QUANTITATIVE RESTRICTIONS ON THE FLOW OF NARCOTICS: SUPPLY AND DEMAND RESTRAINTS IN A NORTH–SOUTH MACRO‐MODEL

This paper constructs a macroeconomic model of North–South interaction where the flow of narcotics from the South to the North is restricted. The economic effects are akin to quantitative restrictions in trade policy. Two alternative policy scenarios will be considered. One involves reducing the supply of drugs at the source, accompanied by aid. Supply‐side restrictions have negative aggregate supply‐side effects in the producing region, because of the monopoly rents generated from that type of control. This makes them a second‐best policy, particularly if the accompanying aid is not used for poverty alleviation and fails to expand domestic aggregate demand. Alternatively, demand side restrictions will be found to be superior.     

The Cyprus puzzle and the Greek - Turkish arms race: Forecasting developments using genetically evolved fuzzy cognitive maps

The scope of this paper is to forecast the extent to which a settlement of the Cyprus issue may be possible given the decisions taken during the Copenhagen EU summit. It aims, in addition, at investigating the possibilities of improvement in Greek-Turkish relations which may lead, in turn, to reducing the arms race between the two countries. The paper uses a Genetically Evolved Certainty Neuron Fuzzy Cognitive Map algorithm to consider a number of scenarios examining the possible reactions of all sides involved in the Cyprus issue, namely Greece, Turkey, Cyprus, the Turkish-Cypriot community and the international environment. All simulation exercises suggest that the Greek and the Cypriot side should not necessarily rely on the decisions taken during the Copenhagen summit conference. The forecasts point out, in addition, that the optimism of the Greek government concerning the outlook of its relations with Turkey, and a subsequent reduction of the arms race against it, is far from being justified.     

How to Fight Terrorism: Alternatives to Deterrence

Deterrence has been a crucial element in fighting terrorism, both in actual politics and rational choice analyses of terrorism. But there are superior strategies to deterrence. One is to make terrorist attacks less attractive. Another to raise the opportunity cost - rather than the material cost - to terrorists. These alternative strategies effectively dissuade potential terrorists. The strategies suggested here build on the "benevolence" system and tend to produce a positive sum game among the interacting parties. In contrast, the deterrence system is based on "threats" and tends to produce a negative sum game interaction.     

9/11: WHAT DID WE KNOW AND WHEN DID WE KNOW IT?

In February 1998, Osama Bin Laden published a signed statement calling for a fatwa against the United States for its having ‘declared war against God’. As we now know, the fatwa resulted in the unprecedented attack of 9/11. The issue of whether or not 9/11 was in any way predictable culminated in the public debate between Richard Clarke, former CIA Director George Tenet and the White House. This paper examines whether there was any evidence of a structural change in the terrorism data at or after February 1998 but prior to June 2001, controlling for the possibility of other breaks in earlier periods. In doing so, we use the standard Bai–Perron procedure and our sequential importance sampling (SIS) Markov Chain Monte Carlo (MCMC) method for identifying an unknown number of breaks at unknown dates. We conclude that sophisticated statistical time‐series analysis would not have predicted 9/11.     

ANGOLAN DEADLOCK

Children on the African continent have suffered immensely from the proliferation and misuse of small arms, including death, injury, displacement, separation from families, loss of access to health, humanitarian and educational services, and lack of economic opportunities. Further, over 300,000 children serve as child soldiers, relying on small arms as their tools of war. The international community has worked to establish protections for children for over 50 years, yet children continue to suffer. The recent UN Special Session on Children adopted ‘A world fit for children’, which, in combination with the Programme of Action agreed upon at the July 2001 UN Conference on Small Arms, begins to address a comprehensive approach to eliminating the negative impacts of small arms proliferation on children in conflict.     

THE EFFECTS ON SOUTH ASIA OF DEEP US NUCLEAR REDUCTIONS

Significant nuclear reductions by the United States can affect other states in one of five ways: by directly altering their strategic calculations and postures; by indirectly altering their strategic calculations and postures by affecting the behavior of third-party states; by undermining formal US deterrence commitments; by eroding the United States's perceived ability to provide “informal” deterrence through the maintenance of an active global presence; and by creating normative pressure for states to emulate US nuclear reductions. Only the erosion of “informal” deterrence is likely to affect South Asia; to the extent that significant US nuclear reductions affect South Asia, then, their impact is likely to be destabilizing.     

New maximum entropy methods for modeling lifetime distributions

This article introduces two new maximum entropy (ME) methods for modeling the distribution of time to an event. One method is within the classical ME framework and provides characterizations of change point models such as the piecewise exponential distribution. The second method uses the entropy of the equilibrium distribution (ED) for the objective function and provides new characterizations of the exponential, Weibull, Pareto, and uniform distributions. With the same moment constraints, the classical ME and the maximum ED entropy algorithms generate different models for the interarrival time. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 427–434, 2014     

多波切仑柯夫振荡器的设计

采用相对论全电磁模粒子模拟程序，对多波切仑柯夫振荡器进行了设计，给出了一套结构参数。模拟结果表明：所设计的器件在较宽的运行条件下（Ud＝300～500kV，Ib＝0．45～10kA，τγ＝10～102ns）能产生相干微波，微波频率位于X波段（～10GHz），辐射效率在10％左右，最大输出功率约300MW．     

基于SVD的机动目标自适应滤波研究与仿真

由于计算误差等因素的影响,致使滤波协方差阵不对称或负定,从而导致滤波器发散,影响滤波算法的收敛速度和稳定性.该研究在机动加速度"当前"统计自适应卡尔曼滤波算法的基础上,引入了基于奇异值分解(SVD)的协方差平方根滤波的自适应卡尔曼滤波算法.仿真结果表明,该算法可以较好地跟踪机动目标,具有精度高、稳定好、收敛快等特点.     

Continuous quality production and machine maintenance

This paper formulates a problem of continuous quality production and maintenance of a machine. Quality is assumed to be a known function of the machine's (Markov diffusion process) degradation states. Applications to a specific quality function are used to obtain analytical solutions to an open-loop and feedback stochastic control maintenance problem.