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Criminal defendants can face significant pressures to plead guilty, but wrongful conviction scholarship has largely overlooked the study of guilty pleas. This study content analyzed 139 Australian appellate court judgments in which a guilty plea conviction was overturned, investigating the types of errors involved in these convictions, and the stage of the criminal justice process at which the errors occurred. The findings revealed that errors occurred during the police investigation, pretrial preparations, and formal court procedures, with the most frequent errors involving incorrect or inappropriate charges, inadequate legal representation, and the courts erroneously accepting a guilty plea. The findings raise important implications regarding the adequacy of safeguards to ensure guilty pleas are appropriate or factually and legally accurate. [ABSTRACT FROM AUTHOR]

Radar error is a significant factor restricting the detection accuracy of radar. Improving the detection accuracy of radar is crucial to accurate target localization in an ocean environment. With a large amount of measured data, this paper presents the correlation analysis of radar errors, and gives the assumptions needed for radar error modeling. This provides theoretical support for calibrating the modeling method based on the radar error in the simultaneous observation of double targets. First, three error correction models were developed with constant, first-order, and second-order fitting methods, based on the origin and transfer of error in the radar system and the principles of error elimination and reduction in a cooperative platform. Subsequently, the advantages of using a cooperative platform including information sharing were used to detail the collection and preliminary processing of measured radar data as well as the establishment of datasets. Ultimately, the measured radar data were analyzed considering the random error of radar, the strategy for the selection of the optimal error correction model, and the detection error correlation of double targets. In particular, the second-order fitting model with the strongest azimuthal systematic error correlation calculated the root mean square error, which was 32.07% higher compared to the other two models. As revealed in the results of the error analysis, the random error of radar does not agree with the vector superposition characteristic, and it is strongly correlated with the system error of a single radar system that observes different targets within a short period. This provides a way for resolving some problems such as accurate target localization and time variance of error in the complex ocean environment.

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Parallel radiofrequency transmission (pTx) remains a promising technology for addressing high‐field magnetic resonance imaging (MRI) challenges, particularly regarding the safety of patients with implanted deep brain stimulation (DBS) devices. Radiofrequency (RF) shim optimization methods utilizing pTx technology have shown the potential to minimize induced RF heating effects at the electrode tips of DBS devices at 3 T. Purpose: Research pTx system implementations often involve the combination of custom and commercial hardware that are integrated onto an existing MRI system. As a result, system characterization is important to ensure implant‐friendly safe imaging conditions are satisfied for the operating range of the hardware. Methods: Utilizing electromagnetic and thermal simulations, the impact of system uncertainty is studied for the proposed 4‐ and 8‐channel pTx system setup and its associated "safe mode" for DBS applications. Results: Electromagnetic simulations indicated that instrumentation errors can affect the overall electric field strength experienced at the DBS lead tip, and a worst‐case system uncertainty analysis predicted temperature elevations of +1.5°C in the 4‐channel setup and +0.9°C in the 8‐channel setup. Conclusions: In conclusion, system uncertainty can impact the precision of pTx RF inputs which in the worst‐case, may lead to an unsafe imaging scenario and the proposed 8‐channel setup may provide more robustness and thus, safer conditions for MRI of DBS patients. [ABSTRACT FROM AUTHOR]

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The precision index is the primary basis for judging the GNSS positioning result, and the positioning mean error is usually used as the precision index in practical applications. In order to solve the problem of mismatch between positioning deviation and mean error in the priori situation, this paper proposed a positioning precision calculation method based on the posteriori unit weight variance and deduced the formulas combining sequential adjustment or Kalman filter, respectively. This method uses the characteristic that there are system errors in error corrections to calculate and screen the posterior unit weight variance. This method introduces the system error's influence into the mean error, which can improve positioning precision. The application of static difference and RTK proved that this method has remarkable effects, which can significantly alleviate the problem of false high precision and improve the reliability of positioning mean errors. [ABSTRACT FROM AUTHOR]

