Добірка наукової літератури з теми "Robust weak measurement"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Robust weak measurement".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Robust weak measurement"
1
Betz, Timm. "Robust Estimation with Nonrandom Measurement Error and Weak Instruments." Political Analysis 21, no. 1 (2013): 86–96. http://dx.doi.org/10.1093/pan/mps037.
Повний текст джерелаАнотація:
Two common problems in applications of two-stage least squares (2SLS) are nonrandom measurement error in the endogenous variable and weak instruments. In the presence of nonrandom measurement error, 2SLS yields inconsistent estimates. In the presence of weak instruments, confidence intervals andp-values can be severely misleading. This article introduces a rank-based estimator, grounded in randomization inference, which addresses both problems within a unified framework. Monte Carlo studies illustrate the deficiencies of 2SLS and the virtues of the rank-based estimator in terms of bias and efficiency. A replication of a study of the effect of economic shocks on democratic transitions demonstrates the practical implications of accounting for nonrandom measurement error and weak instruments.
2
Bhuvaneswari, S., R. Muthuganesan, and R. Radha. "Signatures of intrinsic decoherence and weak measurement on quantum correlations." Laser Physics Letters 19, no. 1 (December 2, 2021): 015204. http://dx.doi.org/10.1088/1612-202x/ac3b41.
Повний текст джерелаАнотація:
Abstract In this article, we consider a pair of spin-1/2 particles with squeezing coupling serving as the physical carrier of quantum information. We then examine the dynamics of quantum correlation quantified by the entanglement and measurement-induced nonlocality (MIN) under the intrinsic decoherence. The impact of intrinsic decoherence on the dynamical behaviors of quantum correlations is investigated. We show that the MIN quantities are more robust, while intrinsic decoherence cause sudden death in entanglement. Besides, we highlight the role of spin squeezing coupling and external magnetic field on quantum correlation measures. Finally, we investigate the impact of weak measurement on MIN.
3
Faujdar, Jyoti, and Atul Kumar. "Analysing the Efficiencies of Partially Entangled Three-Qubit States for Quantum Information Processing Under Real Conditions." Zeitschrift für Naturforschung A 74, no. 6 (June 26, 2019): 523–37. http://dx.doi.org/10.1515/zna-2018-0521.
Повний текст джерелаАнотація:
AbstractIn this article, we revisit the question of analysing the efficiencies of partially entangled states in three-qubit classes under real conditions. Our results show some interesting observations regarding the efficiencies and correlations of partially entangled states. Surprisingly, we find that the efficiencies of many three-qubit partially entangled states exceed that of maximally entangled three-qubit states under real noisy conditions and applications of weak measurements. Our analysis, therefore, suggests that the efficiencies of partially entangled states are much more robust to noise than those of maximally entangled states at least for the GHZ (Greenberger–Horne–Zeilinger) class states, for certain protocols; i.e. less correlations in the initially prepared state may also lead to better efficiency and hence one need not always consider starting with a maximally entangled state with maximum correlations between the qubits. For a set of partially entangled states, we find that the efficiency is optimal, independent of the decoherence and state parameters, if the value of weak measurement parameter is very large. For other values of the weak measurement parameter, the robustness of the states depends on the decoherence and state parameters. Moreover, we further show that one can achieve higher efficiencies in a protocol by using non-optimal weak measurement strengths instead of optimal weak measurement strengths.
4
Gebhart, Valentin, Kyrylo Snizhko, Thomas Wellens, Andreas Buchleitner, Alessandro Romito, and Yuval Gefen. "Topological transition in measurement-induced geometric phases." Proceedings of the National Academy of Sciences 117, no. 11 (March 2, 2020): 5706–13. http://dx.doi.org/10.1073/pnas.1911620117.
