Total Number Of Measurements Research Articles

Multi-Sensor Multi-Object Tracking With the Generalized Labeled Multi-Bernoulli Filter

This paper proposes an efficient implementation of the multi-sensor generalized labeled multi-Bernoulli (GLMB) filter. Like its single-sensor counterpart, such implementation requires truncating the GLMB sum. However the single-sensor case requires solving 2-D ranked assignment problems whereas the multi-sensor case require solving multi-dimensional ranked assignment problems, which are NP-hard. The proposed implementation exploits the GLMB joint prediction and update together with a new technique for truncating the GLMB filtering density based on Gibbs sampling. The resulting algorithm has a quadratic complexity in the number of hypothesized objects and linear in the total number of measurements from all sensors.

Fading channel estimation for free-space continuous-variable secure quantum communication

We investigate estimation of fluctuating channels and its effect on security of continuous-variable quantum key distribution. We propose a novel estimation scheme which is based on the clusterization of the estimated transmittance data. We show that uncertainty about whether the transmittance is fixed or not results in a lower key rate. However, if the total number of measurements is large, one can obtain using our method a key rate similar to the non-fluctuating channel even for highly fluctuating channels. We also verify our theoretical assumptions using experimental data from an atmospheric quantum channel. Our method is therefore promising for secure quantum communication over strongly fluctuating turbulent atmospheric channels.

A Closed-Form Formula of Radiation and Total Efficiency for Lossy Multiport Antennas

This letter proposes a closed-form expression of the radiation and the total efficiency for the entire lossy multiport antenna system with simultaneous excitations. The equivalent circuit model and the detailed analysis process of the two-element lossy multiport antennas as well as a generalized expression for N -element lossy multiport antennas were considered. The required inputs to the closed-form expression are S -parameters, embedded radiation efficiency of each antenna element, and radiation efficiency of the entire antenna pair with identical simultaneous excitations. This method can be used for the analysis of multiple-input–multiple-output (MIMO) and antenna arrays, when the multiple elements are simultaneously excited with arbitrary amplitude and phase. To validate the proposed method, two different lossy MIMO antennas, namely, a pair of parallel end-fed dipoles and 4 × 1 layout printed bowtie antennas, were studied with various amplitude- and phase-feeding schemes. Full-wave numerical simulations were performed to provide inputs to the closed-form expression. Excellent agreement was observed between the radiation efficiencies of these antennas obtained through the closed-form expression and the full-wave numerical simulations, which demonstrates accuracy of the proposed closed-form expression. Furthermore, the proposed method can significantly reduce the total number of measurements for charactering the efficiency of the entire simultaneously excited lossy multiport antennas.

Incidence Rates of Critical Low Glucoses (

Abstract Objectives/Background Beginning in 2017, the American Diabetes Association defined clinically significant hypoglycemia (CSH) as glucose <54 mg/dL. In January 2018, our hospital initiated a call-back policy for inpatient CSH results made in the central laboratory, along with a new nursing policy for CSH response to measurements made either by the central laboratory or by point-of-care testing. Our objective was to determine whether these new policies had affected the incidence rate of low critical values for glucose (CRITICAL, <40 mg/dL) among inpatients at our institution, a 950-bed academic medical center hospital. Methods Glucose results for two 12-week intervals before (PRE) and after (POST) adoption of the CSH call-back policy were obtained retrospectively for both central laboratory (C) and point-of-care (P) measurements. Critical incidence rate (R) was defined as number of critical results per total number of measurements of glucose in the interval. Results There were four data sets: C-PRE (n = 44,142; CRITICAL = 35), C-POST (n = 46,341; CRITICAL = 66), P-PRE (n = 76,745; CRITICAL = 169), and P-POST (n = 78,838; CRITICAL = 218). For C, R increased in POST by 80% (PRE = 0.79E-3; POST = 1.42E-3). For P, R increased in POST by 26% (PRE = 2.20E-3; POST = 2.77E-3). Combining C and P data, overall R increased in POST by 34% (PRE = 1.69E-3; POST = 2.27E-3). These calculations for R did not, however, exclude possible repeated measurements on individual patients. Counting first or only CRITICAL results from unique individual patients, obtained either from C or P, a revised overall R was still significantly increased in POST, by 22% (PRE = 0.87E-3; POST = 1.06E-3) (P < .01). Conclusion After CSH policy changes, the rate of identification of new patients having critical low glucose increased substantially (+22%). This increase was unanticipated, and the exact cause was unknown. Potentially, the increase may reflect an increased awareness of CSH by clinical staff, leading to a higher preselection rate for measurement of CRITICALS and identification of a greater number of patient cases.

