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Fusion of Activation Functions: An Alternative to Improving Prediction Accuracy in Artificial Neural Networks
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作者 Justice Awosonviri Akodia Clement K. Dzidonu +1 位作者 David King Boison Philip Kisembe 《World Journal of Engineering and Technology》 2024年第4期836-850,共15页
The purpose of this study was to address the challenges in predicting and classifying accuracy in modeling Container Dwell Time (CDT) using Artificial Neural Networks (ANN). This objective was driven by the suboptimal... The purpose of this study was to address the challenges in predicting and classifying accuracy in modeling Container Dwell Time (CDT) using Artificial Neural Networks (ANN). This objective was driven by the suboptimal outcomes reported in previous studies and sought to apply an innovative approach to improve these results. To achieve this, the study applied the Fusion of Activation Functions (FAFs) to a substantial dataset. This dataset included 307,594 container records from the Port of Tema from 2014 to 2022, encompassing both import and transit containers. The RandomizedSearchCV algorithm from Python’s Scikit-learn library was utilized in the methodological approach to yield the optimal activation function for prediction accuracy. The results indicated that “ajaLT”, a fusion of the Logistic and Hyperbolic Tangent Activation Functions, provided the best prediction accuracy, reaching a high of 82%. Despite these encouraging findings, it’s crucial to recognize the study’s limitations. While Fusion of Activation Functions is a promising method, further evaluation is necessary across different container types and port operations to ascertain the broader applicability and generalizability of these findings. The original value of this study lies in its innovative application of FAFs to CDT. Unlike previous studies, this research evaluates the method based on prediction accuracy rather than training time. It opens new avenues for machine learning engineers and researchers in applying FAFs to enhance prediction accuracy in CDT modeling, contributing to a previously underexplored area. 展开更多
关键词 Artificial Neural Networks Container Dwell Time Fusion of Activation Functions Randomized Search CV Algorithm Prediction accuracy
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Effects of Mapping Methods on Accuracy of Protein Coding Regions Prediction
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作者 马玉韬 张成 +2 位作者 杨泽林 李琦 杨婷 《Agricultural Science & Technology》 CAS 2011年第12期1802-1806,1860,共6页
[Objective] To discuss the effects of major mapping methods for DNA sequence on the accuracy of protein coding regions prediction,and to find out the effective mapping methods.[Method] By taking Approximate Correlatio... [Objective] To discuss the effects of major mapping methods for DNA sequence on the accuracy of protein coding regions prediction,and to find out the effective mapping methods.[Method] By taking Approximate Correlation(AC) as the full measure of the prediction accuracy at nucleotide level,the windowed narrow pass-band filter(WNPBF) based prediction algorithm was applied to study the effects of different mapping methods on prediction accuracy.[Result] In DNA data sets ALLSEQ and HMR195,the Voss and Z-Curve methods are proved to be more effective mapping methods than paired numeric(PN),Electron-ion Interaction Potential(EIIP) and complex number methods.[Conclusion] This study lays the foundation to verify the effectiveness of new mapping methods by using the predicted AC value,and it is meaningful to reveal DNA structure by using bioinformatics methods. 展开更多
关键词 Prediction accuracy Protein coding regions Mapping method Windowed Narrow pass-band filter
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Prognostic value of liver outcome score and hemoglobin in autoimmune liver disease overlap syndromes
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作者 Kai Wang Lei-Yang Jin Qin-Guo Zhang 《World Journal of Hepatology》 2025年第2期316-319,共4页
This letter addresses the study by Jayabalan et al,which underscores the liver outcome score(LOS)and hemoglobin(Hb)as key prognostic markers for patients with autoimmune liver disease overlap syndromes(AILDOS),with pa... This letter addresses the study by Jayabalan et al,which underscores the liver outcome score(LOS)and hemoglobin(Hb)as key prognostic markers for patients with autoimmune liver disease overlap syndromes(AILDOS),with particular relevance to the autoimmune hepatitis-primary biliary cholangitis(AIH-PBC)subgroup.The findings indicate that an LOS threshold of 6 achieves high sensitivity and specificity in predicting liver-related mortality among AIH-PBC patients.Moreover,low Hb levels emerge as a significant mortality predictor across all AILDOS cases.These results contribute valuable perspectives on risk stratification in AILDOS,highlighting the promise of non-invasive prognostic tools.Future studies with larger cohorts are needed to substantiate LOS and Hb as robust markers for clinical application. 展开更多
关键词 Autoimmune liver disease overlap syndromes ANEMIA Autoimmune hepatitis Clinical decision-making HEMOGLOBIN Liver outcome score Predictive accuracy Risk stratification
