• Imaging Science in Dentistry
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• v.50 no.4
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• pp.309-318
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• 2020

Purpose: This study investigated correlations between findings on panoramic radiographs and cone-beam computed tomography (CBCT) to assess the relationship between the maxillary sinus floor and the roots of maxillary posterior teeth. In addition, radiographic signs indicating actual root protrusion into the maxillary sinus were evaluated on panoramic radiographs. Materials and Methods: Paired panoramic radiographs and CBCT images from 305 subjects were analyzed. This analysis classified 2,440 maxillary premolars and molars according to their relationship with the maxillary sinus floor on panoramic radiographs and CBCT images. In addition, interruption of the sinus floor was examined on panoramic radiographs. Results: Root protrusion into the maxillary sinus occurred most frequently in the mesiobuccal roots of the second molars. The classification according to panoramic radiographs and CBCT images was the same in more than 90% of cases when there was no contact between the root apex and the sinus floor. When the panoramic radiograph showed root protrusion into the sinus, the CBCT images showed the same classification in 67.5% of second molars, 48.8% of first molars, and 53.3% of second premolars. There was a statistically significant relationship between interruption of the sinus floor on panoramic radiographs and root protrusion into the sinus on CBCT images. Conclusion: The presence of root protrusion into the sinus on panoramic radiographs demonstrated a moderate ability to predict root protrusion into the maxillary sinus. Interruption of the maxillary sinus floor could be considered an indicator of actual root protrusion into the maxillary sinus.

• Health Policy and Management
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• v.32 no.2
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• pp.154-163
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• 2022

Background: The costliness index (CI) is an index that is used in various ways to improve the quality of medical care and the management of appropriate treatment in medical institutions. However, the current calculation method for CI has a limitation in reflecting the actual medical cost of the patient unit because the outpatient and inpatient costs are evaluated separately. It is desirable to calculate the CI by integrating the medical cost into the episode unit. Methods: We developed an episode-based CI method using the episode classification system of the Centers for Medicare and Medicaid Services to the National Inpatient Sample data in Korea, which can integrate the admission and ambulatory care cost to episode unit. Additionally, we compared our new method with the previous method. Results: In some episodes, the correlation between previous and episode-based CI was low, and the proportion of outpatient treatment costs in total cost and readmission rates are high. As a result of regression analysis, it is possible that the level of total medical costs of the patient unit in low volume medical institute and rural area has been underestimated. Conclusion: High proportion of outpatient treatment cost in total medical cost means that some medical institutions may have provided medical services in the ambulatory care that are ancillary to inpatient treatment. In addition, a high readmission rate indicates insufficient treatment service for inpatients, which means that previous CI may not accurately reflect actual patient-based treatment costs. Therefore, an integrated patient-unit classification system which can be used as a more effective CI indicator is needed.

• Health Policy and Management
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• v.32 no.2
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• pp.125-136
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• 2022

The costliness index (CI) is an index that is used in various ways to improve the quality of medical care and the management of appropriate treatment in medical institutions. However, the current calculation method for CI has a limitation in reflecting the actual medical cost of the patient unit because the outpatient and inpatient costs are evaluated separately. It is desirable to calculate the CI by integrating the medical cost into the episode unit. We developed an episode-based CI method using the episode classification system of the Centers for Medicare and Medicaid Services to the National Inpatient Sample data in Korea, which can integrate the admission and ambulatory care cost to episode unit. Additionally, we compared our new method with the previous method. In some episodes, the correlation between previous and episode-based CI was low, and the proportion of outpatient treatment costs in total cost and readmission rates are high. As a result of regression analysis, it is possible that the level of total medical costs of the patient unit in low volume medical institute and rural area has been underestimated. High proportion of outpatient treatment cost in total medical cost means that some medical institutions may have provided medical services in the ambulatory care that are ancillary to inpatient treatment. In addition, a high readmission rate indicates insufficient treatment service for inpatients, which means that previous CI may not accurately reflect actual patient-based treatment costs. Therefore, an integrated patient-unit classification system which can be used as a more effective CI indicator is needed.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.407-412
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• 2022

