• Title/Summary/Keyword: Trace analysis

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Size-resolved Source Apportionment of Ambient Particles by Positive Matrix Factorization at Gosan, Jeju Island during ACE-Asia (PMF 분석을 이용한 ACE-Asia 측정기간 중 제주 고산지역 입자상 물질의 입경별 발생원 추정)

  • Moon K.J.;Han, J.S.;Kong, B.J.;Jung, I.R.;Cliff Steven S.;Cahill Thomas A.;Perry Kelvin D.
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.5
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    • pp.590-603
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    • 2006
  • Size-and time-resolved aerosol samples were collected using an eight-stage Davis rotating unit for monitoring (DRUM) sampler from 23 March to 29 April 2001 at Gosan, Jeju Island, Korea, which is one of the super sites of Asia-Pacific Regional Aerosol Characterization Experiment(ACE-Asia). These samples were analyzed using synchrotron X-ray fluorescence for 3-hr average concentrations of 19 elements including Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, and Pb. The size-resolved data sets were then analyzed using the positive matrix factorization(PMF) technique to identify possible sources and estimate their contributions to particulate matter mass. PMF analysis uses the uncertainty of the measured data to provide an optimal weighting. Twelve sources were resolved in eight size ranges($0.09{\sim}12{\mu}m$) and included continental soil, local soil, sea salt, biomass/biofuel burning, coal combustion, oil combustion, municipal incineration, nonferrous metal source, ferrous metal source, gasoline vehicle, diesel vehicle, and volcanic emission. The PMF result of size-resolved source contributions showed that natural sources represented by local soil, sea salt, continental soil, and volcanic emission contributed about 79% to the predicted primary particulate matter(PM) mass in the coarse size range ($1.15{\sim}12{\mu}m$) while anthropogenic sources such as coal combustion and biomass/biofuel burning contributed about 58% in the fine size range($0.56{\sim}2.5{\mu}m$). The diesel vehicle source contributed mostly in ultra-fine size range($0.09{\sim}0.56{\mu}m$) and was responsible for about 56% of the primary PM mass.

Development of Separation and Trace Analysis Methods for Platinum Group Elements-Separation and Retention Behavior of Platinoid Metal Acetylacetonates in Reversed-Phase Liquid Chromatography (백금족 원소의 분리 및 미량분석법 개발에 관한 연구: 역상 액체 크로마토그래피에 의한 백금족 금속-아세틸아세톤 킬레이트들의 분리 및 머무름 거동)

  • Lee, Dai Woon;Kim, Kyung Soo;Park, Young Hun;Czea, Myoung Zoon;Chung, Koo Soon
    • Analytical Science and Technology
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    • v.6 no.1
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    • pp.107-119
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    • 1993
  • The purpose of this study is to investigated the elution behavior of platinoid metal acetylacetonates, which is the key to elucidate their retention mechanism and optimize their RPLC separation conditions. The retention data of four platinoid metal acetylacetonates have been measured on four different columns in methanol-water and acetonitrile-water systems. The retention of uncharged platinoid metal acetylacetonates is interpreted by solvophobic effect. The retention of platinoid metal acetylacetonates is also greatly influenced by the geometric structure of the complexes. The square planar chelates, $Pd(acac)_2$, $Pt(acac)_2$, are retained longer than the octahedral chelates, $Rh(acac)_3$, $Ir(acac)_3$. It is likely due to that square planar chelates show greater interaction with nonpolar stationary phase than octahedral chelates. The results of van't Hoff plots have shown that platinoid metal acetylacetonates is operated on the same retention mechanism in the temperature range of $25{\sim}45^{\circ}C$. The study of the retention mechanism by the enthalpy-entropy compensation phenomenon has indicated that the retention mechanism of octahedral chelates and square planar chelates do not vary with the composition change of methanol-water mobile phase, respectively. In acetonitrile-water mobile phase, however, the retention mechanism is observed to be more complicated. Optimum condition for the separation of four platinoid metal acetylacetonates is found to be 40% methanol, polymeric C18 column, and $45^{\circ}C$.