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Towards personalized care in minimally invasive esophageal surgery:An adverse events prediction model
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作者 Ioannis Karniadakis Alexandra Argyrou +1 位作者 Stamatina Vogli Stavros P Papadakos 《World Journal of Gastroenterology》 2025年第13期155-157,共3页
This letter addressed the impactful study by Zhong et al,which introduced a risk prediction and stratification model for surgical adverse events following minimally invasive esophagectomy.By identifying key risk facto... This letter addressed the impactful study by Zhong et al,which introduced a risk prediction and stratification model for surgical adverse events following minimally invasive esophagectomy.By identifying key risk factors such as chronic obstructive pulmonary disease and hypoalbuminemia,the model demonstrated strong predictive accuracy and offered a pathway to personalized perioperative care.This correspondence highlighted the clinical significance,emphasizing its potential to optimize patient outcomes through tailored inter-ventions.Further prospective validation and application across diverse settings are essential to realize its full potential in advancing esophageal surgery practices. 展开更多
关键词 Minimally invasive esophagectomy Surgical adverse events Risk prediction model Risk stratification HYPOALBUMINEMIA Predictive accuracy Personalized perioperative care Tailored interventions Esophageal surgery
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Forecasting Solar Energy Production across Multiple Sites Using Deep Learning
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作者 Samira Marhraoui Basma Saad +2 位作者 Hassan Silkan Said Laasri Asmaa El Hannani 《Energy Engineering》 2025年第7期2653-2672,共20页
Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficie... Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficiency and how they process solar radiation.This study evaluates the effectiveness of deep learning models in predicting PV power generation for three panel technologies:Hybrid-Si,Mono-Si,and Poly-Si,across three forecasting horizons:1-step,12-step,and 24-step.Among the tested models,the Convolutional Neural Network—Long Short-Term Memory(CNN-LSTM)architecture exhibited superior performance,particularly for the 24-step horizon,achieving R^(2)=0.9793 and MAE 0.0162 for the Poly-Si array,followed by Mono-Si(R^(2)=0.9768)and Hybrid-Si arrays(R^(2)=0.9769).These findings demonstrate that the CNN-LSTM model can provide accurate and reliable PV power predictions for all studied technologies.By identifying the most suitable predictive model for each panel technology,this study contributes to optimizing PV power forecasting and improving energy management strategies. 展开更多
关键词 CNN-LSTM deep learning models forecasting horizons PV energy prediction accuracy solar panel technologies
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Application and Performance Optimization of SLHS-TCN-XGBoost Model in Power Demand Forecasting
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作者 Tianwen Zhao Guoqing Chen +1 位作者 Cong Pang Piyapatr Busababodhin 《Computer Modeling in Engineering & Sciences》 2025年第6期2883-2917,共35页
Existing power forecasting models struggle to simultaneously handle high-dimensional,noisy load data while capturing long-term dependencies.This critical limitation necessitates an integrated approach combining dimens... Existing power forecasting models struggle to simultaneously handle high-dimensional,noisy load data while capturing long-term dependencies.This critical limitation necessitates an integrated approach combining dimensionality reduction,temporal modeling,and robust prediction,especially for multi-day forecasting.A novel hybrid model,SLHS-TCN-XGBoost,is proposed for power demand forecasting,leveraging SLHS(dimensionality reduction),TCN(temporal feature learning),and XGBoost(ensemble prediction).Applied to the three-year electricity load dataset of Seoul,South Korea,the model’s MAE,RMSE,and MAPE reached 112.08,148.39,and 2%,respectively,which are significantly reduced in MAE,RMSE,and MAPE by 87.37%,87.35%,and 87.43%relative to the baseline XGBoost model.Performance validation across nine forecast days demonstrates superior accuracy,with MAPE as low as 0.35%and 0.21%on key dates.Statistical Significance tests confirm significant improvements(p<0.05),with the highest MAPE reduction of 98.17%on critical days.Seasonal and temporal error analyses reveal stable performance,particularly in Quarter 3 and Quarter 4(0.5%,0.3%)and nighttime hours(<1%).Robustness tests,including 5-fold cross-validation and Various noise perturbations,confirm the model’s stability and resilience.The SLHS-TCN-XGBoost model offers an efficient and reliable solution for power demand forecasting,with future optimization potential in data preprocessing,algorithm integration,and interpretability. 展开更多
关键词 Power demand forecasting SLHS-TCN-XGBoost ensemble learning prediction accuracy noise robustness
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Evaluation of surgical strategy for low anterior resection syndrome using preoperative low anterior resection syndrome score in China
