The Identification and Decomposition of Hierarchical Tasks

1977 ◽  
Vol 14 (3) ◽  
pp. 189-212 ◽  
Author(s):  
John W. Cotton ◽  
John P. Gallagher ◽  
Sandra P. Marshall

The definition of hierarchical structure is reviewed, together with psychometric and experimental evidence regarding the existence of specific structures. Exceptions to hierarchical ordering are frequent enough to merit consideration of an assumption that skill on an item may simply transfer to the next higher item rather than being fully prerequisite to it. In some cases an alternate route hierarchy may occur, with persons either learning an item and then the next item or learning both at the same time. A mathematical model including hierarchical and nonhierarchical options fir a two-component task is presented; an experimental design appropriate to testing the model and related transfer hypotheses is also presented.

One of the approaches to the development of a complex mathematical model of a production system is considered. Keywords mathematical model; target subsystem; quality criterion; controlling parameter; hierarchical structure


Author(s):  
V. M. Makarov

We consider the problem of rational statistical control technical parameters of automatic spacecraft (AKA) in the process of their ground testing in autonomous and complex testing in a three-tier hierarchical structure: independent product testing, independent testing systems and comprehensive testing of the AKA in general. The mathematical model of control, the formalized statement of a problem and algorithm of optimization of statistical control of sets of products and their technical parameters on hierarchy of working off is given. At the same time, the model and algorithm allow you to select the optimal product range of each level of the hierarchy from the sets that are subject to mandatory control, take into account the specified requirements for technical parameters and the results of monitoring the technical parameters of the lower levels of products when planning and carrying out control of the parameters of the higher levels.


Author(s):  
Volodymyr Kotsyuruba ◽  
Ruslan Cherevko

At the current stage of the reformation of the Armed Forces of Ukraine in the context of the operation of the United Nations (Anti-Terrorist Operation (ATO)), there was a need to increase the effectiveness of the use of troops without increasing the cost of the resource. In the context of increasing capabilities of the armies of the leading countries in the world to investigate and defeat the forces of the opposite side, the problem of maintaining and restoring combat capability in the course of hostilities is very acute. One of the important components that determines combat capability is the maneuverability of the control points (PU). In the course of the defense, the problem of increasing the survivability of the PU system is important because the forces of the opposite side, with the onset of aggression, will try, first of all, to dismantle the PU using modern means of defeat and the massive use of high-precision weapons (WTZ), as well as aircraft and artillery strikes, electronic information and information fight, the use of sabotage and reconnaissance groups and tactical airborne troops to disrupt the control of defending troops. Important importance of the ability to timely carry out maneuver (organized movement) of PU and its elements into a new area in the preparation and in the course of military operations. The traditional approach to ensuring the survivability of PU does not allow to ensure the proper stability of their functioning. There is an objective necessity in the development of such a mathematical model of maneuverability, which in its characteristics would meet the dynamically increasing requirements of the control system of troops in the difficult conditions of projected operations. To ensure the quality management of military units, various measures to ensure the survivability of PU are considered. The article outlines approaches to the definition of indicators of estimation of maneuverability of PU and methods of their calculation. The research is carried out in modern conditions of combat operations, taking into account the movement of the line of the combat collision of the parties and the disclosure of the PU to the enemy's intelligence.


2020 ◽  
Vol 5 ◽  
pp. 30-32
Author(s):  
Norov Yunus Dzhumaevich ◽  
Mehmonov Maksud Rabbonokul ugli

The article presents a developed mathematical model for calculating the granulometric composition of the blasted rock mass based on the mechanism of action of an explosion in rocks, a mathematical description of the determination of natural units (blocks) in the rock mass, the relationship between the degree of rock fragmentation and the size of the units and the definition of sections of the controlled pressure zone.


2020 ◽  
pp. 55-57
Author(s):  
M.G. Galkin ◽  
A.S. Smagin ◽  
A.S. Pupyireva

An algorithm for the development of a mathematical model of cutting processing, as a multifactorial process, which determines the influence of significant parameters of the cutting mode on the roughness of the processed surface, is proposed. In the development of the algorithm, the method of extreme experimental design is used. Keywords cutting, mode, manufacturing process, surface roughness, mathematical model. [email protected]


2008 ◽  
Vol 6 (34) ◽  
pp. 463-469 ◽  
Author(s):  
Chrisantha T Fernando ◽  
Anthony M.L Liekens ◽  
Lewis E.H Bingle ◽  
Christian Beck ◽  
Thorsten Lenser ◽  
...  

