Showing 241 - 250 of 954
Multidimensional scaling is a statistical technique to visualize dissimilarity data. In multidimensional scaling, objects are represented as points in a usually two dimensional space, such that the distances between the points match the observed dissimilarities as closely as possible. Here, we...
Persistent link: https://www.econbiz.de/10004991099
We propose a novel statistic to test the rank of a matrix. The rank statistic overcomes deficiencies of existing rank statistics, like: necessity of a Kronecker covariance matrix for the canonical correlation rank statistic of Anderson (1951), sensitivity to the ordering of the variables for the...
Persistent link: https://www.econbiz.de/10004991100
We present the Lagrange multiplier rule, one of the basic optimization methods, in a new way. Novel features include: • Explanation of the true source of the power of the rule: reversal of tasks, but not the use of multipliers. • A natural proof based on a simple picture, but not the...
Persistent link: https://www.econbiz.de/10004991102
In this paper we discuss several methods to solve large real-world instances of the vehicle and crew scheduling problem. Although, there has been an increased attention to integrated approaches for solving such problems in the literature, currently only small or medium-sized instances can be...
Persistent link: https://www.econbiz.de/10004991103
The induced path function $J(u, v)$ of a graph consists of the set of all vertices lying on the induced paths between vertices $u$ and $v$. This function is a special instance of a transit function. The function $J$ satisfies betweenness if $w \in J(u, v)$ implies $u \notin J(w, v)$ and $x \in...
Persistent link: https://www.econbiz.de/10004991105
In this article we propose and implement an instrumental variable estimation procedure to obtain treatment effects on duration outcomes. The method can handle the typical complications that arise with duration data of time-varying treatment and censoring. The treatment effect we define is in...
Persistent link: https://www.econbiz.de/10004991106
In this paper we proposed an efficient algorithm to solve the joint replenishment problem to optimality. We perform a computational study to compare the performance of the proposed algorithm with the best one reported in Viswanathan [6]. The study reveals that for large minor set-up costs and...
Persistent link: https://www.econbiz.de/10004991107
Many authors have written about Mass Customization and its features and categories. Literature on the implementation of Mass Customization, and in particular the supporting information technology, is scant. This paper attempts to fill this gap by focusing on this subject. We determine the key...
Persistent link: https://www.econbiz.de/10004991109
We consider tests for sudden changes in the unconditional volatility of conditionally heteroskedastic time series based on cumulative sums of squares. When applied to the original series these tests suffer from severe size distortions, where the correct null hypothesis of no volatility change is...
Persistent link: https://www.econbiz.de/10004991110
This paper presents two different models and algorithms for integrated vehicle and crew scheduling in the multiple-depot case. The algorithms are both based on a combination of column generation and Lagrangian relaxation. Furthermore, we compare those integrated approaches with each other and...
Persistent link: https://www.econbiz.de/10004991111