Повний текст джерелаАнотація:
The state of a quantum system, adiabatically driven in a cycle, may acquire a measurable phase depending only on the closed trajectory in parameter space. Such geometric phases are ubiquitous and also underline the physics of robust topological phenomena such as the quantum Hall effect. Equivalently, a geometric phase may be induced through a cyclic sequence of quantum measurements. We show that the application of a sequence of weak measurements renders the closed trajectories, hence the geometric phase, stochastic. We study the concomitant probability distribution and show that, when varying the measurement strength, the mapping between the measurement sequence and the geometric phase undergoes a topological transition. Our finding may impact measurement-induced control and manipulation of quantum states—a promising approach to quantum information processing. It also has repercussions on understanding the foundations of quantum measurement.
5
Peng, Gang, Zezao Lu, Jiaxi Peng, Dingxin He, Xinde Li, and Bin Hu. "Robust Tightly Coupled Pose Measurement Based on Multi-Sensor Fusion in Mobile Robot System." Sensors 21, no. 16 (August 17, 2021): 5522. http://dx.doi.org/10.3390/s21165522.
Повний текст джерелаАнотація:
Currently, simultaneous localization and mapping (SLAM) is one of the main research topics in the robotics field. Visual-inertia SLAM, which consists of a camera and an inertial measurement unit (IMU), can significantly improve robustness and enable scale weak-visibility, whereas monocular visual SLAM is scale-invisible. For ground mobile robots, the introduction of a wheel speed sensor can solve the scale weak-visibility problem and improve robustness under abnormal conditions. In this paper, a multi-sensor fusion SLAM algorithm using monocular vision, inertia, and wheel speed measurements is proposed. The sensor measurements are combined in a tightly coupled manner, and a nonlinear optimization method is used to maximize the posterior probability to solve the optimal state estimation. Loop detection and back-end optimization are added to help reduce or even eliminate the cumulative error of the estimated poses, thus ensuring global consistency of the trajectory and map. The outstanding contribution of this paper is that the wheel odometer pre-integration algorithm, which combines the chassis speed and IMU angular speed, can avoid the repeated integration caused by linearization point changes during iterative optimization; state initialization based on the wheel odometer and IMU enables a quick and reliable calculation of the initial state values required by the state estimator in both stationary and moving states. Comparative experiments were conducted in room-scale scenes, building scale scenes, and visual loss scenarios. The results showed that the proposed algorithm is highly accurate—2.2 m of cumulative error after moving 812 m (0.28%, loopback optimization disabled)—robust, and has an effective localization capability even in the event of sensor loss, including visual loss. The accuracy and robustness of the proposed method are superior to those of monocular visual inertia SLAM and traditional wheel odometers.
6
Kannawadi, Arun, Erik Rosenberg, and Henk Hoekstra. "Mitigating the effects of undersampling in weak lensing shear estimation with metacalibration." Monthly Notices of the Royal Astronomical Society 502, no. 3 (January 29, 2021): 4048–63. http://dx.doi.org/10.1093/mnras/stab211.
Повний текст джерелаАнотація:
ABSTRACT metacalibration is a state-of-the-art technique for measuring weak gravitational lensing shear from well-sampled galaxy images. We investigate the accuracy of shear measured with metacalibration from fitting elliptical Gaussians to undersampled galaxy images. In this case, metacalibration introduces aliasing effects leading to an ensemble multiplicative shear bias about 0.01 for Euclid and even larger for the Roman Space Telescope, well exceeding the missions’ requirements. We find that this aliasing bias can be mitigated by computing shapes from weighted moments with wider Gaussians as weight functions, thereby trading bias for a slight increase in variance of the measurements. We show that this approach is robust to the point-spread function in consideration and meets the stringent requirements of Euclid for galaxies with moderate to high signal-to-noise ratios. We therefore advocate metacalibration as a viable shear measurement option for weak lensing from upcoming space missions.
7
Shea, Mark J., Anika Weightman, Bradley Wibrow, and Matthew H. Anstey. "A Prospective Evaluation of Grip Strength Comparing a Low-Tech Method to Dynanometry in Preoperative Surgical Patients and Weak Intensive Care Patients." Critical Care Research and Practice 2022 (October 19, 2022): 1–6. http://dx.doi.org/10.1155/2022/3428851.
