某汽车企业零部件采购量价模型分析

针对某汽车企业在零部件采购过程中面对采购量增加,供应商给予的降价幅度低于企业预期,该企业无法制定出合理的采购价格,从而不能有效控制采购成本的问题,结合该企业的实际情况,在分析真实数据的基础上,通过建立相应的零部件采购量价模型,找出合理的降价区域,帮助该企业制定出合理的采购价格,控制零部件采购成本。

数智化转型、多元回归模型与产品多维决策分析——长安汽车量价分析模型(CA-MDM)应用探索

针对传统产品量本利分析模型的多重局限性、企业数智化管控加速转型和汽车行业市场竞争进入白热化,汽车新产品、新赛道、新场景等诸多方面日新月异的背景,重庆长安汽车创造性地提出了量价分析模型(CAMDM)。这是以汽车行业和客户数智化为基础,运用市场需求理论,通过Facebook开源框架Prophet模型进行销量预测,结合延续(Carry-Over)价格指数对各类影响因子进行量化分析,建立以市占率和价格为核心的多元回归模型。该模型利用岭回归算法预测相关产品的均衡销量和价格,强调产品经营的前瞻性,强化新品上市的规模、价格与市场实际需求的匹配度和互动,确保产品上市的量价和市场需求基本一致,为企业资源精准投放、盈利能力持续提升和管理经验积淀推广提供了系统方案,应该成为中国企业数智化财务管理的最佳实践案例。

量价存决策模型在企业销售管理中的应用

由一个具体案例引出企业存在的产品销量、价格和存量之间的关系问题。介绍了在运用概率方法定量预测市场价格的基础上,按照利润最大化、产销均衡、库存合理的原则建立量价存决策函数模型。同时,运用该模型进行决策,使案例中的实际问题得到了解决。

我国股市量价规律实证分析

文章定性描述了我国股市运行中业已存在的量价关系,并结合实际数据给出实证定量模型予以分析、验证,旨在用更有说服力的数学语言更深刻地揭示股市内在量价规律。

GEOTHERMAL RESOURCES ASSESSMENT AND NUMERICAL SIMULATION IN TUANBO REGION

This paper mainly deals with the reservoir on the heat and mass transfer and mass and energy balance in a geothermal field.On the basis of briefing the general characteristics of the reservoir and the supposition of the reservoir modeling,the paper emphasizes the mathematical descriptions of hydra thermal transportation and convection by two methods according to the different models,such as lumped parameter model and distributed parameter model.It is effective to use these models in simulating the heterogeneous,and anisotropical fracture reservoir for the designed lifetime of 15 years.

Soil Quality Assessment Using Weighted Fuzzy Association Rules

Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the importance variability of the rules, can be redundant and far from optimal. In this study, we developed a method applying different weights to traditional FARs to improve accuracy of soil quality assessment. After the FARs for soil quality assessment were mined, redundant rules were eliminated according to whether the rules were significant or not in reducing the complexity of the soil quality assessment models and in improving the comprehensibility of FARs. The global weights, each representing the importance of a FAR in soil quality assessment, were then introduced and refined using a gradient descent optimization method. This method was applied to the assessment of soil resources conditions in Guangdong Province, China. The new approach had an accuracy of 87%, when 15 rules were mined, as compared with 76% from the traditional approach. The accuracy increased to 96% when 32 rules were mined, in contrast to 88% from the traditional approach. These results demonstrated an improved comprehensibility of FARs and a high accuracy of the proposed method.

Evaluation of the fishery status for King Soldier Bream Argyrops spinifer in Pakistan using the software CEDA and ASPIC

