Sector-improved residue subtraction: Improvements and Applications

We discuss two recent developments of the sector-improved residue subtraction scheme for handling real radiation at NNLO in QCD. We present a new phase space construction which minimizes the number phase space configurations for subtraction terms and we rederive the four-dimensional formulation of the scheme.Comment: Contribution to the proceedings of the Loops and Legs 2018 conference, St. Goar, German

Zero-jettiness beam functions at N3^3LO

The zero-jettiness beam functions describe collinear emissions from initial state legs and appear in the factorisation theorem for cross sections in the limit of small zero-jettiness. They are an important building block for slicing schemes for colour-singlet production at hadron colliders. We report on our ongoing calculation of this quantity at next-to-next-to-next-to-leading order (N$^3$LO) in QCD, highlighting in particular the aspects of partial fraction relations and the calculation of master integrals

Zero-jettiness beam functions at N3^3LO

The zero-jettiness beam functions describe collinear emissions from initial state legs and appear in the factorisation theorem for cross sections in the limit of small zero-jettiness. They are an important building block for slicing schemes for colour-singlet production at hadron colliders. We report on our ongoing calculation of this quantity at next-to-next-to-next-to-leading order (N$^3$LO) in QCD, highlighting in particular the aspects of partial fraction relations and the calculation of master integrals

Evaluating The Use Of Recycled Concrete Aggregate In French Drain Applications

Recycled concrete aggregate (RCA) is often used as a replacement of virgin aggregate in road foundations (base course), embankments, hot-mix asphalt, and Portland cement concrete. However, the use of RCA in exfiltration drainage systems, such as French drains, is currently prohibited in many states of the U.S. The French drain system collects water runoff from the road pavement and transfers to slotted pipes underground and then filters through coarse aggregate and geotextile. The primary concerns with using RCA as a drainage media are the fines content and the precipitation of calcium carbonate to cause a reducing in filter fabric permittivity. Additional concerns include the potential for rehydration of RCA fines. The performance of RCA as drainage material has not been evaluated by many researchers and the limited information limits its use. A literature review has been conducted on the available information related to RCA as drainage material. A survey was issued to the Departments of Transportation across the nation in regards to using RCA particularly in French drains. Some state highway agencies have reported the use of RCA as base course; however, no state reports the use of RCA in exfiltration drainage systems. This thesis describes the investigations on the performance of RCA as backfill material in French drains. RCA was tested for its physical properties including, specific gravity, unit weight, percent voids, absorption, and abrasion resistance. RCA cleaning/washing methods were also applied to evaluate the fines removal processes. The potential for RCA rehydration was iv evaluated by means of heat of hydration, pH, compressive strength, and setting time. The permeability of RCA was tested using the No. 4 gradation. Long term permeability testing was conducted to evaluate the tendency for geotextile clogging from RCA fines. Calcium carbonate precipitation was also evaluated and a procedure to accelerate the precipitation process was developed. The results show that RCA has a high abrasion value, that is, it is very susceptible to break down from abrasion during aggregate handling such as transportation, stockpiling, or placing. The most effective cleaning method was found to be pressure washing with agitation. RCA has not demonstrated the tendency to rehydrate and harden when mixed with water. The permeability test results show that the No. 4 gradation does not restrict the flow of water; the flow rate is highly dependent on the hydraulic system itself, however excessive fines can cause large reductions in permeability over time. It has been determined that No. 4 gradation of RCA can provide a suitable drainage media providing the RCA is properly treated before its use

Zero-jettiness beam functions at N3^3LO

The zero-jettiness beam functions describe collinear emissions from initial state legs and appear in the factorisation theorem for cross sections in the limit of small zero-jettiness. They are an important building block for slicing schemes for colour-singlet production at hadron colliders. We report on our ongoing calculation of this quantity at next-to-next-to-next-to-leading order (N$^3$LO) in QCD, highlighting in particular the aspects of partial fraction relations and the calculation of master integrals.Comment: 12 pages, 2 figures, contribution to the proceedings of "Loops and Legs in Quantum Field Theory - LL2022, 25-30 April, 2022, Ettal, Germany

Methods and applications of systems identification

A Schmidt filter is proposed to compute an optimal orthonormal basis for a set of noisy filter input functions. Procedures for determining the transfer function and inverse transfer function of the filter are given. The Schmidt filter is applied to the problem of determining mathematical models of discrete, stationary, linear, dynamic systems for the case where measurements may be corrupted by noise of unknown statistics. The identification problem is reconsidered for the case where noise and signal moments are specified. Procedures are given which insure unbiased, adaptive estimates of system order and parameters for this case. These theoretical propositions are applied to the modeling of speculative prices. The stock market is formulated as a discrete, linear, dynamic system and the results of several simulation studies are presented. Evidence indicates that certain segments of the market can be approximated by high-order linear systems computed from small samples and tends to refute the random walk hypothesis. Computer programs (written in PL/1) are presented which allow for efficient digital realization of the theoretical procedures discussed in the body of this work --Abstract, page iii

Langfristig wieder steigende Baunachfrage - wo bleibt der Wohnungsbau?

In der Bauvorausschätzung Deutschland geht das ifo Institut davon aus, dass die Wohnungsneubaunachfrage äußerst zurückhaltend bleiben und erst 2015 das Niveau von 2000 erreichen wird. Der Wohnungsneubau hat eine rasante Talfahrt hinter sich: Von über 600 000 Fertigstellungen in 1995 sank er auf weniger als die Hälfte mit 268 000 Einheiten in 2003. Im Jahr 2004 kam es zwar zu einem Anstieg der Neubautätigkeit auf knapp 280 000 Fertigstellungen. Für 2005 wird mit einem erneuten kräftigen Rückgang der Fertigstellungszahlen gerechnet. Insgesamt dürften nur rund 260 000 Einheiten neu gebaut worden sein. Bezieht man in die Einschätzung der zukünftigen Neubauentwicklung die demographischen Wirkungen mit ein, so lässt sich eine im Verlauf des erwarteten konjunkturellen Aufschwungs langfristig leicht steigende Nachfrage nach neuen Wohnungen absehen. Bis 2015 wird es zu einem moderaten Wiederanstieg der Neubautätigkeit kommen.Wohnungsbau, Prognose, Wohnungsbaupolitik, Nachfrage, Privater Haushalt, Bevölkerungsentwicklung, Wohnungsbauinvestition, Deutschland

Analytical and experimental methods for determining the properties of materials at very high rates of loading

In the following report, some of the properties of ALCOA 7075 T651 aluminum, when subjected to high rates of loading, are experimentally investigated by impacting two rods of the material longitudinally. One rod is accelerated to a uniform velocity with an air gun launcher. The stationary second rod is instrumented with strain gages on its lateral surface in order to determine the strain-time history following impact. A detailed description of the experimental equipment is included. Simple, one-dimensional theory is used to determine the dynamic, elastic modulus of the test material under the impact condition. Several observations regarding the behavior of the material under dynamic, plastic loading conditions are made. The importance of equipment frequency response is noted and a method is suggested for estimating the experimental error in strain measurement resulting from equipment frequency response limitations. Several other possibilities of experimental error are noted and suggestions for improvement of the experimental apparatus are given. A theoretical development for the case of the longitudinal impact of two viscoelastic rods is presented and the numerical results are summarized for the impact of two rods of a Maxwell material. Computer programs to facilitate the determination of air gun parameters and to evaluate the solutions for the viscoelastic case are included --Abstract, page ii