排序方式: 共有98条查询结果,搜索用时 15 毫秒
61.
Wai Ki Ching 《海军后勤学研究》2001,48(1):65-78
This paper studies production planning of manufacturing systems of unreliable machines in tandem. The manufacturing system considered here produces one type of product. The demand is assumed to be a Poisson process and the processing time for one unit of product in each machine is exponentially distributed. A broken machine is subject to a sequence of repairing processes. The up time and the repairing time in each phase are assumed to be exponentially distributed. We study the manufacturing system by considering each machine as an individual system with stochastic supply and demand. The Markov Modulated Poisson Process (MMPP) is applied to model the process of supply. Numerical examples are given to demonstrate the accuracy of the proposed method. We employ (s, S) policy as production control. Fast algorithms are presented to solve the average running costs of the machine system for a given (s, S) policy and hence the approximated optimal (s, S) policy. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 65–78, 2001 相似文献
62.
Abdur R. Chowdhury 《Defence and Peace Economics》2016,27(5):583-608
We examine the role of war in retarding state fiscal capacity in developing countries, measured by tax revenue ratios to GDP. We build a simple theoretical model of a factionalized state, where patronage substitutes for common interest public goods, along with violent contestation over a rent or prize. Our dynamic panel empirical analysis applied to 79 developing countries, during 1980–2010, indicates that war, especially civil war, retards fiscal capacity, along with imperfect democracy, political repression, poor governance, and dependence on oil and macroeconomic mismanagement. High intensity conflict is particularly destructive of state capacity. In countries experiencing low intensity wars, other institutional factors may matter more than war. The diminution of fiscal capacity due to war appears less pronounced after the end of the cold war. 相似文献
63.
Aysegul Kayaoglu 《Defence and Peace Economics》2016,27(1):117-136
Uprising tensions during 2010 in eastern and southeastern regions of Turkey provoked arguments about the necessity for a State of Emergency (SOE; ‘Ola?anüstü Hal’ in Turkish) declaration in those regions, with a belief of enduring political sustainability. The discussion is inflamed by a speech of the Nationalist Movement Party’s leader about the suggestion to announce a SOE ruling after the death of 24 Turkish soldiers in Hakkari (a city in the southeast of Turkey) in an attack of the PKK (Kurdistan Workers’ Party) on the 19 October 2011. Although a new announcement of SOE did not take place, the discussion itself induced the idea behind this paper which is to provide a quantitative analysis of the SOE in Turkey. In fact, the SOE ruling is not a new concept for Turkey and it has been implemented in 13 cities in the eastern and southeastern regions from 1987 to 2002. Although there have been many discussions about the costs of these 15 years of the SOE ruling in terms of military expenditure and, thus, on the national budget, there is a lack of quantitative analytical examination of the economic and social costs of it. Difference-in-differences analysis reveals negative spillover impacts of the SOE, especially on the forced migration, unemployment, and educational investments. The results also show that SOE ruling is an important factor for the underdevelopment of the eastern and southeastern regions in Turkey and, thus, a new SOE will bring enormous inequalities, both economically and socially, and an intensification of the ethnic tensions in Turkey. 相似文献
64.
Previous work has documented a negative correlation between internal conflict and state capacity. We attempt to shed light on mechanisms that underlie this relationship, using data for Colombian municipalities. We rely on identifying heterogeneous effects of different types of violent events on state capacity, taking advantage of variability across municipalities in the prevalence of specific manifestations of conflict and their intensity. Our findings suggest that events making civilians feel targeted affect the state’s capacity to collect taxes, while those reflecting a stronger military capacity of illegal armies, in particular their large-scale attacks, affect the state’s capacity to provide public goods. 相似文献
65.
Jahara Matisek 《Defense & Security Analysis》2018,34(3):267-290
ABSTRACTThe United States has provided substantial amounts of military assistance and aid since the end of World War Two. During the Cold War, it proved vital in protecting numerous regimes from communist takeovers. Successful outcomes occurred when American leaders made large initial aid commitments, and the states had the capacity and political willpower to use it effectively. However, Vietnam was an example of how U.S. support lagged, as leaders in Saigon preferred political survival instead of creating regime legitimacy. Following 9/11, American security aid focused on making weak countries develop stronger security forces. Unfortunately, this created Fabergé egg militaries: expensive and easily broken by insurgents. This article suggests long-term strategic commitments need to be made alongside more resources for the American State Department and similar organizations to focus on the politics of state-building. Finally, this article suggests strategies, such as “whole-of-government” approaches, to improve long-term security and political institution building. 相似文献
66.