Повний текст джерелаАнотація:
Objective. Grip strength testing offers a mechanism to identify patients in whom frailty might be present, discriminate between robust elderly and vulnerable younger patients, and can be used as a tool to track changes in muscle bulk over the course of an inpatient stay. We compared gold-standard quantitative grip strength measurement to a low-tech alternative, a manual bedside sphygmomanometer. Design. Under supervision, subjects performed hand-grip strength testing with each instrument. A mean score is calculated from three measurements on the dominant and nondominant hand. Setting. Testing was performed in a tertiary centre in Perth, Western Australia, in both outpatient clinics and intensive care units. Participants. 51 adult pre-operative surgical outpatients were assessed, alongside 20 intensive care inpatients identified as being weak. Main outcome measures. A statistical correlation between the two measures was evaluated. Feasibility, safety, and convenience were also assessed in outpatient and bedside settings. Results. Highly correlated results in both tertiary surgical outpatients (rs = 0.895, p ≤ 0.001 , N = 102; r (100) = 0.899, p ≤ 0.001 ) and weak intensive care patients (rs = 0.933, p ≤ 0.001 , N = 39 r (37) = 0.935, p ≤ 0.001 ) Conclusions. Modifying a manual bedside sphygmomanometer to measure grip strength is feasible and correlates well with a formal dynamometer in preadmission surgical patients and weak patients in the intensive care unit. The use of an existing, safe, and available device removes barriers to the measurement of weakness in patients and may encourage uptake of objective measurement in multiple settings.
8
Takeuchi, Kiyoshi, Tomoko Mizutani, Takuya Saraya, Masaharu Kobayashi, and Toshiro Hiramoto. "A robust single device MOSFET series resistance extraction method considering horizontal-field-dependent mobility." Japanese Journal of Applied Physics 61, SC (February 10, 2022): SC1016. http://dx.doi.org/10.35848/1347-4065/ac3eb7.
Повний текст джерелаАнотація:
Abstract A simple MOSFET series resistance extraction method using multiple drain current versus gate voltage curves of a single device is proposed, where mobility modulation by a horizontal electric field (i.e., weak velocity saturation) is taken into account. The method is validated using TCAD, where series resistance determined from internal potential distributions was used as a reliable reference. Measurement results were also obtained which further support the validity of the method.
9
Bae, Junhyung. "Cost-Effective Placement of Phasor Measurement Units to Defend against False Data Injection Attacks on Power Grid." Energies 13, no. 15 (July 28, 2020): 3862. http://dx.doi.org/10.3390/en13153862.
Повний текст джерелаАнотація:
This study presents the phasor measurement unit (PMU) placement strategy in the presence of false data injection attacks which is one of the most serious security threats against power grid. It is focused on applications related to supervisory control and data acquisition (SCADA) systems where measurement data can be easily corrupted by adversaries without getting caught by the system. To safeguard power grids against malicious attacks, procedures have been proposed to facilitate the placement of secure PMUs to defend against false data injection attacks in a highly cost-effective way. It has formulated a method of identifying measurements that are vulnerable to false data injection attacks. It was discovered that a weak power grid can be transformed into a robust power grid by adding a few PMUs at vulnerable locations. Simulations on the IEEE standard test systems demonstrate the benefits of the proposed procedure.
10
Zhao, Chunran, Mengzheng Zhu, and Liu Ye. "Robust scheme for the preparation of polarization-photon cluster state with homodyne measurement via weak cross-Kerr nonlinearity." Journal of the Optical Society of America B 28, no. 7 (June 24, 2011): 1740. http://dx.doi.org/10.1364/josab.28.001740.
Повний текст джерелаЧастини книг з теми "Robust weak measurement"
1
Watson, David, and Michael W. O’Hara. "The Structure, Specificity, and Validity of Depression Symptoms." In Understanding the Emotional Disorders, 61–86. Oxford University Press, 2017. http://dx.doi.org/10.1093/med:psych/9780199301096.003.0003.
