共查询到20条相似文献，搜索用时 31 毫秒
1.
中国大规模生猪养殖的成本与主要国际竞争者的比较 总被引：2，自引：0，他引：2
本研究选取中国规模化生猪养殖的成本收益数据与丹麦、加拿大和巴西3个国家进行对比分析。通过比较2005—2010年生猪养殖成本的变化趋势以及成本构成情况,分析总结出中国规模化生猪养殖业在成本控制方面所存在的优势和不足。并且进一步从饲料成本、人工成本以及现代化管理投入3个方面进行了分析。结果表明,相对其他国家而言,中国生猪养殖成本构成中饲料成本所占比例最高,存在着从业人员技术水平有限并且现代化管理投入较少的问题。结合各国生猪养殖业发展经验,从而提出大力培养专业人才,加大科技投入以及促进生猪养殖业规模化和一体化的政策建议。 相似文献
2.
Product design now has a significant influence on the profitability of a business. Enterprise simulation can not only overcome the limitations of current product scheme cost evaluation methods , but also support Product Scheme Cost design of Dynamic Enterprise. Product Scheme Cost Design basing on Value Innovation Method aim at value increase , and use Enterprise simulation as Product design tools. To evaluate different design options, a series of runs are performed in Enterprise simulation system for each design variant. In this way , Product design face on enterprise business. This paper focus on value chain,and use it in Product design, provide a new way for Product design of Dynamic Enterprise. 相似文献
3.
Based on Petri net theory and workflow model, a 9 tuple colored Petri net simulation model of earthmoving operations was presented focusing on the equipment management in the earthmoving construction. The dynamic changes of workflow and information flow in the construction process were illustrated in the model, and the constraint relationship between equipment and construction conditions was taken into account. Based on the information of the number of equipment and cost, the simulation for the construction situation, estimated completion time, cost, and equipment productivity were conducted. The model was operated based on the CPN Tools platform. And sensitivity analysis and model validation on the model were carried out by simulating the data collected in a real case, which demonstrates that the model can improve the accuracy of the simulation results in the earthmoving operation construction process. 相似文献
4.
For requirements of suppressing harmonics on the dc side of HVDC system,a new hybrid filtering system a shunt passive and a small rated reactor transformer coupling series active filter is presented,and the harmonic compensation and control principles are discussed theoretically in this paper.Digital simulation results show excellent filtering characteristics of harmonic current and very high performance/cost by using a new hybrid filtering system proposed int this paper. 相似文献
5.
Due to lack of estimation during initial stage of traditional physical design process for industry product, the efficiency of conduct development is low with high cost. A basic framework of twisted blade virtual design is set up based on the theory and method of product virtual design, and aiming at the thermodynamic process of middle or lower stage of steam turbine. The molding rule of twisted blade is found by thermodynamic computation program. The study of blade virtual design is carried through from 3-dimensional modeling to simulation test. The combination of thermal power theory, computer simulation technology and CAD system forms a kind of design method with the superiority such as high efficiency, low cost and good decidability is represented in the virtual design of turbine blade. 相似文献
6.
In order to reduce development time and cost of dual clutch automated mechanical transmission(DCT) control system,the dynamic model of automobile DCT control system is established by Matlab/SimDriveLine and the engine model is improved by neural network.Based on Matlab/Simulink,the simulation models of DCT control during starting phase,shift phase and shift rule are set up,and then the whole system of DCT is simulated.The simulation result indicates that the DCT system dynamic model and the designed controller are reasonable and feasible,and proofs that the model is suitable for developing DCT control system and improves the design efficiency of DCT system. 相似文献
7.
For the high density of distributed heterogeneity nodes in wireless sensor networks (WSNs), the optimal sensor deployment is studied. A cost optimal heterogeneous sensor deployment scheme based on genetic algorithm is proposed. The cost of sensor node deployment is used as objective function for optimization computation subjected to network coverage and fault tolerance to obtain the suitable types and positions of the sensors. The algorithm can be used for boolean sensing model as well as probabilistic sensing model. The simulation results demonstrate that the proposed algorithm converges fast toward the optimal solutions and reduces the cost of sensor deployment, which is feasible for heterogenous nodes deployment in WSNs. 相似文献
8.
