Artificial Intelligence paper

The design of the dust was the result of a project funded by the Greek Secretariat of Research and Technology . It depart feed in the National Center of Immediate Assistance ( shish kebab in Greek), which deals with emergency medical fortuitys by organize and routing ambulances to appropriate hospitals and health units as well as go medical cargon to patients during their transport to hospitals. Our enquiry unit was mainly responsible for designing the GIS subsystem, which constitutes the primary focus of this paper.The paper is an extended version of wiz presented at Delegate 2000 (Drinkers, Gorillas, Makers, Presents, Siestas, & Disallows, 2000). An operation with substantial importance for the handling of emergency calamitys is the routing of an ambulance to an incident site and from there to the close appropriate hospital. The optimal avenues correspond to minimum required transportation condemnations. finding such routes may prove to be fourth dimension-consuming i n the case of large cities such as Athens with in truth dense avenue networks.However, by exploiting juvenile advances in the field of data body structures, the military operation of a shortest-path algorithmic ruleic rule in terms of the required computational time can be significantly intensify. The incorporation of the enhanced shortest-path algorithm thin the GIS go away lower our systems response time, thus increasing its inability. This paper is organized as follows. slit 2 briefly presents primary aspects of a Gigs facilities in mold and analyzing spacial networks. In theatrical role 3 the overall integrated system is described. Section 4 deals with the GIS subsystem and describes its key functions.Section 5 briefly explains how the performance of a shortest-path algorithm can be enhanced, while Section 6 demonstrates how to incorporate this enhanced algorithm within a commercial GIS such as Raccoon. Finally, Section 7 summarizes the results of the project. . Model ing and analysis of spatial networks GIS technology integrates common database operations such as query and statistical analysis with the unique visualisation and geo graphic analysis benefits offered by maps (SERIES Web site Franklin, 1992 Mueller, 1993). Among other things, a GIS eases the modeling of spatial networks (e. . way networks), Other partners in this project were the University of Piraeus, the National Technical University of Athens, the Aristotle University of Thessalonians and the companies ITCH G. Drinkers et al. / Compute. , Environ. And Urban Systems 25 (2001) 267-278 69 offering algorithms to query and analyze them. Spatial networks be modeled with graphs. In the case of driveway networks, the graphs arcs correspond to avenue segments whereas the nodes correspond to roadway segment interbreedings. Each arc has a weight associated with it, representing the resistance (cost) of traversing it.In most cases, an arcs impedance is a function of the correspondin g street segments length and merchandise volume. A GIS usually provides a add of tools for the analysis of spatial networks. It generally offers tools to find the shortest or minimum impedance route wrought a network and heuristic procedures to find the most in effect(p) route to a series of locations, commonly called the traveling salesman problem. every(prenominal)ocation functions assign portions of the network to a resource supply location and tracing tools provide a means to determine whether peerless location in a network is connected to another.Distance matrix numeration can be use to calculate distances between models of origins and destinations whereas location-allocation functions determine site locations and assign demand to sites. Moreover, street addresses can be converted to map coordinates (address coding). Finally, dynamic segmentation operations offer ways of modeling events (e. G. Pavement quality, speed zones) on routes (SERIES Web site). These capabiliti es of GIS for analyzing spatial networks en adequate to(p) them to be utilize as ratiocination support systems for the districting and routing of vehicles (Grassland, Wynn, & Perkins, 1995 Keenan, 1996, 1998). . The overall integrated system Up till now, Kebabs employees were using paper maps and their own get a line in order to achieve the effective routing and districting of ambulances. However, these two functions, which constitute significant areas in the field of closing support yeasts (Eom, Lee, & Kim, 1993), require the integration of a computer-based system with geographic analysis and visualization tools and a telecommunication network. The operation of the integrated system volition automate and enhance many of Kebabs services. The systems architecture is depicted in Fig. 1.It is based on the integration of GIS, GASP and GSM technologies. The GASP and GSM technologies will be used to transmit the subscribe to positions of ambulances to the GIS operating in Kebabs ope rations Center. The integration of these technologies enables the vigilance of vehicles such as many trucks, patrol cars and ambulances (Hauberk, 1995). All these applications are parts of the new emerging disciplines of teleprocessing and telecommunication (Laurie, 1999, 2000 Tanzania, 2000). Each ambulance will be outfit with a GASP receiver to determine its exact position based on the signal catching by satellites.In addition, it will have a GSM modem in order to transmit its position to the base berth in the Operations Center. This will be achieved through the GSM network. Furthermore, through the GSM network other be equip with a computer or a 270 Fig. 1 . The overall integrated system. Mobile data last(a) to display the route computed by the GIS operating in the Operations Center. Kebabs Operations Center will change data with the ambulances through the GSM network. It will receive the ambulance positions and will use the GIS to perform the functions described in Sectio n 4.The optimal route calculated for a specific ambulance will be transmitted to it. In the Operations Center there will be a computer dedicated to communication with the ambulances and another one for the operation of the GIS. In addition, there will be one or more computers for the operation of the database management system (DBS) containing data used by the GIS. Nowadays, most GIS software packages offer a rich set of tools and extensions, enabling the incorporation of GASP data and offering real-time tracking capabilities.SERIES Archive, for instance, offers an extension called Tracking psychoanalyst that allows direct feed and playback of real-time data within the Archive GIS environment (SERIES Web site). The systems architecture follows the modify approach (Laurie, 2000 Tanzania, 2000) whereby a control focalize (in our case Kebabs Operations Center) coordinates the fleet of mobile vehicles. info from the vehicles and sensors are sent to this center and, after being evalu ated, data and instructions are transmitted to the vehicles. A weapons-grade point of this architecture is the easiness with which it is designed. 71 However, the danger of a crash in the control center constitutes a major weakness (Lament, 2000 -rant, 2000). 