The Surgical Patient Safety System (SURPASS) has been proven to improve patient outcomes. However, few studies have evaluated the details of litigation and its prevention in terms of systemic and diagnostic errors as potentially preventable problems. The present study explored factors associated with accepted claims (surgeon-loss). We retrospectively searched the national Japanese malpractice claims database between 1961 and 2017. Using multivariable logistic regression models, we assessed the association between medical malpractice variables (systemic and diagnostic errors, facility size, time, place, and clinical outcomes) and litigation outcomes (acceptance). We evaluated whether or not the factors associated with litigation could have been prevented with the SURPASS checklist. We identified 339 malpractice claims made against general surgeons. There were 159 (56.3%) accepted claims, and the median compensation paid was 164,381 USD. In multivariable analyses, system (odds ratio, 27.2 95% confidence interval 13.8–53.5) and diagnostic errors (odds ratio 5.3, 95% confidence interval 2.7–10.5) had a significant statistical association with accepted claims. The SURPASS checklist may have prevented 7% and 10% of the accepted claims and systemic errors, respectively. It is unclear what proportion of accepted claims indicated that general surgeon loses should be prevented from performing surgery if the SURPASS checklist were used. In conclusion, systemic and diagnostic errors were associated with accepted claims. Surgical teams should adhere to the SURPASS checklist to enhance patient safety and reduce surgeon risk. [ABSTRACT FROM AUTHOR]

The all-sky meteor radar is an important means to detect 70–110 km wind fields. Previous studies have shown that the wind field retrieved by all-sky meteor radars is closely related to the meteor count detected by the radar. However, the precision of the wind field is still unclear. In this paper, the influence of the meteor counts detected by two all-sky meteor radars operating simultaneously at Kunming station on wind fields is analyzed based on the observations of the two radars from 1 November 2013 to 31 December 2014. First, the meteor counts detected by the two meteor radars are approximately 100–3000 per hour, and the meteor count detected by the 37.5 MHz meteor radar is more than that according to the 53.1 MHz meteor radar. The meteor counts detected by the two radars vary with the local time and altitude. The meteor counts detected from 20 UTC to 02 UTC are the largest in the altitude range of 84–92 km, while the meteor counts detected from 09 UTC to 15 UTC are the lowest at other altitudes. Second, the more meteors detected by the two radars, the smaller the wind field differences retrieved by the two radars, and the closer the wind fields are to the real average wind field. Third, because the performance of the two radars is basically identical, except that the meteor counts detected by the two radars are different due to their different operating frequencies, the meteor count is the main system error of the wind fields retrieved, and the errors can be determined by the correlation coefficients of the wind fields retrieved by the two radars. Finally, in the altitude range of 76–100 km, the mean wind field differences of the two radars are less than 5 m/s. [ABSTRACT FROM AUTHOR]

To reduce the error of the odometer positioning system and improve the positioning accuracy of four-wheel-steering mobile robots, three types of coupling errors are considered, based on the University of Michigan Benchmark (UMBmark) method: unequal track width, unequal wheel diameter, and speed difference of ipsilateral wheels. A "dual direction square path experiment" is designed to decouple the error, a new system error model is defined, and an improved UMBmark method for a four-wheel mobile robot is proposed. In the mobile robot positioning system, a laser tracker is used to measure the absolute positions of the starting and ending points of the robot. The positioning test results of the robot using the improved UMBmark method show that the odometer system error is 69.103 mm, which is 2.6 times less than that in the traditional UMBmark method. Hence, the improved UMBmark can better compensate for the system error of four-wheel-steering mobile robots. [ABSTRACT FROM AUTHOR]

Due to the development of manufacturing and launch technologies for satellites, there are now more and more satellite networks. Hence, cooperative reconnaissance is possible to implement among satellite networks, aerial vehicles and ground stations. In this paper, we study the method of geolocation and tracking by time difference of arrival (TDOA) measurements based on space–air–ground integrated (SAGI) network. We first analyze the Cramer Rao lower bound (CRLB) for the source localization accuracy in different coordinate systems. Then, we compare the effects of different system errors, such as clock synchronization error, position bias of the observers, elevation bias of the target and non-horizontal velocity of the target. Further, we also develop a maximum likelihood (ML) estimator for target position and velocity. Finally, the theoretical performance of the proposed estimator is validated via computer simulations. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ability to measure diameter, tree height, and tree volume is of great value in forestry investigations. These three factors are not considered together when error analyses of measurement results are conducted. The aim of this study was to quantify the system error analysis of the three factors mentioned above. Based on the principle of electronic theodolite non-destructive measurement of stem and error propagation theory, a mathematical model for calculating diameter, tree height, and volume error was derived to calculate the error in theoretical measurements. Moreover, a method utilizing F tests was proposed for analyzing the relative error based on the diameter, tree height, and volume factors. A total of 87 trees in Beijing were chosen as the experimental sample; the trees were divided into three sample groups according to size. The accuracy was assessed using the traditional method. The results showed that the error varied slightly with the size of the tree. The system error of the measured diameter was 0.44–0.59%; for tree height, this was 0.29–0.89%, and for the volume, it was 0.31–0.99%. There were no significant differences between the measured values and the true values of the resolved wood. The relative mean errors of volume, tree height, and diameter in practice were 4.47%, 1.18%, and 2.02%, respectively. The results suggest that the precision in electronic theodolite measurements in China is much higher than the accuracy requirement of relative error not exceeding 3–5%. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Earth Science (1001-8166) is the property of Advances in Earth Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

