• Smart Media Journal
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• v.12 no.6
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• pp.9-14
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• 2023

The longest increasing subsequence is a fundamental problem which has been studied for a long time in computer science. In this paper, we consider the maximal increasing subsequence problem where the constraint is released from the longest to the maximal. For two kinds of increasing (monotone increasing and strictly increasing), we propose linear-time algorithms computing a maximal increasing subsequence of an input sequence from an alphabet Σ. Our algorithm for computing a maximal monotone increasing subsequence requires O(1) space and our algorithm for computing a maximal strictly increasing subsequence requires O(|Σ|) space.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.76-79
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• 2007

수화는 하나의 제스처가 하나의 단어를 나타내는 수화 단어와 한글을 알파벳으로 표현하는 지문자로 구성되어 있다. 본 논문에서는 USB 카메라로부터 촬영한 영상을 얻고 히스토그램을 이용하여 피부색 영역을 추출한다. 얼굴 영역 추적을 활용하여 이미지를 그리드화하고 지문자의 위치를 파악하여 초성, 중성, 종성을 구분하고 한글 음절을 구성하였다.

• Korean Journal of Cognitive Science
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• v.7 no.1
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• pp.57-74
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• 1996

This paper presents a comparison of recognition performance of the features used inthe recent handwritten korean character recognition.This research aims at providing the basis for feature selecion in order to improve not only the recognition rate but also the efficiency of recognition system.For the comparison of feature performace,we analyzed the characteristics of theose features and then,classified them into three rypes:global feature(image transformation)type,statistical feature type,and local/ topological feature type.For each type,we selected four or five features which seem more suitable to represent the characteristics of korean alphabet,and performed recongition experiments for the first consonant,horizontal vowel,and vertical vowel of a korean character, respectively.The classifier used in our experiments is a multi-layered perceptron with one hidden layer which is trained with backpropagation algorithm.The training and test data in the experiment are taken from 30sets of PE92. Experimental results show that 1)local/topological features outperform the other two type features in terms of recognition rates 2)mesh and projection features in statical feature type,walsh and DCT features in global feature type,and gradient and concavity features in local/topological feature type outperform the others in each type, respectively.

• Archives of design research
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• v.13 no.1
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• pp.103-110
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• 2000

Hangul came to life as part of the East Asian culture of the Chinese ideograph. Korean letter-culture is starkly different from that of Western letter-culture. In the Orient, letters were sacred and incantory; they were objects of awe, which incorporated elements of the majestic, mysterious, and of ritual. Here we had cultural tradition that acknowledged the intrinsic value of the letters. And it was in this context that Hangul was born as a completely phonetic system of writing. However, the characteristics of Hangul are quite different from those of Chinese ideographs, which are designed to convey a certain meaning. Despite the fact that Hangul is phonetic, its roots lie most definitely in the image of Chinese ideographs. This is something that contrasts with the roots of the Latin alphabet, which have been lost in its long journey of evolution. As a phonetic writing system, a notable characteristic of Hangul is that it has this and the attributes of image. In other words, in that Hangul is a compound, it shares some of the same attributes as Chinese ideographs, but also in that it is a phonetic writing system it is dose to the Latin alphabet. Hangul is definitely a visual writing system that has its origins in the visual culture of Chinese characters as well as being functionally a highly developed phonetic writing system. In short, Hangul has both of these attributes in one writing system. These characteristics of Hangul, for us living in the era of the image, are parts that awaken us to the meaning of existence in our visual culture. Unique among the world's writing systems, the identity of Hangul typography will become none other than the essence of our visual culture.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.90-95
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• 2014

The researchs using brain-computer interface, the new interface system which connect human to macine, have been maded to implement the user-assistance devices for control of wheelchairs or input the characters. In recent researches, there are several trials to implement the speech recognitions system based on the brain wave and attempt to silent communication. In this paper, we studied how to extract features of vowel based on international phonetic alphabet (IPA), as a foundation step for implementing of speech recognition system based on electroencephalogram (EEG). We conducted the 2 step experiments with three healthy male subjects, and first step was speaking imagery with single vowel and second step was imagery with successive two vowels. We selected 32 channels, which include frontal lobe related to thinking and temporal lobe related to speech function, among acquired 64 channels. Eigen value of the signal was used for feature vector and support vector machine (SVM) was used for classification. As a result of first step, we should use over than 10th order of feature vector to analyze the EEG signal of speech and if we used 11th order feature vector, the highest average classification rate was 95.63 % in classification between /a/ and /o/, the lowest average classification rate was 86.85 % with /a/ and /u/. In the second step of the experiments, we studied the difference of speech imaginary signals between single and successive two vowels.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.1
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• pp.10-20
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• 2017

