The 22 September 1979 Vela Incident: Radionuclide and Hydroacoustic Evidence for a Nuclear Explosion

This article offers a new analysis of radionuclide and hydroacoustic data to support a low-yield nuclear weapon test as a plausible explanation for the still contentious 22 September 1979 Vela Incident, in which U.S. satellite Vela 6911 detected an optical signal characteristic of an atmospheric nuclear explosion over the Southern Indian or Atlantic Ocean. Based on documents not previously widely available, as well as recently declassified papers and letters, this article concludes that iodine-131 found in the thyroids of some Australian sheep would be consistent with them having grazed in the path of a potential radioactive fallout plume from a 22 September low-yield nuclear test in the Southern Indian Ocean. Further, several declassified letters and reports which describe aspects of still classified hydroacoustic reports and data favor the test scenario. The radionuclide and hydroacoustic data taken together with the analysis of the double-flash optical signal picked up by Vela 6911 that was described in a companion 2017 article (“The 22 September 1979 Vela Incident: The Detected Double-Flash”) can be traced back to sources with similar spatial and temporal origins and serve as a strong indicator for a nuclear explosion being responsible for the 22 September 1979 Vela Incident.     

Compromise allocation in multivariate stratified sampling: An integer solution

The problem of determining the sample sizes in various strata when several characteristics are under study is formulated as a nonlinear multistage decision problem. Dynamic programming is used to obtain an integer solution to the problem. © 1997 John Wiley & Sons, Inc.     

From rivals to partners: AirSea Battle and the US air force–navy relationship

AirSea Battle (ASB) has generated significant publicity, controversy, and debate among scholars, analysts, commentators, and observers of US defense strategy. However, a research gap exists concerning formal analysis of the impact of the operational concept on the relationship between the US Air Force (USAF) and the US Navy (USN). The impact of the ASB operational concept on the USAF–USN relationship is examined across the issue areas of strategy, budgets, weapons procurement, and training. These four issue areas represent important areas of historical conflict and competition between the Air Force and Navy. The conclusion is that ASB is ushering in a new era of Air Force–Navy partnership that advances the inter-service dynamic from “jointness” toward integration. The emergent USAF–USN partnership therefore represents a significant development in US defense politics and defense strategy.     

Sensor placement in active multistatic sonar networks

The idea of deploying noncollocated sources and receivers in multistatic sonar networks (MSNs) has emerged as a promising area of opportunity in sonar systems. This article is one of the first to address point coverage problems in MSNs, where a number of points of interest have to be monitored in order to protect them from hostile underwater assets. We consider discrete “definite range” sensors as well as various diffuse sensor models. We make several new contributions. By showing that the convex hull spanned by the targets is guaranteed to contain optimal sensor positions, we are able to limit the solution space. Under a definite range sensor model, we are able to exclude even more suboptimal solutions. We then formulate a nonlinear program and an integer nonlinear program to express the sensor placement problem. To address the nonconvex single‐source placement problem, we develop the Divide Best Sector (DiBS) algorithm, which quickly provides an optimal source position assuming fixed receivers. Starting with a basic implementation of DiBS, we show how incorporating advanced sector splitting methods and termination conditions further improve the algorithm. We also discuss two ways to use DiBS to find multiple source positions by placing sensors iteratively or simultaneously. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 287–304, 2017     

Preemptive parallel‐machine scheduling with a common server to minimize makespan

We consider parallel‐machine scheduling with a common server and job preemption to minimize the makespan. While the non‐preemptive version of the problem is strongly NP‐hard, the complexity status of the preemptive version has remained open. We show that the preemptive version is NP‐hard even if there is a fixed number of machines. We give a pseudo‐polynomial time algorithm to solve the case with two machines. We show that the case with an arbitrary number of machines is unary NP‐hard, analyze the performance ratios of some natural heuristic algorithms, and present several solvable special cases. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 388–398, 2017     

The long term effects of an aging fleet on operational availability and cost: evidence from the U.S. coast guard

This paper empirically examines whether the aging of a fleet affects operational availability and operating cost using a unique data-set on the 117 47-foot Motor Lifeboats (MLBs) of the United States Coast Guard (USCG). Procured from 1997 to 2003, the 47-foot MLB is the standard lifeboat of the USCG and all 117 MLBs remain in service. The aging of the MLB fleet has resulted in higher annual operating costs and lower operational availability, although the nature of this relationship remains unclear. Our estimation strategy utilizes an error components estimator to examine these issues. We employ three variants of the dependent variables (i.e. the standard logarithmic transformation as is most commonly seen in the literature, inverse hyperbolic sine [IHS], and level outcomes). The point estimates from the standard logarithmic model finds operational availability for the MLBs decreases at a rate between 0.83 and 1.8% per year and cost increases at a rate between 0.33 and 7.81% per year. Similar effects are shown with the IHS and level outcome specifications. In terms of nonlinearity effects, we find the most pronounced changes in operational availability and cost occur for MLBs aged 15 years or more (in comparison to younger MLBs).     

矿区生态型和非矿区生态型蜈蚣草对铅胁迫的生理响应

探讨不同矿区生态型蜈蚣草对铅的耐性及其耐铅机理,为进一步研究蜈蚣草植物修复射击场土壤的铅污染提供理论依据。在水培铅胁迫的环境条件,对矿区生态型和非矿区生态型蜈蚣草生长过程中的生物量、色素含量、MDA质量摩尔浓度和CAT,POD,SOD活性等进行了研究。研究发现,营养液中铅的加入抑制了蜈蚣草的生长,降低了羽叶中的色素含量,大幅度提高了MDA质量摩尔浓度和CAT,POD,SOD活性。结果表明,蜈蚣草对铅有一定的耐性,并且矿区生态型蜈蚣草的耐性明显高于非矿区生态型。主要表现为矿区生态型蜈蚣草的抗氧化酶活性高于非矿区生态型,生物量和色素含量受铅胁迫影响的程度相对较小。当铅质量浓度达到300 mg/L,铅胁迫15 d后,非矿区生态型蜈蚣草抗氧化酶系统紊乱,植株接近枯死状态,而矿区生态型蜈蚣草的耐性表现相对较好。     

The burglar problem with multiple options

We consider the burglar problem in which a burglar can either retire or choose among different types of burglaries, with each type having its own success probability and reward distribution. Some general structural results are established and, in the case of exponentially distributed reward distributions, a solution technique is presented. The burglar problem's relationship to a stochastic knapsack problem with a random exponentially distributed knapsack capacity is shown. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 359–364, 2014     

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.