Speed of convergence to the quasi-stationary distribution for L\'evy input fluid queues

In this note we prove that the speed of convergence of the workload of a L\'evy-driven queue to the quasi-stationary distribution is of order $1/t$. We identify also the Laplace transform of the measure giving this speed and provide some examples

Development of sea port in Gdynia

Seaports operate on a highly competitive global transport market. To retain its competitive position a port (terminal) must strengthen its competitive advantages in all fields of activity. Ports are to expand and modernize their infrastructure and superstructure, and develop links with the hinterland and the foreland. The article describes how the port of Gdynia manages to meet these challenges. The author analyses the period 2007-2015. Special attention is paid to the port development plan for 2020. The EU Structural Funds has provided a good opportunity to strengthen the competitive position of the port by making investments in the port infrastructure and superstructure. It allowed the port to strengthen its links with the hinterland. The author uses a set of fundamental, analytical and technical research methods to analyse materials provided by the port authority and the port terminal operators. By the end of 2015, the port authority had completed five investment projects, including the modernization of th ree wharfs and a rail terminal, the development of the port infrastructure aimed to provide services to ro-ro ships. Strategically important projects for the coming years include dredging and widening of the port channel, fairways and the internal basin. Cooperation between the port and the city authorities allowed the port administration to improve road access to the port of Gdynia. The key investment project aims to link the port of Gdynia to the TriCity ring road. Apart from it, there are plans to improve access to the railroad network. Railway line 201 to Bydgoszcz is to be modernised to transport cargoes from Gdynia further inland. The current and future strategic investments create conditions for growth in handling both container and other types of cargo in the port of Gdynia and significantly improve competitiveness of the maritime sector

Baltic Cooperation in Marine Spatial Planning

Marine spatial planning is a relatively new area of cooperation in the Baltic Sea region — a site of long-term joint efforts towards environmental protection and sustainable development. At the beginning of the 21st century, the integrated management of coastal zones and marine spatial planning emerged as a new area of international cooperation. Despite intensive theoretical work on the mentioned concepts, the development of a harmonised spatial planning in the Baltic Sea region is complicated by the complex nature of the problem, a relatively intensive exploitation of marine resources, diverse interests of the stakeholders, and differences in national institutional systems. We describe the key stages of the process, which is regulated by the EU standards on the one hand and affected by the activity of such organisations as VASAB and HELCOM, on the other. In this article, we examine basic documents defining the principles and scope of marine planning and analyse recent research works into spatial development. We conclude that marine spatial planning is a principal tool of the EU’s integrated policy. Many European countries of the Baltic region are seeking cooperation with Russia to preserve the natural and economic environment of the Baltic Sea. Most joint spatial planning projects have been initiated by Finland, Sweden, Germany, and Poland

On Gerber-Shiu functions and optimal dividend distribution for a L\'{e}vy risk process in the presence of a penalty function

This paper concerns an optimal dividend distribution problem for an insurance company whose risk process evolves as a spectrally negative L\'{e}vy process (in the absence of dividend payments). The management of the company is assumed to control timing and size of dividend payments. The objective is to maximize the sum of the expected cumulative discounted dividend payments received until the moment of ruin and a penalty payment at the moment of ruin, which is an increasing function of the size of the shortfall at ruin; in addition, there may be a fixed cost for taking out dividends. A complete solution is presented to the corresponding stochastic control problem. It is established that the value-function is the unique stochastic solution and the pointwise smallest stochastic supersolution of the associated HJB equation. Furthermore, a necessary and sufficient condition is identified for optimality of a single dividend-band strategy, in terms of a particular Gerber-Shiu function. A number of concrete examples are analyzed.Comment: Published at http://dx.doi.org/10.1214/14-AAP1038 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Association Between Participant Retention and the Proportion of Included Elderly People in Rheumatology Trials: Results From a Series of Exploratory Meta‐Regression Analyses

