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Ruin Probability with Variable Premium Rate and Disturbed by Diffusion in a Markovian Environment 被引量:2
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作者 LIUYan HUYi-jun 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第4期399-403,共5页
We consider a risk model with a premium rate which varies with the level of free reserves. In this model, the occurrence of claims is described by a Cox process with Markov intensity process, and the influence of stoc... We consider a risk model with a premium rate which varies with the level of free reserves. In this model, the occurrence of claims is described by a Cox process with Markov intensity process, and the influence of stochastic factors is considered by adding a diffusion process. The integro-differential equation for the ruin probability is derived by a infinitesimal method. Key words ruin probability - variable premium rate - diffusion process - Markov intensity CLC number O 211.9 Foundation item: Supported by the National Natural Science Foundation of China (10071058, 70273029) 展开更多
关键词 ruin probability variable premium rate diffusion process Markov intensity
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Effect of flow rate on environmental variables and phytoplankton dynamics:results from field enclosures 被引量:3
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作者 张海平 陈瑞弘 +1 位作者 李飞鹏 陈玲 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第2期430-438,共9页
To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrient... To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrients,temperature,dissolved oxygen,p H,conductivity,turbidity,chlorophyll-a and phytoplankton levels. The lower biomass in all flowing enclosures showed that flow rate significantly inhibited the growth of phytoplankton. A critical flow rate occurred near 0.06 m/s,which was the lowest relative inhibitory rate. Changes in flow conditions affected algal competition for light,resulting in a dramatic shift in phytoplankton composition,from blue-green algae in still waters to green algae in flowing conditions. These findings indicate that critical flow rate can be useful in developing methods to reduce algal bloom occurrence. However,flow rate significantly enhanced the inter-relationships among environmental variables,in particular by inducing higher water turbidity and vegetative reproduction of periphyton( Spirogyra). These changes were accompanied by a decrease in underwater light intensity,which consequently inhibited the photosynthetic intensity of phytoplankton. These results warn that a universal critical flow rate might not exist,because the effect of flow rate on phytoplankton is interlinked with many other environmental variables. 展开更多
关键词 environmental variables PHYTOPLANKTON enclosure experiment flow rate
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Optimum control strategy for all-variable speed chiller plant 被引量:3
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作者 蒋小强 龙惟定 李敏 《Journal of Central South University》 SCIE EI CAS 2011年第2期573-579,共7页
The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation ... The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation model of water source chiller plant established in dynamic transient simulation program (TRNSYS),the four-variable quadratic orthogonal regression experiments were carried out by taking cooling load,cooling water supply temperature,cooling water flow rate and chilled water flow rate as variables,and the fitting formulas expressing the relationships between the total energy consumption of chiller plant with the four selected parameters was obtained. With the SAS statistical software and MATHEMATICA mathematical software,the optimal chilled water flow rate and cooling water flow rate which result in the minimum total energy consumption were determined under continuously varying cooling load and cooling water supply temperature. With regard to a chiller plant serving an office building in Shanghai,the total energy consumptions under different control strategies were computed in terms of the forecasting function of cooling load and water source temperature. The results show that applying the optimal control strategy to the chiller plant can bring a saving of 23.27% in power compared with the corresponding conventional variable speed plant,indicating that the optimal control strategy can improve the energy efficiency of chiller plant. 展开更多
关键词 chiller plant control strategy variable speed cooling water flow rate chilled water flow rate
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Cotton Response to Variable Nitrogen Rate Fertigation through an Overhead Irrigation System 被引量:3
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作者 Phillip B. Williams Ahmad Khalilian +4 位作者 Michael W. Marshall Joe Mari Maja Haibo Liu Dara Park Ali Mirzakhani Nafchi 《Agricultural Sciences》 2019年第1期66-80,共15页
