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Fundamental error in tree-based machine learning model selection for reservoir characterisation

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Energy Geoscience

Energy Geoscience 2024年第2期5卷 214-224页

作者： Daniel asante Otchere Centre of Excellence in Subsurface Seismic Imaging and Hydrocarbon Prediction Universiti Teknologi PETRONAS32610Seri IskandarPerak Darul RidzuanMalaysia

Over the past two decades,machine learning techniques have been extensively used in predicting reservoir *** this approach has significantly contributed to the industry,selecting an appropriate model is still challenging for most *** solely on statistical metrics to select the best model for a particular problem may not always be the most effective *** study encourages researchers to incorporate data visualization in their analysis and model selection *** evaluate the suitability of different models in predicting horizontal permeability in the Volve field,wireline logs were used to train Extra-Trees,Ridge,Bagging,and XGBoost *** Random Forest feature selection technique was applied to select the relevant logs as inputs for the *** on statistical metrics,the Extra-Trees model achieved the highest test accuracy of 0.996,RMSE of 19.54 mD,and MAE of 3.18 mD,with XGBoost coming in ***,when the results were visualised,it was discovered that the XGBoost model was more suitable for the problem being *** XGBoost model was a better predictor within the sandstone interval,while the Extra-Trees model was more appropriate in non-sandstone *** this study aims to predict permeability in the reservoir interval,the XGBoost model is the most *** contrasting results demonstrate the importance of incorporating data visualisation techniques as an evaluation *** the heterogeneity of the subsurface,relying solely on statistical metrics may not be sufficient to determine which model is best suited for a particular problem.

关键词： Data visualisation Permeability Machine learning Statistical metrics

In vivo assessment of the toxic potential of Dissotis rotundifolia whole plant extract in Sprague–Dawley rats

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Asian Pacific Journal of Tropical Biomedicine 2016年第7期6卷 574-579页

作者： Charles Ansah michael Buenor Adinortey Jerry Asiedu-Larbi Benjamin Aboagye Du-Bois asante Alexander Kwadwo Nyarko Department of Pharmacology Faculty of Pharmacy and Pharmaceutical SciencesCollege of Health SciencesKwame Nkrumah University of Science and Technology Department of Biochemistry School of Biological Sciences College of Agriculture and Natural Sciences University of Cape Coast Pharmacology Unit Centre for Plant Medicine Research Department of Biomedical and Forensic Sciences School of Biological Sciences College of Agriculture and Natural SciencesUniversity of Cape Coast Department of Clinical Pathology Noguchi Memorial Institute for Medical ResearchUniversity of Ghana

Objective: To assess the toxic potential of Dissotis rotundifolia(***) whole plant extract in Spraque–Dawley rats within a 2-week period of ***: Methanolic extract of D. rotundifolia was administered orally once daily at dose levels of 0,100, 300 and 1 000 mg/kg body weight for 14 days. Toxicity was assessed using mortality, clinical signs, body and organ weights, hematological indices,serum chemistry parameters and histopathological ***: There were no treatment-related mortalities or differences in clinical signs,hematology and serum biochemistry. This was confirmed by micrographs obtained from histopathological ***: The results obtained from the sub-acute toxicological assessment of D. rotundifolia extract suggest that the extract is non-toxic at doses up to 1 000 mg/kg/day administered for a period of 14 days.

关键词： Dissotis rotundifolia Ghana Melastomataceae Toxic potential

Improvement of Rice Production under Drought Conditions in West Africa:Application of QTLs in Breeding for Drought Resistance

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Rice science 2022年第6期29卷 512-521页

