• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1315-1319
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• 2011

As government's policy is enacted to reduce greenhouse gas emission in transportation sector, railroad sector has to estimate amount of emission and propose feasible methods to reduce emission. To calculate accurate emission of railroad sector, we performed a study on the calculation model development for Tier 3 GHG emission factors. According to IPCC guide line, Tier 3 emission factor reflects individual characteristic of diesel locomotive. For this reason, we estimated GHG emission factor by stratified diesel locomotive and the result show difference of emission factor by notch changing. Therefore, the analysis of notch frequency during operation is required to develop Tier 3 emission factor, and we analysed a running pattern of diesel locomotive. As a result, idle and 8 notch consist about 70% of total running distance. In conclusion, the calculation model suppose that Tier 3 GHG emission factor is the sum of multiplied emission factor by weights in each notch. This result can contribute to Tier 3 emission factor calculation and reduction method development of emission in railroad sector by managing driving efficiency and technology development.

• Journal of Institute of Convergence Technology
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• v.1 no.2
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• pp.6-15
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• 2011

This paper reports the design and fabrication of a micro-electro-mechanical-system(MEMS)-based electrostatic angular microactuator for a dual-stage servo. The proposed actuator employs a novel electrode pattern named "skewed electrode array(SEA)" scheme. It is shown that SEA has better linearity than a parallel plate type actuator and stronger force than a comb-drive based actuator. The moving and the fixed electrodes are arranged to make the driving force perpendicular to the rotating moment of arm. By changing the electrode overlap length, the magnitude of electrostatic force and stable displacement will be changed. In order to optimize the design, an electrostatic FE analysis was carried out and an empirical force model was established for SEA. A new assembly method which will allow the active electrodes to be located beneath the slider was developed. The active electrodes are connected by inner and outer rings lifted on the base substrate, and the inner and outer rings are connected to platform on which the slider locates. Electrostatic force between active electrodes and platform can be used for exiting out of plane modes, so this provides the possibility of the flying height control. A microactuator that can position the pico-slider over ${\pm}0.5{\mu}m$ using under 20 volts for a 2 kHz fine-tracking servo was designed and fabricated using SoG process.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.3
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• pp.302-308
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• 2008

Composite materials are widely used as structural materials for aerospace engineering because of its excellent mechanical properties such as light weight, high stiffness, and low thermal expansion. In driving, impact damage is one of the common but dangerous damages, caused by internal failure of the laminas interface which is not detected by in the surface. Many techniques to detect defects or delaminate between laminates have been reported. Shearography is a kind of laser speckle pattern interferometry with the advantages of non-destructive, non-contact, high resolution and displacement slope measurement. In this paper, the shearography is used to evaluate non-destructively impact damaged surface of the composite material and a measuring method using shearography for the thermal deformation of a impact damaged composite material is discussed. The basic principles of the technique are also described briefly.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.101-105
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• 2009

The purpose of this study is to figure out the trends of the community facilities patterns in the designated apartments through the method of analyzing a case of a community housing yet to be open to its tenants. The thesis is based on document research and analysis of apartments categorized into five different groupings all in a status of being a prospective dwelling. The conclusion of the case study results as follows. Firstly, the distribution of a plan is either centrifugal or widespread. Secondly, the elevation plan contains its facilities in the basements or low-rise floors. Thirdly, sports facilities such as an indoor driving range, a fitness club and a GX-room and a open square on the outer space were unifiably common to all five groupings. In conclusion, in light of the facility patterns shown in the five extracted groupings of apartments, it seems that it will be difficult for all residents to benefit from the public facilities because the facilities are perceived as being limited to only a specific tower which hampers the improvement of the quality of life of the rest of the tenants and dampens an active social gatherings. Therefore, the public facilities must be planned and constructed to meet the satisfaction of the residents in whole, in place of being a commercially lucrative space.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.385-397
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• 1992

Current measurements at 3 sections and numerical experiments were carried out in Masan Bay to understand the effect of the wind on the residual currents and pollutant transport. The vertical distribution of horizontal velocities were directly affected by the wind at the depths of 1m and 2m beneath the sea surface. Analysis of the velocity data suggested that changes in the vertical gravitational circulation contributed to the net circulation. The net transport of water through the northern part of the bay was observed to be landward, with wind-induced transport of about 100m super(3)/s. Hence, wind is concluded to be the dominant mechanism driving the net circulation in the northern area of Masan Bay. Numerical experiments are shown that when S wind with 5m/s blew, northern area of the bay was generated the horizontal circulation of clockwise and local gyre. On the contrary of those, N wind made her to the anti-clockwise. In the case of no wind, the tidal residual current(constant flow) is very small or neglected except the bay-mouth. The inflow or outflow pattern of the mouth is considered as the flows generated by tidal residual current only. The distance of wind-induced transport of pollutant was as long as 2 times of no wind during the one tidal period.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.92-102
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• 2003

