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Modular zonal fluid sampling and pressure testing technology for production well
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作者 XU Jianguo YANG Qinghai +5 位作者 YI Peng HOU Ze JIA Weite FU Tao ZHANG Zonglin YUE Qingfeng 《Petroleum Exploration and Development》 CSCD 2022年第2期438-447,共10页
To accurately obtain development dynamic data such as zonal pressure and fluid parameters of each oil layer in the late development stage of a high water-cut old oilfield, a modular zonal sampling and testing technolo... To accurately obtain development dynamic data such as zonal pressure and fluid parameters of each oil layer in the late development stage of a high water-cut old oilfield, a modular zonal sampling and testing technology with the characteristics of modularization, full electronic control and rapidity was proposed and developed. Lab testing and on-site testing was carried out. The modular zonal sampling and testing system is composed of 10 functional modules, namely ground control system, downhole power supply module, drainage pump, electronically controlled anchor, electronically controlled packer, electronically controlled sampler, magnetic positioning sub, terminal sub, adapter cable, and quick connector. Indoor tests have confirmed that the performance parameters of each module meet the design requirements. The downhole function modules of the system can withstand pressures up to 35 MPa and temperatures up to 85 ℃. The rubber cylinder of the electronically controlled packer can withstand a pressure difference of more than 10 MPa. The electronically controlled anchor has an anchoring force of greater than 6.9 t, and can be forcibly detached in the event of an accident. The discharge pump has a displacement of 0.8 m;/d and a head of 500 m. The electronically controlled sampler can meet the requirement of taking 500 mL of sample in each of the 3 chambers. Field tests in Jilin Oilfield show that the system can realize rapid isolation and self-check of isolation of a certain production interval downhole, as well as layer-by layer pressure build-up test. The drainage pump can be used to discharge the mixed liquid between the upper and lower packers and near the wellbore to obtain real fluid samples of the tested formation interval. The data obtained give us better understanding on the pay zones in old oilfields, and provide important basis for development plan adjustment, reservoir stimulation, and EOR measures. 展开更多
关键词 zonal sampling zonal testing MODULARIZATION full electronic control RAPIDITY enhanced oil recovery fluid sampling pressure testing
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Modified DS np Chart Using Generalized Multiple Dependent State Sampling under Time Truncated Life Test
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作者 Wimonmas Bamrungsetthapong Pramote Charongrattanasakul 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2471-2495,共25页
This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of t... This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of the product based on the time truncated life test employing theWeibull distribution.The control chart developed supports the examination of the mean lifespan variation for a particular product in the process of manufacturing.Three control limit levels are used:the warning control limit,inner control limit,and outer control limit.Together,they enhance the capability for variation detection.A genetic algorithm can be used for optimization during the in-control process,whereby the optimal parameters can be established for the proposed control chart.The control chart performance is assessed using the average run length,while the influence of the model parameters upon the control chart solution is assessed via sensitivity analysis based on an orthogonal experimental design withmultiple linear regression.A comparative study was conducted based on the out-of-control average run length,in which the developed control chart offered greater sensitivity in the detection of process shifts while making use of smaller samples on average than is the case for existing control charts.Finally,to exhibit the utility of the developed control chart,this paper presents its application using simulated data with parameters drawn from the real set of data. 展开更多
关键词 Modified DS np chart generalizedmultiple dependent state sampling time truncated life test Weibull distribution average run length average sample size
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Adaptive sampling strategy for characterizing spatial distribution of soil liquefaction potential using cone penetration test 被引量:1
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作者 Zheng Guan Yu Wang Tengyuan Zhao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第4期1221-1231,共11页
