• Title/Summary/Keyword: true values

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Study on Estimating the Optimal Number-right Score in Two Equivalent Mathematics-test by Linear Score Equating (수학교과의 동형고사 문항에서 양호도 향상에 유효한 최적정답율 산정에 관한 연구)

  • 홍석강
    • The Mathematical Education
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    • v.37 no.1
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    • pp.1-13
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    • 1998
  • In this paper, we have represented the efficient way how to enumerate the optimal number-right scores to adjust the item difficulty and to improve item discrimination. To estimate the optimal number-right scores in two equivalent math-tests by linear score equating a measurement error model was applied to the true scores observed from a pair of equivalent math-tests assumed to measure same trait. The model specification for true scores which is represented by the bivariate model is a simple regression model to inference the optimal number-right scores and we assume again that the two simple regression lines of raw scores and true scores are independent each other in their error models. We enumerated the difference between mean value of $\chi$* and ${\mu}$$\_$$\chi$/ and the difference between the mean value of y*and a+b${\mu}$$\_$$\chi$/ by making an inference the estimates from 2 error variable regression model. Furthermore, so as to distinguish from the original score points, the estimated number-right scores y’$\^$*/ as the estimated regression values of true scores with the same coordinate were moved to center points that were composed of such difference values with result of such parallel score moving procedure as above mentioned. We got the asymptotically normal distribution in Figure 5 that was represented as the optimal distribution of the optimal number-right scores so that we could decide the optimal proportion of number-right score in each item. Also by assumption that equivalence of two tests is closely connected to unidimensionality of a student’s ability. we introduce new definition of trait score to evaluate such ability in each item. In this study there are much limitations in getting the real true scores and in analyzing data of the bivariate error model. However, even with these limitations we believe that this study indicates that the estimation of optimal number right scores by using this enumeration procedure could be easily achieved.

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Determination of True Modulus of Elasticity and Modulus of Rigidity for Domestic Woods with Different Slenderness Ratios Using Nondestructive Tests (서로 다른 세장비에 대한 비파괴실험으로 국산재의 실질탄성계수와 전단탄성계수 결정)

  • Cha, Jae Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.1
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    • pp.36-42
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    • 2015
  • This study examined true modulus of elasticity (MOE) and modulus of rigidity (G) for domestic woods with different slenderness ratios (L/D) using the static bending and stress wave tests. Bending properties of small clear wood specimen of three domestic wood species were determined at 12% moisture content. The results of this study indicated that both MOR and MOE of domestic woods were affected by the slenderness ratio. As the slenderness ratio increased, MOR and MOE increased. G and true MOE of domestic timber beams were obtained at different slenderness ratios by flexure test and stress wave test. The values reported here can be useful if these species woods are used for structural purposes. However, the reported values are only indicative and do not represent the true average of wood species due to the limited number of specimens tested.

Factors Affecting True Metabolizable Energy Determination of Poultry Feedingstuffs IV. The Effect of Protein Levels of Basal Diets on the Corrected Apparent Metabolizable Energy of Farrell and True Metabolizable Energy Values of Corn and Soybean Meal (양계사료의 True Metabolizable Energy 측정에 영향하는 요인에 관한 시험 IV. 기초사료의 단백수준이 옥수수와 대두백의 Corrected Apparent Metabalizable Energy of Farrell 및 True Metabolizable Energy 가에 미치는 영향)

