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Application of Statistical Methods to Assess Carbon Monoxide Pollution Variations within an Urban Area 被引量:1
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作者 Carmen Capilla 《International Journal of Geosciences》 2012年第5期885-890,共6页
In recent years there have been considerable new legislation and efforts by vehicle manufactures aimed at reducing pollutant emission to improve air quality in urban areas. Carbon monoxide is a major pollutant in urba... In recent years there have been considerable new legislation and efforts by vehicle manufactures aimed at reducing pollutant emission to improve air quality in urban areas. Carbon monoxide is a major pollutant in urban areas, and in this study we analyze monthly carbon monoxide (CO) data from Valencia City, a representative Mediterranean city in terms of its structure and climatology. Temporal and spatial trends in pollution were recorded from a monitoring net- work that consisted of five monitoring sites. A multiple linear model, incorporating meteorological parameters, annual cycles, and random error due to serial correlation, was used to estimate the temporal changes in pollution. An analysis performed on the meteorologically adjusted data reveals a significant decreasing trend in CO concentrations and an annual seasonal cycle. The model parameters are estimated by applying the least-squares method. The standard error of the parameters is determined while taking into account the serial correlation in the residuals. The decreasing trend im- plies to a certain extent an improvement in the air quality of the study area. The seasonal cycle shows variations that are mainly associated with traffic and meteorological patterns. Analysis of the stochastic spatial component shows that most of the intersite covariances can be analyzed using an exponential variogram model. 展开更多
关键词 Carbon MONOXIDE Monitoring Network STATISTICAL Model URBAN Air POLLUTION
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Association of Human Whole-blood NAD+Levels with Nabothian Cyst
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作者 XU Ling WANG Yue Xuan +9 位作者 WANG Wei FAN Xue CHEN Xue Yu ZHOU Tian Yun LIU Yu He YU Ye YANG Fan JU Zhen Yu ZHOU Yong WANG Deng Liang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第5期471-478,共8页
Objective Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD^(+))levels and nabothian cysts.This study aimed to assess the association between NAD^(+)levels and nabothian c... Objective Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD^(+))levels and nabothian cysts.This study aimed to assess the association between NAD^(+)levels and nabothian cysts in healthy Chinese women.Methods Multivariate logistic regression analysis was performed to analyze the association between NAD^(+)levels and nabothian cysts.Results The mean age was 43.0±11.5 years,and the mean level of NAD^(+)was 31.3±5.3μmol/L.Nabothian cysts occurred in 184(27.7%)participants,with single and multiple cysts in 100(15.0%)and84(12.6%)participants,respectively.The total nabothian cyst prevalence gradually decreased from37.4%to 21.6%from Q1 to Q4 of NAD^(+)and the prevalence of single and multiple nabothian cysts also decreased across the NAD^(+)quartiles.As compared with the highest NAD^(+)quartile(≥34.4μmol/L),the adjusted odds ratios with 95%confidence interval of the NAD^(+)Q1 was 1.89(1.14–3.14)for total nabothian cysts.The risk of total and single nabothian cysts linearly decreased with increasing NAD^(+)levels,while the risk of multiple nabothian cysts decreased more rapidly at NAD^(+)levels of 28.0 to35.0μmol/L.Conclusion:Low NAD^(+)levels were associated with an increased risk of total and multiple nabothian cysts. 展开更多
关键词 Nicotinamide adenine dinucleotide Nabothian cyst FEMALE Risk factor
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Average Run Length in TEWMA Control Charts:Analytical Solutions for AR(p)Processes and Real Data Applications
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作者 Sirawit Makaew Yupaporn Areepong Saowanit Sukparungsee 《Computer Modeling in Engineering & Sciences》 2025年第5期1617-1634,共18页
This study aims to examine the explicit solution for calculating the Average Run Length(ARL)on the triple exponentially weighted moving average(TEWMA)control chart applied to autoregressive model(AR(p)),where AR(p)is ... This study aims to examine the explicit solution for calculating the Average Run Length(ARL)on the triple exponentially weighted moving average(TEWMA)control chart applied to autoregressive model(AR(p)),where AR(p)is an autoregressive model of order p,representing a time series with dependencies on its p previous values.Additionally,the study evaluates the accuracy of both explicit and numerical integral equation(NIE)solutions for AR(p)using the TEWMA control chart,focusing on the absolute percentage relative error.The results indicate that the explicit and approximate solutions are in close agreement.Furthermore,the study investigates the performance of exponentially weighted moving average(EWMA)and TEWMA control charts in detecting changes in the process,using the relative mean index(RMI)as a measure.The findings demonstrate that the TEWMA control chart outperforms the EWMA control chart in detecting process changes,especially when the value ofλis sufficiently large.In addition,an analysis using historical data from the SET index between January 2024 and May 2024 and historical data of global annual plastic production,the results of both data sets also emphasize the superior performance of the TEWMA control chart. 展开更多
