296 results
Search Results
2. Dataset Related Experimental Investigation of Chess Position Evaluation Using a Deep Neural Network
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Wieczerzak, Dawid, Czarnul, Paweł, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Wyrzykowski, Roman, editor, Dongarra, Jack, editor, Deelman, Ewa, editor, and Karczewski, Konrad, editor
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- 2023
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3. ODIN AD: A Framework Supporting the Life-Cycle of Time Series Anomaly Detection Applications
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Zangrando, Niccoló, Fraternali, Piero, Torres, Rocio Nahime, Petri, Marco, Pinciroli Vago, Nicoló Oreste, Herrera, Sergio, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Guyet, Thomas, editor, Ifrim, Georgiana, editor, Malinowski, Simon, editor, Bagnall, Anthony, editor, Shafer, Patrick, editor, and Lemaire, Vincent, editor
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- 2023
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4. Brand-driven identity development of places: application, evaluation and improvement suggestions of the BIDP-framework
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Maffei, Davide
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- 2024
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5. 崩岗土壤水分特征曲线与非饱和渗透系数分析.
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杨茂进, 张越, 施梦璐, 杨雨珂, and 黄炎和
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STANDARD deviations ,RED soils ,HYDRAULIC conductivity ,FILTER paper ,SANDY soils ,SOIL moisture - Abstract
Copyright of Journal of Forest & Environment is the property of Journal of Forest & Environment Editorial and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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- View/download PDF
6. How real is the quantitative turn? Investigating statistics as the new normal in linguistics.
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Buschfeld, Sarah, Leuckert, Sven, Weihs, Claus, and Weilinghoff, Andreas
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LINGUISTICS ,CORPORA ,STATISTICS ,LINGUISTS ,LANGUAGE & languages - Abstract
Statistical approaches in linguistics seem to have gained in importance in recent times, especially in the field of Corpus Linguistics. In particular, the last ten years have seen an upsurge of linguists being dedicated to statistical methods and the improvement of statistical knowledge. This has repeatedly been described as 'the quantitative turn' in linguistics. In the present paper, we assess how real this quantitative turn actually is and whether statistics can be considered the 'new normal' in (corpus) linguistics. To this end, we have analyzed the contributions to six high-impact journals (Corpora, Corpus Linguistics and Linguistic Theory, ICAME Journal, English World-Wide, Journal of English Linguistics, and Language Variation and Change) for a period of eleven years (January 2011 until December 2021). Our results suggest that, indeed, statistical methods seem to be on the rise in linguistic studies. However, their frequency strongly varies between the journals, and, in general, we have identified some room for improvement in the use of advanced statistical methods, in particular the discussion of true prediction. [ABSTRACT FROM AUTHOR]
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- 2024
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7. SubEpiPredict: A tutorial-based primer and toolbox for fitting and forecasting growth trajectories using the ensemble n-sub-epidemic modeling framework.
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Chowell, Gerardo, Dahal, Sushma, Bleichrodt, Amanda, Tariq, Amna, Hyman, James M., and Luo, Ruiyan
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EPIDEMICS ,COVID-19 ,EPIDEMIOLOGY ,DATA ,PLATEAUS - Abstract
An ensemble n-sub-epidemic modeling framework that integrates sub-epidemics to capture complex temporal dynamics has demonstrated powerful forecasting capability in previous works. This modeling framework can characterize complex epidemic patterns, including plateaus, epidemic resurgences, and epidemic waves characterized by multiple peaks of different sizes. In this tutorial paper, we introduce and illustrate SubEpiPredict, a user-friendly MATLAB toolbox for fitting and forecasting time series data using an ensemble n-sub-epidemic modeling framework. The toolbox can be used for model fitting, forecasting, and evaluation of model performance of the calibration and forecasting periods using metrics such as the weighted interval score (WIS). We also provide a detailed description of these methods including the concept of the n-sub-epidemic model, constructing ensemble forecasts from the top-ranking models, etc. For the illustration of the toolbox, we utilize publicly available daily COVID-19 death data at the national level for the United States. The MATLAB toolbox introduced in this paper can be very useful for a wider group of audiences, including policymakers, and can be easily utilized by those without extensive coding and modeling backgrounds. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Assessing the Reliability of Machine Learning Models Applied to the Mental Health Domain Using Explainable AI.
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Pendyala, Vishnu and Kim, Hyungkyun
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MACHINE learning ,ARTIFICIAL intelligence ,MENTAL health - Abstract
Machine learning is increasingly and ubiquitously being used in the medical domain. Evaluation metrics like accuracy, precision, and recall may indicate the performance of the models but not necessarily the reliability of their outcomes. This paper assesses the effectiveness of a number of machine learning algorithms applied to an important dataset in the medical domain, specifically, mental health, by employing explainability methodologies. Using multiple machine learning algorithms and model explainability techniques, this work provides insights into the models' workings to help determine the reliability of the machine learning algorithm predictions. The results are not intuitive. It was found that the models were focusing significantly on less relevant features and, at times, unsound ranking of the features to make the predictions. This paper therefore argues that it is important for research in applied machine learning to provide insights into the explainability of models in addition to other performance metrics like accuracy. This is particularly important for applications in critical domains such as healthcare. [ABSTRACT FROM AUTHOR]
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- 2024
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9. SynBPS: a parametric simulation framework for the generation of event-log data.
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Riess, Mike
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In the pursuit of ecological validity, current business process simulation methods are calibrated to data from existing processes. This is important for realistic what-if analysis in the context of these processes. However, this is not always the "right tool for the job." To test hypotheses in the area of predictive process monitoring, it can be more helpful to simulate event-log data from a theoretical process, where all aspects can be manipulated. One example is when assessing the influence of process complexity or variability on the performance of a new prediction method. In this case, the ability to include control variables and systematically change process characteristics is a key to fully understanding their influence. Calibrating a simulation model from observed data alone can in these cases be limiting. This paper proposes a simulation framework, Synthetic Business Process Simulation (SynBPS), a Python library for the generation of event-log data from synthetic processes. Aspects such as process complexity, stability, trace distribution, duration distribution, and case arrivals can be fully controlled by the user. The overall architecture is described in detail, and a demonstration of the framework is presented. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Evaluation of Soil–Structure Interface Models.
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Wang, Hai-Lin, Yin, Zhen-Yu, Jin, Yin-Fu, and Gu, Xiao-Qiang
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SOIL density ,GEOTECHNICAL engineering ,PARAMETER identification ,KAOLIN ,ELASTOPLASTICITY - Abstract
Modeling of the soil–structure interface has been a critical issue in geotechnical engineering. Numerous studies have simulated complex soil–structure interface behaviors. These models usually are assessed by direct comparisons between the simulations and experiments. However, little work has been done to compare the specific interface behaviors simulated by different interface models. This paper evaluated some frequently recognized interface behaviors for six different interface models. These models either were adopted from the existing literature or modified from the existing soil models, including the exponential model, hyperbolic model, hypoplastic model, MCC model, SANISAND model, and SIMSAND model. Global comparisons and effects of the soil density, normal stiffness, and shearing rate were investigated to evaluate the interface models based on Fontainebleau sand–steel interface experiments and kaolin clay–steel interface experiments. The limitations and advantages of different models under different conditions were discussed. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Applications and Extensions of Metric Stability Analysis.