作者： Kossi Lorimpo ADJAH Maxwell Darko asante Aboubacar TOURE Mawuli AZIADEKEY Francis Osei AMOAKO-ANDOH michael FREI Yacouba DIALLO Komi AGBOKA West African Science Service Center on Climate Change and Adapted Land Use/Climate Change and Agriculture Program IPR/IFRAP.O.Box 224KatibougouMali Council for Scientific and Industrial Research-Crops Research Institute P.O.Box 3785Fumesua-KumasiGhana University of Sciences Techniques and Technologies of Bamako(USTTB)P.O.Box 423BamakoMali International Crops Research Institute for the Semi-Arid Tropics P.O.Box 320BamakoMali University of Lomé(UL) P.O.Box 1515LoméTogo Institute for Agronomy and Plant Breeding of Justus-Liebig-University of Giessen Giessen 35392Germany Polytechnic Rural Institute of Training and Applied Research(IPR/IFRA) P.O.Box 224KatibougouMali Council for Scientific and Industrial Research-College of Science and Technology Department of Plant Resources DevelopmentP.O.Box 3785Fumesua-KumasiGhana

Rice plays a paramount role in food and nutrition security in many West African *** the doubling of production during the last decade,rice consumption has grown faster,creating a deficit between the demand and *** the West African sub-region remains the main rice-producing centre on the continent,production is severely hampered by biotic and abiotic *** is one of the factors that most severely reduce grain yields of *** of production need to be established in order to mitigate yield loss as a result of *** review discusses the effects of drought on rice production in West Africa and its mitigation with an emphasis on the improvement of tolerance to drought *** stability can be achieved by developing drought-tolerant varieties through several processes encompassing profiling of known QTLs and identification of new ones,marker-assisted selection,genomic selection,and extensive multi-locational yield *** suggest a comprehensive strategy for breeding drought-tolerant rice varieties in West Africa.

关键词： West Africa rice drought-tolerant variety QTL high-throughput genotyping

Experimental investigation of gaseous solvent huff-n-puff in the Middle Bakken Formation

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Petroleum Science 2023年第6期20卷 3488-3497页

作者： Samuel asante Afari Kegang Ling Demetrius Maxey Billel Sennaoui Jerjes Hurtado Porlles Department of Petroleum Engineering University of North Dakota2844 Campus RdStop 8154Grand ForksND58202-6116USA

The efficacy of gaseous solvents in enhancing oil recovery(EOR)in unconventional reservoirs and the influence of operational and design parameters are still debated among the oil recovery research *** work investigated the recovery-enhancing capabilities of two potent gaseous solvents,CO_(2) and ethane,in tight core *** huff-n-puff(H-n-P)experiments were conducted under three miscibility conditions to investigate the influence of the key operating parameters and the dependency of their impact on the miscibility conditions and gas *** results show that oil recovery increased with increasing pressure from below(BM)to above(AM)miscibility pressure in a non-linear trend,irrespective of the gas ***,the influence of the soak period was noticeably dependent on the miscibility condition,specifically more remarkable under AM conditions and less apparent under BM ***,the effect of the production period was more pronounced at AM conditions for both ***,the impact of rock surface area-to-volume(SA/V)was only observed at BM,where both gases recovered more oil in the core samples with high SA/*** general,ethane showed a higher efficacy for oil recovery than CO_(2);CO_(2) recovered 21%–70%of oil in small core samples,while ethane could recover 32%–88%.The highest recovery was achieved with ethane injected under AM conditions,with a prolonged soak time,a short production period and into a core sample with a high SA/*** believe the findings from this work will help better understand and design H-n-P EOR projects.

关键词： Unconventional reservoirs Huff-n-puff Gas solvent Ethane CO_(2)miscibility

Factors Contributing to Students’ Academic Performance in Public Senior High Schools in Sawla-Tuna-Kalba District Ghana

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Factors Contributing to Students’ Academic Performance in P...

