• Title/Summary/Keyword: fuming

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A study on the distribution of latent fingerprints on paper knife sheaths (간이 칼집에서의 잠재지문 분포에 관한 연구)

  • Kim, Hyo-Mi;Park, Gi-Hyun;Lee, Su-Bhin;Yu, Je-Seol
    • Analytical Science and Technology
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    • v.34 no.6
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    • pp.251-258
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    • 2021
  • Knives are most frequently used as weapons in violent crimes. Criminals leave behind knife sheaths made of paper and tape at crime scenes. It is difficult to develop fingerprints using tape attached to a porous surface, resulting in the need to explore effective techniques for identifying fingerprints as well as the distribution of fingerprints on each surface, when evidence such as paper knife sheaths are found. In this study, 50 knife sheaths were prepared. The cyanoacrylate fuming (CA fuming) method was applied to develop fingerprints on the non-adhesive side of the tape, and a dual-purpose 1,2-indanedione/Zn (1,2-IND/Zn) reagent was used to separate tape from paper while simultaneously developing fingerprints on the paper. The fingerprints on the adhesive side of the tape were developed using Wet Powder Black®. Using the R statistical analysis program (The R Foundation for Statistical Computing), we used a heat map to indicate the location of fingerprints developed from each surface. More fingerprints were detected at the ends than in the center of the adhesive side of the tape, and although the non-adhesive sides of tape and paper did not present clear distribution patterns, many fingerprints were developed that had sufficient clarity for personal identification. The results of this study may be applicable for processing evidence when paper sheaths are found at crime scenes.

A study on Enhancement Effectiveness of Cyanoacrylate Fumed Fingermark by the Solvent of Rhodamine 6G (Rhodamine 6G 용매에 따른 CA 훈증 지문 증강 효과에 관한 연구)

  • Shim, Yea-Ra;Yu, Je-Seol
    • The Journal of the Korea Contents Association
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    • v.17 no.7
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    • pp.294-302
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    • 2017
  • In this study, latent fingermarks deposited in porous or non-porous surface was developed by cyanoacrylate fuming, and then the developed fingermark is enhanced by using Rhodamine 6G. Between water-based R6G and organic solvent-based R6G, author studied about which material have higher effectiveness in enhancing fingermark. In all seven types of surfaces depositing fingermark, water-based R6G have higher effectiveness in enhancing fingermark and lower surface coloring than organic solvent-based R6G. But because the surfaces found in crime scene have multicolor background and various quality, the additional study about various surfaces is needed.

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.

Development of 500 Kgf Thrust Liquid Propellant Rocket Engine (추력 500 Kgf 액체추진제 로켓엔진 개발)

  • 정동호;조용재;정규상
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1997.04a
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    • pp.3-10
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    • 1997
  • 본 연구에서는 추력 500 Kgf의 액체 추진기관을 설계, 제작 및 연소시험을 수행하여 연소 특성을 살펴보았다. 추진제로는 우주발사체 Booster용으로 폭넓게 사용되는 탄화수소계 연료인 kerosene과 산화제로 취급이 용이하고 저장 특성을 지닌 98 % White Fuming Nitric Acid(WFNA)를 사용하였고, 엔진 점화를 위해 WFNA와 접촉 발화성 (Hypergolic)을 갖는 Furfuryl Alcohol/Aniline 혼합액을 사용하였다. 로켓엔진은 20 Kgf/$cm^2$의 연소실 압력으로 500 Kgf의 평균 추력을 내도록 설계되었고, 연소실벽을 고온 연소가스로 부터 보호하기 위해 Film Cooling 방식을 적용하였다.

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Application of Frost Detecting Sensors in Refrigerators to Reduce Energy Consumption (냉장고 소비전력 저감을 위한 착상감지센서의 응용 연구)

  • 성창용;나승유;이희영
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.147-150
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    • 2000
  • Manual and predictive defrosting method is used in current refrigerators, which have several problems in terms of energy consumption and efficiency. fuming the defrosting system on by the amount of frost remains to be an important problem which has to be improved by refrigerator manufacturers. The sensing of the amount of frost by FDS(Frost Detecting Sensor) and its proper mounting point are investigated in the paper. Also the realization of actual defrosting system through experiments of operation, energy consumption and sensing mechanism is presented.

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CONVERGENCE RATE OF EXTREMES FOR THE GENERALIZED SHORT-TAILED SYMMETRIC DISTRIBUTION

  • Lin, Fuming;Peng, Zuoxiang;Yu, Kaizhi
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.5
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    • pp.1549-1566
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    • 2016
  • Denote $M_n$ the maximum of n independent and identically distributed variables from the generalized short-tailed symmetric distribution. This paper shows the pointwise convergence rate of the distribution of $M_n$ to exp($\exp(-e^{-x})$) and the supremum-metric-based convergence rate as well.

