• Journal of the Korean Institute of Gas
• /
• v.27 no.2
• /
• pp.57-64
• /
• 2023

As the meter reading method of gas meters develops, smart gas meters capable of remote meter reading (leak checking meters and multi-function safety meters) are being used. These meters have a function to judge leakage by utilizing the flow rate and pressure data collected as an additional function. Leakage judgment function using flow rate data has valid cases in the actual field, but the pressure data-based leakage judgment standard is based on not only the pressure value change due to leakage but also various factors (pressure regulator pressure, connection with adjacent meters, usage of adjacent houses, location of meters, etc.). There is a problem with pressure magnitude changes (levels). In this paper, as a technique that can judge leaks by using pressure data collected from smart gas meters, it was developed through preprocessing of pressure data, criteria for pressure value ranges related to leaks, leak judgment techniques, and application case verification.

• Journal of Magnetics
• /
• v.8 no.4
• /
• pp.160-163
• /
• 2003

In magnetic flux measurement, output voltage drift of electronic integrator is an essential problem. In this work, we have developed a new kind of Miller type integrator using a sample and hold amplifier. Input bias current was measured and this value was hold in the sample and hold amplifier, after that input bias current of Miller integrator was compensated automatically using the value which holds in the sample and hold amplifier. Developed flux-meter shows the drift of flux-meter are smaller than 10$^{-5}$ Wb/min in full scale of 10$^{-2}$, and we could also measure multi-channel magnetic flux simultaneously.

• The Journal of the Korea Contents Association
• /
• v.9 no.7
• /
• pp.121-129
• /
• 2009

Inspection of an Electrical Meter is an action of measuring power usage to charge electricity rates and Electricity AMR(Automatic Meter Reading) is a system to automatize the action. AMR has been highlighted because it can reduce metering cost by substituting an automatic system for personnel and strengthen customer service. In this paper, we proposed and developed a smart card based AMR framework SCEMS as an alternative to other current AMR Models. This proposed SCEMS uses a java card based multi-application smart card and supports customer service such as various meter rates according to electricity consumption pattern data per household and transaction data that are accumulated in a smart card. This research can be a solution to the problems such as diversity, heterogeneity, and complexity that environmental changes will cause soon to the power supply industry.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.10
• /
• pp.414-419
• /
• 2016

Air flow measurement is a fundamental and important task for testing, adjusting, and balancing of HVAC system. However, it is difficult to carry out in the field due to the large size and weight of the flow meter. In this study, for the purpose of developing a small and portable flow meter, we proposed a different method of static pressure measurement and verified it experimentally. In the proposed method, static pressure difference was measured by inserting a tube inside the chamber before and after the nozzles. The results were compared with measurements according to the ANSI/ASHRAE standard. The results were in good agreement, indicating that the inserted tube method could be used for static pressure measurement of a portable flow meter. The proposed method eliminates the pressure tubes that are attached outside, which results in smaller size and easy handling.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.776-782
• /
• 2003

This paper develops an approach to fuse 1-meter resolution spatial panchromatic and 4-meter resolution multi-spectral IKONOS images. The approach is based on the characteristics of four-band wavelet transformation. The experiment shows that the fused images based on four-band wavelet method contain with not only high spatial resolution but also rich spectral characteristic.

• ETRI Journal
• /
• v.42 no.4
• /
• pp.585-595
• /
• 2020

Integration of multiple communication technologies in a smart grid (SG) enables employing cognitive radio (CR) technology for improving reliability and security with low latency by adaptively and effectively allocating spectral resources. The versatile features of the CR enable the smart meter to select either the unlicensed or the licensed band for transmitting data to the utility company, thus reducing communication outage. Demand response management is regarded as the control unit of the SG that balances the load by regulating the real-time price that benefits both the utility company and consumers. In this study, joint allocation of the transmission power to the smart meter and consumer's demand is formulated as a two stage multi-armed bandit game in which the players select their optimal strategies noncooperatively without having any prior information about the media. Furthermore, based on historical rewards of the player, a real-time pricing adaptation method is proposed. The latter is validated through numerical results.

• Journal of ILASS-Korea
• /
• v.21 no.1
• /
• pp.58-63
• /
• 2016

This study presents the dynamic characteristics of an impinging droplet on hydrophobic and hydrophilic surfaces with various texture area fractions. The flat surface was fabricated by using the drilling technique to make micro-meter hole-patterned surfaces, which shows hydrophobic textured surfaces. Moreover, the hydrophilic textured surfaces were manufactured by anodizing technique on the micro-meter hole-patterned surfaces to generate multi-layer surfaces. Impinging droplet experiments were conducted for various hole-patterned surfaces, with changing impact velocity and texture area fractions. It is observed that an anodizing technique increases wettability by decrease in hole diameter on the textured surfaces. However, micro-drilled surfaces decreases wettability because the hole diameter was so large that air can be trapped under the holes. In addition, the maximum spreading diameter decreases with the texture area fraction for the micro-drilled surfaces because of decrease in wettability.

• Economic and Environmental Geology
• /
• v.32 no.2
• /
• pp.169-175
• /
• 1999

The water leakage of reservoir embankment usually occurs through water vein, which gives little influence on the embankment in a normal state. However, the embankment can be destroyed when the water level of reservoir increases with heavy rain in summer. Investigating the water vein and its path is therefore very important from the viewpoint of disater prevention and embankment protection. This paper presents survey results of one-meter-depth ground temperature and multi-point temperature logging in an embankment in Japan to delineate water veins and permeable formations. Four water veins have been predicted in the embankment by comparing measured one-meter-depth ground temperatures with the background ones which have no effect of water vein. The multi-point temperature logging was carried out in the borehole drilled at one of the predicted water veins. Depth and thickness of the permeable formation in the borehole can be determined from temperature restoration ratios with elapsed time. From these results we can find that the water leakage of reservoir embankment mainly occurs in sandy soil formation in the embankment.

• Journal of Sensor Science and Technology
• /
• v.19 no.6
• /
• pp.475-482
• /
• 2010

Rogowski coil which detects magnetic flux on current changes. It is used for digital integration with watt-hour meter's current sensor, because, Rogowski coil has non-cored or non-magnetic core structure, so that, it cannot be saturated magnetically. This is a study for inventing accurate electric current sensors that have been applied on multi-layer ceramic substrate. We have confirmed its properties from each different layer's materials and pattern sizes by MWS 3D Electromagnetic field analysis program. And, after sensor manufacturing on multi-layer ceramic substrate, we confirmed its sensing quality is reliable as accurate electric current sensor for watt-hour meter.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.05a
• /
• pp.76-76
• /
• 2002