关键词 EWMA control chart TEWMA control charts average run length shift detection explicit formula Fredholm integral equation Banach’s fixed-point theorem AR(p)process
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A new integrated neurosymbolic approach for crop-yield prediction using environmental data and satellite imagery at field scale
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作者 Khadija Meghraoui Teeradaj Racharak +2 位作者 Kenza Ait El Kadi Saloua Bensiali Imane Sebari 《Artificial Intelligence in Geosciences》 2025年第1期202-227,共26页
Crop-yield is a crucial metric in agriculture,essential for effective sector management and improving the overall production process.This indicator is heavily influenced by numerous environmental factors,particularly ... Crop-yield is a crucial metric in agriculture,essential for effective sector management and improving the overall production process.This indicator is heavily influenced by numerous environmental factors,particularly those related to soil and climate,which present a challenging task due to the complex interactions involved.In this paper,we introduce a novel integrated neurosymbolic framework that combines knowledge-based approaches with sensor data for crop-yield prediction.This framework merges predictions from vectors generated by modeling environmental factors using a newly developed ontology focused on key elements and evaluates this ontology using quantitative methods,specifically representation learning techniques,along with predictions derived from remote sensing imagery.We tested our proposed methodology on a public dataset centered on corn,aiming to predict crop-yield.Our developed smart model achieved promising results in terms of crop-yield prediction,with a root mean squared error(RMSE)of 1.72,outperforming the baseline models.The ontologybased approach achieved an RMSE of 1.73,while the remote sensing-based method yielded an RMSE of 1.77.This confirms the superior performance of our proposed approach over those using single modalities.This in-tegrated neurosymbolic approach demonstrates that the fusion of statistical and symbolic artificial intelligence(AI)represents a significant advancement in agricultural applications.It is particularly effective for crop-yield prediction at the field scale,thus facilitating more informed decision-making in advanced agricultural prac-tices.Additionally,it is acknowledged that results might be further improved by incorporating more detailed ontological knowledge and testing the model with higher-resolution imagery to enhance prediction accuracy. 展开更多
关键词 Crop-yield prediction Neuro-symbolic AI ONTOLOGY Ontology embedding Satellite imagery Machine learning
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The Role of Cover Crops towards Sustainable Soil Health and Agriculture—A Review Paper 被引量:10
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作者 Parmodh Sharma Atinderpal Singh +4 位作者 Charanjit Singh Kahlon Amandeep Singh Brar Kulbhushan K. Grover Mahendra Dia Robert L. Steiner 《American Journal of Plant Sciences》 2018年第9期1935-1951,共17页
Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide seve... Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops. 展开更多
关键词 COVER CROPS SUSTAINABLE AGRICULTURE SOIL HEALTH Legumes SOIL Properties
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LEARNING RATES OF KERNEL-BASED ROBUST CLASSIFICATION 被引量:1
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作者 Shuhua WANG Baohuai SHENG 《Acta Mathematica Scientia》 SCIE CSCD 2022年第3期1173-1190,共18页
This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship b... This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship between the excess misclassification error and the excess generalization error is provided;from this,along with the convex analysis theory,a kind of learning rate is derived.The results show that the performance of the classifier is effected by the outliers,and the extent of impact can be controlled by choosing the homotopy parameters properly. 展开更多
关键词 Support vector machine robust classification quasiconvex loss function learning rate right-sided directional derivative
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Product Spacing of Stress–Strength under Progressive Hybrid Censored for Exponentiated-Gumbel Distribution 被引量:1
