基于内容分析法的智力资本报表(InCaS)与中国企业的适配问题研究

作为一种战略管理工具,智力资本报表(InCaS)已经广泛用于欧洲企业.但这种工具是否适用于中国企业?为了探讨这一问题,通过分析InCaS的运行机制和InCaS在欧洲的最佳应用实践,得出其适用的边界条件.在这种边界条件之下,选取204家中国的上市公司,在对其进行行业、规模和生命周期阶段分类的基础之上,运用内容分析法对204家企业的年报进行分析.进而探讨不同行业、规模和生命周期阶段的企业在智力资本披露方面的现状和差异.对比InCaS在欧洲的应用情况探讨InCaS与中国企业的适配问题.     

Decision threshold adjustment in class prediction

Standard classification algorithms are generally designed to maximize the number of correct predictions (concordance). The criterion of maximizing the concordance may not be appropriate in certain applications. In practice, some applications may emphasize high sensitivity (e.g., clinical diagnostic tests) and others may emphasize high specificity (e.g., epidemiology screening studies). This paper considers effects of the decision threshold on sensitivity, specificity, and concordance for four classification methods: logistic regression, classification tree, Fisher's linear discriminant analysis, and a weighted k-nearest neighbor. We investigated the use of decision threshold adjustment to improve performance of either sensitivity or specificity of a classifier under specific conditions. We conducted a Monte Carlo simulation showing that as the decision threshold increases, the sensitivity decreases and the specificity increases; but, the concordance values in an interval around the maximum concordance are similar. For specified sensitivity and specificity levels, an optimal decision threshold might be determined in an interval around the maximum concordance that meets the specified requirement. Three example data sets were analyzed for illustrations.     

城市轨道交通运营规模与经济发展的耦合协调性分析

城市轨道交通运营规模与经济协调发展是城市轨道交通健康发展的基础.为研究城市轨道交通运营规模与经济发展的耦合协调性,采用了物理学的耦合模型对2007-2019年城市轨道交通和经济发展数据进行了实证分析,对城市轨道交通运营规模和经济发展的综合水平、耦合度、耦合协调度进行了测算.研究表明:城市轨道交通运营规模和经济发展综合水平持续上升,城市轨道交通运营规模滞后于经济发展水平;城市轨道交通运营规模与经济发展两者具有较高的耦合度;城市轨道交通运营规模—经济发展耦合协调度是逐年提高的,2016年以后城市轨道交通运营规模和经济发展进入一个较好互动影响阶段.     

Fe (II)-activated persulfate oxidation effectively degrades iodoform in water: Influential factors and kinetics analysis

Iodoform (CHI₃) is one of the disinfection by-products (DBPs) that is formed in the pre-oxidation and disinfection processes of drinking water treatment. In this study, Fe(II)-activated persulfate oxidation (Fe²⁺/PS) was employed to degrade iodoform, the effects of initial reactants concentration, reaction parameters, kinetics model were investigated, and the underlying mechanisms of CHI₃ degradation in Fe²⁺/PS oxidation process was unveiled. The results showed that the mole ratio Fe²⁺/PS of 1:5, initial PS concentration of 15 μmmol/L, and pH of 3.0 were identified as the optimum operating parameters. In addition, a relatively higher temperature could enhance CHI₃ removal and deiodination. The kinetic model has two different reaction steps: a fast one during the first ten minutes of reaction; then followed by a much slower one. Suppression of the reaction by TBA and MeOH showed that the combined effects of SO₄⁻· and ·OH contributed to the degradation of CHI₃, but ·OH played a dominant role. The degradation pathways and the products of total liberated iodine species demonstrate that the applicability of the Fe²⁺/PS oxidation process for CHI₃ degradation. These results indicated that the Fe²⁺/PS oxidation process is an effective advanced oxidation process for CHI₃ removal in water treatment.     

