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Genetic variation of height growth rhythm between clones of Larix kaempferi × L. gmelini based on logistic models 被引量:1
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作者 Chunming Li Hui Xia +4 位作者 Hui Bai Hongmei Wang Yajuan Xing Xiyang Zhao Xiaomei Sun 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第5期1387-1394,共8页
Fifty-three larch interspecific hybrid clones(Larix kaempferi × L.gmelini) and their parent clones were used for growth curve analysis of height variations.The growth curves of the 55 clones were 'S'-shaped a... Fifty-three larch interspecific hybrid clones(Larix kaempferi × L.gmelini) and their parent clones were used for growth curve analysis of height variations.The growth curves of the 55 clones were 'S'-shaped and 36 exhibited similar curves as the male parent.The coefficients of the logistic models were higher than 0.943,indicating that our results were effective in the simulation of the growth curves.ANOVA analysis showed significant differences in height of different clones (P/0.01).Average date of maximum height growth was Day 173,and average duration of rapid growth lasted for 50 days.Annual average increase in height was 9.7cm d^(-1) and daily average increase was 0.2 cm.The ratio of GR to the total annual increase in height ranged from 51.2 to 68.8%,with the average being 59.8%.There was a positive correlation between k values and plant heights which benefited from the evaluation of early plant height.There was also a positive correlation between GR(growth stage),GD(plant height) and annual increase in height.These results are informative to the evaluation of the elite clone selection and provide a theoretical basis for breeding and management. 展开更多
关键词 Larix kaempferi ×L. gmelini Hybrid clones logistic modeling Plant height variation
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Enhancing PDF Malware Detection through Logistic Model Trees
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作者 Muhammad Binsawad 《Computers, Materials & Continua》 SCIE EI 2024年第3期3645-3663,共19页
Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection a... Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection approaches.The study article discusses the growing danger to cybersecurity that malware hidden in PDF files poses,highlighting the shortcomings of conventional detection techniques and the difficulties presented by adversarial methodologies.The article presents a new method that improves PDF virus detection by using document analysis and a Logistic Model Tree.Using a dataset from the Canadian Institute for Cybersecurity,a comparative analysis is carried out with well-known machine learning models,such as Credal Decision Tree,Naïve Bayes,Average One Dependency Estimator,Locally Weighted Learning,and Stochastic Gradient Descent.Beyond traditional structural and JavaScript-centric PDF analysis,the research makes a substantial contribution to the area by boosting precision and resilience in malware detection.The use of Logistic Model Tree,a thorough feature selection approach,and increased focus on PDF file attributes all contribute to the efficiency of PDF virus detection.The paper emphasizes Logistic Model Tree’s critical role in tackling increasing cybersecurity threats and proposes a viable answer to practical issues in the sector.The results reveal that the Logistic Model Tree is superior,with improved accuracy of 97.46%when compared to benchmark models,demonstrating its usefulness in addressing the ever-changing threat landscape. 展开更多
关键词 Malware detection PDF files logistic model tree feature selection CYBERSECURITY
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Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression
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作者 Yuqiao Zhou Xinyang Xu Wenjing Ma 《Applied Mathematics》 2024年第1期51-64,共14页
In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluste... In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics. 展开更多
关键词 Glass Composition L1 Regularization logistic Regression Model K-Means Clustering Analysis Elbow Rule Parameter Verification
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Evaluation of Inference Adequacy in Cumulative Logistic Regression Models:An Empirical Validation of ISW-Ridge Relationships 被引量:3
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作者 Cheng-Wu CHEN Hsien-Chueh Peter YANG +2 位作者 Chen-Yuan CHEN Alex Kung-Hsiung CHANG Tsung-Hao CHEN 《China Ocean Engineering》 SCIE EI 2008年第1期43-56,共14页
Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ri... Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ridge height and potential energy during wave-ridge interaction with a binary and cumulative logistic regression model. In testing the Global Null Hypothesis, all values are p 〈0.001, with three statistical methods, such as Likelihood Ratio, Score, and Wald. While comparing with two kinds of models, tests values obtained by cumulative logistic regression models are better than those by binary logistic regression models. Although this study employed cumulative logistic regression model, three probability functions p^1, p^2 and p^3, are utilized for investigating the weighted influence of factors on wave reflection. Deviance and Pearson tests are applied to cheek the goodness-of-fit of the proposed model. The analytical results demonstrated that both ridge height (X1 ) and potential energy (X2 ) significantly impact (p 〈 0. 0001 ) the amplitude-based refleeted rate; the P-values for the deviance and Pearson are all 〉 0.05 (0.2839, 0.3438, respectively). That is, the goodness-of-fit between ridge height ( X1 ) and potential energy (X2) can further predict parameters under the scenario of the best parsimonious model. Investigation of 6 predictive powers ( R2, Max-rescaled R^2, Sorners' D, Gamma, Tau-a, and c, respectively) indicate that these predictive estimates of the proposed model have better predictive ability than ridge height alone, and are very similar to the interaction of ridge height and potential energy. It can be concluded that the goodness-of-fit and prediction ability of the cumulative logistic regression model are better than that of the binary logistic regression model. 展开更多
关键词 binary logistic regression cumulative logistic regression model GOODNESS-OF-FIT internal solitary wave amplitude-based transmission rate
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Partial Oscillation of m-dimensional Logistic Ecologic Models 被引量:1
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作者 Luo Qi(Department of Basic Science, Wuhan Yejin University of Science and Technology, Wuhan 430081, China) 《Wuhan University Journal of Natural Sciences》 CAS 1998年第1期5-10,共6页
We present and discuss the partial oscillation with respect to equilibrium state ofm-dimensional Logistic delay ecologic models, and obtain some simple criteria.
关键词 logistic ecologic model partial oscillation diffusion CONSTANT Liapunov functional
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Adequacy of Logistic models for describing the dynamics of COVID-19 pandemic
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作者 Abdallah Abusam Razan Abusam Bader Al-Anzi 《Infectious Disease Modelling》 2020年第1期536-542,共7页
Logistic models have been widely used for modelling the ongoing COVID-19 pandemic.This study used the data for Kuwait to assess the adequacy of the two most commonly used logistic models(Verhulst and Richards models)f... Logistic models have been widely used for modelling the ongoing COVID-19 pandemic.This study used the data for Kuwait to assess the adequacy of the two most commonly used logistic models(Verhulst and Richards models)for describing the dynamics COVID-19.Specifically,the study assessed the predictive performance of these two models and the practical identifiability of their parameters.Two model calibration approaches were adopted.In the first approach,all the data was used to fit the models as per the heuristic model fitting method.In the second approach,only the first half of the data was used for calibrating the models,while the other half was left for validating the models.Analysis of the obtained calibration and validation results have indicated that parameters of the two models cannot be identified with high certainty from COVID-19 data.Further,the models shown to have structural problems as they could not predict reasonably the validation data.Therefore,they should not be used for long-term predictions of COVID-19.Suggestion have been made for improving the performances of the models. 展开更多
关键词 Infectious disease modeling logistic growth models Parameter identification Model performance COVID-19 in Kuwait
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Synergistic effects of planting density and nitrogen fertilization on chlorophyll degradation and leaf senescence after silking in maize
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作者 Tianqiong Lan Lunjing Du +9 位作者 Xinglong Wang Xiaoxu Zhan Qinlin Liu Gui Wei Chengcheng Lyu Fan Liu Jiaxu Gao Dongju Feng Fanlei Kong Jichao Yuan 《The Crop Journal》 SCIE CSCD 2024年第2期605-613,共9页
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act... Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield. 展开更多
关键词 DENSITY Nitrogen fertilization Leaf senescence Chlorophyll-degrading enzyme logistic model
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Comparison of machine learning models for gully erosion susceptibility mapping 被引量:7
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作者 Alireza Arabameri Wei Chen +6 位作者 Marco Loche Xia Zhao Yang Li Luigi Lombardo Artemi Cerda Biswajeet Pradhan Dieu Tien Bui 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第5期1609-1620,共12页
