• Analytical Science and Technology
• /
• v.29 no.6
• /
• pp.283-292
• /
• 2016

Conventional fingerprint powders used during crime scene investigations pose potential health hazards. Thus, multiple natural replacement powders, including squid ink powder, indigo and rice powder were used to develop (visualize) latent fingerprints on non-porous surfaces (e.g., glass, plastic and tile). Fingerprints developed using the natural powders were compared using the Automatic Fingerprint Identification System (AFIS) with those developed with traditional black powder. The peak areas of ridges were also compared using densitometric image analyses. Collectively, objective and quantitative evaluation methods were developed. The effectiveness of natural powders varied depending on the surface but, in general, squid ink powder performed well on most surfaces. Indigo powder performed well on tile surfaces, while rice powder performed well on glass surfaces. Plastic was the most difficult surface from which to develop fingerprints. Image analysis using Field Emission Scanning Electron Microscopy (SEM) demonstrated the importance of the size and shape of natural powder particles to properly adhere to the ridges. Although densitometric image analyses did not correlate the number of minutiae and ridge peak areas, an unbiased, objective evaluation method would be possible using image analyses with a reference image. Additional experimentation will yield safe and cost-effective natural powders with which adequate fingerprint development can be performed.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.3
• /
• pp.61-69
• /
• 2007

This paper proposes new preprocessing algorithm to extract minutiae in the process of fingerprint recognition. Fingerprint images quality enhancement is a topic phase to ensure good performance in a topic phase to ensure good performance in a Automatic Fingerprint Identification System(AFIS) based on minutiae matching. This paper proposes an algorithm to improve fingerprint image preprocessing to extract minutiae accurately based on directional filter. We improved the suitability of low quality fingerprint images to better suit fingerprint recognition by using valid ridge vector and ridge probability of fingerprint images. With the proposed fingerprint improvement algorithm, noise is removed and presumed ridges are more clearly ascertained. The algorithm is based on five step: computation of effective ridge vector, computation of ridge probability, noise reduction, ridge emphasis, and orientation compensation and frequency estimation. The performance of the proposed approach has been evaluated on two set of images: the first one is self collected using a capacitive semiconductor sensor and second one is DB3 database from Fingerprint Verification Competition (FVC).

• Analytical Science and Technology
• /
• v.33 no.4
• /
• pp.197-207
• /
• 2020

The current comparison methods with scoring systems that are used to compare visualized latent fingerprints (LF) have disadvantages. Evaluators using these methods are prone to make errors and fail to discriminate LFs correctly to notice the differences among those LFs. Therefore, a comparative and quantitative evaluation method that is capable of obtaining more objective and quantitative results is needed. Densitometric image analysis (DIA) is used in other fields as a reliable semi-quantitative comparison method. To apply DIA to LFs, the potential variables that can occur during the DIA process were tested. The visualized ridges of LFs can be compared using the concentration of dots against the background to make it possible to analyze the ridges with DIA. The variables that can be present during the DIA process include the thickness of the analysis line, the number of ridges to be taken, the number of divided zones within each of the fingerprints, and the angles of the analysis line against the ridge lines that were selected. From the analysis of the inked fingerprints and circular lines that are similar to fingerprints, the angle of the analysis lines with the ridge line was the most significant variable. The preliminary test result was applied to the comparison of LFs that were developed with the powder method and then compared with the AFIS analysis. A similar trend was found, and a more detailed and semi-quantitative comparison of the visualized LFs was possible. In the future, it is necessary to check the evaluative ability of the DIA method by analyzing the visualized LFs with other various development methods. However, DIA is currently an option that can be used as an objective comparative evaluation method during fingerprint studies with supplementary role.

