文化软实力绘就武陵山区美丽乡村新图景 ——以石柱县金铃乡银杏村为实践标杆

位于武陵山区石柱土家族自治县的金铃乡银杏村，是集少数民族、革命地区、集中连片的特困地区。一方面该村以自然山水风光为资源禀赋，以培育民族文化精神高地为乡村振兴“铸魂”、“赋能”；以“非遗文化+扶贫”的路子，激活了乡村的内生动力；文化扶贫直抵人心取得了“点石成金”的效果，让土家人充分享受到文化释放的红利。另一方面，该村作为“民族团结进步示范村”，以做深做实民族团结工作为抓手，充分让民族政策惠及土家万户，生动地实现了民族团结之花在土家大地上常开常盛。一个个串联成珠的实践案例，为武陵山打赢脱贫攻坚战更好地接续乡村振兴发挥了活标杆的示范引领作用，向世人展示一幅色彩斑斓的美丽乡村新图景。     

自驾偏好、居民异质与居住选址——基于单中心城市模型的空间均衡分析

基于线性单中心城市模型，研究了自驾偏好和居民拥有车辆异质性对双方式交通走廊沿线居民出行方式选择和居住区位选址均衡的影响.将有车居民对自驾出行的偏好集成到直接效用函数中，建立了空间均衡模型.分析发现，当城市居民全部自驾出行时，租金-距离可能呈现先提高后降低的趋势.考虑只有部分居民拥有自驾车辆的一般情形，推导出了有车和无车居民在城市走廊沿线居住分布的不同均衡模式.通过理论解析，进一步考察了小汽车保有量和城市居民数量的变化对城市空间结构和居民效用水平的影响.     

Estimation of the additive hazards model with interval-censored data and missing covariates

The additive hazards model is one of the most commonly used regression models in the analysis of failure time data and many methods have been developed for its inference in various situations. However, no established estimation procedure exists when there are covariates with missing values and the observed responses are interval-censored; both types of complications arise in various settings including demographic, epidemiological, financial, medical and sociological studies. To address this deficiency, we propose several inverse probability weight-based and reweighting-based estimation procedures for the situation where covariate values are missing at random. The resulting estimators of regression model parameters are shown to be consistent and asymptotically normal. The numerical results that we report from a simulation study suggest that the proposed methods work well in practical situations. An application to a childhood cancer survival study is provided. The Canadian Journal of Statistics 48: 499–517; 2020 © 2020 Statistical Society of Canada     

信心、货币政策与中国经济波动关系的统计检验

文章基于时变视角,依据行为经济学理论,构建了一个包含企业家信心、投资者信心、利率、货币增长率、经济增长率和通货膨胀率六变量的TVP-VAR模型,研究信心、货币政策与经济波动之间的时变特征。结果表明:企业家信心和投资者信心能够影响利率和货币增长率,即信心可以通过影响货币政策进而作用于宏观经济。货币增长率和利率能够影响投资者信心和企业家信心,进而可以通过信心影响宏观经济。从时变角度看,企业家信心一单位的正向冲击在整个样本区间内均会促进经济的增长;在短期内投资者信心和货币增长率对经济增长具有促进作用,但是在长期内货币增长率的提高会阻碍经济的增长。     

Negotiating Accessibility for Electronic Resources

Abstract

Accessibility of library electronic resources is a must. Its importance derives from professional ethics of librarianship, rising total costs of acquisition, and mounting legal challenges to colleges and universities that fail to provide resources accessible to users with disabilities. Library staff are responsible for ensuring the accessibility of vendor-licensed eresources. This column reviews the accessibility clauses of nine model license agreements for electronic resources. It describes terms that should go into an optimal accessibility clause and creates a composite model clause. It also provides guidance for library staff seeking to negotiate stronger accessibility language into vendor license agreements. Finally, it addresses the impact of accommodation requests on the total cost of acquiring library eresources, concluding with a call to redouble efforts to advocate for greater accessibility and educate both vendors and library staff about its importance.     

