• 국제초고층학회논문집
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• 제10권2호
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• pp.99-107
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• 2021

This research investigates the potential of Adaptive TMDs for tall building damping. The Adaptive TMD under consideration is based on real-time controlled hydraulic dampers generating purely dissipative control forces. The control approach is designed to enhance the Adaptive TMD efficiency for moderate wind loads with return periods below 50 years. The resulting enhanced TMD efficiency is used to reduce the pendulum mass by 15% compared to the passive TMD while still guaranteeing the acceleration limits of the one and ten year return period winds. Furthermore, the adaptive control approach is designed to disproportionally increase the controlled damping force at wind loads with return periods of 50 years and more in order to reduce the maximum relative motion of the Adaptive TMD with only 85% pendulum mass. Compared to the passive TMD with 100% pendulum mass the maximum relative motion is reduced by 20%. Both the pendulum mass reduction and the maximum relative motion reduction significantly reduce the foot print of the Adaptive TMD which is highly desirable from the economic point of view.

• 제어로봇시스템학회논문지
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• 제13권10호
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• pp.962-969
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• 2007

In this paper, an approach is developed for relative state estimation of satellite formation flying. To estimate relative states of two satellites, the Extended Kalman Filter Algorithm is adopted with the relative distance and speed between two satellites and attitude of satellite for measurements. Numerical simulations are conducted under two circumstances. The first one presents both chief and deputy satellites are orbiting a circular reference orbit around a perfectly spherical Earth model with no disturbing acceleration, in which the elementary relative orbital motion is taken into account. In reality, however, the Earth is not a perfect sphere, but rather an oblate spheroid, and both satellites are under the effect of $J_2$ geopotential disturbance, which causes the relative distance between two satellites to be on the gradual increase. A near-Earth orbit decays as a result of atmospheric drag. In order to remove the modeling error, the second scenario incorporates the effect of the $J_2$ geopotential force, and the atmospheric drag, and the eccentricity in satellite orbit are also considered.

• 대한화학회지
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• 제35권6호
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• pp.659-666
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• 1991

질소를 함유한 흥분제와 마약성 진통제 18종류의 약물들을 gas chromatography-nitrogen phosphorus detector(GC-NPD)를 사용하여 human urine으로부터 동시에 신속하게 분석할 수 있는 최적조건을 찾기 위하여 pH 변화와 추출용매 변화에 따른 회수율을 조사하였다. pH 8.5에서 에테르를 추출용매로 사용하였을 때 가장 적은 방해영향과 가장 좋은 회수율을 나타냈다. NPD에 대한 각 약물들의 상대 감응인자를 구하였고, 이 상대감응인자는 약물이 가지고 있는 질소원자의 갯수가 증가할수록 작은 값을 나타냈다. 생체시료 중의 약물들을 신속하게 검정하기 위하여 내부표준물질인 diphenylamine에 대한 relative retention time(RRT)을 작성하였다. 상대머무름 시간은 0.1% 이하의 정밀도를 나타냈다.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.227-233
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• 2002

A vehicle longitudinal control strategy with guaranteed string stability for vehicle stop-and-go(SG) cruise control is presented in this paper. The SG cruise control systems should be designed such that string stability can be guaranteed in addition to that every vehicle in a string of SG cruise control vehicles must track any bounded acceleration and velocity profile of its preceding vehicle with a bounded spacing and velocity error. An optimal vehicle following control law based on the information of the 1311owing distance (clearance) and its velocity relative to the vehicle ahead (relative velocity) has been used and string stability analysis has been done based on the control law and constant time gap spacing policy, A validated multi-vehicle simulation package has been shown that the string stability analysis using the approximate model of the vehicle servo-loop which includes vehicle powertrain and brake control system dynamics is valid in the design of the SG cruise control law with guaranteed string stability.

