Multidimensional Sequence Alignment Methods for Activity‐Travel Pattern Analysis: A Comparison of Dynamic Programming and Genetic Algorithms

Quantitative comparisons of space‐time activity‐travel patterns have been made at length in regional science. Traditionally, Euclidean Hamming distances have been widely used to measure the similarity between activity‐travel patterns that involve several attribute dimensions such as activity type, location, travel mode, accompanying person, etc. Other techniques, such as pattern recognition in signal processing theory, have also been introduced for this purpose. All these measures, however, lack the ability to capture the sequential information embedded in activity‐travel patterns. Recently, the sequence alignment methods (SAMs), developed in molecular biology that are concerned with the distances between DNA strings, have been introduced in time use research. These SAMs do capture the similarity of activity‐travel patterns, including sequential information, but based on a single attribute only. Unfortunately, the extension of the unidimensional SAMs to a multidimensional method induces the problem of combinatorial explosion. To solve this problem, this paper introduces effective heuristic methods for the comparison of multidimensional activity‐travel patterns. First, following a brief review of existing measures of activity‐travel pattern comparison, the problem of multidimensional sequential information comparison and the combinatorial nature of the method are discussed. The paper then develops alternative multidimensional SAMs employing heuristics based on dynamic programming and genetic algorithms, respectively. These heuristic SAMs are compared using empirical activity‐travel pattern data. The paper ends by discussing avenues of future research.     

Counting the Costs of the Nuclear Age

Stephen L. Schwartz, Atomic audit: the costs and consequences of US nuclear weapons since 1940     

The Role of Personal Factors in the Location Decision of Software Services Start-up Firms

This paper explores the factors which influence the business location decisions of start-ups, focusing in particular on the role of personal factors. Established explanations of industry location emphasize proximity to firms in the same or related industries and proximity to a wider set of business services, though recent research suggests that personal factors may play an important role in explanations of industry location—particularly in technology-enabled sectors. A survey of 97 new firms, founded between 2008 and 2012, in the Irish software services sector, shows that the business location decision is influenced by the personal motivation of entrepreneurs to attain a desired quality of life, and that this outweighs economic factors such as proximity to firms within the same or related industries, proximity to a broader set of supporting business services, infrastructure or the availability of government support schemes. Personal factors are particularly important to firms located outside the Dublin metropolitan area and to home-based businesses. This has important policy implications for national and regional governments seeking to encourage entrepreneurship in technology-enabled service sectors.     

The Peace of God,the ‘weakness’ of Robert the Pious and the struggle for the German throne, 1023–5

The author of The Deeds of the Bishops of Cambrai accused Bishops Berold of Soissons and Warin of Beauvais of overstepping the boundaries of episcopal authority and usurping royal rights by promoting the Peace of God and attributed their initiative to the weakness of King Robert the Pious. This paper argues that the author was misrepresenting the situation to hide the vulnerability of the bishop of Cambrai during the succession of Conrad II. Instead, Berold and Warin's peace council was patronized by Robert the Pious and was a symptom of French royal assertiveness in the period 1023–5. The reasons for the Cambrai author's distortions are to be found in the significance of kings in the rallying of support on a local and regional level.