• Title/Summary/Keyword: complex variable

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Technique for the ECG Bio-sounds Visualization Analysis Based on the MIT-BIH Database (MIT-BIH 데이터베이스 기반 ECG 생체신호 시각화 분석을 위한 기술)

  • Kim, Jong-Wook;Lee, Myoung-Jin;Ko, Kwang-Man;So, Kyoung-Young
    • Journal of Digital Contents Society
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    • v.17 no.2
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    • pp.97-103
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    • 2016
  • This work introduces techniques experienced for the electrocardiogram(ECG) visual analysis, able to characterize the major parameters and events with clinical relevance for heart failure management and cardiovascular risk assessment. In particular, it includes approaches for ECG data visual processing such as the variable charts, graphs base on the complex MIT-BIH ECG database. Through the experienced this works of ECG database visualization, so many researcher more easily access the complex ECG database and can intuitionally understand the meanings via a variable ECG visualized data.

The Curved Interfacial Crack Analysis between Foam and Composite Materials under Anti-plane Shear Force (반평면 전단하중력하에서 곡면형상 접합면을 가지는 폼과 복합재료 접합부의 계면크랙에 관한 연구)

  • 박상현;전흥재
    • Composites Research
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    • v.13 no.4
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    • pp.67-74
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    • 2000
  • The general solution of the anti-plane shear problem for the curved interfacial crack between viscoelastic foam and composites was investigated with the complex variable displacement function. Kelvin-Maxwell three parameter model is used to present viscoelasticity and the Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The stress intensity factor near the interfacial crack tip was predicted by considering both anisotropic and viscoelastic properties of two different materials. The results showed that the stress intensity factor increased with increasing the curvature of the curved interfacial crack and it also increased and eventually converged to a specific value with increasing time. The stress intensity factor increased with increasing the ratio of stiffness coefficients between foam and composites and the effect of fiber orientation on the stress intensity factor decreased with increasing the ratio of stiffness coefficients between foam and composites.

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Integrated Thermochemical Approach to Collision-Induced Dissociation Process of Peptides

  • Shin, Seung Koo;Yoon, Hye-Joo
    • Mass Spectrometry Letters
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    • v.12 no.4
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    • pp.131-136
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    • 2021
  • Collision-induced dissociation of peptides involves a series of proton-transfer reactions in the activated peptide. To describe the kinetics of energy-variable dissociation, we considered the heat capacity of the peptide and the Marcus-theory-type proton-transfer rate. The peptide ion was activated to the high internal energy states by collision with a target gas in the collision cell. The mobile proton in the activated peptide then migrated from the most stable site to the amide oxygen and subsequently to the amide nitrogen (N-protonated) of the peptide bond to be broken. The N-protonated intermediate proceeded to the product-like complex that dissociated to products. Previous studies have suggested that the proton-transfer equilibria in the activated peptide affect the dissociation kinetics. To take the extent of collisional activation into account, we assumed a soft-sphere collision model, where the relative collision energy was fully available to the internal excitation of a collision complex. In addition, we employed a Marcus-theory-type rate equation to account for the proton-transfer equilibria. Herein, we present results from the integrated thermochemical approach using a tryptic peptide of ubiquitin.

Effects of Environmental Factors on the Adaptation to University Dormitory Life - The Case of Seoul National University Dormitories - (단지형 대학 기숙사의 거주환경요소가 기숙사생활 적응에 미치는 영향에 관한 연구 - 서울대학교 관악학생생활관을 대상으로 -)

  • Baek, Sooyeon;Choi, Jaepil
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.1
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    • pp.3-14
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    • 2020
  • Dormitories of Korean university are planned to pursue qualitative growth after a period of quantitative growth in the 1970s. However, since the 1990s, the physical plan for qualitative growth has not changed significantly and the effects of these changes on dormitory residents has not been verified. The purpose of this study is to identify the environmental factors influencing dormitory life adaptation and to provide a basis for qualitative growth of university dormitories to help dormitory residents adapt to the environment. The research was conducted in three stages. First, the elements of the residential environment of the dormitory complex, which is an independent variable, were derived. The dormitory life adaptation scale was developed to measure the dependent variable. Secondly, a questionnaire survey was conducted to obtain the environmental factors of current dormitory and previous residence and three elements of dormitory life adaptation; 'acceptance of change', 'familiarity', and 'anxiety'. Third, statistical analysis was conducted to determine whether each factor influenced dormitory life adaptation.

Process Development of Variable Curvature Extrusion for Automotive Aluminum Bumper (자동차 알루미늄 범퍼의 가변 곡률 압출공정 개발)

  • Kim, Byung-Min;Jo, Young-June;Oh, Kae-Hee;Park, Sang-Woo;Lee, Sang-Kon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.4
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    • pp.327-332
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    • 2008
  • The effectiveness of vehicle parts made through extrusion is in the limelight because of the advantages of high strength stiffness materials can be produced and the number of processes can be drastically reduced. Therefore, the parts should have sufficient stiffness and be lightweight enough to improve fuel efficiency. However, the application of extruded aluminum requires pre-bending technologies that can manufacture the complex designs profiles demanded by vehicle parts. The aim of this research is that the development of the variable curvature extrusion technology that can produce a variety of curvature. In order to produce a variable curvature, the guide transfer speed and transfer time should be controlled properly. The guide transfer speed and transfer time were examined by the theoretical analysis. A model was developed to simulate the deformation behaviors of extrusion and bending process from the symmetric bumper with range of radii from 1863mm to 2163mm. The theoretical analysis and FE analysis were verified through experimental method.

