Matching Requirements Research Articles

A Hybrid CMOS Digital-to-Analogue Converters Design for High Resolution SAR ADC

The paper describes the design and implementation of a 14-bit differential Digital-to-Analogue Converter (DAC) based on the Silterra 0.18µm Complementary Metal-Oxide-Semiconductor (CMOS) process to be established in a Successive Approximation Register (SAR) Analogue-to-Digital Converter (ADC) for the purpose of high-resolution, high accuracy and low power applications. The proposed differential DAC aims to eliminate the issue of stringent matching requirements imposed on high-resolution DACs while leveraging both linearity performance and power consumption parameters at a balanced point. The overall differential circuit consists of two parallel single-ended DACs that utilize a 4-bit Capacitor DAC (CDAC) and 10-bit Resistor DAC (RDAC) on each end, thereby establishing a hybrid-based architecture. Furthermore, the authors illustrate the proposed switching procedures applied to the sub-DAC circuits to ensure a low-power design is established. The new method effectiveness evaluation is confirmed by detailed transient simulations implemented on the DAC where the circuit performs the required conversions at a maximum conversion frequency of 2.5 MS/s with a peak power consumption of 0.1496mW for the standard voltage supply of 2.1V. Meanwhile, the schematic and post-layout simulations performed on the DAC registers peak DNL errors of -0.1612 and -0.8272, respectively. New research results depict performance improvements in terms of resolution and power consumption which facilitates the DAC implementation in contemporary electronic devices such as microcontroller peripherals and audio amplification devices. The overall deigned circuit is capable of achieving the desired 14-bit digital-to-analogue conversions under the CMOS 0.18µm technology, proving the DAC’s high-resolution efficacy.

Highly sensitive air pressure sensor based on harmonic Vernier effect by Fabry-Perot and Sagnac interferometers cascading

A high sensitivity harmonic Vernier effect air pressure sensor is proposed based on Fabry-Perot interferometer (FPI) and Sagnac interferometer (SI) cascading. FPI consists of an F-P cavity with micro-pore, detecting the changes of environmental air pressure. The reference interferometer SI is composed of panda fiber rings and cascaded with FPI to generate a harmonic Vernier effect. In harmonic Vernier effect sensor, using inner envelope intersection to measure air pressure can achieve more accurate sensitivity and measurement accuracy. Meanwhile, the harmonic Vernier effect has lower requirements for free spectral range matching between two interferometers, making it easier to achieve harmonic Vernier effect and its sensitivity is i + 1 times that of the fundamental Vernier effect. The sensitivity of the first-order harmonic Vernier effect sensor obtained in the experiment is 132.32 nm/MPa, while the corresponding the fundamental Vernier effect sensor has the sensitivity of only 68.78 nm/MPa, almost doubling. The experimental results also confirm that the proposed sensor has excellent long-term stability and repeatability. Meanwhile, the temperature cross-sensitivity of the proposed air pressure sensor is only 0.0124 MPa/°C, which is small. This sensor is expected to play a crucial role in precise and highly sensitive air pressure measurement applications.

Reorganisation and Construction of an Age-Friendly Smart Recreational Home System: Based on Function–Capability Match Methodology

Elderly users are unable to adapt to the technological dividend brought by the internet of everything as soon as possible due to the deterioration in cognitive and perceptual functions, especially in the state of development of modern intelligent homes whose users’ practical operational capabilities cannot be matched. This situation creates a digital divide in which older users also need helpmate intelligent home systems. Current research on innovative home systems often lacks a focus on the elderly and a matching mapping between smart homes and operational capabilities. Therefore, this study proposes a theoretical approach and model based on the matching between smart home functions and older users’ abilities. This modelling path provides specific guidance for actual smart home design practices. This study outlines the methodology, theoretical derivation, and construction of the user capability gradient for matching functions and requirements of elderly users. Based on a theoretical model, experimental data, and threshold law in practical application, the age-appropriate intelligent home control system is developed independently, and the integrated development of hardware and software cloud synergy is realised for the user pain points of elderly users to make up for the gap at this research level.

