• Journal of the Korean Vacuum Society
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• v.20 no.4
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• pp.307-312
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• 2011

As a technique for removing cancerous tumors from normal tissue, radio-frequency electromagnetic waves were employed to heating target cells up to the critical temperature, which kills the cancerous cells. However, its use in treating tumors in soft organs is limited by inconvenient factors, which are use of high-currents and long time operation. In this work, the feasibility of the localized heating by inserting four conducting electrodes with tiny direct current is investigated. The heat source is resulting from the electric field as known as resistive heating. We have investigated the temperature distribution as a function of applying DC voltages ranging from 10 V to 30 V with 10 V step. From the simulation results, the mushroom-like lesion shape by applying 20 V is generated by four electrodes within a few minutes, that is proper to the clinical application.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.259-267
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• 2002

We present a novel 3D fabrication method with single X-ray process utilizing an X-ray mask in which a micro-actuator is integrated. An X-ray absorber is electroplated on the shuttle mass driven by the integrated micro-actuator during deep X-ray exposures. 3D microstructures are revealed by development kinetics and modulated in-depth dose distribution in resist, usually PMMA. Fabrication of X-ray masks with integrated electrothermal xy-stage and electrostatic actuator is presented along with discussions on PMMA development characteristics. Both devices use $20-\mu\textrm{m}$-thick overhanging single crystal Si as a structural material and fabricated using deep reactive ion etching of silicon-on-insulator wafer, phosphorous diffusion, gold electroplating, and bulk micromachining process. In electrostatic devices, $10-\mu\textrm{m}-thick$ gold absorber on $1mm{\times}1mm$ Si shuttle mass is supported by $10-\mu\textrm{m}-wide$, 1-mm-long suspension beams and oscillated by comb electrodes during X-ray exposures. In electrothermal devices, gold absorber on 1.42 mm diameter shuttle mass is oscillated in x and y directions sequentially by thermal expansion caused by joule heating of the corresponding bent beam actuators. The fundamental frequency and amplitude of the electrostatic devices are around 3.6 kHz and $20\mu\textrm{m}$, respectively, for a dc bias of 100 V and an ac bias of 20 VP-P (peak-peak). Displacements in x and y directions of the electrothermal devices are both around $20{\;}\mu\textrm{m}$at 742 mW input power. S-shaped and conical shaped PMMA microstructures are demonstrated through X-ray experiments with the fabricated devices.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.39-45
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• 2004

A computer simulation about removal of the 0-th order diffraction is achieved by using numerical reconstruction in digital holography and the Fourier transform method. A light intensity distribution hologram is generated through numerical calculation of the interference pattern. Additionally a phase hologram without the 0-th order diffraction is generated. The removal function for elimination of the 0-the order diffraction is introduced and the numerical reconstructions with several conditions for the removal of the 0-th order diffraction and the production of high quality numerically reconstructed images are tested and compared. The removal function is proven to be more effective at the suppression of the 0-th order diffraction compared with the DC suppression method.

• The Research Journal of the Costume Culture
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• v.26 no.5
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• pp.727-743
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• 2018

In this study, we used the 3D simulation program to create bodice patterns for adolescents boy students and analyze the fitting and air gap through 3D simulation. The purpose of this study was to select the bodice pattern method that best suited the body shapes of the adolescents male students. The subjects of this study were the French E pattern, Japanese N pattern, and Korean industrial L and J patterns. The applied size was the sixth Korean human body size survey data of 2010 Korea. The age range of the subjects was 13-18 years. DC Suite Program Ver. 5.1 was used, and SPSS 23.0 program was used for data analysis. As a result of comparing the shapes of the bodice patterns in the 3D simulation program, the E pattern had two waist darts on the front and one shoulder dart and one waist dart on the back, and the J and L patterns only had one dart on the back. The N pattern had no darts on either the front or back. As a result of examining the appearance evaluation of the pattern, air gap, color distribution, and clothing cross-section, the E pattern was evaluated as the closest to the body, and the N pattern was evaluated as the pattern with the largest allowance. The J pattern was evaluated as the best fit for body shape of the male adolescents. However, it is necessary to develop a pattern system by adding extra ease in setting the center front length.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.173-179
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• 2001

This paper represents the control algorithm of the instantaneous voltage sag corrector for the power quality enhancement in distribution line. Especially, a novel detection technique of the symmetrical components is proposed for the analysis of the three-phase unbalanced and asymmetrical problems caused by the single line ground fault which is he most frequent event. This proposed method is based on the simple calculation and the control references of the symmetrical components for voltage compensation can be described as dc value without any other phase detection procedure. And also, for the generation of the reference voltages, the UF and MF defined by IEC is considered. Using this proposed control algorithm, the compensator has the fast dynamic characteristics and the THD of the compensated voltage waveform is very low. Finally, the validity of the proposed algorithm is proved by the PSCAD/EMTDC simulation and experimental results.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.110-115
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• 2018

