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This paper uncovers a novel component for exchange rate predictability based on the price difference between sovereign credit default swaps denominated in different currencies. This new forecasting variable – the credit-implied risk premium – captures the expected currency depreciation conditional on a severe but rare credit event. Using data for 16 Eurozone countries, we find that the credit-implied risk premium positively forecasts the dollar-euro exchange rate return at various horizons. Moreover, a currency strategy that exploits the informative content of our predictor generates substantial out-of-sample economic value against the na¨ıve random walk benchmark.

Arctic pipelines (PL) are located north of the 60th parallel. The main factors that characterize features of such pipelines are the climatic conditions in their areas of installation. Arctic pipeline routes pass through tundra with dwarf vegetation, marshes, and large areas with permafrost lenses, in watery and swampy areas with unique geological and hydrological conditions. The absolute difference of temperatures ranges from –56 degrees Centigrade in winter to 34 Centigrade in summer; and strong winds with speed over 40 m/s. Under these conditions, reliability and safety assessment of pipelines is associated with many principal difficulties, one of which is the need to take into account the simultaneous action (a combination) of many natural and technological loads on the pipeline infrastructure, which are random by nature and can be adequately described only by stochastic processes. Currently, reliability assessment of such systems is not performed due to lack of valid calculation methods. In this paper a description is given of the first stage of assessing reliability of a pipeline subject to a combination of loads described as random Markov processes. This method, developed by S. A. Timashev in [1], a. k.a. assessment of reliability in the space of loads, assumes the ability of constructing admissible areas in this load space with respect to different limit states. The method is applied to a segment of an above ground arctic oil pipeline with surface corrosion type defects, subjected to a combination (simultaneous action) of four loads: 1) dead weight of the pipe with insulation and oil being pumped, 2) operating pressure, 3) wind load, and 4) exposure to a uniform wall thickness thinning. The pipeline is considered as a continuous multi-bay thin wall cylindrical beam. The pipeline design is performed according to the (conditional) limit state which is reached when the equivalent stresses in pipe wall reach the yield stress of pipe material. The main purpose of the presented work is reliability assessment of PL in the space of load (impacts). At this the dead load of the pipeline structure is considered to be deterministic. The influence of the wind load, uniform corrosion, and operating pressure (OP) are considered to be variables. For them the permissible region is constructed using the above limit state. Арктические трубопроводы находятся к северу от 60?й параллели. Основными факторами, характеризующими особенности таких трубопроводов, являются климатические условия в местах их прокладки. Арктические трассы трубопроводов проходят через тундру с карликовой растительностью, болота и большие территории с вечной мерзлотой, обводненную и заболоченную местность с уникальными геологическими и гидрологическими условиями. Разница температур составляет от –56 зимой до +34 °C в летний период; скорость ветра свыше 40 м/с. В таких условиях оценка надежности и безопасности трубопроводов связана с множеством проблем, одной из которых является необходимость учитывать одновременное воздействие на трубопроводы многих природных и технологических нагрузок, которые носят случайный характер и могут быть адекватно описаны только с помощью случайных процессов. В настоящее время оценка надежности таких систем не выполняется из-за отсутствия научно обоснованных методов расчета. В данной статье описывается первый этап оценки надежности трубопровода при условии описания сочетания нагрузок как случайного процесса Маркова. Этот метод, разработанный С. А. Тимашевым [1], называется методом оценки надежности в пространстве нагрузок и предполагает возможность построения допустимых областей в пространстве нагрузки с учетом различных предельных состояний. Метод применен к сегменту наземного арктического нефтепровода с коррозией поверхности, подверженному комбинации (одновременному действию) четырех нагрузок: 1) собственный вес трубы с изоляцией и перекачиваемой нефти, 2) рабочее давление, 3) ветровая нагрузка и 4) утоньшение стенки. Трубопровод рассматривается как непрерывная многосекционная тонкостенная цилиндрическая балка. Проектирование трубопровода осуществляется по предельному состоянию, которое достигается, когда эквивалентные напряжения в стенке трубы достигают предела текучести материала трубы. Основной целью данной работы является оценка надежности трубопровода в пространстве нагрузок (воздействий). Здесь постоянные нагрузки на трубопровод считаются неизменными. Влияние ветровой нагрузки, равномерной коррозии и рабочее давление считаются переменными. Для них построена допустимая область с учетом описанного выше предельного состояния.

