Evaluating Suitability of Multiple Precipitation Products for the Lancang River Basin

Global reanalysis precipitation products could provide valuable meteorological information for flow forecasting in poorly gauged areas, helping to overcome a long-standing challenge in the field. But not all data sources are suitable for all regions or perform the same way in hydrological modeling, so it is essential to test the suitability of precipitation products before applying them. In this study, five widely used global high-resolution precipitation products—Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation of Water Resources(APHRODITE), National Centers for Environmental Prediction Climate Forecast System Reanalysis(NCEP-CFSR), Climate Hazards Group InfraRed Precipitation with Station Data(CHIRPS), China Gauge-based Daily Precipitation Analysis developed by China Meteorological Administration(CMA) and Agricultural Model Intercomparison and Improvement Project based on the NASA Modern-Era Retrospective Analysis for Research and Applications(AgMERRA)—were evaluated using statistical methods and a hydrological approach for their suitability for the Lancang River Basin. The results indicated that APHRODITE, CMA, AgMERRA and CHIRPS were more accurate precipitation indicators than NCEP-CFSR in terms of the multiyear average and seasonal spatial distribution pattern, all of the CHIRPS, Ag MERRA and APHRODITE perform better than CMA and NCEP-CFSR at the small, medium and high precipitation intensities ranges in subbasin11 and sunbabsin46. All five products performed better in subbasin46(a low-altitude region) than in subbasin11(a high-altitude region) on the daily and monthly scales. In addition to NCEP-CFSR, the other four products all presented encouraging potential for streamflow simulation at daily(Yunjinghong) and monthly(Yunjinghong, Jiuzhou and Gajiu) scale. Hydrological simulations forced with APHRODITE were the best of the five for the Yunjinghong station in capturing daily and monthly measured streamflow. Except for NCEP-CFSR, all products were very good for hydrological simulations for the Gajiu and Jiuzhou stations.

Models for Ordering Multiple Products Subject to Multiple Constraints, Quantity and Freight Discounts

One of the most important responsibilities of a supply chain manager is to decide “how much” (or “many”) of inventory items to order and how to transport them. This paper presents four mixed-integer linear programming models to help supply chain managers make these decisions for multiple products subject to multiple constraints when suppliers offer quantity discounts and shippers offer freight discounts. Each model deals with one of the possible combinations of all-units, incremental quantity discounts, all-weight and incremental freight discounts. The models are based on a piecewise linear approximation of the number of orders function. They allow any number of linear constraints and determine if independent or common (fixed) cycle ordering has a lower total cost. Results of computational experiments on an example problem are also presented.

Ordering and Pricing Strategies for Fresh Products with Multiple Quality Levels Considering Consumer Utility

In this paper, considering a scenario in which there are two quality levels of fresh products and introduction of consumer utility function, we studied the optimal ordering and pricing strategies under certain quantity. Our results showed that, facing the two quality levels of fresh products, retailers would not benefit from sales of lower quality of fresh products with the deterministic demand. In the pursuit of profit maximization, the initial order quantity is smaller than the potential demand for market.

农村电商流通效率优化赋能甘肃乡村振兴——基于DEA-Multiple Regression模型

产业兴旺是乡村振兴的重中之重,也是解决众多农村问题的前提,而农产品流通效率水平是农村相关产业发展的关键。在乡村振兴视角下,以2021年甘肃省面板数据为样本,基于DEA模型分析得出当前甘肃农产品流通效率整体水平较低,其他市区可以吸取兰州、陇南等农产品流通水平较高地区的经验,与电商融合发展来提升农产品流通效率。在基于DEA计量分析的基础上,依据农村电商产品流通过程提取变量指标,通过Multiple Regression模型分析得出以下结论:劳动投入、资金投入、农村电商组织化程度、新型基础设施建设、营销能力、物流运输方式、物流运输技术、物流站点均是甘肃农村电商产品流通效率的制约因素,以此为根据得出相关结论和建议。

Evaluation of gas production from multiple coal seams： A simulation study and economics

Gas production from multiple coal seams has become common practice in many coal basins around the world. Although gas production rates are typically enhanced, the economic viability of such practice is not well studied. In order to investigate the technical and economic feasibility of multiple coal seams production, reservoir simulation integrated with economics modelling was performed to study the effect of important reservoir properties of the secondary coal seam on production and economic performance using both vertical and horizontal wells. The results demonstrated that multiple seam gas production of using both vertical and horizontal wells have competitive advantage over single layer production under most scenarios. Gas content and permeability of the secondary coal seam are the most important reservoir properties that have impact on the economic feasibility of multiple seam gas production. The comparison of vertical well and horizontal well performance showed that horizontal well is more economically attractive for both single well and gas field. Moreover, wellhead price is the most sensitive to the economic performance, followed by operating costs and government subsidy. Although the results of reservoir simulation combined with economic analysis are subject to assumptions, multiple seam gas production is more likely to maintain profitability compared with single layer production.

