General Forms of a Class of Multivariable Regression Models

2014 ◽  
Vol 11 (2) ◽  
pp. 22-28
Author(s):  
A. Efremov

Abstract There are two possible general forms of multiple input multiple output (MIMO) regression models, which are either linear with respect to their parameters or non-linear, but in order to estimate their parameters, at a certain stage it could be assumed that they are linear. This is in fact the basic assumption behind the linear approach for parameters estimation. There are two possible representations of a MIMO model, which at a certain level could be fictitiously presented as linear functions of its parameters. One representation is when the parameters are collected in a matrix and hence, the regressors are in a vector. The other possible case is the parameters to be in a vector, but the regressors at a given instant to be placed in a matrix. Both types of representations are considered in the paper. Their advantages and disadvantages are summarized and their applicability within the whole experimental modelling process is also discussed.

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3415
Author(s):  
Hursuong Vongsachang ◽  
Aleksandra Mihailovic ◽  
Jian-Yu E ◽  
David S. Friedman ◽  
Sheila K. West ◽  
...  

Understanding periods of the year associated with higher risk for falling and less physical activity may guide fall prevention and activity promotion for older adults. We examined the relationship between weather and seasons on falls and physical activity in a three-year cohort of older adults with glaucoma. Participants recorded falls information via monthly calendars and participated in four one-week accelerometer trials (baseline and per study year). Across 240 participants, there were 406 falls recorded over 7569 person-months, of which 163 were injurious (40%). In separate multivariable regression models incorporating generalized estimating equations, temperature, precipitation, and seasons were not significantly associated with the odds of falling, average daily steps, or average daily active minutes. However, every 10 °C increase in average daily temperature was associated with 24% higher odds of a fall being injurious, as opposed to non-injurious (p = 0.04). The odds of an injurious fall occurring outdoors, as opposed to indoors, were greater with higher average temperatures (OR per 10 °C = 1.46, p = 0.03) and with the summer season (OR = 2.69 vs. winter, p = 0.03). Falls and physical activity should be understood as year-round issues for older adults, although the likelihood of injury and the location of fall-related injuries may change with warmer season and temperatures.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Amy K Guzik ◽  
Rema Raman ◽  
Kain Ernstrom ◽  
Dawn M Meyer ◽  
Ajeet Sodhi ◽  
...  

Background: Patients with advanced age or high NIHSS have poorer tPA outcomes. When combined, old age (≥80yo) and elevated NIHSS (≥20) may have an even worse outcome. Patients who are also in this “Stroke100 Club” (any combination of age and NIHSS ≥100) by other means, have not been fully assessed. We evaluated discharge destination, 90-day mRS, sICH and death in treated and untreated Stroke100 Club patients. We further compared patients with age ≥ 80 and NIHSS ≥ 20 (“80/20s”), those who reached 100 without both characteristics (“non80/20s”) and ‘controls’. Methods: The UCSD SPOTRIAS prospectively collected database was analyzed for AIS patients (with and without tPA). Multivariable regression models including the Stroke100 group as an independent variable was used. Outcomes were adjusted for baseline mRS. For comparing categorical outcomes between controls, “80/20s” and “non80/20s” subgroups, a Fisher’s exact was used. Results: The IV tPA subset included 257 patients (mean age 71, 52% male, 85% white, mean NIHSS 12). 53 were in the “Stroke100 Club” (28 80/20, 25 non80/20), with more women (68% p= 0.002), higher NIHSS (22.5 p<0.0001), older age (mean age 86.4 p<0.0001), higher pre stroke mRS (34.6% mRS 3-6 vs 7.84%, p<0.0001), more HTN (p=0.045) and more afib (p= 0.008). There were 284 non tPA patients (mean age 69.52, 54% male, 85% white, mean NIHSS 5.92). 21 were in the “Stroke100 Club” (14 80/20, 7 non80/20), with higher NIHSS (23 p<0.0001), older age (mean 86.2 p<0.0001), higher pre stroke mRS (45.5% 3-6 vs 9.5%, p= 0.0001), and more afib (p= 0.0002). Stroke100 Club 90day mRS(3-6) outcomes were worse in both tPA treated patients (OR=6.77, p= 0.0001) and nontreated patients (OR 31.57, p= 0.001). sICH rates (in tPA subjects) were not different (3.8% vs 3.4%, p> 0.99). Conclusions: There is a question of treatment outcome in patients with various permutations of stroke severity and advanced age. Our data corroborates the concern of poor outcomes for Stroke100 Club patients, but notes no increased sICH with tPA. Though outcome may be poor, withholding tPA should be discouraged as worse outcomes were not due to sICH. Young patients with severe strokes or old patients with mild strokes may have outcomes similar to the standard “80/20” Stroke100 patients, however further adjusted analysis is ongoing. In addition, further analyses are being done to compare tPA to non tPA patients.


Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2453 ◽  
Author(s):  
Guangyong Zheng ◽  
Siqi Na ◽  
Tianyao Huang ◽  
Lulu Wang

Distributed multiple input multiple output (MIMO) radar has attracted much attention for its improved detection and estimation performance as well as enhanced electronic counter-counter measures (ECCM) ability. To protect the target from being detected and tracked by such radar, we consider a barrage jamming strategy towards a distributed MIMO. We first derive the Cramer–Rao bound (CRB) of target parameters estimation using a distributed MIMO under barrage jamming environments. We then set maximizing the CRB as the criterion for jamming resource allocation, aiming at degrading the accuracy of target parameters estimation. Due to the non-convexity of the CRB maximizing problem, particle swarm optimization is used to solve the problem. Simulation results demonstrate the advantages of the proposed strategy over traditional jamming methods.


2019 ◽  
Vol 35 (12) ◽  
pp. 1465-1470 ◽  
Author(s):  
Patrick M. Wieruszewski ◽  
Erin F. Barreto ◽  
Jason N. Barreto ◽  
Hemang Yadav ◽  
Pritish K. Tosh ◽  
...  

Background: Corticosteroid therapy is a well-recognized risk factor for Pneumocystis pneumonia (PCP); however, it has also been proposed as an adjunct to decrease inflammation and respiratory failure. Objective: To determine the association between preadmission corticosteroid use and risk of moderate-to-severe respiratory failure at the time of PCP presentation. Methods: This retrospective cohort study evaluated HIV-negative immunosuppressed adults diagnosed with PCP at Mayo Clinic from 2006 to 2016. Multivariable regression models were used to evaluate the association between preadmission corticosteroid exposure and moderate-to-severe respiratory failure at presentation. Results: Of the 323 patients included, 174 (54%) used preadmission corticosteroids with a median daily dosage of 20 (interquartile range: 10-40) mg of prednisone or equivalent. After adjustment for baseline demographics, preadmission corticosteroid therapy did not decrease respiratory failure at the time of PCP presentation (odds ratio: 1.23, 95% confidence interval: 0.73-2.09, P = .38). Additionally, after adjusting for inpatient corticosteroid administration, preadmission corticosteroid use did not impact the need for intensive care unit admission ( P = .98), mechanical ventilation ( P = .92), or 30-day mortality ( P = .11). Conclusions: Corticosteroid exposure before PCP presentation in immunosuppressed HIV-negative adults was not associated with a reduced risk of moderate-to-severe respiratory failure.


Allergy ◽  
2017 ◽  
Vol 73 (3) ◽  
pp. 549-559 ◽  
Author(s):  
M. R. Datema ◽  
R. van Ree ◽  
R. Asero ◽  
L. Barreales ◽  
S. Belohlavkova ◽  
...  

2020 ◽  
Vol 10 (4) ◽  
pp. 6092-6101
Author(s):  
G. O. Ajisegiri ◽  
F. L. Muller

This paper addresses the application of the Agent-Based Model (ABM) to simulate the evolution of Multiple Input Multiple Output (MIMO) eco-industrial parks to gain insight into their behavior. ABM technique has proven to be an effective tool that can be used to express the evolution of eco-industrial parks. The ABM represents autonomous entities, each with dynamic behavior. The agents within the eco-industrial park are factories, market buyers, and market sellers. The results showed that the Réseau agent-based model allowed the investigation of the behaviors exhibited by different agents in exchange for materials in the industrial park.


2020 ◽  
Vol 30 (4) ◽  
pp. 303-305
Author(s):  
Dmitry Tumin ◽  
Mary Hayney ◽  
Rebecca P Winsett

2019 ◽  
Vol 153 (6) ◽  
pp. 239-242
Author(s):  
Adrián González-Marrón ◽  
Jordi Real ◽  
Carles Forné ◽  
Albert Roso-Llorach ◽  
Eva María Navarrete-Muñoz ◽  
...  

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