To detect electrical faults of a TFT (Thin Film Transistor) panel for the LCD (Liquid Crystal Display), techniques of converting electric field to an image are used One of them is the PDLC (polymer-dispersed liquid crystal) modulator which changes light transmittance under electric field. The advantage of PDLC modulator in the electric field detection is that it can be used without physically contacting the TFT panel surface. Specific pattern signals are applied to the data and gate electrodes of the panel to charge the pixel electrodes and the image sensor detects the change of transmittance of PDLC positioned in proximity distance above the pixel electrodes. The image represents the status of electric field reflected on the PDLC so that the characteristic of the PDLC itself plays an important role to accurately quantify the defects of TFT panel. In this paper, the image of the PDLC modulator caused by the change of electric field of the pixel electrodes on the TFT panel is acquired and how the characteristics of PDLC reflect the change of electric field to the image is analyzed. When the holding time of PDLC is short, better contrast of electric field image can be obtained by changing the instance of applying the driving voltage to the PDLC.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.2
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• pp.62-70
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• 2007

The aiming ability is a to improve accuracy performance of the firing vehicle. This paper describes the detection method of chatter vibration using disturbance acceleration in the pointing structure. In order to analysis vibration trends of the pointing system occurred during vehicle drive, acceleration data was processed by using data processing algorithm with moving average and Hilbert transform. Specific mode constants of acceleration were obtained under various disturbances. Vehicle velocity, road condition, property of pointing structure were considered as factors which make change of vibration trend in vehicle dynamics. Finally, back propagation neural networks have been applied to the pattern recognition for the classification of vibration signal in various driving conditions. Results of signal processing were compared and analysed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.587-592
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• 2017

In the three-phase four-wire low-voltage power distribution equipment, single-phase and three-phase load have been used mainly mixed. Also linear and nonlinear loads have been used together in the same conditions. In a three-phase four-wire distribution line, the current distribution of three-phase linear load is almost constant in each phase during driving or stopping, but the single-phase load is different from each other for each phase in accordance with the operation and stop. So that the voltage unbalance is caused by the current difference of each phase. In the three-phase four-wire distribution system, non-linear load is used with linear load. The presence of single-phase nonlinear loads can produce an increase in harmonic currents in three-phase and neutral line. It can also cause voltage unbalance. In the present study, we analyzed for the voltage unbalance fluctuations by the operation pattern of the single and three-phase linear and non-linear load in three-phase four-wire low voltage distribution system.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.491-498
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• 2017

This study is to determine the significant effect of white and pink noise on brain. The brain synchronization has been analyzed under the condition of non-noise, white nose and pink noise(male 10, female 10, mean age $23.3{\pm}2.14$). As a result of analysis, pink noise stimulus, alpha, low beta band, and high beta band were significantly decreased than non-noise and white noise. In addition, these brain response pattern significantly increased at frontal lobe and temporal lobe, and dominated on the right hemisphere. This result is considered to be useful of sound design in driving quality of human life on the basis of neuroscience.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.93-105
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• 2012

The purpose of this study was to investigate drivers' postures in different car pedal systems and skilled levels under fatigue. Twenty four subjects participated in this experiment. For three-dimensional analyses, six cameras (Proreflex MCU-240, Qualisys) were used to acquire raw data. The parameters were calculated and analyzed with Visual-3D. In conclusion, ROAs of two leg-pedal system were less than one leg pedal system by pattern analysis. Through statistical tests, skilled levels have effects on ROAs(X, Y, Z) of ankle joint at breaking a pedal and ROAs(Y, Z) of ankle joint at accelerating a pedal. Also, car pedal systems have effects on ROAs(Y, Z) of ankle joint, and ROA(Z) of knee joint at accelerating a pedal. In addition, skilled levels and car pedal systems (cross effects) have an effect on ROA(Z) of ankle joint. These findings suggested that we should improve a present single pedal system.