• Journal of Animal Science and Technology
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• 제63권4호
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• pp.827-840
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• 2021

Several studies have focused on Ca and P requirements for pigs. These requirements are estimated from their retention and bone formation. However, modern pig breeds have different responses to dietary Ca and P than traditional breeds, and their requirements are expected to change on an annual basis. Besides individual Ca and P needs, the Ca to P ratio (Ca/P) is an important factor in determining requirements. This study aimed to implement a linear and quadratic regression analysis to estimate Ca and P requirements based on average daily gain (ADG), apparent total tract digestibility (ATTD) of Ca (ATTD-Ca), ATTD of P (ATTD-P), and crude protein (CP) digestibility. Results show that Ca/P had linear and quadratic effects on ADG in the phytase-supplemented (PS) group in both the 6-11 kg and 11-25 kg categories. In the latter category, the CP digestibility was linearly increased in response to increasing Ca/P in the without-phytase (WP) group. In the 25-50 kg category, there was a linear response of ADG and linear and quadratic responses of CP digestibility to Ca/P in the PS group, while a linear and quadratic increase in CP digestibility and a quadratic effect on ATTD-Ca were observed in the WP group. In the 50-75 kg category, Ca/P had significant quadratic effects on ADG in the PS and WP groups, along with significant linear and quadratic effects on ATTD-Ca. In addition, Ca/P had significant quadratic effects on ATTD-P and led to a significant linear and quadratic increase in the CP digestibility in the WP group. In the 75-100 kg category, analysis showed a significant decrease in ATTD-Ca and ATTD-P in the PS and WP groups; in the latter, ATTD-P and ATTD-Ca were linearly decreased by increasing Ca/P. In conclusion, our equations predicted a higher Ca/P in the 6-25 kg bodyweight categories and a lower Ca/P in the 50-100 kg category than that recommended in the literature.

• 한국환경과학회지
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• 제27권5호
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• pp.333-340
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• 2018

This study aimed to estimate the effect of inoculant application level on chemical composition and bacterial count of fermented chestnut meal (FCM), and its rumen fermentation characteristics. The inoculant contained Lactobacillus acidophilus ($1.2{\times}10^{10}cfu/g$), Bacillus subtilis ($2.1{\times}10^{10}cfu/g$), and Saccharomyces cerevisiae ($2.3{\times}10^{10}cfu/g$). The chestnut meal mixed with molasses, double distilled water, and inoculant at 1 kg, 3 g, 480 mL, and 20 mL ratio for the basal chestnut meal diet. The double distilled water from basal chestnut meal diet was substituted with bacterial inoculant at a level of 0 (Control), 20 (Medium), and 40 mL (High) in the experimental diets. The mixed experimental diets were incubated at $39^{\circ}C$ for 7, 14, and 21 days, respectively. On 7 days of FCM incubation, the contents of crude protein (CP) (quadratic, P=0.043) and neutral detergent fiber (quadratic, P=0.071) decreased by increases of inoculant application levels, whereas bacterial count (quadratic, P=0.065) and rumen $NH_3-N$ (linear, P=0.063) increased. By increases of inoculant application levels on 14 days of FCM incubation, the increases were found on dry matter (DM) (quadratic, P=0.085), CP (quadratic, P=0.059), acid detergent fiber (quadratic, P=0.056), in vitro DM digestibility (linear, P=0.002), rumen total volatile fatty acid (VFA) (linear, P=0.057), and rumen iso-butyrate (linear, P=0.054). However, the decreases were found on bacterial count (linear, P=0.002), propionate (linear, P=0.099), and butyrate (quadratic, P=0.082). On 21 days of FCM incubation, in vitro DM digestibility (linear, P=0.002) and total VFA (linear, P=0.001) increased by increases of inoculant application levels, whereas the contents of CP (quadratic, P=0.034) and neutral detergent fiber (quadratic, P=0.047) decreased. These results indicate that the FCM with a medium level of inoculant application and 14 of fermentation had beneficial effects by increasing DM digestibility and rumen total VFA content, without altering bacterial count.

• Structural Engineering and Mechanics
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• 제61권6호
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• pp.765-773
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• 2017

The quadratic B-spline finite element method yields mass and stiffness matrices which are half the size of matrices obtained by the conventional finite element method. We solve the free vibration problem of a rotating Rayleigh beam using the quadratic B-spline finite element method. Rayleigh beam theory includes the rotary inertia effects in addition to the Euler-Bernoulli theory assumptions and presents a good mathematical model for rotating beams. Galerkin's approach is used to obtain the weak form which yields a system of symmetric matrices. Results obtained for the natural frequencies at different rotating speeds show an accurate match with the published results. A comparison with Euler-Bernoulli beam is done to decipher the variations in higher modes of the Rayleigh beam due to the slenderness ratio. The results are obtained for different values of non-uniform parameter ($\bar{n}$).

