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Statistical methodology for spatio‐temporal point processes is in its infancy. We consider second‐order analysis based on pair correlation functions and K‐functions for general inhomogeneous spatio‐temporal point processes and for inhomogeneous spatio‐temporal Cox processes. Assuming spatio‐temporal separability of the intensity function, we clarify different meanings of second‐order spatio‐temporal separability. One is second‐order spatio‐temporal independence and relates to log‐Gaussian Cox processes with an additive covariance structure of the underlying spatio‐temporal Gaussian process. Another concerns shot‐noise Cox processes with a separable spatio‐temporal covariance density. We propose diagnostic procedures for checking hypotheses of second‐order spatio‐temporal separability, which we apply on simulated and real data.  相似文献   

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This article focuses on the material and discursive constructions of nature and children in the city. While dominant representations and idealizations of nature and childhood depend on the binary logic of the nature/culture and rural/urban divide, there is also a simplification and romanticization of nature in children's geographies and a lack of children and their spaces in urban political ecology. We argue that children and nature in cities need to be removed from a binary model of being and attended to in more nuanced ways in urban political ecology and children's geographies. In this regard, we suggest that both nature and children in cities need to be queered. We need to ask how the production of urban spaces (re)creates particular romantic and idealized relations with natures that reify the binaries between nature/culture, and male/female through a heteronormative framework. The purpose of this article is to bring the critical nature–society theories of urban political ecology into conversation with work in children's geographies that explores the ‘nature' of childhood, and in doing so queer the relationship between children and nature. Drawing on research on queer ecologies, and queered childhoods, we aim to provide a framework to rethink and queer both nature and children in cities.  相似文献   

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A test statistic is considered for testing a hypothesis for the mean vector for multivariate data, when the dimension of the vector, p, may exceed the number of vectors, n, and the underlying distribution need not necessarily be normal. With n,p→∞, and under mild assumptions, but without assuming any relationship between n and p, the statistic is shown to asymptotically follow a chi‐square distribution. A by product of the paper is the approximate distribution of a quadratic form, based on the reformulation of the well‐known Box's approximation, under high‐dimensional set up. Using a classical limit theorem, the approximation is further extended to an asymptotic normal limit under the same high dimensional set up. The simulation results, generated under different parameter settings, are used to show the accuracy of the approximation for moderate n and large p.  相似文献   

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近年来,越来越多上市公司在推出的同一期股权激励计划中同时包含两种以上股权激励模式.以2006-2020 年实施股权激励模式组合计划的沪深A股上市公司为研究对象,实证研究管理层风险偏好异质性对上市公司股权激励模式组合选择行为的影响,并探究股权结构对两者关系的调节作用.研究发现:管理层风险偏好异质性越大,公司越有可能选择股权激励模式组合,以匹配管理层异质性的风险偏好,从而实现管理层风险承担总水平最优;股权结构对管理层风险偏好异质性与股权激励模式组合选择之间关系具有显著的调节效应,国有控股和股权集中度增大能够弱化管理层风险偏好异质性对股权激励模式组合选择的正向影响;股权激励模式组合能够匹配管理层风险偏好异质性,使得管理层风险承担总水平实现最优,进而提升公司价值.  相似文献   

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This paper reports research conducted on detailed behavioural information from the UK Non‐Executive Director (NED) Awards 2006. The key findings were that outstanding Chairmen have a high level of integrity, showing high ethical standards in their own behaviour, as well as providing a lead on corporate governance matters. They promote investors' confidence and ensure high returns to investors. They spend significant time mentoring, developing and advising their colleagues, are team builders, are empathetic and very effective. They encourage contributions from fellow directors and achieve consensus yet they challenge and probe colleagues, especially the executive directors. They have an acute critical faculty and a critical thinking ability.  相似文献   

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This study examines a sample of 573 German credit institution‐year observations covering 2009–2011, a period when not all credit institutions were designated as public‐interest entities (PIEs) in Germany. The results show that a credit institution's business risk is associated with audit fees. In addition, the statistically significant findings reveal that PIE credit institutions pay approximately 27.29% higher audit fees, on average. There is also some evidence of an association between the interaction of a credit institution's business risk and PIE status and audit fees even if, on average, the business risk of credit institutions seems not to vary systematically between PIEs and non‐PIEs. Ultimately, since a dummy variable for PIE versus non‐PIE might not only, or even primarily, capture effects attributable to PIE status, the results should be interpreted with caution.  相似文献   

