• Analytical Science and Technology
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• v.22 no.2
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• pp.166-171
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• 2009

Powder method is simple and very effective method for developing latent finger and palm print in crime scene. This technique has been actively studied to enhance effectiveness. In general, the evaluation for developing powder is mainly performed by the subjective opinion of researcher from comparison of the results obtained with existing and new one to develope finger and palm deposition. The purpose of this work is to present objective method of powder-treated latent fingerprint for evaluating method by developing efficiency. We indicated three evaluating methods of objective developing efficiency, which are measuring the number of minutiae in same sections on print, scattering level of developing reagent and contrast between developing reagent and background materials.

• Fire Science and Engineering
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• v.26 no.6
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• pp.7-14
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• 2012

This paper is to develop analytical techniques of flammable liquids which have been used for accelerating fire in accidental fires and arsons. We tested the temperature distribution of ceiling, fire patterns on the floor, and existence of flammable liquids and a check with GC/MS about flammable liquids comparing with papers, newspapers, and clothing. Research findings are as follows. The temperature of ceiling is influenced by flame. So gasoline and thinner was observed that combustible materials would be burned by flame. The fire patten on the floor was observed that flammable liquids had specialized pattern comparing combustible materials. When combustible materials on the PVC (Polyvinyl chloride) floor was burned, they didn't react to the gas detector. But flammable liquids had opposite results. After 7 days, we identified components of fire residues with the GC/MS (Gas Chromatography/Mass Spectrometry) about existence of flammable liquids and got components of flammable liquids. Fire investigation is a complicated processes. But we understand characteristics of materials, need detail investigations, and use the GC/MS to analyse flammable materials.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.383-391
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• 2020

Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.321-328
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• 2006

In the present study extensisve numerical experiments are conducted using the CFD code, FLUENT, to investigate the energy dissipation due to perforated walls for various wall-thickness and flow conditions. A new empirical formula for energy loss coefficient considering the effect of the thickness of perforated wall is obtained based on the results of computational experiments. It is found that the energy loss coefficient decreases as the wall-thickness increases and the maximum coefficient reduction reaches upto 40% of the value calculated using the conventional formulas for the sharp-crested orifice. To check the validity of the new formula the reflection coefficient of waves due to perforated wall is evaluated and compared with the results of existing theories and hydraulic experiments. The result shows that the new formula is superior to the conventional ones.

• Fire Science and Engineering
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• v.29 no.4
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• pp.73-80
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• 2015

In this study, the conditions of explosion range of gasoline, which is used as combustion improver, are experimentally analyzed. Two types of compartment, which is the small scale ($0.5m{\times}0.5m{\times}1.0m$) and the middle scale ($0.5m{\times}0.5m{\times}1.0m$), are mocked-up and the auto-control systems are installed in order to measure the vaporized gasoline and the moment of pressure, ignition time and maximum pressure. In case the maximum flammable limit of gasoline is up to 22.4 Vol% not the generalized range of 1.4~7.6 Vol% when nichrome igniter of $700^{\circ}C$ is used. These results can be appled to the analytical prediction of fire identification in the field of explosion.

• Fire Science and Engineering
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• v.28 no.4
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• pp.64-72
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• 2014

Flammable liquids residues in fire debris and pyrolysis products of flammable materials were analyzed by using Gas detecting tube, Gas Chromatograph/Mass Spectrometers (GC/MS), and Pyrolyzer. Comparison studies between chemical components detected in debris fired with and without Flammable liquids were performed. Though Flammable liquids were not present in debris, Gas detecting tube colors were also changed. Chemical components produced from conventional combustions were different from those produced from pyrolysis. Due to the difference of the reaction conditions between combustions and pyrolysis, different chemical products were produced. Petrochemical products of PVC wood-linoleum block could produce ignitable chemicals, such as toluene, ethylbenzene, undecane, and dodecane. So, for better fire investigation more consideration of those chemicals will be porformed.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.569-575
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• 2017

Forensic light source is commonly used for enhancing evidence in a nondestructive way. Latent fingerprints play an important role in an aspect of crime scene investigation. In this study, researchers compared enhancement of standard fingerprints treated with DFO and 1,2-IND in accordance with laser and LED light sources. As a result, laser light source has a better effect rather than LED light sources. However, each light source has strengths and weaknesses in terms of performance and portability. Therefore, researchers recommend that crime scene investigators need to use laser and LED light sources depending on the situation.

• Analytical Science and Technology
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• v.23 no.1
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• pp.83-88
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• 2010

For the evaluation of our laboratory's 11-nor-${\Delta}^9$-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) urinalysis test, THCCOOH urinalysis test was carried out with Certified Reference Material (CRM). The used CRM was THCCOOH in freeze-dried urine produced by NIST as Standard Reference Material 1507b. Comparing the estimated value of our laboratory with CRM, the results was coincided in the confidence level of approximately 95%.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.169-174
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• 2006

A distinctive difference of hydrocarbon in crude oil and petroleum products exists. Depending on the origin where it comes from, crude oil shows its own unique pattern which is different from petroleum products containing characteristics according to their operating process and production period. A process of mixing behavior in a tank containing residual amounts of oil draws its own pattern when analysis is conducted. The analytical process described above is named oil fingerprint method. This study investigates an effectiveness of the method for comparing data sets produced by conventional gas chromatography with mass spectrometer (GC/MS) and comprehensive two-dimensional gas chromatography (GC X GC) which is known as powerful new technology for chemical analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.4
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• pp.325-332
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• 2002

In the process of designing pareto optimal insurance contract, it is necessary to assume that insurance contract conditions are endogenous to build a model. The expected utility, the non-expected utility and the state-dependent utility function can be applied as a insurance decision making principle. The insurance costs may have the linear, convex, and concave ralationship with the indemnity schedule. However, the sunk cost and fixed cost must be recognized. The deductible which decides whether an insurance contract to be a full or partial insurance contract can exist in the forms of straight deductible or diminishing deductible. Indeciding the level of deductible, the types of the insurance and the risks to be insured should be the deciding factors. Especially for recall insurance, there is relatively high chance that the recalling company being bankrupt. Therefore, the possibility of bankrupcy should be the considering factor in deciding the policy limit. The existence of the incomplete market and uninsurable background risk should be understood as restricting conditions of the pareto-optimal insurance contract.