Main Error Research Articles

Impact of orthognathic surgery on voice and speech: a systematic review and meta-analysis.

Orthognathic surgical procedures, whether in one or both jaws, can affect structures regarding the articulation and resonance of voice and speech. Evaluating the impact of orthognathic surgery on voice and speech performance in individuals with skeletal dentofacial disharmony. Word combinations and truncations were adapted for the following electronic databases: EMBASE, PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Latin American and Caribbean Literature in Health Sciences (LILACS), and grey literature. The research included studies on nonsyndromic adults with skeletal dentofacial disharmony undergoing orthognathic surgery. These studies assessed patients before and after surgery or compared them with individuals with good facial harmony using voice and speech parameters through validated protocols. Two independent reviewers performed all stages of the review. The Joanna Briggs Institute tool was used to assess risk of bias in the cohort studies, and ROBINS-I was used for nonrandomized clinical trials. The authors also performed a meta-analysis of random effects. A total of 1163 articles were retrieved after the last search, of which 23 were read in full. Of these, four were excluded, totalling 19 articles for quantitative synthesis. When comparing the pre- and postoperative periods, both for fundamental frequency, formants, and jitter and shimmer perturbation measures, orthognathic surgery did not affect vowel production. According to the articles, the main articulatory errors associated with skeletal dentofacial disharmonies prior to surgery were distortions of fricative sounds, mainly/s/ and/z/. Orthognathic surgery may have little or no impact on vocal characteristics during vowel production. However, due to the confounding factors involved, estimates are inconclusive. The most prevalent articulatory disorders in the preoperative period were distortion of the fricative phonemes/s/ and/z/. However, further studies must be carried out to ensure greater robustness to these findings. PROSPERO (CRD42022291113).

Нетипичные ошибки аспирантов в научных текстах на английском языке: способы устранения и предотвращения

The aim of the research is to identify the relationship between atypical errors of graduate students and the level of their foreign language competence of academic writing. The paper analyses the variants of translations of articles, annotations and reports made by students, examines the types of atypical errors found and offers tasks to eliminate and prevent them. The novelty of the research lies in systematising and providing rationale for atypical errors of graduate students when creating scientific texts in English. As a result, it has been proved that the main errors that arise among young scholars during the compilation of an English text are related to interference, i.e. the transfer of the rules of the native language into a foreign language; author’s exercises have been developed to improve the quality and competitiveness of student research papers in the international academic environment. The tasks proposed in the study are aimed at overcoming the negative influence of the Russian language when students write scientific papers in English.

Assessing the Level of Pollution and Effectiveness of Soil Rehabilitation Technologies in Case of Crude Oil Spills

It was shown that the use of methods of chemical analysis of oil-contaminated soils recommended for environmental control, showed no more than 50% of the mass of oil introduced into the soil, even in freshly contaminated samples. It was found that main errors were associated with the loss of light oil fractions during drainage of contaminated soil samples, incomplete extraction of pollutant oil from soils, ignoring high-molecular polar oil fractions, resinous and asphaltenic fractions when using these methods. A slight modification of the applied preparatory analytical methods was proposed, wich consisted in replacing the cold extraction of contaminated soil with a hot one, followed by additional weighing of the extracted chloroform prior swing absorption to assess the content of oil products, as well as soil samples for extraction at a natural moisture level without air- dry preconditionning. It was concluded that these changes significantly reduce analytical errors and increase the reliability of monitoring soil pollution during crude oil spills, as well as the effectiveness of rehabilitation actions.