Evaluation of Sweet Sorghum as a Feedstock by Multiple Harvests for Sustainable Bioenergy Production

Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.

Better use of experience from other reservoirs for accurate production forecasting by learn-to-learn method

To assess whether a development strategy will be profitable enough,production forecasting is a crucial and difficult step in the process.The development history of other reservoirs in the same class tends to be studied to make predictions accurate.However,the permeability field,well patterns,and development regime must all be similar for two reservoirs to be considered in the same class.This results in very few available experiences from other reservoirs even though there is a lot of historical information on numerous reservoirs because it is difficult to find such similar reservoirs.This paper proposes a learn-to-learn method,which can better utilize a vast amount of historical data from various reservoirs.Intuitively,the proposed method first learns how to learn samples before directly learning rules in samples.Technically,by utilizing gradients from networks with independent parameters and copied structure in each class of reservoirs,the proposed network obtains the optimal shared initial parameters which are regarded as transferable information across different classes.Based on that,the network is able to predict future production indices for the target reservoir by only training with very limited samples collected from reservoirs in the same class.Two cases further demonstrate its superiority in accuracy to other widely-used network methods.

Ratio-Cum-Product Estimator Using Multiple Auxiliary Attributes in Single Phase Sampling

In this paper, we have proposed a class of ratio-cum-product estimator for estimating population mean of study variable for single phase sampling using multi-auxiliary attributes. The expressions for mean square error are derived. An empirical study is given to compare the performance of the estimator with existing estimators. It has been found that the ratio-cum-product estimator using multiple auxiliary attributes is more efficient than mean per unit, product and ratio estimators using one auxiliary attribute, and Product and Ratio estimators using multiple auxiliary attributes in single phase sampling.

Ratio-Cum-Product Estimator Using Multiple Auxiliary Attributes in Two-Phase Sampling

In this paper, we have proposed three classes of ratio-cum-product estimators for estimating population mean of study variable for two-phase sampling using multi-auxiliary attributes for full information, partial information and no information cases. The expressions for mean square errors are derived. An empirical study is given to compare the performance of the estimator with the existing estimator that utilizes auxiliary attribute or multiple auxiliary attributes. The ratio-cum-product estimator in two-phase sampling for full information case has been found to be more efficient than existing estimators and also ratio-cum-product estimator in two-phase sampling for both partial and no information case. Finally, ratio-cum-product estimator in two-phase sampling for partial information case has been found to be more efficient than ratio-cum-product estimator in two-phase sampling for no information case.

Multiple cropping and soil fertility in sustainable production of paddy fields

Multiple cropping has been popularized on morethan two thirds of the total area of paddy fields inSouth China.It demands more nutrients due tohigher cropping index.Therefore,how to keepmoderately higher yields of multiple crops and to

Multiple pollutants from crop and livestock production in the Yangtze River: status and challenges

The rapid increase in the proportion of cash crops and livestock production in the Yangtze River Basin has led to commensurate increases in fertilizer and pesticide inputs. Excessive application of chemical fertilizer, organophosphorus pesticides and inappropriate disposal of agricultural waste induced water pollution and potentially threaten Agriculture Green Development(AGD). To ensure food security and the food supply capacity of the Yangtze River Basin, it is important to balance green and development, while ensuring the quality of water bodies. Multiple pollutants affect the transfer, adsorption, photolysis and degradation of each other throughout the soil-plant-water system. This paper considers the impact of multi-pollutants on the nitrogen and phosphorus cycles especially for crops, which are related to achieving food security and AGD. It presents prospective on theory, modeling and multi-pollutant control in the Yangtze River Basin for AGD that are of potential value for other developing regions.

