• Journal of Chest Surgery
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• v.21 no.4
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• pp.727-733
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• 1988

Two cases of the discrete membranous subaortic stenosis were experienced at the Department of Thoracic & Cardiovascular Surgery, National Medical Center, Seoul, Korea. Case I was 31 years old male with a history of aortic valve replacement[Ionescu-Shiley, 19mm] at the other hospital in 1980. Heart failure was noticed 6 years later. On cardiac catheterization, pressure gradient between left ventricle 4 aorta was 104 mmHg, but subvalvular aortic stenosis was not detected by preoperative 2-D echo <% left ventriculogram. Above case revealed stenoinsufficiency of the prosthetic valve. Under the diagnosis of the prosthetic valve failure, re-do aortic valve replacement[Bjork-Shiley, 23 mm] was done. During operation, the discrete membranous subaortic stenosis was incidentally found, and it was completely resected. So we thought that above discrete membranous subaortic stenosis was not detected at first operation, and it was progressed during 6 years, and accelerated the degeneration of the prosthetic valve. Case II was 20 years old female. Her complaints were exertional dyspnea, angina, syncope, which were aggravated since 5 years ago. 2-D echo <% left ventriculogram revealed the discrete membranous subaortic stenosis. Pressure gradient was 20 mmHg, but her symptoms were serious. Associated cardiac anomaly was the persistent left superior vena cava without connection with right superior vena cava. Complete excision of the membranous tissue was done. Post-operative pressure gradient between left ventricle & aorta was absent, and her complaints were nearly subsided. Both cases were type I according to the Newfeld classification of the discrete subvalvular aortic stenosis, and complete excision of the membranous tissue was done without myotomy or mymectomy. And short-term follow-up results[Case I:2 years, Case II: 1 ~ years] were good except soft systolic murmur[grade II/VI] at the aortic area in both cases.

• Journal of Korea Water Resources Association
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• v.49 no.10
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• pp.877-885
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• 2016

In this study, the Standard Precipitation Index(SPI), meteorological drought index, was used to evaluate the temporal and spatial assessment of drought forecasting results for all cross Korea. For the drought forecasting, the Multi Layer Perceptron-Artificial Neural Network (MLP-ANN) was selected and the drought forecasting was performed according to different forecasting lead time for SPI (3) and SPI (6). The precipitation data observed in 59 gaging stations of Korea Meteorological Adminstration (KMA) from 1976~2015. For the performance evaluation of the drought forecasting, the binary classification confusion matrix, such as evaluating the status of drought occurrence based on threshold, was constituted. Then Receiver Operating Characteristics (ROC) score and F score according to conditional probability are computed. As a result of ROC analysis on forecasting performance, drought forecasting performance, of applying the MLP-ANN model, shows satisfactory forecasting results. Consequently, two-month and five-month leading forecasts were possible for SPI (3) and SPI (6), respectively.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.53-57
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• 2013

This study was performed to examine the possibility of water extracts for several medicinal plants, such as Amomum tsao-ko, Alpinia oxyphylla, and Citrus unshiu, as an active packaging ingredient for prevention of lipid oxidation. Chicken breast meats were packed with medicinal plant extracts incorporated carrageenan based films and their physico-chemical and microbial properties during storage at $5^{\circ}C$ were investigated. In chicken meat samples packed with A. tsao-ko (TF) or A. oxyphylla (OF) extract incorporated carrageenan based films, pH value, thiobarbituric acid reactive substances (TBARS), and the population of total microbes were significantly lower than those of the negative control (film of no extract was incorporated, CF) after 5 d of storage (p<0.05). Especially, TBARS value of TF ($0.12{\pm}0.01$ mg malonaldehyde/kg meat) was significantly lower than chicken meat samples packed with positive control (ascorbic acid incorporated film, AF, $0.16{\pm}0.01$ mg malonaldehyde/kg meat) at 3 d of storage, and it means TF has enough antioxidative activity to prevent the lipid oxidation of chicken meat. However, there was no consistent effect on VBN values of chicken meats packed with medicinal plant extracts incorporated films during storage. Based on the obtained results, it is considered that A. tsao-ko extract has potential for being used as a natural antioxidant ingredient in active packaging areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4161-4166
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• 2010

