• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.107-114
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• 2003

The effect of uncertainties caused by measured parameters, which are propagated to the uncertainty of total-to-total efficiency, are analyzed from a turbine performance test. The degree of reaction is 0.373 at the mean radius on a tested 3-D axial type turbine, and the performance test is conducted at the low pressure and cold temperature status. The uncertainty of turbine inlet and exit total pressure shows the strong propagation effect to the uncertainty of total-to-total efficiency. This means that a high precision pressure measuring system is required to reduce the uncertainty propagated by the pressure. In the uncertainty portion of each measured parameters to the uncertainty of total- to-total efficiency, the uncertainty by torque is the highest and the uncertainty by RPM is the lowest. In case of the total pressure, the effect of the uncertainty by torque is increased with the increasing RPM. The uncertainty of total pressure at the turbine exit is more important than that at the turbine exit.

• Structural Engineering and Mechanics
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• v.40 no.4
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• pp.453-469
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• 2011

A one-story, wooden-frame, intermediate-bay model with Dou-Gon designed according to the Building Standards of the Song Dynasty (A.D.960-1279), was tested on a unidirectional shaking table. The main objectives of this experimental study were to investigate the seismic performance of Chinese historic wooden structure under various base input intensities. El Centro wave (N-S), Taft wave and Lanzhou wave were selected as input excitations. 27 seismic geophones were instrumented to measure the real-time displacement, velocity and acceleration respectively. Dynamic characteristics, failure mode and hysteretic energy dissipation performance of the model are analyzed. Test results indicate that the nature period and damping ratio of the model increase with the increasing magnitude of earthquake excitation. The nature period of the model is within 0.5~0.6 s, the damping ratio is 3~4%. The maximum acceleration dynamic magnification factor is less than 1 and decreases as the input seismic power increases. The frictional slippage of Dou-Gon layers (corbel brackets) between beams and plates dissipates a certain amount of seismic energy, and so does the slippage between posts and plinths. The mortise-tenon joint of the timber frame dissipates most of the seismic energy. Therefore, it plays a significant part in shock absorption and isolation.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.333-338
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• 2004

Today CCTV can be come across easily in public institutions, banks and etc. These CCTV plays very important roles for preventing many kinds of crimes and resolving those crime affairs. But in the case of recording a image of a specific person far from the CCTV, the original image needs to be enlarged and recovered in order to identify the person more obviously. The interpolation is usually used for the enlargement and recovery of the image. This interpolation has a certain limitation. As the magnification of enlargement is getting bigger, the quality of the original image can be worse than before. This paper uses FDP(Face Definition Parameter) of MPEG-4 SNHC FBA group and introduces a new algorithm that the face outline of a face image using Vector Descriptor based on the FDP makes possible better image recovery than the known methods until now.

• Wind and Structures
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• v.25 no.1
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• pp.1-24
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• 2017

This paper presents a 1:25 multi-freedom aero-elastic model for a high lighting pole at the Zhoushan stadium. To validate the similarity characteristics of the model, a free vibration test was performed before the formal test. Beat phenomenon was found and eliminated by synthesis of vibration in the X and Y directions, and the damping ratio of the model was identified by the free decay method. The dynamic characteristics of the model were examined and compared with the real structure; the similarity results were favorable. From the test results, the major along-wind dynamic response was the first vibration component. The along-wind wind vibration coefficient was calculated by the China code and Eurocode. When the peak factor equaled 3.5, the coefficient calculated by the China code was close to the experimental result while Eurocode had a slight overestimation of the coefficient. The wind vibration coefficient during typhoon flow was analyzed, and a magnification factor was suggested in typhoon-prone areas. By analyzing the power spectrum of the dynamic cross-wind base shear force, it was found that a second-order vortex-excited resonance existed. The cross-wind response in the test was smaller than Eurocode estimation. The aerodynamic damping ratio was calculated by random decrement technique and the results showed that aerodynamic damping ratios were mostly positive at the design wind speed, which means that the wind-induced galloping phenomenon is predicted not to occur at design wind speeds.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1865-1875
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• 2018

Enhanced application of solid-state fermentation (SSF) in industrial production and the influence of SSF of Rhizopus K1 on glucoamylase productivity were analyzed using the flat band method. A growth model was implemented through SSF of Rhizopus K1 in this experiment, and spectrophotometric method was used to determine glucoamylase activity. Results showed that in bran and potato culture medium with 70% moisture in a loose state, ${\mu}$ of mycelium reached to $0.15h^{-1}$ after 45 h of culture in a thermostatic water bath incubator at $30^{\circ}C$. Under a low-magnification microscope, mycelial cells appeared uniform, bulky with numerous branches, and were not easily ruptured. The generated glucoamylase activity reached to 55 U/g (dry basis). This study has good utilization value for glucoamylase production by Rhizopus in SSF.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.39-44
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• 2009

