nternational Journal of Futuristic Machine Intelligence & Application (IJFMIA) (e-Journal) ISSN : 2395-308x ,Vol 1 Issue 3 2D Packaging Problem Using Swarm Intelligence Shital R.Kumbhar Dept. of Computer Engineering MIT AOE,Alandi,Pune Email_id: shitalkumbhar04@gmail.com Vidya M. Shingade Dept. of Computer Engineering MIT AOE,Alandi,Pune Email_id: vidyashingade05@gmail.com Sonali H. Khandve Dept. of Computer Engineering MIT AOE,Alandi,Pune Email_id: sonalikhandve58@gmail.com Abstract- We consider the NP-complete problem of finding an enclosing rectangle of minimum area that will contain a given a set of rectangles. We present two different constraint satisfaction formulations of this problem. The first searches a space of absolute placements of rectangles in the enclosing rectangle, while the other searches a space of relative placements between pairs of rectangles. Both approaches dramatically out perform previous approaches to optimal rectangle packing. For problems where the rectangle dimensions have low precision, such as small integers, absolute placement is generally more efficient, whereas for rectangles with high-precision dimensions, relative placement will be more effective. Two-dimensional packing problems are a class of optimization problems in mathematics which involve attempting to pack objects together in the packing region as densely as possible. There are many variations of this problem, such as two-dimensional packing, linear packing, packing by weight, height. KeywordsRectangle packing ・ Constraint satisfaction ・ Search global best position, global second best position, personal best position. INTRODUCTION: Packing problems are very often in the real world and industries. Many solutions are already provided to solve such problems. Two dimensional rectangle packing problem is one of the most important problem. As all packing problems of NP-hard, so this rectangle packing problem is also a NP-hard type of problem. To solve such kind of NP-hard problems, conventional methods are not sufficient. Most of the researchers used heuristic and meta-heuristic methods to solve the problem. Some of the methods from these called as evolutionary computational methods. The main problem discussed here is rectangle packing problem which is occurred very frequently in the industry. Different types of conventional, heuristic and metaheuristic methods are discussed to efficiently solve the problem. Packing problems are very often in the real world and industries. Many solutions are already provided to solve such problems. Two dimensional rectangle packing problem is one of the most important problem. As all packing problems of NP-hard, so this rectangle packing problem is also a NP-hard type of problem. To solve such kind of NP-hard problems, conventional methods are not sufficient. Most of the researchers used heuristic and meta-heuristic methods to solve the problem. Some of the methods from these called as evolutionary computational method. The main problem discussed here is rectangle packing problem which is occurred very frequently in the industry. Different types of conventional, heuristic and metaheuristic methods are discussed to efficiently solve the problem. A. RECTANGLE PACKING PROBLEM In these problems both the objects to be packed and the container in which they will be packed are rectangles. So the container can be called as bounding box of rectangle shaped and the objects to be packed inside the bounding box will also be rectangle shaped. Oriented & un-oriented rectangle packing are the categories where in oriented type rectangle position is fixed whereas in un-oriented individual rectangle can be rotated by 90 degrees. There is only one condition about the placement of rectangles i.e. all the sides of rectangles must be parallel with the sides of bounding box and overlapping is not permitted. Rectangle packing has several practical applications. One is the design of VLSI circuits, where rectangular circuit blocks are assigned to physical regions of a rectangular chip. Another is loading a set of rectangular objects onto a cargo pallet, without stacking.yet another application is cutting a set of rectangles from rectangular piece of stock material and many more. There are two important problems here, first one is the containment problem in which rectangle shaped bounding box and also rectangle shaped items. B. RECTANGLE PACKING IS NP-COMPLETE Both oriented & un-oriented rectangle containment problems are NPComplete by a reduction of 1-D Bin Packing. The problem is: Set of rectangles and a bounding box are given; we have to find that all the rectangles can fit into the bounding box without