The Na low temperature gettering in $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films was investigated using dynamic SIMS(secondary ion mass spectrometry) analysis. DC magnetron sputter, APCVD and PECVD techniques were utilized for the deposition of Al-1%Si thin films, $SiO_2/PSG/SiO_2$ and $SiO_2/TEOS/SiO_2$ passivations, respectively. Heat treatment was carried out at $300^{\circ}C$ for 5 h in air. SIMS depth profiling was used to determine the distribution of Na, Al, Si and other elements throughout the $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films. XPS was used to analyze chemical states of Si and O elements in $SiO_2$ passivation layers. Na peaks were observed throughout the $PSG/SiO_2$ and $TEOS/SiO_2$ passivation layers on the Al-1%Si thin films and especially at the interfaces. Na low temperature gettering in $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films is considered to be caused by a segregation type of gettering.

• Geophysics and Geophysical Exploration
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• v.7 no.1
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• pp.80-87
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• 2004

During excavation work for the construction of a highway bridge in a limestone area in Korea, several cavities were found, and construction work was stopped temporarily. Cavities under the bridge piers might seriously threaten the safety of the planned bridge, because they could lead to excessive subsidence and differential settlement of the pier foundations. In order to establish a method for reinforcement of the pier foundations, borehole radar reflection and tomography surveys were carried out, to locate cavities under the planned pier locations and to determine their sizes where they exist. Since travel time data from the crosshole radar survey showed anisotropy, we applied an anisotropic tomography inversion algorithm assuming heterogeneous elliptic anisotropy, in order to reconstruct three kinds of tomograms: tomograms of maximum and minimum velocities, and of the direction of the symmetry axis. The distribution of maximum velocity matched core logging results better than that of the minimum velocity. The degree of anisotropy, defined by the normalized difference between maximum and minimum velocities, was helpful in deciding whether an anomalous zone in a tomogram was a cavity or not. By careful examination of borehole radar reflection and tomography images, the spatial distributions of cavities were delineated, and most of them were interpreted as being filled with clay and/or water. All the interpretation results implied that two faults imaged clearly by a DC resistivity survey were among the most important factors controlling the groundwater movement in the survey area, and therefore were closely related to the development of cavities. The method of reinforcement of the pier foundations was based on the interpretation results, and the results were confirmed when construction work was resumed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.303-308
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• 2001

An objection of this study is to develop a high stable measuring circuits and a analytic system for radioactive pulses. The proposed system consists of a pulse detection units for neutrons and gamma-rays a programmable high voltage supply unit and a digital signal processor. The programmable high voltage supply unit designed can generate DC voltage up to 1,500 V at 5 V input and have a series voltage regulator to maintain the output voltage constantly, resulting in less than 1.63% of voltage regulation. The pulse detection parts consists of an active integrator, a pole-zero circuit, and a 3-stage amplifier of 60 dB, and its frequency bandwidth is from 37 Hz to 300 kHzAlso, pulse height distribution in accordance with pulse counts is important data in analyzing radioactive pulses. In this study, A/D convertor (12bit, 100ms) and DSP (TMS320C31-60) are used to analyze the pulse height, and the analytic system is designed to be operated in PC-base.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.1-8
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• 2012

The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I $Cos{\Phi}$) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.527-537
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• 2016

Recent automakers are trying to be more precise with the dimension check and moving parts to guarantee high quality and satisfy customer requirements. The aim of this paper is to investigate the design tolerance suitability of door operating mechanism linked arms, lever, and cam-shaft in a mobile air handling unit. These parts are complicated because doors, arms, lever and cam-shaft are connected nonlinearly in 3D. The current tolerance analysis method poses problems in design analysis because the moving doors are reasonably suitable for the AHU function. The 3-DCS analysis method provided useful results not only in establishing the inspection criteria for the quality control of products but also in enabling economical production. As a result, the vent door had $1.62^{\circ}{\sim}1.72^{\circ}$ and the defrost door had $0.84^{\circ}{\sim}0.9^{\circ}$ for the directly connected arms operating-type. For the lever connected arm operating-type, the foot door had $2.0^{\circ}{\sim}2.24^{\circ}$ tolerance, while the tolerance values satisfied the air flow volume distribution rate criteria in the AHU. Finally, the results have confirmed the design's tolerance suitability by using 3-DCS analysis at the early design stages. Reliability can be achieved by analyzing accumulated tolerance during the sub-parts assembly process and the moving mechanism linked especially by arms, lever, and cam-shaft.