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作者 Yang-Tao Pan Yi-Min Lv +4 位作者 Shi-Chao Zhou Dan-Yan Luo Hao Sun Wei-Feng Lao Wei Zhou 《World Journal of Gastrointestinal Surgery》 2025年第1期175-183,共9页
BACKGROUND Despite improved survival rates in rectal cancer treatment,many patients experience low anterior resection syndrome(LARS).The preoperative LARS score(POLARS)aims to address the limitations of LARS assessmen... BACKGROUND Despite improved survival rates in rectal cancer treatment,many patients experience low anterior resection syndrome(LARS).The preoperative LARS score(POLARS)aims to address the limitations of LARS assessment by predicting outcomes preoperatively to enhance surgical planning.AIM To investigate the predictive accuracy of POLARS in assessing the occurrence of LARS.METHODS This study enrolled a total of 335 patients who underwent laparoscopic or robotic low anal sphincter-preserving surgery for rectal tumors.Patients were categorized into three groups according to their POLARS score:no LARS(score 0-20),minor LARS(score 21-29),and major LARS(score 30-42).The QLQ-C30/CR29 scores were compared among these groups,and the agreement between POLARS predictions and the actual LARS scores was analyzed.RESULTS The study population was divided into three groups:major LARS(n=51,27.42%),minor LARS(n=109,58.6%),and no LARS(n=26,13.98%).Significant differences in the QLQ-C30 scales of social function,diarrhea,and financial impact were detected between the no LARS and major LARS groups(P<0.05)and between the minor LARS and major LARS groups(P<0.05).Similarly,significant differences were detected in the QLQ-CR29 scales for blood and mucus in the stool,fecal incontinence,and stool frequency between the no LARS and minor LARS groups(P<0.05),as well as between the minor LARS and major LARS groups(P<0.05).The predictive precision for major LARS using the POLARS score was 82.35%(42/51),with a recall of 35.89%(42/117).The mean absolute error(MAE)between the POLARS score and the actual LARS score was 8.92±5.47.In contrast,the XGBoost(extreme gradient boosting)model achieved a lower MAE of 6.29±4.77,with a precision of 84.39%and a recall of 74.05%for predicting major LARS.CONCLUSION The POLARS score demonstrated effectiveness and precision in predicting major LARS,thereby providing valuable insights into postoperative symptoms and patient quality of life.However,the XGBoost model exhibited superior performance with a lower MAE and higher recall for predicting major LARS compared to the POLARS model. 展开更多
关键词 Low anterior resection syndrome Preoperative assessment Predictive accuracy Quality of life Machine learning
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Using machine learning to improve the accuracy of genomic prediction of reproduction traits in pigs 被引量:16
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作者 Xue Wang Shaolei Shi +5 位作者 Guijiang Wang Wenxue Luo Xia Wei Ao Qiu Fei Luo Xiangdong Ding 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2022年第5期1293-1304,共12页
Background:Recently,machine learning(ML)has become attractive in genomic prediction,but its superiority in genomic prediction over conventional(ss)GBLUP methods and the choice of optimal ML methods need to be investig... Background:Recently,machine learning(ML)has become attractive in genomic prediction,but its superiority in genomic prediction over conventional(ss)GBLUP methods and the choice of optimal ML methods need to be investigated.Results:In this study,2566 Chinese Yorkshire pigs with reproduction trait records were genotyped with the GenoBaits Porcine SNP 50 K and PorcineSNP50 panels.Four ML methods,including support vector regression(SVR),kernel ridge regression(KRR),random forest(RF)and Adaboost.R2 were implemented.Through 20 replicates of fivefold cross-validation(CV)and one prediction for younger individuals,the utility of ML methods in genomic prediction was explored.In CV,compared with genomic BLUP(GBLUP),single-step GBLUP(ssGBLUP)and the Bayesian method BayesHE,ML methods significantly outperformed these conventional methods.ML methods improved the genomic prediction accuracy of GBLUP,ssGBLUP,and BayesHE by 19.3%,15.0% and 20.8%,respectively.In addition,ML methods yielded smaller mean squared error(MSE)and mean absolute error(MAE)in all scenarios.ssGBLUP yielded an improvement of 3.8% on average in accuracy compared to that of GBLUP,and the accuracy of BayesHE was close to that of GBLUP.In genomic prediction of younger individuals,RF and Adaboost.R2_KRR performed better than GBLUP and BayesHE,while ssGBLUP performed comparably with RF,and ssGBLUP yielded slightly higher accuracy and lower MSE than Adaboost.R2_KRR in the prediction of total number of piglets born,while for number of piglets born alive,Adaboost.R2_KRR performed significantly better than ssGBLUP.Among ML methods,Adaboost.R2_KRR consistently performed well in our study.Our findings also demonstrated that optimal hyperparameters are useful for ML methods.After tuning hyperparameters in CV and in predicting genomic outcomes of younger individuals,the average improvement was 14.3% and 21.8% over those using default hyperparameters,respectively.Conclusion:Our findings demonstrated that ML methods had better overall prediction performance than conventional genomic selection methods,and could be new options for genomic prediction.Among ML methods,Adaboost.R2_KRR consistently performed well in our study,and tuning hyperparameters is necessary for ML methods.The optimal hyperparameters depend on the character of traits,datasets etc. 展开更多
