• Imaging Science in Dentistry
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• v.54 no.3
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• pp.276-282
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• 2024

Purpose: This study aimed to assess the performance of 2-dimensional (2D) imaging with microscopy coils in delineating teeth and periodontal tissues compared with conventional 3-dimensional(3D) imaging on a 3 T magnetic resonance imaging (MRI) unit. Materials and Methods: Twelve healthy participants (4 men and 8 women; mean age: 25.6 years; range: 20-52 years) with no dental symptoms were included. The left mandibular first molars and surrounding periodontal tissues were examined using the following 2 sequences: 2D proton density-weighted (PDw) images and 3D enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) images. Two-dimensional MRI images were taken using a 3 T MRI unit and a 47 mm microscopy coil, while 3D MRI imaging used a 3 T MRI unit and head-neck coil. Oral radiologists assessed dental and periodontal structures using a 4-point Likert scale. Inter- and intra-observer agreement was determined using the weighted kappa coefficient. The Wilcoxon signed-rank test was used to compare 2D-PDw and 3D-eTHRIVE images. Results: Qualitative analysis showed significantly better visualization scores for 2D-PDw imaging than for 3D-eTHRIVE imaging (Wilcoxon signed-rank test). 2D-PDw images provided improved visibility of the tooth, root dental pulp, periodontal ligament, lamina dura, coronal dental pulp, gingiva, and nutrient tract. Inter-observer reliability ranged from moderate agreement to almost perfect agreement, and intra-observer agreement was in a similar range. Conclusion: Two-dimensional-PDw images acquired using a 3 T MRI unit and microscopy coil effectively visualized nearly all aspects of teeth and periodontal tissues.

• International Journal of Stem Cells
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• v.15 no.4
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• pp.347-358
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• 2022

Background and Objectives: The search for a suitable alternative for urethral defect is a challenge in the field of urethral tissue engineering. Induced pluripotent stem cells (iPSCs) possess multipotential for differentiation. The in vitro derivation of urothelial cells from mouse-iPSCs (miPSCs) has thus far not been reported. The purpose of this study was to establish an efficient and robust differentiation protocol for the differentiation of miPSCs into urothelial cells. Methods and Results: Our protocol made the visualization of differentiation processes of a 2-step approach possible. We firstly induced miPSCs into posterior definitive endoderm (DE) with glycogen synthase kinase-3𝛽 (GSK3𝛽) inhibitor and Activin A. We investigated the optimal conditions for DE differentiation with GSK3𝛽 inhibitor treatment by varying the treatment time and concentration. Differentiation into urothelial cells, was directed with all-trans retinoic acid (ATRA) and recombinant mouse fibroblast growth factor-10 (FGF-10). Specific markers expressed at each stage of differentiation were validated by flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR) assay, immunofluorescence staining, and western blotting Assay. The miPSC-derived urothelial cells were successfully in expressed urothelial cell marker genes, proteins, and normal microscopic architecture. Conclusions: We built a model of directed differentiation of miPSCs into urothelial cells, which may provide the evidence for a regenerative potential of miPSCs in preclinical animal studies.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.52-62
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• 2017

Overseas landscape practices have already benefited from the awareness of BIM while landscape-related organizations are encouraging its use and the number of landscape projects using BIM is increasing. However, since BIM has not yet been introduced in the domestic field, this study investigated and analyzed overseas landscape projects and discussed the positive effects and implementation of BIM. For this purpose, landscape projects were selected to show three effects of BIM: improvement of design work efficiency, building of a platform for cooperation, and performance of topography design. These three projects were analyzed across four aspects of implementation methods: landscape information, 3D modeling, interoperability, and visualization uses of BIM. First, in terms of landscape information, a variety of building information was constructed in the form of 3D libraries or 2D CAD format from detailed landscape elements to infrastructure. Second, for 3D modeling, a landscape space including simple terrain and trees was modeled with Revit while elaborate and complex terrain was modeled with Maya, a professional 3D modeling tool. One integrated model was produced by periodically exchanging, reviewing, and finally combining each model from interdisciplinary fields. Third, interoperability of data from different fields was achieved through the unification of file formats, conversion of differing formats, or compliance with information standards. Lastly, visualized 3D models helped coordination among project partners, approval of design, and promotion through public media. Reviewing of the case studies shows that BIM functions as a process to improve work efficiency and interdisciplinary collaboration, rather than simply as a design tool. It has also verified that landscape architects could play an important role in integrated projects using BIM. Just as the introduction of BIM into the architecture, engineering and construction industries saw great benefits and opportunities, BIM should also be introduced to landscape architecture.

