• 대한수학회지
• /
• 제58권1호
• /
• pp.45-67
• /
• 2021

In this paper, a mathematical dynamical system involving both deterministic (with or without delay) and stochastic "SIR" epidemic model with nonlinear incidence rate in a continuous reactor is considered. A profound qualitative analysis is given. It is proved that, for both deterministic models, if ��d > 1, then the endemic equilibrium is globally asymptotically stable. However, if ��d ≤ 1, then the disease-free equilibrium is globally asymptotically stable. Concerning the stochastic model, the Feller's test combined with the canonical probability method were used in order to conclude on the long-time dynamics of the stochastic model. The results improve and extend the results obtained for the deterministic model in its both forms. It is proved that if ��s > 1, the disease is stochastically permanent with full probability. However, if ��s ≤ 1, then the disease dies out with full probability. Finally, some numerical tests are done in order to validate the obtained results.

• ETRI Journal
• /
• 제46권3호
• /
• pp.513-525
• /
• 2024

Deep neural networks trained on labeled medical data face major challenges owing to the economic costs of data acquisition through expensive medical imaging devices, expert labor for data annotation, and large datasets to achieve optimal model performance. The heterogeneity of diseases, such as Alzheimer's disease, further complicates deep learning because the test cases may substantially differ from the training data, possibly increasing the rate of false positives. We propose a reconstruction-based self-supervised anomaly detection model to overcome these challenges. It has a dual-subnetwork encoder that enhances feature encoding augmented by skip connections to the decoder for improving the gradient flow. The novel encoder captures local and global features to improve image reconstruction. In addition, we introduce an entropy-based image conversion method. Extensive evaluations show that the proposed model outperforms benchmark models in anomaly detection and classification using an encoder. The supervised and unsupervised models show improved performances when trained with data preprocessed using the proposed image conversion method.

• The Plant Pathology Journal
• /
• 제36권1호
• /
• pp.54-66
• /
• 2020

This study was conducted to evaluate usefulness of numerical weather prediction data generated by the Unified Model (UM) for plant disease forecast. Using the UM06- and UM18-predicted weather data, which were released at 0600 and 1800 Universal Time Coordinated (UTC), respectively, by the Korea Meteorological Administration (KMA), disease forecast on bacterial grain rot (BGR) of rice was examined as compared with the model output based on the automated weather stations (AWS)-observed weather data. We analyzed performance of BGRcast based on the UM-predicted and the AWS-observed daily minimum temperature and average relative humidity in 2014 and 2015 from 29 locations representing major rice growing areas in Korea using regression analysis and two-way contingency table analysis. Temporal changes in weather conduciveness at two locations in 2014 were also analyzed with regard to daily weather conduciveness (C_i) and the 20-day and 7-day moving averages of C_i for the inoculum build-up phase (C_inc) prior to the panicle emergence of rice plants and the infection phase (C_inf) during the heading stage of rice plants, respectively. Based on C_inc and C_inf, we were able to obtain the same disease warnings at all locations regardless of the sources of weather data. In conclusion, the numerical weather prediction data from KMA could be reliable to apply as input data for plant disease forecast models. Weather prediction data would facilitate applications of weather-driven disease models for better disease management. Crop growers would have better options for disease control including both protective and curative measures when weather prediction data are used for disease warning.

• 대한한의학방제학회지
• /
• 제15권1호
• /
• pp.145-161
• /
• 2007

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with cutaneous hyperreactivity to environmental triggers. The clinical phenotype that characterizes AD is the product of interactions between susceptible genes, the environmental factors, defective skin barrier function, and immunologic responses. This review summarizes recent progress in our understanding of the immunopathophysiology of AD and the implications for mouse models of AD in drug discovery from medicinal plants.

