Adjustment Procedure Research Articles

Structural reliability analysis based on probability density evolution method and stepwise truncated variance reduction

To address the substantial computational burden associated with probability density evolution method (PDEM) in structural reliability analysis, this study proposes a novel look-ahead learning function named stepwise truncated variance reduction (STVR), integrating polynomial chaos Kriging (PCK) and PDEM. Three key features of STVR are highlighted. First, it enables quantifying the maximum reduction in predictive errors of PCK within the regions of interest (ROI) when adding a new point. Second, closed-form expression for STVR is derived through Kriging update formulas, eliminating the need for computationally intensive Gauss–Hermite quadrature or extensive conditional simulations of PCK. Third, a dynamic adjustment procedure is proposed for the probability level-related parameter in STVR, with the aim of achieving a good balance between the exploitation and exploration of ROI during the sequential experimental design process. The performance of STVR is demonstrated through two benchmark analytical functions and three numerical examples of varying complexity. Results indicate that the dynamic adjustment procedure for the probability level-related parameter in STVR outperforms the empirical setting of a minor value. Then, STVR proves more advantageous than existing pointwise and look-ahead learning functions, particularly in addressing complex dynamic reliability problems.

Development of a New Generation High Crushing Capacity Jaw Crusher with an Automatically Adjusted Closed Side Settings

The design and development of a new generation high crushing capacity jaw crusher, developed for the first time in Turkey and whose Closed Side Settings (CSS) may be automatically adjusted hydraulically, were investigated in this study. The calculations for the crusher developed for this purpose were included in the paper. The design modifications made to expand the crusher's jaw stroke from 27 mm to 40 mm were documented, and the capacity increase resulting from this was theoretically calculated and proven by a wide range of field tests conducted after the jaw crusher was manufactured. Field testing and their findings were also thoroughly covered in the paper. The forces on the crusher jaw and bearings, the crusher body geometry and crusher material (via fatigue analysis), and the dynamic performance of the system (via vibration analysis of the carrier system) were examined as the outcome of the FEM (Finite Element Method) and DEM (Discrete Element Method) analyses performed after the theoretical calculations. With improvements made based on the findings gained, the theoretical and practical harmony of the created jaw crusher system was realized. Field testing has proven that the adjustment procedure takes no more than 3 minutes and requires no human participation. As a result of this research, a patent application for the created automation algorithm was filed.

Kontrastlı BT'nin Karaciğer Lezyonlarının Karakterizasyonunda FDG PET'e Katkısı ve Kantitatif Etkileri

Background: The goals of this study was to evaluate the diagnostic capability of enhanced/unenhanced 18F-FDG-PET/CT scans for identifying primary-secondary liver malignancies in terms of size and localization, to decide the quantitative impact of contrast agent on the SUVmax values of liver lesions and normal liver tissue, and to assess the impact in SUVmax metrics following contrast substance administration. Materials and Methods: This was a prospective research that included patients with suspicious primary and secondary hepatic cancers. Patients had non-enhanced & enhanced regional PET/CT examinations. The dimen-sion, position, densities (HU), visually assessment outcome, and SUVmax values for all pathological lesions were recorded, as well as the HU and SUVmax data of normal hepatic tissue. Results: There were 97 liver lesions in total. Visually assessment outcome of lesions, the introduction of a contrast substance considerably enhanced the HU and SUVmax measurements for normal hepatic tissue. The HU measurements for lesions bigger than 1cm increased statistically significantly, as did the SUVmax levels of centralized lesions bigger than 1cm. The attenuation adjustment procedures, resulted in an average inaccuracy in computed SUVmax values at the ratio of %5 for normal liver tissue and %6 for all hepatic pathologies follow-ing the contrast substance delivery. Conclusions: The inclusion of contrast substance increases the identification, localization, and characterization of the liver lesions with PET/CT substantially.

