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71.
本文通过解读准噶尔汗国灭亡后卫拉特蒙古佚名氏史家撰写的几篇托忒文史籍,探讨当时卫拉特人对汗国灭亡的反思及对清准战争的历史记忆.几位史家的文本反映了"四卫拉特"这一历史框架的稳定性,以及卫拉特人在政治认同方面的一些变化.  相似文献   
72.
A heteroscedastic regression based on the odd log-logistic Marshall–Olkin normal (OLLMON) distribution is defined by extending previous models. Some structural properties of this distribution are presented. The estimation of the parameters is addressed by maximum likelihood. For different parameter settings, sample sizes and some scenarios, various simulations investigate the performance of the heteroscedastic OLLMON regression. We use residual analysis to detect influential observations and to check the model assumptions. The new regression explains the mass loss of different wood species in civil construction in Brazil.  相似文献   
73.
In the production planning and control of discrete-parts manufacture, aggregation of parts into families, on the basis of similarity, is carried out to ease both long-horizon planning and short-horizon scheduling. Additional advantages are related to those of group technology (GT), such as simplifying the flow of parts and tools and reducing both set-up and production costs. The problem of formally forming part families is presented and discussed. Previous work is reviewed and assessed. Two solution approaches, one based on a location model, the other on simulated annealing, are presented and compared along with test results. The location formulation, which results in an integer programming model solved by Lagrangian relaxation, proved capable of producing solutions of excellent quality, but only for relatively small problem instances. In contrast, simulated annealing, which is a general heuristic approach to combinatorial optimization, produced solutions of comparable quality and could handle realistically large problem instances. However, careful design of the simulated annealing algorithm is crucially important. An effective design is presented.  相似文献   
74.
In this article, we first propose the modified Hannan–Rissanen Method for estimating the parameters of autoregressive moving average (ARMA) process with symmetric stable noise and symmetric stable generalized autoregressive conditional heteroskedastic (GARCH) noise. Next, we propose the modified empirical characteristic function method for the estimation of GARCH parameters with symmetric stable noise. Further, we show the efficiency, accuracy and simplicity of our methods with Monte-Carlo simulation. Finally, we apply our proposed methods to model the financial data.  相似文献   
75.
Human Resources managers are distressingly aware that more than half the middle and senior managers (40- and 50-year-olds) in their organizations are technologically incompetent. Having spent millions on technology, most corporate CEOs, many of whom can't use a computer either, are drawing a bead on middle managers who are passively resisting the computer revolution. Physician executives are no exception. Given the current shortage of physician managers with good track records and people skills, can middle managers skirt technology issues until retirement if they dance slowly enough? It's doubtful. Organizations are using new tactics to bar technically challenged managers from their ranks: They will only interview candidates with mastery of specific software and they're posting job opportunities on their web sites. Those who still believe they can ride out the computer revolution may want to rethink that strategy.  相似文献   
76.
It is commonly assumed that contractors are largely calculative, instrumental and self-interested in their relationship with organizations and interface with them accordingly (e.g. low corporate interest and emotional investment). This paper describes a survey involving 117 contractors (62 on 'permanent' agency contracts and 55 on 'temporary' agency contracts) and a comparable (age, job level/grade, years of work experience) group of 86 direct employees (on fixed-term contracts). The survey comprised measures of the psychological contract, of organizational identification, social (corporate) attraction, team spirit and intention to leave. The findings show that contractors are not inevitably 'emotionally' detached from their place of work, in some cases investing in it as much as direct company employees. While transactional (e.g. financial gain, instrumentality) exchange considerations were more salient among contractors than employees, this did not appear to preclude the development of a relational (e.g. corporate integration and long-term investment) contractual orientation. 'Team spirit' and 'organizational identification' predicted the development of relational contracts over and above contractual status. The findings and their management implications are discussed in terms of 'strategic partnership'.  相似文献   
77.
Examining the relationship between the competitive processes between and within organizations, we use selection system theory to link resource value to product value. We identify three dimensions (in‐selection, before‐selection and after‐selection) that facilitate determining the value of resources based on the functions they serve in the competitive process between organizations in the product market, i.e. the external selection system. Subsequently, we use these dimensions to explore the competitive process among resource providers within organizations, i.e. the internal selection system. This leads us to formulate three propositions that link the competitive process within organizations to the competitive process between organizations. First, we posit that if resources that individually score highly along only one of the three dimensions are bundled, it is more likely that organizational performance can be sustained. Second, we argue that providers of resources scoring highly along multiple dimensions will enjoy stronger means of appropriation in comparison with providers of resources scoring highly along only one of the three dimensions. Third, we contend that the extent to which an organization endeavours to remunerate its resource providers based on their perceived contribution to the organization's competitive position has a curvilinear (inverted U‐shaped) relationship with organizational performance.  相似文献   
78.
Historically, U.S. regulators have derived cancer slope factors by using applied dose and tumor response data from a single key bioassay or by averaging the cancer slope factors of several key bioassays. Recent changes in U.S. Environmental Protection Agency (EPA) guidelines for cancer risk assessment have acknowledged the value of better use of mechanistic data and better dose–response characterization. However, agency guidelines may benefit from additional considerations presented in this paper. An exploratory study was conducted by using rat brain tumor data for acrylonitrile (AN) to investigate the use of physiologically based pharmacokinetic (PBPK) modeling along with pooling of dose–response data across routes of exposure as a means for improving carcinogen risk assessment methods. In this study, two contrasting assessments were conducted for AN-induced brain tumors in the rat on the basis of (1) the EPA's approach, the dose–response relationship was characterized by using administered dose/concentration for each of the key studies assessed individually; and (2) an analysis of the pooled data, the dose–response relationship was characterized by using PBPK-derived internal dose measures for a combined database of ten bioassays. The cancer potencies predicted for AN by the contrasting assessments are remarkably different (i.e., risk-specific doses differ by as much as two to four orders of magnitude), with the pooled data assessments yielding lower values. This result suggests that current carcinogen risk assessment practices overestimate AN cancer potency. This methodology should be equally applicable to other data-rich chemicals in identifying (1) a useful dose measure, (2) an appropriate dose–response model, (3) an acceptable point of departure, and (4) an appropriate method of extrapolation from the range of observation to the range of prediction when a chemical's mode of action remains uncertain.  相似文献   
79.
Social interaction, particularly in older adolescents, increasingly involves computer‐mediated communication. Although studies of public computer‐mediated communication are increasingly common, studies of private text messaging remain rare. As approaches for obtaining such data evolve with technological advances, developmental scientists need designs in which to use such approaches that reduce sampling biases in both participants and text messages. In this study (n = 854; 46% male; 22% African American, 60% European American), we examined selection biases in the participant sample (i.e., factors associated with actual participation), procedural biases in the participant sample (i.e., factors related to failed data capture due to technological or procedural issues), and selection biases in the sample of text messages (i.e., based on self‐reported reasons for texting). Findings from our study suggest that studying human interaction directly through analysis of text message data is not only feasible, but also may be successfully undertaken with minimal biases regarding sample selection and text message selection among those who are engaged in research and engaged in text messaging outside of the study context. However, biases may occur depending on the type of platform (iPhone vs. Android) used by participants for texting.  相似文献   
80.
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