Abstract P192: Implications of a Simplified Hypertension Screening Approach for Low-and Middle-Income Countries

Background: In low- and middle- income settings, standardized protocols that require triplicate blood pressure (BP) readings pose substantial logistical barriers to hypertension (HTN) screening. We assessed algorithms using fewer measurements. Methods: We evaluated the efficiency, % HTN missed and % misdiagnosed as HTN associated with algorithms based on the 1st and/or 2nd measurements. For reference, we defined HTN as recommended by the WHO, i.e. average of 2nd and 3rd BP ≥ 140/90. We focused on 11,999 and 7,382 adults without anti-HTN medication use in Nepal and India, respectively, from May Measurement Month 2017-2018 and contrasted them with 21,751 from the US National Health and Nutrition Examination Survey 1999-2014. Results: The prevalence of HTN was 18.8% in Nepal, 27.0% in India, and 10.2% in the US. Using only the 1st BP, 7.8%, 11.7%, and 10.1% of cases would be missed in each country respectively. The % of misdiagnosed HTN would be 9.9%, 9.4%, and 4.2%, respectively. Using a 2nd BP among those with a 1 st BP ≥ 135/85 (“Two-Step Simple”) missed fewer cases (4.7%, 9.4%, and 7.7%), and misdiagnosed fewer people (2.8%, 3.5%, and 1.6%). Under this approach, 36.3%, 44.1%, and 18.7% would receive a 2 nd BP reading. Alternative, more complex, algorithms were able to further minimize misclassification and improve efficiency ( Table ). Conclusions: Using screening data from Nepal, India, and the US, we found several algorithms based on <3 BP readings had low misclassification rates. These algorithms reduce the total number of measurements by more than half from the standard triplicate protocol and appear to be practical for large-scale screening in resource-constrained settings.

SAT-128 Evaluating the Accuracy of Glycemic Markers and Risk of Hypoglycemia in Patients with Type 2 Diabetes Mellitus and Chronic Kidney Disease by Continuous Glucose Monitoring

Background: Chronic kidney disease (CKD) is a growing global health problem due to the increasing prevalence of Type 2 Diabetes Mellitus (T2DM). Consequently, the management of T2DM becomes challenging with advancing non-dialysis CKD (n-CKD). Prior studies have not confirmed the accuracy of markers such as serum fructosamine (SF) and glycosylated hemoglobin A1c (HbA1c) in this population. Also, there is a paucity of data on the incidence of hypoglycemia in these patients. The present study is twofold; evaluating the accuracy of HbA1c and exploring the frequency and severity of hypoglycemia in T2DM patients with n-CKD by continuous glucose monitoring (CGM). Methods: We studied 80 patients with T2DM and n-CKD defined as eGFR 0-45 ml/min. Patients wore the CGM (Abbott FreeStyle Libre Pro) for up to 14 days, with glucose recorded every 15 minutes, with a maximum of 1,344 glucose measurements. Blood tests were performed in the fasting state at the end of the 14 day CGM. HbA1C and SF were compared by linear regression to patients’ average glucose concentration (AGC) calculated as all of a patient’s CGM glucose results divided by the total number of measurements. Hypoglycemia was defined as plasma glucose below 70 mg/dL. Results: 80 patients wore the CGM for a mean of 12.6±2.8 days. Mean age was 71.3±10.9 years, 77% of patients were men, 12% were black, and mean eGFR 27.0±11.1 ml/min. The mean glucose concentration was 151.4±55.7 mg/dL, mean HbA1C 7.2±1.5% and SF 304.1±57.2 μmol/L. HbA1C significantly correlated with AGC, r=0.82, p<0.0001. The relationship was characterized by the formula, AGC=31.8 x HbA1C - 73.3. There was no significant correlation between serum fructosamine and AGC, r=0.54, p=0.8. 61/80 (76.2%) patients had at least one hypoglycemic episode. The mean number of episodes was 7.4±8.9, with a range of 0-53 episodes. The mean number of minutes of hypoglycemia was 1501±2165. This represents a mean of 7.4±10.1% of total measurement time being hypoglycemic, compared to studies in T2DM without CKD where the number is closer to 1.5%. Conclusion: HbA1C, but not serum fructosamine, was an excellent measure of glycemic control in patients with T2DM and n-CKD. Confirming this with a larger sample size is imperative for disease management. The high burden of hypoglycemia highlights the need to avoid medications that increase risk of hypoglycemia and consider adjusting glycemic targets in this patient population.

