Probability Of Correct Decision Research Articles

Multicomponent Signal Detection and Parameter Estimation Algorithm of Synchronization Nyquist Folding Receiver

Nyquist Folding Receiver is a novel reconnaissance receiver structure which is able to use single ADC to sample Ultra-wideband signals. And the Synchronous Nyquist Folding Receiver (SNYFR) is an improved structure of NYFR. When input is multicomponent single-frequency signal, with the consideration of the characteristics of the output we propose an algorithm of Nyquist Zone(NZ) judgment and parameters estimation based on scaling search in Fractional Fourier Transform (FRFT) domain to avoid detection error occurring when the input signal components locate in the NZ fuzzy area. Computer simulation show that when SNR beyond, the Probability of Correct Decision(PCD) of signal detection can be achieved 100% and the mean square error of parameters estimation can be approached Cramer-Rao Bound(CRB) simultaneously.

Optimal Selection of the Most Reliable Design Based on Gamma Degradation Processes

Manufacturers are often faced with the problem of how to select the most reliable design among several competing designs in the stage of development. It becomes complicated if products are highly reliable. Under the circumstances, recent work has focused on the study with degradation data by assuming that degradation paths follow Wiener processes or random-effect models. However, it is more appropriate to use gamma processes to model degradation data with monotone-increasing pattern. This article deals with the selection problem for such processes. With a minimum probability of correct decision, optimal test plans can be obtained by minimizing the total cost.

Relay Advantage Criterion for Multihop Decode-and-Forward Relaying Systems

We define a symbol transition matrix (STM) as a matrix whose entries are the symbol transition probabilities of a relay in a decode-and-forward (DF) relaying system. Using the STM as a state transition matrix of a discrete-time Markov chain, the source-to-destination STM is shown to be the product of intermediate STMs in multihop DF relaying systems. We show that the probability of correct decision at the destination is the trace of the source-to-destination STM divided by the modulation order. The symbol error probabilities (SEPs) of multihop DF relaying systems with any modulation scheme in any independent and nonidentically distributed (ind) channels are derived using the STM. For multihop DF relaying systems in independent and identically distributed (iid) channels, the eigenvalues of the single link STM are used to simplify the calculation of the SEP for any modulation scheme. Also, the SEP of multihop DF relaying systems with 16-quadrature amplitude modulation (QAM) signals in ind Rayleigh fading channels is derived using the STM. A relay advantage criterion is derived for multihop DF relaying systems in iid Nakagami-m fading channels with both the total transmitted energy and the source-to-destination distance fixed. The relay advantage criterion can be used for deciding whether putting more relays between the source and the destination increases or decreases the SEP.

Comments on “A Representation for the Symbol Error Rate Using Completely Monotone Functions”

It was shown in the above-titled paper by Rajan and Tepedelenlioglu (see ibid., vol. 59, no. 6, p. 3922-31, June 2013) that the symbol error rate (SER) of an arbitrary multidimensional constellation subject to additive white Gaussian noise is characterized as the product of a completely monotone function with a nonnegative power of signal-to-noise ratio (SNR) under minimum distance detection. In this comment, it is proved that the probability of correct decision of an arbitrary constellation admits a similar representation as well. Based on this fact, it is shown that the stochastic ordering { ≤ Gα, α ≥ 0} proposed by the authors as an extension of the existing Laplace transform order to compare the average SERs over two different fading channels actually predicts that the average SERs are equal for any constellation of dimensionality smaller than or equal to 2α. Furthermore, it is noted that there are no positive random variables X1 and X2 such that the proposed stochastic ordering is satisfied in the strict sense, i.e., X1 <; Gα X2 when α = N/2 for any positive integer N. Additional remarks are noted about the fading scenarios at low SNR and the generalization to additive compound Gaussian noise originally discussed in the subject paper.

A new Bayesian acceptance sampling plan considering inspection errors

A sampling plan is a statement of criteria of acceptance applied to a batch, based on appropriate examination of a required number of sample units by specific methods. In this paper, a new acceptance sampling plan is introduced in which it is assumed that every defective item cannot be detected with complete certainty. To model the problem, the probability distribution function of the number of defective items in the batch is determined through Bayesian inference, and based on this probability density function, the probability of correct decisions in different actions is evaluated. An objective function is defined for each decision that minimizes the ratio of the system cost to the system correct decision probability, including the cost of rejecting the batch, and the cost of defectives items remaining in an accepted batch. Three numerical examples are provided to illustrate the applications of the proposed models.

