• Title/Summary/Keyword: forward modeling

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A syudy of Algorithm using the method of HLMF and NCD on the 'Lak-seo nine palace' (HLMF 및 NCD 기법을 적용한 낙서구궁의 Algorithm에 관한 연구)

  • Han, Doung-Soo;Cho, Sung-Je
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.2
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    • pp.141-151
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    • 2011
  • This paper aim at producing a Digital Modeling of the science of divination using a study of a new method with a mathematical function on "Lak-seo nine palace". For that goal, we must study a new law of moving forward and a new common difference on 'Lak-seo nine place'. We call this "the method of HLMF and NCD". Therefore, When drawing up 'a plan of Lak-seo nine palace', we will provide convenience in the field, so we don't make it by handwrite, but will produce it by a digital mode.

2.5 Dimensional Electromagnetic Finite Element Numerical modeling using linear conductivity variation (선형적 물성변화를 고려하는 유한요소법을 이용한 2.5차원 전자탐사 수치모델링)

  • Ko, Kwang-Beom;Suh, Baek-Soo
    • Journal of Industrial Technology
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    • v.18
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    • pp.131-138
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    • 1998
  • Numerical modeling for electromagnetic exploration methods are essential to understand behaviours of electromagnetic fields in complex subsurfaces. In this study, a finite element method was adopted as a numerical scheme for the 2.5-dimensional forward problem. And a finite element equation considering linear conductivity variation was proposed when 2.5-dimensional differential equation to couple eletric and magnetic field was implemented. Model parameters were investigated for near-field with large source effects and far-field with responses dominantly by homogeneous half-space. Numerical responses by this study were compared with analytic solutions in homogeneous half-space and compared with other three dimensional numerical results.

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Higher Order Parabolic Equation Modeling Using Galerkin's Method (Galerkin방법을 이용한 고차 포물선 방정식 수중음 전달 해석)

  • 이철원;성우제;정문섭
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.4
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    • pp.71-77
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    • 1999
  • Exact forward modeling of acoustic propagation is crucial in MFP such as inverse problems and various other acoustic applications. As acoustic propagation in shallow water environments become important, range dependent modeling has to be considered of which PE method is considered as one of the most accurate and relatively fast. In this paper higher order numerical rode employing the PE method is developed. To approximate the depth directional operator, Galerkin's method is used with partial collocation to lessen necessary calculations. Linearization of tile depth directional operator is achieved via expansion into a multiplication form of (equation omitted) approximation. To approximate the range directional equation, Crank-Nicolson's method is used. Final1y, numerical self stater is employed. Numerical tests are performed for various occan environment scenarios. The results of these tests are compared to exact solutions, OASES and RAM results.

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Neural Network Modeling of PECVD SiN Films and Its Optimization Using Genetic Algorithms

  • Han, Seung-Soo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.87-94
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    • 2001
  • Silicon nitride films grown by plasma-enhanced chemical vapor deposition (PECVD) are useful for a variety of applications, including anti-reflecting coatings in solar cells, passivation layers, dielectric layers in metal/insulator structures, and diffusion masks. PECVD systems are controlled by many operating variables, including RF power, pressure, gas flow rate, reactant composition, and substrate temperature. The wide variety of processing conditions, as well as the complex nature of particle dynamics within a plasma, makes tailoring SiN film properties very challenging, since it is difficult to determine the exact relationship between desired film properties and controllable deposition conditions. In this study, SiN PECVD modeling using optimized neural networks has been investigated. The deposition of SiN was characterized via a central composite experimental design, and data from this experiment was used to train and optimize feed-forward neural networks using the back-propagation algorithm. From these neural process models, the effect of deposition conditions on film properties has been studied. A recipe synthesis (optimization) procedure was then performed using the optimized neural network models to generate the necessary deposition conditions to obtain several novel film qualities including high charge density and long lifetime. This optimization procedure utilized genetic algorithms, hybrid combinations of genetic algorithm and Powells algorithm, and hybrid combinations of genetic algorithm and simplex algorithm. Recipes predicted by these techniques were verified by experiment, and the performance of each optimization method are compared. It was found that the hybrid combinations of genetic algorithm and simplex algorithm generated recipes produced films of superior quality.

