• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.6
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• pp.614-619
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• 2009

The STW(servo track writing) system which is the process of writing servo signals on disks before assembling in drives uses the spindle motor-chuck mechanism to realize low cost because the spindle motor-chuck mechanism has merit which can simultaneously write multi-disk by piling up disks in hub. Therefore, when the spindle motor-chuck mechanism of horizontal type operates in high rotation speed it is necessary to reduce the effect of RRO(repeatable run-out) and NRRO(non-repeatable run-out) to achieve the high precision accuracy of nano-meter level during the STW process. In this paper, we analyzed that the slip in assembly surfaces can be caused by the mechanical tolerance and clamping force in hub-chuck mechanism and can affect NRRO performance. We designed springs for centering and clamping considering centrifugal force by the rotation speed and assembly condition. The experimental result showed NRRO performance improves about 30 % than case of weak clamping force. The result shows that the optimal design of the spindle motor-chuck mechanism can effectively reduce the effect of NRRO and RRO in STW process.

• Journal of Computing Science and Engineering
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• v.10 no.2
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• pp.39-50
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• 2016

In this paper, we present a comparative study of spatial domain features for writer identification and verification with different ink width conditions. The existing methods give high error rates, when comparing two handwritten images with different pen types. To the best of our knowledge, we are the first to design the feature with different ink width conditions. To address this problem, contour based features were extracted using a chain code method. To improve accuracy at higher levels, we considered histograms of chain code and variance in bins of histogram of chain code as features to discriminate handwriting samples. The system was trained and tested for 1,000 writers with two samples using different writing instruments. The feature performance is tested on our newly created dataset of 4,000 samples. The experimental results show that the histogram of chain code feature is good compared to other methods with false acceptance rate of 11.67%, false rejection rate of 36.70%, average error rates of 24.18%, and average verification accuracy of 75.89% on our new dataset. We also studied the effect of amount of text and dataset size on verification accuracy.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.160-165
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• 2023

In this study, we propose an SNS sentence writing assistance system that utilizes YOLO and GPT to assist users in writing texts with images, such as SNS. We utilize the YOLO model to extract objects from images inserted during writing, and also extract meta-information such as GPS information and creation time information, and use them as prompt values for GPT. To use the YOLO model, we trained it on form image data, and the mAP score of the model is about 0.25 on average. GPT was trained on 1,000 blog text data with the topic of 'restaurant reviews', and the model trained in this study was used to generate sentences with two types of keywords extracted from the images. A survey was conducted to evaluate the practicality of the generated sentences, and a closed-ended survey was conducted to clearly analyze the survey results. There were three evaluation items for the questionnaire by providing the inserted image and keyword sentences. The results showed that the keywords in the images generated meaningful sentences. Through this study, we found that the accuracy of image-based sentence generation depends on the relationship between image keywords and GPT learning contents.

• School Mathematics
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• v.3 no.2
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• pp.325-354
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• 2001

The study aims to develop balanced performance assessment tasks for primary school mathematics which can be implemented in the primary school easily. In order to these purposes, I suggest the types of performance assessment tasks and the framework of assessment standards for the balanced performance assessment with describing the procedures of developing tasks and rubrics. The types of task are journal writing, problem posing, constructed task, and descriptive task. In the framework of assessment standards, I suggest holistic scoring which are classified as four levels according to the degree of excellence which students perform totally concerning about the criterion of implication, reasoning, accuracy, and communication. Also I analyse the responses of children to the task “make a beautiful pattern” and suggest its assessment rubric and anchor papers for each level for illustrating the process of developing a rubric in holistic scoring. In order to reflect the viewpoints of children and their Parents concerning about the tasks, the responses in self assessment and parent assessment are analysed. Finally, methods of implementing the assessment tasks and considerations are discussed.

