The characteristic state

2012 ◽  
Vol 16 (7) ◽  
pp. 777-794 ◽  
Author(s):  
Eric Vincens ◽  
Cécile Nouguier-Lehon
Keyword(s):  
2020 ◽  
Vol 174 ◽  
pp. 01029
Author(s):  
Danil Zorkov ◽  
Alexey Renev ◽  
Konstantin Filimonov ◽  
Rinat Zainulin

Submitted by generalized experience entry longwall into pre- driven recovery room (PDRR) in foreign and Russian mine.Submitted by research characteristic state parameters of the roof at failed entry. Give a classification of roof collapse at the entrance longwall into PDRR.On the example of longwall panel 5а-10-18 mine Raspadskaya reviewed formation process of stress-strain condition in area for PDRR. Has been modeled process of entry longwall into PDRR in the conditions of heavy roof. Determine the expected load on the anchor and standing support, installed in the PDRR. Assessed the load on the longwall shield. When calculating the loads was taken into account the following parameters: width pre-driven recovery room, number of standing support in the PDRR and especially its placement, the rate of entry longwall into PDRR.


1986 ◽  
Vol 51 (6) ◽  
pp. 1405-1411 ◽  
Author(s):  
G. A. Frolov ◽  
A. A. Korol' ◽  
V. V. Pasichnyi ◽  
V. Ya. Berezhetskaya ◽  
E. I. Suzdal'tsev ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4869
Author(s):  
Mingkun Yang ◽  
Gexin Chen ◽  
Jianxin Lu ◽  
Cong Yu ◽  
Guishan Yan ◽  
...  

The electro-hydraulic servo pump control system (EHSPCS) is a volume control system that uses a permanent magnet synchronous motor (PMSM) with a fixed displacement pump to directly drive and control the hydraulic cylinder. The energy transmission law of the system is very complicated due to the transformation of electrical, mechanical and hydraulic energy as well as other energy fields, and qualitative analysis of the energy transfer efficiency is difficult. Energy transfer analysis of the EHSPCS under different working conditions and loads is proposed in this paper. First, the energy flow transfer mechanism was analyzed, and the mathematical and energy transfer models of the key components of the system were established to explore the energy characteristic state transition rule. Second, a power bond diagram model was built, its state equation and state matrix were deduced, and a system simulation model was built. Finally, combined with the EHSPCS experimental platform, simulation experiments were carried out on the dynamic position following and steady-state position holding conditions of the system, and the variation rules of the power of each energy characteristic state and the system energy transfer efficiency under different loads were obtained. The research results provide a foundation for the study of power matching and energy-saving mechanism of the EHSPCS.


2003 ◽  
Vol 58 (2-3) ◽  
pp. 183-185
Author(s):  
T. Sato ◽  
Y. Okamoto

The density of molten terbium chloride at 993 to 1213 K, as measured by the γ -ray attenuation method, is found to be d = [3.937±0.028−(4.76±0.25) · 10−4T] g/cm3. The characteristic state parameters of molten TbCl3 are found to be 1129 K and 78.0 ml for T* and ν*, respectively.


Author(s):  
Liping Zhang ◽  
Delun Wang ◽  
Jian S. Dai

A new methodology for automated conceptual design of hybrid combined mechanical system based on the characteristic state space approach is developed. The goal is to conceive the appropriate hybrid system given only the kinematic function posed in the problem specifications. The key enabler of the conceptual synthesis is the method of capturing kinematic behavior and transforming the continuous and non-linear motion into the discrete states and linear relation characteristic stack representation. A new characteristic state analyzing method for multi-dof primary mechanism blocks is proposed. Then the characteristic state equations are established by motion relationship between the multiple inputs and the outputs, which including characteristic transformation matrices and the characteristic state vectors established through the method of linearization for kinematic equations according to the specific input and output motion transformation. Thus the multi-dof primary mechanism blocks are identified, classified and represented qualitatively from characteristic perspectives. And then, generalized characteristic state modeling method is used to describe the behavior of the multi-loop combined mechanism. The generalized characteristic state model sets are established according to the classified primary combination patterns. The mathematical model of the hybrid combination system facilitates the characterization of the primary mechanism blocks and primary combination patterns, transformation of problem specifications, decomposition into sub-problems, and the ability to search for alternate solutions. The characteristic state space graph theory and the space vector routing model between the random input-output dual vectors in state space are established. Furthermore, with the manipulation of the dual vectors, the mathematic synthesis model is presented leading to the characteristic equation operation and the groundwork is laid for the conceptual design. To fine present the automated decomposition and the synthesis algorithm, the suggested design examples are compact and compatible with the general design principles.


Author(s):  
Wenyong Ma ◽  
Delun Wang ◽  
Kwun-Lon Ting

A new approach for automated conceptual design of hydraulic system is developed in this paper based on the energy characteristic state model. The energy characteristics of hydraulic systems are firstly represented by qualitative vectors, and the integral hydraulic systems are visualized as a set of subsystems with single-action for synthesis. Then, two categories of basic transformation units are defined from general hydraulic components, and the qualitative matrix representations for these basic transformation units are also established according to the function analysis. Finally, the conceptual design model for hydraulic system is established, in which the design processes of single-action subsystems are transformed into the decomposition of system-level matrices and the matching of component-level matrices. A design example is also given to illustrate the proposed approach.


2018 ◽  
Vol 27 (2) ◽  
pp. 33-48
Author(s):  
Ignacio De la Peña Zarzuelo ◽  
Beatriz López Bermúdez ◽  
María Jesús Freire Seoane

As investigacións iniciadas nos anos 60 que tentan determinar o impactoeconómico dos portos nas economías da súa hinterland fóronse depurando, e asmetodoloxías foron converxendo ata permitir realizar comparacións entre uns portos eoutros. No sistema portuario español leváronse a cabo importantes estudos de impactoeconómico e, entre eles, destaca o do porto de Ferrol-San Cibrao, tanto polo carácterpioneiro como pola diversidade de enfoques, como polas metodoloxías que se utilizaronpara a súa determinación. Neste traballo, considéranse os estudos máis relevantes e, parao caso do porto de Ferrol-San Cibrao, harmonízanse os datos ao ano de referencia 2016 através dos coeficientes deflatores do PIB, e realízase unha análise comparativa conrespecto aos portos estatais de características semellantes.The research initiated in the 60s in an atempt to determine the economicimpact of ports in the economies of their hinterland have been refined, and themethodologies have been converging to allow comparisons between ports.In the Spanish port system, important economic impact studies have been carried out,including the port of Ferrol-San Cibrao, both for its pioneering nature and for the diversityof approaches and methodologies that have been used for its determination. In this paper,the most relevant studies are analyzed, the data are harmonized to the reference year2016 through the deflator coefficients of the GDP, and a comparison is made in relation tothe similar characteristic state ports.


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