• 생물환경조절학회지
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• 제18권3호
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• pp.200-207
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• 2009

This study was conducted to analyze the variations of air temperature, relative humidity and pressure in a low pressure chamber for plant growth. The low pressure chamber was composed of an acrylic cylinder, a stainless plate, a mass flow controller, an elastomer pressure controller, a read-out-box, a vacuum pump, and sensors of air temperature, relative humidity, and pressure. The pressure leakage in the low pressure chamber was greatly affected by the material and connection method of tubes. The leakage rate in the low pressure chamber with the welding of the stainless tubes and a plate decreased by $0.21kPa{\cdot}h^{-1}$, whereas the leakage in the low pressure chamber with teflon tube and rubber O-ring was given by $1.03kPa{\cdot}h^{-1}$. Pressure in the low pressure chamber was sensitively fluctuated by the air temperature inside the chamber. An elastomer pressure controller was installed to keep the pressure in the low pressure chamber at a setting value. However, inside relative humidity at dark period increased to saturation level.. Two levels (25 and 50kPa) of pressure and two levels (500 and 1,000sccm) of mass flow rate were provided to investigate the effect of low pressure and mass flow rate on relative humidity inside the chamber. It was concluded that low setting value of pressure and high mass flow rate of mixed gas were the effective methods to control the pressure and to suppress the excessive rise of relative humidity inside the chamber.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.37.2-37
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• 2002

1. Introduction 2. Problem Formulation 3. Avoidability Measure And Relative Distance 4. Artificial Potential Field in Terms of Relative Distance 5. Simulation Results 6. Conclusions 7. Reference

• 한국조경학회지
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• 제37권4호
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• pp.94-99
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• 2009

본 연구는 하이드로컬쳐 실내녹화방법을 실내습도 개선의 중요한 수단으로 활용하기 위해, 관엽식물로 매우 보편화된 스킨답서스(Scindapsus aureus)와 싱고늄(Syngonium podophyllum)을 대상으로 하이드로컬쳐 식재 부피비율인 2%, 3%, 5% 차이와 3%의 동일한 하이드로컬쳐 식재대에서의 화분용토, 식물종의 차이에 따른 실내습도 변화를 실측하였으며, 그 결과는 다음과 같다. 하이드로컬쳐 부피비율에 따른 습도 변화에 있어서 스킨답서스의 경우, 식물이 투입하지 않았던 대조구에 비해 식물이 있는 생장상 내 상대습도가 높았다. 특히, 식물과 식재대의 용적비율이 높아질수록 습도가 높아졌다. 상대습도 25%인 대조구에 비해, 2%는 40%를, 3%는 45%를, 5%는 50%로 측정되었다. 싱고늄은 하이드로컬쳐 부피비율 2%는 40%를, 3%는 44%를, 5%는 46%로 각각 나타내어 대조구인 25%의 상대습도보다는 높았으나 부피비율에 따른 상대습도 차이는 확연하지 않았다. 하이드로컬쳐 식재대 내의 화분용토와 식물종에 따른 상대습도 변화를 살펴보면, 대조구인 하이드로볼 식재대 내의 하이드로볼 처리구에서 초기 상대습도가 다소 높았으나, 시간이 지남에 따라 물 식재대 내의 흙화분 처리구와 유사한 약 45%의 상대습도를 유지하였다. 물 식재대 내의 하이드로볼 처리구에서 상대습도가 약 30%로 나타났으며, 하이드로볼 식재대 내의 하이드로볼 처리한 산호수는 상대습도 약 38%로 측정되었다.

• Journal of Korean Biological Nursing Science
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• 제1권1호
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• pp.71-85
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• 1999

