• 한국정보통신학회논문지
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• 제20권9호
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• pp.1649-1656
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• 2016

기존의 센서 기반 화재 감지 시스템은 주변 환경이 센서에 미치는 요인들에 따라 성능이 크게 제한될 수 있다. 이러한 문제를 해결하기 위해 영상 기반의 화재 감지 시스템이 다수 등장했지만, 영상에서 화염의 특성을 사람이 직접 정의하여 알고리즘을 개발하기 때문에 유사 개체에 대해 오경보를 발생시킬 수 있다. 또한 영상 프레임간의 움직임을 이용할 경우, 네트워크가 원활하지 않은 환경에서는 의도한 알고리즘이 정확하게 동작하지 않는 단점이 있다. 본 논문에서는 입력 영상 프레임으로부터 색상정보를 이용하여 화염의 후보 영역을 먼저 검출한 다음, 학습된 CNN(Convolutional Neural Network)을 활용해서 최종적으로 화재를 감지하는, CNN을 활용한 영상 기반의 화재 감지 방법을 제안하였다. 또한, 검출률과 미검출율 및 오검출률의 비교를 통해서 기존 연구에 비해 성능이 크게 향상되었음을 보였다.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1976-1980
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• 2010

A simple and reliable method has been developed to selectively separate and concentrate trace amounts of Fe(III) ions from water and food samples by using flame atomic absorption spectrometry. A new reagent, 5-hydroxy-4-ethyl-5,6-di-pyridin-2-yl-4,5-dihydro-2H-[1,2,4] triazine-3-thione, was synthesized and characterized by using FT-IR spectroscopy and elemental analysis. Effects of pH, concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of Fe(III) were investigated. The optimum pH was found to be 5. Eluent for quantitative elution was 10 mL of 2 M HCl. The preconcentration factor of the method, detection limit (3s/b, ${\mu}gL^{-1}$) and relative standard deviation values were found to be 25, 4.59 and 1%, respectively. In order to verify the accuracy of the method, two certified reference materials (TMDA 54.4 lake water and SRM 1568a rice flour) were analyzed. The results obtained were in good agreement with the certified values. The method was successfully applied to the determination of Fe(III) ions in water and food samples.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.861-865
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• 2002

A sensitive method for the determination of trace copper(II) after the preconcentration by adsorbing its cupferron complex onto microcrystalline benzophenone was developed.Several experimental conditions such as the pH of sample solution,concentration of cupferron, amount of benzophenone and atirring time were optimized. Trace compper(II) in 100mL solution was chelated with $3.0\;{\times}\;10^3$ M cupferron at pH 5.0. After 0.20g benzophenone, The benzophenone adsorbing Cu-cupferron complex was filtered and then Cu-cupferron complex was desorbed in 10 mL ethanol. Copper was determined by a flame atomic absorption spectrophotomethry. The interfering effects of diverse concomitant ions were investigated. Fe(III) interfered seriously with, but the interference by Fe(III) was completely eliminated by adjusting the concentration of copferron to $5.0\;{\times}\;10^3$ M. The detection limit of this method was 8.6${\times}$10 M(5.5 ngmL$^1$). Recoveries of 97% and 96% were obtained for Cu(II) in a stream water and a brass sample, respectively. Based on the results from the experiment. this proposed technique could be applied to the determination of copper(II) in real samples.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1133-1136
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• 2004

The need for highly reliable methods for the determination of trace metals is recognized in analytical chemistry and environmental science. A method based on the cloud-point extraction (CPE) technique for the trace analysis of Pb and Cu in water samples is described in this study. The analytes in the initial aqueous solution are complexed with pyrogallol, and 0.1%(w/v) Triton X-114 is added as surfactant. Following phase separation at $50^{\circ}C$, based on the cloud point of the mixture and dilution of the surfactant-rich phase with acidified methanolic solution, the enriched analytes are determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, the enrichment factors of Pb and Cu were found to be 72 and 85, respectively. Under optimum conditions, the preconcentration of 60 mL of samples in the presence of 0.1%(w/v) Triton X-114 permitted the detection of 0.4 ${\mu}gL^{?1}$ of Pb and 0.05 ${\mu}gL^{?1}$ of Cu. The proposed method was applied successfully to the determination of Pb and Cu in water samples.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1309-1313
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• 2004

A simple and reliable method has been developed to selectively separate and concentrate trace amounts of thallium ion from real samples for the subsequent measurement by flame atomic absorption spectrometry (FAAS). Thallium ions are absorbed quantitatively during passage of aqueous real samples through an octadecyl bonded silica membrane disk modified by 4-(4-Chloro-phenylazo)-2-[(4-hydroxy-phenylamino)-methyl]-phenol. The retained $Tl^+$ ions are then stripped from the disk quantitatively with a minimal amount of thiosulfate solution as eluent. The proposed method permitted large enrichment factors of about 130 and higher. The relative standard deviation for ten replicate extraction of thallium from 1 L samples containing 5 ${\mu}g$ thallium is 1.2%. The break through volume for 5 ${\mu}g$ thallium is 1000 mL. The limit of detection of the proposed method is 11.2 ng of $Tl^+$ per 1000 mL. The effects of various cationic interferences on the recovery of thallium in binary mixtures were studied. The method was applied to the recovery of $Tl^+$ ions from natural water and human hair samples.