Evaluation of the Radiometric Calibration of ZY1-02E Thermal Infrared Data

Following the launch of the ZY1-02E satellite, the thermal infrared sensor aboard the satellite experienced alterations in the space environment, leading to varying degrees of attenuation in some components. The laboratory calibration accuracy could not satisfy the demands of quantitative production, and a certain degree of deviation was observed in on-orbit calibration. To accurately characterize the on-orbit radiation properties of thermal infrared remote sensing payloads, an absolute radiometric calibration campaign was carried out at the Ulansuhai Nur and Baotou calibration sites in Inner Mongolia in July 2022. This paper outlines the processes of onboard calibration and vicarious calibration for the ZY1-02E satellite, comparing the outcomes of onboard calibration with those of vicarious calibration. The onboard calibration method involved internal calibration, while the vicarious calibration method utilized an on-orbit absolute radiometric calibration technique based on various natural features that were not constrained by satellite–Earth spectrum matching requirements. Calibration coefficients were acquired, and the absolute radiometric calibration results of on-orbit vicarious and onboard calibration were compared, analyzed, and verified using the radiance computed from measured data and the reference sensor data. The accuracy of on-orbit absolute vicarious calibration was determined, and the causes for the decline in the radiation calibration accuracy on the orbiting satellite were examined. The findings revealed that the vicarious calibration results exhibited a lower percentage of radiance deviation compared with the onboard calibration results, meeting the quantitative requirements of remote sensing data. These results were significantly better than those obtained from onboard blackbody calibration, offering a data foundation for devising satellite calibration plans and enhancing calibration algorithms. In the future, the developmental trend of on-orbit radiometric calibration technology will encompass high-precision and slow-attenuation onboard calibration techniques, as well as high-frequency and simplified-step vicarious calibration methods.

Diversity and composition of mixed-ploidy unisexual salamander assemblages reflect the key influence of host species.

Understanding processes that govern and sustain biological diversity is a central goal of community ecology. Unisexual complexes, where reproduction depends on sperm from males of one or more bisexual host species, are rare and the processes driving their diversity and structure remain poorly understood. Unisexual Ambystoma salamanders produce distinct biotypes ('genomotypes') depending on which bisexual species they 'steal' sperm from. This reproductive mode should generate distinct assemblages depending on the locally available bisexual host species. Yet, how availability and relative abundance of multiple bisexual hosts influences composition and diversity of natural unisexual assemblages at local or regional scales remains unknown. We hypothesize that host identity most directly drives local assemblage composition, with host variation associated with increased beta and gamma diversity within unisexuals. We collected genetic samples from Ambystoma salamanders across Pelee Island, Ontario, Canada (2015-2022). Two host species were identified (A. texanum and A. laterale) with nine sites having a single host and one site having both. Unisexual assemblages were grouped into four clusters by similarity, with host identity being a key determinant. Gamma diversity increased as a result of distinct host-specific assemblages forming at different sites on the island (i.e., high beta diversity). Assemblage composition, but not diversity, was correlated with relative host abundance, which may reflect matching niche requirements between host and unisexual forms they produce. Our results demonstrate that diversity and structure of unisexual assemblages are clearly shaped by their host(s) and such systems may serve as models for studying how biotic interactions shape ecological communities.

Effect of excitation vibration on mechanical property and stress corrosion resistance of cast steel

Cast steel parts can realize rapid prototyping effectively, which is suitable for complex structural design. However, due to the large residual stress, the problem of mechanical property degradation is more obvious. In order to solve this problem, a high temperature excitation vibration treatment scheme is proposed in this paper. By applying different excitation frequencies and impact forces, the effects of mechanical properties and stress corrosion properties are studied and verified. Based on the finite element software ANSYS, the modal shape and resonant frequency of the cast steel parts are obtained, and verified by the sweep frequency module in the excitation vibration system. According to the characteristics of modal shape, five typical detection paths are set, and stress sensors are arranged every 200 mm. In order to obtain the specific effects of excitation frequency and impact force amplitude on mechanical properties, nine parts samples were prepared on the same production line according to the matching requirements of test parameters. In addition, the main external parameters that remain unchanged during vibration excitation are set as initial 750 ℃ and vibration excitation time of 60 s, which can fully affect the effect of austenite transformation. Keeping the synchronization of test parameters in different samples, the distribution rules of residual stress under different excitation frequencies and forces are obtained and analyzed. In the aspect of mechanical properties, the microstructure, hardness, yield strength and tensile strength of the specimens subjected to vibration were compared and analyzed. In the aspect of stress corrosion performance research, stress corrosion cracking test was carried out in weak acid environment to obtain the tensile stress curve and fracture morphology of the specimen. The results show that the excitation vibration at high temperature can effectively eliminate the residual stress of cast steel parts, but the increase of excitation frequency does not correspond to the effect of residual stress elimination. When the exciting force exceeds a certain value, the stress relief effect cannot be further improved. Excitation vibration can reduce the internal hardness of cast steel parts to a certain extent, and improve the yield strength and tensile strength. At the same time, it has a positive role in promoting the improvement of stress corrosion resistance.