  • 이영철
    • Korean Journal of Poultry Science
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    • v.11 no.2
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    • pp.99-108
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    • 1984
  • The experiment was performed with the aim to study not only the effect of protein levels of basal diets on apparent and true metabolizable energy (AME and THM), AME of Farrell(AME$\_$F/), and corrected AME$\_$FC/ values of corn and soybean meal but also the effect of collection time of excreta on AME and TME values of corn and soybean meal. The AME$\_$F/ and AME$\_$FC/ values of test materials were determined through rapid AME bioassay, and AME and TME by the TME bioassay. The protein levels of basal diets had range from 10% crude protein(CP) to 30% CP. The results obtained were as follows; 1. The AME$\_$F/ values of basal diets showed much difference among treatments (P<0.05) but those of corn and soybean meal had no significant differences (P>0.05)and the AHE$\_$FC/ values of basal diets were proved to be variable according to level of protein of the diets. the AME$\_$FC/ values of com were not different while those of soybean meal in 20% and 30% were reduced significantly(P<0.05). 2. The protein intake/bird/day did not differ significantly due to variation of feed intake using rapid AME bioassay. 3. The protein levels of basal diets did not influence upon the AME value of basal diets, corn and soybean meal (P>0.05), and no clear trend was found in the TME values of corn and soybean meal because of the variation of metabolic fecal energy plus endogenous urinary energy (FEm+UEe) losses fed different diets. 4. Collection time of excreta affected the AME and TME values of basal diets in 10, 15, 20% CP treatments, but the AME and TME of corn and soybean meal were not affected by collection time; Thus, a time of 24 hours was mough for 24 hr to clean the digestive tract when fed corn and soybean meal substituted diets regardless of protein levels.

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Corns with Different Nutritional Profiles on Growing and Finishing Pigs Feeding (30 to 90 kg)

  • De Oliveira, Gisele Cristina;Moreira, Ivan;De Souza, Ana Lucia Pozzobon;Murakami, Alice Eiko;Parra, Angela Rocio Poveda;De Oliveira Carvalho, Paulo Levi;Borile, Maicon Danner
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.7
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    • pp.982-992
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    • 2011
  • Three experiments were carried out to determine the nutritional value and to verify the pig performance in growing and finishing phases (30 to 90 kg) fed on diets containing common corn (CC), high-lysine corn (HLC) and high-oil corn (HOC). In the total digestibility trial (Exp. I) 12 barrows were used. Values of digestible energy (DE) and metabolizable energy (ME) as-fed basis for CC, HLC and HOC, were: 3,396 and 3,275 kcal/kg; 3,248 and 3,139 kcal/kg; 3,445 and 3,308 kcal/kg, respectively. In order to determine the apparent and true ileal digestibility coefficients of amino acids, as well as the values of true digestible amino acids of the CC, HLC and HOC, an ileal digestibility trial was done (Exp. II) with T-cannulated barrows ("T" simple). The treatments consisted of three diets, with one of them as the sole source of protein (CC, HLC and HOC). In the performance experiment (Exp. III), 36 crossbred pigs, allotted in a completely randomized design with three treatments and 12 replications were used. Treatments consisted of three diets: 1 - CC; 2 - HLC and 3 - HOC. It was observed no difference for performance and carcass variables among the corns with different nutritional profiles. Results of the three experiments highlighted the importance of segregating corns in their real chemical and energetic composition as well as the values of true digestible amino acids for formulating diets for growing and finishing pigs.

Contents of 'true education' in the Era of New Media and the Consciousness Structure of Modern People (뉴미디어 시대 속 '참교육' 콘텐츠와 현대인의 의식구조)

  • Kim, Se-Yeon
    • The Journal of the Korea Contents Association
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    • v.22 no.4
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    • pp.468-478
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    • 2022
  • 'True education', which was the core ideology of 'the Korean Teachers & Educational Workers Union', is re-appropriated in the new media era. This word, which is actively used by young people, means 'punishment against the object of social condemnation'. One of the characteristics of 'true education contents' commonly seen on the Internet is that it shows a tendency to 'fragmentation'. True educational contents are short in length, and the contents are very local. This reflects the characteristics of a postmodern society where totality disappears and small stories are consumed. Second, the standard for dividing good and evil is extremely 'arbitrary'. Whereas the existing stories of rewarding virtue and punishing vice had universal values such as love, consideration, and peace, the content of true education distinguishes good and evil with an extremely narrow perspective. The way to justify arbitrary standard is to incite public outrage. Third, 'humour' is added. Here, humor is combined with the emotion of hatred, causing the problem of weakening people's critical consciousness.