• 농업과학연구
• /
• 제41권1호
• /
• pp.23-27
• /
• 2014

Potato late blight occurrence is caused by various environmental factors, and the progress can be regularly predicted so that several predictive models have been developed. The models predict the timing of the disease occurrence, but they do not include the methods of the disease control. Effective fungicide control, economic threshold, prediction models were investigated in the study to reflect on customized control modules for the model forecasting the occurrence of potato late blight.

• 농업과학연구
• /
• 제41권1호
• /
• pp.29-34
• /
• 2014

Phytophthora blight occurrence is caused by various environmental factors, and the progress can be regularly predicted so that several predictive models have been developed. The models predict the timing of the disease occurrence, but they do not include the methods of the disease control. Effective fungicide control, control threshold, prediction models were investigated in the study to reflect on customized control modules for the model forecasting the occurrence of Phytophthora blight on hot pepper.

• BMB Reports
• /
• 제44권7호
• /
• pp.435-445
• /
• 2011

Serous ovarian cancer is one of the most lethal gynecological malignancies. Progress on effective diagnostics and therapeutics for this disease are hampered by ambiguity as to the cellular origins of this histotype of ovarian cancer, as well as limited suitable animal models to analyze early stages of disease. In this report, we will review current animal models with respect to the two proposed progenitor cells for serous ovarian cancer, the ovarian surface epithelium and the fallopian tube epithelium.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권5호
• /
• pp.672-679
• /
• 2010

Diabetes mellitus is a worldwide epidemic with high mortality. As concern over this disease rises, the number and value of research grants awarded by the National Research Foundation of Korea (NRF) have increased. Diabetes mellitus is classified into two groups. Type 1 diabetes requires insulin treatment, whereas type 2 diabetes, which is characterized by insulin resistance, can be treated using a variety of therapeutic approaches. Hyperglycemia is thought to be a primary factor in the onset of diabetes, although hyperlipidemia also plays a role. The major organs active in the regulation of blood glucose are the pancreas, liver, skeletal muscle, adipose tissue, intestine, and kidney. Diabetic complications are generally classified as macrovascular (e.g., stroke and heart disease) or microvascular (i.e., diabetic neuropathy, nephropathy, and retinopathy). Several animal models of diabetes have been used to develop oral therapeutic agents, including sulfonylureas, biguanides, thiazolidinediones, acarbose, and miglitol, for both type 1 and type 2 diseases. This review provides an overview of diabetes mellitus, describes oral therapeutic agents for diabetes and their targets, and discusses new developments in diabetic drug research.

• 응용통계연구
• /
• 제29권1호
• /
• pp.145-155
• /
• 2016

이 논문에서는 기상에 따른 고령 환자의 질병 발생빈도를 예측하는 방법을 비교한다. 분석을 위해 건강보험심사평가원의 고령 환자 의료 자료와 기상청 자료를 주별, 권역별로 병합한다. 기상에 영향을 받는 질병의 주별 발생 빈도를 ARMAX모형, VARMAX모형, TSCS회귀모형으로 분석하고 MSE, MAPE, MAE 기준으로 모형을 비교했다.

• Journal of the Korean Data and Information Science Society
• /
• 제27권5호
• /
• pp.1225-1239
• /
• 2016

We investigate pediatric tumor incidence data collected by the Florida Association for Pediatric Tumor program using various models commonly used in disease mapping analysis. Particularly, we consider Poisson normal models with various conditional autoregressive structure for spatial dependence, a zero-in ated component to capture excess zero counts and a spatio-temporal model to capture spatial and temporal dependence, together. We found that intrinsic conditional autoregressive model provides the smallest Deviance Information Criterion (DIC) among the models when only spatial dependence is considered. On the other hand, adding an autoregressive structure over time decreases DIC over the model without time dependence component. We adopt weighted ranks squared error loss to identify high risk regions which provides similar results with other researchers who have worked on the same data set (e.g. Zhang et al., 2014; Wang and Rodriguez, 2014). Our results, thus, provide additional statistical support on those identied high risk regions discovered by the other researchers.