LMS versus Wiener filter for a decision feedback equalizer

In this paper we study an LMS-DFE. We use the ODE framework to show that the LMS-DFE attractors are close to the true DFE Wiener filter (designed considering the decision errors) at high SNR. Therefore, via LMS one can obtain a computationally efficient way to obtain the true DFE Wiener filter under high SNR. We also provide examples to show that the DFE filter so obtained can significantly outperform the usual DFE Wiener filter (designed assuming perfect decisions) at all practical SNRs. In fact, the performance improvement is very significant even at high SNRs (up to 50%), where the popular Wiener filter designed with perfect decisions, is believed to be closer to the optimal one.

Spatial Decision Support System for Assessing Micro, Mini and Small Hydel Potential

This study describes the design and implementation of DSS for assessment of Mini, Micro and Small Schemes. The design links a set of modelling, manipulation, spatial analyses and display tools to a structured database that has the facility to store both observed and simulated data. The main hypothesis is that this tool can be used to form a core of practical methodology that will result in more resilient in less time and can be used by decision-making bodies to assess the impacts of various scenarios (e.g.: changes in land use pattern) and to review, cost and benefits of decisions to be made. It also offers means of entering, accessing and interpreting the information for the purpose of sound decision making. Thus, the overall objective of this DSS is the development of set of tools aimed at transforming data into information and aid decisions at different scales.

Decision support system for regional electricity planning

Electricity appears to be the energy carrier of choice for modern economics since growth in electricity has outpaced growth in the demand for fuels. A decision maker (DM) for accurate and efficient decisions in electricity distribution requires the sector wise and location wise electricity consumption information to predict the requirement of electricity. In this regard, an interactive computer-based Decision Support System (DSS) has been developed to compile, analyse and present the data at disaggregated levels for regional energy planning. This helps in providing the precise information needed to make timely decisions related to transmission and distribution planning leading to increased efficiency and productivity. This paper discusses the design and implementation of a DSS, which facilitates to analyse the consumption of electricity at various hierarchical levels (division, taluk, sub division, feeder) for selected periods. This DSS is validated with the data of transmission and distribution systems of Kolar district in Karnataka State, India.

Bounds on Probability of Error in Decision Feedback Equalizers

Evaluation of the probability of error in decision feedback equalizers is difficult due to the presence of a hard limiter in the feedback path. This paper derives the upper and lower bounds on the probability of a single error and multiple error patterns. The bounds are fairly tight. The bounds can also be used to select proper tap gains of the equalizer.

Decision tree design and applications in speech processing

The design and operation of the minimum cost classifier, where the total cost is the sum of the measurement cost and the classification cost, is computationally complex. Noting the difficulties associated with this approach, decision tree design directly from a set of labelled samples is proposed in this paper. The feature space is first partitioned to transform the problem to one of discrete features. The resulting problem is solved by a dynamic programming algorithm over an explicitly ordered state space of all outcomes of all feature subsets. The solution procedure is very general and is applicable to any minimum cost pattern classification problem in which each feature has a finite number of outcomes. These techniques are applied to (i) voiced, unvoiced, and silence classification of speech, and (ii) spoken vowel recognition. The resulting decision trees are operationally very efficient and yield attractive classification accuracies.

Validation of Decision Tables Used in Process Control

Process control rules may be specified using decision tables. Such a specification is superior when logical decisions to be taken in control dominate. In this paper we give a method of detecting redundancies, incompleteness, and contradictions in such specifications. Using such a technique thus ensures the validity of the specifications.

A new pentameric structure of rotavirus NSP4 revealed by molecular replacement

The region spanning residues 95-146 of the rotavirus nonstructural protein NSP4 from the asymptomatic human strain ST3 has been purified and crystallized and diffraction data have been collected to a resolution of 2.6 angstrom. Several attempts to solve the structure by the molecular-replacement method using the available tetrameric structures of this domain were unsuccessful despite a sequence identity of 73% to the already known structures. A more systematic approach with a dimer as the search model led to an unexpected pentameric structure using the program Phaser. The various steps involved in arriving at this molecular-replacement solution, which unravelled a case of subtle variation between different oligomeric states unknown at the time of solving the structure, are presented in this paper.

Injection-molded high-density polyethylene-hydroxyapatite-aluminum oxide hybrid composites for hard-tissue replacement: Mechanical, biological, and protein adsorption behavior

In this article, we report the mechanical and biocompatibility properties of injection-molded high-density polyethylene (HDPE) composites reinforced with 40 wt % ceramic filler [hydroxyapatite (HA) and/or Al2O3] and 2 wt % titanate as a coupling agent. The mechanical property measurements revealed that a combination of a maximum tensile strength of 18.7 MPa and a maximum tensile modulus of about 855 MPa could be achieved with the injection-molded HDPE20 wt % HA20 wt % Al2O3 composites. For the same composite composition, the maximum compression strength was determined to be 71.6 MPa and the compression modulus was about 660 MPa. The fractrography study revealed the uniform distribution of ceramic fillers in the semicrystalline HDPE matrix. The cytocompatibility study with osteoblast-like SaOS2 cells confirmed extensive cell adhesion and proliferation on the injection-molded HDPE20 wt % HA20 wt % Al2O3 composites. The cell viability analysis with the 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay revealed a statistically significant difference between the injection-molded HDPE20 wt % HA20 wt % Al2O3 composites and sintered HA for various culture durations of upto 7 days. The difference in cytocompatibility properties among the biocomposites is explained in terms of the difference in the protein absorption behavior. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Geometric Decision Tree

In this paper, we present a new algorithm for learning oblique decision trees. Most of the current decision tree algorithms rely on impurity measures to assess the goodness of hyperplanes at each node while learning a decision tree in top-down fashion. These impurity measures do not properly capture the geometric structures in the data. Motivated by this, our algorithm uses a strategy for assessing the hyperplanes in such a way that the geometric structure in the data is taken into account. At each node of the decision tree, we find the clustering hyperplanes for both the classes and use their angle bisectors as the split rule at that node. We show through empirical studies that this idea leads to small decision trees and better performance. We also present some analysis to show that the angle bisectors of clustering hyperplanes that we use as the split rules at each node are solutions of an interesting optimization problem and hence argue that this is a principled method of learning a decision tree.

An Online Actor-Critic Algorithm with Function Approximation for Constrained Markov Decision Processes

We develop an online actor-critic reinforcement learning algorithm with function approximation for a problem of control under inequality constraints. We consider the long-run average cost Markov decision process (MDP) framework in which both the objective and the constraint functions are suitable policy-dependent long-run averages of certain sample path functions. The Lagrange multiplier method is used to handle the inequality constraints. We prove the asymptotic almost sure convergence of our algorithm to a locally optimal solution. We also provide the results of numerical experiments on a problem of routing in a multi-stage queueing network with constraints on long-run average queue lengths. We observe that our algorithm exhibits good performance on this setting and converges to a feasible point.