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In this paper, we use the local influence method to study a vector autoregressive model under Students t‐distributions. We present the maximum likelihood estimators and the information matrix. We establish the normal curvature diagnostics for the vector autoregressive model under three usual perturbation schemes for identifying possible influential observations. The effectiveness of the proposed diagnostics is examined by a simulation study, followed by our data analysis using the model to fit the weekly log returns of Chevron stock and the Standard & Poor's 500 Index as an application.  相似文献   

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One‐sample and multi‐sample tests on the concentration parameter of Fisher‐von Mises‐Langevin distributions on (hyper‐)spheres have been well studied in the literature. However, only little is known about their behaviour under local alternatives, which is due to complications inherent to the curved nature of the parameter space. The aim of the present paper therefore consists in filling that gap by having recourse to the Le Cam methodology, which has recently been adapted from the linear to the spherical setup. We obtain explicit expressions of the powers for the most efficient one‐ and multi‐sample tests. As a nice by‐product, we are also able to write down the powers (against local Fisher‐von Mises‐Langevin alternatives) of the celebrated Rayleigh test of uniformity. A Monte Carlo simulation study confirms our theoretical findings and shows the empirical powers of the above‐mentioned procedures.  相似文献   

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In the case of two independent samples, it turns out that among the procedures taken in consideration, BOSCHLOO'S technique of raising the nominal level in the standard conditional test as far as admissible performs best in terms of power against almost all alternatives. The computational burden entailed in exact sample size calculation is comparatively modest for both the uniformly most powerful unbiased randomized and the conservative non‐randomized version of the exact Fisher‐type test. Computing these values yields a pair of bounds enclosing the exact sample size required for the Boschloo test, and it seems reasonable to replace the exact value with the middle of the corresponding interval. Comparisons between these mid‐N estimates and the fully exact sample sizes lead to the conclusion that the extra computational effort required for obtaining the latter is mostly dispensable. This holds also true in the case of paired binary data (McNemar setting). In the latter, the level‐corrected score test turns out to be almost as powerful as the randomized uniformly most powerful unbiased test and should be preferred to the McNemar–Boschloo test. The mid‐N rule provides a fairly tight upper bound to the exact sample size for the score test for paired proportions.  相似文献   

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This paper takes stock of megaproject management, an emerging and hugely costly field of study, by first answering the question of how large megaprojects are by measuring them in the units of mega, giga, and tera, and concluding with how we are presently entering a new “tera era” of trillion‐dollar projects. Second, total global megaproject spending is assessed, at US$6 to US$9 trillion annually, or 8% of the total global gross domestic product (GDP), which denotes the biggest investment boom in human history. Third, four “sublimes”—political, technological, economic, and aesthetic—are identified and used to explain the increased size and frequency of megaprojects. Fourth, the “iron law of megaprojects” is laid out and documented: Over budget, over time, over and over again. Moreover, the “break–fix model” of megaproject management is introduced as an explanation of the iron law. Fifth, Albert O. Hirschman's theory of the “Hiding Hand” is revisited and critiqued as unfounded and corrupting for megaproject thinking in both the academy and policy. Sixth, it is shown how megaprojects are systematically subject to “survival of the unfittest,” which explains why the worst projects get built rather than the best. Finally, it is argued that the conventional way of managing megaprojects has reached a “tension point,” in which tradition is being challenged and reform is emerging.  相似文献   

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This paper examines the Men's Sheds movement – an Australian innovation that is now spreading internationally. This movement has significance for human resource management, both in providing a useful alternative to paid employment for older workers, and as a research site where the human resources challenges peculiar to voluntary organisations can be observed. The paper is underpinned by social exchange theory. The paper's empirical focus is on the factors that govern the level of participation of members in the Men's Sheds movement. The research employs a case study methodology, with focus groups of 34 members in two Australian men's sheds. Predictably, we found that the decision to participate is driven primarily by altruistic motives and reciprocal relationships. However, professional HRM practices remain important. Our findings lend support for the importance of leadership and human resource practices, such as training and development, occupational health and safety, and human resource planning that are used to facilitate effective participation in the sheds.  相似文献   

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Previous studies have called for the investigation of individual‐level factors that influence performance management systems. Drawing on self‐regulation theory, this study investigates subordinate's proactivity in performance planning. Self‐regulation theory suggests that individuals can actively participate in planning for the future by having standards and monitoring themselves through self‐regulatory processes. Given the integral role that subordinates play in the effectiveness of performance management systems, this study carefully examines their self‐regulation in the form of proactivity in relation to performance planning. Using matched data obtained from 225 subordinates and their respective supervisors in an organisation in Australia, results show that proactive personality or the tendency of an individual to be relatively unconstrained by situational factors is found to be positively and significantly related to proactive performance planning. In addition, results show that proactive feedback‐seeking behaviour or the active solicitation of feedback partially mediates the relationship between proactive personality and proactive performance planning.  相似文献   