Catch and effort data were analyzed to estimate the maximum sustainable yield （MSY） of King Soldier Bream, Argyrops spinifer （Forsskal, 1775, Family： Sparidae）, and to evaluate the present status of the fish stocks exploited in Pakistani waters. The catch and effort data for the 25-years period 1985-2009 were analyzed using two computer software packages, CEDA （catch and effort data analysis） and ASPIC （a surplus production model incorporating covariates）. The maximum catch of 3 458 t was observed in 1988 and the minimum catch of 1 324 t in 2005, while the average annual catch ofA. spinifer over the 25 years was 2 500 t. The surplus production models of Fox, Schaefer, and Pella Tomlinson under three error assumptions of normal, log-normal and gamma are in the CEDA package and the two surplus models of Fox and logistic are in the ASPIC package. In CEDA, the MSY was estimated by applying the initial proportion （IP） of 0.8, because the starting catch was approximately 80% of the maximum catch. Except for gamma, because gamma showed maximization failures, the estimated results of MSY using CEDA with the Fox surplus production model and two error assumptions, were 1 692.08 t （R^2=0.572） and 1 694.09 t （R^2=0.606）, respectively, and from the Schaefer and the Pella Tomlinson models with two error assumptions were 2 390.95 t （R^2=0.563）, and 2 380.06 t （R^2=0.605）, respectively. The MSY estimated by the Fox model was conservatively compared to the Schaefer and Pella Tomlinson models. The MSY values from Schaefer and Pella Tomlinson models were the same. The computed values of MSY using the ASPIC computer software program with the two surplus production models of Fox and logistic were 1 498 t （R^2=0.917）, and 2 488 t （R^2=0.897） respectively. The estimated values of MSY using CEDA were about 1 700-2 400 t and the values from ASPIC were 1 500-2 500 t. The estimates output by the CEDA and the ASPIC packages indicate that the stock is overfished, and needs some effective management to reduce the fishing effort of the species in Pakistani waters.

A Service Selection Approach Based on Availability-Aware in Mobile Ad Hoc Networks

Service composition is considered to be an effective way for resource sharing and node collaboration in Mobile Ad hoc NETworks (MANETs) environment.In order to improve the reliability and shorten the response time of composite services,this paper first analyzes the node environments and network environments that affect the component services' availability,and then proposes an Environment-aware Quantitative Evaluation Model for Service Availability (EQEM-SA).In addition,based on EQEM-SA,a service field concept is proposed as well as the availability attenuation equation,where the availability value is considered as the field strength.Then the service selection approach based on service field model is presented.The effectiveness of the proposed approach is illustrated and compared with related references,and the results of experimental evaluations indicate that our approach significantly reduces the failure rate and shortens the service delay.

Evaluation of wind vectors observed by HY-2A scatterometer using ocean buoy observations,ASCAT measurements,and numerical model data

The first Chinese microwave ocean environment satellite HY-2A was launched successfully in August, 201 I. This study presents a quality assessment of HY-2A scatterometer （HYSCAT） data based on comparison with ocean buoy data, the Advanced Scatterometer （ASCAT） data, and numerical model data from the National Centers for Environmental Prediction （NCEP）. The in-situ observations include those from buoy arrays operated by the National Data Buoy Center （NDBC） and Tropical Atmosphere Ocean （TAO） project. Only buoys located offshore and in deep water were analyzed. The temporal and spatial collocation windows between HYSCAT data and buoy observations were 30 min and 25 km, respectively. The comparisons showed that the wind speeds and directions observed by HYSCAT agree well with the buoy data. The root-mean-squared errors （RMSEs） of wind speed and direction for the HYSCAT standard wind products are 1.90 m/s and 22.80°, respectively. For the HYSCAT-ASCAT comparison, the temporal and spatial differences were limited to 1 h and 25 km, respectively. This comparison yielded RMSEs of 1.68 m/s for wind speed and 19.1° for wind direction. We also compared HYSCAT winds with reanalysis data from NCEP. The results show that the RMSEs of wind speed and direction are 2.6 m/s and 26°, respectively. The global distribution of wind speed residuals （HYSCAT-NCEP） is also presented here for evaluation of the HYSCAT-retrieved wind field globally. Considering the large temporal and spatial differences of the collocated data, it is concluded that the HYSCAT-retrieved wind speed and direction met the mission requirements, which were 2 rn/s and 20° for wind speeds in the range 2-24 m/s. These encouraging assessment results show that the wind data obtained from HYSCAT will be useful for the scientific community.

Cr(Ⅲ) adsorption by sugarcane pulp residue and biochar

A batch experiment was conducted to investigate the adsorption of trivalent chromium （Cr（Ⅲ）） from aqueous solutions by sugarcane pulp residue （SPR） and biochar. The results show that Cr（Ⅲ） adsorption by SPR and biochar is highly pH-dependent and Cr（Ⅲ） adsorption amount increases with the increase of pH. The adsorption kinetics of Cr（Ⅲ） fits well with the pseudo-second-order model. The maximum Cr（Ⅲ） adsorption capacities of 15.85 mg/g and 3.43 mg/g for biochar and SPR were calculated by Langmuir model. This indicates that biochar has a larger ability for Cr（Ⅲ） adsorption than SPR. The free energy change value （AG） reveals a spontaneous sorption process of Cr（Ⅲ） onto SPR and non-spontaneous sorption process onto biochar. The entropy change （AS） and enthalpy change （AH） are found to be 66.27 J/（mol＇K） and 17.13 kJ/mol for SPR and 91.59 J/（mol-K） and 30.875 kJ/mol for biochar which further reflect an affinity of Cr（Ⅲ） onto SPR and biochar. It is suggested that biochar has potential to be an efficient adsorbent in the removal of Cr（Ⅲ） from industrial wastewater.