Cerebral aneurysm coil embolization has the advantages of accurate, low patient burden, and fast recovery time, but efforts are needed to reduce dose due to the burden of exposure radiation dose during interventional procedures. In this study, the area dose product(DAP/Gy·cm²) and fluoro time(min) according to the size of the aneurysm and the location of aneurysm were investigated according to insurance recognition regulations aneurysm classification cerebral aneurysm coil embolization. According to the research method, classification according to the size and location of the aneurysm is first, the size of the aneurysm is divided into less than 4mm, more than 4mm to less than 8mm, and more than 8mm, and second, the dose to the area based on the location site (DAP/Gy·cm²) and fluoro time(min) based on the location site were observed. As a result, the location of the cerebral aneurysm procedure was found to be the Paraclinoid site. During cerebral aneurysm coil embolization, the area dose was 107 Gy·cm² and fluoro time was 47.41 minutes, showing lower results than domestic studies, and when comparing the area dose product with foreign studies, the area dose product results were similar to that of Turkey and Saudi Arabia. It is expected that it can be used as an objective analysis indicator to establish diagnostic reference levels (DRLs) and patient radiation defense guidelines according to the size of cerebral aneurysm and location of cerebral aneurysm procedures during interventional procedures.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.3
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• pp.209-220
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• 2022

Objectives: This study was performed to suggest how to re-establish criterion for toxic substances under the Chemical Control Act (CCA) in South Korea by comparing the GHS (Globally Harmonized System of Classification and Labeling of Chemicals) score and toxic properties. Methods: Toxic substances were classified into seven groups (Acute toxicity (1A), Chronic toxicity (2C), Environmental hazards (3E), Acute toxicity & chronic toxicity (4AC), Chronic toxicity & environmental hazards (5CE), Acute toxicity & environmental hazards (6AE), and Acute toxicity & chronic toxicity & environmental hazards (7ACE)) according to their toxic properties. The GHS score was calculated to sum up five toxicity indicators (health acute toxicity, health repeated toxicity, carcinogenicity, health other chronic toxicity and environmental hazards). Results: The GHS score of 7ACE was higher by 7 times that of 1A. 1A is the only group which has lower than the total GHS score. The highest score was 47, for sodium chromate (CAS no. 7775-11-3), which belongs to group 7ACE. This is classified as acute toxicity, carcinogenicity, germ cell mutagenicity, reproductive toxicity, and acute and chronic environmental hazard. On the other hand, the lowest score was 2.75, which was assigned to 177 chemicals belonging to group 1A. When the health acute toxicity indicator was omitted from the toxic criterion, toxic substances could be divided into the sub-groups 'human chronic hazards group' (HCG) and 'environmental hazards group' (EG) according to their GHS score and properties. Conclusions: The proposed criterion for toxic substances is to establish sub-groups defined as HCG and EG for separate control and that the 1A group be moved to substances requiring preparation for accidents under the CCA.

• Journal of The Geomorphological Association of Korea
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• v.17 no.3
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• pp.1-16
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• 2010

Phytoliths, silica microfossil that produced within and between cells and tissues of plants are especially yielded in Gramineae with many different forms and can attribute to the reconstruction of climatic and environmental changes and agriculture activity of the Quaternary. The phytoliths in soil can remain for long periods of time, because of strong resistance to physical and chemical weathering. The spatial range of study is too small due to deposition of phytoliths directly to the soil. There are difficulties of phytoliths identification because of multiplicity and redundancy, so far uniform and exact classification scheme has not been adopted. Therefore we attempted phytolith classification system applied to Korea. The paleoenvironmental reconstruction research using phytholith are applicated in many parts of studies. Also high-resolution paleoclimatic reconstruction expected to be possible using phytolith indices of Iph and Ic as well as climatic indicator of phytolith morphology.

