• Structural Engineering and Mechanics
• /
• v.80 no.6
• /
• pp.749-765
• /
• 2021

Suspension bridges bear large eccentric live loads in rush hours when most vehicles travel in one direction on the left or right side of the bridge. With the increasing number and weight of vehicles and the girder widening, the eccentric live load effect on the bridge behavior, including bending and distortion of the main girder, gets more pronounced, even jeopardizing bridge safety. This study proposes an analytical algorithm based on multi-catenary theory for predicting the suspension bridge responses to eccentric live load via the nonlinear generalized reduced gradient method. A set of governing equations is derived to solve the following unknown values: the girder rigid-body displacement in the longitudinal direction; the horizontal projection lengths of main cable's segments; the parameters of catenary equations and horizontal forces of the side span cable segments and the leftmost segments of middle span cables; the suspender tensions and the bearing reactions. Then girder's responses, including rigid-body displacement in the longitudinal direction, deflections, and torsion angles; suspenders' responses, including the suspender tensions and the hanging point displacements; main cables' responses, including the horizontal forces of each segment; and the longitudinal displacement of the pylons' tower top under eccentric load can be calculated. The response of an exemplar suspension bridge with three spans of 168, 548, and 168 m is calculated by the proposed analytical method and the finite element method in two eccentric live load cases, and their results prove the former's feasibility. The nonuniform distribution of the live load in the lateral direction is shown to impose a greater threat to suspension bridge safety than that in the longitudinal direction, while some other specific features revealed by the proposed method are discussed in detail.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.83-91
• /
• 2000

A numerical study was carried out to investigate the 'unstart' process of thermally-choked combustion in model scramjet engines. The combustion mechanism of supersonic combustor will be compared with the experimental results obtained from the T3 free-piston shock tunnel at ANU (Australian National University) and the high enthalpy supersonic wind tunnel at UT (University of Tokyo). For the numerical simulation of supersonic combustion. multi-species Navier-Stokes equations were considered. and detailed chemistry reaction mechanism of $H_2$-Air were adopted. The governing equations were solved by Roe's FDS method and LU-SGS method with MUSCL scheme. In this study. it is found that the thermal choking process could result from excessive heat release due to combustion. In detail, sufficient heat release could be generated at local region of very high temperature increased by reflection of shock waves or vortex sheets. Accordingly the flow of downstream of the combustor fell to subsonic field propagated upstream along the combustor. Sometimes the subsonic flow field propagated into isolator could generate precombustion shock waves in the isolator.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.3
• /
• pp.321-327
• /
• 2015

Nocardia salmonicida is one of the main pathogens of fish nocardiosis. The purpose of this study was to build a loop-mediated isothermal amplification (LAMP) method for the rapid and sensitive detection of N. salmonicida. A set of four primers were designed from the 16S-23S rRNA intergenic spacer region of N. salmonicida, and conditions for LAMP were optimized as incubating all the reagents for 60 min at 64℃. LAMP products were judged with agar gel electrophoresis as well as with the naked eye after the addition of SYBR Green I. Results showed the sensitivity of the LAMP assay was 1.68 × 10³ CFU/ml (16.8 CFU per reaction) and 10-fold higher than that of PCR. The LAMP method was also effectively applied to detect N. salmonicida in diseased fish samples, and it may potentially facilitate the surveillance and early diagnosis of fish nocardiosis.

• Journal of the Korean Chemical Society
• /
• v.33 no.3
• /
• pp.304-308
• /
• 1989

The spectrophotometric determination of $Lu^{3+},\;Eu^{3+}$ and some other rare earths have been investigated using Methyl Thymol Blue(MTB) as spectrophotometric reagent. Rare earth elements form a stable complex with MTB abount pH 6.5 and the ratio of its complex is 1 to 1. MTB has a absorption maxima at 440nm and rare earth MTB complex has absorption maxima 610nm at pH 6.5, respectively. The absorbance of the rare earth MTB complex is stable in 7 hours after color developing and obey the Beer law in the range of $0{\sim}110{\mu}g/50ml$. The ligand such as phosphate, citrate and EDTA decrease the absorbance of its complex considerably, and this method has a poor selectivity of each rare earth element and the molar absorptivity is $1.2{\sim}2.0{\times}10^4mol^{-1}{\cdot}l{\cdot}cm^{-1}$. In methyl alcohol, ethyl alcohol and acetone medium we did not find out any absorption change of the rare earth MTB complex.

