• 호남수학학술지
• /
• 제30권2호
• /
• pp.247-258
• /
• 2008

In this paper, we show how certain topologies associate with ideals of subtraction algebras on subtraction algebras. We show subtraction algebras to be topological subtraction algebras with respect to theses topologies. Furthermore, we show how certain standard properties may arise. In addition we demonstrate that it is natural for these topologies to have many clop en sets and thus to be highly disconnected via the ideal theory of subtraction algebras.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2003년도 춘계종합학술대회논문집
• /
• pp.406-410
• /
• 2003

B.M. Schen([2])은 함수의 합성 "${\circ}$" 과 차집합 연산 "-"에 대하여 닫혀있는 함수들의 집합 ${\Phi}$에서의 대수적 구조인 subtraction semigroup (${\Phi}$; ${\circ}$,-)를 정의하였다. 이 구조에서 (${\Phi}$; ${\circ}$)는 semgroup, (${\Phi}$; -)는 [1]에서 정의한 subtraction algebra를 이룬다. B.M. Schen은 [2]에서 모든 subtraction semigroup은 invertible function들의 difference semigroup과 동형이라는 사실을 밝혔다. 본 논문에서는 이 subtraction semigroup의 일반화로써 near subtraction semigroupd을 정의하고 이의 한 특수한 형태인 strong near subtraction semigroup의 개념을 정의하여 이들의 일반적인 성질과 ideal의 특성을 조사하고 이들의 응용도를 조사하고자 한다.

• 대한수학회논문집
• /
• 제22권1호
• /
• pp.1-7
• /
• 2007

Subtraction algebras with additional conditions, so called complicated subtraction algebras, are introduced, and several properties are investigated. In a complicated subtraction algebra, characterizations of ideals are provided, and showed that the set of all ideals in a complicated subtraction algebra is a complete lattice.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제7권2호
• /
• pp.115-119
• /
• 2007

The notion of ideals in subtraction algebras and characterizations of ideals introduced by Y.B.Jun et al. [?]. Using this idea, we consider the fuzzification of an ideal of a subtraction algebra. In this paper, we define the concept of a fuzzy ideal of a subtraction algebra and study characterizations of a fuzzy ideal. We give some conditions to show that a fuzzy set in a subtraction algebra is a fuzzy ideal of a subtraction algebra. We investigate the generalization of some properties of a fuzzy ideal of a subtraction algebra.

• 아동학회지
• /
• 제14권1호
• /
• pp.23-37
• /
• 1993

The purpose of this study was to examine the development of rational counting, addition and subtraction competence and the correlation between competence in rational counting, addition, and subtraction in three-, four- and five-year-old children. The subjects were 156 preschoolers living in Seoul. The experimental materials consisted of a set of 20 props for rational counting, addition, and subtraction tasks. The addition and subtraction tasks each consisted of a set of 6 problems. The data were analyzed by ANOVA, Duncan multiple range test, and Pearson's r. The results indicated that 1) there were significant differences in the development of competence in rational counting, addition, and subtraction by age, 2) there were no significant differences in competence in rational counting, addition, and subtraction by gender, 3) there were positively high correlations of competence rational counting, addition, and subtraction by age.

• 음성과학
• /
• 제4권2호
• /
• pp.5-15
• /
• 1998

This paper proposes a speech state-dependent spectral subtraction method to regulate the blind spectral subtraction for improved enhancement. In the proposed method, a modified subtraction rule is applied over the speech selectively contingent to the speech state being voiced or unvoiced, in an effort to incorporate the acoustic characteristics of phonemes. In particular, the objective of the proposed method is to remedy the subtraction induced signal distortion attained by two state-dependent procedures, spectrum sharpening and minimum spectral bound. In order to remove the residual noise, the proposed method employs a procedure utilizing the masking effect. Proposed spectral subtraction including state-dependent subtraction and residual noise reduction using the masking threshold shows effectiveness in compensation of spectral distortion in the unvoiced region and residual noise reduction.

• 호남수학학술지
• /
• 제29권3호
• /
• pp.465-474
• /
• 2007

We provided characterizations of complicated in a subtraction algebra, and we showed that the complicated subtraction algebra is a ring.

• Imaging Science in Dentistry
• /
• 제32권3호
• /
• pp.123-127
• /
• 2002

Purpose : To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Materials and Methods: Thirty-six teeth with 57 proximal surfaces were radiographied using a size #2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. Results: The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. Conclusion: The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제12권2호
• /
• pp.137-142
• /
• 2012

The temporal subtraction technique as one of computer aided diagnosis has been introduced in medical fields to enhance the interval changes such as formation of new lesions and changes in existing abnormalities on deference image. With the temporal subtraction technique radiologists can easily detect lung nodules on visual screening. Until now, two-dimensional temporal subtraction imaging technique has been introduced for the clinical test. We have developed new temporal subtraction method to remove the subtraction artifacts which is caused by mis-registration on temporal subtraction images of lungs on MDCT images. In this paper, we propose a new computer aided diagnosis scheme for automatic enhancing the lung nodules from the temporal subtraction of thoracic MDCT images. At first, the candidates regions included nodules are detected by the multiple threshold technique in terms of the pixel value on the temporal subtraction images. Then, a rule-base method and artificial neural networks is utilized to remove the false positives of nodule candidates which is obtained temporal subtraction images. We have applied our detection of lung nodules to 30 thoracic MDCT image sets including lung nodules. With the detection method, satisfactory experimental results are obtained. Some experimental results are shown with discussion.

• 대한방사선기술학회지:방사선기술과학
• /
• 제7권1호
• /
• pp.13-21
• /
• 1984

Subtraction is an essential technic to improve imaging quality in various radiological procedures. The limitations of subtraction, however, are well known. Blurred under-subtraction (BUS) method has been suggested to overcome and compensate these limitations. Ten cases of angiography were subtracted by conventional subtraction and BUS technic. Results of this study revealed that BUS method is simple to perform and imaging quality obtained by BUS is excellent. Comparing to conventional subtraction, BUS method has advantages. For example, BUS need no mask film or no immobilization of patient during examination. Improvement of imaging Qualify is achieved by edge enhancement, homogeneous blurring of background density and increasing contrast. With emphasis of its simplicity in technic, we would report that BUS method is a useful adjunct imaging technic in various radiological procedures.