True Summing Research Articles

Toward Accurate and Fast Summation

We introduce a new accurate summation algorithm based on the error-free summation into floating-point buckets. Our algorithm exploits ideas from Zhu and Hayes’ OnlineExactSum , but it uses a significantly smaller number of accumulators and has a better instruction-level parallelism. In the default setting, our implementation aaaSum returns a faithfully rounded floating-point approximation of the true sum. We also discuss possible modifications for the computation of reproducible, correctly rounded, and multiple precision floating-point approximations. The computational overhead for any of these modifications is kept comparably small. Numerical tests demonstrate that aaaSum performs well for very small to large problem sizes, independent of the condition number of the problem. We compare our algorithm with other accurate and high-precision summation approaches.

Cancer-Related Care Costs and Employment Disruption: Recommendations to Reduce Patient Economic Burden as Part of Cancer Care Delivery.

Cancer survivors are frequently unprepared to manage the out-of-pocket (OOP) costs associated with undergoing cancer treatment and the potential for employment disruption. This commentary outlines a set of research recommendations stemming from the National Cancer Institute'sFuture of Health Economics Research Conference to better understand and reduce patient economic burden as part of cancer care delivery. Currently, there are a lack of detailed metrics and measures of survivors' OOP costs and employment disruption, and data on these costs are rarely available at the point of care to guide patient-centered treatment and survivorship care planning. Future research should improve the collection of data about survivors' OOP costs for medical care, other cancer-related expenses, and experiences of employment disruption. Methods such as microcosting and the prospective collection of patient-reported outcomes in cancer care are needed to understand the true sum of cancer-related costs taken on by survivors and caregivers. Better metrics and measures of survivors' costs must be coupled with interventions to incorporate that information into cancer care delivery and inform meaningful communication about OOP costs and employment disruption that is tailored to different clinical situations. Informing survivors about the anticipated costs of their cancer care supports informed decision making and proactive planning to mitigate financial hardship. Additionally, system-level infrastructure should be developed and tested to facilitate screening to identify survivors at risk for financial hardship, improve communication about OOP costs and employment disruption between survivors and their health-care providers, and support the delivery of appropriate financial navigation services.

Approximate Adiabatic Logic for Low-Power and Secure Edge Computing

Approximate computing is a promising approach for error-tolerant applications running on the Internet-of-Things edge devices to reduce power consumption. However, approximate computation is susceptible to side-channel attacks, such as attacks based on differential power analysis (DPA). Energy efficiency could be further enhanced by applying adiabatic logic in approximate edge computing while increasing its protection against the side-channel attacks. As a case study, we are presenting two approximate adders based on adiabatic logic to illustrate the benefits of approximate computation combined with adiabatic logic. The proposed approximate adders leverage the dual-rail property of adiabatic logic to minimize the overall size and further decrease energy consumption. In this article, the first design is true sum approximate adder (TSAA), whereas the second design is True Carry-out Approximate Adder (TCAA). There are fewer transistors in adiabatic logic-based TSAA and TCAA compared to CMOS-based accurate mirror adder (AMA). At 12.5-MHz operating frequency and 45-nm technology node, the adiabatic TSAA and TCAA achieved power savings of 95.4% and 95.48% and energy savings of 90.80% and 90.96% in comparison with the standard CMOS AMA. We also show that both designs proposed are more secure against DPA attacks.

Coincidence summing correction factors for 238U and 232Th decay series using the Monte Carlo method

Environmental samples analyzed in gamma spectrometry laboratories usually contain natural radionuclides such as 238U and 232Th. Using gamma spectrometry techniques is possible to estimate the activity of these radionuclides by measuring the gamma emissions of radionuclides belonging to their decay chain. Nonetheless, some of these radionuclides emit photons in cascade presenting Coincidence Summing (CS), which if not corrected, may affect the final activity quantification. The aim of this work is to apply the Monte Carlo method to calculate the True Summing Correction Factors (TSCFs) for 238U and 232Th decay series for different sample configurations (geometry and matrix) using the GEANT4 toolkit. In order to validate the results provided by GEANT4 using the RDM, the software TRUECOINC has been applied to calculate also the TSCFs. In addition, the influence of the geometry/matrix on the TSCFs is analyzed.

