• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.230-235
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• 2005

Reversed-phase high-performance liquid chromatography (RP-HPLC) was used to determine the equilibrium isotherm of single and multi-components of dUrd(2'-deoxyuridine), dGuo(2'-deoxyguanosine), and dAdo(2'-deoxyadenosine) of 2'-deoxyribonucleosides by dynamic method. The composition of mobile phase was 90/10 vol.% (water/MeOH). With an increase in the injection volumes, the retention times were shorter and the peak shapes were triangle-shaped, so Langmuir-type isotherm was assumed. The Langmuir adsorption parameters were estimated by PIM (pulsed-input method), and the competitive Langmuir adsorption isotherm was further utilized. For the sample of the dUrd and dGuo whose retention times were relatively short, the agreement of between the calculated value and experimental data was fairly good in both single and multi-components, but for the dAdo, the last eluting component, some deviations were caused by non-linear and non-ideal properties.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.57-66
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• 2007

The membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and happen large deformation phenomenon. Therefore, in this paper, we investigate the convergence of solution and the speed according to the control variables and the method of shape analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1354-1360
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• 2001

Calculated velocity distribution was used to visual information by image that is obtained from camera. The visual velocity of object that is obtained from this visual information were fused and experimented. That is, need motion of eye that motion of head that happen by external disturbance or move of camera itself to get stable image in environment that receive external disturbance can be compensated. In this treatise, algorithm that control gaze which vision and sense of equilibrium are fused in environment with external disturbance proposed, and thing that compare with that it controls gaze only that control gaze which vision and sense of equilibrium are fused in the experiment result and position deflection is few confirmed. This was because action of camera prop is effect that record conclusion error of the speed because the appearance speed is decreased being compensated by angular velocity sensor.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.749-754
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• 2005

For the binary system of methanol/3-methyl-1-butanol mixture vapor-liquid equilibrium data were measured isothermally at 50, 55, 60, 65, and $70^{\circ}C$. An empirical relation to predict vapor-liquid equilibrium data was obtained from the above measured data. The predicted values compared with the measured ones were in a good agreement, within accuracy ${\pm}0.0007$. The excess molar volume, measured for the binary system of methanol/3-methyl-1-butanol mixture, was positive $V^Eover$ the entire composition range. The maximum values were shown to be about $0.096cm^3/mol$ at x= 0.683.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.7-12
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• 2020

Astragalus uliginosus L.-stems as a by-product of oriental medicine are produced largely in a northern area of Chungbuk province. These by-products do not have any demand and thus usually discarded into the fields as a waste. In this work, a biochar was prepared from the Astragalus uliginosus L.-stem waste for recycling. The biochar was used to investigate the removal characteristics of cadmium and manganese ions dissolved in water. When adsorption equilibrium experiments were performed to treat 50 and 100 mg/L of cadmium ions, the removal efficiencies of cadmium were 100 and 95%, respectively. In addition, the maximum of adsorption amount for manganese ions in 5 h at an initial concentration of 50 and 100 mg/L was found to be as 36.1 and 37.9 mg/g, respectively. Based on the experimental results, it was found that the adsorption amount of Astragalus uliginosus L.-stem biochar for the removal of both cadmium and manganese ions was four times higher than that of the activated carbon. The surface analysis of both biochar and activated carbon samples using X-ray photoelectron spectroscopy (XPS) analysis showed that the oxygen content and O/C ratio of biochar was 2.1 and 2.4 times higher than that of the activated carbon, respectively. In order to enhance the removal capability of manganese, 50 and 100 mg/L of manganese ions were operated at different temperatures. It was observed that these equilibrium was attained in 4 h under 45 ℃ and removal efficiencies were 92 and 53%, respectively. Consequently, the experimental results can be utilized as a new removal technology for eco-friendly and economically treating cadmium and manganese ions dissolved in water.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.62-69
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• 2009

This paper describes the development of the new type equilibrium sensation measuring system for human with handicap in the equilibrium sensation. The medium and small hospital could not use the developed equilibrium sensation measuring system, because it is very high prices. Therefore, the new type system should be developed to measure the numerical value of the equilibrium sensation in human with handicap. In this paper, First, two 3-axis force/moment sensors which can measure force Fz, moments Mx and My simultaneous were designed and manufactured, second, the high speed measuring device which can acquire the output from two 3-axis force/moment sensors, third, the new type equilibrium sensation measuring system was developed, then the characteristic test of the developed equilibrium sensation measuring system carried out, it is confirmed that the system could measure the swing body of human with handicap.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.116-116
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• 2012

위성의 발사, 천이궤도, 운영궤도 등에서 위성체에 주어지는 극한 온도와 진공상태에서 위성체와 열제어시스템이 요구 조건을 만족시키는가를 확인하기 위하여 열진공시험을 수행한다. 우주에서 일어나는 환경변화는 극도로 심해서 지상에서 이와 유사한 열적 환경을 모사하는 방법은 쉽지가 않고, 일반적으로 위성체에 대한 열진공/평형 시험을 위해서는 열유속 흡수법과 열유속 투사법의 두 가지 방법을 사용한다. 한국항공우주연구원에서는 종래 접촉식 히터를 위성체에 직접 부착하는 방법에서 탈피하여 새로이 IR Lamp를 이용한 열유속 흡수법을 이용하여 위성체에 계산된 열유속을 인가하는 방법으로 위성체 열진공/평형시험을 수행하였으며, IR Lamp는 요구되는 100W~400W 사이의 열량을 오차 범위 5% 이내로 인가하여 균일한 온도 분포를 유지하고 성공적인 시험을 수행하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.90-95
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• 2006

The wall of thermal vacuum chamber which is used for the satellite thermal balance test doesn't absorb satellite's IR emission perfectly and reflects some part of that. It is estimated that small thermal vacuum chamber has relatively larger wall effect than the big one. The small thermal vacuum chamber is required for the small satellite test to reduce the test cost. A quantitative analysis was carried out to investigate the chamber wall effect. As a result, temperature errors caused by chamber wall effect was calculated, and the temperature data acquired in the thermal balance test have been compensated. By defining the optimized area ratio between chamber surface and satellite surface area, the baseline to be able to determine the minimum size of thermal vacuum chamber was established to minimize the wall effect. Also, theoretical analysis about transparent material coating which can reduce the chamber wall effect is conducted.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.463-468
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• 1998

수직 관다발형 비등관에서의 밀도파 진동 및 유동 폭주형 이상유동 불안정성을 해석하기 위하여 선형화 기법 및 D-partition 방법론에 근거한 해석 코드(ALFS)를 개발하고 기존 실험자료 분석을 통해 코드의 예측 성능을 평가하였다. 그 결과 이상유동이 평형상태에 있는 것으로 가정하는 가장 단순한 모델인 HEM은 전반적으로 유동 불안정성 발생 시점의 열출력을 실험치보다 약 20% 정도 낮게 예측하였으며, 이상 유동의 속도 및 온도의 비평형 상태를 고려하는DEM과 DNEM에 의한 예측 결과는 7∼15%의 평균 오차 범위에서 실험 자료를 예측하는 것으로 나타났다.

• Computational Structural Engineering
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• v.3 no.3
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• pp.125-131
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• 1990

A finite element technique for the time dependent large structural problems is presented. It is based on the error estimation for the bases of solution spaces. An a-posteriori energy norm of residual error serves as the error indicator. Mode shapes which are calculated by scaling the Ritz vectors are applied to discretize the continuous spatial domain. Finally, the performance of the proposed methods is demonstrated by solving simple examples.