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作者 R.Alshenawy Mohamed A.H.Sabry +1 位作者 Ehab M.Almetwally Hisham M.Elomngy 《Computers, Materials & Continua》 SCIE EI 2021年第3期2973-2995,共23页
Maximum product spacing for stress–strength model based on progressive Type-II hybrid censored samples with different cases has been obtained.This paper deals with estimation of the stress strength reliability model ... Maximum product spacing for stress–strength model based on progressive Type-II hybrid censored samples with different cases has been obtained.This paper deals with estimation of the stress strength reliability model R=P(Y<X)when the stress and strength are two independent exponentiated Gumbel distribution random variables with different shape parameters but having the same scale parameter.The stress–strength reliability model is estimated under progressive Type-II hybrid censoring samples.Two progressive Type-II hybrid censoring schemes were used,Case I:A sample size of stress is the equal sample size of strength,and same time of hybrid censoring,the product of spacing function under progressive Type-II hybrid censoring schemes.Case II:The sample size of stress is a different sample size of strength,in which the life-testing experiment with a progressive censoring scheme is terminated at a random time T 2 e0;1T.The maximum likelihood estimation and maximum product spacing estimation methods under progressive Type-II hybrid censored samples for the stress strength model have been discussed.A comparison study with classical methods as the maximum likelihood estimation method is discussed.Furthermore,to compare the performance of various cases,Markov chain Monte Carlo simulation is conducted by using iterative procedures as Newton Raphson or conjugate-gradient procedures.Finally,two real datasets are analyzed for illustrative purposes,first data for the breaking strengths of jute fiber,and the second data for the waiting times before the service of the customers of two banks. 展开更多
关键词 Exponentiated Gumbel distribution stress-strength model progressive Type-II hybrid censoring maximum product spacing maximum likelihood
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Medium effects on micropropagation and genetic stability of Citrullus lanatus oleaginous type 被引量:1
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作者 Yah Gwladys Gnamien Irié Arsène Zoro Bi +2 位作者 Yatty Justin Kouadio Yves Brostaux Jean-Pierre Baudoin 《Agricultural Sciences》 2013年第7期32-44,共13页
To regenerate adventitious shoots from the cotyledon proximal parts of Citrullus lanatus (Thunb.) Matsum. and Nakai ssp. mucosospermus (Fursa) oleaginous type, different concentrations of MS mineral elements, sucrose,... To regenerate adventitious shoots from the cotyledon proximal parts of Citrullus lanatus (Thunb.) Matsum. and Nakai ssp. mucosospermus (Fursa) oleaginous type, different concentrations of MS mineral elements, sucrose, 6-benzylaminopurine (BAP) and agar were tested. Shoot induction proved to depend on the interaction between levels of sucrose, BAP and MS mineral elements in the medium. The medium containing 3/2 strength of MS mineral elements, 35 g/l sucrose and 1 mg/l BAP solidified with 6 g/l agar allowed the production of numerous shoots without a callus phase. After 3 weeks of culture, 76.7% of the cotyledon proximal parts induced shoots with an average of 12.26 shoots per explant and a mean shoot length of 17.13 mm. The induced shoots were directly rooted and thus complete plants ready for acclimatization were obtained using a two steps procedure. Depending on the genotype, the shoot induction from cotyledon proximal parts ranged from 54% to 96%. Rooted plantlets were acclimatized and transferred to field, where they grew well, developed flowers and fruits like seeded plants. The assessment of the genetic stability of the in-vitro-regenerated plantlets by means of an Amplified Fragment Length Polymorphism (AFLP) analysis with the combination of 5 primers revealed no differences between regenerated plantlets and mother plants. 展开更多
关键词 AFLP Genetic Stability In Vitro Oleaginous Seeds ORGANOGENESIS
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A Competing Risk Hazard Model for Complications of Diabetes Mellitus
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作者 Parvin Akter Khanam Mohammed Ataharul Islam +4 位作者 Mohammed Abu Sayeed Tanjima Begum Mohammed Golam Rabbani Subhagata Choudhury Hajera Mahtab 《Journal of Biosciences and Medicines》 2014年第5期1-11,共11页