关键词 Genomic prediction Machine learning PIG Prediction accuracy
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A higher prediction accuracy–based alpha–beta filter algorithm using the feedforward artificial neural network 被引量:3
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作者 Junaid Khan Eunkyu Lee Kyungsup Kim 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第4期1124-1139,共16页
The alpha–beta filter algorithm has been widely researched for various applications,for example,navigation and target tracking systems.To improve the dynamic performance of the alpha–beta filter algorithm,a new pred... The alpha–beta filter algorithm has been widely researched for various applications,for example,navigation and target tracking systems.To improve the dynamic performance of the alpha–beta filter algorithm,a new prediction learning model is proposed in this study.The proposed model has two main components:(1)the alpha–beta filter algorithm is the main prediction module,and(2)the learning module is a feedforward artificial neural network(FF‐ANN).Furthermore,the model uses two inputs,temperature sensor and humidity sensor data,and a prediction algorithm is used to predict actual sensor readings from noisy sensor readings.Using the novel proposed technique,prediction accuracy is significantly improved while adding the feed‐forward backpropagation neural network,and also reduces the root mean square error(RMSE)and mean absolute error(MAE).We carried out different experiments with different experimental setups.The proposed model performance was evaluated with the traditional alpha–beta filter algorithm and other algorithms such as the Kalman filter.A higher prediction accuracy was achieved,and the MAE and RMSE were 35.1%–38.2%respectively.The final proposed model results show increased performance when compared to traditional methods. 展开更多
关键词 alpha beta filter artificial neural network navigation prediction accuracy target tracking problems
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Effects of Different Spatial Resolutions on Prediction Accuracy of Thunnus alalunga Fishing Ground in Waters Near the Cook Islands Based on Long Short-Term Memory(LSTM)Neural Network Model 被引量:2
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作者 XU Hui SONG Liming +4 位作者 ZHANG Tianjiao LI Yuwei SHEN Jieran ZHANG Min LI Kangdi 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第5期1427-1438,共12页
Albacore tuna(Thunnus alalunga)is one of the target species of tuna longline fishing,and waters near the Cook Islands are a vital albacore tuna fishing ground.Marine environmental data are usually presented with diffe... Albacore tuna(Thunnus alalunga)is one of the target species of tuna longline fishing,and waters near the Cook Islands are a vital albacore tuna fishing ground.Marine environmental data are usually presented with different spatial resolutions,which leads to different results in tuna fishery prediction.Study on the impact of different spatial resolutions on the prediction accuracy of albacore tuna fishery to select the best spatial resolution can contribute to better management of albacore tuna resources.The nominal catch per unit effort(CPUE)of albacore tuna is calculated according to vessel monitor system(VMS)data collected from Chinese distantwater fishery enterprises from January 1,2017 to May 31,2021.A total of 26 spatiotemporal and environmental factors,including temperature,salinity,dissolved oxygen of 0–300 m water layer,chlorophyll-a concentration in the sea surface,sea surface height,month,longitude,and latitude,were selected as variables.The temporal resolution of the variables was daily and the spatial resolutions were set to be 0.5°×0.5°,1°×1°,2°×2°,and 5°×5°.The relationship between the nominal CPUE and each individual factor was analyzed to remove the factors irrelavant to the nominal CPUE,together with a multicollinearity diagnosis on the factors to remove factors highly related to the other factors within the four spatial resolutions.The relationship models between CPUE and spatiotemporal and environmental factors by four spatial resolutions were established based on the long short-term memory(LSTM)neural network model.The mean absolute error(MAE)and root mean square error(RMSE)were used to analyze the fitness and accuracy of the models,and to determine the effects of different spatial resolutions on the prediction accuracy of the albacore tuna fishing ground.The results show the resolution of 1°×1°can lead to the best prediction accuracy,with the MAE and RMSE being 0.0268 and 0.0452 respectively,followed by 0.5°×0.5°,2°×2°and 5°×5°with declining prediction accuracy.The results suggested that 1)albacore tuna fishing ground can be predicted by LSTM;2)the VMS records the data in detail and can be used scientifically to calculate the CPUE;3)correlation analysis,and multicollinearity diagnosis are necessary to improve the prediction accuracy of the model;4)the spatial resolution should be 1°×1°in the forecast of albacore tuna fishing ground in waters near the Cook Islands. 展开更多
