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Fertility Evaluation of Upland Fields by Combination of Landscape and Soil Survey Data with Chemical Properties in Soil (토양 화학성과 지형 및 토양 조사자료를 활용한 밭 토양의 비옥도 평가)

  • Hong, Soon-Dal;Kim, Jai-Joung;Min, Kyong-Beum;Kang, Bo-Goo;Kim, Hyun-Ju
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.4
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    • pp.221-233
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    • 2000
  • Evaluation method of soil fertility by application of geographic information system (GIS) which includes landscape characteristics and soil map data was investigated from productivities of red pepper and tobacco grown on the fields with no fertilization. Total 131 fields experiments, 64 fields of red pepper and 67 fields of tobacco were conducted from 22 and 23 fields for red pepper and tobacco, respectively, located at Cheangweon and Eumseong counties in 1996, from 20 and 25 fields at Boeun and Goesan counties in 1997, and 22 and 19 fields at Jincheon and Chungju counties in 1998. All the experimental sites were selected on the basis of wide range of distribution in landscape and soil attributes. Dry weights and nutrients (N, P and K) uptakes by red pepper plant and tobacco leaves were considered as basic fertility of the soil (BFS). The BFS was estimated by twenty-five independent variables including 13 chemical properties and 12 GIS data. Twenty-five independent variables were classified by two groups, 15 quantitative variables and 10 qualitative variables, and were analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Dry weight of red pepper (DWRP) and dry weight of tobacco leaves (DWTL) every year showed high variations by five times in difference plots with minimum yield and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including independent variables was better than that by simple regression showing gradual improvement by adding chemical properties, quantitative variables, and qualitative variables of the GIS. However the evaluation for the BFS by the MLR showed the better result for tobacco than red pepper. For example the variability in the DWTL by MLR was explained 34.2% by only chemical properties, 35.0% by adding quantitative variables, and 72.5% by adding both the quantitative and qualitative variables of the GIS compared with 21.7% by simple regression with $NO_3-N$ content in soil. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for upland field.

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Relationship between disk displacement of temporomandibular joint and dentofacial asymmetry (측두하악관절 원판 변위와 치열 및 안면부 비대칭의 관계에 대한 연구)

  • Nahm, Kyoung-Soo;Kim, Tae-Woo
    • The korean journal of orthodontics
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    • v.33 no.3 s.98
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    • pp.211-222
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    • 2003
  • The purpose of this study was to determine whether there is an association between disk displacement of the Temporomandibular Joint (TMJ) and dentofacial asymmetry In orthodontic patients. The subjects consisted of 60 female orthodontic patients between the ages of 18 and 38 years (mean age 23.3 years) who had visited the Department of Orthodontics at Seoul National University Dental Hospital from January 2000 to April 2002. On the basis of magnetic resonance imaging (MRI) of their bilateral TMJs, the subjects were divided Into four groups'. bilateral normal group (twenty-one persons); disk displacement of right TMJ group (six persons); disk displacement of left TMJ group (nine persons); and disk displacement of both TMJs group (twenty-four persons) Postero-anterior (PA) cephalograms and diagnostic models which had been taken before orthodontic treatment were measured. In the linear measurements, a line connecting the right and left Latero-Orbitale (Lo) represented the horizontal reference line (H). The vertical reference line (V) was constructed as a line bisecting and running perpendicular to H. One-way analysis of variance (ANOVA) was used to test whether the mean values of measurements between groups were significantly different. In addition, Bonferronil's multiple comparison test was performed at a level of 0.05. The results were as follows; 1 In the diagnostic model analysis, the overjet, nght molar relationship, and left molar relationship were significantly different among the four groups. 2. In the PA cephalometric analysis, differences in the right and left vertical position of the lower first molar and Ag were significantly dissimilar among the four groups. 3. If the disk displacement of TMJ was present on one side, the ipsilateral ramus was shorter, resulting in asymmetry in the vertical position of Ag. This study indicated that dentofacial asymmetry might be related to the disk displacement of TMJ.