• 한국작물학회지
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• 제37권4호
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• pp.320-328
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• 1992

춘천, 수원, 청주, 광주, 이리, 진주의 20년간 (1971년 부터 1990년 까지) 기온, 일조시수, 강우 기상자료에 따른 콩 수량 예측모형을 SAS의 STEPWISE, MAXR, $C_{P}$에 의하여 작성 되었으며 선정된 설명변수들(explanatory variables)은 GLM에 의하여 유의차 검정을 하였다. 6개 지역 콩 수량에 영향을 미치는 기상요소의 반응은 다음과 같다. 1. 춘천 지역의 주효과 기상 요소에서 1차 효과(linear term)는 8월일조시수, 2차 효과(quadratic term)는 8월강우, 교호작용(interaction)은 6월기온과 8월강우, 5월기온과 8월강우였으며 8월강우는 고도의 유의성이 인정 되었다. 콩수량 예측 평균값은 198.0kg/10a였으며 년차 변이가 인정되었다. 2. 수원 지역의 기상 요소 1차 효과는 6월기온이 부영향 이었으며 2차 효과는 6월일조시수, 6월강우(부효과)였다. 교호작용은 7월의 기온과 일조시수, 6월일조시수와 7월강우, 5월기온과 7월강우, 6, 7월강우가 유의성이 인정 되었으며 년차 변이가 있었다. 콩 수량 예측값은 178.1kg /10a 였다. 3. 청주 지역은 1차 효과는 6월기온, 2차 효과는 8월강우, 교호작용은 5월기온과 6월강우, 7월과 8월의강우, 7월기온과 6월강우이었다. 콩수량 예측 값은 197.9kg /10a였다. 4. 광주 지역의 1차 효과는 7월강우(부), 2차 효과는 6월기온과 7월강우였으며 6, 7월일조시수가 부교호작용 이었다. 콩 수량 예측 평균값은 227.4kg /10a였다. 5. 이리 지역의 기상요소 1차 효과는 5월일조시수, 2차 효과는 5월일조시수와 7월일조시수, 교호작용은 5월의 기온과 강우, 5, 7월의 일조시수, 6, 7월의 강우였고 7월일조시수의 quadratic term은 부효과 였다. 5월의기온과 강우, 6, 7월의강우도 부교호작용 이었다. 콩 수량 예측값은 160.4kg /10a였다. 6. 진주 지역의 기상 요소 반응에 따른 1차 효과는 6월과 8월강우, 교호작용은 8월의기온과 일조시수, 6월일조시수와 7월강우, 6, 8월강우였다. 6, 8월강우는 linear term에서 부효과, 8월의 기온과 일조시수는 부교호작용이었다. 콩 수량 예측 평균값은 208.0kg /10a였다. 7. 춘천, 수원, 광주, 진주 지역의 모형식에 선정된 년차변이(YR)는 기술 개선 요인(technological improvement factors)으로 인정된다.다.

• Journal of the Korean Statistical Society
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• 제34권2호
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• pp.141-151
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• 2005

Under the assumption that the three-level factors are quantitative, the linear effects are taken more attention than the quadratic effects of the interaction terms. Webb (1971) presented some small incomplete factorial designs that are mixed two- and three-level designs with 20 or fewer runs. The designs provided the estimating linear-by-linear components of interactions between the three-level factors; moreover, they could also offer estimation of interactions that interest the experiments. Webb used ad hoc methods to find these plans; hence, there was still no unified structure to those experiments. In this paper, we develop the methods to construct the $2^{n}3^3$ and $2^{1}3^3$ designs. The designs constructed by these methods not only supply orthogonal estimates of all the main effects but also permit estimation of all the two-factor interactions not involving the quadratic effects. Furthermore, the designs we find are nearly orthogonal.