Characterizing spatial distribution of soil liquefaction potential is critical for assessing liquefactionrelated hazards(e.g.building damages caused by liquefaction-induced differential settlement).However,in engineer... Characterizing spatial distribution of soil liquefaction potential is critical for assessing liquefactionrelated hazards(e.g.building damages caused by liquefaction-induced differential settlement).However,in engineering practice,soil liquefaction potential is usually measured at limited locations in a specific site using in situ tests,e.g.cone penetration tests(CPTs),due to the restrictions of time,cost and access to subsurface space.In these cases,liquefaction potential of soil at untested locations requires to be interpreted from limited measured data points using proper interpolation method,leading to remarkable statistical uncertainty in liquefaction assessment.This underlines an important question of how to optimize the locations of CPT soundings and determine the minimum number of CPTs for achieving a target reliability level of liquefaction assessment.To tackle this issue,this study proposes a smart sampling strategy for determining the minimum number of CPTs and their optimal locations in a selfadaptive and data-driven manner.The proposed sampling strategy leverages on information entropy and Bayesian compressive sampling(BCS).Both simulated and real CPT data are used to demonstrate the proposed method.Illustrative examples indicate that the proposed method can adaptively and sequentially select the required number and optimal locations of CPTs. 展开更多
关键词 Liquefaction potential Information entropy Cone penetration test(CPT) Site characterization Compressive sampling
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Designing Adaptive Multiple Dependent State Sampling Plan for Accelerated Life Tests 被引量:1
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作者 Pramote Charongrattanasakul Wimonmas Bamrungsetthapong Poom Kumam 《Computer Systems Science & Engineering》 SCIE EI 2023年第8期1631-1651,共21页
A novel adaptive multiple dependent state sampling plan(AMDSSP)was designed to inspect products from a continuous manufacturing process under the accelerated life test(ALT)using both double sampling plan(DSP)and multi... A novel adaptive multiple dependent state sampling plan(AMDSSP)was designed to inspect products from a continuous manufacturing process under the accelerated life test(ALT)using both double sampling plan(DSP)and multiple dependent state sampling plan(MDSSP)concepts.Under accelerated conditions,the lifetime of a product follows the Weibull distribution with a known shape parameter,while the scale parameter can be determined using the acceleration factor(AF).The Arrhenius model is used to estimate AF when the damaging process is temperature-sensitive.An economic design of the proposed sampling plan was also considered for the ALT.A genetic algorithm with nonlinear optimization was used to estimate optimal plan parameters to minimize the average sample number(ASN)and total cost of inspection(TC)under both producer’s and consumer’s risks.Numerical results are presented to support the AMDSSP for the ALT,while performance comparisons between the AMDSSP,the MDSSP and a single sampling plan(SSP)for the ALT are discussed.Results indicated that the AMDSSP was more flexible and efficient for ASN and TC than the MDSSP and SSP plans under accelerated conditions.The AMDSSP also had a higher operating characteristic(OC)curve than both the existing sampling plans.Two real datasets of electronic devices for the ALT at high temperatures demonstrated the practicality and usefulness of the proposed sampling plan. 展开更多
关键词 Accelerated life test acceleration factor adaptive of multiple dependent state sampling plan average sample number total cost of inspection weibull distribution
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A Novel Multiple Dependent State Sampling Plan Based on Time Truncated Life Tests Using Mean Lifetime 被引量:1
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作者 Pramote Charongrattanasakul Wimonmas Bamrungsetthapong Poom Kumam 《Computers, Materials & Continua》 SCIE EI 2022年第12期4611-4626,共16页
The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by apply... The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by applying the concept of the double sampling plan and existing multiple dependent state sampling plans.A warning sign for acceptance number was proposed to increase the probability of current lot acceptance.The optimal plan parameters were determined simultaneously with nonlinear optimization problems under the producer’s risk and consumer’s risk.A simulation study was presented to support the proposed sampling plan.A comparison between the proposed and existing sampling plans,namely multiple dependent state(MDS)sampling plans and a modified multiple dependent state(MMDS)sampling plan,was considered under the average sampling number and operating characteristic curve values.In addition,the use of two real datasets demonstrated the practicality and usefulness of the proposed sampling plan.The results indicated that the proposed plan is more flexible and efficient in terms of the average sample number compared to the existing MDS and MMDS sampling plans. 展开更多
关键词 Adaptive version of multiple dependent state sampling plan time truncated life test quality level weibull distribution mean lifetime
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Acceptance Sampling Plans with Truncated Life Tests for the Length-Biased Weighted Lomax Distribution 被引量:1
