• Journal of Biosystems Engineering
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• v.25 no.5
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• pp.409-414
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• 2000

A machine vision system was built to obtain single stationary image from an egg. This system includes a CCD camera, an image processing board and a lighting system. A computer program was written to acquire, enhance and get histogram from an image. To minimize the evaluation time, the artificial neural network with the histogram of the image was used for eggshell evaluation. Various artificial neural networks with different parameters were trained and tested. The best network(64-50-1 and 128-10-1) showed an accuracy of 87.5% in evaluating eggshell. The comparison test for the elapsed processing time per an egg spent by this method(image processing and artificial neural network) and by the processing time per an egg spent by this method(image processing and artificial neural network) and by the previous method(image processing only) revealed that it was reduced to about a half(5.5s from 10.6s) in case of cracked eggs and was reduced to about one-fifth(5.5s from 21.1s) in case of normal eggs. This indicates that a fast eggshell evaluation system can be developed by using machine vision and artificial neural network.

• Atmosphere
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• v.28 no.2
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• pp.123-139
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• 2018

The prediction skills of stratospheric sudden warming (SSW) events and its impacts on the tropospheric prediction skills in global seasonal forecasting system version 5 (GloSea5), an operating subseasonal-to-seasonal (S2S) model in Korea Meteorological Administration, are examined. The model successfully predicted SSW events with the maximum lead time of 11.8 and 13.2 days in terms of anomaly correlation coefficient (ACC) and mean squared skill score (MSSS), respectively. The prediction skills are mainly determined by phase error of zonal wave-number 1 with a minor contribution of zonal wavenumber 2 error. It is also found that an enhanced prediction of SSW events tends to increase the tropospheric prediction skills. This result suggests that well-resolved stratospheric processes in GloSea5 can improve S2S prediction in the troposphere.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.235-239
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• 2015

The purpose of this study was to investigate the unstable plate system for the advanced balance ability. 7 male volunteers (age $33.7{\pm}1.2$ years, height $174.7{\pm}3.8cm$, weight $86.0{\pm}3.6kg$, BMI $28.2{\pm}2.0kg/m^2$) performed the partial squat motion on the shape of CAP type(${\cap}$) and BOWL type(${\cup}$) plate system. The range of motion (ROM) and muscle activation were acquired by the motion analysis system and the EMG system. Results of ROMs of the CAP type plate system were shown the widely range of the deviation in the ankle joint on the sagittal plane (sagittal plane - hip joint $10.7^{\circ}$ > $5.4^{\circ}$, knee joint $16.3^{\circ}$ > $6.4^{\circ}$, ankle joint $18.8^{\circ}$ > $6.3^{\circ}$ ; transverse plane - hip joint $3.5^{\circ}$ > $1.8^{\circ}$, knee joint $5.3^{\circ}$ > $3.4^{\circ}$, ankle joint $11.3^{\circ}$ > $5.3^{\circ}$ ; frontal plane - hip joint $0.9^{\circ}$ > $0.5^{\circ}$, knee joint $0.8^{\circ}$ > $0.6^{\circ}$, ankle joint $4.8^{\circ}$ > $3.7^{\circ}$). Muscle activation results of the CAP type plate system were indicated higher in major muscles for balance performance than the BOWL type plate system (vastus lateralis 0.90 > 0.62, peroneus longus 0.49 > 0.21, biceps femoris 0.38 > 0.14, gastrocnemius 0.11 > 0.05). These findings may indicate that the CAP type plate system would expect better effectiveness in perform the balance training. This paper is primary study for developing balance skills enhancement training device.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.43-54
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• 2017

This paper analyzes the performance of two three-leg inverters and a five-leg inverter and proposes the optimal operation conditions in applying the five-leg inverter for the train propulsion system. The five-leg inverter offers a saving of two switches compared with the standard two three-leg inverters and it is possible to control two three-phase motors independently by using a control board. All of these features lead to a potential reduction in capital cost and miniaturization of system. In this paper, first, the analysis of the existing motor control method and PWM method for two-traction motor drive of urban railway is implemented. Next, the operation principle and performance of five-leg inverter is introduced. Through the analysis, when it applies the same motor control method and the same PWM method for three-leg inverter and five-leg inverter, the characteristic of motor's speed and torque is compared.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.91-98
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• 2012

The objective of this study was to analyze the effects on the growth of Sedum species by different soil in shallow green roof module system, and to find the best soil mixture. The experiment used a module system, 7cm soil depth, five types of soil mixture ratio, and it was carried out on 7th Hoar rooftop in December of 2010. The growth status of the plant showed the most superior of the P5C7P2V1, next P10C1P2V1 and P1P1V1, P1 and C1 showed very poor growth. This result showed that the soil mixture ratio (P5C7P2V1) in green roof module system with minimum management can contribute to the proliferation of rooftop greening in urban settings.