Variable Speed Control of Wind Turbines Using Robust Fuzzy Algorithm (강인 퍼지 이론을 이용한 풍력 터빈의 가변 속도 제어)

  • Sung, Hwa-Chang;Park, Jin-Bae;Joo, Young-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.1
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    • pp.1-6
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    • 2008
  • In this paper, we present the robust fuzzy algorithm for variable speed control of wind turbines. Generally, the plants of wind turbines are consisted of complex nonlinearities, and the parameters of variable speed of wind turbines are represented as uncertain terms. For solving these complexity, we propose the robust fuzzy algorithm. At first, the exact fuzzy modeling are performed for variable speed of wind turbines. Next, we design the fuzzy controller for reanalyzed T-S fuzzy model of the wind turbines, then, we prove the stability of the plant through the Lyapunov stability theorem. At last, an example is included for visualizing the efficiency of the proposed technique.

Determination of optical constants and thickness of organic electroluminescence thin films using variable angle spectroscopic ellipsometry (가변입사각 분광타원 법을 이용한 유기 발광 박막의 광학상수 및 두께 결정)

  • 김상열;류장위;김동현;정혜인
    • Korean Journal of Optics and Photonics
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    • v.12 no.6
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    • pp.472-478
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    • 2001
  • We determined the optical constants and thickness of organic electroluminescence thin films using variable angle spectroscopic ellipsometry. Using the measured transmittance spectra and the spectroscopic ellipsomeoy data of the organic films on glass substrates in the optically transparent region, we determined the effective thickness and the refractive indices of organic thin films. Then by applying a numerical inversion method to variable angle spectro-ellipsometry data, we determined the complex refractive index at each wavelength including the optically absorbing region, as well as the thickness and surface micro-roughness of the organic thin films. The calculated transmittance spectra showed a tight agreement with the measured ones, confining the validity of the present model analysis.

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Data-Based Model Approach to Predict Internal Air Temperature of Greenhouse (데이터 기반 모델에 의한 온실 내 기온 변화 예측)

  • Hong, Se Woon;Moon, Ae Kyung;Li, Song;Lee, In Bok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.3
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    • pp.9-19
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    • 2015
  • Internal air temperature of greenhouse is an important variable that can be influenced by the complex interaction between outside weather and greenhouse inside climate. This paper focuses on a data-based model approach to predict internal air temperature of the greenhouse. External air temperature, solar radiation, wind speed and wind direction were measured next to an experimental greenhouse supported by the Electronics and Telecommunications Research Institute and used as input variables for the model. Internal air temperature was measured at the center of three sections of the greenhouse and used as an output variable. The proposed model consisted of a transfer function including the four input variables and tested the prediction accuracy according to the sampling interval of the input variables, the orders of model polynomials and the time delay variable. As a result, a second-order model was suitable to predict the internal air temperature having the predictable time of 20-30 minutes and average errors of less than ${\pm}1K$. Afterwards mechanistic interpretation was conducted based on the energy balance equation, and it was found that the resulting model was considered physically acceptable and satisfied the physical reality of the heat transfer phenomena in a greenhouse. The proposed data-based model approach is applicable to any input variables and is expected to be useful for predicting complex greenhouse microclimate involving environmental control systems.

Design of on Automotive HID Ballast using Variable Frequency Switching Flyback Converter (가변주파수 스위칭 Flyback 컨버터를 이용한 자동차용 고압방전등 안정기의 설계)

  • Um, Tae-Wook;Kim, Yoon-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.4
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    • pp.166-171
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    • 2008
  • This paper presents high efficiency control system of automotive 35W electronic ballast for high intensity discharge(HID) lamp using switching flyback converter with variable frequency. Considering performance, size and efficiency of ballast, the flyback converter is designed with planar transformer in converter stage. HID lamp demands a highly efficient ballast and very complex control circuitry that can control complex transient state for applying to automotive. The proposed electronic ballast system is composed of a flyback converter using planar transformer, a full bridge inverter, and a step up igniter. In this system, switching frequency of flyback converter is controlled by varying input voltage of HID ballast and the price and the size of HID ballast using planar transformer can be reduced. The performance and efficiency of the posed system are verified through various the experiment results.

The Effects of Complex Commercial Facility on the Prices of Nearby Apartments (복합상업시설이 인근 아파트 가격에 미치는 영향)

  • Kim, Yen-Uk;Chun, Hae-Jung
    • Journal of Digital Convergence
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    • v.20 no.3
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    • pp.231-240
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    • 2022
  • This study empirically analyzed the effect of complex commercial facilities on the price of nearby apartments in a Hedonic price model. The spatial range of this study was the walking area of H Department Store located in Pangyo among the second new towns suburb of Seoul, and the time range was 2020. The dependent variable was the real transaction price of the apartment, and independent variable were the characteristics of the housing, the characteristics of the complex, and the characteristics of the region. As a result of the analysis, the area of exclusive use space, the transaction floor, and the highway accessibility had a positive effect on the price of the apartment, and the elapsed year had a negative effect on the price of the apartment. However, the size of the apartment had little effect on apartment prices, and the distance from the complex commercial facilities was shown to be related to apartment prices, indicating that apartment prices declined as it moved away from the complex commercial facilities. Therefore, this is much more influential than the influence of distance from subway stations on apartment price. This confirms that the effect factors of apartment prices and the size of their influence appear differently in the new town area and the existing metropolitan area.