• Title/Summary/Keyword: representative value

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Estimation of extreme wind pressure coefficient in a zone by multivariate extreme value theory

  • Yang, Qingshan;Li, Danyu;Hui, Yi;Law, Siu-Seong
    • Wind and Structures
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    • v.31 no.3
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    • pp.197-207
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    • 2020
  • Knowledge on the design value of extreme wind pressure coefficients (EWPC) of a specific zone of buildings is essential for the wind-resistant capacity of claddings. This paper presents a method to estimate the representative EWPC introducing the multivariate extreme value model. The spatial correlations of the extreme wind pressures at different locations can be consider through the multivariate extreme value. The moving average method is also adopted in this method, so that the measured point pressure can be converted to wind pressure of an area. The proposed method is applied to wind tunnel test results of a large flat roof building. Comparison with existing methods shows that it can give a good estimation for all target zones with different sizes.

An Experimental Study on the Performance of Heat Pump Unit Using Geothermal Heat for New Renewable Energy (신재생에너지 지열을 이용한 열펌프유닛의 성능에 관한 실험적 연구)

  • JEONG, SOON YOUNG
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.6
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    • pp.630-636
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    • 2020
  • This paper presents a experimental study on the performance of the heat pump. Uncertainty of measurement means the degree of uncertainty in the measurement. Therefore, it estimates a section where expected value of the measurement might be within a certain confidence level and suggests a range where measured representative value might be incorrect. Uncertainty of measurement is a parameter that shows characteristics of dispersion of measured value that was reasonably estimated from measured quantity. Measurement result of performance experiment is not a true value but estimated value that was estimated reasonably. Therefore, uncertainty of measurement needs to be calculated and presented with the result of measurement.

A User Sentiment Classification Using Instagram image and text Analysis (인스타그램 이미지와 텍스트 분석을 통한 사용자 감정 분류)

  • Hong, Taekeun;Kim, Jeongin;Shin, Juhyun
    • Smart Media Journal
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    • v.5 no.1
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    • pp.61-68
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    • 2016
  • According to increasing SNS users and developing smart devices like smart phone and tablet PC recently, many techniques to classify user emotions with social network information are researching briskly. The use emotion classification stands for distinguishing its emotion with text and images listed on his/her SNS. This paper suggests a method to classify user emotions through sampling a value of a representative figure on a trigonometrical function, a representative adjective on text, and a canny algorithm on images. The sampling representative adjective on text is selected as one of high frequency in the samplings and measured values of positive-negative by SentiWordNet. Figures sampled on images are selected as the representative in figures; triangle, quadrangle, and circle as well as classified user emotions by measuring pleasure-unpleased values as a type of figures and inclines. Finally, this is re-defined as x-y graph that represents pleasure-unpleased and positive-negative values with wheel of emotions by Plutchik. Also, we are anticipating for applying user-customized service through classifying user emotions on wheel of emotions by Plutchik that is redefined the representative adjectives and figures.

Blast Coefficient for Bench Blasting (벤치발파 설계에서 발파계수 설정에 관한 연구)

  • Kim, Hee-Do;Kim, Jung-Kyu;Ko, Young-Hun;Noh, You-Song;Shin, Myeong-Jin;Yang, Hyung-Sik
    • Explosives and Blasting
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    • v.33 no.1
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    • pp.1-12
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    • 2015
  • In this study, the domestic bench blasting sites were researched to set the blast coefficient C according to the type of rock and type of industry. With the use of the experimental data on the representative industrial explosives and the data of the manufacturers'data on explosives, powder coefficient e was set up. The blast coefficient C was 0.21~0.30 when the average value for 5 representative kinds of rocks including granite was searched. The blast coefficient C for quarrying, mining and construction sites were 0.22, 0.13 and 0.26 respectively. On the other hand, powder coefficient e was obtained in four elements such as reactive energy, ballistic mortar test, VOD, Langefors'strength per unit weight. e value for emulsion which is one of the representative explosives was found to be 1 while those of high performance emulsion and ANFO were found to be 0.9 and 1, respectively.

A Study on Developing the Optimal Sizing System for Ready-to-wear - Based on Elementary School Girls - (기성복의 최적 사이즈 시스템 개발을 위한 연구 - 학령기 여아를 중심으로 -)

  • Kim Ran-do;Lee Sang-youl;Kim Seon-young;Nam Yun-ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.8 s.145
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    • pp.1102-1113
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    • 2005
  • The propose of this study is to develop the optimal sizing system of ready-to-wear f3r elementary school girls using a newly invented statistical technique. The body measurements was classified by the method that equalizes the distribution of the subjects using the probability density function, to theoretically systemize a method to determine a size range of ready-to-wear for elementary school girls between 6 to 12 years old. The statistical method were 1) The total of 11 height groups, which size interval from one another is 6 cm that is an average height gap between each age. 2) In order to determine an approximate figure (m ${\times}$ n) to establish the appropriate sizes far each height group that fit to the combinations of bust and hip girth, which based on their means and standard deviations on the probability density curve to produce the standard normal distribution. 3) m and n were aligned by 4cm -the grading increments used for patterns making- and determined the size ranges by confirming the approximate figures of m and n. 4) The representative values were determined by an area ratio calculated by dividing the area determined from the range of bust and hip girth with the representative value. Considering the characteristics of subjects' distribution, the area ratios was used. 5) Weight was calculated by seeking a growth exponent for each age and multiplying it by the number of girls that fit to each size range. As sections that show the highest weight are more likely sought by the consumers, these sections were determined as the optimal size standards. 6) This optimal sizing system consists of sizes determined by the optimal size standards and its sizes are marked with height, bust and hip girth.