关键词 albacore tuna fishing ground prediction accuracy VMS spatial resolution LSTM the Cook Islands
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Convergence of Y Chromosome STR Haplotypes from Different SNP Haplogroups Compromises Accuracy of Haplogroup Prediction 被引量:9
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作者 Chuan-Chao Wang Ling-Xiang Wang +5 位作者 Rukesh Shrestha Shaoqing Wen Manfei Zhang Xinzhu Tong Li Jin Hui Li 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2015年第7期403-407,共5页
The paternally inherited Y chromosome has been widely used in forensics for personal identification, in anthropology and population genetics to understand origin and migration of human populations, and also in medical... The paternally inherited Y chromosome has been widely used in forensics for personal identification, in anthropology and population genetics to understand origin and migration of human populations, and also in medical and clinical studies (Wang and Li, 2013; Wang et al., 2014). There are two kinds of extremely useful markers in Y chromosome, single nucle- otide polymorphism (SNP) and short tandem repeats (STRs). With a very low mutation rate on the order of 3.0 x 10-8 mutations/nucleotide/generation (Xue et al., 2009), SNP markers have been used in constructing a robust phylogeny tree linking all the Y chromosome lineages from world pop- ulations (Karafet et al., 2008). Those lineages determined by the pattern of SNPs are called haplogroups. That is to say, we have to genotype an appropriate number of SNPs in order to assign a given Y chromosome to a haplogroup. Compared with SNPs, the mutation rates of STR markers are about four to five orders of magnitude higher (Gusmgo et al., 2005; Ballantyne et al., 2010). Typing STR has advantages of saving time and cost compared with typing SNPs in phylogenetic assignment of a Y chromosome (Wang et al., 2010). A set of STR values for an individual is called a haplotype. Because of the disparity in mutation rates between SNP and STR, one SNP haplogroup could actually comprise many STR haplotypes (Wang et al., 2010). It is most interesting that STR variability is clustered more by haplogroups than by populations (Bosch et al., 1999; Behar et al., 2004), which indicates that STR haplotypes could be used to infer the haplogroup information of a given Y chromosome. There has been increasing interest in this cost- effective strategy for predicting the haplogroup from a given STR haplotype when SNP data are unavailable. For instance, Vadim Urasin's YPredictor (http://predictor.ydna.ru/), Whit Atheys' haplogroup predictor (http://www.hprg.com/hapest5/) (Athey, 2005, 2006), and haplogroup classifier of Arizona University (Schlecht et al., 2008) have been widely employed in previous studies for haplogroup prediction (Larmuseau et al., 2010; Bembea et al., 2011; Larmuseau et al., 2012; Tarlykov et al., 2013). 展开更多
关键词 STR Convergence of Y Chromosome STR Haplotypes from Different SNP Haplogroups Compromises accuracy of Haplogroup Prediction SNP SNPs
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Prognostic Kalman Filter Based Bayesian Learning Model for Data Accuracy Prediction
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作者 S.Karthik Robin Singh Bhadoria +5 位作者 Jeong Gon Lee Arun Kumar Sivaraman Sovan Samanta A.Balasundaram Brijesh Kumar Chaurasia S.Ashokkumar 《Computers, Materials & Continua》 SCIE EI 2022年第7期243-259,共17页
Data is always a crucial issue of concern especially during its prediction and computation in digital revolution.This paper exactly helps in providing efficient learning mechanism for accurate predictability and reduc... Data is always a crucial issue of concern especially during its prediction and computation in digital revolution.This paper exactly helps in providing efficient learning mechanism for accurate predictability and reducing redundant data communication.It also discusses the Bayesian analysis that finds the conditional probability of at least two parametric based predictions for the data.The paper presents a method for improving the performance of Bayesian classification using the combination of Kalman Filter and K-means.The method is applied on a small dataset just for establishing the fact that the proposed algorithm can reduce the time for computing the clusters from data.The proposed Bayesian learning probabilistic model is used to check the statistical noise and other inaccuracies using unknown variables.This scenario is being implemented using efficient machine learning algorithm to perpetuate the Bayesian probabilistic approach.It also demonstrates the generative function forKalman-filer based prediction model and its observations.This paper implements the algorithm using open source platform of Python and efficiently integrates all different modules to piece of code via Common Platform Enumeration(CPE)for Python. 展开更多
关键词 Bayesian learning model kalman filter machine learning data accuracy prediction
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AI Method for Improving Crop Yield Prediction Accuracy Using ANN
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作者 T.Sivaranjani S.P.Vimal 《Computer Systems Science & Engineering》 SCIE EI 2023年第10期153-170,共18页
