Networked control systems for intelligent transportation systems and industrial automation

This thesis presents a study of two different applications of Networked Control Systems. The first is: Ethernet Networked Control System On-board of Train-wagons. An Ethernet backbone is shared between control and entertainment. The wagon contains a dedicated control server and a dedicated entertainment server, which act as fault-tolerant machines for one another. In the event of a server failure, the remaining machine can serve both entertainment and/or control. The study aims at enhancing system design in order to maximize the tolerable entertainment load in the event of a control/entertainment server failure, while not causing any control violations. This fault-tolerant system is mathematically analyzed using a performability model to relate failure rates, enhancements and rewards. The model is taken further to test two identical wagons, with a total of four fault-tolerant servers. All possible failure sequences are simulated and a different communication philosophy is tested to further minimize the degradation of the entertainment load supported during the failure of up to three of the four servers. The system is shown to be capable of operating with minimal degradation with one out of four servers. The second is: Wireless Networked Control Systems (WNCS) for Industrial Automation. A WNCS using standard 802.11 and 802.3 protocols for communication is presented. Wireless Interface for Sensors and Actuators (WISA) by ABB is used as a benchmark for comparison. The basic unit is a single workcell, however, there is a need to cascade several cells along a production line. Simulations are conducted and a nontraditional allocation scheme is used to ensure correct operation under the effect of co-channel interference and network congestion. Next, fault-tolerance at the controller level is investigated due to the importance of minimizing downtime resulting from controller failure. Two different techniques of interconnecting neighboring cells are investigated. The study models both a two and three-cell scenario, and all systems show that fault-tolerance is achievable. This is mathematically studied using a performability analysis to relate failure rates with rewards at each failure state. All simulations are conducted on OPNET Network Modeler and results are subjected to a 95% confidence analysis

The Fluid Dynamics of Mayfly Naiads

During their aquatic phase, mayflies Centroptilum triangulifer use a series of tracheal gills to facilitate gas exchange. Recent experimental studies on nymphal mayflies have identified two coupled features associated with the ontogenic progression of their ventilatory kinematics: 1) there is an abrupt shift from a rowing mechanism in small instars to a flapping mechanism in larger instars, and 2) the flapping mechanism is associated with the development of a flexural hinge that permits the passive movement of a distal flap. The primary role of the tracheal gills is tied to ventilation rather than locomotion. As such, it is not yet understood why such a transition happens and which performance metric is improved, if any. Hence, the goal of the current research is to investigate both features using numerical simulations. First, a computational model of the mayfly is built from a dissected animal. Then, a 3-level prescribed kinematic chain is introduced to a previously in-house developed and in-house validated explicit parallel Navier-Stokes solver where both the advective and diffusive terms are advanced explicitly using a third-order, low-storage, Runge-Kutta scheme. Finally, an immersed boundary method based on a moving least squares reconstruction is implemented to enforce the correct moving boundary conditions. Two different parametric spaces are constructed. The first one investigates the transition from rowing to flapping kinematics, the morphological effects on the flow field and on the proposed performance parameters while the second aims to provide an explanation for the hinge development. Two metrics based on control volume analysis are proposed to quantify the performance of each numerical case. The first metric is simply the mechanical efficiency of the energy transfer from the moving gills to the surrounding flow field while the second incorporates the mass flow rate across the control surface. The second metric is promising because it is able to provide a plausible explanation of both features by showing that the rate of work done by the mayfly is diminished throughout ontogeny with respect to the induced mass flow rate

Seroprevalence of hepatitis A antibodies among children in a Saudi community

ObjectiveTo determine the current seroprevalence of antibodies against hepatitis A virus in selected group of children aged 1-6 years in Northern borders region, Saudi Arabia, and to identify risk factors for infection.MethodsA cross-sectional sero-epidemiological study of 950 children who attended 10 randomly selected primary health care centers (5 urban and 5 rural) was done. Parents of all children were subjected to a questionnaire including sociodemographic and housing environmental data. The determination of anti-HAV antibodies was carried out by ELISA-test.ResultsThe prevalence of HAV-IgG was 33.8% overall, 35.5% among males and 32.0% among females with no statistically significant difference. Multivariate logistic regression analysis revealed that increasing age, rural residence, non Saudi nationality, and non availability of safe municipal water source were the most important independent predictors for HAV seropositivity in the studied children.ConclusionsThere is a clear decrease in hepatitis A prevalence in the studied children particularly in urban areas and indicates that a transition may be underway to intermediate endemicity and possible shift of the risk to the adult age with increased morbidity. So, we recommend including Hepatitis A in the schedule of routine childhood vaccinations

Diagnostic evaluation of blunt abdominal trauma scoring system (BATSS)