Color image storage and retrieval using quantum mechanics

In this paper, two algorithms for storing and retrieving a color image using quantum mechanics are proposed. The first algorithm encodes a pixel’s color information with an angle. In this case, it has some advantages in retrieval speed, required qubits and quantum measurements. In the second algorithm, a pixel’s color is divided into three channels: R, G and B, and each channel is encoded with an angle. In this case, it has an advantage in retrieval accuracy. By example analysis, the proposed algorithms are compared with the other algorithms in some aspects, e.g., the total number of qubits, the total number of measurements and the accuracy of retrieval. It can be found that the first algorithm has the advantage in the speed of retrieval, the total number of qubits and the total number of measurements, and the second algorithm has the advantage in the accuracy of retrieval.

Assessment of Nonuniform Batch Distribution in Blast Furnace

In industry, nonuniform distribution of the material and energy resources significantly affects the stability of production processes and impairs product quality. In particular, in blast furnaces, nonuniform distribution of the batch components and the gas temperature significantly affects furnace performance. A literature review shows that the nonuniformity is usually assessed by means of various coefficients taking account of the variability in the material and energy resources in the course of production. The variation coefficient introduced by Pearson in 1895 is most commonly used. The relation between the square of the variation coefficient V2 and X2 = [n(N–1)/N]V2 is established. According to this relation, the random quantity V2 has a χ2k distribution with k degrees of freedom: k = N–1. Here n = n1 + n2 + … + nN; ni is the ith measurement (\(i = \overline {1,N} \) ); and N is the total number of measurements. The proposed method of assessing the nonuniformity is based on the statistics χ2k and X2, as proposed by Pearson in 1901 and 1904, respectively. Here X0 is intended for verification of hypothesis H0: that the empirical and statistical distributions agree. The azimuthal nonuniformity of the distribution of materials and gases in the blast furnace is based on the consistency of the Pearson statistics χ2k and X2. The quantile factor q is employed if the calculations of X2 do not employ the frequency of the measured quantities but, by analogy, the magnitudes of the physical quantities. In this method, after correction, X2 is used to assess the deviation p from a uniform distribution (the nonuniformity factor): p = p(χ2k), p ∈ (0; 1–α); χ2k= X2co-qX2. If X2 and χ2k are to be consistent for measurements of physical quantities (the temperature or pressure) or of materials (friable materials, gases), X2 must be corrected so that qX2max ≈ χ2k(α), X2max ⊂ (X21, …,X2M), where M is the number of experiments for which X2 is determined; χ2k(α) is the upper α quantile of χ2k; q is the quantile factor introduced for correction of X2; X2max is the limiting value of X2max permissible in determining the nonuniformity measure. The method is tested in estimating the relative nonuniformity of the batch components and the distribution of the azimuthal temperature for 2014- and 1370-m3 blast furnaces at OAO Magnitogorskii Metallurgicheskii Kombinat. The influence of the sequence in which the batch components are selected in the bunker of the nonconical furnace-charging system on the azimuthal nonuniformity of the materials and the smelting characteristics is analyzed.

Non-severe hypoglycaemia is associated with weight gain in patients with type 1 diabetes: Results from the Diabetes Control and Complication Trial.