Повний текст джерелаАнотація:
This chapter examines key symptom criteria of major depression. It begins by developing a comprehensive measurement model based on six symptom dimensions: dysphoria, lassitude, insomnia, suicidality, appetite loss, and appetite gain. It then demonstrates that these symptom dimensions are robust and show impressive convergent and discriminant validity across multiple methods (self-reports, clinicians’ ratings, interview assessments). Three types of symptoms—dysphoria, lassitude, and suicidality—exhibit strong criterion validity and significant specificity in relation to diagnoses of major depression. In contrast, symptoms of insomnia and appetite disturbance display unimpressive criterion validity and poor specificity. Moreover, these nonspecific symptoms provided little or no incremental information in logistic regression analyses. Taken together, these results suggest that the diagnosis of depression can be improved by focusing primarily on strong and specific symptoms (such as dysphoria and lassitude) and deemphasizing weak and nonspecific symptoms (i.e., insomnia and appetite disturbance).
2
Haddas, R., S. Kisinde, D. Mar, and I. Lieberman. "Does improved radiographic alignment truly enhance dynamic functional balance?" In Studies in Health Technology and Informatics. IOS Press, 2021. http://dx.doi.org/10.3233/shti210433.
Повний текст джерелаАнотація:
Prospective, concurrent-cohort study. To establish the relationship between radiographic alignment parameters and functional CoE measurements at one week before and at three months after realignment surgery in ADS patients. Adult degenerative scoliosis (ADS) represents a significant healthcare burden with exceedingly high and increasing prevalence, particularly among the elderly. Radiographic alignment measures and patient-reported outcomes currently serve as the standard means to assess spinal alignment, deformity, and stability. Neurological examinations have served as qualitative measures for indicating muscle strength, motor deficits, and gait abnormalities. Three-Dimensional motion analysis is increasingly being used to identify and measure gait and balance instability. Recently, techniques have been established to quantify balance characteristics described by Dubousset as the “cone of economy” (CoE). The relationship between radiographic alignment parameters and CoE balance measures of ADS patients before and after realignment surgery is currently unknown. 29 ADS patients treated with realignment surgery. Patients were evaluated at one week before realignment surgery and at their three-month follow-up examination. During each evaluation, patients completed self-reported outcomes (visual analog scales for pain, Oswestry Disability Index, SRS22r) and a functional balance test. Mean changes in dependent measures from before to after surgery were compared using paired t-tests. Pearson correlations were used to test for significant correlations between changes in radiographic and CoE measures. Significant improvements were found for all patient-reported outcomes, in several radiographic measures, and in CoE measures. Improvements of scoliosis Cobb angle, coronal pelvic tilt, lumbar lordosis, and thoracic kyphosis showed significant correlations with CoE sway and total distance measures at both the center of mass and center of the head. Improved radiographic alignment measures significantly correlated with improved CoE balance measures among ADS patients treated with realignment surgery at their three-month follow-up. These findings indicate that functional balance evaluations when used in conjunction with radiographic measurements, may provide a more robust and improved patient-specific sensitivity for postoperative assessments. CoE balance may represent a new measure of added value for surgical intervention of ADS.
Тези доповідей конференцій з теми "Robust weak measurement"
1
Iinuma, Masataka, Yutaro Suzuki, Gen Taguchi, Yutaka Kadoya, and Holger F. Hofmann. "A method for weak measurement of photon polarization robust against experimental imperfections." In International Quantum Electronics Conference. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/iqec.2011.i347.
Повний текст джерела
2
Iinuma, Masataka, Yutaro Suzuki, Gen Taguchi, Yutaka Kadoya, and Holger F. Hofmann. "A method for weak measurement of photon polarization robust against experimental imperfections." In 2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim. IEEE, 2011. http://dx.doi.org/10.1109/iqec-cleo.2011.6193752.
Повний текст джерела
3
Albakri, Mohammad I., Vijaya V. N. Sriram Malladi, and Pablo A. Tarazaga. "Acoustoelastic-Based Stress Measurement Utilizing Low-Frequency Flexural Waves." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3858.
