bluuebunny/crossref_metadata_2025 huggingface dataset:
Assure the Matchable Degree in Selective Assembly via PCI-Based Tolerance
Authors: Zhang Yu , Fang X. Daniel
Published: January 2022

Selective assembly is a method to achieve high precision fit using low precision parts. The current practices in selective assembly lack a physical process model to guide the design and process of mating parts, consequently, selective assembly is often a nightmare for manufacturing people. Process capability indices (PCIs) are the widely accepted process parameters, functioning as a measure of process performance. In this paper, the concept of PCI-based tolerance is proposed as an interface between quality requirements and statistical process control (SPC) parameters. An analytical model involving PCI-based tolerance is developed to predict and assure the matchable degree in selective assembly. As matchable degree and other process quality requirements can be assured at the stage of design by introducing PCI-based tolerance, the process of selective assembly can be improved significantly as an effective way to achieve precision assembly with economical manufacturing processes.
A Differential Geometry Model of Assembly of Compliant Developable Sheet Components
Authors: Panton Stephen M. , Lissington Tony R. , Duncan John L.
Published: January 2022

In this paper we use the techniques of differential geometry to examine the geometric characteristics that might remain invariant throughout the shape changes of a compliant sheet component during assembly. We work from the premise that such shape changes take place by the easy deformation mode of bending, and that the membrane strains remain unchanged. To demonstrate the concepts, and to facilitate physical modelling, we restrict the compliant parts to ones which are developable. We examine two assembly conditions, those of a joint along a curve, and of fitting a compliant part to a physical or notional surface. We show that the first condition requires that the geodesic curvature of the curve remains unchanged, and the second condition requires that the Gaussian curvature distribution of the surface remains unchanged.
New Metrics for Evaluating Monte Carlo Tolerance Analysis of Assemblies
Authors: Cvetko Robert , Chase Kenneth W. , Magleby Spencer P.
Published: January 2022

Monte Carlo simulation may be used by engineering designers to predict the effects of manufacturing variations in mechanical assemblies. Validity of the predictions depends on the accuracy of the input variations, simulation sample size and the fit of a statistical distribution to the resultant assembly data. New metrics are presented for assessing the accuracy of variation analysis methods. Errors due to sample size are estimated for the mean, variance, skewness and kurtosis of the resultant distribution, and the predicted rejects.

Simple algebraic expressions are derived, which can be used to predict the error in the assembly variation parameters without having to repeat the simulation.
Simultaneous In-Process Roughness Control and Tool Wear Monitoring via a Distributed Open Architecture Controller
Authors: Hu Songhua , Shin Yung C.
Published: January 2022

This paper presents in-process roughness control and tool wear monitoring during a machining process. An in-process surface roughness monitoring system which uses ultrasonic sensing techniques was adopted in this research to provide roughness feedback. A roughness model which describes the relationship between surface finish, cutting parameters, and tool flank wear was developed and used as the basis of roughness control and tool wear monitoring. The roughness control and tool wear monitoring scheme was implemented using a distributed open architecture controller which provides an open environment for integration and development. The experimental results show that the tool flank wear can be monitored accurately by surface roughness and the control scheme can effectively compensate for the effect of tool wear and other disturbances to produce a constant surface finish throughout the life of the cutting tool.
Analysis of Stiffness Control and Vibration of Wire in Wiresaw Manufacturing Process
Authors: Wei Songbin , Kao Imin
Published: January 2022

In this paper, we study the stiffness and vibration behaviors of wire in wiresaw manufacturing process. The result of stiffness control and vibration analysis can be used to predict and reduce the kerf loss during the wiresaw manufacturing process. In modeling stiffness, the wire is treated as a wire stretched over a spherically bowed surface. The flexibility influence function (or the inverse of stiffness) of the wire under such geometry is studied. It is found that both the tension in the wire and geometry play important roles in the modeling of the stiffness of stretched wire in the wiresaw manufacturing process. The stiffness influence function is plotted and the results suggest control of stiffness through varying geometry and process parameters. Dynamically, the transverse vibration behavior of the axially moving wire is studied. The response under harmonic excitation is investigated with both closed-form and numerical method. The wire vibration is also simulated and plotted with three dimensional time history showing the vibration patterns of wire as a function of time.
Finite Element Analysis of Orthogonal Cutting With Blunt-Edge Tool
Authors: Chen Y. Richard , Ni Jun
Published: January 2022

