• Title/Summary/Keyword: Method of Measurement

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A Study on Sensibility Measurement Method

  • Kwon, Kyu-Sik;Kim, Sun-Woong
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.04a
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    • pp.426-430
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    • 2000
  • This study is about the human sensibility measurement method. Researches on human sensibility measurement have been performed in many aspects. However, due to the subtlety and intricacy of human sensibility, it has been difficult to exactly measure human sensibility.At present, Semantic Differential(SD) method is most widely used to quantify human sensibility. In SD method, complicate human sensibility is represented on a scale with equal interval or equal ratio. However, this method has a critical problem in that human sensibility cannot be expressed with equal interval or equal ratio.In order to complement SD method and represent human sensibilities appropriately, we proposed an alternative method using the chroma-scale with saturation that had not equal interval or ratio. In experiment, proposed method shown that subjects understood a new scale easily and they could express their sensibilities on a new scale without any limitation. As a result, the chroma-scale can be used not only for measuring consumer's preference but also for evaluating or selecting sensibility words.

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Performance Analysis of Range and Velocity Measurement Algorithm for Multi-Function Radar using Discriminator Estimation Method (변별기 추정방식을 적용한 다기능 레이다용 거리 및 속도 측정 알고리즘 성능 분석)

  • Choi Beyung Gwan;Lee Bum Suk;Kim Whan Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.1
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    • pp.109-117
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    • 2005
  • Range and velocity measurement algorithm is a procedure for estimating the accurate target position by using matched filter outputs equally spaced both in range and doppler frequency domain. Especially, in measurement algorithm for multi-function radar, it is necessary to consider processing time as well as accuracy in order to track multi-targets simultaneously. In this paper, we analyze range and velocity measurement algorithm using discriminator estimation method which is a technique applied to angle measurement of monopulse radar. The applied method required constant processing time for estimation can be used in multiple target tacking. But, it is necessary to consider measurement accuracy because of using minimum channel outputs for estimation. In the simulation, we show that the applied method is superior to the traditional gravity center measurement algorithm with respect to the accuracy performance and also analyze the characteristics of the proposed technique by calculating RMS error level as the processing parameters such as pulse width , channel step, etc. change.

Application of Recursive Least Squares Method to Estimate Rail Irregularities from an Inertial Measurement Unit on a Bogie (대차 관성측정 장치에서 궤도틀림 추정을 위한 반복 최소자승법의 적용)

  • Lee, Jun-Seok;Choi, Sung-Hoon;Kim, Sang-Soo;Park, Choon-Soo
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.427-434
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    • 2011
  • This paper is focused on application of recursive least squares method to estimate rail irregularities from the acceleration measurement on an axle-box or a bogie for the rail condition monitoring with in-service high-speed trains. Generally, the rail condition was monitored by a special railway inspection vehicle but the monitoring method needs an expensive measurement system. A monitoring method using accelerometers on an axle-box or a bogie was already proposed in the previous study, and the displacement was successfully estimated from the acceleration data by using Kalman and frequency selective band-pass filters. However, it was found that the displacement included not only the rail irregularities but also phase delay of the applied filters, and effect of suspension of the bogie and conicity of the wheel. To identify the rail irregularities from the estimated displacement, a compensation filter method is proposed. The compensation filters are derived by using recursive least squares method with the estimated displacement as input and the measured rail irregularity as output. The estimated rail irregularities are compared with the true rail irregularity data from the rail inspection system. From the comparison, the proposed method is a useful tool for the measurement of lateral and vertical rail irregularity.

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A Multi-objective Placement of Phasor Measurement Units Considering Observability and Measurement Redundancy using Firefly Algorithm

  • Arul jeyaraj, K.;Rajasekaran, V.;Nandha kumar, S.K.;Chandrasekaran, K.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.474-486
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    • 2015
  • This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.

Assessment on shock pressure acquisition from underwater explosion using uncertainty of measurement

  • Moon, Seok-Jun;Kwon, Jeong-Il;Park, Jin-Woo;Chung, Jung-Hoon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.6
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    • pp.589-597
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    • 2017
  • This study aims to verify experimentally the specifications of the data acquisition system required for the precise measurement of signals in an underwater explosion (UNDEX) experiment. The three data acquisition systems with different specifications are applied to compare their precision relatively on maximum shock pressures from UNDEX. In addition, a method of assessing the acquired signals is suggested by introducing the concept of measurement uncertainty. The underwater explosion experiments are repeated five times under same conditions, and assessment is conducted on maximum quantities acquired from underwater pressure sensors. It is confirmed that the concept of measurement uncertainty is very useful method in accrediting the measurement results of UNDEX experiments.

