• 대한수학회보
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• 제59권4호
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• pp.827-841
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• 2022

In this paper, we study the uniqueness of two finite order transcendental meromorphic solutions f(z) and g(z) of the following complex difference equation A₁(z)f(z + 1) + A₀(z)f(z) = F(z)e^𝛼(z) when they share 0, ∞ CM, where A₁(z), A₀(z), F(z) are non-zero polynomials, 𝛼(z) is a polynomial. Our result generalizes and complements some known results given recently by Cui and Chen, Li and Chen. Examples for the precision of our result are also supplied.

• 한국토양비료학회지
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• 제36권4호
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• pp.181-192
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• 2003

기상 자료와 토양 수리 특성을 입력하여 토양수분의 수직 이동 및 분포를 예측할 수 있는 수치모형을 개발하고, 이 모형을 검정하기 위해 중동사양토를 대상으로 추정한 결과와 중성자 산란법에 의해 측정한 수분단면을 비교하였다. 이 모형에서 토양수분 포텐셜을 기준으로 한 Richards 방정식의 해를 predictor-corrector 격자에 투영한 음함수 유한차분법에 의해 구하였다. 이 모형에서는 토양단면의 수리특성은 균질하고, 토양수분은 등온적으로 흐르고, 수분이력현상은 고려하지 않고, 수증기 및 열 이동은 일어나지 않고, 빗물은 토양 단면에 부분 치환원리에 의해 분배된다고 가정하였다. 이 모형의 입력 자료는 크게 강우량, 최고 및 최저 기온, 상대습도 및 일사량의 일일 기상자료와 불포화 수리전도도 및 수분보유 특성 함수를 추정하기 위한 토양 수리 자료로 구분하였다. Chebyshev 다항식과 최소 자승차를 이용하여 추정한 토양 수리 다항식은 입력 자료와 매우 잘 일치하였다. 다양한 지표 및 하부 경계조건에서 53일 동안 상대적으로 시간증가분을 크게 하여 추정한 Richards 방정식의 해인 토양수분 수직 단면은 지표 10 cm를 제외하고는 중성자 산란법에 의해 측정한 결과와 잘 일치하였다.

• 통합자연과학논문집
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• 제7권2호
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• pp.145-147
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• 2014

Let $T_n(x)$ be the Chebyshev polynomials of first kind of degree n. In this paper, we show that for a > 1, the polynomial with integer coefficients $\frac{T_n(z)-T_n(a)}{z-a}$ has all its roots in $|z|{\leq}a$.

• 대한전자공학회논문지SP
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• 제40권1호
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• pp.43-50
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• 2003

오늘날 멀티미디어의 응용이 크게 늘면서 영상 취득 장치의 수요가 증대되고 있다. 그중 필름 스캐너는 고해상도와 고화질의 디지털 영상을 취득할 수 있는 장치이다. 그러나 필름 스캐너에서는 광원 및 센서의 비선형적 특성으로 인해 원 필름 영상의 컬러와 스캔된 영상의 컬러가 정확히 일치하지 않는 문제가 발생한다. 따라서, 필름 스캐너에서는 스캔된 디지털 영상에 대한 색보정이 필수적이다. 본 논문에서는 스캔된 RGB 색공간의 데이터를 CIE L/sup */a/sup */b/sup */ 색공간으로 변환한 후 다항회귀를 이용하여 색보정한다. 또한, TMS320C32 DSP 칩과 고해상도 라인 센서를 사용하여 R, G, B 각각 12 비트의 색분해도와 2400 dpi 급의 해상도를 갖는 스캐너 하드웨어를 구현하였다. 제작한 스캐너의 색보정 성능을 평가하기 위한 실험 결과, 색보정 전에는 평균색차 (ΔE/sup *//sub ab/)가 13.48 이었던 것이 색보정 후에는 8.46으로 감소함을 확인하였다.

• 한국수자원학회논문집
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• 제42권9호
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• pp.681-690
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• 2009

본 연구에서는 기상인자를 반영하여 확률강수량을 산정하고 불확실성을 평가하였다. 기상인자는 범지구적으로 관측되고 있는 해수면온도와 습윤지수 자료를 이용하였다. 분석 방법은 기상인자와 연최대시간강수량 사이의 지체상관계수를 산정하여 비교함으로써, 우리나라의 시간최대강수량과 상관관계가 큰 기상인자의 관측지역과 지체시간을 선정하고 지역가중다항식을 이용하여 회귀관계를 설정하였다. 다음으로 기상인자를 변동핵밀도함수를 이용하여 확률 밀도함수를 추정하여 모의발생을 수행하였다. 마지막으로 모의된 기상인자를 지역가중다항식을 통해 강수량을 추정하여 확률강수량을 산정하였다. 분석 결과에서 기상인자를 반영한 확률강수량은 강수자료를 빈도해석한 확률강수량과 큰 차이를 보이지 않는 것으로 나타났다. 또한 지구온난화와 같은 기후변화를 반영하는 기상인자를 반영한 확률강수량 산정의 기초자료로 활용할 수 있을 것으로 판단된다.