Adjunct Therapy with T Regulatory Cells Decreases Inflammation and Preserves the Anti-Tumor Activity of CAR T Cells.

With greater accessibility and an increased number of patients being treated with CAR T cell therapy, real-world toxicity continues to remain a significant challenge to its widespread adoption. We have previously shown that allogeneic umbilical cord blood-derived (UCB) regulatory T cells (Tregs) can resolve inflammation and treat acute and immune-mediated lung injuries. Allogeneic, cryopreserved UCB Tregs have shown a clinical benefit in patients suffering from COVID-19 acute respiratory distress syndrome. The unique properties of UCB Treg cells include a lack of plasticity under inflammatory micro-environments, no requirement for HLA matching, a long shelf life of cryopreserved cells, and immediate product availability, which makes them attractive for treating acute inflammatory syndromes. Therefore, we hypothesized that adjunct therapy with UCB Tregs may resolve the undesirable inflammation responsible for CAR T cell therapy-associated toxicity. In in vitro analysis, no interference from the addition of UCB Tregs was observed on CD19 CAR T cells' ability to kill CD19 Raji cells at different CAR T: Raji cell ratios of 8:1 (80.4% vs. 81.5%); 4:1 (62.0% vs. 66.2%); 2:1 (50.1% vs. 54.7%); and 1:1 (35.4% vs. 44.1%). In the xenogeneic B-cell lymphoma model, multiple injections of UCB Tregs were administered 3 days after CD19 CAR T cell injection, and no detrimental effect of add-on Tregs was noted on the circulating CD8+ T effector cells. The distribution of CAR T cells in multiple organs remained unaffected by the addition of the UCB Tregs. Specifically, no difference in the overall tumor burden was detected between the UCB Treg + CAR T vs. CAR T alone recipients. No tumor was detected in the liver or bone marrow in CAR T cells + UCB Tregs recipients, with a notable corresponding decrease in multiple circulating inflammatory cytokines when compared to CART alone recipients. Here we show the proof of concept for adjunct therapy with UCB Tregs to mitigate the hyper-inflammatory state induced by CAR T cells without any interference in their on-target anti-tumor activity. Administration of UCB Tregs after CAR T cells allows sufficient time for their synapse formation with tumor cells and exerts cytotoxicity, such that the UCB Tregs are diverted to interact with the antigen-presenting cells at the site of inflammation. Such a differential distribution of cells would allow for a two-pronged strategy of a UCB Treg "cooling blanket" effect and lay the groundwork for clinical study.

Integrated scheduling for remanufacturing system considering component commonality using improved multi-objective genetic algorithm

The existing researches on scheduling for remanufacturing system explicitly or implicitly subjects to the component matching requirements while ignoring the repaired component commonality, which is inconsistent with reality. Thus, this paper proposes a novel integrated scheduling method for remanufacturing system with disassembly-reprocessing-reassembly considering component commonality, where components obtained by reprocessing no longer only be used to reassemble their original product, but also be used to reassemble other remanufacturing products. And a mathematic model is formulated to simultaneously minimize the completion time and total energy consumption. Then, an improved multi-objective genetic algorithm (IMOGA) with a new double-layer representation scheme is developed to handle the considered problem. In the IMOGA, a left-shift strategy is developed to utilize workstation idle time and a component-relink strategy is designed to solve the reassembly decision with component commonality. In addition, the crossover and mutation operators based on grouping strategy are designed to enhance algorithm search ability. After, a local search with two heuristic strategies is proposed to further improve the quality of solutions in the elite set. Finally, a series of comparative experiments are carried out and the results show that IMOGA can tackle this scheduling problem effectively.

