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Mixed-Effects Parametric Proportional Hazard Model with Generalized Log-Logistic Baseline Distribution
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作者 Maryrose Wausi Peter Samuel Musili Mwalili +1 位作者 Anthony Kibira Wanjoya Abdsalam Hassan Muse 《Journal of Data Analysis and Information Processing》 2023年第2期81-102,共22页
Clustered survival data are widely observed in a variety of setting. Most survival models incorporate clustering and grouping of data accounting for between-cluster variability that creates correlation in order to pre... Clustered survival data are widely observed in a variety of setting. Most survival models incorporate clustering and grouping of data accounting for between-cluster variability that creates correlation in order to prevent underestimate of the standard errors of the parameter estimators but do not include random effects. In this study, we developed a mixed-effect parametric proportional hazard (MEPPH) model with a generalized log-logistic distribution baseline. The parameters of the model were estimated by the application of the maximum likelihood estimation technique with an iterative optimization procedure (quasi-Newton Raphson). The developed MEPPH model’s performance was evaluated using Monte Carlo simulation. The Leukemia dataset with right-censored data was used to demonstrate the model’s applicability. The results revealed that all covariates, except age in PH models, were significant in all considered distributions. Age and Townsend score were significant when the GLL distribution was used in MEPPH, while sex, age and Townsend score were significant in MEPPH model when other distributions were used. Based on information criteria values, the Generalized Log-Logistic Mixed-Effects Parametric Proportional Hazard model (GLL-MEPPH) outperformed other models. 展开更多
关键词 Survival Analysis Generalized Log-Logistic PARAMETRIC proportional Hazard mixed-Effects Monte Carlo Maximum Likelihood Estimation
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Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract
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作者 Sebastián Díaz-López Jerónimo Jiménez-Castro +2 位作者 Carlos Enrique Robles-Barraza Carlos Ayala-de Miguel Manuel Chaves-Conde 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第4期1166-1179,共14页
Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE com... Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE compo-nent in at least 30%of each tumour.The non-NE component can include different histological combinations of glandular,squamous,mucinous and sarcomatoid phenotypes,and one or both of the components can be low-or high grade malignant.Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion,and the lack of specific clinical trials is the main reason why their management is difficult.The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data.It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that,due to their low incidence,will require long recruitment periods. 展开更多
关键词 mixed neuroendocrine non-neuroendocrine neoplasms mixed adenoneuroendocrine carcinomas mixed tumours Gastroenteropancreatic Treatment ETIOLOGY Diagnosis
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Dendroclimatological study of Sabina saltuaria and Abies faxoniana in the mixed forests of the Qionglai Mountains,eastern Tibetan Plateau
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作者 Teng Li Jianfeng Peng +3 位作者 Tsun Fung Au Jingru Li Jinbao Li Yue Zhang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期72-82,共11页
Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-e... Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although S.saltuaria was more sensitive than A.faxoniana.The strong-est correlation was between S.saltuaria chronology and regional mean temperatures from June to November.Based on this relationship,a regional mean temperature from June to November for the period 1605-2016 was constructed.Reconstruction explained 37.3%of the temperature variance during th period 1961-2016.Six major warm periods and five major cold periods were identified.Spectral analysis detected significant interannual and multi-decadal cycles.Reconstruction also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau. 展开更多
关键词 Tree-ring analysis mixed forests DENDROCLIMATOLOGY Qionglai Mountains
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Soil properties and not plant factors affect both abundant and rare microbial taxa after thinning in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu
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作者 Wanxia Peng Tongqing Song +5 位作者 Hu Du Feng Wang Fuping Zeng Yang Wang Shulin Chen Yinzhu Chen 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期81-94,共14页
Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communiti... Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communities(i.e.,bacterial,fungal),were evaluated under various thinning treatments in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu using Mi Seq sequencing.Thinning did not significantly change either abundant or rare bacterial and fungal community composition,but affected their alpha diversity.The Shannon–Wiener indexes of rare fungal taxa under medium thinning were significantly lower than in the light thinning(P<0.05 level).Xanthobacteraceae dominated the abundant bacterial taxa,and Saitozyma and Mortierlla the abundant fungal taxa.The most common rare bacterial taxa varied;there was no prevalent rare fungal taxa under different thinnings.In addition,soil available nitrogen,total phosphorus,and p H had significant effects on rare bacterial taxa.Nutrients,especially available phosphorus,but not nitrogen,affected abundant and rare soil fungi.The results indicate that soil properties rather than plant factors affect abundant and rare microbial communities in soils of mixed stands.Thinning,through mediating soil properties,influences both abundant and rare bacterial and fungal communities in the mixed C.lanceolata and S.tzumu stand. 展开更多
关键词 Diversity Abundant taxa Rare taxa THINNING mixed stand
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On the Application of Mixed Models of Probability and Convex Set for Time-Variant Reliability Analysis
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作者 Fangyi Li Dachang Zhu Huimin Shi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1981-1999,共19页
In time-variant reliability problems,there are a lot of uncertain variables from different sources.Therefore,it is important to consider these uncertainties in engineering.In addition,time-variant reliability problems... In time-variant reliability problems,there are a lot of uncertain variables from different sources.Therefore,it is important to consider these uncertainties in engineering.In addition,time-variant reliability problems typically involve a complexmultilevel nested optimization problem,which can result in an enormous amount of computation.To this end,this paper studies the time-variant reliability evaluation of structures with stochastic and bounded uncertainties using a mixed probability and convex set model.In this method,the stochastic process of a limit-state function with mixed uncertain parameters is first discretized and then converted into a timeindependent reliability problem.Further,to solve the double nested optimization problem in hybrid reliability calculation,an efficient iterative scheme is designed in standard uncertainty space to determine the most probable point(MPP).The limit state function is linearized at these points,and an innovative random variable is defined to solve the equivalent static reliability analysis model.The effectiveness of the proposed method is verified by two benchmark numerical examples and a practical engineering problem. 展开更多
关键词 mixed uncertainty probability model convex model time-variant reliability analysis
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Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties
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作者 Kang He Liangyu Zhu Yanmei Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期19-30,共12页
Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated... Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored substrates.The mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force microscopy.The mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon resonance.When the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1%,and 93.5%,respectively.It is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=10^(-3)mol·L^(-1)for pepsin,and pH 5,I=10^(-5)mol·L^(-1)for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=10^(-1)mol·L^(-1)for pepsin,and pH 9,I=10^(-1)mol·L^(-1)for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=10^(-5)mol·L^(-1),while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-10^(-1)mol·L^(-1).However,alkaline protein(lysozyme,whose isoelectric point was higher than the pK_(a) of PDMAEMA)exhibited slight adsorption on PMOXA/PDMAEMA mixed brushes under test conditions,regardless of whether PMOXA or PDMAEMA occupied the outermost layer.The antibacterial property of the mixed brushes against Escherichia coli was investigated.PMOXA/PDMAEMA mixed brushes showed significant bactericidal activity at pH 3,I=10^(-3)mol·L^(-1),while the rinse of pH 9,I=10^(-1)mol·L^(-1)solution could remove most of the residual bacteria.This work not only enables controlled adsorption of proteins with different isoelectric points but also ensures that the surface of the coating is minimized from bacterial contamination. 展开更多
关键词 Switchable conformation transition Controllable protein adsorption mixed brushes Isoelectric point Antibacterial surface
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Investigation on photonic crystal nanobeam cavity based on mixed diamond–circular holes
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作者 Jingtong Bin Kerui Feng +4 位作者 Shang Ma Ke Liu Yong Cheng Jing Chen Qifa Liu 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第1期63-70,共8页