This study was to examine the effectiveness of neurofeedback training by observing the pre and post brainwave measurement results of about 52 (experimental group 26. comparative group 26) subjects who have shown self regulation ability. The study took place at neuro-training center B, in between the months of Jan. 2008 and Dec. 2008. As the brainwaves are adjusted by timeseries linear analysis, the tool used to measure the self regulation ability was 5 Likert Scale questionnaire. The result confirmed the differences of both self regulation quotient, training protocol, upper deviation and questionnaire. The result of the study suggest prefrontal lobe neurofeedback technique's possibility in positively affecting the subjects' self regulation ability. This result suggested that follow-up researches should be figuring out more detailed explanations for journal of adolescent welfare.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.55-63
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• 2001

Populus euramericana and Betula platyphylla var. japonica have been identified as possible species for use for phytoremediation of landfills. To identify the effects of waste leachate on growth and physiological characteristics in Populus euramericana and Betula platyphylla var. japonica, four different treatments were applied to seedlings for 3 months: leachate solution(100% leachate), 50% dilution(50% leachate: 50% water, v/v), 75% dilution(25% leachate: 75% water, v/v) and control(tab water) were applied to these two species. Treatment with waste leachate significantly stimulated both Populus euramericana and Betula platyphylla var. japonica height, diameter at root collar and biomass production relative to the water control. Chlorophyll contents, photosynthesis and transpiration of leachate irrigated-trees were significantly higher than those of water control. These results suggested that these two species could be suitable species for phytoremediation in landfills because these species showed good growth performance and were capable of taking up waste leachate.

• Progress in Medical Physics
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• v.29 no.4
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• pp.150-156
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• 2018

This study aims to develop an improved Feldkamp-Davis-Kress (FDK) reconstruction algorithm using anisotropic total variation (ATV) minimization to enhance the image quality of low-dose cone-beam computed tomography (CBCT). The algorithm first applies a filter that integrates the Shepp-Logan filter into a cosine window function on all projections for impulse noise removal. A total variation objective function with anisotropic penalty is then minimized to enhance the difference between the real structure and noise using the steepest gradient descent optimization with adaptive step sizes. The preserving parameter to adjust the separation between the noise-free and noisy areas is determined by calculating the cumulative distribution function of the gradient magnitude of the filtered image obtained by the application of the filtering operation on each projection. With these minimized ATV projections, voxel-driven backprojection is finally performed to generate the reconstructed images. The performance of the proposed algorithm was evaluated with the catphan503 phantom dataset acquired with the use of a low-dose protocol. Qualitative and quantitative analyses showed that the proposed ATV minimization provides enhanced CBCT reconstruction images compared with those generated by the conventional FDK algorithm, with a higher contrast-to-noise ratio (CNR), lower root-mean-square-error, and higher correlation. The proposed algorithm not only leads to a potential imaging dose reduction in repeated CBCT scans via lower mA levels, but also elicits high CNR values by removing noisy corrupted areas and by avoiding the heavy penalization of striking features.

• Journal of radiological science and technology
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• v.42 no.4
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• pp.271-277
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• 2019