ANALYSIS OF DEFECTS IN DIAGNOSIS AND FORENSIC MEDICAL ASSESSMENT OF SKULL BONE FRACTURES

Determining the age of skull bone fractures, especially flat fractures, is a challenging task for forensic medical expertise, as these fractures don't always heal properly due to poor alignment of their edges.
 Aim of the work. To investigate diagnostic defects and forensic medical expert defects that complicate the assessment of skull bone fractures by analyzing the archive database of the Main Bureau of Forensic Medical Examination of the Ministry of Health of Ukraine for the years 2017-2021.
 Materials and methods. The material consisted of 928 forensic medical commission examinations of traumatic brain injuries conducted at the Main Bureau of Forensic Medical Examination of the Ministry of Health of Ukraine from 2017 to 2021.
 Statistical indicators were used: mean values, standard deviation (M±ϭ), frequency of cases (N), confidence interval (Р±95%СІ), Student's criterion for relative values (t) to assess the statistical significance of differences between fractions (p<0.05).
 Results. Diagnostic defects of skull fractures by physicians included: insufficient detailing of fracture description in medical documentation, unreliability of soft tissue injury description, inadequate use of neurovisualization methods, incorrect recording of trauma circumstances in medical records, and incomplete description of neurological symptoms. The main expert errors in affected individuals were the absence of correlation between skull bone fractures and intracranial injuries and soft tissue head injuries, while in corpses, there was incorrect description of skull fracture morphology.
 Conclusion. The use of additional neurovisualization methods and a comprehensive approach correlating all head injuries can improve forensic medical assessment of skull bone fractures.

Analysis of Risks Arising from the Use of Autonomous Vessels

This paper focuses on the analysis of risks arising from the use of autonomous ships. The concept of autonomy is defined, different levels of autonomy are mentioned, and the differences between unmanned vessels and autonomous ships are well known. The transition to autonomous ships brings certain risks that need to be managed. Therefore, this paper analyses the risks associated with autonomous ships, which have received significant attention in recent years. An important aspect in considering risks is human error, which according to various studies is the most common cause of maritime accidents. However, autonomy also has the potential to create accidents, which manifest in five unacceptable hazards in the initial configuration of the ship. The main hazard human error, interaction with manned vessels and object detection, interaction with the physical environment, system failure, cyber-attacks, and equipment failure. The focus of the ship’s work is to prevent and reduce the probability of critical events and their causes and maximize operational efficiency and performance.

Development of Cloud-Based Data Integration for Non-Profit Organization System

Palang Merah Indonesia (PMI) noted that the stock of blood in Indonesia reached 87,238 bags as of June 14, 2022, where it should be estimated that Indonesia needs 5.1 million bags of blood every year. The conventional blood donor process procedure is one of the main reasons the younger generation does not intend to donate blood. A new system is needed to regulate the flow of the blood donation process so that it is faster and attracts the interest of young people to donate blood. This research resulted in a blood donation system in the form of a website application for each blood donor unit and a mobile application for users who are blood donors. The system was developed with the Agile method which makes it easy for researchers to adapt to the evolving needs of users. The system usability test is based on Nielsen's Criteria which includes 5 main aspects, including learnability, efficiency, memorability, errors and satisfaction. The results of the trial on the targeted respondents showed that almost all of them were interested in using and would routinely donate blood with the new system that had been built, because it was considered to simplify the blood donation procedure which was previously considered complicated. In addition, data between blood donor units can be well integrated with the system that has been built. In the end, this research has the main goal of changing people's habits, especially young people to continue to regularly donate blood, not only is it good for health, but also can help others in need.

Identification of Adolescent Menarche Status Using Biplanar X-ray Images: A Deep Learning-Based Method.

The purpose of this study is to develop an automated method for identifying the menarche status of adolescents based on EOS radiographs. We designed a deep-learning-based algorithm that contains a region of interest detection network and a classification network. The algorithm was trained and tested on a retrospective dataset of 738 adolescent EOS cases using a five-fold cross-validation strategy and was subsequently tested on a clinical validation set of 259 adolescent EOS cases. On the clinical validation set, our algorithm achieved accuracy of 0.942, macro precision of 0.933, macro recall of 0.938, and a macro F1-score of 0.935. The algorithm showed almost perfect performance in distinguishing between males and females, with the main classification errors found in females aged 12 to 14 years. Specifically for females, the algorithm had accuracy of 0.910, sensitivity of 0.943, and specificity of 0.855 in estimating menarche status, with an area under the curve of 0.959. The kappa value of the algorithm, in comparison to the actual situation, was 0.806, indicating strong agreement between the algorithm and the real-world scenario. This method can efficiently analyze EOS radiographs and identify the menarche status of adolescents. It is expected to become a routine clinical tool and provide references for doctors' decisions under specific clinical conditions.