Gully erosion is a disruptive phenomenon which extensively affects the Iranian territory,especially in the Northern provinces.A number of studies have been recently undertaken to study this process and to predict it o... Gully erosion is a disruptive phenomenon which extensively affects the Iranian territory,especially in the Northern provinces.A number of studies have been recently undertaken to study this process and to predict it over space and ultimately,in a broader national effort,to limit its negative effects on local communities.We focused on the Bastam watershed where 9.3%of its surface is currently affected by gullying.Machine learning algorithms are currently under the magnifying glass across the geomorphological community for their high predictive ability.However,unlike the bivariate statistical models,their structure does not provide intuitive and quantifiable measures of environmental preconditioning factors.To cope with such weakness,we interpret preconditioning causes on the basis of a bivariate approach namely,Index of Entropy.And,we performed the susceptibility mapping procedure by testing three extensions of a decision tree model namely,Alternating Decision Tree(ADTree),Naive-Bayes tree(NBTree),and Logistic Model Tree(LMT).We dichotomized the gully information over space into gully presence/absence conditions,which we further explored in their calibration and validation stages.Being the presence/absence information and associated factors identical,the resulting differences are only due to the algorithmic structures of the three models we chose.Such differences are not significant in terms of performances;in fact,the three models produce outstanding predictive AUC measures(ADTree=0.922;NBTree=0.939;LMT=0.944).However,the associated mapping results depict very different patterns where only the LMT is associated with reasonable susceptibility patterns.This is a strong indication of what model combines best performance and mapping for any natural hazard-oriented application. 展开更多
关键词 Oil erosion GIS Alternating decision tree model logistic model tree model
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PERSISTENCE AND EXTINCTION OF A STOCHASTIC LOGISTIC MODEL WITH DELAYS AND IMPULSIVE PERTURBATION 被引量:2
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作者 卢春 丁效华 《Acta Mathematica Scientia》 SCIE CSCD 2014年第5期1551-1570,共20页
A stochastic logistic model with delays and impulsive perturbation is proposed and investigated. Sufficient conditions for extinction are established as well as nonpersistence in the mean, weak persistence and stochas... A stochastic logistic model with delays and impulsive perturbation is proposed and investigated. Sufficient conditions for extinction are established as well as nonpersistence in the mean, weak persistence and stochastic permanence. The threshold between weak persistence and extinction is obtained. Furthermore, the theoretical analysis results are also derivated with the help of numerical simulations. 展开更多
关键词 logistic model white noise DELAY PERSISTENCE impulsive perturbation
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Predictors of in-hospital mortality by logistic regression analysis among melioidosis patients in Northern Malaysia:A retrospective study 被引量:1
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作者 Kamaruddin Mardhiah Nadiah Wan-Arfah +2 位作者 Nyi Nyi Naing Muhammad Radzi Abu Hassan Huan-Keat Chan 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2021年第8期356-363,共8页
Objective:To identify the predictors of mortality among in-hospital melioidosis patients.Methods:A total of 453 patients in Hospital Sultanah Bahiyah,Kedah,and Hospital Tuanku Fauziah,Perlis with culture-confirmed mel... Objective:To identify the predictors of mortality among in-hospital melioidosis patients.Methods:A total of 453 patients in Hospital Sultanah Bahiyah,Kedah,and Hospital Tuanku Fauziah,Perlis with culture-confirmed melioidosis were retrospectively included in the study.Advanced multiple logistic regression was used to obtain the final model of predictors of mortality from melioidosis.The analysis was performed using STATA/SE 14.0.Results:A total of 50.11%(227/453)of the patients died at the hospital,and a majority(86.75%,393/453)of cases were bacteremic.The logistic regression estimated that the bacteremic type of melioidosis,low platelet count,abnormal white blood cell counts,and increased urea value were predictors of mortality.The results showed that bacteremic melioidosis increased the risk of death by 4.39 times(OR 4.39,95%CI 1.83-10.55,P=0.001)compared to non-bacteremic melioidosis.Based on laboratory test,the adjusted ORs from the final model showed that all three blood investigations were included as the associated factors of mortality for the disease[high white blood cell(>10×10^(9)/L):OR 2.43,95%CI1.41-4.17,P<0.001;low white blood cell(<4×10^(9)/L):OR 3.82,95%CI 1.09-13.34,P=0.036;low platelet(<100×10^(9)/L):OR 4.19,95%CI 1.89-9.30,P<0.001;high urea(>7800μmol/L):OR 5.53,95%CI 2.50-12.30,P<0.001;and low level of urea(<2500μmol/L):OR 3.52,95%CI 1.71-7.23,P=0.001].Conclusions:Routine blood investigations during a hospital admission can early identify predictors of mortality in melioidosis patients. 展开更多
关键词 MELIOIDOSIS Infectious disease MORTALITY PREDICTORS Prognostic factors logistic model
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Classifying Machine Learning Features Extracted from Vibration Signal with Logistic Model Tree to Monitor Automobile Tyre Pressure 被引量:1
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作者 P.S.Anoop V.Sugumaran 《Structural Durability & Health Monitoring》 EI 2017年第2期191-208,共18页
