• 전기학회논문지
• /
• 제67권12호
• /
• pp.1690-1698
• /
• 2018

Recent advances in ICT technology have transformed many of our daily lives and attracted a lot of attention to personal health. Heart beat measurement that reflects cardiac activities has been used in various fields such as exercise evaluation and psychological state evaluation for a long time, but its utilization method is limited due to its differentiation from clinical electrocardiogram. Therefore, in this study, we could observe the change of the measured signal according to the change of the distance and the position of the measuring electrodes which are non-standard electrode configuration. Based on the electric dipole model of the heart, correlation with clinical electrocardiogram could be confirmed by synthesizing multiple surface potentials measured with a shorter electrode distance than standard one. From the electromagnetic point of view, the distance between the measuring electrodes corresponds to the distance that the electric potential by the cardiac electric dipole moves, and the electric potential measured at the body surface is proportional to the moving distance of the electric potential. Therefore, it is preferable to make the distance between electrodes as long as possible, and to position the measuring electrode close to the ventricle rather than the atrium. In addition, it was found that standard electrocardiographic waveforms could be synthesized by using arithmetic sum of multiple measuring electrodes due to the relationship of electrical dipole vectors, which is obtained by dividing and positioning a plurality of measuring electrodes on a reference electrode line, such as Lead-I, Lead-II direction. Also, we obtained a significant Pearson correlation coefficient ($r=0.9113{\pm}0.0169$) as a result of synthetic experiments on four subjects.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.453-458
• /
• 2004

A capacitate sensor is a proper device for measuring high small displacement. General design parameters and procedure are discussed and a test sensor was built to have a measuring range of 100$\mu\textrm{m}$ and a sensitivity about 30nm. This sensor has too opposing electrode of comparably large area and has nominal gap distance about 150$\mu\textrm{m}$. So as to achieve a nano order displacement sensitivity, both sensor and target system have to be considered. This is important for the sensitivity can be achieved by minimizing a system total noise level in electronic type sensor application. Typical performance of the developed sensor is demonstrated in precision moving stage having 0.1$\mu\textrm{m}$ moving resolution.

• 조명전기설비학회논문지
• /
• 제28권2호
• /
• pp.54-59
• /
• 2014

The electric power can be converted into the mechanical power by a corona discharge system. This way has not stronger force than a electric motor. But it has been applied in various industrial fields because of many advantages, no moving parts, smaller noise, simpler structure, minimizing et al. In this paper, corona discharge system with multiple corona electrode installed in form of the ring, has been studied by focusing on the electrical and mechanical characteristics. Intensity of the corona discharge depends on applied electric field, and electric field is related to the applied voltage, discharge gap spacing(s), distance between each corona electrodes(d). As a result, in the case d/s=0.9, most intensive discharge occurred in this experiments. In the region of d/s<0.9, ionic wind velocity has saturation value in spite of decreasing corona current, because each ion velocities increase by the increasing electric field.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.305-308
• /
• 2007

The field of dye-sensitized solar cell (DSC) is being researched actively at present. Because DSC has several advantages to pass the limits of Si solar cells such as a low manufacturing expense, a simple manufacturing process and its transparency. A lot of researches are underway about materials and processes in the field of dye-sensitized solar cell but its structure has been fixed up as the sandwich structure that both edges are used as positive and negative terminals. But the structure as of present is a factor of decreasing efficiency because the more electrons are recombined the further distance from terminal, considering about the characteristic of dye-sensitized solar cell that electrons generated inside cell are moved by diffusion. In this study, we made experiment on expanding the terminal to shorten internal moving distance of electron and compared the results according to the variation of active area to find out the effect of this trial. As a result, we achieved about 15.5% improvement of maximum power and 0.5% improvement of efficiency from terminal-expanded dye-sensitized solar cell of $2cm^{2}$ active area and concluded that the increasing rate of efficiency is raised as the active area becomes wider.

• 조명전기설비학회논문지
• /
• 제21권4호
• /
• pp.73-79
• /
• 2007

In order to analyze the potential rise of grounding systems installed in buildings, a hemispherical grounding simulation system was studied. Potential rise was measured and analyzed regarding the shape and distance of the grounding electrodes by using this system. The system was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured in real time by the horizontal moving probe of be potentiometer. The test grounding electrodes were fabricated through reducing the grounding electrode installed in real buildings such as the ground rod, grounding grid and so on. The potential rise was displayed in a two-dimensional profile and was analyzed regarding the shapes of the ground electrodes. The potential rise of the grounding grid combined with a ground rod was the lowest of every grounding electrode tested. The proposed results can be applicable to evaluating ground potential rise in grounding systems, and the analytical data can be used to stabilize the electrical installations and prevent electrical disasters.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2008년도 추계종합학술대회 B
• /
• pp.161-164
• /
• 2008

본 논문은 근전도 신호를 검출하고 로봇팔의 수직제어시스템을 구현하기 위한 연구이다. EMG 신호는 사람의 팔 근육에 흐르는 미세한 생체신호가 표면전극센서에 의해서 사용하여 검출되고 고성능 증폭, 필터링, ADC과 로봇팔의 서보 모터 구동 시스템으로 구현된다. 실험은 팔근육 움직임에 따른 EMG신호와 로봇팔의 다단계 수직제어 각도를 모니터링 한다. 시스템의 실험결과 수직제어각도는 2도 정도이며 평균오차는 5%이다.

