Vehicle routing problem with time-varying speed ( VRPTS) is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day. This paper pr...Vehicle routing problem with time-varying speed ( VRPTS) is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day. This paper proposes a simple model for estimating time-varying travel speeds in VRPTS that relieves much burden to the data-related problems. The study further presents three heuristics ( saving technique,proximity priority searching technique,and insertion technique) for VRPTS,developed by extending and modifying the existing heuristics for conventional VRP. The results of computational experiments demonstrate that the proposed estimation model performs well and the saving technique is the best among the three heuristics.展开更多
Starting from the basic assumptions and equations of Big Bang theory, we present a simple mathematical proof that this theory implies a varying (decreasing) speed of light, contrary to what is generally accepted. We c...Starting from the basic assumptions and equations of Big Bang theory, we present a simple mathematical proof that this theory implies a varying (decreasing) speed of light, contrary to what is generally accepted. We consider General Relativity, the first Friedmann equation and the Friedmann-Lema?tre- Robertson-Walker (FLRW) metric for a Comoving Observer. It is shown explicitly that the Horizon and Flatness Problems are solved, taking away an important argument for the need of Cosmic Inflation. A decrease of 2.1 cm/s per year of the present-day speed of light is predicted. This is consistent with the observed acceleration of the expansion of the Universe, as determined from high-redshift supernova data. The calculation does not use any quantum processes, and no adjustable parameters or fine tuning are introduced. It is argued that more precise laboratory measurements of the present-day speed of light (and its evolution) should be carried out. Also it is argued that the combination of the FLRW metric and Einstein’s field equations of General Relativity is inconsistent, because the FLRW metric implies a variable speed of light, and Einstein’s field equations use a constant speed of light. If we accept standard Big Bang theory (and thus the combination of General Relativity and the FLRW metric), a variable speed of light must be allowed in the Friedmann equation, and therefore also, more generally, in Einstein’s field equations of General Relativity. The explicit form of this time dependence will then be determined by the specific problem.展开更多
The formulation of boundary element method for handling contact problems with friction and the technique for high speed contact analysis are presented. This formulation is based on the idea of modifying the length of...The formulation of boundary element method for handling contact problems with friction and the technique for high speed contact analysis are presented. This formulation is based on the idea of modifying the length of contact elements without altering the total number of elements. The high precision of solution and high speed analysis are verified according to the results of conventional method and analysis method.展开更多
文摘Vehicle routing problem with time-varying speed ( VRPTS) is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day. This paper proposes a simple model for estimating time-varying travel speeds in VRPTS that relieves much burden to the data-related problems. The study further presents three heuristics ( saving technique,proximity priority searching technique,and insertion technique) for VRPTS,developed by extending and modifying the existing heuristics for conventional VRP. The results of computational experiments demonstrate that the proposed estimation model performs well and the saving technique is the best among the three heuristics.
文摘Starting from the basic assumptions and equations of Big Bang theory, we present a simple mathematical proof that this theory implies a varying (decreasing) speed of light, contrary to what is generally accepted. We consider General Relativity, the first Friedmann equation and the Friedmann-Lema?tre- Robertson-Walker (FLRW) metric for a Comoving Observer. It is shown explicitly that the Horizon and Flatness Problems are solved, taking away an important argument for the need of Cosmic Inflation. A decrease of 2.1 cm/s per year of the present-day speed of light is predicted. This is consistent with the observed acceleration of the expansion of the Universe, as determined from high-redshift supernova data. The calculation does not use any quantum processes, and no adjustable parameters or fine tuning are introduced. It is argued that more precise laboratory measurements of the present-day speed of light (and its evolution) should be carried out. Also it is argued that the combination of the FLRW metric and Einstein’s field equations of General Relativity is inconsistent, because the FLRW metric implies a variable speed of light, and Einstein’s field equations use a constant speed of light. If we accept standard Big Bang theory (and thus the combination of General Relativity and the FLRW metric), a variable speed of light must be allowed in the Friedmann equation, and therefore also, more generally, in Einstein’s field equations of General Relativity. The explicit form of this time dependence will then be determined by the specific problem.
文摘The formulation of boundary element method for handling contact problems with friction and the technique for high speed contact analysis are presented. This formulation is based on the idea of modifying the length of contact elements without altering the total number of elements. The high precision of solution and high speed analysis are verified according to the results of conventional method and analysis method.
