• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.206-216
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• 1997

The purpose of this study was to determine the pore size distributions (PSDs) of polyester woven fabrics by using liquid extraction method. Three types of PSDs-percent PSD, PSD per unit area of sample and PSD per unit weight of sample-were evaluated. Plain, twill and satin polyester fabrics with various fabric counts were used as specimens. Results showed that the interyarn PSDs reflected the fabric characteristics such as the fabric count and the weave type and the intrayarn PSDs reflected the thread characteristics such as the number of fibers, the fiber diameter, the thread diameter and the thread twist. Of three types of PSDs, the PSD per unit area of sample best reflect fabric and thread characteritics. As the fabric count decreased, rc increased and interyarn pore volume increased. The PSDs were skewed to the small pore sizes and the pore volumes decreased in the order of plain> twill> satin. As the number of fibers, the fiber diameter and the thread twist decreased, the intrayarn pore volumes were increased.

• ETRI Journal
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• v.40 no.2
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• pp.246-256
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• 2018

A spatial augmented reality (SAR) system enables a virtual image to be projected onto the surface of a real-world object and the user to intuitively control the image using a tangible interface. However, occlusions frequently occur, such as a sudden change in the lighting environment or the generation of obstacles. We propose a robust object tracker based on a multithreaded system, which can track an object robustly through occlusions. Our multithreaded tracker is divided into two threads: the detection thread detects distinctive features in a frame-to-frame manner, and the tracking thread tracks features periodically using an optical-flow-based tracking method. Consequently, although the speed of the detection thread is considerably slow, we achieve real-time performance owing to the multithreaded configuration. Moreover, the proposed outlier filtering automatically updates a random sample consensus distance threshold for eliminating outliers according to environmental changes. Experimental results show that our approach tracks an object robustly in real-time in an SAR environment where there are frequent occlusions occurring from augmented projection images.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.792-801
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• 1996

A thinning algorithm -based image analysis technique was developed to measure corn root lengths. The root length measurement method was evaluated by comparing thread lengths measured by the image analysis system with actual thread lengths. The length measurement method accurately estimated actual thread lengths (less than 2% calculated error). Also, a rapid root length density measurement procedure, which utilizes the above root length measurement method, was developed to estimate corn root length density without washing the roots. Root length densities estimated from the cut soil surface of core samples taken from the field were paired with the root length densities determined from washed roots from the same soil core sample. A linear relationship between these two values was expected and was found. Eliminating the root washing procedure reduces the time required for measuring corn root length density substantially.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.2
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• pp.57-64
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• 2013

As the clothing materials have been more functional and advanced, the cotton fabrics for dress shirts or blouses have been more qualified and the sewability for high degree of completion has been required. This study aims to identify the seam strength depending on the change of stitch density of fine cotton fabrics by fabric and thread and so the general seam performance of fine cotton fabrics by analyzing the seam efficiency and breaking mode of seams. For an experiment, 3 kinds of fine cotton fabrics and 2 kinds of threads were selected and the sample was made by changing the stitch density by four steps. Then, the seam strength was measured. Next, the seam efficiency and breaking mode of seams were analyzed on the basis of the results of seam strength measurement. The results are as follows: All fabrics showed the similar tendency in seam strength. The seam strength is related to the tensile strength and thread strength, it increased only to a certain stitch density. When the stitch density exceeded a certain level, fabrics were destroyed or threads were cut. Then, the seam strength didn't increase. Furthermore, the more the seam strength increased, the more the seam efficiency increased. For increasing the maximum stitch density, it was required to use the fabrics and threads which had similar properties, in other words, the high thread strength for the high tensile strength and the low thread strength for the high tensile strength.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.343-350
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• 2022

Purpose: This study evaluated the prevalence of dental implant positioning errors and the most frequently affected oral regions. Materials and Methods: A sample was obtained of CBCT images of 590 dental implants from 230 individuals who underwent diagnosis at a radiology center using cone-beam computed tomography from 2017 to 2020. The following variables were considered: thread exposure, violation of the minimum distance between 2 adjacent implants and between the implant and tooth, and implant contact with anatomical structures. Descriptive data analysis and the Pearson chi-square test(P<0.05) were performed to compare findings according to mouth regions. Results: Most (74.4%) of the 590 implants were poorly positioned, with the posterior region of the maxilla being the region most frequently affected by errors. Among the variables analyzed, the most prevalent was thread exposure (54.7%), followed by implant contact with anatomical structures, violation of the recommended distance between 2 implants and violation of the recommended distance between the implant and teeth. Thread exposure was significantly associated with the anterior region of the mandible (P<0.05). The anterior region of the maxilla was associated with violation of the recommended tooth-implant distance (P<0.05) and the recommended distance between 2 adjacent implants(P<0.05). Implant contact with anatomical structures was significantly more likely to occur in the posterior region of the maxilla (P<0.05). Conclusion: Many implants were poorly positioned in the posterior region of the maxilla. Thread exposure was particularly frequent and was significantly associated with the anterior region of the mandible.

• Journal of Acupuncture Research
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• v.41 no.2
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• pp.96-106
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• 2024

This study aimed to provide the basis of treatment effects by analyzing randomized control trials (RCTs) on the use of thread embedding acupuncture (TEA) for low back pain that were published between February 2018 and July 2023. In total, 2,865 articles were retrieved from international and Korean databases. Nine of these articles were selected and evaluated based on the following categories: (1) year of publication, (2) type of disease, (3) sample size, (4) treatment interventions, (5) treatment frequency and duration, (6) insertion point and depth of thread embedding, (7) types and sizes of threads and needles, (8) evaluation indexes, (9) treatment outcomes, and (10) side effects. The risk of bias in RCTs was also assessed. This study also emphasizes the importance of further research on TEA for clinical treatment and the use of objective approaches. Furthermore, detailed method descriptions and results are important in determining the efficacy of TEA.