A finite element model is developed for the simulation of orthogonal cutting of ductile material with blunt-edge tools. The model assumes the machining process as a quasi-static process, is capable of performing the coupled thermal-mechanical analysis, and adopts the continuous remeshing techniques. Based on this model, as well as the material property data of a low-carbon steel obtained from previous researches, orthogonal cutting process with blunt-edge tools is thoroughly analyzed. The analysis focuses on strain and stress distributions, deformation zones, chip flow characteristics, and cutting forces with the variation of process parameters such as uncut chip thickness and edge radius. Due to the computational load, thermal effect is not incorporated in the analysis. Some critical issues, such as chip stagnation point and recovery after ploughing, are investigated. It is found that uncut chip thickness and edge radius have some important influences on the strain and stress values, the shapes of deformation zones, and the cutting forces. The chip stagnation point has a consistent position on the cutting edge when the ratio of uncut chip thickness to edge radius is between 0.7 to 5. The recovery from ploughing is not significant. The intent of the study is to improve the basic understanding of the cutting process with blunt-edge tool for more precise modeling in the future.
Mixed-Integer Programming Model for Fixture Layout Optimization
Authors: Sayeed Quazi A. , De Meter Edward C.
Published: January 2022

Workpiece deformation during machining is a significant source of machined feature geometric error. This paper presents a linear, mixed integer programming model for determining the optimal locations of locator buttons, supports, and their opposing clamps for minimizing the affect of static workpiece deformation on machined feature geometric error. This model operates on discretized candidate regions as opposed to continuous candidate regions. In addition it utilizes a condensed FEA model of the workpiece in order to minimize model size and computation expense.

This model has two advantages over existing nonlinear programming (NLP) formulations. The first is its ability to solve problems in which fixture elements can be placed over multiple regions. The second is that a global optimal solution to this model can be obtained using commercially available software.
Effect of Workpiece Flatness and Surface Finish on the Holding Force of a Magnetic Chuck
Authors: Felix Alejandro , Melkote Shreyes N.
Published: January 2022

Magnetic chucks are commonly used for workholding in precision grinding and turning of ferromagnetic materials. The workholding force produced by the chuck is strongly influenced by the texture and form of the workpiece surface in contact with the chuck surface. This paper presents the results of an experimental investigation into the effects of workpiece surface flatness, finish, and texture on the normal and frictional workholding forces produced by a radial 4-pole electromagnetic chuck. Ring shaped case-hardened steel specimens are used in the experiments. The results show that the normal holding force decreases with increasing flatness deviation. The effect of surface roughness on the normal holding force is found to be small compared to the effect of flatness but significantly impacts the tangential holding force. The workpiece surface texture is also found to have an effect on the workholding forces.
Methodology for Detecting and Measuring Workpiece Distortion Caused by Fixture Clamping Forces
Authors: Carr Kirsten M. , Rodin Yelena M. , Smith Gregory H.
Published: January 2022

Fixture designers focus primarily on workpiece positioning and minimized movement. Ensuring minimized movement may lead to large clamping forces that distort the workpiece. Manufacturing engineers have difficulty determining if and how clamping forces distort a workpiece. A distortion detection method would provide valuable insights into identifying the clamping forces as a quality problem and contribute to a solution.

The proposed methodology determines the amount of distortion caused by fixturing by directly comparing the workpiece surface while in a fixtured state to the surface while in an unfixtured state. This methodology represents each fixturing state of the workpiece as a set of high resolution 3-dimensional point data. High Resolution Form Metrology compares these sets of data and produces color coded 3D images that detail the differences between various fixturing states. If clamping forces are causing workpiece deflection, these color coded images will indicate both the location and magnitude of the deflections.
Prediction of Optimal Clamping Force for Controlling an Intelligent Fixturing System
Authors: Wang Yunfeng , Fuh Jerry Y. H. , Wong Yoke San
Published: January 2022

This paper presents an Intelligent Fixturing System (IFS) which can adaptively adjust the clamping intensities to achieve minimum deformation of the workpiece according to the cutter position and the cutting forces during the entire machining process. The concept, architecture, control scheme, models and methodologies for the IFS are described. Using off-line simulations and on-line experiments, the performance of the IFS is evaluated and verified. Since adaptive clamping forces appropriate to the dynamic machining environment are provided, the proposed IFS offers higher quality of machined parts and more flexibility to disturbances. This system is suitable for application in a high-precision machining environment where a combined optimal machining and fixturing process is required.
Stress Analysis and Strength of Bonded Shrink Fitted Joint of Hollow Shafts Subjected to Torsional Load (The Effect of Bonded Shrink Fitted Position)
Authors: Yoneno Masahiro , Sawa Toshiyuki , Nakamura Takeshi
Published: January 2022

Recently, joints combining shrink fit with anaerobic adhesives have been introduced in order to increase the joint strength. This paper deals with stress analysis and strength estimation of bonded shrink fitted joints in which a ring is fitted at the end of the shaft subjected to torsional loads. The stress distributions at the interfaces of the joint are analyzed using the axisymmetric theory of elasticity. The effect of the outer diameter, height and stiffness of ring on the interface stress distributions are examined in the numerical calculations. It is seen that rupture of adhesive layer initiates from the edge of the interface close to the end of the shaft to which torsional load is applied. The numerical results show more conservative values than the experimental results. In addition, stress distributions in the present study are compared with those in which a ring is fitted at the middle of the shaft. It is found that the effect of shrink fitted position is negligible.
Stress Analysis and Strength Evaluation of Single-Lap Band Adhesive Joints Subjected to External Bending Moments
Authors: Liu Jiemin , Sawa Toshiyuki
Published: January 2022

