The method of adding the initial elements greatly affects the structure and mechanical properties of a tungsten alloy. In this study, the 90(W–20Ta)–Ni–Fe alloy was prepared by the direct addition of elements and W–Ta pre-alloying. The element diffusion and phase transformation behavior...

W-Ni-Fe alloys exhibit high density and excellent mechanical properties, making it attractive in the kinetic energy penetrators. However, its impact fracture behavior has not been fully understood. To investigate the relationship between microstructural parameters and impact behavior, the impact...

A logical strategy to contain the COVID-19 pandemic is to completely isolate everyone for two weeks (the incubation period of the virus). However, such a strategy can have prohibitive economic and social costs and, therefore, will be difficult to implement. At the same time, the current...

In this paper we present a budget-constrained optimal control model aimed at finding the optimal enforcement profile for a street-level, illicit drug crackdown operation. The objective is defined as minimizing the number of dealers dealing at the end of the crackdown operation, using this as a...

Panic-buying and shortages of essential commodities is common during early phases of a disaster or an epidemic. The goal of this paper is develop a methodology which includes social media information in optimization models of searching essential commodities during disasters and improves the...

This paper presents a dynamic game model of international terrorism. The time horizon is finite, about the size of one presidency, or infinite. Quantitative and qualitative analysis of incentive Stackelberg strategies for both decision-makers of the game (“The West” and “International...

Spreadsheets are commonly used and commonly flawed, but it is not clear how often spreadsheet errors lead to bad decisions. We interviewed 45 executives and senior managers / analysts in the private, public, and non-profit sectors about their experiences with spreadsheet quality control and with...

Background: There is ongoing interest in assessing the effectiveness of various drug control strategies, including policy intended to reduce initiation and prevalence. Compartmental models of trajectories of drug use have been developed that demonstrate that drug “systems” display...

Markets for illicit drugs present an interesting case study for economics, combining non-standard characteristics such as addiction and product illegality. One response has been to argue the generality of economic principles by suggesting that they apply even in the extreme case of markets for...

There is consensus in the literature that spreadsheets are both ubiquitous and error-prone, but little direct evidence concerning whether spreadsheet errors frequently lead to bad decision making. We interviewed 45 executives and senior managers/analysts in the private, public, and non-profit...