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961.
在全面分析钻井机械的组成、钻进过程的特点和人的特性的基础上,建立钻机钻进过程人机系统可靠性模型。整个系统由人的行为、钻进参数采集、井喷预兆监测、钻进参数调节和井喷控制5个子系统,通过人机接口构成。根据人的感知、判断决策、执行操作行为进程.引入行为形成因子和差错纠正能力,构成人的行为模式,导出人的行为可靠度,进而得出钻机钻进过程人机系统的可靠度。  相似文献   
962.
In this article we define a multi-factor equity–interest rate hybrid model with non-zero correlation between the stock and interest rate. The equity part is modeled by the Heston model and we use a Gaussian multi-factor short-rate process. By construction, the model fits in the framework of affine diffusion processes, allowing fast calibration to plain vanilla options. We also provide an efficient Monte Carlo simulation scheme.  相似文献   
963.
Under a no-arbitrage assumption, the futures price converges to the spot price at the maturity of the futures contract, where the basis equals zero. Assuming that the basis process follows a modified Brownian bridge process with a zero basis at maturity, we derive the closed-form solutions of futures and futures options with the basis risk under the stochastic interest rate. We make a comparison of the Black model under a stochastic interest rate and our model in an empirical test using the daily data of S&P 500 futures call options. The overall mean errors in terms of index points and percentage are ?4.771 and ?27.83%, respectively, for the Black model and 0.757 and 1.30%, respectively, for our model. This evidence supports the occurrence of basis risk in S&P 500 futures call options.  相似文献   
964.
What is the relationship between niche and performance? We identify two types of niche positions—product niche and process niche—defined by the extent to which a firm offers distinctive products and has distinctive operational processes, respectively. We argue that the effect of each niche on firm performance is contingent upon network embeddedness—the extent to which a firm is involved in a network of interconnected inter‐firm relationships. Using data covering the period 1995–98 pertaining to venture capital firms and their holdings in initial public offerings (IPOs), we show that both product niche and process niche interact with network embeddedness to determine firm performance. Our findings suggest that the extent to which a firm offers distinctive products or processes will be more positively associated with firm performance when network embeddedness is high. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
965.
为了维持长期的竞争优势,企业需要不断进行技术创新和产品创新。如何在有限的研发资源下使创新项目组合的绩效最大化是企业进行创新管理中面临的主要问题。本文从创新项目组合的战略一致性、平均项目绩效和业务协同3个指标来度量创新项目组合管理绩效,并从流程和管理者的视角研究其关键影响因素。通过实证研究发现,高管参与和项目组合管理流程的设计与实施对项目组合的战略一致性有显著的正向影响;高管参与、项目经理胜任力和项目终止质量对平均项目绩效有显著正向影响;项目经理胜任力、项目组合管理流程的设计与实施和项目中止质量对业务协同有显著正向影响。  相似文献   
966.
In this paper, we will consider exponential additive processes as a financial market model. Under a mild condition, we will determine the minimal entropy martingale measures (MEMMs) for the exponential additive processes. To this end, we will prepare several results on the exponential moment of additive processes and integrals based on them. As an application of our result, we will deduce optimal strategy for exponential utility maximization problem. We will also investigate our result through several examples, such as time-dependent versions of double Poisson model, Merton model and Kou model.  相似文献   
967.
This paper considers the stochastic volatility process with contemporaneous and correlated jumps in returns and volatility, which was proposed by Eraker, B., Johannes, M. and Poison, N. G. (Journal of Finance 53, 2003, 1269--1300) and proposes the Lagrange multiplier test for the presence of jumps in volatility. The test statistic is derived by regarding the degenerate density of volatility jumps with zero variance under the null as Dirac's delta function. The correlation parameter between jumps, which is a nuisance parameter unidentified under the null, is cancelled out in this test statistic and hence the test is free from the Davies problem (Davies, R. B., Biometrika 64, 1977, 247–254).  相似文献   
968.
We present a dual-process risk perception model that integrates cognitive and emotional as well as consequentialist and deontological components by distinguishing between two modes of evaluative processing: (a) a consequentialist evaluation that focuses on potential consequences and (b) a deontological evaluation that focuses on moral values. Each of these two modes is assumed to trigger specific cognitive evaluations, specific emotions, and specific behavioral tendencies concerning a perceived risk. We conducted an experiment (N = 270) that tested whether the relative dominance of the two evaluative modes would depend on the causal structure of the environmental risk being evaluated and on the social role of the evaluator. Three types of causal structure were varied by providing scenario information: (a) anthropogenic risks that endanger only nature, (b) naturally caused risks with potential harmful consequences for humans, and (c) anthropogenic risks that may harm humans. Participants evaluated each scenario from the perspective of one of three social roles: mayor, expecting parent, and environmental activist. For each scenario, participants specified their focus and evaluated the event’s morality and perceived risk, the intensity of specific emotions, and their preferences for prospective behaviors. Results showed that the consequentialist evaluation was generally stronger than the deontological evaluation and was less affected by the experimental manipulations. The deontological evaluation was substantially affected by the risk’s causal structure. It was stronger for anthropogenic than for natural causation; risks caused by humans were associated with greater perceived moral blameworthiness, more intense morality-based emotions (e.g. outrage), and a stronger tendency to perform agent-related behaviors (e.g. aggression) than naturally occurring risks. The effect of the social role was less pronounced than that of the causal structure. Furthermore, the effect of an evaluative focus on behavior was fully mediated by emotions for deontological evaluations and partially mediated for consequentialist evaluations. The implications for environmental risk perception and communication are discussed.  相似文献   
969.
This paper reports the findings of a longitudinal comparative case study of three National Health Service (NHS) hospital Trusts in England, investigating the perceptions of clinical, managerial and accounting professionals towards changing cost accounting and performance measurement practices. It incorporates both qualitative and quantitative data analysis, and is based on a contextualist understanding of change management, utilising the content‐process‐context approach (Pettigrew and Lapsley, 1994) to investigate the influence of receptive versus non‐receptive contexts on change. The analysis reveals limited success in improving performance measurement practices (the content of change) in Trusts. Nevertheless the specific context within which change was operationalised was found to be very important, with central mangers playing a key role in influencing change. The process of change indicated slow shifts in clinical‐accountant‐managerial relations, partly driven by changes in financial flows within the organisations.  相似文献   
970.
信贷经营作为商业银行的核心业务之一,其流程的科学性、合理性将直接关系到工商银行对优质信贷市场变化的响应效率和综合竞争能力.本文运用分工理论和机制理论等相关理论,总结国内外优秀商业银行信贷流程的先进做法,在深入调研的基础上,剖析工商银行现有信贷流程的弊端,明确信贷流程改造的目标,着重从授权机制、组织架构以及岗位职能设置等角度,提出工商银行信贷流程改造的对策建议,旨在进一步优化信贷流程,防范风险,提高效率,促进全行信贷业务全面、协调、稳健发展.  相似文献   
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