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Determination of ibuprofen and its metabolites in human urine by GC-MS (GC-MS에 의한 소변 중 Ibuprofen의 대사체 규명 및 대사 연구)

  • Yu, Dae-Hyung;Cho, Jung-Hum;Hong, Jong-Ki
    • Analytical Science and Technology
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    • v.23 no.2
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    • pp.179-186
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    • 2010
  • The oxidative metabolism of ibuprofen in healthy male urine collected at 3, 6, 9, 12 and 15 h after oral administration of ibuprofen was studied by GC/MS assay. To detect conjugated metabolites of ibuprofen, urine sample was acid-hydrolyzed with 6 M HCl at $100^{\circ}C$ for 30 min. To effectively extract ibuprofen and its metabolites, liquid-liquid extraction (LLE) was conducted at pH 3, 5, and 7, respectively. As a result, LLE at pH 3 was shown to be the best extraction condition. For the determination of trace amounts of ibuprofen and its metabolites in extract, trimethylsilylation (TMS) with BSTFA was applied and followed by GC/MS analysis. In this study, main 5 metabolites including parent drug were detected and these metabolites were assigned as three hydroxylated forms and one carboxylated form. Each metabolite was tentatively identified by both interpretation of mass spectrum and comparison with previously reported results. In addition, time profile of urinary excretion rate for parent drugs and metabolites was studied. Finally, the metabolic pathways of ibuprofen were suggested on the basis of the structural elucidation of its metabolites and excretion profiles.

A Study of the Advanced Strategy for ICT-based Public Compensation Business (ICT 기반 공익사업 보상업무 첨단화 방안 연구)

  • Seo, Myoung Bae
    • Smart Media Journal
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    • v.9 no.1
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    • pp.75-83
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    • 2020
  • Compensation services that are indispensable during large-scale public utilities projects have been gradually increasing with the recent increase in construction, but there are no systematic compensation services due to the complicated procedures and manual work. For this reason, various problems such as construction period delays due to various complaints, corruption in compensation work, and impossible to trace the history of compensation data in the past are emerging. In this paper, in order to solve this problem, in-depth interviews and questionnaires were conducted to find out the problems of each compensation status. Based on this, 3 core technologies and 10 technical needs based on ICT were selected to improve the compensation work by deriving STEEP analysis and Issue Tree. The three core technologies are big data-based decision-making and prediction technology, advanced measurement technology, and open cloud-based compensation platform technology. In order to introduce the derived technologies to the institutions in charge of compensation, the possibility of technology diffusion by project operators was suggested based on the results of the current status of informatization by institution. Based on the core technology derived from this paper, it is necessary to make a prototype that can be advanced in compensation work and apply it to each institution and analyze the effect.

Algorithm of Generating Adaptive Background Modeling for crackdown on Illegal Parking (불법 주정차 무인 자동 단속을 위한 환경 변화에 강건한 적응적 배경영상 모델링 알고리즘)

  • Joo, Sung-Il;Jun, Young-Min;Choi, Hyung-Il
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.6
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    • pp.117-125
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    • 2008
  • The Object tracking by real-time image analysis is one of the major concerns in computer vision and its application fields. The Object detection process of real-time images must be preceded before the object tracking process. To achieve the stable object detection performance in the exterior environment, adaptive background model generation methods are needed. The adaptive background model can accept the nature's phenomena changes and adapt the system to the changes such as light or shadow movements that are caused by changes of meridian altitudes of the sun. In this paper, we propose a robust background model generation method effective in an illegal parking auto-detection application area. We also provide a evaluation method that judges whether a moving vehicle stops or not. As the first step, an initial background model is generated. Then the differences between the initial model and the input image frame is used to trace the movement of object. The moving vehicle can be easily recognized from the object tracking process. After that, the model is updated by the background information except the moving object. These steps are repeated. The experiment results show that our background model is effective and adaptable in the variable exterior environment. The results also show our model can detect objects moving slowly. This paper includes the performance evaluation results of the proposed method on the real roads.

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A 90 Day Repeated Dose-Oral Toxicity Study of Extracts from Astragalus membranaceus-Aboveground Parts in Rats (랫드를 이용한 황기의 지상부 추출물에 대한 90일 반복경구투여 독성시험)

  • Park, Yeong Chul;Lee, Ji Sun;Kim, Dong Yoon;Son, Hye Young;Lee, Jung Woo;Cheoi, Yu Soon;Kim, Kwang Ki;Yu, Chang Yeon;Chung, Ill Min;Im, Moo Hyeog;Lee, Kyung Jae;Choi, Ri Na;Shim, Hoon Seob;Lim, Jung Dae
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.6
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    • pp.474-485
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    • 2013
  • Pharmacological studies and clinical practices have indicated that Radix Astragali, a dried root of Astragalus membranaceus possesses a lot of biological activities, including antioxidant, hepatoprotective, anti-diabetic, tonic, diuretic, antimicrobial, antiviral, and immunological activities. These biological activities approved by the modern pharmacological studies are mainly due to the constituents of Astragalus membranaceus including polysaccharides, saponins, flavonoids, amino acids, and trace elements. In resent, the main constituents in the root part showing a lot of biological activities has been isolated also from the aboveground parts such as leaves and sprouts in our laboratory. However, the safety evaluation for the aboveground parts of Astragalus membranaceus should be checked before expanding their application as one of food. In the study, a 90-day rat oral gavage study has been conducted with the extracts from Astragalus membranaceus-above-ground parts at doses of 1000, 3000, and 5000mg/kg/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000mg/kg/day of the water-extracts from Astragalus membranaceus-aboveground parts.