• Journal of KIISE:Software and Applications
• /
• v.32 no.11
• /
• pp.1136-1146
• /
• 2005

Fingerprint classification is useful in an automated fingerprint identification system (AFIS) to reduce the matching time by categorizing fingerprints. Based on Henry system that classifies fingerprints into S classes, various techniques such as neural networks and support vector machines (SVMs) have been widely used to classify fingerprints. Especially, SVMs of high classification performance have been actively investigated. Since the SVM is binary classifier, we propose a novel classifier-combination model, multiple decision templates (MuDTs), to classily fingerprints. The method extracts several clusters of different characteristics from samples of a class and constructs a suitable combination model to overcome the restriction of the single model, which may be subject to the ambiguous images. With the experimental results of the proposed on the FingerCodes extracted from NIST Database4 for the five-class and four-class problems, we have achieved a classification accuracy of $90.4\%\;and\;94.9\%\;with\;1.8\%$ rejection, respectively.

• The KIPS Transactions:PartB
• /
• v.10B no.5
• /
• pp.497-502
• /
• 2003

Fingerprint classification plays a role of reduction of precise joining time and improvement of the accuracy in a large volume of database. Patterns of fingerprint are classified as 5 patterns : left loop, right loop, arch, whorl, and tented arch by numbers and the location of core point and delta point. The existing fingerprint classification is useful in a captured fingerprint image of core point and delta point using paper and ink. However, this system is unapplicable in modern Automatic Fingerprint Identification System (AFIS) because of problems such as size of input and way of input. To solve the problem, this study is to suggest the way of being able to improve accuracy of fingerprint by fingerprint classification based on the entropy of ridges using fingerprint captured mage of core point and prove this through the experiment.

• Nuclear Engineering and Technology
• /
• v.48 no.2
• /
• pp.482-494
• /
• 2016

The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

• Korean journal of applied entomology
• /
• v.27 no.1
• /
• pp.28-34
• /
• 1988

Henosepilachna vigintioctomaculata (Motschulsky) (Coleoptera: Coccinellidae), important pests of agricultural crops in Korea, including eggplant and potato, were collected in the Kyonggido area each summer from 1983 to 1986. Data were recorded for rates of parasitism against each host stage and seasonal activity. The parasitoids NothoserPhus afissae (Watanabe), (Hymenoptera: Proctotrupidae), Uga menoni (Kerrich), (Hymenoptera: Cha1cididae), and Pediobius foveolatus (Crawford), (Hymenoptera: Eulophidae) were reared from the host insects. A solitary larval parasitoid, N. afissae, was reared from 2nd to 4th instar brval hosts, with parasitism being highest in the 3rd instar collection. U. menoni, a solitary larval-pupal parasitoid, was reared from 3rd instar larvae to pupae, and parasitism was highest in the pupal collection. N. afissae and U. menoni occurred during June to September. N. afissae showed relatively high parasitism during the entire study period as compared with other species, while parasitization by U. menoni was highest in July. P. foveolatus, a gregarious larval parasitoid, did not generally appear until September, although it appeared in early August in the southern part of Korea. The number of P. foveolatus emerging from a mummy varied, ranging from 7 to 26 (mean = 13. 8).

• Korean Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.263-270
• /
• 2010

This is a research on development of water purification equipment called artificial floating island (=AFI) for the stagnant water area which can secure exuberant landscape and water-friendility. The equipment devised in this study is designed to make up the weakness of conventional AFIs and improves the removal efficiency of pollutants using the mixture of media and plants. The air compressor positioned at the inlet releases air with inflow continuously, the water pump at the outlet sprays as a form of fountain with causing a disturbance on stable water column, then, both of them contribute improvement of water quality over a large area. We applied Bio-stone as a media in this system and performed an experiment of pre-efficiency test, and we concluded that the higher pollutants concentration of inflow, the higher removal efficiency we obtained. At the result of lab-scale experiment, in the case of high-concentration inflow, in the removal efficiency of SS is 62.2%, BOD is 50.2%, COD is 55.1%, T-N is 31.6%, T-P is 38.4%. In addition, to evaluate the field application, we set up the facilities in Sin-gal lake located in Yongin-Si Gyeonggi-Do, and researched on the removal efficiency of outflow relative to the inflow. As a result, SS is 53.5%, BOD is 32.8%, COD is 36.9%, T-N is 22.6%, T-N is 33.2%.