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Wyniki wyszukiwania dla: chemical sensors
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Spectral reflectance modeling of ZnO layers made with Atomic Layer Deposition for application in optical fiber Fabry-Perot interferometric sensors
PublikacjaSuitability of zinc oxide (ZnO) layers grown using Atomic Layer Deposition for operation in optical-fiber extrinsic Fabry-Perot sensors is investigated using a numerical model. Reflectance spectra obtained using the developed model indicate that the application of these layers in optical-fiber extrinsic Fabry-Perot sensors is difficult as it may require a source whose spectrum width is about 300 nm. A series of ZnO layers grown...
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Preliminary results from HEDGEHOG REXUS project – A sounding rocket experiment on accelerations, vibrations and heat flow
PublikacjaDuring flight, a sounding rocket is subject to a unique environment - severe vibrations and substantial heat flux. In order to design payloads, precise measurement of these conditions is required. This paper presents preliminary results from HEDGEHOG REXUS Project, whose scientific goal was to characterise the thermal and dynamic environment of REXUS sounding rockets. For this purpose, two new sensors have been designed - mechanical...
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New approaches for improving selectivity and sensitivity of resistive gas sensors: A review
PublikacjaResistive gas sensors are very popular and reliable but suffer from low selectivity and sensitivity. Various methods have been suggested to improve both features without increasing the number of sensors in gas detection systems. Fluctuation enhanced gas sensing was proposed to improve gas detection efficiency by analyzing low-frequency resistance fluctuations, and noise parameters can be more informative than the single DC resistance...
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Gesture Recognition With the Linear Optical Sensor and Recurrent Neural Networks
PublikacjaIn this paper, the optical linear sensor, a representative of low-resolution sensors, was investigated in the multiclass recognition of near-field hand gestures. The recurrent neural network (RNN) with a gated recurrent unit (GRU) memory cell was utilized as a gestures classifier. A set of 27 gestures was collected from a group of volunteers. The 27 000 sequences obtained were divided into training, validation, and test subsets....
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Method of selecting the LS-SVM algorithm parameters in gas detection process
PublikacjaIn this paper we showed the method of resistive gas sensors data processing. The UV irradiation and temperature modulation was applied to improve gas sensors’ selectivity and sensitivity. Noise voltage across the sensor’s terminals (proportional to its resistance fluctuations) was recorded to estimate power spectral density. This function was an input data vector for LS-SVM (least squares – support vector machine) algorithm, which...
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The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
PublikacjaPresent-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters...
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Detection of gaseous compounds with different techniques
PublikacjaSensing technology has been developed for detection of gases in some environmental, industrial, medical, and scientific applications. The main tasks of these works is to enhance performance of gas sensors taking into account their different applicability and scenarios of operation. This paper presents the descriptions, comparison and recent progress in some existing gas sensing technologies. Detailed introduction to optical sensing...
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Features extraction from the electrocatalytic gas sensor responses
PublikacjaOne of the types of gas sensors used for detection and identification of toxic-air pollutant is an electrocatalytic gas sensor. The electrocatalytic sensors are working in cyclic voltammetry mode, enable detection of various gases. Their response are in the form of I-V curves which contain information about the type and the concentration of measured volatile compound. However,...
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Optical monitoring of electrochemical processes with ITO-based lossy-mode resonance optical fiber sensor applied as an electrode
PublikacjaIn this work we discuss the application of optical fiber sensors based on lossy-mode resonance (LMR) phenomenon for real-time optical monitoring of electrochemical processes. The sensors were obtained by a reactive high power impulse magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. The LMR effect made monitoring of changes in optical properties of both ITO and its surrounding medium...
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Food analysis using artificial senses.
PublikacjaNowadays, consumers are paying great attention to the characteristics of food such as smell, taste, and appearance. This motivates scientists to imitate human senses using devices known as electronic senses. These include electronic noses, electronic tongues, and computer vision. Thanks to the utilization of various sensors and methods of signal analysis, artificial senses are widely applied in food analysis for process monitoring...
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Emotion Monitoring – Verification of Physiological Characteristics Measurement Procedures
PublikacjaThis paper concerns measurement procedures on an emotion monitoring stand designed for tracking human emotions in the Human-Computer Interaction with physiological characteristics. The paper addresses the key problem of physiological measurements being disturbed by a motion typical for human-computer interaction such as keyboard typing or mouse movements. An original experiment...
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Evaluation of the prediction ability of air pollutants based on the electronic nose responses
PublikacjaElectronic noses are able to perform on-line measurements of the toxic volatile compounds in air. Due to their low cost and compact size they can be placed in the areas exposed to pollution, outside the laboratory. Those advantages, on the other side, force the need for development of the reliable sensors data analysis procedures. One of the most important issues connected with electronic noses is the lack of stability of the gas...
