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Dongguang Li

Publications and source records attributed to Dongguang Li.

2 recordsLinked to original sources

Ballistics projectile image analysis for firearm identification.

This paper is based upon the observation that, when a bullet is fired, it creates characteristic markings on the cartridge case and projectile. From these markings, over 30 different features can be distinguished, which, in combination, produce a "fingerprint" for a firearm. By analyzing features within such a set of firearm fingerprints, it will be possible to identify not only the type and model of a firearm, but also each and every individual weapon just as effectively as human fingerprint identification. A new analytic system based on the fast Fourier transform for identifying projectile specimens by the line-scan imaging technique is proposed in this paper. This paper develops optical, photonic, and mechanical techniques to map the topography of the surfaces of forensic projectiles for the purpose of identification. Experiments discussed in this paper are performed on images acquired from 16 various weapons. Experimental results show that the proposed system can be used for firearm identification efficiently and precisely through digitizing and analyzing the fired projectiles specimens.

Algorithms↗

The importance of temporal effects in evaluating the prognostic impact of joint ERPR expression in premenopausal women with node-positive breast cancer.

Although there is abundant information about the independent effects of estrogen receptor (ER) and progesterone receptor (PR) on outcomes of breast cancer, comparatively little is known about the impact of joint (ER+PR+, ER+PR-, ER-PR+ and ER-PR-) ERPR expression. The purpose of this study was to evaluate the prognostic relevance of joint ERPR expression to progression free survival (PFS). Data from 710 patients with a median follow-up of 119 months has been analyzed retrospectively. Our results indicate that the effect of the ER+PR+ phenotype on PFS was significantly time-dependent (p<0.0001); favorable in the first 3 years of follow-up (HR=0.67, p=0.0175) compared to ER-PR- phenotype, but unfavorable during the later follow-up period (HR=2.89, p=0.0006). Similar patterns were also observed for ER+PR- and ER-PR+ phenotypes, but the effect did not reach statistical significance. In the tree-based analysis, we found that, among patients with more than 4 positive nodes and age greater than 40, those with ER-PR+ tumors had the worst PFS ( p=0.025), and among patients with 1--3 positive nodes and stage of T1 and T2, those with ER+PR- had the worst outcome ( p=0.006). Our results demonstrate that failure to recognize the time-varying effect of the steroid hormonal receptors can obscure their role in the prognosis of breast cancer. We also provide more evidence to support the concept that ER-PR+ is a real group representing a distinct clinical entity.

Adult↗