• Archives of Plastic Surgery
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• v.41 no.6
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• pp.679-685
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• 2014

Background Frontal sinus fractures, particularly anterior sinus fractures, are relatively common facial fractures. Many agree on the general principles of frontal fracture management; however, the optimal methods of reduction are still controversial. In this article, we suggest a simple reduction method using a subbrow incision as a treatment for isolated anterior sinus fractures. Methods Between March 2011 and March 2014, 13 patients with isolated frontal sinus fractures were treated by open reduction and internal fixation through a subbrow incision. The subbrow incision line was designed to be precisely at the lower margin of the brow in order to obtain an inconspicuous scar. A periosteal incision was made at 3 mm above the superior orbital rim. The fracture site of the frontal bone was reduced, and bone fixation was performed using an absorbable plate and screws. Results Contour deformities were completely restored in all patients, and all patients were satisfied with the results. Scars were barely visible in the long-term follow-up. No complications related to the procedure, such as infection, uncontrolled sinus bleeding, hematoma, paresthesia, mucocele, or posterior wall and brain injury were observed. Conclusions The subbrow approach allowed for an accurate reduction and internal fixation of the fractures in the anterior table of the frontal sinus by providing a direct visualization of the fracture. Considering the surgical success of the reduction and the rigid fixation, patient satisfaction, and aesthetic problems, this transcutaneous approach through a subbrow incision is concluded to be superior to the other reduction techniques used in the case of an anterior table frontal sinus fracture.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.489-498
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• 2012

This paper consists of two parts: In the first part, we describe our work to build hierarchical knowledge base of digital library patron's research interests and learning topics in various scholarly areas through analyzing well classified Electronic Theses and Dissertations (ETDs) of NDLTD Union catalog. Journal articles from ACM Transactions and conference web sites of computing areas also are added in the analysis to specialize computing fields. This hierarchical knowledge base would be a useful tool for many social computing and information service applications, such as personalization, recommender system, text mining, technology opportunity mining, information visualization, and so on. In the second part, we compare four grouping algorithms to select best one for our data mining researches by testing each one with the hierarchical knowledge base we described in the first part. From these two studies, we intent to show traditional verification methods for social community miming researches, based on interviewing and answering questionnaires, which are expensive, slow, and privacy threatening, can be replaced with systematic, consistent, fast, and privacy protecting methods by using our suggested hierarchical knowledge base.

• Progress in Medical Physics
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• v.9 no.4
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• pp.207-215
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• 1998

There have been many radiation measurement methods so far among which film dosimetry, TLD, and ion chamber are the most frequently used methods. But this study describes a new radiation measurement method which uses polymer gel and magnetic resonance imaging(MRI). The objective of this study is to fabricate a polymer gel sensitive to radiation and to generate a dose to MRI contrast relationship, and to apply this results to the radiation measurement for the brachytherapy. To do this, 12 cm diameter cylindrical gel phantom was made, and the phantom was irradiated using the 30 mm diameter circular collimator which was used for radiosurgery. And this irradiated phantom was scanned with MRI. To find out the relationship between the radiation dose and the transversal relaxation time, an image processing software(IDL) was used. From this study it is found out that the radiation dose showed linear relationship to the transversal relaxation time of the gel up to 17 Gy($R^2$=0.993) and they had a different relationship above 17 Gy. The dose distributions were calculated using these results for the Ir-192 sources, one for the HDR afterloading system and the other for a 2 mCi seed source. And these calculated dose distributions were compared to the ones from the treatment planning computers. From this study the dose to the irradiated gel's transversal relaxation time relationship was examined, and this result was tried for the measurement of the brachytherapy.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.137-144
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• 2004

ECG signals are often contaminated with high-frequency noise such as muscle artifact, power line interference, and others. In the ECG signal processing, especially during a pre-processing stage, numerous noise removal techniques have been used to reduce these high-frequency noise without much distorting the original signal. This paper proposes a new type of digital filter with a continuously variable cutoff frequency to improve the signal quality This filter consists of a cutoff frequency controller (CFC) and variable cutoff frequency lowpass filter (VCF-LPF). From the noisy input ECG signal, CFC produces a cutoff frequency control signal using the signal slew rate. We implemented VCF-LPF based on two new filter design methods called convex combination filter (CCF) and weight interpolation fille. (WIF). These two methods allow us to change the cutoff frequency of a lowpass filter In an arbitrary fine step. VCF-LPF shows an excellent noise reduction capability for the entire time segment of ECG excluding the rising and falling edge of a very sharp QRS complex. We found VCF-LPF very useful and practical for better signal visualization and probably for better ECG interpretation. We expect this new digital filter will find its applications especially in a home health management system where the measured ECG signals are easily contaminated with high-frequency noises .