The high cost of grid connected photovoltaic (PV) system is an important reason that hinders its market application. The control cost can be partly cut down by using sensorless Maximum Power Point Tracking (MPPT). However, the sensorless MPPT control proposed by previous literatures has drawbacks of poor estimation accuracy, bad real time performance, and poor dynamic responses, which has great impact on the MPPT and the output performance of the whole system. Aiming at these problems, an Adaptive Sliding Mode Observer (ASMO) for estimation of photovoltaic array voltage is proposed. The external disturbance and modeling errors are suppressed while the real time performance and the estimation accuracy are improved greatly by the proposed method. The favorable performance of the output performance and MPPT performance of the PV system based on the ASMO are validated by simulation and experimental results. 相似文献
9.
With the reform toward power market processing, how to decide electricity price becomes a key problem which one power plant have to face. So in this paper, the authors show two ways to the problem, a pricing model by account and a pricing model by economics, then they analyze the cost structure and counting principle of three-electricity price, which is determined by the methods of repayment of capital with interest (RCI pricing), of the operation period (OP pricing) and of marginal cost (MC pricing). Then similarities and differences among these three pricing methods existing in the transitional period are examined by a case in china. The indicate that it is important and inevitable to reform RCI pricing, to popularize OP pricing and to transfer to MC pricing. 相似文献
10.
实现持续低碳化发展是冷链物流技术创新与优化的重要方向。基于成本约束视角,将冷链物流存储、配运、交付诸环节的运营成本和碳排放成本纳入企业总成本目标函数,构建冷链物流配送路径优化模型,使用蚁群算法与遗传算法变异算子结合求解,提高了算法迭代收敛速度。以医药冷链物流配送为例进行算法仿真优化与分析,验证了降低物流成本与节能减排可协同优化,获得良好的经济效益。模型和算法对环境可持续视角下的冷链物流配送路径问题有理论和实践意义。 相似文献
11.
The construction method of concreting layer by layer and segment by segment could reduce the use of steel and save construction cost, when concrete box arch ring was built cast in place with aid of arch centering. According to the simulation of large scal 相似文献
12.
This paper uses motorcycle as the research object and uses ADAMS/View as tools to deal with the inconvenience of constructing Motorcycle simulation model in ADAMS/View.The parameterized design system of Motorcycle is developed according to the requirements of simulation model by using ADAMS/View secondary development technology.The system has solved very complicated problem of motorcycle modeling in ADAMS/View,whose spatial structure is very complicated,and solved the problem of model imported by other CAD software which has information lose,model scale tends to heavy,follow-up simulation difficult and so on.The system is used to make the simulation model in ADAMS/View easier for follow-up simulation according to the basic dimension of Motorcycle and user's needs,and shorten the development period of the motorcycle,reduce the development cost,and carry on the series design. 相似文献
13.
In order to solve the scheduling problem of frequent distribution of a little goods in one batch between regions in logistics system, We use time slices to manage orders, thus disassembling, combining orders and optimizing the planning to cut the cost. A product-scheduling model in region distribution is presented based on the retailing chain system. A method is presented which spends little cost on logistics plans under constraint conditions (time constraint conditions and space constraint conditions) by using combination and optimizing based on the three layers framework of distribution center, region distribution center and retail shop. The simulation result shows that the model and algorithm is indeed effective to solve the supply problems in multicommodity or multi-shop. 相似文献
14.
15.
Transmission lines are easily hit by lightning, and lightning shielding failure is an important reason of lightning accidents of transmission line. So researches on lightning shielding of transmission line should be strengthened. On the basis of the abundant understand to known lightning shielding models of transmission line, a new lightning shielding simulation model of transmission line is presented in the paper. In this model, the effect of attracting lightning of upward leader is considered reasonably, and the method of variable descending step is adopted to simulate the descending process of lightning leader. The simulation calculating results show that the model is in good agreement with field experience of transmission line. It can guide lightning shielding design of transmission line and estimate the performance of lightning shielding of transmission line. 相似文献
16.