Recent increases in irrigated hectares in the Southeastern US have enabled growers to obtain higher yields through applying nutrients through irrigation water. Therefore, many growers apply nutrients through irrigatio... Recent increases in irrigated hectares in the Southeastern US have enabled growers to obtain higher yields through applying nutrients through irrigation water. Therefore, many growers apply nutrients through irrigation systems, known as fertigation. Currently, there are no practical decision-making tools available for variable-rate application of nitrogen (N) through overhead sprinkler irrigation systems. Therefore, field tests were conducted on cotton (Gossypium hirsutum L.) during the 2016 and 2017 growing seasons to 1) adapt the Clemson sensor-based N recommendation algorithms from a single side-dress application to multiple applications through an overhead irrigation system;and 2) to compare sensor-based VRFS with conventional nutrient management methods in terms of N use efficiency (NUE) and crop responses on three soil types. Two seasons of testing Clemson N prediction algorithms to apply multiple applications of N were very promising. The multiple applications of N compared to the grower’s conventional methods (even though less N was applied) had no impact on yields in either growing season. There was no difference in cotton yields between 101 and 135 kg/ha N applications in either management zone. Also, there were no differences in yield between sensor-based, multiple N applications and conventional N management techniques. In relation to comparisons of the sensor methods only applying N in three or four applications, statistically increased yields compared to single or split applications in 2016. Applying N in four applications, statistically increased yields compared to single, split or triple applications in 2017. When the sensor-based methods were compared to the grower’s conventional methods averaged over four treatments, the sensor-based N applications reduced fertilizer requirement by 69% in 2016 and 57% in 2017 compared to grower’s conventional methods. When comparing N rates among the four sensor-based methods (three or four) applications, increased N rates by 22 kg/ha in 2016 and 26 kg/ha in 2017 compared to single or split applications but increased the cotton lint yields by 272 and 139 kg/ha, for 2016 and 2017, respectively. 展开更多
关键词 COTTON Nitrogen FERTILITY FERTIGATION Irrigation variable rate Sensor NUTRIENT Management Precision Agriculture Normalized Difference Vegetation Index (NDVI)
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Inequalities of Maximum of Partial Sums and Convergence Rates in the Strong Laws for ρ^-mixing Random Variables 被引量:1
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作者 TAN Cheng-liang WU Qun-ying HE Yan-mei 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第1期114-119,共6页
In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The re... In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The result obtained extends the corresponding result. 展开更多
关键词 convergence rates rosenthal type inequality ρ—-mixing random variables ρ~mixing random variables negatively associated random variables
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The Determination Method of Product Engineering Features Based on Linguistic Variables
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作者 Guo Mao 《Journal of World Architecture》 2024年第1期18-23,共6页
To overcome the problem of imprecise and unclear information in the development of quality functions,a method for determining the priority of engineering features based on mixed linguistic variables is proposed.First,... To overcome the problem of imprecise and unclear information in the development of quality functions,a method for determining the priority of engineering features based on mixed linguistic variables is proposed.First,the evaluation member uses the determined linguistic variable to give the correlation strength evaluation matrix of customer requirements and engineering features.Secondly,the relative importance of the evaluation member and customer requirements are aggregated.Finally,the priority of engineering features is obtained by calculating the deviation.The feasibility and practicability of this method are proven by taking the design of a new product of a long bag low-pressure pulse dust collector as an example. 展开更多
关键词 Quality function deployment Engineering features Linguistic variable Priority ratings
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The Relations of Change Rate of Constitutive Variables for the Freezing and Thawing of Water Saturated Porous Media
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作者 陆宏轮 《Journal of Modern Transportation》 1999年第2期173-180,共8页
The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, ar... The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, are derived from the definition of the porosity of water saturated porous media; and the relations of the change rates of another two independent variables, pressure of the pore liquid water and temperature, with the change rates of another kind of constitutive variables, such as pressure of the pore ice, average pressure of the pore liquid water and ice, and average stress of the solid matrix, are obtained from the Clausius Clapeyron relation in the process of freezing or thawing, definitions of the average pore pressure and effective stress. Based on the hypothesis of linear thermoelasticity, principle of effective stress and these relations, the change rates of all constitutive variables may be described with the change rates of the three independent variables. 展开更多
