Process based model sheds light on climate sensitivity of Mediterranean tree-ring width

We use the process-based VS (Vaganov-Shashkin) model to investigate whether a regional <i>Pinus halepensis</i> tree-ring chronology from Tunisia can be simulated as a function of climate alone by employing a biological model linking day length and daily temperature and precipitation (AD 1959–2004) from a climate station to ring-width variations. We check performance of the model on independent data by a validation exercise in which the model's parameters are tuned using data for 1982–2004 and the model is applied to generate tree-ring indices for 1959–1981. The validation exercise yields a highly significant positive correlation between the residual chronology and estimated growth curve (<i>r</i>=0.76 <i>p</i><0.0001, <i>n</i>=23). The model shows that the average duration of the growing season is 191 days, with considerable variation from year to year. On average, soil moisture limits tree-ring growth for 128 days and temperature for 63 days. Model results depend on chosen values of parameters, in particular a parameter specifying a balance ratio between soil moisture and precipitation. Future work in the Mediterranean region should include multi-year natural experiments to verify patterns of cambial-growth variation suggested by the VS model

Research trends in combinatorial optimization

Acknowledgments This work has been partially funded by the Spanish Ministry of Science, Innovation, and Universities through the project COGDRIVE (DPI2017-86915-C3-3-R). In this context, we would also like to thank the Karlsruhe Institute of Technology. Open access funding enabled and organized by Projekt DEAL.Peer reviewedPublisher PD

A Qualitative Analysis of Organisational Commitment in an Algerian Pharmaceutical Industry

Quiet quitting, bullshit jobs , the great resignation are recurrent words referring to disturbances increasingly observed in work life and new concepts characterizing the job market. They mainly indicate the evolution of work perception, the deterioration of work relations, and a quest for meaning among employees. In this context, this research attempts to look closely into the relationship between an organisation and its employees through a qualitative case study. This paper will first present a literature review as thoroughly as possible about the evolution of the concept of organisational commitment from the 1960s up to now; the literature review will also encompass the main antecedents and outcomes of this concept on organisational performance. Then, qualitative research following the socio-economic approach to management will be conducted in the Algerian pharmaceutical industry to grasp the complexity of the concept. A series of 38 semi-guided interviews is conducted, starting with the CEO of the company and including each Division Director and Chief of Department. The results of the research allowed us to identify several pivotal ideas that are likely to hinder organisational commitment, including the size of the premises is no longer fitted to the size of the company, which deteriorates the work environment and impedes performance; lack of work organisation and information communication following the growth of the company such as the absence of a Human Resource Management and a Management control division; centralization of decision making and communication about company objectives which contributes to a blurred role distribution; HRM practices characterized by limited career evolution option and a flawed personnel appraisal process; and finally, organisational changes put the company at challenge because of resistance to change ERP, skills shortage, skills destruction, flawed training and dissonant communication

The genetic algorithm approach for identifying the optimal operation of a multi-reservoirs on-demand irrigation system

A stochastic methodology, based on real-coded genetic algorithms for optimising the operation of reservoirs in an on-demand irrigation system, is presented. The methodology analyzes the adequacy of the difference between supply and demand taking into account the storage capacity of the reservoirs. It determines adequate inflow hydrographs to ensure the optimal regulation of reservoirs during the peak demand period. To take into account the variability of farmers' requirements, demand hydrographs were randomly generated within a pre-determined confidence interval. A weighted objective function, including violations of the admissible reservoir water levels (maximum, minimum and target water levels), is proposed. To solve the optimisation problem, a computer program was developed. The model was applied and tested on the Sinistra Ofanto irrigation scheme (Foggia, Italy), comprising five reservoirs fed with water from an upstream dam, each of them serving different irrigation districts. Results show that the model is efficient and robust

Multi-objective optimization of water distribution networks via NSGA-II and Pseudo-Weights

Managing water distribution networks via pumps scheduling programs is a multi-objective optimization problem with dynamic and various site-specific challenges. Metaheuristics-based approaches, with respect to mathematical solvers, offer data-driven strategies for manageable and adaptive control. Some evolutionary approaches are suitable for multi-criteria decision making and decentralized coordination on programmable logic controllers. This paper focuses on the development of a testbed and an early assessment of an approach based on NSGA-II and Pseudo-Weights. The experimental studies are based on a physically developed case study, and on a scalable case study with realistic water demand and source patterns. The testbed has been publicly released