Seven Sins in Portfolio Optimization

Although modern portfolio theory has been in existence for over 60 years, fund managers often struggle to get its models to produce reliable portfolio allocations without strongly constraining the decision vector by tight bands of strategic allocation targets. The two main root causes to this problem are inadequate parameter estimation and numerical artifacts. When both obstacles are overcome, portfolio models yield excellent allocations. In this paper, which is primarily aimed at practitioners, we discuss the most common mistakes in setting up portfolio models and in solving them algorithmically

The Challenge of Reforming the WTO Dispute Settlement Understanding

The May 2003 deadline for the completion of the negotiations on improvements and clarifications of the Dispute Settlement Understanding (DSU) under the Doha Mandate has not been met. However, Members agreed in July 2003 to extend the deadline for the review until the end of May 2004. This article briefly summarises the past six years of negotiations on the DSU review, the most contentious issues and the systemic difficulties of the negotiations. We conclude with prospects for the forthcoming negotiations until 2004.WTO Dispute Settlement Understanding DSU Review

Pre-fabrication for providing biocapacity to support vaccine manufacturing

The industry landscape is evolving rapidly and requires new and innovative approaches for more rapidly addressing the growing global demand for drug products as well as the challenges of unpredictability and inflexibility that have historically burdened the industry. Over the past two years, the industry’s herculean response to the COVID-19 pandemic has proven that with the proper focus, investment, science, and manufacturing technologies, these historic challenges can be overcome as well as establishing new benchmarks for how the industry can perform in the future to ensure availability of drug products and therapies to the global patient base Prefabricated modular construction of cleanrooms, utilities, and facility structures, is an innovative approach to building new manufacturing facilities that the industry has benefited from and is currently being utilised in critical COVID related projects. Prefabricated and modular facilities have been utilized in many industries such as food, chemical, and consumer products in the past, and have started to see significant adoption within the pharma and biopharma industries over the past ten years. This has largely been driven by the need to reduce project timelines, improve capability and flexibility, and minimize the risks associated with traditional construction for manufacturing facilities. It has helped as well to make Biopharma manufacturing more accessible to emerging regions, where in the past biomanufacturing was too complex to establish. Please click Download on the upper right corner to see the full abstract

Scalar susceptibility of a diluted classical XY model

We analyze the amplitude fluctuations in a diluted 3D classical XY model near the magnetic phase transition, motivated by the unusual localization properties of the amplitude (Higgs) mode recently found at the disordered superfluid-Mott glass quantum phase transition. We calculate the amplitude correlation function and the corresponding scalar susceptibility by means of Monte Carlo simulations. In contrast to the quantum case, in which the scalar susceptibility was found to violate naive scaling, we find that the scalar susceptibility of the classical system fulfills naive scaling (employing the clean critical exponents, as expected from the Harris criterion) as the temperature is varied across the phase transition for several dilutions. We discuss possible reasons for this discrepancy as well as the generality of our findings.Comment: 7 pages, 8 figures embedde

Fan blade protection system

In one type of aircraft propulsion system, propeller blades are mounted on a ring which surrounds a turbine. An annular space exists between the turbine and the ring. If a propeller blade should break free, the unbalanced centrifugal load tends to deform the ring. The invention reduces the deformation, as by locating spacers between the turbine and the ring

Flexible connector for use in aircraft

The invention concerns a connector, in an aircraft engine, for mounting a ring to a turbine rotor which the ring surrounds. The ring carries propeller blades, and the connector transmits both thrust and torque loads between the ring and the rotor, without significant deformation. However, the connector does deform in order to accommodate differential thermal growth between the ring and the rotor

Finding a job: Consequences for life satisfaction and interactions with job quality

Mit deutschen und britischen Panel-Daten analysieren wir, wie sich der Übergang aus Arbeitslosigkeit in (Vollzeit-)Beschäftigung auf die Lebenszufriedenheit auswirkt, und berücksichtigen dabei insbesondere den Einfluss der Arbeitsplatzqualität. Im Durchschnitt sind deutliche positive Effekte einer Beschäftigungsaufnahme in beiden Ländern festzustellen, auch wenn man für Einkommensänderungen und andere Faktoren kontrolliert. Diese Effekte sind in Deutschland kleiner, wenn es sich um Niedriglohn-Jobs handelt (aber nicht in Großbritannien), und sie sind in beiden Ländern kleiner, wenn eine befristete Beschäftigung aufgenommen wird; aber auch für die letztere Gruppe ist im Vergleich zu Personen, die arbeitslos bleiben, ein signifikanter Zuwachs an Lebenszufriedenheit zu verzeichnen. Das gilt allerdings nicht, wenn man Arbeitszufriedenheit als Indikator für die Arbeitsplatzqualität verwendet: Wiederbeschäftigte Personen mit niedriger Arbeitsplatzqualität sind nicht signifikant zufriedener mit ihrem Leben als diejenigen, die weiterhin arbeitslos sind

Finding a job: consequences for life satisfaction and interactions with job quality

"Using German and British panel data, we analyse the impact of transitions from unemployment to full-time employment on life satisfaction, with special focus on the influence of job quality. On average there are pronounced positive effects of a new job in both countries, even after controlling for income changes and other factors. These effects are smaller for people taking up low-paid jobs (in Germany, but not in Britain) or temporary jobs, but even this group is significantly better off compared to people remaining unemployed in both countries. We also use job satisfaction as an alternative indicator of job quality. Re-employed persons with low job satisfaction scores are not likely to experience a significant rise in life satisfaction." (author's abstract)"Mit deutschen und britischen Panel-Daten analysieren wir, wie sich der Übergang aus Arbeitslosigkeit in (Vollzeit-)Beschäftigung auf die Lebenszufriedenheit auswirkt, und berücksichtigen dabei insbesondere den Einfluss der Arbeitsplatzqualität. Im Durchschnitt sind deutliche positive Effekte einer Beschäftigungsaufnahme in beiden Ländern festzustellen, auch wenn man für Einkommensänderungen und andere Faktoren kontrolliert. Diese Effekte sind in Deutschland kleiner, wenn es sich um Niedriglohn-Jobs handelt (aber nicht in Großbritannien), und sie sind in beiden Ländern kleiner, wenn eine befristete Beschäftigung aufgenommen wird; aber auch für die letztere Gruppe ist im Vergleich zu Personen, die arbeitslos bleiben, ein signifikanter Zuwachs an Lebenszufriedenheit zu verzeichnen. Das gilt allerdings nicht, wenn man Arbeitszufriedenheit als Indikator für die Arbeitsplatzqualität verwendet: Wiederbeschäftigte Personen mit niedriger Arbeitsplatzqualität sind nicht signifikant zufriedener mit ihrem Leben als diejenigen, die weiterhin arbeitslos sind." (Autorenreferat