Total Deviation Research Articles

Development of a machine learning finite-range nonlocal density functional.

Kohn-Sham density functional theory has been the most popular method in electronic structure calculations. To fulfill the increasing accuracy requirements, new approximate functionals are needed to address key issues in existing approximations. It is well known that nonlocal components are crucial. Current nonlocal functionals mostly require orbital dependence such as in Hartree-Fock exchange and many-body perturbation correlation energy, which, however, leads to higher computational costs. Deviating from this pathway, we describe functional nonlocality in a new approach. By partitioning the total density to atom-centered local densities, a many-body expansion is proposed. This many-body expansion can be truncated at one-body contributions, if a base functional is used and an energy correction is approximated. The contribution from each atom-centered local density is a single finite-range nonlocal functional that is universal for all atoms. We then use machine learning to develop this universal atom-centered functional. Parameters in this functional are determined by fitting to data that are produced by high-level theories. Extensive tests on several different test sets, which include reaction energies, reaction barrier heights, and non-covalent interaction energies, show that the new functional, with only the density as the basic variable, can produce results comparable to the best-performing double-hybrid functionals, (for example, for the thermochemistry test set selected from the GMTKN55 database, BLYP based machine learning functional gives a weighted total mean absolute deviations of 3.33kcal/mol, while DSD-BLYP-D3(BJ) gives 3.28kcal/mol) with a lower computational cost. This opens a new pathway to nonlocal functional development and applications.

Glomerular filtration rate measurement during platinum treatment for urothelial carcinoma: optimal methods for clinical practice

BackgroundWe assessed the accuracy of four estimated glomerular filtration rate (eGFR) methods: MDRD, Cockcroft–Gault, CKD-EPI, and Wright.MethodThe four methods were compared to measure GFR (mGFR) in patients with urothelial urinary tract cancer (T2-T4bNxMx) receiving platinum-based chemotherapy at Rigshospitalet, Copenhagen, from January 2019 to December 2021. Using standardized assays, creatinine values were measured, and mGFR was determined using Technetium-99 m diethylenetriaminepentaacetic acid (Tc-99 m-DTPA) or Cr-51-ethylenediaminetetraacetic acid (Cr-51-EDTA) plasma clearance. Patients (n = 146) with both mGFR and corresponding creatinine values available were included (n = 345 measurements).ResultsThe CKD-EPI method consistently demonstrated superior accuracy, with the lowest Total Deviation Index of 21.8% at baseline and 22.9% for all measurements compared to Wright (23.4% /24.1%), MDRD (26.2%/25.5%), and Cockcroft–Gault (25.x%/25.1%). Bland Altman Limits of agreement (LOA) ranged from − 32 ml/min (Cockcroft–Gault) to + 33 ml/min (MDRD), with CKD-EPI showing the narrowest LOA (− 27 ml/min to + 24 ml/min and lowest bias (0.3 ml/min). Establishing an eGFR threshold at 85 ml/min—considering both the lower limit of agreement (LOA) and the minimum cisplatin limit at 60 ml/min—allows for the safe omission of mGFR in 30% of patients in this cohort.ConclusionCKD-EPI equation emerged as the most suitable for estimating kidney function in this patient group although not meeting benchmark criteria. We recommend its use for initial assessment and ongoing monitoring, and suggest mGFR for patients with a CKD-EPI estimated GFR below 85 ml/min. This approach could reduce costs and decrease laboratory time for 30% of our UC patients.

Effect of implant shape and length on the accuracy of robot-assisted immediate implant surgery: An invitro study.