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Feuerstahler, Leah
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ITEM response theory ,BAYESIAN analysis ,ORAL health ,ANALYSIS of covariance ,PROSTHODONTICS - Abstract
Item response theory models and applications are affected by many sources of variability, including errors associated with item parameter estimation. Metric stability analysis (MSA) is one method to evaluate the effects of item parameter standard errors that quantifies how well a model determines the latent trait metric. This paper describes how to evaluate MSA in dichotomous and polytomous data and describes a Bayesian implementation of MSA that does not require a positive definite variance–covariance matrix among item parameters. MSA analyses are illustrated in the context of an oral-health-related quality of life measure administered before and after prosthodontic treatment. The R code to implement the methods described in this paper is provided. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Fairness as adequacy: a sociotechnical view on model evaluation in machine learning
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Grote, Thomas
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- 2024
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13. A Model Average Algorithm for Housing Price Forecast with Evaluation Interpretation.
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Jintao Fu, Yong Zhou, Qian Qiu, Guangwei Xu, and Neng Wan
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HOME prices ,COMPUTER algorithms ,MACHINE learning ,REGRESSION analysis ,PREDICTION models - Abstract
In the field of computer research, the increase of data in result of societal progress has been remarkable, and the management of this data and the analysis of linked businesses have grown in popularity. There are numerous practical uses for the capability to extract key characteristics from secondary property data and utilize these characteristics to forecast home prices. Using regression methods in machine learning to segment the data set, examine the major factors affecting it, and forecast home prices is the most popular method for examining pricing information. It is challenging to generate precise forecasts since many of the regression models currently being utilized in research are unable to efficiently collect data on the distinctive elements that correlate y with a high degree of house price movement. In today's forecasting studies, ensemble learning is a very prevalent and well-liked study methodology. The regression integration computation of large housing datasets can use a lot of computer resources as well as computation time, and ensemble learning uses more resources and calls for more machine support in integrating diverse models. The Average Model suggested in this paper uses the concept of fusion to produce integrated analysis findings from several models, combining the best benefits of separate models. The Average Model has a strong applicability in the field of regression prediction and significantly increases computational efficiency. The technique is also easier to replicate and very effective in regression investigations. Before using regression processing techniques, this work creates an average of different regression models using theAM(Average Model) algorithm in a novelway. By evaluating essential models with 90% accuracy, this technique significantly increases the accuracy of house price predictions. The experimental results show that the AM algorithm proposed in this paper has lower prediction error than other comparison algorithms, and the prediction accuracy is greatly improved compared with other algorithms, and has a good experimental effect in house price prediction. [ABSTRACT FROM AUTHOR]
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- 2022
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14. Precision-Driven Product Recommendation Software: Unsupervised Models, Evaluated by GPT-4 LLM for Enhanced Recommender Systems.
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Roumeliotis, Konstantinos I., Tselikas, Nikolaos D., and Nasiopoulos, Dimitrios K.
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SUPERVISED learning ,K-means clustering ,ELECTRONIC commerce ,HIERARCHICAL clustering (Cluster analysis) ,EVALUATION - Abstract
This paper presents a pioneering methodology for refining product recommender systems, introducing a synergistic integration of unsupervised models—K-means clustering, content-based filtering (CBF), and hierarchical clustering—with the cutting-edge GPT-4 large language model (LLM). Its innovation lies in utilizing GPT-4 for model evaluation, harnessing its advanced natural language understanding capabilities to enhance the precision and relevance of product recommendations. A flask-based API simplifies its implementation for e-commerce owners, allowing for the seamless training and evaluation of the models using CSV-formatted product data. The unique aspect of this approach lies in its ability to empower e-commerce with sophisticated unsupervised recommender system algorithms, while the GPT model significantly contributes to refining the semantic context of product features, resulting in a more personalized and effective product recommendation system. The experimental results underscore the superiority of this integrated framework, marking a significant advancement in the field of recommender systems and providing businesses with an efficient and scalable solution to optimize their product recommendations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Optimal Error Quantification and Robust Tracking under Unknown Upper Bounds on Uncertainties and Biased External Disturbance.
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Sokolov, Victor F.
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LINEAR programming ,ROBUST control ,CONTROL theory (Engineering) ,COMPUTER simulation ,ADAPTIVE control systems ,LINEAR time invariant systems ,TRACKING algorithms - Abstract
This paper addresses a problem of optimal error quantification in the framework of robust control theory in the 1 setup. The upper bounds of biased external disturbance and the gains of coprime factor perturbations in a discrete-time linear time invariant SISO plant are assumed to be unknown. The computation of optimal data-consistent upper bounds under a known bias of external disturbance has been simplified to linear programming. This allows for the computation of optimal estimates in real-time and their application to achieve optimal robust steady-state tracking even when facing an unknown bias in the external disturbance. The presented results have been illustrated through computer simulations. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Predicting Runoff from the Weigan River under Climate Change.
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Su, Jingwen, Zhang, Pei, Deng, Xiaoya, Ren, Cai, Zhang, Ji, Chen, Fulong, and Long, Aihua
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RUNOFF ,RADIATIVE forcing ,ARID regions ,GOVERNMENT policy on climate change ,RUNOFF models ,MOUNTAIN soils ,CLIMATE change - Abstract
With the warming and humidification process in the Northwest Arid Zone over the past 30 years, the runoff of a vast majority of rivers has been affected to different degrees. In this paper, the runoff from the Weigan River, a typical inland river in the arid zone of Northwest China, is taken as an example, and seven types of CMIP6 data are selected with the help of a SWAT model to predict the runoff volume of the Weigan River in the next 30 years under climate change. The results show that (1) the SWAT model can simulate the runoff from the Weigan River well and has good applicability in this study area. (2) With an increase in radiative forcing, the temperature, precipitation and runoff in the study area show an increasing trend. (3) Under the four radiative forcing scenarios in 2030 and 2050, the runoff from the Weigan River out of the mountain is predicted to be maintained at 25.68 to 30.89 × 10
8 m3 , which is an increase of 1.35% to 21.91% compared with the current runoff, of which the contribution to the increase in future runoff caused by the changes in temperature and precipitation is 68.71% and 27.24%, respectively. It is important to explore the impact of climate change on the runoff from the Weigan River to understand the impact of climate change on the Northwest Arid Region scientifically and rationally, and to provide a scientific basis for evaluating the risk of climate change and formulating policies to deal with it. [ABSTRACT FROM AUTHOR]- Published
- 2024
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17. Best Practice Data Sharing Guidelines for Wind Turbine Fault Detection Model Evaluation.