• Korean Institute of Interior Design Journal
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• v.23 no.2
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• pp.30-39
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• 2014

Korean society is running fast toward a super aging society. This means that new solutions for new problems of aged people are needed. An important area to prove is the aging-friendly neighborhood environments supporting casual contacts and meetings of old residents. This study attempts to suggest neighborhood design indicators which support casual contacts and meetings of old residents. The subjects were 24 professionals who had studied on housing environment for the elderly. They answered through the on-line questionnaire. The questionnaire consisted of items which evaluate the appropriateness of classification of neighborhood area and the indicators of each area using 5-points Likert scale. Also open questions asking adding or eliminating areas or indicator and other opinions were included. On the basis of these answers, the aging-friendly neighborhood design indicators supporting contacts and meetings of old residents was developed. They are consisted of 7 areas in neighborhood and 60 indicators. Those areas were semi-public residential area, commercial area, cultural & educational area, health & medical area, park & green area, walkway, and public traffic facilities. This would be used to design the neighborhood environments that are aging-friendly and facilitating casual contacts and meetings of all residents, especially old residents.

• Journal of Korean Society on Water Environment
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• v.35 no.6
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• pp.539-549
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• 2019

In 2016, Benthic Macroinvertebrates Streambed Index (BMSI) was proposed as an index to evaluate streams as benthic macroinvertebrate depending on the substrate type of streambed. However, orignal BMSI were selected without consideration of water quality. Analyzes without water quality do not constitute biological indices based solely on the substrate type of streambed. Therefore, in this study, the indicator value was improvement in consideration of water quality, and the distribution characteristics of benthic macroinvertebrates according to the substrate type of streambed were analyzed under relatively equal water quality conditions. We surveyed 20,155 sampling units in Korea from 2008 to 2018, and we re-estimated each lithophility of 191 taxa. As a result of estimating the streambed of each newly lithophilic value classification group considering the water quality, it was different from the original lithophilic value. Representative integer lithophilic values were newly calculated from 126 taxa among the 191 index taxa used in the analysis. The correlation between new constructed BMSI and community structure was compared and analyzed. It showed extreamely significance (p<0.001) in the dominance index, diversity index, abundance index, and evenness index of the community structure. Diversity index, abundance index, and evenness index showed positive correlation, and dominance index showed negative correlation. The correlation coefficient (r) was the highest in the richness index of about 0.664.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1760-1778
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• 2018

For image segmentation with intensity inhomogeneity, many region-based level set methods have been proposed. Some of them however can't get the relatively ideal segmentation results under the severe intensity inhomogeneity and weak edges, and without use of the image gradient information. To improve that, we propose a new level set method combined with local direction gradient in this paper. Firstly, based on two assumptions on intensity inhomogeneity to images, the relationships between segmentation objects and image gradients to local minimum and maximum around a pixel are presented, from which a new pixel classification method based on weight of Euclidian distance is introduced. Secondly, to implement the model, variational level set method combined with image spatial neighborhood information is used, which enhances the anti-noise capacity of the proposed gradient information based model. Thirdly, a new diffusion process with an edge indicator function is incorporated into the level set function to classify the pixels in homogeneous regions of the same segmentation object, and also to make the proposed method more insensitive to initial contours and stable numerical implementation. To verify our proposed method, different testing images including synthetic images, magnetic resonance imaging (MRI) and real-world images are introduced. The image segmentation results demonstrate that our method can deal with the relatively severe intensity inhomogeneity and obtain the comparatively ideal segmentation results efficiently.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.3
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• pp.41-48
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• 2020

The purpose of this research is to manage the physical sectors systematically, needed for the selection and direction of declining areas, such as urban regeneration and revitalization projects, by grading the density of decline indicators of buildings in small and medium cities. In five small and medium-sized cities in Jeollanam-do, the data were divided into three stages according to the density, according to the use, structure, and age of the building. Rating by element of Census Output Area, detailed designation, and management of declining areas in small and medium-sized cities are required, rather than setting the scope of declining areas based on administrative districts. It is also necessary to manage cities through complex and intra-element phasing rather than single elements in defining physical decline. The analysis based on the complex factors and boundary of the Census Output Area is meaningful in order to maintain and manage such cities in a more detailed and precise manner according to such characteristics of each region.