IEEE Transactions on Instrumentation and Measurement最新文献

{"title":"Determination of Trap Distribution Based on Voltage Response Measurement for Condition Monitoring of Nuclear Power Plant I&C Cables","authors":"Zoltán Ádám Tamus","doi":"10.1109/TIM.2024.3481580","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481580","url":null,"abstract":"The voltage response (VR) measurement was developed decades ago as a condition monitoring technique for oil-paper insulation of electrical equipment. Later, the improved version of the method, namely, the extended voltage response (EVR), was introduced as an efficient tool for determining the electrical model and the dielectric response of insulations. This article presents a new interpretation of the EVR measurement results, namely, the deduction of how the trap distribution could be determined from the measurement results and how the trap distribution provided by the method can be used as a potential condition indicator for nuclear cables. The proposed method was tested on gamma-irradiated and thermally aged ethylene-propylene rubber (EPR)-insulated instrumentation and control (I&C) cable samples. The shallow and deep traps around 0.76- and 0.86-eV energy depth were identified, and the trap densities showed an increasing trend with aging time for irradiation and thermal aging. The results were compared with elongation at break (EaB) data, the most generally accepted condition indicator for polymeric cable components in the nuclear industry. Since a strong correlation between the EaB and deep trap density was shown, regression curves were calculated. In addition, based on the regression curves, threshold trap density values were determined for 25% of the remaining lifetime. The results revealed that the deep trap density can be a reliable condition indicator for nuclear power plant (NPP) cables.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Different Coupling Types of Fiber-Optic Fabry–Perot Ultrasonic Sensing for Detecting Partial Discharge Faults in Oil-Paper Insulated Equipment","authors":"Hong Liu;Zhixian Zhang;Haoyuan Tian;Yuxuan Song;Jianxin Wang;Zhiqing Shu;Weigen Chen","doi":"10.1109/TIM.2024.3481543","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481543","url":null,"abstract":"Power transformer internal partial discharge fault detection is a guarantee for the safe operation of the power system. Fiber-optic Fabry–Perot (F-P) sensors are widely used in the partial discharge detection of power equipment due to the antielectromagnetic interference, high sensitivity, and built-in fault location. Based on two different types of sensing principles, F-P sensors are divided into two categories: F-P cavity length change (indirect-coupled F-P) and medium refractive index change (direct-coupled F-P). At present, most scholars focus on indirect-coupled F-P studies, and direct-coupled F-P sensors based on the change of refractive index of the medium are less studied. This article focuses on the effect of fluid parameter variations on its internal spatial optical waveguide in the liquid-phase environment, revealing the acousto-optic direct-coupled F-P sensing mechanism in oil. Two types of F-P sensors were developed and the band characteristics, directional performance, and sensitivity of F-P sensors were comparatively tested. The results show that the indirect-coupled F-P sensors have a narrow and highly sensitive response region, typically 20–30 kHz, but are less directional and insensitive to lateral signals. Direct-coupled F-P sensors have a wide bandwidth, a wide dynamic range, a flat response in the 1–200 kHz range, and omnidirectional detectability. In this article, a comparison of partial discharge fault detection of oil-paper insulation equipment was carried out using two types of F-P sensors. The results show that indirect-coupled F-P sensors detect partial discharges with partial signal distortion, while direct-coupled F-P sensors can effectively detect different types of partial discharge ultrasonic signals of oil-paper insulated equipment.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A General Multistage Deep Learning Framework for Sensor-Based Human Activity Recognition Under Bounded Computational Budget","authors":"Xing Wang;Lei Zhang;Dongzhou Cheng;Yin Tang;Shuoyuan Wang;Hao Wu;Aiguo Song","doi":"10.1109/TIM.2024.3481549","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481549","url":null,"abstract":"In recent years, sliding windows have been widely employed for sensor-based human activity recognition (HAR) due to their implementational simplicity. In this article, inspired by the fact that not all time intervals in a window are activity-relevant, we propose a novel multistage HAR framework named MS-HAR by implementing a sequential decision procedure to progressively process a sequence of relatively small intervals, i.e., reduced input, which is automatically cropped from the original window with reinforcement learning. Such a design naturally facilitates dynamic inference at runtime, which may be terminated at an arbitrary time once the network obtains sufficiently high confidence about its current prediction. Compared to most existing works that directly handle the whole window, our method allows for very precisely controlling the computational budget online by setting confidence thresholds, which forces the network to spend more computation on a “difficult” activity while spending less computation on an “easy” activity under a finite computational budget. Extensive experiments on four benchmark HAR datasets consisting of WISMD, PAMAP2, USC-HAD, and one weakly labeled dataset demonstrate that our method is considerably more flexible and efficient than the competitive baselines. Particularly, our proposed framework is general since it is compatible with most mainstream backbone networks.