Crop Yield Prediction(CYP)is critical to world food production.Food safety is a top priority for policymakers.They rely on reliable CYP to make import and export decisions that must be fulfilled before launching an ag... Crop Yield Prediction(CYP)is critical to world food production.Food safety is a top priority for policymakers.They rely on reliable CYP to make import and export decisions that must be fulfilled before launching an agricultural business.Crop Yield(CY)is a complex variable influenced by multiple factors,including genotype,environment,and their interactions.CYP is a significant agrarian issue.However,CYP is the main task due to many composite factors,such as climatic conditions and soil characteristics.Machine Learning(ML)is a powerful tool for supporting CYP decisions,including decision support on which crops to grow in a specific season.Generally,Artificial Neural Networks(ANN)are usually used to predict the behaviour of complex non-linear models.As a result,this research paper attempts to determine the correlations between climatic variables,soil nutrients,and CYwith the available data.InANN,threemethods,Levenberg-Marquardt(LM),Bayesian regularisation(BR),and scaled conjugate gradient(SCG),are used to train the neural network(NN)model and then compared to determine prediction accuracy.The performance measures of the training,as declared above,such as Mean Squared Error(MSE)and correlation coefficient(R),were determined to assess the ANN models that had been built.The experimental study proves that LM training algorithms are better,while BR and SCG have minimal performance. 展开更多
关键词 Crop prediction accuracy ANN precision agriculture crop yield
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Trajectory Control: Directional MWD Inversely New Wellbore Positioning Accuracy Prediction Method
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作者 Ahmed Abd Alaziz Ibrahim Tagwa Ahmed Musa 《Journal of China University of Geosciences》 SCIE CSCD 2004年第4期425-433,共9页
The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coinci... The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coincides exactly with the planned path, which is usually a plane curve with straight, building, holding, and dropping sections in succession. The drilling direction is of course dependant on the direction of the resultant forces acting on the bit and it is quite a tough job to hit the optimum target at the hole bottom as required. The traditional passive methods for correcting the drilling path have not met the demand to improve the techniques of deviation control. A method for combining wellbore surveys to obtain a composite, more accurate well position relies on accepting the position of the well from the most accurate survey instrument used in a given section of the wellbore. The error in each position measurement is the sum of many independent root sources of error effects. The relationship between surveys and other influential factors is considered, along with an analysis of different points of view. The collaborative work describes, establishes a common starting point of wellbore position uncertainty model, definition of what constitutes an error model, mathematics of position uncertainty calculation and an error model for basic directional service. 展开更多
关键词 wellbore trajectory bit trajectory actual/planned path steerable directional tool measurement while drilling (MWD) logging while drilling (LWD) position uncertainty error accuracy prediction weighting function
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Error Prediction in Industrial Robot Machining: Optimization Based on Stiffness and Accuracy Limit
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作者 Yair Shneor Vladimir Chapsky 《Engineering(科研)》 2021年第6期330-351,共22页
Among the advantages of using industrial robots for machining applications instead of machine tools are flexibility, cost effectiveness, and versatility. Due to the kinematics of the articulated robot, the system beha... Among the advantages of using industrial robots for machining applications instead of machine tools are flexibility, cost effectiveness, and versatility. Due to the kinematics of the articulated robot, the system behaviour is quite different compared with machine tools. Two major questions arise in implementing robots in machining tasks: one is the robot’s stiffness, and the second is the achievable machined part accuracy, which varies mainly due to the huge variety of robot models. This paper proposes error prediction model in the application of industrial robot for machining tasks, based on stiffness and accuracy limits. The research work includes experimental and theoretical parts. Advanced machining and inspection tools were applied, as well as a theoretical model of the robot structure and stiffness based on the form-shaping function approach. The robot machining performances, from the workpiece accuracy point of view were predicted. 展开更多
关键词 Robot Stiffness Robot Machining Performances accuracy Prediction
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Postoperative serum tumor markers-based nomogram predicting early recurrence for patients undergoing radical resections of pancreatic ductal adenocarcinoma 被引量:1
