• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.284-288
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• 2010

The aim of this report is to compare quantitatively computed radiography (CR) and screen-film radiography (SFR) in the detection of peritoneal effusion in dogs. Normal four beagle dogs and one Maltese dog were used. Each five CR and SFR abdominal images of right lateral and ventro-dorsal position were obtained after lodge of 6 ml, 8 ml, 12 ml, 15 ml, and 18 ml of normal saline by intraperitoneal injection within the abdomen. The reviewers were asked to evaluate each SFR and CR images for the presence of peritoneal effusion using the score by the presence of a peritoneal effusion on a five-point ordinal scale. A receiver operating curve (ROC) analysis compared the two imaging modalities. The present study showed that there was no statistical difference between SFR and CR in the detecting peritoneal effusion, but CR was relatively more sensitive based on the increased area under its ROC analysis. Moreover, Readers were more likely to detect peritoneal effusion on CR images than SFR.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.125-133
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• 2008

Motion blur is a blurring effect on an image caused by the relative motion between the camera and objects in the scene. When an image is captured, motion blurs are caused by relative motion between the camera and the scene. When different objects are moving at different speeds, the characteristics of the blur effect for each object appear differently. To restore the spatially variant blurred image, each of the blur extents should be identified. In this paper, we propose a new method for the identification of blur extent locally using RATS from the image in which the spatially variant motion blur is caused Experiment shows that the proposed algorithm successfully segments the objects with different blurs and identifies the blur extents quite well.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.352-354
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• 2022

Position measurement using a camera has been studied for a long time. This is being studied for distance recognition or object recognition in autonomous vehicles, and it is being studied in the field of indoor navigation, which is a limited space where GPS is difficult to apply. In general, in a method of measuring the distance using a camera, the distance is measured using a distance between the cameras using two stereo cameras and a value measured through a captured image or photo. In this paper, we propose a method of measuring the distance of an object using a single camera. The proposed method measures the distance by using the distance between cameras, such as a stereo camera, and the value measured by the photographed picture through the gap of the photographing time and the distance between photographing.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.10-18
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• 2009

Color rendition method is necessary for improving the low contrast images which are achieved by PDA, mobile phone camera or PC camera. There are some methods for color rendition. However, after correcting the color, image quality degradations, such as graying-out, halo-artifact and color noise, may occur. In order to overcome these problems, this paper proposes a retinex-based color rendition method. The proposed method uses the HSV color coordinate system to avoid the graying-out, and the advanced image formation model to reduce the halo-artifact in which the image is divided into three components as the global illumination, the local illumination, and reflectance. The experiment results show that the proposed method yields better performance of color correction over the conveniently method.

• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.43-48
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• 2018

In this paper, we present a method for removing shadows from scanned documents. Compared to the existing methods such as one based on image pyramid representation or adaptive thresholding, our method produces more robust and higher quality results. The basic idea of the approach is to use the local image statistics and to separate interesting regions from the image such as the regions around letters and figures. For the separated regions, we adaptively adjust the local brightness and contrast, and apply the sigmoid function to the intensity values as well to enhance the clarity of the image. For separated the other empty regions, we apply the gradient-base image hole filling method to fill the region with smooth color change.

• The korean journal of orthodontics
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• v.35 no.5 s.112
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• pp.341-350
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• 2005

The Purpose of this study was to compare the degree of vortical head rotation and to evaluate the reproducibility of natural Head posture (NHP) according to two guiding methods, the head posture aligner (HPA) method and the solf balance posture (SBP) method. The subjects consisted of 30 adults. On the first day. lateral and frontal cephalometric radiographs were obtained through the two guiding methods. One mouth later. lateral and frontal cephalometric radiographs were obtained again through both guiding methods. The degrees of vertical head rotation of both guiding methods were compared and the reproducibility was evaluated for each guiding method. A comparison of the degrees of vortical head rotation for the two methods revealed that the vertical head posture was lower in the SBP method than in the HPA method by an average of $2.79^{\circ}$. All measurements obtained using the HPA and SBP methods with a time interval of one north did not show any significant difierence in lateral and frortal cephalometric radiographs. The results of the present study suggest that the SBP method may be used as an alternative to the HPA method in case the HPA method can not be applied.