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Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublikacjaA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
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Time-domain measurement methods for R, L and C sensors based on aversatile direct sensor-to-microcontroller interface circuit
PublikacjatIn the paper new time-domain measurement methods for determining values of resistive (R), inductive(L) and capacitive (C) sensors based on a versatile direct sensor-to-microcontroller interface for microcon-trollers with internal analog-to-digital converters (ADCs) and analog comparators (ACs) are presented.The interface circuit consists of a reference resistor Rrworking as a voltage divider, a given R, L or C sensorand a microcontroller...
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Agricultural products' storage control system
PublikacjaThe paper discusses the idea and the design of a remote control system for storage management of agricultural products which temperature may rise as the result of biological processes during the storage. An actual potatoes storehouse is discussed as an application for the proposed automation system. Because of existing buildings and infrastructure at the farm, wireless data transfer system has been proposed for communication between...
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Testing of the longest span soil-steel bridge in Europe – new quality in measurements
PublikacjaThe article describes interdisciplinary and comprehensive diagnostic tests of final bridge inspection and acceptance proposed for a soil – steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure response was collected. The load test design was based on the nonlinear numerical simulations performed by...
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Determination of vertical displacements by using the hydrostatic levelling systems with the variable location of the reference sensor,
PublikacjaAbstract: In this paper, the author proposed a new method for determination of vertical displacements with the use of hydrostatic levelling systems. The traditional method of hydrostatic levelling uses a rule in which a position of reference sensor is stable. This assumption was not adapted in the proposed method. Regarding the issue mentioned above, the reference sensor is treated in the same way as the others sensors that measure...
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Study of ZrS3-based field-effect transistors toward the understanding of the mechanisms of light-enhanced gas sensing by transition metal trichalcogenides
PublikacjaExtending knowledge of the properties of low-dimensional van der Waals materials, including their reactivity to the ambiance, is important for developing innovative electronic and optoelectronic devices. Transition metal trichalcogenides with tunable optical band gaps and anisotropic conductivity are an emerging class among low- dimensional structures with the possibility of gate tunability and photoreactivity. These properties...
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Graphene field-effect transistor application for flow sensing
PublikacjaMicroflow sensors offer great potential for applications in microfluidics and lab-on-a-chip systems. However, thermal-based sensors, which are commonly used in modern flow sensing technology, are mainly made of materials with positive temperature coefficients (PTC) and suffer from a self-heating effect and slow response time. Therefore, the design of novel devices and careful selection of materials are required to improve the overall...
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Multimodal Surveillance Based Personal Protection System
PublikacjaA novel, multimodal approach for automatic detection of abduction of a protected individual, employing dedicated personal protection device and a city monitoring system is proposed and overviewed. The solution is based on combining four modalities (signals coming from: Bluetooth, fixed and PTZ cameras, thermal camera, acoustic sensors). The Bluetooth signal is used continuously to monitor the protected person presence, and in case...
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CLICK 'n' Sleep: Light-Switch Behavior of Triazole-Containing Tris(bipyridyl)ruthenium Complexes
PublikacjaA set of RuII complexes incorporating triazole subunits are presented. They show a solvent-dependent light-switch effect. Theoretical calculations revealed the excited states involved in the emission process. The findings are highly important for future design of light-switch sensors and suggest a severe restriction for functional photomolecular devices synthesized by CLICK chemistry.
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Novel Complementary Multiple Concentric Split Ring Resonator for Reliable Characterization of Dielectric Substrates with High Sensitivity
PublikacjaAccurate characterization of dielectric substrates with high sensitivity remains an important challenge in a variety of industrial applications. This paper proposes an innovative strategy to address this challenge by developing and optimizing a unique Complementary Multiple Concentric Split Ring Resonator (CMC-SRR). The major goal is to propose a sensor design with increased sensitivity and reliability for dielectric characterization....
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A plateau-valley separation approach (PVSA) for reduction of the end-effect in surface metrology
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Reference Electrodes with Ionic Liquid Salt Bridge: When Will These Innovative Novel Reference Electrodes Gain Broad Acceptance?
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Kinetic Description of the Membrane–Solution Interface for Ion-Selective Electrodes
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Optimum Choice of Randomly Oriented Carbon Nanotube Networks for UV-Assisted Gas Sensing Applications
PublikacjaWe investigated the noise and photoresponse characteristics of various optical transparencies of nanotube networks to identify an optimal randomly oriented network of carbon nanotube (CNT)-based devices for UV-assisted gas sensing applications. Our investigation reveals that all of the studied devices demonstrate negative photoconductivity upon exposure to UV light. Our studies confirm the effect of UV irradiation on the electrical...
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Fluctuation-Enhanced Sensing
PublikacjaFluctuation-enhanced sensing (FES) is an exciting and relatively new research field that promises to extend the range of information that can be extracted from a single sensor. In FES, the stochastic fluctuations of the sensor signal, rather than its average value, are recorded and analyzed. Typical components of such fluctuations are due to interactions at the microscopic level. Proper statistical analysis provides optimum sensory...
