• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.63-70
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• 1989

This paper describes to design and to examine the mechanical characteristics of high frequency jet ventilator. The device consists of Phase lock loop(PLL) system, solenoid valve driving control part and Air regulating system. This study is carried out by changing several factors such as endotracheal tube(E.T. tube)diameter, injector cannula diameter, 1%, and frequency(breaths/mim.) having direct effects on the gas exchange as well as parameters of the entrained gas by venturi effects, so as to measure the tidal volume and minute volume. This system characteristics were as follows : 1) Frequency : 6-594bpm 2) Inspiration time : 1-99% 3) Variance of input air pressure : 1-30PSI.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.103-110
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• 1998

This experiment is performed to investigate the effects of the emulsion on the flame temperature and soot formation in a diesel engine. The two-color method is used to measure the flame temperature for combustion of emulsified diesel in the Rapid Compression and Expansion Machine(RCEM). The concentration of soot is estimated via calculation of the KL factor. The solenoid valve, elecronic controller and needle lift sensor are used to control the exact injection timing and duration under various operating conditions. According to the results the soot concentration is reduced with the increasing W/O while the temperature reduced. The pressure data and the flame images captured by a high speed camera show that the ignition delay of emulsified diesel increase the duration of premixed combustion. The sizes of water drops are measured to be about 10${\mu}m$ by a microscope.

• Journal of Energy Engineering
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• v.17 no.2
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• pp.47-53
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• 2008

The objective of this paper is to clarify the flow characteristic, velocity distribution, pressure loss, and other such fundamental data for the canister during loading and purging. The amount of gas that is loaded increases as the loading rate is decreased and the time increased, and the purging improves as the purge rate is increased. The hydrocarbons that are purged initially have a high concentration, and a large amount is purged. During loading and purging, the temperature initially increases and decreases drastically due to heat generation and heat loss.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.353-353
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• 2010

Alcohol is a vesatile polar solvent for molecules. As a preparation to deposit large molecules, we studied interaction of solvent molecules on metallic surface. in this work, we report on methanol adsorption on NiAl(110) with scanning tunneling microscopy (STM). These alcohol solvent molecules were deposited by a pulse injection method suitable for deposition of thermally unstable molecules. The injection of liquid alcohol onto the substrate in UHV was performed by using a high-speed solenoid valve with the back-pressure reduced down to 100 Torr. This technique allowed precise control over the amount of dosing of molecules to less than 1 L. Alcohol-induced features, attributed to methoxy, were found on bare NiAl(110) surface.

• Journal of the Korean Society of Combustion
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• v.3 no.1
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• pp.59-69
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• 1998

The results of study on the active control of naturally occurring combustion oscillations with a single dominant frequency in an atmospheric dump combustor are presented. Control was achieved by an oscillatory infection of secondary fuel at the dump plane. A high speed solenoid valve with a maximum frequency of 250Hz was used as the actuator and a sound level meter, located at the combustor exit, measured the pressure fluctuations which served as the feedback signal for the control loop. Instability characteristics were mapped over a range of mean mixing section velocities from 6.7 m/s-9.3 m/s and with three mixing conditions. Different fuel/air mixing conditions were investigated by introducing varying percentages of primary fuel at two locations, one at the entrance to the mixing section and one 6 mixing tube diameters upstream of the dump plane. Control studies were conducted at a mean velocity of 9.3 m/s, with an air temperature of $415^{\circ}C$, and from flame blowout to the stoichiometric condition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.451-454
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• 2000

Invasive methode and Non-invasive methode are used in blood pressure measurement. The Invasive methode can Set the correct measured blood pressure but, it has patient feels uncomfortable. So most of cases use Non-invasive methode. The Oscillometric method is commonly apply to modem electric sphygmomanometer and using various algorithm. In this paper describe about a algorithm it control and to determinate the cuff pressure, and filtering that data for measure the blood pressure. The communicating with personal computer can pressure deflation is by Solenoid valve and it uses RS-232 system in packet communication. The main using algorithm for blood pressure measurements are maximum amplitude algorithm and oscillometric algorithm. MAA(maximum amplitude algorithm) has various measured oscillation it depend on patient's age, height, weight and arm circumference size. In this paper, 1 studied the various measured oscillation apply to characteristic ratio and can get the result of systolic blood pressure, diastolic blood pressure, mean blood pressure. It was not used same ratio to measuring oscillation. In the MAA(maximum amplitude algorithm), we hope for reduce the difference with the real blood pressure and the measured blood pressure, when it applied with various specific ratio.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.163-168
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• 2009