overlap? Both oriented & un-oriented rectangle packing problems can be solved in nondeterministic polynomial time. As the position of rectangles are assigned in bounding box, its easy to find in polynomial time that no rectangle can extends beyond the boundary of the box and there is no overlapping of rectangles. nternational Journal of Futuristic Machine Intelligence & Application (IJFMIA) (e-Journal) ISSN : 2395-308x ,Vol 1 Issue 3 To show that rectangle packing is NP-hard, one demonstrate that the NP-complete problem of one-dimensional bin packing (Garey and Johnson 1979) can be reduced in polynomial time to rectangle packing. In other words, if rectangle packing can be solved in polynomial time, then so can bin packing. An instance of the bin packing decision problem consists of a set of numbers, along with a given number of bins, each with the same fixed capacity. The problem is to assign each number to one of the bins, so that the sum of the numbers in each bin does not exceed the bin capacity. Given a bin packing instance, it generates a corresponding instance of oriented rectangle packing as follows. For each number in the bin packing problem, it generates a rectangle of unit height whose width is the number. It also generates a bounding box whose height is the number of bins, and whose width is the capacity of the bins. Thus each bin corresponds to a horizontal row of the bounding box.In the resulting rectangle packing problem, each rectangle must be assigned to a row (bin) of the bounding box, such that the sum of the widths (numbers) of the rectangles assigned to each row (bin) does not exceed the width (bin capacity) of the bounding box. Thus, this oriented rectangle packing problem is equivalent to the original bin packing problem. If it can solve any oriented rectangle packing problem in polynomial time, then it can solve any bin packing problem in polynomial time. To reduce bin packing to un-oriented rectangle packing, one make the rectangles long enough and thin enough that they can only fit in the bounding box horizontally. For example, if there are k bins, and one is the smallest number, it make all the rectangles less than 1/k units high, so the bounding box is less than one unit high, and none of the rectangles will fit vertically. This turns the problem into an oriented rectangle packing problem. Thus, both oriented and un-oriented rectangle packing are NP-hard, and since they are also in NP, they are both NP-complete. C.PARTICLE SWARM OPTIMIZATION PSO was developed by Kennedy and Eberhart. The PSO is inspired by the social behavior of a flock of migrating birds trying to reach an unknown destination. In PSO, each solution is a ‘bird’ in the flock and is referred to as a ‘particle’. A particle is analogous to a chromosome (population member) in GAs. As opposed to GAs, the Evolutionary process in the PSO does not create new birds from parent ones. Rather, the birds in the population only evolve their social behavior and accordingly their movement towards a destination. Physically, this mimics a flock of birds that communicate together as they fly. Each bird looks in a specific direction, and then when communicating together, they identify the bird that is in the best location. Accordingly, each bird speeds towards the best bird using a velocity that depends on its current position. Each bird, then, investigates the search space from its new local position, and the process repeats until the flock reaches a desired destination. It is important to note that the process involves both social interaction and intelligence so that birds learn from their own experience (local search) and also from the experience of others around them (global search). D. ANT-COLONY OPTIMIZATION Similar to PSO, ant-colony optimization (ACO) algorithms evolve not in their genetics but in their social behavior. ACO was developed by Dorigo et al. based on the fact that ants are able to find the shortest route between their nest and a source of food. This is done using pheromone trails, which ants deposit whenever they travel, as a form of indirect communication. As shown in Figure 5, when ants leave their nest to search for a food source, they randomly rotate around an obstacle, and initially the pheromone deposits will be the same for the right and left directions. When the ants in the shorter direction find a food source, they carry the food and start returning back, following their pheromone trails, and still depositing more pheromone. As indicated in Figure, an ant will most likely choose the shortest path when returning back to the nest with food as this path will have the most deposited pheromone. For the