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151.
Radioactive sealed sources have a long history and a much wider worldwide distribution than do weapons-usable fissile materials. This article compares the mechanisms for controlling radioactive sources with those of weapons-usable materials and makes the case for improved policy making on the safe and secure management of radioactive sources (often referred to simply as “sources”). Such sources have been widely distributed with commercial and government support to nearly every country, yet there are no legally binding, international agreements or regulations to control any aspect of their life cycle. This is problematic because some sources that are disused, abandoned, or otherwise fall out of regulatory control could be used in the form of a radiological dispersal device (RDD, or dirty bomb). An RDD could pose significant economic and psychological impacts with the potential for detrimental effects on public health. The lack of international measures to control sources is troubling for several reasons: creating an RDD is much easier than fashioning a nuclear weapon from scratch or from stolen fissile materials; given the many incidents involving diversion from regulatory control and the misuse of sources, an RDD attack would be one of the more likely scenarios; materials security for sources is generally weak and inconsistent; it is nearly impossible to determine the total amount of sources manufactured and distributed; used sources are frequently found uncontrolled and transiting borders, and penalties are light at best; the market-based supply and demand of sources facilitates their rapid and loosely regulated distribution; and the “peaceful uses” aspect of the Treaty on the Non-Proliferation of Nuclear Weapons along with norms that began developing around the time of Atoms for Peace have promoted the nearly unchecked global distribution of sources. Several immediate and long-term actions are suggested to reduce the threat posed by radiological sources.  相似文献   
152.
The eastern Democratic Republic of Congo (DRC) has been characterised by chaos and insecurity for a number of years, but the rise of the M23 rebellion in 2012 once again highlighted just how dire the humanitarian and security situation is. For most of 2012, the crisis was addressed through negotiations between M23 and Kinshasa, mediated by the International Conference on the Great Lakes Region (ICGLR). However, 2013 marked the signing of the Peace, Security and Cooperation Framework Agreement (PSC Framework), and the United Nations Security Council's adoption of Resolution 2098, which contains the mandate of the long-awaited Intervention Brigade (IB). The PSC Framework calls on Kinshasa to implement substantial political reforms while also urging the neighbours of the DRC to stop interfering in its internal affairs. The IB is mandated to carry out targeted operations against the so-called ‘negative forces’ that operate in the eastern DRC. For now, hope of resolving this ongoing crisis hinges on the continuing ICGLR negotiations, the implementation of the PSC Framework and the success of the IB. However, there are critical questions about all of these processes that need to be answered and understood, as the expectations for these processes – especially in the case of the IB – are extremely high. Will the ICGLR manage to negotiate a peace agreement and will the IB succeed, or will they go down in history as yet another failure to save the eastern DRC?  相似文献   
153.
ABSTRACT

Nuclear disarmament is often seen as eventually requiring access to nuclear warheads or to the warhead-dismantlement process to verify that a state has not hidden weapons or weapon-materials despite promising to disarm. This article suggests this view is misplaced, and that what is needed is a verification mechanism able to provide reliable assurances of the absence of fissile materials available for use in weapons after a state has disarmed. Such a mechanism will need an initial declaration of the amount of fissile materials held by a state for all purposes, military and civilian. In a state with a nuclear arsenal awaiting elimination, this declaration would have to include materials that may not be available for verification because they are in nuclear weapons or are in other classified or proliferation-sensitive forms. This article describes a verification arrangement that does not require access to materials in weapons and in sensitive forms while still allowing checks on the overall accuracy of the declaration. Verification of the completeness and correctness of the declaration is deferred to the time when the weapons-relevant material enters the disposition process, at which point it no longer has any sensitive attributes. By removing the focus on monitoring warheads and dismantlement, this new approach could provide a more manageable path to nuclear disarmament.  相似文献   
154.
ABSTRACT

There is a lingering disagreement among scholars on how the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) affects nonproliferation and disarmament outcomes. Drawing on constructivist scholarship on international norms, this article examines the extent of the NPT's effect in the case of Ukraine's nuclear disarmament. In the wake of the Soviet Union's collapse, Ukraine found itself host to the world's third largest nuclear arsenal. Despite Ukraine's initial commitment to become a non-nuclear state, it proceeded along a difficult path toward NPT accession. Most controversial and directly at odds with the NPT was Ukraine's claim to ownership of its nuclear inheritance as a successor state of the Soviet Union. This article argues that, while much domestic discourse about the fate of these nuclear weapons was embedded in the negotiation of Ukraine's new identity as a sovereign state vis-à-vis Russia and the West, the NPT played an important, structural role by outlining a separate normative space for nuclear weapons and providing the grammar of denuclearization with which Ukraine's decision makers had to grapple.  相似文献   
155.