In this study, we would be developed the fuzzy controlled PGO that controlled the flexion and the extension of each PGO's hip joint using the bio-signal and FSR sensor. The PGO driving system is to couple the right and left sides of the orthosis by specially designed hip joints and pelvic section. This driving system consists of the orthosis, sensor, control system. An air supply system of muscle is composed of an air compressor, 2-way solenoid valve (MAC, USA), accumulator, pressure sensor. Role of this system provide air muscle with the compressed air at hip joint constantly. According to output signal of EMG sensor and foot sensor, air muscles and assists the flexion of hip joint during PGO gait. As a results, the maximum hip flexion angles of RGO's gait and PGO's gait were about $16^{\circ}\;and\;57^{\circ}$ respectively. The maximum angle of flexion/extention in hip joint of the patients during RGO's gait are smaller than normal gait, because of the step length of them shoes a little bit. But maximum angle of flexion/extention in hip joint of the patients during PGO's gait are larger than normal gait.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.52-60
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• 2012

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of modifying the lubricating system to lubricate cylinder parts optimally by an electronically controlled quill device according to changes of engine load and revolution speed. In order to apply the developed accumulating distributor to an integrated cylinder lubricator by the electronically controlled system as the third research stage, the lubricating system is improved in the electronically controlled quill device with a solenoid valve. In this study, the effects of lubricator revolution speed, driving pressure and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the integrated cylinder lubricator system with an accumulated distribution by the electronic control. It is found that the oil feed rate of the developed integral cylinder lubricator system is less than that of the motor-driven cylinder lubricator by the electronically controlled quill system equipped with an accumulating distributor because of the decrease of delivery speed by increasing the maximum delivery pressure in the same experimental condition.

• Journal of Drive and Control
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• v.17 no.2
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• pp.55-62
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• 2020

There are two types of IMV for MCV, the spool type and the poppet type. The spool type is used in the existing excavator MCV and easily meets large-capacity flow conditions, but has a flow force problem which affects the spool control. The poppet type stably blocks the flow and has excellent rapid response. However, the larger the capacity, the larger the diameter of the poppet needed, requiring a strong spring to withstand the oil pressure. In this study, a bi-directional three-stage IMV for MCV that can be used in medium and large hydraulic excavators was proposed. This is a poppet type, enabling bi-directional flow control and resolves the problem of proportional solenoid suction force limitation. To investigate the validity of the proposed valve, the system was mathematically modeled and the static and dynamic characteristics were investigated through the simulation using commercial software. It has been concluded that the reverse flow is possible in a regeneration circuit and that the proposed IMV can be used to perform various excavation modes.

• International Journal of Automotive Technology
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• v.3 no.1
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• pp.27-32
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• 2002

Semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspensions fur passenger cars. In this study, a continuous variable damper for a passenger car suspension is developed. It is controlled actively and exhibits high performance with light weight, low cost, and low energy consumption. To get fast response of the damper, reverse damping mechanism is adapted, and to get small pressure change rate after blow-off, a pilot controlled proportional valve is designed and analyzed. The reverse continuous variable damper is designed as a HS-SH damper which offers good body control with reduced transferred input force from tire, compared with any other type of suspension system. The damper structure is designed, so that rebound and compression damping force can be tuned independently, of which variable valve is placed externally. The rate of pressure change with respect to the flow rate after blow-offbecomes smooth when the fixed orifice size increases. Damping forces are measured with the change of the solenoid current at the different piston velocities to confirm the maximum hysteresis of 20N, linearity, and variance of damping farce. The damping farce variance is wide and continuous, and is controlled by the spoof opening, of which scheme is usually adapted in proportional valves. The reverse continuous variable damper developed in this study is expected to be utilized in the semi-active suspension systems in passenger cars after its performance and simplicity of the design is confirmed through real car test.