Повний текст джерелаАнотація:
Current acoustoelastic-based stress measurement techniques operate at the high-frequency, weakly-dispersive portions of the dispersion curves. The weak dispersive effects at such high frequencies allow the utilization of time-of-flight measurements to quantify the effects of stress on wave speed. However, this comes at the cost of lower sensitivity to the state-of-stress of the structure, and hence calibration at a known stress state is required to compensate for material and geometric uncertainties in the structure under test. In this work, the strongly-dispersive, highly stress-sensitive, low-frequency flexural waves are utilized for stress measurement in structural components. A new model-based technique is developed for this purpose, where the acoustoelastic theory is integrated into a numerical optimization algorithm to analyze dispersive waves propagating along the structure under test. The developed technique is found to be robust against material and geometric uncertainties. In the absence of calibration experiments, the robustness of this technique is inversely proportional to the excitation frequency. The capabilities of the developed technique are experimentally demonstrated on a long rectangular beam, where reference-free, un-calibrated stress measurements are successfully conducted.
4
Rebufello, Enrico, Fabrizio Piacentini, Alessio Avella, Muriel Aparecida De Souza, Marco Gramegna, Jan Dziewior, Eliahu Cohen, Lev Vaidman, Ivo Pietro Degiovanni, and Marco Genovese. "Experimental realization of robust weak measurements." In Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology II, edited by Selim M. Shahriar and Jacob Scheuer. SPIE, 2020. http://dx.doi.org/10.1117/12.2542097.
Повний текст джерела
5
Al-Aamri, Mohammed, Ahmed Al-Kindi, Yan Terras, Hussain Ajmi, Saud Khaldi, Dhiresh Govind Rao, Satya Perumalla, Ashok Shinde, Tanguy Lhomme, and Christophe Germay. "Using Continuous Core Measurements to Reduce the Uncertainty on Rock Strength vis-à-vis Geomechanical Modeling in a Tight Gas Reservoir in Sultanate of Oman." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2022. http://dx.doi.org/10.2118/200217-ms.
Повний текст джерелаАнотація:
Abstract This paper focuses on the case study of the geomechanical evaluation of a tight gas reservoir in Oman. Rock strength was characterized using data inputs/measurements with the objective to reduce uncertainty on predictions of wellbore stability in four deep gas wells. As a primary input for many standard geomechanical models, rock strength parameter is routinely measured on rock samples using triaxial/uniaxial tests. This parameter is traditionally named as Uniaxial Compressive Strength (UCS) measured during the axial loading and crushing of cylindrical "core plugs" extracted from cores. Although considered as a standard for rock strength evaluation, this method has some limitations such as (i) sample destruction, (ii) natural bias in weak formations (iii) natural dispersion, (iv) discretization of the measurement along sampled intervals and (v) sample preparation challenges. The scratch test has been developed as a rapid and cost effective rock strength testing method addressing these limitations. The relative advantages of the scratch test as an alternative to standard rock strength testing are discussed and its added value demonstrated in the context of practical applications for a tight gas reservoir. Geomechanical data was acquired from four different wells with the following measurements: (i) Acoustic wireline log, (ii) Uniaxial compressive strength resulting from laboratory tests on plug samples, (iii) a continuous high-resolution strength profile interpreted from scratch tests performed on whole cores. Then, the data from all these sources has been integrated following a dedicated workflow designed to reduce the uncertainty in the output of strength models from wireline logs, through careful handling of data resolution differences and heterogeneity mapping. Encouraging correlations between core-based measurements and scratch test suggests that the scratch test has emerged as a valid alternative to standard rock mechanical tests in suitable situations. Robust statistics are provided for strength and explanations are proposed for outlier values from tests on plug samples. Furthermore, the continuity and the high resolution of the strength profile enables a much better calibration of strength proxies from acoustic wireline logs. Finally, the scratch test yield values from shale intervals that were traditionally overlooked by plug site selections for rock mechanical testing. The strength assessment protocol from the scratch test handles rock heterogeneity with a much larger data set than conventional rock strength testing methods. This enables more robust core property-log calibration at different length scales. Such continuous high resolution profiles of rock properties leads to a significant reduction in uncertainty in petrophysical and geomechanics models, and better decision making in well design and field management.
