• Title/Summary/Keyword: Limit of Detection

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Hazard Analysis of Autonomous Vehicle due to V2I Malfunction (V2I 오작동에 의한 자율주행자동차의 위험성 분석)

  • Ahn, Dae-ryong;Shin, Seong-geun;Baek, Yun-soek;Lee, Hyuck-kee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.6
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    • pp.251-261
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    • 2019
  • The importance of autonomous driving systems that utilize V2X services such as V2V(Vehicle to Vehicle) and V2I(Vehicle to Infrastructure) for safer and more comfortable driving is increasing with the recent development of autonomous vehicles. Partly autonomous vehicles based on environmental sensors have limitations for predicting and determining areas beyond the recognition distance of the mounted sensors and in response to atypical objects that are difficult to detect. Therefore, it is important to utilize the V2X service to improve the limit of sensor detection performance and to make driving safer and more comfortable. However, there may be an accident risk of autonomous vehicles due to incorrect information provided by V2X. Thus, the application of technology to prevent this needs to be considered. In this pater, we used the ISO-26262 Part3 Process and performed HARA (Hazard Analysis and Risk Assessment) to derive the risk sources of autonomous vehicles due to V2I malfunctions by using the communication between vehicles and infrastructure among V2X. We also developed ASIL ratings based on the simulations and real vehicle tests of the malfunctions of major cases of usnig V2I.

Study on High-speed Cyber Penetration Attack Analysis Technology based on Static Feature Base Applicable to Endpoints (Endpoint에 적용 가능한 정적 feature 기반 고속의 사이버 침투공격 분석기술 연구)

  • Hwang, Jun-ho;Hwang, Seon-bin;Kim, Su-jeong;Lee, Tae-jin
    • Journal of Internet Computing and Services
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    • v.19 no.5
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    • pp.21-31
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    • 2018
  • Cyber penetration attacks can not only damage cyber space but can attack entire infrastructure such as electricity, gas, water, and nuclear power, which can cause enormous damage to the lives of the people. Also, cyber space has already been defined as the fifth battlefield, and strategic responses are very important. Most of recent cyber attacks are caused by malicious code, and since the number is more than 1.6 million per day, automated analysis technology to cope with a large amount of malicious code is very important. However, it is difficult to deal with malicious code encryption, obfuscation and packing, and the dynamic analysis technique is not limited to the performance requirements of dynamic analysis but also to the virtual There is a limit in coping with environment avoiding technology. In this paper, we propose a machine learning based malicious code analysis technique which improve the weakness of the detection performance of existing analysis technology while maintaining the light and high-speed analysis performance applicable to commercial endpoints. The results of this study show that 99.13% accuracy, 99.26% precision and 99.09% recall analysis performance of 71,000 normal file and malicious code in commercial environment and analysis time in PC environment can be analyzed more than 5 per second, and it can be operated independently in the endpoint environment and it is considered that it works in complementary form in operation in conjunction with existing antivirus technology and static and dynamic analysis technology. It is also expected to be used as a core element of EDR technology and malware variant analysis.

High Energy Resolution Alpha Spectrometer Using a Cryogenic Detector (저온검출기를 이용한 에너지 고 분해능 알파분광 구현)

  • Kim, M.S.;Lee, S.H.;Yoon, W.S.;Jang, Y.S.;Lee, S.J.;Kim, Y.H.;Lee, M.K.
    • Journal of Radiation Protection and Research
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    • v.38 no.3
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    • pp.132-137
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    • 2013
  • Cryogenic particle detectors have recently been adopted in radiation detection and measurement because of their high energy resolution. Many of these detectors have demonstrated energy resolutions better than the theoretical limit of semiconductor detectors. We report the development of alpha spectrometer using a micro-fabricated magnetic calorimeter coupled to a large-area particle absorber. A piece of gold foil of $2{\times}2{\times}0.05mm^3$ was glued to the paramagnetic temperature sensor made of sputtered Au:Er film to serve as an absorber for incident alpha particles. We performed experiments with 241Am source at cryogen free adiabatic demagnetization refrigerator (CF-ADR). A high energy resolution of 6.8 keV in FWHM was obtained for 5.5 MeV alpha particles.

