• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.135-148
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• 2005

This paper considers a six sigma project for reducing the project costs through project risk management. The project follows a disciplined process of five phases: define, measure, analyze, improve, and control. A risk management process map is used to identify process input and output variables. Seven key process input variables are selected by using C&E diagram and X-Y matrix and finally four vital few input variables are selected by the related statistical analysis. The optimum alternatives of the vital few input variables are obtained by the method of PUGH matrix. The process is running on control plan and we obtained substantial project cost reductions in early stage of the control phase.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.6
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• pp.562-567
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• 2010

A passenger vehicle has various and complicated transmission paths of sound and vibration. In order to identify the mechanism of transfer path, estimation of excitation force and exact modeling of transfer path are required. In this paper vector synthesis technique is employed to identify the characteristics of road noise and its transmission to vehicle compartment through noise and vibration analysis. Vibration reduction efficiency of each transfer path is evaluated by comparing individual vector components obtained virtual simulation. The degree of effect is used to estimate the contribution of vibration input components to total output. And in this paper presents a new technique based on simulation studies using vector synthesis diagram and design of experiments, by which the effects of magnitude and phase change of input paths can be predicted.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.46-51
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• 2002

The measurement of velocity and stain rate field has been conducted in opposed impinging jet combustion. When a smaller diameter (5mm) orifice of pre-chamber was used, previous studies had reported that the combustion phase showed a shift from weak turbulent combustion to moderate turbulent combustion in the modified Borghi Diagram. In the case with smaller orifice diameter (5mm), NOx emission was substantially reduced by a factor 1/2 while the combustion pressure remains at the same as that in the conventional combustion. Hence, in this study, the experiment setup using PIV technique was designed to identify the relation of the strain rate distribution and NOx reduction associated with moderate turbulent combustion.

• Ocean Systems Engineering
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• v.2 no.1
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• pp.17-31
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• 2012

This study investigated the behavior of a non-isothermal $CO_2$ bubble formed through a leak process from a high-pressure source in a deep sea. Isenthalpic interpretation was employed to predict the state of the bubble just after the leak. Three modes of mass loss from the rising bubble were demonstrated: dissolution induced by mass transfer, condensation by heat transfer and phase separation by pressure decrease. A graphical interpretation of the last mode was provided in the pressure-enthalpy diagram. A threshold pressure (17.12 bar) was identified below which the last mode was no longer present. The second mode was as effective as the first for a bubble formed in deep water, leading to faster mass loss. To the contrary, only the first mode was active for a bubble formed in a shallow region. The third mode was insignificant for all cases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.213-216
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• 1997

The Maxwell displacement current was investigated in the connection with phase diagram of monolayers on a water surface. We measwed the displacement current of 8A5H monolayers on the water surface. The displacement current generated during 8A5H monolayers compression. Also, displacement current pulses were found to be generated when isomerizations were induced in 8A5H monolayers by irradiation with ultraviolet light ($lambda_1=340nm$) and visible light($lambda_2=450nm$).

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.326-326
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• 2006

The combination of living anionic and coordination polymerization techniques enabled to synthesize the polystyrene-b-polyisoprene-b-poly (butyl isocyanate) triblock polymers. Their microphase-separated structures were zig-zag structures for high ${\phi}_{PIC}$ samples, and hockey-puck structures were also observed. The phase diagram for PSt-b-PIp-b-PIC rod-coil polymers was different from that for PS-PBd-PMMA triblock polymers, and it was found that ${\phi}_{PIC}$ was the important factor to determine the microphase-separated structures.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1521-1523
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• 2005

PID controller is applied mostly to two-order system. In third-order or higher- system, it's impossible to get high response quality because of having more zero point than the number of zero point being in the PID controller. To solve those, Jung & Dorf suggested a new type of PIDA controller and solved problen of a third-order system.. But, as the result of getting step response using PIDA controller, rising time is very quickly but wide overshoot is happened. Beside designing PIDA controller with using CDM(Coefficient Diagram Method) of Shunji Manabe decreases overshoot to desired but rising time is very slow. Therefore this paper suggest a I-PDA controller for low overshoot and fast responsibility. This paper applied designed PD-PIDA controller to position control of 3-Phase induction motor.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.2
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• pp.65-70
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• 1998

In this paper, we will to check and to correct mis-recognized word using Eojeol information. First, we divided into 16 classes that constituents in a Eojeol after we analyzed Korean statement into Eojeol units. Eojeol-Constituent state diagram constructed these constitutents, find the Left-Right Connectivity Information. As analogized the speech of connectivity information, reduced the number of cadidate words and restricted case of morphological analysis for mis-recognition Eojeol. Then, we improved correction speed uisng heuristic information as the adjacency information for Eojeol each other. In the correction phase, construct Reverse-Order Word Dictionary. Using this, we can trace word dictionary regardless of mis-recongnition word position. Its results show that improvement of recognition rate from 97.03% to 98.02% and check rate, reduction of chadidata words and morpholgical analysis cases.

• Journal of The Korean Astronomical Society
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• v.29 no.1
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• pp.31-41
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• 1996

We present results of time-series CCD photometry for 178 stars in the young open cluster M29 (=NGC6913). Total 1036 V-band CCD frames were collected for five nights between August 12 and September 13, 1994. The photometric precision is about 7.6 mmag for 9th-10th mag stars in M29 with exposure times of 30 seconds. From the dispersion diagram and the light curves, one detached eclipsing binary (HD194378) and two suspected variables are newly discovered. $A\;\gamma\;Cas$ type variable, V1322 Cyg, which has been known as a member of M29, did not show any light variations during the period of present observations, indicating that it passed the steady phase without the eruption during our observing runs.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.151.3-151
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• 2001

A design of PI controller to be used to control the first-order lag plus dead time process, such as a flow process, by the coefficient diagram method (CDM) is investigated. The factor of the dead time of process is first approximated to be the first-order by the Pade approximation. The response of the flow control system designed by CDM satisfy both transient and steady state specifications. However, the transient response generally still has long rise time. In order to improve the speed of the system response, a feedforward controller (FFC) is added into the PI control system. The structure of the FFC is a phase lead structure with two designed parameters and one derivative time obtained from the reaction curve of the flow process ...