No prediction models using use conventional logistic models and machine learning exist for medical litigation outcomes involving medical doctors. Using a logistic model and three machine learning models, such as decision tree, random forest, and light-gradient boosting machine (LightGBM), we evaluated the prediction ability for litigation outcomes among medical litigation in Japan. The prediction model with LightGBM had a good predictive ability, with an area under the curve of 0.894 (95% CI; 0.893–0.895) in all patients' data. When evaluating the feature importance using the SHApley Additive exPlanation (SHAP) value, the system error was the most significant predictive factor in all clinical settings for medical doctors' loss in lawsuits. The other predictive factors were diagnostic error in outpatient settings, facility size in inpatients, and procedures or surgery settings. Our prediction model is useful for estimating medical litigation outcomes. [ABSTRACT FROM AUTHOR]

The all-sky meteor radar is an important means to detect 70–110 km wind fields. Previous studies have shown that the wind field retrieved by all-sky meteor radars is closely related to the meteor count detected by the radar. However, the precision of the wind field is still unclear. In this paper, the influence of the meteor counts detected by two all-sky meteor radars operating simultaneously at Kunming station on wind fields is analyzed based on the observations of the two radars from 1 November 2013 to 31 December 2014. First, the meteor counts detected by the two meteor radars are approximately 100–3000 per hour, and the meteor count detected by the 37.5 MHz meteor radar is more than that according to the 53.1 MHz meteor radar. The meteor counts detected by the two radars vary with the local time and altitude. The meteor counts detected from 20 UTC to 02 UTC are the largest in the altitude range of 84–92 km, while the meteor counts detected from 09 UTC to 15 UTC are the lowest at other altitudes. Second, the more meteors detected by the two radars, the smaller the wind field differences retrieved by the two radars, and the closer the wind fields are to the real average wind field. Third, because the performance of the two radars is basically identical, except that the meteor counts detected by the two radars are different due to their different operating frequencies, the meteor count is the main system error of the wind fields retrieved, and the errors can be determined by the correlation coefficients of the wind fields retrieved by the two radars. Finally, in the altitude range of 76–100 km, the mean wind field differences of the two radars are less than 5 m/s.

This study examined health information technology-related incidents to characterise system issues as a basis for improvement in Swedish clinical practice. Incident reports were collected through interviews together with retrospectively collected incidents from voluntary incident databases, which were analysed using deductive and inductive approaches. Most themes pertained to system issues, such as functionality, design, and integration. Identified system issues were dominated by technical factors (74%), while human factors accounted for 26%. Over half of the incidents (55%) impacted on staff or the organisation, and the rest on patients - patient inconvenience (25%) and patient harm (20%). The findings indicate that it is vital to choose and commission suitable systems, design out "error-prone" features, ensure contingency plans are in place, implement clinical decision-support systems, and respond to incidents on time. Such strategies would improve the health information technology systems and Swedish clinical practice., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Due to the development of manufacturing and launch technologies for satellites, there are now more and more satellite networks. Hence, cooperative reconnaissance is possible to implement among satellite networks, aerial vehicles and ground stations. In this paper, we study the method of geolocation and tracking by time difference of arrival (TDOA) measurements based on space–air–ground integrated (SAGI) network. We first analyze the Cramer Rao lower bound (CRLB) for the source localization accuracy in different coordinate systems. Then, we compare the effects of different system errors, such as clock synchronization error, position bias of the observers, elevation bias of the target and non-horizontal velocity of the target. Further, we also develop a maximum likelihood (ML) estimator for target position and velocity. Finally, the theoretical performance of the proposed estimator is validated via computer simulations.

