), a female and a male cocoon layer weights (FL, ML) and a female and a male cocoon layer ratios (FR, MR). Only the reciprocal combining ability (RCA) effects appeared high significant level in the total and the fifth instar periods (TP, FP). 2. The Japanese original silkworm lines varied in the general combining ability effects from -0.864 to 0.578, and the Chinese original silkworm lines did in ones from -0.570 to 1.018. 3. The specific combining ability effects of the silkworm lines made in order of the crossing types of JL (Japanese lines) $\times$CL (Chinese lines)>CL$\times$JL>JL$\times$JL> CL$\times$CL in a total cocoon weights and a cocoon layer weights. 4. The reciprocal combining ability effects of the silkworm lines was in order of the crossing types of JL$\times$CL>JL$\times$JL> CL$\times$CL>CL$\times$JL in a total cocoon weights and cocoon layer weights.

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Modification of N-Terminal Amino Acids of Fungal Benzoate Hydroxylase (CYP53A15) for the Production of p-Hydroxybenzoate and Optimization of Bioproduction Conditions in Escherichia coli

  • Tamaki, Shun;Yagi, Mitsuhiko;Nishihata, Yuki;Yamaji, Hideki;Shigeri, Yasushi;Uno, Tomohide;Imaishi, Hiromasa
    • Journal of Microbiology and Biotechnology
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    • v.28 no.3
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    • pp.439-447
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    • 2018
  • The aromatic compound p-hydroxybenzoate (PHBA) is an important material with multiple applications, including as a building block of liquid crystal polymers in chemical industries. The cytochrome P450 (CYP) enzymes are beneficial monooxygenases for the synthesis of chemicals, and CYP53A15 from fungus Cochliobolus lunatus is capable of executing the hydroxylation from benzoate to PHBA. Here, we constructed a system for the bioconversion of benzoate to PHBA in Escherichia coli cells coexpressing CYP53A15 and human NADPH-P450 oxidoreductase (CPR) genes as a redox partner. For suitable coexpression of CYP53A15 and CPR, we originally constructed five plasmids in which we replaced the N-terminal transmembrane region of CYP53A15 with a portion of the N-terminus of various mammalian P450s. PHBA productivity was the greatest when CYP53A15 expression was induced at $20^{\circ}C$ in $2{\times}YT$ medium in host E. coli strain ${\Delta}gcvR$ transformed with an N-terminal transmembrane region of rabbit CYP2C3. By optimizing each reaction condition (reaction temperature, substrate concentration, reaction time, and E. coli cell concentration), we achieved 90% whole-cell conversion of benzoate. Our data demonstrate that the described novel E. coli bioconversion system is a more efficient tool for PHBA production from benzoate than the previously described yeast system.

Expression of the Functional Recombinant Interleukin-16 in E. coli and Mammalian Cell Lines

  • Kim, Seon-Young;Lee, Chang-Hun;Kim, Kyung-Joo;Kim, Yeon-Soo
    • Journal of Microbiology and Biotechnology
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    • v.11 no.2
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    • pp.234-241
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    • 2001
  • The C-terminal 393 bp region of the human interleukin-16 (IL-16) gene was cloned and expressed in E. coli along with mammalian cell lines. Recombinant IL-16 expressed from E. coli was 22 kDa on SDS-PAGE and showed 260% of chemoattractant activity at a concentration of $0.1\;{\mu}g/ml$. HeLa, COS, and Neuro-2a cells were transduced by recombinant retrovirus vector pLNC/IL-16/IRES/TK and the intracellular and secreted amounts of IL-16 produced by HeLa/IL-16/TK, COS/IL-16/TK, and Neuro-2a/IL-16/TK cells were determined by enzyme-linked immunosorbent assay (ELISA). HeLa/IL-16/TK $(1{\times}10^5)$ and COS/IL-16/TK $(1{\times}10^5)$ cells secreted 36.1 and 13.3 ng of IL-16 for 48 h, respectively. Forty-nine ng and 86.4 ng of IL-16 remained in the cell lysates of HeLa/IL-16/TK and COS/IL-16/TK. Intracellular and secreted amounts of IL-16 from Neuro-2a/IL-16/TK $(5{\times}10^5)$ cells during 24 h cultivation were 50 ng and 3.3 ng, respectively. Also, HeLa and COS cells wee stably transfected with mammalian expression vector pCRIII/IL-16. Both culture media and cell lysates prepared from HeLa/IL-16 cells and COS/IL-16 cells showed chemoattractant activity ranging from 190% to 460% as compared to the control experiment. Expression of the herpes simplex virus thymidine kinase (HSV0tk) gene in pLNC/IL-16/ IRES/TK bicistronic retroviral expression vector was verified by performing a genciclovir (GCV) sensitivity assay. Finally, IL-16 repressed Tat-transactivated human immunodeficiency virus type 1 long terminal repeat (HIV-1 LTR) promoter activity.

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