Assessing seawater quality with a variable fuzzy recognition model

With the rapid development of the marine economy industry, human exploitation of marine resources is increasing, which is contributing to the growing trend of eutrophication and frequent occurrence of red tide. Accordingly, investigations of seawater quality have attracted a great deal of attention. This study was conducted to construct a seawater environmental quality assessment model based on the variable fuzzy recognition model. The uncertainty and ambiguity of the seawater quality assessment were then considered, combining the monitoring values of evaluation indicators with the standard values of seawater quality. Laizhou Bay was subsequently selected for a case study. In this study, the correct variable model for different parameters was obtained according to the linear and nonlinear features of evaluation objects. Application of the variable fuzzy recognition model for Laizhou Bay, water quality evaluation and comparison with performance obtained using other approaches revealed that the generated model is more reliable than traditional methods, can more reasonably determine the water quality of various samples, and is more suitable for evaluation of a multi-index, multi-level, nonlinear marine environment system; accordingly, the generated model will be an effective tool for seawater quality evaluation.

Analysis of Wind Power Assessment Based on the WRF Model

Assessing wind energy is a key step in selecting a site for a wind farm. The accuracy of the assessment is essential for the future operation of the wind farm. There are two main methods for assessing wind power: one is based on observational data and the other relies on mesoscale numerical weather prediction(NWP). In this study, the wind power of the Liaoning coastal wind farm was evaluated using observations from an anemometer tower and simulations by the Weather Research and Forecasting(WRF) model, to see whether the WRF model can produce a valid assessment of the wind power and whether the downscaling process can provide a better evaluation. The paper presents long-term wind data analysis in terms of annual, seasonal, and diurnal variations at the wind farm, which is located on the east coast of Liaoning Province. The results showed that, in spring and summer, the wind speed, wind direction, wind power density, and other main indicators were consistent between the two methods. However, the values of these parameters from the WRF model were significantly higher than the observations from the anemometer tower. Therefore, the causes of the differences between the two methods were further analyzed. There was much more deviation in the original material, National Centers for Environmental Prediction(NCEP) final(FNL) Operational Global Analysis data, in autumn and winter than in spring and summer. As the region is vulnerable to cold-air outbreaks and windy weather in autumn and winter, and the model usually forecasted stronger high or low systems with a longer duration, the predicted wind speed from the WRF model was too large.

Study on quality evaluation model in multi-station assembly processes

Based on features of dimension variation propagation in multi-station assembly processes,a new quality evaluation model of assembly processes is established. Firstly,the error source of multi-station assembly system is analyzed,the relationship of dimension variation propagation in multi-station assembly processes is studied and the state equation for variation propagation is constructed too. Then,the feature parameters which influence variation propagation and accumulation in multi-station assembly processes are found to evaluate quality characteristic of the assembly system. Through the derivation of equation on dimension variation propagation,station coefficient matrices which are combined and conversed to determine the max eigenvalue are educed. The max eigenvalue is multiplied by the weight coefficient to establish the quality evaluation model in multi-station assembly processes. Furthermore,assembly variation indexes are proposed to judge of the assembly technology process. Finally,through the practical example,the application of the model and assembly variation indexes are presented.

Development of land valuation approach based on hedonic model--A case study of Vientiane capital city Laos

The aim of this study is to identify the variables affecting land value. Examined land was selected from the village in Vientiane capital city Laos. Data was collected from 100 villages in center of Vientiane capital city by using survey methods. A hedonic price analysis was conducted to determine the marginal return to different land characteristics using an econometric model corrected for correlation. Parcel characteristics such as distance to public park, village income, distance of population, number of the school within 500 meters buffer, distance to the temple, distance to the major market and distance to the business center （CBD）. Arc GIS 9.2 was applied to calculate the distance of the factors, after that SPSS 15.0 was used to calculate the land price characteristic based on hedonic price model. The results showed that the distance to the center of population was the main factor influencing to the land price, and followed by school and village income. Map of the land price before and after hedonic price analysis were produced. The land price valuation approaches based on hedonic price model for Vientiane capital city were developed and land price map were predicted. Hedonic price model and GIS were very useful for this research, and finally the policy of the land valuation based on GIS was developed.

