• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1192-1201
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• 2009

Analysis of the vibration characteristic for cylindrical shell is more complex than plates since the coupling effects are considered on three dimensions. Based on Love's equation, spectral finite element method(SFEM) is introduced to predict frequency response function of finite circular cylindrical shell in the air with simply supported - free boundary condition without simplifying the equation of motion. And for the radiated noise analysis of cylindrical shell, indirect boundary element method(BEM) is applied using out-of-plane displacements as an input from structural vibration analysis. Comparisons of the structural vibration results by the spectral finite element method and commercial code, NASTRAN(FEM based) are carried out. Likewise, for verification of radiated noise analysis results, commercial code, SYSNOISE(BEM based) are used.

• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.83-89
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• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.3
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• pp.91-98
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• 2003

The importance of improving the quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and systems. The transient over-voltages on low-voltage power distribution systems are induced by direct or indirect lightning return strokes. These can cause damage and/or malfunction of the utility systems for home automation, office automation, factory automation, medical automation, etc. The behaviors of lightning overvoltages transferred through the transformer to the low-voltage distribution systems using a Marx generator were experimentally investigated. Furthermore, the coupling mechanisms of lightning overvoltages transferred to the low-voltage systems were clearly illustrated through a theoretical simulation using a Pspice program. The overvoltages in low-voltage ac power systems are rarely limited by the application of the surge arrester to the primary side of the distribution transformer. A superior surge protection scheme is to install surge protection devices at the service entrance switchboard and/or at the load devices in TN power systems.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.87-101
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• 2023

The constituents of a watershed control a wide range of ecosystem processes, such as, carbon sequestration, nutrient retention, and biodiversity preservation. Maintenance of a healthy watershed is advantageous to humans in many direct and indirect ways. Dissolved organic matter fluorescence analysis is one of the most commonly utilized parameters for water quality measurement, pollution source tracking, and determination of the ecological state of a watershed. Throughout the recent decades, the advancement in data processing, instrumentation, and methods has resulted in many improvements in the area of watershed study with fluorescence analysis. The current trend of coupling advanced instrumentations and new comparative parameters, such as, microplastics of different types, antibiotics, and specific bacterial contaminants have been reported in watershed studies. However, conventional methodologies for obtaining fluorescence excitation emission matrices and for calculating the fluorescence and spectral indices are preferred to advanced methods, due to their easiness and simple data collection. This review aims to gain a general understanding of the use of dissolved organic matter fluorescence analysis for diagnosis and source identification of watershed pollutions, by focusing on how the studies have utilized fluorescence analysis to improve existing knowledge and techniques in recent years.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1239-1248
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• 2004

The methylotrophic yeast Hansenula polymorpha has been extensively studied as a model organism for methanol metabolism and peroxisome biogenesis. Recently, this yeast has also attracted attention as a promising host organism for recombinant protein production. Here, we describe the fabrication and evaluation of a DNA chip spotted with 382 open reading frames (ORFs) of H. polymorpha. Each ORF was PCR-amplified using gene-specific primer sets, of which the forward primers had 5'-aminolink. The PCR products were printed in duplicate onto the aldehyde-coated slide glasses to link only the coding strands to the surface of the slide via covalent coupling between amine and aldehyde groups. With the partial genome DNA chip, we compared efficiency of direct and indirect cDNA target labeling methods, and found that the indirect method, using fluorescent-labeled dendrimers, generated a higher hybridization signal-to-noise ratio than the direct method, using cDNA targets labeled by incorporation of fluorescence-labeled nucIeotides during reverse transcription. In addition, to assess the quality of this DNA chip, we analyzed the expression profiles of H. polymorpha cells grown on different carbon sources, such as glucose and methanol, and also those of cells treated with the superoxide­generating drug, menadione. The profiles obtained showed a high-level induction of a set of ORFs involved in methanol metabolism and oxidative stress response in the presence of methanol and menadione, respectively. The results demonstrate the sensitivity and reliability of our arrays to analyze global gene expression changes of H. polymorpha under defined environmental conditions.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.584-594
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• 2014

To increase of surface hydrophilicity of polymeric thin films is an important approaching technique for introduction of self-cleaning and/or antifogging properties on the surfaces of those films. In general, hydrophilic surface can be produced by coating non ionic surfactants or by increasing surface energy. Various non-ionic surfactants, such as Tween, Span, and PEG-PPG block copolymers were selected for our experiments, because they are cheap and well soluble in toluene system as well as they contain several reactive hydroxy fuctional groups with coupling agents. Blending conditions influence the PET film surface hydrophilicities. However, the introduction of only these surfactants on the surface of PET films did not show the high durability of hydrophilic properties after washing with water. To improve the durability two types of coupling agents such as epoxide and diisocyanate were adopted. Contact angle of water on hydrophilically coated PET film surface with 6 wt% of isophrone diisocyanate(IPDI) containing coating solution was reached to $8.7^{\circ}$, which was an indirect evidence for very high surface hydrophilicity. A light(500 nm of wavelength) transmittance value of coated PET film was changed only from 87% to 85% with keeping a good transparent property. This film can be usable for self-cleaning film industries.