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Barber, Sarah, Izagirre, Unai, Serradilla, Oscar, Olaizola, Jon, Zugasti, Ekhi, Aizpurua, Jose Ignacio, Milani, Ali Eftekhari, Sehnke, Frank, Sakagami, Yoshiaki, and Henderson, Charles
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GEARBOXES ,PARTICLE swarm optimization ,WIND turbines ,ARTIFICIAL neural networks ,INFORMATION sharing ,REMAINING useful life - Abstract
In this paper, a set of best practice data sharing guidelines for wind turbine fault detection model evaluation is developed, which can help practitioners overcome the main challenges of digitalisation. Digitalisation is one of the key drivers for reducing costs and risks over the whole wind energy project life cycle. One of the largest challenges in successfully implementing digitalisation is the lack of data sharing and collaboration between organisations in the sector. In order to overcome this challenge, a new collaboration framework called WeDoWind was developed in recent work. The main innovation of this framework is the way it creates tangible incentives to motivate and empower different types of people from all over the world to share data and knowledge in practice. In this present paper, the challenges related to comparing and evaluating different SCADA-data-based wind turbine fault detection models are investigated by carrying out a new case study, the "WinJi Gearbox Fault Detection Challenge", based on the WeDoWind framework. A total of six new solutions were submitted to the challenge, and a comparison and evaluation of the results show that, in general, some of the approaches (Particle Swarm Optimisation algorithm for constructing health indicators, performance monitoring using Deep Neural Networks, Combined Ward Hierarchical Clustering and Novelty Detection with Local Outlier Factor and Time-to-failure prediction using Random Forest Regression) appear to exhibit high potential to reach the goals of the Challenge. However, there are a number of concrete things that would have to have been done by the Challenge providers and the Challenge moderators in order to ensure success. This includes enabling access to more details of the different failure types, access to multiple data sets from more wind turbines experiencing gearbox failure, provision of a model or rule relating fault detection times or a remaining useful lifetime to the estimated costs for repairs, replacements and inspections, provision of a clear strategy for training and test periods in advance, as well as provision of a pre-defined template or requirements for the results. These learning outcomes are used directly to define a set of best practice data sharing guidelines for wind turbine fault detection model evaluation. The guidelines can be used by researchers in the sector in order to improve model evaluation and data sharing in the future. [ABSTRACT FROM AUTHOR]
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- 2023
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18. The Representation of Soil Moisture-Atmosphere Feedbacks across the Tibetan Plateau in CMIP6
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Talib, Joshua, Müller, Omar V., Barton, Emma J., Taylor, Christopher M., and Vidale, Pier Luigi
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- 2023
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19. A Time Neighborhood Method for the Verification of Landfalling Typhoon Track Forecast.
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Xu, Daosheng, Leung, Jeremy Cheuk-Hin, and Zhang, Banglin
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TYPHOONS ,LANDFALL ,NEIGHBORHOODS ,FORECASTING ,EVALUATION methodology - Abstract
Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
20. Assessment of Typhoon Precipitation Forecasts Based on Topographic Factors.
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Chen, Xu-Zhe, Ma, Yu-Long, Lin, Chun-Qiao, and Fan, Ling-Li
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TYPHOONS ,PRECIPITATION forecasting ,ATMOSPHERIC models ,RAINFALL - Abstract
For this paper, a new global atmospheric model (Global-to-Regional Integrated forecast SysTem; GRIST) with improved sub-grid scale orographic parameterization was verified and assessed, with an emphasis on the precipitation caused by typhoons. Four typical typhoon cases were selected for the verification of the model. The results indicate that, compared to the control experiments, the sensitivity experiments consistently simulated the trends in the three-hour cumulative precipitation changes and the high-value regions of total precipitation better. However, the improved experiments only had an ameliorating effect on the cumulative precipitation modelling biases for Typhoon LEKIMA and Typhoon HAGUPIT, not all of them. Precipitation bias is smaller on flat land than that on mountainous land, but the precipitation bias on windward/leeward slopes depends on the typhoon case. Precipitation modelling accuracy varies considerably between flat and mountainous terrain but very little between windward and leeward slopes. The precipitation simulation is poor for all terrains, with large precipitation thresholds in three typhoon cases, but for Typhoon HOTA, after improving the terrain, the model has the ability to forecast the heavy rainfall scenarios of the mountainous terrain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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21. Sem@K: Is my knowledge graph embedding model semantic-aware?
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Hubert, Nicolas, Monnin, Pierre, Brun, Armelle, and Monticolo, Davy
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KNOWLEDGE graphs ,PREDICTION models ,SEMANTIC Web ,NOMOGRAPHY (Mathematics) - Abstract
Using knowledge graph embedding models (KGEMs) is a popular approach for predicting links in knowledge graphs (KGs). Traditionally, the performance of KGEMs for link prediction is assessed using rank-based metrics, which evaluate their ability to give high scores to ground-truth entities. However, the literature claims that the KGEM evaluation procedure would benefit from adding supplementary dimensions to assess. That is why, in this paper, we extend our previously introduced metric Sem@K that measures the capability of models to predict valid entities w.r.t. domain and range constraints. In particular, we consider a broad range of KGs and take their respective characteristics into account to propose different versions of Sem@K. We also perform an extensive study to qualify the abilities of KGEMs as measured by our metric. Our experiments show that Sem@K provides a new perspective on KGEM quality. Its joint analysis with rank-based metrics offers different conclusions on the predictive power of models. Regarding Sem@K, some KGEMs are inherently better than others, but this semantic superiority is not indicative of their performance w.r.t. rank-based metrics. In this work, we generalize conclusions about the relative performance of KGEMs w.r.t. rank-based and semantic-oriented metrics at the level of families of models. The joint analysis of the aforementioned metrics gives more insight into the peculiarities of each model. This work paves the way for a more comprehensive evaluation of KGEM adequacy for specific downstream tasks. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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22. Ultimate strength models for spherical shells under external pressure: a comparative study.
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Zhao, Liang and Bai, Yong
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ULTIMATE strength ,OFFSHORE structures ,COMPARATIVE studies ,STATISTICAL models - Abstract
The ultimate strength of spherical shells under external pressure has been an attractive topic in the field of marine structures. However, recent studies have revealed that the current theoretical approaches are hardly compatible with the actual hulls, which indicates that the ultimate strength models still need to be reevaluated and unified. To address this challenge, a comparative study has been conducted in this paper. Various analytical approaches and codified rules are compared through screened experiment data that have realistic imperfections and different shape parameters in the range generally applied for marine structures. The model evaluation criteria have been established by implementing statistical model uncertainty factors in terms of bias and coefficient of variation. A comparison of the results has been made from three different aspects including shell shape, R/t and geometrical parameters to evaluate their performance. Based on the calculation outcome, analysis has been made to study the theory behind those models and determine their limitations and recommended application range. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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23. Methodology and evaluation in sports analytics: challenges, approaches, and lessons learned
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Davis, Jesse, Bransen, Lotte, Devos, Laurens, Jaspers, Arne, Meert, Wannes, Robberechts, Pieter, Van Haaren, Jan, and Van Roy, Maaike
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- 2024
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24. Top-K Pairwise Ranking: Bridging the Gap Among Ranking-Based Measures for Multi-label Classification
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Wang, Zitai, Xu, Qianqian, Yang, Zhiyong, Wen, Peisong, He, Yuan, Cao, Xiaochun, and Huang, Qingming
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- 2024
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25. Methodological guidance for the evaluation and updating of clinical prediction models: a systematic review.
