• 제목/요약/키워드: TOF method

검색결과 262건 처리시간 0.024초

지상레이저스캐닝 기반 3차원 실내 모델링 (3D Indoor Modeling Based on Terrestrial Laser Scanning)

  • 홍승환;조형식;김남훈;손홍규
    • 대한토목학회논문집
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    • 제35권2호
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    • pp.525-531
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    • 2015
  • 3차원 실내공간정보에 구축 시 경제성, 효율성 및 정확도 향상을 위한 지상레이저스캐너의 활용이 주목을 받고 있다. 그러나 실내공간정보 구축에 있어 지상레이저스캐너 관측방식과 기존 측량방식 방식에 대한 비교 연구는 미비한 실정이다. 본 연구에서는 설계도면 갱신 및 3차원 실내 모델링에 AMCW 방식 및 direct TOF 방식의 지상레이저스캐너와 토탈스테이션의 작업시간 및 위치정확도를 비교하여 지상레이저스캐너의 효율성과 경제성을 제시하였다. 비교결과, AMCW 방식은 direct TOF 방식에 비해 시간효율성이 뛰어났으며 두 관측값 사이의 RMSE는 ${\pm}1mm$ 수준으로 나타났다. 또한 지상레이저스캐닝 방식은 토탈스테이션 관측방식에 비해 2배 이상의 시간효율성을 보였으며 두 관측값 사이의 RMSE는 ${\pm}3.4cm$로 나타났다. 제시된 지상레이저스캐너를 이용한 3차원 실내모델링의 경제성과 효율성을 바탕으로 향후 3차원 실내공간 정보 구축에 지상레이저스캐닝 방식이 효과적으로 활용될 수 있을 것으로 기대된다.

$SiH_4-Ar$ 혼합기체의 평균 에너지에 관한 연구 (Analysis of the Mean Energy in $SiH_4-Ar$ Mixture Gases)

  • 김상남
    • 전기학회논문지P
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    • 제55권2호
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    • pp.57-61
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    • 2006
  • This paper calculates and gives the analysis of mean energy in pure $SiH_4,\;Ar-SiH_4$ mixture gases ($SiH_4-0.5[%],\;5[%]$) over the range of $E/N =0.01{\sim}300[Td]$, p = 0.1, 1, 5.0 [Torr] by Monte Carlo the Backward prolongation method of the Boltzmann equation using computer simulation without using expensive equipment. The results have been obtained by using the electron collision cross sections by TOF, PT, SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation. The calculations of electron swarm parameters require the knowledge of several collision cross-sections of electron beam. Thus, published momentum transfer, ionization, vibration, attachment, electronic excitation, and dissociation cross-sections of electrons for $SiH_4$ and Ar, were used. The differences of the transport coefficients of electrons in $SiH_4$, mixtures of $SiH_4$ and Ar, have been explained by the deduced energy distribution functions for electrons and the complete collision cross-sections for electrons. A two-term approximation of the Boltzmann equation analysis and Monte Carlo simulation have been used to study electron transport coefficients.

SiH4-Ar혼합기체의 전자분포함수 해석 (The analysis on the Energy Distribution Function for Electron in SiH4-Ar Gas Mixtures)

  • 김상남
    • 전기학회논문지P
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    • 제53권2호
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    • pp.65-69
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    • 2004
  • This paper calculates and gives the analysis of electron swarm transport coefficients as described electric conductive characteristics of pure Ar, pure $SiH_4$, Ar-$SiH_4$ mixture gases($SiH_4$-0.5%, 2.5%, 5%) over the range of E/N = 0.01~300[Td], P = 0.1, 1, 5.0 [Torr] by Monte Carlo the backward prolongation method of the Boltzmann equation using computer simulation without using expensive equipment. The results have been obtained by using the electron collision cross sections by TOF, PT, SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation. Electron swann parameters in argon were drastically changed by adding a small amount of mono-silane. The electron drift velocity in these mixtures showed unusual behaviour against E/N. It had negative slope in the medium range of E/N, yet the slope was not smooth but contained a small hump. The longitudinal diffusion coefficient also showed a corresponding feature in its dependence on E/N. A two-tenn approximation of the Boltzmann equation analysis and Monte Carlo simulation have been used to study electron transport coefficients.

