Measurement Scheme Research Articles

Complete Bell state measurement for polarization–path high-dimensional hyperentangled photons

We present a theoretical scheme for the complete Bell state measurement (BSM) for high-dimensional hyperentangled photons in polarization and path degrees of freedom (DOFs), in which the polarization entanglement is in two-dimensional Hilbert space and the path entanglement is in four-dimensional Hilbert space. This 2×4-dimensional photonic quantum system contains 64 mutually orthogonal high-dimensional hyperentangled Bell states, which can be unambiguously discriminated by using weak cross-Kerr nonlinearity, linear optical element, and single-photon detector. This is the first complete BSM scheme for high-dimensional hyperentangled photons in two DOFs assisted by the quantum nonlinear effect, and we also demonstrate its application in the quantum superdense coding protocol, which allows the transmission of log264=6 bits of classical information via just sending one photon. Moreover, our scheme only requires the achievable small nonlinear phase shift, and it can provide new avenues for other BSM-based quantum information technologies involving photonic high-dimensional hyperentanglement.

Quantum Reference Frames, Measurement Schemes and the Type of Local Algebras in Quantum Field Theory

We develop an operational framework, combining relativistic quantum measurement theory with quantum reference frames (QRFs), in which local measurements of a quantum field on a background with symmetries are performed relative to a QRF. This yields a joint algebra of quantum-field and reference-frame observables that is invariant under the natural action of the group of spacetime isometries. For the appropriate class of quantum reference frames, this algebra is parameterised in terms of crossed products. Provided that the quantum field has good thermal properties (expressed by the existence of a KMS state at some nonzero temperature), one can use modular theory to show that the invariant algebra admits a semifinite trace. If furthermore the quantum reference frame has good thermal behaviour (expressed in terms of the properties of a KMS weight) at the same temperature, this trace is finite. We give precise conditions for the invariant algebra of physical observables to be a type II1 factor. Our results build upon recent work of Chandrasekaran et al. (J High Energy Phys 2023(2): 1–56, 2023. arXiv:2206.10780), providing both a significant mathematical generalisation of these findings and a refined operational understanding of their model.

PENGUKURAN EKSISTING BANGUNAN BALI DENGAN KETINGGIAN TERTENTU MELALUI METODE MODUL MATERIAL BANGUNAN, PHYTAGORAS DAN 3D MODELING STUDI KASUS BANGUNAN BALE BANJAR TENGANAN, BALI

Balinese building concepts such as nawa sanga, tri mandala, Tri Angga and others are the basic concepts for Balinese buildings in the past and present. One concept that is often found in Balinese buildings is the tri angga concept, this concept reflects the feet, body and head of the building. Balinese buildings always have feet (foundation), body (wall) and head (roof) in each building, this has also become an official regulation of the Balinese government requiring buildings that want to have a building permit must have the Tri Angga concept. Many old Balinese buildings have the tri angga concept, but it is very unfortunate that old Balinese buildings have begun to be abandoned, dismantled and renovated to the current era. This problem is caused by the existing old Balinese buildings not having technical drawing data that can be used as a basis for buildings to be renovated. People prefer buildings to be dismantled and replaced with new buildings because it will be easier to build new buildings than to renovate old buildings without technical drawings. The problem of why old buildings do not have technical drawings is because the building measurement process requires many people and must be measured manually to the top of the building. Many costs will be incurred for one building resulting in this measurement process not being carried out. This problem becomes the mindset of the purpose of this research. The purpose of this research is to find the development of measurement methods, from manual methods to easy-to-do measurement coding systems. In this study, quantitative methods will be used with the help of material modules, Pythagorean formulas and 3D methods. The results of this study found that old Balinese buildings can be measured from the angle of the building, using material modules can calculate the distance from the structure, and the Pythagorean geometry formula is the key to this measurement scheme.

Optical characterization of parasitic motion in a long-stroke shaker

Abstract We present an optical scheme to simultaneously characterize the cross-axis and rotational parasitic motions of a long-stroke shaker. By leveraging the geometric properties of a corner cube retroreflector mounted on the shaker load table, we independently sample pitch, yaw, and horizontal and vertical displacements with sampling rates above 10 kHz. We have applied our optical apparatus to a 400-mm-stroke shaker operated from 0.1 Hz to 100 Hz and present two forms of analysis: (A) Frequency-domain data for the four measured parasitic degrees of freedom, with the resulting implications for accelerometer calibration uncertainties, and (B) extracted trajectories of the shaker table, allowing visualization of the bowed linear guide below 0.5 Hz and higher harmonics and hysteresis above 10 Hz. Our findings demonstrate our optical measurement scheme to be an effective tool for the characterization of parasitic motion for long-stroke shakers. As an example, we determine the ‘gravity error’ in accelerometer calibration with our shaker to be ( 1.3 ± 0.1 ) % times the acceleration amplitude at 0.1 Hz, providing a correction to reduce uncertainty from this effect by an order of magnitude.

