• Progress in Superconductivity and Cryogenics
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• v.23 no.3
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• pp.20-25
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• 2021

Milking parlor wastewater contains high concentration suspended solid (SS), nitrogen, and/or phosphate as well as organic compounds. A new biological wastewater process by magnetic separation, magnetic activated sludge (MAS) process, was applied to milking parlor wastewater treatment process. A three step wastewater treatment process of coagulation sedimentation / ammonia stripping (C/S), magnetic activated sludge process and contact oxidation (CO) was proposed for removal of these pollutants. First step, C/S process recovered 96% TN and 96% PO₄^3--P as resource for fertilizer from the wastewater. 81% biochemical oxygen demand (BOD) in wastewater was removed after MAS process. As a results, all pollutant concentrations satisfied Japanese effluent standards. Most of residual BOD and SS were removed by the CO process. It was estimated that the proposed process could reduce the process space to 1/7.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.150-150
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• 2000

We as modal parameter estimation technique by developing a residual based system reconstruction and using the system matrix coordinate transformation. The modal parameters can be estimated from and residues of the system transfer functions expressed in modal coordinate basis, derived from the state space system matrices. However, for modal parameter estimation of multivariable and order structural systems over broad frequency bands, this non-iterative algorithm gives high accuracy in the natural fre- and damping ratios. From vibration tests on cross-ply and angle-ply composite laminates, the natural frequencies and damping ratios on be estimated using tile coordinates of the structural system reconstructed fro the experimental frequency response. These results are compared with those of finite element analysis and single-degree-of-freedom curve-fitting.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.527-527
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• 2000

Wean modal parameter estiimation technique by developing a residual based system reconstruction and using the system matrix coordinate transformation. The modal parameters can be estimated from and residues of the system transfer functions expressed in modal coordinate basis, derived from the state space system matrices. However, for modal parameter estimation of mllltivariable and order structural systems over broad frequency bands, this non-iterative algorithm gives high accuracy in the natural fre and damping ratios. From vibration tests on cross-ply and angle-ply composite laminates, the natural frequencies and damping ratios can be estimated using the coordinates of the structural system reconstructed from the experimental frequency response. These results are compared with those of finite element analysis and single-degree-of-freedom curve-fitting..

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.117.1-117.1
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• 2011

We present the smoothness of mid-infrared sky brightness from the Japanese infrared astronomical satellite, AKARI observations. AKARI monitored the north ecliptic pole (NEP) during its cold phase with nine wavebands from 2.4 to 24 ${\mu}m$, out of which six mid-infrared bands are used in this study. Simple sinusoidal fit to the seasonal variation of the sky brightness shows that the mid-infrared brightness towards the NEP is not affected by small-scale features of the interplanetary dust cloud. We applied the power spectrum analysis to the images to search for the fluctuation of sky brightness. The fluctuation powers at 200 arcsecond are estimated to be at most $1.58{\pm}0.33\;nW\;m^{-2}sr^{-1}$ or 0.13% of the total brightness at $7{\mu}m$ and a tleast $0.64{\pm}0.11\;nW\;m^{-2}sr^{-1}$ or 0.02% at $18{\mu}m$. The residual fluctuations at a few arcminute scales at short mid-infrared wavelengths (7, 9, and 11 ${\mu}m$) are consistent with those expected from the diffuse galactic light. At long mid-infrared wavelengths (15, 18, and 24 ${\mu}m$) the measured fluctuations are comparable to or smaller than the one caused by photon noise and their sources are not identified. We conclude that the upper limit of the fluctuation in the zodiacal light is about 0.02% of the sky brightness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.17-24
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• 2011

It is reported that an intermittently rotating chamber system will improve the ratio of firepower to armament space in the case of mid-calibre automatic guns. However, the parallel index, which is a main component of the system, tends to be torsionally flexible due to the low lateral stiffness of cam followers on the index turret. This may cause the shaft system connecting the turret with the chamber prone to considerable residual torsional vibration so that serious misalignment problems occur during ammunition loading and firing processes. Herein, an electrorhelogical (ER) fluid actuator that can suppress such vibrations and the associated semiactive control algorithm are proposed. By mathematical modeling and computer simulations, the performance of the entire system is proved satisfactory.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.74.1-74.1
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• 2010

