This paper describes a comprehensive simulation modeling approach to the problem of locating warehousing facilities in a fashion that minimizes the cost associated with operating a multi-product, multi-source, multi-destination distribution system. The digital simulation model presented in the study is derived within an “industrial dynamics” framework, utilizes input from an existing management information system, and employs a number of relatively simple heuristic procedures to analyze various alternative warehousing networks. Simulation results, in terms of the distribution costs associated with various warehouse locations, are presented for cases involving the effect of provision of a 100% service level, the effect of constraining product availability and/or inventory capacities at various warehouses, and the effect of deleting various warehouses from the existing warehouse network. 相似文献
AbstractBalakrishnan et al. proposed a two-piece skew logistic distribution by making use of the cumulative distribution function (CDF) of half distributions as the building block, to give rise to an asymmetric family of two-piece distributions, through the inclusion of a single shape parameter. This paper proposes the construction of asymmetric families of two-piece distributions by making use of quantile functions of symmetric distributions as building blocks. This proposition will enable the derivation of a general formula for the L-moments of two-piece distributions. Examples will be presented, where the logistic, normal, Student’s t(2) and hyperbolic secant distributions are considered. 相似文献
Researchers consistently report links between psychological control and adolescent behavior problems, but the processes linking psychological control with behavior problems are unclear. Adolescents’ negative emotional reactions and psychological reactance were tested as potential longitudinal mediators linking parental psychological control with both internalizing and externalizing behavior problems. Data were collected from a sample of 242 adolescents (M age = 15.4 at Time 1; 50.8% female; 50% white, non‐Hispanic, 18% African American, 16% Hispanic, and 16% of other or multiple ethnicities) at three time points over a 2‐year period. Adolescents self‐reported depressive symptoms, antisocial behavior, negative emotional reactions, and psychological reactance. Adolescents and their parents provided ratings of parental psychological control. Cross‐sectional models replicated patterns previously reported suggesting that negative emotional reactions and reactance mediate between psychological control and internalizing and externalizing behavior problems. However, in cross‐lagged panel models, neither negative emotional reactions nor reactance emerged as a mediator between psychological control and internalizing or externalizing problems. In contrast, results suggested that psychological control is an outcome of rather than contributor to, negative emotional reactions. Moreover, the addition of random intercepts to cross‐lagged models indicated that associations between psychological control, emotional and behavioral reactions, and internalizing/externalizing behavior may represent stable trait‐like patterns. 相似文献
Academics, politicians, and citizens around the world are calling for multidimensional measures of national well‐being to be included in public policy‐making. Under the motto “The Future of Well‐Being,” the 6th OECD World Forum recently pushed forward this debate in Incheon, Korea. Comparing multidimensional well‐being measures across countries, Korea ranks well in income and health, but shows deficiencies in social support, perceived freedom over life choices, air quality, and work‐life balance. Multidimensional measures of well‐being are increasingly being adopted by policy‐makers around the world to improve people's lives. 相似文献
Particle Markov Chain Monte Carlo methods are used to carry out inference in nonlinear and non-Gaussian state space models, where the posterior density of the states is approximated using particles. Current approaches usually perform Bayesian inference using either a particle marginal Metropolis–Hastings (PMMH) algorithm or a particle Gibbs (PG) sampler. This paper shows how the two ways of generating variables mentioned above can be combined in a flexible manner to give sampling schemes that converge to a desired target distribution. The advantage of our approach is that the sampling scheme can be tailored to obtain good results for different applications. For example, when some parameters and the states are highly correlated, such parameters can be generated using PMMH, while all other parameters are generated using PG because it is easier to obtain good proposals for the parameters within the PG framework. We derive some convergence properties of our sampling scheme and also investigate its performance empirically by applying it to univariate and multivariate stochastic volatility models and comparing it to other PMCMC methods proposed in the literature. 相似文献
The Pacific Small Island Developing States are often considered on the frontline of climate change due to high levels of exposure to climate-related hazards and limited adaptive capacity to respond. In this context, Pacific Islanders may be displaced, or choose to migrate to escape risk and find more secure livelihoods. On the other hand, Pacific political and community leaders stress that mobility can be a threat to sovereignty and culture and should only be considered as a last resort. This paper adopts a cultural ecology framing to gain a greater understanding of these contested local discourses on climate change and human mobility in Kiribati, Tuvalu and Nauru through the use of the Q method. The results reveal a range of shared subjective understandings of climate change and human mobility which show that reasons for, and perceived outcomes of moving are inextricably linked. These subjective understandings highlight that culture, and in particular how Islanders relate to land and religion can influence decision-making, promoting or hindering mobility. The findings therefore support the need for further engagement with communities to recognise and validate their positions on climate change and human mobility to facilitate the planning and implementation of effective policy.
This paper contributes to the literature by assessing expectation effects from monetary policy for G7 economies. We rely on expectation data from Consensus Economics and a panel vector autoregression framework, which accounts for international spillovers and time‐variation. We analyze whether monetary policy has changed the degree of information rigidity after the emergence of the subprime crisis and estimate effects of interest rate changes on expectations, disagreements, and forecast errors. We find strong evidence for information rigidities and identify higher forecast errors by professionals after monetary policy shocks. Our results suggest that the international transmission of monetary policy shocks introduces noisy information and partly increases disagreement among forecasters. (JEL E31, E52) 相似文献
ABSTRACT The development of a ‘mobility as a service’ model for accessing urban transport via autonomous vehicles may be expected to have far-reaching implications for the economics of road transport. In particular, it would offer a new opportunity to price access to the roads in accordance with the principles of the free market. Once people are paying for mobility on the roads on a ‘per trip’ basis, it will be possible to offer different levels of access – and service – at different prices. According to hegemonic ideas in the transport planning and economics literature the introduction of such a ‘market in mobility’ would be an economically efficient way of allocating access to the scarce good of space on the roads. In this paper we draw attention to a number of ethical and political challenges to the appropriateness of the use of such a pricing mechanism in the context of urban mobility. 相似文献