The stresses in single-lap band adhesive joints of similar adherends subjected to external bending moments are analyzed as a three-body contact problem by using a two-dimensional theory of elasticity (plain strain state). In the analysis, the upper and lower adherends and the adhesive bonds which are bonded at two regions are replaced by finite strips, respectively. In the numerical calculations, the effects of the ratio of Young’s moduli of the adherends to that of the adhesives, the ratio of the adherend thickness to that of the adhesive bonds and the ratio of the bonding length to the total lap length on the stress distributions at the interfaces are examined. A method for estimating the joint strength is proposed using the interface stress and strain obtained by the analysis. Experiments to measure strains and rupture strength are carried out. A fairly good agreement is found between the estimated and the experimental results. For verification of the analysis, a finite element analysis (FEA) is also conducted. The results show that the strength of a single-lap band adhesive joint is almost the same as that of a single-lap adhesive joint in which the two adherends are completely bonded at the interfaces. Thus, the single-lap band adhesive joints are shown to be useful in the design of single-lap joints.
Hydroaccumulator Influence on SB LOCA Transients at PMK-2 Test Facility
Authors: Petelin S. , Parzer I.
Published: January 2022

In 1993 the International Atomic Energy Agency Standard Problem Exercise no.4 (IAEA-SPE-4), a small break LOCA scenario simulation with no high pressure injection system available, was performed on the PMK-2 integral test facility in Budapest. Later, in 1994, another SB LOCA experiment was performed. The analyses of the PMK-2 facility response, a model of WER-440 nuclear power plant, have been performed using the MOD3.2.1.2 version of the RELAP5 thermal-hydraulic computer code.
Mechanisms Governing Cyclic Deformation and Damage During Elevated Temperature Fatigue of High Strength Aluminum Alloy 7055
Authors: Srivatsan T. S. , Anand S.
Published: January 2022

The cyclic stress response, deformation and damage characteristics of aluminum alloy 7055 was studied at ambient and an elevated temperature. The specimens were cyclically deformed using tension-compression loading under total strain-amplitude control. The alloy showed evidence of softening to failure at the two test temperatures. The degree of cyclic softening increased with an increase in test temperature. The presence of deformable matrix strengthening precipitates and particles in the T7751 microstructure results in a local decrease in resistance to the motion of ’mobile dislocations, causing a progressive loss of strengthening contributions to hardening. At the elevated temperature, localized oxidation and embrittlement at the grain boundaries are promoted by the applied cyclic stress and play an important role in accelerating crack initiation and subsequent crack propagation. The damage response of the alloy is discussed in terms of competing influences of intrinsic microstructural effects, matrix deformation characteristics arising from a combination of mechanical and microstructural contributions, cyclic plastic strain amplitude and concomitant response stress, and test temperature.
A Comparison of the Fatigue Crack Growth Behavior of Single Crystal and Polycrystalline Inconel 718
Authors: Mercer C. , Soboyejo W. O. , Soboyejo A. B. O.
Published: January 2022

The fatigue behavior of a conventional, polycrystalline Inconel 718 alloy is compared to that of an experimental, single crystal alloy of equivalent nominal chemical composition. Differences between the fracture mechanisms exhibited by the two materials under cyclic loading were determined by scanning electron microscopy. The results of the fractographic analyses are presented on fracture mechanism maps that show the dependence of the fatigue fracture mechanisms on the maximum stress intensity factor, Kmax, and the stress intensity factor range, ΔK. The relative effects of ΔK and Kmax on the fatigue crack growth behavior of these two alloys are discussed within the context of a two-parameter crack growth law. The influence of grain boundaries on the fatigue crack growth resistance of materials such as Inconel 718 is also discussed in light of the results of this investigation.
Friction and Wear in Lubricated MEMS
Authors: Senft D. C. , Dugger M. T. , Smith B. K.
Published: January 2022

The friction coefficient of a plasma-deposited hydrophobic, teflon-like film is measured using a surface micromachined (SMM) friction test device. At a contact pressure of 84 MPa, the initial friction coefficient is 0.13, rising to 0.20 after 4 × 105 wear cycles. The wear of the surfaces is characterized qualitatively by SEM.
Holistic Approach for Problems in Heterogeneous Media
Authors: Fish Jacob
Published: January 2022