CareDose 4D which is the Siemens's Automatic Exposure Control (AEC) can adjust the level of radiation dose distribution which is based on organ characteristic unlike other manufacturer's AEC. Currently, a wide scan range containing different organs is sometimes examined at once (defined as one scan). The purpose of this study was to figure out which organ characteristic option is suitable when one scan method is utilized. Two types of anthropomorphic phantoms were scanned in the same range which were from frontal bone to carina level according to three different organ characteristics such as Thorax, Abdomen, and Neck. All scans and image reconstruction parameters were equally applied and radiation dose were compared. Radiation dose with Thorax organ characteristic was lower than that with Neck. Also, that with Abdomen oran characteristic was lower than Thorax. There were significant differences in radiation dose according to different organ characteristics at the same parameters (P<0.05). Usage of Neck organ characteristic had a result of the highest radiation dose to all phantom. On the other hand, utilization of Abdomen organ characteristic showed the lowest radiation dose. As a result, it is desirable to set appropriate organ characteristic according to examined body part when you checkup patients. Also, when you implement one scan method, selection of Abdomen-based organ characteristic has reduced more radiation dose compared with two different organ characteristic.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.195-200
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• 2019

The purpose of this study is to analyze the characteristics of National Health Insurance claim data and to construct a pilot medical episode data considering it. In this study, the trends of respiratory disease (ICD10: J00-J99) cardiovascular disease (ICD10: I00-I99) from the day of onset of treatment to re-admission after admission were confirmed in Seoul, and the largest decrease was observed when the no-treatment period was 0 day. The data reduction rate when the no-treatment period is 0 day is judged to be due to the monthly separation claim of the health insurance claim data. Also, the result that there is a tendency of monthly separation request according to the type of medical treatment. Through this study, we constructed epidemic data for the pilot medical treatment considering the characteristics of the claim data of health insurance, and based on this, it can be used as a data processing method for calculating basic epidemiological information.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.188-193
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• 2019

Objective: The aim of this finite element study was to clarify the mechanics of tooth movement in palatal en-masse retraction of segmented maxillary anterior teeth by using anchor screws and lever arms. Methods: A three-dimensional finite element method was used to simulate overall orthodontic tooth movements. The line of action of the force was varied by changing both the lever arm height and anchor screw position. Results: When the line of action of the force passed through the center of resistance (CR), the anterior teeth showed translation. However, when the line of action was not perpendicular to the long axis of the anterior teeth, the anterior teeth moved bodily with an unexpected intrusion even though the force was transmitted horizontally. To move the anterior teeth bodily without intrusion and extrusion, a downward force passing through the CR was necessary. When the line of action of the force passed apical to the CR, the anterior teeth tipped counterclockwise during retraction, and when the line of action of the force passed coronal to the CR, the anterior teeth tipped clockwise during retraction. Conclusions: The movement pattern of the anterior teeth changed depending on the combination of lever arm height and anchor screw position. However, this pattern may be unpredictable in clinical settings because the movement direction is not always equal to the force direction.

• Korea Journal of Hospital Management
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• v.25 no.4
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• pp.13-28
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• 2020

Purposes: The purpose of this study is to analyze the institutional and personal factors that affect the medical utilization of patients transferred to tertiary medical institutions. Methodology: We retrospectively analyzed the 2 weeks electronic medical records of 1,556 patients, who were referred to the tertiary hospital, from June 15 to 26, 2015. The patient's personal characteristics, referral hospital, referral path, medical experiences and expenses were analyzed for 6 months after the patient's first visit. Findings: The largest proportion (848; 54.5%) of referrals was referred from primary clinic but the referrals of the same tertiary hospital level were one in seven (228; 14.7%) of the patients. Most patients (1,401; 90%) were referred from the clinics and hospitals directly and only one in ten (155; 10%) of the patients utilized the medical referral center. Patients who had been referred from tertiary care institutions had significantly higher medical costs than those referred to primary care (7,560,000 vs 2,333,000 won). The institutional factors including the numbers of visits to outpatient clinic, previous history of hospitalization and operation, consultation to other medical departments and hospitalization fee significantly influenced on medical utility pattern. Personal factors including patient's medical diagnosis and department of disease have a highly correlation with patient's referrals. Practical implications: The medical utilization of medical expenses and experiences is influenced by institutional and individual factors, and it is important to establish a referral system considering the institutional factors of the type of referral hospital.