关键词 change rate constitutive variables independent variables freezing and thawing porous media
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Development and Testing of a Variable Rate Nitrogen Application System through an Overhead Irrigation System
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作者 Phillip B. Williams Ahmad Khalilian +4 位作者 Michael W. Marshall Joe Mari Maja Haibo Liu Dara Park Ali Mirzakhani Nafchi 《Journal of Water Resource and Protection》 2018年第10期994-1011,共18页
Nutrients are injected through overhead irrigation systems at a uniform rate in a process known as fertigation. The highly variable soils in the Southeastern US pose challenges for effective fertigation. Currently, th... Nutrients are injected through overhead irrigation systems at a uniform rate in a process known as fertigation. The highly variable soils in the Southeastern US pose challenges for effective fertigation. Currently, there is no variable-rate fertigation system available to apply the correct amount of N within a field through an overhead irrigation system. Therefore, the objective of this study was to develop and test a variable-rate N application system that works independently of irrigation water flow for site-specific N application. The variable-rate fertigation system (VRFS) was designed to apply different rates N using a pulse width modulation technique. The VRFS utilized the Clemson Lateral Irrigation Control software which controlled the solenoids in each zone by turning the N supply on and off (pulsing) for each zone. In this study, four tests were conducted to determine the uniformity of the VRFS. In test # 1, the pump output showed a linear slope relationship and was the same for water and N. In test # 2, nozzle flow and uniformity were determined using four different irrigation system travel speeds at N application rates of 31, 59, 88, and 113 kg/ha. There was a strong correlation (R2 = 0.9998) between irrigation system speed and N rate. In test # 3, the uniformity across the length of the irrigation system was determined. The nozzles produced an average flow of 31.1, 58.7, 87.6, and 112.7 kg N/ha with an overall average error of 0.1% across all N rates. Results also showed the system was capable of accurately applying N based on prescription maps with an error of less than 1.8%. Test # 4 was conducted to determine the accuracy of the map-based controller system for applying variable rate N. There was a strong correlation between target N and actual N rates (R2 = 0.9999). In summary, the VRFS applied the correct amounts of N within each zone by either manually controlling the pulsing mechanism or utilizing a prescription map to apply different rates throughout the field. 展开更多
关键词 COTTON NITROGEN FERTIGATION IRRIGATION variable rate NUTRIENT Management Precision Agriculture
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Variable Rate Characteristic Waveform Interpolation Speech Coder Based on Phonetic Classification
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作者 王晶 匡镜明 赵胜辉 《Journal of Beijing Institute of Technology》 EI CAS 2007年第2期187-192,共6页
A variable-bit-rate characteristic waveform interpolation (VBR-CWI) speech codec with about 1.8 kbit/s average bit rate which integrates phonetic classification into characteristic waveform (CW) decomposition is p... A variable-bit-rate characteristic waveform interpolation (VBR-CWI) speech codec with about 1.8 kbit/s average bit rate which integrates phonetic classification into characteristic waveform (CW) decomposition is proposed. Each input frame is classified into one of 4 phonetic classes. Non-speech frames are represented with Bark-band noise model. The extracted CWs become rapidly evolving waveforms (REWs) or slowly evolving waveforms (SEWs) in the cases of unvoiced or stationary voiced frames respectively, while mixed voiced frames use the same CW decomposition as that in the conventional CWI. Experimental results show that the proposed codec can eliminate most buzzy and noisy artifacts existing in the fixed-bit-rate characteristic waveform interpolation (FBR-CWI) speech codec, the average bit rate can be much lower, and its reconstructed speech quality is much better than FS 1 016 CELP at 4.8 kbit/s and similar to G. 723.1 ACELP at 5.3 kbit/s. 展开更多
关键词 variable bit rate speech coding characteristic waveform interpolation phonetic classification
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Finite Time Ruin Probability with Variable Interest Rate and Extended Regular Variation
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作者 WEIXiao HUYi-jun 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第6期863-866,共4页