• Journal of Acupuncture Research
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• v.34 no.1
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• pp.59-66
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• 2017

Objectives : This study aims to report the effectiveness and safety of Korean medicine with thread embedding acupuncture in the treatment of trigeminal neuralgia (TN). Methods : A 73-year-old man who had suffered from severe facial pain for one year and who had had a healthy tooth extracted due to the pain is reported. He could not eat or sleep due to the severe pain. Acupuncture, thread embedding acupuncture, cupping, herbal steam, and herbal medicines were used for the treatment. Numeric Rating Scale (NRS) and adverse events were checked daily, and other outcomes (Baseline Evaluation, Visual Analogue Scale [VAS], Short Form Health Survey 36-Bodily Pain [SF-36 BP], and Patient Global Assessment [PGA]) were measured at hospital admission and discharge. During the follow-up examinations, his pain was evaluated roughly, without using any formal measurements, on the basis of a global assessment. Results : All measured parameters, including pain, quality of life, and patient satisfaction were noted to have improved at the time of discharge compared to admission: VAS from 10 to 1.5, NRS from 7-8 to 1-2, and SF-36 BP from 0 to 22.5, and the patient's global assessment was somewhat improved. He did not take any analgesics after discharge and noted only mild adverse events, like pain where the acupuncture and thread embedding acupuncture needles were inserted. His pain relief was maintained for 6 months. Conclusion : Korean medicine with thread embedding acupuncture might be a safe and effective treatment for TN. In the future, larger sample sizes and high quality randomized clinical trials are warranted to confirm its efficacy and safety.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.2
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• pp.123-134
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• 2023

Fashion design, CAD production, and the use of digital software can shorten the time and production processes in the fashion industry, but there are still many limitations in how to similarly express textile textures. Having this awareness, how to implement the visual effects of textile texture similar to that of the real world in the virtual world is one of the major exploration tasks in the fashion industry. Therefore, this study aims to analyze examples of embroidery techniques in Christian Dior collections and explore how embroidery techniques in 3D CLO fashion design can express the texture of real clothes more similarly by creating virtual works through 3D samples and 3D CLO software. First, the analysis criteria and theoretical basis of this study were derived through a literature review on fashion textile embroidery techniques, identifying types and characteristics of embroidery techniques, and classifying them into 12 types. Second, photos of the Dior 2017-2023 SS/FW Ready-to-Wear collections were collected and analyzed through the case analysis VOGUE site. Third, it presents the production of 3D CLO works by deriving a method of implementing embroidery techniques through the design of sample textile embroidery techniques using substances 3D sample software. The study's has some limitations. First, in 3D CLO fashion design, the needle gap for embroidery must be widened to see the thread pattern. Second, by reducing the number of needles, it is necessary to imitate the actual embroidery effect. Third, it is judged that it will be effective to lengthen the thread and adjust the thickness of the thread. Fourth, the thickness of the entire embroidery pattern must be increased to enable a three-dimensional texture.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.563-580
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• 1991

The purpose of this study was to investigate and compare the biomechanical properties of orthodontic rubber elastic materials. Latex bands, nylon-covered elastic threads and polyurethane-based elastic modules, delivering $205{\pm}10$ grams force at 30mm stretching state were selected and stored separately in 3 environments-air ($22{\pm}3^{\circ}C$), distilled water ($37{\pm}1^{\circ}C$), or natural saliva ($37{\pm}1^{\circ}C$). And, the amount of remaining force and permanent elongation of each sample were measured on Instron at interval of 1 hour, 6 hours, 12 hours, 24 hours, 1 week, and 2 weeks. So the data derived were analyzed statistically. The results were as follows: 1. Force decay and permanent elongation of all materials increased with time lapsed; elastic module, latex band and nylon-covered elastic thread in that order of the amount of force decay; elastic module, elastic thread, latex band in that order of the amount of permanent elongation. 2. Among environmental conditions, force decay and permanent elongation in natural saliva, most increased, and those in air, least increased. 3. There was a negative correlation between force decay and permanent elongation. 4. Force decay and permanent elongation were most affected by the material itself, time and environments in that order. 5. After 24 hours in saliva, the percentage of remaining force in elastic module was 51.9% (107.37grams); in latex band, 83.2%(172.62grams); in elastic thread, 85.0%(179.25grams). After 2 weeks in saliva, the percentage of remaining force in elastic module was 42.9%(88.75grams); in latex band, 74.5%(154.50grams); in elastic thread, 77.6%(163.75grams).

• Journal of the Korea Computer Graphics Society
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• v.16 no.3
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• pp.1-10
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• 2010

In this paper, we propose a novel noiseless method of BRDF rendering on a GPU in real-time. Illumination at a surface point is formulated as an integral of BRDF producted with incident radiance over the hemi-sphere domain. The most popular method to compute the integral is the Monte Carlo method, which needs a large number of samples to achieve good image quality. But, it leads to increase of rendering time. Otherwise, a small number of sample points cause serious image noise. The main contribution of our work is a new importance sampling scheme producing a set of incoming ray samples varying continuously with respect to the eye ray. An incoming ray is importance-based sampled at different latitude angles of the eye ray, and then the ray samples are linearly connected to form a curve, called a thread. These threads give continuously moving incident rays for eye ray change, so they do not make image noise. Since even a small number of threads can achieve a plausible quality and also can be precomputed before rendering, they enable real-time BRDF rendering on the GPU.