We have investigated the radial g-r color gradients of early-type galaxies in the Sloan Digital Sky Survey (SDSS) DR6 in the redshift range 0.00$H{\beta}$ absorption-line strengths and/or emission-line ratios that are indicative of the presence of young stellar populations. This implies that most of the residual star formation in early-type galaxies is centrally concentrated. Blue-cored galaxies are predominantly low-velocity dispersion systems. A simple model shows that the observed positive color gradients are visible only for a billion years after a star formation episode for the typical strength of recent star formation. The observed effective radius decreases and the mean surface brightness increases due to this centrally concentrated star formation episode. As a result, the majority of blue-cored galaxies may lie on different regions in the fundamental plane (FP) from red-cored ellipticals. However, the position of the blue-cored galaxies on the FP cannot be solely attributed to recent star formation but requires substantially lower velocity dispersion. We conclude that a low-level of residual star formation persists at the centers of most of low-mass early-type galaxies, whereas massive ones are mostly quiescent systems with metallicity-driven red cores.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.528-538
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• 2014

PURPOSE. The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS. The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS. In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness ($0.07{\mu}m$ in Bio-Oss group Vs. $0.08{\mu}m$ in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness ($8.35{\mu}m$ in Bio-Oss group Vs. $13.12{\mu}m$ in AutoBT group) (P=.025). CONCLUSION. AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.37-49
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• 2000

This paper is for the first essential study on the development of unified finite element formulations for solving problems related to the dynamics/thermoelastics behavior of solids. In the first part of formulations, the finite element method is based on the introduction of a new quantity defined as heat displacement, which allows the heat conduction equations to be written in a form equivalent to the equation of motion, and the equations of coupled thermoelasticity to be written in a unified form. The equations obtained are used to express a variational formulation which, together with the concept of generalized coordinates, yields a set of differential equations with the time as an independent variable. Using the Laplace transform, the resulting finite element equations are described in the transform domain. In the second, the Laplace transform is applied to both the equation of heat conduction derived in the first part and the equations of motions and their corresponding boundary conditions, which is referred to the transformed equation. Selections of interpolation functions dependent on only the space variable and an application of the weighted residual method to the coupled equation result in the necessary finite element matrices in the transformed domain. Finally, to prove the validity of two approaches, a comparison with one finite element equation and the other is made term by term.

• Tunnel and Underground Space
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• v.17 no.3 s.68
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• pp.186-196
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• 2007

In this study, direct shear tests were carried out on the 30 rock joint samples in order to investigate the influence of roughness and normal stress on the shear behaviour. Joint roughness profiles were measured by use of 3D laser profiler, and then the samples were equally classified into three individual groups according to the roughness index of rock joints. Peak shear strength, residual shear strength, shear stiffness, dilation angle of rock joints were investigated in condition of five different constant normal load. Peak shear strength was increased as roughness index was increased, and the influence of roughness on strength was found to be more considerable in case of lower normal stress condition. Residual shear strength and shear stiffness were increased as roughness index and normal stress were increased. Finally dilation angle was decreased as normal stress was increased, but it was increased as roughness index was increased in the same normal stress condition.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.301-311
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• 2024

In South Korea, following the 2016 Gyeongju and 2017 Pohang earthquakes, the need for earthquake disaster prevention has been increasing. Reliable techniques for probabilistic seismic hazard analysis and ground motion models are required for quantifying earthquake damage. Recently, there has been growing demand for deep underground facilities, necessitating accurate quantification techniques for earthquake damage in deep underground. In this study, ground motion models within rock were proposed using ground motion data measured at borehole seismic stations. A regression analysis, a type of empirical technique, was applied to 17 periods selected in a range from 0.01 to 10 s of spectral accelerations to develop the ground motion models. Residual analysis was performed to evaluate and improve the prediction performance of the ground motion model, with correction factors added to the model equation. When applying the proposed model, the group means of residuals approached zero, and the standard deviation of total residuals, similar to existing models proposed in other countries, confirmed the reliability of the proposed model.