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作者 Amer Ibrahim Al-Omari Ibrahim M.Almanjahie Olena Kravchuk 《Computers, Materials & Continua》 SCIE EI 2021年第4期285-301,共17页
In this paper,we considered the Length-biased weighted Lomax distribution and constructed new acceptance sampling plans(ASPs)where the life test is assumed to be truncated at a pre-assigned time.For the new suggested ... In this paper,we considered the Length-biased weighted Lomax distribution and constructed new acceptance sampling plans(ASPs)where the life test is assumed to be truncated at a pre-assigned time.For the new suggested ASPs,the tables of the minimum samples sizes needed to assert a specific mean life of the test units are obtained.In addition,the values of the corresponding operating characteristic function and the associated producer’s risks are calculated.Analyses of two real data sets are presented to investigate the applicability of the proposed acceptance sampling plans;one data set contains the first failure of 20 small electric carts,and the other data set contains the failure times of the air conditioning system of an airplane.Comparisons are made between the proposed acceptance sampling plans and some existing acceptance sampling plans considered in this study based on the minimum sample sizes.It is observed that the samples sizes based on the proposed acceptance sampling plans are less than their competitors considered in this study.The suggested acceptance sampling plans are recommended for practitioners in the field. 展开更多
关键词 Acceptance sampling plan producer’s risk truncated life tests operating characteristic function length-biased weighted lomax distribution consumer’s risk
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Improved Attribute Chain Sampling Plan for Darna Distribution 被引量:1
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作者 Harsh Tripathi Amer Ibrahim Al-Omari +1 位作者 Mahendra Saha Ayed R.A.Alanzi 《Computer Systems Science & Engineering》 SCIE EI 2021年第9期381-392,共12页
Recently,the Darna distribution has been introduced as a new lifetime distribution.The two-parameter Darna distribution represents is a mixture of two well-known gamma and exponential distributions.A manufacturer or a... Recently,the Darna distribution has been introduced as a new lifetime distribution.The two-parameter Darna distribution represents is a mixture of two well-known gamma and exponential distributions.A manufacturer or an engineer of products conducts life testing to examine whether the quality level of products meets the customer’s requirements,such as reliability or the minimum lifetime.In this article,an attribute modified chain sampling inspection plan based on the time truncated life test is proposed for items whose lifetime follows the Darna distribution.The plan parameters,including the sample size,the acceptance number,and the past lot result of the proposed sampling plan,are determined with the help of the two-point approach considering the acceptable quality level(AQL)and the limiting quality level(LQL).The plan parameters and the corresponding operating characteristic functions of a new plan are provided in tabular form for various Darna distribution parameters.Also,a few illustrated examples are presented for various distribution parameters.The usefulness of the proposed attribute modified chain sampling plan is investigated using two real failure time datasets.The results indicate that the proposed sampling plan can reduce the sample size when the termination ratio increases for fixed values of the producer’s risk and acceptance number.Hence,the proposed attribute modified chain sampling inspection plan is recommended to practitioners in the field. 展开更多
关键词 Attribute chain sampling inspection plan consumer’s risk Darna distribution operating characteristic curve producer’s risk truncated life test
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The Impact of Selected Parameters of a Modified Sampling Synthesis on the Result of Its Auditory Assessment
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作者 R. J. Delekta L. J. Spale M. Pluta 《Journal of Applied Mathematics and Physics》 2016年第2期221-226,共6页
One of the main shortcomings of standard sampling synthesis is the very limited number of sound parameters that are user-controllable. In the most general case, the user can choose a particular pitch, duration, and am... One of the main shortcomings of standard sampling synthesis is the very limited number of sound parameters that are user-controllable. In the most general case, the user can choose a particular pitch, duration, and amplitude. If the sampler allows control over articulation, it simply switches from one sound sample to another. This makes fine-tuning of musical performances demanding and time-consuming if not an impossibility altogether. A synthesis system has been developed at the Academy of Music in Krakow, Poland. It uses a large collection of samples that contain short sequences of notes. The system implements a number of techniques to seamlessly connect recorded sequences, to control note durations as well as the tempo and the dynamics envelopes. Samples are automatically chosen, modified, and connected to keep the recorded, natural note transitions intact. The system uses performance rules to introduce variations into the regular playback akin to live performances by musicians. A user can either control the parameters manually or choose a desired expression and leave the particular decisions to the system. However, it is necessary to examine which parameters have the greatest impact on the listeners’ impression and determine useful values. 15 expert listeners compared and evaluated variants of musical performances produced by the synthesis system with different sets of parameters. The paper discusses a selection of the examined parameters, the test methods employed and the results obtained. 展开更多