We demonstrate how a single-celled organism could undertake associative learning. Although to date only one previous study has found experimental evidence for such learning, there is no reason in principle why it should not occur. We propose a gene regulatory network that is capable of associative learning between any pre-specified set of chemical signals, in a Hebbian manner, within a single cell. A mathematical model is developed, and simulations show a clear learned response. A preliminary design for implementing this model using plasmids within Escherichia coli is presented, along with an alternative approach, based on double-phosphorylated protein kinases.


Author(s):  
Marco Lamieri ◽  
Diana Mangalagiu

In this chapter we present a model of organization aimed to understand the effect of formal and informal structures on the organization’s performance. The model considers the interplay between the formal hierarchical structure and the social network connecting informally the agents emerging while the organization performs a task-set. The social network creation and evolution is endogenous, as it doesn’t include any function supposed to optimize performance. After a review of the literature, we propose a definition of performance based on the efficiency in allocating the task of a simulated organization that can be considered as a network-based problem-solving system. We analyze how the emergence of a stable process in decomposing tasks under different market conditions can alleviate the rigidity and the inefficiencies of a hierarchical structure and we compare the performance of different hierarchical structures under variable environment conditions.


2011 ◽  
Vol 300 (5) ◽  
pp. H1678-H1687 ◽  
Author(s):  
Espen W. Remme ◽  
Anders Opdahl ◽  
Otto A. Smiseth

We investigated the determinants of ventricular early diastolic lengthening and mechanics of suction using a mathematical model of the left ventricle (LV). The model was based on a force balance between the force represented by LV pressure (LVP) and active and passive myocardial forces. The predicted lengthening velocity ( e′) from the model agreed well with measurements from 10 dogs during 5 different interventions ( R = 0.69, P < 0.001). The model showed that e′ was increased when relaxation rate and systolic shortening increased, when passive stiffness was decreased, and when the rate of fall of LVP during early filling was decreased relative to the rate of fall of active stress. We first defined suction as the work the myocardium performed to pull blood into the ventricle. This occurred when contractile active forces decayed below and became weaker than restoring forces, producing a negative LVP. An alternative definition of suction is filling during falling pressure, commonly believed to be caused by release of restoring forces. However, the model showed that this phenomenon also occurred when there had been no systolic compression below unstressed length and therefore in the absence of restoring forces. In conclusion, relaxation rate, LVP, systolic shortening, and passive stiffness were all independent determinants of e′. The model generated a suction effect seen as lengthening occurring during falling pressure. However, this was not equivalent with the myocardium performing pulling work on the blood, which was performed only when restoring forces were higher than remaining active fiber force, corresponding to a negative transmural pressure.


mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Gaurav D. Sankhe ◽  
Narendra M. Dixit ◽  
Deepak K. Saini

ABSTRACT Two-component signaling systems (TCSs) are central to bacterial adaptation. However, the mechanisms underlying the reactions involving TCS proteins and their reaction rates are largely undetermined. Here, we employed a combined experimental and theoretical approach to elucidate the kinetics of autophosphorylation of three histidine kinases (HKs) of Mycobacterium tuberculosis , viz. , MtrB, PrrB, and PhoR, all known to play a role in regulating its virulence. Using wild-type and mutant proteins, we performed dimerization assays, thermophoretic-affinity measurements, and competition-based phosphorylation assays to establish that for HK, MtrB autophosphorylation occurs in cis , similar to what has been proposed for the PhoR and PrrB HKs. Next, to determine the kinetics of cis autophosphorylation, we used a quantitative high-throughput assay and identified a two-step mechanism of HK activation, involving (i) the reversible association of HK with ATP, followed by (ii) its phosphorylation. We developed a mathematical model based on this two-step cis mechanism that captured the experimental data. Best-fit parameter values yielded estimates of the extent of HK-ATP association and the rates of HK autophosphorylation, allowing quantification of the propensity of HK autophosphorylation. Our combined experimental and theoretical approach presents a facile, scalable tool to quantify reactions involving bacterial TCS proteins, useful in antibacterial drug development strategies. IMPORTANCE Two-component systems consisting of an input-sensing histidine kinase (HK) and an output-generating response regulator (RR) are one of the key apparatuses utilized by bacteria for adapting to the extracellular milieu. HK autophosphorylation is shown to occur primarily in trans (intermolecular) and more recently shown to occur in cis (intramolecular). Although the catalysis of HK activation remains universal, the reaction scheme for evaluation of the kinetic parameter differs between these designs and cis mode largely remains unexplored. We combined experimental and theoretical approach to unravel two-step mechanism of activation of three cis mode HKs of M. tuberculosis . The new mathematical model yields best-fit parameters to estimate the rates of HK-ATP association and HK autophosphorylation.


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