• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.34-41
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• 2006

A 3-dimensional stress measurement system based on the bore hole bottom deformation method, which is one of the stress relief methods, was developed. A pilot bore hole is drilled from the bottom of a bore hole and the stress meter is inserted into the pilot bore hole in the method. The bore hole is advanced as an over coring and the deformations in seven directions are measured by cantilever type-sensors. Using the cantilever type-sensors saves time for hardening of glue. No cable connection between the stress meter and a data logger is necessary since a compact data logger is installed in the stress meter. The accuracy of the stress meter was confirmed by a biaxial test for a Shikotsu welded tuff block although in-situ tests have not been carried out yet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.3
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• pp.207-215
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• 2013

This paper is channel assignment and scheduling techniques for efficient wireless AMI network. In AMI system, the multi-channel cluster network to be proposed defines the communication channel between NC (Network Coordinator) and CDA (Clustered Data Aggregator) as the network channel. CDA and OMD(Out Meter display) and communication channel between SMD(Smart Meter Device) are defined as the group channel. AMI network of the multi-channel cluster based in which the network channel and group channel is mixed increases the administration efficiency through the physical/logical consumer channel clustering. The reliability of inspection data through the channel use distinguished between the adjacent cluster is enhanced. In addition, the fast aggregation of data is possible and the size of a metering network is increased through the channel allocation of the multichannel cluster based.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.1
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• pp.34-41
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• 1991

The effect of flow conditions on flow measurement is difficult to identify from the inherent characteristics of the flowmeters and flow standard system. A new experimental approach has been attempted to detect the turbine meter error due to inlet flow conditions. In this try not only the design of the turbine meter package but also the data analysis method was altered. It was found that k factor slope of the turbine meter responds to the change of flow conditions in the test line with higher sensitivity than the degree of the data scattering. The flow standard system of $0.1m^3/s$ was chosen for the investigation. The systematic and random error of the system were less than ${\pm}0.08%$ and ${\pm}0.13%$ respectively.

• Survey Research
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• v.1 no.1
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• pp.125-134
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• 2000

It is very important to keep scientific principles in marketing research, Especially in sampling we have to select the scheme to avoid self-selection bias Internet index is ready-made-research service produced by analyzing the log data transferred from PcMeter installed in panelists PC with panelists profile and site data base following the scientific principles Through the index we can figure out the actual behaviour of Korean netizen surfing various web sites and understand their cybergraphics.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.208-211
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• 2012

전력시스템에서 MDMS(Meter Data Management System)는 HAN(Home Area Network)과 Smart Meter, SUN(Smart energy Utility Network)와 같은 AMI(Advanced Metering Infrastructure) 기반 환경에서 수많은 전력 또는 수도 가스 사용량과 같은 데이터를 수집, 취득하고, 이들 데이터를 처리, 가공, 분석하여 가치 있는 정보로 변환시켜, 요금서비스 및 다양한 부가서비스 창출에 활용되는 소프트웨어 인프라이다. 최근 MDMS 개발은 기능의 중요성 뿐만 아니라 다른 응용 시스템들과의 상호 운용성을 고려하여 개발하는 요구 기능을 가진다. 본 논문에서는 스마트그리드 환경에 적합한 AMI의 전력처리시스템(MDMS) 개발을 위한 설계 방안을 기술하였다.

• Journal of Korea Multimedia Society
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• v.20 no.7
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• pp.1046-1053
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• 2017

We propose a design method of high accuracy power measuring device and the method of securing the reliability of the measured data. As a design method for the development of the high accuracy power measuring device, the circuit was made by reflecting the high accuracy power measuring ICs and the CT (Current Transformer). To ensure the reliability of the power meter, we requested to the watt-hour meter certified testing organization to measure the error rate, and the error rate of active power based on the "Wattmeter Technical Standard(Revision notify 2014-283)" was measure, and the error rate was confirmed to be less than 0.1%.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.163-165
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• 1999

This work presents the performance characteristic of digital watthour meter under the harmonics of voltage and current. Each waveform involved is different in magnitude phase, and THD(Total Harmonic Distortion). It is possible to generate harmonics and control those waveforms using RTDS(Real Time Digital Simulator). Tests were performed on a selected sample of three-phase digital watthour meter which is coupled with data acquisition system via RS 485/232 converter. The percentage error rate of the watthour meter is compared for both sinusoidal and nonsinusoidal cases and the results are given.

• Journal of the Ergonomics Society of Korea
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• v.7 no.1
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• pp.13-20
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• 1988

The purpose of this study is to provide basic research data on the readability of the car number license plate in Korea by experimental procedure. This study is performed by the combination of color contrasts, character forms, and stroke widths. Additionally it is focused on the distance of distinct vision and misreading rate. The results of the this study are as follows: First, as to the color contrasts, the plate which has black on yellow contrast has better readability than current contrast between white and green (white character on green plate, vice versa). Second, as the character forms, it is showed that Quasigothic and NAMEL types have less misreading rates by 42.86% and 42.15%, respectively, than current Gothic type, and they also increase distance of distant vision by 4 meter. Third, as to the stroke widths, it is showed that 12 milli-meter and 14 milli-meter of stroke widths have less misreading rates by 63.94% and 65.33 %, respectively, than current 6 milli-meter of stroke width.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.8-19
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• 2020

We see an energy fucused smart city evolution of the UK along with the project of "Smart London Plan (SLP)." A theoretical logic of business model innovation has been discussed and a research framework of evolving energy focused smart city is formulated. The starting point is the silo system. In the second stage, the private investment in smart meters establishes a basement for next stages. As results, the UK's smart energy sector has evolved from smart meter installation through smart grid to new business models such as water-energy nexus and microgrid. Before smart meter installation of the government, the electricity system was centralized. However, after consumer engagement plan has been set to make them understand benefits that they can secure through smart meters, the customer behavior has been changed. The data analytics firm enables greater understanding of consumer behavior and it helps energy industry to be smart via controlling, securing and using that data to improve the energy system. In the third stage, distribution network operators (DNOs)' access to smart meter data has been allowed and the segmentation starts. In the fourth stage, with collaboration of Ofwat and Ofgem, it is possible to eliminate unnecessary duplication of works and reduce interest conflict between water and electricity. In the fifth stage, smart meter and grid has been integrated as an "adaptive" system and a transition from DNO to DSO is accomplished for the integrated operation. Microgrid is a prototype for an "adaptive" smart grid. Previous steps enable London to accomplish a platform leadership to support the increasing electrification of the heating and transport sector and smart home.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.85-93
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• 2011

In this paper, we analyzed the function elements of the Integrated meter reading system based on PLC which is working in Mok-dong, Seoul and studied how to improve the vulnerability. Also we propose an efficient method for the estimation of abnormal life status through frequency domain processing of utility meter readings. We found out that even after removing the high-frequency components from the raw meter data, the shape of the graph still maintains the original graph characteristics. The graph of the inverse transformed data has simpler and smoother curve than the original graph pattern. The original graph is not good to be used in deciding whether the residence's life pattern is normal or not. We could find out that the graph which is processed frequency signal has simple and intuitive graph pattern.