A photonic crystal nanobeam cavity(M-PCNC)with a structure incorporating a mixture of diamond-shaped and circular air holes is pro-posed.The performance of the cavity is simulated and studied theoretically.Using thefin... A photonic crystal nanobeam cavity(M-PCNC)with a structure incorporating a mixture of diamond-shaped and circular air holes is pro-posed.The performance of the cavity is simulated and studied theoretically.Using thefinite-difference time-domain method,the parameters of the M-PCNC,including cavity thickness and width,lattice constant,and radii and numbers of holes,are optimized,with the quality factor Q and mode volume Vm as performance indicators.Mutual modulation of the lattice constant and hole radius enable the proposed M-PCNC to realize outstanding performance.The optimized cavity possesses a high quality factor Q 1.45105 and an ultra-small mode=×volume Vm 0.01(λ/n)[Zeng et al.,Opt Lett 2023:48;3981–3984]in the telecommunications wavelength range.Light can be progres-=sively squeezed in both the propagation direction and the perpendicular in-plane direction by a series of interlocked anti-slots and slots in the diamond-shaped hole structure.Thereby,the energy can be confined within a small mode volume to achieve an ultra-high Q/Vm ratio. 展开更多
关键词 Photonic crystal nanobeam cavity mixed diamond–circular holes Slots and anti-slots FDTD simulation Quality factor Mode volume
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Analysis of factors impacting postoperative pain and quality of life in patients with mixed hemorrhoids:A retrospective study
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作者 Xiao-Wen Sun Jing-Yi Xu +3 位作者 Chang-Zhen Zhu Si-Jia Li Lu-Jia Jin Zhi-Dong Zhu 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第3期731-739,共9页
BACKGROUND Hemorrhoids are among the most common and frequently encountered chronic anorectal diseases in anorectal surgery.They are venous clusters formed by con-gestion,expansion,and flexion of the venous plexus in ... BACKGROUND Hemorrhoids are among the most common and frequently encountered chronic anorectal diseases in anorectal surgery.They are venous clusters formed by con-gestion,expansion,and flexion of the venous plexus in the lower part of the rec-tum.Mixed hemorrhoids bleed easily and recurrently,and this can result in severe anemia.Hence,they may have a negative effect on the health of the patient and surgical treatment is required.Milligan-Morgan hemorrhoidectomy has been widely used since 1937 for the treatment of grade III and IV hemorrhoids.How-ever,most patients experience different degrees of postoperative pain that may cause anxiety.with mixed hemorrhoids post-surgery.METHODS The clinical data of patients with mixed hemorrhoids who underwent Milligan-Morgan hemorrhoidectomy were collected retrospectively.The basic character-istics of the enrolled patients with mixed hemorrhoids were recorded,and based on the Goligher clinical grading system,the hemorrhoids were classified as grades III or IV.The endpoint of this study was the disappearance of pain in all patients.Quantitative data were presented as mean±SD,such as age,pain score,and QoL score.Student’s t-test was used to compare the groups.RESULTS A total of 164 patients were enrolled.The distribution of the visual analog scale pain scores of all patients at 3,7,14 and 28 d after surgery showed that post-surgery pain was significantly reduced with the passage of time.Fourteen days after the operation,the pain had completely disappeared in some patients.Twenty-eight days after the surgery,none of the patients experienced any pain.Comparing the World Health Or-ganization Quality of Life-BREF self-reporting questionnaire scores of patients between 14 and 28 d after surgery,we observed that the quality-of-life scores of the patients post-surgery had significantly improved.There were six items that were compared at 14-and 28-d post-surgery.The mean QoL score 28 d after surgery(4.79±0.46)was higher than that at 14 d post-surgery(3.79±0.57).The mean health condition score 28 d after surgery(4.80±0.41)was also higher than that at 14 d post-surgery(4.01±0.62).The mean physical health score 28 d after surgery(32.10±2.96)was significantly higher than that at 14 d post-surgery(23.41±2.85).The mean psychological health score 28 d after surgery(27.22±1.62)was significantly higher than that at 14 d post-surgery(21.37±1.70).The mean social relations score 28 d after surgery(12.21±1.59)was significantly higher than that at 14 d post-surgery(6.32±1.66).The mean surrounding environment score 28 d after surgery(37.13±2.88)was significantly higher than that at 14 d post-surgery(28.42±2.86).The differences in quality-of-life scores at day 14 and day 28 post-surgery were ob-served to be statistically significant(P<0.001).CONCLUSION Milligan-Morgan hemorrhoidectomy can significantly improve the postoperative QoL of patients.Age,sex,and the number of surgical resections were important factors influencing Milligan-Morgan hemorrhoidectomy. 展开更多
