• Imaging Science in Dentistry
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• v.54 no.1
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• pp.71-80
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• 2024

Purpose: This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography. Materials and Methods: In total, 210 joints from 183 patients(144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model(α=0.05). Results: The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05). Conclusion: Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

• Geomechanics and Engineering
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• v.36 no.5
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• pp.489-509
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• 2024

Slope stability analysis and prediction are of critical importance to geotechnical engineers, given the severe consequences associated with slope failure. This research endeavors to forecast the factor of safety (FOS) for slopes through the implementation of six distinct ML techniques, including back propagation neural networks (BPNN), feed-forward neural networks (FFNN), Takagi-Sugeno fuzzy system (TSF), gene expression programming (GEP), and least-square support vector machine (Ls-SVM). 344 slope cases were analyzed, incorporating a variety of geometric and shear strength parameters measured through the PLAXIS software alongside several loss functions to assess the models' performance. The findings demonstrated that all models produced satisfactory results, with BPNN and GEP models proving to be the most precise, achieving an R² of 0.86 each and MAE and MAPE rates of 0.00012 and 0.00002 and 0.005 and 0.004, respectively. A Pearson correlation and residuals statistical analysis were carried out to examine the importance of each factor in the prediction, revealing that all considered geomechanical features are significantly relevant to slope stability. However, the parameters of friction angle and slope height were found to be the most and least significant, respectively. In addition, to aid in the FOS computation for engineering challenges, a graphical user interface (GUI) for the ML-based techniques was created.

• Journal of Digital Policy
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• v.3 no.1
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• pp.27-32
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• 2024

In this paper, proposes a super resolution method that enhances the quality of results by refining texture features, contrasting each, and utilizing the results as weights. For the improvement of quality, a precise and clear restoration result in details such as boundary areas is crucial in super resolution, along with minimizing unnecessary artifacts like noise. The proposed method constructs a residual block structure with multiple paths and skip-connections for feature estimation in conventional Convolutional Neural Network (CNN)-based super resolution methods to enhance quality. Additional learning is performed for sharpened and blurred image results for further texture analysis. By contrasting each super resolution result and allocating weights through this process, the proposed method achieves improved quality in detailed and smoothed areas of the image. The experimental results of the proposed method, evaluated using the PSNR and SSIM values as quality metrics, show higher results compared to existing algorithms, confirming the enhancement in quality.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1391-1396
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• 2023

Malignant lymphoma has various pulmonary manifestations on chest CT, including nodules, masses, areas of consolidation, and ground-glass opacity. These presentations can pose a diagnostic challenge, as they mimic other disease patterns. Herein, we report a case of diffuse large B-cell lymphoma (DLBCL) manifesting as miliary nodules in a 67-year-old male initially presenting with dyspnea and fever. Radiologic findings included diffuse, bilateral, multiple tiny nodules consistent with metastasis, miliary tuberculosis, and fungal infection. However, further investigations, including laboratory tests, imaging, and biopsies, led to the diagnosis of DLBCL involving the lungs. Herein we reported a rare case of lymphoma involvement of the lung presenting as miliary nodules. Accurate diagnosis relies on a comprehensive evaluation of the clinical history, physical features, laboratory test results, and imaging findings.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.159-169
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• 2024

This paper proposes a new real-time fire monitoring and evacuation navigation system by integrating Augmented Reality (AR) technology with Internet of Things (IoT) technology. The proposed system collects temperature data through IoT temperature measurement devices installed in buildings and automatically transmits it to a MySQL cloud database via an IoT platform, enabling real-time and accurate data monitoring. Subsequently, the real-time IoT data is visualized on a 3D building model generated through Building Information Modeling (BIM), and the model is represented in the real world using AR technology, allowing intuitive identification of the fire origin. Furthermore, by utilizing Vuforia engine's Device Tracking and Area Targets features, the system tracks the user's real-time location and employs an enhanced A^* algorithm to find the optimal evacuation route among multiple exits. The paper evaluates the proposed system's practicality and demonstrates its effectiveness in rapid and safe evacuation through user experiments based on various virtual fire scenarios.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.510-518
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• 2002

