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1.
在单因素试验的基础上,确定以滚筒蒸汽压力、滚筒转速和料膜厚度为3个主要因素,以成膜率、色泽和水分含量为响应值,采用响应面法设计优化滚筒干燥工艺参数。结果表明:米粉滚筒干燥工艺最优参数为:滚筒蒸汽压力0.45 MPa、滚筒转速3.5 r·min-1、料膜厚度0.2 mm。验证结果与理论值接近,说明所得工艺参数准确可靠,可用于实际生产操作。  相似文献   
2.
Ledermann et al. (2011) propose random orthogonal matrix (ROM) simulation for generating multivariate samples matching means and covariances exactly. Its computational efficiency compared to standard Monte Carlo methods makes it an interesting alternative. In this paper we enhance this method׳s attractiveness by focusing on applications in finance. Many financial applications require simulated asset returns to be free of arbitrage opportunities. We analytically derive no-arbitrage bounds for expected excess returns to be used in the context of ROM simulation, and we establish the theoretical relation between the number of states (i.e., the sample size) and the size of (no-)arbitrage regions. Based on these results, we present a No-Arbitrage ROM simulation algorithm, which generates arbitrage-free random samples by purposefully rotating a simplex. Hence, the proposed algorithm completely avoids any need for checking samples for arbitrage. Compared to the alternative of (potentially frequent) re-sampling followed by arbitrage checks, it is considerably more efficient. As a by-product, we provide interesting geometrical insights into affine transformations associated with the No-Arbitrage ROM simulation algorithm.  相似文献   
3.
The paper presents an adjusted Faustmann Rule for optimal harvest of a forest when there is a social cost of carbon emissions. The theoretical framework takes account of the dynamics and interactions of forests’ multiple carbon pools and assumes an infinite time horizon. Our paper provides a theoretical foundation for numerical model studies that have found that a social cost of carbon implies longer optimal rotation periods and that if the social cost of carbon exceeds a certain threshold value the forest should not be harvested. At the same time we show that it could be a net social benefit from harvesting even if the commercial profit from harvest is negative. If that is the case, the optimal harvest age is decreasing in the social cost of carbon.  相似文献   
4.
针对传统黏度计可调档位少,测量精度低、范围小等方面存在的不足,设计了一种基于旋转法的油墨黏度测量系统。系统以光栅转矩传感器作为数据采集装置,通过AT89S52单片机结合可编程逻辑器件(CPLD)搭建系统硬件平台。在软件方面,提出了一种基于恒力矩旋转磁场微步细分理论的步进电机多级细分驱动方法驱动电机,实现转速的多档连续调节,提高系统的黏度测量范围和精度。  相似文献   
5.
李树松 《科技与企业》2014,(20):185-187
海宇宙中的任何物质系统从最小到最大都具有直接或间接的"旋转"特性,"旋转"也是宇宙所固有的"基元粒子"单元的唯一内禀属性。在旋转、互绕原理的作用下,充满宇宙的"基元粒子"产生了最原始的"引力"与"斥力"作用,导致了基元粒子即称磁子自身有规律的循环组合,逐级生成了宇宙间的粒子、星体等各层级物质系统,同时四种物理作用力也相伴发生。  相似文献   
6.
Using data from the 1994 US National Establishment Survey, the author investigates differences between manufacturing and service establishments in the use of five innovative work practices: total quality management, self-managed teams, job rotation, job sharing and flextime. Service establishments are more likely to use job sharing and flextime. Manufacturing establishments are more likely to use total quality management and self-managed teams. These results hold when controlling for establishments’ business strategies, worker demographics, institutional connections and use of technology. Determinants of adoption of total quality management, self-managed teams and flextime also varied by sector.  相似文献   
7.
Crop rotation and other input management practices are of particular interest for their potential impacts on economic and agro-environmental components of potato production. Although crop yield and experimental impacts of rotations of grains, oilseed and legume crops have been published for several experimental studies in Canada there are few models related to the economic and environmental dynamics of potato production. We describe a dynamic model which integrates environmental and economic processes in potato production. The potato rotation model consists of interconnected modules of irrigation and precipitation, soil characteristics, soil erosion, soil water, phosphorus, nitrogen, soil organic matter, farming operations, crop yield and the related calculation of economic return. While not all aspects of crop production have been interlinked, including nitrogen carry-over, this model is the first step in the analysis of experimental data for irrigated potato rotations conducted in southern Manitoba.   相似文献   
8.
本文从审计师-客户长期关系的视角出发,对审计师强制轮换与审计质量之间的关系进行了探讨.研究发现:对于财务状况较差的公司,若审计师与客户之间不存在长期关系,则强制轮换后的审计质量显著提高,若审计师与客户之间存在长期关系,则强制轮换后审计质量的提高被弱化;而对于财务状况较好的公司,无论审计师与客户之间是否存在长期关系,强制轮换后的审计质量均未发生显著变化.本文研究对审计师强制轮换的监管具有借鉴意义.  相似文献   
9.
Previous work in forest management under uncertainty has been based on the assumption that landowners face a risk of only one damaging event during any forest rotation, with the main result being that landowners choose shorter rotation ages. These models are universal in an assumption that, should the disturbance arise in a given rotation, the landowner salvages what is possible through a harvest and replants to begin a new rotation. However, a real possibility exists that multiple disturbances may occur in one rotation, with the landowner retaining the damaged stand thereby waiting through the first or even a subsequent disturbance to harvest and begin a new rotation. We develop a new approach for rotations models and choices that allows more than one event and flexibility in the timing of harvest, where tree recovery and damage may make continuance of the rotation, rather than starting over, a rent maximizing strategy. We thereby generalize the highly-cited body of literature based on Paul Samuelson's and William Reed's seminal contributions. Results demonstrate that failure to consider these new features leads to suboptimal harvest decisions and highly suboptimal land rent values. Important parameters are found to be arrival rates of future disturbances and survival proportions and growth rates after each disturbance.  相似文献   
10.
We develop a model to explain why firm behavior differs in the market for small cars. Firms such as Honda compete in output (Cournot) and produce marketing campaigns with universal appeal, while firms such as Scion compete in price (Bertrand) and produce targeted marketing campaigns. We show that this mixture of Cournot and Bertrand behavior can occur when advertising rotates demand. When behaving as a Cournot-type firm such as Honda, it is more profitable to pursue a mass-market advertising campaign that rotates demand counterclockwise when it faces relatively low unit costs and a flat demand function. When behaving as a Bertrand-type firm such as Scion, it pays to pursue a niche-market advertising campaign that rotates demand clockwise when it faces relatively high unit costs and a steep demand.  相似文献   
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