Assessment Scheme Research Articles

Geological-genetic structure of Irpin city, the role of lithological factors during engineering-geological zoning and construction assessment

The scheme of engineering-construction assessment created based on engineering-geological zoning of the city’s territory is desirable among additional graphic materials in the design of master plans projects as determined by building regulations. Engineering-geological zoning provides for different ranks’ selection of engineering-geological units (EG units), which have a particular range of common engineering-geological conditions that ultimately determine the construction sites’ affiliation to a specific suitability category. Geological-genetic structure of Irpin city of Kyiv region (Ukraine) is explored in this article. A variant of the creation of a large-scale engineering-geological map and corresponding geological-lithological sections by supporting boreholes in the borders of the city based on the engineering-geological survey conducted is presented. The obtained result allowed the selection of engineering geological zoning units – engineering geological districts by general conditions of geological development and subdistricts by engineering-geological complexes of Quaternary rocks’ thickness. The analysis of soils’ geomechanical properties (engineering-geological elements) lays the foundations for the selection of engineering-geological sites based on the comparison of this information with geomorphological, hydrogeological and geodynamic data. Accounting of geological-lithological factors in the preparation of the construction assessment scheme in the project of Irpin city’s master plan has become the ultimate result.

Examining psychopathy as a predictor of recidivism in a sample of women who have sexually offended

PurposeAs there are no validated risk assessment tools to predict recidivism for females who have sexually offended, the current study examines the utility of PCL-R to predict recidivism for this population. MethodsPsychopathy scores were collected from a sample of 244 women that received risk assessments before they were released from prison for a sexual offense. ResultsResults indicate that only one woman in the sample sexually recidivated during the follow-up time. However, 40% of the sample recidivated with any type of arrest, including general, violent, and breach offenses. Harrell's C and Cox Regression analyses found significant predictions for the PCL-R total score, factors, and items on overall recidivism and criminal recidivism for the sample, with most of the relationships small to moderate in effect. Additionally, some of the PCL-R items were significant predictors, offering more detailed information about connections to recidivism for this population. However, when control variables were added to multivariate prediction, age and number of total prior arrests negated many significant predictors for the PCL-R. ConclusionsThe construct of psychopathy may be part of a risk assessment scheme when assessing risk of women who have sexually offended, especially in relation to items on the PCL-R.

Retracted: Construction Scheme of Quantitative Assessment of College Teachers’ Performance Based on Big Data Analysis

Retracted: Construction Scheme of Quantitative Assessment of College Teachers’ Performance Based on Big Data Analysis

Classification of "Near-patient" and "Point-of-Care" SARS-CoV-2 Nucleic Acid Amplification Test Systems and a first approach to evaluate their analytical independence of operator activities.

European legislation defines as "near-patient testing" (NPT) what is popularly and in other legislations specified as "point-of-care testing" (POCT). Systems intended for NPT/POCT use must be characterized by independence from operator activities during the analytic procedure. However, tools for evaluating this are lacking. We hypothesized that the variability of measurement results obtained from identical samples with a larger number of identical devices by different operators, expressed as the method-specific reproducibility of measurement results reported in External Quality Assessment (EQA) schemes, is an indicator for this characteristic. Legal frameworks in the EU, the USA and Australia were evaluated about their requirements for NPT/POCT. EQA reproducibility of seven SARS-CoV-2-NAAT systems, all but one designated as "POCT", was calculated from variabilities in Ct values obtained from the respective device types in three different EQA schemes for virus genome detection. A matrix for characterizing test systems based on their technical complexity and the required operator competence was derived from requirements of the European In Vitro Diagnostic Regulation (IVDR) 2017/746. Good EQA reproducibility of the measurement results of the test systems investigated implies that different users in different locations have no recognizable influence on their measurement results. The fundamental suitability of test systems for NPT/POCT use according to IVDR can be easily verified using the evaluation matrix presented. EQA reproducibility is a specific characteristic indicating independence from operator activities of NPT/POCT assays. EQA reproducibility of other systems than those investigated here remains to be determined.

