• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.16 no.5
• /
• pp.85-95
• /
• 2017

This study aims to identify the throw distance in terms of truck weight, bumper height, and speed in a truck and pedestrian collision, and to propose a model for throw distance estimates. For this purpose, a simulation analysis is performed using the PC-crash program with the following experiment conditions: Truck weight of 5t, 15t, and 25t, Bumper height from 0.3m to 0.6m by 0.1m, and speed from 10km/h to 100km/h by 10 km/h. Experimental results show that the truck speed and bumper height are found to be significant factors for pedestrian throw distance, but truck weight is not a significant factor. Also, a regression model is developed for pedestrian throw distance estimate from the multiple regression analysis. The adjusted $R^2$ value of the model is 93.3%, which is very good explanatory power.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.512-512
• /
• 2017

날로 심각해지는 해수 오염, 유류사고, 해파리에 의한 인명피해 및 발전소의 경제적 피해사고, 해양 쓰레기 등과 같은 해양 환경 문제가 발생하고 있다. 이러한 해양환경문제를 해결하기위해 생물학적 방법과 물리적 방법이 있으나 생물학적 방법은 개체군과 종류의 변화로 그 적용이 어려운 실정이고, 물리적 방법은 지속적인 제거를 위한 비용적인 문제와 인부 및 자원봉사자의 안전문제가 발생한다. 따라서 에어버블을 이용한 각종 친환경적 방법이 주목받고 있다. 본 연구에서는 에어버블 차단막의 차단율을 증가시키기 위해 현장조건 내에서 에어버블의 거동특성에 대한 실험을 하였다. 실험을 위해 회류식 개수로 에어버블 거동실험장치를 제작하였다. 실험장치는 길이 8.1m, 높이 1.2m, 폭 0.7m이며, 두께 10mm의 투명 아크릴를 사용하여 에어버블의 거동을 관찰 할 수 있게하였다. 대형펌프를 사용하여 물이 회류함을 통해 흐름유속을 만들어 현장조건을 고려하였다. 에어버블을 분사하기 위해 압축공기 저장탱크와 연결된 분사구가 있으며, 노즐의 크기(0.5mm~1.0mm)로 분사량을 조절하고 분사압은 별도의 조절장치를 이용하여 0~5bar 범위의 분사압 조절을 가능하게 하였다. 초고속 카메라와 3축유속계를 사용하여 에어버블의 이동경로, 유속 및 에어버블의 거동을 측정하였다. 실험을 통한 구간별 에어버블의 거동 분석 결과, 상승속도는 분사구에서 분출되는 구간인 0~0.8m 에서는 상승속도가 증가하고, 0.8~1.2m구간에서는 속도가 다시 상승하는 경향을 확인하였다. 이는 수표면에 가까워질수록 수압이 작아져서 에어버블의 크기가 커짐에 따라 부력이 커짐으로 판단된다. 같은 이유로 분사량이 많을수록 상승속도도 같이 증가되는 것으로 나타났다. 유속에 따른 거동은 유속을 0.1m/s~0.5m/s로 조정하여 유속별 에어버블이 수표면까지 도달하는 거리, 속도 및 이동경로를 분석하였다. 유속과 에어버블이 수표면까지 도달하는 거리는 비례하여 증가하는 것을 확인하였다. 실험결과를 바탕으로 조건에 따른 에어버블 거동 경험식을 도출하였다. 본 실험은 회류식 개수로 에어버블 거동실험장치를 활용하여 에어버블 거동 경험식을 제시하였으며, 이를 바탕으로 에어버블 차단막 기술 개발을 위한 기초자료로 이용될 수 있을 것이다.

• Resources Recycling
• /
• v.30 no.2
• /
• pp.24-30
• /
• 2021

Dismantling tests were performed to separate components from waste printed circuit boards (PCBs) using HCl solution with Sn4+. Then, the effects of agitation speed, reaction temperature, initial Sn4+ concentration, and HCl concentration on the dismantling of components were investigated. No significant effect on the dismantling speed was observed upon changing the agitation speed from 100 to 300 rpm. However, the dismantling rate increased with increasing reaction temperature, Sn4+ concentration, and HCl concentration. In the all-component dismantling tests, when the dismantling ratio increased to 100%, no solder was observed on the boards, and the Sn4+ concentration was ~1,500 mg/L. The dismantling ratio of the components from the PCB increased to 100% within 2 h when 1 mol/L HCl solution with 10,000 mg/L Sn4+ was used at an agitation speed and temperature of 200 rpm and 90 ℃, respectively.