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

No prediction models using use conventional logistic models and machine learning exist for medical litigation outcomes involving medical doctors. Using a logistic model and three machine learning models, such as decision tree, random forest, and light-gradient boosting machine (LightGBM), we evaluated the prediction ability for litigation outcomes among medical litigation in Japan. The prediction model with LightGBM had a good predictive ability, with an area under the curve of 0.894 (95% CI; 0.893–0.895) in all patients’ data. When evaluating the feature importance using the SHApley Additive exPlanation (SHAP) value, the system error was the most significant predictive factor in all clinical settings for medical doctors’ loss in lawsuits. The other predictive factors were diagnostic error in outpatient settings, facility size in inpatients, and procedures or surgery settings. Our prediction model is useful for estimating medical litigation outcomes.

Background: The safety of telemedicine in general and telephone triage (teletriage) safety in particular have been a focus of concern since the 1970s. Today, telehealth, now subsuming teletriage, has a basic structure and process intended to promote safety. However, inadequate telehealth systems may also compromise patient safety. The COVID-19 pandemic accelerated rapid but uneven telehealth growth, both technologically and professionally. Within 5-10 years, the field will likely be more technologically advanced; however, these advances may still outpace professional standards. The need for an evidence-based system is crucial and urgent., Objective: Our aim was to explore ways that developed teletriage systems produce safe outcomes by examining key system components and questioning long-held assumptions., Methods: We examined safety by performing a narrative review of the literature using key terms concerning patient safety in teletriage. In addition, we conducted system analysis of 2 typical formal systems, physician led and nurse led, in Israel and the United States, respectively, and evaluated those systems' respective approaches to safety. Additionally, we conducted in-depth interviews with representative physicians and 1 nurse using a qualitative approach., Results: The review of literature indicated that research on various aspects of telehealth and teletriage safety is still sparse and of variable quality, producing conflicting and inconsistent results. Researchers, possibly unfamiliar with this complicated field, use an array of poorly defined terms and appear to design studies based on unfounded assumptions. The interviews with health care professionals demonstrated several challenges encountered during teletriage, mainly making diagnosis from a distance, treating unfamiliar patients, a stressful atmosphere, working alone, and technological difficulties. However, they reported using several measures that help them make accurate diagnoses and reasonable decisions, thus keeping patient safety, such as using their expertise and intuition, using structured protocols, and considering nonmedical factors and patient preferences (shared decision-making)., Conclusions: Remote encounters about acute, worrisome symptoms are time sensitive, requiring decision-making under conditions of uncertainty and urgency. Patient safety and safe professional practice are extremely important in the field of teletriage, which has a high potential for error. This underregulated subspecialty lacks adequate development and substantive research on system safety. Research may commingle terminology and widely different, ill-defined groups of decision makers with wide variation in decision-making skills, clinical training, experience, and job qualifications, thereby confounding results. The rapid pace of telehealth's technological growth creates urgency in identifying safe systems to guide developers and clinicians about needed improvements., (©Motti Haimi, Sheila Quilter Wheeler. Originally published in JMIR Human Factors (https://humanfactors.jmir.org), 25.03.2024.)

A fault observer of the MIMO (multiple input multiple output) feedback fault system with measurement error and system error is designed and analysed based on the linear time-invariant system. First, the disturbance system with system error and measurement error in the case of failure is given. Second, the expression form of system error is obtained, and the system error is divided into the random error part and the error part generated by the system error at the last moment. Then, a fault diagnosis observer is given for a fault system with both system error and measurement error. Finally, simulation results are presented to show the effectiveness of the proposed method.

Although in the United States wrongful convictions and imprisonments are a major public and scientific concern, this topic has been largely ignored in Germany for decades. The present article offers for the first time an overview of all accessible German cases of successful retrials involving convicted persons who served a prison sentence since 1990. The data refer to 31 wrongfully convicted persons in 29 independent cases. Although the largest group consists of cases of false allegations, some of the wrongly convicted were considered not guilty by reason of insanity, and a few wrongful convictions occurred because of eyewitness misidentification and false confessions. In addition, incorrect expert testimony contributed considerably to the wrongful conviction in some cases. [ABSTRACT FROM AUTHOR]