关键词 Sound Synthesis sampling Listening Tests
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Geochemical sampling with special reference to environmental risk assessment 被引量:1
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作者 Weidong YANG Baojin ZHAO William Pulle 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期25-26,共2页
关键词 地球化学 环境危险评估 取样质量 环境调查
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pyvine:The Python Package for Regular Vine Copula Modeling,Sampling and Testing
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作者 Zhenfei Yuan Taizhong Hu 《Communications in Mathematics and Statistics》 SCIE 2021年第1期53-86,共34页
Regular vine copula provides rich models for dependence structure modeling.It combines vine structures and families of bivariate copulas to construct a number of multivariate distributions that can model a wide range ... Regular vine copula provides rich models for dependence structure modeling.It combines vine structures and families of bivariate copulas to construct a number of multivariate distributions that can model a wide range dependence patterns with different tail dependence for different pairs.Two special cases of regular vine copulas,C-vine and D-vine copulas,have been extensively investigated in the literature.We propose the Python package,pyvine,for modeling,sampling and testing a more generalized regular vine copula(R-vine for short).R-vine modeling algorithm searches for the R-vine structure which maximizes the vine tree dependence in a sequential way.The maximum likelihood estimation algorithm takes the sequential estimations as initial values and uses L-BFGS-B algorithm for the likelihood value optimization.R-vine sampling algorithm traverses all edges of the vine structure from the last tree in a recursive way and generates the marginal samples on each edge according to some nested conditions.Goodness-of-fit testing algorithm first generates Rosenblatt’s transformed data E and then tests the hypothesis H^(∗)_(0):E∼C_(⊥)by using Anderson–Darling statistic,where C_(⊥)is the independence copula.Bootstrap method is used to compute an adjusted p-value of the empirical distribution of replications of Anderson–Darling statistic.The computing of related functions of copulas such as cumulative distribution functions,Hfunctions and inverse H-functions often meets with the problem of overflow.We solve this problem by reinvestigating the following six families of bivariate copulas:Normal,Student t,Clayton,Gumbel,Frank and Joe’s copulas.Approximations of the above related functions of copulas are given when the overflow occurs in the computation.All these are implemented in a subpackage bvcopula,in which subroutines are written in Fortran and wrapped into Python and,hence,good performance is guaranteed. 展开更多
关键词 Regular vine copula Dependence structure Multivariate modeling Multivariate sampling Rosenblatt’s transformation anderson–Darling test Bivariate copula PYTHON
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Preparation and Testing of Cementing and Coating Nano-Subnanocomposites of Slow/Controlled-Release Fertilizer 被引量:5
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作者 LIU Xiu-mei FENG Zhao-bin +2 位作者 ZHANG Fu-dao ZHANG Shu-qing HE Xu-sheng 《Agricultural Sciences in China》 CAS CSCD 2006年第9期700-706,共7页
To select the cementing and coating materials of slow/controlled-release fertilizer, the natural kaoline and abandoned foam plastics were used to prepare nano-subnanocomposites through the methods of organic material ... To select the cementing and coating materials of slow/controlled-release fertilizer, the natural kaoline and abandoned foam plastics were used to prepare nano-subnanocomposites through the methods of organic material intercalation, semiemulsification, and cut at high velocity techniques. Besides, two kinds of nano-subnanocomposites were tested in this study using several instruments, including the scanning electron microscope (SEM), the X-ray diffraction (XRD), the infrared ray spectrum (IR), and the laser granularity. The main results were as follows: 1) The organic material was intercalated in the layers of kaoline clays, and the natural kaoline exfoliated into nanometer-sized layers. The organic agent and clays formed nanocomposites through hydrogen bond combination. 2) The SEM pictures of polystyrenestarch nano-subnanocomposites showed that many pores and rugas were present on the surface of film at sizes ranging from 10 to 20 nm. These nano-subnanocomposites were used as the cementing and coating materials of slow/controlledrelease fertilizer. 展开更多
