• 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.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 Korean Library and Information Science Society
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• v.50 no.2
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• pp.339-359
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• 2019

The purpose of this study is to clarify the case and process of the application of the sign system in order to enable the user to reach the target site more efficiently in the library. For this purpose, a new sign system was applied to the S University library through procedures such as library structure, sign status, user observation, cyan production and preference survey. Detailed production process and user's reaction were identified. Based on this we suggested improvements to the library stacks signage system.

• Structural Engineering and Mechanics
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• v.55 no.2
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• pp.365-377
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• 2015

Large-amplitude vibration of overhead sign structures can cause unfavorable psychological responses in motorists, interfere with readability of the signs, and lead to fatigue cracking in the sign structures. Field experience in Texas suggests that an overhead sign structure can vibrate excessively when supported within the span of a highway bridge instead of at a bent. This study used finite element modeling to analyze the dynamic displacement response of three hypothetical sign structures subjected to truck-passage-induced vertical oscillations recorded for the girders from four actual bridges. The modeled sign bridge structures included several span lengths based on standard design practices in Texas and were mounted on precast concrete I-girder bridges. Results revealed that resonance with bridge girder vertical vibrations can amplify the dynamic displacement of sign structures, and a specific range of frequency ratios subject to undesirable amplification was identified. Based on these findings, it is suggested that this type of sign structure be located at a bridge bent if its vertical motion frequency is within the identified range of bridge structure excitation frequencies. Several alternatives are investigated for cases where this is not possible, including increasing sign structure stiffness, reducing sign mass, and installing mechanical dampers.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.105.2-105
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• 2001

This paper studies continuous Korean Sign Language (KSL) recognition using color vision. In recognizing gesture words such as sign language, it is a very difficult to segment a continuous sign into individual sign words since the patterns are very complicated and diverse. To solve this problem, we disassemble the KSL into 18 hand motion classes according to their patterns and represent the sign words as some combination of hand motions. Observing the speed and the change of speed of hand motion and using state automata, we reject unintentional gesture motions such as preparatory motion and meaningless movement between sign words. To recognize 18 hand motion classes we adopt Hidden Markov Model (HMM). Using these methods, we recognize 5 KSL sentences and obtain 94% recognition ratio.

• The Mathematical Education
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• v.55 no.1
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• pp.1-19
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• 2016

Given the importance of understanding the equal sign in developing early algebraic thinking, this paper investigated how a total of 695 students in grades 2~6 understood the equal sign. The students completed a questionnaire with three types of items (equation structure, equal sign definition, and open equation solving) based on the construct map by four different levels of understanding the equal sign. The questionnaire was analyzed by Rasch model. The results showed that about 80% of the students were at least Level 3 which means a basic relational understanding of the equal sign. However, the success rates varied across grades and it was noticeable that about 70% of the second graders remained at Level 1 or 2 which maintains an operational understanding of the equal sign. The results of item types demonstrated that item difficulty for the advanced relational thinking was the highest and this is the same even for the Level 4 students. This paper is expected to investigate elementary school students' understanding of the equal sign and provide implications of how to deal with the equal sign in the elementary school.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.333-336
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• 1996

The sign language is a method of communication for deaf person. For sign communication, sign language and manual alphabet are used continuously. In this paper is proposed a system which recognize Korean sign language(KSL) and Korean manual alphabet(KMA) continuously. For recognizing KSL and KMA, basic elements for sign language, namely, the 14 hand directions, 23 hand postures, and 14 hand orientations are used. At first, this system recognize current motion state using speed and change of speed in motion by state automata. Using state, basic element classifiers using Fuzzy Min-Max Neural Network and Fuzzy Rule are executed. Meaning of signed gesture is selected by using basic elements which was recognized.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.19-20
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• 2015

Sign system currently used for traditional heritage villages in Korea does not have any well-defined concept and method so that somewhat improper signs can be developed like for general urban or tourism area. In this paper, we present a new method or guideline of sign system based on DPD(disaster prevention design) concept for our traditional heritage villages. We can enhance both safety of residents and satisfaction of visitors throughout this guideline. According to our investigations on the heritage villages, sign systems in Korea are mainly developed for tourism, on the other hand, sign development in Japan mainly focuses on prevention or protection against big disasters like earthquakes. Considering residents and their safety, we can submit a proper guideline to develop sign system for our traditional heritage villages based on the concept of DPD which can be applied to each space. Asan 'Oeam Village' and Beppu 'Onsen Village' are used as application sites compared between Korea and Japan.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.17-22
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• 2021

It is difficult for the hearing impaired to use the counseling service without sign language interpretation. Due to the shortage of sign language interpreters, it takes a lot of time to connect to sign language interpreters, or there are many cases where the connection is not available. Therefore, in this paper, we propose a system that captures sign language as an image using OpenCV and CNN (Convolutional Neural Network), recognizes sign language motion, and converts the meaning of sign language into textual data and provides it to users. The counselor can conduct counseling by reading the stored sign language translation counseling contents. Consultation is possible without a professional sign language interpreter, reducing the burden of waiting for a sign language interpreter. If the proposed system is applied to counseling services for the hearing impaired, it is expected to improve the effectiveness of counseling and promote academic research on counseling for the hearing impaired in the future.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.10a
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• pp.116-117
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• 2004