Purpose: To design a mini optical system photographing the iris, which is used in the iridology. Methods: We designed a mini optical system photographing the iris by using the Sigma 2000 design program. Results: We designed a mini optical system photographing the iris, which is suitable in the CCD using a micro actuator for auto-focusing, of which characteristics have the TCL of 30 mm, a magnification of -0.65, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and about 1 mm of the effective stop diameter. Also the resolution line width of this system is characterised by 92 lps/mm at the 30% MTF value criterion. Conclusions: By designing an optical system of which characteristics have the TCL of 30 mm, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and the resolution line width of $5.4{\mu}m$ at the 30% MTF value criterion, we could miniaturize the iris photographing optical system.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.65-69
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• 2008

Purpose: To develop a dot sight device for a sighting shot using the doublet reflector. Methods: We designed the singlet reflector and the doublet reflector by Sigma 2000 program and compared the one to the other. Results: In analysis of finite ray aberration, we could confirm that it has the effective field of view with the free-parallax which is 3.3 times wider than the existing dot sight device using the singlet reflector. If you use the doublet reflector, the central thickness of optical system become more than two times bigger than the existing one. As a result, when the image of a target object is made on the observer's retina, if you make the first side's radius of curvature equal with the second one as the case of the singlet reflector, changes in magnification are appeared. To conquer this problem, we had to make be satisfied with the afocal condition in the case of doublet reflector. Conclusions: we could develop the dot sight device for a sighting shot using the doublet reflector which has the effective field of view with the free-parallax which is 3.3 times wider than the existing dot sight device using the singlet reflector.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.121-134
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• 2006

Purpose : Cuscuta chinensis Lam. is utilized extensively as important medicines for threatened abortion habitual abortion. However, objective data related to an embryo is not existed until now. Therefore, this study is focused to find out stability of Cuscuta chinensis Lam. about an embryo during pregnancy based on data related to stability of nerve cell and antioxydative effect by using neural cell line, PC 12 cell. Methods : Experimentation concerns cytotoxic effects and antioxydative effect through methods such as MTT ssay, western botting after abstracting an undiluted solution from domestic Cuscuta chinensis Lam. Results : 1. As a result of experimentation on MTT assay according to each magnification from Cuscuta chinensis Lam. extraction solution with different abstraction methods, cytotoxic effect is not observed to all extract except an undiluted solution which is abstracted from MeOH stiring. Also, an undiluted solution in stiring with MeOH could not confirm whether come from Cuscuta chinensis Lam. or not. 2. As a result of revelation of Bax and GSK-3${\beta}$ which is responsive to the first stage from general stress in order to observe antioxydative effects of Cuscuta chinensis Lam. revelation of Bax by Cuscuta chinensis Lam. appeared to decrease. Conclusion : Cytotoxic effects with Cuscuta chinensis Lam. about PC12 cell is not discovered and it assume that it would be anti apoptotic effect by ROS as Bax and GSK-3${\beta}$ inviable effect. In the future, this study could be used as basic data for additional research on Cuscuta chinensis Lam. and effect and stability of complicated prescriptions for keeping pregnancy.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.720-726
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• 2009

We investigated the most effective pre-treatment processes and LC/MS/MS condition for microcystins analysis. With a step-by-step pre-treatment, efficiencies of several established methods were compared. At the level of cell burst, sonication method was found to be the most efficient. As a mycrocystins first extraction solvent, 5% acetic acid showed the highest efficiency. An isolation and recovery rate of mycrocystins of ODS Sep-Pak $C_{18}$ cartridge was higher than HLB SPE cartridge. As a final elution solvent from cartridge, 100% MeOH had a better efficiency than others. Using a LC/MS/MS, effective analytical methods were established. C18 reverse column was used and gradient elution was performed with using acetonitrile, 0.1% formic acid as a mobile phase. We analysed to 0.8 mL/min flow rate fit to the $5{\mu}m$ particle size column and $55^{\circ}C$ housing temperature. The validity of established analytical method was evaluated that MDL as average $0.050{\pm}0.014{\mu}g/L$ and LOQ as average $0.160{\pm}0.045{\mu}g/L$ had a good sensitivity over 40 magnification rather than $2{\mu}g/L$ detection limit of HPLC.

• Journal of Acupuncture Research
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• v.22 no.6
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• pp.135-140
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• 2005

Objectives : There have been several studies about the quality of acupuncture needle tip recently. We have investigated the condition of the tip of the acupuncture needles in the last studies. In the former studies, we discovered the metallic scuff, lumps and irregularities of the acupuncture needle tips under the microscope. But, no information was available on those foreign materials' identity. Methods : We have selected 200 needles of 1000 pieces from several companies by randomized methods. And we observed the tip of the 6 needles selected finally at ${\times}1000\;or\;{\times}3000$ magnification and analyzed the components of the metallic scuff, lumps and irregularities of the needle tips with a SEM-EDX analyser. Results : We found that the identity of the metallic scuff, lumps and irregularities of the needle tips were metallic materials and silicon. For example, A point was composed of Fe(69.78%), Cr(17.71%), Ni(8.11%), Zn(2.04%), Si(1.23%), Mn(1.12%), and B point was composed of Si(66.40%), Fe(26.76%), Cr(6.84%). Conclusion : The results of this study confirm that there is a real possibility of the remaining of metallic materials and silicon in body of patient, after acupuncture treatment. Therefore, it is necessary to intensify our efforts to make needles of good quality and to concentrate on manufacturing process of acupuncture needles completely to be free from danger in acupuncture treatment.