| 1. |
- Alinia, Bahram, et al.
(författare)
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Competitive Online Scheduling Algorithms with Applications in Deadline-Constrained EV Charging
- 2018
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Ingår i: 2018 IEEE/ACM 26th International Symposium on Quality of Service, IWQoS 2018. - : IEEE. - 9781538625422
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Konferensbidrag (refereegranskat)abstract
- This paper studies the classical problem of online scheduling of deadline-sensitive jobs with partial values and investigates its extension to Electric Vehicle (EV) charging scheduling by taking into account the processing rate limit of jobs and charging station capacity constraint. The problem lies in the category of time-coupled online scheduling problems without availability of future information. This paper proposes two online algorithms, both of which are shown to be (2-\frac{1}{U})-competitive, where U is the maximum scarcity level, a parameter that indicates demand-to-supply ratio. The first proposed algorithm is deterministic, whereas the second is randomized and enjoys a lower computational complexity. When U grows large, the performance of both algorithms approaches that of the state-of-the-art for the case where there is processing rate limits on the jobs. Nonetheless in realistic cases, where U is typically small, the proposed algorithms enjoy a much lower competitive ratio. To carry out the competitive analysis of our algorithms, we present a proof technique, which is novel to the best of our knowledge. This technique could also be used to simplify the competitive analysis of some existing algorithms, and thus could be of independent interest.
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| 2. |
- AlGannas, Nayef S., et al.
(författare)
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Assessment of the levels of antispike SARS-CoV-2 IgG antibodies and their association with clinical characteristics in cohort of patients in Saudi Arabia
- 2022
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Ingår i: Journal of Family Medicine and Primary Care. - : Medknow Publications. - 2249-4863 .- 2278-7135. ; 11:11, s. 7372-7377
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Tidskriftsartikel (refereegranskat)abstract
- Background: Coronavirus disease 2019 (COVID-19) has caused a global public health crisis. The disease is known to be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, but the detailed characteristics of the immune response to this novel virus have not been fully elucidated yet. In this study, we aimed to determine the level of immunoglobulin G (IgG) antibodies and their correlation with clinical features at three time points postinfection in a group of patients in Saudi Arabia.Method: In this prospective observational study, we collected the demographic and clinical data from 43 polymerase chain reaction (PCR)-confirmed patients and measured the COVID-19 antispike IgG levels at three different visits.Result: The seroconversion rate after COVID-19 infection was 88.4% in the study participants, with no significant changes in the IgG levels through the three visits. The duration of shortness of breath had a significant positive correlation with the IgG level of the patients. Using the logistic regression model, participants having coughs were found to be 12.48 times more likely to develop positive IgG. The IgG levels were less in smokers than nonsmokers [Odds ratio = 6.42 (95% CI 2.11-19.48); P = 0.001].Conclusion: Positive IgG levels have been developed in most COVID-19 patients and did not significantly change over 3 months following the diagnosis. The level of IgG antibodies was found to be significantly associated with the presence of cough, duration of shortness of breath, and the smoking habit of the patients. These findings have clinical and public health significance and need to be validated in larger studies in different populations.
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| 3. |
- Ali, Abukar, 1988, et al.
(författare)
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CTLA4-Ig but not anti-TNF therapy promotes staphylococcal septic arthritis in mice.
- 2015
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Ingår i: The Journal of infectious diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 212:8, s. 1308-1316
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Tidskriftsartikel (refereegranskat)abstract
- The development of biologics has greatly increased the quality of life as well as the life expectancy of many RA patients. However, a large number of these patients are at an increased risk of developing serious infections. The aim of this study was to examine differential effects of anti-TNF versus CTLA4-Ig treatment on both immunological response and host defense in a murine model of septic arthritis.
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| 4. |
- Ali, Abukar, 1988, et al.
(författare)
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IL-1 Receptor Antagonist Treatment Aggravates Staphylococcal Septic Arthritis and Sepsis in Mice.
- 2015
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-1 receptor antagonist (IL-1Ra) is the primary therapy against autoinflammatory syndromes with robust efficacy in reducing systemic inflammation and associated organ injury. However, patients receiving IL-1Ra might be at increased risk of acquiring serious infections.
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| 5. |
- Ali, Mohammad, 1982, et al.
(författare)
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A PREDICTIVE APPROACH TO ROADWAY DEPARTURE PREVENTION
- 2009
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Ingår i: 21st IAVSD Symposium on Dynamics of Vehicles on Roads and Tracks, Stockholm, 17-21 August 2009.
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Konferensbidrag (refereegranskat)abstract
- In this paper, we investigate predictive control approaches to the problem ofroadway departure prevention via steering and braking. We assume a sensinginfrastructure detecting road geometry and consider a two layers architectureconsisting of a threat assessment and an intervention layer. In particular, theupper threat assessment layer detects the risk of roadway departure or vehi-cle instability within a future time horizon. If a risk of roadway departure orvehicle instability is detected, the lower intervention layer is enabled. The lat-ter is designed based on Model Predictive Control (MPC) approaches, wheresteering and braking interventions are the result of an optimization problem.This is formulated on the basis of vehicle state measurements and coming roadinformation (e.g., road geometry, surface adhesion) and repeatedly solved overa moving future time horizon.Simulation and experimental results are presented, showing that the proposedapproach effectively exploits road preview capabilities in order to issue earlierand less intrusive interventions, compared to standard Electronic Stability Con-trol (ESC) systems.
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| 6. |
- Ali, Mohammad, 1982, et al.
