scholarly journals Editorial for the Launching of Dynamics

Dynamics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 18-21
Author(s):  
Christos Volos
Keyword(s):  

Nowadays, the subject of studying system dynamics behavior has become very important in many branches of technology [...]


Author(s):  
Dongmei Chen ◽  
Zheren Ma ◽  
Brandon C. Li ◽  
Zeyu Yan ◽  
Wei Li

The electrooculography (EOG) signal is considered most suitable for drowsiness detection. Besides its simplicity and low cost, EOG signals are not affected by environmental factors such as light intensity and driver movement. However, existing EOG-based drowsiness detection techniques employ arbitrarily chosen features for classifier training, leading to results that are less robust against changes in the measurement method, noise level, and individual subject variability. In this study, we propose a system dynamics-based approach to drowsiness detection. The EOG signal is treated as a neurophysiological response of the oculomotor system. Each blink action is considered as a result of a series of neuron firing impulses entering the system. Blink signatures are thus extracted to identify the system transfer function, from which system poles are computed to characterize the drowsiness state of the subject. It was found that the location of system poles on the pole–zero map for blink signatures from an alert state was distinctly different from those from a drowsy state. A simple criterion was subsequently developed for drowsiness detection by counting the ratio of real and complex poles of the system over any given period of time. The proposed methodology is a systematic approach and does not require extensive classifier training. It is robust against variations in the subject condition, sensor placement, noise level, and blink rate.



2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Larissa do Nascimento Sancheta ◽  
Gisele de Lorena Diniz Chaves ◽  
Renato Ribeiro Siman

Abstract Urban solid waste management is a complex system due to the many variables that compose it, which makes it difficult for managers to make decisions. Among the decision-making tools is system dynamics. To identify the gaps between the literature and the studies about urban solid waste management by using system dynamics method, a survey of published papers on the subject was made, which were later analyzed using some defined criteria, such as the level of the study, the software used for modeling, the variables included in the model, among others. The research identified that, among the stages of solid waste management, the collection process is still little incorporated in the models, being mentioned in only nine studies analyzed. Besides, the environmental, financial and institutional requirements were not adequately explored in the models. Future research should endeavor to include these elements in the models, which will allow the proposed system to be approximated to the complex reality of solid waste management.



2010 ◽  
Vol 38 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Bernat Crosas ◽  
Rosa Farràs ◽  
Gemma Marfany ◽  
Manuel S. Rodríguez ◽  
Timothy M. Thomson

The ubiquitin–proteasome field has matured, as is evident from the wide diversity of systems and mechanisms in which it participates and that are the subject of investigation, presented in the Ubiquitin–Proteasome System, Dynamics and Targeting meeting held in Barcelona, co-sponsored by the Biochemical Society, the Spanish Ministry of Science, the Spanish Research Council and the Catalan Academy of Sciences. Several of the aspects dealt with in the meeting are discussed in detail in the collection of review papers included in this issue of Biochemical Society Transactions. These papers reflect the importance of ubiquitin and ubiquitin-like modifiers as enormously versatile signalling entities that modulate and direct pathways in specific directions through modification-induced interactions. One conclusion from the meeting is that the field has become so rich and dense that, in order to be useful and informative, future meetings may need to focus on particular aspects of the ubiquitin–proteasome system.



2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
António M. Lopes ◽  
J. A. Tenreiro Machado

For integer-order systems, there are well-known practical rules for RL sketching. Nevertheless, these rules cannot be directly applied to fractional-order (FO) systems. Besides, the existing literature on this topic is scarce and exclusively focused on commensurate systems, usually expressed as the ratio of two noninteger polynomials. The practical rules derived for those do not apply to other symbolic expressions, namely, to transfer functions expressed as the ratio of FO zeros and poles. However, this is an important case as it is an extension of the classical integer-order problem usually addressed by control engineers. Extending the RL practical sketching rules to such FO systems will contribute to decrease the lack of intuition about the corresponding system dynamics. This paper generalises several RL practical sketching rules to transfer functions specified as the ratio of FO zeros and poles. The subject is presented in a didactic perspective, being the rules applied to several examples.



PMLA ◽  
1935 ◽  
Vol 50 (4) ◽  
pp. 1320-1327
Author(s):  
Colbert Searles

THE germ of that which follows came into being many years ago in the days of my youth as a university instructor and assistant professor. It was generated by the then quite outspoken attitude of colleagues in the “exact sciences”; the sciences of which the subject-matter can be exactly weighed and measured and the force of its movements mathematically demonstrated. They assured us that the study of languages and literature had little or nothing scientific about it because: “It had no domain of concrete fact in which to work.” Ergo, the scientific spirit was theirs by a stroke of “efficacious grace” as it were. Ours was at best only a kind of “sufficient grace,” pleasant and even necessary to have, but which could, by no means ensure a reception among the elected.



1966 ◽  
Vol 25 ◽  
pp. 363-371
Author(s):  
P. Sconzo

In this paper an orbit computation program for artificial satellites is presented. This program is operational and it has already been used to compute the orbits of several satellites.After an introductory discussion on the subject of artificial satellite orbit computations, the features of this program are thoroughly explained. In order to achieve the representation of the orbital elements over short intervals of time a drag-free perturbation theory coupled with a differential correction procedure is used, while the long range behavior is obtained empirically. The empirical treatment of the non-gravitational effects upon the satellite motion seems to be very satisfactory. Numerical analysis procedures supporting this treatment and experience gained in using our program are also objects of discussion.



1966 ◽  
Vol 27 ◽  
pp. 159-161

Rule: I'd like at this point to bring up the subject of cables and wireways around the telescope. We've touched upon this twice during previous sessions: the cable wrap up problem, the communications problem, and data multiplexing problem. I think we'll ask Bill Baustian if he will give us a brief run down on what the electrical run problems are, besides doubling the system every year.



Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.



Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.



Author(s):  
Gladys Harrison

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.



Sign in / Sign up

Export Citation Format

Share Document