• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.353-360
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• 2002

In this paper we study when a sign pattern matrix A and a sign pattern vector b have the property that the convex hull of the columns of each matrix with sign pattern A contains a vector with sign pattern b. This study generalizes the notion of sign central matrices.

• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.305-318
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• 2019

A sign pattern is a matrix whose entries belong to the set {+, -, 0}. An n-by-n sign pattern ${\mathcal{A}}$ is said to allow an eventually positive matrix or be potentially eventually positive if there exist at least one real matrix A with the same sign pattern as ${\mathcal{A}}$ and a positive integer $k_0$ such that $A^k>0$ for all $k{\geq}k_0$. Identifying the necessary and sufficient conditions for an n-by-n sign pattern to be potentially eventually positive, and classifying the n-by-n sign patterns that allow an eventually positive matrix are two open problems. In this article, we focus on the potential eventual positivity of broom sign patterns. We identify all the minimal potentially eventually positive broom sign patterns. Consequently, we classify all the potentially eventually positive broom sign patterns.

• Communications of the Korean Mathematical Society
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• v.10 no.3
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• pp.561-573
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• 1995

A matrix whose entries consist of the symbols +, - and 0 is called a sign pattern matrix. In [1], a graph theoretic characterization of sign idempotent pattern matrices was given. A question was given for the sign patterns which allow idempotence. We characterized the sign patterns which allow idempotence in the sign idempotent pattern matrices.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.209-216
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• 2010

A spectrally arbitrary complex sign pattern A is a complex sign pattern of order n such that for every monic nth degree polynomial f(x) with coefficients from $\mathbb{C}$, there is a matrix in the qualitative class of A having the characteristic polynomial f(x). In this paper, we show a necessary condition for a spectrally arbitrary complex sign pattern and introduce a minimal spectrally arbitrary complex sign pattern $A_n$ all of whose superpatterns are also spectrally arbitrary for $n\;{\geq}\;2$. Furthermore, we study the minimum number of nonzero parts in a spectrally arbitrary complex sign pattern.

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.665-671
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• 2000

A matrix whose entries consist of the symbols +.- and 0 is called a sign pattern matrix . In 1994 , Eschenbach gave a graph theoretic characterization of irreducible sign idempotent pattern matrices. In this paper, we give a characterization of reducible sign idempotent matrices. We show that reducible sign idempotent matrices, whose digraph is contained in an irreducible sign idempotent matrix, has all nonnegative entries up to equivalences. this extend the previous result.

• Communications of the Korean Mathematical Society
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• v.25 no.1
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• pp.11-18
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• 2010

The work in this paper was motivated by [3], where Eschenbach and Li listed four 4 by 4 sign patterns, conjectured to be nilpotent sign patterns of nilpotence index at least 3. These sign patterns with no zero entries, called full sign patterns, are shown to be potentially nilpotent of nilpotence index 3. We also generalize these sign patterns of order 4 so that we provide classes of n by n sign patterns of nilpotence indices at least 3, if they are potentially nilpotent. Furthermore it is shown that if a full sign pattern A of order n has nilpotence index k with $2{\leq}k{\leq}n-1$, then sign pattern A has nilpotent realizations of nilpotence indices k, k + 1, $\ldots$, n. Hence, the four 4 by 4 sign patterns in [3, page 91] also allow nilpotent realizations of nilpotence index 4.

• Communications of the Korean Mathematical Society
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• v.12 no.1
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• pp.27-36
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• 1997

A matrix whose entries consist of the symbols +, -, 0 is called a sign-pattern matrix. We characterize the $n \times n$ irreducible sign-pattern matrices that are sign tripotent.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.1
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• pp.47-55
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• 2012

Purpose: Dysmenorrhea mostly depends on the causative factor, which usually falls under the categories of Deficiency and Excess pattern in traditional Oriental medical theories and diagnosis. Thus, we investigated menstruation symptom and sign related to dysmenorrhea and verified the validity of Deficiency and Excess pattern identification. Methods: We investigated menstruation symptom and sign related to dysmenorrhea in total 14 gynecology-medical books including the book ${\ll}$Exemplar Of Korean Medicine (Dongui Bogam)${\gg}$ and whole body symptom and sign identifying Deficiency and Excess pattern at the same time. A survey based on this investigation was carried out targeting women of childbearing age. Results: Total of 14 gynecology-medical books have mostly narrated pre-menstrual and mid & post-menstrual pelvic pain depending on the time of its manifestation for identifying Deficiency and Excess pattern. Dysmenorrhea in pre-menstrual period belonged to Excess pattern and dysmenorrhea in mid & post-menstrual period belonged to Deficiency pattern. Among a total of 343 women, 196 subjects suffered from dysmenorrhea. The number of dysmenorrhea in pre-menstrual period (Excess pattern) was 116 people and in mid & post-menstrual period (Deficiency pattern) was 80 people. Deficiency and Excess pattern of dysmenorrhea in menstrual period significantly correlated to Deficiency and Excess pattern of whole body symptom and sign in the statistics(P-value < 0.05). Conclusion: The results suggest that pre-menstrual and mid & post-menstrual pelvic pain depending on the time of its manifestation is preferentially utilized as symptom and sign related to dysmenorrhea identifying Deficiency and Excess pattern.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.11
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• pp.1410-1420
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• 2005

The purpose of this study was to analyze characteristics of effective expression on T-shirts pattern by peirce's semiotic theory. The methods of this study was to analyze 721 T-shirts patterns in designer's collection from 2000 to 2004. The results of this study were as follows: First of all, iconic expression showed high frequency after 2000. Characteristics of effective expression were as follows: In geometric expression, repetition was presented as a symbolic sign by regular proportion and rule of dot, line, plane, irregularity, mixture of irregular dot, line, plane. Mixed expression was presented as a iconic and symbolic sign by collage, mixture of dot, line, plane, icon and letter. In iconic expression, simplification of iconic sigrl was presented as a iconic sign by simplification of form, color, texture, realistic expression using digital as a iconic sign, and symbolic face, body as a symbolic sign. Pop art's expression was presented as a iconic sign by a cartoon and commercial character and illusion was presented as a iconic sign. In letter's expression, brand logo was presented as a symbolic sign by transformation of letter's design, a symbolic sign of numeral by transformation of size, thickness, form, color. Symbolic message phrase was presented by slogan, fashion trend, brand image, descriptive indication message as a index sign by using icon or singleness. In conclusion, characteristics of effective expression on T-shirts pattern will present not only the theoretical foundation to raise the value added, but also the information about beauty sense of times, political and social value.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.193-198
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• 2011

By a nonnegative sign pattern we mean a matrix whose entries are from the set {+, 0}. A nonnegative sign pattern A is said to allow normality if there is a normal matrix B whose entries have signs indicated by A. In this paper we investigated some nonnegative normal pattern that is different to the pattern in [1]. Some interesting constructions of nonnegative integer normal matrices are provided.