In analyzing composite structures it is common practice to carry out distinct levels of analysis corresponding to different length scales: (i) macroscale (structural level), (ii) mesoscale (laminate level), and (iii) microscale (the level of microconstituents). On the structural level structural components are treated discretely, while individual plies are not recognized, except in determining the stiffness of the shell. On the laminate level, individual plies are treated discretely, while microconstituents are treated collectively as a homogenized medium. The ply properties can be determined experimentally, or they can be predicted from micromechanics. For micromechanical analysis individual phases (matrix, fiber and their interphases) are treated discretely, while the atomic scale is not recognized. These steps comprise a sequence of interdependent analyses in the sense that the output from one level is used as input to the next level, where constitutive laws serve as bridging mechanisms between the scales. It is important to note that any level of analysis is currently performed totally independent of others provided that the required input data is available, perhaps from the experiment. There is no doubt, that this approach reflects a compromise aimed at bridging the length scales in excess of six orders of magnitude.
The Transverse Interface Strength of the Fiber-Matrix Interface in Polymer Matrix Composites
Authors: Criswell T. , Majumdar B. S. , Dutton R. E. , Matikas T. E. , Pagano N. J.
Published: January 2022

The transverse tensile strength of the fiber-matrix interface plays an important role in controlling a number of failure modes in polymer matrix composites (PMCs). These include the transverse failure of 90° plies, as well edge delamination in PMC laminates. On the other hand, while significant attention has been focused in the PMC literature on interface shear failure, such as under pull-out conditions, little attention has been focused on the interface tensile strength. In order to avoid edge effects, a cruciform geometry was selected for evaluating the tensile strength. SiC fibers with different types of coatings were evaluated inside an epoxy matrix, and the bond strength was estimated from the mechanical test data. Interface failure was confirmed using optical, dye penetrant, and an ultrasonic shear wave back reflection technique. Tests using straight sided specimens confirmed that singularities at specimen edges have significant influence on interface failure, and hence must be avoided for obtaining valid interface strength data.
An Atlas of Asymptotically Singular Stress Fields in Axisymmetric Fiber Push-Out Model
Authors: Pochiraju Kishore
Published: January 2022

Extracting fiber-matrix interface properties from single fiber push-out experimentation results requires careful micro-mechanical modeling. The axisymmetric concentric cylinder model is widely used to determine stress and damage state in the fiber, matrix, and at the interface. Several mechanics models developed for analyzing this model recognize the existence of asymptotically singular local regions for analyzing the stress fields in fiber push-out, but a comprehensive description of the nature of these stress fields and estimates for the regions of their influence is not available. Early work by Zak has shown that plane strain singularities which are separable in radial and angular directions dominate in the axisymmetric model at regions close to the point of singularity. Later efforts characterized the power of the radial singularity and angular variations of the singular stress fields in the model.

In this paper the qualitative and quantitative nature of the singular stress fields, their regions of dominance, and scaling of the stress intensity with applied load for several fiber-matrix interface conditions are described. The presented results are obtained using a local-global matching technique which uses combined asymptotic and finite element methods to determine the stress fields in the local regions.

The results are presented for both edge/corner singularities and for crack tip singularities in the model. The fiber radius and fiber volume fraction are considered as the geometric parameters. The material mismatch effects are considered using a wide spectrum of Dundurs mismatch parameters. Several interface conditions including perfectly bonded, partially cracked, debonding with frictional sliding of the crack tips and the oscillatory bi-material singularities are considered. Two different loading conditions, namely the thermal residual stresses and the push-in displacement loads are considered. The paper focuses on the local stress fields as determined by the first and second (when singular) terms of the asymptotic expansion and their scaling with applied loading.

The paper provides an atlas of the nature of the stress singularities (power of the stress singularity, mode mixity, the angular variation, and region of dominance) and the approximate stress intensity factors in the model for the two loading types for most practical fiber-matrix combinations, interface frictions and model geometric parameters.
Free-Edge Delamination in Layered Composites: A Historical Review of the Past 30 Years
Authors: Wang A. S. D.
Published: January 2022

In the inaugural issue of the Journal of Composite Materials in January, 1967, Editor S.W. Tsai elaborated in the Editorial the purpose and mission of his Journal. In it, interdisciplinary approaches to the basic problems of composites were emphasized. In particular, it called for the metallurgist and polymer chemist to face the problems of microscopic complex stresses and macroscopic material anisotropy, and for the elastician to go beyond the idealized elasticity problems, in order to include such real and practical effects as random fiber packing, imperfect interfacial bond, material inelasticity and fracture; only a close coupling of these disciplines could make the advancing composites technology fulfill it’s glowing promise.
Mechanics of Microvoid Formation During Resin Transfer Molding
Authors: Kang Moon Koo , Hahn H. Thomas
Published: January 2022

In resin transfer molding (RTM), the formation of air voids within fiber preform depends on the flow rate and surface tension of the resin during mold filling. The resin velocity in regions between fiber tows is mostly controlled by the induced pressure gradient whereas the resin flow within each fiber tow depends more on the capillary pressure. As these two flows compete in their advancement, the size and location of air voids vary from point to point. Capillary number, defined as the ratio of the viscous force to the capillary force, has been found through experiments to be the critical parameter controlling the type of microvoids.

