Litteraturanmeldelse

This article examines the notion of distortion of copulas, a natural extension of distortion within the univariate framework. We study three approaches to this extension: (1) distortion of the margins alone while keeping the original copula structure; (2) distortion of the margins while simultaneously altering the copula structure; and (3) synchronized distortion of the copula and its margins. When applying distortion within the multivariate framework, it is important to preserve the properties of a copula function. For the first two approaches, this is a rather straightforward result; however, for the third approach, the proof has been exquisitely constructed in Morillas (2005). These three approaches unify the different types of multivariate distortion that have scarcely scattered in the literature. Our contribution in this paper is to further consider this unifying framework: we give numerous examples to illustrate and we examine their properties particularly with some aspects of ordering multivariate risks. The extension of multivariate distortion can be practically implemented in risk management where there is a need to perform aggregation and attribution of portfolios of correlated risks. Furthermore, ancillary to the results discussed in this article, we are able to generalize the formula developed by Genest &; Rivest (2001) for computing the distribution of the probability integral transformation of a random vector and extend it to the case within the distortion framework. For purposes of illustration, we applied the distortion concept to value excess of loss reinsurance for an insurance policy where the loss amount could vary by type of loss.     

立板补焊试件的焊接工艺

根据第三届全国职工职业技能大赛立板补焊项目的培训经验,介绍此项目的操作方法及具体工艺措施。焊后经检测,焊缝外观成形及无损探伤均满足相关标准要求。     

浅谈混凝土表面裂缝的成因、控制及修复

混凝土表面的裂缝是混凝土结构中的一种极为普遍的现象。本文着重论述了混凝土表面裂缝产生的原因,以及裂缝对混凝土的结构性能的影响,提出了混凝土表面裂缝处理的控制和修复方法,为保证建筑物施工的安全运行以及建筑物的正常使用打下良好的基础。     

On the short-time behavior of the implied volatility for jump-diffusion models with stochastic volatility

In this paper we use Malliavin calculus techniques to obtain an expression for the short-time behavior of the at-the-money implied volatility skew for a generalization of the Bates model, where the volatility does not need to be a diffusion or a Markov process, as the examples in Sect. 7 show. This expression depends on the derivative of the volatility in the sense of Malliavin calculus. E. Alòs’ research is supported by grants MEC FEDER MTM 2006 06427 and SEJ2006-13537. J.A. León’s research is partially supported by the CONACyT grant 45684-F. J. Vives’ research is supported by grant MEC FEDER MTM 2006 06427.     

Food insecurity,customer to volunteer transition and self-concept repair: a free store example

ABSTRACT

Food insecurity poses profound threats to self-concept which impacts on physical and mental health. Two Free Stores specialising in food rescue were selected for this research. Drawing on the narratives of 34 volunteers, we examined the working practices of the Free Stores and the personal experiences of the volunteers. The Free Stores adopted the operational principles of a store format, absence of means testing and customer to volunteer transition to modify the social context from whence the threats derive. Involvement with the Free Stores provides the recipients and volunteers with multiple strategies for self-concept repair to restore positive self-views. The operational principles are effective for gaining insights into the creation and transformation of the personal and social identities of the volunteers.     

水泥混凝土路面微裂缝修补材料及性能探讨

目前,在我国高质量等级的路面结构中,水泥混凝土路面是最主要的形式之一。由于自然环境以及庞大交通载荷的作用,路面出现早期的微裂缝现象也在增多,水泥混凝土路面微裂缝的防治就越来越重要。文章介绍了以普通水泥作为基质材料,用聚合物和高效减水剂作为主要改性剂形成的新型水泥路面微裂缝修补材料,并对其性能特点做了简要探讨。     

汽车维修接待学习领域的设计

汽车维修接待工作是汽车维修企业经营管理的重要组成部分。从提高维修接待人员的培养质量出发,进行汽车维修接待学习领域的设计,将该岗位人才培养的全部课程分为基本素质群、专业基本技能群、岗位能力群三大块,并具体分析这三大块课程的课程设计、教学方法和保障条件。     

Economic evaluation of BST-CarGel as an adjunct to microfracture vs microfracture alone in knee cartilage surgery

Objectives:

Knee cartilage damage is a common cause of referral for orthopedic surgery. Treatment aims to reduce pain and symptoms by repairing cartilage. Microfracture, the current standard of care, yields good short-term clinical outcomes; however, treatment might fail after 2–3 years. A Chitosan-Beta glycerolphosphate-based medical device (BST-CarGel) is used as an adjunct to microfracture and demonstrates improvements in quantity and quality of repaired tissue, potentially reducing the risk of treatment failure. This study aimed to establish the economic value of BST-CarGel vs microfracture alone in knee cartilage repair from the societal perspective, using Germany as the reference market.

Methods:

A decision tree with a 20-year time-horizon was constructed, in which undesirable clinical events were inferred following initial surgery. These events consisted of pain management, surgery, and total knee replacement. Clinical outcomes were taken from the pivotal clinical trial, supplemented by other literature. Data and assumptions were validated by a Delphi panel. All relevant resource use and costs for procedures and events were considered.

Results:

In a group of patients with all lesion sizes, the model inferred that BST-CarGel yields a positive return on investment at year 4 (with 20-year cumulative cost savings of €6448). Reducing the incremental risk of treatment failure gap between the device and microfracture by 25–50% does not alter this conclusion. Cost savings are greatest for patients with large lesions; results for patients with small lesions are more modest.

Limitations:

Clinical evidence for microfracture and other interventions varies in quality. Comparative long-term data are lacking. The comparison is limited to microfracture and looks only at costs without considering quality-of-life.

Conclusion:

BST-CarGel potentially represents a cost-saving alternative for patients with knee cartilage injury by reducing the risk of clinical events through regeneration of chondral tissue with hyaline characteristics. Since the burden of this condition is high, both to the patient and society, an effective and economically viable alternative is of importance.     

组织内部人际信任关系的破裂与修复

从信任内容、信任性质与信任角色三个方面出发,指出人际信任关系研究的三条路径。从信任者、被信任者、环境因素三个角度梳理出人际信任关系破裂的原因。最后,我们依据信任关系破裂存在的萌芽、僵持、对峙、和解四个阶段,阐述了组织内部人际关系修复的途径与相应策略。     

《高等应用数学》定积分的教学探索

数学教学改革多年都流于形式,传统性强,权威性高,是问题所在。本人将传统16课时定积分教学,打破传统模式,改造成6课时教学,收到了很好的效果,现在拿出来与读者共享。