The safety of Generations II and III nuclear power plants relies on the availability of AC power, which is required for decay heat removal. This AC power (designated offsite power) is provided by sources outside the power plant via a grid that is susceptible to both random and induced failures. When offsite power is lost, alternative emergency sources on-site are started to drive the plant's safety systems. If, however, a situation arises where these sources are also unavailable or unable to provide the required power for the entire period the offsite sources are unavailable, a complete loss of power to the safety buses ensues. This phenomenon is known as Station Blackout (SBO), and its severity depends on its duration as well as, the plant's initial status. Consequently, the time-dependent non-recovery probability of AC power is a key parameter in the risk assessment and management of nuclear power plants. In this work, an easy-to-use and generally applicable reliability framework is proposed to model power recovery in station blackout sequences. It employs a load flow technique integrated into an efficient event-driven Monte-Carlo simulation algorithm. The resulting framework quantifies the probability of power recovery as a function of both time and power level, including other relevant indices. It, therefore, serves the purpose of a rational decision support tool in the mitigation of station blackout accidents. The proposed framework is used to analyse station blackouts emanating from grid and switchyard failures at the Maanshan nuclear power plant in Taiwan.

Studying failure scenarios allows one to gain insights into their cause and consequence, providing information for effective mitigation, contingency planning and improving system resilience. A new efficient algorithm is here proposed to solve applications where an expensive-to-evaluate computer model is involved. The algorithms allows to generate the conditional samples for the Subset simulation by representing each random variable by an arbitrary number of hidden variables. The resulting algorithm is very simple yet powerful and it does not required the use of the Markov Chain Monte Carlo method. The proposed algorithm has been implemented in a open source general purpose software, OpenCossan allowing the solution of large scale problems of industrial interest by taking advantages of High Performance Computing facilities. The applicability and flexibility of the proposed approach is shown by solving a number of different problems.

In many engineering applications, the assessment of reliability has to be done within a limited amount of information, which does not allow to use exact values for the distributional hyperparameters. This is achieved defining probability boxes and assessing the reliability computing the failure probability bounds. Probability boxes are often obtained from known probability distribution functions represented by interval hyper-parameters. In the applications, not only it is of interest estimating the failure probability bounds, but it is also required to identify the extreme realizations leading to the estimated bounds. In this paper, we propose a strategy, based on the Kolmogorov-Smirnov test, to identify the parental distribution function that best fit the distribution of extreme realizations, obtained from the minmax propagation. From the results obtained comparing the strategy with a direct search, it has emerged that the proposed method is generally applicable and efficient.

In the automotive industry a significant part of research is dedicated to design and produce better products. The unavoidable presence of uncertainties in manufacturing processes and structural parameters leads to the necessity to develop stochastic models able to correctly represent physical behaviours. This paper presents numerical and experimental investigations on the effects of the fitting process on the stress/strain map of assembled automotive rim-disk systems. Different strategies of geometrical decomposition are used to condense large volumes of data by retaining essential information for the whole design process including not only manufacturing pre-stresses and operational loads but also dimensional tolerances of mating parts by means of a probabilistic model. Efficient approaches are used to identify the relative importance of input factors on the output uncertainties. A real test case of a wheel assembly is presented and discussed.

In order to investigate the possible association between mast cells (MCs) and the fibrous plaque of La Peyronie's disease, the number of MCs in normal penile tissue and in the fibrous plaque was determined.The control group consisted of 5 total and 3 partial penectomies with no fibrotic lesions, while the study group consisted of 23 excisional biopsies from cases of La Peyronie's disease dating back to at least 2 years earlier and with no signs of activity. The biopsies included tissues from the tunica albuginea (TA), the areolar tissue (Br) between the tunica and the erectile tissue (CC) and from the latter. The number of MCs was counted with the aid of an image analysis program following staining the antibody antitryptase.In the cases of La Peyronie's disease the number of MCs/mm(2) was significantly higher in the TA and Br but lower in the CC. The MCs were related to fibroblasts and vasculonervous channels in the TA, and were concentrated around the fibrous plaques and granulation tissue between the TA and BR and between the latter and the CC.Our data indicate that MCs have a role in the genesis of the fibrous plaque in the TA and in the persistent inflammation in the Br. Medical treatment aimed at repressing MC activation and proliferation locally might be useful in La Peyronie's disease.