Trinomial tree model of the real options approach used in mining investment price forecast and analysis

In order to effectively avoid the defects of a traditional discounted cash flow method, a trinomial tree pricing model of the real option is improved and used to forecast the investment price of mining. Taking Molybdenum ore as an example, a theoretical model for the hurdle price under the optimal investment timing is constructed. Based on the example data, the op- tion price model is simulated. By the model, mine investment price can be computed and forecast effectively. According to the characteristics of mine investment, cut-off grade, reserve estimation and mine life in different price also can be quantified. The result shows that it is reliable and practical to enhance the accuracy for mining investment decision.

Remote Sensing of Ecosystem Services:An Opportunity for Spatially Explicit Assessment

Ecosystem service is an emerging concept that grows to be a hot research area in ecology.Spatially explicit ecosystem service values are important for ecosystem service management.However,it is difficult to quantify ecosystem services.Remote sensing provides images covering Earth surface,which by nature are spatially explicit.Thus,remote sensing can be useful for quantitative assessment of ecosystem services.This paper reviews spatially explicit ecosystem service studies conducted in ecology and remote sensing in order to find out how remote sensing can be used for ecosystem service assessment.Several important areas considered include land cover,biodiversity,and carbon,water and soil related ecosystem services.We found that remote sensing can be used for ecosystem service assessment in three different ways:direct monitoring,indirect monitoring,and combined use with ecosystem models.Some plant and water related ecosystem services can be directly monitored by remote sensing.Most commonly,remote sensing can provide surrogate information on plant and soil characteristics in an ecosystem.For ecosystem process related ecosystem services,remote sensing can help measure spatially explicit parameters.We conclude that acquiring good in-situ measurements and selecting appropriate remote sensor data in terms of resolution are critical for accurate assessment of ecosystem services.

An equivalent magnetic dipoles model for quantitative damage recognition of broken wire

By simplifying saturatedly magnetized wire-rope to magnetic dipoles of the same magnetic field strength, an equivalent magnetic dipoles model is developed and the measuring principle for recognising damage of broken wire was presented. The relevant calculation formulas were also deduced. A composite solution method about nonlinear optimization was given. An example was given to illustrate the use of the equivalent magnetic dipoles method for quantitative damage recognition, and demonstrates that the result of this method is consistent with the real situation, so the method is valid and practical. wire-rope, damage of broken wires, quantitative recognition, equivalent magnetic dipoles, simulate

Evaluation of line brattice length in an empty heading to improve air flow rate at the face using CFD

The effectiveness of line brattice(LB) ventilation system depends on the associated system variables.However, the effect of these variables on the air flow rates close to the face of the heading is not extensively studied. In this paper, the effect of the LB length in relation to the LB-wall distance on the air flow rate reaching the face is analysed. Scenarios were developed using four LB lengths, two LB-wall distances and two heading depths. These scenarios were simulated with a validated CFD model. The air flow rates and patterns at various locations inside the heading were analysed. This helped to find the minimum LB-face distance that should be maintained for each LB-wall distance to maximise the air flow rate at the face. The minimum length when used will improve ventilation and reduce energy cost.

Evaluation of straightening capacity of plate roll straightener

Straightening machine is widely used for improving the quality of the defective mild steel plates.In general,the capacity of straightening machine is affected by material properties,the initial shape of the incoming plate and the plastic ratio.The mechanics model describing the capacity of the machine was developed.The deviation of the straightening capacity curves was studied.Then,the presented model was evaluated by comparative study to filed production data.Finally,the influences of overstretch,straightening speed,strengthening coefficient,elastic modulus,width of the plate on the straightening capacity were studied.It is convenient to determine whether the plate can be straightened or not by a series of straightening capacity curves.The straightening speed,width of the plate and elastic modulus of the material are more sensitive to the straightening capacity than the strengthening coefficient.

A Support Vector Machine-based Evaluation Model of Customer Satisfaction Degree in Logistics

This paper presents a novel evaluation model of the customer satisfaction degree （CSD） in logistics based on support vector machine （SVM）. Firstly, the relation between the suppliers and the customers is analyzed. Seondly, the evaluation index system and fuzzy quantitative methods are provided. Thirdly, the CSD evaluation system including eight indexes and three ranks based on one-against-one mode of SVM is built, last simulation experint is presented to illustrate the theoretical results.