• Title/Summary/Keyword: Fingerprints

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A preliminary study and its application for the development of the quantitative evaluation method of developed fingerprints on porous surfaces using densitometric image analysis (다공성 표면에서 현출된 지문의 정량적인 평가방법 개발을 위한 농도계 이미지 분석을 이용한 선행연구 및 응용)

  • Cho, Jae-Hyun;Kim, Hyo-Won;Kim, Min-Sun;Choi, Sung-Woon
    • Analytical Science and Technology
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    • v.29 no.3
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    • pp.142-153
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    • 2016
  • In crime scene investigation, fingerprint identification is regarded to be one of the most important techniques for personal identification. However, objective and unbiased evaluation methods that would compare the fingerprints with diverse available and developing methods are currently lacking. To develop an objective and quantitative method to improve fingerprint evaluation, a preliminary study was performed to extract useful research information from the analysis with densitometric image analysis (CP Atlas 2.0) and the Automated Fingerprint Identification System (AFIS) for the developed fingerprints on porous surfaces. First, inked fingerprints obtained by varying pressure (kg.f) and pressing time (sec.) to find optimal conditions for obtaining fingerprint samples were analyzed, because they could provide fingerprints of a relatively uniform quality. The extracted number of minutiae from the analysis with AFIS was compared with the calculated areas of friction ridge peaks from the image analysis. Inked fingerprints with a pressing pressure of 1.0 kg.f for 5 seconds provided the most visually clear fingerprints, the highest number of minutiae points, and the largest average area of the peaks of the friction ridge. In addition, the images of the developed latent fingerprints on thermal paper with the iodine fuming method were analyzed. Fingerprinting condition of 1.0 kg.f/5 sec was also found to be optimal when generating highest minutiae number and the largest average area of peaks of ridges. Additionally, when the concentration of ninhydrin solution (0.5 % vs. 5 %) was used to compare the developed latent fingerprints on print paper, the best fingerprinting condition was 2.0 kg.f/5 sec and 5 % of ninhydrin concentration. It was confirmed that the larger the average area of the peaks generated by the image analysis, the higher the number of minutiae points was found. With additional tests for fingerprint evaluation using the densitometric image analysis, this method can prove to be a new quantitative and objective assessment method for fingerprint development.

A preliminary study to determine the order of the latent fingerprint deposition on thermal paper - A short term study - (감열지상 잠재지문의 남겨진 순서결정에 대한 예비적 연구 - 단기연구 -)

  • Lim, Dong-A;Ok, Yun-Seok;Heo, Bo-Reum;Choi, Sung-Woon
    • Analytical Science and Technology
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    • v.30 no.5
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    • pp.279-286
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    • 2017
  • Determination of the order of latent fingerprints deposition on the surface of thermal paper, often found in crime scenes, is related to the study of time course and aging of fingerprints and can provide additional information in criminal investigations. A preliminary study was performed to determine the deposition order of fingerprints left with two different conditions of deposition pressure and time (in seconds) after 1 day intervals for 7 days on thermal paper (receipt and fax thermal paper) using an iodine fuming method. The resultant images of the visualized fingerprints were analyzed with densitometric image analysis to measure the changes in the areas of the ridges, which can be correlated to the deposition order. No significant variation was found with the different types of thermal paper. The average areas of the friction ridges increased gradually or were similar to the values from day 1 for 3 days, and then a continual decrease was shown from day 4 through day 7. The area values from day 6 and day 7 were less than half of those from day 1. Furthermore, the test with overlapped fingerprints showed the possibility of differentiation between fingerprints that are 1-3 and 6-7 days old based on the clarity visible to the naked eye. Additional experiments with the deposition conditions can prove that the current method is valuable for the determining the order of fingerprint deposition on thermal paper.

A Study on Adaptive Feature-Factors Based Fingerprint Recognition (적응적 특징요소 기반의 지문인식에 관한 연구)

  • 노정석;정용훈;이상범
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1799-1802
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    • 2003
  • This paper has been studied a Adaptive feature-factors based fingerprints recognition in many biometrics. we study preprocessing and matching method of fingerprints image in various circumstances by using optical fingerprint input device. The Fingerprint Recognition Technology had many development until now. But, There is yet many point which the accuracy improves with operation speed in the side. First of all we study fingerprint classification to reduce existing preprocessing step and then extract a Feature-factors with direction information in fingerprint image. Also in the paper, we consider minimization of noise for effective fingerprint recognition system.

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Hierarchical classification of Fingerprints using Discrete Wavelet Transform (이산 웨이블릿 변환을 이용한 지문의 계층적 분류)

  • Kwon, Yong-Ho;Lee, Jung-Moon
    • Journal of Industrial Technology
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    • v.19
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    • pp.403-408
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    • 1999
  • An efficient method is developed for classifying fingerprint data based on 2-D discrete wavelet transform. Fingerprint data is first converted to a binary image. Then a multi-level 2-D wavelet transform is performed. Vertical and horizontal subbands of the transformed data show typical energy distribution patterns relevant to the fingerprint categories. The proposed method with moderate level of wavelet transform is successful in classifying fingerprints into 5 different types. Finer classification is possible by higher frequency subbands and closer analysis of energy distribution.