Copyright of Hydrographic Surveying & Charting / Haiyang Cehui is the property of Hydrographic Surveying & Charting Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problem of single structure style and less system variable for traditional chaotic system, this paper proposed a chaotic circuit, which had more complex dynamic behaviors, high er sensitivity to variable and stronger anti-interference. With the change of circuit parameters, this pa per discussed the different dynamic behaviors of the system in detail based on the adaptive stability criterion and chaos motion theory. In addition, it constructed the corresponding circuit and observed the system dynamics phenomena by oscilloscope. The dynamics phenomena were in accordance with the simulation results of MATLAB, which further proved the feasibility and flexibility of the circuit. On this basis, it put forward and studied the multi-stage combination synchronization based on this system. By constructing different controllers, this paper realized the multi-stage combination synchronization among the eight systems. The simulation results show th at the synchronization scheme has a good effect on convergence speed and precision. [ABSTRACT FROM AUTHOR]

Natural gas hydrate (NGH), a high-efficiency and clean unconventional energy, is an important alternative energy of fossil fuels in the future. 98% of the world's NGH is distributed in the sea area. BSR, anomalous attributes, and inversion techniques are widely used to predict the accumulation degree of NGH in the sea, but none of them can be used to directly predict NGH saturation. Therefore, we have relatively limited ability to represent the accumulation degree of NGH in the sea area. Although there are currently some methods for directly predicting the saturation of NGH, the method is based on test and no prediction result is obtained. The disadvantages of this method are the long calculation time and that the system error is not taken into account, and therefore it may lead to difficulty in practical promotion of the method. In view of the problems in the prediction of NGH saturation, a new idea of prediction has been developed in this research, with the main advantage that it can better eliminate the system error, thus to improve the prediction accuracy; this idea is then introduced to the existing three classic NGH saturation prediction methods; finally, based on the data of the Shenhu sea area of China, Wood method with the smallest prediction error is selected from the three prediction methods, which is the most applicable NGH saturation prediction method. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present paper is two-fold. First, it reviews the Hippocratic collection to identify instances related to the issue of medical malpractice and medical negligence. Second, it discusses the results viewed from today's perspective, in the context of contemporary theories of liability in malpractice cases. Method: A careful review of the books of Hippocratic collection was performed, as well as a narrative review of the currently available academic literature, focusing on topics of contemporary theories of liability in malpractice cases, which correspond roughly to the medical malpractice instances identified in Hippocratic collection. Results: The Hippocratic authors touch on some issues which are essential to the contemporary theory of medical error and negligence, which, however, cannot yet unquestionably address these issues. Among others, they refer to errors that contemporarily might be viewed as technical human errors, errors of omission, or errors which were unavoidable in the context of applied ancient Greek medicine as is the case of injuries that are not based on physician's fault, or situations where the diagnosis of the particular disease or causal link between the physician's breach of duty and the damage suffered, was difficult or even impossible. Interestingly, the Hippocratic authors underscore some errors which might not be based on physician's fault. Conclusion: The passages mentioned in this paper, originating from the Hippocratic collection that refer to medical malpractice, imply an awareness of what is currently discussed as medical malpractice. This consideration may carry some weight, in particular when adopting a flexible traditionalist approach to the medical liability rules. [ABSTRACT FROM AUTHOR]

To improve the accuracy of unmanned helicopter, geometry calibration is compulsory. Direct geo-reference experiment is first carried out to verify system's accuracy without any calibration; and then the free network bundle adjustment experiment is undertaken to verify the positioning accuracy of the system without ground control points; finally, a self calibration bundle adjustment is undertaken to calibrate and compensate the camera distortion, interior elements changes, IMU alignment angle. Experimental results show that the unmanned helicopter has high positioning accuracy. The accuracy of direct geo-reference can meet the requirements of emergency mapping, and can be aided by a few ground control points, the positioning accuracy is much better than that of 1:500 mapping requirements, which can be used for conventional surveying and mapping production. After system error compensation, the direct geo-reference accuracy has improved significantly:the planar accuracy has improved by 46.37% and the height accuracy has improved by 62.49%. The flight test of Songshan calibration field shows that the method of calibration and compensation is correct and effective, and the unmanned helicopter has a good prospect for surveying and mapping applications. [ABSTRACT FROM AUTHOR]