Micro Machining Technology Using Turning and Grinding ($\cdot$연삭에 의한 Micro Machining 기술)

  • 이응숙;제태진;신영재
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.7
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    • pp.5-13
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    • 2000
  • 지금까지의 기계산업의 발달은 대규모의 플랜트 혹은 대형기계 개발 등 대형화를 추구해왔다. 그러나, 최근 에너지와 환경에 대한 인식과 정보 통신, 전자산업, 생명산업의 발달로 소형화와 미세화의 기술 개발이 요구되고 있다. 그 예로 크기가 micron혹은 sub-millimeter 단위인 초소형기계 (Micro Machine)이 등장하게 되었고, 이러한 부품 및 시스템을 제작하는 미세 가공 기술을 Micro Machining이라고 할 수 있다.(중략)

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A Study on Backing Up the Bus Stop Line according to the Left Turn at Intersection on the Median Bus Lane (중앙버스전용차로의 교차로 좌회전에 따른 버스 정지선 후퇴에 관한 연구)

  • oh Hoon;Lee Jin-woo;Lee Young-ihn
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.2 s.5
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    • pp.75-83
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    • 2004
  • July 1, 2004 Seoul Metropolitan city is operating the Median Bus Lane System on Gangnam Main Street, Seongsan-Susaek-ro (Road) and Dobong- Mia-ro (Road) as one of the systematic reorganizations in public transportation. It has been assumed that there was an improvement in the speed of bus considering that the Median Bus Lane System practiced on Cheonho-daero (Main Street) since 1996 have had 35km/h on the average. If the Median Bus Lane goes into effect, there is a problem with the left turn on the crossroad. The buses go on the existing first lane so that the left fuming cars cannot help but turn left on the second lane. In case that the Median Bus Lane is put into practice, the left turn on the crossroad should not be allowed. However, if the left turn is not permitted on the crossroads in the aforementioned main streets, neighboring residents will complain about it and there will be some difficulties in finding other detour. On the premise that the prevalent left turn on the crossroads is allowed while the Median Bus Lane is being put into practice, this study suggests the separation of a stop line between buses and other vehicles as a way of fuming left in a safe manner and a way to calculate the appropriate distance.

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Development of Aged Fingermarks Deposited on Expanded Polystyrene(Styrofoam) Using Multi-metal Deposition I(MMD I) (Multi-metal Deposition I(MMD I)을 사용한 스티로폼 표면의 오래된 지문 현출)

  • Kim, Chae-Won;An, Jae-Young;Yu, Je-Seol
    • The Journal of the Korea Contents Association
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    • v.20 no.3
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    • pp.687-694
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    • 2020
  • Styrofoam is one of the most commonly used materials in everyday life, such as various packaging containers, toys, and buoys, and is likely to be found in crime scenes. However, due to the structural characteristics of Styrofoam, fingerprints cannot be deposited well. According to previous researches, powdering or cyanoacrylate fuming method was applied for developing fingerprints on Styrofoam. The purpose of this study was to investigate the effect of MMD I through comparative experiments of powdering. As a result of applying powder method and MMD I, MMD I was more effective than powder method on styrofoam.

Washing effect of fingermark contaminated with flammable liquids (인화성액체에 오염된 지문의 세척 효과)

  • Ho-Won, Jang;Ji-Yun, Kwon;Hyo-Mi, Kim;Seung-Ju, Yoo;Sungwook, Hong
    • Analytical Science and Technology
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    • v.35 no.6
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    • pp.237-241
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    • 2022
  • The effect of washing fingerprints deposited on glass that were contaminated with a flammable liquid (gasoline, kerosene, diesel, and thinner) was studied by washing with hexane or heptane. The fingerprints were visualized using fuming cyanoacrylate, followed by basic yellow 40 staining. After comparing the washing effect, by dividing one fingerprint into four sections, it was confirmed that the ridge detail was damaged by dissolving the fingerprints in flammable liquid. As a result of washing fingerprints contaminated with flammable liquids using hexane or heptane, fingerprints contaminated with gasoline, kerosene, and thinner did not show a washing effect because the ridge detail was damaged at the time of contamination, and only fingerprints contaminated with diesel exhibited improved ridge detail quality. Because hexane and heptane washing damage the ridge detail, it was found that fingerprints contaminated with gasoline, kerosene, and thinner were better enhanced directly without the washing process. In addition, it was found that the amount of the washing solvent and contact time should be minimized when washing fingerprints contaminated with diesel.