Tyre pressure monitoring system(TPMS)is compulsory in most countries like the United States and European Union.The existing systems depend on pressure sensors strapped on the tyre or on wheel speed sensor data.A diffe... Tyre pressure monitoring system(TPMS)is compulsory in most countries like the United States and European Union.The existing systems depend on pressure sensors strapped on the tyre or on wheel speed sensor data.A difference in wheel speed would trigger an alarm based on the algorithm implemented.In this paper,machine learning approach is proposed as a new method to monitor tyre pressure by extracting the vertical vibrations from a wheel hub of a moving vehicle using an accelerometer.The obtained signals will be used to compute through statistical features and histogram features for the feature extraction process.The LMT(Logistic Model Tree)was used as the classifier and attained a classification accuracy of 92.5%with 10-fold cross validation for statistical features and 90.5% with 10-fold cross validation for histogram features.The proposed model can be used for monitoring the automobile tyre pressure successfully. 展开更多
关键词 Machine learning Vibration ACCELEROMETER Statistical Features Histogram Features logistic model tree(LMT) Tyre pressure monitoring system
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POSITIVE PERIODIC SOLUTION FOR A NONAUTONOMOUS LOGISTIC MODEL WITH LINEAR FEEDBACK REGULATION 被引量:1
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作者 Ding Xiaoquan Cheng Shuhan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第3期302-312,共11页
A nonautonomous delayed logistic model with linear feedback regulation is proposed in this paper. Sufficient conditions are derived for the existence, uniqueness and global asymptotic stability of positive periodic so... A nonautonomous delayed logistic model with linear feedback regulation is proposed in this paper. Sufficient conditions are derived for the existence, uniqueness and global asymptotic stability of positive periodic solution of the model 展开更多
关键词 logistic model periodic solution global asymptotic stability linear feedback regulation.
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A COMPARISON OF FORECASTING MODELS OF THE VOLATILITY IN SHENZHEN STOCK MARKET 被引量:1
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作者 庞素琳 邓飞其 王燕鸣 《Acta Mathematica Scientia》 SCIE CSCD 2007年第1期125-136,共12页
Based on the weekly closing price of Shenzhen Integrated Index, this article studies the volatility of Shenzhen Stock Market using three different models: Logistic, AR(1) and AR(2). The time-variable parameters o... Based on the weekly closing price of Shenzhen Integrated Index, this article studies the volatility of Shenzhen Stock Market using three different models: Logistic, AR(1) and AR(2). The time-variable parameters of Logistic regression model is estimated by using both the index smoothing method and the time-variable parameter estimation method. And both the AR(1) model and the AR(2) model of zero-mean series of the weekly dosing price and its zero-mean series of volatility rate are established based on the analysis results of zero-mean series of the weekly closing price, Six common statistical methods for error prediction are used to test the predicting results. These methods are: mean error (ME), mean absolute error (MAE), root mean squared error (RMSE), mean absolute percentage error (MAPE), Akaike's information criterion (AIC), and Bayesian information criterion (BIC). The investigation shows that AR(1) model exhibits the best predicting result, whereas AR(2) model exhibits predicting results that is intermediate between AR(1) model and the Logistic regression model. 展开更多
关键词 logistic regression model AR(1) model AR(2) model VOLATILITY
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The asymptotic stability analysis in stochastic logistic model with Poisson growth coefficient 被引量:1
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作者 Shaojuan Ma Duan Dong 《Theoretical & Applied Mechanics Letters》 CAS 2014年第1期26-34,共9页
The asymptotic stability of a discrete logistic model with random growth coefficient is studied in this paper. Firstly, the discrete logistic model with random growth coefficient is built and reduced into its determin... The asymptotic stability of a discrete logistic model with random growth coefficient is studied in this paper. Firstly, the discrete logistic model with random growth coefficient is built and reduced into its deterministic equivalent system by orthogonal polynomial approximation. Then, the linear stability theory and the Jury criterion of nonlinear deterministic discrete systems are applied to the equivalent one. At last, by mathematical analysis, we find that the parameter interval for asymptotic stability of nontrivial equilibrium in stochastic logistic system gets smaller as the random intensity or statistical parameters of random variable is increased and the random parameter’s influence on asymptotic stability in stochastic logistic system becomes prominent. 展开更多
关键词 stochastic logistic model random growth coefficient asymptotic stability
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Application of a Novel Method for Machine Performance Degradation Assessment Based on Gaussian Mixture Model and Logistic Regression 被引量:3
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作者 LIU Wenbin ZHONG Xin +2 位作者 LEE Jay LIAO Linxia ZHOU Min 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期879-884,共6页