Survey on the Foodborne Illness Experience and Awareness of Food Safety Practice Among Korean Consumers (식중독 경험 및 식품안전에 대한 인식 조사)

  • Park, Gyung-Jin;Chun, Seok-Jo;Park, Ki-Hwan;Hong, Chong-Hae;Kim, Jeong-Weon
    • Journal of Food Hygiene and Safety
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    • v.18 no.3
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    • pp.139-145
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    • 2003
  • The purpose of this study was to investigate the awareness and practice of Korean consumer on food safety. A telephone survey was conducted from 1,040 adults randomly selected from each province and large city of Korea. Therefore, 12.4% of the subjects experienced foodborne illness at least once a year and 0.3% was hospitalized due to the illness. General restaurant (37.2%) and home (21.2%) were the main causative place of foodborne illness, and the most frequently associated foods were meat and meat products (41.7%) and fish and fish products (18.7%). Regarding the causative agent of foodborne illness, the respsondents were aware of Cholera (75.5%), Vibrio gastroenteritis (73%), Shigellosis (65.5%), Bacillary dysentery (65.5%) and Salmonellosis (47.5%) very well; however very few were aware of Listeriosis (9.9%) and brucellosis (8.3%) and ever believed they were not food-related illness. When the survey data were analyzed based on 3 models (Model 1: Knowledge about the pathogens associated food and water, Model 2: The awareness of food safety, Model 3: Attitudes and behavior about foodborne disease prevention and measure) by Multiple regression analysis. The results showed that the awareness of the causative agent of foodborne illness was significantly related with the previous experience of foodborne illness (OR: 1.714) followed by education level (OR: 0.536) and married status (OR: 0.527). The awareness of food safety was significatly related with education level (OR: 0.702). Education (OR: 0.816) and gender (OR:0.650) were the main factors affecting the awareness of the practice to prevent foodborne illness. However, the previous experience of foodborne illness and food safety education, and the awareness of food safety did not show any correlation, suggesting that the experience and awareness of foodborne illness do not affect the real practice of food safety.

The Relationships between Dry Matter Yield and Days of Summer Depression in different Regions with Mixed Pasture (혼파초지에서 지역별 건물수량과 하고일수 간 관계)

  • Oh, Seung Min;Kim, Moonju;Peng, Jinglun;Lee, Bae Hun;Kim, Ji Yung;Chemere, Befekadu;Kim, Si Chul;Kim, Kyeong Dae;Kim, Byong Wan;Jo, Mu Hwan;Sung, Kyung Il
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.38 no.1
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    • pp.53-60
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    • 2018
  • Yield prediction model for mixed pasture was developed with a shortage that the relationship between dry matter yield (DMY) and days of summer depression (DSD) was not properly reflected in the model in the previous research. Therefore, this study was designed to eliminate the data of the regions with distinctly different climatic conditions and then investigate their relationships DMY and DSD using the data in each region separately of regions with distinct climatic characteristics and classify the data based on regions for further analysis based on the previous mixed pasture prediction model. The data set used in the research kept 582 data points from 11 regions and 41 mixed pasture types. The relationship between DMY and DSD in each region were analyzed through scatter plot, correlation analysis and multiple regression analysis in each region separately. In the statistical analysis, DMY was taken as the response variable and 5 climatic variables including DSD were taken as explanatory variables. The results of scatter plot showed that negative correlations between DMY and DSD were observed in 7 out of 9 regions. Therefore, it was confirmed that analyzing the relationship between DMY and DSD based on each region is necessary and 5 regions were selected (Hwaseong, Suwon, Daejeon, Siheung and Gwangju) since the data size in these regions is large enough to perform the further statistical analysis based on large sample approximation theory. Correlation analysis showed that negative correlations were found between DMY and DSD in 3 (Hwaseong, Suwon and Siheung) out of the 5 regions, meanwhile the negative relationship in Hwaseong was confirmed through multiple regression analysis. Therefore, it was concluded that the interpretability of the yield prediction model for mixed pasture could be improved based on constructing the models using the data from each region separately instead of using the pooled data from different regions.

