• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.4
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• pp.429-441
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• 2002

This paper concerns extracting 3D motion information from a 3D input device in real time focused to enabling effective human-computer interaction. In particular, we develop a novel algorithm for extracting 6 degrees-of-freedom motion information from a 3D input device by employing an epipolar geometry of stereo camera, color, motion, and structure information, free from requiring the aid of camera calibration object. To extract 3D motion, we first determine the epipolar geometry of stereo camera by computing the perspective projection matrix and perspective distortion matrix. We then incorporate the proposed Motion Adaptive Weighted Unmatched Pixel Count algorithm performing color transformation, unmatched pixel counting, discrete Kalman filtering, and principal component analysis. The extracted 3D motion information can be applied to controlling virtual objects or aiding the navigation device that controls the viewpoint of a user in virtual reality setting. Since the stereo vision-based 3D input device is wireless, it provides users with a means for more natural and efficient interface, thus effectively realizing a feeling of immersion.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1375-1381
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• 2011

Combustion processes in an optically-accessible single-cylinder heavy-duty diesel engine equipped with a highpressure common-rail injection system were investigated for JP-8 and diesel. Direct imaging and two-color thermometry were employed to verify the emission trend for both fuels. The combustion process was characterized by image analysis with focus on luminosity. The results of two-color thermometry were analyzed on the basis of the flame temperature and KL factor distribution. Analysis of the combustion process by direct imaging showed that the ignition delay was longer for JP-8 than for diesel, while the flame was extinguished rapidly. Analysis of the flame luminosity showed that the combustion intensity was higher for diesel and that the flame lasted for a longer duration in this case. Two-color thermometry results showed that the high-temperature region extended over a large area during JP-8 combustion, implying the formation of a large amount of $NO_x$. In addition, the KL factor showed low level over a large area and relatively homogeneous in the case of JP-8 combustion, which implied that less smoke was produced when using this fuel.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.129-138
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• 2014

Various interpolations for digital imaging devices with a single image sensor have proposed. However, conventional methods did not consider the resolution modus of image sensor using periodic sampling. Therefore, the resulting images have problems such as quality degradation and color artifacts(color moire, zipper). In this paper, we propose a color interpolation algorithm for pixel resolution modus of image sensor. The proposed algorithm consisted of an initial step to compensate edge prediction effectively and refinement step using minimum directions for pixel resolution modus. To analyze a result of the proposed algorithm with conventional methods, we evaluated subjectively using images quality comparison and objectively using PSNR(Peak Signal to Noise Ratio). Experimental results showed that the proposed algorithm was more successful in eliminating the color artifacts than conventional methods judged by both objective and subjective criteria.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.139-149
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• 2023

Objective: To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC). Methods: This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO₂) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE₀₀), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05). Results: Significant difference existed among the groups regarding ΔE₀₀t0t2 (p < 0.001). The APA group showed minimum (ΔE₀₀ = 1.15 ± 0.53) and the control group showed maximum (ΔE₀₀ = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ΔTPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02). Conclusions: Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE₀₀ and ΔTP did not exceed the acceptability threshold.

• Journal of Digestive Cancer Research
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• v.12 no.2
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• pp.90-101
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• 2024

The incidence of colon cancer in South Korea has recently been the highest among gastrointestinal cancers. Early diagnosis is critical, and image-enhanced endoscopy (IEE) is a key diagnostic method. Colon tumors primarily include serrated polyps, adenomatous polyps, and colon cancer. Early endoscopic techniques relied on simple visual inspection for diagnosis, with tumor size and shape being the primary considerations. Low-resolution images made these methods ineffective for detecting small or early-stage lesions. IEE now enables detailed examination using high-resolution images and various color and structure analyses. Techniques like narrow band imaging (NBI) allow precise observation of vascular patterns and surface structures. Hyperplastic polyps often appear similar in color to the surrounding mucosa, with no visible vascular pattern. Sessile serrated lesions have a cloudy surface with distinct boundaries and irregular patterns, often with black spots in the crypts. Adenomatous polyps are darker brown, with a visible white epithelial network and various pit patterns. Magnified images help differentiate between low- and high-grade dysplasia, with low-grade showing regular patterns and high-grade showing increased irregularities. The NBI International Colorectal Endoscopic classification identifies malignant colon tumors as brown or dark brown with disorganized vascular patterns. The Japan NBI Expert Team classification includes loose vascular areas and disrupted thick vessels. The Workgroup serrAted polypS and Polyposis classification aids in differentiating between hyperplastic polyps and sessile serrated lesions/adenomas when deciding whether to resect polyps larger than 5 mm. Suspected high-grade dysplasia warrants endoscopic submucosal dissection and follow-up. Future advancements in IEE are expected to further enhance early detection and diagnostic accuracy.