The present paper proposes a model that can account for the dependence of the size and quantity of air voids on the capillary number. At low capillary numbers, the soaking flow within individual fiber tows dominates mold filling, and hence voids are more likely to form between fiber tows. At high capillary numbers, the situation is reversed so that the inter-fiber-tow flow outruns the intra-fiber-tow flow resulting in voids within fiber tows. At an optimum capillary number, the two flows are comparable, minimizing the possibility of void formation. The proposed model can quantify the effect of capillary number on void formation. The model has been validated through experiments.
Permeability Measurements of Fiber Preforms and Applications
Authors: Han Ken , Lee Bill , Rice Brian
Published: January 2022

Permeability plays a key role in liquid composite molding processes for mold and process design. A new technique is developed to measure permeabilities for anisotropic fiber preforms with a high fiber content. In this method, four pressure transducers are used to measure the pressure distribution in a radial flow. In this way, permeabilities in the different directions can be determined. The racetracking effects, the permeability of the high permeability layer used in vacuum assisted RTM and the equivalent permeability in the channels used in SCRIMP were also investigated in this study. The measured fiber preform permeability, resin viscosity and kinetic models were used in a 3D flow model to simulate the liquid composite molding process for aerospace applications.
Evaluation of Complex Stress Intensity Factors in Debonded Sandwich Beams
Authors: Sankar Bhavani V. , Dharmapuri Sreerama M.
Published: January 2022

The overall objective of the project are to develop methods to characterize the damage tolerance of sandwich panels with disbonded face sheets under inplane compression, and to develop a criterion for predicting the allowable disbond for a given set of inplane loading. As part of the study we characterize the mixed mode fracture toughness by conducting double cantilever beam and UCSB four-point bend tests. The complex stress intensity factors for the test conditions are computes using a plane finite element model of the beam. The results include the effect of various parameters such as core thickness, face sheet thickness and core density on the mode mixity as well as the absolute value of the stress intensity factor. The validity of simple beam theory models also explored for the purpose of estimating the mode mixity.
Risperidone and aripiprazole for autism spectrum disorder in children: an overview of systematic reviews
Authors: Fieiras Cecilia , Chen Michael Hao , Escobar Liquitay Camila Micaela , Meza Nicolás , Rojas Valeria , Franco Juan Victor Ariel , Madrid Eva
Published: January 2022

Objectives

To assess the effectiveness and safety of risperidone and aripiprazole in children with autism spectrum disorder (ASD).

Design and setting

Overview of systematic reviews (SRs).

Search methods

In October 2021, we searched Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycInfo and Epistemonikos placing no restrictions on language or date of publication.

Participants

Children aged 12 years or less with ASD.

Interventions

Risperidone and aripiprazole with no dosage restrictions.

Data collection and analysis

We rated the methodological quality of the included SRs using A Measurement Tool to Assess Systematic Reviews (AMSTAR 2). We reported the Grading of Recommendations, Assessment, Development and Evaluation certainty of the evidence according to the analysis conducted by the authors of the included SRs.

Main outcomes measured

A multidisciplinary group of experts agreed on analysing nine critical outcomes evolving core and non-core ASD symptoms.

Patient and public involvement

Organisations of parents of children with ASD were involved during part of the process, participating in external revision of the final version of the report for the Chilean Ministry of Health with no additional comments (ID 757-22-L120 DIPRECE, Ministry of Health, Chile). The organisations involved were: Fundación Unión Autismo y Neurodiversidad, Federación Nacional de Autismo, Vocería Autismo del Sur, and Vocería Autismo del Norte.

Results

We identified 22 SRs within the scope of this overview, of which 16 were of critically low confidence according to AMSTAR 2 and were excluded from the analysis. Both aripiprazole and risperidone were effective for reducing autism symptoms severity, repetitive behaviours, inappropriate language, social withdrawal and behavioural problems compared with placebo. The certainty of the evidence for most outcomes was moderate. Risperidone and aripiprazole are associated with metabolic and neurological adverse events. Follow-up was short termed.

Conclusions

We found that aripiprazole and risperidone probably reduce symptom severity at short-term follow-up but may also cause adverse events. High-quality and updated SRs and larger randomised controlled trials with longer term follow-up are needed on this topic.

Overview protocol

PROSPERO CRD42020206535.
The cost of illness for childhood clinical pneumonia and invasive pneumococcal disease in Nigeria
Authors: Adamu Aishatu Lawal , Karia Boniface , Bello Musa M , Jahun Mahmoud G , Gambo Safiya , Ojal John , Scott Anthony , Jemutai Julie , Adetifa Ifedayo M
Published: January 2022

Background

Pneumococcal disease contributes significantly to childhood morbidity and mortality and treatment is costly. Nigeria recently introduced the pneumococcal conjugate vaccine (PCV) to prevent pneumococcal disease. The aim of this study is to estimate health provider and household costs for the treatment of pneumococcal disease in children aged <5 years (U5s), and to assess the impact of these costs on household income.

