• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.1-11
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• 2016

The domestic and foreign seismic design codes have specified that time history covers design response spectrum when the response spectrum, which calculated from the time history, is smaller than the design response spectrum at five points or less. In order to verify the design codes, time history analysis for a pier was performed by using five artificial time histories conforming design code with various characteristics and its member forces were evaluated according to them. It was confirmed from analysis results that, regardless of the conformity to design code requirement, seismic design using the artificial time histories could not guarantee earthquake resistant design if the response spectrum from them is lower than design response spectrum at the similar period to the natural frequency of structure. Thus, the time history generating method to make its acceleration response spectrum to be greater than design response spectrum at all period was proposed by two modification function in this study. It was also verified whether time histories from the proposed method satisfy the seismic design codes or not.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.677-691
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• 2018

Reliability assessment of complex structures using simulation methods is time-consuming. Thus, surrogate models are usually employed to reduce computational cost. AK-MCS is a surrogate-based Active learning method combining Kriging and Monte-Carlo Simulation for structural reliability analysis. This paper proposes three modifications of the AK-MCS method to reduce the number of calls to the performance function. The first modification is related to the definition of an initial Design of Experiments (DoE). In the original AK-MCS method, an initial DoE is created by a random selection of samples among the Monte Carlo population. Therefore, samples in the failure region have fewer chances to be selected, because a small number of samples are usually located in the failure region compared to the safe region. The proposed method in this paper is based on a uniform selection of samples in the predefined domain, so more samples may be selected from the failure region. Another important parameter in the AK-MCS method is the size of the initial DoE. The algorithm may not predict the exact limit state surface with an insufficient number of initial samples. Thus, the second modification of the AK-MCS method is proposed to overcome this problem. The third modification is relevant to the type of regression trend in the AK-MCS method. The original AK-MCS method uses an ordinary Kriging model, so the regression part of Kriging model is an unknown constant value. In this paper, the effect of regression trend in the AK-MCS method is investigated for a benchmark problem, and it is shown that the appropriate choice of regression type could reduce the number of calls to the performance function. A stepwise approach is also presented to select a suitable trend of the Kriging model. The numerical results show the effectiveness of the proposed modifications.

• Speech Sciences
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• v.3
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• pp.83-92
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• 1998

Vowels are classified by vocal tract shapes. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as $F_l,\;F_2,\;F_3$, and so on. This study reviews the perturbation theory of the tract and determines the corresponding formant frequencies from modified vocal tracts using vocal tract area function. Then, formant variation is observed from the theory. Finally, each set of $F_l,\;F_2,\;and\;F_3$ frequency is input to a speech synthesis software to make a vowel sound. Auditory impression of each sound without any modification of its vocal tract shape is almost the same as the corresponding phonetic symbol. Formant frequencies of $F_l,\;F_2,\;F_3$ vary according to the perturbation theory. Generally, constriction along the node causes formant values to decrease while constriction along the anti-node cause it to increase. Vocal tracts modified by more than $3\;cm^2$ change vowel qualities of /a/ and /i/ into those of f /v/ and /$\varepsilon$/, respectively. This study will be helpful in simulating sounds from modified vocal tracts before any operation. Further studies are desirable to compare vocal tract shapes of various languages and their sounds together.

• Journal of Microbiology
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• v.45 no.1
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• pp.34-40
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• 2007

In budding yeast, G2/M transition is tightly correlated with bud morphogenesis regulated by Swel and septin that plays as a scaffold to recruits protein components. BNI5 isolated as a suppressor for septin defect is implicated in septin organization and cytokinesis. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we show that Bni5 phosphorylation is required for mitotic entry regulated by Swel pathway. Bni5 modification was evident from late mitosis to G1 phase, and CIP treatment in vitro of affinity-purified Bni5 removed the modification, indicative of phosphorylation on Bni5. The phosphorylation-deficient mutant of BNI5 (bni5-4A) was defective in both growth at semi-restrictive temperature and suppression of septin defect. Loss of Bni5 phosphorylation resulted in abnormal bud morphology and cell cycle delay at G2 phase, as evidenced by the formation of elongated cells with multinuclei. However, deletion of Swel completely eliminated the elongated-bud phenotypes of both bni5 deletion and bni5-4A mutants. These results suggest that the bud morphogenesis and mitotic entry are positively regulated by phosphorylation-dependent function of Bni5 which is under the control of Swel morphogenesis pathway.