关键词 HEMORRHOIDS mixed hemorrhoids Milligan organ hemorrhoidectomy Postoperative pain Quality of life Anesthesia mode
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Mixed Neuroendocrine-Non-Neuroendocrine Neoplasm (MiNEN) of the Colon: A Case Report
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作者 Amira Mohammad Azah Syahrina Alias 《Open Journal of Pathology》 2024年第1期16-24,共9页
Here we report a rare case of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). A 51-year-old lady with no known family history of malignancies developed this rare type of malignancy without any active gastr... Here we report a rare case of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). A 51-year-old lady with no known family history of malignancies developed this rare type of malignancy without any active gastrointestinal symptoms. However, during a routine health check, physicians noticed a raised Carcinoembryonic Antigen (CEA) level and the patient subsequently was referred to the surgical department for further management. A colonoscopy and CECT abdomen were done and she was electively admitted for a left hemicolectomy operation for a splenic flexure tumour. The histopathological report revealed the tumour is a case of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) [moderately differentiated adenocarcinoma and neuroendocrine tumour grade 3]. TNM (8th edition, 2016): pT3, pN2 (20/21), pMX. Both resection margins were clear from malignant cells. Colorectal MiNENs, constitute a rare group of gastrointestinal tumours composed of both neuroendocrine and non-neuroendocrine components. Given their non-diagnostic macroscopic features, specific histological features and lack of disease awareness which are responsible for the underestimated incidence and conflicting data. In this case, a multidisciplinary team approach is important in managing patients with this malignancy to achieve the best outcome. 展开更多
关键词 mixed Neuroendocrine-Non-Neuroendocrine Neoplasms (MiNENs) Contrast-Enhanced Computed Tomography (CECT) Carcinoembryonic Antigen (CEA)
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The Regularity of Solutions to Mixed Boundary Value Problems of Second-Order Elliptic Equations with Small Angles
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作者 Mingyu Wu 《Journal of Applied Mathematics and Physics》 2024年第4期1043-1049,共7页
This paper considers the regularity of solutions to mixed boundary value problems in small-angle regions for elliptic equations. By constructing a specific barrier function, we proved that under the assumption of suff... This paper considers the regularity of solutions to mixed boundary value problems in small-angle regions for elliptic equations. By constructing a specific barrier function, we proved that under the assumption of sufficient regularity of boundary conditions and coefficients, as long as the angle is sufficiently small, the regularity of the solution to the mixed boundary value problem of the second-order elliptic equation can reach any order. 展开更多
关键词 mixed Boundary Value Problems for Elliptic Equations Small-Angle Boundary Value Problems Regularity of Solutions to Elliptic Equations
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Discussion on the Application of Technical and Tactical Skills in Mixed Martial Arts Competitions
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作者 Yu Huang 《Journal of Contemporary Educational Research》 2024年第2期8-13,共6页
This article mainly analyzes the application of technical and tactical skills in mixed martial arts competitions,including mixed martial arts and its competition characteristics,the main application significance of te... This article mainly analyzes the application of technical and tactical skills in mixed martial arts competitions,including mixed martial arts and its competition characteristics,the main application significance of technical and tactical skills in mixed martial arts competitions,and its primary application strategies.It is hoped that this analysis can provide some guidelines for the appropriate application of mixed martial arts athletes’technical and tactical skills to improve their winning rate in mixed martial arts competitions. 展开更多
关键词 mixed martial arts competition Technical and tactical skills Fighting awareness Fighting movements Competition rhythm
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Clinical Observation of Chinese Medicinal Prescriptions for Swelling and Pain in The Postoperative Treatment of Mixed Hemorrhoids
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作者 Yuru Duan Guangliang Xu +3 位作者 Lei Ge Wei Zhang Xu Zhang Yi Yang 《Journal of Clinical and Nursing Research》 2024年第3期101-107,共7页