• Communications for Statistical Applications and Methods
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• 제25권3호
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• pp.275-282
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• 2018

This paper discusses the use of projections for the sums of squares in the analyses of variance for two-way nested design data. The model for this data is assumed to only have random effects. Two different sizes of experimental units are required for a given experimental situation, since nesting is assumed to occur both in the treatment structure and in the design structure. So, variance components are coming from the sources of random effects of treatment factors and error terms in different sizes of experimental units. The model for this type of experimental situation is a random effects model with more than one error terms and therefore estimation of variance components are concerned. A projection method is used for the calculation of sums of squares due to random components. Squared distances of projections instead of using the usual reductions in sums of squares that show how to use projections to estimate the variance components associated with the random components in the assumed model. Expectations of quadratic forms are obtained by the Hartley's synthesis as a means of calculation.

• 대한수학교육학회지:학교수학
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• 제16권4호
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• pp.827-845
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• 2014

본 연구의 목적은 이차곡선에 관한 대학교 사범대학 수학교육과의 교육이 고등학교 교육과정과 관련하여 어떻게 이루어지고 있는지, 이에 대한 교수, 교사, 예비교사의 인식은 어떠한지에 대하여 알아보는 것이다. 이를 위해 3개 대학의 수학교육과와 1개 고등학교를 선정하여, 이차곡선이 강의되는 강좌의 강의담당 교수와 그 강좌를 수강했던 예비교사, 그리고 경기도 소재 1개 고등학교의 수학교사를 대상으로 교육내용과 이에 대한 인식에 관한 연구를 수행하였다. 본 연구의 결과는 다음과 같다. 첫째, 이차곡선에 관한 사범대학 교육과정은 고등학교 교육과정과 관련하여 적절하게 운영되고 있는 것으로 판단된다. 사범대학 교육과정에는 이차곡선에 관한 내용이 강의되는 강좌가 포함되어 있으며, 그 강좌에서 이차곡선에 관한 학교수학과 연결된 학문적 수학 내용이 충분히 강의되고 있으며, 그 강의를 수강한 학생들의 66.1%가 이차곡선에 관한 이해도가 좋아졌다고 인식했으며, 현직교사들 또한 대부분의 내용에 대하여 필요한 것으로 인식하고 있다. 둘째, 사범대학 교육과정에서 실제 고등학교 교육 현장과의 연결성 강화가 요구된다. 사범대학 교육과정에서 배우는 이차곡선에 관한 내용은 고등학교 교육과정과의 관련성이 크고, 사범대학에서 이에 대하여 배울 필요성 또한 큰 것으로 인식하고 있지만, 사범대학에서 학습하는 내용들이 현장에서의 활용과는 유리되어 배우고 있다는 인식과 함께 이에 대한 개선의 필요성을 느끼고 있다. 셋째, 이차곡선에 관한 내용지식의 범위를 학교수학과 연결된 학문적 수학의 범위로 확대하려는 자발적 노력을 촉진, 장려하는 제도적 장치의 마련과 지원이 요구된다.

• Communications for Statistical Applications and Methods
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• 제27권5호
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• pp.523-533
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• 2020

This paper suggests three available methods for finding nonnegative estimates of variance components of the random effects in mixed models. The three proposed methods based on the concepts of projections are called projection method I, II, and III. Each method derives sums of squares uniquely based on its own method of projections. All the sums of squares in quadratic forms are calculated as the squared lengths of projections of an observation vector; therefore, there is discussion on the decomposition of the observation vector into the sum of orthogonal projections for establishing a projection model. The projection model in matrix form is constructed by ascertaining the orthogonal projections defined on vector subspaces. Nonnegative estimates are then obtained by the projection model where all the coefficient matrices of the effects in the model are orthogonal to each other. Each method provides its own system of linear equations in a different way for the estimation of variance components; however, the estimates are given as the same regardless of the methods, whichever is used. Hartley's synthesis is used as a method for finding the coefficients of variance components.

• Structural Engineering and Mechanics
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• 제2권4호
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• pp.345-357
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• 1994

The differential equations governing free, in-plane vibrations of linearly elastic circular arches with variable cross-sections are derived and solve numerically for quadratic arches with three types of rectangular cross sections. Frequencies, mode shapes, cross-sectional load distributions, and the effects of rotatory inertia on frequencies are reported. Experimental measurements of frequencies and their corresponding mode shapes agree closely with those predicted by theory. The numerical methods presented here for computing frequencies and mode shapes are efficient and reliable.

• 대한전자공학회논문지
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• 제25권8호
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• pp.867-873
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• 1988

The degradation due to channel distortion in a quadrature modulation system from the ideal constant values over the bandwidth of a direct sequence spread spectrum signal are considered. Through using series expansion for the channel gain and phase response, the degradation in the correlator output at the receiver is found as a function of the parameters involved , including phase error, delay error, linear gin variation, quadratic gain variation, and quadratic phase variation.