• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.275-284
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• 2008

Purpose: We intended to evaluate myocardial oxygen consumption ($MVO_2)$ by applying recirculation correction and modified one-compartment model to have a reference range of $MVO_2$ in normal young population and to reveal the effect of recirculation on time-activity curve (TAC). Materials and Methods: In nine normal male volunteers with mean age of $26.3{\pm}4.0$, $MVO_2$ was estimated with 925 MBq (25mCi) of $^{11}C$-Acetate (Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea) and PET/CT (Biograph 6, Siemens Medical Solution, Germany). Analysis software such as $MATLAB^{(R)}$ v7.1 (Mathworks, Inc., United States), $Excel^{(R)}$ 2007 (Microsoft, United States), and $SPSS^{(R)}$ v12.0 (Apache Software Foundation, United States) were used. Twenty three frames were of $12{\times}10$, $5{\times}60$, $3{\times}120$, $2{\times}300's$ duration, respectively. The modified one-compartmental model and the recirculation correction method were applied. Statistical analysis was performed by using Test of Normality, ANOVA and Post-Hoc (Scheffe's) analysis, and p-value less than 0.05 was considered as significant. Results: The normal reference ranges of $MVO_2$ were presented as $3.18-4.64\;{\times}\;10^{-4}\;ml/g/sec$, $1.91-3.94\;{\times}\;10^{-4}\;ml/g/sec$, $4.31-6.40\;{\times}\;10^{-4}\;ml/g/sec$, $2.84-4.53\;{\times}\;10^{-4}\;ml/g/sec$ and $3.42-5.00\;{\times}\;10^{-4}\;ml/g/sec$ in the septum, the inferior wall, the lateral wall, the anterior wall and the entire wall, respectively. In addition, it was noted that the dual exponentiality of the clearance curve is due to the recirculation effect and that the characteristic of the curve is essentially mono-exponential. Conclusion: $^{11}C$-Acetate is a radiotracer worthwhile to assess $MVO_2$. Re-circulated $^{11}C$ can influence TAC of $^{11}C$ in myocadia and so the recirculation correction must be considered when measuring $MVO_2$.

• Anxiety and mood
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• v.7 no.1
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• pp.48-53
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• 2011

Objective : Korean Version of Beck-II Depression Inventory to verify the reliability and validity of the proposed standards are practical and standardized, cut-off score by establishing a baseline indicating the presence of depression and depression On in the evaluation was to evaluate the clinical usefulness. Methods : 739 patients with major depression using the SCID and normal controls were 302 study subjects. Of patients with clinically significant medical condition, or psychotic disorders, organic mental disorder, epilepsy or seizure disorder, eating disorders are associated with patients taking anti-convulsants experienced in the past, patients were excluded from the study. Results : The main findings of this study were as follows. First, with respect to the KBDI-II items, the correlation between them ranged from 0.51 to 0.74, and was 0.60 over all questions. Further, the overall correlation of the KBDI-II plates showing confidence 'normal' than it was verified that. Second, the BDIII was used in each group to examine internal consistency and thus, whether Cronbach's alpha values were greater than 0.94. Third, the principal component analysis sought to extract factors in a way consistent with the results inspected last 3 factors were extracted and the total variance explained was 47.3%. Fourth, the Cutting calculated the score on the KBDI-II for ROC (Receiver operator characteristic) analysis yielding 18 dot, with the highest sensitivity and specificity was seen. Conclusion : Based on the results of this Study, the KBDI-II cut-off point should be valid as prescribed in 18 is considered.

• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.65-75
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• 2021

Coin cell is a basic testing platform for battery research, discovering new materials and concepts, and contributing to fundamental research on next-generation batteries. Li metal batteries (LMBs) are promising since a high energy density (~500 Wh kg^-1) is deliverable far beyond Li-ion. However, Li dendrite-triggered volume fluctuation and high surface cause severe deterioration of performance. Given that such drawbacks are strongly dependent on the cell parameters and structure, such as the amount of electrolyte, Li thickness, and internal pressure, reliable Li metal coin cell testing is challenging. For the LMB-specialized coin cell testing platform, this study suggests the optimal coin cell structure that secures performance and reproducibility of LMBs under stringent conditions, such as lean electrolyte, high mass loading of NMC cathode, and thinner Li use. By controlling the cathode/anode (C/A) area ratio closer to 1.0, the inactive space was minimized, mitigating the cell degradation. The quantification and imaging of inner cell pressure elucidated that the uniformity of the pressure is a crucial matter to improving performance reliability. The LMB coin cells exhibit better cycling retention and reproducibility under higher (0.6 MPa → 2.13 MPa) and uniform (standard deviation: 0.43 → 0.16) stack pressure through the changes in internal parts and introducing a flexible polymer (PDMS) film.

• Journal of the International Relations & Interdisciplinary Education
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• v.3 no.1
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• pp.1-28
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• 2023

This study was conducted to examine the quantitative trend of domestic studies in invention gifted education, identify the intrinsic meaning and connection attributes in these research analysis, and provide basic data to explore future development plans. To this end, 97 domestic academic papers were finally selected as "Invention Gifted Education" by the Korea Research and Information Service (RISS), technical statistical analysis was conducted with SPSS on publication year, author composition, researcher's affiliation and location area, and published journal. The trend, which had been on the rise since 2007, confirmed by academic papers on gifted education in invention, peaked at the time of the 3rd comprehensive plan for gifted education and has since declined again. As a result of technical statistical analysis of the author's characteristics, half of the papers were jointly published, followed by a number of independent authors. The papers published alone were identified as belonging to universities, research institutes, elementary schools, and middle schools, and the cooperative papers were many studies cooperated with young researchers and professional researchers, and only one collaborative study was conducted between young researchers. When looking at the regions and journals in which the Invention Gifted Education thesis was published, it was concentrated in some regions or journals, and the deviation was very large. As a result of language network analysis using academic paper keywords, creativity and programs were identified as meaningful keywords that showed top appearance, and the keyword pair with high co-appearance was invention gifted-creativity. The keyword of connection-centeredness at the top served as an intermediary for creativity, problem-solving, development, and company to expand to other research topics, and served as a research topic that could be expanded to various topics. In the case of mediation-centeredness, creativity, programs, and effects showed high mediation-centeredness, indicating that it is an important keyword that plays a role in mediating or mediating other keywords. Through these research results, national policy measures need to be prepared for the development of gifted education, and the need to create an invention ecological culture that can enhance teachers' expertise while increasing social responsibility for gifted education.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.186-200
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• 2023

This study aims to improve the usability of the white cane, which is walking equipment that most local visually impaired people use and carry when going out, and to contribute to the prevention of safety accidents and the walking rights of visually impaired people by providing improvement and resolution measures for the problems identified. Also, this study is a study on the visually impaired, primarily targeting the 1st to 2nd degree visually impaired people, who cannot go out on their own without walking equipment such as a white cane, corresponding to 20% among approximately 250,000 blind and low vision people in the Korean population. In the study process, the concept has been developed from the user's point of view in order that the white cane becomes a real help in the walking step of the visually impaired and the improvement of usability of the white cane, the main walking equipment for the visually impaired, are done by problem identification through the Double Diamond Model of Design Thinking (Empathize → Define → Ideate → Prototype → Test (verify)). As a result of the investigation in the process of Empathy, a total of five issues was synthesized, including an increase in the proportion of the visually impaired people, an insufficient workforce situation to help all the visually impaired, an improvement and advancement of assistive devices essential for the visually impaired, problems of damage, illegal occupation, demolition, maintenance about braille blocks, making braille block paradigms for the visually impaired and for everyone. In Ideate and Prototype steps, situations derived from brainstorming were grouped and the relationship were made through the KJ method, and specific situations and major causes were organized to establish the direction of the concept. The derived solutions and major functions are defined in four categories, and representative situations requiring solutions and major functions are organized into two user scenarios. Ideas were visualized by arranging the virtual Persona and Customer Journey Map according to the situation and producing a prototype through 3D modeling. Finally, in the evaluation, the final concept derived is a device such a smart cane for guidance for the visually impaired as ① a smart cane emphasizing portability + ② compatibility with other electronic devices + ③ a product with safety and convenience.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.185-196
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• 2023

