27074889
On pilot pattern design for PSAM-OFDM system
Pilot symbol assisted modulation (PSAM) of subcarriers is an attractive scheme for high data-rate OFDM transmission systems and has been widely used in broadcasting systems like DVB-T. In this paper, a new and simple pilot pattern for PSAM-OFDM system operated in the mobile communication environment is proposed and analyzed in terms of its bit error rate. Analytical and simulation results show that the proposed clustered pilot pattern for OFDM channel estimation gives a better performance than the conventional equally spaced pilot pattern in fading channel, yet without sacrificing the bandwidth efficiency.
33837023
Comments on "Maximum diversity in single-carrier frequency-domain Equalization"
It was claimed in the above correspondence that "single-carrier frequency-domain equalization (SC-FDE) is capable of collecting full multipath diversity even without channel coding." However, this is not correct because Proposition 2 and Theorem 1 of the above correspondence, which lead to the claim, are both incorrect. In this correspondence, Proposition 2 and Theorem 1 are disproved. As a consequence, the main claim of the above correspondence is denied. Furthermore, a new theorem is given to show that the multipath diversity cannot be achieved by SC-FDE without channel coding. An example is also presented to disprove the main claim of of the above correspondence meanwhile supporting the new theorem proposed in this correspondence
139970
Immune Clonal MO Algorithm for 0/1 Knapsack Problems
In this paper, we introduce a new multiobjective optimization (MO) algorithm to solve 0/1 knapsack problems using the immune clonal principle. This algorithm is termed Immune Clonal MO Algorithm (ICMOA). In ICMOA, the antibody population is split into the population of the nondominated antibodies and that of the dominated antibodied. Meanwhile, the nondominated antibodies are allowed to survive and to clone. A metric of Coverage of Two Sets is adopted for the problems. This quantitative metric is used for testing the convergence to the Pareto-optimal front. Simulation results on the 0/1 knapsack problems show that ICMOA, in most problems, is able to find much better spread of solutions and better convergence near the true Pareto-optimal front compared with SPEA, NSGA, NPGA and VEGA.
5425522
Temporal Interpolation of Spatially Dynamic Object
During the past decade there has been increasing research into the temporal component of geographic information systems (GIS). Most of the research has focused on the treatment of discrete changes in spatial objects, for example in cadastral parcels. However less attention has been paid to the treatment of continuous change which occurs primarily in dynamic objects found in the natural environment, for example in seasonal coastal changes. In order to represent these objects appropriately in a GIS, which by their inherent structure tend to treat the real-world in a discrete manner, temporal interpolation techniques are required. The aim of this paper is to discuss the techniques available for handling the temporal interpolation of spatially dynamic objects, with particular emphasis on changes to their geometric properties. The paper also proposes a range of interpolation methods for three key variants of geometric change.
8235488
Enhancing data cache reliability by the addition of a small fully-associative replication cache
Soft error conscious cache design is a necessity for reliable computing. ECC or parity-based integrity checking technique in use today either compromises performance for reliability or vice versa, and the N modular redundancy (NMR) scheme is too costly for microprocessors and applications with stringent cost constraint. This paper proposes a novel and cost-effective solution to enhance data reliability with minimum impact on performance. The idea is to add a small fully-associative cache to store the replica(s) of every write to the L1 data cache. The replicas can be used to detect and correct soft errors. The replication cache can also be used to increase performance by reducing the L1 data cache miss rate. Our experiments show that more than 97% read hits of the L1 data cache can find replicas available in a replication cache of 8 blocks.
28687598
Some Basic Data Structures and Algorithms for Chemical Generic Programming
Here, we report a template library used for molecular operation, the Molecular Handling Template Library (MHTL). The library includes some generic data structures and generic algorithms, and the two parts are associated with each other by two concepts: Properties and Molecule. The concept Properties describes the interface to access objects' properties, and the concept Molecule describes the minimum requirement for a molecular class. Data structures include seven models of Properties, each using a different method to access properties, and two models of molecular classes. Algorithms include molecular file manipulation subroutines, SMARTS language interpreter and matcher functions, and molecular OpenGL rendering functions.
46568605
Reinforcement Learning Based on Multi-agent in RoboCup
Multi-agent systems form a particular type of distributed artificial intelligence systems. As an important character of players in game, autonomous agents' learning has become the main direction of researchers. In this paper, based on basic reinforcement learning, multi-agent reinforcement learning with specific context is proposed. The method is applied to RoboCup to learn coordination among agents. In the learning, the game field is divided into different areas, and the action choice is made dependent on the area in which the ball is currently located. This makes the state space and the action space decrease. After learning the optimal joint policy is determined. Comparison experiment between stochastic policy and this optimal policy shows the effectiveness of our approach.