Multi-objectives nonlinear structure optimization for actuator in trajectory correction fuze subject to high impact loadings

This paper presents an actuator used for the trajectory correction fuze, which is subject to high impact loadings during launch. A simulation method is carried out to obtain the peak-peak stress value of each component, from which the ball bearings are possible failures according to the results. Subsequently, three schemes against impact loadings, full-element deep groove ball bearing and integrated raceway, needle roller thrust bearing assembly, and gaskets are utilized for redesigning the actuator to effectively reduce the bearings' stress. However, multi-objectives optimization still needs to be conducted for the gaskets to decrease the stress value further to the yield stress. Four gasket's structure parameters and three bearings' peak-peak stress are served as the four optimization variables and three objectives, respectively. Optimized Latin hypercube design is used for generating sample points, and Kriging model selected according to estimation result can establish the relationship between the variables and objec-tives, representing the simulation which is time-consuming. Accordingly, two optimization algorithms work out the Pareto solutions, from which the best solutions are selected, and verified by the simulation to determine the gaskets optimized structure parameters. It can be concluded that the simulation and optimization method based on these components is effective and efficient.     

Civil wars and economic growth: A regional comparison

The paper examines the impact of civil wars on income per-capita growth at home and in neighbors for four regional groupings of countries: Africa, Asia, Latin America, and a pooled Asian and Latin American sample. Both macroeconomic and civil-war influences on growth differ by region. With the use of a distance measure, we demonstrate that the spatial reach from the negative consequences of a civil war are region and time period specific. Generally, there was less dispersion in Africa than in Asia and Latin America. Moreover, Africa demonstrates a greater ability to recover from the adverse effects of civil wars than the other regions tested.     

Civil-military relations and human security in a post-dictatorship

This article explores current developments in Chile, where since the return to democracy in 1990, the elected authorities have reconfigured the nation’s military resources in favour of four action pillars: peacekeeping and international conflict management, landmine removal and gun disarmament, emergency and catastrophe response, and a concern for human, economic and social rights. Successive defence policies offer a valuable case study for exploring the trade-offs between security, traditional and non-traditional threat management and institutional capabilities. The article argues that human security policymaking is not free from undesired outcomes; specifically, regarding how to reconvene the role of the armed forces when conventional war seems a thing of the past. The paper focuses on the interagency policy implications and the challenges ahead for civilians and the military.     

Urban violence and the militarisation of security: Brazilian ‘peacekeeping’ in Rio de Janeiro and Port-au-Prince

Despite problems of violence domestically, Brazil has played a key leadership role as part of MINUSTAH peacekeeping operations in Haiti since 2004. This article addresses how Brazil's international military engagement is shaping domestic approaches to urban security, and what may be the implications of the use of military strategies, operations, and norms to address issues of public security in Brazilian cities. It is argued that current approaches toward urban security employing military-trained peacekeepers actually represent a continuation of old paradigms, yet these recent militarised approaches are likely evolving into newer and potentially more accountable forms by constraining indiscriminate use of force and establishing a positive state presence in marginal urban areas. As such, the article connects long-established issues of dealing with urban violence in Latin America with ongoing debates in the United States and beyond about post-counterinsurgency approaches to increasingly urban conflict settings. It reflects on potential lessons to be learned from the Latin American perspective, while showing also how these have changed over the last decade. The article concludes that despite the potential utility of force in some urban conflict settings, this approach could entail a normative shift towards legitimising forceful containment of violence, and hinder democratic consolidation in Brazil.     

CONTRIBUTORS

ABSTRACT

Narratives about Brazil's nuclear program are distorted by supporters and critics alike. In Brazil, the national nuclear infrastructure is undergoing a period of expansion, with plans to build new nuclear power plants and industrial-scale fuel production facilities. While Brazil's leaders herald the nuclear sector as a triumph for indigenous science and technology, foreigners view the nuclear program as a dangerous legacy of the military regime. This discrepancy becomes even more apparent in discussions about the ongoing construction of Brazil's first nuclear powered submarine. Brazil's military touts the submarine as a symbol of political status, economic growth, and military might. But from abroad, the military's involvement in nuclear development is considered unnecessary, worrisome, and even irresponsible. These narratives—often incomplete or selective—have polarized discussions about Brazil's nuclear submarine program and caused considerable political antagonism during safeguards negotiations. This article works to dispel myths, highlight legitimate concerns, and explain historical perspectives that shed light on some difficulties that can be anticipated in future negotiations.     