Background: Blunt force abdominal trauma is a typical emergency room presentation in both adults and children. Trauma is widely acknowledged as one of the primary causes of illness and mortality in poor nations, as well as the greatest cause of death in those under the age of 45.Objectives: This study aims to study the diagnostic evaluation of blunt abdominal trauma scoring system (BATSS) in patients with blunt abdominal trauma in Zagazig University Hospital.Patients and methods: This study was conducted on 48 patients suffering from blunt abdominal trauma in Emergency Department of Zagazig University Hospital from January 2021 to June 2021.Result: The mean age of patients in the study was 25.87±10.7 years (range 17–61 years). Of the forty eight patients in the study there were 13 females (27.1%) and thirty five males (72.9%).There was statistically significant difference between blunt abdominal trauma scoring system (BATSS) and types of injury p<0.001. There was no statistically significant difference between blunt abdominal trauma scoring system (BATSS) and each of patients' sex and causes of injury p>0.05. Conclusion: The BATSS score system can be used as an initial screening to predict blunt abdominal trauma outcome and can be the basis of management in patients who experience blunt abdominal trauma

Rare Mucinous Colorectal Adenocarcinoma: Analysis of the Epidemiological Factors in Relation to Survival in Egyptian Patients

Colorectal carcinoma (CRC) is one of the leading causes of cancer related deaths; in Egypt it constitutes 6.5% of all cancers. Previous studies have shown conflicting results on clinicohistopathological features and survival of patients with colorectal mucinous (MA) and non-mucinous adenocarcinoma (NMA). To the best of our knowledge, this study is the first to investigate these features in Egypt. In this work, we studied tumor tissue specimens from 150 patients with colorectal MA and NMA who underwent radical surgery from Jan 2007 to Jan 2012 at Gastroenterology Centre, Mansoura University, Egypt. Their clinicohistopathological parameters and survival were analyzed using established statistical methodologies. Incidence of MA and its subtypes was much higher in Egypt than worldwide incidence. MA was significantly associated with younger age, more depth of invasion, lymph node metastasis, less microscopic abscess formation and less peri-tumoral lymphocytic response (Crohn-like response) than NMA. Both groups were not significantly different "among others" in other clinicopathological parameters including lymphovascular and perineural invasion, association with adenoma and schistosomiasis. Multivariate analyses for disease free and overall survival revealed that mucinous histology is an independent prognostic factor. Among several factors, only distant metastasis and presentation with recurrent disease were independent prognostic factors within MA patients. In conclusion, MA represents a distinct clinicopathological entity with worse survival than NMA. Distant metastasis and presentation with recurrent disease are independent prognostic factors. Further molecular investigations considering genetic features of MA will lead to drug development and better management

MotionLM: Multi-Agent Motion Forecasting as Language Modeling

Reliable forecasting of the future behavior of road agents is a critical component to safe planning in autonomous vehicles. Here, we represent continuous trajectories as sequences of discrete motion tokens and cast multi-agent motion prediction as a language modeling task over this domain. Our model, MotionLM, provides several advantages: First, it does not require anchors or explicit latent variable optimization to learn multimodal distributions. Instead, we leverage a single standard language modeling objective, maximizing the average log probability over sequence tokens. Second, our approach bypasses post-hoc interaction heuristics where individual agent trajectory generation is conducted prior to interactive scoring. Instead, MotionLM produces joint distributions over interactive agent futures in a single autoregressive decoding process. In addition, the model's sequential factorization enables temporally causal conditional rollouts. The proposed approach establishes new state-of-the-art performance for multi-agent motion prediction on the Waymo Open Motion Dataset, ranking 1st on the interactive challenge leaderboard.Comment: To appear at the International Conference on Computer Vision (ICCV) 202

Pedestrian Crossing Action Recognition and Trajectory Prediction with 3D Human Keypoints

Accurate understanding and prediction of human behaviors are critical prerequisites for autonomous vehicles, especially in highly dynamic and interactive scenarios such as intersections in dense urban areas. In this work, we aim at identifying crossing pedestrians and predicting their future trajectories. To achieve these goals, we not only need the context information of road geometry and other traffic participants but also need fine-grained information of the human pose, motion and activity, which can be inferred from human keypoints. In this paper, we propose a novel multi-task learning framework for pedestrian crossing action recognition and trajectory prediction, which utilizes 3D human keypoints extracted from raw sensor data to capture rich information on human pose and activity. Moreover, we propose to apply two auxiliary tasks and contrastive learning to enable auxiliary supervisions to improve the learned keypoints representation, which further enhances the performance of major tasks. We validate our approach on a large-scale in-house dataset, as well as a public benchmark dataset, and show that our approach achieves state-of-the-art performance on a wide range of evaluation metrics. The effectiveness of each model component is validated in a detailed ablation study.Comment: ICRA 202