Objective : The purpose of this study was to investigate the effect of proprioceptive-vestibular based sensory integrative intervention on handwriting and fine motor function in elementary school students in grades 1 to 3. Methods : In this study, eight students in an elementary school in Busan were enrolled. The intervention was conducted twice a week from May to October, 2016, and a total of 14 intervention sessions were conducted. In order to evaluate the writing ability and the fine-motor exercise ability before and after the intervention, the fine-motor movement items of the Korean alphabet writing test and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) evaluation were used. Results : There was a statistically significant difference between the total scores of consonant writing and the Korean alphabet writing assessment after the intervention. In BOTMP-Fine motor, the response speed items showed statistically significant difference. Visual-motor control scores increased during intervention, but the statistical significance was not found. Conclusion : Sensory integration interventions might have positive effects on elementary school students' writing skills and fine motor functions.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.102-109
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• 2008

In this paper, the robust hybrid modulation type classifier which use both HOS and WT key features and can recognize 10 digitally modulated signals without a priori information in multipath fading channel conditions is proposed. The proposed classifier developed using data taken field measurements in various propagation model (i,e., rural area, small town and urban area) for real world scenarios. The 9 channel data are used for supervised training and the 6 channel data are used for testing among total 15 channel data(i.e., holdout-like method). The Proposed classifier is based on HOS key features because they are relatively robust to signal distortion in AWGN and multipath environments, and combined WT key features for classifying MQAM(M=16, 64, 256) signals which are difficult to classify without equalization scheme such as AMA(Alphabet Matched Algorithm) or MMA(Multi-modulus Algorithm. To investigate the performance of proposed classifier, these selected key features are applied in SVM(Support Vector Machine) which is known to having good capability of classifying because of mapping input space to hyperspace for margin maximization. The Pcc(Probability of correct classification) of the proposed classifier shows higher than those of classifiers using only HOS or WT key features in both training channels and testing channels. Especially, the Pccs of MQAM 3re almost perfect in various SNR levels.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.803-812
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• 2018

The Morse code was firstly used for a wire telegraph service on May 1884 in USA. After about 10 years Korean researchers developed the Morse code in 1884 and the Morse code was firstly introduced in Korea for the wire telegraph service in September 1885. For about 130 years later, the Hangul Jamo Morse code has been used without any serious modification up to now. The Morse code is the variable length code system which each codes have a different code length. The related reference shows that English alphabet Morse code was applied in the coding theory. However, a result of analysis showed that the Hangul Jamo Morse code was not applied in the coding theory as the english alphabet code system. This paper presents the analysis result of Hangul Jamo Morse code according to the variable length coding theory. As a result of the analysis, when Hangul Jamo are coded with application of the variable length coding theory, the transmission data rate could be increased up to 25% compare to the existing code system. This paper shows a new Hangul Jamo Morse code system based on the analysis result.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.658-667
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• 2021

Our study aimed to analyze and reinterpret, by an acoustic approach, the descriptions of the 18th century prosody and introduce the figurative pronunciation system, which is the International Phonetic Alphabet pioneer. Our methodology compares and analyzes grammars and documents on the transcription system and restructures the prosodic structure. It is certain that the 18th century grammarians widely accepted the prosody theories made by Arnauld & Lancelot of the seventeenth century. In particular, grammar scholars accepted the dichotomous classification of the accent structures as prosodic and oratorical accents. The prosodic accent has a relation to intonation, and the oratorical accent has as its key elements intonation and intensity. Regarding the temporal structure, the lengthening of the final syllable was observed systematically by grammarians of the 18th century. This time structure is similar to that of today. Therefore, we can conclude that the final elongation, an essential characteristic of the modern French accent, has already played an imbued role in 18th century prosody. Despite this, the 18th century grammarians did not assign it the status of accent, as it was a stereotype that matches accent with intonation.

• Imaging Science in Dentistry
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• v.32 no.3
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• pp.129-134
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• 2002

Purpose : To implement the database system of oral and maxillofacial radiological images using a commercial medical image management software with personally developed classification code. Materials and methods : The image database was built using a slightly modified commercial medical image management software, Dr. Image v.2.1 (Bit Computer Co., Korea). The function of wild card '*' was added to the search function of this program. Diagnosis classification codes were written as the number at the first three digits, and radiographic technique classification codes as the alphabet right after the diagnosis code. 449 radiological films of 218 cases from January, 2000 to December, 2000, which had been specially stored for the demonstration and education at Dept. of OMF Radiology of Dankook University Dental Hospital, were scanned with each patient information. Results: Cases could be efficiently accessed and analyzed by using the classification code. Search and statistics results were easily obtained according to sex, age, disease diagnosis and radiographic technique. Conclusion : Efficient image management was possible with this image database system. Application of this system to other departments or personal image management can be made possible by utilizing the appropriate classification code system.