• Journal of Conservation Science
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• v.38 no.2
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• pp.154-165
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• 2022

The color appearance of cultural heritage are essential factors for manufacturing technique interpretation, conservation treatment usage, and condition monitoring. Therefore, this study systematically established color reproduction procedures based on the digital color management system for the portrait of Gwon Eungsu. Moreover, various application strategies for recording and conserving the cultural heritage were proposed. Overall color reproduction processes were conducted in the following order: photography condition setting, standard color measurements, digital photography, color correction, and color space creation. Therefore, compared with the color appearance, the digital image applied to a camera maker profile indicated an average color difference of 𝜟10.1. However, the digital reproduction result based on the color management system exhibits an average color difference of 𝜟1.1, which is close to the color appearance. This means that although digital photography conditions are optimized, recording the color appearance is difficult when relying on the correction algorithm developed by the camera maker. Therefore, the digital color reproduction of cultural heritage is required through color correction and color space creation based on the raw digital image, which is a crucial process for documenting the color appearance. Additionally, the recording of color appearance through digital color reproduction is important for condition evaluation, conservation treatment, and restoration of cultural heritage. Furthermore, standard data of imaging analysis are available for discoloration monitoring.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3555-3559
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• 2014

Background: The triple-negative breast cancer (TNBC) is an aggressive cancer characterized by the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). Preoperative mammography and ultrasound features of TNBC may potentially suggest characteristics of the disease and assist in treatment decisions. Materials and Methods: The study covered 153 patients with TNBC from May 2011 to May 2012 who were confirmed by postoperative pathology results in our hospital. We compared the radiological findings among the patients and sought to determine the significant iconographic features. The biomarkers p53 and Ki-67 are regarded as significant factors in TNBC. They were therefore used to divide the TNBC into four groups for assessment of relationships with TNBC imaging features. Results: On mammography, most TNBCs exhibit obscure (44.3%) masses. On ultrasound, the majority of masses (95.4%) were predominantly indistinct (50.7%), irregular (76.0%) or featuring posterior echo enhancement/shadowing. Color Doppler flow imaging (CDFI) emphasized hypervascular (32.9%) masses. Differences in CDFI by ultrasound among the four groups were statistically significant (p=0.009). There were obvious differences in the percentages of spiculated margin (p=0.049) and intensive posterior echo (p=0.006) with spotty flow imaging by ultrasound between the Ki-67 (+) p53 (+) and other groups. Conclusions: A combination of mammography and ultrasound revealed the imaging characteristics of TNBC included an obscure mass with less attenuated posterior echoes and some vascularity. A worse prognosis was associated with spiculated margin and intensive posterior echoes with spotty flow imaging.

• Journal of Veterinary Clinics
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• v.37 no.2
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• pp.100-105
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• 2020

A 9-month-old, 11.3 kg, intact, male, mixed-breed dog was referred for treatment of cor triatriatum dexter (CTD); a 5-month-old, 1.9 kg, intact, male Maltese for pulmonic stenosis (PS); and a 3-year-old, 6.62 kg, intact, female West Highland white terrier for esophageal stricture with regurgitation. A balloon catheter intervention was performed in the dog with CTD, and subsequent color Doppler ultrasound and abdominal ultrasound showed normal blood flow across the perforated membrane dividing the right atrium and the disappearance of the severe ascites present before treatment. Balloon catheter intervention in the dog with PS reduced the blood flow through the stenosis from 5.82 m/s to 3.97 m/s. In the dog with esophageal stricture, balloon catheter intervention widened the esophagus and no subsequent regurgitation was observed. Balloon catheter intervention is an interventional radiology procedure that represents a definitive treatment option for various stenotic lesions in dogs, including CTD, PS, and esophageal stricture. Although interventional radiology procedures for these diseases have already been reported, details of procedures and successful outcome have not been reported in Korea.

• The Journal of Society for e-Business Studies
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• v.22 no.1
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• pp.1-13
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• 2017

Though digital imaging devices such as smart phones, digital cameras and office scanners have improved significantly over the past years, they are seldom used for industrial application. This may be attributable to high level of quality and performance requirement for industrial application, but there lacks a test or an objective evaluation whether the upgraded performance of entry-level device is sufficiently enough to replace existing industrial equipments or not. If there exists an industrial application area where the applicability of entry-level equipment is proved by some objective tests, then companies will be able to reduce investment on expensive industrial equipment. In this study, applicability of entry-level digital devices for color difference discrimination of PVC (Polyvinyl chloride) color sheet is tested. By testing smart phone, digital camera, and office scanner for color difference discrimination, authors have found that office scanner shows consistent result with less measurement error. Additional experiment on comparing office scanner with industrial spectrophotometer has confirmed that there exists high correlation between the two devices' results. Based on this result, office scanner may be applicable to discriminate the color difference of PVC sheet instead of expensive industrial spectrophotometer if proper management criteria are established.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.3
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• pp.168-175
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• 2024

Purpose: The presence of alcoholic stool in biliary atresia (BA) patients is the basis of a stool color card (SCC), a screening tool that has led to more patients receiving Kasai portoenterostomy earlier. This study aimed to evaluate the color image processing of stool images captured using smartphones. We propose that measuring digital color parameters is a more objective method for identifying BA stools and may improve the sensitivity of BA screening. Methods: A prospective study was conducted in five hospitals in Thailand between October 1, 2020, and December 31, 2021. Stools from infants presenting with jaundice, acholic stool, or dark-colored urine were photographed. Digital image color analysis was performed, and software was developed based on the color on the original SCC. Sensitivity and specificity for predicting BA stools were compared between the SCC and the software. Results: Of 33 infants eligible for data collection, 19 were diagnosed with BA. Saturation and blue were two potential digital color parameters used to differentiate BA stools. The receiver operating characteristic curve was used to determine the optimum cutoff point of both values, and when saturation ≤56 or blue ≥61 was set as a threshold for detecting BA stool, high accuracy was achieved at 81.8% and 78.8%, respectively. Conclusion: Digital image processing is a promising technology. With appropriate cutoff values of saturation in hue, saturation, value and blue in red, green, blue color models, BA stools can be identified, and equivocal-colored stools of non-BA patients can be differentiated with acceptable accuracy in infants presenting with jaundice.