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Binuya, M. A. E., Engelhardt, E. G., Schats, W., Schmidt, M. K., and Steyerberg, E. W.
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PREDICTION models ,DATABASE searching ,CALIBRATION - Abstract
Background: Clinical prediction models are often not evaluated properly in specific settings or updated, for instance, with information from new markers. These key steps are needed such that models are fit for purpose and remain relevant in the long-term. We aimed to present an overview of methodological guidance for the evaluation (i.e., validation and impact assessment) and updating of clinical prediction models. Methods: We systematically searched nine databases from January 2000 to January 2022 for articles in English with methodological recommendations for the post-derivation stages of interest. Qualitative analysis was used to summarize the 70 selected guidance papers. Results: Key aspects for validation are the assessment of statistical performance using measures for discrimination (e.g., C-statistic) and calibration (e.g., calibration-in-the-large and calibration slope). For assessing impact or usefulness in clinical decision-making, recent papers advise using decision-analytic measures (e.g., the Net Benefit) over simplistic classification measures that ignore clinical consequences (e.g., accuracy, overall Net Reclassification Index). Commonly recommended methods for model updating are recalibration (i.e., adjustment of intercept or baseline hazard and/or slope), revision (i.e., re-estimation of individual predictor effects), and extension (i.e., addition of new markers). Additional methodological guidance is needed for newer types of updating (e.g., meta-model and dynamic updating) and machine learning-based models. Conclusion: Substantial guidance was found for model evaluation and more conventional updating of regression-based models. An important development in model evaluation is the introduction of a decision-analytic framework for assessing clinical usefulness. Consensus is emerging on methods for model updating. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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26. Ensemble‐based monthly to seasonal precipitation forecasting for Iran using a regional weather model.
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Najafi, Mohammad Saeed and Kuchak, Vahid Shokri
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- *
WATER management , *PRECIPITATION forecasting , *METEOROLOGICAL research , *WEATHER forecasting , *LEAD time (Supply chain management) - Abstract
Monthly and seasonal precipitation forecasts can potentially assist disaster risk reduction and water resource management. The aim of this study is to assess the skill of an ensemble framework for monthly and seasonal precipitation forecasts over Iran by focusing on system design and model performance evaluation. The ensemble framework presented in this paper is based on a one‐way double‐nested model that uses Weather Research and Forecasting (WRF) modelling system to downscale the second version of the NCEP Climate Forecast System (CFSv2). The performance is evaluated for October–April period at 1‐, 2‐ and 3‐month lead time. Multiple initial conditions, model parameters and physics are used to construct ensemble members. Using quantile mapping (QM) method, the outputs of the model are bias corrected. This methodology is applied for two periods: (i) climatology from 2000 to 2019 to evaluate the model's ability to precipitation forecast on a monthly and seasonal time scale; (ii) the forecast for 2020 to evaluate the model's performance operationally. The model evaluation is performed using the continuous (e.g., RMSE, r, MBE, NSE) and categorical (e.g., POD, FAR, PC, Heidke skill score) assessment metrics. We conclude that model outputs were improved by the QM bias correction method. According to results, the proposed ensemble framework can accurately predict amount of monthly and seasonal precipitation in Iran with an accuracy of 58 to 45% for lead‐1 to 3. For all three lead times, the averaged NSE, CC, MBE, and RMSE were 0.4, 0.56, −15.5, and 41.6, indicating that the framework has reasonable performance. Our results suggest that precipitation forecast accuracy varies with lead time, so the accuracy for lead‐1 is higher than lead‐2 and lead‐3. Additionally, the model's accuracy differs in various regions of the country and decreases in the spring. Using the approach for an operational case, it was found that the spatial features of precipitation predicted by the framework were close to those observed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. Unveiling the impact of unchanged modules across versions on the evaluation of within‐project defect prediction models.
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Liu, Xutong, Zhou, Yufei, Lu, Zeyu, Mei, Yuanqing, Yang, Yibiao, Qian, Junyan, and Zhou, Yuming
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- *
PREDICTION models , *SOURCE code , *MULTIPLE comparisons (Statistics) , *DATA modeling , *FORECASTING - Abstract
Background Problem Method Results Conclusion Software defect prediction (SDP) is a topic actively researched in the software engineering community. Within‐project defect prediction (WPDP) involves using labeled modules from previous versions of the same project to train classifiers. Over time, many defect prediction models have been evaluated under the WPDP scenario.Data duplication poses a significant challenge in current WPDP evaluation procedures. Unchanged modules, characterized by identical executable source code, are frequently present in both target and source versions during experimentation. However, it is still unclear how and to what extent the presence of unchanged modules affects the performance assessment of WPDP models and the comparison of multiple WPDP models.In this paper, we provide a method to detect and remove unchanged modules from defect datasets and unveil the impact of data duplication in WPDP on model evaluation.The experiments conducted on 481 target versions from 62 projects provide evidence that data duplication significantly affects the reported performance values of individual learners in WPDP. However, when ranking multiple WPDP models based on prediction performance, the impact of removing unchanged instances is not substantial. Nevertheless, it is important to note that removing unchanged instances does have a slight influence on the selection of models with better generalization.We recommend that future WPDP studies take into consideration the removal of unchanged modules from target versions when evaluating the performance of their models. This practice will enhance the reliability and validity of the results obtained in WPDP research, leading to improved understanding and advancements in defect prediction models. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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28. An Algebraic Evaluation Framework for a Class of Car-Following Models.
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Wang, Zejiang, Zhou, Xingyu, and Wang, Junmin
- Abstract
Car-following models describe how a driver follows the leading vehicle in the same lane. They serve as the cornerstone of microscopic traffic-flow simulations and play an essential role in analyzing human factors in traffic casualty, congestion, efficiency, and emissions. An extensive and continuously growing number of car-following models in the literature raises the requirement to evaluate and compare different models objectively. Generally, a car-following model is evaluated after model parameter calibration: the optimal residual between the calibrated model output and the measured counterpart is used as a metric to assess a car-following model’s performance. However, model parameter calibration, usually formed as a numerical optimization problem, suffers from several issues, such as local optimality and heavy computational burden. More importantly, different formulations of the cost function can lead to distinct calibration outcomes and contradictory conclusions of the model evaluation results. This paper proposes instead a purely algebraic framework for evaluating a class of car-following models whose parameters can be linearly identified. Car-following models with nonlinear relationships among parameters, e.g., the behavioral car-following models, are out of the scope of analysis in this paper. Algebraic manipulations performed on a model finally produce a system error index, which is a uniform metric for evaluating and comparing different car-following models. During the whole process, no cost function needs to be designed a priori, and no computationally expensive numerical optimization is involved. Three car-following models are evaluated and compared under the proposed algebraic framework. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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29. A New Framework for Evaluating Model Simulated Inland Tropical Cyclone Wind Fields.