A quality control scheme for solar irradiance measurements on facades in urban environments

A quality control scheme for solar irradiance measurements on facades in urban environments

A Coloring-Based Packet Loss Rate Measurement Scheme on Network Nodes

Network measurement is an efficient way to understand network behavior. Traditional measurement techniques focus on internet protocol (IP) networks, where the processing capacity of network nodes is limited and primarily dedicated to packet forwarding. As a result, these techniques typically rely on end hosts or external systems to analyze traffic and evaluate network performance. This reliance introduces several challenges, such as increased measurement latency and scalability limitations, particularly in large-scale networks. With the emergence of next-generation internet architectures, especially information-centric networking (ICN), network nodes have gained enhanced capabilities, enabling measurement tasks to be performed directly at these nodes. This paper proposes a distributed measurement scheme where network nodes collaborate to monitor the packet loss rate on the intermediate link. By setting an unused bit in the packet header, the upstream node “colors” the packets into different color blocks. The minimum duration of each block is determined by the degree of reordering on the link, and the number of packets in each block must be a power of two. The downstream node recognizes blocks, assigns packets to the right block, and deduces the original number of packets for each block to calculate packet loss. Moreover, the upstream node adjusts the number of packets in each block based on the packet transmission rate on the link, aiming to balance measurement accuracy and frequency. A P4-based implementation on a BMv2 software switch is presented to demonstrate the feasibility of the proposed scheme. Simulations show that this scheme improves measurement accuracy and is more robust against packet reordering. Additionally, the proposed scheme maintains relatively low network overhead and, at higher measurement frequencies, exhibits the lowest overhead compared to existing methods.

Electrical spectra characterization of mode-locked fiber laser and application for high-speed optoelectronic devices measurement

A calibration-free and three-in-one electro-optic frequency sweeping-based method is proposed for the electrical spectra and frequency response characterization of mode-locked fiber laser (MLFL) MLFL, intensity modulators (IMs), and photodetectors (PDs) with a shared measurement scheme. By carefully setting the frequency relationship between the swept frequency, the extra influence from other assisted devices besides device under test (DUT) is fully cancelled out by analyzing the power ratio between the single-tone driving signal and electrical signals of the MLFL after photodetection. Moreover, the wideband requirement of the assistant devices is reduced by half to that of the DUT in the cases of the MLFL, IM, and PD measurement, respectively. The microwave characterization of the MLFL, IM and PD are experimentally extracted with the proposed method and the measured results are compared to those obtained with the traditional electro-optic frequency sweeping method to check the consistency and accuracy.

DEWS: A Distributed Measurement Scheme for Efficient Wireless Sensing

DEWS: A Distributed Measurement Scheme for Efficient Wireless Sensing

High-precision measurement of the magneto-optical Faraday effect via difference weak measurements

We propose a modified difference weak measurement scheme that permits precise measurements of the magneto-optical Faraday effect. By making normalized difference processing for a set of post-selected light intensity, a linear-response regime with a significant weak-value amplification effect is established. In the proof-of-principle experiment, we measure the magnetic intensity using the polarization system and achieve precision at the order of ∼10−7 T. Our scheme can be applied to measure other magneto-optical effects, providing a method for future ultra-sensitive sensing and metrology in magnetic physics.

Optimization of the method for determining the velocity of surface acoustic waves

The methodological aspects of measuring the velocity of Rayleigh surface waves are considered. The main attention is paid to the method for determining the change in surface wave velocity under the influence of certain factors on the object of study. The main sources of error in determining the change in surface acoustic wave velocity are discussed. The use of a transducer with rigidly connected elements for exciting and recording surface acoustic waves to determine the change in velocity is examined. A distinctive feature of such a transducer is the stable measurement base length, which eliminates the need for its determination during the measurement process. It is shown that the main sources of decreased surface acoustic wave measurement accuracy are the temperature instability of the measuring equipment and the transducer, as well as the instability of the acoustic contact layer between the transducer ele-ments and the object of study. The instability of the acoustic contact is caused by the uncertainty in the distribution of the coupling fluid between the transducer and the specimen during the bonding process, leading to changes in the acoustic signal propagation time. The source of temperature instability is random changes in the ambient temperature. Another source of such instability is the heating of equipment elements due to the release of heat when electrical and acoustic energy pass through them. This is particularly important for the transducer, where electrical energy is converted into acoustic energy, as a significant portion of it is transformed into heat. The magnitude of temperature instability arising from prolonged system operation, as well as the instability caused by the installation of the transducer on the object of study, is experimentally evaluated. The use of a reference sample to compensate for the temperature instability of the measurement system is considered. The possibility of using a measurement scheme with a reference sample to reduce temperature instability and the error caused by the instability of the acoustic contact between the transducer and the object of study is analyzed.

