• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7599-7602
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• 2015

Background: In this study, we aimed to determine platelet indices such as platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), Plateletcrit (PCT) platelet count (PLT) in lung cancer cases, and evaluate any relationships between these parameters and stage or histologic types. Materials and Methods: This retrospective study covered 44 lung cancer patients and 47 healthy subjects. Platelet indices including PLT, PCT, MPV, PDW were estimated and compared with normal subjects. The results were evaluated statistically. Results: The PDW value was significantly higher in the cancer group compared to the control group; however, the values for PCT and MPV were lower. Conclusions: We suggest potential use of platelet indices in diagnosis of lung cancer.

• Proceedings of the KWS Conference
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• 1998.05a
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• pp.150-154
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• 1998

The purpose of this paper is to investigate optimum welding conditions of STS 304 thin sheet by GTA welding and control 6 $\delta$--fenite which is harmful in mechanical processing, corrosion problem and can be formed brittle a phase in using long term at high temperature. One series of automatic welds was made using argon plus 10, 20, 30 % nitrogen to ensure a fully austenite deposit. Results obtained were summarized as follows: 1) 6 $\sigma$ferrite content in the weld metals is influenced largely by the nitrogen content. 2) Additions of nitrogen to the shielding gas can significantly reduce the amount of retained delta ferrite and result in an increase in hot cracking. 3) Bead width was increased when Ar + $N_2$ shielding gas was used and travel speed was increased. 4) Ar+$N_2$ shielding gas made weld metal ductile and reduce 6 -$\delta$-ferrite.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.514-520
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• 2004

In WDM networt a WDM buffer is one of essential elements for realizing all-optical packet switching system. In this paper, we propose and demonstrate a single loop type all-optical WDM buffer system. The proposed one consists of NOLM and feedback loop, and provides more than 40 turns buffering (more than 20${\mu}\textrm{s}$) for single input pulse (1550nm, width: 20㎱) before selected by control signal pulse (1553nm, width: 30㎱).

• Journal of Power Electronics
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• v.12 no.3
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• pp.448-457
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• 2012

This paper proposes a carrier-based pulse width modulation (PWM) method to control an indirect matrix converter (IMC) by analyzing the relationship between the space vector PWM (SVPWM) and the carrier-based PWM. The complexity of the SVPWM method for an IMC can be reduced by using an equivalent carrier-based PWM method. The advantage of the proposed algorithm is its ability use only one symmetrical triangular carrier signal to generate the gate signals for all of the power switches in both the rectifier and inverter stages as compared to the conventional method where the carrier signal used in the rectifier stage is different from that of the inverter stage. In addition, by using a suitable offset voltage component in the modulation signals, the output voltage magnitude reaches 0.866 of the input voltage magnitude. Simulation and experimental results are provided in order to validate the proposed method.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.1
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• pp.102-109
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• 2015

In Korea, Lunar exploration program has been prepared with the aim of launching in the 2020's. As a part of it, a lunar lander demonstrator was developed, which was the model for verifying the system such as structure, propulsion, and control system, before launching into the deep space. This paper deals with the path tracking performance of the lunar lander demonstrator with respect to the thruster controller based on Pulse Width Pulse Frequency Modulator (PWPFM) and Pulse Width Modulator (PWM). First, we derived equations of motion, considering the allocation of the thrusters, and designed the path tracking controller based on Euler angle. The signal generated from the path tracking controller is continuous, so PWPFM and PWM modulator are adopted for generating ON/OFF signal. Finally, MATLAB simulation is performed for evaluating the path tracking ability. We compared the path tracking performances of PWPFM and PWM based thrust controller, using performance measures such as the total impulse and the position error with respect to the desired path.

• The Journal of the Korean dental association
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• v.11 no.4
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• pp.277-280
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• 1973

The author observed the changes of dental arch dimensions and compared spae-maintainer group with non-space-maintainer group after primary tooth extraction. The results were as follows 1) The rate of growth of dental arch of expeirmental group in intercanine width and in inter-1st molar width was more rapid than that of the control group. 2) Arch length is almost no dimensions but it was slightly decreased in lower arch. 3) Dental arch growth and tooth eruption were stimulated by space-maintainer appliance, so it is the best way to replace a new appliance at least once a year. 4) It is thought that satisfactory conclusions in this observation must be researched successively until the mixed dentition completes.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.7
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• pp.320-326
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• 2003

Slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force, this paper applies the neural network to inserted core type of slotless PMLSM. The, Magnetic pole ratio, the width of the inserted core and the width of the coil are selected as a design parameter to minimize detent force. In comparison with inserted core type one, thrust ripple greatly decreases by minimizing detent force and also thrust increases in this optimal model.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.107-114
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• 2012

In this paper, we propose a new modulation scheme called multi-coded variable pulse position modulation (MC-VPPM) for visible light communication systems. Two groups of signals (Pulse Width Modulation (PWM) and Pulse Position Modulation (PPM) groups) are multi-coded by orthogonal codes for transmitting data simultaneously. Then, each multi-level value of the multi-coded signal is converted to pulse width and position which results in not only an improved data rate, but also a processing gain in reception. In addition, we introduce average duty ratio and cyclic shift concepts in PWM through which dimming control for light illumination can be supported without any degradation in communication performance. Through simulation, we confirm that the proposed MC-VPPM shows a comparable BER curve and much greater achievable data rate than the conventional VPPM scheme using a visible light optical channel environment.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.46-48
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• 1998

This paper introduces the design method of a variable reluctace liner pulse motor to be analysed by a 3-dimensional problem in the 2-dimension. And it shows the thrust force density with respect to the ratio of the slot width to the teeth width, the height of mover and the height of tooth.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.695-698
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• 1995

The shape and width of fuzzy membership function has an effect on performance of fuzzy controller. In this paper, fuzzy controller is proposed to improve the control performance of fuzzy controller. It has two fuzzy inference engine. The one is typical fuzzy inference engine, the other is proposed to infer optimal width of membership function in fuzzy controller from plant constant (K,T,L). To show the effectiveness of this fuzzy controller with double fuzzy inference engine, it is applied to plant (dead time + 1st order delay) with various plant constant.