50 research outputs found
Export Production, Hedging Exchange Rate Risk: The Duopoly Case
This paper studies a Cournot duopoly in international trade so that the firms are exposed to exchange rate risk. A hedging opportunity is introduced by a forward market where the foreign currency can be traded on. We investigate two settings: First we assume that hedging and output decisions are taken simultaneously. We show that hedging is just done for risk managing reasons as it is not possible to use hedging strategically. In this setting the well-known separation result of the competitive firm holds if both firms have the hedging opportunity. In the second setting the hedging decisions are made before the output decisions. We show that hedging is used not only to manage the risk exposure but also as a strategic device. Furthermore we find that no separation result can be stated
Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry
OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc).
METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers.
RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group.
CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies
Second-Order Analytical Uncertainty Analysis in Life Cycle Assessment
Life cycle assessment (LCA) results
are inevitably subject to uncertainties.
Since the complete elimination of uncertainties is impossible, LCA
results should be complemented by an uncertainty analysis. However,
the approaches currently used for uncertainty analysis have some shortcomings:
statistical uncertainty analysis via Monte Carlo simulations are inherently
uncertain due to their statistical nature and can become computationally
inefficient for large systems; analytical approaches use a linear
approximation to the uncertainty by a first-order Taylor series expansion
and thus, they are only precise for small input uncertainties. In
this article, we refine the analytical uncertainty analysis by a more
precise, second-order Taylor series expansion. The presented approach
considers uncertainties from process data, allocation, and characterization
factors. We illustrate the refined approach for hydrogen production
from methane-cracking. The production system contains a recycling
loop leading to nonlinearities. By varying the strength of the loop,
we analyze the precision of the first- and second-order analytical
uncertainty approaches by comparing analytical variances to variances
from statistical Monte Carlo simulations. For the case without loops,
the second-order approach is practically exact. In all cases, the
second-order Taylor series approach is more precise than the first-order
approach, in particular for large uncertainties and for production
systems with nonlinearities, for example, from loops. For analytical
uncertainty analysis, we recommend using the second-order approach
since it is more precise and still computationally cheap