• 대한수학회보
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• 제43권2호
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• pp.265-275
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• 2006

In this paper, we introduce a fractional domination game arising from fractional domination problems on graphs and focus on its balancedness and concavity. We first characterize the core of the fractional domination game and show that its core is always non-empty taking use of dual theory of linear programming. Furthermore we study concavity of this game.

• Journal of applied mathematics & informatics
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• 제10권1_2호
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• pp.371-376
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• 2002

The aim of this paper is to study the condition of η-concavity. We will give examples of η-functions in Hilbert spaces on two different domains.

• 자원ㆍ환경경제연구
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• 제19권3호
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• pp.633-658
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• 2010

본 연구에서는 1970년~2005년 기간 동안 한국 제조업의 Translog 비용함수를 분석함에 있어, 비제약 모형과 사전적으로 오목성을 부과한 제약 모형을 추정하여 그 결과를 비교하였다. 제약 모형은 비제약 모형에 비해 다소 낮은 로그우도값에 불구하고, 전 자료 구간에 대하여 정규성을 만족하여 비용함수와 생산기술 간의 쌍대성을 만족하는 추정 결과가 도출되었다. 제약 모형의 가격탄력성 분석 결과, 전력과 자본 사이에는 보완성이 존재하여 자본 수요가 증가함에 따라 전력 수요가 증가하는 것으로 나타났다. 한편 전력 수요는 노동, 연료 및 재료 수요를 모두 대체하는 방향성이 관측되어 한국 제조업이 전력 사용이 증가하는 방향으로의 구조변화를 경험하고 있는 것으로 분석되었다.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.165-177
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• 1994

To investigate the depth of the root concavity and root surface area of the maxillary first premolar, 40 maxillary first premolars were used. All the teeth which extracted because of advanced periodontal disease and orthodontic treatment procedure, were sectioned every 1.5mm from cementoenameljunction to the apex with hard tissue microtome. Each sectioned root was taken photograph with slide film, and projected for measuring with a calibrated digital Curvi-Meter. The root surface area, percentage of the RSA and the linear variation of the RSA were calibrated for each 1.5mm section. Linear variation of the depth of root concavity was measured on mesial and distal root surface for each section using computer-aided digitizer. The results were as follows. 1. The total mean root length of maxillary first premolar was 13.48mm. Mean buccal root length of 2-rooted tooth was 12.59mm, mean palatal root length was 12.73mm, and mean root length of single rooted tooth was 13.78mm. 2. The total mean root surface area of maxillary first premolar was $194.17mm^2$, mean root surface area for 2-rooted tooth was $205.97mm^2$ and mean root surface area for single rooted tooth was $188.49mm^2$. 3. It was 59.93% of the total root surface area that the area from CEJ to coronal 6mm. And, the coronal half of the root length accounted for approximately 71.76% of the total root surface area. 4. Most deepest concavity of the mesial root surface was 0.65mm at apical 3.0mm, 4.5mm level in maxillary first premolar. And, that of the distal root surface was 0.37mm at apical 4.5mm level. 5. All of the maxillary first premolar had mesial root surface concavity. This mesial root surface concavity appeared to be more pronounced in 2-rooted tooth than single rooted tooth.

• 대한수학회보
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• 제51권2호
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• pp.539-545
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• 2014

We show that roots of log-concave Alexander knot polynomials are dense in C. This in particular implies that the log-concavity and Hoste's conjecture on the Alexander polynomial of alternating knots are (essentially) independent.

• Journal of applied mathematics & informatics
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• 제6권3호
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• pp.915-920
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• 1999

We showed the upper p-estimate and p-power concavity are the necessary and sufficient condition of the space $M_{\Psi}$to be weak $L_pX>.

• 전기전자학회논문지
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• 제19권4호
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• pp.526-534
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• 2015

In this paper, we studied the use of the foreground and background features and SVM classifier to improve the accuracy of offline handwritten numeral recognition. The foreground features are two directional features: directional gradient feature by Kirsch operators and directional stroke feature by local shrinking and expanding operations, and the background feature is concavity feature which is extracted from the convex hull of the numeral, where the concavity feature functions as complement to the directional features. During classification of the numeral, these three features are combined to obtain good discrimination power. The efficiency of our scheme is tested by recognition experiments on the handwritten numeral database CENPARMI, where SVM classifier with RBF kernel is used. The experimental results show the usefulness of our scheme and recognition rate of 99.10% is achieved.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (2)
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• pp.613-615
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• 2003

본 논문은 문서 구조분석을 통해 얻어진 텍스트 영상에 대해 낱자 단위 분할 과정과 분할된 낱자에 대한 언어 구분 방법을 제안한다. 먼저 8방향 연결 요소를 이용한 레이블링을 수행하고 각 레이블의 거리관계와 한글 종모음의 특징을 이용하여 낱자 분리를 수행한다. 분리가 이루어진 낱자의 언어 구분은 각 낱자에 존재하는 concavity 특징을 이용하여 한글과 영어로 구분하게 된다. Concavity 특징을 찾기 위해 낱자를 이루는 흑화소 중 수직런을 이루는 흑화소 중 일부와 세리프 성분을 제거하며 그 방법을 기술한다. concavity 특징은 분리기를 통해 한글과 영어 두 가지로 분리되며, 분류기는 신경망을 이용한다. 제안된 방법은 20개의 텍스트 영상에 총 7923개의 낱자를 대상으로 실험하였으며, 낱자 분리는 97.20%의 정확도를 보였으며 분리된 낱자에 대한 언어 구분은 92.70%의 정확도를 얻을 수 있었다.

• 대한수학회보
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• 제47권6호
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• pp.1251-1258
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• 2010

For an M/G/1 processor-sharing queue with batch arrivals, Avrachenkov et al. [1] conjectured that the conditional mean sojourn time is concave. However, Kim and Kim [5] showed that this conjecture is not true in general. In this paper, we show that this conjecture is true if the service times have a hyperexponential distribution.

• 대한수학회보
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• 제38권3호
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• pp.565-573
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• 2001

In this paper, we first rove the strict quasi-concavity of maximizing function, and next prove a new maximum theorem using Fan’s generalization of the classical KKM theorem. Also an existence theorem of social equilibrium can be proved when an additional assumption on the constraint correspondence is assumed. Finally, we give illustrative two examples of constrained optimization problems.