- Author
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Chen, Jie, Gao, Kun, Harris, Lucas, Marchok, Timothy, Zhou, Linjiong, and Morin, Matthew
- Subjects
TROPICAL cyclones ,HURRICANE forecasting ,GEOPHYSICAL fluid dynamics ,LANDFALL ,WIND forecasting ,STRUCTURAL analysis (Engineering) - Abstract
Though tropical cyclone (TC) models have been routinely evaluated against track and intensity observations, little work has been performed to validate modeled TC wind fields over land. In this paper, we present a simple framework for evaluating simulated low‐level inland winds with in‐situ observations and existing TC structure theory. The Automated Surface Observing Systems, Florida Coastal Monitoring Program, and best track data are used to generate a theory‐predicted wind profile that reasonably represents the observed radial distribution of TC wind speeds. We quantitatively and qualitatively evaluated the modeled inland TC wind fields, and described the model performance with a set of simple indicators. The framework was used to examine the performance of a high‐resolution two‐way nested Geophysical Fluid Dynamics Laboratory model on recent U.S. landfalling TCs. Results demonstrate the capacity of using this framework to assess the modeled TC low‐level wind field in the absence of dense inland observations. Plain Language Summary: Some of the biggest human impacts of tropical cyclone (TC) winds come after the TC makes landfall. A skillful prediction of the radial distribution of winds is essential for forecasting TC‐induced inland hazards. However, the forecast skill of numerical hurricane models on inland TC wind fields has rarely been evaluated since it is challenging to collect wind observations during landfall, and the network of regular weather observations is too spread out to capture the strongest winds associated with a TC. This inhibits the improvement of forecast models and limits our understanding of the TC's inland evolution. Our work combines available inland in‐situ wind observations over the southeastern U.S. with existing TC structure theory, and presents a new "optimal" estimate of the post‐landfall winds. Our framework is found to be useful for evaluating the post‐landfall TC winds in hurricane forecast models. In addition, the new evaluation technique can intuitively demonstrate how well the model simulates TC intensity and structure. Key Points: We introduce a new framework for evaluating modeled inland tropical cyclone (TC) wind fields with observation‐based, theory‐predicted wind profilesThe theory‐predicted wind profile well represents the observed radial distribution of inland TC wind speedsWe propose simple indicators to summarize the model performance on inland wind field predictions [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. A Blockchain-Based Trustworthy Model Evaluation Framework for Deep Learning and Its Application in Moving Object Segmentation.
- Author
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Jiang, Rui, Li, Jiatao, Bu, Weifeng, and Shen, Xiang
- Subjects
DEEP learning ,TRUST ,ACCESS control ,COMPUTER vision ,RECORDS management ,INFORMATION sharing - Abstract
Model evaluation is critical in deep learning. However, the traditional model evaluation approach is susceptible to issues of untrustworthiness, including insecure data and model sharing, insecure model training, incorrect model evaluation, centralized model evaluation, and evaluation results that can be tampered easily. To minimize these untrustworthiness issues, this paper proposes a blockchain-based model evaluation framework. The framework consists of an access control layer, a storage layer, a model training layer, and a model evaluation layer. The access control layer facilitates secure resource sharing. To achieve fine-grained and flexible access control, an attribute-based access control model combining the idea of a role-based access control model is adopted. A smart contract is designed to manage the access control policies stored in the blockchain ledger. The storage layer ensures efficient and secure storage of resources. Resource files are stored in the IPFS, with the encrypted results of their index addresses recorded in the blockchain ledger. Another smart contract is designed to achieve decentralized and efficient management of resource records. The model training layer performs training on users' servers, and, to ensure security, the training data must have records in the blockchain. The model evaluation layer utilizes the recorded data to evaluate the recorded models. A method in the smart contract of the storage layer is designed to enable evaluation, with scores automatically uploaded as a resource attribute. The proposed framework is applied to deep learning-based motion object segmentation, demonstrating its key functionalities. Furthermore, we validated the storage strategy adopted by the framework, and the trustworthiness of the framework is also analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. semPower: General power analysis for structural equation models
- Author
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Moshagen, Morten and Bader, Martina
- Published
- 2024
- Full Text
- View/download PDF
32. Predictive performance of presence‐only species distribution models: a benchmark study with reproducible code.
- Author
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Valavi, Roozbeh, Guillera‐Arroita, Gurutzeta, Lahoz‐Monfort, José J., and Elith, Jane
- Subjects
SPECIES distribution ,RANDOM forest algorithms ,REGRESSION trees ,SUPPORT vector machines - Abstract
Species distribution modeling (SDM) is widely used in ecology and conservation. Currently, the most available data for SDM are species presence‐only records (available through digital databases). There have been many studies comparing the performance of alternative algorithms for modeling presence‐only data. Among these, a 2006 paper from Elith and colleagues has been particularly influential in the field, partly because they used several novel methods (at the time) on a global data set that included independent presence–absence records for model evaluation. Since its publication, some of the algorithms have been further developed and new ones have emerged. In this paper, we explore patterns in predictive performance across methods, by reanalyzing the same data set (225 species from six different regions) using updated modeling knowledge and practices. We apply well‐established methods such as generalized additive models and MaxEnt, alongside others that have received attention more recently, including regularized regressions, point‐process weighted regressions, random forests, XGBoost, support vector machines, and the ensemble modeling framework biomod. All the methods we use include background samples (a sample of environments in the landscape) for model fitting. We explore impacts of using weights on the presence and background points in model fitting. We introduce new ways of evaluating models fitted to these data, using the area under the precision‐recall gain curve, and focusing on the rank of results. We find that the way models are fitted matters. The top method was an ensemble of tuned individual models. In contrast, ensembles built using the biomod framework with default parameters performed no better than single moderate performing models. Similarly, the second top performing method was a random forest parameterized to deal with many background samples (contrasted to relatively few presence records), which substantially outperformed other random forest implementations. We find that, in general, nonparametric techniques with the capability of controlling for model complexity outperformed traditional regression methods, with MaxEnt and boosted regression trees still among the top performing models. All the data and code with working examples are provided to make this study fully reproducible. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. RobustNPR: Evaluating the robustness of neural program repair models.