It is unclear whether the frequent non-severe episodes of hypoglycaemia observed during intensive glucose control in individuals with type 1 diabetes (T1D) are associated with subsequent weight gain. We analysed the association between non-severe hypoglycaemia and weight gain in 1441 Diabetes Control and Complication Trial (DCCT) participants. Non-severe hypoglycaemia was assessed by hypo-score (ie, number of blood glucose values <70 mg/dL divided by the total number of measurements during the DCCT quarterly visits). Significant associations were observed between the hypo-score and annual and total weight gain. The annual weight gain by hypo-score tertiles was 0.8 ± 1.2 (T1), 1.3 ± 1.5 (T2) and 1.4 ± 1.3 kg/y (T3), P < .001 for T2 and T3 vs T1, and for T3 vs T2. The odds ratio for a weight gain of 1.8 kg/y was 2.14 (95% CI, 1.56-2.93) for T2, and 2.53 (95%CI, 1.85-3.45) for T3 vs T1. These differences in weight gain and in risk of weight gain remained significant after adjustment for sex, age, duration of diabetes, HbA1c at baseline and treatment arms. In conclusion, our analysis shows a significant association between non-severe hypoglycaemia and weight gain in individuals with T1D from the DCCT.

Reducing unnecessary measurements in clinical trials with multiple primary endpoints

Clinical trials often involve two or more primary endpoints. However, observing or measuring high-cost endpoints often reduces the efficiency of the study because of high medical costs, highly invasive measurements, or long-term follow-up. Further, the individual powers to demonstrate the overall efficacy of a new intervention for the multiple endpoints often differ under a given sample size. We propose an efficient clinical trial design in which the sample size for each of the endpoints is individually determined, taking into consideration both the cost and the individual power for each endpoint. We compared the efficiency of the proposed design with that of the conventional design using three variables: (1) the number of participants in the study, (2) the total number of measurements for all endpoints, and (3) the cost of enrolling the participants and obtaining the measurements for all endpoints. We extended the proposed design to a group-sequential design. Numerical examples show that the proposed design can reduce unnecessary measurements and adjust the individual powers for the endpoints, especially when the individual power for one endpoint is relatively higher than that for other endpoints in a study with multiple co-primary endpoints.

Optimum Experimental Design for Patient Specific Mathematical Leukopenia Models

Abstract: Mathematical models are essential for simulation-driven decision support for clinical doctors. For an estimation of parameters for patient specific models, values such as the number of certain blood cells need to be measured. In this paper we focus on leukopenia, a clinically important side effect arising from the treatment of leukemia with chemotherapy. A mathematical leukopenia model is presented describing the dynamics of leukocytes and we show that the standard deviations of the parameter estimates depend strongly on the timing of the measurements. We discuss the issue of measurement time points for two patients being in the consolidation phase of acute myeloid leukemia and provide optimal solutions. Optimized measurement time points and the thus enabled accurate simulations have a large impact: drug treatments can be adapted individually and patients may safely leave the hospital for longer and more convenient time intervals. The dynamics of leukocytes are modeled by a system of ordinary differential equations and the chemotherapy with cytarabine is described by a pharmacokinetics/pharmacodynamics model consisting of two compartments and a log-linear function representing the drug effect. The measurement time points are optimized by optimal experimental design. With optimal experimental design an average parameter uncertainty reduction of 57% ( Patient 1 ) and 80% ( Patient 2 ) can be achieved compared to the clinical experimental designs, with the same total number of measurements. These encouraging results motivate further research and an extension of the data basis to more patients.

