• Journal of the Korean Institute of Intelligent Systems
• /
• v.19 no.3
• /
• pp.304-310
• /
• 2009

In this paper, target extraction method in FLIR(forward-looking infrared) images based on fuzzy thresholding which used bi-modality and adjacency to determine membership value is proposed. The bi-modality represents how a pixel is classified into a part of target using distribution of pixel values in a local region, and The adjacency is a measure to represent how each pixel is far from the target region. First, membership value is calculated using above two measures, and then fuzzy thresholding is performed to extract the target. To evaluate performance of proposed target extraction method, we compare other segmentation methods using various FLIR tank image. Experimental results show that the proposed algorithm is a good segmentation performance.

• Journal of Korea Multimedia Society
• /
• v.15 no.3
• /
• pp.291-298
• /
• 2012

In automatic target recognition(ATR) systems, target extraction techniques are very important because ATR performance depends on segmentation result. So, this paper proposes a multi-sensor image fusion method based on adaptive weights. To incorporate the FLIR image and CCD image, we used information such as the bi-modality, distance and texture. A weight of the FLIR image is derived from the bi-modality and distance measure. For the weight of CCD image, the information that the target's texture is more uniform than the background region is used. The proposed algorithm is applied to many images and its performance is compared with the segmentation result using the single image. Experimental results show that the proposed method has the accurate extraction performance.

• Journal of the Korean Data and Information Science Society
• /
• v.23 no.4
• /
• pp.797-805
• /
• 2012

Many circular distributions are known to be not only asymmetric but also bimodal. Hidden truncation method of generating asymmetric distribution is applied to a bivariate circular distribution to generate an asymmetric circular distribution. While many other existing asymmetric circular distributions can only model an asymmetric data, this new circular model has great flexibility in terms of asymmetry and bi-modality. Some properties of the new model, such as the trigonometric moment generating function, and asymptotic inference about the truncation parameter are presented. Simulation and real data examples are provided at the end to demonstrate the utility of the novel distribution.

• The Journal of Korean Medicine
• /
• v.43 no.2
• /
• pp.61-74
• /
• 2022

Objectives: This study aimed to explore the short-term effects of bilateral masticatory training using an intraoral device on memory and concentration, which is an advanced form of Gochi, compared to the unilateral form with gum. Methods: Thirty young healthy participants (age, 16-30 years) were screened and randomly assigned to one of two sequences in a crossover design. The participants assigned to sequence A (n=15) performed bilateral mastication using an intraoral device with a total of 300 taps, followed by unilateral mastication using gum with the same number of repetitions and frequency, separated by a 7-day washout period. A reverse order was used for sequence B. The primary and secondary outcomes were the digit span test result and the symbol digit modality test and the word list recall results, respectively, which were conducted before and after each intervention. Results: Symbol digit modality test scores increased by 12.03±8.33 with bilateral mastication, which was significantly higher than that obtained with chewing gum (5.17 points;95% confidence interval: 0.99, 9.34; p<0.05). Changes in the digit span test and word list recall scores were not significantly different between the two groups. In the digit span test forward, symbol digit modality test, and word list recall test, bilateral mastication was not inferior to unilateral mastication in improving memory and concentration. Conclusions: Bilateral masticatory exercises using an intraoral device are not inferior to unilateral mastication with gum for improving memory in healthy young individuals. Further research is needed to determine the efficacy of bilateral masticatory training on cognitive function.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.2
• /
• pp.140-150
• /
• 2021

A total of 580 patients, who visited and received an orthodontic diagnosis in the Department of Pediatric Dentistry, Seoul National University Dental Hospital from 2017 to 2019, were investigated in this study. The aim of this study was to evaluate skeletal patterns of pediatric orthodontic patients determined with lateral cephalometric analysis and to analyze the relationship between skeletal pattern and probable associated clinical features. Also, the modality of orthodontic treatment for each skeletal classification was investigated to aid in therapeutic decisions. Patients aged 7 year accounted for the largest age group; 54.2% of patients showed a skeletal class I pattern, 22.2% showed a skeletal class II pattern, and 23.6% showed a skeletal class III pattern. Bi-maxillary retrusion for skeletal class I, retruded mandible with normal positioning of the maxilla for skeletal class II, and retrusion of the maxilla with protrusion of the mandible for skeletal class III were the largest subgroups by skeletal pattern. Brachyfacial type accounted for 55.0% of patients, followed by 31.9% of mesofacial type and 13.1% of dolichofacial type. The prevalence of anterior crossbite in the study was 43.3%, higher than that in previous studies.