• 치과방사선
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• 제29권2호
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• pp.387-396
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• 1999

In dentistry. RadioVisioGraphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter. many types of direct digital radiographic system have been produced in the last decade. They are based either on charge-coupled device(CCD) or on storage phosphor technology. In addition. new types of digital radiographic system using amorphous selenium. image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose. image processing, computer storage. electronic transfer of images and so on. Image processing includes image enhancement. image reconstruction. digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system(IMACS) for dentomaxillofacial radiology was reported in 1992. IMACS in dental hospital has been increasing. Meanwhile. researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible. feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis. have been performed actively in the last decade. Further developments in digital radiographic imaging modalities. image transmission system. imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

• 대한세포병리학회지
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• 제17권2호
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• pp.116-119
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• 2006

The diagnosis of papillary thyroid cancer is generally based on the findings of intranuclear cytoplasmic inclusions and nuclear grooves. Although anisokaryosis and poikilokaryosis, in papillary thyroid cancer, are not distinct when compared to other cancers, cytological examination can provide useful preoperative information. Our study evaluated the diagnostic role of computer-assisted image analysis for the pre-surgical assessment of papillary thyroid carcinoma. Thyroid aspirates from twenty female patients who were histologically confirmed to have both papillary carcinoma and benign nodules were studied. Different populations of 50 benign cells and 50 malignant cells were analyzed. Five morphometric parameters were selected for analysis: nuclear area, perimeter, maximum length, maximum width and intensity standard variation. The values obtained for papillary carcinomas were higher than the surrounding benign nodules as follows: nuclear area 63.5 vs. 36.1 (p=0.000), nuclear perimeter were 29.4 vs. 22.0 (p=0.000), maximum length 9.6 vs. 7.1 (p=0.000), maximum width 8.2 vs. 6.3 (p=0.000), the ratio between maximal length and maximal width 1.16 vs. 1.13 (p=0.000), the standard variation of intensity 14.9 vs. 15.9 (p=0.101) respectively. Therefore, morphometric information can be helpful for the differential cytological diagnosis of papillary thyroid carcinoma.

• 기본간호학회지
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• 제19권1호
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• pp.122-133
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• 2012

Purpose: The purpose of this study was to develop a web-based education program on control vancomycin-resistant enterococci (VRE) infections and to identify the effects of the program on knowledge and performance of nursing students. Methods: The web-based VRE infection control education program was developed by using the network-based instructional systems design model. The nursing students in the experimental group could access this web-based education program at any time, and as many times as they wanted, during the clinical training period. Effects were evaluated by assessing knowledge and performance of VRE infection control measures during the clinical training period. Results: The contents of the education program included diagnosis, transmission, and treatment of VRE, contact precautions, hand washing, personal protective equipment, environment management, and quizzes. The lecture portion was filmed in a virtual screen studio using flash animation, video, and sound effects, and it was uploaded on an internet site. The knowledge and performance scores of the experimental group after using the education program were significantly higher than those of the control group. Conclusion: The results suggest that the web-based VRE infection control education program is an effective educational method to enhance knowledge and performance of VRE infection control measures.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.129-135
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• 2014

Purpose: The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Materials and Methods: Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. Results: A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). Conclusion: It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

• Imaging Science in Dentistry
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• 제44권4호
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• pp.279-285
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• 2014

Purpose: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. Materials and Methods: Tubes containing solutions with different concentrations of $K_2HPO_4$ were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the $K_2HPO_4$ solutions were measured. The relationship between CT number and $K_2HPO_4$ concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. Results: The relationship between $K_2HPO_4$ concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. Conclusion: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.109-115
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• 2023

Purpose: The aim of this study was to evaluate changes in the trabecular bone through texture analysis and compare the texture analysis characteristics of different areas in patients with medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: Cone-beam computed tomographic images of 16 patients diagnosed with MRONJ were used. In sagittal images, 3 regions were chosen: active osteonecrosis(AO); intermediate tissue (IT), which presented a zone of apparently healthy tissue adjacent to the AO area; and healthy bone tissue (HT) (control area). Texture analysis was performed evaluating 7 parameters: secondary angular momentum, contrast, correlation, sum of squares, inverse moment of difference, sum of entropies, and entropy. Data were analyzed using the Kruskal-Wallis test with a significance level of 5%. Results: Comparing the areas of AO, IT, and HT, significant differences (P<0.05) were observed. The IT and AO area images showed higher values for parameters such as contrast, entropy, and secondary angular momentum than the HT area, indicating greater disorder in these tissues. Conclusion: Through texture analysis, changes in the bone pattern could be observed in areas of osteonecrosis. The texture analysis demonstrated that areas visually identified and classified as IT still had necrotic tissue, thereby increasing the accuracy of delimiting the real extension of MRONJ.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.383-387
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• 2015