To compare the accuracy of immediate implant placement of cylindrical implants (CI) and tapered implants (TI) of different lengths using a robotic dental implant system. CI and TI of three lengths (8, 10, and 12 mm) each were digitally planned and placed in a three-dimensional printed extraction socket model under robotic guidance. There were six groups with three samples in each group, resulting in a total of 18 samples. Implant angular deviation, platform point deviation (total, lateral, depth), and implant apical point deviation (total, lateral, depth) were recorded and compared between the different groups. The angular deviations for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 1.32° ± 0.19°, 1.03° ± 0.56°, 1.31° ± 0.38°, 1.27° ± 0.64°, 1.10° ± 0.43° and 1.05° ± 0.45°, respectively. The total deviations of platform and apical points for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 0.79 ± 0.18 mm, 0.77 ± 0.33 mm; 0.64 ± 0.21 mm, 0.55 ± 0.17 mm; 0.64 ± 0.37 mm, 0.65 ± 0.34 mm; 0.68 ± 0.26 mm, 0.71 ± 0.20 mm; 0.70 ± 0.12 mm, 0.66 ± 0.23 mm; and 0.71 ± 0.15 mm, 0.77 ± 0.29 mm, respectively, and had no significant differences. Within the limitation of this study, acceptable accuracy can be achieved for both TI and CI using robotic systems. Our study demonstrated that the implant shape and length did not affect the accuracy of immediate implant placement under robotic guidance invitro. However, further trials are required to confirm their efficacy in clinical practice.

Prediction of component activities in the ternary molten slags containing titanium oxide by pseudo-multicomponent approach of MIVM

Based on the molecular interaction volume model (MIVM) and the coexistence theory model (CTM), the component activities were predicted in the ternary slags FeO-MnO-SiO2, FeO-MnO-TiO2, MnO-SiO2-TiO2 and FeO-SiO2-TiO2. In com parison with the experiment data, the total average relative errors of the predicted value by pseudo-multicomponent approach of MIVM were 16%, the total average standard deviations were 0.062. On the other hand, the total average relative errors of the predicted value by coexistence theory model were 28%, the total average standard deviations were 0.077. The predicted effect of the pseudo-multicomponent approach of MIVM has better stability and reliability than coexistence theory. Therefore, the activities of component TiO2 were predicted in the ternary slags FeO-MnO-TiO2, MnO-SiO2-TiO2 and FeO-SiO2-TiO2 by MIVM, the corresponding isoactivity curves were plotted and the thermodynamic behavior tendency of constituent TiO2 in different slag systems was analyzed. This work has enriched the thermodynamic data of titanium-containing slag system and made up for the deficiency of high temperature experiment to some extent.

Static term structure of interest rate construction with tension interpolation splines

<abstract><p>Traditional theories of term structure of interest rate consist of four major classical theories, including Pure Expectation Theory, Liquidity Preference Theory, Preferred Habitat Theory and Market Segmentation Theory. However, they cannot be well interpreted by the traditional static term structure of interest rate methods such as polynomial spline and exponential spline. To address problems on low precision and weak stability of traditional methods in constructing static interest rate term structure curve, in this paper, we introduce the tension interpolation spline based on a fourth-order differential equation with local tension parameters calculated by Generalized Reduced Gradient (GRG) algorithm. Our primary focus is to illustrate its better prediction effect and stability with an empirical study conducted using datum of treasury bonds. Then, we divided the datum into intra-sample datum for estimating tension parameters and out-of-sample datum for evaluating their robustness of predicting stochastics collected from Shanghai Stock Exchange on $ {2^{{\rm{nd}}}} $ February, 2019. According to the principle of total least squares and total least absolute deviations, the result shows that the tension interpolation spline model has better precision and stronger stability in prediction of out-of-sample treasury bonds prices compared with the model established by polynomial spline and exponential spline. In addition, it can better explain the Liquidity Preference Theory, which confirms that it is suitable for constructing the static term structure of interest rates in the securities exchange market.</p></abstract>

Exploring the effects of cooperative adaptive cruise control-based transit bus operation on signalized corridors