作者： ISAAC KWAKU asante 江苏大学

学位级别：硕士

The main aim of this study was to investigate factors which have the probable influence on Senior High School students’ academic performance within Sawla-Tuna-Kalba *** study used self-designed survey and stratified sample technique to select the *** study was conducted among four hundred and twenty（420）participants which consisted of hundred（100）teachers,twenty（20）Heads of Department,and three hundred（300）students from three Senior High Schools in Sawla-Tuna-Kalba *** main data collection tool used were an online questionnaire（primary）and student’s terminal report（secondary）.The study used student’s perception on school climate,student’s evaluation of classroom environment,teacher’s perception about the school climate and teacher’s professionalism in the classroom as independent variables and Student Academic Performances as a dependable variable for the ***（1982）Educational Production Theory was adopted as the main theoretical framework which guided the selection of the *** Analysis with Principal Component Analysis（PCA）was used to reduce the dimensionality of the data and identified the critical factors that influence students’ academic performance in the selected Senior High *** study further used confirmatory factor analysis（CFA）and Path Analysis to justify the model fit of all the schools’ *** results indicated that students’ positive perception of their schools,students’ evaluation of classroom environment and teachers’ professionalism in the classroom variables were consistent in influencing students’ academic performance across all the three Senior High Schools in Sawla-Tuna-Kalba ***,the study recognized that teachers’ level of professionalism influenced students’ academic performance directly and indirectly because they used both their experience and talents to impress on students’ *** study suggested that the schools within the district should endeavour to

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Detection and assessment of nitrogen effect on cold tolerance for tea by hyperspectral reflectance with PLSR, PCR, and LM models

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Information Processing in Agriculture 2021年第1期8卷 96-104页

作者： Eric Amoah asante Zhe Du Yongzong Lu Yongguang Hu School of Agricultural Equipment Engineering Institute of Agricultural EngineeringJiangsu UniversityZhenjiangJiangsu 212013China Department of Mechanical Engineering Faculty of EngineeringKoforidua Technical UniversityKoforiduaGhana

Knowledge of nutrients effect on freezing tolerance is vital for protecting tea plants against cold injury(CI).Freezing injury treatments on tea leaves with different low temperature and nitrogen(N)concentration was evaluated by hyperspectral imaging based on the reflectance as potential analytical ***,quantitative evaluation of the CI was improved by comparing analyzed results using partial least squares regression(PLSR),principle component regression(PCR)and linear model(LM)*** of the CI was obtained by hyperspectral imaging system in the band between 871 and 1766 *** results showed that average reflectance increases with the rise of N concentration.A substantial portion of the leaf from the plant with 100%N dosage had the darkest image and resulted in the highest reflectance because the N weakened the negative effect of freezing *** of the five spectral domains tested,the best predictive accuracy for the CI of the tea leaf was achieved by PCR(R^(2)=0.9971,RMSE=0.0609)in 1410–1766 nm wavelength,followed by LM(R^(2)=0.9999,RMSE=0.0805)in 871–1000 *** whole interval had the worse prediction accuracy which could be caused by large variations in the data for a specific treatment and high absorption peak occurring around 1450 nm in the reflectance *** averages,R^(2) and RMSE for all the three statistical models showed that the worse prediction accuracy occurred in 1410–1766 nm,followed by the whole interval 871–1766 *** prediction accuracy was low which could be due to the strong water absorption peaks that appeared in both range of *** models without absorption bands had improved correlation coefficient and reduced RMSE values between the measured and the predicted CI(R^(2)=0.9676;RMSE=0.3067)compared to the model developed with the reflectance values in the entire waveband(R^(2)=0.9504;RMSE=0.6629).The reflectance values where absorption bands occurred had detrimental effect on the model performance,which

关键词： Cold injury Hyperspectral imaging Reflectance Principal component

Sprinkler irrigation system for tea frost protection and the application effect

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International Journal of Agricultural and Biological Engineering 2016年第5期9卷 17-23页

作者： Hu Yongguang Zhao Chen Liu Pengfei asante Eric Amoah Li Pingping Key Laboratory of Modern Agricultural Equipment and Technology Jiangsu UniversityZhenjiang 212013China College of Biology and the Environment Nanjing Forestry UniversityNanjing 210037China