• Korean Chemical Engineering Research
• /
• v.47 no.5
• /
• pp.639-645
• /
• 2009

In this study, alkanolamine was used to achieve high absorption rates for $CO_2$ as suggested at several literatures. The absorption rates of aqueous AMP and MEA solutions with $CO_2$, $SO_2$, $NO_2$ were measured using a stirredcell reactor. The reaction rate constants were determined from the measured absorption rates. The performances were evaluated under various operating conditions. As a result, the reactions with $SO_2$, $NO_2$ into aqueous AMP and MEA solutions were classified as an instantaneous reaction respectively. The absorption rates increased with increase of the reaction temperature and the concentration of absorbents. The simultaneous absorption rate of $CO_2/SO_2/NO_2$ into 3, 5, 10 wt.% MEA at various pressure of $CO_2/SO_2/NO_2$, was more increased 14~20% than AMP solution. We investigated the effect of $SO_2$ and $NO_2$ on the simultaneous absorption of $CO_2/SO_2/NO_2$ from a flue gas. The performances were evaluated under various operating conditions in order to investigate the absorption characteristic.

• Journal of Astronomy and Space Sciences
• /
• v.8 no.1
• /
• pp.85-98
• /
• 1991

Geomagnetism was used to control the attitude of the small scientific satellite at low altitude in sun-synchronous orbit. First, we analyzed the telemetry data. The rotation state of the satellite, can be known from the magnitude and variations of the magnetic field which is measured from the 3 axis magnetometer. In axisymmetric case, it is possible to control the attitude of the satellite by changing the rotation velocity of each 3 axis. The algorithm and the program were developed to calculate the supply time of the current operating the magnetorquer. This attitude control can be applied when the satellite is in tumbling motion and after passive control is attained by the Gravity gradient boom.

• KIPS Transactions on Software and Data Engineering
• /
• v.1 no.3
• /
• pp.195-200
• /
• 2012

To steer a camera is done based on system parameters of the vision system. However, the system parameters when they are used might be different from those when they were measured. As one method to compensate for this problem, this research proposes a gaze-steering method based on LMI(Linear Matrix Inequality) that is robust to variations in the system parameters of the vision system. Simulation results show that the proposed method produces less gaze-tracking error than a contemporary linear method and more stable gaze-tracking error than a contemporary nonlinear method. Moreover, the proposed method is fast enough for realtime processing.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1415-1422
• /
• 2019

Background subtraction is the major task of computer vision and image processing to detect changes in video. The best performing background subtraction is computationally expensive that cannot be used in real time in a typical computing environment. The proposed algorithm improves the background subtraction algorithm of the widely used MOG with the image resizing algorithm. The proposed image resizing algorithm is designed to drastically reduce the amount of computation and to utilize local information, which is robust against noise such as camera movement. Experimental results of the proposed algorithm have a classification capability that is close to the state of the art background subtraction method and the processing speed is more than 10 times faster.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.11
• /
• pp.62-72
• /
• 2003

This paper deals with a crosstalk minimization method by wire spacing. The suggested method uses linear programming method and consider crosstalk of both horizontal segments and vertical segments. In this paper, we suggest a method which can predict the coupling length between vertical segments in the final routing result using longest path algorithm. By the suggested method, we can make LP problem without integer variable. Therefore, it is much faster to solve the problem. In the case of crosstalk optimization, the suggested method optimized peak crosstalk 11.2%, and 3% total crosstalk more than wire perturbation method. The execution time of the suggested method is as fast as it takes 11 seconds when Deutsch is optimized.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.6
• /
• pp.585-591
• /
• 2015

In transcription for spoken language research, labeling is a work linking text-represented utterance to recorded speech. Most existing labeling tools have been working manually. Semi-automatic labeling we are proposing consists of automation module and manual adjustment module. Automation module extracts voice boundaries utilizing G.Saha's algorithm, and predicts utterance boundaries using the number and length of utterance which established utterance text. For maintaining existing manual tool's accuracy, we provide manual adjustment user interface revising the auto-labeling utterance boundaries. The implemented tool of our semi-automatic algorithm speed up to 27% than existing manual labeling tools.

• Proceedings of the KIEE Conference
• /
• 2002.06a
• /
• pp.25-28
• /
• 2002

본 논문은 마이크로 프로세스로 처리되는 여러 제어장치들 중에서 PI제어기의 최적 자동동조에 관한 개선된 방법을 제안하고자 한다. 이 방법은 Relay 자동동조 법으로서 이를 마이크로 프로세스에 응용하여 제어대상에 최적의 PI계수를 입력하게된다. 이를 위해 먼저 Computer와 DSP사이에 통신이 가능하도록 RS-232를 설치하고, 컴퓨터의 제어신호에 따라 모터의 속도가 Relay와 PI제어기에 의해 목표값에 도달할 수 있도록 설계하였다. 내부적으로 사용된 Relay 동조방식은 Relay로 제어대상의 출력을 강제로 진등시켜서 출력의 진폭과 주기를 이용하여 PI 계수를 조정하고 제어기의 입력값으로 선택된다. Relay동조 법은 동조과정이 간단하여 동조 방식의 구현이 쉽다. 또 위상여유를 고려하여 제어기의 계수를 조정하기 때문에 시스템의 견실성을 향상시킬 수 있을 뿐 아니라, 비례 제어만으로 임계 진동을 하지 않는 시스템의 경우에도 사용할 수 있고, 원점에 극점이 있는 경우에도 적용할 수 있어서 기존의 제어방식이 가지는 제약성의 한계를 극복할 수 있어서 적용성이 우수하다.