High range resolution spectral-scanning LiDAR based on optical frequency-domain reflectometry.

Spectral scanning, which utilizes the dispersive effect of light, is a simple and robust method for solid-state beam steering in light detection and ranging (LiDAR) applications. Powered by a tunable laser source, optical frequency-domain reflectometry (OFDR) is a high-precision measurement scheme that is inherently compatible with spectral scanning. Here, we propose a spectral-scanning LiDAR based on OFDR technology and demonstrate that, by connecting the measured spectral reflectivity and group delay of the targets with the dispersion equation, their cloud point data can be obtained. Moreover, compared to the spectral-scanning LiDAR based on the frequency-modulated continuous-wave (FMCW) ranging method, our proposed LiDAR scheme offers a more than tenfold improvement in range resolution with a large number of angular pixels. This enhancement enables high-resolution 3D imaging along both the angular and range axes.

Fluctuation theorems, quantum channels and gravitational algebras

In this note we study nonequilibrium fluctuations in gravitational algebras within de Sitter space. An essential aspect of this study is quantum measurement theory, which allows us to access the dynamical fluctuations of observables via a two-point measurement scheme. Using this formalism, we establish specific fluctuation theorems. Additionally, we demonstrate that quantum channels are represented by subfactors, using the relationship between measurement theory and quantum channels. We also comment on implementing a quantum channel using Jones’ theory of subfactors.

Overview of High-Performance Timing and Position-Sensitive MCP Detectors Utilizing Secondary Electron Emission for Mass Measurements of Exotic Nuclei at Nuclear Physics Facilities.

Timing and/or position-sensitive MCP detectors, which detect secondary electrons (SEs) emitted from a conversion foil during ion passage, are widely utilized in nuclear physics and nuclear astrophysics experiments. This review covers high-performance timing and/or position-sensitive MCP detectors that use SE emission for mass measurements of exotic nuclei at nuclear physics facilities, along with their applications in new measurement schemes. The design, principles, performance, and applications of these detectors with different arrangements of electromagnetic fields are summarized. To achieve high precision and accuracy in mass measurements of exotic nuclei using time-of-flight (TOF) and/or position (imaging) measurement methods, such as high-resolution beam-line magnetic-rigidity time-of-flight (Bρ-TOF) and in-ring isochronous mass spectrometry (IMS), foil-MCP detectors with high position and timing resolution have been introduced and simulated. Beyond TOF mass measurements, these new detector systems are also described for use in heavy ion beam trajectory monitoring and momentum measurements for both beam-line and in-ring applications. Additionally, the use of position-sensitive timing foil-MCP detectors for Penning trap mass spectrometers and multi-reflection time-of-flight (MR-TOF) mass spectrometers is proposed and discussed to improve efficiency and enhance precision.

Correlation-based polarity-check algorithm for instrument transformers

A polarity identification is very important for operation of transformers, measurement and protection equipment, where it is useful in analyzing of transformer connections and operation as well as testing of protective systems. Moreover, it’s essential in assessment of power systems performance during both normal and abnormal operation. Ensuring the correct polarity of the primary and secondary windings in voltage and current transformers is of paramount importance for various measurement and protection schemes in power networks. This paper proposes a digital polarity detector and tester using correlation coefficients and nine polarity indices calculated for instrument transformer signals. In order to test the performance of the proposed polarity tester algorithm, MATLAB code is imported to the LABVIEW model, and the numerical data obtained from the synchronous generator terminals via instrument transformers are interfaced with the computer through the Data Acquisition Card (DAC). The experimental system consists of a motor-generator set supplying a three-phase inductive load with instrument transformers connected to measure each phase voltage and current. The obtained results for various operating conditions and different types of abnormal conditions prove that the suggested algorithm is accurate, reliable and applicable to smart grids and substation automation systems. It can be considered as an integrated system incorporated with digital fault recorders, relays and meters.

Cascaded compressed-sensing single-pixel camera for high-dimensional optical imaging

Single-pixel detectors are popular devices in optical sciences because of their fast temporal response, high sensitivity, and low cost. However, when being used for imaging, they face a fundamental challenge in acquiring high-dimensional information of an optical field because they are essentially zero-dimensional sensors and measure only the light intensity. To address this problem, we developed a cascaded compressed-sensing single-pixel camera, which decomposes the measurement into multiple stages, sequentially reducing the dimensionality of the data from a high-dimensional space to zero dimension. This measurement scheme allows us to exploit the compressibility of a natural scene in multiple domains, leading to highly efficient data acquisition. We demonstrated our method in several demanding applications, including enabling tunable single-pixel full-waveform hyperspectral light detection and ranging (LIDAR) for the first time.