Prediction of Correct Answer Rate and Identification of Significant Factors for CSAT English Test Based on Data Mining Techniques (데이터마이닝 기법을 활용한 대학수학능력시험 영어영역 정답률 예측 및 주요 요인 분석)

  • Park, Hee Jin;Jang, Kyoung Ye;Lee, Youn Ho;Kim, Woo Je;Kang, Pil Sung
    • KIPS Transactions on Software and Data Engineering
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    • v.4 no.11
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    • pp.509-520
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    • 2015
  • College Scholastic Ability Test(CSAT) is a primary test to evaluate the study achievement of high-school students and used by most universities for admission decision in South Korea. Because its level of difficulty is a significant issue to both students and universities, the government makes a huge effort to have a consistent difficulty level every year. However, the actual levels of difficulty have significantly fluctuated, which causes many problems with university admission. In this paper, we build two types of data-driven prediction models to predict correct answer rate and to identify significant factors for CSAT English test through accumulated test data of CSAT, unlike traditional methods depending on experts' judgments. Initially, we derive candidate question-specific factors that can influence the correct answer rate, such as the position, EBS-relation, readability, from the annual CSAT practices and CSAT for 10 years. In addition, we drive context-specific factors by employing topic modeling which identify the underlying topics over the text. Then, the correct answer rate is predicted by multiple linear regression and level of difficulty is predicted by classification tree. The experimental results show that 90% of accuracy can be achieved by the level of difficulty (difficult/easy) classification model, whereas the error rate for correct answer rate is below 16%. Points and problem category are found to be critical to predict the correct answer rate. In addition, the correct answer rate is also influenced by some of the topics discovered by topic modeling. Based on our study, it will be possible to predict the range of expected correct answer rate for both question-level and entire test-level, which will help CSAT examiners to control the level of difficulties.

Bankruptcy Type Prediction Using A Hybrid Artificial Neural Networks Model (하이브리드 인공신경망 모형을 이용한 부도 유형 예측)

  • Jo, Nam-ok;Kim, Hyun-jung;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.21 no.3
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    • pp.79-99
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    • 2015
  • The prediction of bankruptcy has been extensively studied in the accounting and finance field. It can have an important impact on lending decisions and the profitability of financial institutions in terms of risk management. Many researchers have focused on constructing a more robust bankruptcy prediction model. Early studies primarily used statistical techniques such as multiple discriminant analysis (MDA) and logit analysis for bankruptcy prediction. However, many studies have demonstrated that artificial intelligence (AI) approaches, such as artificial neural networks (ANN), decision trees, case-based reasoning (CBR), and support vector machine (SVM), have been outperforming statistical techniques since 1990s for business classification problems because statistical methods have some rigid assumptions in their application. In previous studies on corporate bankruptcy, many researchers have focused on developing a bankruptcy prediction model using financial ratios. However, there are few studies that suggest the specific types of bankruptcy. Previous bankruptcy prediction models have generally been interested in predicting whether or not firms will become bankrupt. Most of the studies on bankruptcy types have focused on reviewing the previous literature or performing a case study. Thus, this study develops a model using data mining techniques for predicting the specific types of bankruptcy as well as the occurrence of bankruptcy in Korean small- and medium-sized construction firms in terms of profitability, stability, and activity index. Thus, firms will be able to prevent it from occurring in advance. We propose a hybrid approach using two artificial neural networks (ANNs) for the prediction of bankruptcy types. The first is a back-propagation neural network (BPN) model using supervised learning for bankruptcy prediction and the second is a self-organizing map (SOM) model using unsupervised learning to classify bankruptcy data into several types. Based on the constructed model, we predict the bankruptcy of companies by applying the BPN model to a validation set that was not utilized in the development of the model. This allows for identifying the specific types of bankruptcy by using bankruptcy data predicted by the BPN model. We calculated the average of selected input variables through statistical test for each cluster to interpret characteristics of the derived clusters in the SOM model. Each cluster represents bankruptcy type classified through data of bankruptcy firms, and input variables indicate financial ratios in interpreting the meaning of each cluster. The experimental result shows that each of five bankruptcy types has different characteristics according to financial ratios. Type 1 (severe bankruptcy) has inferior financial statements except for EBITDA (earnings before interest, taxes, depreciation, and amortization) to sales based on the clustering results. Type 2 (lack of stability) has a low quick ratio, low stockholder's equity to total assets, and high total borrowings to total assets. Type 3 (lack of activity) has a slightly low total asset turnover and fixed asset turnover. Type 4 (lack of profitability) has low retained earnings to total assets and EBITDA to sales which represent the indices of profitability. Type 5 (recoverable bankruptcy) includes firms that have a relatively good financial condition as compared to other bankruptcy types even though they are bankrupt. Based on the findings, researchers and practitioners engaged in the credit evaluation field can obtain more useful information about the types of corporate bankruptcy. In this paper, we utilized the financial ratios of firms to classify bankruptcy types. It is important to select the input variables that correctly predict bankruptcy and meaningfully classify the type of bankruptcy. In a further study, we will include non-financial factors such as size, industry, and age of the firms. Thus, we can obtain realistic clustering results for bankruptcy types by combining qualitative factors and reflecting the domain knowledge of experts.