Delay Error Shaping in ΔΣ Modulators Using Time-Interleaved High Resolution Quantizers

As wideband Delta-Sigma-Modulators (DSMs) are restricted in oversampling ratio (OSR), and low OSR reduces the benefit of higher order loop filters, the increase of the internal resolution is an obvious way to achieve high signal-to-quantization-noise ratio (SQNR). State-of-the-art implementations restrict the internal resolution to mostly 4-6 bits, as efficient QTZs with higher resolution add excessive delay into the DSM. Multi-step or time-interleaved-quantizer (TI-QTZs) are an effective way to enhance resolution at high sampling rate, but the resulting latency in excess of one clock cycle usually prohibits their usage in DSMs. This paper proposes a new architecture to employ high resolution multi-step QTZs, such as TI SAR or pipeline ADCs. In the proposed architecture, an excess loop delay (ELD) of several clock cycles in the LSBs is purposefully allowed. While the MSBs are conventionally ELD-compensated, the LSBs are not. The resulting error is corrected in the digital domain. It is shown that matching requirements are relaxed by first-order shaping. The idea is also applicable to a Leslie-Singh and noise-coupling architecture, which are compared to the proposed architecture in an extensive system-level analysis and simulation. Depending on the target application, an advantageous design recommendation can be given based on the presented results depending on OSR, internal bitwidth and expected analog-digital matching.

Lifetime of evaporating two-dimensional sessile droplets.

Prevailing diffusion-limited analyses of evaporating sessile droplets are facilitated by a quasisteady model for the evolution of vapor concentration in space and time. When attempting to employ that model in two dimensions, however, one encounters an impasse: the logarithmic growth of concentration at large distances, associated with the Green's function of Laplace's equation, is incompatible with the need to approach an equilibrium concentration at infinity. Observing that the quasisteady description breaks down at large distances, the diffusion problem is resolved using matched asymptotic expansions. Thus the vapor domain is conceptually decomposed into two asymptotic regions: one at the scale of the drop, where vapor transport is indeed quasisteady, and one at a remote scale, where the drop appears as a point singularity and transport is genuinely unsteady. The requirement of asymptotic matching between the respective regions furnishes a self-consistent description of the time-evolving evaporation process. Its solution provides the droplet lifetime as a universal function of a single physical parameter. Our scheme avoids the use of a remote artificial boundary, which introduces a nonremovable dependence upon a nonphysical parameter.

Design and research on pneumatic system of tire wheel hub matching machine

With the increasingly fierce competition in the automotive industry, the requirements for the automobile wheel hub assembly line weregetting higher and higher, and the matching machine has become an indispensable part of the assembly line. In this paper, the structure of pneumatic drive and servo drive was adopted by the tire wheel hub matching machine, which ensured the production rhythm and the matching accuracy requirements. According to the overall index requirements of the automatic matching machine,the pneumatic system schematic diagram was determined by the detailed research and comparison of the principle and system composition of the representative pneumatic circuit.

Construction of Boundary Conditions for Navier–Stokes Equations from the Moment System

This work concerns with boundary conditions (BCs) of the linearized moment system for rarefied gases. Under the acoustic scaling, we analyze the boundary-layer behaviors of the moment system by resorting to a three-scale asymptotic expansion. The asymptotic analysis casts the flows into the outer solution, the viscous layer, and the Knudsen layer. Starting from the BCs of the moment system, we construct BCs for the Navier–Stokes equations by a matching requirement. The obtained BCs contain the effect of second-order terms on the velocity slip and temperature jump. For the illustrative case of the Rayleigh problem, we prove the validity of the constructed BCs through error estimates. Meanwhile, numerical tests are presented to show the performance of the constructed BCs.

Designing and simulation a 15-bit successive approximation register analog-to-digital converter

Analog-to-digital converters (ADC) are widely employed to monitor long-term signal characteristics in wireless sensor networks and healthcare electronic devices. It is critical in these applications to use an energy-efficient ADC to extend battery life. This paper presents a 15-bit successive-approximation register (SAR) ADC for using in biomedical processing systems. The segmentation degrees (the amount of bits in each divided capacitive sub-array) are optimized to minimize switching power and area based on linearity and matching requirements. The proposed SAR ADC is simulated by using Simulink of Matlab. The simulated results show that the ADC achieves 14.78-bit of effective numbers of bits (ENoB), 111.5 dB of the spurious-free dynamic range (SFDR) with 90.74 dB of signal-to-noise ratio (SNR) at a sampling rate of 10MHz.

