Capacity Based Evacuation with Dynamic Exit Signs

Exit paths in buildings are designed to minimise evacuation time when the building is at full capacity. We present an evacuation support system which does this regardless of the number of evacuees. The core concept is to even-out congestion in the building by diverting evacuees to less-congested paths in order to make maximal usage of all accessible routes throughout the entire evacuation process. The system issues a set of flow-optimal routes using a capacity-constrained routing algorithm which anticipates evolutions in path metrics using the concept of "future capacity reservation". In order to direct evacuees in an intuitive manner whilst implementing the routing algorithm's scheme, we use dynamic exit signs, i.e. whose pointing direction can be controlled. To make this system practical and minimise reliance on sensors during the evacuation, we use an evacuee mobility model and make several assumptions on the characteristics of the evacuee flow. We validate this concept using simulations, and show how the underpinning assumptions may limit the system's performance, especially in low-headcount evacuations

A Modelling Approach To Human Navigation in Constrained Spaces

In this thesis, we consider algorithms and systems which dynamically guide evacuees towards exits during an emergency to minimise building evacuation time. We observe that the "shortest safe path" routing approach is inadequate when congestion is a predominant factor, and therefore focus on systems which manage congestion. We first implement a "Reactive" metric which compares paths based on real-time transit times. We find that regular route corrections must be issued to address the constant changes in path delays, and that routes oscillate. We also implement a model-based "Proactive" metric which forecasts the increase in future congestion that results from every routing decision, allowing the routing algorithm to operate offline. We combine both metrics with the Cognitive Packet Network (CPN), a distributed self-aware routing algorithm which uses neural networks to efficiently explore the building graph. We also present the first thorough sensitivity analysis on CPN's parameters, and use this to tune CPN for optimal performance. We then compare the proactive and reactive approaches through simulation and find both approaches reduce building evacuation times -- especially when evacuees are not evenly distributed in the building. We also find major differences between the Proactive and Reactive approach, in terms of stability, flexibility, sensory requirements, etc. Finally, we consider guiding evacuees using dynamic exit signs, whose pointing direction can be controlled. Dynamic signs can readily be used with Reactive routing, but since Proactive routing issues routes on an individual basis, one display is required for each evacuee. This is incompatible with dynamic signs; therefore we propose a novel algorithm which controls the dynamic signs according to the Proactive algorithm's output. We simulate both systems, compare their performance, and review their practical limitations. For both approaches, we find that updating the sign's display more often improves performance, but this may reduce evacuee compliance and make the system inefficient in real-life conditions.Open Acces

Graph and Analytical Models for Emergency Evacuation

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Ambient intelligence through Wireless Ad-hoc Control Networks

The potential of Wireless Ad-hoc Control Networks (WACNets) in realising ambient intelligence in a home environment is explored in this paper. The main objective is to achieve energy and resource efficiency while maintaining optimal comfort. WACNets is a novel concept developed by the Centre for Intelligent Mechatronics Research at the University of Wollongong for the purpose of providing a framework for highly distributed, intelligent wireless control networks. A WACNet consists of intelligent nodes developed on the IEEE 1451 Smart Sensor and ZigBee standards. The WACNet platform is fully selforganizing and employs a mesh of star-topology clusters. The development of an intelligent behaviour- learning control algorithm running on WACNet is described in this paper. The learning algorithm is part of an application which aims at reducing the consumption of resources (such as electricity and water). The main objective of this research project is to embed on a WACNet an algorithm capable of learning the factors influencing the use of resources. The WACNet acts as a platform for a highly distributed implementation of agent-based human behaviour learning algorithm, using fuzzy logic. The concept of WACNet is introduced and the test-bed developed for its study is explained. The suitability of WACNets in creating ambient intelligence in a home environment is addressed. A computer simulation developed to demonstrate the concept of fuzzy learning is presented, along with the results of the first test-bed experiments. Finally, some conclusions are drawn

Omentopexy for correction of right abomasal displacement: results in 135 cows

One hundred and thirty-five cows were surgically treated for correction of right displaced abomasum (RDA) using the right flank omentopexy technique. In 33 cows an abomasal dilatation was diagnosed. Abomasal volvulus was found in 99 animals and omaso-abomasal volvulus in three. In-hospital mortality was 15% (n = 20). None of the cows with abomaso-omasal torsion survived. Ninety-seven percent (n = 32) of the cows with abomasal dilatation and 84% (n = 83) of the cows with abomasal volvulus were discharged from the clinic. Six months after surgery, respectively 94% of the cows with abomasal dilatation had survived. This percentage fell to 88.5% after another half year. For cows with abomasal volvulus, these survival rates were 74% and 62%, respectively. Regardless of the type of abomasal dislocation, 77% of the total group of animals survived after six months and 66% after one year. Six months after surgery, good milk production was reported in 67% (n = 58) of the surviving cows; this figure rose to 91% of the surviving cows (n = 63) after 12 months

Koliek bij het paard: een retrospectieve studie : prevalentie, resultaten van conservatieve en operatieve behandeling

