• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.310-314
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• 2008

The exploitation of the wind energy resource is a rapidly growing area world-wide. The number of installed units is continuously increasing, and it is important to respect and to deal with the impact of wind turbine. This paper addresses the power quality characteristics of U57 Wind Turbine. 750kW gearless type wind turbine for low wind speed, named U57, is developed by UNISON. The power quality measurement system consists of measuring WTG output current, line-to line voltage and wind speed signal. With using measured data, power quality measurement is evaluated about maximum power, reactive power, voltage fluctuation, harmonics according to IEC 61400-21.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.219-224
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• 2011

The quality management for mobile internet voice services currently being used widely cannot be achieved by the conventional quality management depending on a specific measurement equipment. For more systematic quality management, a real-time or preventive quality management scheme is proposed. The proposed scheme required a quality management software installed in a service user's terminal. In order to implement and realize the proposed scheme, it is a very important issue to ensure the reliability of the measurement results from the developed quality management software. Therefore, we have performed a large number of tests to verify the reliability of the software and discuss on the results in this paper.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.59-65
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• 2019

In this paper, we propose a software quality measurement metrics of ISO / IEC 25023, which is newly proposed for software quality evaluation, to compare the difference with ISO / IEC 9126-2 which was used for software quality evaluation. In this paper, we propose a method for evaluating the quality of reliability based on the software reliability growth model among the eight quality characteristics presented in ISO / IEC 25023. Based on ISO / IEC 25023, software-quality evaluations demonstrate that there is some risk in evaluating reliability when based on data.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.3
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• pp.269-274
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• 2010

Recently IPTV service is becoming an emerging service representing IP convergence that is enabled on the broadband networks. It is an essential and very important issue to manage the service quality of IPTV service effectively for its successful deployment because of the innate nature of current Internet that cannot support quality of service (QoS). In particular, it is required that subscriber can measure and judge the service quality of IPTV service directly, which is impossible with the current method usually depending on a measurement equipment. In this paper, therefore, we introduce an implementation of a software that is installed at a set-top on the subscriber side and measures the quality of IPTV service in real time. In order to verify the performance of the implemented software, we perform a number of tests and compare the result with the measurement equipments in common use. By the comparison, it is shown that the measurement by the implemented software is precise and reliable.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.796-801
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• 1994

Measuring noise, sound quality or acoustical comfort presents a difficult task for the acoustic engineer. Sound and noise are ultimately jugded by human beings acting as analysers. Regulations for determining noise levels are based on A-weighted SPL measurement performed with only one microphone. This method of measurement is usually specified when determining whether the ear can be physically damaged. Such a simple measurement procedure is not able to determine annoyance of sound events or sound quality in general. For some years investigations with binaural measurement analysis technique have shown new possibilities for the objective determination of sound quality. By using Artificial Head technology /1/, /2/ in conjunction with psychoacoustic evaluation algorithms - and taking into account binaural signal processing of human hearing, considerable progress regarding the analysis of sounds has been made. Because sound events often arise in a complex way, direct conclusions about components subjectively judged to be annoying with regard to their causes and transmission paths, can be drawn in a limited way only. A new procedure, complementing binaural measurement technology combined with mulit-channel measuements of acceleration sensor signals has been developed. This involves correlating signals influencing sound quality, analyzed by means of human hearing, with signals form different acceleration sensors fixed at different positions of the sound source. Now it is possible to recognize the source and the transmission way of those signals which have an influence on the annoyance of sound.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3139-3144
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• 2010

A model system has been established for the evaluation of the uncertainty of the value from measurements of multiple subsamples by isotope dilution mass spectrometry (IDMS). In this report, we apply this model system for the evaluation of measurement uncertainty in determination of folic acid in infant formula. Five subsamples were analyzed by IDMS. The mean of the measurement results of the five subsamples was assigned as the final measurement value. The standard deviation (s) of the results from five subsamples was attributable to repeatability of the measurement. The uncertainty components in the IDMS measurement methods were categorized into two groups. Group I includes uncertainty components which give common systematic effects to all subsamples and do not contribute to the variation among multiple measurements (repeatability). Group II includes uncertainty components that give random effects on the measurement results, and are related with the measurement repeatability. These random effects are attributed to s. Therefore, the uncertainty of the final value was calculated by combining the standard deviation of the mean of multiple measurements, $s/{\surd}n$ (where n = 5), and the measurement uncertainty associated with the uncertainty components that give systematic effects.

• Journal of Information Processing Systems
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• v.18 no.2
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• pp.223-234
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• 2022

The evaluation of the print quality of 3D printing has traditionally relied on manual work using dimensional measurements. However, the dimensional measurement method has an error value that depends on the person who measures it. Therefore, we propose the design of a new print quality measurement method that can be automatically measured using the field-of-view (FOV) model and the intersection over union (IoU) technique. First, the height information of the modeling is acquired from a camera; the output is measured by a sensor; and the images of the top and isometric views are acquired from the FOV model. The height information calculates the height ratio by calculating the percentage of modeling and output, and compares the 2D contour of the object on the image using the FOV model. The contour of the object is obtained from the image for 2D contour comparison and the IoU is calculated by comparing the areas of the contour regions. The accuracy of the automated measurement technique for determining, which derives the print quality value was calculated by averaging the IoU value corrected by the measurement error and the height ratio value.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.211-221
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• 1998

It is very important to have a satisfactory measurement system, since it is useless to try to improve the manufacturing process without an adequate measurement system. Therefore, evaluation of the measurement system is the first step for the quality improvement of the manufacturing process. To estimate the measurement error we must conduct a controlled gage repeatability and reproducibility(gage R&R) study. Many manufacturers use a gage or instrument to measure multiple dimensions for the overall quality of the manufactured parts. In this case, it is necessary to estimate the gage R&R for multiple dimensions. When a gage measures a large number of dimensions of a part, it is very time-consuming and costly to measure all the dimensions. In this paper we propose the use of the principal component analysis method to identify a few principal components out of the original multivariate measurement capability to explain most of the measurement system variation pattern.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.3-9
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• 2004

The machining parts must be produced within the specification of drawing and those will be able to meet function and efficiency. At that time. it is necessary not only precision machine or machining technique but also the measurement technique is very important. So. the improvement of precise measurement technique is to be joined together at once with improvement of product technique. Finally. he quality and value of the parts are decided by precision measurement. This paper aims to study on he measurement uncertainty when the machined parts are inspected with 3-dimensional coordinate measuring machine. The objectives are to remove an error of measurement and to improve quality and productivity of the mass products.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.84-95
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• 1990

The objective of this study is to understand the effect of measurement-related investment. That is, this study aims at verifying the correlation between the measurement-related investment and inferiority rate of products by statistical analysis. The samples of this study are 376 industrial companies in Korea, and the research data was analysed on inferiority state of industrial companies with a measurement standard laboratory. The analysis was made by the elementary statistics, the correlation analysis and the regression analysis. The results are summarized as follows : First, the inferioriy rate of the industrial companies with a measurement standard laboratory was relatively lower than that of the other companies without the laboratory by statistical significance. Second, the increment on measurement-related investment had a negative correlation with the increment of inferiority rate, and the increase of measurement-related investment showed decrease of the inferiority rate by regression analysis.