28941391
Optimum nested Miller compensation for low-voltage low-power CMOS amplifier design
An optimum structure of nested Miller compensation (NMC) is developed. The developed structure using a feedforward transconductance stage and null resistor on NMC, called NMCFNR, solves the bandwidth reduction and poor transient response problems of low-voltage low-power NMC amplifiers. For comparison, amplifiers compensated by NMC and NMCFNR have been fabricated. Experimental results show that NMCFNR improves the gain-bandwidth product, slew rate and settling time by more than three times with 8/spl deg/ increase on the phase margin and no increase of the power consumption. Moreover, it improves the negative power supply rejection ratio by at least 54 dB. The die area of the NMCFNR amplifier is about half of that of the NMC amplifier.
18463934
Design of a 1.5-V high-order curvature-compensated CMOS bandgap reference
A low-voltage low-noise high-order curvature-compensated CMOS bandgap reference is proposed in this paper. Two resistor strings are added to the bandgap circuit to reduce the supply voltage. In addition, a temperature-dependent resistor ratio generated by a high-resistive poly resistor is used to provide the high-order compensation. The proposed bandgap voltage reference can operate down to a 1.5V supply (where V/sub th/ = 0.9V at 0/spl deg/C) with a temperature coefficient of less than 15.2ppm//spl deg/C and an average line regulation of 5.5mV/V.
9755080
A 1.2V buck converter with a novel on-chip low-voltage current-sensing scheme
A low-voltage on-chip current-sensing circuit for buck power converter is proposed. The minimum supply voltage of the proposed current-sensing circuit is 1.2V (where V/sub th/ = 0.85V at room temperature), and the sensing accuracy is higher than 94%. The proposed buck converter is able to operate at a 1.2-V supply with higher than 98% power-conversion efficiency and with a maximum output current of 120mA.
15996223
A low-voltage CMOS low-dropout regulator with enhanced loop response
A 1.5-V 100-mA CMOS low-dropout regulator with a double pole-zero cancellation scheme and a linearly operated power PMOS transistor at dropout to enhance the loop-gain response, is presented. The circuit realization is well-studied and developed with respect to the loop-gain response, the transient response, the output noise and the output accuracy, as well as the standby power consumption. Implemented in a 0.6 /spl mu/m CMOS process, experimental results show that the regulator provides a full load transient response of less than 1-/spl mu/s settling time and less than 50-mV overshoots and undershoots. Moreover, it provides a ripple rejection of better than -26 dB and an output noise of 0.07 /spl mu/V/sqrt Hz at 100 kHz.
18141920
Learning functional dependency networks based on genetic programming
Bayesian Network (BN) is a powerful network model, which represents a set of variables in the domain and provides the probabilistic relationships among them. But BN can handle discrete values only; it cannot handle continuous, interval and ordinal ones, which must be converted to discrete values and the order information is lost. Thus, BN tends to have higher network complexity and lower understandability. In this paper, we present a novel dependency network which can handle discrete, continuous, interval and ordinal values through functions; it has lower network complexity and stronger expressive power; it can represent any kind of relationships; and it can incorporate a-priori knowledge though user-defined functions. We also propose a novel Genetic Programming (GP) to learn dependency networks. The novel GP does not use any knowledge-guided nor application-oriented operator, thus it is robust and easy to replicate. The experimental results demonstrate that the novel GP can successfully discover the target novel dependency networks, which have the highest accuracy and the lowest network complexity.
320235
Handling signature purposes in workflow systems
Abstract In paper-based workflow systems, signatures of individuals or groups of people have been used extensively for different purposes. Currently there are numerous studies on computerizing workflow systems. Also there are studies on implementing digital signatures in electronic media. But the diversified purposes of a signature in workflow makes a straightforward implementation of digital signature schemes inadequate. There are few studies on the implication of different signature purposes on electronic workflow systems. The purposes of signature are closely associated with the two modes of decision making, namely single and group. These two modes of decision making in turn lead to single and group signatures. This paper reports our comprehensive studies on signature purposes. These include the analysis of common signature purposes in workflow, classification of these purposes, classification of modes of decision making associated with these signature purposes, signing and validation requirements for handling these signature purposes, and finally an architecture to be incorporated in workflow engines for handling these signature purposes. In summary, this paper addresses a commonly neglected problem in information systems research: management control by signature in workflow.
6404798
A hybridized genetic parallel programming based logic circuit synthesizer
Genetic Parallel Programming (GPP) is a novel Genetic Programming paradigm. Based on the GPP paradigm and a local search operator - FlowMap, a logic circuit synthesizing system integrating GPP and FlowMap, a Hybridized GPP based Logic Circuit Synthesizer (HGPPLCS) is developed. To show the effectiveness of the proposed HGPPLCS, six combinational logic circuit problems are used for evaluations. Each problem is run for 50 times. Experimental results show that both the lookup table counts and the propagation gate delays of the circuits collected are better than those obtained by conventional design or evolved by GPP alone. For example, in a 6-bit one counter experiment, we obtained combinational digital circuits with 8 four-input lookup tables in 2 gate level on average. It utilizes 2 lookup tables and 3 gate levels less than circuits evolved by GPP alone.
11001415
Automatic refinement of knowledge bases with fuzzy rules
Abstract The knowledge-acquisition bottleneck obstructs the development of expert systems. Refinement of existing knowledge bases is a subproblem of the knowledge-acquisition problem. The paper presents a HEuristic REfinement System (HERES), which refines rules with mixed fuzzy and nonfuzzy concepts represented in a variant of the rule representation language Z-II automatically. HERES employs heuristics and analytical methods to guide its generation of plausible refinements. The functionality and effectiveness of HERES are verified through various case studies. It has been verified that HERES can successfully refine knowledge bases. The refinement methods can handle imprecise and uncertain examples and generate approximate rules. In this aspect, they are better than other famous learning algorithms such as ID3 15–18 , AQ11, and INDUCE 14, 19, 20 because HERES' methods are currently unique in processing inexact examples and creating approximate rules.
13138848
Data Classification Using Genetic Parallel Programming
A novel Linear Genetic Programming (LGP) paradigm called Genetic Parallel Programming (GPP) has been proposed to evolve parallel programs based on a Multi-ALU Processor. It is found that GPP can evolve parallel programs for Data Classification problems. In this paper, five binary-class UCI Machine Learning Repository databases are used to test the effectiveness of the proposed GPP-classifier. The main advantages of employing GPP for data classification are: 1) speeding up evolutionary process by parallel hardware fitness evaluation; and 2) discovering parallel algorithms automatically. Experimental results show that the GPP-classifier evolves simple classification programs with good generalization performance. The accuracies of these evolved classifiers are comparable to other existing classification algorithms.