A sprinkler irrigation system was designed and applied for a tea field to achieve frost protection through latent heat release when water turning into *** protection effects during night were tested at different irrigation application rates by monitoring air temperature around tea canopy(Tc).Temperature sensors were arranged at different distances from the *** preliminary results showed that,when the sprinkler system worked continuously at the application rate of 2-4 mm/h before sunrise,tea canopy was covered with ice and Tc remained around 0℃,preventing tea plants from frost *** no more temperature rise was obviously observed at the application rates above 4 mm/h,which means less cost *** system was stopped after sunrise when background air temperature rose back to 0℃and Tc increased by 2.2℃in one hour,while Tc of non-irrigated area increased by 4.8℃,which might cause thawing injuries to tea *** leaf surface temperature was lower than Tc,and the difference between the leaf surface temperature and Tc decreased with the increase of application ***,the sprinkler irrigation system could achieve tea frost protection,and the recommended application rate was 2-4 mm/h for better protection *** system should keep running throughout frost night till half an hour after *** start and stop of the sprinkler irrigation system should be controlled based on Tc.

关键词： sprinkler irrigation frost protection Camellia Sinensis L application rate temperature rise frost damage

Control system of a performance test-bed for frost protection wind machines

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International Journal of Agricultural and Biological Engineering 2016年第6期9卷 36-43页

作者： Hu Yongguang Liu Ping asante Eric Amoah Wu Wenye Li Pingping Key Laboratory of Modern Agricultural Equipment and Technology Jiangsu UniversityZhenjiang 212013China College of Biology and the Environment Nanjing Forestry UniversityNanjing 210037China

To test the performance and optimize operational parameters of various frost protection wind machines,a control system of performance test-bed was designed and developed based on Programmable Logic Controller(PLC)and touch *** system realized automatic control of operational parameters including hydraulic platform height,impeller rotation speed,depression angle,rotation range and *** case study results shows that the control accuracy of all the parameters was achieved with the average errors of 2.11 cm for height,9.5 r/min for impeller rotation speed,0.83°for pan-tilt rotation range and 0.061 min for rotation *** the control of the test-bed,the performances of various wind machines,such as the distribution of airflow and temperature,and frost protection effect,could be tested under various working conditions,which provide experiment supports for developing wind machines adapted to different conditions with higher frost protection effect.

关键词： frost protection wind machines performance test-bed design control PLC

Review of air disturbance technology for plant frost protection

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International Journal of Agricultural and Biological Engineering 2018年第3期11卷 21-28页

作者： Yongguang Hu Eric Amoah asante Yongzong Lu Ashraf Mahmood Noman Ali Buttar Shouqi Yuan School of Agricultural Equipment Engineering Jiangsu UniversityZhenjiang 212013China Faculty of Engineering Koforidua Technical UniversityKoforiduaGhana Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China

Confronted with severe frost damage to plants,methods,technologies and equipment have been developed and applied during the past *** paper presents a comprehensive review on the most effective and active technology to protect plants from radiation frost based on air disturbance *** working principle of the technology was elaborated with frost protection mechanism,structures and applicability of three types of working patterns:conventional wind machines,selective inverted sink and portable vertical *** an automatic mechanized technology,control strategy,applicable occasion and proper parameters are introduced for each type of working *** operation of the technology and equipment depends on plant critical temperature,prevailing climatic conditions,thermal inversions strength,as well as *** frost protection performance and effectiveness of conventional horizontal wind machines,selective inverted sinks and helicopters are discussed and compared from the cost-effectiveness and application aspects,and the feasibility of selective inverted sinks is still ***,conventional wind machines are the best choice for plant frost protection and consequently are widely used in temperate and subtropical areas throughout the *** frost protection application with helicopters is not easy to use during the frost nights with high *** paper also provides researchers with some perspectives on improving air disturbance technology and its equipment,and some practice recommendations for growers.

关键词： thermal inversion plant frost protection air disturbance technology wind machine cost-effectiveness control technology