scholarly journals Characterization of Hamiltonian input-output systems

Author(s):  
P. E. Crouch ◽  
A. J. van der Schaft
Keyword(s):  
2013 ◽  
Vol 62 (3) ◽  
pp. 286-293 ◽  
Author(s):  
Ruiyue Ouyang ◽  
Vincent Andrieu ◽  
Bayu Jayawardhana

2010 ◽  
Vol 18 (24) ◽  
pp. 25108 ◽  
Author(s):  
Kenji Kintaka ◽  
Katsuya Shimizu ◽  
Yuki Kita ◽  
Satoshi Kawanami ◽  
Junichi Inoue ◽  
...  

2016 ◽  
Author(s):  
Ben Kravitz ◽  
Douglas G. MacMartin ◽  
Philip J. Rasch ◽  
Hailong Wang

Abstract. We introduce system identification techniques to climate science wherein multiple dynamic input-output relationships can be simultaneously characterized in a single simulation. This method, involving multiple small perturbations (in space and time) of an input field while monitoring output fields to quantify responses, allows for identification of different timescales of climate response to forcing without substantially pushing the climate far away from a steady state. We use this technique to determine the steady state responses of low cloud fraction and latent heat flux to heating perturbations over 22 regions spanning Earth's oceans. We show that the response characteristics are similar to those of step-change simulations, but in this new method, the responses for 22 regions can be characterized simultaneously. Furthermore, we can estimate the timescale over which the steady state response emerges. The proposed methodology could be useful for a wide variety of purposes in climate science, including characterization of teleconnections and uncertainty quantification to identify the effects of climate model tuning parameters.


2018 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Frida Agung Rakhmadi ◽  
Siti Rofikhoh

<p class="abstrak">The research on making detection system of Cu contaminated water based on red diode laser and photodiode sensor has been done. The purpose of this research was to know the characteristic of photodiode sensor, to make and to test the detection system of Cu contaminated water based on red diode laser and photodiode sensor. This research was conducted in five phases: characterization of photodiode sensor, making data acquisition system, processing and analyzing of training sample data, making of the detection system, and implementation of detection system on test samples. The results of research showed that photodiode sensor used in this research has transfer function of  V = 0,0156 * I + 1,1897 with relation of input-output was very strong (r = 0,989); sensitivity was 0,0156 volts / lux; repeatability was 98,31 %; and saturation for the light intensity &gt;200 lux. Meanwhile, the success rate of detection system implementation on Cu contaminated water was 97,5 %.</p>


2020 ◽  
Author(s):  
Akshay Parundekar ◽  
Ganesh A Viswanathan

AbstractOperating regimes characterizing the input-output behaviour of an activated phosphorylation-dephosphorylation reaction cycle (PdPC) such as a single MAPK cascade are dictated by the saturated/unsaturated state of the two underlying enzymatic reactions. Four combinations of the states of these two enzymatic reactions led to identification of distinct operating regimes, viz., Hyperbolic (H), Signal transducing (ST), Threshold-hyperbolic (TH) and Ultrasensitive (U). A single PdPC without an explicit feedback have been classically viewed as a module offering signal flow from upstream to downstream, that is, one-way communication. Recently it has been shown that load due to sequestration of the phosphorylated or unphosphorylated form of the substrate by corresponding downstream targets permits retroactive signalling that offers two-way communication. We systematically characterize the operating regimes of a single PdPC subject to retroactivity in either of the substrate forms. We identify five possible regime transitions that could be achieved by increasing the retroactivity strength on either of the two substrate forms. Remarkably, a retroactivity strength of 0.30 in the unphosphorylated form of the substrate is sufficient to induce a transition from ST to H regime indicating that the input-output behaviour of a PdPC is highly sensitive to the presence of a downstream load. Using sensitivity and rate-balance analysis, we show that modulation of the saturation levels of the two enzymatic reactions by increasing retroactivity is the fundamental mechanism governing operating regime transition.HighlightsCharacterization of operating regimes in the presence of retroactivity.Retroactivity can induce a transition between different operating regimes.Saturation levels of the two enzymatic reactions govern the regime transition.Sensitivity of the protein levels to retroactivity is dictated by saturation levels.


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