The world’s transportation system is overburdened by ever-growing travel demand, which brings mobility, safety, and pollution problems. To combat these issues and make better use of existing road capacity on urban arterials, public transit buses are designed to carry more people in fewer vehicles. However, transit buses travel slowly and make frequent intermittent stops, resulting in unreliable travel times and inconvenient riding experiences; this hinders people from choosing to travel on public transit buses. However, a research gap exists in using connected and automated vehicle (CAV) technologies specifically for transit bus operation optimization. To bridge this gap, the present study extended CAV applications to transit bus operation and developed a transit bus control method based on cooperative adaptive cruise control (CACC). The proposed model first optimized bus segment speeds to minimize schedule deviations and fuel consumption. Then, a CACC algorithm was integrated with optimal segment speed. The proposed control method was implemented through micro-simulations of an actual corridor in Jinan, Shandong, China. The evaluation results indicate that the proposed control method reduced the total arrival deviation up to 65.1% and total fuel consumption up to 6.8%. The study adapts CAV technologies to transit bus operation. The findings in this study validate CAV applications in transit bus operation.

Application of Covariance Matrix Adaptation‐Evolutionary Strategy for Modified Constrained Optimal Power Flow Problem Incorporating Valve Point and Emission Effect

A prevailing problem in power and energy subsystems is the smooth operation of electric energy systems. This work presents recent, efficient, and reliable evolutionary algorithm for solving the optimal power flow (OPF) analysis. All various practical complex equality and inequality constraints, namely, bus voltages, real powers of the generator buses, tap settings of the transformers and the reactive power generations, shunt compensation, and emission, are considered for the real‐world scenario. Primary feature in a gas power plant that raises a lot of computational shortcomings with nonlinear structure in fuel cost is valve point effect. The existing research works have not factored the valve point effect and lack the accuracy in the fuel cost minimization and do not reflect the various practical complexities such as valve point and emission effects in the OPF problem formulation. This paper, for the first time, introduces modified OPF problem formulation incorporating valve point effect and applies covariance matrix adaptation‐evolution strategy (CMA‐ES) for solving the modified OPF problem. The algorithm is scrutinised and tested on a modified IEEE‐30‐bus platform for various OPF objectives such as cost minimization, transmission loss, and total voltage deviation, subjected to practical constraints. Load flow analysis has been carried out using the Newton–Raphson method. This work aims to lay the foundation in such a way that it can be applicable in a real‐world scenario for any number of buses.

Efficacy of antioxidant supplementation in improving endocrine, hormonal, inflammatory, and metabolic statuses of PCOS: a meta-analysis and systematic review.