The Effect of Mentoring on the Mentor's Job Satisfaction: Mediating Effects of Personal Learning and Self-efficacy (멘토링이 멘토의 직무만족도에 미치는 영향: 개인학습 및 자기효능감의 매개효과)

  • Lee, In Hong;Dong, Hak Lim
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.3
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    • pp.157-172
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    • 2023
  • The recent Fourth Industrial Revolution is accelerating changes due to digital transformation. According to this trend, the existing start-up paradigm is changing, and new business models based on new technologies and creative ideas are emerging. In addition, the diversity of mentoring relationships and environments such as online mentoring, reverse mentoring, group mentoring, and multiple mentoring is also increasing. However, most mentors in their 50s and 60s, who are mainly active in the start-up field, have been able to help mentees a lot based on their own experience and expertise, but they are having difficulty responding to the changing environment due to a lack of understanding and experience of new technologies and environments. To cope with these changes well, mentors must constantly study, acquire and apply the latest technologies to improve their understanding of new technologies and the environment. In addition, it is necessary to have an understanding and respect for the diversity of mentoring relationships and environments, and to maximize the effectiveness of mentoring by actively utilizing them. Therefore, mentors should recognize that they directly affect the growth and development of mentees, constantly acquire new knowledge and skills to maintain and develop expertise, and actively deliver their knowledge and experiences to mentees. Therefore, in this study, was tried to empirically analyze the relationship between mentoring's influence on mentor's job satisfaction through mentor's personal learning and self-efficacy. The results of the empirical analysis were as follows. Among the functions of mentoring, career function and role modeling were found to have a positive effect on both personal learning and self-efficacy, which are parameters, and job satisfaction, which is a dependent variable. On the other hand, psychological and social functions have a positive effect on personal learning, but they do not have an effect on self-efficacy and job satisfaction. In addition, as a result of analyzing the mediating effect, all mediating effects were confirmed for career functions, and only the mediating effect of self-efficacy was confirmed for role modeling. Through this study, mentoring is an important factor in promoting job satisfaction, personal learning and self-efficacy, and this study can be said to be academically and practically meaningful in that it confirmed personal learning and self-efficacy as factors that increase mentor's job satisfaction, and the focus of mentoring research was shifted from mentee to mentor to study the impact of mentoring on mentors.