Consider an insurance risk model, in which the surplus process satisfies a recursive equationU n =U n?1(1+r n )?X n forn≥1, whereU 0=x≥0 is the initial surplus, {r n ;n≥1} the interest rate sequence, {X n ;n≥1} th... Consider an insurance risk model, in which the surplus process satisfies a recursive equationU n =U n?1(1+r n )?X n forn≥1, whereU 0=x≥0 is the initial surplus, {r n ;n≥1} the interest rate sequence, {X n ;n≥1} the sequence of i. i. d. real-valued random variables with common distribution functionF, which denotes the gross loss during thenth year. We investigate the ruin probability within a finite time horizon and give the asymptotic result asx→∞. Key words variable interest rate - extend regular variation - finite time ruin probability CLC number O 211.9 Foundation item: Supported by the National Natural Science Foundation of China (10071058, 70273029)Biography: WEI Xiao (1979-), female, Ph. D candidate, research direction: large deviations and its applications, insurance mathematics. 展开更多
关键词 variable interest rate extend regular variation finite time ruin probability
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A unified result for variable-rate linear network coding 被引量:1
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作者 马松雅 卓新建 +2 位作者 郭钦 罗明星 杨义先 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第5期657-660,共4页
Fong et al.analyzed variable-rate linear network coding for linear broadcast.However,the authors didn't investigate it for the other three types of linear network codes.In this paper,by simple and clear proofs,it ... Fong et al.analyzed variable-rate linear network coding for linear broadcast.However,the authors didn't investigate it for the other three types of linear network codes.In this paper,by simple and clear proofs,it is found that there are similar results for variable-rate linear generic and linear dispersion if the field size is large enough.It means that linear generics and linear dispersions of different dimensions can be implemented on the same network,while each non-source node is required to store only one copy of the local encoding kernel within a session.Moreover,an example is given to show that there isn't a similar result for linear multicast. 展开更多
关键词 variable-rate linear generic linear dispersion linear broadcast linear multicast
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A numerical study of comparison of two one-state-variable,rate-and state-dependent friction evolution laws 被引量:2
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作者 Jeen-Hwa Wang 《Earthquake Science》 CSCD 2009年第2期197-204,共8页
The two one-state-variable, rate- and state-dependent friction laws, i.e., the slip and slowness laws, are com- pared on the basis of dynamical behavior of a one-degree-of-freedom spring-slider model through numerical... The two one-state-variable, rate- and state-dependent friction laws, i.e., the slip and slowness laws, are com- pared on the basis of dynamical behavior of a one-degree-of-freedom spring-slider model through numerical simulations. Results show that two (normalized) model parameters, i.e., A (the normalized characteristic slip distance) and β-α (the difference in two normalized parameters of friction laws), control the solutions. From given values of △, β, and α, for the slowness laws, the solution exists and the unique non-zero fixed point is stable when △〉(β-α), yet not when △ 〈(β-α). For the slip law, the solution exists for large ranges of model parameters and the number and stability of the non-zero fixed points change from one case to another. Results suggest that the slip law is more appropriate for controlling earthquake dynamics than the slowness law. 展开更多
关键词 one-state-variable rate- and state-dependent friction law direct effect evolution effect characteristic slip displacement
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Dynamic Spectrum Access Scheme of Variable Service Rate and Optimal Buffer-Based in Cognitive Radio
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作者 Qiang Peng Youchen Dong +2 位作者 Weimin Wu Haiyang Rao Gan Liu 《Communications and Network》 2013年第3期232-237,共6页
Dynamic spectrum access (DSA) scheme in Cognitive Radio (CR) can solve the current problem of scarce spectrum resource effectively, in which the unlicensed users (i.e. Second Users, SUs) can access the licensed spectr... Dynamic spectrum access (DSA) scheme in Cognitive Radio (CR) can solve the current problem of scarce spectrum resource effectively, in which the unlicensed users (i.e. Second Users, SUs) can access the licensed spectrum in opportunistic ways without interference to the licensed users (i.e. Primary Users, PUs). However, SUs have to vacate the spectrum because of PUs coming, in this case the spectrum switch occurs, and it leads to the increasing of SUs’ delay. In this paper, we proposed a Variable Service Rate (VSR) scheme with the switch buffer as to real-time traffic (such as VoIP, Video), in order to decrease the average switch delay of SUs and improve the other performance. Different from previous studies, the main characteristics of our studying of VSR in this paper as follows: 1) Our study is on the condition of real-time traffic and we establish three-dimension Markov model;2) Using the internal optimization strategy, including switching buffer, optimizing buffer and variable service rate;3) As to the real-time traffic, on the condition of meeting the Quality of Service(QoS) on dropping probability, the average switch delay is decreased as well as improving the other performance. By extensive simulation and numerical analysis, the performance of real-time traffic is improved greatly on the condition of ensuring its dropping probability. The result fully demonstrates the feasibility and effectiveness of the variable service rate scheme. 展开更多
