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Optimal operating policy for a controllable queueing model with a fuzzy environment

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 311-318页

作者： Chuen-horng LIN jau-chuan ke Department of Information Management Department of Applied Statistics National Taichung Institute of Technology

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.

关键词： Controllable queue Fuzzy sets Membership function Nonlinear programming

Optimization on bicriterion policies for M/G/1 system with second optional service

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1437-1445页

作者： jau-chuan ke Yunn-kuang CHU Department of Applied Statistics National Taichung Institute of Technology Taichung 404 Taiwan China

We compare the optimal operating cost of the two bicriterion policies, and , 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 policy or 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.

关键词： Average operating cost Bicriterion policy Optimization comparisons Optional service Optimal threshold values

RANDOMIZED POLICY OF A POISSON INPUT QUEUE WITH J VACATIONS

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Journal of Systems Science and Systems Engineering 2010年第1期19卷 50-71页

作者： jau-chuan ke Kai-Bin HUANG Wen Lea PEARN Department of Applied Statistic National Taichung lnstitute of Technology Taichung 404 Taiwan China Department of Industrial and Engineering Management National Chiao Tutig University Hsing Chu 300 Taiwan China

This paper studies the operating characteristics of an M/G/1 queuing system with a randomized control policy and at most J vacations. After all the customers are served in the queue exhaustively, the server immediately takes at most J vacations repeatedly until at least N customers are waiting for service in the queue upon returning from a vacation. If the number of arrivals does not reach N by the end of the jth vacation, the server remains idle in the system until the number of arrivals in the queue reaches N. If the number of customers in the queue is exactly accumulated N since the server remains idle or returns from vacation, the server is activated for services with probability p and deactivated with probability （l-p）. For such variant vacation model, other important system characteristics are derived, such as the expected number of customers, the expected length of the busy and idle period, and etc. Following the construction of the expected cost function per unit time, an efficient and fast procedure is developed for searching the joint optimum thresholds （N＊,J＊） that minimize the cost function. Some numerical examples are also presented.

关键词： Cost 〈 p N 〉 -policy supplementary variable technique vacation

Hybrid Dynamic Variables-Dependent Event-Triggered Fuzzy Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 723-733页

作者： Xiongbo Wan Chaoling Zhang Fan Wei chuan-ke Zhang Min Wu IEEE the School of Automation China University of Geosciencesthe Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systemsand the Engineering Research Center of Intelligent Technology for Geo-ExplorationMinistry of EducationWuhan 430074China

This article focuses on dynamic event-triggered mechanism(DETM)-based model predictive control(MPC) for T-S fuzzy systems.A hybrid dynamic variables-dependent DETM is carefully devised,which includes a multiplicative dynamic variable and an additive dynamic *** addressed DETM-based fuzzy MPC issue is described as a “min-max” optimization problem(OP).To facilitate the co-design of the MPC controller and the weighting matrix of the DETM,an auxiliary OP is proposed based on a new Lyapunov function and a new robust positive invariant(RPI) set that contain the membership functions and the hybrid dynamic variables.A dynamic event-triggered fuzzy MPC algorithm is developed accordingly,whose recursive feasibility is analysed by employing the RPI *** the designed controller,the involved fuzzy system is ensured to be asymptotically *** examples show that the new DETM and DETM-based MPC algorithm have the advantages of reducing resource consumption while yielding the anticipated performance.

关键词： Dynamic event-triggered mechanism(DETM) hybrid dynamic variables model predictive control(MPC) robust positive invariant(RPI)set T-S fuzzy systems

Axial enantiomers with donor-regulated TADF feature for multicolor circularly polarized electroluminescence

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Science China Chemistry 2024年第6期67卷 2039-2045页

作者： Chen-Hao Guo Wen-Long Zhao ke-ke Tan Wei-Chen Guo Liheng Feng chuan-Feng Chen Meng Li School of Chemistry and Chemical Engineering Shanxi UniversityTaiyuan030006China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

