In geometrical program, degenerated input needs to be dealt with exceptionally. Since there are large variety of degeneracies, it is difficult to deal with all of those degeneracies individually. Conventional unified treatments for degeneracies require programmers to rewrite a quite amount in each program while what we propose in this paper deals with degeneracies almost automatically avoiding the rewrite of the program in C. For geometric programs in C, we introduce a new class in C++, replace the type of some variables with it and make the programs deal with degeneracies by symbolic perturbation with operator overloading in C++.
In this paper, we prove the one-soliton solutions to the solitonic dynamical system over finite fields that may be regarded as an analogue of the box-ball systems. It turns out that the one-soliton solution has a nested structure similar to fractals, and as far as we know such a system seems to be novel. Furthermore, in spite of such a complex internal structure, numerical simulations show stable propagations before and after collisions among multiple solitons with preserving their patterns.
Rational interpolation is one of the methods to interpolate the function from the interpolation points on some real interval. In this paper, we propose an algorithm for rational interpolation based on the Krylov subspace methods. The validity of this algorithm is verified by some numerical experiments.
Many mathematical models have been proposed for analysis of traffic jams, and applied to simulation of traffic flow. Grouping cars based on the properties of driving, and then modeling each group eneables us to obtain an appropriate model. The simulation with the model will be more precise than a single model for whole cars. In this paper, we focus on modeling by TASEP, which is the most basic cellular automaton. Applying a multi-species TASEP to spatio-temporal data, we propose statistical clustering methods of cars.
Computed results by floating-point arithmetic may not be accurate due to accumulation of rounding errors. Therefore, verifying the accuracy of the approximate solutions has been frequently discussed. In this paper, we focus on 2D orientation problem (Orient2D) which is one of the basic problems in computational geometry. It is assumed in most previous works that given data is rigorously represented by floating-point numbers. We assume that given floating-point numbers are results of rounding from real numbers. We develop floating-point filters of this problem and apply them to the convex hull algorithm.
Due to recent repeated financial crises, discussions on systemic risk have been activated from both theoretical and practical aspects. Practical policies for preventing worldwide bankruptcy of financial system are examined by regulators and financial institutes, and theoretical studies are also rapidly progressing. In this paper, we review research topics on systemic risk, especially focus on mathematical and theoretical studies. In addition, we give some comments on future prospects of systemic risk management.