• Journal of Korea Multimedia Society
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• v.24 no.12
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• pp.1614-1623
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• 2021

In this paper, the purpose is evaluation of the effect of using fractal feature in machine learning based pancreatic tumor classification. We used the data that Pancreas CT series 469 case including 1995 slice of benign and 1772 slice of malignant. Feature selection is implemented from 109 feature to 7 feature by Lasso regularization. In Fractal feature, fractal dimension is obtained by box-counting method, and hurst coefficient is calculated range data of pixel value in ROI. As a result, there were significant differences in both benign and malignancies tumor. Additionally, we compared the classification performance between model without fractal feature and model with fractal feature by using support vector machine. The train model with fractal feature showed statistically significant performance in comparison with train model without fractal feature.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.56-63
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• 2018

Severe dental attrition causes pathological changes of the tooth, collapsed occlusion, and functional and aesthetic complications and can also result in a decrease in occlusal vertical dimension. Before increasing the vertical dimension with full-mouth rehabilitation, it is important to determine the amount of vertical dimension through accurate diagnosis. In this case, a 77 year old elderly male patient on anticoagulant medication with generalized attrition and fracture of teeth was treated with full-mouth rehabilitation in order to recover vertical dimension and aesthetics. Accurate clinical and radiographic examination, diagnostic, wax-up, and occlusal vertical dimension evaluation were step by step performed considering pre-medical history and old age. Patient adaptability was evaluated using an occlusal splint and interim restoration. After 3 months of stabilization with interim restoration, definitive prostheses were fabricated. Satisfactory functional and esthetic outcomes are observed after 6 months of follow up.

• Journal of Science Education
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• v.36 no.2
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• pp.341-353
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• 2012

The purpose of this study is to explore how science teachers' views about physics and biology are different. From a survey of 45 science teachers who majored in physics, this study found that their views about physics were closer to the experts' views than their views about biology. But it seemed that their views about neither physics nor biology were similar to the experts' views. Compared their views about physics with their views about biology in six dimensions, in four dimensions including structure dimension, methodology dimension, validity dimension, and reflective thinking dimension, the scores of the views about physics were higher, in learnability dimension, the scores of the views about biology were higher, and in personal relevance dimension, the scores of the two kinds of views were similar. Specially the their views about physics in learnability dimension were closer to novices'. In addition, science teachers majored in physics seemed to think that compared with biology, physics is coherent, systematic and reasoning, but it is not learnable.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.129-135
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• 2015

The objective grading system for the facial palsy is needed. In this study, the facial palsy grading system was developed with combination of three dimensional image processing and Nottingham scale. The developed system is composed of 4 parts; measurement part, image processing part, computational part, facial palsy evaluation & display part. Two web cam were used to get images. The 8 marker on face were recognized at image processing part. The absolute three dimensional positions of markers were calculated at computational part. Finally, Nottingham scale was calculated and displayed at facial palsy evaluation & display part. The effects of measurement method and position of subject on Nottingham scale were tested. The markers were measured with 2-dimension and 3-dimension. The subject was look at the camera with $0^{\circ}$ and $11^{\circ}$ rotation. The change of Scale was large in the case of $11^{\circ}$ rotation with 2-dimension measurement. So, the developed system with 3-dimension measurement is robust to the orientation change of subject. The developed system showed the robustness of grading error originated from subject posture.

• Imaging Science in Dentistry
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• v.35 no.3
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• pp.121-125
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• 2005

Purpose : The purpose of this study was to investigate whether the fractal dimension of successive panoramic radiographs of bone after implant placement is useful in the characterization of structural change in alveolar bone. Materials and Methods. Twelve subjects with thirty-five implants were retrospectively followed-up from one week to six months after implantation. Thirty-six panoramic radiographs from twelve patients were classified into 1 week, 1-2 months and 3-6 months after implantation and digitized. The windows of bone apical and mesial or distal to the implant were defined as periapical region of interest (ROI) and interdental ROI; the fractal dimension of the image was calculated. Results There was not a statistically significant difference in fractal dimensions during the period up to 6 months after implantation. The fractal dimensions were higher in 13 and 15mm than 10 and 11.5mm implant length at interdental ROIs in 3-6 months after implantation (P<0.01). Conclusion : Longer fixtures showed the higher fractal dimension of bone around implant. This investigation needs further exploration with large numbers of implants for longer follow-up periods.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.211-211
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• 2000