- Author
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Ge, Hongliang, Zhong, Wenkang, Li, Chuanyi, Ge, Jidong, Hu, Hao, and Luo, Bin
- Subjects
- *
SUCCESS - Abstract
Due to the high cost of repairing defective programs, many researches focus on automatic program repair (APR). In recent years, the new trend of APR is to apply neural networks to mine the relations between defective programs and corresponding patches automatically, which is known as neural program repair (NPR). The community, however, ignores some important properties that could impact the applicability of NPR systems, such as robustness. For semantic‐identical buggy programs, NPR systems may produce totally different patches. In this paper, we propose an evaluation tool named RobustNPR, the first NPR robustness evaluation tool. RobustNPR employs several mutators to generate semantic‐identical mutants of defective programs. For an original defective program and its mutant, it checks two aspects of NPR: (a) Can NPR fix mutants when it can fix the original defective program? and (b) can NPR generate semantic‐identical patches for the original program and the mutant? Then, we evaluate four SOTA NPR models and analyze the results. From the results, we find that even for the best‐performing model, 20.16% of the repair success is unreliable, which indicates that the robustness of NPR is not perfect. In addition, we find that the robustness of NPR is correlated with model settings and other factors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Incremental Model Fit Assessment in the Case of Categorical Data: Tucker–Lewis Index for Item Response Theory Modeling.
- Author
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Cai, Li, Chung, Seung Won, and Lee, Taehun
- Subjects
ITEM response theory ,SMOKING cessation ,EXPLORATORY factor analysis ,MODEL theory ,APPROXIMATION error - Abstract
The Tucker–Lewis index (TLI; Tucker & Lewis, 1973), also known as the non-normed fit index (NNFI; Bentler & Bonett, 1980), is one of the numerous incremental fit indices widely used in linear mean and covariance structure modeling, particularly in exploratory factor analysis, tools popular in prevention research. It augments information provided by other indices such as the root-mean-square error of approximation (RMSEA). In this paper, we develop and examine an analogous index for categorical item level data modeled with item response theory (IRT). The proposed Tucker–Lewis index for IRT (TLIRT) is based on Maydeu-Olivares and Joe's (2005) M 2 family of limited-information overall model fit statistics. The limited-information fit statistics have significantly better Chi-square approximation and power than traditional full-information Pearson or likelihood ratio statistics under realistic situations. Building on the incremental fit assessment principle, the TLIRT compares the fit of model under consideration along a spectrum of worst to best possible model fit scenarios. We examine the performance of the new index using simulated and empirical data. Results from a simulation study suggest that the new index behaves as theoretically expected, and it can offer additional insights about model fit not available from other sources. In addition, a more stringent cutoff value is perhaps needed than Hu and Bentler's (1999) traditional cutoff criterion with continuous variables. In the empirical data analysis, we use a data set from a measurement development project in support of cigarette smoking cessation research to illustrate the usefulness of the TLIRT. We noticed that had we only utilized the RMSEA index, we could have arrived at qualitatively different conclusions about model fit, depending on the choice of test statistics, an issue to which the TLIRT is relatively more immune. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. L-measure evaluation metric for fake information detection models with binary class imbalance.
- Author
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Li, Li, Wang, Yong, Hsu, Chia-Yu, Li, Yibin, and Lin, Kuo-Yi
- Subjects
INFORMATION modeling ,STATISTICAL correlation ,SOCIAL media - Abstract
Fake information in social media frequently causes social issues. The amount of fake information is smaller than that of real information, this leads to class imbalance. Some improved classification methods and metrics to resolve the imbalance and evaluate model performance have been proposed, respectively. However, the existing metrics for classification methods have many limitations. This paper proposes the robust metric, L-measure, that can reasonably evaluate all models with binary class imbalance with different IRs. L-measure also require less computation than the Matthews correlation coefficient. Finally, this paper demonstrates the validity of the proposed metric under different IRs with examples from UCI and Kaggle. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
36. CapitalVX: A machine learning model for startup selection and exit prediction.
- Author
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Ross, Greg, Das, Sanjiv, Sciro, Daniel, and Raza, Hussain
- Subjects
MACHINE learning ,BIG data ,VENTURE capital ,GOING public (Securities) ,NEW business enterprises - Abstract
Using a big data set of venture capital financing and related startup firms from Crunchbase, this paper develops a machinelearning model called CapitalVX (for "Capital Venture eXchange") to predict the outcomes for startups, i.e., whether they will exit successfully through an IPO or acquisition, fail, or remain private. Using a large feature set, the out-of-sample accuracy of predictions on startup outcomes and follow-on funding is 80e89%. This research suggests that VC/PE firms may be able to benefit from using machine learning to screen potential investments using publicly available information, diverting this time instead into mentoring and monitoring the investments they make. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. Evaluation of Linear Kernel-Driven BRDF Models over Snow-Free Rugged Terrain.
- Author
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Zhu, Wenzhe, You, Dongqin, Wen, Jianguang, Tang, Yong, Gong, Baochang, and Han, Yuan
- Subjects
RELIEF models ,REMOTE sensing ,REFLECTANCE ,SAVANNAS - Abstract
Semi-empirical kernel-driven models have been widely used to characterize anisotropic reflectance due to their simple form and physically meaningful approximation. Recently, several kernel-driven models have been coupled with topographic effects to improve the fitting of bidirectional reflectance over rugged terrains. However, extensive evaluations of the various models' performances are required before their subsequent application in remote sensing. Three typical kernel-driven BRDF models over snow-free rugged terrains such as the RTLSR, TCKD, and the KDST-adjusted TCKD (KDST-TCKD) were investigated in this paper using simulated and observed BRFs. Against simulated data, the fitting error (NIR/Red RMSE) of the RTLSR gradually increases from 0.0358/0.0342 to 0.0471/0.0516 with mean slopes (α) increases from 9.13° to 33.40°. However, the TCKD and KDST-TCKD models perform an overall better fitting accuracy: the fitting errors of TCKD gradually decreased from 0.0366/0.0337 to 0.0252/0.0292, and the best fit from the KDST-TCDK model with NIR/Red RMSE decreased from 0.0192/0.0269 to 0.0169/0.0180. When compared to the sandbox data (α from 8.4° to 30.36°), the NIR/Red RMSE of the RTLSR model ranges from 0.0147/0.0085 to 0.0346/0.0165, for the TCKD model from 0.0144/0.0086 to 0.0298/0.0154, and for the KDST-TCKD model from 0.0137/0.0082 to 0.0234/0.0149. Using MODIS data, the TCKD and KDST-TCKD models show more significant improvements compared to the RTLSR model in rugged terrains. Their RMSE differences are within 0.003 over a relatively flat terrain (α < 10°). When α is large (20°–30° and >30°), the RMSE of the TCKD model has a decrease of around 0.01 compared to that of the RTLSR; for KDST-TCKD, it is approximately 0.02, and can even reach 0.0334 in the savannas. Therefore, the TCKD and KDST-TCKD models have an overall better performance than the RTLSR model in rugged terrains, especially in the case of large mean slopes. Among them, the KDST-TCKD model performs the best due to its consideration of topographic effects, geotropic growth, and component spectra. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Effective Heart Disease Prediction Using Machine Learning Techniques.