Nyquist Folding Receiver for the Interception of Frequency Agile Radar Signal

This work was carried out to improve the probability of interception of frequency sweep and lower the system complexity of non-sweep mode of the electronic intelligence system for frequency agile radar signal. A low complexity receiver structure and its associated demodulation algorithm with high probability of intercept are also presented. Moreover, the applicability of this structure for the wideband radar signal is demonstrated. First, the received signal is modulated by analog signal and treated as the local oscillator to move the local signal with different Nyquist zone into the baseband to extract the zone information. Then, the digital local oscillator synchronized with the analog modulation is used to reconstruct the demodulated sub-sampling signal. Finally, the zone and sub-sampling signal could be used to estimate signal parameters by the classical signal processing methods. Simulation results show that when the signal to noise ratio is more than -16 dB, the probability of correct decision for the Nyquist zone is better than 90%. Key words: Frequency agile, sub-sampling, synchronous Nyquist folding receiver, Nyquist zone.

Kalman filter for parametric fault detection: an internal model principle-based approach

The paramount importance of fault detection (FD) in complex engineering systems has undoubtedly been the main driver behind the development of a plethora of techniques in the FD area. In this study, the authors propose an internal model principle-based Kalman filter (IMP-KF) structure for use in the detection of parametric faults. The authors show that the closed-loop structure of the IMP-KF is indeed a necessary and sufficient condition for generating residuals upon which the FD process hinges. They advocate a residual generator structure similar to that used in the standard Kalman filtering (KF), and judiciously exploit the non-robustness to model mismatch of the proposed IMP-KF scheme to detect faults in the presence of noise and disturbances. With no model mismatch, the KF residual's whiteness is exploited to derive a composite hypothesis testing that accounts for a low probability for false alarm and a high probability of correct decision for various reference inputs. The proposed scheme was successfully evaluated on both simulated and physical systems.

Bacterial biofilm-based water toxicity sensor

Cell-based toxicity bioassays harbor the potential for efficient detection and monitoring of hazardous materials. However, their use in the field has been limited by harsh and unstable environmental conditions that shorten shelf-life, introduce significant noise, and reduce the signal and signal-to-noise ratio; such conditions may thus decrease the probability of correct decisions, increasing both false positive and false negative outcomes. Therefore, there is a need for a stable cell-on-chip integration that offers long-term storage and resilience to environmental factors. The use of intact microbial biofilms as biological elements in a whole-cell biosensor, and their integration into specialized biochips, holds promise for enhancing sensor stability as well as providing an innovative platform for biofilm research. We report here for the first time on the integration of a bacterial biofilm as the sensing element of a whole-cell biosensor, as a means to stabilize and preserve reproducibility, viability and functionality of the bacterial sensor cells. We have employed a genetically engineered Escherichia coli sensor strain, tailored to respond to the presence of genotoxic (DNA damaging) agents by the induction of a reporter enzyme, alkaline phosphatase, and tested its functionality in colorimetric and electrochemical assays. Three different bacterial integration forms were examined: planktonic cells, electronically deposited sessile cells, and biofilms. For all integration forms, a clear dose-dependent positive response to the presence of the model toxicant nalidixic acid was observed, with biofilms displaying higher current density and detection sensitivity than planktonic and sessile cells. We present the electrode apparatus and methods and biochip characterization of such chips, e.g. signal vs. time and induction factor, and discuss the advantage and potential problems of the new biofilm-biochip technology.

