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81.
军用飞机采购价格预测研究   总被引:3,自引:0,他引:3  
分析了我国军用飞机价格预测中存在的困难,从我国国情出发,提出了我国军用飞机价格预测的两种方法:根据制造成本和期间费用预测价格方法与相似飞机预测价格方法.相似飞机预测法是指采用偏最小二乘回归、神经网络或灰色理论等方法,根据相似飞机的性能与价格数据建立价格预测模型,实例表明,相似飞机价格预测法具有较高的精度.  相似文献   
82.
化工企业火灾风险评估对于化工生产至关重要。针对化工行业的火灾风险,结合层次分析法和模糊识别模式的优点,提出了基于层次分析—模糊识别的综合评价方法,并通过实例评估证明了这种评价方法行之有效。  相似文献   
83.
84.
Assemble in Advance (AIA) policy reduces assembly cost due to advance planning, while Assemble to Order (ATO) policy eliminates assembly of excessive (more than demanded) units. The tradeoffs between the two policies have been studied in the past for single product environments. Moreover, it was shown that it is beneficial to employ AIA and ATO simultaneously. In this article, we study the employment of such a composite assembly policy in a multiproduct environment with component commonality. When common components are used, ATO may also enable us to benefit from the risk pooling effect. We provide important managerial insights such as: the multiperiod problem is myopic and changes in inventory levels due to the use of common components, and demonstrate the potential profit increase compared to other policies.© 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
85.
有限精度的 BP 神经网络高速算法   总被引:2,自引:0,他引:2       下载免费PDF全文
精度要求是神经网络硬件实现的一个关键问题。本文提出了一种有限精度的BP高速算法,通过实例验证,该算法适于低精度,且收敛速度快。  相似文献   
86.
针对精确制导弹药制导控制系统低成本的迫切需求,提出了一种弹载低成本制导控制系统设计方法。建立了一种弹载制导控制系统低成本体系架构,从功能、硬件、软件等方面对其进行了GNC一体化设计,并在此基础上提出了一种基于ARM处理器的一体化制导计算机设计方法。针对MEMS导航系统精度低、噪声大特点,设计了一种惯性/卫星数字制导方案。该低成本制导控制系统设计方法可有效减少系统冗余硬件,降低成本,实现较高的制导控制精度,满足未来低成本精确制导武器的需求。  相似文献   
87.
The profession of arms is distinct from other professions for many reasons. One reason which is not so obvious is that, unlike members of other professions, soldiers may go their entire careers preparing for a day that never arrives. All things considered, we should think this to be a very good thing. For soldiers, however, this can feel somewhat odd, since there is a natural desire to want to feel useful and to see one’s role and purpose find realization. Accordingly, the common soldier is forced to adopt a rather paradoxical mindset, one of longing for peace, and therefore for uselessness, while at the same time longing to be useful, which would entail that there be a war. This latter desire to be useful and to vindicate one’s identity as a soldier can sometimes take on an unhealthy life of its own. The pull of wanting too strongly to live up to a warrior identity, I argue, can sometimes skew a soldier’s ability to assess risk rationally. This article will therefore investigate how a soldier’s concept of self influences his or her overall capacity to evaluate risk in war and when such influence might become morally problematic.  相似文献   
88.
An analysis of the security vetting files of 19 employees within a South African national department who had been found guilty of financial misconduct in the last five years uncovered that the existing security vetting processes did not detect the financial misconduct of which these employees have been found guilty. This research sets out to establish whether security vetting can be extended to include the detection of financial misconduct within the department and, if so, how. Moreover, if security vetting can indeed be so extended, can it possibly enhance the management of fraud risk across all South African public sector departments? Qualitative interviews were conducted with 27 employees who are key to fraud risk management and security vetting within the researched department. During the interviews, the following five themes emerged: (1) the reasons why employees commit financial misconduct; (2) why it is not detected by the security vetting process; (3) the potential alignment of the security vetting process to facilitate the detection of financial misconduct; (4) the following through on security vetting findings; and (5) sharing these findings with the internal audit and risk management functions within state departments. These themes were probed and are reported on, establishing firstly that security vetting can indeed be extended to include the detection of financial misconduct within the researched department, and secondly that it can enhance the management of fraud risk across all South African public sector departments, given the specific mandate of the State Security Agency (SSA) and the national security vetting strategy.  相似文献   
89.
This paper empirically examines whether the aging of a fleet affects operational availability and operating cost using a unique data-set on the 117 47-foot Motor Lifeboats (MLBs) of the United States Coast Guard (USCG). Procured from 1997 to 2003, the 47-foot MLB is the standard lifeboat of the USCG and all 117 MLBs remain in service. The aging of the MLB fleet has resulted in higher annual operating costs and lower operational availability, although the nature of this relationship remains unclear. Our estimation strategy utilizes an error components estimator to examine these issues. We employ three variants of the dependent variables (i.e. the standard logarithmic transformation as is most commonly seen in the literature, inverse hyperbolic sine [IHS], and level outcomes). The point estimates from the standard logarithmic model finds operational availability for the MLBs decreases at a rate between 0.83 and 1.8% per year and cost increases at a rate between 0.33 and 7.81% per year. Similar effects are shown with the IHS and level outcome specifications. In terms of nonlinearity effects, we find the most pronounced changes in operational availability and cost occur for MLBs aged 15 years or more (in comparison to younger MLBs).  相似文献   
90.
传统的主动学习方法往往仅基于当前的目标模型来挑选样本,而忽略了历史模型所蕴含的对未标注样本预测稳定性的信息。因此,提出基于不稳定性采样的主动学习方法,依据历史模型的预测差异来估计每个未标注样本对提高模型性能的潜在效用。该方法基于历史模型对样本的预测后验概率之间的差异来衡量无标注样本的不稳定性,并挑选最不稳定的样本进行查询。在多个数据集上的大量实验结果验证了方法的有效性。  相似文献   
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