• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.1937-1940
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• 2008

The P1 duplex of Tetrahymena group I ribozyme is the important system for studying the conformational changes in folding of ribozyme. The formation of the P1 duplex between IGS and substrate RNA and the catalytic activity of ribozyme require a variety of metal ions such as $Mg^{2+}$ and $Mn^{2+}$. In order to investigate the effect of the $Mg^{2+}$ concentration on the conformation of the P1 duplex, the NMR study was performed as a function of $Mg^{2+}$ concentration. This study revealed that the less stable AU-rich region formed duplex at $50{^{\circ}C}$ under high $Mg^{2+}$ concentration condition but melts out under low $Mg^{2+}$ concentration condition. It was also found that in the active conformation under 10 mM $MgCl_2$ condition, the unstable central G${\cdot}$U wobble pair maintains the significant base pairing up to $50{^{\circ}C}$. This study provides the information of the unique feature of the P1 duplex structure and the roll of $Mg^{2+}$ ion on the formation of the active conformation.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.61-75
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• 2003

Comprehensive review on the determination of critical state parameters in sandy soils from standard triaxial testing was performed to facilitate the application of critical state soil mechanics to the shear behavior of sandy soils. First, semantic differences in literature were clarified, inferring that critical state should be considered as the ultimate state at large deformation. Second, the characteristics of critical state parameters were discussed, and also the uniqueness of critical state line and the sensitivity of quasi-steady state condition were verified in relation to initial state, fabric, loading condition, and drainage condition. Third, as an example, the critical state soil mechanics was applied to evaluate the post-liquefaction shear strength, i.e. the reliable ultimate shear strength in liquified soils, in terms of critical state parameters.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.589-598
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• 2013

In order to understand 3D visual fatigue, it is necessary to examine the visual fatigue induced by camera parameters as well as that induced by a pre-existing 3D content. In the present study, we examined the effects of camera parameters, such as roll misalignment error, shooting distance and vergence condition on 3D visual fatigue and we modelled it. The results indicate that roll misalignment error, shooting distance and vergence condition affect 3D visual fatigue and the effect of roll misalignment error on 3D visual fatigue is evident specifically when screen disparity is relatively small.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.28 no.1
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• pp.42-53
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• 2019

I think the following conditions should be met for a successful anterior aesthetic restorations. They include the patient's facial and dental harmony, the coordination between the tooth and periodontal tissue, and the continuity with the adjacent teeth. However, in the laboratory process of making restorations, the dental technician works on the model without meeting the patient in person, so he or she has to rely on his or her knowledge and skills to make restoration within limited information. In this article, I discuss the biological criteria that I think as a dental technician and the forms of restorations and how to grant them to the sound periodontal condition.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.2
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• pp.17-26
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• 2015

In this study the location condition and the management of the Rural Experience Tourism Villages located around unified Cheongju city has been surveyed or investigated. On the basis of the results of the survey or investigation this study is to suggest a way to make activate the Rural Experience Tourism Villages which have been inactive. The ways of the research include the understanding of what means the activation of rural areas and then this study is to find the problems with the Rural Experience Tourism Villages and to suggest final ways or plans after the field investigation of the condition of the location and management of the Villages. In this study I had full understanding of the concept of the activation for rural areas and the humanistic and geographical characteristics and then made a wide investigation and analysis of the location condition and the management of the Rural Experience Tourism Villages in this area. Based on the theory and the results of the actual investigation I made a suggestion of basic direction for the improvement of the Villages and the ways for activation of the Villages. I really expect these suggestions of mine to make active contribution to make the actual plan through the promotion of the Rural Experience Tourism Villages.

• Korean Journal of Optics and Photonics
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• v.7 no.2
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• pp.150-156
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• 1996

RWG MQW-LD has been made with our vertical LPE system from the optimal design condition for the RWG MQW-LD to be activated as weakly index-guided LD. Through several experiments we have established the growth condition which can be used through to grow the MQW-DH wafer and to control the thickness of MQW layer to ~200$\AA$. 4 ${\mu}{\textrm}{m}$-thickness of the ridge pattern has been formed through the photolithographic process on the MQW-DH wafer grown by the former condition, and then we have fabricated the RWG MQW-LD using it. From the result of measuring the electro-optical characteristics we can make sure that it can be lasing as lasing as laterally single mode at even more than $2.7I_{th}$.