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An Instantaneous Engine Speed Estimation Method Using Multiple Matching Synchrosqueezing Transform
PublikacjaInstantaneous rotational speed measurement of the engine is crucial in routine inspection and maintenance of an automobile engine. Since the contact measurement of rotational speed is not always available, the vibration measurement has been used for noncontact rotational speed estimation methods. Unfortunately, the accuracy of the noncontact estimation methods by analyzing engine vibration frequency is not satisfactory due to the...
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Highly Reliable Passive RFID-Based Inductor–Capacitor Sensory System Strengthened by Solvatochromism for Fast and Wide-Range Lactate Detection
PublikacjaA passive radio frequency-identification-based inductor-capacitor (LC) lactate sensory system with a specific dye-containing interdigitated capacitor (IDC) in which the sensing signal is amplified by the solvatochromic effect is proposed. When a lactate solution contacts the IDC of the LC lactate sensor, the capacitance of the IDC changes, changing the resonance frequency of the sensor. This changes the oscillation frequency of...
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GAS SENSORS WITH TEMPERATURE MODULATION – AN OVERVIEW
PublikacjaAlthough different methods of improving semiconductor gas sensor properties have been proposed, a technique involving temperature modulation seems to be the most promising. Semiconductor gas sensors working with modulated temperature can be more stable and are more selective comparing with sensor working at one temperature. In this paper, various approaches to temperature modulation are reviewed.
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Applicability of Emotion Recognition and Induction Methods to Study the Behavior of Programmers
PublikacjaRecent studies in the field of software engineering have shown that positive emotions can increase and negative emotions decrease the productivity of programmers. In the field of affective computing, many methods and tools to recognize the emotions of computer users were proposed. However, it has not been verified yet which of them can be used to monitor the emotional states of software developers. The paper describes a study carried...
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System supporting behavioral therapy for children with autism
PublikacjaIn this paper, a system supporting behavioral therapy for autistic children is presented. The system consists of sensors network, base station and a brooch indicating person's emotional states. The system can be used to measure values of physiological parameters that are associated with changes in the emotional state. In the future, it can be useful to inform the autistic child and the therapist about the emotional state of the...
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A Novel IoT-Perceptive Human Activity Recognition (HAR) Approach Using Multi-Head Convolutional Attention
PublikacjaTogether with fast advancement of the Internet of Things (IoT), smart healthcare applications and systems are equipped with increasingly more wearable sensors and mobile devices. These sensors are used not only to collect data, but also, and more importantly, to assist in daily activity tracking and analyzing of their users. Various human activity recognition (HAR) approaches are used to enhance such tracking. Most of the existing...
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Spatial Visualization Based on Geodata Fusion Using an Autonomous Unmanned Vessel
PublikacjaThe visualization of riverbeds and surface facilities on the banks is crucial for systems that analyze conditions, safety, and changes in this environment. Hence, in this paper, we propose collecting, and processing data from a variety of sensors—sonar, LiDAR, multibeam echosounder (MBES), and camera—to create a visualization for further analysis. For this purpose, we took measurements from sensors installed on an autonomous, unmanned...
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FFT analysis of temperature modulated semiconductor gas sensor response for the prediction of ammonia concentration under humidity interference
PublikacjaThe increasing environmental contamination forces the need to design reliable devices for detecting of the volatile compounds present in the air. For this purpose semiconductor gas sensors, which have been widely used for years, are often utilized. Although they have many advantages such as low price and quite long life time, they still lack of long term stability and selectivity. Namely, environmental conditions have significant...
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OPTIMIZATION OF NASICON PREPARATION METHOD
PublikacjaNasicon is a solid conductor which has an ability to conduct Na+ ions and it is used in solid gas sensors. In this article a method of Nasicon preparation appropriate for gas sensing application by solgel technique is presented. Influence of the fabrication process parameters on properties of obtained samples was determined. Results of X-Ray diffraction, density, porosity, conductivity, and activation energies measurement are presented.
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Analysis of leakage flux in deenergized transformer
PublikacjaThe article presents the numerical analysis of the magnetic field that occurs around the transformer after it has been switched off. The purpose of this analysis was to determine if it is possible to define the residual fluxes in the legs of transformer based on the measurements of this field. These studies have allowed us to determine the quantity and location of the sensors. The influence of the Earth's magnetic field has also...
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Towards Cognitive and Perceptive Video Systems
PublikacjaIn this chapter we cover research and development issues related to smart cameras. We discuss challenges, new technologies and algorithms, applications and the evaluation of today’s technologies. We will cover problems related to software, hardware, communication, embedded and distributed systems, multi-modal sensors, privacy and security. We also discuss future trends and market expectations from the customer’s point of view.