采用欧盟法和国标法对食品中苏丹红的含量进行了检测,并比较了两种方法的差异。结果表明,欧盟法灵敏度高,粉状样品回收率高,但成本较高;国标法油状样品回收率高,成本低,大部分机构可用此法,但氧化铝活性需要控制适当才不会影响检测结果。 相似文献
17.
Breeding oilseed rape for oil and protein contents may have led to differences in seedling emergence in genotypes. New opportunities for deep automated phenotyping of germination and seedling growth are being developed on phenotyping platforms. Our aim was to demonstrate that using these data to parameterize a crop emergence model complements field experiments for the evaluation of differences among genotypes. Five genotypes, chosen in a diverse set of winter oilseed rape for their different germination speeds, were phenotyped for germination at different temperatures and water potentials as well as for radicle and hypocotyl growth. These data were used as parameters to run the SIMPLE crop emergence model over a period of 27 years (1985–2012), at two locations, one in France and one in Germany, and at four sowing dates. Field experiments were performed in 2012, 2013 and 2014, and the emergence of the five genotypes was measured at early and late sowing dates. First, model predictions were compared with observed field emergence in the French sowing trials in 2014. The model proved to be rather good at predicting the emergence of the genotypes. Then, for the simulation study, the model extended the observed differences between locations and sowing dates over a greater number of years. The model also identified the main reasons for non-emerging seedlings and their frequencies in the simulated sowings. Differences between the five genotypes were on average very small, but complex interactions appeared that led to bigger differences under certain sowing conditions. This study demonstrates that combining deep phenotyping with crop models in simulation studies paves the way for more precise and detailed evaluation of genotypes. 相似文献
18.
插装式电液比例流量放大阀特性分析 总被引：1，自引：0，他引：1
插装阀具有通流量大、结构简单和成本低等优点,广泛应用于液压系统中。笔者针对一种主级基于流量放大原理、先导级采用单级伺服比例方向阀的两级插装比例节流阀特性进行分析,建立了该比例节流阀的简化数学模型,获得了简化条件下的特性关系式。以此为基础,在SimulationX软件环境中建立该液压阀的仿真模型,利用实验数据对模型正确性进行验证,运用验证后的仿真模型对比例阀性能特性进行分析。结果表明：该液压阀输出流量静态特性存在死区,阶跃响应存在时间滞后,主阀流量放大倍数并不是常数,性能影响因素与主阀反馈槽预开量、面积梯度、级间过渡容腔体积以及先导阀通流能力等相关。 相似文献
19.
Powertrain parameter design for the electric vehicle with taking the energy consumption of air conditioner into consideration 
下载免费PDF全文
下载免费PDF全文 On the basis of considering the influence of air conditioner on vehicle performance,the parameter determination of the power train composed of a battery,a traction motor and a two-speed transmission of an electric car is carried out. To ensure the economy of operation,a shifting strategy with a principle which emphasizes the high work efficiency of the power train is drawn up and the gear ratios are corrected aiming at the least energy cost over the drive cycle. The simulation results indicate that the designed parameters meet the requirements moderately and the driving range is extended by 5.28% when the air conditioner is turned off and 4.29% when turned on,compared with the initial results through the correction of the gear ratios. 相似文献
20.
HU Wen - fa 《保鲜与加工》2006,(4):98-100105
Political risk is one of the common risks in international construction projects, the political risk is analyzed in this paper and an evaluation model of political risk in international construction projects is presented based on BP algorithm, The model is a self- study and self- adaptive one in risk evaluation. Through the simulation study with practice data, with this model the cost improvement of international construction projects can be predicted in political risks exactly, it is useful in evaluating the comprehensive political risk. 相似文献