• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.6
• /
• pp.797-802
• /
• 2013

In this paper, using the mass/CG measurement equipment and the MOI measurement equipment developed in-house, Pitch MOI and Roll MOI of test specimen were measured and measurement uncertainties on MOI were studied. The possible factors of the measurement uncertainty that could affect accuracy of MOI measurement were mass, spring, frequency, and length measurement-related elements. The each combined standard uncertainty of pitch MOI and roll MOI was estimated from the uncertainties of the above various factors.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.867-868
• /
• 2012

• Journal of Drive and Control
• /
• v.18 no.2
• /
• pp.38-45
• /
• 2021

In recent years, the demand for an onboard scale system which can directly monitor load distribution and overload of vehicles has increased. Depending on the suspension type of the vehicle, the onboard scale system could use different types of sensors, such as, angle sensors, pressure sensors, load cells, etc. In the case of a vehicle equipped with leaf spring suspension system, the load of the vehicle is measured by using the deflection or displacement of the leaf spring. Leaf springs have hysteresis characteristics that vary in displacement depending on the load state. These characteristics cause load measurement errors when moving or removing cargoes. Therefore, this study aimed at developing an onboard scale device for cargo vehicles equipped with leaf springs. A sectional modeling method which can reduce measurement errors caused by hysteresis characteristics was also proposed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.1
• /
• pp.12-17
• /
• 2010

The oil tanker ship over 150GRT must equip oil content meter which satisfy requirements of revised MARPOL 73/78. Online measurement of oil content in complex samples is required to have fast response, continuous measurement, and satisfaction of ${\pm}10ppm$ or ${\pm}10%$ error in this field. The research of this paper is to develop oil content measurement system using analysis of light transmission and scattering among turbidity measurement methods. Light transmission and scattering are analytical methods commonly used in instrumentation for online turbidity measurement of oil in water. Gasoline is experimented as a sample and the oil content approximately ranged from 14ppm to 600ppm. TSK Fuzzy Model may be suitable to associate variously derived spectral signals with specific content of oil having various interfering factors. Proposed Parallel TSK Fuzzy Model is reasonably used to classify oil content in comparison with other models. Those measurement methods would be effectively applied and commercialized to oil content meter that is key components of oil discharge monitoring control equipment.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.1163-1175
• /
• 2016

In recent years, microgrids have been the focus of considerable attention in distributed energy distribution. Microgrids contain a large number of power electronic devices that can potentially cause negative impedance instability. Harmonic impedance is an important tool to analyze stability and power quality of microgrids. Harmonic impedance can also be used in harmonic source localization. Precise measurement of microgrid impedance and analysis of system stability with impedances are essential to increase stability. In this study, we introduce a new square wave current injection method for impedance measurement and stability analysis. First, three stability criteria based on impedance parameters are presented. Then, we present a new impedance measurement method for microgrids based on square wave current injection. By injecting an unbalanced line-to-line current between two lines of the AC system, the method determines all impedance information in the traditional synchronous reference frame d-q model. Finally, the microgrid impedances of each part and the overall microgrid are calculated to verify the measurement results. In the experiments, a simulation model of a three-phase AC microgrid is developed using PSCAD, and the AC system harmonic impedance measuring device is developed.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.241-248
• /
• 2010

A bimodal low-floor tram can provide the punctuality of trains and the flexibility of bus together to the passengers. Its propulsion system is a series hybrid type using a set of CNG engine generator and Li-polymer battery. This paper presents a development of the measurement equipment for fine-tuning of a series hybrid propulsion system of bimodal low-floor tram. Its configuration schemes are described and certified using the measurement data of bimodal low-floor tram.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.4
• /
• pp.695-703
• /
• 2016

The maintenance method for the electrical facility of high speed railway has been evolved from inspection by personnel to the automated way by the detection devices. In particular, the signalling equipment in order to increase the safe and efficient operation of the trains is required to maintain normal operation by periodic maintenance. Because the return current gives the most important effects to the wayside equipment in case of the failures, a method is needed to measure the unbalanced rate of return current on the train at high speed driving. The Hot Box Detector(HBD) device that is installed at track-side has a function to recognize the abnormal axle box by detecting the temperature that occurs in the axle of train passing over its device. In order to implement the measurement equipment for unbalanced rate of return current and axle temperature, the design method is proposed and the experimental test results by test bed are included in the paper.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.3
• /
• pp.999-1006
• /
• 2014

$CO_2$ emission factor for earthwork equipment was made based on fuel consumption quantity using IPCC carbon emission factor. This is presented through the carbon emission estimating guideline each facilities by the Ministry of Land, Infrastructure and Transportation in 2011. However, this method has the defect which don't apply the various condition of site. Therefor it needs the new emission factor supplemented these defects. This study will tries to estimate $CO_2$ emission with the direct measurement method using concentration flow velocity measurement (C-FVM) for earth work equipment and present the new $CO_2$ emission factor for earth work equipment after compare with emission factor of the Ministry of Land, Infrastructure and Transportation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2004.05a
• /
• pp.502-505
• /
• 2004

The purpose of this experiment is to modify diagnosis criterion of isothermal relaxation current(IRC) measurement equipment which is using for distribution cable diagnosis. We're using this system for several years in the field instead of DC leakage current measurement and lots of cables were replaced. But we have to investigate on the reliability of this equipment for our cables because we didn't carried out condition assessment of extracted cables after field diagnosis by this equipment. It is important thing for cable maintenance. If the replacement criterion is improper we can not prevent failures or will waste budget on account of replacement of the sound cables. In this papar we selected field installed cables and injected silicone fluid to the cables for insulation rehabilitation. In order to prove reliability of the diagnosis equipment we compared diagnosis results and AC breakdown strength according to operating time after silicone treatment. This is the results of the field test for 1 year.

• Journal of Environmental Science International
• /
• v.31 no.5
• /
• pp.447-456
• /
• 2022

This study was conducted to propose a way to increase the accuracy and precision of 𝛽-ray measurement equipment. Statistical processing results of equivalent evaluation data from 2016 to 2021 confirmed that the concentration of micro dust measured by 𝛽-ray measurement equipment was higher than that of micro dust sampler. According to quarterly data, it was confirmed that the data from the third quarter (July to September) showed a different trend from other periods, which is assumed to be due to weather conditions. This study indicates that automatic micro-dust measurement equipment evaluation at air pollution measuring stations during the third quarter should be excluded. The evaluation cycle should be changed from once every two years to quarterly. In addition, when the criterion for determining equivalence evaluation falls within the range of the slope and intercept values of the existing trend line, it is necessary to evaluate the R² value together and reduce the slope from 0.9-1.1 to 0.9-1.0.