Background and aim: A large number of recent studies have reported on the use of antioxidants in patients with polycystic ovary syndrome (PCOS). This study aimed to evaluate the antioxidant effects on PCOS. Methods: We searched PubMed, Embase, Web of Science, and The Cochrane Library to identify randomized controlled trials investigating the use of antioxidants in treating PCOS. Statistical analysis was performed using Review Manager 5.4. Stata17.0 software was used to conduct sensitivity analyses. Results: This meta-analysis included 49 articles and 62 studies. The sample comprised 1657 patients with PCOS from the antioxidant group and 1619 with PCOS from the placebo group. The meta-analysis revealed that the fasting blood glucose levels [standardized mean difference (SMD): -0.31, 95% confidence interval (CI): -0.39 to -0.22, P < 0.00001], the homeostatic model assessment of insulin resistance (SMD: -0.68, 95% CI: -0.87 to -0.50], P < 0.00001), and insulin levels (SMD: -0.68, 95% CI: -0.79 to -0.58, P < 0.00001) were significantly lower in patients with PCOS taking antioxidants than those in the placebo group. Further, total cholesterol levels (SMD: -0.38, 95% CI: -0.56 to -0.20, P < 0.001), low-density lipoprotein cholesterol levels (SMD: -0.24, 95% CI: -0.37 to -0.10, P = 0.0008), and very low-density lipoprotein levels (SMD: -0.53, 95% CI: -0.65 to -0.41, P < 0.00001) were lower in patients with PCOS taking antioxidant supplements compared with the placebo group. Total testosterone (TT) level (SMD: -0.78, 95% CI: -1.15 to -0.42, P < 0.0001), dehydroepiandrosterone level (SMD: -0.42, 95% CI: -0.58 to -0.25, P < 0.00001), and mean standard deviation modified Ferriman-Gallway (MF-G scores) (SMD: -0.63, 95% CI: -0.98 to -0.28, P = 0.0004) were lower in patients taking antioxidant supplements. C-reactive protein (CRP) levels (SMD: -0.48, 95% CI: -0.63 to -0.34, P < 0.000001), body mass index [mean difference (MD): -0.27, 95% CI: -0.50 to -0.03, P = 0.03], weight (MD: -0.73, 95% CI: -1.35 to -0.11, P = 0.02), and diastolic blood pressure (MD: -3.78, 95% CI: -6.30 to -1.26, P = 0.003) were significantly lower. Moreover, the levels of sex hormone-binding protein (SMD: 0.23, 95% CI: 0.07-0.38, P = 0.004), high-density lipoprotein cholesterol (SMD: 0.11, 95% CI: 0.01-0.20, P = 0.03), total antioxidant capacity (SMD: 0.59, 95% CI: 0.31-0.87, P < 0.0001), and quantitative insulin sensitivity index (SMD: 0.01, 95% CI: 0.01-0.02, P < 0.00001) were higher in patients with PCOS who took antioxidant supplements compared with the placebo group. Antioxidant supplements did not affect other analyzed parameters in these patients, including follicle-stimulating hormone, free androgen index, nitric oxide, glutathione, malondialdehyde, and diastolic blood pressure. Conclusions: Antioxidants are beneficial in treating PCOS. Our study might provide a new treatment strategy for patients with clinical PCOS. We hope that more high-quality studies evaluating the effects of antioxidants on patients with PCOS will be conducted in the future. Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023448088.

Dual-layer operation strategy of integrated energy system based on multivariate predictive control

Scheduling and control are two key dimensions to ensure the smooth operation of the integrated energy system, but there still exists the problem of insufficient accuracy of scheduling instructions due to modeling deviation between the scheduling model and the actual equipment. In this paper, a dual-layer operation strategy for integrated energy system based on multivariate predictive control is proposed, so as to make real-time corrections to the scheduling power instructions. The results show that the dual-layer operation strategy based on multivariate predictive control can better deal with the uncertainties of renewable energy output and electric load, and effectively reduce the impact of prediction deviation and scheduling model deviation on system operation. In the example calculation, compared with the operation strategy with only the scheduling layer, the total supply energy deviation with the dual-layer operation strategy decreases from 61.16 kWh to 22.96 kWh, which realizes the smooth and efficient operation of the system.

Customized Visual Discrimination Digital Therapy According to Visual Field Defects in Chronic Stroke Patients.

Visual perceptual learning (VPL) may improve visual field defects (VFDs) after chronic stroke, but the optimal training duration and location remain unknown. This prospective study aimed to determine the efficacy of 8 weeks of VFD-customized visual discrimination training in improving poststroke VFDs. Prospectively enrolled patients with poststroke VFDs initially received no training for 8 weeks (no-training phase). They subsequently underwent our customized VPL program that included orientation-discrimination tasks in individualized blind fields and central letter-discrimination tasks three times per week for 8 weeks (training phase). We analyzed the luminance detection sensitivity and deviation as measured using Humphrey visual field tests before and after the no-training and training phases. The vision-related quality of life was assessed at baseline and at a 16-week follow-up using the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). Changes in mean total deviation (MTD) scores were greater during the training phase than during the no-training phase (defective hemifield, p=0.002; whole field, p=0.004). The MTD scores improved during the training phase (defective hemifield, p=0.004; whole field, p=0.016), but not during the no-training phase (defective hemifield, p=0.178; whole field, p=0.178). The difference between the improved and worsened areas (≥6 dB changes in luminance detection sensitivity) was greater during the training phase than during the no-training phase (p=0.009). The vision-specific social functioning subscore of the NEI-VFQ-25 improved after the 16-week study period (p=0.040). Our 8-week VFD-customized visual discrimination training protocol may effectively improve VFDs and vision-specific social functioning in chronic stroke patients.