Multiplicity dependence of charged particle,? meson, and multistrange particle productions in p + p collisions at s^(1/2) = 200 GeV from PYTHIA simulation

We report the multiplicity dependence of charged particle production for the n~±, K~±, p, , and ? mesons at |y|<1:0 in p + p collisions at s^(1/2) = 200 GeV from a PYTHIA simulation. The impact of multiple parton interactions and gluon contributions is studied and found to be a possible source of the splitting of the particle yields as a function of p_T with respect to the multiplicity. No obvious particle species dependence of the splitting is observed.The multiplicity dependence of the ratios Kˉ/πˉ, K^+/π^+,/πˉ, p/π^+, and K_s^0 at mid-rapidity in p+ p collisions is found to follow a tendency similar to that in Au t Au collisions at (s_(NN))^(1/2) = 200 GeV at the Relativistic Heavy Ion Collider, indicating similar underlying initial production mechanisms despite the differences in the initial colliding systems.

Statistical analysis of nitrogen use efficiency in Northeast China using multiple linear regression and Random Forest

Understanding the spatial-temporal dynamics of crop nitrogen(N)use efficiency(NUE)and the relationship with explanatory environmental variables can support land-use management and policymaking.Nevertheless,the application of statistical models for evaluating the explanatory variables of space-time variation in crop NUE is still under-researched.In this study,stepwise multiple linear regression(SMLR)and Random Forest(RF)were used to evaluate the spatial and temporal variation of NUE indicators(i.e.,partial factor productivity of N(PFPN);partial nutrient balance of N(PNBN))at county scale in Northeast China(Heilongjiang,Liaoning and Jilin provinces)from 1990 to 2015.Explanatory variables included agricultural management practices,topography,climate,economy,soil and crop types.Results revealed that the PFPN was higher in the northern parts and lower in the center of the Northeast China and PNBN increased from southern to northern parts during the 1990–2015 period.The NUE indicators decreased with time in most counties during the study period.The model efficiency coefficients of the SMLR and RF models were 0.44 and 0.84 for PFPN,and 0.67 and 0.89 for PNBN,respectively.The RF model had higher relative importance of soil and climatic covariates and lower relative importance of crop covariates compared to the SMLR model.The planting area index of vegetables and beans,soil clay content,saturated water content,enhanced vegetation index in November&December,soil bulk density,and annual minimum temperature were the main explanatory variables for both NUE indicators.This is the first study to show the quantitative relative importance of explanatory variables for NUE at a county level in Northeast China using RF and SMLR.This novel study gives reference measurements to improve crop NUE which is one of the most effective means of managing N for sustainable development,ensuring food security,alleviating environmental degradation and increasing farmer’s profitability.

Scheduling Multiple Orders per Job with Multiple Constraints on Identical Parallel Machines

With a comprehensive consideration of multiple product types, past-sequence-dependent （ p-s-d ） setup times, and deterioration effects constraints in processes of wafer fabrication systems, a novel scheduling model of multiple orders per job（MOJ） on identical parallel machines was developed and an immune genetic algorithm（IGA） was applied to solving the scheduling problem. A scheduling problem domain was described. A non-linear mathematical programming model was also set up with an objective function of minimizing total weighted earliness-tardlness penalties of the system. On the basis of the mathematical model, IGA was put forward. Based on the genetic algorithm （GA）, the proposed algorithm （IGA） can generate feasible solutions and ensure the diversity of antibodies. In the process of immunization programming, to guarantee the algorithm＇s convergence performance, the modified rule of apparent tardiness cost with setups （ATCS） was presented. Finally, simulation experiments were designed, and the results indicated that the algorithm had good adaptability when the values of the constraints＇ characteristic parameters were changed and it verified the validity of the algorithm.

Occurrence of <i>Escherichia coli</i>O157 in Retailed-Beef and Related Meat Products in Zaria, Nigeria

This study evaluated retailed-beef and related meat products for E. coli O157 in Zaria, Nigeria. Sample types included raw meat, “suya” (roasted meat), “balangu” (barbequed meat), “kilishi” (spiced sun dried meat) and “dambu” (shredded fried meat). A total of 182 samples were analyzed for E. coli O157. Isolates were characterized using conventional biochemical methods and Microbact 12E test kit. Susceptibilities of the isolates to 18 commonly used antimicrobial agents were determined by the disk diffusion method. The carriage of stx1 and stx2 genes was determined by PCR. Microbact confirmed 4 E. coli isolates. All isolates exhibited multiple drug resistance to the antimicrobial agents tested. An overall prevalence of 2.2% was obtained for E. coli O157. All 4 isolates of E. coli O157 were isolated from raw meat;two of which harboured the stx1 gene.