The design method for a vector codebook using a variable weight and employing an improved splitting method (개선된 미세분할 방법과 가변적인 가중치를 사용한 벡터 부호책 설계 방법)

  • Cho, Che-Hwang
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.4
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    • pp.462-469
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    • 2002
  • While the conventional K-means algorithms use a fixed weight to design a vector codebook for all learning iterations, the proposed method employs a variable weight for learning iterations. The weight value of two or more beyond a convergent region is applied to obtain new codevectors at the initial learning iteration. The number of learning iteration applying a variable weight must be decreased for higher weight value at the initial learning iteration to design a better codebook. To enhance the splitting method that is used to generate an initial codebook, we propose a new method, which reduces the error between a representative vector and the member of training vectors. The method is that the representative vector with maximum squared error is rejected, but the vector with minimum error is splitting, and then we can obtain the better initial codevectors.

In Vivo Estimation of Emax and Ejection Fraction Using Dynamic Spatial Reconstructor (역동적 삼차원 재구성기로 측정한 In Vivo 상태의 좌심실의 Emax 와 박출계수)

  • 김광호
    • Journal of Chest Surgery
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    • v.21 no.2
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    • pp.223-230
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    • 1988
  • Emax, end-systolic pressure-volume relationship, has been established as a new concept which can be representative of ventricular contractility itself since 1970s. Comparing to ejection fraction[EF], Emax is independent of preload and afterload. However Emax has not been proved precisely in non-thoracotomized condition because current methods have limitation in measuring ventricular chamber volume accurately in in viva state. The Dynamic Spatial Reconstructor[DSR], high speed computerized tomography, can measure ventricular chamber volume accurately throughout cardiac cycle in non-thoracotomized state. So Emax and EF of the left ventricle was tried to measure precisely in in vivo condition with DSR. Emax was compared to EF to estimate its ability to evaluate ventricular contractility. 5 mongrel dogs, weighing 15-16kg, were used for measuring Emax and EF of the left ventricle in 3 or 4 different loading conditions using DSR. Emax value in 5 dogs was from 2.62 to 10.49. Each dog has one Emax value regardless of loading conditions. However EF in 5 dogs varies depending on loading conditions. The conclusions are that Emax is useful in in viva state and EF varies depending on loading conditions. So Emax should be tried to use in clinical situation rather than EF because it is always representative of contractility itself regardless loading conditions in in viva state.

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A Study on Analyzing the Difference Factors Occurred in the Secondary School Mathematics Teachers on the Mathematical Knowledge of Teaching and on Exploring the Enhancement on the Statistical Literacy (수학 중등 교사들 간의 수학교수지식(MKT) 차이 발생 요인 분석 및 이를 통한 통계적 소양 신장 방안)

  • Kim, Seul Bi;Hwang, Hye Jeang
    • East Asian mathematical journal
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    • v.39 no.2
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    • pp.141-166
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    • 2023
  • The purpose of this study is to confirm the MKT(Mathematical Knowledge for Teaching) of the in-service mathematics teachers on the statistics(Representative value, Degree of scattering) through the comparative analysis between the sub-elements of the MKT. In addition, it is to examine the factors that cause the difference of the subjects' MKT. To accomplish this, by the subject of 12 secondary in-service mathematics teachers, in this study the test items of the MKT on the statistics were developed and data were collected and analyzed. As a result of the analysis of the MKT test sheet, the CCK(Common Content Knowledge) and SCK(Specialized Content Knowledge) of the mathematics teacher was confirmed as a high score, whereas the and KCS(Knowledge of Content and Students) and KCT(Knowldge of Curriculum and teaching) were confirmed as low scores. In addition, through these results, it was shown that the difference in MKT's elements the middle school and high school teachers obtain occurred slightly.

Economic Valuation Methods of Biodiversity

  • Cho, Woo-Young;Bae, Doo-Hyun;Kim, Hong-Sok
    • Environmental Engineering Research
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    • v.13 no.1
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    • pp.41-48
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    • 2008
  • The valuation of biodiversity is a fundamental step in conservation. The useful framework for analysing the economic value of biological resources is that of total economic value (TEV) and TEV comprises both use and non-use values, the former related to an actual use made of the resource, the latter to a willingness to pay for the resource independently of any use made of it. There are several valuation approacher in environmental economics literature. However, stated preference approach should be introduced for valuation of biodiversity because it can estimate non-use value as well as use value. Contingent Valuation and Conjoint Analysis are representative methods in stated preference and Conjoint Analysis can be more useful for valuation of biodiversity. Futhermore, the combination of ecology and economics to assess biodiversity leads to an integrated framework. Thus, interdisciplinary work is required, involving both economists and ecologists transferring elements or even theories and models from one discipline to another and transforming them for their specific, mutually consistent purpose.

Reduction of Cake Resistance by Floc Reaggregation in a Membrane-Feed-Pipe (관내 입자 재응집에 의한 케이크 저항의 감소)

  • KIM, Taeyoung;PARK, Heekyung
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.6
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    • pp.717-726
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    • 2007
  • Fully-grown flocs in a mixing tank of membrane filtration with dead-end membrane are ruptured while passing through a pump and the ruptured flocs are aggregated again in a Membrane-Feed-Pipe (MFP). To look at more details, this study tries to relate the reaggregation to a parameter of mixing intensity in MFP, i.e., G-value. The G-value is a function of Reynolds number, pipe diameter, friction factor and average velocity in MFP. To deal with polydispersity condition, we develop a representative particle size called in this study EDPD (Effective Diameter for Polydispersity condition in Dead-end filtration). The experimental results show that as the G-value increases, the EDPD decreases and also the cake resistance increases. Through comparison between EDPD and cake resistance, these results show that cake resistances are controlled by reaggregation phenomenon in MFP. The effect of detention time in MFP, however, does not affect the reaggregation of the broken flocs as G-values are increased.