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Apartment house project cost schedule for integrated management BIM-based BoQ application plan (공동주택 프로젝트 비용일정통합 관리를 위한 BIM 기반 BoQ 구축 및 활용 방안)

  • Zheng, Lianyi;Kim, Woong-Gi;Ham, Nam-Hyuk;Kim, Jae-Jun
    • Journal of KIBIM
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    • v.11 no.2
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    • pp.1-16
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    • 2021
  • Since entering the 21st century, the construction industry has developed faster and faster, and more and more technologies have been applied in the construction industry. BIM technology (Building Information Modeling) was born in this environment. The application of BIM technology can greatly improve the efficiency of cost management and help achieve the goal of cost management. But through BIM to realize project cost management, there is still no good solution. In order to solve this problem, this paper puts forward the concept of WBS structure applied to construction projects by studying the BoQ (Bill of Quantities) list based on BIM, and proposes the numbering method of the structure. The WBS (Work Breakdown Structure) structure proposed in this paper divides more than 5000 cost objects into 133 projects according to the type of work and project schedule. This structure helps to realize the application of BIM in project cost management. Although this article has studied more than 5000 data of three projects, it does not think that it can cover all cost objects in the existing construction industry. The purpose of this article is to propose a solution for cost and Process Control using BIM-based BoQ data.

Hunminjeongeum Phonetics (I): Phonetic and Phoniatric Consideration for Explanation of Designs of Middle Vowel Letters (훈민정음 음성학(I): 중성자(홀소리) 제자해에 대한 음성언어의학적 고찰)

  • Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.33 no.2
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    • pp.77-82
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    • 2022
  • Hunminjeongeum was made by the Great King Sejong, and composed of 17 consonant and 11 vowel letters. All the 28 letters were made according to the shape of vocal organ or space at the point of articulation for each letters. This review article focused on phonetic and phoniatric consideration for explanation of the designs of the middle vowel letters, especially three main vowel letters [ • (天, heaven), ㅡ (地, earth), ㅣ (人, human)] using video-fluoroscopic evaluation as well as computed tomography scanning, etc. During articulating / • / sound, a ball-like space at frontal portion of the oral cavity was found, tongue was contracted, and sound was deep (舌縮而聲深). During /ㅡ/ sound, a flat air space between oral tongue and hard palate was created. Tongue was slightly contacted neither deep nor shallow (舌小縮而聲不深不淺). During /ㅣ/ sound, tongue was not contacted and Sound is light (舌不縮而聲淺). Tongue was moved forward making longitudinal oro-pharyngeal air space. So, I'd like to suggest that we had better change the explanation drawing from a philosophical modeling to a more scientific modeling from real vocal tract space modeling during articulating middle vowels of Hunminjeongeum.

The elbow is the load-bearing joint during arm swing

  • Bokku Kang;Gu-Hee Jung;Erica Kholinne;In-Ho Jeon;Jae-Man Kwak
    • Clinics in Shoulder and Elbow
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    • v.26 no.2
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    • pp.126-130
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    • 2023
  • Background: Arm swing plays a role in gait by accommodating forward movement through trunk balance. This study evaluates the biomechanical characteristics of arm swing during gait. Methods: The study performed computational musculoskeletal modeling based on motion tracking in 15 participants without musculoskeletal or gait disorder. A three-dimensional (3D) motion tracking system using three Azure Kinect (Microsoft) modules was used to obtain information in the 3D location of shoulder and elbow joints. Computational modeling using AnyBody Modeling System was performed to calculate the joint moment and range of motion (ROM) during arm swing. Results: Mean ROM of the dominant elbow was 29.7°±10.2° and 14.2°±3.2° in flexion-extension and pronation-supination, respectively. Mean joint moment of the dominant elbow was 56.4±12.7 Nm, 25.6±5.2 Nm, and 19.8±4.6 Nm in flexion-extension, rotation, and abduction-adduction, respectively. Conclusions: The elbow bears the load created by gravity and muscle contracture in dynamic arm swing movement.