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Translocation of DNA bases sandwiched between two graphene layers: an ab-initio study on their energetics and molecular fingerprints.

  • Shim, Yoon Su
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.442-445
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    • 2014
  • In this work, we studied the interactions of the complexes of a DNA base inserted between graphene layers through density functional theory (DFT) calculations. We find that there exists the negligible energy barrier as well as robust and distinguishable electronic fingerprints during the translocation of the DNA bases. Our result shows that the bilayer graphene can be a possible candidate for the future-generation of DNA sequencing device platform.

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Fingerprint Image Sequence Mosaicking in Touchless Fingerprint Sensor (비접촉식 지문센서에서의 지문 영상 시퀀스 융합)

  • Choi, Kyoung-Taek;Choi, Hee-Seung;Kim, Jai-Hie
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.377-378
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    • 2007
  • This paper proposes an system to generate rolled-equivalent fingerprints by mosaicking sequential images captured by an toothless device. To capture rolled-equivalent fingerprints, previous works use multiple cameras. However, the method in this paper captures sequential fingerprint images with a single camera and mosaic the images by estimating the transform between images through optical flow.

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Comparison of vacuum metal deposition (VMD) and powder method for developing latent fingerprint on plastic envelope surface (플라스틱 봉투 표면에서 지문을 현출하기 위한 Vacuum Metal Deposition (VMD)과 분말법의 비교)

  • Kim, Chaewon;Lee, Narae;Kim, Taewon;Yu, Jeseol
    • Analytical Science and Technology
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    • v.33 no.3
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    • pp.159-166
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    • 2020
  • Vacuum metal deposition (VMD) is effective to develop latent fingerprints on non-porous and semi-porous surfaces. VMD can be used in cases when fingerprints that can not be developed by generalized techniques or deposited on difficult surfaces. The recommended surfaces for VMD techniques include vinyl, polymer bills, magnetic coated tickets, etc. In this study, the minimum amount of gold input was explored for developing fingerprints from at least 12 hours to up to 28 days after deposit fingerprint on the pink high density polyethylene envelope (HDPE) and low density polyethylene envelope (LDPE), which are mainly used as delivery envelopes. And the results were compared with the effects of black powder and fluorescent powder. In addition, delivery envelopes used for delivery were collected, then classified as HDPE and LDPE and pseudo-operation test was performed. As a result, VMD method developed good quality of fingerprints.

Post-treatment Enhancement of Ninhydrin-treated Fingermark Using 1,2-IND/Zn (1,2-IND/Zn를 이용한 ninhydrin으로 처리한 지문의 후속 증강 연구)

  • Park, Eun-Jee;Jung, Ha-Na;Hong, Sung-Wook
    • The Journal of the Korea Contents Association
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    • v.18 no.5
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    • pp.105-114
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    • 2018
  • Ninhydrin traditionally used to develop fingerprints on paper is often limited in its use depending on background color and its enhancement effect differs depending on reagent reaction condition. Recently 1,2-indanedione(1,2-IND), etc. which has no limitation of background color has been used to visualize the fingermark on paper. Therefore, this study was carried out for enhancement of fingerprints after 1,2-IND/Zn treatment on paper treated with ninhydrin. Comparison between 1,2-IND/Zn reaction after ninhydrin treatment and single ninhydrin reaction were conducted under various methods. Result shows the fingerprints were enhanced when ninhydrin-treated fingerprints were treated with 1,2-IND/Zn, and their enhancement was observed even after 6 months.

A study on Visualization and Enhancement the Latent Fingerprints on Multi-colored Surfaces using the Forensic Light Sources (법광원을 이용한 복잡한 배경의 잠재지문 시각화 및 증강에 관한 연구)

  • Cho, Hyeong-Woo;Koh, Hyun-Seo;Han, Sang-Gyoun;Yu, Je-Seol
    • The Journal of the Korea Contents Association
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    • v.16 no.3
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    • pp.72-80
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    • 2016
  • There are various methods of developing latent fingerprints from evidence found at crime scenes. Crime scene investigators should choose appropriate techniques among them depending on the conditions of the evidences. In this study, we compared the three methods using forensic light sources to develop latent fingerprints on multi-colored surfaces. We selected the various samples according to color, shape and texture of the surfaces and developed the latent fingerprints using fluorescent powder, IR(Infrared) photography and Episcopic Co-axial Illumination. Fluorescent powder was highly effective on all surfaces. IR photography was also effective, but only on the not dark surfaces. Episcopic Co-axial Illumination was effective only on the flat and polished surfaces. Although fluorescent powder was fine regardless of the characteristics of the surfaces, IR photography was better on certain surfaces.

Fingerprint Classification using Multiple Decision Templates with SVM (SVM의 다중결정템플릿을 이용한 지문분류)

  • Min Jun-Ki;Hong Jin-Hyuk;Cho Sung-Bae
    • Journal of KIISE:Software and Applications
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    • v.32 no.11
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    • pp.1136-1146
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    • 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.