Purpose This study aimed to investigate radiomics analysis of ultrasonographic images to develop a potential biomarker for predicting lymph node metastasis in papillary thyroid carcinoma (PTC) patients. Materials and Methods This study included 431 PTC patients from August 2013 to May 2014 and classified them into the training and validation sets. A total of 730 radiomics features, including texture matrices of gray-level co-occurrence matrix and gray-level run-length matrix and single-level discrete two-dimensional wavelet transform and other functions, were obtained. The least absolute shrinkage and selection operator method was used for selecting the most predictive features in the training data set. Results Lymph node metastasis was associated with the radiomics score (p < 0.001). It was also associated with other clinical variables such as young age (p = 0.007) and large tumor size (p = 0.007). The area under the receiver operating characteristic curve was 0.687 (95% confidence interval: 0.616-0.759) for the training set and 0.650 (95% confidence interval: 0.575-0.726) for the validation set. Conclusion This study showed the potential of ultrasonography-based radiomics to predict cervical lymph node metastasis in patients with PTC; thus, ultrasonography-based radiomics can act as a biomarker for PTC.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.123-138
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• 2017

Since the stock market is driven by the expectation of traders, studies have been conducted to predict stock price movements through analysis of various sources of text data. In order to predict stock price movements, research has been conducted not only on the relationship between text data and fluctuations in stock prices, but also on the trading stocks based on news articles and social media responses. Studies that predict the movements of stock prices have also applied classification algorithms with constructing term-document matrix in the same way as other text mining approaches. Because the document contains a lot of words, it is better to select words that contribute more for building a term-document matrix. Based on the frequency of words, words that show too little frequency or importance are removed. It also selects words according to their contribution by measuring the degree to which a word contributes to correctly classifying a document. The basic idea of constructing a term-document matrix was to collect all the documents to be analyzed and to select and use the words that have an influence on the classification. In this study, we analyze the documents for each individual item and select the words that are irrelevant for all categories as neutral words. We extract the words around the selected neutral word and use it to generate the term-document matrix. The neutral word itself starts with the idea that the stock movement is less related to the existence of the neutral words, and that the surrounding words of the neutral word are more likely to affect the stock price movements. And apply it to the algorithm that classifies the stock price fluctuations with the generated term-document matrix. In this study, we firstly removed stop words and selected neutral words for each stock. And we used a method to exclude words that are included in news articles for other stocks among the selected words. Through the online news portal, we collected four months of news articles on the top 10 market cap stocks. We split the news articles into 3 month news data as training data and apply the remaining one month news articles to the model to predict the stock price movements of the next day. We used SVM, Boosting and Random Forest for building models and predicting the movements of stock prices. The stock market opened for four months (2016/02/01 ~ 2016/05/31) for a total of 80 days, using the initial 60 days as a training set and the remaining 20 days as a test set. The proposed word - based algorithm in this study showed better classification performance than the word selection method based on sparsity. This study predicted stock price volatility by collecting and analyzing news articles of the top 10 stocks in market cap. We used the term - document matrix based classification model to estimate the stock price fluctuations and compared the performance of the existing sparse - based word extraction method and the suggested method of removing words from the term - document matrix. The suggested method differs from the word extraction method in that it uses not only the news articles for the corresponding stock but also other news items to determine the words to extract. In other words, it removed not only the words that appeared in all the increase and decrease but also the words that appeared common in the news for other stocks. When the prediction accuracy was compared, the suggested method showed higher accuracy. The limitation of this study is that the stock price prediction was set up to classify the rise and fall, and the experiment was conducted only for the top ten stocks. The 10 stocks used in the experiment do not represent the entire stock market. In addition, it is difficult to show the investment performance because stock price fluctuation and profit rate may be different. Therefore, it is necessary to study the research using more stocks and the yield prediction through trading simulation.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.558-570
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• 1996