Singular limits for stochastic equations

We study singular limits of stochastic evolution equations in the interplay of disappearing strength of the noise and insufficient regularity, where the equation in the limit with noise would not be defined due to lack of regularity. We recover previously known results on vanishing small noise with increasing roughness, but our main focus is to study for fixed noise the singular limit where the leading order differential operator in the equation may vanish. Although the noise is disappearing in the limit, additional deterministic terms appear due to renormalization effects. We separate the analysis of the equation from the convergence of stochastic terms and give a general framework for the main error estimates. This first reduces the result to bounds on a residual and in a second step to various bounds on the stochastic convolution. Moreover, as examples we apply our result to the singularly regularized Allen–Cahn (AC) equation with a vanishing Bilaplacian, and the Cahn–Hilliard/AC homotopy with space-time white noise in two spatial dimensions.

Improving near-real-time satellite precipitation products through multistage modified schemes

Near-real-time (NRT) satellite precipitation products (SPPs) exhibit great application potential in global precipitation estimation for their convenient acquisition and access. A universal framework was developed to modify precipitation occurrence and intensity in stages to correct and integrate multiple NRT SPPs with open-access gridded observational data. Based on this framework, both machine learning- and statistical-based correction methods were utilized to construct multi-stage modified schemes and three schemes, namely the double machine learning (DML), statistical error correction (SEC) and hybrid (ML-SEC) schemes, were stepwise established. The improvements of NRT SPPs by these three schemes were comparatively analyzed based on a dense network of rain gauges located in the Yiluo River Basin, China, which does not depend on reference data for modification and has derived a reliable evaluation result at grid-point scale. The results indicated that the DML scheme attains the highest accuracy with a grid-averaged Kling-Gupta efficiency (KGE) value of 0.70 and a critical success index (CSI) value of 0.60, followed by the ML-SEC and SEC schemes. The KGE and CSI values of NRT SPPs have been improved by 22.20% ∼ 535.48% and 30.30% ∼ 100.24%, respectively, through the DML scheme. The DML-modified result also outperformed the mainstream post-processed SPPs with a 1.95% ∼ 222.25% and 9.22% ∼ 102.00% higher KGE and CSI values, respectively. The main error sources of the SPPs due to false and hit events were reduced by the multistage schemes, and the DML scheme achieved a balanced efficiency at both occurrence and intensity modification stages. Moreover, the DML scheme was more advantageous than spatial interpolation under the scenario with fewer gauges, particularly in estimating precipitation occurrence. The multistage modified schemes in this study, especially the DML scheme, exhibit potential in near-real time and sub-daily scale applications. Multistage schemes for NRT SPP modification are helpful for obtaining high-quality precipitation estimates.

Surface Properties of Global Land Surface Microwave Emissivity Derived from FY-3D/MWRI Measurements

Land surface microwave emissivity is crucial to the accurate retrieval of surface and atmospheric parameters and the assimilation of microwave data into numerical models over land. The microwave radiation imager (MWRI) sensors aboard on Chinese FengYun-3 (FY-3) series satellites provide valuable measurements for the derivation of global microwave physical parameters. In this study, an approximated microwave radiation transfer equation was used to estimate land surface emissivity from MWRI by using brightness temperature observations along with corresponding land and atmospheric properties obtained from ERA-Interim reanalysis data. Surface microwave emissivity at the 10.65, 18.7, 23.8, 36.5, and 89 GHz vertical and horizontal polarizations was derived. Then, the global spatial distribution and spectrum characteristics of emissivity over different land cover types were investigated. The seasonal variations of emissivity for different surface properties were presented. Furthermore, the error source was also discussed in our emissivity derivation. The results showed that the estimated emissivity was able to capture the major large-scale features and contains a wealth of information regarding soil moisture and vegetation density. The emissivity increased with the increase in frequency. The smaller surface roughness and increased scattering effect may result in low emissivity. Desert regions showed high emissivity microwave polarization difference index (MPDI) values, which suggested the high contrast between vertical and horizontal microwave signals in this region. The emissivity of the deciduous needleleaf forest in summer was almost the greatest among different land cover types. There was a sharp decrease in the emissivity at 89 GHz in the winter, possibly due to the influence of deciduous leaves and snowfall. The land surface temperature, the radio-frequency interference, and the high-frequency channel under cloudy conditions may be the main error sources in this retrieval. This work showed the potential capabilities of providing continuous and comprehensive global surface microwave emissivity from FY-3 series satellites for a better understanding of its spatiotemporal variability and underlying processes.

