• Title/Summary/Keyword: structure equation modeling

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A Study on the Frame Sensor Modeling Using Standard Interface (표준 인터페이스를 적용한 프레임 센서 모델링에 관한 연구)

  • Kwon, Wonsuk;Choi, Sunyong;Lee, Yongwoong
    • Korean Journal of Remote Sensing
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    • v.30 no.1
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    • pp.75-81
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    • 2014
  • Until recently, photogrammetric applications for processing the satellite images and remotely sensed data have been used in different structure of functions and interfaces for sensor modeling by each developer. Thus, a standardized utilization procedure was necessary to solve the problems, such as expandability, cost, inefficiency of sources which were resulted from different approaches. Therefore, National Geospatial Intelligence Agency (NGA) provided unified interfaces by developing Community Sensor Model (CSM) to sensor models in same way. In this study, we suggested the method of design and analyzed main functions needed modeling for the frame sensor using CSM Application Program Interface (API) provided by NGA. We also applied the designed structure to the modeling. The implemented CSM was verified by groundToImage and imageToGround. In the future, the active R&D is expected with using CSM due to the cost saving effect of software development and remarkable expandability of sensor.

A machine learning-based model for the estimation of the critical thermo-electrical responses of the sandwich structure with magneto-electro-elastic face sheet

  • Zhou, Xiao;Wang, Pinyi;Al-Dhaifallah, Mujahed;Rawa, Muhyaddin;Khadimallah, Mohamed Amine
    • Advances in nano research
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    • v.12 no.1
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    • pp.81-99
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    • 2022
  • The aim of current work is to evaluate thermo-electrical characteristics of graphene nanoplatelets Reinforced Composite (GNPRC) coupled with magneto-electro-elastic (MEE) face sheet. In this regard, a cylindrical smart nanocomposite made of GNPRC with an external MEE layer is considered. The bonding between the layers are assumed to be perfect. Because of the layer nature of the structure, the material characteristics of the whole structure is regarded as graded. Both mechanical and thermal boundary conditions are applied to this structure. The main objective of this work is to determine critical temperature and critical voltage as a function of thermal condition, support type, GNP weight fraction, and MEE thickness. The governing equation of the multilayer nanocomposites cylindrical shell is derived. The generalized differential quadrature method (GDQM) is employed to numerically solve the differential equations. This method is integrated with Deep Learning Network (DNN) with ADADELTA optimizer to determine the critical conditions of the current sandwich structure. This the first time that effects of several conditions including surrounding temperature, MEE layer thickness, and pattern of the layers of the GNPRC is investigated on two main parameters critical temperature and critical voltage of the nanostructure. Furthermore, Maxwell equation is derived for modeling of the MEE. The outcome reveals that MEE layer, temperature change, GNP weight function, and GNP distribution patterns GNP weight function have significant influence on the critical temperature and voltage of cylindrical shell made from GNP nanocomposites core with MEE face sheet on outer of the shell.

Wet Drop Impact Response Analysis of CCS in Membrane Type LNG Carriers -I : Development of Numerical Simulation Analysis Technique through Validation- (멤브레인형 LNG선 화물창 단열시스템의 수면낙하 내충격 응답해석 -I : 검증을 통한 수치해석 기법 개발-)

  • Lee, Sang-Gab;Hwang, Jeong-Oh;Kim, Wha-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.6
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    • pp.726-734
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    • 2008
  • While the structural safety assessment of Cargo Containment System(CCS) in membrane type LNG carriers has to be carried out in consideration of sloshing impact pressure, it is very difficult to figure out its dynamic response behaviors due to its very complex structural arrangements/materials and complicated phenomena of sloshing impact loading. For the development of its original technique, it is necessary to understand the characteristics of dynamic response behavior of CCS structure under sloshing impact pressure. In this study, for the exact understanding of dynamic response behavior of CCS structure in membrane Mark III type LNG carriers under sloshing impact pressure, its wet drop impact response analyses were carried out by using Fluid-Structure Interaction(FSI) analysis technique of LS-DYNA code, and were also validated through a series of wet drop experiments for the enhancement of more accurate shock response analysis technique. It might be thought that the structural response behaviors of impact response analysis, such as impact pressure impulses and resulted strain time histories, generally showed very good agreement with experimental ones with very appropriate use of FSI analysis technique of LS-DYNA code, finite element modeling and material properties of CCS structure, finite element modeling and equation of state(EOS) of fluid domain.

Thermal Flux Analysis for the Wearable NOx Gas Sensors (웨어러블 NOx 가스센서의 열유동 해석)

  • Jang, Kyung-uk
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.793-799
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    • 2019
  • In this study, the diffusion process and the thermal energy distribution gradient of the sensor were confirmed by using the finite element analysis program (COMSOL) of the mesh method to analyze the thermal diffusion in the wearable fabric (Nylon) + MWCNT gas sensor. To analyze the diffusion process of thermal energy, the structure of the gas sensor was modeled in a two dimension plane. The proposed modeling was presented with the characteristic value for the component of the sensor, and the gas sensor designed using the mesh finite element method (FEM) was proposed and analyzed by suggesting the one-way partial differential equation in the governing equation to know the degree of thermal energy diffusion and the thermal energy gradient. In addition, the temperature gradient 10[K/mm] of the anode-cathode electrode layer and the gas detection unit was investigated by suggesting the heat velocity transfer equation.

