Aim To assess the impact of National Essential Medicines Policy (NEMP) on use medicines in government-owned primary care institutions Hubei province China. Study design Quasi-experimental and time-trend analysis. Methods A systematic random sampling strategy was employed to select 55 800 prescriptions from 18 organizations who progressively implemented NEMP January 2009 July 2011. We examined change patterns prescriptions. The facilities that at a later stage served as control. Results An...

Fabric defect detection is very important in the textile quality process. Current deep learning algorithms are not effective detecting tiny and extreme aspect ratio fabric defects. In this paper, we proposed a strong method, Priori Anchor Convolutional Neural Network (PRAN-Net), for to improve location accuracy of defects decrease inspection time. First, used Feature Pyramid (FPN) by selected multi-scale feature maps reserve more detailed information Secondly, trick generate sparse priori...

In-situ intelligent manufacturing for large-volume equipment requires industrial robots with absolute high-accuracy positioning and orientation steering control. Conventional mainly employ an offline calibration technology to identify compensate key robotic parameters. However, the dynamic static parameters of a robot change nonlinearly. It is not possible acquire robot's actual control pose high accuracy within large workspace by in real-time. This study proposes real-time online method...

Abstract To address the limitations of six-degree-of-freedom (6-DOF) visual tracking systems in terms low dynamic performance and inability to perform measurements under light occlusion, this paper proposes a novel laser attitude measurement method integrating vision inertial unit (IMU). A tailored real-time calibration model is developed enable precise alignment IMU coordinate during operations. overcome extended Kalman filter (EKF) that rely on static noise assumptions complex scenarios,...

Large-space high-precision attitude dynamic measurement technology has urgent application needs in large equipment manufacturing fields, such as aerospace, rail transportation, automobiles, and ships. In this paper, taking laser tracking the base station, a backpropagation algorithm based on neighborhood search is proposed, which applied to fusion of multi-source information for solving angle. This paper firstly established mathematical model IMU CCD multi-sensor, designed 6-11-3 back...

In order to meet the high-precision measurement requirements of point and line targets for particle accelerators, visual photogrammetry system three-dimensional is proposed, data processing algorithm investigated. First, based on images collected by measurement, pixel observations are converted into universal angle observations. An observation model points relation between global coordinates established. Then, a spatial straight four-parameter expression method an offset Finally, principle...

The real-time and high-precision trajectory prediction of a moving object is core technology in the field aerospace engineering. monitoring tracking are also significant guarantees equipment. A dynamic method called grey filter (GDF) which combines measurement theory system proposed. GDF can use coordinates current period to extrapolate following period. At meantime, keep instantaneity measured by metabolism model. In this paper optimal model length firstly selected improve accuracy. Then...

In order to improve the precision of a binocular vision measurement system, an effective method, named geometrical approximation, is proposed. This method can optimize results by approximation operation based on principles optimization theory and spatial geometry. To evaluate properties proposed both simulative practical experiments are carried out. The influence image noise focal length error discussed. show that performance manifested well. Besides, also compared with Bundle adjustment...

In this Letter, we report on a novel architecture for self-starting mode-locked figure-eight erbium-doped fiber laser using loss-imbalanced nonlinear optical loop mirror (NOLM) with bidirectional output coupler. An all-polarization-maintaining structure is adopted. A 2 × coupler splitting ratio of 50:50 used at the junction to form an NOLM. Another 10:90 introduced one end loop. The plays two roles: power attenuator and This can achieve both large modulation depth good ability...

Particle mass and particulate size are two important parameters used to characterize the aerosol. Currently, there a few methods for measuring particle concentration size. However, existing have their own shortcomings. In this article, we describe novel laser scattering instrument that measures in real time over wide range. This combines time-of-flight aerodynamics one optical device. There innovations paper: (1) Two APD detectors receive scattered light. One receives forward-scattered light...

The Guide to the Expression of Uncertainty in Measurement (GUM) is master document for measurement uncertainty evaluation. However, GUM may encounter problems and does not work well when data have poor information. In most cases, information means a small sample an unknown probability distribution. these evaluation has become bottleneck practical measurement. To solve this problem, novel method called grey relational approach (GRA), different from statistical theory, proposed paper. GRA...

We systematically discussed the principle of dual-comb ranging system and built a theoretical model. To correct phase distortion caused by femtosecond frequency comb noise, correction approach is proposed numerical simulations are conducted subsequently. In simulations, performance method under noise repetition rate offset analyzed respectively. The results indicate that accuracy can be effectively improved method. It verified experiments.

Abstract Layered transition metal dichalcogenides (TMDCs) have shown great potential for a wide range of applications in photonics and optoelectronics. Nevertheless, valley decoherence severely randomizes its polarization which is important to light emitter. Plasmonic metasurface with unique way manipulate the light-matter interaction may provide an effective practical solution. Here by integrating TMDCs plasmonic nanowire arrays, we demonstrate strong anisotropic enhancement excitonic...

Abstract The use of the thermostatic metal bath is becoming more and extensive requirements for its precision reliability are also increasing. To meet needs calibration, a 12-channel temperature field calibration system based on four-wire PT100 has been designed. design includes front-end measurement component, which consists block, signal processing bidirectional constant current source excitation unit, conditioning unit high-precision acquisition unit. STM32f407 used as main control chip,...

Laser trackers are instruments used to measure the three-dimensional coordinates of objects with high precision. It is necessary study calibration methods identify geometric errors laser so as compensate for and improve measurement accuracy. Among offsets, tilts, eccentricity in system, transit tilt offset play important roles have an essential effect on accuracy, which need be calibrated compensated for. Current detecting between standing axes complex time-consuming. In this paper, a fast...

A diode-pumped alkali laser has gained rapid development in recent years. In this study, we take the advantages of high-gain cross section and low upper energy lifetime an to propose, best our knowledge, a novel type time-domain-modulated vapor amplifier. By using amplifier, experimentally demonstrate power scaling modulated seed laser. The study should offer new methodology construct practice high-power high-modulated source for long-distance light detection ranging systems future.

A spectrally resolved interferometry ranging method based on the optical frequency comb of a femtosecond pulse laser was presented. The approach utilized stabilized Ti:sapphire to provide phase-locked summation discrete quasi-monochromatic light modes consecutive frequencies, which is seen as an in domain. In this all interference signals obtained by pulses traveling along different path between reference and measurement arms were measure absolute distance. Fabry-Perot Etalon used filter...

With the advent of era big data and vigorous development consumer electronics, demand for higher-speed processing capacity gigantic amounts is increasing; this requires finer far more numerous connections between dies as an essential component connection electronic communication layers. The coplanarity height micro bumps crucial to ensure reliability chip. triangulation method has been widely used in various types visual inspection applications over past several years due its high...

Spectrally resolved interferometry based on optical frequency comb is an effective way for absolute distance measurement. We introduce wavelet transform to spectrally resolve as data analysis tool. A comparison has been presented between and conventional algorithm. The results demonstrate that the a reliable technique provides good performance over noise resistance