• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.145-149
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• 2015

Objective: This study aims to analyze qualitatively if PTS methods are applicable to the agricultural works of Korea. Background: Many studies on setting standard time have been performed for manufacturing and service industries, not many studies on agricultural work have been carried out domestically and internationally. Method: MTM, MOST, Work Factor, MODAPTS were applied to some agricultural works, and limitations of each method were found out. Results: MTM was found to be more applicable than other methods, except for mental works. Conclusion: In general, many Korean agricultural works need squat postures, which are not taken into account in most of PTS methods. Continuous observation with stop watch is recommended for establishing the standard time for the agricultural works of Korea. Application: The information drawn from this study would be helpful to the farmer safety assurance system being established by Korean government.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.932-934
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• 2006

A relationship between discharge delay time and the aging method were investigated: A-Y (Address electrode - Scan electrode) aging and conventional X-Y(Common electrode - Scan electrode) aging with the variation of sustain voltage beyond self-erasing discharge. Although A-Y aging decreases discharge delay time, it has several drawbacks like non-uniformity of discharge, degradation of luminous efficiency and a color temperature. In a conventional aging condition which is carried out near the mid-margin voltage, discharge delay time is short in low voltage and high frequency condition. As an alternative to conventional voltage aging, high voltage aging is suggested which is carried out at self-erasing sustain voltage region. High voltage aging shows lower discharge delay time and fast aging speed than conventional voltage aging.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.755-762
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• 2015

One of the main objectives of the U.S. Census Bureau is the proper estimation of median household income for small areas. These estimates have an important role in the formulation of various governmental decisions and policies. Since direct survey estimates are available annually for each state or county, it is desirable to exploit the longitudinal trend in income observations in the estimation procedure. In this study, we consider Fay-Herriot type small area models which include time-specific random effect to accommodate any unspecified time varying income pattern. Analysis is carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. We have evaluated our estimates by comparing those with the corresponding census estimates of 1999 using some commonly used comparison measures. It turns out that among three types of time-specific random effects the small area model with a time series random walk component provides estimates which are superior to both direct estimates and the Census Bureau estimates.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.91-107
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• 2009

In order to accurately estimate the seismic behavior of buildings, it is important to consider both nonlinear characteristics of the buildings and the frequency dependency of the soil impedance. Therefore, transform methods of the soil impedance in the frequency domain to the impulse response in the time domain are needed because the nonlinear analysis can not be carried out in the frequency domain. The author has proposed practical transform methods. In this paper, seismic response analyses considering frequency dependent soil impedance in the time domain are shown. First, the formulation of the proposed transform methods is described. Then, the linear and nonlinear earthquake response analyses of a building on 2-layered soil were carried out using the transformed impulse responses. Through these analyses, the validity and efficiency of the methods were confirmed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.658-664
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• 2012

This paper presents an investigation into driveline clonk noise of midi-bus. Test was performed for operational acceleration and pressure, torsional vibration of driveline and FRF to TPA. Wavelet analysis was used to study spectral-time characteristics to all measurement data and specially for torsional vibration, lash analysis was carried out. To investigate the path of the clonk in detail, time domain TPA was introduced. With time domain TPA, the contribution of each path for the clonk was estimated by both subjectively and objectively. As a result, Transmission mount part was came to light as the main contributor of issued clonk. This was verified by reinforcing the bracket of transmission side. And 1D torsional nvh performance simulation model was built with measured torsional vibration. The simulation tool was used for prediction of some clonk behavior in tip in-out transient condition.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.58-59
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• 2018

In this study, firing experiments were carried out to confirm the foamability of the expansive shale collected from the local area. When expansive shales are subjected to high temperature heat, gas is generated inside and voids are formed. Due to this phenomenon, shale is used as a raw material for lightweight aggregate. Experiments were carried out with different plastic temperature and residence time to find the appropriate plastic temperature for this expansive shale. As a result, the higher the plastic temperature, the more the surface viscosity increased and the gas generated inside were retained. Resulting in a number of internal voids. However, even if the plastic temperature or the medium temperature is high, it is confirmed that sufficient gas is not generated when the residence time is shortened.

• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.59-65
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• 2014

Equine herpesvirus myeloencephalopathy, out of symptoms by equine herpesvirus type 1 (EHV-1) infection, can cause devastating losses on individual farms. Although myeloencephalopathy syndromes of horses in Korea have been recognized for a couple of years in horse populations, there is little study regarding the occurrence of EHV-1 infections. The present study was performed to detect the viral infection of horses with neurological syndrome using real-time PCR. Fifteen horses (27.3%) out of 55 horses with neurological deficiency were positive for EHV-1 viral antigen. Among these 7 horses, 4 horses were detected genotype of A2254/N752 and 3 horses G2254/D752 strain, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.177-178
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• 2011

Recently a great deal of people are taking legal action against the housing provider due to the defects of their Apartment house. And most of the housing companies are spending a huge amount of expenses and efforts to keep their brand value. This essay will carry out time series analysis the 20 housing district which are constructed by huge construction companies. This analysis itemised by metropolitan area(Seoul) and others to keep the degree of reliability, and converted future defect maintenance cost into current cost applied by discount rate to figure out suitability of defect maintenance cost. Even though, this essay is not able to represent standard of defect maintenance cost due to the insufficiency of record, while it will be assisted as a referance when long-term record of time series is estabilished.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.625-640
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• 2023

This paper propose a circuit that can measure the inductance of an inductive sensor used in IOT applications. The circuit was constructed using the characteristics of an RL low-pass filter circuit, comparator, current control switch, and capacitor, and the inductance value within the range 1[nH] < L ≤ 1[H] can be derived through the duration time during the output voltage of the RL low-pass filter circuit is greater than the reference voltage.

• Journal of Korean Port Research
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• v.10 no.1
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• pp.25-36
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• 1996

Generally, it is pointed out that a nonlinear analysis is needed to estimate accurately the water surface fluctuation and dynamic responses of a floating structure in case of large wave reflection. In this study, a frequency-domain method is applied and newly developed to analyze the nonlinear characteristics of the air-chamber floating breakwater. The air-chamber floating breakwater in this study can control well the wave transformation, motions of the structure and its natural frequency by adjusting the air depth in the chamber. Experiments are carried out to verify the numerical results. It is appeared that the mean water level is setup in the anti-node and setdown in the node, while the nonlinearity in wave profile is larger in the node than in the anti-node. Because of vertical mooring system, the sway, especially the time-independent nonlinear component, plays predominant role in the motion. On the other hand, the time-dependent component, as well as the time-independent one to the tensile force of mooring line contributes greatly, and the time averaged value presents tensional force oriented to the onshore side due drift force.