Runge–Kutta approximation for $$C_0$$-semigroups in the graph norm with applications to time domain boundary integral equations

We consider the approximation of an abstract evolution problem with inhomogeneous side constraint using A-stable Runge–Kutta methods. We derive a priori estimates in norms other than the underlying Banach space. Most notably, we derive estimates in the graph norm of the generator. These results are used to study convolution quadrature based discretizations of a wave scattering and a heat conduction problem.

Defending Instrumental Rationality against Critical Theorists

Central to much critical theory is the critique of instrumental rationality (roughly, the ability to pick good means to ends). This critique is overstated, I suggest. Critical theorists often depict instrumental rationality too narrowly, and many criticize the wrong target, for example, attacking capitalist instrumental rationality when the fundamental problem is capitalism, not instrumental rationality. Nonetheless, critical theorists’ critique requires certain changes to orthodox accounts of instrumental rationality. I offer a more palatable definition, highlight instrumental rationality’s essential contestability, and show that it can actually help us pick ends. Everyone needs instrumental rationality, especially Habermasian critical theorists. And far from instrumental rationality being amoral, I argue that because instrumental rationality almost always involves multiple ends, one end may prohibit immoral means, acting as a side-constraint. Ultimately, the substance of critical theorists’ critiques remains highly important but should not be framed in opposition to instrumental rationality.

Respect at Prison Mealtime

This chapter continues to subject a series of unexamined beliefs on respect and criminal justice to critical scrutiny and challenge. There is a shift in focus to prison mealtime, whose pivotal role in shaping the experiences of prisoners has been considerably understated. The chapter is prefaced with a short commentary on prison mealtime in historical context. It is then structured around three key stages of contemporary prison mealtime—preparation, consumption, and resistance—which I propose as organising categories for critiquing the practice. When the authorities treat respect as a weak side-constraint on the pursuit of instrumental outcomes rather than a foundational value of the regime itself, it undermines those responsible for preparing food, degrades prisoners who have no choice but to consume it, and exacerbates the experiences of those who—for reasons of religious belief, physical or mental ill-health, or in protest—resist or refuse it.

Sufficiency and Equality

This chapter explores a distributive principle that is integral to pragmatic Confucian democracy—what I call Confucian democratic sufficientarianism. Confucian democratic sufficientarianism critically embraces liberal sufficientarianism’s positive thesis stipulating the threshold of sufficiency but roundly rejects the negative thesis, which allows unlimited desert-based inequalities beyond the threshold of sufficiency. After deriving four propositions from classical Confucianism (namely, equal sufficiency, objectively high threshold standard, deserved inequalities, and constrained inequality) and presenting them as constituting the classical Confucian doctrine of sufficiency, the chapter then reconstructs it into Confucian democratic sufficientarianism by installing public equality as a side constraint that prevents deserved inequalities beyond the threshold of sufficiency from eroding an equal social relationship among citizens. Confucian democratic sufficientarianism is distinguished importantly from liberal democratic sufficientarianism as well because its main currency of distribution is not so much equal public standing as such, but the well-being of the people.

Experimental Study on Two-Side Constraint Steel Plate Shear Wall with Vertical Stiffeners

Two two-side constraint steel plate shear wall specimens with vertical stiffeners had been tested under low cyclic loading to study its seismic performance through the performance indexes of the Initial stiffness, hysteretic behavior, load-carrying capacity, destruction mechanism and so on. Test showed that as main lateral force resisting members two-side constraint steel plate shear wall with vertical stiffeners had a very superior seismic performance. So it is worth popularizing in the area of high seismic intensity.

Effects of Aspect Ratio and Side Constraints on Elastic Buckling of Multi Wall Structures and Tubes

Buckling of plates and tubes plays an important role in structural safety and energy absorption. Although buckling of plates and tubes has been studied theoretically and experimentally in the past, the effects of aspect ratio and side constraint on buckling of multi-wall structures and tubes has not been investigated systematically. In this work, finite element simulations have been carried out to investigate the buckling behavior of multi-wall structures and tubes. A series of one- to three-panel walls and square tubes with various aspect ratios were simulated. The critical aspect ratios causing buckling mode transition were obtained and compared with theoretical predictions available in the literature. Effects of wall angle and side constraint on buckling behavior were investigated. The relevance of research findings to honeycomb-like structures was discussed.

Vermögenspreise, Alterung und Ersparnis / Asset Prices, Aging and Saving

SummaryIn simple overlapping-generation models, the young save by purchasing assets from the old, who in turn finance their consumption by spending the proceeds. If household saving of a shrinking younger generation falls short of planned, constant asset sales by the old generation, asset prices might drop. This note argues that the above asset-meltdown argument holds only in case of a strict cash-in-advance constraint in a model with sharp demarcations between periods. Here, the shrinking size of the young generation establishes a supply-side constraint for production, and the old cannot realize the planned value of asset sales so that goods prices cannot be bidden up. In a more realistic setting of simultaneous and slow changes, only some flexibility and elasticity of the financial system is needed to resolve the cash-in-advance constraint. Excess goods demand then will produce rising prices. Then, necessarily additional savings (in the form of undistributed profits) arise as a flow-of-funds effect, which in turn help to maintain asset market equilibrium. Asset prices nevertheless might fall because of rising interest rates if monetary policy reacts to inflationary tendencies (if goods-supply constraints persist). But this line of reasoning is different from the shortage-of-saving myth.

Retrieving Storm Electric Fields from Aircraft Field Mill Data. Part II: Applications

The Lagrange multiplier theory developed in Part I of this study is applied to complete a relative calibration of a Citation aircraft that is instrumented with six field mill sensors. When side constraints related to average fields are used, the Lagrange multiplier method performs well in computer simulations. For mill measurement errors of 1 V m−1 and a 5 V m−1 error in the mean fair-weather field function, the 3D storm electric field is retrieved to within an error of about 12%. A side constraint that involves estimating the detailed structure of the fair-weather field was also tested using computer simulations. For mill measurement errors of 1 V m−1, the method retrieves the 3D storm field to within an error of about 8% if the fair-weather field estimate is typically within 1 V m−1 of the true fair-weather field. Using this type of side constraint and data from fair-weather field maneuvers taken on 29 June 2001, the Citation aircraft was calibrated. Absolute calibration was completed using the “pitch down method” developed in Part I, and conventional analyses. The resulting calibration matrices were then used to retrieve storm electric fields during a Citation flight on 2 June 2001. The storm field results are encouraging and agree favorably in many respects with results derived from earlier (iterative) techniques of calibration.