Background : The detection of Collapsible airways has important therapeutic implications in chronic airway disease and bronchial asthma. The distinction of a purely collapsible airways disease from that of asthma is important because the treatment of the dormer may include the use of pursed lip breathing or nasal positive pressure ventilation whereas in the latter, pharmacologic approaches are used. One form of irreversible airflow limitation is collapsible airways, which has been shown to be a Component of asthma or to emphysema, it can be assessed by the volume difference between what exits the lung as determined by a spirometer and the volume compressed as measured by the plethysmography. Method : To investigate whether volume difference between slow and forced vital Capacity(SVC-FVC) by spirometry may be used as a surrogate index of airway collapse, we examined pulmonary function parameters before and after bronchodilator agent inhalation by spirometry and body plethysmography in 20 cases of patients with evidence of airflow limitation(chronic obstructive pulmonary disease 12 cases, stable bronchial asthma 7 cases, combined chronic obstructive pulmonary disease with asthma 1 case) and 20 cases of normal subjects without evidence of airflow limitation referred to the Pusan National University Hospital pulmonary function laboratory from January 1995 to July 1995 prospectively. Results : 1) Average and standard deviation of age, height, weight of patients with airflow limitation was $58.3{\pm}7.24$(yr), $166{\pm}8.0$(cm), $59.0{\pm}9.9$(kg) and those of normal subjects was $56.3{\pm}12.47$(yr), $165.9{\pm}6.9$(cm), $64.4{\pm}10.4$(kg), respectively. The differences of physical characteristics of both group were not significant statistically and male to female ratio was 14:6 in both groups. 2) The difference between slow vital capacity and forced vital capacity was $395{\pm}317ml$ in patients group and $154{\pm}176ml$ in normal group and there was statistically significance between two groups(p<0.05). Sensitivity and specificity were most higher when the cut-off value was 208ml. 3) After bronchodilator inhalation, reversible airway obstructions were shown in 16 cases of patients group, 7 cases of control group(p<0.05) by spirometry or body plethysmography d the differences of slow vital capacity and forced vital capacity in bronchodilator response group and nonresponse group were $300.4{\pm}306ml$, $144.7{\pm}180ml$ and this difference was statistically significant. 4) The difference between slow vital capacity and forced vital capacity before bronchodilator inhalation was correlated with airway resistance before bronchodilator(r=0.307 p=0.05), and the difference between slow vital capacity and forced vital capacity after bronchodilator was correlated with difference between slow vital capacity and forced vital capacity(r=0.559 p=0.0002), thoracic gas volume(r=0.488 p=0.002) before bronchodilator and airway resistance(r=0.583 p=0.0001), thoracic gas volume(r=0.375 p=0.0170) after bronchodilator, respectively. 5) The difference between slow vital capacity and forced vital capacity in smokers and nonsmokers was $257.5{\pm}303ml$, $277.5{\pm}276ml$, respectively and this difference did not reach statistical significance(p>0.05). Conclusion : The difference between slow vital capacity and forced vital capacity by spirometry may be useful for the detection of collapsible airway and may help decision making of therapeutic plans.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.1
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• pp.87-102
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• 1999