Balancing the Relationship Between the Union and Member States through the Market Process

There are mainly two paths to fiscal discipline within a federation or within a monetary union: either through markets or through hierarchy. By establishing the no-bailout clause, the Stability and Growth Pact and the Excessive Deficit Procedure, it was thought that the Maastricht Treaty had chosen market mechanisms to achieve that objective. However, the financial crisis showed the severe shortcomings of the model, marking a shift towards surveillance. This article argues that such failure was not due to the market mechanism but by flawed institutional choices. By establishing a procedure for fiscal adjustment, Member States cast doubt on the credibility of the no-bail out clause and took matters into the political realm. As a result, the political process was at the forefront since inception. There are several ways to deliver a certain social goal. Accordingly, goal choice and institutional choice are inextricably linked because it is the institutional choice which connects goals with their legal or public policy results. Importantly, to choose the best avenue comparative institutional analysis needs to be conducted. After briefly considering the political process, this article purports that other processes should be fully explored. When addressing the financial crisis in multi-level governance, some alternatives have already been employed: state default and supranational bailout. Within the EMU, no State has defaulted on its debt obligations prior to receiving a bailout. However, there is room to explore an option that would be based on market mechanisms with judicial elements while reducing dependence on the political process in the long-term: allowing Member States to orderly default on their debts. The article discusses its main problems, constitutional admissibility and democratic necessity.

Ocular-oral synkinesis caused by partial injury of the zygomatic and buccal branches of the facial nerve after mid-face trauma

BackgroundFacial nerve paralysis induced by acute traumatic facial nerve injuries limited to the zygomatic and buccal branches shows unique complication symptoms, such as strong co-contractions of the lower facial muscles around the lips during voluntary eye blinking (ocular-oral synkinesis). We investigated the characteristics of facial complications after facial nerve injury in the mid-face area and report the treatment results. MethodsA total of 21 patients with facial nerve injuries on the zygomatic and/or buccal branches were evaluated for the degree of facial synkinesis and mouth asymmetry. The patients with mild to moderate symptoms were treated with physical rehabilitation therapy combined with botulinum toxin (Botox) injection, and the patients with severe or uncontrolled symptoms were treated with surgical therapy. ResultsInitial/final mean synkinesis scores and mouth asymmetry degrees were 2.17/1.75 and 0.85/0.66 in the physical therapy group, and 3.11/0.78 and 2.41/-0.31 in the surgery group. Physical therapy with Botox injection alone did not result in significant improvements in synkinetic symptoms of the patients with mild to moderate synkinesis (p>0.05), whereas surgical therapy resulted in significant improvements in both synkinesis and mouth asymmetry (p<0.05). ConclusionsSurgical treatment is an effective adjustment procedure for management of facial complications of severe or uncontrolled synkinesis after facial nerve injury in the mid-face area.

The ‚Target Trial Emulation‘ for CAR-T in the AMNOG

The concept of ‚target trial emulation‘ and propensity score-based adjustment procedures are recommended methods for minimising systematic bias in indirect comparisons without a bridging comparator. Based on the comparison of the single-arm evidence for the CAR-T Ciltacel with data from the LocoMMotion study, which was recognised in the medical community as the best prospective study on the standard of care for multiple myeloma with multiple prior treatments, the application of the concept in the AMNOG is presented. The comparison and the dramatic survival benefit shown with Ciltacel, the validity and clinical significance of which is confirmed by medical experts, contrasts with the complete rejection by the G-BA. This discrepancy is worth looking back on.

Clinical Manifestations.