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作者 Hang He Cai-Feng Zou +3 位作者 Feng Yang Yang Di Chen Jin De-Liang Fu 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第10期3211-3223,共13页
BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing i... BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing individualized adjuvant therapies.Postoperative serum tumor markers(STMs)are indicators of tumor progression and may improve current systems for predicting ER.AIM To establish an improved nomogram based on postoperative STMs to predict ER in PDAC.METHODS We retrospectively enrolled 282 patients who underwent radical resection for PDAC at our institute between 2019 and 2021.Univariate and multivariate Cox regression analyses of variables with or without postoperative STMs,were performed to identify independent risk factors for ER.A nomogram was constructed based on the independent postoperative STMs.Receiver operating characteristic curve analysis was used to evaluate the area under the curve(AUC)of the nomogram.Survival analysis was performed using Kaplan-Meier survival plot and log-rank test.RESULTS Postoperative carbohydrate antigen 19-9 and carcinoembryonic antigen levels,preoperative carbohydrate antigen 125 levels,perineural invasion,and pTNM stage III were independent risk factors for ER in PDAC.The postoperative STMs-based nomogram(AUC:0.774,95%CI:0.713-0.835)had superior accuracy in predicting ER compared with the nomogram without postoperative STMs(AUC:0.688,95%CI:0.625-0.750)(P=0.016).Patients with a recurrence nomogram score(RNS)>1.56 were at high risk for ER,and had significantly poorer recurrence-free survival[median:3.08 months,interquartile range(IQR):1.80-8.15]than those with RNS≤1.56(14.00 months,IQR:6.67-24.80),P<0.001).CONCLUSION The postoperative STMs-based nomogram improves the predictive accuracy of ER in PDAC,stratifies the risk of ER,and identifies patients at high risk of ER for tailored adjuvant therapies. 展开更多
关键词 NOMOGRAM Postoperative serum tumor markers Early recurrence Predicting accuracy Adjuvant therapy Pancreatic ductal adenocarcinoma
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Prediction Model of Wax Deposition Rate in Waxy Crude Oil Pipelines by Elman Neural Network Based on Improved Reptile Search Algorithm
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作者 Zhuo Chen Ningning Wang +1 位作者 Wenbo Jin Dui Li 《Energy Engineering》 EI 2024年第4期1007-1026,共20页
A hard problem that hinders the movement of waxy crude oil is wax deposition in oil pipelines.To ensure the safe operation of crude oil pipelines,an accurate model must be developed to predict the rate of wax depositi... A hard problem that hinders the movement of waxy crude oil is wax deposition in oil pipelines.To ensure the safe operation of crude oil pipelines,an accurate model must be developed to predict the rate of wax deposition in crude oil pipelines.Aiming at the shortcomings of the ENN prediction model,which easily falls into the local minimum value and weak generalization ability in the implementation process,an optimized ENN prediction model based on the IRSA is proposed.The validity of the new model was confirmed by the accurate prediction of two sets of experimental data on wax deposition in crude oil pipelines.The two groups of crude oil wax deposition rate case prediction results showed that the average absolute percentage errors of IRSA-ENN prediction models is 0.5476% and 0.7831%,respectively.Additionally,it shows a higher prediction accuracy compared to the ENN prediction model.In fact,the new model established by using the IRSA to optimize ENN can optimize the initial weights and thresholds in the prediction process,which can overcome the shortcomings of the ENN prediction model,such as weak generalization ability and tendency to fall into the local minimum value,so that it has the advantages of strong implementation and high prediction accuracy. 展开更多
关键词 Waxy crude oil wax deposition rate chaotic map improved reptile search algorithm Elman neural network prediction accuracy
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Determination of Soil Parameters in Apple-Growing Regions by Near-and Mid-Infrared Spectroscopy 被引量:9
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作者 DONG Yi-Wei YANG Shi-Qi +5 位作者 XU Chun-Ying LI Yu-Zhong BAI Wei FAN Zhong-Nan WANG Ya-Nan LI Qiao-Zhen 《Pedosphere》 SCIE CAS CSCD 2011年第5期591-602,共12页
Soil quality monitoring is important in precision agriculture.This study aimed to examine the possibility of assessing the soil parameters in apple-growing regions using spectroscopic methods.A total of 111 soil sampl... Soil quality monitoring is important in precision agriculture.This study aimed to examine the possibility of assessing the soil parameters in apple-growing regions using spectroscopic methods.A total of 111 soil samples were collected from 11 typical sites of apple orchards,and the croplands surrounding them.Near-infrared(NIR) and mid-infrared(MIR) spectra,combined with partial least square regression,were used to predict the soil parameters,including organic matter(OM) content,pH,and the contents of As,Cu,Zn,Pb,and Cr.Organic matter and pH were closely correlated with As and the heavy metals.The NIR model showed a high prediction accuracy for the determination of OM,pH,and As,with correlation