• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1019-1026
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• 2008

The goal of this paper is to analysis the trend of stream quality about the upstream, middle stream and high areas of Nakdong River measurement points from January 1998 to December 2006. and to suggest some policy alternatives in Nakdong river. It used the three different monthly time series data such as BOD (biochemical oxygen demand), TN (Total Nitrogen) and TP(Total Phosphorus), of the three of Nakdong River measurement points. BOD, TN and TP data are analyzed with the LOWESS(Locally Weighted Scatter plot Smoother) nonparametric method.

• 품질경영학회지
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• 제19권1호
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• pp.83-94
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• 1991

The purpose of this study is to analyze the economic efficiency of the investment for calibrating measurement instruments in manufacturing industries, and to propose the administration scheme of measurement instruments. To investigate the efficieny of calibration, we estimate a multiple regression model composed of variables - product inferiority-rate, calibration rate, etc-, and verify fitness of the model. According to the statistical analysis by LOGIT method, a forecasting model of product inferiority-rate with calibration-related variables is proposed, and its validity is investigated.

• 전자공학회논문지 IE
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• 제45권1호
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• pp.58-64
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• 2008

본 논문은 인간에 의해 주관적으로 측정되던 이동 멀티미디어 영상 품질에 대한 방법을 개선하기 위한 논문이다. 다양한 열화요인을 가지는 동영상의 정량적이며 객관적인 화질평가를 위해서는 기존의 PSNR의 한계를 보완하고 전송망에서 발생하는 오류를 고려하여야 한다. 따라서, 본 논문에서는 인간의 인지특성을 반영할 수 있는 새로운 객관적 화질측정방법을 제안하였다. 제안된 방법은 멀티미디어 서비스 영상의 품질을 다양하고 정확하게 측정할 수 있으며 서비스 가이드라인을 설정하여 고품질 영상서비스를 제공하는 표준안 설정을 위한 측정 방법과 시스템으로 활용될 수 있다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.10-15
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• 2004

A machining processes for flange panel has been introduced. Contrary to the conventional methods like forming and welding, roll-seaming method has been utilized for better quality and less cost. Several measurement methods including digital image processing have been used to confirm the product quality assurance.

• 한국융합학회논문지
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• 제11권11호
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• pp.25-31
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• 2020

본 연구는 소프트웨어의 시험 평가에 있어 품질 특성에 대한 가중치를 적용하는 방법을 연구한 것이다. 가중치 적용방안은 시험성적서의 텍스트를 분석해서 텍스트의 빈도에 따른 비율을 소프트웨어 시험 성적의 품질 특성에 대한 가중치로 활용한다. 본 연구의 결과에 대한 타당성 검토는 개발자와 사용자를 중심으로 소프트웨어의 중요도를 평가하게 한 설문조사의 결과와 텍스트 분석의 빈도분석 결과를 비교해서 검토했다. ISO/IEC 25023에서 제시한 8가지 품질 특성을 기반으로 품질을 측정할 경우 동일한 가중치를 적용해서 소프트웨어 품질을 평가하는 것에 비하여 본 연구의 결과는 소프트웨어 특성을 고려한 소프트웨어 품질 측정 결과이므로 소프트웨어 시험 평가에 대한 품질 측정의 타당성이 높아진다고 할 수 있다.

• 한국입자에어로졸학회지
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• 제6권3호
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• pp.123-129
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• 2010

As the indoor activity increases in recent years, the indoor air quality becomes more important. One of the major contaminants in office space is the copy machines and the laser based printers. These devices usually emit nano-particles and chemical species that may give some health effect. The amount of particles generated by the printers and copy machines depend on printer models, printing speed, toners, papers, humidity and so on. To evaluate the emission rate of nano-particles from Laser Printers, the mass concentration measurement method has been used (BAM, 2004). However, the mass concentration measurement method for nano-particles is tedious and time consuming. Therefore, for the development of a new nano-particle counting method, the nano-particle emission characteristics and size distributions are evaluated.

• Journal of Astronomy and Space Sciences
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• 제28권4호
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• pp.311-317
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• 2011

Momentum changing actuators like reaction wheels and control moment gyros are generally used for spacecraft attitude control. This type of actuators produces force and torque disturbances. These disturbances must be reduced since they degrade the quality of spacecraft attitude control. Major disturbances are mainly due to static and dynamic imbalances. This paper gives attention to the reduction of the static and dynamic imbalance. Force/torque measurement system is used to measure the disturbance of the test reaction wheel. An identification method for the location and magnitude of the imbalance is suggested, and the corrections of the imbalance are performed using balancing method. Through balancing, the static and dynamic imbalance is remarkably reduced.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.378-381
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• 2003

Efficient development of method on a performance evaluation for machine tools has been regarded as the most important work for accuracy and quality enhancement to every user and manufacturer. A evaluation method of accuracy for machine tools has been studied recently according to the rapid increase of interest in precision machine tools. To this point of view, the circular interpolation test of machine tools is recognized as the most useful method to distinguish a dynamic accuracy of NC machine tools by ISO and ANSI/ASME, etc. In this paper, we have studied and developed the form measurement system with grid encoder to analyse the final accuracy of NC machine tools. we have analyzed the servo system error and geometric error of NC machine tools through measuring a dynamic error signal by this system. and then we verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematic ball-bar system.

• 지역연구
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• 제14권1호
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• pp.21-45
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• 1998

Urban quality of life(QOL) is recently considered as the important determinant of inter-urban migration and industrial location chice. However, there is little concensus in the method of measurement of QOL. This study provides an theoretical framework of the measurement of QOL. This study provides an theoretical framework of the measurement of QOL, and developes a new method, a multi-year$\cdot$mulit-dimensional distance index model. Based on the theoretical framework and the method, the QOLs of 74 urban areas in Korea are measured, and the determinants of the QOL and the changes of the QOL between two years of 1993 and 1995 are analyzed. The results of the analysis are as follows: 1) The interurban differences of the QOL tens to be interban differences of the QOL tend to be intensified over time. 2) The OQLs of the cities in the Capital Region are relatively deteriorated. 3) The conditions of education$\cdot$Culture$\cdot$leisure life determiner over 65% of the QOL of the Korean cities.

• 설비공학논문집
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• 제27권8호
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• pp.440-447
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• 2015

In the shipbuilding process, the confined work spaces of the ship are formed continuously; the ventilation method can therefore be limited to dilution ventilation due to the complex structure and limited opening of the confined space. Also, it is difficult to evaluate air-quality using measurement and an adequate ventilation method. CFD simulation methods are typically used in analyzing ventilation efficiency in these cases. In this study, a method is suggested to analyze the air quality of the complex enclosures in shipbuilding using CFD. Especially, among the conventional indices, the ventilation efficiency scales or indices, the supply air contribution (SVE4), and the age of the air (SVE3) (fit for the confined and complex enclosure) were applied.