Racial and ethnic disparities in ADRD diagnosis are well documented but remain poorly understood. Clinical ADRD diagnosis relies on neuropsychological assessment, which is interpreted by comparing individual performance to demographically adjusted reference group norms. Differential use of demographic adjustment procedures and sources of normative data may compromise diagnostic accuracy of neuropsychological findings in diverse individuals. Using two different demographic adjustment approaches derived from two distinct normative samples, we generated cognitive impairment categories and evaluated their associations with longitudinal trajectories of independent executive functioning and memory scores. Participants were 717 older adults (age: 77.5±6.9, 56% women) enrolled in the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study who completed up to 3 annual visits. The main predictor was cognitive impairment category (no impairment, single-domain, multiple-domain) based on Uniform Data Set Neuropsychological Battery (UDSNB) scores at baseline. UDSNB scores were either demographically unadjusted or adjusted (age, sex, education, and race/ethnicity) using data from the National Alzheimer's Coordinating Center (NACC; N = 8313, 16% Black, 84% White) or KHANDLE (N = 397, 26% Asian, 18% Black, 30% LatinX, 26% White) samples. Linear mixed effect models were used to examine the associations between differentially derived cognitive impairment categories with longitudinal changes on episodic memory and executive functioning composites from an independent cognitive battery (Spanish and English Neuropsychological Assessment Scales, SENAS). Cognitive impairment categories derived from the KHANDLE sample were more strongly associated in all four racial and ethnic groups with longitudinal decline on episodic memory compared to the NACC sample-derived categories (Figure 1). Similar, albeit attenuated, effects were observed in relation to longitudinal decline on the executive function composite. There were no clear differences in the associations between cognitive impairment categories with executive functioning or memory decline using demographically adjusted vs. unadjusted scores. Our results highlight the need for greater representation of diverse individuals in normative samples underlining the limitations of the NACC-derived normative algorithms for cognitive assessment of individuals from diverse populations. Further investigations into the clinical value of the practice of demographic adjustments are also warranted.

Whole-body magnetic resonance imaging in two minutes: cross-sectional real-time coverage of multiple volumes.

This work describes a novel technique for rapid and motion-robust whole-body magnetic resonance imaging (MRI). The method employs highly undersampled radial fast low angle shot (FLASH) sequences to cover large volumes by cross-sectional real-time MRI with automatic slice advancement after each frame. The slice shift typically amounts to a fraction of the slice thickness (e.g., 10% to 50%) in order to generate a successive series of partially overlapping sections. Joint reconstructions of these serial images and their respective coil sensitivity maps rely on nonlinear inversion (NLINV) with regularization to the image and sensitivity maps of a preceding frame. The procedure exploits the spatial similarity of neighboring sections. Whole-body scanning is accomplished by measuring multiple volumes at predefined locations, i.e., at fixed table positions, in combination with intermediate automatic movements of the patient table. Individual volumes may take advantage of different field-of-views, image orientations, spatial and temporal resolutions as well as contrasts. Preliminary proof-of-principle applications to healthy subjects at 3 T without cardiac gating and during free breathing yield high-quality anatomic images with acquisition times of less than 100 ms. Spin-density and T1 contrasts are obtained by spoiled FLASH sequences, while T2-type (i.e., T2/T1) contrast results from refocused FLASH sequences that generate a steady state free precession (SSFP) free induction decay (FID) signal. Total measuring times excluding vendor-controlled adjustment procedures are less than two minutes for a 100 cm scan that, for example, covers the body from head to thigh by three optimized volumes and more than 1,300 images. In conclusion, after demonstrating technical feasibility the proposed method awaits clinical trials.

Resonator-Loaded Waveguide Notch Filters with Broad Tuning Range and Additive-Manufacturing-Based Operating Frequency Adjustment Procedure

This article presents a new class of ring-resonator-loaded waveguide notch filters with a broad tuning range, low cost, and improved performance. The proposed approach employs a complementary asymmetric split-ring resonator coupled to a microstrip transmission line and excited in a rectangular waveguide. An equivalent circuit model is proposed to explain the working principle of the proposed notch filter. The adjustment of the operating frequency is based on the additive manufacturing of a metallic copper patch allocated on the microstrip transmission line, which enables extensive tuning capabilities and consistent performance with minimum variations across the tuning window. For demonstration purposes, a filter employing a WR-28 waveguide and photolithography-manufactured resonator is prototyped and experimentally validated. The measured results indicate a broad 8 GHz tuning range with a consistent insertion loss, ranging from 23.4 to 31.4 GHz. An inverse regression model is constructed using measurement data obtained for tuning patches of various sizes, which allows for determining the relationships between the operating frequency and the copper patch size. The resulting calibration curve enables rapid filter tuning to the required frequency by inserting metallic patches of the model-predicted size.