Background : Bronchial anthracofibrosis (BAF) is a dark black or brown pigmentation of multiple large bronchi associated with a fibrotic stenosis or obliteration that is incidentally found during a diagnostic bronchoscopy some reporters have suggested endobronchial tuberculosis or tuberculous lymphadenitis as a possible cause of BAF. However, some BAF patients do not have any medical history of tuberculosis. The aim of this study was to elucidate the clinical features of simple BAF patients, which were not associated with tuberculosis. Methods : We reviewed the patients' charts retrospectiely and interviewed all BAF patients who were followed up for 1 year or more. Among the 114 BAF patients, 43 patents (38 %) had no associated tuberculosis, cancer and pneumoconiosis. The clinical characteristics, radiological findings and associated pulmonary diseases of these patients were evaluated. Results : Most patients were non-smokers, old aged, housewifes who resided in a farming village. The common respiratory symptoms were dyspnea, cough and hemoptysis. The predominant X-ray findings were a multiple bronchial wall thickening(89%), bronchial narrowing or atelectasis (76%) and a mediastinal lymph node enlargement with/without calcification (78%). Pulmonary function test usually showed mild obstructive ventilatory abnormalities but no patient showed a restrictive ventilatory pattern and the patients were frequently affected with chronic bronchitis(51%), post-obstructive pneumonia(40%) and chronic asthma(4%). Conclusion : Because BAF is frequently associated with chronic bronchitis and obstructive pneumonia as well as tuberculosis, a careful clinical evaluation and accurate differential diagnosis is more essential than empirical anti-tuberculous medication.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.1
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• pp.21-26
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• 2010

Purpose: To analyze clinical, radiological and pathological features as well as clinical outcome after surgical treatment of patients with secondary chondrosarcoma arising from osteochondroma(tosis). Materials and Methods: We retrospectively reviewed clinical records, radiographs, pathologic slides of 14 patients. Nine patients were male and fi ve were female. The mean age was 34 years. The mean follow-up period was 54 months. Results: All patients had a history of previous mass since childhood or puberty. Preexisted osteochondroma was single in 3 patients and multiple in 10. Remaining 1 patient had multiple osteochondromatosis with enchondromatosis. MRI clearly provided thickness of cartilage cap, which was over 2 cm except in 2 cases. Chondrosarcoma was grade 1 in all except 1 case, which was grade 2. Wide excision was performed in 10 patients, marginal excision in 3 and amputation in 1. Twelve patients were doing very well without evidence of disease. Among 3 patients with marginal excision, 1 patient had local recurrence and 1 patient died of disease. Conclusion: Comprehensive understanding of clinical, radiological and pathological features of secondary chondro sarcoma is warranted for accurate diagnosis. The best result can be expected with early recognition of malignant change of osteohcondroma(tosis) and wide excision.

• The Korean Journal of Archival Studies
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• no.13
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• pp.91-134
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• 2006

In general, personally collected archives, manuscripts, are physically badly conditioned and also contextual of the archives and information on the history of production is mostly collected partly in the manuscripts. Therefore they need to control the name of the producers on the archives collected in various ways effectively and accumulate provenance information which is the key element when understanding the production background in the collecting repository. Here, the authority control and provenance information management must be organized from the beginning of acquisition and this means to collect necessary information considering control process of acquisition as well. This thesis is for verifying the necessity of the authority control in collecting repository and accumulation of the provenance information and for suggesting the things to be considered as collecting Archival authority system. For all these, this thesis shows that it has checked out the necessity of the authority control in archival management and archival authority control and researched the standard of archival authority control, work process and accumulation process. Archival provenance information management and authority control in the archival authority control system are organized through the whole steps of the archival management starting from the lead file to the name of the producers at archival registration and archival description at acquisition. And a lot of information is registered and described at the proper point of time and finally all the information including authority control which controls the Heading in the authority management must be organized to use them as an intellectual management of archives and Finding Aids. The features of the Archival authority system are as follows; first of all, Authority file type which is necessary at the archival authority control of democracy movement is made up of the name of the group, person, affair and terminology(subject name). Second of all, basic record structures and description elements in authority collection of Korea Democracy Foundation Archives apply in the paragraph 1 of ISAAR(CPF) adding some necessary elements and details of description rule such as spacing words and using the periods apply in the paragraph 4 of KCR coping with the features of the archival management system. And also the way of input on the authority record is based on EAC(Encoded Archival Context). Third of all, it made users approach to the sources which they want more easily by connecting the authority terms systemically making it possible to connect the relative terms with up and down words, before and after words variously and concretely expanding the term relations rather than earlier traditional authority system which is usually expressed only with relative words (see also). So the authority control of archival management system can effectively collect and manage the function of various and multiple groups and information on main activities as well as its own function which is controlling the Heading and express the multiple and intermediary relationship between archives and producers or between producers and it also provides them with expanded Record information service which satisfies user's various requests through Indexing service. Finally applying in this international standard ISAAR(CPF) through the instance of the authority management like this, it can be referred to making Archival authority system in Collecting repository hereafter by reorganizing the description elements into appropriate formations and setting up the authority file type which is to be managed properly for every service.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.174-179
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• 2008

