• Honam Mathematical Journal
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• v.30 no.2
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• pp.247-258
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• 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.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.406-410
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• 2003

B. M. Schein([1]) considered systems of the form (${\Phi}$; ${\circ}$,-), where ${\Phi}$ is a set of functions closed under the composition "${\circ}$" of functions and the set theoretic subtraction "-". In this structure, (${\Phi}$; ${\circ}$) is a function semigroup and (${\Phi}$;-) is a subtraction algebra in the sense of [1]. He proved that every subtraction semigroup is isomorphic to a difference semigroup of invertible functions. Also this structure is closely related to the mathematical logic, Boolean algebra, Bck-algera, etc. In this paper, we define the near subtraction semigroup as a generalization of the subtraction semigroup, and define the notions of strong for it, and then we will search the general properties of this structure, the properties of ideals, and the application of it.

• Communications of the Korean Mathematical Society
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• v.22 no.1
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• pp.1-7
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• 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
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• v.7 no.2
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• pp.115-119
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• 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.

• Korean Journal of Child Studies
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• v.14 no.1
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• pp.23-37
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• 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.

• Speech Sciences
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• v.4 no.2
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• pp.5-15
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• 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.

• Honam Mathematical Journal
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• v.29 no.3
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• pp.465-474
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• 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
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• v.32 no.3
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• pp.123-127
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• 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
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• v.12 no.2
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• pp.137-142
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• 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.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.13-21
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• 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.