关键词 nano-subnanocomposites preparation testing
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Preparation Process and Quality Standard of Rougan Huaxian Ointment
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作者 Xianyi SHI Li LONG +3 位作者 Yinghong HUANG Jiangcun WEI Bing QING Wen ZHONG 《Medicinal Plant》 2024年第6期18-22,28,共6页
[Objectives] To establish the preparation process and quality standard of Rougan Huaxian ointment.[Methods] The L 9(3 4) orthogonal test was employed to optimize the preparation process by considering the multiplicati... [Objectives] To establish the preparation process and quality standard of Rougan Huaxian ointment.[Methods] The L 9(3 4) orthogonal test was employed to optimize the preparation process by considering the multiplication of water addition, extraction time, and extraction frequency as influencing factors. The dry paste yield was utilized as the evaluation criterion, in conjunction with the actual production conditions. Thin layer chromatography was employed to identify Radix Astragali, Lycii Fructus, Herba Dendrobii, and Rhizoma Polygoni Cuspidati. Ethanol served as the solvent for the determination of ethanol-soluble extractives using the cold immersion method.[Results] The preparation process was conducted as follows: the specified quantity of medicinal materials was combined with water for extraction purposes, performed in two separate stages. In each stage, eight times the amount of water was added. The first extraction lasted for 1.5 h, while the second extraction was completed in 1.0 h. The resulting liquid was then concentrated into a thick paste with a relative density ranging from 1.25 to 1.30 at a temperature of 60 ℃. The thin-layer chromatography analysis of Radix Astragali, Lycii Fructus, Herba Dendrobii, and Rhizoma Polygoni Cuspidati demonstrated distinct spots, effective separation, and the absence of interference from negative samples. Additionally, the ethanol-soluble extractives yielded a minimum of 8.0% in terms of dry weight.[Conclusions] The preparation process for Rougan Huaxian ointment is both stable and feasible. Furthermore, the quality standards established for this preparation are unique and reproducible, thereby facilitating effective quality control. 展开更多
关键词 Rougan Huaxian ointment preparation process Quality standard Orthogonal test Thin-layer chromatography
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Reliability testing and reliability analysis of the over-load protective relay 被引量:4
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作者 ZHAO Jing-ying CHEN Hong-jian +2 位作者 LIU Guo-jin ZHANG Yong WU Pin-hua 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第3期475-480,共6页
The over-load protective relay is widely used directly affects the safe running of a motor. The reliability for motor protection. The reliability of the over-load protective relay testing and reliability analysis of t... The over-load protective relay is widely used directly affects the safe running of a motor. The reliability for motor protection. The reliability of the over-load protective relay testing and reliability analysis of the over-load protective relay is an important way to improve the reliability of products. In this paper, the reliability test method of the over-load protective relay is studied, and the reliability tests of the typical products are carried out on a reliability tester developed by authors. In terms of the testing results, the reliability analysis is finished. The failure reasons are found and the measures are put forward to improve the reliability of the products. 展开更多
关键词 Over-load protective relay Protective success analysis ratio sampling and checking plan Reliability testing Reliability analysis
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Application of EBSD technique to ultrafine grained and nanostructured materials processed by severe plastic deformation:Sample preparation, parameters optimization and analysis 被引量:2
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作者 陈勇军 Jarle HJELEN Hans J.ROVEN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第8期1801-1809,共9页
With the help of FESEM, high resolution electron backscatter diffraction can investigate the grains/subgrains as small as a few tens of nanometers with a good angular resolution (~0.5°). Fast development of EBS... With the help of FESEM, high resolution electron backscatter diffraction can investigate the grains/subgrains as small as a few tens of nanometers with a good angular resolution (~0.5°). Fast development of EBSD speed (up to 1100 patterns per second) contributes that the number of published articles related to EBSD has been increasing sharply year by year. This paper reviews the sample preparation, parameters optimization and analysis of EBSD technique, emphasizing on the investigation of ultrafine grained and nanostructured materials processed by severe plastic deformation (SPD). Detailed and practical parameters of the electropolishing, silica polishing and ion milling have been summarized. It is shown that ion milling is a real universal and promising polishing method for EBSD preparation of almost all materials. There exists a maximum value of indexed points as a function of step size. The optimum step size depends on the magnification and the board resolution/electronic step size. Grains/subgrains and texture, and grain boundary structure are readily obtained by EBSD. Strain and stored energy may be analyzed by EBSD. 展开更多