The Peculiarities of Acoustic Normal Waves Propagation in Thin Porous Sheets of Thermally Expanded Graphite

Thermally expanded graphite belongs to a new class of graphite materials with unique physical, chemical and mechanical properties. Acoustic wave velocity is one of the most important characteristics for study of porous materials including thin porous sheets of thermally expanded graphite. In this paper peculiarities of symmetric mode S0 Lamb wave propagation and SH-wave with horizontal polarization in sheets of thermally expanded graphite are experimentally investigated. To determine their velocities a differential measurement scheme on the base of a low-frequency acoustic flaw detector DIO1000 LF and specialized piezoelectric transducers with dry point contact was used. Additionally the longitudinal wave velocity in direction of sheet thickness was determined using piezoelectric transducers based on polyvinylidene fluoride. Indicatrices of normal wave velocities in the rolling plane were plotted and it was shown that the maximum acoustic anisotropy is characteristic for the S0-mode. The velocity minimum corresponds to the longitudinal direction of the rolling plane in which the maximum elongation of gas pores was observed. Influence of thickness and density of thermally expanded graphite sheets on the velocities of normal waves was investigated and presence of the thickness range where the minimum velocity values were observed due to the maximum inhomogeneity of layers formed in the rolling process. Method for determination of dynamic elastic moduli of porous thermally expanded graphite sheets using experimentally measured velocities of normal waves was proposed. It was shown that in the longitudinal direction of the rolling plane the Poisson's ratio took negative values which allow to attribute the specified material to auxetics ones.

Time-encoded photonic quantum states: Generation, processing, and applications

Encoding and processing quantum information in the time-of-arrival of photons offer significant advantages for quantum information science and technology. These advantages include ease of experimental realization, robustness over photon state transmission, and compatibility with existing telecommunication infrastructure. Additionally, time-of-arrival encoding has the potential for high-rate quantum communication and holds promise for the future development of quantum internet. This review explores the generation, processing, and applications of time-encoded quantum states, focusing on both single-photon states, energy–time entanglement, and time-bin entanglement. We summarize the nonlinear optics platforms and advanced laser and modulation techniques utilized for photon sources that enable quantum information encoding onto the photons' time-of-arrival. We also highlight advanced quantum state processing methods in the time domain, including the Franson interferometry, optical switch-based schemes, and state-of-the-art measurement and detection schemes that allow for high-speed and multi-dimensional quantum operations. Finally, we review the mainstream implementations mainly including the quantum communication demonstrations and outline future directions for developing practical quantum networks leveraging time-encoded photon states.

A wearable iontronic sensor for nasal cannula-facial interface pressure distribution evaluation

Enhancing the comfort of high-flow nasal cannulas holds practical significance in clinical settings, as it can alleviate pain during treatment, improve patient compliance, and reduce the occurrence of facial pressure sores during extended wear. The pressure distribution at the nasal cannula-facial interface is a key factor affecting comfort. In this paper, we present a flexible iontronic sensor with ultra-high sensitivity (up to 0.6 nF/mmHg), low activation pressure (as low as 1 mmHg), and a fast response time (up to 30 ms) for measuring pressure at the nasal cannula-facial interface. The introduction of a poly (methyl methacrylate) (PMMA) bonding layer enables the ionic layer to form a robust sensing interface with the electrode. A unified pressure distribution measurement scheme was established, and 10 subjects were recruited to wear four brands of commercially available nasal cannulas to evaluate the dynamic pressure distribution in different states. The proposed device provides a feasible solution for assessing nasal cannula comfort and provides a quantitative evaluation framework for optimizing nasal cannula designs, with direct implications for patient care.

Comprehensive Compensation Scheme for Fetal Magnetocardiography Measurement

Comprehensive Compensation Scheme for Fetal Magnetocardiography Measurement

Innovation in nitrogen concentration measurement method based on TRIZ

Abstract The current UV curing (Ultra-Violet Ray Curing) process necessitates the absence of oxygen, and the industrial standard often achieves this by replacing air with nitrogen to attain a nitrogen concentration of 99.97%, thereby fulfilling process requirements. However, the existing nitrogen concentration measuring instruments with a response time of 30 s are incapable of directly ascertaining whether the nitrogen concentration within the chamber has already reached 99.97% prior to those 30 s. This paper systematically analyzes the issues in the current measurement system through the application of the Theory of Inventive Problem Solving (TRIZ), encompassing Function Analysis, Cause -Effect Chain Analysis, Engineering Contradiction and Inventive Principles [1, 2]. Furthermore, a novel nitrogen measurement scheme is proposed to clarify the temporal profile of nitrogen concentration during the displacement process, thereby providing a basis for accurately setting the nitrogen displacement time. This approach can lead to a reduction in nitrogen wastage and shorten production cycles.