Stochastic identification of masonry parameters in 2D finite elements continuum models

  • Giada Bartolini;Anna De Falco;Filippo Landi
    • Coupled systems mechanics
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    • v.12 no.5
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    • pp.429-444
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    • 2023
  • The comprehension and structural modeling of masonry constructions is fundamental to safeguard the integrity of built cultural assets and intervene through adequate actions, especially in earthquake-prone regions. Despite the availability of several modeling strategies and modern computing power, modeling masonry remains a great challenge because of still demanding computational efforts, constraints in performing destructive or semi-destructive in-situ tests, and material uncertainties. This paper investigates the shear behavior of masonry walls by applying a plane-stress FE continuum model with the Modified Masonry-like Material (MMLM). Epistemic uncertainty affecting input parameters of the MMLM is considered in a probabilistic framework. After appointing a suitable probability density function to input quantities according to prior engineering knowledge, uncertainties are propagated to outputs relying on gPCE-based surrogate models to considerably speed up the forward problem-solving. The sensitivity of the response to input parameters is evaluated through the computation of Sobol' indices pointing out the parameters more worthy to be further investigated, when dealing with the seismic assessment of masonry buildings. Finally, masonry mechanical properties are calibrated in a probabilistic setting with the Bayesian approach to the inverse problem based on the available measurements obtained from the experimental load-displacement curves provided by shear compression in-situ tests.

Development of an Inversion Analysis Technique for Downhole Testing and Continuous Seismic CPT

  • Joh, Sung-Ho;Mok, Young-Jin
    • Geotechnical Engineering
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    • v.14 no.3
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    • pp.95-108
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    • 1998
  • Downhole testing and seismic CPT (SCPT) have been widely used to evaluate stiffness profiles of the subgrade. Advantages of downhole testing and SCPT such as low cost, easy operation and a simple seismic source have got these testings more frequently adopted in site investigation. For the automated analysis of downhole testing and SCPT, the concept of interval measurements has been practiced. In this paper. a new inversion procedure to deal tilth the interval measurements for the automated downhole testing and SCPT (including a newlydeveloped continuous SCPT) is proposed. The forward modeling in the new inversion procedure incorporates ray path theory based on Snell's law. The formulation for the inversion analysis is derived from the maximum likelihood approach, which estimates the maximum likelihood of obtaining a particular travel time from a source to a receiver. Verification of the new inversion procedure was performed with numerical simulations of SCPT using synthesized profiles. The results of the inversion analyses performed for the synthetic data show that the new inversion analysis is a valid procedure which enhances Va profiles determined by downhole testing and SCPT.

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2.5-Dimensional Electromagnetic Numerical Modeling and Inversion (2.5차원 전자탐사 수치모델링 및 역해)

  • Ko Kwang-Beom;Suh Jung-Hee;Shin Chang-Soo
    • Geophysics and Geophysical Exploration
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    • v.2 no.1
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    • pp.43-53
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    • 1999
  • Numerical modeling and inversion for electromagnetic exploration methods are essential to understand behaviour of electromagnetic fields in complex subsurface. In this study, a finite element method was adopted as a numerical scheme for the 2.5-dimensional forward problem. And a finite element equation considering linear conductivity variation was proposed, when 2.5-dimensional differential equation to couple eletric and magnetic field was implemented. Model parameters were investigated for near-field with large source effects and far-field with responses dominantly by homogeneous half-space. Numerical responses by this study were compared with analytic solutions in homogeneous half-space. Blocky inversion model was modified to be applied to the forward calculation in this study and it was also adopted in the inversion algorithm. Resolution for isolated bodies were investigated to confirm possibility and limitation of inversion for electromagnetic exploration data.

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