Computer Adaptive Testing Method for Measuring Disability in Patients With Back Pain

  • Choi, Bongsam
    • Physical Therapy Korea
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    • v.19 no.3
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    • pp.124-131
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    • 2012
  • Most conventional instruments measuring disability rely on total score by simply adding individual item responses, which is dependent on the items chosen to represent the underlying construct (test-dependent) and a test statistic, such as coefficient alpha for the estimate of reliability, varying from sample to sample (sample-dependent). By contrast, item response theory (IRT) method focuses on the psychometric properties of the test items instead of the instrument as a whole. By estimating probability that a respondent will select a particular rating for an item, item difficulty and person ability (or disability) can be placed on same linear continuum. These estimates are invariant regardless of the item used (test-free measurement) and the ability of sample applied (sample-free measurement). These advantages of IRT allow the creation of invariantly calibrated large item banks that precisely discriminate the disability levels of individuals. Computer adaptive testing (CAT) method often requiring a testing algorithm promise a means for administering items in a way that is both efficient and precise. This method permits selectively administering items that are closely matched to the ability level of individuals (measurement precision) and measuring the ability without the loss of precision provided by the full item bank (measurement efficiency). These measurement properties can reasonably be achieved using IRT and CAT method. This article aims to investigate comprehensive overview of the existing disability instrument for back pain and to inform physical therapists of an alternative innovative way overcoming the shortcomings of conventional disability instruments. An understanding of IRT and CAT method will equip physical therapist with skills in interpreting the measurement properties of disability instruments developed using the methods.

The Evaluation Tool and Process for Effective Education Outcomes Measurement and Analysis of Computer Education

  • Kim, Young-Tak;Sim, Gab-Sig
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.9
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    • pp.149-156
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    • 2016
  • This paper is concerned with education courses operating practices for basic computer literacy training. In this study, we propose an example for students to effectively measure and evaluate the achievement of defined ability in the performance measurement and analysis, learning objectives and learning outcomes set in operation throughout the course. Through research and development use case presents the tools for teaching method and effective and objective measurement of the related subjects. And based on the results, we propose the possibility of utilizing NCS-based course operation and education certification. In this study, the measurement process is based on the association with the objective of the development and operation, and measurement tools, measuring tools for measuring learning outcomes associated with the curriculum design methods for the measurement and evaluation of the case of the operation of the course units of learning outcomes and the method proposed.

A Study on the Analysis and Measurement for the Elasticity of the Catenary System (전차선로 탄성도 해석 및 측정에 관한 연구)

  • 조용현;최강윤;조기조;권삼영
    • Proceedings of the KSR Conference
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    • 2002.10b
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    • pp.1100-1105
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    • 2002
  • The elasticity of the contact wire is one of important static parameters for the catenary system. This paper presents how to analyse the elasticity of the catenary system using both simple string model method and finite element method with their formula. Analysis results obtained by these two methods for KTX catenary system are compared. A measurement of the elasticity for the KTX catenary under construction which is located near Kumkang bridge is made for the comparison with the analysis results. Both a dynamic and a static methods are tried for the measurement. Because of wave propagation, the dynamic method with 5 km/h running presented an asymmetric variational pattern of the elasticity while the static method presented a symmetric pattern of the elasticity in the span. Measured elasticity using the static method is found to be a little higher than the analysis results. But, the static method can presented us a variational pattern of the elasticity in the span similar to the analysed results. Therefore, the static method can be used for evaluating the elasticity of the catenary system

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Development of Gas Chromatography/Mass Spectrometry for the Determination of Essential Fatty Acids in Food Supplemental Oil Products

  • Ahn, Seonghee;Yim, Yoon-Hyung;Kim, Byungjoo
    • Mass Spectrometry Letters
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    • v.4 no.4
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    • pp.75-78
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    • 2013
  • A gas chromatography/mass spectrometric (GC/MS) method was developed as a candidate reference method for the accurate determination of essential fatty acids (linoleic acid, ${\alpha}$- and ${\gamma}$-linolenic acids) in food supplemental oil products. Samples were spiked with three internal standards (stearic acid-$d_{35}$, $^{13}C_{18}$-linoleic acid, and $^{13}C_{18}$-${\alpha}$-linolenic acid). Samples were then subject to saponification, derivatization for methylation, and extraction by organic solvent. For GC/MS measurement, an Agilent HP-88 column, designed for the separation of fatty acid methyl esters, was selected after comparing with other columns as it provided better separation for target analytes. Target analytes and internal standards were detected by selected ion monitoring of molecular ions of their methyl ester forms. The GC/MS method was applied for the measurement of three botanical oils in NIST SRM 3274 (borage oil, evening primrose oil, and flax oil), and measurement results agreed with the certified values. Measurement results for target analytes which have corresponding isotope-labeled analogues as internal standard were calculated based on isotope dilution mass spectrometry (IDMS) approach, and compared with results calculated by using the other two internal standards. Results from the IDMS approach and the typical internal standard approach were in good agreement within their measurement uncertainties. It proves that the developed GC/MS method can provide similar metrological quality with IDMS methods for the measurement of fatty acids in natural oil samples if a proper fatty acid is used as an internal standard.

An Experimental Study on the Field Measurement Methods of the Sound Insulation Performance of Window (현장에서의 창의 차음성능 측정방법에 관한 실험적 연구)

  • Lee, Ok-Kyun;Park, Hyeon-Ku;Choi, Hyung-Wook;Song, Hyuk;Kim, Sun-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.600-605
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    • 2000
  • The aim of this study is to compare the sound insulation performances of window depending on the measurement methods through the field test and analyze the factors that affect the sound insulation performances. Four measurement methods which are specified in the Koran Standard 2235 and the International Standard 140-5 were selected for the study; the outdoor sound source method which is classified the l000mm method and the 10mm method, the indoor sound source method, and the ISO method. The result of this study is that the sound insulation performance of the windows was the best when measured according to the ISO method and the worst the indoor sound source method. Through the study it was found that the main factors affecting the sound insulation performance of the windows were the correction of the specimen's area and the equivalent sound absorption area of the receiving room.

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