This paper describes the optimal flight of a discus. Two objective functions are considered. One is the flight distance, and the other is robustness. Robustness is defined as insensitivity to deviations from the local optimal release conditions. The aim of the optimization is to maximize both flight distance and robustness. There are ten control and design variables, which include variables con...

The physics of thermomechanical coupling of the continental lithosphere and its surrounding mantle is studied using a simple hydrodynamic model in which a fluid is heated from below and is bounded by rigid side walls. Rayleigh numbers up to 10 are considered. A series of finite-element stability analyses is employed to characterize systematically the nature of convective instability in such a s...

Using new large-scale wave-flume experiments we examine the cross-section and planform geometry of wave-formed ripples in coarse sand (median grain sizeD50 = 430 μm) under high-energy shoaling and plunging random waves. We find that the ripples remain orbital for the full range of encountered conditions, even for wave forcing when in finer sand the ripple length λr is known to become independen...

The No Child Left Behind Act of 2001 (NCLB) requires that schools make “adequate yearly progress” (AYP) towards the goal of having 100 percent of their students become proficient by year 2013-14. Through simulation analyses of Maine and Kentucky school performance data collected during the 1990s, this study investigates how feasible schools would have met the AYP targets if the mandate had been...

In China, the Lower Jingjiang Reach (LJR) of the Yangtze River could be one of the most complicated areas in terms of channel migration. The river had undergone many channel changes in the reach since the 18th century. Intensive human activities in recent decades, such as the construction of upstream dams and revetments, had directly affected the channel migration characteristics. The revetment...

Abstract Why did Japan choose to attack the United States, and why at Pearl Harbor? The story has ancient roots, starting with parallels antiparallels in geostrategic positions long-run economic development of Britain Japan. Japan’s recognition its inferiority strategic vulnerability mid-nineteenth century prompted strikingly rapid modernization. nation quickly became highly competitive Western...