same reason, new ants that later starts out from the nest to find food will also choose the shortest path. Over time, this positive feedback (autocatalytic) process prompts all ants to choose the shorter path. nternational Journal of Futuristic Machine Intelligence & Application (IJFMIA) (e-Journal) ISSN : 2395-308x ,Vol 1 Issue 3 The application of PSO for solving two-dimensional packing problems was presented in this study. Since the storage and the ship cabin are designed so that their sizes are equal to the integral multiple of the container sizes, usually it is assumed that the items are placed every certain intervals. The problem was solved by the original and improved PSOs. In the original PSO, the particle position vectors are updated by the global and the personal best positions. The improved PSO utilizes, in addition to them, the global second best position of all particles. The use of the global second best position is determined in the probabilistic way. E. PSO IS A MEMBER OF SWARM INTELLIGENCE VI. ACKNOWLEDGEMENT Swarm intelligence (SI) is based on the collective behavior of decentralized, self organized systems. It may be natural or artificial. Natural examples of SI are antcolonies, fish schooling, bird flocking, bee swarming and so on. Besides multi robot systems, some computer program for tackling optimization and data analysis problems are examples for some human artifacts of SI. The most successful swarm intelligence techniques are Particle Swarm Optimization (PSO) and Ant Colony Optimization (ACO). In PSO, each particle flies through the multidimensional space and adjusts its position in every step with its own experience and that of peers toward an optimum solution by the entire swarm. Therefore PSO algorithm is a member of Swarm Intelligence. F.ADVANTAGES AND DISADVANTAGES OF PSO It is said that PSO algorithm is the one of the most powerful methods for solving the non-smooth global optimization problems while there are some disadvantages of the PSO algorithm. The advantages and disadvantages of PSO are discussed below: Advantages of the PSO algorithm: 1) PSO algorithm is a derivative-free algorithm. 2) It is easy to implementation, so it can be applied both in scientific research and engineering problems. 3) It has a limited number of parameters and the impact of parameters to the solutions is small compared to other optimization techniques. 4)The calculation in PSO algorithm is very simple. 5) There are some techniques which ensure convergence and the optimum value of the problem calculates easily within a short time. 6) PSO is less dependent of a set of initial points than other optimization techniques. 7) It is conceptually very simple. Disadvantages of the PSO algorithm 1) PSO algorithm suffers from the partial optimism, which degrades the regulation of its speed and direction. 2) Problems with non-coordinate system (for instance, in the energy field) exit. V. CONCLUSION I express true sense of gratitude towards my project guide Prof. V.D.Rughwani, HOD Prof. Uma Nagraj for her invaluable co-operation and guidance that she gave us in this semester for inspiring and providing required facilities, which made this project work very convenient. I would also like to express thanks to all my friends who have assisted and encouraged me in the project work. VII. REFEREANCES [1] J.H. Holland. Adaptation in Natural and Artificial Systems. University of Michigan Press, 1st. edition, 1975. [2] S. Kirkpatrick, C.D. Gelatt Jr., M.P. Vecchi. Optimization by simulated annealing. Science, 220(4598): 671–680, 1983. [3] J. Kennedy, R.C. Eberhart. Particle swarm optimization. In Proceedings of IEEE the International Conference on Neural Networks, volume 6, pages 1942–1948, 1995. [4] Hallard T. Croft, Falconer Kenneth J., Guy Richard K. Unsolved Problems in Geometry. Springer-Verlag, 1991. [5] J. Melissen. Packing 16, 17 or 18 circles in an equilateral triangle. Discrete Mathematics, 145: 333–342, 1995. [6] Erich Friedman. Packing unit squares in squares: a survey and new results. The Electronic Journal of Combinatorics, DS7, 2005. [7] D.S. Liu, K.C. Tan, S.Y. Huang, C.K. Goh, W.K. Ho. On solving multiobjective bin packing problems using evolutionary particle swarm optimization. European Journal of Operational Research, 190(2): 357–382, 2008. [8] Chen Zhao, Liu Lin, Cheng Hao, Liu Xinbao. Solving the rectangular packing problem of the discrete particle swarm algorithm. In Business and Information Management, 2008. ISBIM ’08. International Seminar on, volume 2, pages 26–29, 2008. nternational Journal of Futuristic Machine Intelligence & Application (IJFMIA) (e-Journal) ISSN : 2395-308x ,Vol 1 Issue 3