• 대한수학회논문집
• /
• 제22권3호
• /
• pp.359-363
• /
• 2007

In this paper, we introduce the notion of a fuzzy ideal in subtraction algebras, and give some conditions for a fuzzy set to be a fuzzy ideal in subtraction algebras. We also pose three questions on fuzzy ideals of subtraction algebras.

• 대한수학회보
• /
• 제45권3호
• /
• pp.437-444
• /
• 2008

As a weak form of a subtraction algebra, the notion of weak subtraction algebras is introduced, and its examples are given. A method to make a weak subtraction algebra from a quasi-ordered set is provided.

• 호남수학학술지
• /
• 제41권2호
• /
• pp.435-447
• /
• 2019

The notions of a neutrosophic subalgebra and a neutrosohic ideal of a subtraction algebra are introduced. Characterizations of a neutrosophic subalgebra and a neutrosophic ideal are investigated. We show that the homomorphic preimage of a neutrosophic subalgebra of a subtraction algebra is a neutrosophic subalgebra, and the onto homomorphic image of a neutrosophic subalgebra of a subtraction algebra is a neutrosophic subalgebra.

• 호남수학학술지
• /
• 제27권4호
• /
• pp.561-570
• /
• 2005

In this paper, we introduce the notion of positive implicative subtraction algebras and study some relations between R(L)-maps and positive implicativity in subtraction algebras.

• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제27권2호
• /
• pp.187-198
• /
• 2024

덧셈과 뺄셈, 곱셈과 나눗셈의 관계는 초등학교 2, 3학년 수학에서 명시적으로 제시된다. 그러나 이후 학습에서 이러한 관계는 더 이상 논의되지 않는다. 본 논문은 초등학교 수학 교과서에서 뺄셈과 나눗셈의 계산 방법을 살펴보고, 이를 바탕으로 아동들의 이해 수준에서 덧셈과 뺄셈, 곱셈과 나눗셈의 관계를 정당화하고 뺄셈과 나눗셈에 활용할 수 있는 문제 상황과 활동을 논의한다. 또한 아동들이 덧셈과 뺄셈, 곱셈과 나눗셈의 관계와 등식의 성질을 뺄셈과 나눗셈에 활용하여 얻을 수 있는 교육적 시사점을 도출한다.

• 대한수학교육학회지:수학교육학연구
• /
• 제19권2호
• /
• pp.307-319
• /
• 2009

현재 학교수학에서는 자연수로부터 실수에 이르는 덧 뺄셈을 자연수, 분수, 소수, 제곱근 등의 순서로 다루고 있다. 그런데 각 단계에서의 덧 뺄셈 계산 방법을 습득하는데 중점을 둔 나머지, 실수 체계 전반을 아우르는 덧 뺄셈의 통합적 원리에 대한 이해가 부족한 상태에서 학습 지도가 이루어지는 것으로 보인다. 본 연구는 이와 같은 덧 뺄셈의 학습지도가 갖는 한계에 대한 문제의식으로부터 출발한다. 여기서는 수 개념 발생의 심리적 기원을 측정이라고 본 Dewey의 통찰을 확장하여, 덧 뺄셈을 측정활동 내에서 파악하고 이 때 드러나는 공통단위를 기반으로 하면 자연수에서 실수에 이르는 덧 뺄셈 연산의 서로 다른 알고리즘 외양 이면에 공통적인 본질이 있음을 밝힌다. 이러한 논의를 바탕으로 학교수학에서 덧 뺄셈 지도 개선의 필요성을 제시하고자 한다.

• 치과방사선
• /
• 제28권1호
• /
• pp.215-224
• /
• 1998

The following conclusions were obtained from the non-reconstructed and reconstructed subtraction images of the standard intraoral radiographs which were taken with paralleling technique with Rinn XCP only and with occlusal bite registration for geometric standardization using bilateral mandibular premolar and molar regions of two dry human skulls. 1. The SD of the overall subtraction images of the premolars and molars of the non-reconstructed, that is, the manual superimposition showed statistically significant difference between the non-registered and registered groups. 2. In non-reconstructed and non-registered cases, the quality of the subtraction images were improved when superimposition was focally done and this was more evident in areas where the radiographic images tend to be distorted due to anatomic reasons. 3. In non-reconstructed and registered cases, the subtraction images were consistent regardless of the anatomic site or the focus of superimposition. This means that the geometric standardization with only occlusal bite registration could produce serial radiographs which is suitable for subtraction. 4. The SD of the overall subtraction images of the premolars and molars of the reconstructed, that is, the automatic superimposition showed statistically insignificant difference between the non-registered and registered groups. This means that using reconstruction, subtraction radiography is possible without occlusal bite registration. 5. In reconstructed and non-registered cases, compatible quality of the subtraction images were obtained regardless of the anatomic site or area of the corresponding points. 6. In reconstructed and registered cases, best subtraction images whose quality showed sensitivity to the areas of corresponding points were obtained.

• Journal of Electrical Engineering and Technology
• /
• 제10권1호
• /
• pp.372-378
• /
• 2015

Background subtraction is the first processing stage in video surveillance. It is a general term for a process which aims to separate foreground objects from a background. The goal is to construct and maintain a statistical representation of the scene that the camera sees. The output of background subtraction will be an input to a higher-level process. Background subtraction under dynamic environment in the video sequences is one such complex task. It is an important research topic in image analysis and computer vision domains. This work deals background modeling based on modified adaptive Gaussian mixture model (GMM) with three temporal differencing (TTD) method in dynamic environment. The results of background subtraction on several sequences in various testing environments show that the proposed method is efficient and robust for the dynamic environment and achieves good accuracy.

• 치과방사선
• /
• 제17권1호
• /
• pp.175-181
• /
• 1987

The purpose of this study is to know the value of the photographic subtraction technic in the transcranial oblique lateral projection of the TMJ. The author examined the transcranial oblique lateral projection radiographs which comprise 50 cases of 32 persons, compared the transcranial oblique lateral projection films and those subtraction films. The following results were obtained. 1) The condyle at closed jaw position had showed a reversed tone image, but the condyle at the opening position had showed a re-reversed ordinary image. Both condyles had showed one subtraction film because radiographic interpretation of TMJ was easy. 2) On 50 cases of subtraction films, 46 cases had showed same radiographic images compared with trascranial oblique lateral projection films. Four cases (3 cases of erosion, 1 cases of sclerosis) had showed additional changes of images so that capability of interpretation was improved.

• 대한수학회논문집
• /
• 제22권3호
• /
• pp.323-330
• /
• 2007

In this paper we introduce the notion of strongly regular near-subtraction semigroups (right). We have shown that a near-subtraction semigroup X is strongly regular if and only if it is regular and without non zero nilpotent elements. We have also shown that in a strongly regular near-subtraction semigroup X, the following holds: (i) Xa is an ideal for every a $\in$ X (ii) If P is a prime ideal of X, then there exists no proper k-ideal M such that P $\subset$ M (iii) Every ideal I of X fulfills $I=I^2$.