Summing coincidence correction for [formula omitted]-ray measurements using the HPGe detector with a low background shielding system

A Monte Carlo method based on the GEANT4 toolkit has been developed to correct the full-energy peak (FEP) efficiencies of a high purity germanium (HPGe) detector equipped with a low background shielding system, and moreover evaluated using summing peaks in a numerical way. It is found that the FEP efficiencies of 60Co, 133Ba and 152Eu can be improved up to 18% by taking the calculated true summing coincidence factors (TSCFs) correction into account. Counts of summing coincidence γ peaks in the spectrum of 152Eu can be well reproduced using the corrected efficiency curve within an accuracy of 3%.

Seeing past the Zero Sum Game in Environmental Policy Harder Than It Looks

In Nonzero: The Logic of Human Destiny, Robert Wright offers a sweeping view of human evolution that culminates in his argument that modern society has become so complex and interconnected that there are no true “zero sum” games to be played between people or institutions. Indeed, much of environmental policy rests on the promise of improving the greater good by leveraging the ubiquitous presence of nonzerosumness. But Wright’s thesis turns back on itself. There is no question that social-ecological systems (SES) are highly complex and interconnected, making true zero sum games hard to find. But the sheer complexity of massive SESs is what also makes it excruciatingly difficult to connect all the dots of the nonzero sum game within the SES. At a macro scale, nonzero sum rules; at the micro scale of the farmer seeing more water go by the farm in the river, it looks like zero sum. In this short essay I outline six reasons why seeing past these micro zero sum game is so difficult, particularly for those caught in them who consider themselves the losers: (1) mixed metrics; (2) multi-scalar nature of SESs; (3) temporal transitions; (4) distribution of costs and benefits; (5) imprecise valuation; and (6) polarizing effect of government intervention. The essay was written before the 2016 election. An Epilogue offers thoughts on its meaning.

Calculation of Coincidence Summing Correction Factors for an HPGe detector using GEANT4

The aim of this paper was to calculate the True Coincidence Summing Correction Factors (TSCFs) for an HPGe coaxial detector in order to correct the summing effect as a result of the presence of 88Y and 60Co in a multigamma source used to obtain a calibration efficiency curve. Results were obtained for three volumetric sources using the Monte Carlo toolkit, GEANT4. The first part of this paper deals with modeling the detector in order to obtain a simulated full energy peak efficiency curve. A quantitative comparison between the measured and simulated values was made across the entire energy range under study. The True Summing Correction Factors were calculated for 88Y and 60Co using the full peak efficiencies obtained with GEANT4. This methodology was subsequently applied to 134Cs, and presented a complex decay scheme.

A fast partial distortion search algorithm for motion estimation based on the multi-traps assumption

Full search has the best matching accuracy but costs the most time, while fast search algorithms can achieve a high speed but are easy to be trapped in local minimums. To compensate the shortcomings of the existing algorithms, this paper proposes a fast partial distortion motion estimation algorithm based on the multi-traps assumption (MT-PDS). It mainly consists of three steps: (1) estimate the number of traps in the search area, (2) obtain the positions of the traps by using the k-th (k=0,1,2,…15) partial distortion, which contributes most to the true sum of absolute difference (SAD), to perform the coarse search, and (3) get the positions of the deepest traps and search around them to get the global minimum. Besides, the proposed algorithm also introduces an adaptive search method and a sparse search pattern, which further reduce the computations. Experimental results show that the proposed MT-PDS is about 160 times faster than the full search on average; and the speed-up can achieve over 180 times for the low motion contents. What is more, it only degrades the quality by −0.0178dB and slightly increases the bit rate by 0.735%, which can be considered ignorable. Those advantages make the MT-PDS a very useful tool in real time applications, such as video compression, pattern recognition, target tracking, etc.

Evaluating the agreement between the empirical volumes of tumor lesions and the estimated volumes of tumor lesions based on the longest diameter.

