Vehicle Detection Method with Sub-stretching Based on Light Contrast in Fog Road Image

In this paper, detection of a vehicle from a road image with fog is focused to detect an vehicle from a foggy image. Because of the fog in the image, a shape of an object is vague. Therefore an obstacle may occur on the vehicle detection. Thus, features from a foggy road image are surveyed through experinmlts, and a histogram is caloalated with the bright value. The stretching method is then applied with the specific weight as the centre to detect a vehicle smoothly. If the high density area, from the view point of histogram, is applied with the stretching method, the definition of the image can be increased. On this fact, this paper proposed a method to divide the histogram and to determine applicable range of the stretching method. The improved results by the proposed methods are proved with the camparison tests between the proposed and previous methods.

The Effectiveness of Shallow Surface Geophysical Methods in Shear Wave Velocity Derivation

Shear wave velocity Vs is measured by the surface geophysical survey like MASW （multi-channel surface wave analysis） or RWM （refraction wave method） and by the subsurface method like PS logging. PS logging and RWM are direct methods to derive shear wave velocity and MASW retrieves shear wave through the inversion of the surface wave. In this work, the effectiveness of surface methods （MASW and RWM） is compared with PS logging in determining shear wave velocity. For this purpose, shear wave velocity results Vs30 of 12 PS logging and MASW surveys conducted in Mymensingh Municipality in Bangladesh have been utilized. Additionally, the shear wave velocity results of three PS logging have been compared with the refraction profiles of RWM survey conducted in Rooppur nuclear power plant site in Bangladesh. The relative discrepancy between RWM and PS logging is found less （ranges from -3.92 to 0.93） compared to MASW and PS logging （＋/-0.88 to 33.92）. The correlation coefficient of Vs30 derived from RWM and PS logging is observed much better （0.60） compared to MASW and PS logging （0.40）. The result is good considering the lateral lithologic variability and inherent differences among techniques. It is evident from the comparison that the RWM can be used as a cost-effective alternative to traditional borehole PS logging method for Vs30 determination and thus the number of down-hole logging tests might be significantly reduced.

The Expansion of a Wedge of Gas into Vacuum with Small Angle in Two-Dimensional Isothermal Flow

In this paper, the authors consider the expansion problem of a wedge of gas into vacuum for the two-dimensional Euler equations in isothermal flow. By the bootstrapping argument, they prove the global existence of the smooth solution through the direct method in the case 0 〈 θ 〈 -θ=arctan 1/（√2＋√5）, where θ is the half angle of the wedge. Furthermore, they get the uniform C^1,1 estimates of the solution to the expansion problem.

Symmetry Reduction of (2+1)-Dimensional Lax–Kadomtsev–Petviashvili Equation

he Lax-Kadomtsev-Petviashvili equation is derived from the Lax fifth order equation, which is an important mathematical model in fluid physics and quantum field theory. Symmetry reductions of the Lax-Kadomtsev- Petviashvili equation are studied by the means of the Clarkson-Kruskal direct method and the corresponding reduction equations are solved directly with arbitrary constants and functions.