- Author
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Bhatt, Chintan M., Patel, Parth, Ghetia, Tarang, and Mazzeo, Pier Luigi
- Subjects
HEART diseases ,RANDOM forest algorithms ,DECISION trees ,CARDIOVASCULAR disease diagnosis ,MACHINE learning ,CARDIOVASCULAR diseases - Abstract
The diagnosis and prognosis of cardiovascular disease are crucial medical tasks to ensure correct classification, which helps cardiologists provide proper treatment to the patient. Machine learning applications in the medical niche have increased as they can recognize patterns from data. Using machine learning to classify cardiovascular disease occurrence can help diagnosticians reduce misdiagnosis. This research develops a model that can correctly predict cardiovascular diseases to reduce the fatality caused by cardiovascular diseases. This paper proposes a method of k-modes clustering with Huang starting that can improve classification accuracy. Models such as random forest (RF), decision tree classifier (DT), multilayer perceptron (MP), and XGBoost (XGB) are used. GridSearchCV was used to hypertune the parameters of the applied model to optimize the result. The proposed model is applied to a real-world dataset of 70,000 instances from Kaggle. Models were trained on data that were split in 80:20 and achieved accuracy as follows: decision tree: 86.37% (with cross-validation) and 86.53% (without cross-validation), XGBoost: 86.87% (with cross-validation) and 87.02% (without cross-validation), random forest: 87.05% (with cross-validation) and 86.92% (without cross-validation), multilayer perceptron: 87.28% (with cross-validation) and 86.94% (without cross-validation). The proposed models have AUC (area under the curve) values: decision tree: 0.94, XGBoost: 0.95, random forest: 0.95, multilayer perceptron: 0.95. The conclusion drawn from this underlying research is that multilayer perceptron with cross-validation has outperformed all other algorithms in terms of accuracy. It achieved the highest accuracy of 87.28%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. 生成对抗网络的发展与挑战.
- Author
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董永生, 范世朝, 张 宇, and 马尽文
- Abstract
Copyright of Journal of Signal Processing is the property of Journal of Signal Processing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
40. Evaluation of constitutive models used in orthogonal cutting simulation based on coupled Eulerian–Lagrangian formulation
- Author
-
Zhu, Baoyi, Xiong, Liangshan, and Chen, Yuhai
- Published
- 2024
- Full Text
- View/download PDF
41. Evaluation of 3D crustal seismic velocity models in southwest China: Model performance, limitation, and prospects
- Author
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Wang, Xin, Chen, Ling, and Chen, Qi-Fu
- Published
- 2024
- Full Text
- View/download PDF
42. Assessing the Performance of CMIP6 Models in Simulating Droughts across Global Drylands
- Author
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Yu, Xiaojing, Zhang, Lixia, Zhou, Tianjun, and Zheng, Jianghua
- Published
- 2024
- Full Text
- View/download PDF
43. Semisupervised transfer learning for evaluation of model classification performance.
- Author
-
Wang, Linshanshan, Wang, Xuan, Liao, Katherine P, and Cai, Tianxi
- Subjects
- *
SUPERVISED learning , *ASYMPTOTIC normality , *RECEIVER operating characteristic curves - Abstract
In many modern machine learning applications, changes in covariate distributions and difficulty in acquiring outcome information have posed challenges to robust model training and evaluation. Numerous transfer learning methods have been developed to robustly adapt the model itself to some unlabeled target populations using existing labeled data in a source population. However, there is a paucity of literature on transferring performance metrics, especially receiver operating characteristic (ROC) parameters, of a trained model. In this paper, we aim to evaluate the performance of a trained binary classifier on unlabeled target population based on ROC analysis. We proposed S emisupervised T ransfer l E arning of A ccuracy M easures (STEAM), an efficient three-step estimation procedure that employs (1) double-index modeling to construct calibrated density ratio weights and (2) robust imputation to leverage the large amount of unlabeled data to improve estimation efficiency. We establish the consistency and asymptotic normality of the proposed estimator under the correct specification of either the density ratio model or the outcome model. We also correct for potential overfitting bias in the estimators in finite samples with cross-validation. We compare our proposed estimators to existing methods and show reductions in bias and gains in efficiency through simulations. We illustrate the practical utility of the proposed method on evaluating prediction performance of a phenotyping model for rheumatoid arthritis (RA) on a temporally evolving EHR cohort. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. BoltVision: A Comparative Analysis of CNN, CCT, and ViT in Achieving High Accuracy for Missing Bolt Classification in Train Components.
- Author
-
Alif, Mujadded Al Rabbani, Hussain, Muhammad, Tucker, Gareth, and Iwnicki, Simon
- Subjects
MACHINE learning ,TRANSFORMER models ,COMPUTER vision ,CONVOLUTIONAL neural networks ,INSPECTION & review ,DEEP learning - Abstract
Maintenance and safety inspection of trains is a critical element of providing a safe and reliable train service. Checking for the presence of bolts is an essential part of train inspection, which is currently, typically carried out during visual inspections. There is an opportunity to automate bolt inspection using machine vision with edge devices. One particular challenge is the implementation of such inspection mechanisms on edge devices, which necessitates using lighter models to ensure efficiency. Traditional methods have often fallen short of the required object detection performance, thus demonstrating the need for a more advanced approach. To address this challenge, researchers have been exploring the use of deep learning algorithms and computer vision techniques to improve the accuracy and reliability of bolt detection on edge devices. High precision in identifying absent bolts in train components is essential to avoid potential mishaps and system malfunctions. This paper presents "BoltVision", a comparative analysis of three cutting-edge machine learning models: convolutional neural networks (CNNs), vision transformers (ViTs), and compact convolutional transformers (CCTs). This study illustrates the superior assessment capabilities of these models and discusses their effectiveness in addressing the prevalent issue of edge devices. Results show that BoltVision, utilising a pre-trained ViT base, achieves a remarkable 93% accuracy in classifying missing bolts. These results underscore the potential of BoltVision in tackling specific safety inspection challenges for trains and highlight its effectiveness when deployed on edge devices characterised by constrained computational resources. This attests to the pivotal role of transformer-based architectures in revolutionising predictive maintenance and safety assurance within the rail transportation industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. THE MODELLING OF A HYSTERESIS GRAPH OF PIEZOELECTRIC ELEMENTS USING DEEP LEARNING BIDIRECTIONAL LSTM.
- Author
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Al-Inizi, Fawwaz, Płaczek, Marek, Wróbel, Andrzej, and Harazin, Jacek
- Subjects
DEEP learning ,HYSTERESIS graph ,PIEZOELECTRIC materials ,DYNAMICAL systems ,SYSTEM dynamics - Abstract
The phenomenon of hysteresis is an integral part of dynamic systems in many fields of science such as physics, chemistry, biology and many more. It describes an inherent dependence of a system state based on the history of varying number of its previous states. Hysteresis can manifest as a dynamic lag between an input signal and an output system behaviour, which depends on the degree of that system dy-namics. Modelling systems containing hysteresis is a challenging mathematical task given their highly non-linear behaviour. This paper discusses and develop a deep learning model using bidirectional LSTM (long short-term memory) for predicting voltages necessary to stimulate a piezoelectric element to produce displacements in order to cancel or minimize vibrations. The predicted voltages rely on given displacements and time domain of the initial noise input. This noise input can then be amplified to match the resonance frequency of another piezoelectric element to generate the maximum voltage capable by this later piezoelectric element. This sinusoidal voltage then travels to a piezoelectric actuator to generate displacement that can cancel the initial noise. The model resulted a coefficient of determination score of 0.99983, a loss score of 0.0092 and MSE (mean squared error) of 8.5568e-05. Created model has proven that machine learning is a viable method for hysteresis modelling and can be further improved with increased input data availability and further investigation into different deep learning algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Preparation of Cu-Ce@γ-Al 2 O 3 and Study on Catalytic Ozone Oxidation for the Treatment of RO Concentrate Water.