Material Analysis and Coloring Characteristics of Korean Traditional Copper-red Pigment (Jinsa) (동화(진사) 안료의 재료과학적 분석 및 발색특성)

  • Kim, Ji-Young;Cho, Hyun-Kyung;Jun, Byung-Kyu;Cho, Nam-Chul;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.27 no.1
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    • pp.31-40
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    • 2011
  • Copper-red (Dongwha, Jinsa) is Korean traditional inorganic pigment used for red-coloring on the porcelain surface during Goryeo and Joseon Periods. Trace amounts of copper-red porcelains are handed down because of the technical difficulty of making and coloring of the pigment. It is known that copper ore sources were extensively distributed in Korea according to old literatures and some of them are still producing copper ore at this present. Main types of copper-bearing mineral in Korea are chalcopyrite ($CuFeS_2$) and malachite ($Cu_2CO_3(OH)_2$), and they are easily collected from the ground surface. This means Korea had geographical and economic geological advantages for supplying raw material of the pigment. These two minerals showed good red-coloring in color test for porcelain pigment. As a coloring element, copper showed micro size less than $5{\mu}m$ in diameter in glaze matrix. The dispersion of copper particle is the most decisive factor for red chromaticity of copper-red porcelain, as well as copper content of the pigment.

A Study on Chemical Composition and Firing Temperature of White Wares from the Guyre-2ri Kiln Sites, Wonju (원주 귀래2리 가마터 출토 백자의 화학조성과 소성온도 연구)

  • Lee, Byeong Hoon;So, Myoung-Gi
    • Journal of Conservation Science
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    • v.30 no.3
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    • pp.249-261
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    • 2014
  • This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.

Mutiagent based on Attacker Traceback System using SOM (SOM을 이용한 멀티 에이전트 기반의 침입자 역 추적 시스템)

  • Choi Jinwoo;Woo Chong-Woo;Park Jaewoo
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.3
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    • pp.235-245
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    • 2005
  • The rapid development of computer network technology has brought the Internet as the major infrastructure to our society. But the rapid increase in malicious computer intrusions using such technology causes urgent problems of protecting our information society. The recent trends of the intrusions reflect that the intruders do not break into victim host directly and do some malicious behaviors. Rather, they tend to use some automated intrusion tools to penetrate systems. Most of the unknown types of the intrusions are caused by using such tools, with some minor modifications. These tools are mostly similar to the Previous ones, and the results of using such tools remain the same as in common patterns. In this paper, we are describing design and implementation of attacker-traceback system, which traces the intruder based on the multi-agent architecture. The system first applied SOM to classify the unknown types of the intrusion into previous similar intrusion classes. And during the intrusion analysis stage, we formalized the patterns of the tools as a knowledge base. Based on the patterns, the agent system gets activated, and the automatic tracing of the intrusion routes begins through the previous attacked host, by finding some intrusion evidences on the attacked system.

A Method for Detecting Event-Location based on Similar Keyword Extraction in Tweet Text (트윗 텍스트의 유사 키워드 추출을 통한 이벤트 지역 탐지 기법)

  • Yim, Junyeob;Ha, Hyunsoo;Hwang, Byung-Yeon
    • Spatial Information Research
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    • v.23 no.5
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    • pp.1-7
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    • 2015
  • Twitter has the fast propagation and diffusion of information compare to other SNS. Therefore, many researches about detecting real-time event using twitter are progressing. Twitter real-time event detecting system assumes every twitter user as a sensor and analyzes their written tweet in order to detect the event. Researches that are related to this twitter have already obtained good results but confronted the limits because of some problems. Especially, many existing researches are using the method that can trace an event location by using GPS coordinate. However, it can be suggested a definite limitation through the present user's skeptical responses about making personal location information public. Therefore, this paper suggests the method that traces the location information in tweet contents text without using the provided location information from twitter. Associated words were grouped by using the keyword that extracted in tweet contents text. The place that the events have occurred and whether the events have surely occurred are detected by this experiment using this algorithm. Furthermore, this experiment demonstrated the necessity of the suggested methods by showing faster detection compare to the other existing media.