• Title/Summary/Keyword: quantification technique

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The quantification of photon counts using the concept of candela (Candela 개념의 광량정량화 활용에 관한 연구)

  • Kim, Hyeon Sik;Choi, Eun Seo;Lee, Byeong-Il
    • Journal of Integrative Natural Science
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    • v.1 no.1
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    • pp.1-4
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    • 2008
  • We developed quantification method based on the concept of candela in physics. The measurement of fluorescence signal from a nude mouse in the research of molecular biology. In the measurement of the optical signal with CCD, the quantification method for photon counts based on bio-luminescence imaging technique can provide comparative reference data. In this paper, we described theoretical derivation of our proposed concept. We hope this method could be a useful standard reference for quantitative date analysis in optical imaging.

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Alternating Acquisition Technique for Quantification of in vitro Hyperpolarized [1-13C] Pyruvate Metabolism

  • Yang, Seungwook;Lee, Joonsung;Joe, Eunhae;Lee, Hansol;Song, Ho-Taek;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.20 no.1
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    • pp.53-60
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    • 2016
  • Purpose: To develop a technique for quantifying the $^{13}C$-metabolites by performing frequency-selective hyperpolarized $^{13}C$ magnetic resonance spectroscopy (MRS) in vitro which combines simple spectrally-selective excitation with spectrally interleaved acquisition. Methods: Numerical simulations were performed with varying noise level and $K_p$ values to compare the quantification accuracies of the proposed and the conventional methods. For in vitro experiments, a spectrally-selective excitation scheme was enabled by narrow-band radiofrequency (RF) excitation pulse implemented into a free-induction decay chemical shift imaging (FIDCSI) sequence. Experiments with LDH / NADH enzyme mixture were performed to validate the effectiveness of the proposed acquisition method. Also, a modified two-site exchange model was formulated for metabolism kinetics quantification with the proposed method. Results: From the simulation results, significant increase of the lactate peak signal to noise ratio (PSNR) was observed. Also, the quantified $K_p$ value from the dynamic curves were more accurate in the case of the proposed acquisition method compared to the conventional non-selective excitation scheme. In vitro experiment results were in good agreement with the simulation results, also displaying increased PSNR for lactate. Fitting results using the modified two-site exchange model also showed expected results in agreement with the simulations. Conclusion: A method for accurate quantification of hyperpolarized pyruvate and the downstream product focused on in vitro experiment was described. By using a narrow-band RF excitation pulse with alternating acquisition, different resonances were selectively excited with a different flip angle for increased PSNR while the hyperpolarized magnetization of the substrate can be minimally perturbed with a low flip angle. Baseline signals from neighboring resonances can be effectively suppressed to accurately quantify the metabolism kinetics.

Development of a real-time PCR method for detection and quantification of the parasitic protozoan Perkinsus olseni

  • Gajamange, Dinesh;Yoon, Jong-Man;Park, Kyung-Il
    • The Korean Journal of Malacology
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    • v.27 no.4
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    • pp.387-393
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    • 2011
  • The objective of this study was to develop a real-time PCR method for the rapid detection and quantification of the protozoan pathogen Perkinsus olseni using a TaqMan probe. For the standard, genomic DNA was extracted from $10^5$ in vitro-cultured P. olseni trophozoites, and then 10-fold serial dilutions to the level of a single cell were prepared. To test the reliability of the technique, triplicates of genomic DNA were extracted from $5{\times}10^4$ cells and 10-fold serial dilutions to the level of 5 cells were prepared. The standards and samples were analyzed in duplicate using an $Exicycler^{TM}$ 96 real-time quantitative thermal block. For quantification, the threshold cycle ($C_T$) values of samples were compared with those obtained from standard dilutions. There was a strong linear relationship between the $C_T$ value and the log concentration of cells in the standard ($r^2$ = 0.996). Detection of DNA at a concentration as low as the equivalent of a single cell showed that the assay was sensitive enough to detect a single cell of P. olseni. The estimated number of P. olseni cells was similar to the original cell concentrations, indicating the reliability of P. olseni quantification by real-time PCR. Accordingly, the designed primers and probe may be used for the rapid detection and quantification of P. olseni from clam tissue, environmental water, and sediment samples.