현대인들의 불규칙한 생활과 서구화된 식습관에 의해 대장 및 직장 질환이 증가하고 있는 추세로, 특히 직장암은 전체 대장암의 50%를 차지하고 있다. 초기 직장암의 경우 표면으로 돌출되는 부분이 없으므로 초음파로 조직 내부를 보지 않으면 직장 농양으로 오진하는 오류를 범하기도 한다. 그러나 초음파 진단을 하더라도 직장암의 병기에 따라 농양과 육안으로 구별이 어려운 경우가 있기 때문에 보다 정확한 진단이 필요하다. 그러므로 본 연구에서는 직장암과 농양 영상에 대한 컴퓨터 알고리즘을 이용하여 정량적인 분석을 하였다. GLCM을 적용하여 정상 20증례와 농양, 직장암 각 20증례를 분석영역($50{\times}50$ 픽셀)으로 설정하고, 각 영상에서 Autocorrelation, Max probability, Sum average, Sum variance 4가지 파라미터를 비교하여 분석하였다. 결과적으로 Autocorrelation, Max probability, Sum variance 3개의 파라미터에서는 100%, Sum average 파라미터에서는 암 95%, 농양에서 90% 이상의 높은 병변 질감 검출 효율이 나타났다. 이러한 파라미터들이 직장에서의 정상조직, 농양조직, 암조직 간의 판별의 기준으로 가치가 있다고 사료된다. 임상에서의 활용정도에 따라 컴퓨터 보조진단으로서의 충분한 유용성을 볼 수 있을 것이다.

• Imaging Science in Dentistry
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• 제47권1호
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• pp.51-55
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• 2017

Purpose: This study was conducted to suggest the development of a learning management system for dental radiology education using the Modular Object-Oriented Dynamic Learning Environment(Moodle). Materials and Methods: Moodle is a well-known and verified open-source software-learning management system (OSS-LMS). The Moodle software was installed on a server computer and customized for dental radiology education. The system was implemented for teaching undergraduate students to diagnose dental caries in panoramic images. Questions were chosen that could assess students' diagnosis ability. Students were given several questions corresponding to each of 100 panoramic images. Results: The installation and customization of Moodle was feasible, cost-effective, and time-saving. By having students answer questions repeatedly, it was possible to train them to examine panoramic images sequentially and thoroughly. Conclusion: Based on its educational efficiency and efficacy, the adaptation of an OSS-LMS in dental school may be highly recommended. The system could be extended to continuing education for dentists. Further studies on the objective evaluation of knowledge acquisition and retention are needed.

• 비파괴검사학회지
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• 제29권1호
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• pp.36-42
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• 2009

역공학의 한 방법으로 엑스선 전산 단층촬영 장치에서 획득한 삼차원 데이터를 CAD(computeraided design) 데이터로 변환하여 쾌속조형 모델을 제작할 수 있고, 또한 삼차원 가시화를 통해 피검사체의 오차를 확인하고 분석할 수 있는 알고리즘들에 대한 연구를 수행하였다. 연구 결과를 바탕으로 GUI(graphical user interface) 기반의 소프트웨어를 개발하였다. 개발한 소프트웨어의 검증을 위하여 산업 및 의료용 샘플들에 대한 전산 단층촬영 스캐닝을 수행하고 CAD 데이터 변환 및 컴퓨터 원용 결함진단 시뮬레이션을 수행하였다. 이를 통해 컴퓨터 원용 결함진단의 산업 및 의료분야 적용 가능성을 확인하였다.

• 정보교육학회논문지
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• 제7권2호
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• pp.227-237
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• 2003

기존의 CAI나 ITS 연구물은 문제 해결 과정이 일반화되어 있어, 특별한 문제를 해결하기 위해서는 학습자가 수동적인 입장을 가지고 불필요한 과정을 거쳐서 시스템의 요구에 따라 해결할 수밖에 없었다. 결과적으로 본 연구와 같은 분수의 연산과 분야에서는 창의적이고 개별화된 문제 풀이 과정을 지원할 수 없었다. 본 연구는 보충학습자들을 위한 분수의 연산에 관한 ITS 시스템의 설계와 구현에 관한 연구이다. 본 연구는 학습 오류를 진단하고 학습 오류 상태를 학습자가 분명하게 인지할 수 있도록 안내한다. 또한 본 시스템은 학습자의 자기 주도적인 학습을 지원하며, 학습자 자신의 학습 결손을 보충할 수 있으며 또한 분수연산 과정을 학습자의 수준에서 창의적으로 스스로 조정이 가능하다. 우리는 이 시스템이 학교 교사 부족으로 인해 보충 학습자에 대한 배려가 소홀할 수밖에 없는 문제점이 개선됨을 보여주었고, 학습자도 이 시스템으로 인해 스스로 문제를 해결하는 능력이 신장되어 보다 높은 학습 효과를 얻는 것을 발견할 수 있었다.