4. The GIS subsystem The GIS will make use of non-homogeneous data that are any stored in spatial databases and DBS or transmitted through the GSM network. Spatial data will cover the road network, the locations of hospitals and medical centers, the positions of ambulances, he distribution of incidents occurring in the past, the distribution of population characteristics (e. G. Demographic characteristics or disease spreading), and locations of various landmarks.Basic spatial data for the road network relate to intersections and the road segments are coded based on intersection type (e. G. Railroad crossing, street intersection) and the type of traffic control device present (e. G. Stop sign, curb light). Road segments form the framework for a number of other geographic features defined using route systems. Street names, for instance, are defined as routes. Along them speed zones ND speed limit signs are recorded as linear and point events, respectively. In addition, lanes are recorded as linear events along these routes.Since the majority of streets are only two-lane residential streets, only sections with more than two lanes are recorded. other important aspect is the recording of the locations of hospitals and gas stations. Moreover, address information related to the road network is being stored, facilitating coding operations. Data concerning road traffic will be very useful for the routing of ambulances. These data will be updated by processing traffic statistics and simultaneously taking into inconsideration online data deriving from traffic sensors installed on the road network.The National Technical University of Athens has installed loop sensors on the road network of Athens, providing inb red information on traffic conditions. Traffic data will be stored in a DBS. Data pertaining to events such as road works or demonstrations that also affect road traffic will be made available from the municipality or the police. Data concerning hospitals, ambulances, and their personnel will also be stored in the DBS and used by the GIS whenever it is necessary. Information linking conventional loophole numbers with addresses is also stored in a DBS.Its importance will become evident in the next section. Some of the primary functions performed by the GIS operating in KEBAB will be the following 1 . Depiction on a map of ambulance positions and hospital locations. serviceable queries that will be performed take the display of information about an ambulance or a hospital chosen from the map, locating all ambulances positioned within a block, all ambulances that are closer to a hospital or some other spot, etc. Different symbols will be used for displaying an ambulance, 272 2. 3. 4. . 6. Pending on its side an ambulance may be standing by, handling an incident, or tools of the GIS will take into consideration the data concerning the road network, past incident distribution, population distribution, hospital locations, locations of gas stations and traffic conditions and will propose efficient distributions of ambulances. A variety of criteria should be considered in order to perform this operation. For example, areas where many incidents take place should be allocated more ambulances. A densely populated area entails a higher probability of an incident occurring.Additionally, an areas urban planning affects the way incidents are clutchesd. Areas close to major streets facilitate ambulance access to whereas areas with narrow streets inhibit it. If the decision maker of the GIS chooses to distribute ambulances according to his/her own criteria, the depiction on the map of all the available information and the interaction with the GIS will be of significant assistance. Finding the site of the incident. Based on the address given by the person calling Kebabs Operations Center for help, the GIS can use address coding functions to find the incidents coordinates on the map.However, in many cases the person calling for help may be at a passing play for words and thus unable to give precise information about the site of the incident. Therefore, the system should include a mechanism for matching a call to an address. The DBS linking conventional telephone numbers with addresses will facilitate this matching. Things are more complicated if the call is made from a cellular phone, however. In this case, the assistance of the cellular phone providers will be required in order to match a callers location to the closest address or landmark. Choosing the appropriate ambulance to Andre an emergency incident.According to ambulance positions, the type and location of the incident and traffic conditions, the GIS finds the ambulance requiring the least time to reach the site of the incident. The choice of ambulance depends on the type of incident because some ambulances are equipped to handle special emergency cases. Routing an ambulance to the incident site and from there to the closest appropriate hospital. The GIS will be used to find the optimal routes corresponding to minimum required transportation time. The distance as well as traffic data will be taken into account. The appropriate hospital will furthermore depend on the type of incident.Such information will be derived from communication through the GSM network between the ambulance personnel and the personnel in the Operations Center. The GIS can also present the driver with directions corresponding to the routes generated (e. G. Go straight off ahead, turn right to Armor Street, etc. ). These directions will be transmitted to the ambulance. In a real- time system like ours, the time performance of the routing function is of vital significance. Generation of statistic s regarding incidents. The GIS, in cooperation with the DBS annotating incident records, can significantly assist in the statistical analysis of incidents.Consequently, important conclusions supporting the ambulance districting can be obtained. 5. The most efficient implementation of Disasters algorithm An operation with substantial importance for the handling of emergency incidents is the routing of an ambulance to an incident site and from there to the closest appropriate hospital. The optimal routes correspond to minimum required transportation times. Finding such routes may prove to be time-consuming in the case of large cities such as Athens with very dense road networks. A real-time system however, must be able to give a prompt reply to such queries.Disasters algorithm is a simple and consequently substantially implemented algorithm for finding shortest routes and is the most widely used in GIS software packages. Its performance depends on the data structures (e. G. Heaps or priority queues) used to implement the graph representing the spatial network. By exploiting recent advances in the field of data structures the performance of a significantly enhanced. We assume that we are given a graph with n nodes, m arcs, and integral arc lengths in the range 0,.. C, where C is the largest arc length. This graph represents the road network.Boris V. Characters, Andrew V. Goldberg and Craig Silversides developed the hot queue data structure (Characters, Goldberg, & Silversides, 1996, 1999) that combines the best features of heaps and multi-level buckets (Denary & Fox, 1979) in a natural way. They proved in theory that if C is very small compared to n, the data structure performs as a multi-level bucket structure. If C is very large, the data structure performs as the heap used in it. For intermediate values of C, the data structure performs better than either the heap or the multi-level cover structure.