CRACK RESISTANCE OF BRIDGE REINFORCED CONCRETE STRUCTURES BASED ON THE FRACTURE MECHANICS PRINCIPLES

Purpose The work purpose is to establish the real technical condition of reinforced concrete and steel-reinforced concrete bridges based on the surveys and tests, as well as the analysis and synthesis of scientific and technical sources. Methodology. To achieve the goal, a review and synthesis of scientific and technical sources and regulatory documents regarding the technical condition of reinforced concrete and steel-reinforced concrete bridges and overpasses of Ukraine is carried out. It is shown that the development and implementation of new technologies for repairing the existing bridge defective structures, in particular on the highways of Ukraine is an urgent problem. A thorough analysis of experience and publications on the operation of newly built and long-term specified bridges in the mentioned environments is carried out. The data on the main unacceptable defects and faults of bridge structures as well as the causes, including concrete and reinforcement corrosion, and other defects and faults are presented. The quality indicators of reinforced concrete and steel-reinforced concrete bridge structures are considered, the problems and analysis of ensuring reliability and durability in the operation conditions on the highways of Ukraine are formulated. Results. The analysis of domestic and foreign scientific and technical sources as well as the experience of surveys and tests regarding the technical condition of reinforced concrete bridges structures in Ukraine is carried out. In particular, the analysis and synthesis of the problems of ensuring the reliability and durability of the specified bridges in the operation conditions on the highways of Ukraine is carried out. The design errors, construction defects and faults, and long-term operational faults in the mentioned environments are summarized and clarified. In addition, the obtained data are as the basis to specify the criteria and models of the destruction mechanics in relation to reinforced concrete bridge structures. In particular, based on the obtained data, the methods to determine the VAT and the residual resource of the specified bridges are created. Scientific novelty. Based on the analysis and synthesis of scientific and technical sources and a number of surveys and tests, reinforced concrete and steel-reinforced concrete structures and long-term bridges newly built after the floods in 1998 and 2001, it is possible to summarize the main reasons that significantly affect the structures degradation of both the newly built and long-term bridges. This allows generalizing the design errors, construction defects and faults, and long-term operational faults. In addition, the state data served as the basis to specify the criteria and models of the destruction mechanics in relation to reinforced concrete bridge structures. In particular, based on these data, the methods to determine the assessment of the strength and crack resistance and the VAT and the residual resource of such bridges are created. Practical significance. Based on the given data and observations of real objects for 30 years, the main faults, defects and errors of the design, construction, and long-term bridges are summarized and set up. The methods to determine the VAT and calculate the residual resource, giving an opportunity to work out the repair and restoration method to increase the durability and reliability of long-term bridges are created.

Cases of Syntactic Interference in Students’ translations between English and Azerbaijani

By definition, translation requires the knowledge of at least two languages: a native and a foreign language. Depending on the extent to which a person knows a language, we can distinguish symmetrical and asymmetrical, autonomous and combined bilingualism. Particularly important in the case of translation asymmetric bilingualism – when one language is known to a greater extent, and combined bilingualism – when speech is built based on the native language. The aim of this article is to identify syntactic errors in the English translations of Azerbaijani students and find solutions to them. We will therefore primarily consider negative syntactic interference since it is the negative transfer that creates noticeable difficulties for translation. In translation, interference is expressed by a violation of the syntactic norms and rules of the studied foreign language under the influence of the transfer of skills and abilities of the native language. Students often make this mistake when harmonising the grammatical units of one language in accordance with the grammatical structures of another, or when they do not follow a certain rule in one language due to its absence in another. Syntactic interference describes violations in terms of typological differences and functioning. In order to establish interference, it is necessary to consider the features of each of the interacting languages. Comparative analysis of English and Azerbaijani languages helps to compare and see the main inconsistencies in the two language systems, to find the main errors in the foreign language speech of Azerbaijan-speaking students. For this purpose, the students were offered two types of tasks: translation from Azerbaijani into English and vice versa. A study of the students’ translations showed that the most typical errors are errors at the level of the sentence structure. Keywords: syntactic interference, comparative analysis, English-Azerbaijani languages, typological differences, typical errors .