Longitudinal Evaluation of Biomechanical Indices in Fellow Eyes of Patients With Keratoconus Classified as Having Very Asymmetric Ectasia With Normal Topography.

To evaluate the biomechanical longitudinal variability and progression of tomographically normal fellow eyes of patients with keratoconus. Of 513 patients with keratoconus, 30 patients with tomographically normal fellow eyes were included in this study. Tomographic and biomechanical parameters of the Pentacam and Corvis ST (Oculus Optikgeräte GmbH) were analyzed in multiple follow-up examinations, including the ABCD grading, Belin/Ambrósio Enhanced Ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI), Corvis Biomechanical Factor (CBiF), and Tomographic and Biomechanical Index (TBI). A mixed regression model was applied. The results were compared to a healthy control group (n = 17) and a keratoconus group (n = 20). Within a maximum observation period of 3.3 years, no fellow eye (0%) showed a progression to tomographically evident keratoconus. No significant change in tomographic or biomechanical parameters was detected over the study period. The indices BAD-D, CBI, CbiF, and TBI exhibited a certain variability over time, whereas the tomographic ABC parameters and maximum keratometry barely changed. This was also shown in the control group and for all parameters in the keratoconus group, except the TBI. During the observation period none of the normal fellow eyes progressed to tomographically detectable keratoconus. However, biomechanical parameters CBI, CbiF, and TBI showed pathological values in 43.3% of eyes and certain variability. Subsequent studies with a longer observation period are warranted to confirm the biomechanical trends seen in this study and to rate the ability of single measurements to diagnose early keratoconus. [J Refract Surg. 2024;40(1):e48-e56.].

FREE-LIVING HEART RATE VARIABILITY/PHYSICAL ACTIVITY AND COGNITIVE FUNCTION AND DEMENTIA IN ARIC

Abstract Low heart rate variability (HRV) and physical activity (PA) are associated with cognitive dysfunction in clinical settings. Yet, associations with these measures among older adults in the free-living environment remain unexplored. We hypothesize higher free-living HRV and PA are associated with higher cognitive test scores and less likelihood of mild cognitive impairment (MCI)/dementia. This study includes 1,590 ARIC participants aged 72-94 years who wore the Zio XT Patch for 14-days to simultaneously capture ECG and accelerometry, from which we derived HRV as the standard deviation (SDNN) or root mean squared successive difference (rMSSD) of normal RR intervals and PA as total mean amplitude deviation (TMAD; higher values represent more movement). Linear or ordinal regression models were fitted to estimate cross-sectional associations between log transformed HRV or PA with latent-variable derived global and domain-specific cognitive factor scores or adjudicated MCI/dementia, respectively. Participants were on average 79 years, 57% female, and 32% Black. There were no significant associations between either HRV measure and cognition. After adjusting for demographic and medical covariates, 1-unit higher in log TMAD was associated with a 0.30-point higher global factor score (95% CI: 0.16-0.44), 0.38-point higher executive function factor score (95% CI: 0.22-0.53), 62% lower odds of MCI (95% CI: 0.22-0.67) and 75% lower odds of dementia compared to normal cognition (95% CI: 0.08-0.74). In summary, free-living PA, but not HRV of RR intervals, is associated with cognitive and dementia status. Further investigation of other objective HRV measures and directionality of associations between PA and cognition is needed.