The multiple targets tracking problem has been one of main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimension filter, input estimation filter, interacting multiple model (IMM) filter, federated variable dimension filter with input estimation, probable data association (PDA) filter etc. have been proposed to address the tracking and sensor fusion issues. In this paper, two existing tracking algorithms, i.e. the IMMPDA filter and the variable dimension filter with input estimation (VDIE), are combined for the purpose of improving the tracking performance of maneuvering targets in clutter. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns i.e. Waver, Pop-Up, and High-Diver motions, are defined and are applied to the modified IMMPDA filter considered as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMMPDA filter than the standard IMM filter are demonstrated through computer simulations.

• Journal of Mechanical Science and Technology
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• v.15 no.10
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• pp.1417-1422
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• 2001

Since fracture surface presents clear evidence to describe the circumstances of material failure event, analysis of fracture surface should provide plenty of useful information for failure prevention. Thus if we extract proper information from the fracture surface, the safety evaluation, for plant component could be more accurate. In general, the chaotic morphology of fracture surface is determined by the degree of material degradation as well as by other factors such as type of load, geometry of specimen, notch condition, microstructure of material and environment. In this research, we developed a fractal analysis technology for the fracture surface of aged turbine rotor steel based on the slit-island technique using an image analyzer. Moreover the correlation between the fractal dimension and the aging time was studied.

• Journal of Community Nutrition
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• v.8 no.3
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• pp.153-159
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• 2006

The current exploratory study investigates and compares the perceptions of the service quality of in-flight meals through the evaluation of recent consumers (within 2 weeks) of services provided by Korean and foreign-based airlines. Twenty (20) items for measuring service quality were categorized into three factor dimensions of 'food quality', 'employee service', and 'professionalism'. Among these, 'employee service' was rated highest by Korean and foreign-based airlines. When items representing each service quality dimension were analyzed and compared, only the 'food quality' dimension of Korean-based airlines was perceived higher than that of other foreign-based airlines. Findings also revealed a spectrum with some items with higher or lower mean values within each service quality dimension. Results of this study can expectedly be used to benefit both from a theoretical and practical point of view by providing empirical data that measure the service quality of in-flight meal service.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.431-441
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• 2021

Full-mouth rehabilitation with increasing vertical dimension can be used for patients with severely worn teeth. In severely worn teeth also, the alveolar process can be elongated to compensate for the reduced vertical dimension, and the patient's vertical dimension of occlusion can be kept constant. However, full-mouth rehabilitation with increasing vertical dimension must be carefully chosen, because the vertical dimension can be reduced by tooth wear. It is important to establish a treatment plan with the systematic diagnosis of the change in the vertical dimension and gain space for the prosthesis. It is necessary to change the vertical dimension to secure the restoration space and select the minimum vertical dimension elevation for the esthetic and functional goal. In this case report, the patient complained of difficulty during chewing due to a worn dentition and wanted esthetic improvement of the short mandibular anterior teeth. After systematic evaluation and diagnosis, we performed full-mouth rehabilitation with minimum vertical dimension elevation to obtain the space for restoration. This resulted in a stable and harmonious occlusion, and the functional and esthetic problems of the patient were solved after treatment. The patient was satisfied with the results of the treatment and maintained stable occlusion during the follow-up period.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.121-126
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• 2011

This study is a preliminary study to develop design guidelines on shared spaces of apartment for healthy housing. It was tried to set the basic direction of the guideline development by comparing and analyzing related literatures based on the previously identified evaluation indicators of healthy housing of apartment. The major findings were as followings: 1) based on the research conducted before, the characters of shared spaces for healthy housing were classified as physical, mental and social dimensions. 2) According to the comparison and analysis of relevant standards and guidelines, focuses were mostly on the physical dimension, particularly on the human traffic lines of the convenience attributes. Other focuses were on the attractiveness of the apartment complex of the vitality attribute under the mental dimension, and community facilities of the residential stability attributes under the social dimension. Therefore, it was identified that it is required to take complementary measure regarding mental and social dimensions, and design concrete steps to include different attributes of each dimension, in order to develop comprehensive guidelines for shared space.