- Author
-
Sun, Wenquan, Xiao, Zhiqiang, Sun, Yongjun, Ding, Lei, and Zhou, Jun
- Subjects
REVERSE osmosis ,CATALYTIC oxidation ,REVERSE osmosis process (Sewage purification) ,SEWAGE disposal plants ,WATER treatment plants ,CATALYTIC activity ,ORGANIC compounds ,CERIUM oxides - Abstract
In this paper, a high-efficiency and stable Cu-Ce@γ-Al
2 O3 catalyst was prepared by taking the reverse osmosis (RO) concentrated water of a sewage treatment plant as the treatment object and activated alumina as the carrier. The preparation factors that affected the catalytic activity of Cu-Ce@γ-Al2 O3 were investigated. SEM, EDS, XRD, BET, XRF, and XPS techniques were applied to characterize the catalyst. Optimal working conditions, and degradation mechanism of RO concentrated water were researched. In comparison with the ozone oxidation alone, the Cu-Ce@γ-Al2 O3 catalytic ozonation has more reactive groups, significantly improving the treatment effect. Characterization results show that Cu and Ce are successfully supported on the surface of the activated alumina support and mainly exist in the form of oxides (e.g., CuO and CeO2 ). The loading of metal led to a larger specific surface area and pore volume. The repeated use had an insignificant effect on the peaks of Cu2p and Ce3d energy spectra and caused a small loss of active components. Under these conditions, the removal rate of COD from RO concentrated water by Cu-Ce@γ-Al2 O3 catalyst was 85.2%. The stability and salt tolerance of Cu-Ce@γ-Al2 O3 catalysts were investigated by catalyst wear rate and repeated use times, respectively. The degradation of organic matter and residual tryptophan-like organic compounds were observed through UV absorption spectroscopy and 3D-EEM. Hydroxyl radicals participated in organic pollutants degradation. Finally, a multi-level-fuzzy analysis evaluation model was developed to quantitatively assess the catalytic ozone oxidation system of the Cu-Ce @γ-Al2 O3 catalyst for the treatment of RO concentrated water. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
47. Efficient evaluation of prediction rules in semi‐supervised settings under stratified sampling.
- Author
-
Gronsbell, Jessica, Liu, Molei, Tian, Lu, and Cai, Tianxi
- Subjects
ELECTRONIC health records ,DIABETIC neuropathies ,NONLINEAR regression ,REGRESSION analysis ,FORECASTING ,MULTIPLE imputation (Statistics) ,BINARY codes - Abstract
In many contemporary applications, large amounts of unlabelled data are readily available while labelled examples are limited. There has been substantial interest in semi‐supervised learning (SSL) which aims to leverage unlabelled data to improve estimation or prediction. However, current SSL literature focuses primarily on settings where labelled data are selected uniformly at random from the population of interest. Stratified sampling, while posing additional analytical challenges, is highly applicable to many real‐world problems. Moreover, no SSL methods currently exist for estimating the prediction performance of a fitted model when the labelled data are not selected uniformly at random. In this paper, we propose a two‐step SSL procedure for evaluating a prediction rule derived from a working binary regression model based on the Brier score and overall misclassification rate under stratified sampling. In step I, we impute the missing labels via weighted regression with nonlinear basis functions to account for stratified sampling and to improve efficiency. In step II, we augment the initial imputations to ensure the consistency of the resulting estimators regardless of the specification of the prediction model or the imputation model. The final estimator is then obtained with the augmented imputations. We provide asymptotic theory and numerical studies illustrating that our proposals outperform their supervised counterparts in terms of efficiency gain. Our methods are motivated by electronic health record (EHR) research and validated with a real data analysis of an EHR‐based study of diabetic neuropathy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. 湖泊光伏电站蒸发量变化特征及模型评估的对比研究.
- Author
-
叶天歌 and 高晓清
- Subjects
PHOTOVOLTAIC power systems ,PHOTOVOLTAIC effect ,WATER vapor ,HYDROLOGIC cycle ,SOLAR energy - Abstract
Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
49. Application of Machine Learning on Food Storage Quality Prediction.
- Author
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Dai Shuaishuai, Wu Weijie, Niu Ben, Fang Xiangjun, Chen Huizhi, Chen Hangjun, and Gao Haiyan
- Subjects
FOOD storage ,FOOD quality ,MACHINE learning ,FOOD transportation ,FOOD science ,ARTIFICIAL neural networks - Abstract
During the process of food storage and circulation, there will be different degrees of quality deterioration. With the improvement of people's attention to food quality and safety, it is of great significance to carry out quality prediction research in the process of food storage and transportation for quality control. This paper reviews the research progress of machine learning in food storage quality prediction, including conventional quality prediction methods and limitations, and then focuses on the rapid development and wide application of integrated learning and artificial neural network algorithms, and prediction performance evaluation methods in recent years. Finally, it summarizes and looks forward to the future development trend of machine learning in the food field, and provides relevant references for the development of food science cross research. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Open Source Assessment of Deep Learning Visual Object Detection.
- Author
-
Paniego, Sergio, Sharma, Vinay, and Cañas, José María
- Subjects
DEEP learning ,OBJECT recognition (Computer vision) ,VISUAL learning ,ARTIFICIAL neural networks ,BATCH processing ,KEY performance indicators (Management) - Abstract
This paper introduces Detection Metrics, an open-source scientific software for the assessment of deep learning neural network models for visual object detection. This software provides objective performance metrics such as mean average precision and mean inference time. The most relevant international object detection datasets are supported along with the most widely used deep learning frameworks. Different network models, even those built from different frameworks, can be fairly compared in this way. This is very useful when developing deep learning applications or research. A set of tools is provided to manage and work with different datasets and models, including visualization and conversion into several common formats. Detection Metrics may also be used in automatic batch processing for large experimental tests, saving researchers time, and new domain-specific datasets can be easily created from videos or webcams. It is open-source, can be audited, extended, and adapted to particular requirements. It has been experimentally validated. The performance of the most relevant state-of-the-art neural models for object detection has been experimentally compared. In addition, it has been used in several research projects, guiding in selecting the most suitable network model architectures and training procedures. The performance of the different models and training alternatives can be easily measured, even on large datasets. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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