Mining has been observed as a high-risk industry for a long time. Accident statistics of Indian mines still shows very high rate of injuries and fatalities. The current death rate per 1000 person employed in coal and non-coal mines is 0.27 and 0.40 respectively. The serious injury rate in the current year is also very high and unacceptable. More disturbing is the fact that a few causes are repeated for fatal, non-fatal and serious accidents. Even though all the accidents are being investigated by different agencies and recommendations are made against them in each cases but still similar accidents are repeated. Therefore question mark is automatically put against the effectiveness of present-day investigation methodology. In this paper a few recent fatal accidents in Indian mines have been reviewed and identified causes and recommendations analyzed. The review highlights certain deficiencies in the current investigation methodology of India. The aim of this study is to analyse the investigation report to identify the gaps in the current investigation procedure (i.e. where are we?) and suggest for changing the focus of investigation from human error to system deficiency i.e. where do we go from here? [ABSTRACT FROM AUTHOR]

Introduction: We aimed to determine how serious adverse events in obstetrics were assessed by supervision authorities.Material and Methods: We selected cases investigated by supervision authorities during 2009-2013. We analyzed information about who reported the event, the outcomes of the mother and infant, and whether events resulted from errors at the individual or system level. We also assessed whether the injuries could have been avoided.Results: During the study period, there were 303 034 births in Norway, and supervision authorities investigated 338 adverse events in obstetric care. Of these, we studied 207 cases that involved a serious outcome for mother or infant. Five mothers (2.4%) and 88 infants (42.5%) died. Of the 207 events reported to the supervision authorities, patients or relatives reported 65.2%, hospitals reported 39.1%, and others reported 4.3%. In 8.7% of cases, events were reported by more than 1 source. The supervision authority assessments showed that 48.3% of the reported cases involved serious errors in the provision of health care, and a system error was the most common cause. We found that supervision authorities investigated significantly more events in small and medium-sized maternity units than in large units. Eighteen health personnel received reactions; 15 were given a warning, and 3 had their authority limited. We determined that 45.9% of the events were avoidable.Conclusions: The supervision authorities investigated 1 in 1000 births, mainly in response to complaints issued from patients or relatives. System errors were the most common cause of deficiencies in maternity care. [ABSTRACT FROM AUTHOR]

A fault observer of the MIMO (multiple input multiple output) feedback fault system with measurement error and system error is designed and analysed based on the linear time-invariant system. First, the disturbance system with system error and measurement error in the case of failure is given. Second, the expression form of system error is obtained, and the system error is divided into the random error part and the error part generated by the system error at the last moment. Then, a fault diagnosis observer is given for a fault system with both system error and measurement error. Finally, simulation results are presented to show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Copyright of Hydrographic Surveying & Charting / Haiyang Cehui is the property of Hydrographic Surveying & Charting Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In view of the current error separation method cannot successfully separate the dissimilar systematic error components from the whole surface machining data, a method for machining errors decomposition based on blind signal separation is proposed which can distinguish those dissimilar systematic error components. Firstly, the error transfer model to describe the errors synthesizing from the single error component caused by corresponding individual error source to the synthesis machining surface error is conducted. To determine the number of the systematic error components, the principal component analysis (PCA) method is used. Then according to the theory of blind source separation, negative entropy based fixed point algorithm is proposed to fulfill the machining error components separation, which can realize the separation of the systematic error components even in close frequency scale. Finally, a shaft surface finish turning data and a flat surface milling data are used as examples to verify the proposed method. The result shows that the proposed error separation method can effectively realize the machining error separation in close frequency scale. [ABSTRACT FROM AUTHOR]

Autonomous satellite navigation is based on the ability of a Global Navigation Satellite System (GNSS), such as Beidou, to estimate orbits and clock parameters onboard satellites using Inter-Satellite Link (ISL) measurements instead of tracking data from a ground monitoring network. This paper focuses on the time synchronization of new-generation Beidou Navigation Satellite System (BDS) satellites equipped with an ISL payload. Two modes of Ka-band ISL measurements, Time Division Multiple Access (TDMA) mode and the continuous link mode, were used onboard these BDS satellites. Using a mathematical formulation for each measurement mode along with a derivation of the satellite clock offsets, geometric ranges from the dual one-way measurements were introduced. Then, pseudoranges and clock offsets were evaluated for the new-generation BDS satellites. The evaluation shows that the ranging accuracies of TDMA ISL and the continuous link are approximately 4 cm and 1 cm (root mean square, RMS), respectively. Both lead to ISL clock offset residuals of less than 0.3 ns (RMS). For further validation, time synchronization between these satellites to a ground control station keeping the systematic time in BDT was conducted using L-band Two-way Satellite Time Frequency Transfer (TWSTFT). System errors in the ISL measurements were calibrated by comparing the derived clock offsets with the TWSTFT. The standard deviations of the estimated ISL system errors are less than 0.3 ns, and the calibrated ISL clock parameters are consistent with that of the L-band TWSTFT. For the regional BDS network, the addition of ISL measurements for medium orbit (MEO) BDS satellites increased the clock tracking coverage by more than 40% for each orbital revolution. As a result, the clock predicting error for the satellite M1S was improved from 3.59 to 0.86 ns (RMS), and the predicting error of the satellite M2S was improved from 1.94 to 0.57 ns (RMS), which is a significant improvement by a factor of 3–4. [ABSTRACT FROM AUTHOR]