• English Language & Literature Teaching
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• v.15 no.3
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• pp.83-104
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• 2009

This study examined whether self-correction or metalinguistic explanation might make a difference in the ability to accurately write two English grammatical structures when learners received indirect teacher feedback in the form of underlining target errors in a Korean EFL college classroom. With the goal of helping low-proficiency students improve their ability to accurately write sentences including nonfinite present participial relative clauses and present participial constructions, four groups were formed: a group which received indirect feedback, a group which received indirect feedback and metalinguistic explanation, a group which received indirect feedback and self-corrected errors, and a group which received indirect feedback and self-corrected errors after receiving metalinguistic explanation. The results showed that the effects of either metalinguistic explanation or self-correction integrated with indirect feedback on learners' ability to accurately write the target structures were not meaningful, while the combined effects of metalinguistic explanation and self-correction were statistically significant.

• English Language & Literature Teaching
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• v.17 no.4
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• pp.157-175
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• 2011

The purpose of this study is to compare learners' view on Korean and native teachers of English with regard to competence of teaching skills. A total of 166 high school students attending the same high school in Korea participated in a questionnaire survey. The students were asked a series of questions about their five Korean teachers of English and three natives. The analysis of the results indicates that the learners believed Korean English teachers would be better in teaching vocabulary, grammar and reading than native English teachers. The learners answered native English teachers would be better in teaching speaking, listening, and writing. In the areas of the accuracy of classroom language, the level of teacher-centeredness, and the amount of cultural information given in a classroom, there were no significant differences in the learners' responses between Korea and native teacher of English. By recognizing the differences of the learners' views on two different types of ELT teachers, we suggest that it would be beneficial for learners if we would utilize their views in designing and administrating a team-teaching program.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.10a
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• pp.7-19
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• 1992

An efficient approach to limit analysis is presented whereby a continuous perfectly plastic structure is replaced by a discrete mathematical model. It is formulated as a mathematical programming problem using the static theorem of plasticity. The discretization is accomplished by writing the governing equilibrium equations in finite difference form, and is combined with piecewise linearization of the nonlinear yield curve, thus converting the formulation into a linear programming exercise. Examples of reported cases involving plates and shells are solved to illustrate the ease of application of the present method, its flexibility and accuracy - features which it make attractive to practising engineers.

• Journal of Korea Multimedia Society
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• v.22 no.4
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• pp.455-462
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• 2019

This paper proposes a method of utilizing convolutional neural network to classify the images of Bender Gestalt Test (BGT), which is a tool to understand and analyze a person's characteristic. The proposed network is composed of 29 layers including 18 convolutional layers and 2 fully connected layers, where the network is to be trained with augmented images. To verify the proposed method, 10 fold validation was adopted. In results, the proposed method classified the images into 9 classes with the mean f1 score of 97.05%, which is 13.71%p higher than a previous method. The analysis of the results shows the classification accuracy of the proposed method is stable over all the patterns as the worst f1 score among all the patterns was 92.11%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.1098-1101
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• 2022

With the development of computer music notation programs, when drawing sheet music, it is often drawn using a computer. However, there are still many use of hand-written notations for educational purposes or to quickly draw sheet music such as listening and dictating. In previous studies, OMR focused on recognizing the printed music sheet made by music notation program. the result of handwritten OMR with camera is poor because different people have different writing methods, and lens distortion. In this study, as a pre-processing process for recognizing handwritten music sheet, we propose a method for recognizing a staff using linear regression and a method for recognizing a bar using CNN. F₁ scores of staff recognition and barline detection are 99.09% and 95.48%, respectively. This methodologies are expected to contribute to improving the accuracy of handwriting.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.45-53
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• 2014

This paper suggests methods to chronicle and track the history of dialogues exchanged among characters to prevent logical errors of a story. As for stories that are long with many characters, especially in full-length novels and co-written stories, cognitive burden is imposed on a writer. If the writer has confused understanding of a character, then a logical error would enter the story. This would compromise completeness and integrity of writing. Against the backdrop, this paper shows how dialogues among characters are chronicled and tracked by using the aforementioned tracking methods through design of a writer support system that relieves a writer's cognitive burden while supporting the writing and through an analysis of existing novels. In addition, we showed the accuracy results of average 68.5% through the performance evaluation of the query used in the dialogue history tracking.