635 Background: Tumor lesions are commonly evaluated by RECIST or WHO criteria, which involves reducing the development of a three-dimensional tumor to a two-dimensional process. However, volume measurements might reflect the clinical impact of the disease process more precisely. Therefore, we investigated if the volume of a tumor lesion can be reconstructed from RECIST- or WHO-based measurements. Methods: 20 colorectal cancer patients underwent routine staging MDCT examinations as part of the multicenter phase II CIOX trial comparing cetuximab + XELOX versus cetuximab + XELIRI. Two hepatic target lesions per patient were defined at baseline and measured using 1) semi-automated volumetry (Siemens Syngo Via Oncology, Siemens Healthcare) with manual correction and 2) semi-automated measurement of the longest diameter (LD) according to RECIST 1.1 and the corresponding longest orthogonal diameter (LOD). Patient lesions were followed over time using the same measurement strategies. An algorithm was developed for reconstructing the volume of a lesion based on the LD and the corresponding LOD. Agreement of the volume data generated by both methods was analyzed by a Bland-Altman plot. The limits of agreements were calculated using a variance components model considering repeated tumor assessments based on the log-transformed sum over the volume of a patient’s lesions. Results: 151 lesions from the 20 patients were measured at 73 tumor assessments. Volume was slightly overestimated by the algorithm compared to the volumetric measurements (p = 0.07). The Bland-Altman plot showed good agreement (mean difference −0.05, limits of agreement [−0.40, 0.30]). As expected, three out of the 73 measurements fell outside the limits of agreement. Conclusions: The proposed algorithm for the WHO-based reconstruction of the tumor volume provides a good approximation to the true sum of the volumes of the lesions. In future studies, volumetric tumor information can be included even if not all centers have full volumetric software available. This enables further research on the impact of changes in tumor volume on disease prognosis and/or prediction of treatment efficacy.

Multiuser Diversity for Successive Zero-Forcing Dirty Paper Coding: Greedy Scheduling Algorithms and Asymptotic Performance Analysis

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Dirty paper coding (DPC) scheme is the capacity achieving transmission technique in multiuser MIMO downlink channels. As a suboptimal solution to DPC, successive zero-forcing DPC (SZF-DPC) has been proposed recently. The zero-interference constraint in designing the precoding matrices limits the number of supportable users. In this correspondence, we propose three low-complexity suboptimal user scheduling algorithms to exploit the multiuser diversity gain in SZF-DPC as the number of users grows. The first algorithm greedily maximizes the true sum rate. The second algorithm is based on eigenvalues. The third algorithm relies on the diagonal elements of the effective channel matrix since eigenvalues and diagonal entries of a Hermitian matrix have a strong relationship. Simulation results show that the proposed scheduling algorithms can obtain a significant fraction of sum rate of the optimal solution. Furthermore, the performance analysis is provided to prove that the proposed user selection algorithms can achieve the same asymptotic sum rate as that of DPC. </para>

New sorting-based partial distortion elimination algorithm for fast optimal motion estimation

In this paper, we present a new sorting-based partial distortion elimination (PDE) algorithm for fast optimal motion estimation. By analyzing the contributions to the true sum of absolute differences (SAD), we found that there is a close relationship between the distances from the mean value of the current block and the contributions to the true SAD. By sorting the distances from the pixels to the current block and subtracting them from a mean value, then applying this order to the typical PDE, we can eliminate impossible candidates faster and save substantial computations. Experimental results show that the proposed algorithm reduces computational complexity by about 45% on average compared with the typical PDE.

Inverse Born approximation for the generalized nonlinear Schrödinger operator in two dimensions

This work deals with the inverse scattering problems for two nonlinear Schrödinger operators in two dimensions. One operator has a finite combinations of any power-like nonlinearity and another has a saturation-like nonlinearity. Both these operators can be met in nonlinear optics. The coefficients of these operators are assumed to be the real-valued functions from LlocP(R2) with certain behaviour at infinity. We prove Saito's formula for both operators which implies the uniqueness result and a representation formula for a sum of the unknown coefficients in the sense of tempered distributions. What is more, we prove that the leading order singularities of the sum can be obtained exactly by the inverse Born approximation method from general scattering data at arbitrarily large energies. Especially, we show for the functions in LlocP(R2), for certain values of p, that the approximation agrees with the true sum up to the functions from the Sobolev spaces H8(R2). In particular, for the sum being the characteristic function of a smooth bounded domain this domain is uniquely determined by this scattering data.