《防务技术》2019,15(3):409-418
A three-stage theoretical model is presented herein to predict the perforation of a thick metallic plate struck normally by a long rod at high velocities. The model is suggested on the basis of the assumption that the perforation of a thick metallic plate by a long rod can be divided into three stages: (1) initial penetration; (2) plug formation and (3) plug slipping and separation. Various analytical equations are derived which can be employed to predict the ballistic limit, residual velocity and residual length of the long rod. It is demonstrated that the present model predictions are in good agreement with available experimental results for the perforation of finite steel targets struck normally by steel as well as tungsten alloy long rods at high velocities. It is also demonstrated that the dynamic maximum shear stress of a plate material has strong effect on plug formation and plug thickness which, in turn, exerts considerable influence on the residual velocities and lengths of a long rod at impact velocities just above the ballistic limit. 相似文献
67.
Thomas Bruneau 《战略研究杂志》2016,39(1):120-141
The United States has returned to Iraq, this time to combat the Islamic State. President Barack Obama’s strategy to ‘degrade, and ultimately destroy the terrorist group’ faces serious problems due to political obstacles in obtaining Congressional Authorization for the Use of Military Force (AUMF) and more importantly because of neglect of the crucial role of private contractors. Although the narrative has changed, and there is no public mention of contractors, they remain central to all that the Department of Defense does in the US and abroad. Suggestions are offered on how their performance can be improved to support President Obama’s strategy. 相似文献
68.
Olivier Chopin 《战略研究杂志》2017,40(4):532-553
ABSTRACTThis article argues that the intelligence sector is a privileged vantage point to observe and analyse a transformation of the State in France, as this transformation deeply affects the heart of the executive power and the French intelligence and security apparatus. Traditionally, intelligence was not conceived in France as a functional tool in the hands of the decision-maker but was rather defined as a ‘regalian power’. Intelligence activities were derived from a very specific conception of the State, and especially the particular notion of ‘reason of State’ (raison d’État). The current intelligence reform prompts speculation as to whether it represents more than a ‘simple’ functional reorganisation or in fact could signify that intelligence is now recognised as a tool in the hands of a ‘État de droit’ (‘liberal state’). The idea of a French ‘exceptionalism’ is addressed through a theoretical approach of the way France redefines intelligence and surveillance in relation with a major evolution of the notion of ‘reason of State’ itself. Then the article illustrates the assumption of a ‘lost tradition’ of reason of State through an analysis of the current reform of the intelligence sector in France. This reform is based on processes of rationalisation, centralization, modernisation and normalisation of both intelligence activities and intelligence services in France. As a conclusion, the article addresses the reactions to the January and November 2015 terrorist attacks in Paris, and asks whether resilience towards terrorism requires to accelerate the pace of the transformation of the French intelligence sector. 相似文献
69.
Shahab Enam Khan 《Small Wars & Insurgencies》2017,28(1):191-217
Bangladesh is currently facing an incremental growth of radicalization. This radicalization can be traced back to the country’s early post-Independence years. Over time, political violence, ideological clashes between secular and right-wing ideologies, and weak governance have created conditions for the growth of radical Islam. The public rhetoric on corruption, weakening of democratic institutions, inadequate law enforcement agencies, fragile justice delivery system, fledgling educational and social institutions and growing unemployment provides further space for alternative narratives by extremist ideologues. Home-grown extremist outfits have received ideological and tactical supports from transnational terrorist network such as Islamic State (IS) and Al-Qaeda in Indian Subcontinent (AQIS), but only in a limited manner. The supply and demand side of radicalization in Bangladesh has not yet been addressed by actors such as the government, private sector, civil society and media. The failures in multiple sectors in the state governance have led to a situation where IS and AQIS now see Bangladesh as a potential ground for exerting their supremacy as flag bearers of radical forms of Islam. 相似文献
70.
Belgin San Akca 《战略研究杂志》2013,36(4):589-613
States have suffered equally, if not more, from violence generated by Non-state Armed Groups (NAGs), such as ethnic and religious insurgencies and terrorists, than violence directly generated by their counterparts. This does not undermine the fact that states occasionally provide support to these groups in the form of safe havens, weapons, and funding. This paper argues that state support is a function of the states’ vulnerability in extracting and mobilizing resources to secure their borders. In contrast to the conception that weak or failed states provide the largest pool of resources to NAGs, the relatively strong states still prevail as their most fervent supporters. The preliminary evidence also suggests that NAGs serve as substitutes for allies. 相似文献