(författare)
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Automotive Threat Assessment Design for Combined Braking and Steering Maneuvers
- 2013
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Ingår i: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; PP:99, s. 1-1526
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Tidskriftsartikel (refereegranskat)abstract
- The active safety systems available on the passenger cars market today, automatically deploy automated safety interventions in situations where the driver is in need of assistance. In this paper, we consider the process of determining whether such interventions are needed. In particular, we design a threat assessment method which evaluates the risk that the vehicle will either leave the road or its maneuverability will be significantly reduced within a finite time horizon. The proposed threat assessment method accounts for combined braking and steering maneuvers, which results in a nonlinear dynamical vehicle behavior. We formulate the threat assessment problem as a nonconvex constraint satisfaction problem and implement an algorithm that solves it through interval-based consistency techniques. Experimental validation of the proposed approach indicates that constraint violation can be predicted, while avoiding the detection of false threats.
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| 7. |
- Ali, Mohammad, 1982
(författare)
-
Decision Making and Control for Automotive Safety
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis proposes a novel automotive safety function that utilizes information about the host vehicle's state and the road ahead to predict and prevent unintended roadway departures. For this purpose predictive threat assessment, decision making and control algorithms are developed. The developed algorithms take into account fundamental limitations in a vehicle's dynamical capabilities while using road information to maintain the vehicle's maneuverability and keep it on the road.Particular attention is given to the threat assessment problem. A threat assessment algorithm that activates interventions when it can be theoretically guaranteed that it is no longer possible for a driver to avoid departing the road or losing vehicle maneuverability is developed. The algorithm is based on reachability analysis tools for linear systems. An algorithm that recursively estimates the driver's steering behavior as an affine function of the vehicle state is also developed. The explicit representation of the driver's steering behavior is used to form an alternative threat assessment algorithm that, in addition to considering vehicle dynamics, accounts for limitations in the driver's capabilities. Moreover, it is shown how uncertainty in the state, disturbance and parameter estimates can be accounted for in order to maintain the theoretical guarantees of avoiding unnecessary intervention activation also in the presence of uncertainty. In order to maintain such guarantees considering model parameter uncertainty, we derive and prove theoretical results. In addition, a threat assessment algorithm that accounts for the nonlinearities in the system dynamics that are exhibited e.g. during combined braking and steering is developed. For this purpose, we use interval based consistency techniques to solve the threat assessment problem.The developed methods are validated using simulations, logged experimental data and real-time experiments.
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| 8. |
- Ali, Mohammad, 1982, et al.
(författare)
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Impact of Different Vehicle Models on Threat Assessment in Critical Curve Situations
- 2009
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Ingår i: 21st International Conference on Enhanced Safety of Vehicles.
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Konferensbidrag (refereegranskat)abstract
- Curve speed warning systems (CSW) utilize information about the road and warn drivers if they are about to enter a curve too fast. Recent research shows that CSW is successful in warning for upcoming curves. However no statistically significant change in driver behaviour due to CSW has been shown. In addition, a common requirement cited by drivers is that the amount of false alarms needs to be reduced. This paper evaluates how the level of detail in the modelled vehicle dynamics influences the threat assessment in a situation with an oncoming curve. The point mass model that is commonly used by CSW is compared with more detailed models. Maximum velocity the vehicle can have while still following a curve is investigated and compared for the point mass model, the single track model and the double track model. It is shown that as the level of detail in the modelled dynamics increase, the maximum velocity profile is significantly reduced. This implies that in order to make a reliable threat assessment that can reduce the amount of false alarms and even be used as a base for an autonomous intervention, a more complex vehicle model than the point mass model is required.
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| 9. |
- Ali, Mohammad, 1982, et al.
(författare)
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Model-Based Threat Assessment for Lane Guidance Systems
- 2011
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Ingår i: American Control Conference. - 0743-1619. - 9781457700804 ; , s. 4586-4591
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Konferensbidrag (refereegranskat)abstract
- This paper considers a threat assessment problem in a lane guidance application for semi-autonomous vehicles. In particular, in order to issue an autonomous assisting intervention, we assess the vehicle’s ability to safely travel along a path subject to limitations arising from the vehicle’s dynamics and the driver’s ability.We first introduce a set of constraints describing “safedriving”. For the specific lane guidance application considered in this paper, the constraints are set by the lane boundaries and the vehicle’s stability limits. We then formulate the threat assessment problem as a constraints satisfaction problem over a finite time horizon, solved by resorting to reachabililty analysisand invariant set theory.Validation with experimental data demonstrates the capability of the proposed threat assessment method of predicting vehicle instability or crossing of the lane boundaries.
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| 10. |
- Ali, Mohammad, 1982, et al.
(författare)
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Model-Based Threat Assessment in Semi-Autonomous Vehicles with Model Parameter Uncertainties
- 2011
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Ingår i: Proceedings of the IEEE Conference on Decision and Control. - 2576-2370 .- 0743-1546. - 9781612848006 ; , s. 6822-6827
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Konferensbidrag (refereegranskat)abstract
- In this paper, we consider model-based threat assessment methods which rely on vehicle and driver mathematical models and are based on reachability analysis tools and set invariance theory. We focus on the parametric uncertainties of the driver mathematical model and show how these can be accounted for in the threat assessment. The novelty of the proposed methods lies in the inclusion of the driver model uncertainties in the threat assessment problem formulation and in their validation through experimental data. We show how different ways of accounting for the model uncertainties impact the capabilities and the effectiveness of the proposed algorithms in detecting hazardous driving situations.
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