• Title/Summary/Keyword: complex analytical method

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Deep learning in nickel-based superalloys solvus temperature simulation

  • Dmitry A., Tarasov;Andrey G., Tyagunov;Oleg B., Milder
    • Advances in aircraft and spacecraft science
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    • v.9 no.5
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    • pp.367-375
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    • 2022
  • Modeling the properties of complex alloys such as nickel superalloys is an extremely challenging scientific and engineering task. The model should take into account a large number of uncorrelated factors, for many of which information may be missing or vague. The individual contribution of one or another chemical element out of a dozen possible ligants cannot be determined by traditional methods. Moreover, there are no general analytical models describing the influence of elements on the characteristics of alloys. Artificial neural networks are one of the few statistical modeling tools that can account for many implicit correlations and establish correspondences that cannot be identified by other more familiar mathematical methods. However, such networks require careful tuning to achieve high performance, which is time-consuming. Data preprocessing can make model training much easier and faster. This article focuses on combining physics-based deep network configuration and input data engineering to simulate the solvus temperature of nickel superalloys. The used deep artificial neural network shows good simulation results. Thus, this method of numerical simulation can be easily applied to such problems.

Electromagnetic design and optimization of the multi-segment dielectric-loaded accelerating tube using genetic algorithm

  • M. Nikbakht;H. Afarideh;M. Ghergherehchi
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4625-4635
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    • 2022
  • A low-energy dielectric loaded accelerator with a non-uniform, multi-segment structure is studied and optimized. So far, no analytical solution is provided for such structures. Also, due to the existing nonlinear behavior and a large number of geometric parameters, the problem of numerical optimizations is complex. For this reason, a method is presented to design and optimize such structures using the Genetic Algorithm (GA). Moreover, the GA output results are compared with Trust Region (TR) and Nelder-Mead Simplex (NMS) methods. Comparative results show that the GA is more efficient in achieving optimization goals and also has a higher speed than the two other methods. Finally, an optimized accelerating tube is integrated into a proper coupler. Then, the accelerator is simulated for full electromagnetic investigations using the CST suite of codes. This design leads to a structure with a power of about 80 kW in the X-band, which delivers electrons to the output energy in the range of 300-459 kV. The length and outer diameter of the accelerating tube obtained are 10 cm and 1 cm, respectively.

한어방언(漢語方言) 어음 연구의 이론적 배경

  • Mo, Jeong-Yeol
    • 중국학논총
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    • no.64
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    • pp.23-51
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    • 2019
  • All research methodologies have a certain research purpose and application range. Therefore, it cannot be conclusively said that some methodologies are superior. Each research methodology has only different research purposes and application ranges. The various theories and methodologies related to the study of Chinese dialect sounds have not been in a confrontational relationship with each other. But the need for analysis of new phenomena has led to the emergence of new methodologies and it has been deepening the depth of the study together, supplementing the theories of the past. The emergence of new theories and methodologies has not only always provided another means for dialect analysis methods, but has also deepened awareness of the changing rules of dialects, the interrelationships between rules and the causes of change. The Chinese dialect is richly embedded in various phenomena that can be seen in human languages. In analyzing the phenomenon of the Chinese dialect, we should first closely observe and judge whether it is the result of internal historical changes in the dialect itself or changes formed by contact or influence with the external dialect, and apply the analytical method accordingly. Sometimes there is a phenomenon formed by a number of complex factors, not one, that requires a comprehensive analysis that combines a variety of theories and methodologies.

A novel aerodynamic vibration and fuzzy numerical analysis

  • Timothy Chen;Yahui Meng;Ruei-Yuan Wang;ZY Chen
    • Wind and Structures
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    • v.38 no.3
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    • pp.161-170
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    • 2024
  • In recent years, there have been an increasing number of experimental studies showing the need to include robustness criteria in the design process to develop complex active control designs for practical implementation. The paper investigates the crosswind aerodynamic parameters after the blocking phase of a two-dimensional square cross-section structure by measuring the response in wind tunnel tests under light wind flow conditions. To improve the accuracy of the results, the interpolation of the experimental curves in the time domain and the analytical responses were numerically optimized to finalize the results. Due to this combined effect, the three aerodynamic parameters decrease with increasing wind speed and asymptotically affect the upper branch constants. This means that the aerodynamic parameters along the density distribution are minimal. Taylor series are utilized to describe the fuzzy nonlinear plant and derive the stability analysis using polynomial function for analyzing the aerodynamic parameters and numerical simulations. Due to it will yield intricate terms to ensure stability criterion, therefore we aim to avoid kinds issues by proposing a polynomial homogeneous framework and utilizing Euler's functions for homogeneous systems. Finally, we solve the problem of stabilization under the consideration by SOS (sum of squares) and assign its fuzzy controller based on the feasibility of demonstration of a nonlinear system as an example.