Methods

We recruited U5s with clinical pneumonia, pneumococcal meningitis or pneumococcal septicaemia from a tertiary level hospital and a secondary level hospital in Kano, Nigeria. We obtained resource utilisation data from medical records to estimate costs of treatment to provider, and household expenses and income loss data from caregiver interviews to estimate costs of treatment to households. We defined catastrophic health expenditure (CHE) as household costs exceeding 25% of monthly household income and estimated the proportion of households that experienced it. We compared CHE across tertiles of household income (from the poorest to least poor).

Results

Of 480 participants recruited, 244 had outpatient pneumonia, and 236 were hospitalised with pneumonia (117), septicaemia (66) and meningitis (53). Median (IQR) provider costs were US$17 (US$14–22) for outpatients and US$272 (US$271–360) for inpatients. Median household cost was US$51 (US$40–69). Overall, 33% of households experienced CHE, while 53% and 4% of the poorest and least poor households, experienced CHE, respectively. The odds of CHE increased with admission at the secondary hospital, a diagnosis of meningitis or septicaemia, higher provider costs and caregiver having a non-salaried job.

Conclusion

Provider costs are substantial, and households incur treatment expenses that considerably impact on their income and this is particularly so for the poorest households. Sustaining the PCV programme and ensuring high and equitable coverage to lower disease burden will reduce the economic burden of pneumococcal disease to the healthcare provider and households.
Estimating need and coverage for five priority assistive products: a systematic review of global population-based research
Authors: Danemayer Jamie , Boggs Dorothy , Delgado Ramos Vinicius , Smith Emma , Kular Ariana , Bhot William , Ramos-Barajas Felipe , Polack Sarah , Holloway Cathy
Published: January 2022

Introduction

To improve access to assistive products (APs) globally, data must be available to inform evidence-based decision-making, policy development and evaluation, and market-shaping interventions.

Methods

This systematic review was undertaken to identify studies presenting population-based estimates of need and coverage for five APs (hearing aids, limb prostheses, wheelchairs, glasses and personal digital assistants) grouped by four functional domains (hearing, mobility, vision and cognition).

Results

Data including 656 AP access indicators were extracted from 207 studies, most of which (n=199, 96%) were cross-sectional, either collecting primary (n=167) or using secondary (n=32) data. There was considerable heterogeneity in assessment approaches used and how AP indicators were reported; over half (n=110) used a combination of clinical and self-reported assessment data. Of 35 studies reporting AP use out of all people with functional difficulty in the corresponding functional domains, the proportions ranged from 4.5% to 47.0% for hearing aids, from 0.9% to 17.6% for mobility devices, and from 0.1% to 86.6% for near and distance glasses. Studies reporting AP need indicators demonstrated >60% unmet need for each of the five APs in most settings.

Conclusion

Variation in definitions of indicators of AP access have likely led to overestimates/underestimates of need and coverage, particularly, where the relationship between functioning difficulty and the need for an AP is complex. This review demonstrates high unmet need for APs globally, due in part to disparate data across this sector, and emphasises the need to standardise AP data collection and reporting strategies to provide a comparable evidence base to improve access to APs.
Higgs-mass constraints on a supersymmetric solution of the muon $$g-2$$ anomaly
Authors: Ke Wenqi , Slavich Pietro
Published: January 2022

The prediction for the quartic coupling of the SM-like Higgs boson constrains the parameter space of SUSY models, even in scenarios where all of the new-particle masses are above the scale probed so far by the LHC. We study the implications of the Higgs-mass prediction on a recently-proposed SUSY model that features two pairs of Higgs doublets, and provides a solution to the $$(g-2)_\mu $$

(
g
-
2
)

μ

anomaly thanks to a suitable enhancement of the muon Yukawa coupling.
Production of axion-like particles via vector boson fusion at future electron-positron colliders
Authors: Yue Chong-Xing , Zhang Hua-Ying , Wang Han
Published: January 2022

One kind of particularly interesting pseudoscalar particles, called axion-like particles (ALPs), have rich physical phenomenology at high- and low-energy collider experiments. After discussing most of single production channels of ALP at electron-positron colliders, we investigate the possibility of detecting this kind of new particles through the W$$^{+}$$

+

W$$^{-}$$

-

fusion process e$$^{+}$$

+

e$$^{-}$$

-

$$\rightarrow $$
→
$${\overline{\nu }}_{e}$$

ν
¯

e

$$\nu _{e}a$$

ν
e

a

$$(\rightarrow \gamma \gamma )$$

(
→
γ
γ
)

at the CLIC. The 3$$\sigma $$
σ
and 5$$\sigma $$
σ
bounds on the ALP parameter space at the three energy stages of the CLIC are obtained. We find that the bounds given by the CLIC are complementary to the existing experiments exclusion regions.
Security analysis and improvements of XOR arbitrated quantum signature-based GHZ state
Authors: Ding Li , Xin Xiangjun , Yang Qinglan , Sang Yongxuan
Published: January 2022