Patterns of fetal lung growth in fetuses with isolated left-sided congenital diaphragmatic hernia

Objective: To evaluate right lung growth pattern in fetuses with isolated left-sided congenital diaphragmatic hernia (iL-CDH) and to analyze the pattern according to postnatal outcome. Methods: Lung-to-head ratio (LHR) and observed-to-expected LHR (O/E LHR) were obtained in 58 cases. Correlation and regression analysis for the total number of measurements, general linear models for those cases with a least three serial measurements and linear mixed effect models were used to analyze the influence of gestational age on the right lung size. Cases expectantly managed and those with fetal endoscopic tracheal occlusion were analyzed separately. Results: LHR, but not O/E LHR, increased significantly with gestational age (GA) (r = 0.43, p = 0.003 and r = −0.13, p = 0.30, respectively). According to neonatal mortality, in those fetuses that died, LHR remained unchanged and O/E LHR decreased significantly with GA (r = 0.07, p = 0.65 and r = −0.37, p = 0.02, respectively). In those cases with at least three serial measurements, the same two patterns were found. Similarly, in cases with expectant management, surviving fetuses showed a significantly higher weekly increase in LHR (p = 0.01) and a trend to a lower weekly decrease in O/E LHR (p = 0.17) than in those that died. Conclusions: Patterns of right lung growth in iL-CDH differ according to postnatal survival. Serial measurements, but not a single one, might increase the prediction of neonatal death.

Determining the optimal allocation of parameters for multivariate measurement system analysis

Measurement system analysis (MSA) plays an important role in helping organizations to improve their product quality. Usually, a gauge repeatability and reproducibility (GRR) study needs to be conducted prior to the process capability analysis for assessing the adequacy of gauge variation. In performing multivariate MSA for multivariate measurement systems, the existing multivariate precision-to-tolerance (P/T) ratio does not take the correlation coefficients among tolerances into account. Moreover, the optimal allocation of several parameters such as the number of quality characteristics (v), sample size of parts (p), number of operators (o) and replicate measurements (r) have not been considered in the multivariate GRR study either. As the total number of measurements (n) increase, the estimated total variation becomes more precise, but the related inspection time and costs will be increased as well. Striking the right balance between the precision of measurement system while still maintaining cost-effectiveness in determining the optimal allocation of opr parameters for correlated quality characteristics becomes an important issue in practical applications.In this paper, a revised precision-to-tolerance (P/T) ratio for multivariate MSA with correlated quality characteristics is proposed. The simulation results show that our revised P/T ratio outperforms the existing ones in terms of MSE and MAPE. We have also found that two parameters (number of parts p and a total number of measurements n) significantly affect the expected length of confidence interval of P/TR. A reference table with the optimal allocation of por parameters is constructed accordingly if the inspection cost is limited. Finally, a numerical example with a step-by-step procedure for conducting a MGRR study is given to illustrate the appropriateness of our proposed P/T ratio. Hopefully, it can be served as a useful guideline for quality practitioners when performing a multivariate measurement system analysis in industries.

K-Optimal Gradient Encoding Scheme for Fourth-Order Tensor-Based Diffusion Profile Imaging.

The design of an optimal gradient encoding scheme (GES) is a fundamental problem in diffusion MRI. It is well studied for the case of second-order tensor imaging (Gaussian diffusion). However, it has not been investigated for the wide range of non-Gaussian diffusion models. The optimal GES is the one that minimizes the variance of the estimated parameters. Such a GES can be realized by minimizing the condition number of the design matrix (K-optimal design). In this paper, we propose a new approach to solve the K-optimal GES design problem for fourth-order tensor-based diffusion profile imaging. The problem is a nonconvex experiment design problem. Using convex relaxation, we reformulate it as a tractable semidefinite programming problem. Solving this problem leads to several theoretical properties of K-optimal design: (i) the odd moments of the K-optimal design must be zero; (ii) the even moments of the K-optimal design are proportional to the total number of measurements; (iii) the K-optimal design is not unique, in general; and (iv) the proposed method can be used to compute the K-optimal design for an arbitrary number of measurements. Our Monte Carlo simulations support the theoretical results and show that, in comparison with existing designs, the K-optimal design leads to the minimum signal deviation.

Peer-to-Peer Compressive Sensing for Network Monitoring

Monitoring large-scale networks is a critical yet challenging task. Enormous number of nodes and links, limited power, and lack of direct access to the entire network are the most important difficulties. In applications such as network routing, where all nodes need to monitor the status of the entire network, the situation is even worse. In this letter, a collaborative model in which nodes pick up information from measurements generated by other nodes is proposed. Using this model, for the first time, an upper bound is derived for the number of measurements that each node must generate, such that the expected number of measurements observed by each node is sufficient to provide a global view of the entire networked data. Finally, by using this upper bound, an efficient optimization method is introduced to minimize the total number of measurements. The feasibility and accuracy of the proposed method is verified through extensive numerical simulations.