• Journal of Electrical Engineering and information Science
• /
• 제2권4호
• /
• pp.66-71
• /
• 1997

The dielectrophoretic(DEP) force acting on a cell in an electric field is experimentally determined. A cell is accelerated by the DEP force in an electric field generated between micro planar electrodes. the position of the cell is measured and the velocity and acceleration of the cell are calculated based on the measured position data. The DE force is determined from the motion equation of a moving cell in suspension. The electrode structure is fabricated by micromachining technology and the height of electrodes is 1 $\mu\textrm{m}$. Radish cell and yeast are used in th experiments. In the case of radish cell, the DEP force increases as voltage or frequency(1MHz∼3MHz) increases. The voltage dependence can be explained that the DEP force increases when ▽│E│$^2$increases. The frequency dependence means that Re[x\ulcorner] of radish cell is maximized in a certain frequency. In the case of yeast, the DEP force increases only as voltage increases. The reason for the voltage dependence is the same with the case of radish. The DEP force increases only as voltage increases. The reason for the voltage dependence is the same with the case of radish. The DEP force on a yeast does not vary when the frequency varies from 1MHz to 3MHz. This result coincides with the fact that the value of calculated Re[x\ulcorner] is constant in the test frequency range.

• 한국광학회지
• /
• 제16권2호
• /
• pp.133-137
• /
• 2005

본 논문에서는 테이퍼된 구조를 갖는 광섬유 브래그 격자를 이용한 광학적 RF 실시간 지연 소자를 제안하고 구현하였다. 광섬유격자 표면에는 금속 박막의 히팅용 전극이 코팅되어 있다. 전극에 인가되는 전압에 의해 유발되는 열광학 효과를 통하여 광섬유 격자로부터 반사되는 광신호의 반사 위치를 변화시킴으로써 광신호에 변조용 신호로 실려서 전달되는 RF 신호의 시간 지연을 조절할 수 있다. 따라서 이 제안된 소자는 기존의 소자들과는 달리 기계적 변형이나 움직임 없이 전압에 의하여 연속적으로 정밀하게 시간지연 값을 제어할 수 있는 특징을 갖는다. 측정된 최대 시간 지연은 소비 전력이 $250{\cal}mW$일 때 약 120 ps였다.

• 대한기계학회논문집B
• /
• 제26권4호
• /
• pp.570-577
• /
• 2002

Charged liquid particle's behavior in electric and flow field was simulated to define the effect of electric field on the contact area and its dispersion. For the simulation of flow and electric field finite volume method was applied. To find out the particle's moving path in that field lagrangian equation of motion was solved by Runge-Kutta methods. We assumed that the particle was charged 10% of Rayleigh limit while the particle passing through the electrode and the particle does not have an effect on the electric field. In case of 30[Kv] of voltage charging the particles injected from the central 60% of the nozzle injection area adhere to the grounded moving plate and no dispersion occurred. Increasing the charged voltage to 40[Kv], it brought about the same phenomena as that of 30[Kv] charging except the dispersion. Voltage increasing from 30[Kv] to 40 [Kv] caused higher Coulomb force acts on the particle and it made the particle dispersion.

• 한국의류학회지
• /
• 제31권2호
• /
• pp.292-299
• /
• 2007

Development of portable device measuring the vital sign continuously with no limit of time and space is absolutely prerequisite for the U-health care that grafts the ubiquitous concept into medical system. Accordingly, it requires to develop a garment style apparatus for measuring vital-sign that is easy to wear on for a long time period. This study suggests a method to improve the insulation of electric cable and the skin adhesion of electrode by integrating the electric conductive material to garment, in order to develop a garment apparatus for measuring ECG for U-health care. Results of the research are as follows; In order to provide the adjacent conductive yarns with insulation, braid with narrow woven end was interlaced using polyester yarn. As a result, the direct contact between electric conductive yarns was restrained, which would be interposed into pin-tuck structured cable. Washable silicone gel applied around the electrode made of electric conductive fabric improved the adhesion, which prevents electrodes from dropping off from the skin surface during body movement. ECG signals on the human subject were tested using the garment apparatus developed by the above method. And the result was that the clear QRS wave formation in the typical form of ECG could be measured in both conditions of still and moving state as well. The result of this study is expected to contribute for the production of U-health care related medical apparatus by accelerating the practical uses of the garment measuring vital sign at a reasonable price.