• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.627-637
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• 2020

In this paper, the 1.24 million elderly patient medical data (HIRA-APS-2014-0053) provided by the Health Insurance Review and Assessment Service and weather data are analyzed with generalized estimating equation (GEE) model and long short term memory (LSTM) based recurrent neural network (RNN) model to predict the number of disease occurrence. To this end, we estimate the patient's residence as the area of the served medical institution, and the local weather data and medical data were merged. The status of disease occurrence is divided into three categories(occurrence of disease of interest, occurrence of other disease, no occurrence) during a week. The probabilities of categories are estimated by the GEE model and the RNN model. The number of cases of categories are predicted by adding the probabilities of categories. The comparison result shows that predictions of RNN model are more accurate than that of GEE model.

• Asian Oncology Nursing
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• v.2 no.1
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• pp.5-16
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• 2002

Purpose: This study was to develop a stress-adaptation model for family caregivers of cancer patients that could provide the basis of planning nursing intervention. Method: A hypothetical model was developed using the family adaptation model proposed by Haley et al. (1987). In the literature, the stressor was identified as patient's characteristics, caregiver's characteristics, duration of illness, and family life events. It affected stress appraisal, family resources, family coping and finally caregiver's adaptation. In this model, 18 paths were constructed. Data were collected from 241 caregivers, whose family members were in treatment between June and August 2000, at 3 university hospitals and were analyzed by SPSS and LISREL programs. Results: 1) The overall fitness indices of the hypothetical model were x 2=267.78 (P= .0), GFI= .92, AGFI= .87, NFI= .93, NNFI= .93, PNFI= .64, PGFI= .55, and RMR= .43. Ten of the eighteen paths proved to be significant. 2) To improve the model fitness, the hypothetical model was modified considering modification indices and the paths proved not significant. Final model excluded 3 paths demonstrated to be improved by x2=161.96 (P= .00), GFI= .95, AGFI= .91, NFI= .96, NNFI= .96, and RMR= .23. Twelve of fifteen paths proved to be significant. 3) Stress appraisal was influenced by disease related characteristics and duration of illness and was explained 22% of the variance. Family resources were influenced by stress appraisal and was explained 57% of variance. Family coping was influenced by disease related characteristics, caregiver's characteristics, duration of illness, family life event, and stress appraisal and was explained 57% of variance. Family caregiver adaptation was influenced by disease related characteristics, caregiver's characteristics, stress appraisal, and family coping and was explained 31% of variance. Twelve of fifteen paths were significant. Conclusion: Based on this study, to help family caregivers to adapt, individual intervention is necessary with consideration of disease related and caregiver's characteristics and duration of illness. The intervention should include efforts to raise the family resources and to identify positively the stress they encounter, and there is a need to establish an adaptation model that considers emotional aspects of family caregivers. Since there is a difference in emotional status depending on the disease stage, a study needs to be done to analyze the differences among the disease stages (diagnosis, treatment, recurrence, and terminal stages).

• Kyungpook Mathematical Journal
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• v.60 no.2
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• pp.319-334
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• 2020

We propose a mathematical model with Holling type II functional response, to study the dynamics of vaccination. In order to make our model more realistic, we have incorporated the recruitment of infected individuals as a continuous process. We have assumed that vaccination cannot be perfect and there is always a possibility of re-infection. We have obtained the existence of a disease free and endemic equilibrium point, when the recruitment of infective is not considered and also obtained the existence of at least one endemic equilibrium point when recruitment of infective is considered. We have proved that if R_v < 1, disease free equilibrium is locally asymptotically stable, which leads to the elimination of the disease from the population. The persistence of the model has also been established. Numerical simulations have been done to establish the results obtained.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.779-793
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• 2009

This paper deals with a delayed SEIRS epidemic model with pulse vaccination and crowded incidence rate. Moreover, the case of vertical and horizontal transmission is considered. By using the discrete dynamical system determined by the stroboscopic map, the exact infection-free periodic solution of the SEIRS model is obtained. Further, by employing the comparison arguments, we prove that under the condition that $R_*$ < 1 the infection-free periodic solution is globally attractive, and that under the condition that $R^*$ > 1 the disease is uniformly persistent, which means that after some period of time the disease will become endemic.

• Communications for Statistical Applications and Methods
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• v.13 no.1
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• pp.177-190
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• 2006

The aim of this study is to propose a Bayesian model for fitting mortality rate of colon cancer. For the analysis of mortality rate of a disease, factors such as age classes of population and spatial characteristics of the location are very important. The model proposed in this study allows the age class to be a random effect in addition to its conventional role as the covariate of a linear regression, while the spatial factor being a random effect. The model is fitted using Metropolis-Hastings algorithm. Posterior expected predictive deviances, standardized residuals, and residual plots are used for comparison of models. It is found that the proposed model has smaller residuals and better predictive accuracy. Lastly, we described patterns in disease maps for colon cancer.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.97-107
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• 2016

Although many diseases could be treated by the development of modern medicine, there are some incurable diseases including brain cancer, Alzheimer disease, etc. To study human brain cancer, various animal models were reported. Among these animal models, mouse models are valuable tools for understanding brain cancer characteristics. In spite of many mouse brain cancer models, it has been difficult to find a new target molecule for the treatment of brain cancer. One of the reasons is absence of large animal model which makes conducting preclinical trials. In this article, we review a recent study of molecular characteristics of human brain cancer, their genetic mutation and comparative analysis of the mouse brain cancer model. Finally, we suggest the need for development of large animal models using somatic cell nuclear transfer in translational research.

