• Tuberculosis and Respiratory Diseases
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• v.51 no.6
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• pp.517-529
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• 2001

Background : Surfactant protein C(SP-C) is a hydrophobic 5,000 dalton molecule. SP-C has the primary roles in accelerating surface spreading of a surfactant phospholipid. The filter hybridization and solution hybridization assays are both rapid and sensitive and can be used to measure the RNAs complementary to any cloned DNA sequence. Methods : The authors measured the SP-C mRNA levels quantitatively using solution hybridization and filter hybridization assays to obtain a standard curve equation to quantify the mRNA of unknown samples comparatively. Results : 1. The minimum level of the specimens by solution hybridization was 3 pg for SP-C mRNA. 2. The standard curve equation of the solution hybridization assay between the counts per minute(Y) and the SP-C mRNA transcript input(X) was Y=6.46 X+244. The correlation coefficient was 0.99. 3. The minimum detection level of specimens by filter hybridization was 0.1 ng for SP-C mRNA. 4. The standard curve equation of the filter hybridization assay between the counts per minute(Y) and SP-C mRNA transcript input(X) is Y=2541.6 X+252.7. The correlation coefficient was 0.99. Conclusions : A comparison of CPM/filter in the linear range allowed an accurate and reproducible estimation of the SP-C mRNA copy number. Filter hybridization and solution hybridization assays are both rapid and sensitive and can be used to measure the RNAs complementary to any cloned DNA sequence. It is ideally suited to situations where accurate quantitation of multiple samples is required.

• Journal of Microbiology
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• v.41 no.3
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• pp.239-247
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• 2003

The LRV1-4 capsid protein possesses an endoribonuclease activity that is responsible for the single site-specific cleavage in the 5' untranslated region (UTR) of its own viral RNA genome and the formation of a conserved stem-loop structure (stem-loop IV) in the UTR is essential for the accurate RNA cleavage by the capsid protein. To delineate the nucleotide sequences, which are essential for the correct formation of the stem-loop structure for the accurate RNA cleavage by the viral capsid protein, a wildtype minimal RNA transcript (RNA 5' 249-342) and several synthetic RNA transcripts encoding point-mutations in the stem-loop region were generated in an in vitro transcription system, and used as substrates for the RNA cleavage assay and RNase mapping studies. When the RNA 5' 249-342 transcript was subjected to RNase T1 and A mapping studies, the results showed that the predicted RNA secondary structure in the stem-loop region using FOLD analysis only existed in the presence of Mg$\^$2＋/ ions, suggesting that the metal ion stabilizes the stem-loop structure of the substrate RNA in solution. When point-mutated RNA substrates were used in the RNA cleavage assay and RNase T1 mapping study, the specific nucleotide sequences in the stem-loop region were not required for the accurate RNA cleavage by the viral capsid protein, but the formation of a stem-loop like structure in a region (nucleotides from 267 to 287) stabilized by Mg$\^$2＋/ ions was critical for the accurate RNA cleavage. The RNase T1 mapping and EMSA studies revealed that the Ca$\^$2＋/ and Mn$\^$2＋/ ions, among the reagents tested, could change the mobility of the substrate RNA 5' 249-342 on a gel similarly to that of Mg$\^$2＋/ ions, but only Ca$\^$2＋/ ions identically showed the stabilizing effect of Mg$\^$2＋/ ions on the stem-loop structure, suggesting that binding of the metal ions (Mg$\^$2＋/ or Ca$\^$2＋/) onto the RNA substrate in solution causes change and stabilization of the RNA stem-loop structure, and only the substrate RNA with a rigid stem-loop structure in the essential region can be accurately cleaved by the LRV1-4 viral capsid protein.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.939-953
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• 2023

Shallow water equations (SWE) serve as fundamental equations governing the movement of the water. Traditional numerical approaches for solving these equations generally face various challenges, such as sensitivity to mesh generation, and numerical oscillation, or become more computationally unstable around shock and discontinuities regions. In this study, we present a novel approach that leverages the power of physics-informed neural networks (PINNs) to approximate the solution of the SWE. PINNs integrate physical law directly into the neural network architecture, enabling the accurate approximation of solutions to the SWE. We provide a comprehensive methodology for formulating the SWE within the PINNs framework, encompassing network architecture, training strategy, and data generation techniques. Through the results obtained from experiments, we found that PINNs could be an accurate output solution of SWE when its results were compared with the analytical method. In addition, PINNs also present better performance over the Artificial Neural Network. This study highlights the transformative potential of PINNs in revolutionizing water resources research, offering a new paradigm for accurate and efficient solutions to the SVE.