Regulatory Perspectives on Multiplicity in Adaptive Design Clinical Trials throughout a Drug Development Program

A clinical research program for drug development often consists of a sequence of clinical trials that may begin with uncontrolled and nonrandomized trials, followed by randomized trials or randomized controlled trials. Adaptive designs are not infrequently proposed for use. In the regulatory setting, the success of a drug development program can be defined to be that the experimental treatment at a specific dose level including regimen and frequency is approved based on replicated evidence from at least two confirmatory trials. In the early stage of clinical research, multiplicity issues are very broad. What is the maximum tolerable dose in an adaptive dose escalation trial? What should the dose range be to consider in an adaptive dose-ranging trial? What is the minimum effective dose in an adaptive dose-response study given the tolerability and the toxicity observable in short term or premarketing trials? Is establishing the dose-response relationship important or the ability to select a superior treatment with high probability more important? In the later stage of clinical research, multiplicity problems can be formulated with better focus, depending on whether the study is for exploration to estimate or select design elements or for labeling consideration. What is the study objective for an early-phase versus a later phase adaptive clinical trial? How many doses are to be studied in the early exploratory adaptive trial versus in the confirmatory adaptive trial? Is the intended patient population well defined or is the applicable patient population yet to be adaptively selected in the trial due to the potential patient and/or disease heterogeneity? Is the primary efficacy endpoint well defined or still under discussion providing room for adaptation? What are the potential treatment indications that may adaptively lead to an intended-to-treat patient population and the primary efficacy endpoint? In this work we stipulate the multiplicity issues with adaptive designs encountered in regulatory applications. For confirmatory adaptive design clinical trials, controlling studywise type I error and type II error is of paramount importance. For exploratory adaptive trials, we define the probability of correct selection of design features, e.g., dose, effect size, and the probability of correct decision for drug development. We assert that maximizing these probabilities would be critical to determine whether the drug development program continues or how to plan the confirmatory trials if the development continues.

Sensitivity of harvest decisions to errors in stand characteristics

In forest planning, the decision maker chooses for each stand a treatment schedule for a predefined planning period. The choice is based either on optimization calculations or on silvicultural guidelines. Schedules for individual stands are obtained using a growth simulator, where measured stand characteristics such as the basal area, mean diameter, site class and mean height are used as input variables. These characteristics include errors, however, which may lead to incorrect decisions. In this study, the aim is to study the sensitivity of harvest decisions to errors in a dataset of 157 stands. Correct schedules according to silvicultural guidelines were first determined using error-free data. Different amounts of errors were then generated to the stand-specific characteristics, and the treatment schedule was selected again using the erroneous data. The decision was defined as correct, if the type of harvest in these two schedules were similar, and if the timings deviated at maximum ±2 for thinning and ±3 years for clear-cut. The dependency of probability of correct decisions on stand characteristics and the degree of errors was then modelled. The proposed model can be used to determine the required level of measurement accuracy for each characteristics in different kinds of stands, with a given accuracy requirement for the timing of treatments. This information can further be utilized in selecting the most appropriate inventory method.

Clipping value estimate for iterative tree search detection

The clipping value, defined as the log-likelihood ratio (LLR) in the case wherein all the list of candidates have the same binary value, is investigated, and an effective method to estimate it is presented for iterative tree search detection. The basic principle behind the method is that the clipping value of a channel bit is equal to the LLR of the maximum probability of correct decision of the bit to the corresponding probability of erroneous decision. In conjunction with multilevel bit mappings, the clipping value can be calculated with the parameters of the number of transmit antennas, N t ; number of bits per constellation point, M c ; and variance of the channel noise, σ2, per real dimension in the Rayleigh fading channel. Analyses and simulations show that the bit error performance of the proposed method is better than that of the conventional fixed-value method.

A performance comparison of erasure tests with diversity reception for noncoherent M-ary FSK signaling [Transactions Papers

A l-Bayesian erasure test (BET) based on order statistics with diversity reception for noncoherent M-ary frequency shift keying (FSK) signaling is examined. In the l-BET, the M-ary FSK symbol is erased whenever the a posteriori probability of correct decision, which is a function of the l-largest sums of energy detector outputs, is less than a threshold. For binary FSK signaling in Rayleigh flat fading channels, the 2-BET is found to be the same as the difference threshold test (DTT), which declares an erasure whenever the difference between the largest and the second largest sums of energy detector outputs is less than a threshold. The output threshold test (OTT), which declares an erasure whenever the largest sum of energy detector outputs is less than a threshold, is proved equivalent to the 1-BET for the Rayleigh flat fading channel. Closed-form expressions for the probabilities of correct decision and symbol error for the DTT, Viterbi's ratio threshold test (RTT), and the OTT are derived when square-law combining (SLC) diversity is used. Several erasure tests including the Z-BET, the RTT, the OTT, and the DTT are compared in terms of probability of codeword error. The 2-BET provides almost the same performance as the BET that requires all the sums of energy detector outputs. The 2-BET provides power gains of 0.9 dB and 0.7 dB over the RTT for (7, 3) and (15, 7) Reed-Solomon (RS) codes, respectively, when the probability of codeword error is 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> and the diversity order is one.