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A MEMS-INS/GNSS Integrated System With FM Radio Signal-Aided Distance Increment Estimation During GNSS Outages","authors":"Li Cong;Jing Zhang;Jingnan Tian;Xiaojie Yang;Hongmin Li","doi":"10.1109/TIM.2024.3481531","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481531","url":null,"abstract":"The global navigation satellite system (GNSS) and inertial navigation system (INS) integrated navigation can realize accurate and reliable positioning for land vehicles. However, during GNSS outages, the cumulative errors caused by inertial sensors pose a threat to the GNSS/INS integrated system, especially when low-cost microelectromechanical system (MEMS) inertial sensors are utilized. The existing methods usually apply nonholonomic constraint (NHC) and machine-learning (ML)-/deep-learning (DL)-based modeling techniques to constrain the errors. Nevertheless, the performance of using NHC alone is limited if the forward velocity is not accurate enough, so additional constraints are needed, while the existing ML-/DL-based modeling techniques only utilize acceleration or angular velocity features, which are still susceptible to the stochastic errors of MEMS sensors. In this article, an ML-based modeling technique combining acceleration and frequency modulation (FM) radio signal is applied to further improve the performance of NHC-constrained MEMS-INS/GNSS integrated system. First, we derive the relationship between the received signal strength indicator (RSSI) of FM signal and vehicle distance increment to provide theoretical basis for the proposed algorithm. Then, FM signal features related to distance increment are extracted. Afterward, an availability assessment strategy is proposed to eliminate the moments when errors of using RSSI are large. Subsequently, we apply support vector regression (SVR) to estimate distance increment by combining FM signal and acceleration features. Finally, extended Kalman filter (EKF) is applied to fuse the predicted distance with INS during GNSS outages. Results show that the introduction of FM signal can significantly reduce distance estimation errors, thus improving positioning performance.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tilt-Induced Noise Improvement of a Nano-g MEMS Accelerometer for Lunar Seismograph With Omnidirectional Deployment","authors":"Hao Ouyang;Ruikun Li;Qiu Wang;Yue Liu;Libo Qiu;Shaobo Qu;Huafeng Liu","doi":"10.1109/TIM.2024.3481586","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481586","url":null,"abstract":"China’s Lunar Exploration plans to deploy a Lunar Seismograph on the moon’s surface to detect moonquakes. Given the unknown inclination angle of the lunar landing, these sensors must possess the capability to adapt to different slopes. This article introduces an MEMS accelerometer that is capable of automatic leveling with omnidirectional deployment. Unlike traditional high-precision accelerometers, which require manual or motorized leveling at a large tilt angle, this accelerometer achieves leveling without any mechanical leveling system. In this article, a precise theoretical noise model is established, and by measuring each noise source against their theoretical noise gains, a total theoretical noise floor is calculated. The theoretical noise floor aligns perfectly with the actual measured noise floor, validating the correctness of the model. The noise tests indicate a noise floor reaching \u0000<inline-formula> <tex-math>$3~rm {ng/sqrt {Hz}}$ </tex-math></inline-formula>\u0000 @1–30 Hz, with low-frequency noise performance achieving \u0000<inline-formula> <tex-math>$20~rm {ng/sqrt {Hz}}$ </tex-math></inline-formula>\u0000 @0.01 Hz. The dual-axis turntable tests demonstrate that the accelerometer can work at any angle. Furthermore, it clearly detected earthquake signals of M5.5 from distances over 2000 km, matching the signals detected by a co-located commercial seismometer with a residual of 8.6 ng. This article provides new insights into the leveling system design of subsequent MEMS accelerometers or seismometers.