关键词 COGNITIVE Radio Dynamic Spectrum Access variable Service rate OPTIMAL BUFFER MARKOV DECISION
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Development of a Portable Electro-Mechanical Educational Model for Variable Rate Center Pivot Irrigation Technology
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作者 Young J. Han Ahmad Khalilian +1 位作者 Jose Payero Nicholas Rogers 《Journal of Water Resource and Protection》 2016年第4期449-458,共10页
Center pivot irrigation systems usually apply a relatively uniform amount of water to fields that are often inherently variable, which could lead to significant waste of water and energy. To address this issue, our te... Center pivot irrigation systems usually apply a relatively uniform amount of water to fields that are often inherently variable, which could lead to significant waste of water and energy. To address this issue, our team is now developing an Intelligent Center Pivot (ICP) by integrating sensor-based irrigation scheduling with variable rate irrigation technology. However, before this technology can be applied in commercial production, it is necessary to educate growers about its practicality and potential benefits. The objective of this study was to develop a portable tabletop intelligent center pivot model (ICPDemo) to demonstrate and promote adoption of the ICP technology. This paper describes an ICPDemo constructed in 2014, including the design specifications, electro-mechanical design, control strategy, and performance. The ICPDemo has performed according to design specifications and is successfully being used to demonstrate the benefits and effectiveness of ICP technology for irrigation scheduling. 展开更多
关键词 IRRIGATION Center Pivot Irrigation Electro-Mechanical Model SENSORS Control variable rate Irrigation
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Variable Rate Technology and Cotton Yield Response in Texas
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作者 Shyam Nair Chenggang Wang +2 位作者 Eduardo Segarra Jeff Johnson Roderick Rejesus 《Journal of Agricultural Science and Technology(B)》 2012年第9期1034-1043,共10页
Variable Rate Technology (VRT) takes within-field variability into consideration and aims to match resource application to crop requirement. Even though Texas is the most important cotton producing state in the US, ... Variable Rate Technology (VRT) takes within-field variability into consideration and aims to match resource application to crop requirement. Even though Texas is the most important cotton producing state in the US, the rate of VRT adoption is very low here. Hence, analyzing the factors influencing the adoption and providing a regional estimate of the impact of VRT adoption on cotton yield is very important. This study used the 2009 Southern Cotton Precision Farming Survey to analyze the farm and farmer characteristics affecting the adoption of VRT among Texas cotton farmers and to empirically estimate the impact of adoption of VRT on cotton yield in Texas. A two-stage least square procedure with a logistic regression model in the first stage and a multiple linear regression model in the second stage was used to analyze the data. The study revealed that there are significant regional differences in adoption pattern within the state of Texas; and the farmers from the coastal region, where there is higher within-field variability, were more likely to adopt VRT compared to other regions. Younger farmers, farmers managing larger farms, and farmers who use computers for farming operations were more likely to adopt VRT. The results also showed that, on an average, the adoption of VRT does not lead to significant yield improvements for cotton in Texas. Since the impact of VRT adoption on yield is not significant, the source of economic advantage of VRT adoption in Texas may be the reduction of input cost. 展开更多
关键词 Precision agriculture technology adoption COTTON site specific management variable rate technology
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Evaluation of Variable Rate Technology for Fertilizer Application in Permanent Pastures
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作者 J. M. Serrano J. M. Peca Shahidian 《Journal of Agricultural Science and Technology(A)》 2011年第4X期489-499,共11页
This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a signifi... This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs (about 20%). This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field. 展开更多
关键词 Calibration centrifugal fertilizer spreader evaluation precision agriculture variable rate technology.