On October 1, 2008, Congress enacted a proposal that originated with President George W. Bush in 2005 to approve an unprecedented nuclear trade pact with India by removing a central pillar of US nonproliferation policy. Despite the numerous political challenges confronting the Bush administration, the initiative won strong bipartisan support, including votes from Democratic Senators Joseph Biden, Hillary Clinton, and Barack Obama. The four-year struggle to pass the controversial US-India nuclear trade agreement offers an exceptionally valuable case study. It demonstrates a classic tradeoff between the pursuit of broad multilateral goals such as nuclear nonproliferation and advancement of a specific bilateral relationship. It reveals enduring fault lines in executive branch relations with Congress. It vividly portrays challenges confronting proponents of a strong nonproliferation regime. This article is based on an analysis of the negotiating record and congressional deliberations, including interviews with key participants. It assesses the lessons learned and focuses on three principal questions: how did the agreement seek to advance US national security interests?; what were the essential elements of the prolonged state-of-the-art lobbying campaign to win approval from skeptics in Congress?; and what are the agreement's actual benefits—and costs—to future US nonproliferation efforts?  相似文献   
156.
Governments are increasingly recognizing the problem posed by internally weak nuclear-capable states. The problem, however, is under-theorized. This article brings together literature on sovereignty and international order, the nonproliferation regime, and weak states, and introduces new concepts to provide a more structured understanding of this problem. Insight comes from focusing attention on the function and governance of two nuclear estates (termed the production and operational estates), and on their resilience to decay and disorder occurring within the state and society. Drawing on empirical observation, the authors suggest a typology of weakness in nuclear states, involving state fragmentation typified by the former Soviet Union, the “hard weak state” typified by North Korea, and the internally conflicted state typified by Pakistan. Although these types give rise to distinctive difficulties, their alleviation depends heavily on the maintenance of internal authority within the state and estates, the presence or absence of cooperative relations, and the international regulatory framework's vitality.  相似文献   
157.
SAVING THE NPT     
For more than forty years, the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) has provided major security benefits to the international community; however, the treaty is suffering from internal and external pressures, and benign neglect on the part of its members is undermining its authority. To ensure the treaty's continued viability, it is time for member states to start showing the NPT the respect it deserves and to renew their commitments to its fundamental purposes. Achieving this requires remedial action in at least four areas of vulnerability: reinvigorating nuclear disarmament; strengthening nonproliferation; overcoming the NPT's institutional deficit; and fostering a rapprochement between NPT and non-NPT states that does not abandon the goal of treaty universalization. There is still time before the 2010 NPT Review Conference for concerted action to restore the NPT's vitality and for the United States to resume its leadership role on behalf of the treaty and its membership.  相似文献   
158.
基于PXI总线技术,对某型导弹内场测试仪的校准设备进行了集成化、小型化研究,依靠计算机强大的计算储存显示等功能,实现了设备操作界面的虚拟化及智能化.最后,对在LabVIEW平台上开发的测量校准软件进行了实验验证,达到了界面友好、操作简单、测量精度高、工作效率高等要求.  相似文献   
159.
相机内置预处理环节中的白平衡、色度空间转换是数码成像过程中的重要环节,sRGB和Adobe RGB是数码相机2种常用的色空间.为进一步研究色空间对HDRI亮度测量方法的影响,在荧光灯照明的实验室,分别利用sRGB和Adobe RGB色空间对色板成像,测量该亮度测量方法中各色板的标定因数,计算各色板标定因数的相对不确定度.实验结果表明:2种不同色空间获得的标定因数不同,且Adobe RGB色空间标定因数相对不确定度的平均值小于sRGB色空间的;色空间改变后,标定因数需要重新进行标定,且优先选用色域较宽的Adobe RGB色空间.  相似文献   
160.
针对计算机辅助指挥调度舰载机甲板作业的决策过程无法脱离人参与这一特点,引入基于逆向学习的强化学习方法,将指挥员或专家的演示作为学习对象,通过分析舰载机的甲板活动,建立舰载机甲板调度的马尔可夫决策模型(MDP)框架;经线性近似,采用逆向学习方法计算得到回报函数,从而能够通过强化学习方法得到智能优化策略,生成舰载机甲板调度方案。经仿真实验验证,本文所提方法能够较好地学习专家演示,结果符合调度方案优化需求,为形成辅助决策提供了基础。  相似文献   
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