Objectives : The purposes of this study were to estimate the prevalence rate of eating disorders in Korean males and to clarify their characteristics in sociodemograhic data, the eating traits, and general psychopathology through the comparison with those of female high scored group on the Korean version of Eating Attitudes Test-26(KEAT-26). Methods : Using a multi-stage questionnaire sampling method including area sampling, proportionated stratified sampling, and quota sampling, we surveyed a total of 4,400 Korean adults over 18 in a nationwide area(9 kus, 10 middle or small cities, and 17 kuns), obtaining usable responses on 3,896. Of the 3,062 subjects(1249 males and 1813 females) who were available for analysis, we ascertained 52 males and 208 females who had high score($\geq$ cutoff point 21) on the KEAT-26. Results : 1) The proportion of this high score group was 1.7% in male and 6.8% in female with a sex ratio(male versus female) of 1 : 4. 2) The mean age was higher in the male group than in the female group, although it was not statistically significant(p=0.0514). Mean Body Mass Index(BMI) of the male group was significantly higher than that of female group, and the number of male subjects with below 20 of BMI was also significantly lower than in the female group. 3) There were no significant difference in past history of physical illness between two groups. However, frequency of smoking and alcohol use, and mean amount of alcohol consumption per month were significantly higher in the male group than in the female group. There were no significant differences between the two groups on various socio-demographic correlates such as economic status, total duration of education, number of family, marital status, religious status, and area of residence, but the exception of being occupational status. 4) The 'Eating Habits Scale' score and score of 'preference for vegetables and fish, and dislike for sweet-tasting food' of the male group were significantly lower than those of the female group. Although there was no significant difference between the two groups in total scores of the KEAT-26, the mean score on 'pursuit of thinness' subscale was higher in the female group than in the male group, while scores of 'food preoccupation' and 'self-control' subscales were higher in the male group than in the female group. 5) Scores on 'psychoticism' was significantly higher in the male group than in the female group, although there were no significant differences between the two groups on 'locus of control for weight', 'depression' and 'hypochondriasis'. Conclusion : These results support a possibility of a high prevalence of eating disorders in Korean males. These results suggest that eating related characteristics of high scorer on the EAT are different by sex in spite of the same high score on the EAT, and also suggest that male patients with eating disorders have more serious personality pathology than female patients with eating disorders.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.2
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• pp.218-230
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• 2010

This study was conducted to survey isoflavone intake among adult women in menopause with diseases such as metabolic syndrome and osteoporosis and to analyze the relationship between each of these chronic diseases followed by isoflavone intake and the related health risk index. The average age of the subjects was 49.97 years old, while that of the pre-menopausal subjects was 45.14 years, and the post-menopausal subjects was 55.99 years. The average body mass index (BMI), waist-hip circumference, body fat percentage, blood pressure, blood sugar and blood lipid content of the post-menopausal subjects were higher in significant difference than those of the pre-menopausal subjects. The bone density of the hip and spine in post-menopausal subjects was lower in significant difference than that of the pre-menopausal subjects. After menopause, the subjects had a lower ratio of individuals at risk of anemia when compared with the subjects before menopause, but had higher health risk ratio related to each type of chronic disease, including obesity, hypertension, high cholesterol and osteoporosis than the subjects before menopause. The intake frequency of each soybean food was similar among subjects before/after menopause. The most common soybean based foods consumed by the subjects were soybean, soybean curd and soybean paste. The average daily intake level of isoflavone among subjects before menopause was 25.48 mg, while that of subjects after menopause was 32.25 mg. Evaluation of the distribution of the isoflavone level revealed that the pre-menopausal subjects consumed 3.29~78.36 mg and the post-menopausal subjects consumed 3.18~116.59 mg. The intake level by each individual varied greatly. The pre-menopausal subjects had a low BMI index and systolic blood pressure as much as their isoflavone intake level was high. Additionally, the post-menopausal subjects had a low menarche age and high menopause age when their isoflavone intake level was high, the BMI index and waist-hip circumference ratio was highest among individuals with lowest isoflavone intake level. This study showed that there was a possible relationship between soybean isoflavone intake and health problems such as obesity, high cholesterol, and osteoporosis in women after menopause with diseases such as metabolic syndrome and osteoporosis, even if this relationship was not great.