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Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer
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作者 Zhang Ying-zi Chen Hai-tao +4 位作者 Hou Shou-yin Ji Wen-yi Ouyang Bin-lin Dun Guo-qiang Zhang Ji-cheng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第2期73-79,共7页
In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core pr... In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer. 展开更多
关键词 variable-rate fertilization control system mathematical model
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AVariablebitrateVideoCodingSchemeBasedonMorphologicalOperationsforATMNetworks
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作者 ChenHuifang DaiWenqi 《通信学报》 EI CSCD 北大核心 1998年第5期84-89,共6页
AVariablebitrateVideoCodingSchemeBasedonMorphologicalOperationsforATMNetworksChenHuifangDaiWenqiQiuPeilian... AVariablebitrateVideoCodingSchemeBasedonMorphologicalOperationsforATMNetworksChenHuifangDaiWenqiQiuPeiliang(InstituteofInfo... 展开更多
关键词 视频编码 ATM网络 异步传输网 多位率 数学形态操作
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A numerical model of wire melting rate in variable-polarity submerged arc welding
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作者 程方杰 武云龙 +2 位作者 王颖 张建优 王东坡 《China Welding》 EI CAS 2013年第3期36-41,共6页
Based on the pre-existing wire melting rate model of direct-current submerged arc welding ( DC-SAW) , a new numerical model of wire melting rate was developed for variable-polarity submerged are welding (VP-SAW) b... Based on the pre-existing wire melting rate model of direct-current submerged arc welding ( DC-SAW) , a new numerical model of wire melting rate was developed for variable-polarity submerged are welding (VP-SAW) by accounting for the combined effects of duty cycle β and offset α. The experimental measurements are in a good agreement with the results calculated by this new wire melting rate model, with the maximum discrepancy being less than 10%. Therefore it is evident that this new numerical model can successfully describe the dependence of wire melting rate on the duty cycle β and offset α. 展开更多
关键词 wire melting rate duty cycle OFFSET variable-polarity welding
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一类线性errors-in-variables模型的参数强相合估计及其a.s.收敛速度 被引量:1
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作者 程龙生 姚景尹 《高校应用数学学报(A辑)》 CSCD 北大核心 1996年第3期313-320,共8页
本文讨论了如下一类线性errors-in-variables模型——多元线性结构关系模型β′xk+α=0,ξk=xk+εk.{k=1,2,…,n.其中,{xk:k=1,2,…,n}为一组i.i.d.的m维随机向量,{... 本文讨论了如下一类线性errors-in-variables模型——多元线性结构关系模型β′xk+α=0,ξk=xk+εk.{k=1,2,…,n.其中,{xk:k=1,2,…,n}为一组i.i.d.的m维随机向量,{εk:k=1,2,…,n}是i.i.d.的随机误差,E(ε1)=0,Var(ε1)=σ2Im.且{xk:k=1,2,…,n}与{εk:k=1,2,…,n}相互独立.在一些条件下,我们证明了估计量β,α,σ2的强相合性、唯一性,并给出了估计量的收敛速度为o(n-1-1q),这里q∈[1,2). 展开更多
关键词 收敛速度 线性模型 强相合估计 多元分析
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