coefficients(r) of 0.89,0.89,and 0.90,respectively.The predictions of these three parameters by MIR showed reduced accuracy,with r values of 0.77,0.84,and 0.92,respectively.The heavy metals could also be measured by spectroscopy due to their correlation with organic matter.Both NIR and MIR had high correlation coefficients for the determination of Cu,Zn,and Cr,with standard errors of prediction of 2.95,10.48,and 9.49 mg kg-1 for NIR and 3.69,5.84,and 6.94 mg kg-1 for MIR,respectively.Pb content behaved differently from the other parameters.Both NIR and MIR underestimated Pb content,with r values of 0.67 and 0.56 and standard errors of prediction of 3.46 and 2.99,respectively.Cu and Zn had a higher correlation with OM and pH and were better predicted than Pb and Cr.Thus,NIR spectra could accurately predict several soil parameters,metallic and nonmetallic,simultaneously,and were more feasible than MIR in analyzing soil parameters in the study area. 展开更多
关键词 heavy metals partial least square regression prediction accuracy soil quality spectroscopic method
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A new model for predicting the total tree height for stems cut-to-length by harvesters in Pinus radiata plantations 被引量:2
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作者 Chenxi Shan Huiquan Bi +3 位作者 Duncan Watt Yun Li Martin Strandgard Mohammad Reza Ghaff ariyan 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第1期21-41,共21页
A new model for predicting the total tree height for harvested stems from cut-to-length(CTL)harvester data was constructed for Pinus radiata(D.Don)following a conceptual analysis of relative stem profi les,comparisons... A new model for predicting the total tree height for harvested stems from cut-to-length(CTL)harvester data was constructed for Pinus radiata(D.Don)following a conceptual analysis of relative stem profi les,comparisons of candidate models forms and extensive selections of predictor variables.Stem profi les of more than 3000 trees in a taper data set were each processed 6 times through simulated log cutting to generate the data required for this purpose.The CTL simulations not only mimicked but also covered the full range of cutting patterns of nearly 0.45×106 stems harvested during both thinning and harvesting operations.The single-equation model was estimated through the multipleequation generalized method of moments estimator to obtain effi cient and consistent parameter estimates in the presence of error correlation and heteroscedasticity that were inherent to the systematic structure of the data.The predictive performances of our new model in its linear and nonlinear form were evaluated through a leave-one-tree-out cross validation process and compared against that of the only such existing model.The evaluations and comparisons were made through benchmarking statistics both globally over the entire data space and locally within specifi c subdivisions of the data space.These statistics indicated that the nonlinear form of our model was the best and its linear form ranked second.The prediction accuracy of our nonlinear model improved when the total log length represented more than 20%of the total tree height.The poorer performance of the existing model was partly attributed to the high degree of multicollinearity among its predictor variables,which led to highly variable and unstable parameter estimates.Our new model will facilitate and widen the utilization of harvester data far beyond the current limited use for monitoring and reporting log productions in P.radiata plantations.It will also facilitate the estimation of bark thickness and help make harvester data a potential source of taper data to reduce the intensity and cost of the conventional destructive taper sampling in the fi eld.Although developed for P.radiata,the mathematical form of our new model will be applicable to other tree species for which CTL harvester data are routinely captured during thinning and harvesting operations. 展开更多
关键词 Stem profi les Cut-to-length simulations Harvester data Model construction Nonlinear multipleequation GMM estimation Benchmarking prediction accuracy
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Prediction of effluent concentration in a wastewater treatment plant using machine learning models 被引量:9
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作者 Hong Guo Kwanho Jeong +5 位作者 Jiyeon Lim Jeongwon Jo Young Mo Kim Jong-pyo Park Joon Ha Kim Kyung Hwa Cho 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第6期90-101,共12页
Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process mi... Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen(T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models-artificial neural networks(ANNs) and support vector machines(SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination(R^2), Nash-Sutcliff efficiency(NSE), relative efficiency criteria(d rel). Additionally, Latin-Hypercube one-factor-at-a-time(LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage.However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process. 展开更多
关键词 Artificial neural network Support vector machine Effluent concentration Prediction accuracy Sensitivity analysis
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