Skidding characteristics of urban rail vehicle axle-box bearings considering surface waviness on races

As one of the core transmission components, axle-box bearings have been widely applied in urban rail vehicles and played a crucial role in their safe and stable operation. No matter in the starting and stopping stage or stable operation stage of the vehicle, the skidding phenomenon in axle-box bearings exists and impacts their own dynamic characteristics. Furthermore, as one of the main shape errors of the bearing surface, waviness may cause fluctuations for skidding characteristics of axle-box bearings. This study investigates the skidding dynamic analysis of axle-box bearings, taking into account race surface waviness. Firstly, a dynamics model for double-row cylindrical roller bearings is established, considering the cage flexibility and friction forces between different components. Then, this model is coupled with a three-dimension vehicle–track model, allowing for more precise dynamic simulation of axle-box bearings under actual running conditions. Furthermore, an excitation related to race surface waviness is added to the coupling model through time-varying displacement and contact stiffness. At last, the influence of race surface waviness on skidding characteristics of axle-box bearings is analyzed. The effectiveness of the proposed model is validated through theoretical analysis and field tests. Simulation results demonstrate that race surface waviness can impact the cage and roller slip ratio of axle-box bearings. Overall, this study provides valuable insights into the skidding dynamic analysis of axle-box bearings, highlighting the importance of considering race surface waviness in designing and maintaining axle-box bearings.

On the seafloor horizontal displacement from cGPS and compass data in the Campi Flegrei caldera

Seafloor deformation monitoring is now routinely performed in the marine sector of the Campi Flegrei volcanic area (Southern Italy). The MEDUSA infrastructure is formed by four buoys deployed at a water depth ranging from 40 to 96 m, and equipped with cGPS receivers, accelerometers and magnetic compasses to monitor the buoy status and a seafloor module with a bottom pressure recorder and other onboard instruments. The analysis of the time series data acquired by the MEDUSA monitoring infrastructure system allows to study the seafloor deformation in the Campi Flegrei caldera with geodetic accuracy. In a previous work, we show that the time series acquired by the Campi Flegrei cGPS onland network and MEDUSA over the period 2017–2020 are in good agreement with the ground deformation field predicted by a Mogi model which is widely used to describe the observed deformation of an active volcano in terms of magma intrusion. Only for one of the buoys, CFBA (A), the data differ significantly from the model prediction, at a level of simeq 6.9 sigma and of simeq 23.7 sigma for the seafloor horizontal speed and direction, respectively. For this reason, we devised a new method to reconstruct the horizontal sea bottom displacement considering in the analysis both cGPS and compass data. The method, applied to the CFBA buoy measurements and validated also on the CFBC (C) buoy, uses compass data to correct cGPS positions accounting for the pole inclination. Including also systematic errors, the internal consistency, always within sim 3 sigma for the speed and sim 2 sigma for the angle, between the results derived for different maximum inclinations of the buoy pole (up to 3.5^{circ }) indicates that the method allows to significantly reduce the impact of the pole inclination which, if not properly taken into account, can alter the estimation of the horizontal seafloor deformation. In particular, we find a good convergence of the retrieved velocity and deformation angle as we include in the analysis data from increasing values of the buoy pole inclination. Taking the result derived assuming the maximum allowed cutoff and accounting for statistical and systematic errors, we found a speed v = (3.521 ± 0.039 (stat) ± 0.352 (syst)) cm/yr and a deformation direction angle alpha = (-115.159 ± 0.670 (stat) ± 7.630 (syst))^{circ } (statistical errors at 1 sigma quoted from the rms of their values, main systematic errors added linearly). The relative impact of the main potential systematic (statistical) effects increases (decreases) with the cutoff. Our analysis provides a horizontal speed consistent with the model at a level of simeq 5.2 sigma (stat only) or of simeq 0.5 sigma (stat and syst added linearly), and a deformation angle consistent with the model at simeq 4.3 sigma level (stat only) or at simeq 0.3 sigma level (stat and syst added linearly). Correspondingly, the module of the vectorial difference between the velocity retrieved from the data and the velocity of the adopted Mogi model diminishes by a factor of simeq 7.65 ± 1.23 (stat) or ± 5.78 (stat + syst) with respect to the previous work. A list of potential improvements to be implemented in the system and instruments is also discussed.