6
Fansler, Todd D. "Photon-Correlation Laser Velocimetry in Reciprocating-Engine Research." In Photon Correlation Techniques and Applications. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/pcta.1988.efd54.
Повний текст джерелаАнотація:
Following a detailed review of practical aspects of photon-correlation laser-Doppler velocimetry, automotive applications are surveyed with emphasis on broad experimental and interpretive concerns common to unsteady flows and confined environments. Such situations typically permit only limited optical access and thereby place a premium on efficient operation with weak (single-photon) signals in the presence of considerable noise. Fast, robust data-acquisition and -reduction techniques that minimize user intervention are described. The survey of automotive applications concentrates on turbulent in-cylinder flow fields and combustion, but briefly includes wind-tunnel and soot-sizing measurements.
7
Söffker, Dirk. "Elastic Robot Arms With Variable Length: Part II — Robust Control of Elastic Vibrations." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0263.
Повний текст джерелаАнотація:
Abstract In the last years modeling, simulation, and control of flexibel structures have made an essential progress, especially stimulated by the requirements of space operations. For this working field, flexible lightweight robots can enhance the work space of space robots very well, if the length of the robot arm is variable. Contributions in the corresponding literature mostly consider models of special configurations and perform simple approximations or even assume linear models to describe the elastic motions of the robot. However, especially in the case of lightweight robots undergoing large reference motion, its nonlinear dynamic behaviour should be modeled as exact as possible. The mechanical system should be controlled to improve its dynamical behaviour. Unfortunately, it is not possible to measure the position of the endeffector. The only measurements that can be done are that of the strains of the beam. The control input should be the velocity (translational and rotational) transmitted to the base of the beam. This includes a correction of the actual path planning values as a kinematical control. Here the specified task is solved in two parts: Firstly, the variable length, the geometric nonlinear beam behaviour and the large reference motion of the driven joint are taken into consideration with a systematic modeling approach in (Söffker, 1995b; Söffker, 1995c). Nonlinear control approaches can often be used only for special classes of problems assumptions have to be made, which cannot be generally fulfilled in practice. Here a new controller is developed which is realizable for on-line applications with the mentioned restrictions. Therefore, in a second part the mechanical plant will be controlled by a new observer-based dynamic compensation scheme. Based on a linear time-invariant model, nonlinear effects and unmodeled dynamics are estimated in a first step by an Proportinal-Integral (PI) observer scheme, whereby the nonlinearities and the effects of the non-considered time-varying parameters etc. are assumed as external disturbances. The used PI-observer (Söffker, 1995a) estimates the states of the system and the external disturbances under some weak assumptions. Using this informations about the external disturbances to the nominal time-invariant system, the task of an extended regulator scheme is to compensate these effects in a second step. Because of the structure of the given mechanical system, usual static disturbance compensation schemes are not useful. Therefore a new dynamic approach is developed, which uses the estimations of the extended observer. The developed method does not depend on the structure of the physical problem and can be also used more generally. This is mainly due to the robustness of the observer-based dynamic compensation scheme. Two examples of a very flexible spatial telescopic robot arm demonstrate the effects of disturbances compensation and control of the elastic vibrations induced by the initial conditions and the reference motion.
8
Patel, N. D., and P. S. Nicholson. "On-Line Tool Monitoring of Tool Wear Chipping/Breakage and Temperature Using Ultrasonic Sensors." In ASME 1997 Turbo Asia Conference. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-aa-062.