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142551999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Multifunctional and Waterproof Wearable Microneedle Piezoresistive Sensor Based on CNT/CB/PDMS With Wide Temperature Range","authors":"Ning Yang;Xiangyu Yin;Hailian Liu;Xue Zhou;Xin Yan;Yong Zhao;Tonglei Cheng","doi":"10.1109/TIM.2024.3481563","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481563","url":null,"abstract":"The rapid development of wearable electronic devices and the diversification of social needs urgently demand high-performance wearable pressure sensors capable of stable operation in special environments. In this article, a flexible pressure sensor composed of biphasic multidimensional hybrid conductive nanocomposites (CNCs) and surface microstructures was proposed. Changes of conductive path happened both at microscopic (CNC-induced) and macroscopic (microneedle-induced) levels, synergistically improving the sensor’s performance. The influence of conductive filler and surface microstructure on the sensitivity and sensing range of the sensor was systematically investigated, revealing the intrinsic connection between material property, geometric structure, and sensing performance, and yielding the optimal fabrication parameters. In addition to high sensitivity over large sensing range, the proposed sensor also provided a fast response time, was unaffected to temperature fluctuations, and exhibited good repeatability and environmental stability. To mimic human fingertip skin, a sandpaper template was used to create external microstructures on the lower electrode of the pressure sensor, enabling the recognition of object roughness and further expanding the sensor’s application range. Additionally, the sensor’s good waterproof property made it suitable for underwater applications. As a proof of concept, the sensor was employed for underwater activity detection and information transmission.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on a Novel Electrode With Automatic Replenishment of Conductive Fluid for Use in the Built Environment","authors":"Fuwang Wang;Daping Chen;Xiaolei Zhang;Rongrong Fu","doi":"10.1109/TIM.2024.3481583","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481583","url":null,"abstract":"There are some limitations in the use of traditional electroencephalogram (EEG) signal acquisition sensors. For example, the conductive paste of wet electrodes volatilizes faster and the operation process is cumbersome. However, the dry electrode has a large contact impedance value when it is used, which affects the quality of the collected signal. The traditional semi-dry electrode may cause a small movement of the electrode when the supplementary conductive solution is manually pressed, thus affecting the accuracy and stability of the signal. To address these issues, this study proposes a novel electrode that can automatically replenish the conductive liquid. The electrode can monitor the humidity of the electrode in real time through the humidity-sensitive material inside the electrode and realize the automatic supplementation of conductive liquid to the electrode. This kind of electrode improves the efficiency of the conductive liquid, increases the stability of the acquisition signal, and realizes the function of long-term uninterrupted acquisition of EEG signals. In addition, to solve the problem of time-consuming and labor-consuming lifting alignment caused by the uncoordinated communication between the tower crane driver and the lower preform lifting operator, this study proposes a method to improve the efficiency of preform lifting alignment based on the deep residual shrinkage network (DRSN). This method can effectively classify the motor imagery (MI) EEG signals of the preform hoisting operator, then convert the classification results into the instructions of the tower crane, and finally realize the accurate movement and alignment of the preform. The novel electrode can effectively collect EEG signals in the real building environment and prolong the effective use time compared with the traditional semi-dry electrode. The DRSN-based method shortens the time of preformed lifting and alignment and improves efficiency. Compared with other traditional methods, the DRSN algorithm performs better in terms of classification accuracy and anti-noise performance.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Image Reconstruction With B₀ Inhomogeneity Using a Deep Unrolled Network on an Open-Bore MRI-Linac","authors":"Shanshan Shan;Yang Gao;David Waddington;Hongli Chen;Brendan Whelan;Paul Liu;Yaohui Wang;Chunyi Liu;Hongping Gan;Mingyuan Gao;Feng Liu","doi":"10.1109/TIM.2024.3481545","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481545","url":null,"abstract":"MRI-Linac systems require fast image reconstruction with high geometric fidelity to localize and track tumors for radiotherapy treatments. However, B0 field inhomogeneity distortions and slow MR acquisition potentially limit the quality of the image guidance and tumor treatments. In this study, we develop an interpretable unrolled network, referred to as RebinNet, to reconstruct distortion-free images from B0 inhomogeneity-corrupted k-space for fast MRI-guided radiotherapy (MRgRT) applications. RebinNet includes convolutional neural network (CNN) blocks to perform image regularizations and nonuniform fast Fourier transform (NUFFT) modules to incorporate B0 inhomogeneity information. The RebinNet was trained on a publicly available MR dataset (3300 images) from eleven healthy volunteers for both fully sampled and subsampled acquisitions. About 768 grid phantom and 12 human brain images acquired from an open-bore 1 T MRI-Linac scanner were used to evaluate the performance of the proposed network. The RebinNet was compared with the conventional regularization algorithm and our recently developed UnUNet method in terms of root-mean-squared error (RMSE), structural similarity (SSIM), residual distortions, and computation time. Imaging results demonstrated that the RebinNet reconstructed images with the lowest RMSE (<0.05)>0.92) at four-time acceleration for simulated brain images. The RebinNet preserved more image details and substantially increased the computational efficiency (3 s, ten-fold faster) compared to the conventional regularization methods (30 s), and had better generalization ability than the UnUNet method. The proposed RebinNet can achieve rapid image reconstruction and overcome the B0 inhomogeneity distortions simultaneously, which would facilitate accurate and fast image guidance in radiotherapy treatments.