INVERSE BORN APPROXIMATION FOR THE GENERALIZED NONLINEAR SCHRÖDINGER OPERATOR IN TWO DIMENSIONS

This work deals with the inverse scattering problems for the two-dimensional Schrödinger equation [Formula: see text] with a power-like nonlinearity, where the real-valued unknown functions αlon belong to [Formula: see text] with certain special behaviour at infinity. We prove Saito's formula which implies the uniqueness result and a representation formula for a sum of the functions αlin the sense of tempered distributions. What is more, we prove that the leading order singularities of this sum can be obtained exactly by the inverse Born approximation method from general scattering data at arbitrarily large energies. Especially, we show for the functions in Lp, for certain values of p, that the approximation agrees with the true sum up to the functions from the Sobolev spaces. In particular, for the sum being the characteristic function of a smooth bounded domain this domain is uniquely determined by this scattering data.

The Analysis of Randomized Response Sum Score Variables

SummaryRandomized response (RR) is an interview technique that ensures confidentiality when questions are sensitive. In RR the answer to a sensitive question depends to a certain extent on a probability mechanism. As a result the observed data are partially misclassified, and the true status of the respondent is obscured. RR data are commonly analysed in a univariate way, with models that relate the observed responses to the prevalence of the sensitive characteristic, and with the more recent logistic regression models that relate the sensitive characteristic to a set of covariates. In an RR design with multiple sensitive questions, interest is usually not confined to the univariate prevalence and regression parameter estimates. Additional multivariate information may be obtained from an RR sum score variable, assessing the sum of sensitive characteristics that are associated with the respondent. However, the construction of an RR sum score variable is by no means straightforward, which might explain why sum scores have not yet been used within the context of RR. We present two models for RR sum score variables: the RR sum score model that relates the observed sum scores to the true sum scores and the RR proportional odds model that relates the true sum scores to covariates. The models are applied to RR data from a Dutch survey on non-compliance with social security regulations.

Inverse Born approximation for the nonlinear two-dimensional Schrödinger operator

This work deals with the inverse Born approximation for the nonlinear two-dimensional Schrödinger equation with cubic nonlinearity where the real-valued unknown functions q and α belong to with some behaviour at infinity. The following problem is studied: to estimate the smoothness of the terms from the Born sequence which corresponds to the scattering data with all arbitrary large energies and all angles in the scattering amplitude. These smoothness estimates allow us to conclude that the leading order singularities of the sum of unknown functions q and α can be obtained exactly by the Born approximation. Especially, we show for the functions in Lp, for certain values of p, that the approximation agrees with the true sum up to the functions from the Sobolev spaces. In particular, for the sum being the characteristic function of a smooth bounded domain this domain is uniquely determined by these scattering data.

Public-good valuation and intra-family allocation

I derive values of marginal changes in a public good for two-person households, measured alternatively by household member i’s willingness to pay (WTP) for the good on behalf of the household, WTP i (H), or by the sum of individual WTP values across family members, WTP(C). Households are assumed to allocate their resources in efficient Nash bargains over private and common household goods. WTP i (H) is then defined by trade-offs between the public good and the household good, and WTP(C) by trade-offs of between the public good and private goods. WTP i (H) is found to be higher (lower) than WTP(C) when member i has a relatively high (low) marginal valuation of the public good, but tends on average to equal WTP(C). As a consequence, individuals tend to represent households correctly on average when questioned about the household’s WTP for a public good, even when they are purely selfish and answer truthfully. Adding all members’ WTP answers on behalf of the household then leads to double counting. Pure and paternalistic altruism (the latter attached to consumption of the public good) move each member’s WTP on behalf of the household closer to the true sum of individual WTP, but only paternalistic altruism raises this sum.