Thermodynamic study of choline chloride-based deep eutectic solvents with dimethyl sulfoxide and isopropanol

The thermodynamic properties of four binary mixtures of deep eutectic solvent (DES), i.e., ChCl/Gly (choline chloride + glycerol at a molar ratio of 1:2) and ChCl/EG (choline chloride + ethylene glycol at a molar ratio of 1:2) with two common co-solvents, i.e., dimethyl sulfoxide (DMSO) and isopropanol (IPA), were studied. Density and viscosity were determined at temperatures from 288.15 to 323.15 K, while measuring the enthalpy of mixing was performed at 308.15 and 318.15 K. The volumetric properties (i.e., excess molar volume and excess partial molar volume) and excess viscosities (i.e., viscosity deviation and logarithmic excess viscosity) were further calculated to investigate the effects of temperature, types of co-solvent and DES, and their contents on the non-ideal behavior of these systems, where the influence of treating the DES as a mixture of two components or a pseudo-component was discussed. The results of volumetric properties indicate that the combined influence of packing effects and H-bonding interactions between the DES and co-solvents led to the contraction of mixture volume, and the results of excess viscosities show H-bonding interactions play an important role in their variations. The results of enthalpy of mixing show that the mixing of DES with IPA is endothermic, while the mixing of DES with DMSO is exothermic. Furthermore, the nonrandom two-liquid (NRTL) model and Gibbs-Helmholtz equation were combined to represent the experimental results of the enthalpy of mixing, and the total average relative deviation (ARD) of all studied systems is 5.43%.

Revolutionizing gear hobbing machine precision: Innovative thermal error compensation and intelligent error control with enhanced crystal structure algorithm and self-attention bidirectional minimal gated unit network

The thermal error stands as a pivotal determinant, significantly impacting both the precision and its stability of gear hobbing processes. Thus far, conspicuous delays in compensation and insufficiencies in precision have been duly noted. To achieve a proficient and exceedingly precise thermal error compensation, an intricate mathematical correlation is expounded, delineating the connection between the spatial pose error of the hob and the inherent thermal error in the gear hobbing machine. In addressing the thermal error linked to the B-axis, a bidirectional-minimal gated unit network is harnessed to characterize long-term memory attributes. An advanced crystal structure algorithm is introduced, encompassing components such as the population initialization mechanism, the nonlinear convergence factor, the Gaussian perturbation mechanism, and an enhanced optimization equation. The weights of the bidirectional-minimal gated unit network are judiciously assigned via the self-attention mechanism. This innovation, recognized as the improved crystal structure algorithm-self-attention-bidirectional-minimal gated unit network, is introduced for the training of the thermal error model for the B-axis. Subsequently, thermal analysis models are formulated, yielding the thermal errors of the X- and Z- axes. An error control model and an error decoupling model are established, employing the thermal errors of the B-, X-, and Z- axes as their input. Ultimately, an intelligent error control system is crafted, in which the error control model, error decoupling model, and thermal error model are seamlessly integrated. The aim is to mitigate tooth flank errors. With the integration of the intelligent error control system, the levels of precision pertaining to gear helix deviation, maximum deviation of a single pitch, and cumulative total pitch deviation are elevated by one, one, and two levels, respectively. More significantly, the geometric error reduction of the tooth flank achieved by the meticulously designed intelligent error control system surpasses that of traditional pitch compensation by a substantial margin. Furthermore, the execution efficiency of the intelligent error control system, when operating within the machine-edge-fog-cloud framework, exhibits a remarkable improvement of 24.18%, 16.20%, and 57.84% when compared to the intelligent error control system operating within the machine-edge-cloud, machine-fog-cloud, and machine-cloud frameworks, respectively.

Experiment and numerical simulation of the performance on scaled compressor cascade and development of a prediction model

In this study, performance variations and predictions of scaled compressor cascades were investigated. A high-subsonic profile from a rotor section of a certain axial compressor was studied. Tests as well as two-dimensional (2D) and three-dimensional (3D) CFD simulations of cascades of different scale ratios were performed to obtain the flow data of 2D and 3D flow conditions. According to the results, a scaling criterion based on aspect ratio of cascade test for the full range of incidence angles was proposed. Test results shows that aspect ratio of 2.16 is sufficient only in the minimum loss condition for test to reflected the performance of the 2D profile. When the aspect ratio was larger than 4.32, the flow at the mid-span of the tests and 3D-CFD results had good two-dimensionality at the range of twice-minimum-loss incidence angles. The relative deviation of 2D and 3D performance was less than 5%. The total pressure loss and deviation angle increased after scaling down. These results were attributed to the change in the Reynolds number corresponding to the scale. Prediction models were proposed for the calculation of the total pressure loss and deviation angle of the original profiles using the results of the scaled profiles based on the boundary layer theory. The models mainly take into account the Reynolds number, and they are applicable for conditions in which the Reynolds number exceeds the critical Reynolds number.

