• 제목/요약/키워드: Stratification algorithm

검색결과 34건 처리시간 0.022초

An Update on Sjögren's Syndrome for Oral Medicine Specialists

  • Lee, Kyung-Eun;Jung, Won
    • Journal of Oral Medicine and Pain
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    • 제46권4호
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    • pp.99-108
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    • 2021
  • Sjögren's syndrome (SjS) is a common autoimmune disorder characterized by lymphocytic infiltration in the salivary and lacrimal glands, resulting in severe dry mouth or eyes. The symptoms are complex and heterogeneous. Several diagnostic criteria have been proposed for SjS and its subsets over the years. However, on the other hands, great efforts have been made searching for reliable biomarkers able to ameliorate the diagnostic algorithm and the prognostic stratification of SjS patients. The aim of this article is to review biomarkers and treatments related to SjS for oral medicine specialists.

Measuring and Modeling the Spectral Attenuation of Light in the Yellow Sea

  • Gallegos, Sonia-C.;Sandidge, Juanita;Chen, Xiaogang;Hahn, Sangbok-D.;Ahn, Yu-Hwan;Iturriaga, Rodolfo;Jeong, Hee-Dong;Suh, Young-Sang;Cho, Sung-Hwam
    • Journal of the korean society of oceanography
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    • 제39권1호
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    • pp.46-56
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    • 2004
  • Spectral attenuation of light and upwelling radiance were measured in the western coast of Korea on board the R/V Inchon 888 of the Korean National Fisheries Research and Development Institute(NFRDI) during four seasons. The goal of these efforts was to determine the spatial and temporal distribution of the inherent and apparent optical properties of the water, and the factors that control their distribution. Our data indicate that while stratification of the water column, phytoplankton, and wind stress determined the vertical distribution of the optical parameters offshore, it was the tidal current and sediment type that controlled both the vertical and horizontal distribution in the coastal areas. These findings led to the development of a model that estimates the spectral attenuation of light with respect to depth and time for the Yellow Sea. The model integrates water leaving radiance from satellites, sediment types, current vectors, sigma-t, bathymetry, and in situ optical measurements in a learning algorithm capable of extracting optical properties with only knowledge of the environmental conditions of the Yellow Sea. The performance of the model decreases with increase in depth. The mean absolute percentage error (MAPE) of the model is 2% for the upper five meters, 8-10% between 6 and 50 meters, and 15% below 51 meters.

Personalized Diabetes Risk Assessment Through Multifaceted Analysis (PD- RAMA): A Novel Machine Learning Approach to Early Detection and Management of Type 2 Diabetes

  • Gharbi Alshammari
    • International Journal of Computer Science & Network Security
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    • 제23권8호
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    • pp.17-25
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    • 2023
  • The alarming global prevalence of Type 2 Diabetes Mellitus (T2DM) has catalyzed an urgent need for robust, early diagnostic methodologies. This study unveils a pioneering approach to predicting T2DM, employing the Extreme Gradient Boosting (XGBoost) algorithm, renowned for its predictive accuracy and computational efficiency. The investigation harnesses a meticulously curated dataset of 4303 samples, extracted from a comprehensive Chinese research study, scrupulously aligned with the World Health Organization's indicators and standards. The dataset encapsulates a multifaceted spectrum of clinical, demographic, and lifestyle attributes. Through an intricate process of hyperparameter optimization, the XGBoost model exhibited an unparalleled best score, elucidating a distinctive combination of parameters such as a learning rate of 0.1, max depth of 3, 150 estimators, and specific colsample strategies. The model's validation accuracy of 0.957, coupled with a sensitivity of 0.9898 and specificity of 0.8897, underlines its robustness in classifying T2DM. A detailed analysis of the confusion matrix further substantiated the model's diagnostic prowess, with an F1-score of 0.9308, illustrating its balanced performance in true positive and negative classifications. The precision and recall metrics provided nuanced insights into the model's ability to minimize false predictions, thereby enhancing its clinical applicability. The research findings not only underline the remarkable efficacy of XGBoost in T2DM prediction but also contribute to the burgeoning field of machine learning applications in personalized healthcare. By elucidating a novel paradigm that accentuates the synergistic integration of multifaceted clinical parameters, this study fosters a promising avenue for precise early detection, risk stratification, and patient-centric intervention in diabetes care. The research serves as a beacon, inspiring further exploration and innovation in leveraging advanced analytical techniques for transformative impacts on predictive diagnostics and chronic disease management.

k-NN기법을 이용한 산림바이오매스 자원량 평가 - 강원대학교 학술림을 대상으로 - (Assessment of Forest Biomass using k-Neighbor Techniques - A Case Study in the Research Forest at Kangwon National University -)

  • 서환석;박동환;임종수;이정수
    • 한국산림과학회지
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    • 제101권4호
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    • pp.547-557
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    • 2012
  • 본 연구는 강원대학교 학술림을 대상으로 현장조사자료와 Landsat TM-5 위성영상 정보를 이용하여 k-NN기법을 통해 산림바이오매스를 추정하는 것을 목적으로 하였다. 임상 층화 및 최소수평 참조거리(HRA)와 공간필터링의 조건변화에 따른 최적의 참조표본점 개수(k)를 검토하였으며, 이에 따른 산림바이오매스량 추정과 정확도를 비교 분석하였다. 침엽수는 $5{\times}5$ 필터링을 적용한 HRA 4 km와 k=8를 적용하였을 때 최소의 RMSE를 나타냈으며, 편차는 1.8 t/ha으로 과대추정되었다. 한편, 잣나무와 활엽수는 필터링을 적용하지 않은 HRA 4km의 k=8과 HRA 10 km의 k=6을 적용하였을 때 최소의 RMSE가 나타났으며, 편차는 각각 -1.6 t/ha, -5.2 t/ha로 과소추정되었다. k-NN기법에 의하여 추정된 총 바이오매스량은 799천t이며, ha당 평균 산림바이오매스량은 237 t/ha로서 표본점자료를 이용한 추정치보다 약 1 t/ha 높게 나타났다.