The currently prevalent machine performance degradation assessment techniques involve estimating a machine's current condition based upon the recognition of indications of failure features,which entail complete data ... The currently prevalent machine performance degradation assessment techniques involve estimating a machine's current condition based upon the recognition of indications of failure features,which entail complete data collected in different conditions.However,failure data are always hard to acquire,thus making those techniques hard to be applied.In this paper,a novel method which does not need failure history data is introduced.Wavelet packet decomposition(WPD) is used to extract features from raw signals,principal component analysis(PCA) is utilized to reduce feature dimensions,and Gaussian mixture model(GMM) is then applied to approximate the feature space distributions.Single-channel confidence value(SCV) is calculated by the overlap between GMM of the monitoring condition and that of the normal condition,which can indicate the performance of single-channel.Furthermore,multi-channel confidence value(MCV),which can be deemed as the overall performance index of multi-channel,is calculated via logistic regression(LR) and that the task of decision-level sensor fusion is also completed.Both SCV and MCV can serve as the basis on which proactive maintenance measures can be taken,thus preventing machine breakdown.The method has been adopted to assess the performance of the turbine of a centrifugal compressor in a factory of Petro-China,and the result shows that it can effectively complete this task.The proposed method has engineering significance for machine performance degradation assessment. 展开更多
关键词 performance degradation assessment Gaussian mixture model logistic regression proactive maintenance sensor fusion
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基于Logistic回归模型的TC4零件激光熔化沉积工艺参数分析(英文) 被引量:1
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作者 KONG Yuan BA De-chun SONG Qing-zhu 《真空》 CAS 2018年第3期34-40,共7页
In this paper, laser melting deposition(LMD), a new advanced manufacture technology. While manufacturing a metal part by LMD process, if we could control the energy distribution in internal different areas such as cla... In this paper, laser melting deposition(LMD), a new advanced manufacture technology. While manufacturing a metal part by LMD process, if we could control the energy distribution in internal different areas such as cladding layer or that between cladding layer and the substrate with optimal process parameters, the probability of internal defects of parts can be reduced, and the mechanical properties of parts will be greatly improved. To address the problem that whether the part made by LMD has internal defects, in this paper we designed the orthogonal rotation experiments through selecting different process parameters. Then a Logistic Regression model was built based on the experiments data. The calculation result of the regression model was in good agreement with the result of authentication test. Therefore, this Logistic Regression model has important reference for selecting LMD process parameters. 展开更多
关键词 Titanium alloys powder laser shaping Processing parameters logistic regression model Experiment design
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A New Aware-Context Collaborative Filtering Approach by Applying Multivariate Logistic Regression Model into General User Pattern 被引量:1
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作者 Loc Nguyen 《Journal of Data Analysis and Information Processing》 2016年第3期124-131,共8页
Traditional collaborative filtering (CF) does not take into account contextual factors such as time, place, companion, environment, etc. which are useful information around users or relevant to recommender application... Traditional collaborative filtering (CF) does not take into account contextual factors such as time, place, companion, environment, etc. which are useful information around users or relevant to recommender application. So, recent aware-context CF takes advantages of such information in order to improve the quality of recommendation. There are three main aware-context approaches: contextual pre-filtering, contextual post-filtering and contextual modeling. Each approach has individual strong points and drawbacks but there is a requirement of steady and fast inference model which supports the aware-context recommendation process. This paper proposes a new approach which discovers multivariate logistic regression model by mining both traditional rating data and contextual data. Logistic model is optimal inference model in response to the binary question “whether or not a user prefers a list of recommendations with regard to contextual condition”. Consequently, such regression model is used as a filter to remove irrelevant items from recommendations. The final list is the best recommendations to be given to users under contextual information. Moreover the searching items space of logistic model is reduced to smaller set of items so-called general user pattern (GUP). GUP supports logistic model to be faster in real-time response. 展开更多
关键词 Aware-Context Collaborative Filtering logistic Regression Model