• Journal of Biomedical Engineering Research
• /
• v.32 no.2
• /
• pp.127-133
• /
• 2011

Arteria radialis is a branch of the brachial artery extending down the forearm around the wrist where it closes to skin surface. In the oriental medicine, the skin above arteria radialis has an important role because oriental medicine practitioners put their finger tips on the area, and diagnose patient's health conditions by feeling the pulsation of the arterial contraction. The finger tip diagnostic method relies on subjective decision of the practitioner; and there is a need to develop an objective diagnostic modality. The pulsation of the arterial contraction appears not only a movement on the site but also as temperature fluctuation due to pulsatile feeding of warmer blood. The goal of this study is to demonstrate a feasibility of using an infrared camera quantitatively to detect the temperature fluctuation on the skin. Clinical important three different areas, called chon, gwan, chuk, near a wrist where the arteria radialis reaches close to skin surface are marked with small pieces of surgical tape. A high-speed and high-resolution infrared camera with a 3 cm of field of view measures these areas for 10 second at 200 frames per second with a 320*240 pixel size. The pulsatile temperature fluctuation is calculated after passing a band pass filter to remove any stationary temperature over 10 second. The temperature fluctuation of a healthy male volunteer is measured at a room temperature as a control, and is compared with another measurement performed after 20 minutes staying in a room at a 40 degree Celsius. This comparison is repeated for three times, and indicates that the fluctuation increases after staying 20 minutes in the warm room. This increase becomes smaller when the person stays in the warm room with an acupuncture treatment that decreases body temperature. So that an objective diagnostics on the site may become feasible.

• Structural Engineering and Mechanics
• /
• v.25 no.5
• /
• pp.577-596
• /
• 2007

Recent development of fiber optic sensor technology has provided an excellent choice for civil engineers for performance monitoring of civil infrastructures. Fiber optic sensors have the advantages of small dimensions, good resolution and accuracy, as well as excellent ability to transmit signal at long distances. They are also immune to electromagnetic and radio frequency interference and may incorporate a series of interrogated sensors multiplexed along a single fiber. These advantages make fiber optic sensors a better method than traditional damage detection methods and devices to some extent. This paper provides a review of recent developments in fiber optic sensor technology as well as some applications of fiber optic sensors to the performance monitoring of civil infrastructures such as buildings, bridges, pavements, dams, pipelines, tunnels, piles, etc. Existing problems of fiber optic sensors with their applications to civil structural performance monitoring are also discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.289-290
• /
• 2018

The purpose of this study is to analyze the emotions of color in Chinese historical film 'Hero'. This study was carried out by questionnaire survey on students and ordinary person of 20 ~ 45 years old Korean-Chinese image content students through sensitive scientific research method. It was evaluated on the color in the background, the lighting of the Chinese historical movie 'Hero'. The results of this study suggest that the color of the film may have an emotional impact on the audience.

• International Journal of Fluid Machinery and Systems
• /
• v.2 no.3
• /
• pp.248-253
• /
• 2009

This paper presents a numerical study for unsteady flows in a high-pressure steam turbine with a partial admission stage. Compressible Navier-Stokes equations are solved by the high-order high-resolution finite-difference method based on the fourth-order compact MUSCL TVD scheme, Roe's approximate Riemann solver, and the LU-SGS scheme. The SST-model is also solved for evaluating the eddy-viscosity. The unsteady two-dimensional flows through whole nozzle-rotor cascade channels considering a partial admission are numerically investigated. 108 nozzle passages with two blockages and 60 rotor passages are simultaneously calculated. The influence of the flange in the nozzle box to the lift of rotors is predicted. Also the efficiency of the partial admission stage changing the number of blockages and the number of nozzles is parametrically predicted.

• Proceedings of the Ginseng society Conference
• /
• 1998.06a
• /
• pp.138-145
• /
• 1998

A validated and reproducible HPLC method was developed for the profiling and quantitative analysis of ginsenosides in commercial products available in North America. Analysis of 280 Panax ginseng and Panax quinquefolius products showed profiles indicative of the presence of ginsenosides in the majority of these products. However, the quantitative contents of the products vary greatly, not only in products of different formulations, but also of products within each of the fromulations examined.

• Journal of the Korean Society of Physical Medicine
• /
• v.10 no.3
• /
• pp.9-17
• /
• 2015

PURPOSE: This paper aims to present the available angle to evaluate the severity of forward head posture (FHP) with the observation method and photographic method. METHODS: A cross-sectional observation research design study consisted of 29 subjects who was divided two groups (slight FHP group, moderate FHP group) in Eulji university was used. We evaluated the FHP and the angles including CranioVertebral Angle (CVA), Head Tilting Angle (HTA), Head Position Angle (HPA) and Forward Shoulder Angle (FSA) with the Body style S-8.0 (South Korea, LU Commerce). RESULTS: The mean of CVA, FSA from the slight FHP group was shown higher than moderate severe FHP group. According to independent t-test result, but there was no difference among all angles in two groups. The linear discriminate analysis showed the size of distinction of FSA was the biggest, and then CVA, HTA and HPA were in the order. 55.6% of FSA is properly classified in the slight FHP group. CONCLUSION: The FSA is the best to distinguish the severity of FHP and then CVA as the second best. Therefore, FSA is recommended to check the FHP.