• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.247.1-247.1
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• 2014

The capacitive coupled plasma is used widely in the semiconductor industries. Especially, the uniformity of the industrial plasma is heavily related with defect ratio of devices. Therefore, the industries need the capacitive coupled plasma source which can generate the uniform plasma and control the plasma's uniformity. To achieving the uniformity of the large area plasma, we designed multi-powered electrodes. We controlled the uniformity by controlling the power of each electrode. After this work, we started to research another concept of the plasma device. We make the plasma chamber that has multi-ground electrodes imaginary (CST microwave studio) and simulate the electric field. The shape of the multi-ground electrodes is ring type, and it is same as the shape of the multi-power electrodes that we researched before. The diameter of the side electrode's edge is 300mm. We assumed that the plasma uniformity is related with the impedance of ground electrodes. Therefore we simulated the imaginary chamber in three cases. First, we connected L (inductor) and C (capacitor) at the center of multi-ground electrodes. Second, we changed electric conductivity of multi-ground electrode. Third, we changed the insulator's thickness between the center ground electrode and the side ground electrode. The driving frequency is 2, 13.56 and 100 MHz. We switched our multi-powered electrode system to multi-ground electrode system. After switching, we measured the plasma uniformity after installing a variable vacuum capacitor at the ground line. We investigate the effect of ground electrodes' impedance to plasma uniformity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1649-1654
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• 2017

The route request (RREQ) packet of the GAODV is propagated in a unicast-manner using the location of the destination, but the application of the GAODV is restricted by the assumption for the known destination's location. In this paper, we propose a virtual destination aided GAODV (VDA-GAODV) that alleviates the uncertainty of the destination's location due to the mobility. Instead of the known location of the destination, the VDA-GAODV disseminates a RREQ packet to an imaginary location on the line connecting the source and the destination. We derive an optimal imaginary destination that makes RREQ rebroadcasts cover the possible locations of the destination as much as possible. The VDA-GAODV enables the RREQ propagation to cover 95 % of the one-hop communication area centered at the originally known location of the destination, which is larger than that of the original GAODV by 23 %.

• Journal for History of Mathematics
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• v.15 no.3
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• pp.17-24
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• 2002

It will be described the discovery of fundamental algebras such as complex numbers and the quaternions. Cardano(1539) was the first to introduce special types of complex numbers such as 5$\pm$$\sqrt{-15}$. Girald called the number a$\pm$$\sqrt{-b}$ solutions impossible. The term imaginary numbers was introduced by Descartes(1629) in “Discours la methode, La geometrie.” Euler knew the geometrical representation of complex numbers by points in a plane. Geometrical definitions of the addition and multiplication of complex numbers conceiving as directed line segments in a plane were given by Gauss in 1831. The expression “complex numbers” seems to be Gauss. Hamilton(1843) defined the complex numbers as paire of real numbers subject to conventional rules of addition and multiplication. Cauchy(1874) interpreted the complex numbers as residue classes of polynomials in R[x] modulo $x^2$＋1. Sophus Lie(1880) introduced commutators [a, b] by the way expressing infinitesimal transformation as differential operations. In this paper, it will be studied general quaternion algebras to finding of algebraic structure in Algebras.

• Korean Journal of Head & Neck Oncology
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• v.26 no.1
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• pp.45-47
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• 2010

Accessory tragus is an uncommon congenital anomaly of the external ear. The tragus derives from the first branchial arch. The accessory tragus can be found along the entire course of embryonic migration. Usually it appears as a small papules arising near the tragus, but rarely, along an imaginary line drawn back from the tragus to the angle of the mouth, or along the anterior edge of the sternocleidomastoid muscle and the sternoclavicular region. We experienced a case of accessory tragi on the suprasternal region in an 9 year-old-boy.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.227-230
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• 2002

In this paper we concentrate on overall direction of the gaze based on a head pose for human computer interaction. To decide a gaze direction of user in a image, it is important to pick up facial feature exactly. For this, we binarize the input image and search two eyes and the mouth through the similarity of each block ( aspect ratio, size, and average gray value ) and geometric information of face at the binarized image. We create a imaginary plane on the line made by features of the real face and the pin hole of the camera to decide the head orientation. We call it the virtual facial plane. The position of a virtual facial plane is estimated through projected facial feature on the image plane. We find a gaze direction using the surface normal vector of the virtual facial plane. This study using popular PC camera will contribute practical usage of gaze tracking technology.

• Journal of Technologic Dentistry
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• v.6 no.1
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• pp.27-30
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• 1984

This investigation was performed to study the relationship of the dental midline(an imaginary line between the centeal incisors) to the philtrum. 2,400 subjects with natural dentitions were examined. The group of the subjects was composed of 1,560 men and 840 women who had all of the upper and lower six anteriors and 0 to 4 missing teeth. Ages of the subjects ranged from 18 to 27 years. The obtained results were as follow: 1. The rates of the subjects whose philtrum and maxillary dental midline coincided was 64.92% and that of the subjects whose upper and lower dental midlines coincided was 29.17%and these rates are statistically significant, when compared respectively with those of the subjects whose philtrum and maxillary dental midline, and whose upper and lower dental midline's didn't coincide. 2. The difference between rates for the two sexes is not statistically significant. 3. Tooth missing significantly decreases the rates of the coincidence of the upper and lower dental midlines but its influence on the rates of coincidence of the dental midline to the philtrum is not significant.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.149-151
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• 2005

This paper deals with the novel control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active power filters. To construct two-axes coordinate, an imaginary second phase was made by giving time delay to line current. In this proposed method, the new signal, which was the delayed through the filtering by the phase-delay property of low-pass filter, is used as the secondary phase. Because two phases have different phase, instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying gain of filter by compensation current using the rotating reference frames that synchronizes with source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames. This paper shows the experimental results, which provide a high accuracy and extremely fast response of single-phase hybrid active Bower filter under the operation with the proposed control method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.6
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• pp.98-104
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• 2002

In this study, we have developed an algorithm by attaching a camera at the end-effector of industrial six-axis robot in order to determine position and orientation of the camera system from cartesian coordinates. Cartesian coordinate as a starting point to evaluate for suggested algorithm, it was easy to confront increase of orientation vector for a linear line point that connects two points from coordinate space applied by recursive least square method which includes previous data result and new data result according to increase of image point. Therefore, when the camera attached to the end-effector has been applied to production location, with a calibration mask that has more than eight points arranged, this simulation approved that it is possible to determine position and orientation of cartesian coordinates of camera system even without a special measuring equipment.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.54-60
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• 2011

In this study, an analytical realization of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive least square(RLS) modeling algorithm and the natural mode for real part and imaginary one was discussed. This recursive approach (RLSM) can be adopted for the on-line system identification and monitoring of an end-milling for this purpose. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF(Frequency response function) and mode analysis. Also the FRF was analysed for the prediction of a end-milling system using recursive algorithm.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.73-79
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• 2011

In this study, an analytical realization of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive least square modelling algorithm and the natural mode for real part and imaginary one was discussed. This recursive approach (RLSM) can be adopted for on-line end-milling identification. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF (Frequency response function) and mode analysis. Also the FRF was analysed for the prediction of a end-milling system using recursive algorithm.