Novel Concepts for the Immunological Detection of Bound Residues

Immunoassays could be applied successfully to the determination of bound residues in soil and other complex matrices. Nevertheless, there was some doubt whether these assays could be regarded as quantitative and selective. We present some results, which imply that several approaches are quite promising. One approach is based on a non-competitive saturation immunoassay, which evens out the different cross-reactivities of the bound species. This may lead to a true molar sum value, which is not an equivalent concentration. For competitive assays, a method for the determination of the affinity constant(s) of the bound species is discussed. This would enable a correction for the cross-reactivity. The selectivity problem could be diminished very much, too. The application of special blocking reagents and the use of inhibition tests essentially solved the problem of non-specific binding (NSB). In addition, it could be proven experimentally that adsorbed analytes do not disturb the non-competitive assays, which have been suspected to be highly selective for covalently bound residues.

Plausible upper bounds: are their sums plausible?

Quantitative cancer risk assessments are typically expressed as plausible upper bounds rather than estimates of central tendency. In analyses involving several carcinogens, these upper bounds are often summed to estimate overall risk. This begs the question of whether a sum of upper bounds is itself a plausible estimate of overall risk. This question can be asked in two ways: whether the sum yields an improbable estimate of overall risk (that is, is it only remotely possible for the true sum of risks to match the sum of upper bounds), or whether the sum gives a misleading estimate (that is, is the true sum of risks likely to be very different from the sum of upper bounds). Analysis of four case studies shows that as the number of risk estimates increases, their sum becomes increasingly improbable, but not misleading. Though the overall risk depends on the independence, additivity, and number of risk estimates, as well as the shapes of the underlying risk distributions, sums of upper bounds provide useful information about the overall risk and can be adjusted downward to give a more plausible [perhaps probable] upper bound, or even a central estimate of overall risk.

Latency of unit responses in cochlear nucleus determined in two different ways.

The latency revealed by poststimulus time histograms of the responses of single units in the cochlear nucleus to tone bursts was compared with the latency of the change in discharge frequency in response to small increments in the amplitude of the stimulus. The latter was derived on the basis of statistical signal analysis of the discharge pattern in response to tones amplitude modulated with pseudorandom noise. The "step response" of the system was computed by time integration of the cross covariance between modulation and spike density. The following observations can be made: 1. The latency of the responses to tone bursts always decreased with increasing sound intensity, whereas the latency of the step response was almost constant for intensities from immediately above threshold to the highest intensity used (60-70 dB above threshold). 2. In most units the latency revealed by the PST histogram of the responses to tone bursts approached the value of latency of the step response asymptotically. 3. In some units with longer latency, the latency of the response to tone bursts was many times greater than the latency of the step response, even at high sound intensities. 4. A histogram of latency values of the step response of the units studied showed narrow peaks at 2.8 and 4.7 ms. 5. On the basis of the present results it is concluded that the latency values of the step response represent the true sum of synaptic and axon dendritical propagation delay, whereas the latency of the responses to tone bursts also includes the temporal summation at the synaptic level.

Decay of 59.3 min 128Sn to levels of 128Sb

Abstract The γ-ray spectra associated with the decay of 59.3 min 128 Sn have been measured with Ge(Li) detectors. In order to recognize γ-rays of 128 Sn and 128m Sb, the decay and/or growth of γ-rays emitted from a tin sample separated chemically from fission products were measured. The decay of 128 Sn is followed by the intense Sb X-rays and 32.1, 45.8, 75.1, 80.9, 115.9, 152.6, 404.4, 482.3, 557.3 and 680.2 keV γ-rays. On the basis of the measured singles and γ-γ coincidence spectra and the analysis of intensities of true sum peaks, a new decay scheme has been constructed. The 10.0 min isomer in 128 Sb decays by β-emission (96.4%) to excited levels in 128 Te and by an isomeric transition (3.6 %) to the 9.1 h ground state.