Development of Analysis and Visualization Tool for Java Source Code Changes using Reverse Engineering Technique (역공학을 이용한 자바 소스 코드의 변화량 분석 및 시각화 도구 개발)

  • Kwon, Jin-Wook;Choi, Yun-Ja;Lee, Woo-Jin
    • The KIPS Transactions:PartD
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    • v.19D no.1
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    • pp.39-48
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    • 2012
  • In order to quickly understand which changes of source codes have been made and to perform effective maintenance of a system, it is important to visualize the changed parts. Although there are many works for analyzing software changes, there are few works for visualizing both of the change types and change quantifications for Java based systems. In this paper, we propose a change analysis technique based on class diagram and provide a change visualization technique by using change quantification information. In order to check the structural changes in source codes, source codes are transformed to class diagrams by reverse engineering methods. On the class diagrams, the changes are analyzed and quantified by numbers. Based on the change quantification, the changes are visualized on the class diagram by color spectrum. By using visualization techniques, maintainers can easily recognize the code changes to reduce the cost and time of maintenance.

Chair side measuring instrument for quantification of the extent of a transverse maxillary occlusal plane cant

  • Naini, Farhad B.;Messiha, Ashraf;Gill, Daljit S.
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.21.1-21.3
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    • 2019
  • Background: Treatment planning the correction of a transverse maxillary occlusal plane cant often involves a degree of qualitative "eyeballing", with the attendant possibility of error in the estimated judgement. A simple chair side technique permits quantification of the extent of asymmetry and thereby quantitative measurements for the correction of the occlusal plane cant. Methods: A measuring instrument may be constructed by soldering the edge of a stainless steel dental ruler at 90° to the flat surface of a similar ruler. With the patient either standing in natural head position, or alternatively seated upright in the dental chair, and a dental photographic retractor in situ, the flat under-surface of the horizontal part of this measuring instrument is placed on a unilateral segment of a bilateral structure, e.g. the higher maxillary canine orthodontic bracket hook. The vertical ruler is held next to the contralateral canine tooth, and the vertical distance measured directly from the canine bracket to the flat under-surface of the horizontal part of the measuring instrument. Results: This vertical distance quantifies the overall extent of movement required to level the maxillary occlusal plane. Conclusions: This measuring instrument and simple chair side technique helps to quantify the overall extent of surgical levelling required and may be a useful additional technique in our clinical diagnostic armamentarium.

The Detection of Molecular Ion $CsX^+$(X=Al, Ga, As) for Quantitative SIMS Analysis ($CsX^+$(X=Al, Ga, As) 분자이온을 이용한 SIMS의 정량분석)

  • 김차연;김선미;김성태;지종열
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.121-125
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    • 1992
  • Secondary Ion Mass Spectrometry (SIMS) is widely known as highly sensitive a surface analysis technique. Efforts for quantification have been hindered, however, by the presence of matrix effects. Here we describe a new technique for the quantitative analysis of AlxGa1-xAs. Instead of Al+, Ga+, As+ ions, CsX+ ions (X=Al, Ga, As) have been detected. Intensity of these molecular ions appears to be much less affected by matrix effects. We have successfully accomplished the compositional analysis with standard deviation better than 2 percent.

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Isotope-Dilution Mass Spectrometry for Quantification of Urinary Active Androgens Separated by Gas Chromatography

  • Lee, Su-Hyeon;Choi, Man-Ho;Lee, Won-Yong;Chung, Bong-Chul
    • Mass Spectrometry Letters
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    • v.1 no.1
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    • pp.29-32
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    • 2010
  • Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with $\beta$-glucuronidase, solid-phase extraction, liquid-liquid extraction using methyl tert-butyl ether and subsequent conversion to pentafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive and selective analysis in selected-ion monitoring mode. Flophemesyl-TMS derivatization not only eliminates matrix interference but also has a good peak resolution within a 6 min-run. A selective and sensitive GC technique with flophemesyl-TMS derivatives also allows accurate quantitative analysis of three active androgens when combined with IDMS. The limit of quantification of the three analytes was <50 pg/mL, and extraction recoveries ranged from 91.9 to 102.1%. The precision and accuracy were 1.2~6.5% and 89.0~106.7%, respectively. This GC-IDMS method can be useful for evaluating the drug efficacy and monitoring the biological processes responsible for male-pattern baldness and prostate diseases.