• Journal of Theoretical and Applied Mechanics
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• v.3 no.1
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• pp.1-15
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• 2002

Reduction methods for large structural systems have been reviewed. Mai emphasis is put on the dynamic reduction. Recently, the computing resources and technologies have been expanded so fast that the huge matrices Invoked In the analysis of structural system can be processed without serious difficulties. For most users, however, the computer facilities are limited and the system reductions in some forms are required. The reduction procedure in static problems is simple and straightforward. The major task is the book-keeping in computations. In dynamic problems and structural optimization. however. the problem is much more complicated. The problem is, in general, nonlinear and hence the exact solution is not available. Therefore, approximate solutions are sought in an iterative manner. A proper convergence criterion needs to be employed in order to get an accurate solution efficiently. Several research works have been reported fer the structural optimization combined with system reductions.

• Advances in nano research
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• v.6 no.2
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• pp.113-133
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• 2018

In this work, free vibration characteristics of functionally graded piezoelectric (FGP) nanobeams based on third order parabolic shear deformation beam theory are studied by presenting a Navier type solution as the first attempt. Electro-mechanical properties of FGP nanobeam are supposed to change continuously throughout the thickness based on power-law model. To capture the small size effects, Eringen's nonlocal elasticity theory is adopted. Using Hamilton's principle, the nonlocal governing equations for third order shear deformable piezoelectric FG nanobeams are obtained and they are solved applying analytical solution. By presenting some numerical results, it is demonstrated that the suggested model presents accurate frequency results of the FGP nanobeams. The influences of several parameters including, external electric voltage, power-law exponent, nonlocal parameter and mode number on the natural frequencies of the size-dependent FGP nanobeams is discussed in detail.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.797-801
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• 2003

One of the largest challenges for quantum chemistry today is to obtain accurate results for large complex molecular systems, and a variety of approaches have been proposed recently toward this goal. We have developed the ONIOM method, an onion skin-like multi-level method, combining different levels of quantum chemical methods as well as molecular mechanics method. We have been applying the method to many different large systems, including thermochemistry, homogeneous catalysis, stereoselectivity in organic synthesis, solution chemistry, fullerenes and nanochemistry, and biomolecular systems. The method has recently been combined with the polarizable continuum model (ONIOM-PCM), and was also extended for molecular dynamics simulation of solution (ONIOM-XS). In the present article the recent progress in various applications of ONIOM and other electronic structure methods to problems of homogeneous catalyses and nanochemistry is reviewed. Topics include 1. bond energies in large molecular systems, 2. organometallic reactions and homogeneous catalysis, 3. structure, reactivity and bond energies of large organic molecules including fullerenes and nanotubes, and 4. biomolecular structure and enzymatic reaction mechanisms.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.156-162
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• 2001

An effective and practical method is presented for solving the forward kinematics of a 6-DOF Stewart Platform, using neural network algorithm together with Newton-Raphson method. An approximated solution is obtained from trained neural network, then it is used as an initial estimate for Newton-Raphson method. A series of accurate solutions are calculated with reasonable speed for the entire workspace of the platform. The solution procedure can be used for driving a real-time simulation platform.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.107-118
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• 1986

A heuristic algorithm (SIMICOM) has been designed and tested for optimizing simulated stochastic systems whose performances are functions of several discrete decision variables. The approach adopted utilizes an integer complex method coupled with techniques of establishing confidence intervals for the system's responses. It can handle a general class of optimization problems that could be constrained or unconstrained. In constrained cases, the constraints could either be explicit analytical functions of decision variables or be expressed as other responses of the simulation model. In addition to obtain a reasonably accurate solution, the economic aspect of obtaining the solution has also been taken into consideration.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1409-1415
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• 2017

The navigation and EDR(Event Data Recorder) have a different roles but also a lot of similar or common functions and elements. A representative element is a GPS. The GPS of navigation is a more higher than the that of EDR in performance. The high performance GPS has a very short initialization time and more accurate than the GPS of EDR. And the informations of OBD(On Board Diagnostics) is able to be shared in navigation and EDR. But these inter-working product between the navigation and EDR has been not yet shown. So, this paper is aimed to show how to interwork in two devices. We utilize USB bulk communication in two devices for inter-working. It is very simple ways and it could interwork in GPS, event video and ODB II data. It could be effective in cost competence and convenience. These was implemented by hardware and software and proved by the standard test.

• Journal of the Korean Magnetic Resonance Society
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• v.24 no.3
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• pp.66-69
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• 2020

In ultra-low field magnetic resonance imaging (ULF-MRI), the strength of a static magnetic field can be comparable to that of gradient field. On that occasion, the gradient field is accompanied by concomitant gradient field, which yields distortion and blurring artifacts on MR images. Here, we focused on the distortion artifact and derived the equations capable of correcting it. Its usefulness was confirmed through the corrections in both simulated and experimental images. This solution will be effective for acquiring more accurate images in low and/or ultra-low magnetic fields.