A study of analytical method for Benzo[a]pyrene in edible oils (식용유지 중 벤조피렌 분석법 비교 연구)

  • Min-Jeong Kim;jun-Young Park;Min-Ju Kim;Eun-Young Jo;Mi-Young Park;Nan-Sook Han;Sook-Nam Hwang
    • Analytical Science and Technology
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    • v.36 no.6
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    • pp.291-299
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    • 2023
  • The benzo[a]pyrene in edible oils is extracted using methods such as Liquid-liquid, soxhlet and ultrasound-assisted extraction. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these drawbacks, this study attempted to improve the current complex benzo[a]pyrene analysis method by applying the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method that can be analyzed in a simple and short time. The QuEChERS method applied in this study includes extraction of benzo[a]pyrene into n-hexane saturated acetonitrile and n-hexane. After extraction and distribution using magnesium sulfate and sodium chloride, benzo[a]pyrene is analyzed by liquid chromatography with fluorescence detector (LC/FLR). As a result of method validation of the new method, the limit of detection (LOD) and quantification (LOQ) were 0.02 ㎍/kg and 0.05 ㎍/kg, respectively. The calibration curves were constructed using five levels (0.1~10 ㎍/kg) and coefficient (R2) was above 0.99. Mean recovery ratio was ranged from 74.5 to 79.3 % with a relative standard deviation (RSD) between 0.52 to 1.58 %. The accuracy and precision were 72.6~79.4 % and 0.14~7.20 %, respectively. All results satisfied the criteria ranges requested in the Food Safety Evaluation Department guidelines (2016) and AOAC official method of analysis (2023). Therefore, the analysis method presented in this study was a relatively simple pretreatment method compared to the existing analysis method, which reduced the analysis time and solvent use to 92 % and 96 %, respectively.

Acoustic technology-assisted rapid proteolysis for high-throughput proteome analysis (대량 발굴 프로테옴 분석을 위한 어쿠스틱 기술 기반 고속 단백질 절편화)

  • Kim, Bo-Ra;Huyen, Trang Tran;Han, Na-Young;Park, Jong-Moon;Yu, Ung-Sik;Lee, Hoo-Keun
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.510-518
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    • 2011
  • Recent developments and improvements of multiple technological elements including mass spectrometry (MS) instrument, multi-dimensional chromatographic separation, and software tools processing MS data resulted in benefits of large scale proteomics analysis. However, its throughput is limited by the speed and reproducibility of the protein digestion process. In this study, we demonstrated a new method for rapid proteolytic digestion of proteins using acoustic technology. Tryptic digests of BSA prepared at various conditions by super acoustic for optimization time and intensity were analyzed by LC-MS/MS showed higher sequence coverage in compared with traditional 16 hrs digestion method. The method was applied successfully for complex proteins of a breast cancer cells at 30 min of digestion at intensity 2. This new application reduces time-consuming of sample preparation with better efficiency, even with large amount of proteins, and increases high-throughput process in sample preparation state.

Introduction of a New Method for Total Organic Carbon and Total Nitrogen Stable Isotope Analysis of Dissolved Organic Matter in Aquatic Environments (수환경 내 용존성 유기물질의 총 유기탄소 및 총 질소 안정동위원소 신규 분석법 소개)

  • Si-yeong Park;Heeju Choi;Seoyeon Hong;Bo Ra Lim;Seoyeong Choi;Eun-Mi Kim;Yujeong Huh;Soohyung Lee;Min-Seob Kim
    • Korean Journal of Ecology and Environment
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    • v.56 no.4
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    • pp.339-347
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    • 2023
  • Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ13C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ13C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ13C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

Experimental Study of Flow Resistance and Flow Characteristics over Flexible Vegetated Open Channel (개수로 내 식생구간의 흐름저항 및 흐름특성에 관한 실험적 고찰)