Type-II Censored analysis based on Exponentiated Inverted Weibull distribution

Abstract: Order statistics are widely used in Statistical modeling and its Statistical inference. Inferential aspects based on complete and incomplete data. Parameter estimation for the Exponentiated Inverted Weibull distribution based on order statistics is studied. In this paper deals with a detailed discussion on density function order statistics for complete and ordering of the data of different parameters in EIW distribution. To estimate the parameters, calculate the Mean Square Error, Total Deviation and data is tested with Kolmogrov and Smirnov method.

Measuring and modeling the tool path of the small-sized drill bit in wood-based materials

ABSTRACT The aim of this study was to investigate the trajectory of a hole drilled using a small-dimension drill bit (0.5 mm) in wood-based materials. Computer vision was used to determine the three-dimensional position of the hole. Scans were made to a depth of 5 mm every 0.5 mm (access to subsequent layers was obtained by milling with three three-blade cutter with a diameter of 26 mm). The obtained results allowed us to determine the parameters of the obtained hole, allowing to correlate the quantities, such as deviations (initial, relative, total) and angle of relative azimuth. A good correlation (R2 > 0.75) between total deviation and initial deviation for medium-density boards and hardboards can be found. The initial deviation of the drill determines the direction of the tool into the material and the initial deviation forces a specific direction of further deviation.

Comparison of Structural and Functional Features in Primary Angle Closure and Open Angle Glaucomas.

Using a large data set, we showed structural and functional differences between primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG). Primary angle closure glaucoma has relative structural preservation and worse functional loss inferiorly. To identify structural and functional differences in PACG and POAG. In this large cross-sectional study, differences in structural and functional damage were assessed among patients with POAG and PACG with optical coherence tomography and reliable visual field testing. In all, 283 patients with PACG and 4110 patients with POAG were included. Despite similar mean deviation on visual fields (mean [SD] -7.73 [7.92] vs. -7.53 [6.90]dB, P =0.72), patients with PACG had thicker global retinal nerve fiber layer (RNFL), smaller cup volume, smaller cup-to-disc ratio, and larger rim area than POAG (77 [20] vs. 71 [14]µm, 0.32 [0.28] vs. 0.40 [0.29]mm 3 , 0.6 [0.2] vs. 0.7 [0.1], 1.07 [0.40] vs. 0.89 [0.30]mm 2 , P <0.001 for all), while patients with POAG had more pronounced inferior RNFL thinning (82 [24] vs. 95 [35]µm, P <0.001). In a multivariable analysis, hyperopia [odds ratio (OR): 1.24, confidence interval (CI): 1.13-1.37], smaller cup-to-disc ratio (OR: 0.69, CI: 0.61-0.78), thicker inferior RNFL (OR: 1.15, CI: 1.06-1.26) and worse mean deviation (OR: 0.95, CI: 0.92-0.98) were associated with PACG. Functionally, POAG was associated with superior paracentral loss and PACG with inferior field loss. After adjusting for average RNFL thickness, PACG was associated with more diffuse loss than POAG (total deviation differences 1.26-3.2dB). Patients with PACG had less structural damage than patients with POAG despite similar degrees of functional loss. Regional differences in patterns of functional and structural loss between POAG and PACG may improve disease monitoring for these glaucoma subtypes.