Expression of Antihypertensive Peptide, His-His-Leu, as Tandem Repeats in Escherichia coli

  • Jeong, Do-Won;Shin, Dong-Seok;Ahn, Chang-Won;Song, In-Sang;Lee, Hyong-Joo
    • Journal of Microbiology and Biotechnology
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    • 제17권6호
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    • pp.952-959
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    • 2007
  • His-His-Leu (HHL), a tripeptide derived from a Korean soybean paste, is an angiotensin-I-converting enzyme (ACE) inhibitor. We report here a method of producing this tripeptide efficiently by expressing tandem multimers of the codons encoding the peptide in E. coli and purifying the HHL after hydrolysis of the peptide multimers. The HHL gene, tandemly multimerized to a 40-mer, was ligated with ubiquitin as a fusion gene (UH40). UH40 was inserted into vector pET29b; the UH40 fusion protein was then produced in E. coli BL21. The recombinant UH40 protein was purified by cation-exchange chromatography with a yield of 17.3mg/l and analyzed by matrixassisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and protein N-terminal sequencing. Leucine aminopeptidase was used to cleave a 405-Da HHL monomer from the UH40 fusion protein and the peptide was purified using reverse-phase high-performance liquid chromatography (HPLC) on a C18 HPLC column, with a final yield of 6.2mg/l. The resulting peptide was confirmed to be HHL with the aid of MALDI-TOF mass spectrometry, glutamine-TOF mass spectrometry, N-terminal sequencing, and measurement of ACE inhibiting activity. These results suggest that our production method is useful for obtaining a large quantity of recombinant HHL for functional antihypertensive peptide studies.

질량분석 시스템을 이용한 극지 토양 유래 신규 미생물의 지질 A 화학적 구조 분석 (Determination of Lipid A Profile of Gram-Negative Bacteria from Arctic Soils Using Mass Spectrometric Approaches)

  • 황철환;박한규;김윤곤
    • KSBB Journal
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    • 제31권4호
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    • pp.263-269
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    • 2016
  • For decades, the microorganisms in arctic soils have been newly discovered according to the climate change and global warming. In this study, the chemical structure of a lipid A molecule from Pseudomonas sp. strain PAMC 28615 which was newly discovered from arctic soils was characterized by mass spectrometric approaches such as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and MALDI multi-stage tandem mass spectrometry (MS). First, lipopolysaccharide (LPS) from Pseudomonas sp. strain PAMC 28615 was extracted and subsequently hydrolyzed to obtain the lipid A. The parent ion peak at m/z 1632 was determined by MALDI-TOF MS, which also can validate our lipid A purification method. For detailed structural determination, we performed the multiple-stage tandem mass analysis ($MS^4$) of the parent ion, and subsequently the abundant fragment ions in each MS stage are tested. The fragment ions in each MS stage were produced from the loss of phosphate groups and fatty acyl groups, which could be used to confirm the composition or the position of the lipid A components. Consequently, the mass spectrometry-based lipid A profiling method could provide the detail chemical structure of lipid A from the Pseudomonas sp. strain PAMC 28615 as an arctic bacterium from the frozen arctic soil.

The Method of Reducing Echo Time in 3D Time-of-flight Angiography

  • Park, Sung-Hong;Park, Jung-Il;Lee, Heung-Kyu
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.367-369
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    • 2002
  • We have designed ramp profile excitation pulse based on the Shinnar-Le Roux (SLR) algorithm. The algorithm provides many advantages to pulse designers. The first advantage is the freedom of deciding the amplitudes, frequencies, and ripple sizes of stopband, passband, and transition band of pulse profile. The second advantage is the freedom of deciding the pulse phase, more specifically, minimum phase, linear phase, maximum phase, and any phase between them. The minimum phase pulse is the best choice in the case of 3D TOF, because it minimizes the echo time, which implies the best image quality in the same MR examination condition. In addition, the half echo technique is slightly modified in our case. In general, using the half echo technique means that the acquired data size is half and the rest part can be filled with complex conjugate of acquired data. But in our case, the echo center is just shifted to left, which implies the reduction of echo time, and the acquired data size is the same as the one without using the half echo technique. In this case, the increase of right part of data leads to improvement of the resolution and the decrease of left part of data leads to decrease of signal to noise ratio. Since in the case of 3D TOF, the signal to noise ratio is sufficiently high and the resolution is more important than signal to noise ratio, the proposed method appears to be significantly affective and gives rise to the improved high resolution angiograms.

