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关键词： 辅助检验   鉴定依据   鉴定内容   发挥作用  

摘要： 司法鉴定为多渠道、有效地化解社会矛盾提供证据,满足构建社会主义和谐社会的实际需求。司法鉴定工作的目西是帮助法庭发现真实,全面细致分析鉴定材料是科学、公平、公正鉴定的前提。而辅助检验则是鉴定不可缺少的环节、系统鉴定的必要步骤。辅助鉴定不仅有利于鉴定人判别委托要求是否有利于解决纷争,而且其检验结果也有助于法官的理解和鉴定人质证。

关键词： 线性规划   对偶问题   检验数   单纯形乘子  

摘要： 在求解线性规划中,检验数起到判定是否最优解的作用。实际上,在求解对偶问题中,检验数也起到很重要的作用,它和对偶问题的解存在着密切的关系,甚至直接就是对偶问题的解;利用检验数往往可以直接或间接地写出对偶问题的解,它是原问题和对偶问题有关解方面的桥梁,在求解对偶问题时,起到了重要的作用。

关键词： 卖空交易   融资融券   会计信息质量  

摘要： 2011年中国23家海外上市公司因会计信息"瑕疵"受到"卖空袭击",导致股价大跌,这表明在允许卖空的资本市场中,会计信息的市场环境不同于"单边市"市场,"信息瑕疵"本身也是一种投资机会,并且股价往往会放大对负面消息的反应。因此,上市公司管理层应审慎对待市场环境的变化,规范信息披露行为,尽可能避免公司受"卖空袭击"而带来的市值损失。基于中国证券市场首批融资融券试点标的股数据研究发现,我国上市公司信息披露行为并未充分考虑卖空交易机制对市场环境带来的影响,融资融券标的股上市公司会计信息质量与其他上市公司无显著差别。这可能有两个方面的原因:一是我国卖空机制试点期间尚存在较为严格的卖空约束,二是上市公司管理层对卖空风险反应不足。

关键词： Population statistics  

摘要： A typical small-sample biomarker classification paper discriminates between types of pathology based on, say, 30,000 genes and a small labeled sample of less than 100 points. Some classification rule is used to design the classifier from this data, but we are given no good reason or conditions under which this algorithm should perform well. An error estimation rule is used to estimate the classification error on the population using the same data, but once again we are given no good reason or conditions under which this error estimator should produce a good estimate, and thus we do not know how well the classifier should be expected to perform. In fact, virtually, in all such papers the error estimate is expected to be highly inaccurate. In short, we are given no justification for any claims. Given the ubiquity of vacuous small-sample classification papers in the literature, one could easily conclude that scientific knowledge is impossible in small-sample settings. It is not that thousands of papers overtly claim that scientific knowledge is impossible in regard to their content;rather, it is that they utilize methods that preclude scientific knowledge. In this paper, we argue to the contrary that scientific knowledge in small-sample classification is possible provided there is sufficient prior knowledge. A natural way to proceed, discussed herein, is via a paradigm for pattern recognition in which we incorporate prior knowledge in the whole classification procedure (classifier design and error estimation), optimize each step of the procedure given available information, and obtain theoretical measures of performance for both classifiers and error estimators, the latter being the critical epistemological issue. In sum, we can achieve scientific validation for a proposed small-sample classifier and its error estimate.

关键词： Monte Carlo experiments   auto-correlated series   climate change   Pre-whitening  

摘要： Pre-whitening approaches have been widely used to remove the influence of serial correlations on the Mann-Kendall trend test (MK_prew). However, previous studies indicate that this procedure may lead to a false reduction of the significance of a trend. An alternative approach (MK_interact) has been proposed to improve the assessment of the significance of a trend in auto-correlated data. Therefore, the present study compared the performance of the MK_prew and MK_interact for detecting trends in auto-correlated series. Sets of Monte Carlo experiments were carried out to evaluate the occurrence of type I and II errors obtained from both approaches. The analyses were also based on 10-day values of the difference between precipitation and potential evapotranspiration (P-EP) obtained from the location of Campinas, State of Sao Paulo, Brazil. The results found in this study allow us to conclude that the MK_interac outperformed the MK_prew in correctly identifying the significance of trends and that, concerning agricultural interests, the decreasing trend described by the MK_interac during the beginning of the crop growing seasons may reveal an unfavorable temporal distribution of the P-EP values.