Experimental study on structural adhesive properties of aluminum plate and carbon fiber-reinforced polymer heterogeneous materials

Structural adhesive bonding between aluminum and carbon fiber-reinforced polymer (CFRP) is an important part of the vehicle's lightweight design and must ensure high strength and durability during the life of the structural member. The paper presents a precise assessment scheme to accurately and reliably infer the performance of adhesive joints through a short-term experimental test method that focuses on intrinsic and extrinsic factors affecting bond strength. The experimental results show that the surface of CFRP is polished, which is beneficial to improve the bonding quality, and the damage type transitioned from adhesion damage to substrate or cohesion damage. Aluminum alloy electrophoresis and non-electrophoresis have no significant effect on the bonding performance. Secondly, the design of the bonding nodes should be considered to bring them into a state of shear stress and be able to withstand greater loads. Meanwhile, the moderate thickness of the adhesive layer and increased bonding area serve to enhance bond reliability. In addition, various environments can cause various physical and chemical changes within structural adhesives, which can reduce the cohesive strength and durability of adhesives. This experiment is designed to select process parameters and adhesive applications for structural adhesives, which are crucial in predicting and evaluating the performance of newly developed structural adhesives and bonded joints.

Children's Pain Identification Based on Skin Potential Signal.

Pain management is a crucial concern in medicine, particularly in the case of children who may struggle to effectively communicate their pain. Despite the longstanding reliance on various assessment scales by medical professionals, these tools have shown limitations and subjectivity. In this paper, we present a pain assessment scheme based on skin potential signals, aiming to convert subjective pain into objective indicators for pain identification using machine learning methods. We have designed and implemented a portable non-invasive measurement device to measure skin potential signals and conducted experiments involving 623 subjects. From the experimental data, we selected 358 valid records, which were then divided into 218 silent samples and 262 pain samples. A total of 38 features were extracted from each sample, with seven features displaying superior performance in pain identification. Employing three classification algorithms, we found that the random forest algorithm achieved the highest accuracy, reaching 70.63%. While this identification rate shows promise for clinical applications, it is important to note that our results differ from state-of-the-art research, which achieved a recognition rate of 81.5%. This discrepancy arises from the fact that our pain stimuli were induced by clinical operations, making it challenging to precisely control the stimulus intensity when compared to electrical or thermal stimuli. Despite this limitation, our pain assessment scheme demonstrates significant potential in providing objective pain identification in clinical settings. Further research and refinement of the proposed approach may lead to even more accurate and reliable pain management techniques in the future.

Diametral compression of short cylinders with a central hole as a method for assessing the tear resistance of brittle materials

The possibility of evaluating the tear resistance of brittle materials by diametral compression test of short cylinders (solid and central with a central hole) has been analyzed. The computational analysis was performed by the finite element method using the ANSYS program. It is shown that the stress distribution in a disk with a hole is similar that without a hole but contains disturbances introduced by a stress concentrator in the form of a hole. The normalized values of the maximum first principal stresses for a disk with a hole exceed the values for a disk without a hole by more than 5 times. The experimental analysis was carried out by testing short cylinders, both solid and with a central hole, made of brittle materials: cast iron and graphite. It is noted that the fracture resistance, determined by the formula recommended by the ASTM D3967 – 95a standard, practically does not differ for solid cast iron samples, and for graphite differs by 1.5 times from the true tear resistance of materials; when testing samples with a central hole, the tear resistance differs from the standard values by a factor of 1.5 and almost 2.5, respectively. The different nature of the sample destruction is also noted: slow controlled rupture of cast iron and dynamic destruction of graphite with the corresponding deformation diagrams. The results of testing fuel pellets of uranium dioxide are given as an example of testing real cylindrical samples with a central hole. It is shown that the test results of ARV-1 graphite samples are in good agreement with the test results of fuel samples. Thus, the possibility of testing small-sized short cylinders according to the diametral compression scheme for indirect assessment of the tensile strength of brittle materials has been confirmed. A calculation formula is proposed for an indirect assessment of the tensile strength of brittle materials based on the results of testing small-sized short cylinders, both with and without a central hole according to the diametral compression scheme.