Practical guide for setting up a Fourier light-field microscope.

A practical guide for the easy implementation of a Fourier light-field microscope is reported. The Fourier light-field concept applied to microscopy allows the capture in real time of a series of 2D orthographic images of microscopic thick dynamic samples. Such perspective images contain spatial and angular information of the light-field emitted by the sample. A feature of this technology is the tight requirement of a double optical conjugation relationship, and also the requirement of NA matching. For these reasons, the Fourier light-field microscope being a non-complex optical system, a clear protocol on how to set up the optical elements accurately is needed. In this sense, this guide is aimed to simplify the implementation process, with an optical bench and off-the-shelf components. This will help the widespread use of this recent technology.

A Framework for Cybersecurity Requirements Management in the Automotive Domain

The rapid development of intelligent connected vehicles has increased the attack surface of vehicles and made the complexity of vehicle systems unprecedented. Original equipment manufacturers (OEMs) need to accurately represent and identify threats and match corresponding security requirements. Meanwhile, the fast iteration cycle of modern vehicles requires development engineers to quickly obtain cybersecurity requirements for new features in their developed systems in order to develop system code that meets cybersecurity requirements. However, existing threat identification and cybersecurity requirement methods in the automotive domain cannot accurately describe and identify threats for a new feature while also quickly matching appropriate cybersecurity requirements. This article proposes a cybersecurity requirements management system (CRMS) framework to assist OEM security experts in conducting comprehensive automated threat analysis and risk assessment and to help development engineers identify security requirements prior to software development. The proposed CRMS framework enables development engineers to quickly model their systems using the UML-based (i.e., capable of describing systems using UML) Eclipse Modeling Framework and security experts to integrate their security experience into a threat library and security requirement library expressed in Alloy formal language. In order to ensure accurate matching between the two, a middleware communication framework called the component channel messaging and interface (CCMI) framework, specifically designed for the automotive domain, is proposed. The CCMI communication framework enables the fast model of development engineers to match with the formal model of security experts for threat and security requirement matching, achieving accurate and automated threat and risk identification and security requirement matching. To validate our work, we conducted experiments on the proposed framework and compared the results with the HEAVENS approach. The results showed that the proposed framework is superior in terms of threat detection rates and coverage rates of security requirements. Moreover, it also saves analysis time for large and complex systems, and the cost-saving effect becomes more pronounced with increasing system complexity.

Application of differential equation in the field of acoustic

The current study examines a classification of physical problems involving the attenuation and propagation of structure and fluid-coupled acoustic waves in a discontinuous waveguide. In acoustics, the response of sound to boundaries is important. Therefore, it is expected that all of the discontinuous waveguide’s boundaries have the same walls, which can be either hard or impedance. The impedance and hard walls of the waveguide are mathematically modeled with respective Robin and Neumann boundary conditions together with the second-order field differential equation. The physical challenge is solved using the mode-matching (MM) approach, which also matches the continuity criteria for the acoustic pressure and normal velocities at matching connections. Transmission loss and powers scattering graphs against various frequencies and waveguides dimension parameters are shown to evaluate how well the waveguide predicts the sound to enhance or attenuate for both fluid and structure-borne modes incidents. By reconstructing the matching continuity requirements at matching junctions and using the conserved power identity, the accuracy of the derived algebra is confirmed. The current study has significant implications for improving sound quality for audible applications.

On the Bayesian model updating based on model reduction using complex modal data for damage detection

An approach for the Bayesian model updating of a linear dynamic system using complex modal data identified from dynamic test data is proposed in this paper. Very few works have utilized complex modal data for Bayesian model updating, and these works consider only the Most Probable Value (MPV) of the modal parameters as the modal data. On the other hand, the present work considers the posterior uncertainties of the modal parameters along with the MPVs as the modal data. Additionally, dynamic reduction has been applied to downsize the full system model to a reduced model with master Degrees of Freedom (DOFs) of the reduced model confined to the observed DOFs. Dynamic reduction facilitates updating of structural parameters without the requirement of mode matching. Additional uncertain parameters in the form of system modal frequencies, damping ratios, and partial mode shapes are introduced to establish a link between the structural model parameters and the modal data through the eigenvalue equation. Detailed formulation leading to the development of the posterior Probability Density Function (PDF) is presented, and a new Metropolis-within-Gibbs (MWG) sampler is proposed to simulate samples from the posterior PDF. Furthermore, a formulation is presented for evaluating the probability of damage based on the posterior samples obtained using the proposed approach from the structure's undamaged and possibly-damaged state. The proposed approach is validated and demonstrated comprehensively through simulated examples and an experimental study. Lastly, the performance of the proposed approach is compared with an alternative approach which is developed by integrating out the partial system mode shape from the posterior PDF.