Objective. The elderly, a population defined by an age of ≥65 years, are underrepresented in rheumatology trials, possibly due to investigators' concerns of increased premature discontinuations in higher age groups. The present study was undertaken to evaluate whether the proportion of included elderly individuals (PE) is independently associated with participant retention in rheumatology trials. Methods. Medline was searched for randomized controlled trials (RCTs) in rheumatoid arthritis (RA) and osteoarthritis (OA) of any intervention (years 2016 and 2017). PE was either extracted from the research manuscript or estimated from an assumed (truncated) normal distribution. We used mixed-effects meta-regression models including several covariates to assess whether there is an independent association between PE and participant retention. Using sensitivity analyses, we evaluated whether associations were connected to attrition due to lack of efficacy (LoE) or adverse events (AE). Results. In total, 243 RCTs comprising >48,000 participants were included. Pooled participant retention was 88%. PE was not associated with retention in the unadjusted (P = 0.97) or adjusted (all: P ≥0.14) models. Of all covariates, only study duration and type of intervention were associated with retention (both: P < 0.001). Post hoc analyses allowing for interaction revealed a small but statistically significant positive association between PE and retention in pharmacologic interventions and a negative association in physical/physiotherapeutic interventions (overall P for interaction = 0.05). No associations were found for PE and attrition due to LoE or AE. Conclusion. Participant retention in RA and OA trials is high and not associated with PE. These findings should motivate investigators to include more elderly participants in rheumatology trials

A L\'evy input fluid queue with input and workload regulation

We consider a queuing model with the workload evolving between consecutive i.i.d.\ exponential timers $\{e_q^{(i)}\}_{i=1,2,...}$ according to a spectrally positive L\'evy process $Y_i(t)$ that is reflected at zero, and where the environment $i$ equals 0 or 1. When the exponential clock $e_q^{(i)}$ ends, the workload, as well as the L\'evy input process, are modified; this modification may depend on the current value of the workload, the maximum and the minimum workload observed during the previous cycle, and the environment $i$ of the L\'evy input process itself during the previous cycle. We analyse the steady-state workload distribution for this model. The main theme of the analysis is the systematic application of non-trivial functionals, derived within the framework of fluctuation theory of L\'evy processes, to workload and queuing models

Baltic Cooperation in Marine Spatial Planning

Marine spatial planning is a relatively new area of cooperation in the Baltic Sea region — a site of long-term joint efforts towards environmental protection and sustainable development. At the beginning of the 21st century, the integrated management of coastal zones and marine spatial planning emerged as a new area of international cooperation. Despite intensive theoretical work on the mentioned concepts, the development of a harmonised spatial planning in the Baltic Sea region is complicated by the complex nature of the problem, a relatively intensive exploitation of marine resources, diverse interests of the stakeholders, and differences in national institutional systems. We describe the key stages of the process, which is regulated by the EU standards on the one hand and affected by the activity of such organisations as VASAB and HELCOM, on the other. In this article, we examine basic documents defining the principles and scope of marine planning and analyse recent research works into spatial development. We conclude that marine spatial planning is a principal tool of the EU’s integrated policy. Many European countries of the Baltic region are seeking cooperation with Russia to preserve the natural and economic environment of the Baltic Sea. Most joint spatial planning projects have been initiated by Finland, Sweden, Germany, and Poland

Idiopathic intracranial hypertension: a possible association with Imatinib

Idiopathic intracranial hypertension (IIH) is characterized by an increased intracranial pressure in the absence of a tumor and in the absence of a venous thrombosis. Associated risk factors include obesity and several medications such as tetracyclines. We report a 60-year-old patient who developed IIH under treatment with imatinib. To our knowledge such a possible connection has not been reported in the literature, even though intracranial hypertension is now listed as a rare possible side effect of treatment with imatinib in the Swiss List of Medications Arzneimittelkompendium. It remains to be seen, if further case reports will support this observation