A new method based on TGA/FTIR coupling to quantify the different thermal degradation steps of EVA/HNT composites prepared by different processing

The aim of the present article is to expose a new method based on TGA-FTIR coupling to quantify the different steps of the thermal degradation of EVA in the presence of HNT. Moreover, this quantification of the thermal degradation was also correlated to the color change. EVA/HNT composites were processed with different processing conditions: solvent casting in THF or melt blending at different temperatures. The HNT fillers content (from 10 wt% up to 30 wt%) and the melt blending temperature (at 130 °C, 150 °C, 170 °C and 190 °C) were varied. The thermal degradation of EVA in the presence of HNT presents three noticeable steps as evidenced by TG analysis: i) P1, which was identified as the catalytic degradation of vinyl acetate (VA) part of EVA occurring during the heating ramp (around 250 °C), ii) P2, which is the main degradation of VA (around 350 °C) and iii) P3, which is the degradation of the polyethylene chain of EVA (around 500 °C). Nevertheless, in the case of melt blended EVA/HNT composites, macroscopic changes (strong smell and browning color) indicate a thermal degradation occurring during the melt blending process, namely P0. FTIR-TGA coupling allows to quantify the contribution of P0, P1 and P2 (thermal degradation of VA units of EVA) using Gram Schmidt curves of released acetic acid gas which are obtained from the COac. band of acetic acid at 1795 cm−1. The contribution of each thermal degradation step of the VA part of EVA (named P0 to P2) was then quantified and reported as A0 to A2, respectively. The blending process (solvent or melt) such as the HNT fillers content and the melt blending temperatures have a significant influence on the EVA thermal degradation catalyzed by HNT. For example, it was shown that the thermal degradation of VA units occurring during the processing of EVA+ 30HNT composite (named A0 and catalyzed by the HNT) was of 40% for melt blending process (at 170 °C), whereas it was close to 0% for solvent casting process. Moreover, the macroscopic changes were evaluated by color measurements and an interesting correlation could be made between A0 and ΔE* which is the total color deviation. When a significant catalytic effect, during the melt process was observed (A0 values higher than 5%), the total color deviation ΔE* was increased linearly with A0. Finally, in order to avoid the catalytic effect of HNT on the EVA thermal degradation, a functionalization strategy has been developed with an organosilane leading to the suppression of P1, the catalytic degradation of VA in TG analyses.

Proposing new clustering-based algorithms for the multi-skilled resource-constrained multi-project scheduling problem with resource leveling adjustments

PurposeThe target of this research is to develop a mathematical model which combines the Resource-Constrained Multi-Project Scheduling Problem (RCMPSP) and the Multi-Skilled Resource-Constrained Project Scheduling Problem (MSRCPSP). Due to the importance of resource management, the proposed formulation comprises resource leveling considerations as well. The model aims to simultaneously optimize: (1) the total time to accomplish all projects and (2) the total deviation of resource consumptions from the uniform utilization levels.Design/methodology/approachThe K-Means (KM) and Fuzzy C-Means (FCM) clustering methods have been separately applied to discover the clusters of activities which have the most similar resource demands. The discovered clusters are given to the scheduling process as priori knowledge. Consequently, the execution times of the activities with the most common resource requests will not overlap. The intricacy of the problem led us to incorporate the KM and FCM techniques into a meta-heuristic called the Bi-objective Symbiosis Organisms Search (BSOS) algorithm so that the real-life samples of this problem could be solved. Therefore, two clustering-based algorithms, namely, the BSOS-KM and BSOS-FCM have been developed.FindingsComparisons between the BSOS-KM, BSOS-FCM and the BSOS method without any clustering approach show that the clustering techniques could enhance the optimization process. Another hybrid clustering-based methodology called the NSGA-II-SPE has been added to the comparisons to evaluate the developed resource leveling framework.Practical implicationsThe practical importance of the model and the clustering-based algorithms have been demonstrated in planning several construction projects, where multiple water supply systems are concurrently constructed.Originality/valueReviewing the literature revealed that there was a need for a hybrid formulation that embraces the characteristics of the RCMPSP and MSRCPSP with resource leveling considerations. Moreover, the application of clustering algorithms as resource leveling techniques was not studied sufficiently in the literature.