A retrospective study was performed on 2,264 horses pesented with colicn at Ghent University (Belgium) in the period 1986-1994. In this article, parameters not directly related to a specific type of colic are discussed. Approximately 32% of all horses addmitted to the clinic of Internal Diseases were presented because of colic. The colic pathology was observed mainly during the spring. A significantly great number of mares and warmblood riding horses was observed mainly during the spring. A significantly great number of mares and warmblood riding horses were presented, and significantly lower number of stallions and halfblood horses. The prevalence of colic increased with age, stagnating around age 13. One thousand one hundred sixty-eight exploratory laparotomies were performed on 1,069 horses. During the period 1986-1994 the number of surgical interventions gradually increased. The short-term survival rate also increased progressively: by the end of the period studied, it had reached 87% for conservative treatment and 73% for surgical corrections. A variable successn rate after surgery was observed among the different surgeons. The determining factors for this variable success were the surgeon's individual experience in abdominal surgery and the period in which the exploratory laparotomies were performed. the success rate after non-invasive or minimally invasive surgical techniques was significantly better than after the use of invasive techniques. The most commonly observed postoperative complications were thrombophlebitis, diarrhea, wound infection and laminitis

Een retrospectieve studie van chirurgisch behandelde specifieke koliekaandoeningen bij het paard

In the period 1986-1994 a retrospective study was performed on 2,264 horses with colic at the Faculty of Veterinary Medicine of the Ghent University/Belgium. An exploratory laparotomy was performed in 1,069 horses. In this study the observed pathological conditions in the different parts of the gastrointestinal tract are thoroughly discussed in depth. The origin of colic symptoms was determined by rectal examination or exploratory laparotomy: it was localized in the ascending colon in 31% of the horses and in the small intestine in 25% of them. Less frequently observed localizations were the caecum (8%), the descending colon (3%), the stomach (3%) and the rectum (1%). The localization of colic pathology could not or not exactly be determined in 28% of the cases. Short time survival rates were used. The overall survival rate of conservative and surgical treatment of horses with pathology of the descending colon and pathology of the caecum and/or ascending colon was respectively 80% and 75%. The survival rate of horses with pathology of the small intestine, the rectum and the stomach was less favorable: 54%, 35% and 32% respectively. The risk of developing colic was statistically analyzed according to breed, gender and age. Foals less than I year old ran a significantly higher risk of small intestinal volvulus. Geldings and Warmblood horses had a higher incidence of incarceration through the foramen omentale (epiploicon), whereas females and foals had a lower incidence. An inguinal hernia was significantly more often observed in foals and stallions, and significantly less in mares and geldings. Horses aged 9-12 years showed a higher risk of caecal tympany, whereas ponies, males, foals and horses aged 1-4 years ran an increased risk of (ileo)caecal intussusception. Mares and horses aged 1-4 or 5-8 years had a higher incidence of pelvic flexure impaction. The incidence of right colonic displacement was lower in males and foals. Older horses and mares were at significantly greater risk of developing a colon torsion. A higher incidence of left dorsal displacement was observed in geldings and a lower incidence in females

MD-2 is required for disulfide HMGB1-dependent TLR4 signaling

Innate immune receptors for pathogen- and damage-associated molecular patterns (PAMPs and DAMPs) orchestrate inflammatory responses to infection and injury. Secreted by activated immune cells or passively released by damaged cells, HMGB1 is subjected to redox modification that distinctly influences its extracellular functions. Previously, it was unknown how the TLR4 signalosome distinguished between HMGB1 isoforms. Here we demonstrate that the extracellular TLR4 adaptor, myeloid differentiation factor 2 (MD-2), binds specifically to the cytokine-inducing disulfide isoform of HMGB1, to the exclusion of other isoforms. Using MD-2–deficient mice, as well as MD-2 silencing in macrophages, we show a requirement for HMGB1-dependent TLR4 signaling. By screening HMGB1 peptide libraries, we identified a tetramer (FSSE, designated P5779) as a specific MD-2 antagonist preventing MD-2–HMGB1 interaction and TLR4 signaling. P5779 does not interfere with lipopolysaccharide-induced cytokine/chemokine production, thus preserving PAMP-mediated TLR4–MD-2 responses. Furthermore, P5779 can protect mice against hepatic ischemia/reperfusion injury, chemical toxicity, and sepsis. These findings reveal a novel mechanism by which innate systems selectively recognize specific HMGB1 isoforms. The results may direct toward strategies aimed at attenuating DAMP-mediated inflammation while preserving antimicrobial immune responsiveness

Plasma MicroRNA Profiles in Rat Models of Hepatocellular Injury, Cholestasis, and Steatosis

MicroRNAs (miRNAs) are small RNA molecules that function to modulate the expression of target genes, playing important roles in a wide range of physiological and pathological processes. The miRNAs in body fluids have received considerable attention as potential biomarkers of various diseases. In this study, we compared the changes of the plasma miRNA expressions by acute liver injury (hepatocellular injury or cholestasis) and chronic liver injury (steatosis, steatohepatitis and fibrosis) using rat models made by the administration of chemicals or special diets. Using miRNA array analysis, we found that the levels of a large number of miRNAs (121–317 miRNAs) were increased over 2-fold and the levels of a small number of miRNAs (6–35 miRNAs) were decreased below 0.5-fold in all models except in a model of cholestasis caused by bile duct ligation. Interestingly, the expression profiles were different between the models, and the hierarchical clustering analysis discriminated between the acute and chronic liver injuries. In addition, miRNAs whose expressions were typically changed in each type of liver injury could be specified. It is notable that, in acute liver injury models, the plasma level of miR-122, the most abundant miRNA in the liver, was more quickly and dramatically increased than the plasma aminotransferase level, reflecting the extent of hepatocellular injury. This study demonstrated that the plasma miRNA profiles could reflect the types of liver injury (e.g. acute/chronic liver injury or hepatocellular injury/cholestasis/steatosis/steatohepatitis/fibrosis) and identified the miRNAs that could be specific and sensitive biomarkers of liver injury