14 research outputs found
Basis transform in switched linear system state-space models from input-output data
This paper tackles the basis selection issue in the context of state-space
hybrid system identification from input-output data. It is often the case that
an identification scheme responsible for state-space switched linear system
(SLS) estimation from input-output data operates on local levels. Such
individually identified local estimates reside in distinct state bases, which
call for the need to perform some basis correction mechanism that facilitates
their coherent patching for the ultimate goal of performing output predictions
for predefined input test signals. We derive necessary and sufficient
conditions on the submodel set, the switching sequence, and the dwell times
that guarantee the presented approach's success. Such conditions turn out to be
relatively mild, which contributes to the application potential of the devised
algorithm. We also provide a linkage between this work and the existing
literature by providing several insightful remarks that highlight the discussed
method's favorability. We supplement the theoretical findings by an elaborative
numerical simulation that puts our methodology into action
Realization of multi-input/multi-output switched linear systems from Markov parameters
This paper presents a four-stage algorithm for the realization of
multi-input/multi-output (MIMO) switched linear systems (SLSs) from Markov
parameters. In the first stage, a linear time-varying (LTV) realization that is
topologically equivalent to the true SLS is derived from the Markov parameters
assuming that the submodels have a common MacMillan degree and a mild condition
on their dwell times holds. In the second stage, zero sets of LTV Hankel
matrices where the realized system has a linear time-invariant (LTI) pulse
response matching that of the original SLS are exploited to extract the
submodels, up to arbitrary similarity transformations, by a clustering
algorithm using a statistics that is invariant to similarity transformations.
Recovery is shown to be complete if the dwell times are sufficiently long and
some mild identifiability conditions are met. In the third stage, the switching
sequence is estimated by three schemes. The first scheme is based on
forward/backward corrections and works on the short segments. The second scheme
matches Markov parameter estimates to the true parameters for LTV systems and
works on the medium-to-long segments. The third scheme also matches Markov
parameters, but for LTI systems only and works on the very short segments. In
the fourth stage, the submodels estimated in Stage~2 are brought to a common
basis by applying a novel basis transformation method which is necessary before
performing output predictions to given inputs. A numerical example illustrates
the properties of the realization algorithm. A key role in this algorithm is
played by time-dependent switching sequences that partition the state-space
according to time, unlike many other works in the literature in which
partitioning is state and/or input dependent
Tracheostomy practices in intensive care units in Turkey: Turkish Thoracic Society critical care assembly point prevelance trial
TÜRKIYE’DE YOĞUN BAKIM ÜNITELERINDE VENTILATÖR ILIŞKILI PNÖMONIYI ÖNLEMEK IÇIN ALINAN GÜNCEL ÖNLEMLER: TÜRK TORAKS DERNEĞI SOLUNUM YETMEZLIĞI VE YOĞUN BAKIM ÇALIŞMA GRUBU NOKTA PREVALANS ÇALIŞMASI
Objectives: The inadequate quality and nature of sleep is a commonly reported problem among hospitalized patients. The purpose of this study is to examine the effects of progressive muscle relaxation training program on sleep quality, sleep state, pain and life quality of patients who underwent pulmonary resection