Diabetes mellitus is a major public health problem globally. It is the cause of serious and sometimes life-threatening complications leading to death. It is one of the most common non communicable diseases and leading... Diabetes mellitus is a major public health problem globally. It is the cause of serious and sometimes life-threatening complications leading to death. It is one of the most common non communicable diseases and leading cause of death in most developed countries including Bangladesh. It is associated with the increased risk of microvascular (nephropathy and retinopathy), macrovascular (cardiovascular diseases, stroke) and other mixed (cataract, pulmonary tuberculosis, foot ulcer etc.) complications. The aim of this study was to determine the risk factors related to diabetes complications and to propose competing risk models for analyzing complications of diabetes mellitus. We study 2887 diabetic patients from the BIRDEM registry record books for the period from 1984 to 1997 who have at least two follow-up visits and who are free from complications at the first visit. The data on variables such as 2-hBG, age, sex, family history of diabetes, area of residence, educational level, BMI, SBP, DBP and treatment status are obtained. Also, the time from the diagnosis of type 2 diabetes mellitus (T2DM) to the occurrence of complications was recorded. We use the competing risk hazard model and examined the potential risk factors for determining the development of such complications. This study reveals that increase in blood pressure is a potential risk factor for CHD and nephropathy in T2DM. We also found that male and illiterate patients are more affected by nephropathy. In our study, we also revealed that female and illiterate patients are also more influenced by cataract. 展开更多
关键词 Family History of DIABETES Educational Level Type 2 DIABETES MELLITUS CORONARY Heart Disease Mean ARTERIAL Blood Pressure
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The Determinants of Population Growth in Rwanda
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作者 Daniel Ruturwa Sebikabu Ignace H.Kabano 《Journal of Economic Science Research》 2019年第3期37-44,共8页
The fertility occupies a central position in the study of population growth.The growth of the population depends entirely on human fertility,including birth,death rates and life expectancy.Growth of the fertility is o... The fertility occupies a central position in the study of population growth.The growth of the population depends entirely on human fertility,including birth,death rates and life expectancy.Growth of the fertility is one of the key determinants of the Population Growth.This paper focused on the determinant factors of population growth in Rwanda.From the findings,there is a statistically significance of fertility trends at 0.05 percent because the t-statistic in table-4 is greater than its critical value(1.96)at 0.05 percent.The results provides evidence of Fertility,birth,death and life expectancy as factors which boost population to grow in Rwanda.The results founded,indicate the existence of high fertility rates even decreasing,lead to increase population due to its positive values over time.This means that Fertility rates in Rwanda has a positive impact on the country's population growth,especially in the youth who realizes around 48 percent of entire Rwandan’s Population.The relationship between fertility rate and the time describe a decreasing function,which interesting for us showing that fertility has been reduced over time.In other words,as well as the years increased,the fertility decreased.The coefficient of Time is(-0.117035)which implies that a unit change in time will change Total Fertility Rate(TFR)by(-0.117035),table-1.The model of fertility represents a decreasing function while the time function still increasing,as shows in the figure-2.The fertility variable has positive relationships with the population dependent variable even the fertility coefficient is negative,the probability p-value is significant at 0.05 significance level on one hand and the absolute t-statistic is great than the critical value at 0.05 level of significance,which confirm the statistically significance of t-statistic.The coefficients on the death rate and Life expectancy are respectively positive and significant at all confidence level,table-5. 展开更多
关键词 POPULATION FERTILITY BIRTH DEATH LIFE EXPECTANCY Rwanda
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Comprehensive analysis of immune subtype characterization on identification of potential cells and drugs to predict response to immune checkpoint inhibitors for hepatocellular carcinoma 被引量:1
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作者 Guichuan Lai Biao Xie +11 位作者 Cong Zhang Xiaoni Zhong Jielian Deng Kangjie Li Hui Liu Yuan Zhang Anbin Liu Yi Liu Jie Fan Tianyi Zhou Wei Wang Ailong Huang 《Genes & Diseases》 2025年第3期463-477,共15页