• 한국추진공학회지
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• 제11권3호
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• pp.65-72
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• 2007

화재는 인류가 우주 여행을 하거나 우주에서 체류하고자 할 경우, 특히 조심해서 신경을 써야 할 부분이다. 지구상에서와는 달리, 우주에서는 화재를 피하여 외부로 도망을 칠 수도 없고, 진화를 위해 소방서에 도움을 요청할 수도 없다. 따라서 최선책은 화재를 미연에 방지하는 것이 될 것이다. 그러나, 우주에서는 화재가 발생하였을 때, 그 화염의 행태가 지구상에서와는 다른 양상을 띄게 된다. 그 이유는, 지구상에 있는 모든 물질에 작용하는 중력이 우주에서는 없거나 작기 때문이다. 본 논문에서는 미소 중력하에서의 화염의 행태에 대하여 중요한 부분의 연구 결과를 소개하고, 이에 근거하여 유인 우주 탐사선과 우주 정거장 등에서 화염을 방지, 감지, 진화하는 연구에 대하여 미국 NASA의 FPDS 프로그램을 바탕으로 하여 소개하였다.

• Journal of the Korean Wood Science and Technology
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• 제42권4호
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• pp.393-406
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• 2014

방염제 도포 후 나타나는 목조건축물의 문제점을 파악하기 위해 통계자료 분석 및 현장조사를 수행하였다. 방염제 도포 후 백화현상과 단청 박락현상이 목조건축물에서 가장 빈번히 나타났다. 이러한 문제점은 기둥, 연목, 가구부재 등 방염제의 도포가 상대적으로 많이 이루어지는 건축물의 상부에서 가장 높게 나타났다. 현장에서 방염제를 도포한 건물과 도포하지 않은 건물을 파악하기 위해 P-XRF를 이용하여 총 20개 종의 원소를 분석하였다. 이 중 현장의 모든 방염제 처리구에서 황 원소(S)가 나타났기 때문에 이를 방염제 도포의 탐지자로 설정하였다. 이를 통해 현장에서 방염제의 도포를 확인할 수 있는 비파괴분석을 방법을 정립할 수 있었다. 실제 송광사(전남 순천)의 목조건축물을 대상으로 한 잔류성분분석을 통해 실제 현장적용이 가능함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.829-835
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• 2011

A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent, respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to $300\;ng\;mL^{-1}$ of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of $0.1\;ng\;mL^{-1}$. The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and $10.0\;ng\;mL^{-1}$ were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2813-2818
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• 2010

A novel method was developed for the speciation of chromium in natural water samples based on homogeneous liquid-liquid extraction and determination by flame atomic absorption spectrometry (FAAS). In this method, Cr(III) reacts with a new Schiff's base ligand to form the hydrophobic complex, which is subsequently entrapped in the sediment phase, whereas Cr(VI) remained in aqueous phase. The Cr(VI) assay is based on its reduction to Cr(III) by the addition of sodium sulfite to the sample solution. Thus, separation of Cr(III) and Cr(VI) could be realized. Homogeneous liquid-liquid extraction based on the pH-independent phase-separation process was investigated using a ternary solvent system (water-tetrabutylammonium ion ($TBA^+$)-chloroform) for the preconcentration of chromium. The phase separation phenomenon occurred by an ion-pair formation of TBA and perchlorate ion. Then sedimented phase was separated using a $100\;{\mu}L$ micro-syringe and diluted to 1.0 mL with ethanol. The sample was introduced into the flame by conventional aspiration. After the optimization of complexation and extraction conditions such as pH = 9.5, [ligand] = $1.0{\times}10^{-4}\;M$, [$TBA^+$] = $2.0{\times}10^{-2}\;M$, [$CHCl_3$] = $100.0\;{\mu}L$ and [$ClO_4$] = $2.0{\times}10{-2}\;M$, a preconcentration factor (Va/Vs) of 100 was obtained for only 10 mL of the sample. The relative standard deviation was 2.8% (n = 10). The limit of detection was sufficiently low and lie at ppb level. The proposed method was applied for the extraction and determination of chromium in natural water samples with satisfactory results.

• 한국산업보건학회지
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• 제11권3호
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• pp.249-253
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• 2001

The purpose of this study is the development of the simple and precise sampling and analysis method of methyl isocyanate(MIC) in the work place as their secondary aliphatic amine derivatives by gas chromatography with flame ionization detector. The urea derivatives are quantitatively and simultaneously derived from MIC with secondary aliphatic amines such as dipropylamine(DPA), dibutylamine(DBA), and dipentylamine (DAA) in methylene chloride. The method is based on sampling glass tube in XAD-2 resin which is coated with secondary aliphatic amines. The samples are desorbed by $2m{\ell}$ methylene chloride and analysed using gas chromatography with flame ionization detector(GC/FID). In the results, the detection limit of the overall procedure and reliable quantity are $0.020-0.027{\mu}g$($1.347-1.740{\mu}g/m^3$(0.529-0.684 ppb) based on a 15 L air volume) MIC per sample. The average desorption efficiencies are 97.96 - 101.23 %. The results of versus storage time are high and stable recovery rates.