Uncertainty quantification for structural health monitoring applications

  • Nasr, Dana E.;Slika, Wael G.;Saad, George A.
    • Smart Structures and Systems
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    • v.22 no.4
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    • pp.399-411
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    • 2018
  • The difficulty in modeling complex nonlinear structures lies in the presence of significant sources of uncertainties mainly attributed to sudden changes in the structure's behavior caused by regular aging factors or extreme events. Quantifying these uncertainties and accurately representing them within the complex mathematical framework of Structural Health Monitoring (SHM) are significantly essential for system identification and damage detection purposes. This study highlights the importance of uncertainty quantification in SHM frameworks, and presents a comparative analysis between intrusive and non-intrusive techniques in quantifying uncertainties for SHM purposes through two different variations of the Kalman Filter (KF) method, the Ensemble Kalman filter (EnKF) and the Polynomial Chaos Kalman Filter (PCKF). The comparative analysis is based on a numerical example that consists of a four degrees-of-freedom (DOF) system, comprising Bouc-Wen hysteretic behavior and subjected to El-Centro earthquake excitation. The comparison is based on the ability of each technique to quantify the different sources of uncertainty for SHM purposes and to accurately approximate the system state and parameters when compared to the true state with the least computational burden. While the results show that both filters are able to locate the damage in space and time and to accurately estimate the system responses and unknown parameters, the computational cost of PCKF is shown to be less than that of EnKF for a similar level of numerical accuracy.

Study on Statistical Method for Objective Evaluation of Tunnel Portal Slopes (객관적인 터널 갱구사면 평가를 위한 통계기법 연구)

  • Kwon, O-Il;Baek, Yong;Na, Jong-Hwa;Seo, Yong-Seok;Kim, Gyo-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.634-643
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    • 2006
  • This study was intended to develop a high reliable technique by statistically processing on-site data with a general linear model, providing the basic data for construction, analysis of stability and establishment of maintenance measures for tunnel portal slopes in the future. This study evaluated the stability of a tunnel portal slope using a quantified technique, which is based on a general linear model. The important scores of each independent variable were allocated by using the ranges of the quantified values, based on the predicted coefficient of regression and the scores for categories of each independent variable were allocated so that those are equally spaced. The quantification model obtained from the results of evaluating the total data used for the quantification process provided precise results. In addition, it is expected that a more detail subdivision of response variables and sufficient data would produce a better stability evaluation standard.

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A Fast and Sensitive Method for the Simultaneous Determination and Quantification of Six Anionic Surfactants in Surface Water using HILIC-ESI-MS Technique

  • Dash, Upendra N.;Paul, Saroj Kumar
    • Mass Spectrometry Letters
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    • v.3 no.3
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    • pp.78-81
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    • 2012
  • The hydrophobic hydrocarbon chain and the polar sulfate group confer surfactant properties and enable them to be used as anionic surfactants. Anionic surfactants (AS) are known for their adverse impact on environment, particularly on aquatic ecosystem. In the present study a fast, sensitive and selective method for the determination and subsequent quantification of six anionic surfactants was developed using hydrophilic interactive liquid chromatography (HILIC) coupled to a electrospray ionization (ESI) mass spectrometer (MS), in the concentration range 15-20 ${\mu}g/L$. The capability of the method was established using regression analysis and ANOVA. The method performance was evaluated by analyzing real time surface water spiked with 1-dodecyl hydrogen sulfate at 15 ${\mu}g/L$. Combined efficiency of solid phase extraction and MS detection established recovery of 89% in presence of natural matrix. These results point out that HILIC coupled to multistage MS procedures can be a powerful technique for environmental applications concerning the screening of polar contaminants.