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Characteristics Measurement and Analysis of HTS Maglev Vehicle Driven by Permanent Magnet Electrodynamic Wheel","authors":"Yihao Chen;Jingguo Bi;Le Liang;Wangxuan Lin;Xiaofan Liang;Le Xu;Zigang Deng","doi":"10.1109/TIM.2024.3481548","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481548","url":null,"abstract":"High-temperature superconducting (HTS) maglev trains have the unique advantages of self-stabilization, no-drag, environmentally friendly, safe and reliable, and suitable for high speeds. However, the linear motors used as propulsion systems are easy to generate the unavoidable normal forces interference on the train. Thus, improving the traditional propulsion system limitation and reducing the construction cost is an important issue, to promote the development of the HTS maglev technology. In this study, based on the HTS maglev train prototype, the dynamic electromagnetic force of the permanent magnet electrodynamic wheel (PMEDW) is analyzed by a high-speed multifunctional test rig, and its dynamic characteristics are performed on a 165-m test line. Specifically, the basic configuration and operation principle analysis of the proposed PMEDW prototype are presented by the analytical model calculation and finite element simulation. In addition, experimental and simulation results are used to establish the prototype’s dynamics model. The velocity, propulsion force, and acceleration distance at different rotation speeds and working gaps are examined. Finally, the prototype vehicle operation performance is tested on an existing HTS maglev test line. It can be found from the experimental results that the maximum velocity of the prototype can be up to 3 m/s with the number of rotational turns of the PMEDW set to 68, and the test velocity change process of the prototype is consistent with the results of the dynamics simulation. The significance of this study can be used as a novel driving technology in maglev systems by offering reliable performance.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive Generalized Time Interval Cumulative Methodology for Optical Port Degradation Modeling in Cloud Computing Service","authors":"Jie Liu;Dong Wang;Yujie Mou;Zikang Chen;Ming Lu","doi":"10.1109/TIM.2024.3481571","DOIUrl":"https://doi.org/10.1109/TIM.2024.3481571","url":null,"abstract":"In recent years, the rapid development of information technology has led to an increasing demand for computing and storage, especially in the cloud computing field. Optical ports have become indispensable hardware in cloud computing services, and their stable operation is crucial. Performing remaining useful life (RUL) predictionon optical ports can effectively prevent accidents from occurring and reduce economic losses. Most existing RUL prediction methods focus on continuous degradation modeling, which often requires continuous degradation trending to describe degradation uncertainty so as to achieve RUL distributions and uncertainty characterization. However, in some industrial applications, such as optical ports, their degradation is discrete and their trending is hard to describe by the aforementioned function. Therefore, this article aims to develop an adaptive generalized time interval cumulative methodology for discrete degradation modeling and RUL prediction. Here, the proposed new methodology is integrated with newly defined “virtual jump points (VJPs) to realize online adaptive model parameters updating. RUL prediction is ultimately achieved by extrapolating the updated model to reach a preset failure threshold. The results show that the proposed new methodology can well model optical port degradation and provide accurate RUL prediction so as to be beneficial to realizing condition-based optimal port replacement. Note to Practitioners—Optical ports are one of the important hardware in the field of cloud computing, and their physical characteristics determine their discrete characteristics of degradation. Practitioners need to know how to handle data with discrete degradation features. This article proposes an adaptive generalized time interval accumulation methodology, which can achieve adaptive selection of discrete degradation data distribution and RUL prediction, offering valuable guidance for equipment operation and maintenance. This article highlights the superiority of the method by comparing it with existing continuous degradation modeling methods.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}