Objective:To observe the clinical effect of traditional Chinese medicine(TCM)on reducing swelling and pain in patients with mixed hemorrhoids.Methods:Sixty patients with mixed hemorrhoids who were admitted to the Hosp... Objective:To observe the clinical effect of traditional Chinese medicine(TCM)on reducing swelling and pain in patients with mixed hemorrhoids.Methods:Sixty patients with mixed hemorrhoids who were admitted to the Hospital of Traditional Chinese Medicine of Qiqihar from January 2023 to January 2024 were selected and divided into two groups.The treatment group(n=30)was treated with mixed hemorrhoid ligation combined with traditional Chinese swelling and pain medicine,and the control group(n=30)was only treated with mixed hemorrhoid ligation.The pain level,edema score,and prognosis of the two groups after the intervention were analyzed.The clinical efficacy was used as the evaluation criterion to compare the clinical effects of different treatment options.Results:After the treatment,the pain score,edema score,and prognostic wound score of the treatment group were all lower than those of the control group(P 0.05).The total clinical effectiveness of the treatment group(100%)was higher than that of the control group(76.67%),(χ^(2)=4.2857,P<0.05).Conclusion:The application of traditional Chinese swelling and pain medicine in treating patients with mixed hemorrhoids effectively reduced the patient’s pain,reduced the degree of wound edema,promoted wound healing,and improved the patient’s prognosis.The curative effect was significant and had a positive impact. 展开更多
关键词 Chinese herbal prescriptions for reducing swelling and pain mixed hemorrhoids Postoperative treatment
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A Note on an Order Level Inventory Model with Varying Two-Phased Demand and Time-Proportional Deterioration
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作者 Sephali Mohanty Trailokyanath Singh +1 位作者 Sudhansu Sekhar Routary Chinmayee Naik 《American Journal of Operations Research》 2024年第1期59-73,共15页
The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. Th... The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. The two-phased demand function states the constant function for a certain period and the quadratic function of time for the rest part of the cycle time. No shortages as well as partial backlogging are allowed to occur. The mathematical expressions are derived for determining the optimal cycle time, order quantity and total cost function. An easy-to-use working procedure is provided to calculate the above quantities. A couple of numerical examples are cited to explain the theoretical results and sensitivity analysis of some selected examples is carried out. 展开更多
关键词 Deteriorating Items EOQ (Economic Order Quantity) INVENTORY Time-proportional Deterioration Two-Phased Demand
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The improved artificial bee colony algorithm for mixed additive and multiplicative random error model and the bootstrap method for its precision estimation 被引量:3
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作者 Leyang Wang Shuhao Han 《Geodesy and Geodynamics》 EI CSCD 2023年第3期244-253,共10页
To solve the complex weight matrix derivative problem when using the weighted least squares method to estimate the parameters of the mixed additive and multiplicative random error model(MAM error model),we use an impr... To solve the complex weight matrix derivative problem when using the weighted least squares method to estimate the parameters of the mixed additive and multiplicative random error model(MAM error model),we use an improved artificial bee colony algorithm without derivative and the bootstrap method to estimate the parameters and evaluate the accuracy of MAM error model.The improved artificial bee colony algorithm can update individuals in multiple dimensions and improve the cooperation ability between individuals by constructing a new search equation based on the idea of quasi-affine transformation.The experimental results show that based on the weighted least squares criterion,the algorithm can get the results consistent with the weighted least squares method without multiple formula derivation.The parameter estimation and accuracy evaluation method based on the bootstrap method can get better parameter estimation and more reasonable accuracy information than existing methods,which provides a new idea for the theory of parameter estimation and accuracy evaluation of the MAM error model. 展开更多
关键词 mixed additive and multiplicative random ERROR Parameter estimation Accuracy evaluation Artificial bee colony algorithm Bootstrap method
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Improved cat swarm optimization for parameter estimation of mixed additive and multiplicative random error model 被引量:2
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作者 Leyang Wang Shuhao Han 《Geodesy and Geodynamics》 EI CSCD 2023年第4期385-391,共7页
