• Steel and Composite Structures
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• v.17 no.1
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• pp.69-81
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• 2014

The novelty of this paper is the use of trigonometric four variable plate theory for free vibration analysis of laminated rectangular plate supporting a localized patch mass. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The Hamilton's Principle, using trigonometric shear deformation theory, is applied to simply support rectangular plates. Numerical examples are presented to show the effects of geometrical parameters such as aspect ratio of the plate, size and location of the patch mass on natural frequencies of laminated composite plates. It can be concluded that the proposed theory is accurate and simple in solving the free vibration behavior of laminated rectangular plate supporting a localized patch mass.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.641-646
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• 2003

An accurate and efficient method for measuring the mass of hairy roots using conductometry is established. A conductivity equation expressed in terms of the concentration of the ion species in the medium is suggested. By using this equation, the effect of the individual ions on the total conductivity can be quantitatively analyzed. An equation for the in situ estimation of the cell growth coefficient for determining the mass of hairy roots is established based on measurements of the nitrogen concentration and conductivity during cultivation. The proposed equation does not require preliminary experiments to determine the cell growth coefficient. Instead, the physiological characteristics of the plant species are reflected by introducing the cellular nitrogen content. Since the cell growth coefficient is determined by measuring the major ionic nutrient concentrations, it is more effective to express the dynamics of an actual culture system. This improved method for determining the mass of hairy roots was successfully utilized in a fed-batch culture system.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.301-303
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• 2008

Tuning of the speed controller in the linear servo applications needs the accurate information of a mover mass including a load mass. Therefore this paper proposes the mass estimation method of a permanent magnet linear synchronous motor(PMLSM) applied at the vertical axis by using the recursive Least-Squares estimation algorithm. First, this paper derives the deterministic autoregressive moving average(DARMA) model of the mechanical dynamic system used at the vertical axis. Results obtained by the Matlab/Simulink simulation show that the mass of a PMLSM applied at the vertical axis can be accurately estimated both at no-load and at load.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.75.1-75.1
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• 2019

We introduce a novel method for reconstructing the projected dark matter mass maps of merging galaxy clusters by applying the convolutional neural network (CNN) to their weak lensing maps. We generate synthesized grayscale images from given weak lensing maps that preserve their averaged galaxy ellipticity. We then apply them to multi-layered CNN with architectures of alternating convolution and trans-convolution filters to predict the mass maps. We train our architecture with 1,000 Subaru/Suprime-Cam mock weak lensing maps, and our method have better mass map prediction than the Kaiser-Squires method with the following three aspects: (1) better pixel-to-pixel correlation, (2) more accurate finding of density peak position, and (3) free from mass-sheet degeneracy. We also apply our method to the HST weak lensing map of the El Gordo cluster and compare our result to the previous studies.

• Mass Spectrometry Letters
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• v.14 no.3
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• pp.104-109
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• 2023

Anabolic-androgenic steroids (AAS) are used illegally to enhance muscle development and increase strength and power. In this study, a reliable, and sensitive quantitative method was developed and validated using heptafluorobutyric acid anhydride (HFPA) derivatives for the simultaneous detection of prohibited AAS (testosterone [TS], boldenone [BD], 5α-estrane-3β,17α-diol [EAD]) using gas chromatography-tandem mass spectrometry (GC-MS/MS). For processing the samples, solid phase extraction, methanolic hydrolysis, and liquid-liquid extraction were used. For detection using mass spectrometry, the multiple reaction monitoring (MRM) mode was used with the electron ionization (EI) positive mode. The method was evaluated for selectivity, linearity, lower limit of quantification, intra- and inter-day precision, accuracy, and stability. The results showed that the method was accurate and reproducible for the quantitation of the three steroids. The developed method was finally applied to the analysis of a suspect gelding urine sample received from the Asian Quality Assurance Program (AQAP).

• Mass Spectrometry Letters
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• v.15 no.2
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• pp.107-119
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• 2024

We aimed to develop a suitable quantification method for detecting asparagine deamidation and aspartic acid isomerization in peptide mapping using LC-MS. Our assessment of its validity and suitability involved comparing its quantitative findings with those obtained from cation-exchange chromatography and capillary electrophoresis methods. By subjecting trastuzumab to rigorous conditions to induce these modifications, we validated the efficacy of this new analytical method in peptide mapping via LC-MS, evaluating both qualitative and quantitative aspects of asparagine deamidation and aspartic acid isomerization. Our investigation underscored the significance of enzyme selection and the presence of miss-cleaved or non-specific peptides in achieving accurate quantitative results. The experimental results demonstrated a strong correlation with results from cation-exchange chromatography and capillary electrophoresis analyses, confirming the reliability of the LC-MS based peptide mapping approach.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.112-118
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• 2000

A modified repetitive control is formulated and analyzed in the discrete-time domain. Sufficient conditions for the stability of a class of repetitive controllers are given by means of the regeneration spectrum method. When a periodic signal input is drived into the two-mass-spring plant, the performance of the proposed controller which comprises a low-pass filter and two feed-forward compensators, turns out highly accurate by comparing the tracking result from the conventional LQ controller.

• Analytical Science and Technology
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• v.11 no.2
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• pp.120-124
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• 1998

A rapid and accurate determination method of ultra-trace amounts of germanium in spring water by ICP-MS has been developed. Mass number 74 was not only the best mass but also the smallest mass interference. Only 30% of water samples contain germanium more than $0.1{\mu}g/L$, and a few of them has organogermanium species.

• Mass Spectrometry Letters
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• v.5 no.2
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• pp.35-41
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• 2014

Gas chromatography-mass spectrometry (GC-MS) methods have been used extensively in clinical steroid analyses. Evaluating the metabolic ratios of precursors to products by accurate quantification of individual steroid levels in biological samples can reveal the activities of enzymes associated with steroid metabolism. This review article discusses the impact of GC-MS-based steroid profiling on our understanding of the biochemical role of steroids and their metabolic enzymes in hormone-dependent diseases, such as congenital adrenal hyperplasia (CAH), cortisol-mediated hypertension, apparent mineralocorticoid excess (AME), male-pattern baldness, and breast and thyroid cancers. Steroid profiling is a comprehensive analytical technique that can be applied whenever the highest specificity is required and may be a reasonable initial diagnostic approach.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.1-6
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• 2012

The accurate information of mass properties is required for the precise control of the spacecraft. The mass properties, mass and inertia, are changeable by some reasons such as consumption of propellant, deployment of solar panel, sloshing, environmental effect, etc. The gyro-based attitude data including noise and bias reduces the control accuracy so it needs to be compensated for improvement. This paper introduces a real-time inertia estimation method for the attitude determination of STSAT-3, Korea Science Technology Satellite. In this method we first filter the gyro noise with the Extended Kalman Filter(EKF), and then estimate the moment of inertia by using the filtered data from the EKF based on the Recursive Least Square(RLS).