The purpose of this study was to determine the effect of periodic low-intensity exercise during hindlimb suspension on the mass, relative weight, myofibrillar protein content in soleus, plantaris and gastrocnemius muscles. To examine the effectiveness of periodic low-intensity exercise on mass, and myofibrillar protein content of hindlimb muscles, adult female Wistar rats were suspended(HS) and half of these rats walked on a treadmill for 45min/day(15 min every 4h) at 5m/min and a $15^{\circ}$ grade(HS-EX). Soleus wet weight was 33.51% significantly smaller(p<0.005) and relative soleus weight of hindlimb suspended rats was 31.96% smaller(p<0.005) compared with those of control rats following seven days of hindlimb suspension. Plantaris wet weight was 7.5% smaller(p<0.01) and relative plantaris weight was 11.83% smaller(p<0.05) compared with those of control rats following seven days of hindlimb suspension. Gastrocnemius wet weight was 11.31% significantly smaller(p<0.005) and relative gastrocnemius weight was 17.13% significantly smaller(p<0.005) compared with those of control rats following seven days of hindlimb suspension. Soleus wet weight while increased by relative soleus weight increased by 25.13%, 27.59% each through periodic low intensity exercise during hindlimb suspension(p<0.05, p<0.05). Plantaris wet weight and relative plantaris weight increased by 1.04%, 10.98%(p<0.05) each, and gastrocnemius wet weight and relative gastrocnemius weight increased by 1.98%, 12.02%(p<0.05) each through periodic low intensity exercise during hindlimb suspension. Wet weight of soleus, plantaris and gastrocnemius in HS-EX rats did not recover to control level. Myofibrillar protein content of soleus, plantaris and gastrocnemius was 48.24%, 40.85% and 37.33% significantly smaller(p<0.005) respectively compared with those of control rats following seven days of hindlimb suspension. Myofibrillar protein content of soleus, plantaris and gastrocnemius increased by 40.68%, 25.07% and 17.93%(p<0.005) each through periodic low intensity exercise during hindlimb suspension. Myofibrillar protein content of soleus, plantaris, and gastrocnemius in HS-EX rats did not recover to control level. The results suggest that periodic low intensity exercise can attenuate hindlimb muscle atrophy induced by hindlimb suspension.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.213-221
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• 2009

An aircraft collision accident is a disaster that causes great losses of inventories and lives. Though a collision avoidance warning function is provided automatically to pilots in the aircrafts by the enhancement of the aircraft capability, achieving fast decision-making to escape a collision situation is a complex and dangerous work for pilots. If an in-flight collision situation is controlled by the air traffic control system which monitors all airplanes in the air, it would be more efficient to prevent in-flight collisions because it can handle the emergency before the pilot's action. In this paper, we develop the collision avoidance warning function in the air traffic control system. Specifically, we design and implement the five stages of the collision avoidance function, and propose a visualization method which could effectively provide the operators with the trajectories and altitudes of the aircrafts in a collision situation. By developing an in-flight collision warning function in the air traffic control system that visualizes flight patterns through the state transition data of in-flight aircrafts on the flight path lines, it can effectively prevent in-flight collisions with traffic alerts. The developed function allows operators to effectively select and control the aircraft in a collision situation by providing the operators with the expected collision time, the relative distance, and the relative altitude while assessing the level of alert, and visualizing the alert information which includes the Attention-Warning-Alert phase via embodying the TCAS standard. With the developed function the air traffic control system could sense an in-flight collision situation before the pilot's decision-making moment.

• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.491-499
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• 2014

It is important to accurately measure and control the relative humidity of humidified gas entering a PEM (polymer electrolyte membrane) fuel cell stack because the level of humidification strongly affects the performance and durability of the stack. Humidity measurement devices can be used to directly measure the relative humidity, but they cost much to be equipped and occupy spaces in a fuel cell system. We present soft sensors for predicting the relative humidity without actual humidity measuring devices. By combining FIR (finite impulse response) model with PLS (partial least square) and SVM (support vector machine) regression models, DPLS (dynamic PLS) and DSVM (dynamic SVM) soft sensors were developed to correctly estimate the relative humidity of humidified gases exiting a planar-type membrane humidifier. The DSVM soft sensor showed a better prediction performance than the DPLS one because it is able to capture nonlinear correlations between the relative humidity and the input data of the soft sensors. Without actual humidity sensors, the soft sensors presented in this work can be used to monitor and control the humidity in operation of PEM fuel cell systems.