A parallel memetic algorithm for the vehicle routing problem with time windows

Abstract-A parallel memetic algorithm for the NP-hard vehicle routing problem with time windows (VRPTW) is proposed. The algorithm consists of components which are executed as parallel processes. A process runs either a heuristic algorithm or a hybrid of a genetic algorithm and some local refinement procedures. In order to improve the results, processes co-operate periodically using a novel randomized scheme. During each phase of co-operation processes exploit their best solutions found so far. The purpose of the work is to devise the parallel memetic algorithm which determines the VRPTW solutions of the highest possible quality. The experiments on Gehring and Homberger's (GH) benchmarking tests show that the algorithm achieves very good results. By making use of it the best-known solutions to 171 out of 300 GH tests were improved

Crisis management and crisis situation in the organization

PURPOSE: The aim of the article is to present the problems of crisis management and crisis situation in an organisation, taking into consideration that crisis is an integral part of the functioning of any organisation.DESIGN/METHODOLOGY/APPROACH: Realisation of the goal indicated will help find an answer to the research problem: How does the occurrence of a crisis affect the functioning of an organisation, particularly in a time of chaos and uncertainty? Qualitative methods were applied to obtain an answer to the research question posed. The research made use of the latest report containing statistics concerning crisis and resilience of organisations, an analysis was also conducted based on both domestic and foreign scientific articles from recent years.FINDINGS: The authors formulated the following conclusions: Crisis is inevitable, but its effects can be mitigated. Organisations which are prepared for a crisis have a greater chance of successfully overcoming it. Crisis management is a complex process requiring the commitment of the entire team. Organisations should conduct regular reviews of their crisis plans to ensure that they have not become outdated and their effectiveness has not decreased. Organisations should also carry out crisis training to test their plans and prepare employees for the event of a crisis.PRACTICAL IMPLICATIONS: Crises may have various intensities and effects. Some may be short lasting and have no significant impact on the working of the organisation. Others may be long-term and lead to serious losses, or even the collapse of a company. In order to minimise the risk of a crisis, organisations should apply the appropriate crisis management strategies. which indicates the necessity to take these into account in the organisation’s practices, in plans and action strategies, stressing the creation of various scenarios for future development.ORIGINALITY/VALUE: An analysis of the materials gathered proves that crises may become a catalyst for change with regard to generating new solutions in the field of coping with crisis situations in an organisation. Particularly noteworthy are organisations in the energy, technology, media and communications sectors, and in the health industry, due to the experience they have in implementing integrated programmes to increase immunity, which may inspire other organisations to take such decisions.peer-reviewe

KRATTA, a triple telescope array for charged reaction products

KRATTA, a new, low threshold, broad energy range triple telescope array has been built to measure the energy, emission angles and isotopic composition of light charged reaction products. It has been equipped with fully digital chains of electronics. The array performed very well during the ASY-EOS experiment, conducted in May 2011 at GSI. The structure and performance of the array are presented using the first experimental results