关键词 electron backscatter diffraction (EBSD) sample preparation parameters optimization step size severe plastic deformation (SPD)
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Acceptance sampling plan of accelerated life testing for lognormal distribution under time-censoring
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作者 Li Xiaoyang Gao Pengfei Sun Fuqiang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2015年第3期814-821,共8页
Abstract Lognormal distribution is commonly used in engineering. It is also a life distribution of important research values. For long-life products follow this distribution, it is necessary to apply accelerated testi... Abstract Lognormal distribution is commonly used in engineering. It is also a life distribution of important research values. For long-life products follow this distribution, it is necessary to apply accelerated testing techniques to product demonstration. This paper describes the development of accelerated life testing sampling plans (ALSPs) for lognormal distribution under time-censoring conditions. ALSPs take both producer and consumer risks into account, and they can be designed to work whether acceleration factor (AF) is known or unknown. When AF is known, lift testing is assumed to be conducted under accelerated conditions with time-censoring. The producer and con- sumer risks are satisfied, and the size of test sample and the size of acceptance number arc opti- mized. Then sensitivity analyses are conducted. When AF is unknown, two or more predetermined levels of accelerated stress are used. The sample sizes and sample proportion allo- cated to each stress level are optimized. The acceptance constant that satisfies producer and consumer risk is obtdned by minimizing the generalized asymptotic variance of the test statistics. Finally, the properties of the two ALSPs (one for known-AF conditions and one for unknown AF conditions) are investigated to show that the proposed method is corrcct and usablc through numerical examples. 展开更多
关键词 Accelerated life testing Acceleration factor Acceptance sampling Lognormal distribution Producer and consumerrisks Time-censoring
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Empirical likelihood inference and goodness-of-fit test for logistic regression model under two-phase case-control sampling
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作者 Zhen Sheng Yukun Liu Jing Qin 《Statistical Theory and Related Fields》 2022年第4期265-276,共12页
Due tocost effectiveness and hIgh efidengy.two-phase Qse control sampling has been wldely used In epldemlology studles.We dewelop a seml-parametric empinial lkellood approach to two-phase ase-control data under the lo... Due tocost effectiveness and hIgh efidengy.two-phase Qse control sampling has been wldely used In epldemlology studles.We dewelop a seml-parametric empinial lkellood approach to two-phase ase-control data under the logst regresslon model.we show that the maxmum empintal lklhoo estimaton has an aymptotically nomal dstibutlon,n,and the empincal lke-lthood ratlo fllws an aymptotcallycentral chi-square dstibution We find that the maxdmum empintial lkellhood estimator Is equal to Breslow and Holubkow(1997175 madimum lkelhood estimator.Evenso,the lmting dstribution of the lkelhood ratio,helhlodratlo based interval,and test are all new.Futhemmiore,we construct new Kolmogorov-smimnov type godnes-F-fit tests to test the vlldation of the undertying lglstic rgressonmodelLour simulation results and a real pplcaion show that the lola based Interval and test hawe certain mentsowver the wald-type counterparts and that the proposed godness-f-f test Is vald. 展开更多
关键词 BOOTSTRAP case-control data empirical likelihood goodness-of-fit test two-phase case-control sampling
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Gold Characterization by MLA and Technological Tests-Discussion of Sample Preparation and Results 被引量:5
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作者 Carina Ulsen Henrique Kahn +2 位作者 Guilherme Nery Daniel Uliana Juliana L.Antoniassi 《矿物学报》 CAS CSCD 北大核心 2013年第S1期10-10,共1页
Gold has been present throughout the history of mankind and used to make jewelry and coins, and recently, acquired several industrial uses. The price of gold in international market had a significant increasing, surpa... Gold has been present throughout the history of mankind and used to make jewelry and coins, and recently, acquired several industrial uses. The price of gold in international market had a significant increasing, surpassing 100% in the last five years. Thereby, deposits with low levels of gold content, gold with complex associations or in a very fine particle size became exploitable again, allowing new projects and expansion of existing ones. However, for maximum process efficiency is indispensable a deep knowledge of the characteristics of these minerals and their behavior in face of beneficiation processes. Consequently, an accurate routine for mineralogical and technological characterization is essential. 展开更多