Aggregated data from the same laboratories participating in two glucose external quality assessment schemes show that commutability and transfers of values to control materials are decisive for the biases found.

We report the results of glucose measurements performed during one year by the same measurement procedures (MPs) in 58 Norwegian hospital laboratories using control materials provided by external quality assessment (EQA) schemes from two different providers. The providers used materials with presumed vs. verified commutability and transfers of values using reference material vs. using a highest-order reference MP. Data from six Labquality and three Noklus glucose EQA surveys were aggregated for each MP (Abbott Alinity, Abbott Architect, Roche Cobas, and Siemens Advia) in each scheme. For each EQA result, percent difference from target value (% bias) was calculated. Median percent bias for each MP per scheme was then calculated. The median % biases observed for each MP in the Labquality scheme were significantly larger than those in the Noklus scheme, which uses verified commutable control materials and highest-order reference MP target values. The difference ranged from 1.2 (Roche Cobas, 2.9 vs. 1.7 %) to 4.4 percentage points (Siemens Advia, 3.2 % vs.-1.2 %). The order of bias size for the various MPs was different in the two schemes. In contrast to the Labquality scheme, the median % biases observed in the Noklus scheme for Abbott Alinity (-0.1 %), Abbott Architect (-0.5 %), and Siemens Advia (-1.2 %) were not significantly different from target value (p>0.756). This study underlines the importance of using verified commutable EQA materials and target values traceable to reference MPs in EQA schemes designed for assessment of metrological traceability of laboratory results.

Assessing the End-of-Semester Examination Papers During the Implementation of the Bologna Process: Bloom’s Taxonomy as a Framework

One of the significant transformations in the Kurdistan Region of Iraq (KRI) is the implementation of the Bologna process. This alteration of the traditional system to the Bologna process system has also impacted the assessment schemes. More weight has been given to formative assessment that can help improve students’ grades and ease success in the courses. Nonetheless, the final exam still carries most of the grades. Therefore, setting appropriate questions that can meet all the cognition levels represented in Bloom’s taxonomy assists in raising students’ cognition to higher levels rather than only assessing bookish knowledge that is located on the baseline of Bloom’s taxonomy. To this intent, the present study endeavored to identify if instructors at colleges of Nursing and Science adhere to the various dimensions of Bloom’s taxonomy that are central to the Bologna process. More importantly, the association of each of the demographic variables to the level of the final examination questions was also examined. The study employed a quantitative method to tackle the topic. Totally, a sample of 75 final examination papers was collected from instructors, including 524 individual questions. The findings revealed that most of the examination papers revolved around low-order thinking questions and the association of the rate of success to the level of the questions was highly statistically significant.

Pesticide dynamics in three small agricultural creeks in Hesse, Germany.

