Strategia przedsiębiorstwa w okresie kryzysu

The article deals with the logistic strategies enabling an enterprise to create a strategy flexible in terms of business and marketing and stable in terms of manufacturing. In order to create a strategy model the following principles can be applied: shorter periods of capacity planning combined with flexible planning, SYNCRO – MRP principle, the application of forecasting in operative planning, creation with partners one of the cooperation form as supply chain, demand chain, lean supply chain, agile supply chain, leagile supply chain, and using the DBR, APS and SCP systems.W artykule zaprezentowano rozwiązania logistyczne umożliwiające przedsiębiorstwom tworzenie elastycznych strategii biznesowych i marketingowych oraz stabilnych w środowiskach produkcyjnych. Do utworzenia modelu strategii mogą być stosowane następujące zasady: krótsze okresy planowania zdolności w połączeniu z elastycznym planowaniem, zasada Syncro-MRP, stosowanie prognozowania w planowaniu operacyjnym, utworzenie z partnerami jednej z form współpracy w łańcuchu dostaw, łańcuchu popytu, odchudzonym łańcuchu dostaw, zwinnym łańcuchu dostaw oraz wykorzystanie systemów klsy DBR, APS i SCP

Comment on Bernard et al. Association between Urinary Metabolites and the Exposure of Intensive Care Newborns to Plasticizers of Medical Devices Used for Their Care Management. Metabolites 2021, 11, 252

The recent publication “Association between Urinary Metabolites and the Exposure of Intensive Care Newborns to Plasticizers of Medical Devices Used for Their Care Management” by L. Bernard et al. (2021) [...

Multi-GNSS PPP-RTK: Mixed-receiver network and user scenarios

In this contribution, we present full-rank observation equations of the network and user receivers, of mixed types, through an application of S-system theory. We discuss the important roles played by the inter system biases (ISBs), and we show how the three-component structure of PPP-RTK is affected by the inclusion of the ISBs as extra parameters in the model

GNSS ambiguity resolution with controllable failure rate for long baseline network RTK

Many large-scale GNSS CORS networks have been deployed around the world to support various commercial and scientific applications. To make use of these networks for real-time kinematic positioning services, one of the major challenges is the ambiguity resolution (AR) over long inter-station baselines in the presence of considerable atmosphere biases. Usually, the widelane ambiguities are fixed first, followed by the procedure of determination of the narrowlane ambiguity integers based on the ionosphere-free model in which the widelane integers are introduced as known quantities. This paper seeks to improve the AR performance over long baseline through efficient procedures for improved float solutions and ambiguity fixing. The contribution is threefold: (1) instead of using the ionosphere-free measurements, the absolute and/or relative ionospheric constraints are introduced in the ionosphere-constrained model to enhance the model strength, thus resulting in the better float solutions; (2) the realistic widelane ambiguity precision is estimated by capturing the multipath effects due to the observation complexity, leading to improvement of reliability of widelane AR; (3) for the narrowlane AR, the partial AR for a subset of ambiguities selected according to the successively increased elevation is applied. For fixing the scalar ambiguity, an error probability controllable rounding method is proposed. The established ionosphere-constrained model can be efficiently solved based on the sequential Kalman filter. It can be either reduced to some special models simply by adjusting the variances of ionospheric constraints, or extended with more parameters and constraints. The presented methodology is tested over seven baselines of around 100 km from USA CORS network. The results show that the new widelane AR scheme can obtain the 99.4 % successful fixing rate with 0.6 % failure rate; while the new rounding method of narrowlane AR can obtain the fix rate of 89 % with failure rate of 0.8 %. In summary, the AR reliability can be efficiently improved with rigorous controllable probability of incorrectly fixed ambiguities