Ordered physics-based parameter adjustment of a distributed model

Author(s):  
Baxter E. Vieux ◽  
Fekadu G. Moreda

This article describes the proposed approaches to creating distributed models that can, with given accuracy under given restrictions, replace classical physical models for construction objects. The ability to implement the proposed approaches is a consequence of the cyber-physical integration of building systems. The principles of forming the data structure of designed objects and distributed models, which make it possible to uniquely identify the elements and increase the level of detail of such a model, are presented. The data structure diagram of distributed modeling includes, among other things, the level of formation and transmission of signals about physical processes inside cyber-physical building systems. An enlarged algorithm for creating the structure of the distributed model which describes the process of developing a data structure, formalizing requirements for the parameters of a design object and its operating modes (including normal operating conditions and extreme conditions, including natural disasters) and selecting objects for a complete group that provides distributed modeling is presented. The article formulates the main approaches to the implementation of an important practical application of the cyber-physical integration of building systems - the possibility of forming distributed physical models of designed construction objects and the directions of further research are outlined.


Author(s):  
James M. Krause ◽  
Pramod P. Khargonekar

2017 ◽  
Author(s):  
Pascalia Vinca Alvando ◽  
Achmad Darul ◽  
Dasapta Erwin Irawan

Airtanah merupakan salah satu faktor penting yang berkontribusi terhadap ketidakstabilan lereng, air akan mengisi pori tanah sehingga tekanan air pori meningkat. Pada tahun 2009 di Pit E, PT. BC khususnya low wall pernah terjadi longsor, tujuan penelitian ini untuk mengetahui besar penurunan muka airtanah (drawdown) serta melakukan simulasi dalam waktu 8 tahun kedepan setelah upaya dewatering pada tahun 2016 dengan menggunakan sistem drain hole yang dipasang secara inclined. Model konseptual daerah penelitian dibangun dengan data pengamatan muka airtanah mula-mula, curah hujan, topografi dan properti hidrogeologi yang ditentukan berdasarkan asumsi teoriritis. Simulasi numerik menggunakan metode beda hingga dilakukan dalam dua skenario yaitu pada tiga IDH aktif dan penambahan tiga IDH di luar model pada akuifer terkekang dengan variasi kedalaman 50 m dan 80 m. Drawdown hasil simulasi kemudian dikalibrasi dengan perhitungan metode Theis. Hasil studi menunjukan nilai drawdown dari perhitungan Theis lebih kecil dari hasil simulasi numerik. Outflow pada pemodelan juga menghasilkan nilai yang lebih besar dari pengamatan di lapangan. Parameter adjustment berupa nilai konduktivitas hidraulik kemudian dilakukan untuk mengetahui pengaruhnya terhadap besar drawdown. Hasilnya menunjukan bahwa nilai konduktivitas hidraulik memiliki pengaruh yang signifikan terhadap perubahan besar drawdown. (Pre-print)Kata kunci: drawdown, confined aquifer, inclined drain hole, dewatering


2009 ◽  
Vol 297 (1) ◽  
pp. H208-H222 ◽  
Author(s):  
Philippe Reymond ◽  
Fabrice Merenda ◽  
Fabienne Perren ◽  
Daniel Rüfenacht ◽  
Nikos Stergiopulos

A distributed model of the human arterial tree including all main systemic arteries coupled to a heart model is developed. The one-dimensional (1-D) form of the momentum and continuity equations is solved numerically to obtain pressures and flows throughout the systemic arterial tree. Intimal shear is modeled using the Witzig-Womersley theory. A nonlinear viscoelastic constitutive law for the arterial wall is considered. The left ventricle is modeled using the varying elastance model. Distal vessels are terminated with three-element windkessels. Coronaries are modeled assuming a systolic flow impediment proportional to ventricular varying elastance. Arterial dimensions were taken from previous 1-D models and were extended to include a detailed description of cerebral vasculature. Elastic properties were taken from the literature. To validate model predictions, noninvasive measurements of pressure and flow were performed in young volunteers. Flow in large arteries was measured with MRI, cerebral flow with ultrasound Doppler, and pressure with tonometry. The resulting 1-D model is the most complete, because it encompasses all major segments of the arterial tree, accounts for ventricular-vascular interaction, and includes an improved description of shear stress and wall viscoelasticity. Model predictions at different arterial locations compared well with measured flow and pressure waves at the same anatomical points, reflecting the agreement in the general characteristics of the “generic 1-D model” and the “average subject” of our volunteer population. The study constitutes a first validation of the complete 1-D model using human pressure and flow data and supports the applicability of the 1-D model in the human circulation.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4041
Author(s):  
Anca Maxim ◽  
Constantin-Florin Caruntu

Following the current technological development and informational advancement, more and more physical systems have become interconnected and linked via communication networks. The objective of this work is the development of a Coalitional Distributed Model Predictive Control (C- DMPC) strategy suitable for controlling cyber-physical, multi-agent systems. The motivation behind this endeavour is to design a novel algorithm with a flexible control architecture by combining the advantages of classical DMPC with Coalitional MPC. The simulation results were achieved using a test scenario composed of four dynamically coupled sub-systems, connected through an unidirectional communication topology. The obtained results illustrate that, when the feasibility of the local optimization problem is lost, forming a coalition between neighbouring agents solves this shortcoming and maintains the functionality of the entire system. These findings successfully prove the efficiency and performance of the proposed coalitional DMPC method.


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