• Journal of applied mathematics & informatics
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• v.41 no.5
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• pp.1017-1035
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• 2023

In this paper, we construct a monkeypox model which is similar to smallpox infection. It is caused by a monkeypox virus which is related to Poxviridae family. It will occur mostly in West African communities and in remote Central. We develop a system of differential equations for an SEIR (Suspected, Exposed, Infected and Recovered) model and analyze the outbreak of monkeypox disease and its effect on United States(US) population. We establish theorems on asymptotical stability conditions for endemic equilibrium and disease-free equilibrium. The basic reproduction number R₀ has been determined using next generation matrix. We expect that this study will be effective at controlling monkeypox spread in United States. Our goal is to see whether monkeypox can be controlled and destroyed by smallpox vaccination. We find that monkeypox is controllable and can be fully destroyed in disease free state by vaccination. However, in the endemic state, monkeypox cannot be destroyed by vaccination alone.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.111-118
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• 2005

Weather data for disease forecasts are usually derived from automated weather stations (AWS) that may be dispersed across a region in an irregular pattern. We have developed an alternative method to simulate local scale, high-resolution weather and plant disease in a grid pattern. The system incorporates a simplified mesoscale boundary layer model, LAWSS, for estimating local conditions such as air temperature and relative humidity. It also integrates special models for estimating of surface wetness duration and disease forecasts, such as the grapevine downy mildew forecast model, DMCast. The system can recreate weather forecasts utilizing the NCEP/NCAR reanalysis database, which contains over 57 years of archived and corrected global upper air conditions. The highest horizontal resolution of 0.150 km was achieved by running 5-step nested child grids inside coarse mother grids. Over the Finger Lakes and Chautauqua Lake regions of New York State, the system simulated three growing seasons for estimating the risk of grape downy mildew with 1 km resolution. Outputs were represented as regional maps or as site-specific graphs. The highest resolutions were achieved over North America, but the system is functional for any global location. The system is expected to be a powerful tool for site selection and reanalysis of historical plant disease epidemics.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2013-2017
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• 2013

Background: To compare the effects of two adjuvant chemotherapy regimens, anthracycline-based and cyclophosphamide, methotrexate, fluorourical (CMF) on disease free survival for breast cancer patients in the Eastern Mediterranean region and Asia. Methods: In a systematic review with a multivariate mixed model meta-analysis, the reported survival proportion at multiple time points in different studies were combined. Our data sources were studies linking the two chemotherapy regimens on an adjuvant basis with disease free survival published in English and Persian in the Eastern Mediterranean region and Asia. All survival curves were generated with Graphdigitizer software. Results: 14 retrospective cohort studies were located from electronic databases. We analyzed data for 1,086 patients who received anthracycline-based treatment and 1,109 given CMF treatment. For determination of survival proportions and time we usesb the transformation Ln (-Ln(S)) and Ln (time) to make precise estimations and then fit the model. All analyses were carried out with STATA software. Conclusions: Our findings showed a significant efficacy of anthracycline-based adjuvant therapy regarding disease free survival of breast cancer. As a limitation in this meta-analysis we used studies with different types of anthracycline-based regimens.

• Korean Journal of Adult Nursing
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• v.20 no.4
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• pp.652-663
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• 2008

Purpose: This study was conducted to develop and test an explanatory model on functional capacity in patients with chronic obstructive pulmonary disease using path analysis. Methods: Data were collected from 149 chronic obstructive pulmonary disease patients using 6-minute walk test, measurement of oxygen saturation, pulmonary function test, and self-reported questionnaires from June to October, 2005. The collected data were analyzed using SPSS/WIN 12.0 program and AMOS/WIN 4.0 program. Results: The overall fitness indices of modified model were good($x^2$ = 14.324, p = .281 GFI = .981, RMSEA = .006, AGFI = .944, NFI = .927, NNFI = .999, CFI = .999, PNFI = .613, $x^2$/df = 1.194). Functional capacity was influenced directly by age(${\beta}$ = -.304, p = .000), dyspnea(${\beta}$ = -.278, p = .000), self-efficacy(${\beta}$ = .240, p = .000), social support(${\beta}$ = .175, p = .004), pulmonary function(${\beta}$ = .169, p = .008), and oxygen saturation(${\beta}$ = .099, p = .048). These variables explained 39.3% in functional capacity. Conclusion: The findings of this study suggest that comprehensive nursing interventions should focus on decreasing dyspnea and increasing self-efficacy, social support, and oxygen saturation. In this perspective, pulmonary rehabilitation would be an effective strategy for improving functional capacity in patients with chronic obstructive pulmonary disease.