Diagnostic quality of Actigraph‐based physical activity cut‐offs for children: What overweight/obesity references can tell?

There is conflicting literature about Actigraph-based cut-off points (CoP) that define the lower limit of moderate-to-vigorous physical activity (MVPA) among children. The aim of the present study was to compare the diagnostic quality of Actigraph-based CoP relative to different body mass index (BMI) classification systems of the weight status of children. One hundred and thirteen children aged 8-11 years recruited from three randomly selected elementary schools wore the Actigraph, model 7164 (Actigraph Manufacturing Technology) for 3 days. Five CoP, expressed in counts per minute (c.p.m.; CoP 1000 CoP 2000, CoP 3000, CoP 3200, and CoP 3600) were used to compute their MVPA. The area under the receiver operating characteristic curves (AUC) together with specific indices allowed assessment of the performance of these CoP in reference to overweight/obesity status as defined using BMI-based criteria from the International Obesity Task Force (IOTF), French References (FR) and World Health Organization (WHO) standards. Overweight/obesity frequency ranged from 30% to 42%, with no sex-related difference. All AUC (range, 0.623-0.660) were significantly higher than 0.500 except from those of CoP 1000 and 2000 using the IOTF criteria (0.602 +/- 0.058 and 0.601 +/- 0.057, respectively) and the FR (0.608 +/- 0.060 for CoP 1000). Furthermore, with the WHO standards, all the CoP provided non-significant AUC (range, 0.566-0.597). According to the IOTF and the FR criteria, respectively, CoP 3600 had the highest probability of correct decision (0.62 and 0.68), the lowest misclassification errors (0.38 and 0.32), the highest validity coefficient (0.21 and 0.29), and the highest expected maximum utility (59 and 83). When children are classified using BMI-based criteria, the threshold of 3600 c.p.m. should be more appropriate in discriminating non-overweight from overweight/obese.

Partitioning k multivariate normal populations according to equivalence with respect to a standard vector

We propose optimal procedures to achieve the goal of partitioning k multivariate normal populations into two disjoint subsets with respect to a given standard vector. Definition of good or bad multivariate normal populations is given according to their Mahalanobis distances to a known standard vector as being small or large. Partitioning k multivariate normal populations is reduced to partitioning k non-central Chi-square or non-central F distributions with respect to the corresponding non-centrality parameters depending on whether the covariance matrices are known or unknown. The minimum required sample size for each population is determined to ensure that the probability of correct decision attains a certain level. An example is given to illustrate our procedures.

On Some Multiple Decision Procedures for Normal Variances

In this article, we propose a multiple decision procedure to test the homogeneity of normal variances. If the null-hypothesis is rejected, our goal is to select a subset containing the population associated with the largest variance. An approximation for the critical value is obtained by deriving an approximate distribution for a linear combination of independent log-gamma distributed random variables. A lower bound for the probability of correct decision is obtained. We also study the determination of the common sample size in order to satisfy a given probability of correct decision when the largest variance is “sufficiently” larger than the rest.