To estimate the parameters of the mixed additive and multiplicative(MAM)random error model using the weighted least squares iterative algorithm that requires derivation of the complex weight array,we introduce a deriv... To estimate the parameters of the mixed additive and multiplicative(MAM)random error model using the weighted least squares iterative algorithm that requires derivation of the complex weight array,we introduce a derivative-free cat swarm optimization for parameter estimation.We embed the Powell method,which uses conjugate direction acceleration and does not need to derive the objective function,into the original cat swarm optimization to accelerate its convergence speed and search accuracy.We use the ordinary least squares,weighted least squares,original cat swarm optimization,particle swarm algorithm and improved cat swarm optimization to estimate the parameters of the straight-line fitting MAM model with lower nonlinearity and the DEM MAM model with higher nonlinearity,respectively.The experimental results show that the improved cat swarm optimization has faster convergence speed,higher search accuracy,and better stability than the original cat swarm optimization and the particle swarm algorithm.At the same time,the improved cat swarm optimization can obtain results consistent with the weighted least squares method based on the objective function only while avoiding multiple complex weight array derivations.The method in this paper provides a new idea for theoretical research on parameter estimation of MAM error models. 展开更多
关键词 mixed additive and multiplicative random error model Parameter estimation Least squares Cat swarm optimization Powell method
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The Effect of Boreal Summer Intraseasonal Oscillation on Mixed Layer and Upper Ocean Temperature over the South China Sea 被引量:1
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作者 JIA Wentao SUN Jilin +1 位作者 ZHANG Weimin WANG Huizan 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第2期285-296,共12页
Intraseasonal oscillation of the mixed layer and upper ocean temperature has been found to occur over the South China Sea(SCS)in the summer monsoon season based on the multiple reanalysis and observational data in thi... Intraseasonal oscillation of the mixed layer and upper ocean temperature has been found to occur over the South China Sea(SCS)in the summer monsoon season based on the multiple reanalysis and observational data in this study.The method of composite analysis and an upper ocean temperature equation assisted the analysis of physical mechanisms.The results show that the mixed layer depth(MLD)in the SCS has a significant oscillation with a 30-60 d period over the SCS region,which is closely related to boreal summer intraseasonal oscillation(BSISO)activities.The MLD can increase(decrease)during the positive(negative)phase of the BSISO and usually lags behind by approximately one-eighth of the lifecycle(5 days)of the BSISO-related convection.The BSISO may cause periodic anomalies at the air-sea boundary,such as wind stress and heat flux,so it can play a dominant role in modulating the variation in MLD.There also are significant intraseasonal seawater temperature anomalies in both the surface and subsurface layers of the SCS.In addition,during the initial phase of the BSISO,the temperature anomaly signals of the thermocline are obviously opposite to the sea surface temperature(SST),especially in the southern SCS.According to the results from the analysis of the temperature equation,the vertical entrainment term caused by BSISO-related wind stress is stronger than the thermal forcing during the initial stage of convection,and it is more significant in the southern SCS. 展开更多
关键词 boreal summer intraseasonal oscillation South China Sea mixed layer depth upper ocean temperature
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A Mathematical Calculation Model Using Biomarkers to Quantitatively Determine the Relative Source Proportion of Mixed Oils 被引量:3
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作者 CHEN Jianping DENG Chunping +1 位作者 SONG Fuqing ZHANG Dajiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第5期817-826,共10页
从多重来源岩石,和特别地每来源岩石的相对贡献识别混合的油的来源是困难的。当有简历标记的不同集中的二油与对方一起混合时,用不同简历标记的典型的原油和比率的人工的混合实验证明相对贡献变化是非线性的。如果简历标记和一个简单... 从多重来源岩石,和特别地每来源岩石的相对贡献识别混合的油的来源是困难的。当有简历标记的不同集中的二油与对方一起混合时,用不同简历标记的典型的原油和比率的人工的混合实验证明相对贡献变化是非线性的。如果简历标记和一个简单二进制线性方程的比率被用来计算每个结束成员的贡献比例到混合的油,这可以导致一个不正确的结论。有在三的混合模型的结束成员油的混合比例的简历标记比率的变化比在二进制混合模型更复杂。什么时候四或更多的油混合,到混合的油的每结束成员油的贡献比例不能用简历标记比率和一个简单公式被计算。典型的油的人工的混合实验表明在混合的油的简历标记的绝对集中与混合每个结束成员的比例引起一个线性变化。数学推论验证如此的线性变化。一些用到份量上的简历标记的绝对集中或比率的数学计算方法决定在混合的油的每个结束成员的比例从人工的实验并且由理论推理的结果被推出。当混合超过三结束成员时,二个简历标记的比率在二进制混合模型与混合比例作为一条双曲线加重变化,作为在三的混合模型的 hyperboloid,并且作为亢奋的表面。每个结束成员的混合比例能是与这些数学模型一起决定的份量上,用绝对集中和简历标记的比率。数学计算模型比常规人工的混合方法更节俭、方便、精确、可靠。 展开更多
关键词 混合石油 石油资源 数量测定 数学模式
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Effects of Different Tree Species and Proportions on Soil Fertility Quality in Eucalyptus Mixed Plantation
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作者 Haitao JIANG Nianyong ZHAN +5 位作者 Lin JIANG Heng QIN Jianying DENG Yuanli ZHU Junyu ZHAO Jian TANG 《Meteorological and Environmental Research》 CAS 2022年第3期74-77,81,共5页