Automated Control of the Fresh State of Industrial Concrete Behaviour by Rheometer Test Adjustment

This study aimed to develop a rheometer prototype and define a procedure for adjusting the automated control of the fresh state of concrete. Sixteen batches were produced, and their fresh behaviour was measured at different testing times by applying the Abrams cone and flow curve test (FCT) as the rheological protocol. During this test, the yield stress and plastic viscosity of the concretes were measured in relative units. The rheometer prototype was used to define a new protocol to select the most suitable rheometer impeller arrangement and optimal FCT configuration. This protocol considers the torque at the end of the breakdown period, torque reduction during the breakdown period, segregation, and negative values of the yield stress in relative units. This protocol also enabled an iterative adjustment procedure, facilitating the use of a rheometer for the automated control of the homogeneity and behaviour of fresh concrete, as well as real-time decision making.

Corrosion Rate-Based Adjustment of Plastic Hinge Parameters of Corroded RC Elements

In line with the trend towards predictive seismic codes adopting the performance-based design method, this paper presents an integrated protocol to determine the degraded hysteresis parameters of corroded RC hinges based on relationships developed for this purpose together with a calibration procedure using the random-mutation hill-climbing algorithm. The adjustment procedure is integrated into the material library of the OpenSees software and used to perform nonlinear dynamic analyses to investigate the seismic performance of a typical bridge with affected piers at different corrosion levels. In practice the proposed procedure permits to assess the seismic performance of existing or new structures for a given corrosion rate distribution.

Multiple test procedures of disease prevalence based on stratified partially validated series in the presence of a gold standard

ABSTRACT This paper discusses the problem of disease prevalence in clinical studies, focusing on multiple comparisons based on stratified partially validated series in the presence of a gold standard. Five test statistics, including two Wald-type test statistics, the inverse hyperbolic tangent transformation test statistic, likelihood ratio test statistic, and score test statistic, are proposed to conduct multiple comparisons. To control the overall type I error rate, several adjustment procedures are developed, namely the Bonferroni, Single-step adjusted MaxT, Single-step adjusted MinP, Holm’s Step-down, and Hochberg’s step-up procedures, based on these test statistics. The performance of the proposed methods is evaluated through simulation studies in terms of the empirical type I error rate and empirical power. Simulation results show that the Single-step adjusted MaxT procedure and Single-step adjusted MinP procedure generally outperform the other three procedures, and these two test procedures based on all test statistics have satisfactory performance. Notably, the Single-step adjusted MinP procedure tends to exhibit higher empirical power than the Single-step adjusted MaxT procedure. Furthermore, the Step-down and Step-up procedures show greater power compared to the Bonferroni method. The study also observes that as the validated ratio increases, the empirical type I errors of all test procedures approach the nominal level while maintaining higher power. Two real examples are presented to illustrate the proposed methods.

A Randomization-Based Theory for Preliminary Testing of Covariate Balance in Controlled Trials

Randomized trials balance all covariates on average and are the gold standard for estimating treatment effects. Chance imbalances nevertheless exist more or less in realized treatment allocations and intrigue an important question: what should we do if the treatment groups differ with respect to some important baseline characteristics? A common strategy is to conduct a preliminary test of the balance of baseline covariates after randomization, and invoke covariate adjustment for subsequent inference if and only if the realized allocation fails some prespecified criterion. Although such practice is intuitive and popular among practitioners, the existing literature has so far only evaluated its properties under strong parametric model assumptions in theory and simulation, yielding results of limited generality. To fill this gap, we examine two strategies for conducting preliminary test-based covariate adjustment by regression, and evaluate the validity and efficiency of the resulting inferences from the randomization-based perspective. The main result is 2-fold. First, the preliminary-test estimator based on the analysis of covariance can be even less efficient than the unadjusted difference in means, and risks anticonservative confidence intervals based on normal approximation even with the robust standard error. Second, the preliminary-test estimator based on the fully interacted specification is less efficient than its counterpart under the always-adjust strategy, and yields overconservative confidence intervals based on normal approximation. In addition, although the Fisher randomization test is still finite-sample exact for testing the sharp null hypothesis of no treatment effect on any individual, it is no longer valid for testing the weak null hypothesis of zero average treatment effect in large samples even with properly studentized test statistics. These undesirable properties are due to the asymptotic non-normality of the preliminary-test estimators. Based on theory and simulation, we echo the existing literature and do not recommend the preliminary-test procedure for covariate adjustment in randomized trials.

