快速城市化的滨江城区内涝治理研究——以广州市中心城区为例

以广州中心城区为例,分析了快速城市化过程中滨江城市演进与城区内涝的关系和形成机理。研究结果表明,1988年至2005年期间,滨江城区的扩展造成植被等透水面的大量减少,河涌、人工湖及内河水系出现淤积、堵塞并污染严重。江面束窄致使珠江水位异常壅高,而低平地势难以在短时间内排掉极端降雨过程形成的高峰流量,导致城区水涝的频繁发生。提出增加沿江低地势区域的滞水空间和疏通河涌等河网水系等内涝治理措施。     

存货质押贷款中银行对借款人的甄别—分离均衡

抵押贷款仅考虑借款人信用风险,存货质押贷款还应考虑质物价格风险。当银行时借款人事前违约概率具有不对称信息时,在DannyBen—shahar抵押贷款模型基础上,综合考虑借款人信用风险和质物价格风险,证明存在高风险借款人选择（高利率、高贷款价值比）合同,低风险借款人选择（低利率、低贷款价值比合同）的唯一分离均衡。     

Effective ways to grow urban bus markets – a synthesis of evidence

This paper provides a synthesis of the evidence on the patronage growth performance of bus improvement measures in urban settings. The evidence includes a summary of experience in Europe, North America and Australasia focusing on service improvement measures including network structure and service levels, bus priority measures, vehicles and stop infrastructure, fares and ticketing systems, passenger information and marketing, personal safety and security and synergy effects of measures. The source is the research literature and documented experienced from a series of studies undertaken by the authors over the last decade. It includes the results of an international bus expert ‘Delphi’ survey concerning bus improvement measures focussed on patronage growth. The paper synthesises the evidence to identify measures which are most likely to grow patronage including consideration of cost-effectiveness of measures.     

Who gets the job? First-generation college students' perceptions of employer screening methods

What are first-generation college students' (FGCS) perspectives of employment screening methods? The authors investigate which methods FGCS believe are likely to cause an employer to extend a job offer and which methods yield the best pool of job applicants. Survey data were collected from undergraduate business majors. They were analyzed using means comparisons and bivariate correlation t tests. FGCS perceived resumes and interviews as most likely to help applicants get hired. Implications are discussed.     

Optimal model averaging forecasting in high-dimensional survival analysis

This article considers ultrahigh-dimensional forecasting problems with survival response variables. We propose a two-step model averaging procedure for improving the forecasting accuracy of the true conditional mean of a survival response variable. The first step is to construct a class of candidate models, each with low-dimensional covariates. For this, a feature screening procedure is developed to separate the active and inactive predictors through a marginal Buckley–James index, and to group covariates with a similar index size together to form regression models with survival response variables. The proposed screening method can select active predictors under covariate-dependent censoring, and enjoys sure screening consistency under mild regularity conditions. The second step is to find the optimal model weights for averaging by adapting a delete-one cross-validation criterion, without the standard constraint that the weights sum to one. The theoretical results show that the delete-one cross-validation criterion achieves the lowest possible forecasting loss asymptotically. Numerical studies demonstrate the superior performance of the proposed variable screening and model averaging procedures over existing methods.     

论加强地勘单位人才队伍建设

随着地勘业务的不断拓展,笔者深深感到人才已是制约地勘单位发展的重要瓶颈,必须创新机制,大力实施"人才兴院"战略,最大限度发挥人才作用,才能保持单位地勘经济的快速发展。     

A synthesis of homelessness in South Africa: A rapid critical appraisal

Homelessness in South Africa requires collaborative research. Social, political, cultural and economic factors that cause homelessness must be considered to develop a common definition and understanding of homelessness. South Africa’s social complexity and diversity make it challenging to construct available results into one conceptual framework, and this in turn complicates national policy implementation and role allocation. By means of a rapid critical appraisal of literature on homelessness in South Africa, researchers provide evidence to direct and structure contextual research pertaining to homelessness. Four themes transpire: conceptualisation; demography; roles and responsibilities of key stakeholders; and strategic policy and research issues. Researchers caution that the findings are not generalisable, because of the rapid nature of the appraisal and possible selection bias of the literature. Measures of validity were used to ensure that the study accomplished its purpose through the key results and to ensure that the results are a true reflection of available evidence.     

Projecting total costs and health consequences of increasing mt-sDNA utilization for colorectal cancer screening from the payer and integrated delivery network perspectives

Abstract

Aims: To evaluate total costs and health consequences of a colorectal cancer (CRC) screening program with colonoscopy, fecal immunochemical tests (FIT), and expanded use of multitarget stool DNA (mt-sDNA) from the perspectives of Integrated Delivery Networks (IDNs) and payers in the United States.

Materials and methods: We developed a budget impact and cost-consequence model that simulates CRC screening for eligible 50- to 75-year-old adults. A status quo scenario and an increased mt-sDNA scenario were modeled. The status quo includes the current screening mix of colonoscopy (83%), FIT (11%), and mt-sDNA (6%) modalities. The increased mt-sDNA scenario increases mt-sDNA utilization to 28% over 10 years. Costs for both the IDN and the payer perspectives incorporated diagnostic and surveillance colonoscopies, adverse events (AEs), and CRC treatment. The IDN perspective included screening program costs, composed of direct nonmedical (e.g. patient navigation) and indirect (e.g. administration) costs. It was assumed that IDNs do not incur the costs for stool-based screening tests or bowel preparation for colonoscopies.

Results: In a population of one million covered lives, the 10-year incremental cost savings incurred by increasing mt-sDNA utilization was $16.2 M for the IDN and $3.3 M for the payer. The incremental savings per-person-per-month were $0.14 and $0.03 for the IDN and payer, respectively. For both perspectives, increased diagnostic colonoscopy costs were offset by reductions in screening colonoscopies, surveillance colonoscopies, and AEs. Extending screening eligibility to 45- to 75-year-olds slightly decreased the overall cost savings.

Limitations: The natural history of CRC was not simulated; however, many of the utilized parameters were extracted from highly vetted natural history models or published literature. Direct nonmedical and indirect costs for CRC screening programs are applied on a per-person-per modality basis, whereas in reality some of these costs may be fixed.

Conclusions: Increased mt-sDNA utilization leads to fewer colonoscopies, less AEs, and lower overall costs for both IDNs and payers, reducing overall screening program costs and increasing the number of cancers detected while maintaining screening adherence rates over 10 years.     

Ethnic discrimination in hiring,labour market tightness and the business cycle - evidence from field experiments

Several studies using observational data suggest that ethnic discrimination increases in downturns of the economy. We investigate whether ethnic discrimination depends on labour market tightness using data from correspondence studies. We utilize three correspondence studies of the Swedish labour market and two different measures of labour market tightness. These two measures produce qualitatively similar results, and, opposite to the observational studies, suggest that ethnic discrimination in hiring decreases in downturns of the economy.