基于Ф-OTDR的管道光纤预警系统应用统计分析

基于 Ф-OTDR分布式光纤传感的管道光纤预警系统,利用同沟敷设的光缆作为分布式振动传感器,连续实时检测管道周围的振动信号进行提前预警与定位,通过长输油气管道测试与应用效果展示,系统具有较高的预警灵敏度、定位精度和有效预警准确率.结合应用实际,构建"技防+人防"管道安全防护体系.     

Rational IPO Waves

We argue that the number of firms going public changes over time in response to time variation in market conditions. We develop a model of optimal initial public offering (IPO) timing in which IPO waves are caused by declines in expected market return, increases in expected aggregate profitability, or increases in prior uncertainty about the average future profitability of IPOs. We test and find support for the model's empirical predictions. For example, we find that IPO waves tend to be preceded by high market returns and followed by low market returns.     

Exports,Supply Constraints and Growth: An Investigation using Regional Data

In this work we first model the role of demand‐ and supply‐side factors (labour market adjustment, productive efficiency) in explaining economic growth. Empirically testing the model, we evaluate why different growth regimes may appear in the 20 Italian administrative regions. This exercise uses a two‐stage econometric approach. Estimates for the elasticity of manufacturing output to exports are obtained from regional time series: a significant long‐run relationship indicates the existence of a demand‐constrained growth regime. We then ascertain whether the regional dispersion of supply‐side factors has an impact on the regional dispersion of growth regimes. The empirical evidence supports our expectations of strong regional differences. Southern regions are less likely to display demand‐constrained regimes. In explanation of these differences, second‐stage analysis reveals that a strong role is played by such efficiency‐enhancing factors as technological innovation, bank diffusion and ‘social capital’. No role is found for labour market rigidities.     

我国海洋资源开发综合效益的评价探讨

从海洋资源开发形成的产业产值效益角度，选取海米岸线产值、人均产值、占GDP比重等3个相对指标，采用均方差权重法对我国沿海备省、市区海洋资源开发的综合效益做出评价；依据沿海各省、市区海洋资源开发的综合效益评价值及排序结果，把该区划分为3种类型：。低等综合效益开发区，中等综合效益开发区，高等综合效益开发区；得出海洋资源开发的综合效益不仅与资源条件有关，还与各地的经济发展水平、人口数量及其协调程度有关等结论。     

陇海—兰新—北疆铁路沿线城市紧凑度及其影响因素研究

根据紧凑城市的核心内涵,从空间紧凑、结构良好、效率较高三个维度构建了城市紧凑度测度指标体系,运用主成分分析计算了2009年陇海—兰新—北疆铁路沿线40个城市紧凑度的综合得分,并将其划分为紧凑、较紧凑、一般紧凑和不紧凑四种类型。除个别城市外,从总体上来看,沿线城市紧凑度水平按照特大城市、大城市、中等城市、小城市的顺序呈现依次降低的变化规律。通过多元线性逐步回归分析了城市紧凑度的主要影响因素,结果表明目前影响沿线城市紧凑度的主要因素首先是经济增长弹性,其次是人口密度、基础设施建设和城市形态紧凑度等;对于不同规模的城市,城市紧凑度的主要影响因素亦有差异。     

陇海—兰新—北疆铁路沿线城市建设用地时空差异分析

运用极差、标准差、变异系数、基尼系数、综合扩展系数、泰尔指数等分析了陇海—兰新—北疆沿线城市建设用地时空差异,以期在新一轮土地利用规划中为不同城市建设用地供给方向的确定奠定科学基础。结果表明:①在时间上,1991—2009年陇海—兰新—北疆沿线城市建设用地绝对和相对差异均呈扩大趋势;除仓储用地外,其它类型建设用地相对差异呈上下波动或小幅下降趋势;建设用地综合扩展极化现象明显,且整体上城市综合扩展系数陇海沿线城市大于兰新—北疆沿线城市。②在空间上,2009年陇海—兰新—北疆沿线50%以上城市人均建设用地超出国家Ⅳ级标准上限,尤其是中等城市和小城市;各类城市建设用地区域分布的差异度不同;城市建设用地扩张与其经济效益之间并无直接的关联关系。     

Local Crowding-Out in China

In China, between 2006 and 2013, local public debt crowded out the investment of private firms by tightening their funding constraints while leaving state-owned firms' investment unaffected. We establish this result using a purpose-built data set for Chinese local public debt. Private firms invest less in cities with more public debt, with the reduction in investment larger for firms located farther from banks in other cities or more dependent on external funding. Moreover, in cities where public debt is high, private firms' investment is more sensitive to internal cash flow.     

Brokers and Order Flow Leakage: Evidence from Fire Sales

Using trade‐level data, we study whether brokers play a role in spreading order flow information in the stock market. We focus on large portfolio liquidations that result in temporary price drops, and identify the brokers who intermediate these trades. These brokers’ clients are more likely to predate on the liquidating funds than to provide liquidity. Predation leads to profits of about 25 basis points over 10 days and increases the liquidation costs of the distressed fund by 40%. This evidence suggests a role of information leakage in exacerbating fire sales.     

基于投入产出的辽宁省第三产业内部结构关联分析

基于辽宁省2007年投入产出表,结合DPS数据处理系统归纳和计算出2007年辽宁省第三产业16个产业的直接消耗系数、感应度系数和影响力系数,分析辽宁省第三产业的内部结构特征与关联。结果表明,辽宁省第三产业仍是以传统型服务业为主,而且各产业的专业化程度存在较大差异,旅游业和科学研究事业等产业发展缓慢等,基于此提出相应的对策建议。