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Associations between Socioeconomic Factors and Healthy Life Expectancy at Regional Level in Korea (대한민국 지역단위 건강수명과 사회경제적 요인 간의 연관성 분석)

  • Chung-Nyun Kim;Yoon-Sun Jung;Young-Eun Kim;Minsu Ock;Dal-Lae Jin;Seok-Jun Yoon
    • Health Policy and Management
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    • v.34 no.3
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    • pp.261-270
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    • 2024
  • Background: Various researchers are calculating the health adjusted life expectancy (HALE) at the regional level in South Korea using several methods, most studies merely enumerate the differences in healthy life expectancy based on social characteristics. This study aims to analyze the association between various sociodemographic factors and HALE at the regional level. Methods: To calculate HALE, we utilized the various data sources, including National Health Insurance claims data, and applied the Sullivan's method. We conducted multiple linear regression with regional socioeconomic variables from Korean Statistical Information Service. For the multiple linear regression analysis, we designed three regression models. Model 1 comprised solely socioeconomic variables, model 2 involved both socioeconomic variables and individual health behaviors, and model 3 integrated model 2 with healthcare utilization. Results: The analysis shows that an increase in financial independence (p<0.05), population density (p<0.1), and the number of doctors (p<0.05) associated with an increase in HALE, whereas an increase in the number of beds (p<0.01) was associated with a decrease in HALE. In case of the obesity rate, in model 2 (p<0.1) and model 3 (p<0.05), there was a negative association between HALE and obesity rate. Conclusion: Amidst various variables, it was observed that increased financial independence in specific regions had association with an increase in HALE, highlighting the need for stronger local governance in South Korea. Additionally, the inverse association between hospital beds and HALE suggests several implications, such as the appropriate deployment of healthcare resources. To gain a deeper understanding of the relationship between hospital beds and HALE, further analysis distinguishing different types of hospital beds across healthcare institutions seems necessary.

Application of Support Vector Regression for Improving the Performance of the Emotion Prediction Model (감정예측모형의 성과개선을 위한 Support Vector Regression 응용)

  • Kim, Seongjin;Ryoo, Eunchung;Jung, Min Kyu;Kim, Jae Kyeong;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.18 no.3
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    • pp.185-202
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    • 2012
  • .Since the value of information has been realized in the information society, the usage and collection of information has become important. A facial expression that contains thousands of information as an artistic painting can be described in thousands of words. Followed by the idea, there has recently been a number of attempts to provide customers and companies with an intelligent service, which enables the perception of human emotions through one's facial expressions. For example, MIT Media Lab, the leading organization in this research area, has developed the human emotion prediction model, and has applied their studies to the commercial business. In the academic area, a number of the conventional methods such as Multiple Regression Analysis (MRA) or Artificial Neural Networks (ANN) have been applied to predict human emotion in prior studies. However, MRA is generally criticized because of its low prediction accuracy. This is inevitable since MRA can only explain the linear relationship between the dependent variables and the independent variable. To mitigate the limitations of MRA, some studies like Jung and Kim (2012) have used ANN as the alternative, and they reported that ANN generated more accurate prediction than the statistical methods like MRA. However, it has also been criticized due to over fitting and the difficulty of the network design (e.g. setting the number of the layers and the number of the nodes in the hidden layers). Under this background, we propose a novel model using Support Vector Regression (SVR) in order to increase the prediction accuracy. SVR is an extensive version of Support Vector Machine (SVM) designated to solve the regression problems. The model produced by SVR only depends on a subset of the training data, because the cost function for building the model ignores any training data that is close (within a threshold ${\varepsilon}$) to the model prediction. Using SVR, we tried to build a model that can measure the level of arousal and valence from the facial features. To validate the usefulness of the proposed model, we collected the data of facial reactions when providing appropriate visual stimulating contents, and extracted the features from the data. Next, the steps of the preprocessing were taken to choose statistically significant variables. In total, 297 cases were used for the experiment. As the comparative models, we also applied MRA and ANN to the same data set. For SVR, we adopted '${\varepsilon}$-insensitive loss function', and 'grid search' technique to find the optimal values of the parameters like C, d, ${\sigma}^2$, and ${\varepsilon}$. In the case of ANN, we adopted a standard three-layer backpropagation network, which has a single hidden layer. The learning rate and momentum rate of ANN were set to 10%, and we used sigmoid function as the transfer function of hidden and output nodes. We performed the experiments repeatedly by varying the number of nodes in the hidden layer to n/2, n, 3n/2, and 2n, where n is the number of the input variables. The stopping condition for ANN was set to 50,000 learning events. And, we used MAE (Mean Absolute Error) as the measure for performance comparison. From the experiment, we found that SVR achieved the highest prediction accuracy for the hold-out data set compared to MRA and ANN. Regardless of the target variables (the level of arousal, or the level of positive / negative valence), SVR showed the best performance for the hold-out data set. ANN also outperformed MRA, however, it showed the considerably lower prediction accuracy than SVR for both target variables. The findings of our research are expected to be useful to the researchers or practitioners who are willing to build the models for recognizing human emotions.