Reconstruction of bipartite states via unambiguous state discrimination and mutually unbiased measurement

We propose a scheme for reconstructing an unknown two-particle mixed state by means of unambiguous state discrimination. In this protocol, an ancillary particle is introduced for distinguishing four nonorthogonal states. The discrimination process is performed by a bipartite unitary operation on the two-particle system and the ancilla followed by a von Neumann measurement on the ancilla. Then the original two-particle system is measured in mutually unbiased bases. Consequently, the two-particle mixed state can be reconstructed. Furthermore, the total number of measurements in this protocol is less than that of the standard quantum tomography, thus the quantum resources is saved. Additionally, the nonorthogonal states discrimination and mutually unbiased measurement can be experimentally achieved, therefore our protocol may be realized with the current technology.

Experimental demonstration of error-insensitive approximate universal-not gates

We propose and experimentally demonstrate an approximate universal-NOT (U-NOT) operation that is robust against operational errors. In our proposal, the U-NOT operation is composed of stochastic unitary operations represented by the vertices of regular polyhedrons. The operation is designed to be robust against random operational errors by increasing the number of unitary operations (i.e., reference axes). Remarkably, no increase in the total number of measurements nor additional resources are required to perform the U-NOT operation. Our method can be applied in general to reduce operational errors to an arbitrary degree of precision when approximating any anti-unitary operation in a stochastic manner.

Optimizing the Fraction of Expensive Direct Measurements in an Exposure Assessment Study

When designing studies to assess occupational exposures, one persistent decision problem is the selection between two technical methods, where one is expensive and statistically efficient and the other is cheap and statistically inefficient. While a few studies have attempted to determine the relatively more cost-efficient design between two technical methods, no successful study has optimized the fraction of the expensive efficient method in a combined technique intended for long-run exposure assessment studies. The purpose of this study was therefore to optimize the fraction of the expensive efficient measurements by resolving a precision-requiring cost minimization problem. For an indefinite total number of measurements, the total cost of a working posture assessment study was minimized by performing only expensive direct technical measurements. However, for a definite total number of measurements, the use of combined techniques in assessing the posture could be optimal, depending on the constraints placed on the precision and on the research budget.

Gauge R&R studies that incorporate baseline information

The standard plan for gauge reproducibility and repeatability studies is for each of r operators to measure k parts n times for a total of N = krn measurements. These studies are usually planned and conducted in isolation ignoring available baseline data generated by the measurement system used for inspection or process control. This article has two goals. First, it quantifies the substantial benefits of incorporating baseline data into the analysis of measurement study data. Second, it searches for good standard plans with a fixed total number of measurements that take into account available baseline data. With operator effects being considered to be fixed, situations where the part by operator interaction is excluded from or included in the model are investigated. The analysis of the combined data is based on maximum likelihood estimation and the ranking of plans on the approximate standard errors of the estimates using the Fisher information matrix. The benefit of incorporating baseline data into the analysis is significant and most of the gains in precision can be obtained with small baseline sample sizes. In general, depending on the context and number of baseline measurements, the standard plan with either the minimum or maximum number of parts is recommended.

Efficient Experimental Estimation of Fidelity of Linear Optical Quantum Toffoli Gate

We propose an efficiently measurable lower bound on quantum process fidelity of N-qubit controlled-Z gates. This bound is determined by average output state fidelities for N partially conjugate product bases. A distinct advantage of our approach is that only fidelities with product states need to be measured while keeping the total number of measurements much smaller than what is necessary for full quantum process tomography. As an application, we use this method to experimentally estimate quantum process fidelity F of a three-qubit linear optical quantum Toffoli gate and we find that F≥0.83. We also demonstrate the entangling capability of the gate by preparing Greenberger-Horne-Zeilinger-type three-qubit entangled states from input product states.