关键词 GOLD CHARACTERIZATION IMAGE analysis SAMPLE preparation
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Preparation and Properties of PBXs Based on FOX-7 in Controlled Fragmentation Warhead Application 被引量:3
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作者 Karim K Elsharkawy Lin Guo Ahmed M Enew 《含能材料》 EI CAS CSCD 北大核心 2018年第10期843-849,共7页
Polymer bonded explosive(PBX)formulations were successfully prepared in the laboratory scale containing 1,1-diamino-2,2-dinitroethene(FOX-7)and hexogen(RDX)as brisant high explosives and different binder types of poly... Polymer bonded explosive(PBX)formulations were successfully prepared in the laboratory scale containing 1,1-diamino-2,2-dinitroethene(FOX-7)and hexogen(RDX)as brisant high explosives and different binder types of polyurethane(PU)based on glycidyl azide polymer(GAP) and hydroxyl-terminated polybutadiene(HTPB) as an energetic and inert polymeric binder respectively.Casting technique was used for the preparation of different PBX formulations based on FOX-7/RDX and PU(GAP/HTPB)with 14% binder.The sensitivity to different initial impulses and performance characteristics of the explosive and lethal zone of the tested controlled fragmentation warhead by the fragmentation warhead assessment test(arena test)were studied,in which the arena test was carried out with a controlled fragmentation warhead made from Ck45 steel,with dimensions(100 mm length,30 mm outer diameter and 3 mm thickness).Results show that PBXGF4 has lower sensitivity to impact and heat than those of PBXGR4 by 188.4% and 3.2% respectively.Its friction sensitivity is the same as that of PBXGR4.It has better performance,in which detonation velocity increases by 2.1% and brisance increases by 0.5% when compared with those of PBXGR4.It was concluded that PBXGF4 which based on FOX-7 bonded with PU/GAP matrix has good characteristics as PBX,specially in the sensitivity to impact and can be applied for replacing PBXs based on RDX in the advanced PBXs for low sensitive fragmentation warheads. 展开更多
关键词 polymer bonded explosive(PBX) CONTROLLED fragmentation WARHEAD 1 1-diamino-2 2-dinitroethene(FOX-7) hexo-gen(RDX) preparation sensitivity performance characterization ARENA test
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Beverage intake preference and bowel preparation laxative taste preference for colonoscopy
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作者 Adeyinka O Laiyemo Clinton Burnside +7 位作者 Maryam A Laiyemo John Kwagyan Carla D Williams Kolapo A Idowu Hassan Ashktorab Angesom Kibreab Victor F Scott Andrew K Sanderson 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2015年第3期84-88,共5页
AIM: To examine whether non-alcoholic beverage intake preferences can guide polyethylene glycol(PEG)-based bowel laxative preparation selection for patients.METHODS: We conducted eight public taste test sessions using... AIM: To examine whether non-alcoholic beverage intake preferences can guide polyethylene glycol(PEG)-based bowel laxative preparation selection for patients.METHODS: We conducted eight public taste test sessions using commercially procured(A) unflavored PEG,(B) citrus flavored PEG and(C) PEG with ascorbate(Moviprep). We collected characteristics of volunteers including their beverage intake preferences. The volunteers tasted the laxatives in randomly assigned orders and ranked the laxatives as 1st, 2nd, and 3rd based on their taste preferences. Our primary outcome is the number of 1st place rankings for each preparation. RESULTS: A total of 777 volunteers completed the study. Unflavored PEG was ranked as 1st by 70(9.0%), flavored PEG by 534(68.7%) and PEG with ascorbate by173(22.3%) volunteers. Demographic, lifestyle characteristics and beverage intake patterns for coffee, tea, and carbonated drinks did not predict PEG-based laxative preference.CONCLUSION: Beverage intake pattern was not a useful guide for PEG-based laxative preference. It is important to develop more tolerable and affordable bowel preparation laxatives for colonoscopy. Also, patients should taste their PEG solution with and without flavoring before flavoring the entire gallon as this may give them more opportunity to pick a pattern that may be more tolerable. 展开更多
关键词 BOWEL preparation LAXATIVES COLONOSCOPY TASTE tests Colon cancer Screening
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Sample Size Determination and Statistical Hypothesis Testing for Core Centration in Press Coated Tablets
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作者 Pierre Lafaye de Micheaux Vincent Lemaire 《Open Journal of Statistics》 2012年第3期269-273,共5页
A novel statistical approach to evaluate the manufacturing quality of press coated tablets in terms of the centering of their core is presented. We also provide a formula to determine the necessary sample size. This a... A novel statistical approach to evaluate the manufacturing quality of press coated tablets in terms of the centering of their core is presented. We also provide a formula to determine the necessary sample size. This approach is applied to real data. 展开更多
关键词 CORE Centration Statistical HYPOTHESIS testing Dry-Coated TABLETS SAMPLE Size
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