Improved Collision Detection Algorithm Research Articles

Improved Collision Detection Of MD5 Using Sufficient Condition Combination

Abstract Counter-cryptanalysis uses cryptanalytic techniques to detect cryptanalytic attacks. It was introduced by Stevens with a collision detection algorithm that detects whether a message is one of a colliding message pair constructed using a collision attack. Later, Stevens and Shumow improved the collision detection against SHA-1 by using unavoidable conditions. However, there are no results improving collision detection against MD5 due to its weak diffusion properties. In this paper, an improved collision detection algorithm against MD5 is proposed by using the 14-bit sufficient condition combinations. This leads to the dividing the 223 classes into four sets. Each element, belonging to the first two sets, holds the same sufficient condition combination. Our new algorithm can classify 126 classes efficiently. The runtime is 28.6% of the previous collision detection method.

An improved collision detection algorithm based on OBB swept volume for virtual assembly

The speed and precision of collision detection are the main concerns in a virtual assembly environment. The calculation time and accuracy of conventional collision detection algorithms need to be improved. This paper introduces an improved algorithm called OSV (OBB swept volume) based on OBB (oriented bounding box) for continuous collision detection. A bounding volume boxes tree is built by using the OBB bounding boxes model. The rough collision detection is realized by separating axis testing. Then by the exact intersection test algorithm based on the triangular patches, the objects that might be on a collision course with others are further retested. Experiment results show that the algorithm works accurately and has a higher accuracy rate than other similar methods.

An Improved Collision Detection Algorithm Based on GPU

In order to improve the speed of collision detection between objects in the large-scale and complex scene, this paper proposed an improved collision detection algorithm based on GPU, In this method, we first divided the virtual space into several grids to rule out the impossible intersecting objects rapidly using the GPU acceleration technology; secondly, we adopted parallel technology to build K - DOP bounding boxes for the objects in the same grids and then detected whether the K - DOP bounding boxes intervene or collide to conform the potential colliding primitive pairs; Finally we traveled the final triangle intersection tests on GPU. Compared to the traditional K-DOP compared bounding box collision detection, The algorithm can effectively improve the real-time collision detection.

An improved collision detection and cutting algorithm of the soft tissue in virtual surgical simulation

In virtual surgery simulation, we have to balance the realistic biomechanics behaviour and the system real-time performance, hence, the study of soft tissue deformation efficiency and authenticity remain a challenge. In this paper, we first describe a novel interactive method of using a computer mouse to manipulate objects instead of using the haptic device, which makes the system development more convenient. The partial information lost is a serious issue in the medical preoperative diagnosis and surgery planning. Then, we present an improved collision detection algorithm based on the strategy of triangular mesh classification, as well as a surface cutting algorithm based on removing the intersecting grid cells to avoid local deformation. Finally, experimental results show that the improved collision detection method has improved the collision query rate. Furthermore, the cutting algorithm is implemented more easily. Besides, it retains original information better, which helps improve the diagnosis accuracy.