Purpose : The purpose of this study was to investigate the clinical features of adolescent TB. Methods : We retrospectively reviewed the medical records of the adolescents aged 12 to 18 years and who are hospitalized with the diagnosis of TB at Dong Kang General Hospital between January 2003 and December 2007. Results : Of the 29 patients who were identified, 65.5% were male. The median age at diagnosis was 16.9 years (range: 12.1-18.9 years). A tuberculin skin test (TST) was performed for 6 patients (20.7%). Among them, 5 (5 of 8[62.5%]) in the 12-15 years age group (Group A) and 1 (1 of 21[4.8%]) in the 16-18 years of age group (Group B) were TST positive, which showed that the TST performing rate decreased with age (P<0.01). Twenty-five patients (86.2%) were detected by evaluating the clinical symptoms that suggested TB and 4 patients (13.8%) were detected by screening, but no cases were detected by contact tracing. Twenty patients (69.0%) had isolated pulmonary disease. Seven patients (24.1%) had pulmonary and extrapulmonary disease and 2 patients (6.9%) had exclusively extrapulmonary disease. Most patients presented with multiple symptoms, and the most common were cough (79.3%), fever (75.9%), sputum (65.8%) and chest pain (34.5%). M. tuberculosis was isolated from the sputum of 20 patients (69.0%). The culture-positive rate increased with age (range: 62.5% in Group A to 71.4% in Group B), but the difference between the groups was not significant. Cavitary lesions were found 13 patients (44.8%). The cavitary lesion rate increased with age (range: 25.0% in Group A to 52.4% in Group B), but the difference between the groups was not significant. Four patients (13.8%) were lost during follow-up. One patient (6.9%) relapsed. Conclusion : Clinicians need to be aware of the unique features of adolescent TB, and they also need awareness of the importance of TST and contact investigation for an adult suspected of having TB for making the diagnosis of TB.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.551-561
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• 2022

Geophysical exploration methods are very useful for generating high-resolution images of underground structures, and such methods can be applied to investigation of buried cultural properties and for determining their exact locations. In this study, image feature extraction and image segmentation methods were applied to automatically distinguish the structures of buried relics from the high-resolution ground-penetrating radar (GPR) images obtained at the center of Silla Kingdom, Gyeongju, South Korea. The major purpose for image feature extraction analyses is identifying the circular features from building remains and the linear features from ancient roads and fences. Feature extraction is implemented by applying the Canny edge detection and Hough transform algorithms. We applied the Hough transforms to the edge image resulted from the Canny algorithm in order to determine the locations the target features. However, the Hough transform requires different parameter settings for each survey sector. As for image segmentation, we applied the connected element labeling algorithm and object-based image analysis using Orfeo Toolbox (OTB) in QGIS. The connected components labeled image shows the signals associated with the target buried relics are effectively connected and labeled. However, we often find multiple labels are assigned to a single structure on the given GPR data. Object-based image analysis was conducted by using a Large-Scale Mean-Shift (LSMS) image segmentation. In this analysis, a vector layer containing pixel values for each segmented polygon was estimated first and then used to build a train-validation dataset by assigning the polygons to one class associated with the buried relics and another class for the background field. With the Random Forest Classifier, we find that the polygons on the LSMS image segmentation layer can be successfully classified into the polygons of the buried relics and those of the background. Thus, we propose that these automatic classification methods applied to the GPR images of buried cultural heritage in this study can be useful to obtain consistent analyses results for planning excavation processes.