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Kerry Liu 《Economic Affairs》2017,37(2):279-287
On 23 October 2015, the People's Bank of China (PBoC) completed the process of interest rate liberalisation. This study examines China's interest rate pass‐through to the lending rate of commercial banks before and after interest rate liberalisation. Based on data from Q3, 2007 to Q2, 2016, the study shows that the interest rate pass‐through from policy rate to lending rate, which was effective before October 2015, lost effectiveness thereafter. PBoC interventions, the ‘Impossible Trinity’ theory and institutional factors may contribute to this ineffectiveness of the policy rate pass‐through, which may also be related to the higher premium for risk required by banks and to the worsening of their financial condition. The study also offers policy advice in response to the declining effectiveness of China's interest rate pass‐through.  相似文献   

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Investigation of changes in the audit expectation‐performance gap in New Zealand (NZ) and the United Kingdom (UK) revealed that, between 1989 and 1999, in both countries the reasonableness gap widened as developments in auditing's external environment stimulated an increase in society's unreasonable expectations of auditors but the deficient performance gap narrowed as monitoring of auditors' performance resulted in societal perception of improved performance. Between 1999 and 2008, in the UK, widespread discussion of the environmental developments and related audit issues, along with more stringent monitoring of auditors' performance, resulted in a narrowing of the reasonableness and deficient performance gaps. In NZ, lacking these factors, these gaps widened. Additionally, changes to auditing standards resulted in some ‘reasonably expected’ responsibilities becoming actual responsibilities of auditors and, in both countries, the deficient standards gap narrowed. The research findings illuminate the means by which the audit expectation‐performance gap might be narrowed.  相似文献   

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This is the first study to analyze auditors’ market shares and concentration in Germany on the basis of audit fees, which have been subject to disclosure since 2005. Previous studies have all used surrogates to measure concentration, and were therefore unable to distinguish between non‐audit and audit fees. We have at our disposal the data from 175 audits (including three joint audits) and 40 audit firms. These data show that the Big4 obtained 87% of the total audit fees and 90% of the total fees in the period under investigation. PricewaterhouseCoopers (PwC) is the market leader, based on both the total fees and the audit fees. KPMG earns the most in the sub‐market for tax consultancy. The non‐audit fees amount to 41.9% of the total fees. Audit firms specialize in certain industries or stock market segments. Market concentration increases over time. At present, concentration seems to be higher in Switzerland, although it is lower in the United States of America (USA) and the United Kingdom (UK).  相似文献   

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The Negotiable Certificate of Deposit (NCD) is a major financial instrument in China; the value of outstanding Chinese NCDs was approximately RMB8 trillion (equivalent to USD1.2 trillion) in mid‐2017. This article reviews the most recent developments in the Chinese NCD, including its effect on interest rate pass‐through and money creation. Empirical results show that the introduction of the NCD in 2014 influenced the relationship between the policy rate and the lending rate of Chinese commercial banks, and the interest rate pass‐through from the policy rate to the lending rate of commercial banks improved subsequently. However, this process has also been accompanied by maturity mismatch, increasing leverage, and decreasing credit ratings for the assets of banks and other financial institutions. Consequently, systemic risk in the Chinese banking system has increased.  相似文献   

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During the last three decades, integer‐valued autoregressive process of order p [or INAR(p)] based on different operators have been proposed as a natural, intuitive and maybe efficient model for integer‐valued time‐series data. However, this literature is surprisingly mute on the usefulness of the standard AR(p) process, which is otherwise meant for continuous‐valued time‐series data. In this paper, we attempt to explore the usefulness of the standard AR(p) model for obtaining coherent forecasting from integer‐valued time series. First, some advantages of this standard Box–Jenkins's type AR(p) process are discussed. We then carry out our some simulation experiments, which show the adequacy of the proposed method over the available alternatives. Our simulation results indicate that even when samples are generated from INAR(p) process, Box–Jenkins's model performs as good as the INAR(p) processes especially with respect to mean forecast. Two real data sets have been employed to study the expediency of the standard AR(p) model for integer‐valued time‐series data.  相似文献   

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In spite of the abundance of clustering techniques and algorithms, clustering mixed interval (continuous) and categorical (nominal and/or ordinal) scale data remain a challenging problem. In order to identify the most effective approaches for clustering mixed‐type data, we use both theoretical and empirical analyses to present a critical review of the strengths and weaknesses of the methods identified in the literature. Guidelines on approaches to use under different scenarios are provided, along with potential directions for future research.  相似文献   

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