Factors affecting agricultural land transfer-in in China: a semiparametric analysis

We use interview survey data collected randomly from 2677 farm households in nine provinces of China to understand the role of demographic, economic, land, and village characteristics on agricultural land transfer-in by farmers. Results show that variables such as borrowing from informal sources, household labour availability, percentage of total income from agricultural sources, and the household with village cadre have significant positive effects on land transfer-in. Low economic development and low transportation network availability in a county reduces land transfer-in. We also find that two variables (land holding and land idling) should be entered into the model nonparametrically. Land holding and land idling have U- and L-shaped impacts on land transfer-in, respectively. Land transfer-in has endowment equilibrium and provides Chinese households more opportunities to earn agricultural income, thereby reducing rural poverty.     

Discovering bank risk factors from financial statements based on a new semi‐supervised text mining algorithm

This paper aims to comprehensively uncover bank risk factors from qualitative textual risk disclosures reported in financial statements, which contain a huge amount of information on bank risks. We propose a new semi‐supervised text mining approach named naive collision algorithm to analyse the textual risk disclosures, which can more accurately identify bank risk factors compared with the typical unsupervised text mining approach. We identified 21 bank risk factors in total, which is far more than identified in previous studies. We further analyse the importance of each bank risk factor and how the importance of each risk factor changes over time.     

智慧BIM乔木模型：从设计图纸到施工 现场

现有的BIM应用软件提供的乔木模型多为RPC或高 精度3D模型等3D CAD类型。这些模型着重于表达美感或进 行展示，无法反映根系情况。虽然可能包含一定附加属性，但 表达乔木生长和空间需求的功能有限。因而，冲突检查、工序 调度等BIM的优势功能无从应用。风景园林实践领域已就此问 题开始构建自己的模型库，但能够准确反映现状树木真实尺寸 体量，以及现状树木和规划树木未来空间需求的模型仍未广泛 出现。提出一种基于树冠、树干和根系构型与生长功能的实体/ 网面封装建模方法构建BIM乔木模型。模型形态通过一组参数 调整，并根据树龄和反映环境限制因子的值来反映其变化。所 包含的数据和参数数量随后期设计阶段所需的LoD(详细层级) 及专业实践的具体要求而增加。该模型可以与提供本地区内外 苗木商品信息的植物数据库连接使用。     

Designing and evaluating sustainable development pathways for semi‐subsistence crop–livestock systems: lessons from Kenya

Achieving the Sustainable Development Goals (SDGs) in African agriculture requires a better understanding why high levels of poverty and resource degradation persist in African agriculture despite decades of policy interventions and development projects. In this article, we hypothesize that policies need to account for the key features of the semi‐subsistence crop–livestock systems (CLS) in the region to become effective. The semi‐subsistence CLS are characterized by a high degree of biophysical and economic heterogeneity and a complex, diversified production system involving a combination of subsistence and cash crops with livestock. We investigated the potential for interventions proposed by the Government of Kenya to meet the SDGs by 2030. The analysis uses an integrated modeling approach designed to deal with the key features of these systems. A strategy that stimulates rural development, increases farm size to a sustainable level, and reduces distortions and inefficiencies in input and output markets could lead to a sustainable development pathway and achieve the SDGs for rural households dependent on CLS.     

REGULATION STRATEGIES FOR THE PROVISION OF PATERNALISTIC GOODS

In this study, we analyze the regulation of markets for the provision of services whose costs are subsidized for paternalistic reasons. We model the choice of a benevolent regulator who wants to maximize consumer welfare in a setting where quality cannot be verified and the good provided is fully subsidized. The choice is thus made between two types of providers (profit maximizers and altruistic providers) and two frameworks (monopoly franchise and quality competition). Our analysis shows that in this environment the performance of mixed markets is always dominated by pure forms. Moreover, although making efficient providers compete for the market minimizes cost, the choice of quality competition with altruistic providers may be preferable from a welfare point of view whenever service quality is relevant and the productivity differential is not substantial.     

Methods for Scalar‐on‐Function Regression

Recent years have seen an explosion of activity in the field of functional data analysis (FDA), in which curves, spectra, images and so on are considered as basic functional data units. A central problem in FDA is how to fit regression models with scalar responses and functional data points as predictors. We review some of the main approaches to this problem, categorising the basic model types as linear, non‐linear and non‐parametric. We discuss publicly available software packages and illustrate some of the procedures by application to a functional magnetic resonance imaging data set.     

An adaptive approach to forecasting three key macroeconomic variables for transitional China

The macroeconomic forecasts for emerging economies often suffer from the constraints of instability and limited data. In light of these constraints, we propose the use of a local autoregressive (LAR) model with a data-driven estimation window, i.e., a local homogenous interval, that is adaptively identified to strike a balance between information efficiency and stability. When applied to three key macroeconomic variables of China, the LAR model substantially outperforms the alternative models for various forecast horizons of 3 to 12 months, with forecast error reductions of between 4% and 64% for the IP growth, and between 1% and 68% for the inflation rate. The one-quarter ahead performance of the LAR model matches that of a well-known survey forecast. The patterns of the identified local intervals also coincide with the characteristic evolution of the gradual reforms and monetary policy shifts in China. In short, the LAR model is suitable for not only forecasting, but also the real-time monitoring of the effects of regime and policy changes in emerging economies.     

Extreme Value Theory and Statistics of Univariate Extremes: A Review

Statistical issues arising in modelling univariate extremes of a random sample have been successfully used in the most diverse fields, such as biometrics, finance, insurance and risk theory. Statistics of univariate extremes (SUE), the subject to be dealt with in this review paper, has recently faced a huge development, partially because rare events can have catastrophic consequences for human activities, through their impact on the natural and constructed environments. In the last decades, there has been a shift from the area of parametric SUE, based on probabilistic asymptotic results in extreme value theory, towards semi‐parametric approaches. After a brief reference to Gumbel's block methodology and more recent improvements in the parametric framework, we present an overview of the developments on the estimation of parameters of extreme events and on the testing of extreme value conditions under a semi‐parametric framework. We further discuss a few challenging topics in the area of SUE. © 2014 The Authors. International Statistical Review © 2014 International Statistical Institute     

乡村用地规划碳源参数化评估模型

针对目前碳源评估研究主要集中在国家、省、城市层面,而乡村层面的研究十分有限,且大多数现有评估方法难以适用于乡村这种开放的、大尺度的系统等问题,构建了一套面向乡村用地规划的碳源参数化评估模型。该模型包括碳源评估清单的构建、碳排放因子的估算、基于调整系数的碳源评估公式的提出、参数化评估系统的搭建这4个关键环节,对此提出了一系列详细的技术方法。最后,通过一个多情景比较的实际规划案例说明了该模型的应用方法,体现其科学性和高效性,该模型可为低碳乡村规划提供一个实用的定量化工具。     

复杂非限定约束曲面造型

文章介绍了两种曲面建构方法,并阐述了使用ISDX构造自由曲面模型的特点、方法和注意事项,指出了构造自由曲面模型和参数化曲面模型的最大区别是对曲率表的使用方式。