• Progress in Medical Physics
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• v.5 no.1
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• pp.13-24
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• 1994

In the conventional thermograph systems, expensive infrared lens systems are usually used for accomodating infrared beams to high speed optical scanners. In this study, a cheap focussing mirror with a two dimensional scanner are used for the development of medical infrared thermograph system in which high speed imaging is not critically required. The infrared thermograph system can be used for two dimensional imaging of human skin temperature by measuring the amount of infrared lights radiating from it. It has been experimentally proven that the accuracy of temperature measurements using the developed system is under 0.1$^{\circ}C$ with image matrix size of 256${\times}$240, and imaging time of 4 seconds.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.207-227
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• 2001

스프린트는 치주처지료에서 부가적 처치법으로 널리 사용되고 있으며, 한편, 디지털 공제 활영술은 기존방사선촬영술의 한계점을 극복하기 위해 기발된 새로운 방법이다. 이번 연구에서는 치근활택술 단독시행시와 스피린트 병행 처치시의 효과를 임상적, 방사선학적으로 비교하였다. 중정도의 성인성 치주염을 가진 20명의 환자를 대상으로 하되 10명은 치근활택술 단독으로, 나머지 10명은 스프린트 병행처치로 처치하였다. 임상적, 방사선학적인 평가는 처치전, 처치후 6개월에 행하고, 임상적 평가의 경우 3개월에 추가로 실시하였다. 이번 연구에서 사용된 임상 지수로는 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상부착수준, 임상부착증가, 탐침시출혈, 치아동요도 등이며, 방사선학적 평가는 기존 방사선촬영술에 의한 방법과 디지털 공제촬영수렝 의한 방법으로 행하였다. 디지털 공제 촬영술에 의한 평가시, 영상은 Digora 프로그램에 의해 획득하고 Emago 프로그램으로 처리 하여 다음과 같은 결론을 얻었다. 1. 처치후 3개월에 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시 출혈 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈에서 유의성이 있었다. ( p<0.05 ) 그러나 두군간 차이는 인정되지 않았다. ( p>0.05 ) 2. 처치후 6개월에도 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시출혈, 치아동요도 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈, 치태지수, 치아동요도에서 유의성이 있었다. ( p<0.05 ) 그러나 두 군간 차이는 인정되지 않았다. ( p>0.05 ) 3. 켄달 상관분석시, 임상적 평가와 기존 방사선 촬영술에 의한 평가사이의 관련성을 낮았으며 거의 0에 가까운 수치를 보였으며 (r=0.110, p=0.639 ) 임상적 평가와 디지털 공제 방사선 촬영술에 의한 평가사이에서 약간 높은 관련성을 보였다. ( r=0.257, p=0.315 ) 즉 치주치료후의 골변화는 디지털 공제 방사선 촬영술에 의한 평가시 기존 방사선 사진보다 임상적 부착증가와 더욱 긴밀한 관련성을 보여준다. 이상의 결과로 볼 때, 스프린팅 처치는 치주 치료에 있어 치근활택술에 부가적 표과를 제공하지 못한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.273-279
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• 2012

Purpose : This study was aimed to calculate effective dose from cone beam CT and compare effective dose from periapical and panoramic radiography for mesiodens. Materials and Methods : Upper anteiror periapical, panoramic radiography and cone-beam CT were taken for diagnosis of mesiodens. The effective dose were calculated by using an anthropomorphic phantom loaded with thermoluminescent dosimeters at the 23 sites related to sensitive organs. Results : The highest absorbed doses were received by the mandibular body, parotid gland and cheek from periapical, panoramic and cone-beam CT, respectively. The effective doses for periapical, panoramic radiography and cone-beam CT measured 2, 18 and 48 ${\mu}Sv$. Conclusion : Cone-beam CT, although providing additional diagnostic benefits, exposes patients to higher levels of radiation than conventional periapical and panoramic radiography.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.184-190
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• 2012

Purpose: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for one periapical radiography using the portable and wall type dental X-ray machines. Materials and methods: Thermoluminescent chips were placed at 25 sites throughout the layers of the head and neck of a tissue-equivalent human skull phantom. The man phantom was exposed with the portable and wall type dental X-ray machines. For one periapical radiography taken by portable dental X-ray machine, the exposure setting was 60 kVp, 2 mA and 0.2 seconds, while for one periapical radiography taken by wall type dental X-ray machine, exposure setting was 70 kVp, 8 mA and 0.074 seconds. Absorbed dose measurements were performed and equivalent doses to individual organs were summed using ICRP 103 to calculate effective dose. Results: In the upper anterior periapical radiography using portable dental X-ray machine and in the lower posterior periapical radiography using both machines, the highest absorbed dose was recorded at the mandible body. The effective dose in upper anterior periapical radiography using portable and wall type dental X-ray machines was $4{\mu}Sv$, $2{\mu}Sv$, respectively. In the lower posterior periapical radiography, the effective dose for each portable and wall type dental X-ray machines was $6{\mu}Sv$, $2{\mu}Sv$. Conclusion: It was recommended that the operator use prudently potable dental X-ray machine because that the effective dose in the periapical radiography using wall type dental X-ray machine was lower than that in the periapical radiography using portable dental X-ray machine.