Voltammetric Determination of Dopamine with the N-Hydroxysuccinimide Modified Carbon Paste Electrode (N-히드록시숙신이미드로 수식한 탄소반죽전극을 이용한 도파민의 전기화학적 측정)

  • Yoo Jae Hyun;Yoo Byung Wook;Kim Soon Shin;Uhm Jung Hee;Nam Hakhyun;Cha Geun Sig
    • Journal of the Korean Electrochemical Society
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    • v.4 no.3
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    • pp.109-112
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    • 2001
  • An activated carbon paste electrode was modified with the N-Hydroxysuccinimide(NHS) layer and applied to determine the dopamine in the presence of an excess ascorbic acid using square-wave voltammetry. The electrochemical properties of the modified electrode were examined in the solution containing dopamine/ascorbic acid using cyclic voltammetry(CV): the separation between the oxidation peaks of dopamine and ascorbic acid was largely dependent on the pH of the sample solution and became maximum at pH 4.0. Hence, the square-wave voltammetric determination of dopamine was carried out in a pH 4.0, 100mM phosphate buffer saline(PBS) containing 140mM NaCl. The detection limit and response slop were improved from $1.0{\mu}M\;to\;5.0\times10^{-2}{\mu}M\;and\;from\;0.93{\mu}A/{\mu}M\;to\;6.1{\mu}A/{\mu}M$, respectively, upon modification of the electrode surface by NHS.

Analysis on Urinary N-methylformamide of Korean Workers according to Industrial Classification and Countermeasures for Exposure Control of N,N-dimethylformamide (우리나라 근로자들의 업종별 뇨중 N-methylformamide 분석 및 N,N-dimethylformamide 노출관리 대책)

  • Kim, Dohyung;Byun, Kiwhan;Park, Jae-Oh;Lee, Mi-Young;Kim, Eun-A
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.24 no.3
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    • pp.345-352
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    • 2014
  • Objectives: This study is aimed to describe the current situation about urinary biomarker N-methylformamide(NMF) for workers exposed to N,N-dimethylformamide(DMF) according to industrial classification. Materials: Special health examination records of the workers who had undergone urinary biological monitoring in 2013 were collected. The numbers and percentage of workers, whose urinary NMF values were above the limit of detection(LOD) and above the biological exposure index(BEI) were calculated. Health relatedness with DMF as judged by their doctors was also described. All description was classified according to the $9^{th}$ Korean Standard Industrial Classification(KSIC). Results: It appeared that most workers exposed to DMF belong to manufacturing section(80.7%). The geometric mean(GM) values of urinary NMF were 6.25 mg/L, 3.54, and 3.86 for the manufacturing section, professional, scientific and technical activities section, and for the construction section respectively. In detail, it seemed that division of textiles(except apparel) (GM 7.51 mg/L), division of leather, luggage and footwear(11.59 mg/L), and division of rubber and plastic products(6.89 mg/L) were highly exposed to DMF with a high percentage of workers with urinary NMF values above BEI. This was probably due to the effect of skin absorption that the division of leather, luggage and footwear showed the highest urine NMF GM. Conclusions: It seemed that workers in manufacture industries such as textile, leather, luggage, footwear, rubber and plastic products were highly exposed to DMF. So, efforts should be focused on those industries in order to effectively diminish worker's exposure. Further studies to compare DMF air-monitoring with bio-monitoring according to industrial classification should be considered.