Thermal Error Compensation Strategy in Simultaneous Laser Multilateration for Volumetric Verification

Verification systems are needed for periodic verification and calibration of robots and machine tools to maintain and increase their accuracy. One of the ways to verify the volumetric accuracy of a manufacturing system is to measure the position of its head (X, Y, Z coordinates) using measurement systems that provide these results with the appropriate precision. The laser interferometer provides results with accuracy levels suitable for robot and machine tool verification applications. However, to measure the head position of manufacturing systems (X, Y, Z coordinates), the use of laser interferometers requires a prior adjustment to a reference length, since they measure incrementally. This adjustment procedure of the measurement system introduces an error in the resulting head coordinates that depends on the environmental conditions and the material of the standard element used to materialize the reference length. This paper analyzes the temperature effect in the adjustment process and how temperature errors introduced in said process affect the head 3D coordinates calculation of the Manufacturing System under inspection.

Scaling procedures in climate science: Using temporal scaling to identify a paleoclimate analogue

Using past episodes of climate change as a source of evidence to inform our projections about contemporary climate change requires establishing the extent to which episodes in the deep past are analogous to the current crisis. However, many scientists claim that contemporary rates of climate change (e.g., rates of carbon emissions or temperature change) are unprecedented, including compared to episodes in the deep past. If so, this would limit the utility of paleoclimate analogues. In this paper, I show how a data adjustment procedure called “temporal scaling,” which must be applied to both contemporary and past rate data, complicates the claim that contemporary rates are truly unprecedented. On top of giving actionable recommendations to scientists, this paper advances the philosophical literature concerning the use of models that are known to be somewhat disanalogous to their target systems.

MmStress

Long-term exposure to stress hurts human's mental and even physical health,and stress monitoring is of increasing significance in the prevention, diagnosis, and management of mental illness and chronic disease. However, current stress monitoring methods are either burdensome or intrusive, which hinders their widespread usage in practice. In this paper, we propose mmStress, a contact-less and non-intrusive solution, which adopts a millimeter-wave radar to sense a subject's activities of daily living, from which it distills human stress. mmStress is built upon the psychologically-validated relationship between human stress and "displacement activities", i.e., subjects under stress unconsciously perform fidgeting behaviors like scratching, wandering around, tapping foot, etc. Despite the conceptual simplicity, to realize mmStress, the key challenge lies in how to identify and quantify the latent displacement activities autonomously, as they are usually transitory and submerged in normal daily activities, and also exhibit high variation across different subjects. To address these challenges, we custom-design a neural network that learns human activities from both macro and micro timescales and exploits the continuity of human activities to extract features of abnormal displacement activities accurately. Moreover, we also address the unbalance stress distribution issue by incorporating a post-hoc logit adjustment procedure during model training. We prototype, deploy and evaluate mmStress in ten volunteers' apartments for over four weeks, and the results show that mmStress achieves a promising accuracy of ~80% in classifying low, medium and high stress. In particular, mmStress manifests advantages, particularly under free human movement scenarios, which advances the state-of-the-art that focuses on stress monitoring in quasi-static scenarios.