The realization and maintenance of the China geodetic coordinate system 2000 (CGCS2000) depends on GPS technologies, and therefore is a national security risk. BDS began offering services to customers in the Asia-Pacific region in December 2012. It provides a good opportunity to realize and maintain the national terrestrial reference frame (TRF) using BDS system. We focus on how to use BDS observations of BDS/GPS stations with dual-mode receivers to realize the National TRF, aligned to the international terrestrial reference frame (ITRF). Results show that the precision of the horizontal velocity derived from BDS data are comparable to those derived from GPS data at about 2-3 mm/a, using more than two years of observation data. The RMS of the station coordinate residuals, with the linear velocity removed, are better than 0.8 cm and 1.7 cm for the horizontals and verticals, respectively. The current precision of BDS data can allow observation of seasonal displacements in the verticals. System errors related to the longitude and latitude are found in the coordinate differences between BDS and GPS data based on PPP mode. Thus, the current BDS system can be used to realize and maintain the national terrestrial reference frame at cm level. [ABSTRACT FROM AUTHOR]

Vehicle mass is a critical parameter for economic cruise control. With the development of active control, vehicle mass estimation in real-time situations is becoming notably important. Normal state estimators regard system error as white noise, but many sources of error, such as the accuracy of measured parameters, environment and vehicle motion state, cause system error to become colored noise. This paper presents a mass estimation method that considers system error as colored noise. The system error is considered an unknown parameter that must be estimated. The recursive least squares algorithm with two unknown parameters is used to estimate both vehicle mass and system error. The system error of longitudinal dynamics is analyzed in both qualitative and quantitative aspects. The road tests indicate that the percentage of mass error is 16%, and, if the system error is considered, the percentage of mass error is 7.2%. The precision of mass estimation improves by 8.8%. The accuracy and stability of mass estimation obviously improves with the consideration of system error. The proposed model can offer online mass estimation for intelligent vehicle, especially for heavy-duty vehicle (HDV).

In this paper, the system error of inter-satellite-link measurements for autonomous navigation is studied, which is an important parameter for autonomous navigation technology based on inter-satellite-link of Beidou system. The physical meaning of system error of inter-satellite-link measurements and the influence of its error on autonomous navigation are clarified. On this basis, to solve the problem that it is difficult to calibrate the system error of inter-satellite-link measurements precisely on the ground before the satellite launches, a calibration method based on onboard measurement data for this parameter is put forward. Onboard test results show that the mean of the user range error of autonomous orbit determination is less than 6 m in 9 days using the system error of inter-satellite-link measurements calibrated according to the proposed method. Specially, the user range error is less than 3 m when the system error calibrated based on the latest measurement data is used. And in post-process, using the latest system error, the mean of user range error is less than 2.5 m and the error of autonomous time synchronization is within ±10 ns. All the results above prove the effectiveness of the calibration method for the system error of inter-satellite-link measurements and the effectiveness of the autonomous navigation algorithm. [ABSTRACT FROM AUTHOR]

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Considering the wide-range and nonlinear characteristics of strata movement and the demand between large range and high precision in the physical simulation of water-preserved mining, a method for improving displacement measurement precision in physical modeling has been proved by experiments. The results show that the measurement accuracy is improved as the number of reference points and displacements increase. The increase of the number of reference points could reduce the system error which fluctuates in a range depending on the number of reference points and the fluctuation ascribes to the plus or minus of error. The mean error starts to reduce and diminish significantly when the number of reference points is 15 and 25 respectively. Therefore, at least 25 reference points are required to ensure the required precision. The method suggests a way for measuring strata movement in mining physical models. [ABSTRACT FROM AUTHOR]

Copyright of Hydrographic Surveying & Charting / Haiyang Cehui is the property of Hydrographic Surveying & Charting Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)