Mineral Chemistry of Magnetite from the Hongcheon Carbonatite-Phoscorite Complex, Korea (홍천 카보나타이트-포스코라이트 복합체에서 산출되는 자철석의 광물화학)

  • Shin, Dongbok;Oh, Youngbok;Lee, Mi-Jung
    • Journal of the Mineralogical Society of Korea
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    • v.26 no.4
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    • pp.299-312
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    • 2013
  • Magnetite, a major constituent mineral of the Hongcheon carbonatite-phoscorite complex, was produced over three stages in each rock type and decreased in quantity toward the late stage. Electron microprobe analyses for magnetite revealed that Ti and V were detected in traces, but showed increasing tendency from early to late stage. On the contrary, Mg and Mn decreased distinctly, and it is the general differentiation trend of carbonatitic magma. Al also showed decreasing tendency in carbonatite and phoscorite, and Cr was mostly below detection limit except late phoscorite. In early stage, $Fe^{2+}$ was largely replaced by $Mg{2+}$ and $Mn^{2+}$, and $Fe^{3+}$ by $Al^{3+}$ in magnetite, but it has nearly pure composition in late stage. Tendency of increase in V and decrease in Mn toward late stage represents that magma differentiation progressed under the condition of decreasing oxygen fugacity. Low concentrations of Mg, Al, Cr and Ti, as well as the absence of olivine and phlogopite, suggest that the Hongcheon carbonatite-phoscorite complex was generated from depleted magma. Especially, lower concentrations of Mg in magnetite compared to other typical carbonatite-phoscorite complex, and abundant occurrence of Fe-carbonate minerals and quartz in late stage, suggest that magma differentiation of the Hongcheon carbonatite-phoscorite proceeded to the latest stage.

Evaluation of Testosterone Metabolites/Dehydroepiandrosterone As the Indicators of Testosterone Administration in Horse Doping (경주마 약물검사에서 testosterone 투여 여부표지자로서의 testosterone 대사체들에 대한 dehydroepiandrosterone의 비율 평가)

  • Kim, Jin Young;Choi, Man Ho;Kim, Sung Jean;Kyong, Jin Burm;Chung, Bong Chul
    • Analytical Science and Technology
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    • v.12 no.3
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    • pp.190-195
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    • 1999
  • The metabolism of testosterone ($17{\beta}$-hydroxy-androst-4-en-3-one) was confirmed in horse after a single intramuscular administration of testosterone cypionate (750 mg). Solvent extracts of urine obtained with enzymatic hydrolysis and methanolysis were analyzed by GC/MS after oxime t-butyldimethylsilyl (oxime-TBDMS) derivatization. The structures of four urinary metabolite after testosterone administration in horse were determined based on EI mass spectra and $5{\alpha}$-androstane-$3{\beta}$, $17{\alpha}$-diol and $5{\alpha}$-androstane-$3{\beta}$-ol-17-one as major was confirmed with authentic standard. Also the concentrations of $5{\alpha}$-androstane-$3{\beta}$, $17{\alpha}$-diol, $5{\alpha}$-androstane-$3{\beta}$, $17{\beta}$-diol, dehydroepiandrosterone (DHEA), $5{\alpha}$-androstane-$3{\beta}$-ol-17-one and testosterone were determined in the urine of normal subjects and the urine after administration. The recovery and detection limit in the most drugs were 86.3~94.7% and 1~3 ppb, respectively. Correlation coefficients for calibration were in the range of 0.984~0.999. Excretion profile of testosterone presents the rapid and large increasement up to maximum values at days 5 after administration and the slow regression. The relative ratios of testosterone, its metabolites over DHEA were determined for indication of testosterone administration in horse doping.

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Determination of La in $U_3Si/Al$ Spent Nuclear Fuel by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry에 의한 $U_3Si/Al$ 사용후핵연료 중 La의 분리 및 정량)

  • Han, Sun Ho;Choi, Kwang Soon;Kim, Jung Suk;Jeon, Young Shin;Park, Yang Soon;Jee, Kwang Yong;Kim, Won Ho
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.601-607
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    • 2000
  • Lanthanum has been used as one of the burnup monitor in spent nuclear fuel. $U_3Si/Al$ spent nuclear fuel contains small amount of La in high concentration of U and Al. Therefore, chemical separation of La is required to remove matrix elements. At first, ion chromatography (IC) and inductively coupled plasma systems were installed in radiation shielded glove box to handle the radioactive samples. Retention behavior of uranium, aluminum, lanthanum and some interesting fission products (Sr, Zr, Y, Mo, Ru, Pd, Rh, Cs, Ba, Ce, Pr, Nd, Sm, Eu and Cd) was investigated using the CG10 column and ${\alpha}$-HiBA eluent. As all elements were eluted earlier than lanthanum in 0.2 M ${\alpha}$-HiBA eluent, a portion of U and Al was directly passed to waste using a three way valve between the column and the nebulizer. Thus it was possible to determine the lanthanum in a high concentration of U and Al matrix. Retention time of La was about 12 minutes in this separation condition. Optimum range for the determination of La in $U_3Si/Al$ spent nuclear fuel was $1-10{\mu}g/L$ (ppb) with this system and detection limit was $0.25{\mu}g/L$ in case of $200{\mu}L$ of sample volume.