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On a new fractional-order Logistic model with feedback control
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作者 Manh Tuan Hoang A.M.Nagy 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2021年第3期390-402,共13页
In this paper,we formulate and analyze a new fractional-order Logistic model with feedback control,which is different from a recognized mathematical model proposed in our very recent work.Asymptotic stability of the p... In this paper,we formulate and analyze a new fractional-order Logistic model with feedback control,which is different from a recognized mathematical model proposed in our very recent work.Asymptotic stability of the proposed model and its numerical solutions are studied rigorously.By using the Lyapunov direct method for fractional dynamical systems and a suitable Lyapunov function,we show that a unique positive equilibrium point of the new model is asymptotically stable.As an important consequence of this,we obtain a new mathematical model in which the feedback control variables only change the position of the unique positive equilibrium point of the original model but retain its asymptotic stability.Furthermore,we construct unconditionally positive nonstandard finite difference(NSFD)schemes for the proposed model using the Mickens’methodology.It is worth noting that the constructed NSFD schemes not only preserve the positivity but also provide reliable numerical solutions that correctly reflect the dynamics of the new fractional-order model.Finally,we report some numerical examples to support and illustrate the theoretical results.The results indicate that there is a good agreement between the theoretical results and numerical ones. 展开更多
关键词 fractional-order logistic model feedback control Lyapunov functions uniform asymptotic stability nonstandard finite difference schemes
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Transmission Based Conditional Logistic Model for Testing Main and Interaction Effects
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作者 Caixia Li Peixing Li 《Open Journal of Statistics》 2021年第5期713-719,共7页
Transmission disequilibrium test (TDT) is a popular family based genetic association method. Under multiplicative assumption, a conditional logistic regression for matched pair, affected offspring with allele transmit... Transmission disequilibrium test (TDT) is a popular family based genetic association method. Under multiplicative assumption, a conditional logistic regression for matched pair, affected offspring with allele transmitted from parents and pseudo-offspring (control) with allele non-transmitted from parents, was built to detect the <span style="font-family:Verdana;">main </span><span style="font-family:Verdana;">effects of genes and gene-covariate interaction</span><span style="font-family:Verdana;">s</span><span style="font-family:;" "=""><span style="font-family:Verdana;">. When there exist genotype uncertainties, expectation-maximization (EM) algorithm was adopted to estimate the coefficients. The transmission model was applied to detect the association between M235T polymorphism in AGT gene and essential hypertension (ESH). Most of parents are not available in the 126 families from HongKong Chinese population. The results </span><span style="font-family:Verdana;">showed M235T is associat</span></span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> with hypertension and there is interaction between M235T and the case’s sex. The allele T is higher risk for male than female</span><span style="font-family:Verdana;">.</span> 展开更多
关键词 Transmission Disequilibrium Test Gene-Covariate Interaction Conditional logistic Model Expectation-Maximization Algorithm
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An Optimization Model for Aircraft Service Logistics
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作者 Angus Cheung W H Ip +1 位作者 Angel Lai Eva Cheung 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期252-,共1页
Scheduling is one of the most difficult issues in t he planning and operations of the aircraft services industry. In this paper, t he various scheduling problems in ground support operation of an aircraft mainte nance... Scheduling is one of the most difficult issues in t he planning and operations of the aircraft services industry. In this paper, t he various scheduling problems in ground support operation of an aircraft mainte nance service company are addressed. The authors developed a set of vehicle rout ings to cover each schedule flights; the objectives pursued are the maximization of vehicle and manpower utilization and minimization of operation time. To obta in the goals, an integer-programming model with genetic algorithm is formulated . It is found that the company can produce an effective and efficient schedules to deploy the manpower and equipment resources. Simulation is used to verify the method and a MATLAB program is used to code the genetic algorithm. This model i s further illustrated by a case study in Hong Kong and the benefit elaborated. F inally, a conclusion is made to summarize the experience of this project and pro vide further improvement. 展开更多
关键词 An Optimization Model for Aircraft Service logistics
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