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RECENT ADVANCES IN GRAPHENE APPLICATION FOR ELECTRONIC SENSING
PublikacjaThe great interest in graphene is caused by its potential for constructing various sensors exhibiting excellent parameters. The high carrier mobility and the unique band structure of graphene makes it promising especially in the field-effect transistors (GFET) applications. In this article, recent advances of the selected graphene-based sensor applications were presented and the possible directions for further investigations were...
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Radar and Sonar Imaging and Processing
PublikacjaThe 21 papers (from 61 submitted) published in the Special Issue “Radar and Sonar Imaging Processing” highlighted a variety of topics related to remote sensing with radar and sonar sensors. The sequence of articles included in the SI dealt with a broad profile of aspects of the use of radar and sonar images in line with the latest scientific trends. The latest developments in science, including artificial intelligence, were used.
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Potentiometric Oxygen Sensor with Solid State Reference Electrode
PublikacjaThe concentration or the partial pressure of oxygen in an environment can be determined using different measuring principles. For high temperature measurements of oxygen, ceramic-based sensors are the most practical. They are simple in construction, exploration and maintenance. A typical oxygen potentiometric sensor consists of an oxygen ion conducting solid electrolyte and two electrodes deposited...
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Enhanced visible light-activated gas sensing properties of nanoporous copper oxide thin films
PublikacjaMetal oxide gas sensors are popular chemoresistive sensors. They are used for numerous tasks, including environmental and safety monitoring. Some gas-sensing materials exhibit photo-induced properties that can be utilized for enhanced gas detection by modifying the sensor selectivity and sensitivity when illuminated by light. Here, we present the gas sensing characteristics of highly nanoporous Cu2O thin films towards both electrophilic...
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Comparison of direct and inverse methods of satellite observations downscaling for the coastal zone area
PublikacjaThe Earth observation satellite imaging systems have known limitations, especially regarding their spatial and temporal resolution. Therefore, approaches which aim to combine data retrieved from sensors of higher temporal and lower spatial resolution with the data characterized by lower temporal but higher spatial resolution are of high interest. This allows for joint utilization of the advantages of both these types of sensors....
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Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties
PublikacjaA graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)- reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. In order to obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at constant potential of −0.85 V. The GO, RGO...
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Generation-recombination and 1/f noise in carbon nanotube networks
PublikacjaThe low-frequency noise is of special interest for carbon nanotubes devices, which are building blocks for a variety of sensors, including radio frequency and terahertz detectors. We studied noise in as-fabricated and aged carbon nanotube networks (CNNs) field-effect transistors. Contrary to the majority of previous publications, as-fabricated devices demonstrated the superposition of generation-recombination (GR) and 1/f noise...
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Low cost electrochemical sensor module for measurement of gas concentration
PublikacjaThis paper describes a low cost electrochemical sensor module for gas concentration measurement. A module is universal and can be used for many types of electrochemical gas sensors. Device is based on AVR ATmega8 microcontroller. As signal processing circuit a specialized integrated circuit LMP9l000 is used. The proposed equipment will be used as a component of electronic nose system employed for classifying and distinguishing...
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System of breath collection and analysis for diseases detection
PublikacjaCollection and study of composition of the exhaled air is now intensively investigated to develop non-invasive medical diagnostics based on presence of metabolic compounds in the exhaled air. The process of collecting and processing of the exhaled air must fulfill relevant conditions to achieve satisfactory results. The paper presents the system of collecting samples of exhaled breath and the proposed methods of its analysis, using...
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Bridge Non-Destructive Measurements Using a Laser Scanning during Acceptance Testing: Case Study
PublikacjaOwing to the recent proliferation of inventory works on roads and railways, bridge acceptance tests have increased exponentially. These tests’ results are often misinterpreted owing to the use of various measuring equipment types, rendering integrated interpretation problematic. It is also problematic that adjusting the measurement method is difficult when the structure’s response to load is uncertain. Therefore, it is important...
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Radar and Sonar Imaging and Processing (2nd Edition)
PublikacjaThe 14 papers (from 29 submitted) published in the Special Issue “Radar and Sonar Imaging Processing (2nd Edition)” highlight a variety of topics related to remote sensing with radar and sonar sensors. The sequence of articles included in the SI deal with a broad profile of aspects of the use of radar and sonar images in line with the latest scientific trends, in which the latest developments in science, including artificial intelligence,...
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Automatic audio-visual threat detection
PublikacjaThe concept, practical realization and application of a system for detection and classification of hazardous situations based on multimodal sound and vision analysis are presented. The device consists of new kind multichannel miniature sound intensity sensors, digital Pan Tilt Zoom and fixed cameras and a bundle of signal processing algorithms. The simultaneous analysis of multimodal signals can significantly improve the accuracy...