Driver Shift Research Articles

Determining the required number of taxi cars at airports Moscow aviation hub

The article discusses a simulation model of transport services for passengers at the airports of the Moscow Aviation Hub (MAH), on the basis of which the required number of taxi cars at Sheremetyevo, Domodedovo, Vnukovo airports is determined during the simulated day, depending on the duration of the drivers’ shift on the line. Simulation modeling clearly shows that bringing the duration of a driver’s shift, which until recently amounted to 15...17 hours a day, in accordance with current legislation inevitably leads to an increase in their required number. However, the article proposes a method for organizing the work shift of drivers, as a result of which the working hours of taxi drivers are within the framework of current legislation, and the number of cars increases slightly. Keywords transport hub, MAH airports, driver shift duration, taxi transportation, required number of taxi cars, simulation modeling, simulation model

Re-assessment of the climatic controls on the carbon and water fluxes of a boreal aspen forest over 1996-2016: Changing sensitivity to long-term climatic conditions.

Recent evidence suggests that the relationships between climate and boreal tree growth are generally non-stationary; however, it remains uncertain whether the relationships between climate and carbon (C) fluxes of boreal forests are stationary or have changed over recent decades. In this study, we used continuous eddy-covariance and microclimate data over 21 years (1996-2016) from a 100-year-old trembling aspen stand in central Saskatchewan, Canada to assess the relationships between climate and ecosystem C and water fluxes. Over the study period, the most striking climatic event was a severe, 3-year drought (2001-2003). Gross ecosystem production (GEP) showed larger interannual variability than ecosystem respiration (Re ) over 1996-2016, but Re was the dominant component contributing to the interannual variation in net ecosystem production (NEP) during post-drought years. The interannual variations in evapotranspiration (ET) and C fluxes were primarily driven by temperature and secondarily by water availability. Two-factor linear models combining precipitation and temperature performed well in explaining the interannual variation in C and water fluxes (R2 > .5). The temperature sensitivities of all three C fluxes (NEP, GEP and Re ) declined over the study period (p < .05), and, as a result, the phenological controls on annual NEP weakened. The decreasing temperature sensitivity of the C fluxes may reflect changes in forest structure, related to the over-maturity of the aspen stand at 100 years of age, and exacerbated by high tree mortality following the severe 2001-2003 drought. These results may provide an early warning signal of driver shift or even an abrupt status shift of aspen forest dynamics. They may also imply a universal weakening in the relationship between temperature and GEP as forests become over-mature, associated with the structural and compositional changes that accompany forest ageing.

Driver Shift Planning for an Online Store with Short Delivery Times

Abstract In this work we derive daily driver shift plans for an online store which delivers goods to customers within short times. The goal is to minimize the total labor time (total shift lengths) over all shifts. Thereby orders must be assigned to shifts s.t. all orders are delivered in time. We model this optimization problem by means of a mixed integer linear program using a time-index based formulation. This model features strengthening inequalities that allow to solve it also reasonably well with an open source branch-and-cut solver. Furthermore we use a coarse-grained variant of the model to quickly derive high-quality heuristic solutions within one minute even for larger instances with up to two thousand orders. On a realistic benchmark instance set the overall approach is able to obtain solutions with remaining optimality gaps below 1%.

Fatigue analysis to driver of intercity in West Sumatra Province, Indonesia a case study of Padang – Bukittinggi – Payakumbuh route

Traffic accidents were common problems in the implementation of a transportation system, including in West Sumatra Province, Indonesia. Traffic accidents that occur every year were the evidence by the number of traffic accidents that occur every year. One of the causes of traffic violations that result in accidents is the risk of driver fatigue while working. This study analyzed the work-fatigue in the driver of the Intercity in Province bus (AKDP) the scope of this study was all AKDP bus drivers with the origin of Padang City, Bukittinggi City, and Payakumbuh City. Measurement and analysis of work-fatigue were using the reaction timer to light response. The results showed that increasing the number of shifts would increase driver fatigue. 33.33% of drivers run into medium level of fatigue, and 38.89% of drivers run into heavy level of fatigue. The relationship between work-fatigue and the driver's shift correlated very strongly and positively with a correlation value of r = 0.81. The owner of the company needs to take measures to improve management to minimize the level of work on this driver that has the potential to cause traffic accidents.

Planejamento da designação de maquinistas a trens de viagem de longa distância em ferrovias de transporte de carga

As ferrovias brasileiras transportam cargas em viagens longas. O trem é conduzido por um maquinista e, por conta da extensão da viagem com tempo total de duração, geralmente, superior à escala de trabalho do maquinista, fazendo-se necessário realizar a troca de maquinistas durante a viagem em locais pré-definidos, denominados destacamentos. Na literatura, este problema é tratado de forma separada por dois subproblemas: Crew Scheduling e Crew Rostering. Diferentemente, este artigo propõe um modelo matemático para resolver de forma integrada os dois subproblemas, inspirado no Problema de Roteamento de Veículos com Múltiplas Viagens e Múltiplos Depósitos, para planejar a designação de maquinistas para conduzir os trens que passarão pelos destacamentos, buscando minimizar o pagamento de salários e horas extras aos maquinistas. Os resultados demonstram possíveis reduções de custos quando comparados com o planejamento manual da ferrovia analisada e reduções de custo podem ser alcançadas se aumentar o tempo de escala.