Recently, Zheng et al. presented a novel signature protocol with arbitrator based on XOR encryption and GHZ state. Unfortunately, their protocol lacks security. Firstly, a quantum adversary can forge their signature based on the received information. On the other hand, their protocol is vulnerable for the adversary’s repudiation attack. Then, we bring about improvements on its security, efficiency and practicality. The improved protocol not only prevents the security defects of the old protocol, but also has better computation efficiency. On the other hand, our protocol is mainly used to sign the classical messages, which are widely used in the current network.
A Chaotic Encryption System Based on DNA Coding Using a Deep Neural Network
Authors: Sudha K. Antony , Castro V. Cibi , MuthuLakshmi G. , Parithi T. Ilam , Raja S. P.
Published: January 2022

Critical to computer vision applications, deep learning demands a massive volume of training data for great performance. However, encrypting the sensitive information in a photograph is fraught with difficulty, despite rapid technological advancements. The Advanced Encryption System (AES) is the bedrock of classical encryption technologies. The Data Encryption Standard (DES) has low sensitivity, with weak anti-hacking capabilities. In a chaotic encryption system, a chaotic logistic map is employed to generate a key double logistic sequence, and deoxyribonucleic acid (DNA) matrices are created by DNA coding. The XOR operation is carried out between the DNA sequence matrix and the key matrix. Finally, the DNA matrix is decoded to obtain an encrypted image. Given that encrypted images are susceptible to attacks, a rapid and efficient Convolutional Neural Network (CNN) denoiser is used that enhances the robustness of the algorithm by maximizing the resolution of rebuilt images. The use of a key mixing percentage factor gives the proposed system vast key space and great key sensitivity. Its implementation is examined using statistical techniques such as histogram analysis, information entropy, key space analysis and key sensitivity. Experiments have shown that the suggested system is secure and robust to statistical and noise attacks.
NASCENT2: Generic Near-Storage Sort Accelerator for Data Analytics on SmartSSD
Authors: Salamat Sahand , Zhang Hui , Ki Yang Seok , Rosing Tajana
Published: January 2022

As the size of data generated every day grows dramatically, the computational bottleneck of computer systems has shifted toward storage devices. The interface between the storage and the computational platforms has become the main limitation due to its limited bandwidth, which does not scale when the number of storage devices increases. Interconnect networks do not provide simultaneous access to all storage devices and thus limit the performance of the system when executing independent operations on different storage devices. Offloading the computations to the storage devices eliminates the burden of data transfer from the interconnects. Near-storage computing offloads a portion of computations to the storage devices to accelerate big data applications. In this article, we propose a generic near-storage sort accelerator for data analytics, NASCENT2, which utilizes Samsung SmartSSD, an NVMe flash drive with an on-board FPGA chip that processes data in situ.

NASCENT2 consists of dictionary decoder, sort, and shuffle FPGA-based accelerators to support sorting database tables based on a key column with any arbitrary data type. It exploits data partitioning applied by data processing management systems, such as SparkSQL, to breakdown the sort operations on colossal tables to multiple sort operations on smaller tables. NASCENT2 generic sort provides 2 × speedup and 15.2 × energy efficiency improvement as compared to the CPU baseline. It moreover considers the specifications of the SmartSSD (e.g., the FPGA resources, interconnect network, and solid-state drive bandwidth) to increase the scalability of computer systems as the number of storage devices increases. With 12 SmartSSDs, NASCENT2 is 9.9× (137.2 ×) faster and 7.3 × (119.2 ×) more energy efficient in sorting the largest tables of TPCC and TPCH benchmarks than the FPGA (CPU) baseline.
AI education matters
Authors: Zhang Lisa , Fewzee Pouria , Feghali Charbel
Published: January 2022

We introduce a Model AI Assignment (Neller et al., 2021) where students combine various techniques from a deep learning course to build a denoising autoencoder (Shen, Mueller, Barzilay, & Jaakkola, 2020) for news headlines. Students then use this denoising autoencoder to query similar headlines, and interpolate between headlines.

Building this denoising autoencoder requires students to apply many course concepts, including data augmentation, word and sentence embeddings, autoencoders, recurrent neural networks, sequence-to-sequence networks, and temperature. As such, this assignment can be ideal as a final assessment that synthesizes many topics.