• Archives of Plastic Surgery
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• v.37 no.1
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• pp.99-103
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• 2010

Purpose: Blow-out fractures are reduced through transcutaneous or transconjunctival incisions. But the field of orbital surgery is difficult due to lack of visualization of fracture site, blind dissection of orbital floor, susceptibility of injury of orbital structures. In these situations, the former technique of using an antral balloon catheter has advantages over other methods for reconstruction because of its rapidity, simplicity, and inexpensiveness. Furthermore, the antral balloon catheter allows not only elevation of the orbital bone fragment but also expansion of the maxillary sinus in cases where there is a fracture of its walls. But postoperative follow-up method using computed tomography is expensive. Hence, we report a simple and inexpensive follow-up method using radiopaque dye inflation. Methods: We performed endoscopic transantral approach in 5 cases of blow-out fracture under general anesthesia. To accomplish this technique, a rigid 4 mm, 0 or 30 degree angled endoscopy was inserted into the maxillary sinus. Inflation of the catheter started gradually, with 10 to 15 mL of saline mixed radiopaque dye (saline: dye, 5 : 1) by syringe and while observing the elevation of the fracture site with endoscope until a proper contour was reached. For the maintain of the position of fractured site, 12 French urinary balloon foley catheter were used in fracture site for 7 - 10 days. Results: Postoperative assessment was performed by means of clinical and simple radiographic examination to secure the catheter under the inferior orbital wall and in the maxillary sinus. No specific complications occurred related to this procedure. Results of the surgery and follow-up in all cases were satisfactory. Conclusion: It may be a better alternative to the conventional follow-up method, with less cost and effectiveness of the catheter patency. The advantages of using the urinary balloon foley catheter with the radiopaque dye include the following : it is safe, efficacy, simple, and especially low cost. On drawback of this method is the discomfort to the patient caused by the catheter during the treatment.

• Journal of The Korean Association For Science Education
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• v.33 no.7
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• pp.1385-1402
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• 2013

This study analyzes pre-service teachers' PCK dealing with visualization of the contents related to boiling point elevation and teaching methods in mock-lessons. As a result of analyzing pre-service teachers' knowledge based on PCK factors, most of the pre-service teachers accentuated on understanding boiling point elevation conceptually, whereas some of the others inclined to make students understand boiling point elevation in a scientific way, let the kids use numerical formulas to describe the concept, and motivate them to learn through the examples in real life. The pre-service teachers represented majority of the important facts of boiling point elevation as the knowledge required to understand things conceptually. However, they did not focus on improving the scientific thinking and inquiring levels of the students. Also, the pre-service teachers tended to teach at the level and order of the textbook. In some other cases, they considered the vocabularies and materials in the textbook (which could have been highlighted in the editing sequence) as the main topic to learn, or regarded the goal as giving students the ability to solve exercises in the textbook. It turned out that the pre-service teachers had a low level of knowledge of their students. It is recommended that they should make use of the materials given (such as data related to the misconception of students) during the training session. The knowledge of teaching and evaluating students was described superficially by the pre-service teachers; they merely mentioned the applications of models, such as the cyclic model and discovery learning, rather than thinking of a method related to the goals, or listed general assessment methods.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.651-660
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• 2015

This study was conducted to consider application methods of infographic that corresponds to the educational goals of English subject, which is applied with different teaching and learning standards than other subjects. The aim of this study is to analyze the types and the characteristics of 'infographic completed by know-how learning', in other words, 'User behaviors involved infographic', which is frequently used in English textbook. Based on an analysis according to the teaching and learning standards, infographic used in English textbook were suggested in three types, which are 'General Concept', 'Significance' and 'Signification' centered infographic. In addition, according to the level of diagram composition, the main visualization attributes were derived as 'Overview', 'Structure', 'Relationships', 'Sequence', 'Transition between states' and 'Messages'. The major findings of this study are as follows: First, it is necessary to conduct a study on diverse display methods for 'Signification-centered infographic' that need to be displayed on the basis of two or more visual attributes. Second, as the purpose of application for applying infographic in English textbook collides with that in information design fields, it is found that verification is required on the educational effects in relation to this aspect.