• Journal of Industrial Technology
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• v.22 no.A
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• pp.89-94
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• 2002

In this paper, a Exhaust Flow Controller (EFC) technology for uniform application of film coater and developer device is introduced that spread and remove photo resister at semiconductor manufacturing process. Because developed EFC device uses differential pressure sensing method as a differential flow meter and embodied smart A/D conversion by using a one chip microprocessor and devised by feedback Servo control, It has shown excellent performance and stability evaluation, as maximum 2000L/min flow, capability of installation to actual semiconductor equipment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.935-938
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• 2004

This paper describes the quantitative analysis on the improvement of equilibrium sensory using virtual bicycle system. We have used a virtual bicycle system that combines virtual reality technology with a bicycle. In this experiment, 10 subjects were tested to investigate the influencing factors on equilibrium sensory. Straight road and curved road driving at several factors including cycling time, number of times of path deviation, and center of pressure(COP) were extracted and evaluated to quantify the extent of control. Also, To improve the effect of balance training, we investigated the usefulness of virtual feedback information by weight shift. The result showed that the system could be effective for equilibrium sensory rehabilitation training device. The analysis method might also have wider applicability to the rehabilitation field.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.132.5-132
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• 2001

In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important part in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system is hydraulically actuated cylinder with linear position sensor. Particularly Pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of salve cylinder is measured and utilized as the force feedback signal. Also force-reflection gain greatly affects the ...

• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.4
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• pp.137-144
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• 2008

This study deals with on-line fault detection and diagnosis(FDD) for heat exchangers of a variable speed refrigeration system(VSRS) based on current information. The current residual which is the difference between real detected current from current sensors and estimated current from no fault model was utilized to diagnose faults of the heat exchangers. Comparing to the conventional FDD of constant refrigeration system based on temperature and pressure information, the suggested FDD method shows better robustness to the VSRS which has a feedback control loop. Moreover the suggested method can be expected more precise and faster diagnosis of faults about heat exchangers. Throughout some experiments, the validity of the method was verified.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.409-410
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• 2012

본 논문에서는 스마트케어 서비스를 위해, Android 운영체제를 기반으로 하는 Device에서 ADK를 이용해 혈압계를 제어하는 방법을 제안한다. 이 방법은 소프트웨어와 하드웨어를 결합한 kit인 ADK를 사용하여 Hardware를 잘 모르는 사람들도 Android에서 Hardware의 GPIO에 좀 더 쉽게 접근하고 제어할 수 있어 보다 다양한 기능을 구현할 수 있다. 또한 이 방법으로 얻은 혈압계 데이터를 Database에 저장하여 데이터통신망을 통해 전문의에게 Feedback을 받음으로써 굳이 병원을 방문하지 않더라도 개인의 건강을 보다 편리하게 관리할 수 있어 한 단계 수준 높은 진단을 받을 수 있다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.2
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• pp.127-134
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• 2004

In this paper, human motor behaving model based sensory motor coordination(SMC) algorithm is implemented on robotic grasping task. Compare to conventional SMC models which connect sensor to motor directly, the proposed method used biologically inspired human behaving system in conjunction with SMC algorithm for fast grasping force control of robot arm. To characterize various grasping objects, pressure sensors on hand gripper were used. Measured sensory data are simultaneously transferred to perceptual mechanism(PM) and long term memory(LTM), and then the sensory information is forwarded to the fastest channel among several information-processing flows in human motor system. In this model, two motor learning routes are proposed. One of the route uses PM and the other uses short term memory(STM) and LTM structure. Through motor learning procedure, successful information is transferred from STM to LTM. Also, LTM data are used for next moor plan as reference information. STM is designed to single layered perception neural network to generate fast motor plan and receive required data which comes from LTM. Experimental results showed that proposed method can control of the grasping force adaptable to various shapes and types of greasing objects, and also it showed quicker grasping-behavior lumining time compare to simple feedback system.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.135-146
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• 2013

This paper presents a feedforward control algorithm for the EGR and VGT systems of passenger car diesel engines. The air-to-fuel ratio and boost pressure are selected as control indicators and the positions of EGR valve and VGT vane are used as control inputs of the EGR and VGT controller. In order to compensate the non-linearity and coupled dynamics of the EGR and VGT systems, we have proposed a non-linear model-based feedforward control algorithm which is obtained from static model inversion approach. It is observed that the average modeling errors of the feedforward algorithm is about 2% using stationary engine experiment data of 225 operating conditions. Using a feedback controller including proportional-integral, the modeling error is compensated. Furthermore, it is validated that the proposed feedforward algorithm generates physically acceptable trajectories of the actuator and successfully tracks the desired values through engine experiments.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.75-79
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• 1993

Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.

• Transactions of the KSME C: Technology and Education
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• v.1 no.2
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• pp.205-210
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• 2013

In this research, we have developed a ski-simulation system based on a physics-based simulation model using Newton's second law of motion. Key parameters of the model, which estimates skier's trajectory, speed and acceleration change due to skier's control on ski plate and posture changes, were derived from a field test study performed on real ski slope. Skier's posture and motion were measured by motion capture system composed of 13 high speed IR camera, and skier's control and pressure distribution on ski plate were measured by acceleration and pressure sensors attached on ski plate and ski boots. Developed ski-simulation model analyzes user's full body and center of mass using a depth camera(Microsoft Kinect) device in real time and provides feedback about force, velocity and acceleration for user. As a result, through the development of interactive ski-simulation motion recognition system, we accumulated experience and skills based on physics models for development of sports simulator.

• 한국체육학회지인문사회과학편
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• v.58 no.6
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• pp.449-459
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• 2019

The purpose of this study is to identify how postural mechanics affects postural control on balance and stability by using frequency analysis technique from the kinematic data acquired during the one leg standing posture. For this purpose, the experimental group consisted of two groups, the normal group (n=6) and the national Gymnastics group (n=6). Displacement data of CoP were analyzed by frequency analysis of rambling (RM) and trembling (TR) by FFT signal processing. As a results, there was a significant difference in evaluating the stabilization index between the two groups with the eyes open and closed one leg stnading (p <.05). The cause of the difference was found to be the output of the maximum amplitude of RM (f1) and TR (f2) (p <.05). In particular, in the low frequency RM of 8-9 Hz, which is a natural frequency of signal wave involved in postural feedback feedback, the main frequency appeared to be performs the exercise mechanism of stable brain posture control. And in the high frequency TM of 120-135 Hz, it is considered that the adaptation of the reflective muscle response is minimized to minimize posture shaking. In conclusion, this study provides evidence for the intrinsic main frequencies according to the postural control ability which affects the CNS in one leg standing.