Error Budget of Wafer Bonding Alignment System Based on Vision

Abstract Accurate wafer alignment is the key to achieving wafer bonding accuracy. High-precision wafer alignment systems typically use vision to locate the aligned Mark on two wafers, and use complex mechanisms to perform multiple composite movements to achieve functionality, making the coupling effect of multiple types of errors more complex and challenging the error budget of wafer alignment systems. This paper proposes an error budgeting method for such vision based multibody precision systems. This method takes the homogeneous transformation matrix (HTM) method as the core to model the system error and establish two types of error transfer chains. For the error chain involving visual measurement, an analysis method based on geometrical optics is proposed to consider the influence of the position and orientation errors of the optical path components. Then organize the possible error sources in the system and model the parameters of each error based on actual test results. Combined with the process flow, customize the error model for each link. Finally, perform Monte Carlo simulation. Using the aforementioned method to budget errors for a certain configuration of wafer alignment system, main error sources were identified, and accuracy indicators were proposed based on the alignment accuracy requirements of ± 200 nm. The rationality of the error budget conclusion in this study has been verified through experiments on the construction machine.

Modeling of the Variation Propagation for Complex-Shaped Workpieces in Multi-Stage Machining Processes

Variation prediction and quality control for complex-shaped workpieces in automotive and aerospace fields with multi-stage machining processes have drawn significant attention because of the widespread application and increasing diversity of these kinds of workpieces. To finish the final workpieces with complex shapes, multiple setups and operations are often applied in machining processes. However, sources of geometric error, such as fixture error, datum error, machine tool path error, and the dimensional quality of the product, interact complicatedly at different stages. These complex interactions pose significant challenges to final product error prediction and reduction. Manufacturing error prediction based on stream of variation is an effective way to control the machining quality. However, there are few integrated models that can describe the interactions among types of geometric error sources from different stages for different kinds of complex workpieces. This paper proposes a modified error prediction model to systematically capture the interactions of different error sources among different operations for complex-shaped workpieces in multi-stage machining processes. Using differential motion vectors, the connection of all key variations from machine, fixture, and workpiece is established. This modified model can not only handle general fixture layouts for complex workpieces, but also introduce machining-induced variations. Based on this model, the main error sources identification method and error compensation method are proposed. In order to evaluate the effectiveness of the proposed method, engine blocks are used to be machined as an example. Compared with a machining process without a compensating strategy, the average machining error of the key feature is reduced by 80.5% after compensating for the main error sources.

Temperature compensation of MEMS resonant accelerometers with an on-chip platinum film thermometer

Temperature-dominated drift is generally the main error source for high-performance micromachined resonant accelerometers (MRAs) due to inherent thermal stress effect of resonator structure and die-attach process. This paper describes the design and experimental evaluation of a temperature compensation scheme for MEMS resonant accelerometers that demonstrates excellent bias and scale factor stability against temperature variation. An on-chip temperature sensor fabricated by sputtering platinum film on glass substrate is proposed to accurately sense the temperature-induced frequency change of the resonator. A polynomial fitting-based post-compensation model is firstly used to suppress the temperature sensitivity of the MRA over dynamic temperature environment. The temperature drift test and compensation of four accelerometer prototypes in a range from −40 ∘C to 60 ∘C show that the stability of bias and scale factor has been improved greatly with navigation-grade performance. Temperature compensation results with three improved drift models based on polynomial fitting, convolutional neural network and support vector regression respectively are presented and compared to suppress the temperature drift hysteresis in consecutive temperature-varying tests. These experimental results indicate that this resonant accelerometer exhibits excellent temperature stability after compensation, which offers the promise for high-performance inertial navigation applications.

