• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.27-32
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• 2009

The measuring apparatus such as heat meter is legally obliged to be installed and used for heat rating with heat or flow rate in residential buildings in Korea. There are two kinds of apparatus to measure heat consumed at each households, i.e., heat meter and hot water flowmeter. Contrast to the most of buildings with hot water flowmeter well being used for rating, heat meters have been used only 42.6% in the buildings with central heating system. But there is a critical problem in the course of using hot water flowmeter for heat rating, yielding distorted and unfair result which is different from the real value of heat supplied. Experiments with several parameters were carried out in this study to analyze this phenomenon quantively and alternative methods were proposed for rational heat rating.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.581-586
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• 2009

Knowledge of ground thermal properties is most important for the proper design of large scale BHE(borehole heat exchanger) systems. The type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for insitu determination of design data for large diameter BHE for triple-U spacer apply. The main purpose has been to determine insitu values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a circulation pump, a inline heater, temperature sensors, flow meter, power analysis meter and a data logger for recording the temperature, fluid flow data. A constant heat power is injected into the borehole through the tripl-U pipes system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance of large diameter BHE for spacer apply.

• Journal of radiological science and technology
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• v.9 no.1
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• pp.89-92
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• 1986

Generally the inverse square law (ISL) is applied by use of intensity scale method, that is distance scale method, when we practice sensitometry of X-ray film. It was reported that the failure of the ISL had occurred in the many experiments. Thus authors obtained some conclusions of the exponent value of distance by use of dosimeter and fluorescence meter in the range of tube voltage 60 - 120 kvp, that is the range of diagnostic energy. Those conclusions were as follows its exponents were produced as 2.1383 - 2.1763 in dosimeter, as 2.1190-2.2152 in fluorescence meter. This revealed that the perfect ISL was failded and that numerical differences were shown in each measurem apparatus. Therefore it is need to study the exponent at each tube voltage for the precise supply of fixed quantity on the characteristic curve's horizontal axis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.752-754
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• 2016

Power is compared to the overall share of energy continues to increase, so as a way for efficient demand management and value added according to the AMR system was introduced. But there is a risk in a variety of external attack, such as when you use the remote meter reading system, cyber attacks and hacking. It is considered that the measures sought, which can be used to prevent or pre safer urgent. In this paper, I want to point out the current research trends and issues of security authentication technology of remote meter reading system.

• ETRI Journal
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• v.45 no.4
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• pp.650-665
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• 2023

A novel smart metering technique capable of anomaly detection was proposed for real-time home power management system. Smart meter data generated in real-time were obtained from 900 households of single apartments. To detect outliers and missing values in smart meter data, a deep learning model, the autoencoder, consisting of a graph convolutional network and bidirectional long short-term memory network, was applied to the smart metering technique. Power management based on the smart metering technique was executed by multi-objective optimization in the presence of a battery storage system and an electric vehicle. The results of the power management employing the proposed smart metering technique indicate a reduction in electricity cost and amount of power supplied by the grid compared to the results of power management without anomaly detection.

• KIEAE Journal
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• v.16 no.4
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• pp.71-77
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• 2016

Purpose : The energy saving in a residential building (apartment) sector is known as one of the effective solution of energy reduction. In South Korea, the government has recently reinforced regulations associated with the energy performance of buildings. However, there is a lack of research on the methods for the energy performance diagnosis that is used to analyze the wall thermal performance of the existing apartments. Because a reliable diagnosis is necessary to save the building energy, this study analyzed wall thermal performance of an existing apartment in Seoul. Method : This paper applied two methods for analysis of the thermal insulation performance; HFM(Heat Flow Meter) method and ASTR(Air-Surface Temperature Ratio) method. The HFM method is suggested by ISO9869-1 code to measure the thermal performance. The ASTR method is proposed by this study for the simplified In-situ measurement and it uses three temperature data (interior wall surface, interior and exterior air) and the overall heat transfer coefficient. This study conducted the experiment of an existing apartment in Seoul using these methods and analyzed the results. Furthermore, the energy simulation tool of the building was used to suggest retrofit of the building based on the results of measurements. Result : The error rate of HFM method and ASTR method was analyzed in about 17 to 20%. As the results of comparison between the initial design values of the wall and the measured values, the 26% degradation of insulation thermal performance was measured. Lastly, the energy simulation tool of the building shows 10.8% energy savings in accordance with the construction of suggested retrofit.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.1
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• pp.19-21
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• 2012