Quantitative Assessment Technology of Small Animal Myocardial Infarction PET Image Using Gaussian Mixture Model (다중가우시안혼합모델을 이용한 소동물 심근경색 PET 영상의 정량적 평가 기술)

  • Woo, Sang-Keun;Lee, Yong-Jin;Lee, Won-Ho;Kim, Min-Hwan;Park, Ji-Ae;Kim, Jin-Su;Kim, Jong-Guk;Kang, Joo-Hyun;Ji, Young-Hoon;Choi, Chang-Woon;Lim, Sang-Moo;Kim, Kyeong-Min
    • Progress in Medical Physics
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    • v.22 no.1
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    • pp.42-51
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    • 2011
  • Nuclear medicine images (SPECT, PET) were widely used tool for assessment of myocardial viability and perfusion. However it had difficult to define accurate myocardial infarct region. The purpose of this study was to investigate methodological approach for automatic measurement of rat myocardial infarct size using polar map with adaptive threshold. Rat myocardial infarction model was induced by ligation of the left circumflex artery. PET images were obtained after intravenous injection of 37 MBq $^{18}F$-FDG. After 60 min uptake, each animal was scanned for 20 min with ECG gating. PET data were reconstructed using ordered subset expectation maximization (OSEM) 2D. To automatically make the myocardial contour and generate polar map, we used QGS software (Cedars-Sinai Medical Center). The reference infarct size was defined by infarction area percentage of the total left myocardium using TTC staining. We used three threshold methods (predefined threshold, Otsu and Multi Gaussian mixture model; MGMM). Predefined threshold method was commonly used in other studies. We applied threshold value form 10% to 90% in step of 10%. Otsu algorithm calculated threshold with the maximum between class variance. MGMM method estimated the distribution of image intensity using multiple Gaussian mixture models (MGMM2, ${\cdots}$ MGMM5) and calculated adaptive threshold. The infarct size in polar map was calculated as the percentage of lower threshold area in polar map from the total polar map area. The measured infarct size using different threshold methods was evaluated by comparison with reference infarct size. The mean difference between with polar map defect size by predefined thresholds (20%, 30%, and 40%) and reference infarct size were $7.04{\pm}3.44%$, $3.87{\pm}2.09%$ and $2.15{\pm}2.07%$, respectively. Otsu verse reference infarct size was $3.56{\pm}4.16%$. MGMM methods verse reference infarct size was $2.29{\pm}1.94%$. The predefined threshold (30%) showed the smallest mean difference with reference infarct size. However, MGMM was more accurate than predefined threshold in under 10% reference infarct size case (MGMM: 0.006%, predefined threshold: 0.59%). In this study, we was to evaluate myocardial infarct size in polar map using multiple Gaussian mixture model. MGMM method was provide adaptive threshold in each subject and will be a useful for automatic measurement of infarct size.