Measurement Error Variance Estimation Based on Complex Survey Data with Subsample Re-Measurements

  • Heo, Sunyeong;Eltinge, John L.
    • Communications for Statistical Applications and Methods
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    • v.10 no.2
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    • pp.553-566
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    • 2003
  • In many cases, the measurement error variances may be functions of the unknown true values or related covariates. This paper considers design-based estimators of the parameters of these variance functions based on the within-unit sample variances. This paper devotes to: (1) define an error scale factor $\delta$; (2) develop estimators of the parameters of the linear measurement error variance function of the true values under large-sample and small-error conditions; (3) use propensity methods to adjust survey weights to account for possible selection effects at the replicate level. The proposed methods are applied to medical examination data from the U.S. Third National Health and Nutrition Examination Survey (NHANES III).

A Study on the ALS Method of System Identification (시스템동정의 ALS법에 관한 연구)

  • Lee, D.C.
    • Journal of Power System Engineering
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    • v.7 no.1
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    • pp.74-81
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    • 2003
  • A system identification is to estimate the mathematical model on the base of input output data and to measure the output in the presence of adequate input for the controlled system. In the traditional system control field, most identification problems have been thought as estimating the unknown modeling parameters on the assumption that the model structures are fixed. In the system identification, it is possible to estimate the true parameter values by the adjusted least squares method in the input output case of no observed noise, and it is possible to estimate the true parameter values by the total least squares method in the input output case with the observed noise. We suggest the adjusted least squares method as a consistent estimation method in the system identification in the case where there is observed noise only in the output. In this paper the adjusted least squares method has been developed from the least squares method and the efficiency of the estimating results was confirmed by the generating data with the computer simulations.

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A Study on the Measurement Error Induced by Air Gap of Electromagnetic Wave Absorber in the Coaxial Line Method (동축선법을 이용한 전파흡수체 특성 측정시 Air Gap에 의한 오차에 대한 연구)

  • 김경용;김왕섭;주윤돈;김병호
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.11
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    • pp.874-879
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    • 1991
  • The effect of air gap between specimen and jig on the material constant (permittivity, permeability) and attenuation characteristics of electromagnetic wave absorbers in the coaxial line method was investigated. The presence of a air gap made both permittivity and permeability measured lower than true value, and the tendency was greater in the case of permittivity. An inner gap compared to an outer gop was found to yield a larger difference between measured and true values. The effect of air gap was measured for a Ni0.3Zn0.7Fe2O4, with the gap eliminated by metallizing with Ag-paste. The measured characteristics were in good agreement with corrected values by calculation.

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Effect of Plastic Strain on the Surface Integrity of Steel (금속의 Surface Integrity에 미치는 소성스트레인의 영향)

  • Kim, Tae-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.6 no.4
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    • pp.94-102
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    • 1989
  • The effect of plastic strain on the surface integrity of mild steel (SS 41) was studied. This paper shows that the recrystallization technique is adequate to evaluate the plastic strain in a machined surface experimentally. The relations between the plastic strain and the machining conditions are quantitatively evaluated by using the recrystallization technique. The obtained results are summarized as follows. 1. The surface integrity of steel is considerably influenced by the amount of surface region deformation produced by changes in cutting conditions. 2. The plastic strain in machined surface produced by changes of the cutting conditions is evaluated by the recyrstallization technique. 3. The plastic strain increases with the increase of depth of cut and the decrease of rake angle. 4. When the cutting force is high and the rake angle is small, the value of maximum true strain reaches to high. 5. The maximum true strain is related to the cutting energy, and the values increase with the increase of the unit shear and total engergy in constant depth with the increase of the energy values.

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Tracking Control of Mechanical Systems with Partially Known Friction Model

  • Yang, Hyun-Suk;Martin C. Berg;Hong, Bum-Il
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.4
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    • pp.311-318
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    • 2002
  • Two adaptive nonlinear friction compensation schemes are proposed for second-order nonlinear mechanical systems with a partially known nonlinear dynamic friction model to achieve asymptotic position and velocity tracking. The first scheme has auxiliary filtered states so that a simple open-loop observer can be used. The second one has a dual-observer structure to estimate two different nonlinear aspects of the friction state. Conditions for the parameter estimates to converge to the true parameter values are presented. Simulation results are utilized to show control performance and to demonstrate the convergence of the parameter estimates to their true values.