Reform,democratization, and counter-insurgency: evaluating the US experience in Cold War-era Latin America

Current debate on US counter-insurgency doctrine is dominated by the notion that promoting ‘legitimacy’ and ‘good governance’ constitutes a central strategic imperative. This idea is hardly new; during the Cold War US officials often sought to encourage democratization and socio-economic reform as antidotes to revolution in Latin America. This article reviews four such cases – Venezuela during the first half of the 1960s, Guatemala throughout the 1960s, Nicaragua during the late 1970s, and El Salvador during the 1980s. The purpose is to bring a historical perspective to bear on current debates about the feasibility of US counter-insurgency strategy by evaluating the effectiveness of previous campaigns to promote improved governance in developing societies wracked by guerrilla violence.     

Design of accelerated life testing plans under multiple stresses

Accelerated life testing (ALT) using multiple stresses is commonly used in practice to resemble the operating stresses at normal operating conditions and obtain failure observations in a much shorter time. However, to date, there is little research into the theory of planning ALT for reliability estimation with multiple stresses. ALT with multiple stresses can result in a large number of stress‐level combinations which presents a challenge for implementation. In this article, we propose an approach for the design of ALT plans with multiple stresses and formulate multistress test plans based on different objectives and practical constraints. We develop a simulated annealing algorithm to efficiently determine the testing plan parameters. We demonstrate the proposed method with examples based on an actual test conducted using three stress types. The obtained optimal test plans are compared with those based on fractional factorial design. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 468–478, 2013     

BRAZIL AND MEXICO IN THE NONPROLIFERATION REGIME

Latin American countries have historically followed different paths and logics toward the nonproliferation regime. Some states have unconditionally advocated for global and nonproliferation efforts, while others have vehemently opposed such measures or remained ambivalent toward the regime itself. By historically comparing two of Latin America's most influential countries—Brazil and Mexico—this study identifies the underlying domestic conditions and external influences that explain their differences in behavior and policy toward the nonproliferation regime. Because little is known about the reasons why different Latin American countries adopt these different approaches, the purpose of this article is to resolve this problem, primarily by focusing on the ways in which evolving civil-military relations and US influence have shaped nonproliferation policy preferences in Latin America. It concludes with a discussion of how these historical cases might shed light on current nonproliferation policies in Latin America.     

Brazil's new defense paradigm

In 2015, Brazil has taken steps toward re-consolidating its domestic defense industry. In the 1980s, Brazil built a dynamic and diversified defense industry. The state-driven effort resulted in a tripod strategy, where the state, state-run companies, and their private sector became the pillars of Brazil's defense industry. Brazil developed an export-driven defense industry; where close to 80–90% of its output was exported to Latin American, African, Arab, and Asian nations. In the 1980s, Brazil became the world's fifth largest exporter of defense products and services, exporting to over 40 countries. In the 1990s and 2000s, Brazil's defense industry suffered a dramatic reduction in size, diversification, and momentum. Successions of domestic political and economic policies have relegated Brazil's once emerging defense industry to a marginal position in the global defense industry. This article analyzes future prospects, challenges, and growth strategies for Brazil's defense industry.     

一种新的对违法青少年的心理训练项目的分类模式

在美国,对违法青少年的心理训练项目(即心理治疗矫正,这里用心理训练的新概念代替心理治疗矫正更符合现代心理学的道德、尊重、人性的原则)与其违法青少年的类型和特点是紧密联系、不可截然分开的。美国对违法青少年的心理训练项目的分类方法主要有:心理评价分类法、I-level分类制度和行为分类体系等。