• 대한원격탐사학회지
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• 제20권5호
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• pp.353-359
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• 2004

This study proposes an approach to unsupervisedly estimate the number of classes and the parameters of defining the classes in order to train the classifier. In the proposed method, the image is segmented using a spatial region growing based on hierarchical clustering, and fuzzy training is then employed to find the sample classes that well represent the ground truth. For cluster validation, this approach iteratively estimates the class-parameters in the fuzzy training for the sample classes and continuously computes the log-likelihood ratio of two consecutive class-numbers. The maximum ratio rule is applied to determine the optimal number of classes. The experimental results show that the new scheme proposed in this study could be used to select the regions with different characteristics existed on the scene of observed image as an alternative of field survey that is so expensive.

• 대한수학회보
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• 제56권4호
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• pp.815-827
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• 2019

It is well known that the denominator of the Dedekind sum s(c, d) divides 2 gcd(d, 3)d and that no smaller denominator independent of c can be expected. In contrast, here we prove that we usually get a smaller denominator in S(H, d), the sum of the s(c, d)'s over all the c's in a subgroup H of order n > 1 in the multiplicative group $(\mathbb{Z}/d\mathbb{Z})^*$. First, we prove that for p > 3 a prime, the sum 2S(H, p) is a rational integer of the same parity as (p-1)/2. We give an application of this result to upper bounds on relative class numbers of imaginary abelian number fields of prime conductor. Finally, we give a general result on the denominator of S(H, d) for non necessarily prime d's. We show that its denominator is a divisor of some explicit divisor of 2d gcd(d, 3).

• 대한수학회지
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• 제55권5호
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• pp.1179-1192
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• 2018

Several addition formulas for a general class of q-Appell sequences are proved. The q-addition formulas, which are derived, involved not only the generalized q-Bernoulli, the generalized q-Euler and the generalized q-Genocchi polynomials, but also the q-Stirling numbers of the second kind and several general families of hypergeometric polynomials. Some q-umbral calculus generalizations of the addition formulas are also investigated.

• 대한수학회논문집
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• 제28권2호
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• pp.361-369
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• 2013

We introduce a Nielsen type number of a fibre preserving map, and show that it is a lower bound for the number of $n$-orbits in the homotopy class. Under suitable conditions we show that it is equal to the Nielsen type relative essential $n$-orbit number. We also give necessary and sufficient conditions for it and the essential $n$-orbit number to coincide.

• Kyungpook Mathematical Journal
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• 제51권3호
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• pp.345-352
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• 2011

In this article we introduce the fuzzy real valued double sequence spaces $_2{\ell}^F$ (p) where p = ($p_{nk}$) is a double sequence of bounded strictly positive numbers. We study their different properties like completeness, solidness, symmetricity, convergence free etc. We prove some inclusion results also.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.1140-1145
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• 1989

A general dynamic iterative learning control scheme is proposed for a class of nonlinear systems. Relying on stabilizing high-gain feedback loop, it is possible to show the existence of Cauchy sequence of feedforward control input error with iteration numbers, which results in a uniform convergance of system state trajectory to the desired one.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2001년도 춘계학술발표대회
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• pp.137-146
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• 2001

To improve SAR capabilities in Korea, marine casualties during 5 years(1995-1999) were analyzed and drifting experiment of G/T 50 ton class vessel was carried out off Pusan harbor. As a result, it was found that the occurrence of casualty by fishing boat ranked highest and a considerable numbers of casualties took place more than 20 miles off the shore, and leeway was computed by two drifting experiments as 0.045U - 010 $^{\circ}$, 0.037U＋ 021 $^{\circ}$ respectively.

• 대한수학회논문집
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• 제15권2호
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• pp.357-370
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• 2000

In [6], Cheng-Ye You gave a condition equivalent to the Nielsen number product formula for fiber maps. And Jerzy Jezierski also gave a similar condition for coincidences of fiber maps. The main purpose of this paper is to find the condition for which holds the product formula for Nielsen root numbers N(f;a) = N(f;a) N(fb;a).

• Kyungpook Mathematical Journal
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• 제59권3호
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• pp.391-401
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• 2019

A module is said to be ${\pi}$-extending provided that every projection invariant submodule is essential in a direct summand of the module. In this article, we focus on the class of modules having the ${\pi}$-extending property by looking at the singularity of quotient submodules. By doing so, we provide counterexamples, using hypersurfaces in projective spaces over complex numbers, to show that being generalized ${\pi}$-extending is not inherited by direct summands. Moreover, it is shown that the direct sums of generalized ${\pi}$-extending modules are generalized ${\pi}$-extending.

• Journal of Community Nutrition
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• 제6권2호
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• pp.67-77
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• 2004

In order to investigate the differences of nutrient intakes by the economic status and different age groups and to identify the nutritional risk group and its specific nutrition problem, 2001 Korean National Health and Nutrition Survey were analyzed. The subject's numbers of 9,391 were classified into four classes such as low (14.2%), medium (37.2%), high (26.0%), and high above (22.6%) on the basis of the family monthly income and the 2001 Korean minimum cost of living according to the family size. Mean intakes of energy and all nutrients assessed by the RDAs, lipid-energy %, and MAR were increased as the economic status were going up. Na intake expressed per 1,000kcal was in reverse. Nearly a half(45.5%) of the low-income people seemed to take nutritionally inadequate diet in consideration with MAR values. Deficiencies of iron and even energy in the toddlers (1 to 2 years) of low-income class were of great concern. Adolescent age group has been observed that their calcium and iron intakes, and possibly energy, were appeared to be the most deficient among all the age groups regardless of the economic status. For the elderly in all the economic status except high-above class, calcium, vitamin A, and riboflavin were commonly deficient nutrients. Calcium deficiency was appeared throughout nearly all the ages except toddlers and all the economic classes. Even in the high-above class 57.3% took insufficient amount of calcium.