Новый подход к настройке гауссовой суррогатной модели целевой функции в задаче параметрической оптимизации проектных решений

The paper considers methods for solving the problem of design solution parametric optimization based on constructing the Gaussian surrogate model of this problem objective function. The problem is set of finding optimal values of the surrogate model free parameters (hyper-parameters), it is called the problem of its adjustment. The adjustment problem is built over the top of the surrogate model synthesis problem and has a higher computational complexity. The approach to adjusting a surrogate model is proposed, which is able to make the adjustment procedure acceptable in terms of the computational costs. This approach includes the setup and operation stages. The adjustment stage contains the following main steps: formation of a set of test objective functions; generation of a set of learning samples for each of them; determination of their characteristic features values for the generated samples; determination of the hyper-parameters optimal values for all considered test functions and learning samples; formation of a set of pairs, characteristic features of the sample--hyper-parameters optimal values; building on this basis a predictive model forecasting the hyper-parameters optimal values according to the learning sample characteristic features. For the initial problem at the operation stage, a learning sample was generated, its characteristic features were determined, and the hyper-parameters optimal values of the surrogate model were predicted. Based on the specified learning sample, the objective function surrogate model was synthesized. Using the surrogate model, the original optimization problem was solved, where the hyper-parameters predictive values were applied as the optimal values. The approach is able to provide an increase of up to 30 % in efficiency of the basic optimization algorithm

Addressing Non-ignorable Panel Attrition Using External Population Data: Analysis of Demographic Events From Survey Data

Empirical analysis of variation in demographic events within the population is facilitated by using longitudinal survey data because of the richness of covariate measures in such data, but there is wave-on-wave dropout. When attrition is related to the event, it precludes consistent estimation of the impacts of covariates on the event and on event probabilities in the absence of additional assumptions. The paper introduces an adjustment procedure based on Bayes Theorem that directly addresses the problem of nonignorable dropout. It uses population information external to the survey sample to convert estimates of event probabilities and marginal effects of covariates on them that are conditional on retention in the longitudinal data to unconditional estimates of these quantities. In many plausible and verifiable circumstances, it produces estimates of the marginal effect of covariates closer to the true unconditional quantities than the conditional estimates obtained from estimation using the survey data alone.

Optimization consensus analysis for group decision making in view of non-transferable and transferable allocation schemes

Most practical decision-making problems commonly contain several alternatives evaluated by more than one decision maker (DM) according to the built criteria system. It is known as multi-criteria group decision making problems. The decision-making results should be based on highly similar individual opinions to derive the most suitable choice. Nevertheless, the divergence of individual judgments is usually significant due to various subjective and objective reasons. In this case, some DMs need to modify their judgments to derive final results, the consensus adjustment in group decision making. Like supply chain management, the centralized consensus process can minimize individual adjustments under the set consensus condition. Based on the hypothesis of rational humans that individuals always pursue maximum benefits, this paper proposes an iterative consensus process in a centralized environment. According to non-consensus adjustments, the iterative procedure contains non-transferable and transferable two parts. When the non-transferable consensus adjustment procedure is completed, the transferable consensus adjustment procedure is activated using an asymmetrical Nash bargaining game allocation mechanism. Additionally, a case study is provided to demonstrate the efficaciousness and practicality of the new method. Meanwhile, sensitivity and comparison analyses are done.

Comparison of the statistical methods for genome-wide association studies on simulated quantitative traits of domesticated goats (Capra hircus L.)

Genome-wide association studies (GWAS) are one of the essential methods used to find associations between phenotypes and genes. The main problem in GWAS methods is false positives that occur from family relationships and population structure. In this study, the performances and powers of traditional and state-of-the-art statistical methods used in genome-wide association studies were compared on nine simulated quantitative traits using genotypic data of the domesticated goats (Capra hircus L.). The traits were simulated with varying degrees of heritability from 0.05 to 0.8. The findings revealed that Blink and FarmCPU are the outperforming methods to control false positives more efficiently for the medium and high heritability traits. At the same time, Blink promises to identify true positive signals more efficiently for the low heritability traits. The other multi-loci statistical methods SUPER and MLMM perform worse than Blink and FarmCPU but better than all of the single-locus methods GLM, MLM, CMLM and ECLMM. Additionally, Bonferroni or Holm's adjustment procedures were better in multiple testing of associations at the 1 % significance level to get more accurate results for the high heritability traits.