Search results for "Contiguity"
showing 6 items of 6 documents
Determinants and efficiency of Pakistan's chemical products' exports: An application of stochastic frontier gravity model.
2019
The estimation of efficiency of industry-specific exports is very important to find exports' gap and to frame exports promotion policy for targeted industry. This study attempts to investigate the main determinants of chemical products' exports of Pakistan with 62 trading partners by applying Stochastic Frontier Analysis (SFA) on an augmented gravity model for a period 1995-2015. The results corroborate that chemical products' exports follow gravity patterns. This study finds a negative and significant impact of import tariff on exports of chemical products while the positive impact of devaluation has been observed. Further, the estimations also take into account the impact of Preferential …
Solutions for districting problems with chance-constrained balancing requirements
2021
Abstract In this paper, a districting problem with stochastic demands is investigated. The goal is to divide a geographic area into p contiguous districts such that, with some given probability, the districts are balanced with respect to some given lower and upper thresholds. The problem is cast as a p -median problem with contiguity constraints that is further enhanced with chance-constrained balancing requirements. The total assignment cost of the territorial units to the representatives of the corresponding districts is used as a surrogate compactness measure to be optimized. Due to the tantalizing purpose of deriving a deterministic equivalent for the problem, a two-phase heuristic is d…
Thermal buckling optimization of composite laminates by evolution strategies
2000
Abstract Thermal buckling optimization of laminated composite plates subject to a temperature rise is presented in this paper. Aerospace structures require such components that are able to withstand the external environment loads without loss of stability. The discrete optimal design problem, formulated under strain and ply contiguity constraints is solved using evolution strategies, a guided random-search method. Two different constraint handling methods are investigated and compared: the disregarding infeasible solutions and the classical penalty function approach. The results are also compared with an exact enumerative study conducted on the problem, showing the effectiveness and perform…
Candidate localness and voter choice in the 2015 General Election in England
2017
Previous research has demonstrated a significant relationship between the geographical distance from a voter to a candidate and the likelihood of the voter choosing that candidate. However, models of this relationship may be mis- or under-specified, by not taking into account voters’ perceptions of distance or not controlling for other possible factors related to a candidate’s ‘localness’ which may influence vote choice. Using a two-wave panel survey carried out during the 2015 UK General Election, this article tests a more fully specified alternative-specific multinomial probit model of candidate-voter distance. We show that, although the effect size is smaller than in previous tests, cand…
On rural development of NUTS 2 and 3: a non parametric approach of distribution dynamics analysis
2008
This work presents a study about dynamics of territorial gaps in agriculture between EU NUTS 2 and 3 from three perspectives: agricultural production model, rural development and productivity. Our choice of methodology is driven by two considerations. First of all, different performances in agriculture of EU areas may lead to multimodal distributions of indicators, and this implies that no significant average behaviour a parametric estimates refers to can be identified. Secondly, even if one wants to highlight multimodality within distributions, techniques like univariate density estimates can not catch intra-distribution dynamics which lead to the formation of "poles" of units showing a "s…
An Examination of Tourist Arrivals Dynamics Using Short-Term Time Series Data: A Space—Time Cluster Approach
2013
The purpose of this study is to examine the development of Italian tourist areas ( circoscrizioni turistiche) through a cluster analysis of short time series. The technique is an adaptation of the functional data analysis approach developed by Abraham et al (2003), which combines spline interpolation with k-means clustering. The findings indicate the presence of two patterns (increasing and stable) averagely characterizing groups of territories. Moreover, tests of spatial contiguity suggest the presence of ‘space–time clusters’; that is, areas in the same ‘time cluster’ are also spatially contiguous. These findings appear to be more robust in particular for those series characterized by an…