• Journal of Food Hygiene and Safety
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• v.9 no.3
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• pp.123-131
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• 1994

An enzyme-linked immunosorbent assay(ELISA) was developed for the detection of residual gentamicin(GM) in edible animal products. The immunogen(GM-KLH conjugate) and coating antigen(GM-BSA conjugate) were prepared by coupling GM sulfate to keyhole limpet hemocyanin(KLH) and bovine serum albumin(BSA) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, respectively. Polyclonal antibody to GM was produced in rabbits(New Zealand White, female) by using the immunogen and the antibody titer was measured by indirect ELISA. A competitive ELISA was developed using GM-bovine serum albumin conjugate as a coating antigen, GM(as standards or sample), polyclonal antibody to GM, secondary antibody conjugated with horseradish peroxidase as an enzyme, and H2O2 and o-phenylenediamine dihydrochloride as a substrate and a chromophore, respectively. The detection limit of GM was 10 ng/ml and the standard curve of GM(n=26) was linear up to 10 $\mu\textrm{g}$/ml in this competitive ELISA system. There were no cross-reactivities of the partially purified antibody between GM and the various antibiotice such as amikacin, benzyl-penicillin, chloramphenicol, erythromycin, furazlidone, kanamycin, neomycin, oleandomycin, streptomycin, sulfathiazole and thiamphenicol(CR50<0.05%)

• Journal of Engineering Education Research
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• v.19 no.2
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• pp.45-52
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• 2016

The employment rate of a college has long been one of the most important elements in college survival strategies. Employment rates may not be key to colleges' survival in other countries, but they are fundamental to colleges in Korea as seen in the Korean government-led National Competency Standard (NCS), which has been underway since its introduction to colleges in Korea. Against this backdrop, if the engineering accreditation system can contribute to improving employment rate in this context, it can take root more quickly. The process conducive to improving employment rates can be classified as both direct and indirect methods. With dwindling school-age population having impacts on colleges and universities, the environment and the education directions of colleges have rapidly been shifting since the introduction of the NCS. Therefore, various survival strategies for colleges need to be developed. An indicator of employment rate of college graduates is among the most important things during this transition process. The Department of Mechanical Engineering at Koje College has consistently shown good records during the past 5 years by matching the accreditation schemes and employment strategies. The department will help put in place the engineering technology education accreditation system at the college through its various innovative and effective programs. To formulate a better employment strategy, it is needed to reflect and consolidate the engineering accreditation scheme into the existing employment policy of college. In short, this paper examines both the engineering accreditation scheme and the employment policy in ways that helps produce a coupling matrix structure. This study looks into the measures for improving employment rates by better adjusting the engineering education methods under the accreditation scheme.

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.176-181
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• 1980

Yeast invertase was immobilized on the 2 kinds of matrices : one is an indirectly coupled enzyme to the cyanogen bromide activated Sepharose by using ${\omega}-aminohexyl$ group as an extension arm, and the other is a tightly adsorbed enzyme on the modified hydrophobic cellulose derivative which has a phenoxyacetyl group as a linkage. The enzyme preparation coupled on Sepharose retained 26.0% of the original activity against sucrose as a substrate, while the preparation immobilized on phenoxyacetyl cellulose retained 72.9% . The immobilized invertase preparation on ${\omega}-aminohexyl$ Sepharose showed the optimal pH 4.5, optimal temperature $60^{\circ}C$, activation energy $5,941\;cal/mole{\cdot}deg$ and Km' 22.2 mM against sucrose, while the preparation adsorbed on phenoxyacetyl cellulose showed the optimal pH 4.0, optimal temperature $60^{\circ}C$, activation energy $7,769\;cal/mole{\cdot}deg$ and Km' 69.9 mM.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.275-284
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• 2016

PURPOSE. The aim of this study was to evaluate the influence of different surface treatment methods on the microtensile bond strength of resin cement to resin nanoceramic (RNC). MATERIALS AND METHODS. RNC onlays (Lava Ultimate) (n=30) were treated using air abrasion with and without a universal adhesive, or HF etching followed by a universal adhesive with and without a silane coupling agent, or tribological silica coating with and without a universal adhesive, and divided into 6 groups. Onlays were luted with resin cement to dentin surfaces. A microtensile bond strength test was performed and evaluated by one-way ANOVA and Tukey HSD test (${\alpha}$=.05). A nanoscratch test, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy were used for micromorphologic analysis (${\alpha}$=.05). The roughness and elemental proportion were evaluated by Kruskal-Wallis test and Mann-Whitney U test. RESULTS. Tribological silica coating showed the highest roughness, followed by air abrasion and HF etching. After HF etching, the RNC surface presented a decrease in oxygen, silicon, and zirconium ratio with increasing carbon ratio. Air abrasion with universal adhesive showed the highest bond strength followed by tribological silica coating with universal adhesive. HF etching with universal adhesive showed the lowest bond strength. CONCLUSION. An improved understanding of the effect of surface treatment of RNC could enhance the durability of resin bonding when used for indirect restorations. When using RNC for restoration, effective and systemic surface roughening methods and an appropriate adhesive are required.