This assignment is written in PyTorch, uses the torchtext package, and is intended to be completed on the Google Colab platform.
Getting Off the Mad Path
Authors: Neville-Neil George V.
Published: January 2022

KV continues to grind his teeth as he sees code loaded with debugging statements that would be totally unnecessary if the programmers who wrote the code could be both confident in and proficient with their debuggers. If one is lucky enough to have access to a good debugger, one should give extreme thanks to whatever they normally give thanks to and use the damn thing!
Congratulations! You Have Become a Senior Researcher. Now What?
Authors: Balazinska Magdalena
Published: January 2022

It probably seems like yesterday that you were starting at your first post-PhD position, but with this latest promotion, whether it is tenure or promotion to a senior level at your company, you can no longer call yourself "junior". You are now stepping into the shoes of a senior researcher. Congratulations! This is a tremendous accomplishment, and you should celebrate. The road was long and often uphill. You finally made it.
Juliana Freire Speaks Out on Reproducibility and Hard Changes
Authors: Winslett Marianne , Braganholo Vanessa
Published: January 2022

Welcome to ACM SIGMOD Record's series of interviews with distinguished members of the database community. I am Marianne Winslett, and today I have here with me Juliana Freire, who is a professor at New York University. Juliana is an ACM Fellow, and she has a Google Faculty Research Award, an IBM Faculty Award, and an NSF Career Award. She is also the chair of SIGMOD, and her term of office ends in just a few days. Juliana's Ph.D. is from Stony Brook. So, Juliana, welcome!
VLDB 2021
Authors: Bonnet Philippe , Luna Dong Xin , Naumann Felix , Tözün Pinar
Published: January 2022

The 47th International Conference on Very Large Databases (VLDB'21) was held on August 16-20, 2021 as a hybrid conference. It attracted 180 in-person attendees in Copenhagen and 840 remote attendees. In this paper, we describe our key decisions as general chairs and program committee chairs and share the lessons we learned.
Letters Online - Summer 1998
Authors: Yess Mary E.
Published: January 2022

By the time you hold this issue of Interface in your hand (or view it online), chances are you will have seen the Society’s new, rapid-publication journal, Electrochemical and Solid-State Letters.
(Invited) Residual Stress Evolution during Thin Film Growth: Kinetic Modeling and Monte Carlo Simulations
Authors: Chason Eric
Published: January 2022

To reduce failure and enhance performance, it would be desirable to predict and control the residual stress in thin films. This requires a fundamental understanding of how the stress is related to the underlying processes controlling film growth. We describe the results of rate equation models and computer simulations focused on advancing this understanding. The rate equation models explore the competition between different stress-inducing mechanisms occurring simultaneously during growth. Tensile stress is induced by the interaction between islands as they merge to form new segments of grain boundary (island coalescence). At the same time, compressive stress is induced by diffusion of atoms into the grain boundary driven by the non-equilibrium conditions on the surface. The stress can be further modified by densification of the film due to grain growth. The model predictions for the dependence of the stress on growth rate, diffusivity and grain size are compared with measurements for systems with different types of microstructural evolution. To understand how the surface kinetics are related to the stress, we have also developed kinetic Monte Carlo simulations that include similar mechanisms for generating stress at the grain boundaries. This approach enables us to look at the stochastic effect of individual atom dynamics on the stress evolution. For instance, we can study how supersaturation on the surface due to the deposition flux acts as a driving force for compressive stress. Results for the evolution of stress at different growth rates, temperatures and grain sizes will be shown.
Genetic Analysis of Sodium Channel Genes in Pediatric Epilepsy Patients of Pakistan
Authors: Ashfaq Aqsa , Saleem Tayyaba , Sheikh Nadeem , Maqbool Hafsa
Published: January 2022

Epilepsy affects millions of people worldwide. Although antiepileptic drugs work for the majority of epileptic patients, these drugs do not work for some of the patients, subjecting them to drug-resistant epilepsy (DRE). Voltage-gated sodium channels act as targets for a number of antiepileptic drugs, and the genes encoding these channels can play a crucial role in developing drug-resistant epilepsy. This case-control (100 control: 101patients) study evaluated the association of sodium channel genes SCN1A and SCN2A with drug-resistant epilepsy. The cases were further accounted in two categories, drug-resistant and drug-responsive epileptic patients. The polymorphic sites rs794726754, rs1057518252, rs121918809, rs12191792, rs121917932, c.730 G > T, c.735 G > T, c.736 A > T, rs10167228, and rs2298771 of the SCN1A gene and rs17183814 of SCN2A gene were selected for mutational analysis. The DNA was isolated, amplified by PCR, and then, was run through 1% agarose gel. The sequencing was performed, and the sequences were observed through BioEdit software for any change in DNA sequence. In our study, no polymorphism was observed in the studied SNPs except for rs2298771. For rs2298771, a significant difference existed in the distribution of genotypic and allelic frequencies (

p

 < 0.01) among the case and control group. Furthermore, the genotypic and allelic frequencies of the two categories of cases (drug responder drug resistant) were calculated. The genotypic and allelic frequencies of drug-responsive and drug-resistant epileptic patients did not differ significantly (

p

 > 0.01). Our study indicated that the rs2298771 polymorphism of SCN1A may not be associated with chance of developing DRE in the Pakistani population.