The engine oil life of internal combustion engine is shorted by the thermal effect and that causes air pollution. In order to measure the status of engine oil accurately, the exchange of new oil extends the life of combustion engine and reduces environmental pollution. Capacitance probes, such as engine oil and fluids can be used to measure the dielectric constant. In this paper, the degradation of engine oil varies depending on the degree of dielectric properties was analyzed. Depending on the state of the oil, the variant capacitance of the probe was measured by LCR Meter, respectively, and then the permittivity of oil was calculated. In addition, according to the size of the probe by measuring the change in capacitance measurement, accuracy of dielectric constant are presented. According to oil contaminated with the more increase in dielectric constant, we can decide that contaminated oil is available.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.21-33
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• 2017

This paper presents the analysis of plugging effect especially when the large diameter steel pipe pile was installed by considering driveability (BPM, blow per meter). The Coupled Eulerian-Lagrangian (CEL) technique was used to simulate the driving of open-ended piles into soil. To consider the driveability, the applied driving energy for each pile was obtained from the analysis results by using the wave equation. The parametric studies were performed for different pile diameters, penetration depths of pile, soil elastic modulus and BPM. It was found that the SPI is almost constant with increasing both the pile diameter and the required driving energy. It is also found that the plugging effect increases with increasing the pile length, resulting in the increase of lateral earth pressure. Based on this study the apparent magnitude and distribution of the lateral earth pressure is proposed for inside portion mobilizing soil plug.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.640-652
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• 2012

Many studies have investigated the smart grid architecture and communication models in the past few years. However, the communication model and architecture for a smart grid still remain unclear. Today's electric power distribution is very complex and maladapted because of the lack of efficient and cost-effective energy generation, distribution, and consumption management systems. A wireless smart grid communication system can play an important role in achieving these goals. In this paper, we describe a smart grid communication architecture in which we merge customers and distributors into a single domain. In the proposed architecture, all the home area networks, neighborhood area networks, and local electrical equipment form a local wireless mesh network (LWMN). Each device or meter can act as a source, router, or relay. The data generated in any node (device/meter) reaches the data collector via other nodes. The data collector transmits this data via the access point of a wide area network (WAN). Finally, data is transferred to the service provider or to the control center of the smart grid. We propose a wireless cooperative communication model for the LWMN.We deploy a limited number of smart relays to improve the performance of the network. A novel relay selection mechanism is also proposed to reduce the relay selection overhead. Simulation results show that our cooperative smart grid (coopSG) communication model improves the end-to-end packet delivery latency, throughput, and energy efficiency over both the Wang et al. and Niyato et al. models.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1485-1490
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• 2013

The demonstration project of the electrical grid for Smart grid is progressed, the smart digital appliances AV technology, Smart home energy management technology charging the management function of complex energy for the automation management of air conditioning and heating, humidity and air, the health care technology charging the design of housing for the elderly and disabled and the measurement of individual bio information, and the Smart home security technology dealing with the biometric security and motion sensors, etc. have been studied. The power monitoring terminal which uses a variety of wired and wireless networks and protocol is the target additionally to be considered in addition to the security vulnerabilities that was occurred in the existing terminal. In this research paper, the author analyzes the cryptographic techniques corresponding to the smart meter occurred by the problems that are exposed on the outside which are vulnerable to physical attacks, and intends to propose the design of the security systems for the Smart meter terminal being able to maximize the efficiency of the terminal.