Probabilistic Analysis of Dam Accidents Worldwide: Risk Assessment for Dams of Different Purposes in OECD and Non-OECD Countries with Focus on Time Trend Analysis

This study presents probabilistic analysis of dam accidents worldwide in the period 1911–2016. The accidents are classified by the dam purpose and by the country cluster, where they occurred, distinguishing between the countries of the Organization for Economic Cooperation and Development (OECD) and nonmember countries (non-OECD without China). A Bayesian hierarchical approach is used to model distributions of frequency and severity for accidents. This approach treats accident data as a multilevel system with subsets sharing specific characteristics. To model accident probabilities for a particular dam characteristic, this approach samples data from the entire data set, borrowing the strength across data set and enabling to model distributions even for subsets with scarce data. The modelled frequencies and severities are combined in frequency-consequence curves, showing that accidents for all dam purposes are more frequent in non-OECD (without China) and their maximum consequences are larger than in OECD countries. Multipurpose dams also have higher frequencies and maximum consequences than single-purpose dams. In addition, the developed methodology explicitly models time dependence to identify trends in accident frequencies over the analyzed period. Downward trends are found for almost all dam purposes confirming that technological development and implementation of safety measures are likely to have a positive impact on dam safety. The results of the analysis provide insights for dam risk management and decision-making processes by identifying key risk factors related to country groups and dam purposes as well as changes over time.     

How does BREXIT affect production patterns of multinational enterprises?

This paper explores how the British exit from the European Union (EU) potentially affects the United Kingdom (UK) economy and the production patterns of multinational enterprises that choose the UK as either a destination market or a gateway to the EU market. Utilizing an extended version of the knowledge-capital model, which includes six types of firms and four countries grouped into market and non-market, simulation analysis reveals that efforts to enhance attractiveness of the UK as a destination market to increase horizontal-type inward foreign direct investment would be a solution to cover losses from reduction in the number of export-platforms.     

Does the twin deficit hypothesis hold in the OECD countries under different real interest rate regimes?

This paper explores the validity of the twin deficit hypothesis in selected 25 OECD countries with annual data for 2005–2016 by considering different real interest rate regimes. A non-dynamic panel threshold model, introduced by Hansen (1999), is employed. The novelty of the empirical findings from the present study is that there exists a non-linear relationship between the budget deficit and the trade balance, which is driven by a critical threshold level in the real interest rates. The findings suggest that twin deficit hypothesis holds only under the low real interest rate regime, that is, rises in budget deficits lead to deteriorations in the trade balance when the real interest rate is below the threshold level. When the high real interest rate (i.e. above-the-threshold) regime is concerned, increasing budget deficits give rise to improvements in the trade balance, a finding consistent with the twin divergence hypothesis. Thus, the effect on the trade balance of an expansionary fiscal policy that worsens the budget balance reverses substantially depending on the threshold level of the real interest rates. The major policy implication of this paper is that the policy makers in the selected OECD countries should pay a greater attention to fiscal discipline in order to prevent the trade balance from worsening, because the majority of the countries fall into the low real interest rate regime over the recent years of the sample period (i.e. between 2010 and 2016).     

Water cycle algorithm for solving the reliability-redundancy allocation problem with a choice of redundancy strategies

Abstract

This paper proposes a new mathematical model for the reliability-redundancy allocation problem (RRAP) with a choice of redundancy strategies. To maximize the reliability of a system, this model chooses the best redundancy strategy from among both active and standby ones for each subsystem. For those with a standby strategy, a continuous time Markov chain model is used to calculate the exact reliability values. In order to solve the proposed mixed-integer non-linear programing model, a powerful evolutionary algorithm, called water cycle algorithm (WCA), is developed and implemented on three famous benchmark problems. Finally, the results of different benchmark problems are compared with those previously reported to show the superiority of the proposed model and the efficiency of WCA.