Повний текст джерелаАнотація:
High frequency (50–120) MHz, ultrasonic, AIN-sensors have been successfully applied to the study of wear, chipping/breakage and temperature of triangular ceramic and carbide inserts. These sensors readily differentiate between signals from wear and chipping/breakage and, in flight-identify the damage location with simultaneous measurement of signal amplitude and transit time. The signals are unaffected by the machining process. The temperature of the chip/tool interface can be readily obtained during the cutting process by monitoring the transit time. Preliminary studies suggest these sensors also monitor the hardness of the workpiece and the chatter during the cutting. A specially-designed ultrasonic process-control system with 100 ps time resolution with data collection speed 1–10 kHz was necessary to observe the on-line data. The same system integrated with a focused transducer can be used to follow the workpiece dimension and surface finish, on-line. The ultrasonic, process control system that has been developed is robust and can be used for other NDE applications with a resolution of sub-micron thickness. It can also monitor residual stresses.
9
Baruffati, Paul Pasquale, and Marcel Emile Ngueguim. "The Evolution of Hard Rock Drilling in Norway: How New Technology Solved an Old Challenge." In Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213654-ms.
Повний текст джерелаАнотація:
Abstract The Åsgard field in the Norwegian sea contains hard, abrasive, and high temperature formations and the reservoir had never been successfully drilled in a single slimhole run over 10 years. Thorough engineering analysis, the application of lessons learned, and the introduction of new generation technology produced a series of improvements. These advances define a sustainable and systematic approach to efficient, cost-effective hard rock drilling in the Norwegian Sea and elsewhere. The method was to define the limitations of the existing approach and then iterate improvements to the system to increase performance. The first step was to define the existing operating envelope: offset data – drilling, downhole, and post-well analysis – was reviewed and weak points were identified. Then, using the most appropriate lessons from hard rock environments worldwide, initial design changes were made to the drilling approach and procedures. These changes delivered the first failure-free well in the field. New technology was then introduced to expand the drilling envelope further and this culminated in the first single run slimhole section in the field. Flat time was drastically reduced, while ROP and borehole quality were improved. Through scrutiny of drilling dynamics, high frequency torsional resonance (HFTO) was revealed to be driving system mechanical inefficiencies. Log analysis enabled the correlation of the onset of HFTO to lithology type, and new drilling parameter limitations – principally management of Weight On Bit (WOB) – were then defined. Real-time drilling optimization engineers were enlisted to support this approach. Rock strength analysis and post-run equipment inspection determined the need for more durable bit and Bottom Hole Assembly (BHA) designs. A custom drill bit was designed and a ruggedized, new generation Rotary Steerable System (RSS) and Measurement and Logging While Drilling (MWD/LWD) suite introduced. Within the established operating framework, this new technology enabled enhanced drilling parameters to be applied and resulted in a 53% improvement in penetration rate. High density survey data from the new MWD/LWD platform showed that the new generation drilling technology delivered an extremely high quality wellbore, where the cumulative tortuosity was within 5% of the theoretical well plan. This allowed the installation of the completion string in a new record time, reducing the technical limit. Overall, flat time was reduced by 56% and then 76% versus the offset average. Robust, new generation technology and a rigid adherence to system limits as defined by advanced engineering analysis provided a framework for rapid continuous improvement and a blueprint for repeatable, efficient performance. This can be used to drive efficiency improvements in similar offshore hard rock environments elsewhere.
10
Ahmed, Hassaan, Mohammad Rasheed Khan, Abdul Bari, Kamran Rashid, Syed Dost Ali, Sandeep Dhawan, Talha Zubair, Usman Anjum, and Neil Sookram. "Analysis Behind Casing to Assess Zonal Isolation and Casing Deterioration in a High Pressure Exploratory Well - ABC to Z of Well Integrity Barrier Evaluation." In SPE/IADC International Drilling Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/204119-ms.