• Journal of Ocean Engineering and Technology
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• v.27 no.2
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• pp.1-7
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• 2013

This paper aims at contributing to the field of ship design by introducing new systematic variation methods for ship hull forms. Hull form design is generally carried out in two stages. The first is the global variation considering the sectional area curve. Because the geometric properties of a sectional area curve have a decisive effect on the global hydrodynamic properties of ships, the design of a sectional area curve that satisfies various global design conditions, e.g., the displacement, longitudinal center of buoyancy, etc., is important in the initial hull form design stage. The second stage involves the local design of section forms. Section forms affect the local hydrodynamic properties, e.g., the local pressure in the fore- and aftbody. This paper deals with a new method for the systematic variation of sectional area curves. The longitudinal volume distribution of a ship depends on the sectional area curve, which can geometrically be controlled using parametric variation and a variation that uses the modification function. Based on these methods, we suggest a more generalized method in connection with the derivation of the lines for a new design compared to those for similar ships. This is the so-called the volumetric balanced variation (VOB) method for ship forms using a B-spline modification function and an optimization technique. In this paper the global geometric properties of hull forms are totally controlled by the form parameters. We describe the new method and some application examples in detail.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.450-450
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• 2007

Indium tin oxide (ITO), which is used as an electrode in organic thin film transistors (OTFT), was modified with a self-assembled monolayer (SAM) by wet chemical surface modification. The surface of the ITO was treated by dipping method in a solution of 2-chloroethane phosphonic acid (2-CEPA) at room temperature. The work function in the ITO which was modified with the SAM in the 2-CEPA had 5.43eV. A surface energy and a transmittance were unchanged in an error range. On this study, therefore, possibility of ohmic contact is showed in the interface between the ITO and the organic semiconductors. These results suggest that the treatment of the ITO with the SAM can greatly enhance the performance of the OTFT.

• Journal of Life Science
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• v.28 no.12
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• pp.1536-1544
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• 2018

Depression is a common, serious, and recurring mental disorder. The pathogenesis of depression involves many factors such as environmental factor, genetic factor and alteration of structure and function in neurobiological systems. Increasing evidence supports that epigenetic alteration may be associated with depression. The epigenetics is explained as the mechanisms by which environmental factor causes changes in chromatin structure and alters gene expression without changing DNA base sequence. DNA methylation and histone modification involving histone acetylation and methylation are the main epigenetic mechanisms. Animal studies have shown that stressful environment such as early life stress can leave persistent epigenetic marks in the genome, which alter gene expression and influence neural and behavioral function through adulthood. A potentially important gene in depression is brain-derived neurotrophic factor (BDNF). BDNF plays a central role in depression and antidepressant action. In studies of the rodent, exposure to stress at prenatal, postnatal, and adult stages alters BDNF expression through histone modification and DNA methylation of the BDNF gene which results in anxiety and depressive-like behavior. This review discusses recent advances in the study of the epigenetic mechanisms that contribute to depression, particularly histone modification and DNA methylation of the BDNF gene, that may help in the development of new targets for depression treatment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2167-2173
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• 1996

An approximate weight function technique using the indirect boundary integral equation has been presented for the analysis of stress intensity foactors(SIFs) of a thick pipe. One-term boundary integral was introduced to represent the crack surface displacement field for the displacement based weight function technique. An explicit closed-form SIF solution applicable to symmetric cracked pipes without any modification of the solution including both circumferential and radial cracks has been derived. The necessary information in the analysis is two or three reference SIFs. In most cases the SIF solution were in good agreement with those available in the literature.

• Journal of the Korean Data and Information Science Society
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• v.14 no.4
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• pp.929-937
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• 2003

Kernel type estimations of discontinuity point at an unknown location in regression function or its derivatives have been developed. It is known that the discontinuity point estimator based on $Gasser-M\ddot{u}ller$ regression estimator with a one-sided kernel function which has a zero value at the point 0 makes a poor asymptotic behavior. Further, the asymptotic variance of $Gasser-M\ddot{u}ller$ regression estimator in the random design case is 1.5 times larger that the one in the corresponding fixed design case, while those two are identical for the local polynomial regression estimator. Although $Gasser-M\ddot{u}ller$ regression estimator with a one-sided kernel function which has a non-zero value at the point 0 for the modification is used, computer simulation show that this phenomenon is also appeared in the discontinuity point estimation.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.168-174
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• 2005

Reconstruction of the lower lip requires consideration of several factors. There should be retained sensation, maintenance of oral sphincter function, and a large enough opening for the mouth. In addition, it is important to achieve an aesthetically acceptable appearance. Webster's modification of Bernard operation is one of good methods which satisfy above mentioned goals. The purpose of this article is to present the results and review the perioperative problems after reconstruction of the lower lip by this operation. We reviewed seven patients after surgical reconstruction by the same method between January of 1996 and December of 2003. Five patients were male and two were female. The mean follow-up period was 15 months. We obtained functionally and cosmetically acceptable appearance after reconstruction. Most of the reconstructed lower lips were large enough for full mouth opening, but one patient required additional commissuroplasty, and one other patient was treated with wound revision for dehiscence resulting from protrusion of mandibular lateral incisor tooth. All other patients accepted their facial appearance. In conclusion, careful planning and consideration for dental problems and proper closure tension may ensure satisfactory outcome & lower lip competence, when using this modified operative method for lower lip reconstruction.