关键词： threshold gradient descent regularization   hierarchical structure   multiclass classification   lung cancer   adenocarcinoma   squamous cell carcinoma  

摘要： Regularization methods that simultaneously select a small set of the most relevant features and build a classifier using the selected features have gained much attention recently in problems of classification of "omics" data. In many multi- class classification problems, which are of practical importance, the classes are naturally endowed with a hierarchical structure. however, such natural hierarchical structure is often ignored. here, we use an existing regularization algorithm, Threshold Gradient Descent Regularization, in a hierarchical fashion, which takes advantage of natural biological structure to specifically tackle multi-class classification of microarray data. We apply this approach to one of the tasks presented by the sbv IMPROVeR Diagnostic Signature challenge: the Lung cancer Sub-challenge. Gene expression data from non- small cell lung carcinoma were used to classify tumors into adenocarcinoma and squamous cell carcinoma subtypes, and their clinical stages (I and II). Genetic and transcriptomic differences between ac and Scc have been reported, indicating a potentially different pathological mechanism of differentiation and invasion. The results from this analysis show that hierarchical-TGDR outperforms pairwise TGDRs in terms of predictive performance, and is substantially more parsimonious. In conclusion, the hierarchical-TGDR approach trains classifiers in a top-down fashion by considering the naturally existing structure within the data, reducing the number of pairwise-TGDRs to be trained. It also highlights different mechanisms of "invasion" in the two subtypes. This work suggests that incorporating known biological information into classification algorithms, such as data hierarchies, can improve the discriminative performance and biological interpretation of this classifier.

关键词： feature selection   wrappers   Naive Bayes classifiers   microarray data  

摘要： Feature selection is one of the crucial steps in supervised learning, which influences the entire subsequent classification (or regression) process. The approaches to this task can largely be divided into two categories: filter-based and wrapper-based methods. Generally, the latter produces better results than the former with regard to given learning methods, though it consumes more computational resources for searches over the feature subset space. In this paper, we propose an Efficient wRapper based on a Paired t-Test (ERPT) for choosing features from large-scale data consisting of thousands of variables, such as microarrays. Statistical tests are a reasonable option when the number of features is very large because they have more predictable behavior and can be more efficient than most search methods. The proposed method consists of two phases: decrement phase and increment phase. In the decrement phase, it selects strongly relevant features. In the increment phase, it adds weakly relevant features, given the previously selected features. Our method, combined with naive Bayes classifiers, has been tested in an extensive set of experiments on University of California Irvine (UCI) Machine Learning Repository data. The results showed that the performance of the proposed method is comparable to that of the backward search-based wrapper and superior to that of the forward search-based wrapper. Furthermore, it demonstrated much better performance than the forward search-based wrapper when applied to three microarray data sets, for which the backward search-based wrapper was impractical because of the computational burden involved. The proposed method has the following three merits: (1) it is applicable to data sets having thousands of variables, (2) it provides a theoretically sound and controllable criterion for thresholding features, and (3) it finds feature subsets for the maximizing of classification performance on sparse domains.

关键词： 城镇化率   城市居民消费   农村居民消费  

摘要： 本文通过采用1979年－2011年的数据，实证分析了城镇化率对我国居民消费的影响。研究结果表明：城镇化率与我国城乡居民消费之间存在长期协整关系，但不存在格兰杰因果关系，而且实证表明城镇化率对我国城乡居民消费有很强的正效应，其中对城市居民平均消费影响更为显著，对农村居民消费影响不显著，原因可能是城镇化发展使农村相对富裕居民市民化，农村剩余居民消费能力难以快速填补“富裕居民的流失”。

关键词： 社会办医疗机构   医学独立实验室   临床检验  

摘要： 医学独立实验室是具有独立法人资格专业从事医学检验的一类医疗机构。近年来,随着我国医药卫生体制改革的不断深化,该类医疗机构得到了迅速发展,目前浦东新区共有医学独立实验室6家。医学独立实验室能够节省检验成本、提高校验效率、改善检验质量,对于改善浦东区社会办医疗机构的临床检验状况起到一定的积极作用,但医学独立实验室也存在过分追求经济效益,超出诊疗科目登记范围开展检验项目等问题。为此,相关卫生行政管理部门需从加大宣传、加强监管等方面,对其加以引导,促其健康发展。

关键词： 检验专业质控组   区域性   质量控制  

摘要： 目的探讨基层检验专业质控组在区域性质量控制中的作用,为相关组织和机构提供相应的借鉴作用。方法成立都江堰市医疗机构基层检验专业质控组,并依托基层检验专业质控组,对都江堰市市属、乡镇、社区医疗卫生机构的质量工作进行跟踪,对工作中出现的问题进行分析、总结,采取集中培训和单独辅导相结合的方式进行有针对性的指导,提高大家的相关知识水平,加深质量意识。结果通过2010～2012年的工作,都江堰市基层医疗机构的检验质量有了明显提高,合格率从62.5%提升到81.8%,优良率从50%提升到72.7%,质量控制意识明显加强,专业技术人员业务水平得到的有效的提升。结论作为国家、省、市三级医疗机构检验质量控制中心工作的有效补充和完善,通过基层检验专业质控组的建立,发挥在标准制定,统一规范、质量监督、教育培训中的作用,对提高基层检验人员业务技术水平以及区域性的检验质量具有积极意义。