河北省钢铁产业技术效率评价及对策研究

以2001年—2009年面板数据为基础,运用数据包络分析（DEA）方法,对河北省等六省区钢铁产业整体效率、技术效率、规模效率、投入冗余及超效率进行评价,并运用Malmquist效率指数对河北省钢铁产业的全要素生产率变动进行动态分析。研究结果表明,河北省钢铁产业整体效率在不断提高,其中,纯技术效率的贡献要大于规模效率;在产出不变的情况下,河北省钢铁产业存在着一定程度的投入冗余;产业超效率值总体上表现出不断提升的态势;技术进步对本省钢铁产业技术效率的影响并不稳定,呈波动变化状态。河北省要想提高钢铁产业总体效率,必须加快技术进步、优化产品结构、提高产业集中度和有效减少投入冗余。     

3D打印对物流产业的影响及对策创新

3D打印的强劲发展必然对传统物流产业形成重要影响。论文梳理了3D打印的发展态势与典型特征,并在此基础上,系统性地剖析了3D打印对物流产业的12项深远影响,即全球性物流网络面临战略性收缩、物流企业竞争加剧、仓储职能弱化、第四方物流公司强劲发展、原料业务成为新宠儿、零部件物流业面临生死抉择、物流污染得到改善、物流企业与消费者直接交互增多等多个方面。最后,提出了物流业的四大创新性对策,即涉足3D打印业务、借力大数据建设智慧物流、发展控制塔业务和打造供应链战略合作联盟。     

高校微博话题的情感分析

微博是现在深受欢迎的信息交流平台,其中包括着大量的学生用户。作为对高校学生舆情监控的一个方面,通过数据挖掘的方法对微博话题进行情感分析,在高校掌控学生信息交流状况、预见话题演变趋势等工作上都能够起到很大的作用。     

Application of evidential reasoning approach and OWA operator weights in road safety evaluation considering the best and worst practice frontiers

Data envelopment analysis (DEA) has recently become relatively popular with road safety experts. Therefore, various decision-making units (DMUs), such as EU countries, have been assessed in terms of road safety performance (RSP). However, the DEA has been criticized because it evaluates DMUs based only on the concept of self-assessment, and, therefore does not provide a unique ranking for DMUs. Therefore, cross efficiency method (CEM) was developed to overcome this shortcoming. Peer-evaluations in addition to self-evaluation have made the CEM to be recognized as an effective method for ranking DMUs. The traditional CEM is based only on the standard CCR (Charnes, Cooper and Rhodes) model, and it evaluates DMUs according to their position relative to the best practice frontier while neglecting the worst practice frontier. However, the DMUs can also be assessed based on their position relative to the worst practice frontier. In this regard, the present study aims to provide a double-frontier CEM for assessing RSP by taking into account the best and worst frontiers simultaneously. For this purpose, the cross efficiency and cross anti-efficiency matrices are generated.Even though a weighted average method (WAM) is most frequently used for cross efficiency aggregation, the decision maker's (DM) preference structure may not be reflected. For this reason, the present study mainly focuses on the evidential reasoning approach (ERA), as a nonlinear aggregation method, rather than the linear WAM. Equal weights are often used for cross efficiency aggregation; consequently, the effect of the DM's subjective judgments in obtaining the overall efficiency is ignored. In this respect, the minimax entropy approach (MEA) and the maximum disparity approach (MMDA) are applied for determining the ordered weighted averaging (OWA) operator weights for cross efficiency aggregation. The weighted cross efficiencies and cross anti-efficiencies are then aggregated using the ERA. Finally, the proposed method, called DF-CEM-ERA, is used to evaluate the RSP of EU countries as well as Serbian police departments (PDs).     

Correlated daily time series and forecasting in the M4 competition

We participated in the M4 competition for time series forecasting and here describe our methods for forecasting daily time series. We used an ensemble of five statistical forecasting methods and a method that we refer to as the correlator. Our retrospective analysis using the ground truth values published by the M4 organisers after the competition demonstrates that the correlator was responsible for most of our gains over the naïve constant forecasting method. We identify data leakage as one reason for its success, due partly to test data selected from different time intervals, and partly to quality issues with the original time series. We suggest that future forecasting competitions should provide actual dates for the time series so that some of these leakages could be avoided by participants.     

几乎理想需求系统面板数据模型的非参数估计分析

本文探讨几乎理想需求系统的估计问题,充分考虑到各类商品价格数据的局限性和模型中各类商品消费份额的联立内生性,逐步建立一个可以得到估计的几乎理想需求系统非参数面板数据模型;给出其非参数局部线性估计方法,并将非参数估计方法应用于珠三角地区城镇居民消费支出结构的估计和分析,由此对消费支出进行弹性分析。     

军民融合背景下我国上市军工企业结构评价研究

采用“DEA方法”评价我国上市军工企业结构优化度,通过我国各军工产业结构优化效率之间的对比,探究我国军工产业结构现有的问题,进而提出新时期、新常态下,我国军工产业结构升级的对策。最后,就军民融合背景下我国军工企业转型升级问题提出实践性指导。     

中国地区工业绿色全要素生产率增长:——基于方向性距离函数的经验分析

结合方向性距离函数和跨期数据包络分析法,测度绿色全要素生产率增长时尽可能地避免了出现技术倒退结论。中国省份工业的经验分析表明:忽略非期望产出的全要素生产率增长被高估,并混淆了技术进步和技术效率变化的相对贡献;技术无效率普遍存在且省际差异和年际波动性大,但这与经济发展水平无关;绿色全要素生产率变化也存在省际差异和年际波动特点,其中技术进步是其增长的主要源泉,而技术效率恶化是其倒退的根本原因;绿色全要素生产率增长存在明显的倒U型趋势和趋同性,而且外资利用印证了"污染天堂"假说。     

Big Five Audits and Accounting Fraud*

We examine the association between Big Five audits and the incidence of accounting frauds allegedly committed by U.S. public companies between 1981 and 2001. Many commentators argue that the prominent financial reporting failures that led to major corporate governance reforms cast serious doubt on whether the large public accounting firms continue to supply relatively high‐quality audits, especially in recent years. However, in unmatched and matched samples, we provide strong, robust evidence that fraudulent financial reporting becomes less likely with the presence of a Big Five auditor. Importantly, time‐series tests suggest that the Big Five are consistently associated with a lower incidence of fraudulent accounting, including in the last five years of our sample period when the number of frauds soared. Moreover, we find evidence implying that these relations are causal rather than an artifact of endogeneity in auditor choice.     

高速数字传输中的帧同步提取分析

本文讨论具有帧结构的高速数字流的帧同步提取技术。从帧同步器方案的最佳参数设计出发,以误码性能为主要目标,本文较系统地提出了一套有关帧同步过程的基本概念和分析方法,并导出在各种情况下的统计关系及重要结论。本文还以美国陆地卫星TM数据流为例,特别阐述了复帧结构情况下的帧同步提取及其最佳参数设计。