Factors Influencing Environmental Disclosure: A Case Study of Manufacturing Companies in Indonesia

  • FUADAH, Luk Luk;SAFTIANA, Yulia;KALSUM, Umi;ARISMAN, Anton
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.9
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    • pp.23-33
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    • 2021
  • The main objective of this research is to examine the effect of organizational culture, environmental uncertainty, and manager's personnel value on environmental disclosure through the environmental organizational structure of manufacturing companies on the Indonesia Stock Exchange. This research uses the structuration and contingency theory. The sample in this study focused on the level of heads or managers or directors of manufacturing companies listed on the Indonesia Stock Exchange. The research data was obtained through an online questionnaire distributed to heads or managers. The total sample of this study is 161 manufacturing companies. The data comprising of 64 respondents was completed and can be processed. Empirical testing used Structural Equation Modeling (SEM) through Partial Least Square (PLS). The result shows that environmental uncertainty and management personnel value have a positive effect on the environmental organizational structure, as well as the environmental organizational structure has a positive effect on the environmental disclosure. However, organizational culture has no effect on the environmental organizational structure. This research can provide benefits for manufacturing companies. The limitation include the low level of response from the respondents. Also the results cannot be generalized due to its specific focus on the manufacturing companies.

Thermal Transport Phenomena in the FET Typed MWCNT Gas Sensor with the 60 μm Electrode Distance (60 μm의 전극 간극을 갖는 FET식 MWCNT 가스센서에서 열 유동 현상)

  • Jang, Kyung-Uk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.6
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    • pp.403-407
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    • 2015
  • Generally, MWCNT, with thermal, chemical and electrical superiority, is manufactured with CVD (chemical vapor deposition). Using MWCNT, it is comonly used as gas sensor of MOS-FET structure. In this study, in order to repeatedly detect gases, the author had to effectively eliminate gases absorbed in a MWCNT sensor. So as to eliminate gases absorbed in a MWCNT sensor, the sensor was applied heat of 423[K], and in order to observe how the applied heat was diffused within the sensor, the author interpreted the diffusion process of heat, using COMSOL interpretation program. In order to interpret the diffusion process of heat, the author progressed modeling with the structure of MWCNT gas sensor in 2-dimension, and defining heat transfer velocity($u={\Delta}T/{\Delta}x$), accorded to governing equation within the sensor, the author proposed heat transfer mechanism.

Numerical Modeling of Wave Run-up and Internal Set-up on and in Permeable Coastal Structures (투과성 해안구조물의 소상파 및 내부수위변동에 관한 수치모델링)

  • 남인식;김종욱;류청로
    • Journal of Ocean Engineering and Technology
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    • v.16 no.5
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    • pp.34-40
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    • 2002
  • A numerical model has been developed for the permeable coastal structures to simulate hydraulic characteristics on the permeable slopes, which interact with internal four field the structures. The model includes hydraulics in the porous medium. Numerical model was calibrated using hydraulic model experiments performed in 2-D wave flume in the Institute of Ocean Hydraulics in PKNU. Better aggrements were obtained with the model which employed inertia resistance term than with the conventional model, PBREAK.

Fuzzy control for geometrically nonlinear vibration of piezoelectric flexible plates

  • Xu, Yalan;Chen, Jianjun
    • Structural Engineering and Mechanics
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    • v.43 no.2
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    • pp.163-177
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    • 2012
  • This paper presents a LMI(linear matrix inequality)-based fuzzy approach of modeling and active vibration control of geometrically nonlinear flexible plates with piezoelectric materials as actuators and sensors. The large-amplitude vibration characteristics and dynamic partial differential equation of a piezoelectric flexible rectangular thin plate structure are obtained by using generalized Fourier series and numerical integral. Takagi-Sugeno (T-S) fuzzy model is employed to approximate the nonlinear structural system, which combines the fuzzy inference rule with the local linear state space model. A robust fuzzy dynamic output feedback control law based on the T-S fuzzy model is designed by the parallel distributed compensation (PDC) technique, and stability analysis and disturbance rejection problems are guaranteed by LMI method. The simulation result shows that the fuzzy dynamic output feedback controller based on a two-rule T-S fuzzy model performs well, and the vibration of plate structure with geometrical nonlinearity is suppressed, which is less complex in computation and can be practically implemented.

Structural joint modeling and identification: numerical and experimental investigation

  • Ingole, Sanjay B.;Chatterjee, Animesh
    • Structural Engineering and Mechanics
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    • v.53 no.2
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    • pp.373-392
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    • 2015
  • In the present work, structural joints have been modeled as a pair of translational and rotational springs and frequency equation of the overall system has been developed using sub-structure synthesis. It is shown that using first few natural frequencies of the system, one can obtain a set of over-determined system of equations involving the unknown stiffness parameters. Method of multi-linear regression is then applied to obtain the best estimate of the unknown stiffness parameters. The estimation procedure has been developed first for a two parameter joint model and then for a three parameter model, in which cross coupling terms are also included. Two cases of structural connections have been considered, first with a cantilever beam with support flexibility and then a pair of beams connected through lap joint. The validity of the proposed method is demonstrated through numerical simulation and by experimentation.

Active Structural Vibration Control using Forecasting Control Method (예측 제어기법을 이용한 기계 구주물의 능동 진동제어)

  • 황요하
    • Journal of KSNVE
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    • v.2 no.4
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    • pp.293-304
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    • 1992
  • Active vibration control is presented with simulation and experiment. Dynamic Data System(DDS) method is used for system modeling and this model is combined with an forecasting control technique to derive a control equation. In the experiment, on-line digital computer monitors structural vibration and calculates control input. The control input is sent to an electromagnetic actuator which cancels the structural vibration. Experiment is performed first with a simple beam setup to demonstrate the effetiveness of this method. This method is then applied to a color laser printer to actively modify the structure. The beam experiment showed vibration reduction of over 60% with one-and two-DOF models. In the printer structure experiment, the first mode of 308 Hz was successfully controlled with a one-DOF model.

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