Повний текст джерелаАнотація:
Abstract The UHP exploratory well subject of this study faced with myriad challenges, including fishing, side-tracking, and other undesirable incidents with consequences to the 9-7/8" production casing. Torque and drag analysis, preliminary casing wear simulations, and actual drilling parameters pointed towards multiple uncertainties concerning barrier integrity. Consequently, a multi-physics evaluation was conducted including well-integrity logs in a combination of thickness-mode with flexural-mode of the casing. Signals from these independent measurements are then processed to provide robust interpretation of solid-liquid-gas behind casing using acquired flexural attenuation and acoustic impedance data. In addition, casing wear is quantified by thickness changes measured through the resonance frequency of the waveform and represented in the form of a joint-by-joint corrosion summary, reporting the average metal loss. Furthermore, propagation of flexural wave-fronts as it leaks to the third interface is tracked to produce a unique image of the annulus geometry in terms of casing eccentricity and acoustic velocity of the medium. Subsequently, the former, provides a quantifiable, unique in-situ casing standoff measurement to be used for centralization evaluation. Application of the developed data-integrated workflow allowed for comprehensively analyzing well integrity barrier condition. Cement barriers were assessed with confidence by flexural imaging, which were difficult to determine solely with pulse-echo. Additionally, annulus imaging using third interface-echo (TIE) helped in characterizing the potential causes of casing wear and quality of cement behind casing by providing actual in-situ casing standoff. It was observed that casing wear was at the low side of the wellbore where the casing had the least standoff as shown by flexural waveform TIE arrivals. Moreover, high percentage of metal loss was correlated to regions with centralization lower than 40-50%. Integration of these results with casing side forces and remaining casing strength (under worst case scenario) was performed to evaluate casing endurance for future drilling, production, and injection operations.
Звіти організацій з теми "Robust weak measurement"
1
VanderGheynst, Jean, Michael Raviv, Jim Stapleton, and Dror Minz. Effect of Combined Solarization and in Solum Compost Decomposition on Soil Health. United States Department of Agriculture, October 2013. http://dx.doi.org/10.32747/2013.7594388.bard.
Повний текст джерелаАнотація:
In soil solarization, moist soil is covered with a transparent plastic film, resulting in passive solar heating which inactivates soil-borne pathogen/weed propagules. Although solarization is an effective alternative to soil fumigation and chemical pesticide application, it is not widely used due to its long duration, which coincides with the growing season of some crops, thereby causing a loss of income. The basis of this project was that solarization of amended soil would be utilized more widely if growers could adopt the practice without losing production. In this research we examined three factors expected to contribute to greater utilization of solarization: 1) investigation of techniques that increase soil temperature, thereby reducing the time required for solarization; 2) development and validation of predictive soil heating models to enable informed decisions regarding soil and solarization management that accommodate the crop production cycle, and 3) elucidation of the contributions of microbial activity and microbial community structure to soil heating during solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays, and samples were subjected to 16S ribosomal RNA gene sequencing to characterize microbial communities. Amendment of soil with 10% (g/g) compost containing 16.9 mg CO2/g dry weight organic carbon resulted in soil temperatures that were 2oC to 4oC higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. The sequencing data obtained from field samples revealed similar microbial species richness and evenness in both solarized amended and non-amended soil. However, amendment led to enrichment of a community different from that of non-amended soil after solarization. Moreover, community structure varied by soil depth in solarized soil. Coupled with temperature data from soil during solarization, community data highlighted how thermal gradients in soil influence community structure and indicated microorganisms that may contribute to increased soil heating during solarization. Reliable predictive tools are necessary to characterize the solarization process and to minimize the opportunity cost incurred by farmers due to growing season abbreviation, however, current models do not accurately predict temperatures for soils with internal heat generation associated with the microbial breakdown of the soil amendment. To address the need for a more robust model, a first-order source term was developed to model the internal heat source during amended soil solarization. This source term was then incorporated into an existing “soil only” model and validated against data collected from amended soil field trials. The expanded model outperformed both the existing stable-soil model and a constant source term model, predicting daily peak temperatures to within 0.1°C during the critical first week of solarization. Overall the results suggest that amendment of soil with compost prior to solarization may be of value in agricultural soil disinfestations operations, however additional work is needed to determine the effects of soil type and organic matter source on efficacy. Furthermore, models can be developed to predict soil temperature during solarization, however, additional work is needed to couple heat transfer models with pathogen and weed inactivation models to better estimate solarization duration necessary for disinfestation.