Valley-Polarized Interlayer Excitons in 2D Chalcogenide-Halide Perovskite-van der Waals Heterostructures.

Interlayer excitons (IXs) in two-dimensional (2D) heterostructures provide an exciting avenue for exploring optoelectronic and valleytronic phenomena. Presently, valleytronic research is limited to transition metal dichalcogenide (TMD) based 2D heterostructure samples, which require strict lattice (mis) match and interlayer twist angle requirements. Here, we explore a 2D heterostructure system with experimental observation of spin-valley layer coupling to realize helicity-resolved IXs, without the requirement of a specific geometric arrangement, i.e., twist angle or specific thermal annealing treatment of the samples in 2D Ruddlesden-Popper (2DRP) halide perovskite/2D TMD heterostructures. Using first-principle calculations, time-resolved and circularly polarized luminescence measurements, we demonstrate that Rashba spin-splitting in 2D perovskites and strongly coupled spin-valley physics in monolayer TMDs render spin-valley-dependent optical selection rules to the IXs. Consequently, a robust valley polarization of ∼14% with a long exciton lifetime of ∼22 ns is obtained in type-II band aligned 2DRP/TMD heterostructure at ∼1.54 eV measured at 80 K. Our work expands the scope for studying spin-valley physics in heterostructures of disparate classes of 2D semiconductors.

Tuning the Intermolecular Electrostatic Interaction toward High‐Efficiency and Low‐Cost Organic Solar Cells

AbstractOrganic solar cells (OSCs) have achieved much progress with rapidly increasing power conversion efficiencies (PCEs). It should be noted that the top‐performance OSCs are generally consisted of active materials with complex chemical structures, resulting in high costs. Here, combining the material design and morphology control, high‐efficiency OSCs are fabricated by a low‐cost donor: acceptor blend. A completely non‐fused electron acceptor named Tz is designed and synthesized via introducing thiazole units on both sides of a bithiophene core, which shows an outstanding PCE of 13.3% with a typical polythiophene donor. More importantly, optimization guidelines are presented to get excellent morphology for low‐cost donor:acceptor systems. Three polythiophenes are selected, poly(3‐hexylthiophene) and its two derivatives with electron‐withdrawing substitutions (PDCBT and PDCBT‐2F), as donors to fabricate the cell devices. The computational and experimental data reveal that decreasing the electrostatic interaction between polythiophene and Tz is the key to getting a suppressed miscibility and thus a high phase purity. This study provides insight into the molecular design and donor:acceptor matching requirements for high‐efficiency and low‐cost OSCs.

A building polygonal object matching method based on minimum bounding rectangle combinatorial optimization and relaxation labeling

AbstractVolunteered geographic information (VGI) is an emerging phenomenon where anyone can create geographic information and share it with others. Compared with traditional authoritative geospatial data, it has several advantages, such as enriched data, instant updates, and low cost. The object matching method is widely used in VGI quality assessment and data updates. However, VGI matching faces certain challenges, such as the levels of detail that vary from object to object, the uneven distribution of data quality, and the automated matching requirement. To resolve these problems, this article proposes a new matching method that effectively combines the advantages of minimum bounding rectangle combinatorial optimization (MBRCO) and relaxation labeling. The proposed method (1) avoids setting the similarity threshold and weights and does not require training samples. This process is realized based on contextual information and optimization. (2) It overcomes the disadvantage that the MBRCO algorithm cannot distinguish adjacent buildings with similar shapes. Our approach is experimentally validated using two publicly available spatial datasets: OpenStreetMap and AutoNavi map. The experimental studies show that the proposed automatic matching method outperforms all the threshold‐based MBRCO methods and achieves high accuracy with a precision of 97.8% and a recall of 99.2%.