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Comparative Serum Proteomic Analysis of Serum Diagnosis Proteins of Colorectal Cancer Based on Magnetic Bead Separation and MALDI-TOF Mass Spectrometry

  • Deng, Bao-Guo;Yao, Jin-Hua;Liu, Qing-Yin;Feng, Xian-Jun;Liu, Dong;Zhao, Li;Tu, Bin;Yang, Fan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.6069-6075
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    • 2013
  • Background: At present, the diagnosis of colorectal cancer (CRC) requires a colorectal biopsy which is an invasive procedure. We undertook this pilot study to develop an alternative method and potential new biomarkers for diagnosis, and validated a set of well-integrated tools called ClinProt to investigate the serum peptidome in CRC patients. Methods: Fasting blood samples from 67 patients diagnosed with CRC by histological diagnosis, 55 patients diagnosed with colorectal adenoma by biopsy, and 65 healthy volunteers were collected. Division was into a model construction group and an external validation group randomly. The present work focused on serum proteomic analysis of model construction group by ClinProt Kit combined with mass spectrometry. This approach allowed construction of a peptide pattern able to differentiate the studied populations. An external validation group was used to verify the diagnostic capability of the peptidome pattern blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results: The results showed 59 differential peptide peaks in CRC, colorectal adenoma and health volunteers. A genetic algorithm was used to set up the classification models. Four of the identified peaks at m/z 797, 810, 4078 and 5343 were used to construct peptidome patterns, achieving an accuracy of 100% (> CEA, P<0.05). Furthermore, the peptidome patterns could differentiate the validation group with high accuracy close to 100%. Conclusions: Our results showed that proteomic analysis of serum with MALDI-TOF MS is a fast and reproducible approach, which may provide a novel approach to screening for CRC.

Duplex SDS-PAGE를 이용한 단백질 분리향상 (The enhancement of protein separation by duplex SDS-PAGE)

  • 표재성;노시훈;송진수;이경현;김희준;박정일;권성원
    • 분석과학
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    • 제19권6호
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    • pp.529-534
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    • 2006
  • SDS-PAGE를 이용한 일반적인 단백질 분리는 단백질을 분자량에 따라 분리하는 방법이며 가장 보편적이고, 간단한 방법 중의 하나이다. 본 연구는 SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis)를 두 번에 걸쳐 동일한 분리 원리로 이차원으로 전개하는 방법의 전기영동을 시도하여 기존의 일차원 전기영동 분석법과 비교하였으며, 그 결과 향상된 분리능이 본 연구의 이차원 전기영동법에서 확인되었다. Gel에서 분리된 단백질들은 MALDI TOF MS를 이용하여 동정하여 서로 다른 단백질임이 확인되었으며, 이러한 duplex SDS-PAGE 분리법은 상대적으로 적은 비용으로 단백질 분리능을 용이하게 향상시킬 수 있는 경제적인 분석법으로 이용될 수 있을 것이다.

Hemodynamically Induced Aneurysm-mimicking Findings at Anterior Communicating (A-com) Artery Area due to Anatomical Variation on 3D-TOF MRA

  • 강원석;정태섭;심용운;유병규;박인국
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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    • pp.133-133
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    • 2001
  • Purpose: To determine the relationship between anatomical variation at A-com. artery area an hemodynamically induced aneurysm-mimicking findings on 3D-TOF MRA clinically a experimentally. Method: Sixty-two patients who had no aneurysm at A-com artery on DSA were evalua with MRA. MRA was performed with 1.5T MR machine(Vision, Siemens). Scan parameters o MRA included TR/TE/FA=30/6.4/25$\psi$$\circledR$˙¡, 512*192 of matrix with MIP technique. The occurrence of signal defect at shoulder area of bifurcated A-com artery on MRA was evalua for the relationship between the symmetricity of bilateral ACA and the patency of A-c artery. DSA images were acquired at both ICA and VA. To analyze hemodynamical facto of signal defect, experimental studies of MRA and DSA were peformed with elastic silic phantom using conducting pulsatile pump. We also compared the results with those o computational fluid dynamics(CFD).

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LC-MS에 의한 사철쑥에 존재하는 페놀성 화합물의 정성분석 (Qualitative Analysis of Phenolic Substances in Artemisia capillaris by LC-MS)

  • 누그로호 아궁;임상철;박희준
    • 생약학회지
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    • 제43권4호
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    • pp.302-307
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    • 2012
  • The herb of Artemisia capillaris in Chinese medicine is used to treat hepatic diseases. In this research, qualitative analysis was performed using a UPLC/Q-TOF-ESI-MS/MS method for rapid identification of phenolic substances from A. capillaris: three caffeoylquinic acids (chlorogenic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid), three flavonoids (hyperoside, isorhamnetin 3-O-robinobioside and quercetin) and three prenylated coumarins (6,8-diprenylumbelliferone, cedrelopsin and osthol) were identified. The three prenylated coumarins have not been reported from A. capillaris.