  • Yeo, Hong Koo;Park, Moonhyeong;Kang, Joon Gu;Kim, Taewook
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.6
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    • pp.61-74
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    • 2004
  • Hydraulic engineers and scientists working on river restoration recognize the need for a deeper understanding of natural streams as a complex and dynamic system, which involves not only abiotic elements(flow, sediments) but also biotic components. From this point of view, the role played by riverine vegetation dynamics and flow conditions becomes essential. Hydro-mechanic interaction between flow and flexible plants covering a river bed is studied in this paper and some previous works are discussed. Measurements of turbulence and flow resistance in vegetated open channel were performed using rigid and flexible tube. Measuring detailed turbulent velocity profiles within and above submerged and flexible stems allowed to distinguish different turbulent regimes. Some interesting relationships were obtained between the velocity field and the deflected height of the plants, such as a reduced drag coefficient in the flexible stems. Turbulent intensities and Reynolds stresses were measured showing two different regions : above and inside the vegetation domain. In flexible vegetated open channel, the maximum values of turbulent intensities and Reynolds stresses appear above the top of canopy. Method to predict a flow resistance in flexible vegetated open channel is developed by modifying an analytical model proposed by Klopstra et al. (1997). Calculated velocity profiles and roughness values correspond well with flume experiments. These confirm the applicability of the presented model for open channel with flexible vegetation. The new method will be verified in the real vegetated conditions in the near future. After these verifications, the new method should be applied for nature rehabilitation projects such as river restorations.

N-oleoyl-D-erythro-sphingosine-based Analysis of Ceramide by High Performance Liquid Chromatography and Its Application to Determination in Diverse Biological Samples

  • Lee, Youn-Sun;Choi, Heon-Kyo;Yoo, Jae-Myung;Choi, Kyong-Mi;Lee, Yong-Moon;Oh, Sei-Kwan;Kim, Tack-Joong;Yun, Yeo-Pyo;Hong, Jin-Tae;Okino, Nozomu;Ito, Makoto;Yoo, Hwan-Soo
    • Molecular & Cellular Toxicology
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    • v.3 no.4
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    • pp.273-281
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    • 2007
  • Ceramide is involved in cell death as a lipid mediator of stress responses. In this study, we developed an improved method of ceramide quantification based on added synthetic ceramide and thin layer chromatography (TLC) separation, and applied to biological samples. Lipids were extracted from samples spiked with N-oleoyl-D-erythro-sphingosine ($C_{17}$ ceramide) as an internal standard. Ceramide was resolved by TLC, complexed with fatty-acidfree bovine serum albumin (BSA), and deacylated by ceramidase (CDase). The released sphingosine was derivatized with o-phthalaldehyde (OPA) and measured by high performance liquid chromatography (HPLC). The limit of detection for ceramide was about 1-2 pmol and the lower limit of quantification was 5 pmol. Ceramide recovery was approximately 86-93%. Ceramide concentrations were determined in biological samples including cultured cells, mouse tissues, and mouse and human plasma. TLC separation of ceramide provides HPLC chromatogram with a clean background without any interfering peaks and the enhanced solubility of ceramide by BSAceramide complex leads to the increased deacylation of ceramide. The use of an internal standard for the determination of ceramide concentration in these samples provides an accurate and reproducible analytical method, and this method can be applicable to diverse biological samples.

Simulation of non-Gaussian stochastic processes by amplitude modulation and phase reconstruction

  • Jiang, Yu;Tao, Junyong;Wang, Dezhi
    • Wind and Structures
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    • v.18 no.6
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    • pp.693-715
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    • 2014
  • Stochastic processes are used to represent phenomena in many diverse fields. Numerical simulation method is widely applied for the solution to stochastic problems of complex structures when alternative analytical methods are not applicable. In some practical applications the stochastic processes show non-Gaussian properties. When the stochastic processes deviate significantly from Gaussian, techniques for their accurate simulation must be available. The various existing simulation methods of non-Gaussian stochastic processes generally can only simulate super-Gaussian stochastic processes with the high-peak characteristics. And these methodologies are usually complicated and time consuming, not sufficiently intuitive. By revealing the inherent coupling effect of the phase and amplitude part of discrete Fourier representation of random time series on the non-Gaussian features (such as skewness and kurtosis) through theoretical analysis and simulation experiments, this paper presents a novel approach for the simulation of non-Gaussian stochastic processes with the prescribed amplitude probability density function (PDF) and power spectral density (PSD) by amplitude modulation and phase reconstruction. As compared to previous spectral representation method using phase modulation to obtain a non-Gaussian amplitude distribution, this non-Gaussian phase reconstruction strategy is more straightforward and efficient, capable of simulating both super-Gaussian and sub-Gaussian stochastic processes. Another attractive feature of the method is that the whole process can be implemented efficiently using the Fast Fourier Transform. Cases studies demonstrate the efficiency and accuracy of the proposed algorithm.