• Nonlinear Functional Analysis and Applications
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• v.27 no.4
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• pp.709-730
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• 2022

We consider the nonlinear matrix equation (NMEs) of the form 𝓤 = 𝓠 + Σ^k_i=1 𝓐^*_iℏ(𝓤)𝓐_i, where 𝓠 is n × n Hermitian positive definite matrices (HPDS), 𝓐₁, 𝓐₂, . . . , 𝓐_m are n × n matrices, and ~ is a nonlinear self-mappings of the set of all Hermitian matrices which are continuous in the trace norm. We discuss a sufficient condition ensuring the existence of a unique positive definite solution of a given NME and demonstrate this sufficient condition for a NME 𝓤 = 𝓠 + 𝓐^*₁(𝓤²/900)𝓐₁ + 𝓐^*₂(𝓤²/900)𝓐₂ + 𝓐^*₃(𝓤²/900)𝓐₃. In order to do this, we define 𝓕𝓖_w-contractive conditions and derive fixed points results based on aforesaid contractive condition for a mapping in extended Branciari b-metric distance followed by two suitable examples. In addition, we introduce weak well-posed property, weak limit shadowing property and generalized Ulam-Hyers stability in the underlying space and related results.

• Advances in nano research
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• v.14 no.4
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• pp.303-312
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• 2023

In this study, the bifurcation analysis of functionally graded material is done using exponential volume fraction law. Shell theory of Love is used for vibration of shell. The Galerkin's method is applied for the formation of three equations in eigen value form. This eigen form gives the frequencies using the computer software MATLAB. The variations of natural frequencies (Hz) for Type-I and Type-II functionally graded cylindrical shells are plotted for exponential volume fraction law. The behavior of exponent of volume fraction law is seen for three different values. Moreover, the frequency variations of Type-I and -II clamped simply supported FG cylindrical shell with different positions of ring supports against the circumferential wave number are investigated. The procedure adopted here enables to study vibration for any boundary condition but for brevity, numerical results for a cylindrical shell with clamped simply supported edge condition are obtained and their analysis with regard various physical parameters is done.

• Transactions of Materials Processing
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• v.4 no.2
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• pp.169-179
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• 1995

Static restoration mechanism during hot interrupted deformation of Cu-Zn alloy was studied in the temperature range from $550^{\circ}C$ to $750^{\circ}C$ and at a constant strain rate of 0.1/sec. At a given temperature, the hot interrupted deformations were performed with variation of interrupted time $t_i$ form 1 to 50 sec and of interrupted strain ${\varepsilon}_i$ from 0.15 to 0.90. From the analysis of the values of the critical strain of ${\varepsilon}_c$ for tje initiation of dynamic recrystallization and the peak strain of${\varepsilon}_p$, the relationship ${\varepsilon}_c{\fallingdotseq}0.7{\varepsilon}_p$ was obtained. It was clarified that the softening of the interrupted deformation was mainly the static recrystallization and the fractional softening(FS) which was over 30% mostly confirmed this result. The fractional softening of the interrupted time $t_i$ especially and pre-strain. The FS increased with increasing strain rate, interrupted time and pre-strain. The change of microstructures after hot deformation could be predicted by the FS. when the FS was 30~100%, static recrystallization was happened and grain growth was observed at the condition which was $750^{\circ}C$ deformation temperature, 0.45 prestrain and this condition's FS value was over 100%.

• The Mathematical Education
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• v.45 no.4 s.115
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• pp.481-491
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• 2006

Diffy is a simple mathematical puzzle that provides elementary-school students with subtraction practice. The idea appears to have originated in the late nineteenth century with E. Ducci of Itali. Thirty years ago Professor J. Copley of the University of Houston introduced the diffy game to teachers in elementary schools and it widely spreaded out. During the diffy activity we naturally guess many interesting conjectures. First, does diffy always end? Second, does the head of diffy always exist? Third, for an arbitrary given natural number n, is there any possible method to find the diffy with the given length n? In this study I give the necessary and sufficient condition for the existence of the head of diffy. Using this condition I classify all possible heads of diffy and provide an algorithm to find the diffy with any given length n. With this algorithm I find four natural numbers with diffy length 200. To ensure my numbers are correct, I make a diffy program for Mathematica and check they are correct. I suggest the diffy game is good for enlarging the mathematical thinking to all graded students, especially gifted and talented students, It will produce rational consideration and synthetic judgement.