Immunosubtyping enables the segregation of immune responders from non-responders. However, numerous studies failed to focus on the integration of cellular heterogeneity and immunophenotyping in the prediction of hepat... Immunosubtyping enables the segregation of immune responders from non-responders. However, numerous studies failed to focus on the integration of cellular heterogeneity and immunophenotyping in the prediction of hepatocellular carcinoma (HCC) patients’response to immune checkpoint inhibitors (ICIs). We categorized HCC patients into various immune subtypes based on feature scores linked to ICI response. Single-cell sequencing technology was to investigate the cellular heterogeneity of different immune subtypes and acquiresignificant ICI response-associated cells. Candidate drugs were identified using a blend ofvarious drug databases and network approaches. HCC patients were divided into two distinct immune subtypes based on characterization scores of 151 immune-related gene sets. Patientsin both subtypes showed varying overall survival, immunity levels, biological activities, andTP53 mutation rates. Subtype 1-related natural killer cells showed a positive correlation withimmune-promoting scores but a negative correlation with immune-suppressing scores.Notably, docetaxel sensitivity in HCC patients rose as the levels of subtype 1-related naturalkiller cells increased. Our study demonstrated that immune subtypes have cellular heterogeneity in predicting response to ICIs. A combination of subtype 1-associated natural killer cellsand docetaxel may offer new hope for ICI treatment in HCC. 展开更多
关键词 Cellular heterogeneity Drug prediction Hepatocellular carcinoma Immune checkpoint inhibitors Immunosubtyping
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Explicit ARL Computational for a Modified EWMA Control Chart in Autocorrelated Statistical Process Control Models
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作者 Yadpirun Supharakonsakun Yupaporn Areepong Korakoch Silpakob 《Computer Modeling in Engineering & Sciences》 2025年第10期699-720,共22页
This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving ... This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving average behavior—SARMA(1,1)L under exponential white noise.Unlike previous works that rely on simplified models such as AR(1)or assume independence,this research derives for the first time an exact two-sided Average Run Length(ARL)formula for theModified EWMAchart under SARMA(1,1)L conditions,using a mathematically rigorous Fredholm integral approach.The derived formulas are validated against numerical integral equation(NIE)solutions,showing strong agreement and significantly reduced computational burden.Additionally,a performance comparison index(PCI)is introduced to assess the chart’s detection capability.Results demonstrate that the proposed method exhibits superior sensitivity to mean shifts in autocorrelated environments,outperforming existing approaches.The findings offer a new,efficient framework for real-time quality control in complex seasonal processes,with potential applications in environmental monitoring and intelligent manufacturing systems. 展开更多
关键词 Statistical process control average run length modified EWMA control chart autocorrelated data SARMA process computational modeling real-time monitoring
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Optimal operating policy for a controllable queueing model with a fuzzy environment 被引量:3
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作者 Chuen-horng LIN Jau-chuan KE 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第2期311-318,共8页
We construct the membership functions of the fuzzy objective values of a controllable queueing model,in which cost elements,arrival rate and service rate are all fuzzy numbers. Based on Zadeh's extension principle... We construct the membership functions of the fuzzy objective values of a controllable queueing model,in which cost elements,arrival rate and service rate are all fuzzy numbers. Based on Zadeh's extension principle,a set of parametric nonlinear programs is developed to find the upper and lower bounds of the minimal average total cost per unit time at the possibility level. The membership functions of the minimal average total cost are further constructed using different values of the possibility level. A numerical example is solved successfully to illustrate the validity of the proposed approach. Because the object value is expressed and governed by the membership functions,the optimization problem in a fuzzy environment for the controllable queueing models is represented more accurately and analytical results are more useful for system designers and practitioners. 展开更多
关键词 Controllable queue Fuzzy sets Membership function Nonlinear programming
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Predictive Models for Cumulative Confirmed COVID-19 Cases by Day in Southeast Asia 被引量:2
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作者 Yupaporn Areepong Rapin Sunthornwat 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第12期927-942,共16页