Doppler Positioning of Dynamic Targets with Unknown LEO Satellite Signals

A new concept of global navigation based on Doppler measurements from a large low Earth orbit (LEO) constellation is investigated that has potential to serve as a complement or backup to global navigation satellite systems (GNSSs) to provide navigation and positioning services in GNSS denial environments. In this work, we investigate the potential of LEO communication satellite opportunity signals in dynamic navigation, establish LEO satellite Doppler positioning equations, derive the main error sources affecting the Doppler positioning results of a dynamic target, and analyze the impact of each error source on positioning accuracy through a simulation. The results show that the orbit error and clock drift had a large impact on positioning accuracy. This navigation scheme would be more competitive if it could provide high-precision satellite orbits and accurate Doppler measurements. The obtained results show that the LEO satellite signals used as navigation opportunity signals are an attractive alternative in GNSS rejection environments for high dynamic targets.

Determination of Earth rotation parameters by Beidou navigation satellite system

Earth Rotation Parameters (ERP) play an important role in astrometry, geophysics, and space geodesy. Beidou Navigation Satellite System (BDS) has three orbital types of satellites, i.e., Geostationary orbit (GEO), Inclined Geosynchronous Orbit (IGSO), and Medium Earth Orbit (MEO) satellites. The orbital diversity of BDS constellation provides the opportunity to study the influence of system-specific satellite constellation with different orbital characteristic on ERP. In this article, different strategies of ERP estimation are conducted in terms of different solar radiation pressure (SRP) models and different orbital types of satellites. For ERP derived from BDS MEO observations, compared with C04 products from International Earth Rotation and Reference System Service, the results show that the accuracy of ERP with extended Empirical CODE Orbit Model (ECOM) with 9 parameters (ECOM2) outperforms other SRP models (e.g., ECOM with 5 parameters (ECOM1) and ECOM1 with an empirical prior model (EMP + ECOM1)). In EMP + ECOM1 solutions, the application of a prior EMP model would intensify the influence of draconitic year in pole coordinates spectrum, while the visible signal of a period close to 7.4 days with ECOM1 solution can be mitigated. Moreover, the bias of B0 parameter in EMP + ECOM1 would cause a mean offset in Length Of Day (LOD). The accuracy of ERP is also affected by the BDS constellation characteristic. For pole coordinate, MEO-only solution with ECOM2 model shows the best accuracy, while the LOD achieves the best solution when 3 orbital types are employed. Additionally, using the combined constellation of MEO, IGSO, and GEO satellites can decorrelate some of the systematic signals, e.g., the spurious signals of LOD at 2.35-day and 3.5-day in MEO-only solutions are reduced. Likewise, the increase of orbital planes can reduce the amplitude of 3 cycles per draconitic year (close to 121 days) in the pole coordinate spectrum, which is the main error source in pole coordinates estimated from BDS MEO constellation. However, some signals around 10 ∼ 24, 33– and 50-day are found in the Y-pole coordinate and its rate.

TREATMENT AND DIAGNOSTIC ERRORS MADE BY EMERGENCY MEDICAL SERVICES PERSONNEL DURING HOSPITALIZATION OF PATIENTS

The aim of the study is to analyze treatment and diagnostic errors made by emergency medical services personnel during hospitalization of patients. Materials and Methods: The analysis was made based on 412 report sheets to run sheets, taken at one EMS substation for one month. The sample included only report sheets for orders carried out by EMS feldshers. Analyzed materials showed that 42 report sheets contain defects in filling out the documentation: for example, 3 of them did not indicate a referral diagnosis of the EMS team, and 39 – final diagnosis of the hospital, and, therefore, they cannot be included in the statistical data. Analysis of the remaining 370 report sheets showed that in 60 cases there was an overdiagnosis of the disease, and in 31 cases the diagnosis was incorrect. Conclusion: From the analyzed materials, it is possible to identify the main treatment and diagnostic errors in the work of the EMS in cases of patient hospitalization: Incorrect tactics of managing patients at the prehospital stage due to overestimation/underestimation of symptoms, non-core hospitalization or hospitalization in a non-core hospital due to overestimation/underestimation of symptoms; replacement of a nosological unit with its symptoms or complications.