Designing a screening experiment with a reciprocal Weibull degradation rate

Degradation tests and design of experiments are powerful techniques to improve the reliability of highly reliable products. With respect to a resolution III experiment with a linearized degradation model where the degradation rate follows a lognormal distribution, Yu and Chiao [Yu, H. F., & Chiao, C. H. (2002). An optimal designed degradation experiment for reliability improvement. IEEE Transactions on Reliability, 51 (4) 427-433] addressed the problem of how to determine the optimal settings of decision variables such as the inspection frequency, the sample size, and the termination time for each run, which are influential to the precision of identifying significant factors and the experimental cost. In practical applications, Weibull and lognormal distributions are much alike. They may fit the lifetime data well. However, their predictions may lead to a significant difference. In this paper, we will deal with the optimal design of a resolution III experiment with a linearized degradation model where the degradation rate follows a reciprocal Weibull distribution. First, an intuitively appealing identification rule is proposed. Next, under the constraints of a minimum probability of correct decision and a maximum probability of incorrect decision of the proposed identification rule, the optimal test plan is derived by using the criterion of minimizing the total cost of experiment. An example is provided to demonstrate the proposed method. Finally, a simulation study is also provided to discuss the effects of mis-specification between the models of Yu and Chiao (2002) and the present paper on identification efficiency.

Robust decision-feedback equalization with a noncausal filter for ATSC DTV receivers

A robust decision-feedback equalization method for ATSC DTV receivers is presented. Under severe channels, such as 0-dB ghost or a distributed transmission environment, decision-feedback equalizers (DFEs), which have been commonly used in ATSC DTV receivers, suffer from error propagation. To improve the robustness to the error propagation, we incorporate a channel-matched filter (CMF) and an intelligent sheer (IS). The use of the CMF prior to the DFE makes severe channels manageable in the DFE, The IS, a trellis decoder with a trace-back depth of 1, enhances a correct-decision probability in the DFE, especially under low SNR conditions. Adoption of the CMF and the IS clearly enhances the robustness of the DFE but may degrade the output SNR due to unwanted pre-ghosts caused by channel-matched filtering. We employ a noncausal all-pass filter operating in reversed time to preserve the robustness acquired by the CMF and the IS without the degradation of the output SNR. The noncausal filter changes an input channel with pre-ghosts into an approximately minimum-phase channel without pre-ghosts. Simulation results show that the proposed equalization scheme achieves the more stable convergence and the higher SNRs than the existing DFEs.

Multimodal speaker identification using an adaptive classifier cascade based on modality reliability

We present a multimodal open-set speaker identification system that integrates information coming from audio, face and lip motion modalities. For fusion of multiple modalities, we propose a new adaptive cascade rule that favors reliable modality combinations through a cascade of classifiers. The order of the classifiers in the cascade is adaptively determined based on the reliability of each modality combination. A novel reliability measure, that genuinely fits to the open-set speaker identification problem, is also proposed to assess accept or reject decisions of a classifier. A formal framework is developed based on probability of correct decision for analytical comparison of the proposed adaptive rule with other classifier combination rules. The proposed adaptive rule is more robust in the presence of unreliable modalities, and outperforms the hard-level max rule and soft-level weighted summation rule, provided that the employed reliability measure is effective in assessment of classifier decisions. Experimental results that support this assertion are provided.

Effect of Imperfect Phase and Timing Synchronization on the Bit-Error Rate Performance of PSK Modulations

A great deal of attention has been devoted in the recent literature to the study of the bit-error rate (BER) performance of phase-shift keyed (PSK) constellations, due to their high spectral efficiency. It is well known that an error in phase or timing synchronization affects the probability of correct decisions at the receiver. This problem becomes much more significant as data rates increase, and the corresponding symbol durations decrease. In this letter, we look into this problem and analyze the exact BER performance of generalized hierarchical PSK constellations under imperfect phase or timing synchronization over additive white Gaussian noise channels.

Three-dimensional distortion-tolerant object recognition using integral imaging

This paper addresses 3D distortion-tolerant object recognition using Integral Imaging (II). II is one of the techniques considered for 3D image recording and display. Multiple elemental images are captured to record different but continuous viewing zones of 3D scenes. We develop a distortion-tolerant 3D object recognition by using the II capture system. We adopt Principal Component Analysis (PCA) and Fisher Linear Discriminant (FLD) classifier followed by the nearest neighbor decision rule and the statistical distance metric. Performance is analyzed in terms of probability of correct decision, Root Mean Square Error (RMSE) between raw input vectors and reconstructed vectors from the PCA subspace and the PCA-FLD cost function. Decision strategies are compared by the varying number of training data.