Coronavirus disease 2019 outbreak has spread as a pandemic since the end of year 2019.This situation has been causing a lot of problems of human beings such as economic problems,health problems.The forecasting of the ... Coronavirus disease 2019 outbreak has spread as a pandemic since the end of year 2019.This situation has been causing a lot of problems of human beings such as economic problems,health problems.The forecasting of the number of infectious people is required by the authorities of all countries including Southeast Asian countries to make a decision and control the outbreak.This research is to investigate the suitable forecasting model for the number of infectious people in Southeast Asian countries.A comparison of forecasting models between logistic growth curve which is symmetric and Gompertz growth curve which is asymmetric based on the maximumof Coefficient of Determination and theminimumof RootMean Squared Percentage Error is also proposed.The estimation of parameters of the forecasting models is evaluated by the least square method.In addition,spreading of the outbreak is estimated by the derivative of the number of cumulative cases.The findings show that Gompertz growth curve is a suitable forecasting model for Indonesia,Philippines,andMalaysia and logistic growth curve suits the other countries in South Asia. 展开更多
关键词 Coronavirus disease 2019 Gompertz function least square estimation logistic function
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Optimization on bicriterion policies for M/G/1 system with second optional service 被引量:1
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作者 Jau-chuan KE Yunn-kuang CHU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第10期1437-1445,共9页
We compare the optimal operating cost of the two bicriterion policies, <p,T> and <p,N>, for an M/G/1 queueing system with second optional service, in which the length of the vacation period is randomly con... We compare the optimal operating cost of the two bicriterion policies, <p,T> and <p,N>, for an M/G/1 queueing system with second optional service, in which the length of the vacation period is randomly controlled either by the number of arrivals during the idle period or by a timer. After all the customers are served in the queue exhaustively, the server immediately takes a vacation and may operate <p,T> policy or <p,N> policy. For the two bicriterion policies, the total average cost function per unit time is developed to search the optimal stationary operating policies at a minimum cost. Based upon the optimal cost the explicit forms for joint optimum threshold values of (p,T) and (p,N) are obtained. 展开更多
关键词 Average operating cost Bicriterion policy Optimization comparisons Optional service Optimal threshold values
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Exact Run Length Evaluation on a Two-Sided Modified ExponentiallyWeighted Moving Average Chart for Monitoring 被引量:1
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作者 Piyatida Phanthuna Yupaporn Areepong Saowanit Sukparungsee 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第4期23-41,共19页
A modified exponentially weighted moving average (EWMA) scheme is one of the quality control charts suchthat this control chart can quickly detect a small shift. The average run length (ARL) is frequently used for the... A modified exponentially weighted moving average (EWMA) scheme is one of the quality control charts suchthat this control chart can quickly detect a small shift. The average run length (ARL) is frequently used for theperformance evaluation on control charts. This paper proposes the explicit formula for evaluating the average runlength on a two-sided modified exponentially weighted moving average chart under the observations of a first-orderautoregressive process, referred to as AR(1) process, with an exponential white noise. The performance comparisonof the explicit formula and the numerical integral technique is carried out using the absolute relative change forchecking the correct formula and the CPU time for testing speed of calculation. The results show that the ARL ofthe explicit formula and the numerical integral equation method are hardly different, but this explicit formula ismuch faster for calculating the ARL and offered accurate values. Furthermore, the cumulative sum, the classicalEWMA and the modified EWMA control charts are compared and the results show that the latter is better for smalland intermediate shift sizes. In addition, the explicit formula is successfully applied to real-world data in the healthfield as COVID-19 data in Thailand and Singapore. 展开更多
关键词 Explicit formula average run length modified EWMA chart AR(1)process exponential white noise
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On Discordance Tests for the Wrapped Cau-chy Distribution 被引量:1
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作者 A. H. Abuzaid M. M. El-hanjouri M. M. Kulab 《Open Journal of Statistics》 2015年第4期245-253,共9页
Circular data as any other types of data are subjected to contamination with some unexpected observations which are known outliers. In this paper, four tests of discordancy for circular data based on M, C, D, and A st... Circular data as any other types of data are subjected to contamination with some unexpected observations which are known outliers. In this paper, four tests of discordancy for circular data based on M, C, D, and A statistics are extended to the wrapped Cauchy distribution to detect possible outliers. The cut-off points and the power of performances are investigated via extensive simulation study. Results show that tests perform better as the concentration of the samples is increased. Two real circular data sets are analysed for illustration. 展开更多
