Esempio n. 1
0
        public List <RubisStation> Calculate(List <OHCAEvent> eventList, int budget)
        {
            List <RubisStation> prevStationList = new List <RubisStation>();
            List <RubisStation> nextStationList;

            double epsilonTemp      = 0.1;
            double alpha            = 0.995;
            double bestSurvivalRate = 0.0;
            int    tempBudget;
            int    maxStations = (int)(budget / (Utils.STATION_PRICE + Utils.DRONE_PRICE));
            //for (int stations = 1; stations <= maxStations; stations++)
            int stations = 16;

            tempBudget = budget;

            // Step 1. Finds initial stations with a drone using K-Means
            tempBudget = tempBudget - (stations * (Utils.STATION_PRICE + Utils.DRONE_PRICE));
            KMeansResults <OHCAEvent> kMeansStations = KMeans.Cluster <OHCAEvent>(eventList.ToArray(), stations, Utils.KMEANS_ITERATION_COUNT);

            prevStationList.Clear();
            foreach (double[] d in kMeansStations.Means)
            {
                prevStationList.Add(new RubisStation(d[0], d[1], 2));
            }

            // Step 2. Assigns remaining drones to busy stations

            /*int remainingDrones = (int)(tempBudget / Utils.DRONE_PRICE);
             * while (remainingDrones > 0)
             * {
             *  int mostBusyStationIndex = getIndexOfMostBusyStation(prevStationList);
             *  prevStationList[mostBusyStationIndex].droneList.Add(new Drone(prevStationList[mostBusyStationIndex].stationID));
             *  remainingDrones--;
             * }
             */

            // Step 4. Simulated Annealing
            double currentTemp      = 100.0;
            int    iteration        = 0;
            double prevSurvivalRate = GetOverallSurvivalRate(ref prevStationList);
            double delta            = 0.0;
            double nextSurvivalRate = 0.0;

            while (currentTemp > epsilonTemp)
            {
                iteration++;

                // Near search using local optimization
                nextStationList  = MoveOneStepToBestDirection(prevStationList, prevSurvivalRate);
                nextSurvivalRate = GetOverallSurvivalRate(ref nextStationList);
                delta            = nextSurvivalRate - prevSurvivalRate;

                if (delta > 0)
                {
                    CloneList(nextStationList, prevStationList);
                    prevSurvivalRate = nextSurvivalRate;
                }
                else
                {
                    // Even if worst, choose it randomly according to the current temperature
                    double probility = new Random().NextDouble();
                    if (probility < Math.Exp(-delta / currentTemp))
                    {
                        // Far search using random placement
                        nextStationList = FindRandomStationPlacement(prevStationList, 0);
                        CloneList(nextStationList, prevStationList);
                        prevSurvivalRate = GetOverallSurvivalRate(ref prevStationList);

                        if (prevSurvivalRate < bestSurvivalRate * 0.9)
                        //double r = new Random().NextDouble();
                        //if (r < 0.1)
                        {
                            /*
                             * kMeansStations = KMeans.Cluster<OHCAEvent>(eventList.ToArray(), stations, new Random().Next(50, 100));
                             * foreach (double[] d in kMeansStations.Means)
                             * {
                             *  prevStationList.Add(new RubisStation(d[0], d[1], 2));
                             * }*/

                            Random rand = new Random();

                            bool okay = false;
                            while (!okay)
                            {
                                int pos = rand.Next(0, 990000);
                                kMeansStations = KMeans.Cluster <OHCAEvent>(simulator.GetSimulatedEvents().GetRange(pos, 10000).ToArray(), stations, Utils.KMEANS_ITERATION_COUNT);

                                okay = true;
                                foreach (double[] d in kMeansStations.Means)
                                {
                                    if (d[0] == 0.0 || d[1] == 0.0)
                                    {
                                        okay = false;
                                        break;
                                    }
                                }
                            }

                            prevStationList.Clear();
                            foreach (double[] d in kMeansStations.Means)
                            {
                                prevStationList.Add(new RubisStation(d[0], d[1], 2));
                            }

                            /*
                             * remainingDrones = (int)(tempBudget / Utils.DRONE_PRICE);
                             * while (remainingDrones > 0)
                             * {
                             *  int mostBusyStationIndex = getIndexOfMostBusyStation(prevStationList);
                             *  prevStationList[mostBusyStationIndex].droneList.Add(new Drone(prevStationList[mostBusyStationIndex].stationID));
                             *  remainingDrones--;
                             * }
                             */

                            prevSurvivalRate = GetOverallSurvivalRate(ref prevStationList);
                        }
                    }
                }

                // Keep the best solution
                if (prevSurvivalRate > bestSurvivalRate)
                {
                    CloneList(prevStationList, stationList);
                    bestSurvivalRate = prevSurvivalRate;
                }

                // Cool-down
                currentTemp *= alpha;
                Console.WriteLine("[" + iteration + "] Stations = " + stations + ", Temp.: " + String.Format("{0:0.000000000000}", currentTemp) + "℃    " +
                                  "Best = " + String.Format("{0:0.000000}", (bestSurvivalRate * 100)) + "%    " +
                                  "Current = " + String.Format("{0:0.000000}", (prevSurvivalRate * 100)) + "%");
            }

            return(stationList);
        }