This study optimized the TADF feature of axial chiral enantiomers through precise donor engineering,and multicolor CP-TADFwas achieved in the axial chiral *** pairs of axial enantiomers with donor-regulated TADF feature,namely(R/S)-TPCBD,(R/S)-DPCBD,and(R/S)-DPACBD,were synthesized by introducing carbazole donors with different substituents onto biphenyl cyanide *** the electron-donating ability of donors increases,the emission of these axial enantiomers ranges from 455,476 to 552 nm,their singlet-triplet energy gaps(ΔE_(ST))gradually decrease from 0.30,0.22 to 0.02 e V,accompanied by an increasement in the transition rate(k_(RISC))of RISC process,and the k_(RISC)of DPACBD could reach up to 7.16×10^(5)s^(-1).These axial enantiomers also exhibit mirror-image CD and circularly polarized luminescence(CPL)***,OLEDs based on TPCBD,DPCBD,and DPACBD as emitter were then fabricated,which displayed blue,green,and orange electroluminescence with EQE_(max)of 13.0%,16.4%,and 25.0%,*** results also exhibited a phenomenon of device efficiency increasing with the enhancement of donor ***,the CP-OLEDs using(R/S)-TPCBD,(R/S)-DPCBD and(R/S)-DPACBD as emitters displayed intense CPEL signals with g_(EL)values of 3.4×10^(-3)/-4.1×10^(-3),3.2×10^(-3)/-3.1×10^(-3)and2.3×10^(-3)/-2.1×10^(-3),*** convenient molecular engineering of donor regulation in the same molecular skeleton,CP-TADF materials with multicolor CPEL and improved device performance could be conveniently achieved.

关键词： axial chirality thermally activated delayed fluorescence circularly polarized luminescence electroluminescence organic light-emitting diodes

Does type 1 diabetes serve as a protective factor against inflammatory bowel disease:A Mendelian randomization study

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World Journal of Diabetes 2024年第7期15卷 1551-1561页

作者： ke-ke Tong Yun-Feng Yu Xin-Yu Yang Jing-Yi Wu Rong Yu chuan-chuan Tan The First Hospital of Hunan University of Chinese Medicine Changsha 410007Hunan ProvinceChina School of Traditional Chinese Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina The Third Hospital Zhejiang Chinese Medical UniversityHangzhou 310005Zhejiang ProvinceChina

BACKGROUND The impact of type 1 diabetes(T1D)on inflammatory bowel disease(IBD)remains *** To analyze the causal relationship between T1D and IBD using Mendelian randomization(MR).METHODS Single nucleotide polymorphisms were sourced from FinnGen for T1D,IBD,ulcerative colitis(UC)and Crohn’s disease(CD).Inverse variance-weighted,MREgger,and weighted median tests were used to assess exposure-outcome *** MR-Egger intercept was used to assess horizontal ***’s Q and leave-one-out method were used to analyze heterogeneity and sensitivity,*** Our MR analysis indicated that T1D was associated with a reduced risk of IBD[odds ratio(OR):0.959;95%confidence interval(CI):0.938-0.980;P0.05).Cochran’s Q and leave-one-out sensitivity analyses showed that the results were not heterogeneous(P>0.05)and were *** This MR analysis suggests that T1D serves as a potential protective factor against IBD and UC but is independent of CD.

关键词： Type 1 diabetes Inflammatory bowel disease Ulcerative colitis Crohn’s disease Mendelian randomization

Effects of fluid therapy combined with a preoperative glucose load regimen on postoperative recovery in patients with rectal cancer

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2662-2670页

作者： Lv-Chi Xia ke Zhang chuan-Wen Wang Department of Emergency Medicine Jiujiang First People's HospitalJiujiang 332000Jiangxi ProvinceChina

