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Gulou, China

Hu B.,Fuzhou University | Weng B.,Fuzhou University | Ruan S.,Fujian Police College
CSAE 2012 - Proceedings, 2012 IEEE International Conference on Computer Science and Automation Engineering | Year: 2012

The robustness of the traditional face recognition methods is not strong, and the instantaneity and precision of the traditional face retrieval methods are not high. In order to dissolve these problems, a novel face image recognition and retrieval method based on feedback log information is presented. It first extracts the feature vectors by SIFT (Scale Invariant Feature Transform). These extracted features are invariant to illumination, rotation, translation, scale and expression. Then eliminates the false matching points according to the improved SIFT feature vectors matching criteria, calculates the distance between the face images with the residual matching points, and completes the first retrieve, with the result of returning the top 50 similar images. After this, refines the first result by relevance feedback strategy of the feedback log information to solve the semantic gap between the high-level semantics and low-level features of images. The experimental results show that, the proposed method has higher retrieval accuracy and more fast retrieval speed, and it is more suitable for real-time video investigation applications than the traditional relevance feedback. © 2012 IEEE. Source


Jiang J.,Fudan University | Jiang J.,Fujian Police College | Zhang J.,Institute of Forensic Science | Liu X.,Fengtai Bureau of Beijing Municipel Public Security Bureau
Chinese Journal of Forensic Medicine | Year: 2010

Objective: To estimate the injury time and to establish objective evidence of forearm bone fracture by analyzing the digital X-ray radiographs. Methods: 620 follow-up radiographs of fractured ulna and/or radius shaft in 70 patients were examined by eyes and assessed qualitatively by means of Photoshop image analysis system. The procedure of fracture healing was classified 5 grades according to the assessment standard of fracture healing by X-ray. The time interval between injury and the appearance of the radiographic signs were analyzed by SPSS 11.5 statistical software among the different groups of therapy and among the different groups of age. Results: The age and operative therapy were the independent factors which could affect the development or duration of radiographic features according to the index of fracture healing, therefore the healing time chart were listed among different groups striated by the age and the way of therapy. According to the time chart of grade III healing, it was shown that the mean healing time was 12.2 weeks in the group of young by gypsum fixing, 18 weeks in the young by operation, and only 5.8 weeks in juvenile by gypsum fixing. Conclusion: The injury time of fracture is estimated more accurately by observing the X-radiographic signs of digital image in the different groups of age. Source


Meng L.,Fujian Police College | Zhu B.,Fujian Police College | Zheng K.,Fujian Police College | Zhang W.,Traffic Management Bureau | Meng P.,Chinese Peoples Public Security University
Chinese Journal of Chromatography (Se Pu) | Year: 2015

A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) has been developed for the determination of multiple drugs of abuse in biological samples by gas chromatography-triple quadrupole mass spectrometry (GC-QQQ-MS). A total of 100 μL of toluene as extraction solvent was dropped into the sample solution. Then the mixture was sonicated drastically in an ultrasonic bath for 3 min with occasional manual shaking to form a cloudy suspension. After centrifugation at 10 000 r/min for 3 min, the upper layer of low-density extractant was withdrawn and injected into the GC-QQQ-MS for analysis. The parameters affecting extraction efficiency have been investigated and optimized. Under the optimum conditions, good linearities were observed for all analytes with the correlation coefficients ranging from 0.998 4 to 0.999 4. The recoveries of 79.3%-100.3%with RSDs<5.7% were obtained. The LODs (S/N = 3) were in the range from 0.05 to 0.40 μg/L. UA-LDS-DLLME technique has the advantages of less extraction time, suitable for batches of sample pretreatment simultaneously, and higher extraction efficiency. It was successfully applied to the analysis of amphetamines in real human urine samples. Source


Meng L.,Fujian Police College | Zhang W.,Traffic Management Bureau | Meng P.,Chinese Peoples Public Security University | Zhu B.,Fujian Police College | Zheng K.,Fujian Police College
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2015

Two microextraction techniques based on hollow fiber liquid-phase microextraction (HF-LPME) and ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) had been applied for the determination of drugs of abuse (methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, methcathinone, ketamine, meperidine, and methadone) in urine and blood samples by gas chromatography-mass spectrometry. Parameters affecting extraction efficiency have been investigated and optimized for both methods. Under the optimum conditions, linearities were observed for all analytes in the range 0.0030-10. μg/ml with the correlation coefficient (R) ranging from 0.9985 to 0.9995 for HF-LPME and in the range 0.0030-10. μg/ml with the R ranging from 0.9985 to 0.9994 for DLLME. The recovery of 79.3-98.6% with RSDs of 1.2-4.5% was obtained for HF-LPME, and the recovery of 79.3-103.4% with RSDs of 2.4-5.7% was obtained for DLLME. The LODs (S/N. =. 3) were estimated to be in the range from 0.5 to 5. ng/ml and 0.5 to 4. ng/ml, respectively. Compared with HF-LPME, the UA-LDS-DLLME technique had the advantages of less extraction time, suitability for batches of sample pretreatment simultaneously, and higher extraction efficiency, while HF-LPME has excellent sample clean-up effect, and is a robust and suitable technique for various sample matrices with better repeatability. Both methods were successfully applied to the analysis of drugs of abuse in real human blood sample. © 2015 Elsevier B.V. Source


Zhu B.,Fujian Police College | Meng L.,Fujian Police College | Zheng K.,Fujian Police College
Forensic Science International | Year: 2014

Recently a new type of mixed drug oral solution has become prevalent in China, the identification and quantitative inspection of which are demanded in conviction and sentencing as well as drug intelligence. In 2013, inspection was carried out on 86 bottles of substances seized in 13 cases with the adoption of GC-MS methodology for qualitative identification and GC-FID for quantitative identification. 94.1% of the samples were light yellow turbid liquid while 95.3% were detected with more than two drugs. Detection rate of methamphetamine, MDMA and ketamine was up to 89.5%, 37.2% and 83.7% respectively. Quantitative inspection results indicated that concentrations of methamphetamine, MDMA, ketamine were 0.04-13. mg/mL, 0.04-29. mg/mL and 0.1-34. mg/mL, respectively. Appearance, composition and drug concentration of samples vary from case to case. © 2014 Elsevier Ireland Ltd. Source

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