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11.
Despite sustained opposition, legislation criminalising homosexuality persists and threatens human security in Africa in numerous ways. This paper explores the circumstances around the enactment of new anti-homosexual legislation in Nigeria and Uganda, examining five categories of insecurity faced by lesbian, gay, bisexual, and transgender (LGBT) people in the context of these laws: physical violence; extortion and blackmail; arbitrary arrest and detention; displacement from home; and loss of work.  相似文献   
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Maintenance scheduling for modular systems: Modeling and algorithms   总被引:1,自引:0,他引:1       下载免费PDF全文
We study new models of scheduled maintenance management for modular systems, consisting of multiple components with respective cycle limits. The cycle limit of each component specifies the time interval in which this component must be repaired or replaced. The goal is to compute a feasible maintenance schedule that minimizes the cost associated with component maintenance. Applications of these models arise in Air Force aircraft maintenance as well as in other arenas with required preventive maintenance. The typical cost structures that arise in practical settings are submodular, which make the resulting models computationally challenging. We develop two efficient and operationally tenable approximation algorithms. We prove constant factor worst‐case guarantees for both algorithms, and present computational experiments showing that these algorithms perform within a few percent of optimality on operationally relevant instances. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 472–488, 2014  相似文献   
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We develop a simple, approximately optimal solution to a model with Erlang lead time and deterministic demand. The method is robust to misspecification of the lead time and has good accuracy. We compare our approximate solution to the optimal for the case where we have prior information on the lead‐time distribution, and another where we have no information, except for computer‐generated sample data. It turns out that our solution is as easy as the EOQ's, with an accuracy rate of 99.41% when prior information on the lead‐time distribution is available and 97.54–99.09% when only computer‐generated sample information is available. Apart from supplying the inventory practitioner with an easy heuristic, we gain insights into the efficacy of stochastic lead time models and how these could be used to find the cost and a near‐optimal policy for the general model, where both demand rate and lead time are stochastic. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004  相似文献   
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Conclusion     
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Traffic is the lifeblood of every e-commerce platform. The question of how to channel traffic to merchants operating on a platform lies at the heart of platform management. We consider a platform on which two independent merchants sell their products. Merchants compete on inventory in the sense that some of the unmet demand at one merchant will spill over to the other. The platform channels traffic based on products' conversion rates to maximize the total sale on the platform. We show that traffic channeling plays three roles. First, it allows more efficient allocation of traffic; that is, the merchant with a high conversion rate is given a higher priority in receiving traffic. Second, it allows the platform to control demand spillover between the merchants to maximize total sales. The platform either facilitates or prevents demand spillover, depending on product substitutability. Third, traffic channeling intensifies competition between the merchants and hence increases the total inventory. More efficient allocation of traffic and the increase in inventory increase sales inequality between the merchants. In contrast, demand spillover decreases sales inequality. While the platform always benefits from traffic channeling, the merchants do not benefit when their products are moderately substitutable. Interestingly, when the two products are owned and sold by the same merchant, the opposite happens–traffic channeling always benefits the merchant but may hurt the platform. Our study provides a basis for informed discussions on how platforms should channel traffic in response to conversion rates, and how traffic channeling affects the welfare of merchants and platforms.  相似文献   
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ABSTRACT

This article discusses the origins and development of the Sanga insurgency of the 1890s with a view to demonstrating that, contrary to commonly held stereotypes, pre-colonial warfare was neither simple nor unchanging. Its tactics, it is argued here, repay the sort of close analysis commonly reserved for other typologies and theatres of war. The Yeke, against whose exploitative system of rule the Sanga and their allies rose up in 1891, survived the onslaught by entering into a strategic alliance with Lofoi, a newly established station of the Congo Free State, and its limited contingent of regular Force Publique troops. An in-depth examination of the joint Yeke-Force Publique counterinsurgency campaign leads to the conclusion that the novelty of the ‘small wars’ that accompanied the Scramble for Africa should not be overstated. In southern Katanga and, by implication, elsewhere, these confrontations were shaped by processes of mutual borrowing in which African military practices and even political aims were not necessarily subordinate to European ones.  相似文献   
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