• Journal of Biosystems Engineering
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• v.30 no.5 s.112
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• pp.293-298
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• 2005

The purpose of this study was the development of a multi-joint robot manipulator for milking robot system. The multi-joint robot manipulator was controlled by 5 drivers with driver controller through the position information obtained from the image processing system. The robot manipulator to automatically attach each teat cup to the teats of a milking cow was developed and it's motion was accurately measured with error rate. Results were as follows. 1. Maximum errors in position accuracy were 4mm along X-axis, 4.5mm along Y-axis and 0.9mm along Z-axis. Absolute distance errors were maximum 4.8mm, minimum 2.7mm, and average 3.6mm. 2. Errors of repeatability were maximum 3.0mm along X-axis, 3.0mm along Y-axis, and 0.5mm along Z-axis. Distance error values were maximum 3.2mm, minimum 2.2mm, and average 2.5mm. It is envisaged that multi-joint robot manipulator can be applicate to milking robot system being developed in consideration of the experiment results.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.78-86
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• 2013

In this research, dilute colloidal suspension alumina nanofluids were prepared by dispersing alumina nanoparticles in DI water and ethylene glycol as base fluids. Particle size analyzer and TEM test results revealed that the size of the alumina nanofluids(3wt% and 5wt%) with dispersion time 3hrs were 46nm and 60nm respectively. Thermal conductivity of these alumina nanofluids was measured by means of hot wire technique using a LAMBDA system. For water based alumina nanofluids, thermal conductivity enhancement was from 2.29% to 3.06% with 5wt% alumina at temperatures ranging from 15 to $40^{\circ}C$. Whereas in case of ethylene glycol based alumina nanofluids under the same temperature range, thermal conductivity enhancement was from 9.6% to 10% with 5wt% alumina. An enhancement of 37% average convective heat transfer was achieved with 5wt% alumina nanofluids at Re of 1,100.

• Wind and Structures
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• v.5 no.5
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• pp.393-406
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• 2002

Aerodynamic pressures and forces were measured on a model of a solar panel containing six slender, parallel modules. Of particular importance to system design is the aerodynamically induced torque. The peak system torque was generally observed to occur at approach wind angles near the diagonals of the panel ($45^{\circ}$, $135^{\circ}$, $225^{\circ}$ and $315^{\circ}$) although large loads also occurred at $270^{\circ}$, where wind is in the plane of the panel, perpendicular to the individual modules. In this case, there was strong vortex shedding from the in-line modules, due to the observation that the module spacing was near the critical value for wake buffeting. The largest loads, however, occurred at a wind angle where there was limited vortex shedding ($330^{\circ}$). In this case, the bulk of the fluctuating torque came from turbulent velocity fluctuations, which acted in a quasi-steady sense, in the oncoming flow. A simple, quasi-steady, model for determining the peak system torque coefficient was developed.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.191-196
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• 2010

Power system restoration following a massive or complete blackout starts with energizing the primary restorative transmission system. During this primary restoration process, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. In the case of the Myanmar electric power system, there are so many wide outage experiences, including complete blackout cases, caused by 230kV line faults and so on. Consequently, Myanmar's system operators have been well trained to deal with wide blackouts. Howver, system blackout restoration has been conducted by relying on the experience of only a few specialists. So, more scientific analysis is required to meet the requirements necessary to ensure fast and reliable system restoration. This paper presents analytical results on the primary restorative transmission system of Myanmar, focusing on the problems during the early restoration process. Methodologies are presented that handle load pick-up, terminal voltage and the reactive capability limitation of black-start generators to compensate the Ferranti effect. Static and dynamic simulation with the PSSolution and EMTDC programs respectively for the six cases are performed in order to select the primary restorative transmission lines.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.473-475
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• 2001

We report the state of the development of monitoring system for 72.5kV GIS. In the first, the usual outline of the monitoring and diagnostic system for GIS was mentioned, and the detailed specifications and state of development were also described. Especially, we present items of monitoring for GIS such as the operating counter of CB, the leakage condition of $SF_6$ gas, the surge counter of LA and the leakage current of LA.