In order to study the effects of Eucalyptus mixed plantation with different mixed tree species and mixed proportion on soil nutrient accumulation and fertility quality, Eucalyptus-Mytilaria laosensis and Eucalyptus-Ma... In order to study the effects of Eucalyptus mixed plantation with different mixed tree species and mixed proportion on soil nutrient accumulation and fertility quality, Eucalyptus-Mytilaria laosensis and Eucalyptus-Magnolia sumatrana mixed plantations in Guangxi State-owned Qipo Forest Farm were selected as the research objects. Based on 15 conventional soil fertility indexes, the minimum data set and membership function method were used to evaluate the soil fertility quality of mixed plantations with different structures. The results showed that compared with pure forest, the soil organic matter, total nitrogen, total potassium, alkali hydrolyzable nitrogen, available phosphorus, available potassium and other nutrients of mixed plantations with different treatments were significantly increased, and the contents of Cu and Zn in trace elements were most significantly increased. Compared with pure forest, the soil fertility quality of mixed plantations with different structures was significantly improved. The treatment with the highest soil fertility quality was 25% of Eucalyptus-M. sumatrana mixed plantation. When formulating production and management strategies, it can refer to construction measures of the mixed plantation to ensure the sustainability of forest soil fertility, and promote the healthy and sustainable development of Eucalyptus plantation and downstream industries in Guangxi. 展开更多
关键词 Minimum data set Membership function mixed plantation Sustainable management
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Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?
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作者 Cen Chen John Kershaw Jr +1 位作者 Aaron Weiskittel Elizabeth McGarrigle 《Forest Ecosystems》 SCIE CSCD 2023年第1期21-30,共10页
Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately predict.Various modeling strategies have been developed to improve individual tr... Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately predict.Various modeling strategies have been developed to improve individual tree mortality predictions.One less explored strategy is the use of a multistage modeling approach.Potential improvements from this approach have remained largely unknown.In this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model formulation.Extensive permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this study.Our results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional approach.The difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional approach.In addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the data.The new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional models.Finally,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted values.Overall,this new multistage approach deserves to be considered and tested in future studies. 展开更多
关键词 Tree mortality modeling Mortality disaggregation mixed effect model Annualization mixed forests
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Removal of dolomite and potassium feldspar from apatite using simultaneous flotation with a mixed cationic-anionic collector
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作者 Haoyong Yu Yangge Zhu +2 位作者 Liang Lu Xiaoxing Hu Songqing Li 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期783-791,共9页
This study aims to investigate the effect of a cationic-anionic mixed collector(dodecyltrimethyl ammonium bromide/sodium oleate(DTAB/NaOL)on the selective separation of apatite,dolomite,and potassium feldspar.Herein,s... This study aims to investigate the effect of a cationic-anionic mixed collector(dodecyltrimethyl ammonium bromide/sodium oleate(DTAB/NaOL)on the selective separation of apatite,dolomite,and potassium feldspar.Herein,several experimental methods,including flotation experiments,zeta-potential detection,microcalorimetry detection,XPS analysis and FTIR measurements,were used.The flotation tests showed that dolomite and potassium feldspar can be successfully removed from apatite simultaneously when the molar ratio of DTAB to NaOL was 2:1 with pH 4.5.Zeta-potential and microcalorimetry detection suggested that NaOL and DTAB were adsorbed on the surface of dolomite and potassium feldspar respectively,and part of NaOL and DTAB formed co-adsorption on the surface of potassium feldspar to enhance the floatability of potassium feldspar.The XPS and FTIR spectra analysis demonstrated that the cationic collector,DTAB,was first adsorbed on the surface of potassium feldspar through electrostatic attraction in the DTAB/NaOL mixture system.Subsequently,the anionic NaOL collector and cationic DTAB collector form an electron neutralisation complex,thereby resulting in co-adsorption on the surface of potassium feldspar.NaOL was chemically reacted and adsorbed on dolomite surface,but almost no collector was adsorbed on apatite surface.Finally,the adsorption models of different collectors on mineral surface were obtained. 展开更多
关键词 FLOTATION mixed collectors APATITE Potassium feldspar DOLOMITE
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