Well-posedness of cubic Horndeski theories

We study the local well-posedness of the initial value problem for cubic Horndeski theories. Three different strongly hyperbolic modifications of the Arnowitt-Deser-Misner formulation of the Einstein equations are extended to cubic Horndeski theories in the ``weak field'' regime. In the first one, the equations of motion are rewritten as a coupled elliptic-hyperbolic system of partial differential equations. The second one is based on the Baumgarte-Shapiro-Shibata-Nakamura formulation with a generalized Bona-Mass\'o slicing (covering the $1+\mathrm{log}$ slicing) and nondynamical shift vector. The third one is an extension of the CCZ4 formulation with a generalized Bona-Mass\'o slicing (also covering the $1+\mathrm{log}$ slicing) and a gamma driver shift condition. This final formulation may be particularly suitable for applications in nonlinear numerical simulations.

The Variable Neighborhood Search for a Consistent Vehicle Routing Problem under the Shift Length Constraints

This paper addresses a new real-world application of vehicle routing planning in a finite time horizon. A company in the small package shipping industry has a limited fleet of identical vehicles in some depots and must serve a set of clients. There is a frequency for each client stating how often this client must be visited. Time intervals between two consecutive visits must be the same but the visiting schedule is flexible. To get some competitive advantage, a company tries to increase the service quality. To this end, each client should be visited by one driver only. The goal is to minimize the total traveling distance for all vehicles over the planning horizon under the frequency constraints and driver shift length constraints. We present an integer linear programming model for this new consistent vehicle routing problem. To find near optimal solutions, we design the Variable Neighborhood Search metaheuristic with nine neighborhood structures. The driver shift length constraints are penalized and included in the objective function. Empirical results for real test instances from Orenburg region in Russia with up to 900 clients and four weeks in the planning horizon are discussed.

Heavy-Truck Drivers’ Following Behavior With Intervention of an Integrated, In-Vehicle Crash Warning System

This study is designed to evaluate heavy-truck drivers' following behavior and how a crash warning system influences their headway maintenance. Rear-end crashes are one of the major crash types involving heavy trucks and are more likely than other crash types to result in fatalities. Previous studies have observed positive effects of in-vehicle crash warning systems in passenger car drivers. Although heavy-truck drivers are generally more experienced, driver-related errors are still the leading factors contributing to heavy-truck-related rear-end crashes. Data from a 10-month naturalistic driving study were used. Participants were 18 professional heavy-truck drivers who received warnings during the last 8 months of the study (treatment period) but not during the first 2 months (baseline period). Time headway and driver's brake reaction time were extracted and compared with condition variables, including one between-subjects variable (driver shift) and five within-subjects variables (treatment condition, roadway types, traffic density, wiper state, and trailer configuration). The presence of warnings resulted in a 0.28-s increase of mean time headway with dense on-road traffic and a 0.20-s increase with wipers on. Drivers also responded to the forward conflicts significantly faster (by 0.26 s, a 15% enhancement) in the treatment condition compared with responses in the baseline condition. Positive effects on heavy-truck drivers' following performance were observed with the warning system. The installation of such in-vehicle crash warning systems can help heavy-truck drivers keep longer headway distances in challenging situations and respond quicker to potential traffic conflicts, therefore possibly increasing heavy-truck longitudinal driving safety.

Puncture evolution of Schwarzschild black holes

The moving puncture method is analyzed for a single, nonspinning black hole. It is shown that the puncture region is not resolved by current numerical codes. As a result, the geometry near the puncture appears to evolve to an infinitely long cylinder of finite areal radius. The puncture itself actually remains at spacelike infinity throughout the evolution. In the limit of infinite resolution the data never become stationary. However, at any reasonable finite resolution the grid points closest to the puncture are rapidly drawn into the black hole interior by the $\ensuremath{\Gamma}$-driver shift condition. The data can then evolve to a stationary state. These results suggest that the moving puncture technique should be viewed as a type of ``natural excision.''

Simulation of the shift force for a manual transmission

A shift force simulator for manual transmission is developed to estimate the shift force that is transmitted to the driver's hand. In order to develop the simulator, dynamic models of the external linkage, internal linkage, synchronizer and drivetrain are obtained. The synchronizing motion is modelled as seven steps depending on the relative displacement of the sleeve to the ring spring, outer ring chamfer and gear chamfer. The chamfer-to-chamfer contact mechanism is modelled as a linear spring. In addition, a driver model is proposed to simulate the driver's shift lever operation. Based on the dynamic model of each element, a shift force simulator is developed. The simulator calculates the sleeve displacement, cone torque, index torque, sleeve force, shift force and the speed of the input and output shaft. It is found that the shift force by the simulator shows a good correlation with the test results, and it is expected that the shift force simulator developed in this study can be used as a useful design tool to evaluate the shift feeling in the initial design stage.

Fuzzy Logic in Automatic Transmission Control

SUMMARY One of the fastest growing areas in engineering is that of fuzzy logic based technology. This study focuses on the application of fuzzy logic in automatic transmission control of automobiles. The question when and how to apply fuzzy theory is discussed. The usage of fuzzy theory in different existing transmission control systems is summarized and analyzed. Further, the influence of providing road information is observed by modeling a driver's shift action on a winding road.