• Animal Bioscience
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• 제37권8호
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• pp.1333-1344
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• 2024

Objective: Litter size and piglet loss at birth significantly impact piglet production and are closely associated with sow parity. Understanding how these traits vary across different parities is crucial for effective herd management. This study investigates the patterns of the number of born alive piglets (NBA), number of piglet losses (NPL), and the proportion of piglet losses (PPL) at birth in Landrace sows under tropical conditions. Additionally, it aims to identify the most suitable model for describing these patterns. Methods: A dataset comprising 2,322 consecutive reproductive records from 258 Landrace sows, spanning parities from 1 to 9, was analyzed. Modeling approaches including 2nd and 3rd degree polynomial models, the Wood gamma function, and a longitudinal model were applied at the individual level to predict NBA, NPL, and PPL. The choice of the best-fitting model was determined based on the lowest mean and standard deviation of the difference between predicted and actual values, Akaike information criterion (AIC), and Bayesian information criterion (BIC). Results: Sow parity significantly influenced NBA, NPL, and PPL (p<0.0001). NBA increased until the 4th parity and then declined. In contrast, NPL and PPL decreased until the 2nd parity and then steadily increased until the 8th parity. The 2nd and 3rd degree polynomials, and longitudinal models showed no significant differences in predicting NBA, NPL, and PPL (p>0.05). The 3rd degree polynomial model had the lowest prediction standard deviation and yielded the smallest AIC and BIC. Conclusion: The 3rd degree polynomial model offers the most suitable description of NBA, NPL, and PPL patterns. It holds promise for applications in genetic evaluations to enhance litter size and reduce piglet loss at birth in sows. These findings highlight the importance of accounting for sow parity effects in swine breeding programs, particularly in tropical conditions, to optimize piglet production and sow performance.

• 대한수학회지
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• 제50권5호
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• pp.1083-1103
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• 2013

The concepts of reversible, right duo, and Armendariz rings are known to play important roles in ring theory and they are independent of one another. In this note we focus on a concept that can unify them, calling it a right Armendarizlike ring in the process. We first find a simple way to construct a right Armendarizlike ring but not Armendariz (reversible, or right duo). We show the difference between right Armendarizlike rings and strongly right McCoy rings by examining the structure of right annihilators. For a regular ring R, it is proved that R is right Armendarizlike if and only if R is strongly right McCoy if and only if R is Abelian (entailing that right Armendarizlike, Armendariz, reversible, right duo, and IFP properties are equivalent for regular rings). It is shown that a ring R is right Armendarizlike, if and only if so is the polynomial ring over R, if and only if so is the classical right quotient ring (if any). In the process necessary (counter)examples are found or constructed.

• 전기학회논문지
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• 제64권7호
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• pp.1104-1113
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• 2015

In this paper, we propose Two-Dimensional Robust Face Recognition System Realized with the Aid of Facial Symmetry with Illumination Variation. Preprocessing process is carried out to obtain mirror image which means new image rearranged by using difference between light and shade of right and left face based on a vertical axis of original face image. After image preprocessing, high dimensional image data is transformed to low-dimensional feature data through 2-directional and 2-dimensional Principal Component Analysis (2D)2PCA, which is one of dimensional reduction techniques. Polynomial-based Radial Basis Function Neural Network pattern classifier is used for face recognition. While FCM clustering is applied in the hidden layer, connection weights are defined as a linear polynomial function. In addition, the coefficients of linear function are learned through Weighted Least Square Estimation(WLSE). The Structural as well as parametric factors of the proposed classifier are optimized by using Particle Swarm Optimization(PSO). In the experiment, Yale B data is employed in order to confirm the advantage of the proposed methodology designed in the diverse illumination variation

• Journal of Information Processing Systems
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• 제10권3호
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• pp.395-411
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• 2014

Temporal medical data is often collected during patient treatments that require personal analysis. Each observation recorded in the temporal medical data is associated with measurements and time treatments. A major problem in the analysis of temporal medical data are the missing values that are caused, for example, by patients dropping out of a study before completion. Therefore, the imputation of missing data is an important step during pre-processing and can provide useful information before the data is mined. For each patient and each variable, this imputation replaces the missing data with a value drawn from an estimated distribution of that variable. In this paper, we propose a new method, called Newton's finite divided difference polynomial interpolation with condition order degree, for dealing with missing values in temporal medical data related to obesity. We compared the new imputation method with three existing subspace estimation techniques, including the k-nearest neighbor, local least squares, and natural cubic spline approaches. The performance of each approach was then evaluated by using the normalized root mean square error and the statistically significant test results. The experimental results have demonstrated that the proposed method provides the best fit with the smallest error and is more accurate than the other methods.

• 대한기계학회논문집A
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• 제26권4호
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• pp.644-652
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• 2002

Increasing demands for Electric Resistance Welded pipes of high quality with thick wall require c lose investigations in edge deformation by slitting, strip deformation during break down farming, and difference of circumferential length. In order to obtain good quality of a welding zone, it is necessary to predict the edge shape of the initial strip. The modeling of the multi-pass thick tube roll forming process with rigid plastic finite element method ultra the edge shape prediction of an initial strip with 2nd-degree polynomial regression method are presented. Edge shapes of initial strip have been analyzed by the finite element method and designed by the regression method to satisfy the requirements in target fin pass. It is concluded that the proposed edge design method results in optimal edge shapes sat string the design requirements.