Infrared negative luminescent devices and higher operating temperature detectors

Infrared LEDs and negative luminescent devices, where less light is emitted than in equilibrium, have been attracting an increasing amount of interest recently. They have a variety of applications, including as a ‘source’ of IR radiation for gas sensing; radiation shielding for, and non-uniformity correction of, high sensitivity staring infrared detectors; and dynamic infrared scene projection. Similarly, infrared (IR) detectors are used in arrays for thermal imaging and, discretely, in applications such as gas sensing. Multi-layer heterostructure epitaxy enables the growth of both types of device using designs in which the electronic processes can be precisely controlled and techniques such as carrier exclusion and extraction can be implemented. This enables detectors to be made which offer good performance at higher than normal operating temperatures, and efficient negative luminescent devices to be made which simulate a range of effective temperatures whilst operating uncooled. In both cases, however, additional performance benefits can be achieved by integrating optical concentrators around the diodes to reduce the volume of semiconductor material, and so minimise the thermally activated generation-recombination processes which compete with radiative mechanisms. The integrated concentrators are in the form of Winston cones, which can be formed using an iterative dry etch process involving methane/hydrogen and oxygen. We present results on negative luminescence in the mid- and long-IR wavebands, from devices made from indium antimonide and mercury cadmium telluride, where the aim is sizes greater than 1 cm×1 cm. We also discuss progress on, and the potential for, operating temperature and/or sensitivity improvement of detectors, where very high-performance imaging is anticipated from systems which require no mechanical cooling.     

关于物理实验考核的一点思考

本文针对我校大学物理实验考核的现状，指出现行考核方法的不足，提出进行操作考核的想法和实施办法。     

LAD estimation for nonlinear regression models with randomly censored data

The least absolute deviations (LAD) estimation for nonlinear regression models with randomly censored data is studied and the asymptotic properties of LAD estimators such as consistency, boundedness in probability and asymptotic normality are established. Simulation results show that for the problems with censored data, LAD estimation performs much more robustly than the least squares estimation.     

Randomly Orthogonal (g,f)-factorizations in Graphs

Let G be a graph with vertex set V(G) and edge set E(G) and let g and f be two integer-valued functions defined on V(G) such that 2k − 2 ≤ f(x) for all x ∈ V(G). Let H be a subgraph of G with mk edges. In this paper it is proved that every (mg + m − 1,mf − m + 1)-graph G has (g,f)-factorizations randomly k-orthogonal to H and shown that the result is best possible.     

我国交通运输企业经营效率测度与提升

为测度交通运输业经营效率,并挖掘出有针对性的效率提升措施,采用Super-SBM模型考察了交通运输行业上市公司经营效率.实证结果表明,2009-2013年我国交通运输企业的经营效率呈下降趋势.我国交通运输企业经营效率值差异较大,按经营效率和经营效率增长率分为低效率负增长、低效率高增长、高效率负增长和高效率高增长组.人工成本是影响交通运输企业经营效率的重要原因,因此,交通运输企业须组织变革,降低人工成本,提高经营效率.交通运输业行业对固定资产投入的收益需要一定的周期,因此可以建立全国统一的交通运输系统,提高资本利用率等方式来提高交通运输业整体经营效率.     

Synthesis,Molecular Docking Studies,and Anticonvulsant Evaluation of Novel bis‐Phenylhydrazones against Chemically induced Seizures in Mice

A series of novel bis‐phenylhydrazones were synthesized by the condensation of dialdehydes with phenylhydrazine to evaluate them for their anticonvulsant activity. Efficacy of newly synthesized compounds against pentylenetetrazole (PTZ )‐induced, strychnine‐induced, and picrotoxin‐induced convulsions was tested after administration of these compounds to albino mice via the oral route. All the five tested compounds showed anticonvulsant activity against strychnine‐induced and picrotoxin‐induced convulsions in a dose‐dependent manner. However, the effect was more significant against PTZ ‐induced convulsions. Behavioral pattern studies on mice suggested that these compounds are less neurotoxic compared to phenytoin. Molecular docking studies were carried out to correlate the experimental and theoretical results. It was concluded that these compounds exerted their anticonvulsant effect through the modification of the function of GABA receptor‐mediated chloride channels. Molecular docking studies revealed a good correlation, which indicated that in silico studies could provide an alternate tool for the identification and design of more potent anticonvulsant agents.