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Anodic Stripping Voltammetric Determination of Iodide Ion with a Cinchonine-Copper(Ⅱ) Complex Modified Carbon Paste Electrode (Cinchonine-Copper(Ⅱ) 착물로 변성된 탄소반죽전극을 이용한 요오드 이온의 양극벗김전압전류법 정량)

  • Kwak, Myung Keun;Park, Deog Soo;Jeong, Euh Duck;Won, Mi Sook;Shim, Yoon Bo
    • Journal of the Korean Chemical Society
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    • v.40 no.5
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    • pp.341-346
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    • 1996
  • Electrochemical determination of iodide was carried out by stripping voltammetry with a $(Cin)Cu(NO_3)_2$ modified-carbon paste electrode. Iodide was coordinated onto the electrode surface containing $(Cin)Cu(NO_3)_2$ via ion exchange. The oxidation peak potential of incorporated iodide was +0.72 V. The optimum analytical conditions for the determination of iodide were investigated using linear sweep voltammetry. Optimum conditions for the electrochemical determination of iodide were as follows: i) A predeposition solution was 0.1 M $KNO_3.$ ii) The deposition time was 10 min. iii) The composition of the electrode was 40% (w/w). The detection limit for iodide was $1.0{\times}10^{-6}M$ and the relative standard deviation was ${\pm}5.5%\;in\;2.0{\times}10^{-5}M$(four repetitions). The interference effect of other anions were also investigated. $Cl^-,\;Br^-,\;C_2O_4^{2-},\;and\;ClO_4^-$ ions do not interfere for the determination of iodide. When $SCN^-$ was added to the deposition solution, the oxidation peak current of iodide ion was decreased roughly 32%.

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Determination of Niacin in Infant Formula by Solid-phase Clean-up and HPLC with Photodiode Array Detector (고체상 정제 및 HPLC/PDA에 의한 영유아식 중 나이아신의 분석)

  • Hong, Jee-Eun;Kim, Mi-Ran;Cheon, Sang-Hee;Chai, Jung-Young;Park, Eun-Ryong;Mun, Chun-Sun;Gwak, In-Shin;Kim, Ok-Hee;Lee, Kwang-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.3
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    • pp.359-363
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    • 2009
  • This study was performed to establish a rapid and simple analytical method for niacin (nicotinic acid and nicotinamide) using HPLC. A pretreatment method for the extraction and clean-up of niacin in infant formula sample and an instrumental condition for HPLC were optimized. Niacin was extracted by 5 mM hexanesulfonate with ultrasonication for 30 min. For the clean-up of the sample, the extract was applied to a HLB cartridge, and then niacin was eluted from the cartridge using 5 mL of 80% methanol after washing with 5 mL of n-hexane. The total recoveries were $83{\sim}104%$ and relative standard deviation were in the range of $1.5{\sim}3.5%$ during the extraction and clean-up process. Niacin was determined by gradient elution with sodium hexanesulfonate/methanol buffer as a mobile phase and a photodiode array detector (260 nm). It showed a high linearity between the content of niacin and the peak area ($r^2$=1.000) in the range of $0.02{\sim}10.0$ mg/L of nicotinic acid and nicotinamide. The detection limit was 0.02 mg/L (0.2 mg/kg in the sample). The method was successfully applied for the determination of niacin in infant formula. Total niacin contents were in the range of $53.5{\sim}140.3$ mg/kg.