• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.414-420
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• 2006

Online character recognition techniques have been applied in many new fields of PDA, Tablet PC etc. But the recognition techniques can not use such high technologies naturally yet. Hidden Markov Model (HMM) that is much used recently requires high memory space and complex computational tasks because of comparing the input data with entire standard patterns. In this paper we propose a method to recognize the online characters more efficiently. At first we create chain-codes of learning data and recognition data in preprocessing phase, and then we compress dimensions of data using Principal Component Analysis (PCA) and recognize a character compressed data in recognition phrase. Validity of proposed method .is verified. by experiment results.

• Journal of Information Processing Systems
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• v.8 no.4
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• pp.653-668
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• 2012

In this study, an improved HMM based recognition model is proposed for online English and Korean handwritten characters. The pattern elements of the handwriting model are sub character strokes and ligatures. To deal with the problem of handwriting style variations, a modified Hierarchical Clustering approach is introduced to partition different writing styles into several classes. For each of the English letters and each primitive grapheme in Korean characters, one HMM that models the temporal and spatial variability of the handwriting is constructed based on each class. Then the HMMs of Korean graphemes are concatenated to form the Korean character models. The recognition of handwritten characters is implemented by a modified level building algorithm, which incorporates the Korean character combination rules within the efficient network search procedure. Due to the limitation of the HMM based method, a post-processing procedure that takes the global and structural features into account is proposed. Experiments showed that the proposed recognition system achieved a high writer independent recognition rate on unconstrained samples of both English and Korean characters. The comparison with other schemes of HMM-based recognition was also performed to evaluate the system.

• Journal of Platform Technology
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• v.6 no.1
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• pp.3-8
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• 2018

This paper proposes a technique for recognizing online handwritten cursive data obtained by tracing a motion trajectory while a user is in the 3D space based on a convolution neural network (CNN) algorithm. There is a difficulty in recognizing the virtual character input by the user in the 3D space because it includes both the character stroke and the movement stroke. In this paper, we divide syllable into consonant and vowel units by using labeling technique in addition to the result of localizing letter stroke and movement stroke in the previous study. The coordinate information of the separated consonants and vowels are converted into image data, and Korean handwriting recognition was performed using a convolutional neural network. After learning the neural network using 1,680 syllables written by five hand writers, the accuracy is calculated by using the new hand writers who did not participate in the writing of training data. The accuracy of phoneme-based recognition is 98.9% based on convolutional neural network. The proposed method has the advantage of drastically reducing learning data compared to syllable-based learning.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.260-271
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• 2020

Smartphones provide blind users with screenreader as an accessibility tool. However, blind users often experience difficulties accessing online shopping malls via smartphones due to their inconsistent and image-based layouts. To enable screenreader users to get access to the detailed information about products while they are shopping online, we have developed BarrierFreeShop, an accessible mobile shopping application for people with visual impairments. BarrierFreeShop has three accessibility features: (1) layout automation, (2) review summarization, and (3) optical character recognition. We conducted a user study with 80 participants with visual impairments where they were asked to use BarrierFreeShop for a month. The findings revealed the effectiveness of our app in terms of speed and post interview feedback. We have also discovered typical shopping experiences that participants had during the test. This research suggests that computer vision technologies can improve accessibility issues in online shopping malls. In addition, we have confirmed that extracting contents from images help people with visual impairments to get better access to product information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1379-1389
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• 1996

Hangul character always consists of consonants-vowel-consonants in order. Using this point, this paper proposes an approach to design a model for spotting each letter in Hangul, and then recognize characters based on the spotting results. The network model consist of a set of HMMs. The letter search is carried out by Viterbi algorithm, while character recognition is performed by searching the lattice of letter hypotheses. Experimental results show that, in spite of simple architecture of recognition, the performance is quite high reaching 87.47% for discrete regular characters. In particular the approach shows highly plausible segmentation of letters in characters.

• Journal of Information Processing Systems
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• v.11 no.3
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• pp.325-341
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• 2015

This paper describes the Tezpur University dataset of online handwritten Assamese characters. The online data acquisition process involves the capturing of data as the text is written on a digitizer with an electronic pen. A sensor picks up the pen-tip movements, as well as pen-up/pen-down switching. The dataset contains 8,235 isolated online handwritten Assamese characters. Preliminary results on the classification of online handwritten Assamese characters using the above dataset are presented in this paper. The use of the support vector machine classifier and the classification accuracy for three different feature vectors are explored in our research.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.378-380
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• 1998

최근의 HPC같은 초소형 컴퓨터의 발달은 더 자연스럽고 더 사용하기 편한 입출력 시스템을 요구하게 되었다. 본 논문에서는 HPC상에서의 흘림한글을 인식할 수 있는 인식 시스템을 구현한 것을 주제로 하였다. 본 시스템은 획을 인식의 기본 단위로 취급하며, 획 인식을 위하여 ART-1신경망을 사용하였으며, 글자인식을 위해 HMM의 각 스테이트를 탐색하는 방법을 사용하였다. 본 논문에서는 이 시스템을 HPC상에서 구현하였고 좋은 실험결과를 얻었다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.790-792
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• 2005

본 연구에서는 3차원 온라인 필기의 효과적인 인식 방법을 제안한다. 3차원 필기 시 pen-up/pen-down 정보의 구분이 없이 입력하도록 하여 사용자가 편리하게 필기하도록 하고 구분의 부정확함으로 인해 발생하는 오류를 줄인다. 또한, 기존의 2차원 필기 인식 모델을 개선하여 3차원 필기 데이터의 특성을 반영하게 함으로써 경제적이며 안정적인 인식이 가능하다. 실험 결과 제안된 인식 방법을 통해 pen-up/pen-down 정보의 구분이 없는 3차원 필기 숫자에 대해 $91.6\%$의 인식 성능을 얻었으며, 특히 인식 모델의 개선을 통해 여러획으로 이루어진 글자의 경우 높은 인식 성능의 향상을 보임을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.205-208
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• 2010

We introduce a novel feature extraction scheme for online handwritten digit based on utilizing Zernike moment and angulation feature. The time sequential signal from mouse movement on the writing pad is described as a sequence of consecutive points on the x-y plane. So, we can create data-set which are successive and time-sequential pixel position data by preprocessing. Data preprocessed is used for Zernike moment and angulation feature extraction. this feature is scale-, translation-, and rotation-invariant. The extracted specific feature is fed to a BP(backpropagation) neural network, which in turn classifies it as one of the nine digits. In this paper, proposed method not noly show high recognition rate but also need less learning data for 200 handwritten digit data.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.545-554
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• 2014

In this paper, we propose online Chinese character learning machine with a depth camera, where a system presents a Chinese character on a screen and a user is supposed to draw the presented Chinese character by his or her hand gesture. We develop the hand tracking method and suggest the adjusted chain code to represent constituent strokes of a Chinese character. For hand tracking, a fingertip is detected and verified. The adjusted chain code is designed to contain the information on order and relative length of each constituent stroke as well as the information on the directional variation of sample points. Such information is very efficient for a real-time match process and checking incorrectly drawn parts of a stroke.