Optimal search for a moving target with the option to wait

We investigate the problem in which an agent has to find an object that moves between two locations according to a discrete Markov process (Pollock, Operat Res 18 (1970) 883–903). At every period, the agent has three options: searching left, searching right, and waiting. We assume that waiting is costless whereas searching is costly. Moreover, when the agent searches the location that contains the object, he finds it with probability 1 (i.e. there is no overlooking). Waiting can be useful because it could induce a more favorable probability distribution over the two locations next period. We find an essentially unique (nearly) optimal strategy, and prove that it is characterized by two thresholds (as conjectured by Weber, J Appl Probab 23 (1986) 708–717). We show, moreover, that it can never be optimal to search the location with the lower probability of containing the object. The latter result is far from obvious and is in clear contrast with the example in Ross (1983) for the model without waiting. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

The Ethnic Russian as an Enemy of Islam: Frame Analysis of the Kavkaz Center News Agency (2001–2004)

Abstract

Typically, when analysing contemporary Russian–Chechen conflicts, the relegation of the nationalist struggle to a secondary role by the religious battle waged by the North Caucasus insurgency is pinpointed as one of the fundamental differences between the First and Second War in Chechnya. This article discusses how it was reflected in one of the most important media of the Chechen Islamist insurgency: the Kavkaz Center. To this end, 2859 English language news items posted on the website during 2001–04 were reviewed using media frame analysis.     

Between vigilantism and ethnocultural preservation: An investigation into the legitimacy of the non-state policing activities of the Ombatse group among the Eggon people of Nassarawa State,Nigeria

Postmodern contradictions in postcolonial Nigeria have led to the fetishisation of alternative local security measures often labelled as vigilante activities. The profiling of these groups as ethnic militia often undermines their essential bid to provide security while delimiting security needs to the physical. The fallouts of such profiling are frictions between federal security agents and ethnic-based security groups, often resulting in violence, as exemplified by the 7 May 2013 incident between the Nigerian federal security agents and the Ombatse. This study focuses on the emergence and activities of the Ombatse as an alternative security apparatus of the Eggon. It presents three years of field research which entailed the use of ethnography, key informant interviews and observation. The findings reveal that the Ombatse emerged to assert historical legitimacy for both the physical and spiritual securitisation of the Eggon through a return to the ancestral ways of social engineering. The study considers the security challenges in Nigeria, and also situates the Eggon historical context within political, religious, sociocultural and economic intersections of securitisation. It concludes that the Ombatse situates its legitimacy within the Eggon past and retains its relevance through the holistic focus of providing both physical and spiritual security.     

A note on necessary and sufficient conditions for ordering properties of coherent systems with exchangeable components

We give necessary and sufficient conditions based on signatures to obtain distribution‐free stochastic ordering properties for coherent systems with exchangeable components. Specifically, we consider the stochastic, the hazard (failure) rate, the reversed hazard rate, and the likelihood ratio orders. We apply these results to obtain stochastic ordering properties for all the coherent systems with five or less exchangeable components. Our results extend some preceding results. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

To free or not to free (ride): a comparative analysis of the NATO burden-sharing in the Czech Republic and Lithuania

ABSTRACT

The recent rise in the defence budgets among the NATO members reawakens the free-riding dilemma. This article provides an analysis of the defence spending of two new member states, the Czech Republic and Lithuania. Based on the free-riding theory, we explain why some of the new NATO members decide to increase their defence budgets (Lithuania), and others do not (Czech Republic). In contrast to the majority of works which focus either on the US as the biggest spender or on the “old” members of the Alliance, we explain under what circumstances some of the small European states who became new NATO members started to increase their defence budgets even though they do not have to, and the literature suggests that free-riding is easier. In the process, we identify three crucial factors that in?uence the decision-making process in this regard: the level of threat perception, economic situation, and the US pressure.     

The Bullet in the Brick: The Materiality of Conflict in Museum Objects

Tangible traces of conflict in visual artefacts can take viewers uncomfortably close to the realities of war—violence, destruction and fatalities. This article questions the evidential force of objects associated with conflict and their eventual display in exhibitions. Through a study of the display of a brick in which is embedded a bullet that is said to have passed through the body of Francis Sheehy Skeffington when he was executed by firing squad during the Easter Rising in Dublin in 1916, this article explores the historical configuration of the brick and analyses its public display in the National Museum of Ireland (NMI). By examining the actions carried out by the NMI in collecting and archiving the object and analysing the narrative strategies of its display, this article considers how the visual aspects of exhibition displays can perpetuate a particular version of historic events and accredits objects with assumed authenticity.     

Evaluating the Spillover Effects of the Colombian Conflict in Ecuador

The Colombian civil war lasted for nearly six decades with approximately 10 percent of its population being displaced over the same period. The implications of this conflict have transgressed international boundaries. Countries such as Ecuador experienced an exodus of victims as well as an increase in the presence of armed groups, along with the proliferation of illegal businesses. Even though the internal social and economic consequences of the Colombian conflict have been documented in the literature, there is yet to be a study addressing these issues from the perspective of impacted neighboring countries. In this work, we contribute to the literature by evaluating whether the influx of asylum seekers and the increasing presence of armed groups in the bordering provinces of Ecuador have lead to an increase in violence among these provinces. We do not find any link between the arrival of asylum seekers and the incidence of violent crimes in the Ecuadorean bordering provinces. Similarly, our results indicate that despite an increase in the presence of armed groups, these regions did not experience an increase in the homicide rates significantly different from the other provinces. The results are robust to various specifications and econometric techniques.     

The Impact of ETA’s Dissolution on Domestic Tourism in Spain

In late 2011, the Spanish terrorist organization ETA announced the end of armed violence after more than forty years of illegal activity. While the existing literature has already established the negative impact of terrorist actions on international tourism in a particular region, this paper aims to determine whether ETA’s final ceasefire and definitive dissolution had a positive impact on domestic tourism in Basque Country. To that end, a directed gravity model is estimated over a panel data-set of 699 domestic tourist flows between the Spanish regions from 2008 to 2013. Results suggest that the negative impact on visitor flows was localized in the Basque Country. Also, regardless of a permanent ceasefire announced in 2010, only the 2011 ‘definitive cessation of violence’ had an immediate significant impact on the number of visitors to the Basque Country. These results complement the scarce literature on post-conflict tourism analysis and may have implications for regional authorities in affected regions in their efforts to rebuild their destination brands.     

War Size Distribution: Empirical Regularities Behind Conflicts

This paper analyses the statistical distribution of war sizes. Using a new methodology we find moderate support for a Pareto-type distribution (power law), considering data from different sources (COW and UCDP) and periods. A power law is a plausible model for the size distribution of a pool of all wars and a sample of wars in many years, although the log-normal distribution is a plausible alternative model that we cannot reject. The random growth of conflicts could generate both types of distribution. We study the growth rates of battle deaths and random growth cannot be rejected for most of the distribution, although the results also reveal a clear decreasing pattern; the growth of deaths declines faster if the number of initial deaths is greater.