关键词 ARC Length Circular DISTANCE OUTLIER Wrapped NORMAL DISTRIBUTION
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Phase-Shifting-Free Interferometric Cryptosystem
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作者 李拓 史祎诗 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第3期34-37,共4页
Conventional phase-shifting interferometry-based (PSI-based) cryptosystem needs at least two-step phase-shifting. In this work, we propose a phase-shifting-free interferometric cryptosystem, which needs only one int... Conventional phase-shifting interferometry-based (PSI-based) cryptosystem needs at least two-step phase-shifting. In this work, we propose a phase-shifting-free interferometric cryptosystem, which needs only one interferogram recording. Since the phase-shifting step is not required in the proposed cryptosystem, not only the low encryption speed which is a bottleneck problem of the conventional PSI-based one is solved, but also the setup of the cryptosystem is simplified. A series of simulation experimental results demonstrate the validity and robustness of the proposed cryptosystem. 展开更多
关键词 Phase-Shifting-Free Interferometric Cryptosystem PSI MSE CCD FIGURE PZT
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A Remark on Strong Law of Large Numbers for Weighted U-Statistics
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作者 Hyung-Tae HA Mei Ling HUANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2014年第9期1595-1605,共11页
Let (X, Xn; n≥ 1} be a sequence of i.i.d, random variables with values in a measurable space (S,8) such that E|h(X1, X2,..., Xm)| 〈 ∞, where h is a measurable symmetric function from Sm into R = (-∞, ∞).... Let (X, Xn; n≥ 1} be a sequence of i.i.d, random variables with values in a measurable space (S,8) such that E|h(X1, X2,..., Xm)| 〈 ∞, where h is a measurable symmetric function from Sm into R = (-∞, ∞). Let {wn,i1,i2 im ; 1 ≤ i1 〈 i2 〈 …… 〈im 〈 n, n ≥ m} be a matrix array of real numbers. Motivated by a result of Choi and Sung (1987), in this note we are concerned with establishing a strong law of large numbers for weighted U-statistics with kernel h of degree m. We show that whenever SUP n≥m max1〈i1〈i2〈…〈im≤|wn i1,i2 i,im| 〈∞, where 0 = Eh(X1, X2,..., Xm). The proof of this result is based on a new general result on complete convergence, which is a fundamental tool, for array of real-valued random variables under some mild conditions. 展开更多
关键词 Strong law of large numbers weighted U-statistics complete convergence
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EWMA control chart based on its first hitting time and coronavirus alert levels for monitoring symmetric COVID-19 cases
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作者 Areepong Yupaporn Sunthornwat Rapin 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2021年第8期364-374,共11页
Objective:To define the alert levels for the total number of COVID-19 cases derived by using quantile functions to monitor COVID-19 outbreaks via an exponentially weighted moving-average(EWMA)control chart based on th... Objective:To define the alert levels for the total number of COVID-19 cases derived by using quantile functions to monitor COVID-19 outbreaks via an exponentially weighted moving-average(EWMA)control chart based on the first hitting time of the total number of COVID-19 cases following a symmetric logistic growth curve.Methods:The cumulative distribution function of the time for the total number of COVID-19 cases was used to construct a quantile function for classifying COVID-19 alert levels.The EWMA control chart control limits for monitoring a COVID-19 outbreak were formulated by applying the delta method and the sample mean and variance method.Samples were selected from countries and region including Thailand,Singapore,Vietnam,and Hong Kong to generate the total number of COVID-19 cases from February 15,2020 to December 16,2020,all of which followed symmetric patterns.A comparison of the two methods was made by applying them to a EWMA control chart based on the first hitting time for monitoring the COVID-19 outbreak in the sampled countries and region.Results:The optimal first hitting times for the EWMA control chart for monitoring COVID-19 outbreaks in Thailand,Singapore,Vietnam,and Hong Kong were approximately 280,208,286,and 298 days,respectively.Conclusions:The findings show that the sample mean and variance method can detect the first hitting time better than the delta method.Moreover,the COVID-19 alert levels can be defined into four stages for monitoring COVID-19 situation,which help the authorities to enact policies that monitor,control,and protect the population from a COVID-19 outbreak. 展开更多
关键词 COVID-19 alert levels Symmetric pattern of the total number of COVID-19 cases Monitoring COVID-19 situation EWMA control chart
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