BACKGROUND Patients with rectal cancer undergoing radical resection often have poor post-operative recovery due to preoperative fasting and water deprivation and the removal of diseased tissue,and have a high risk of ***,it is of great significance to apply appropriate rehydration regimens to patients un-dergoing radical resection of rectal cancer during the perioperative period to improve the postoperative outcomes of *** To analyze the effects of goal-directed fluid therapy(GDFT)with a preoperative glucose load regimen on postoperative recovery and complications in patients undergoing radical resection for rectal *** Patients with rectal cancer who underwent radical resection(n=184)between January 2021 and December 2023 at our hospital were randomly divided into either a control group or an observation group(n=92 in each group).Both groups received a preoperative glucose load regimen,and routine fluid replacement and GDFT were additionally implements in the control and observation groups,*** operative conditions,blood levels of lactic acid and inflammatory markers,postoperative recovery,cognitive status,hemodynamic indicators,brain oxygen metabolism,and complication rates were compared between the *** The colloidal fluid dosage,total infusion,and urine volume,as well as time to first exhaust,time to food intake,and postoperative length of hospital stay,were lower in the observation group(P0.05).Compared with the control group,in the ob-servation group the lactic acid level was lower immediately after the surgery(P<0.05);the Mini-Mental State Examination score was higher on postoperative day 3(P<0.05);the pulse pressure variability(PPV)was lower at 30 min after pneumoperitone

关键词： Radical resection of rectal cancer Goal-directed fluid therapy Preoperative glucose load Cognitive condition Complication

Geochemical fractionation and potential release behaviour of heavy metals in lead–zinc smelting soils

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Journal of Environmental Sciences 2024年第5期139卷 1-11页

作者： Xinghua Luo Chao Xiang chuan Wu Wenyan Gao Wenshun ke Jiaqing Zeng Waichin Li Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution Central South UniversityChangsha 410083China Department of Science and Environmental Studies The Education University of Hong KongHong Kong 999077China

The lack of understanding of heavy metal speciation and solubility control mechanisms in smelting soils limits the effective pollution *** this study smelting soils were investigated by an advanced mineralogical analysis(AMICS),leaching tests and thermodynamic *** aims were to identify the partitioning and release behaviour of Pb,Zn,Cd and *** integration of multiple techniques was necessary and displayed coherent *** addition to the residual fraction,Pb and Zn were predominantly associated with reducible fractions,and As primarily existed as the crystalline iron oxide-bound *** quantitative analysis further confirmed that Fe oxyhydroxides were the common dominant phase for As,Cd,Pb and *** addition,a metal arsenate(paulmooreite)was an important mineral host for Pb and *** pH-stat leaching indicted that the release of Pb,Zn and Cd increased towards low pH values while release of As increased towards high p H *** separate leaching schemes were associated with the geochemical behaviour under the control of minerals and were confirmed by thermodynamic *** calculations suggested that the formation of arsenate minerals(schultenite,mimetite and koritnigite)and the binding to Fe oxyhydroxides synchronously controlled the release of Pb,Zn,Cd and *** results emphasized the governing role of Fe oxyhydroxides and secondary insoluble minerals in natural attenuation of heavy metals,which provides a novelty strategy for the stabilization of multi-metals in smelting sites.

关键词： Smelting soils Heavy metal Fractionation AMICS Geochemical modelling

Microstructure Recrystallization and Mechanical Properties of a Cold-Rolled TiNbZrTaHf Refractory High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 633-647页

作者： chuan Rong Jieren Yang Xiaoliang Zhao ke Huang Ying Liu Xiaohong Wang Dongdong Zhu Ruirun Chen College of Materials Science and Engineering Sichuan UniversityChengdu610065China key Laboratory of Air-Driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou324000China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined that the recrystallization temperature of the TiNbZrTaHf alloy between 850 and 900 ℃. Complete recrystallization and normal grain growth occurred, the high stability of single phase was maintained after annealing at 1000, 1200, and 1400 ℃. But the precipitated phase appeared after long term annealing, as seen after 500 h at 1000 ℃. After cold working, the tensile strength and the elongation of TiNbZrTaHf were 1137 MPa and 25.1%, respectively. The annealed alloy has a high tensile strength (σ_(b )= 863 MPa) and ductility (ε_(e )= 28.5%). Moreover, the oxidation of TiNbZrTaHf alloy at elevated temperatures has a significant impact on its mechanical properties. The poor oxidation resistance of TiNbZrTaHf can accelerate tensile failure by inducing fractures at grain boundaries.

关键词： Refractory high entropy alloy Cold rolling Recrystallization Oxidation resistance Mechanical properties