Multiple Objective Test Design for Accelerated Destructive Degradation Tests

Accelerated destructive degradation tests(ADDTs)are powerful to provide reliability information in the degradation processes with destructive measurements.In order to carry out an ADDT efficiently,both the estimation precision of parameters and the test cost should be considered.On the basis of the given degradation model and failure criterion,a multiple-objective optimization model for the design of ADDTs is proposed.Under constrains of the maximum measurement time,the total sample size and the number of stress levels,a comprehensive target function is suggested to reflect both the precision of lifetime estimation and total cost,and the optimal test plan is obtained,which is composed by optimal choices for samples size,measurement frequency,and the number of measurements at each stress level.A real example is illustrated to demonstrate the implementation of the proposed approach.

Proof of Riemann Conjecture Based on Contradiction between Xi-Function and Its Product Expression

Riemann proved three results: analytically continue ζ(s) over the whole complex plane s =σ + it with a pole s =1;(Theorem A) functional equation ξ(t) = G(s0)ζ (s0), s0 =1/2 + it and (Theorem B) product expression ξ1(t) by all roots of ξ(t). He stated Riemann conjecture (RC): All roots of ξ (t) are real. We find a mistake of Riemann: he used the same notation ξ(t) in two theorems. Theorem B must contain complex roots;it conflicts with RC. Thus theorem B can only be used by contradiction. Our research can be completed on s0 =1/2 + it. Using all real roots rk and (true) complex roots zj = tj + iaj of ξ (z), define product expressions w(t), w(0) =ξ(0) and Q(t) > 0, Q(0) =1 respectively, so ξ1(t) = w(t)Q(t). Define infinite point-set L(ω) = {t : t ≥10 and |ζ(s0)| =ω} for small ω > 0. If ξ(t) has complex roots, then ω =ωQ(t) on L(ω). Finally in a large interval of the first module |z1|>>1, we can find many points t ∈ L(ω) to make Q(t) . This contraction proves RC. In addition, Riemann hypothesis (RH) ζ for also holds, but it cannot be proved by ζ.

感性工学视域下外卖配送电动车造型设计

目的提出符合用户感性需求特征的外卖配送电动车造型设计方案。方法基于感性工学理论,将感性需求转化成定性分析与定量分析,采用SDM(语意差异法)方法制作调查问卷,收集并筛选描述外卖配送电动车造型的感性意象词汇与样本图片,并结合主成分分析法,提取影响造型设计的主要因子和外卖电动车造型元素,构建感性意象数学模型;通过多元线性回归法,借助SPSS统计软件对四个主要造型构成要素与感性意象进行量化处理。结果对外卖配送电动车的前面板、前大灯、车身架和座垫的造型元素展开分析,设计出与用户“时尚”和“速度”情感需求最匹配的梯形前面板、变异多边形前大灯、多边形车身架和细长型座垫造型元素。结论感性工学不仅能有效挖掘用户需求,而且还能直观表达出感性感受与数值的对应关系,对外卖配送电动车造型要素进行有目的的设计和调整。

宁夏灌区不同牧草复种模式综合效益分析

针对宁夏引黄灌区饲草产量低、栽培技术落后、季节性青饲料极其短缺导致草畜矛盾尖锐等现状,本研究设置了秋播饲用小黑麦(×Triticosecale Wittmack)+高丹草(Sorghum bicolor×S.sudanense)(T-SS)、饲用小黑麦+饲用高粱(S.bicolor)(T-FS)、饲用小黑麦+饲用谷子(Setaria italica)(T-FM)和饲用小黑麦+青贮玉米(Zea mays)(T-SM)4个复种模式处理,通过检测分析不同处理的生长指标、草产量、营养品质(粗蛋白、酸性洗涤纤维、中性洗涤纤维)、经济效益及土壤养分含量,旨在探明4种不同饲草复种模式的生产性能和综合效益,为该区牧草复种技术提供理论依据。结果表明:4种复种牧草的株高、茎粗和SPAD差异极显著,不同复种系统对牧草鲜草、干草产量、枝条数、粗蛋白产量、品质、土壤理化性状和经济效益均有极显著影响。高丹草复种系统草产量最高、枝条数最多、粗蛋白产量最高,饲用谷子粗蛋白含量最大,青贮玉米酸性和中性洗涤纤维含量最低,而相对饲用价值最大;对土壤有机质、全盐和pH的影响不显著,对速效钾和碱解氮含量的影响显著,对速效磷影响极显著;高丹草复种系统的产投比最高。综合评价筛选出饲用小黑麦复种饲用谷子和高丹草的种植模式可推广为宁夏引黄灌区牧草周年栽培模式。