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981.
Wavelet thresholding of spectra has to be handled with care when the spectra are the predictors of a regression problem. Indeed, a blind thresholding of the signal followed by a regression method often leads to deteriorated predictions. The scope of this article is to show that sparse regression methods, applied in the wavelet domain, perform an automatic thresholding: the most relevant wavelet coefficients are selected to optimize the prediction of a given target of interest. This approach can be seen as a joint thresholding designed for a predictive purpose. The method is illustrated on a real world problem where metabolomic data are linked to poison ingestion. This example proves the usefulness of wavelet expansion and the good behavior of sparse and regularized methods. A comparison study is performed between the two-steps approach (wavelet thresholding and regression) and the one-step approach (selection of wavelet coefficients with a sparse regression). The comparison includes two types of wavelet bases, various thresholding methods, and various regression methods and is evaluated by calculating prediction performances. Information about the location of the most important features on the spectra was also obtained and used to identify the most relevant metabolites involved in the mice poisoning.  相似文献   
982.
相对一般的技术创新,高新技术创新有其独有的一些特点,这些特点决定了文化对高新技术创新具有重要作用。高新技术创新的文化路径包括观念文化路径、制度文化路径和行动文化路径三个方面。基于文化视角优化高新技术创新的政策选择,完善我国科技政策,有助于推动高新技术的进一步创新。  相似文献   
983.
为了迎合财务会计的需求,软件公司开发了不少带有逆向操作功能的软件,虽然在使用中对更正会计差错、减少系统数据冗余和提高工作质量等起到了一定的作用,但同样也给财务会计系统的安全带来了威胁。这里在简略介绍会计核算软件逆向操作内涵和功能作用的基础上,针对其可能产生的隐患和危害等进行了分析,并针对其弊端和可能的风险提出了防范性完善措施。  相似文献   
984.
The evaluation of hazards from complex, large scale, technologically advanced systems often requires the construction of computer implemented mathematical models. These models are used to evaluate the safety of the systems and to evaluate the consequences of modifications to the systems. These evaluations, however, are normally surrounded by significant uncertainties related to the uncertainty inherent in natural phenomena such as the weather and those related to uncertainties in the parameters and models used in the evaluation.

Another use of these models is to evaluate strategies for improving information used in the modeling process itself. While sensitivity analysis is useful in defining variables in the model that are important, uncertainty analysis provides a tool for assessing the importance of uncertainty about these variables. A third complementary technique, is decision analysis. It provides a methodology for explicitly evaluating and ranking potential improvements to the model. Its use in the development of information gathering strategies for a nuclear waste repository are discussed in this paper.  相似文献   
985.
通过对地方高师院校毕业生就业形势的深入分析,剖析了引发地方高师院校毕业生就业难的内因和外因。从学校长足发展的角度,对地方高师院校的教育、管理和服务提出了改进措施。  相似文献   
986.
对大遗址管理而言,我国正稳步推进的城镇化既是机遇,也是挑战。为回应这些机遇或挑战,“十一五”前后我国从中央到地方采取了一系列措施,以寻求大遗址管理体制中管理架构和机构的部分突破。这些突破对大遗址保护已经或正在产生积极影响,但也面临着政策不具普适性、无法根除原管理框架痼疾等困境。促成大遗址保护需求与规划的衔接、引入社会力量参与大遗址管理,是突破困境的重要手段。  相似文献   
987.
论法治教育与思想政治教育的统一性   总被引:1,自引:0,他引:1  
法治教育与思想政治教育在教育内容、教育目的、教育理念与方式上存在着统一性,法治教育与思想政治教育的共同任务在于彰显诚信法治教育、道德理想教育和实践理性教育。法治教育有利于加强大学生思想政治教育的实效,有利于促进思想政治教育的认知环节。为此,要关注尊重受教育者的主体地位,加强诚信法治建设,高度重视学校教育与社会、家庭的结合,加强教育环境建设。  相似文献   
988.
We study nonlinear least-squares problem that can be transformed to linear problem by change of variables. We derive a general formula for the statistically optimal weights and prove that the resulting linear regression gives an optimal estimate (which satisfies an analogue of the Rao-Cramer lower bound) in the limit of small noise.  相似文献   
989.
One of the standard variable selection procedures in multiple linear regression is to use a penalisation technique in least‐squares (LS) analysis. In this setting, many different types of penalties have been introduced to achieve variable selection. It is well known that LS analysis is sensitive to outliers, and consequently outliers can present serious problems for the classical variable selection procedures. Since rank‐based procedures have desirable robustness properties compared to LS procedures, we propose a rank‐based adaptive lasso‐type penalised regression estimator and a corresponding variable selection procedure for linear regression models. The proposed estimator and variable selection procedure are robust against outliers in both response and predictor space. Furthermore, since rank regression can yield unstable estimators in the presence of multicollinearity, in order to provide inference that is robust against multicollinearity, we adjust the penalty term in the adaptive lasso function by incorporating the standard errors of the rank estimator. The theoretical properties of the proposed procedures are established and their performances are investigated by means of simulations. Finally, the estimator and variable selection procedure are applied to the Plasma Beta‐Carotene Level data set.  相似文献   
990.
The Belt and Road Initiative is an important decision for the great rejuvenation of the Chinese nation. Maritime security has a significant place in this process. In recent years, there have been frequent violent terrorist incidents at sea, including piracy, armed hijackings and terrorist attacks, posing a dire threat to both international and Chinese maritime transport interests and seriously challenging the fulfillment of the maritime part of the “Belt and Road Initiative.” Five direct measures can be taken to protect ocean shipping from violence at sea. One example is the defensive measures taken against the Somali pirates. The employment of armed guards from professional security companies on board ship is an effective model for guaranteeing maritime security; it not only meets the standards of international law, but is also legally permitted in many developed countries and regions, and is thus strategically significant for overall Chinese maritime security. In the Chinese context, this model carries its own legal risks. We should embrace a new approach to national security law, strengthen legal guarantees and make concerted efforts to provide warship (military aircraft) escorts to jointly build an optimum model of Chinese maritime security in order to ensure the realization of core Chinese maritime interests.  相似文献   
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