Due to their high biodiversity, small water bodies play an important role for freshwater ecosystems. Nonetheless, systematic pesticide monitoring in small creeks with a catchment <30 km2 is rarely conducted. In this study, event-driven water samples were taken from May until November 2017 and March until July 2018 after 20 rain events at three sampling sites with catchment areas of <27 km2 in the Wetterau, a region with intensive agriculture in Southern Hesse, Germany. Additionally, enriched extracts of the native water samples from the campaign in 2018 were used for the Microtox assay to determine baseline toxicity to invertebrates over time and sum of toxic units (STU) were calculated to compare the potential toxicity of the samples. Overall, 37 pesticides and 17 transformation products were found, whereby the herbicide metamitron (79 µg/L) showed the highest concentration. Regularly, pesticide concentrations peaked at the time of the highest water level within each sampling event. Within each sampling event maximum pesticide concentration was mostly reached in water samples taken during the first two hours. The sum of the time-weighted mean concentration values of all pesticides was between 2.0 µg/L and 7.2 µg/L, whereby the measured concentrations exceeded their regulatory acceptable concentration (RAC) at 55% of all sampling events for at least one pesticide. The mean EC50 values varied between 28.6 ± 13.1 to 41.3 ± 12.1 REF (relative enrichment factor). The results indicated that several samples caused baseline toxicity, whereby the highest activity was measured at the time of highest water levels and pesticides concentrations, and then steadily decreased in parallel with the water level. Median STUs of invertebrates ranged from -2.10 to -3.91, of algae/aquatic plants from -0.79 to -1.84 and of fish from -2.47 to -4.24. For one of the three sampling sites, a significant linear correlation between baseline toxicity and STUinvertebratewas found (r2=0.48). The results of the present study suggest that (1) current pesticide monitoring programs underestimate risks posed by the exposure to pesticides for aquatic organisms and (2) pre-authorization regulatory risk assessment schemes are insufficient to protect aquatic environments.

Artificially raised creatinine concentrations due to analytical interference for samples contaminated with total parenteral nutrition fluid.

A sample received in the laboratory from a patient receiving total parenteral nutrition (TPN) indicated that the patient may have renal dysfunction, but the results were not considered to be reliable enough to report. Investigations using a reference method for measurement of creatinine confirmed positive interference in the creatinine assay and distribution of samples via an External Quality Assessment (EQA) Scheme showed that this positive interference was method dependent. Residual TPN fluid (Nutriflex Lipid Special) left in the bag after the patient had completed the infusion was collected and added to a patient serum pool in increasing amounts and distributed to different laboratories for analysis of creatinine and glucose through an EQA Scheme. Positive interference in a number of different creatinine assays was identified as a result of a component in the TPN fluid. Positive interference from high concentrations of glucose has been demonstrated to be a cause for falsely high results in Jaffe creatinine assays. The concern would be that a sample contaminated with TPN fluid would have both abnormal electrolytes and creatinine concentrations and give the impression that the patient was in renal failure due to analytical interference in the creatinine assay and laboratory staff need to be aware of this problem.

Toxicological effectsassessment for wildlife in the 21st century: Review of current methods and recommendations for a path forward.

Model species (e.g., granivorous gamebirds, waterfowl, passerines, domesticated rodents) have been used for decades in guideline laboratory tests to generate survival, growth, and reproductive data for prospective ecological risk assessments (ERAs) for birds and mammals, while officially adopted risk assessment schemes for amphibians and reptiles do not exist. There are recognized shortcomings of current in vivo methods as well as uncertainty around the extent to which species with different life histories (e.g., terrestrial amphibians, reptiles, bats) than these commonly used models are protected by existing ERA frameworks. Approaches other than validating additional animal models for testing are being developed, but the incorporation of such new approach methodologies (NAMs) into risk assessment frameworks will require robust validations against in vivo responses. This takes time, and the ability to extrapolate findings from nonanimal studies to organism- and population-level effects in terrestrial wildlife remains weak. Failure to adequately anticipate and predict hazards could have economic and potentially even legal consequences for regulators and product registrants. In order to be able to use fewer animals or replace them altogether in the long term, vertebrate use and whole organism data will be needed to provide data for NAMvalidation in the short term. Therefore, it is worth investing resources for potential updates to existing standard test guidelines used in the laboratory as well as addressing the need for clear guidance on the conduct of field studies. Herein, we review the potential for improving standard in vivo test methods and for advancing the use of field studies in wildlife risk assessment, as these tools will be needed inthe foreseeable future. Integr Environ Assess Manag 2024;20:699-724. © 2023 His Majesty the King in Right of Canada and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Reproduced with the permission of the Minister of Environment and Climate Change Canada. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

An investigation of eighth-graders’ mathematical communication competency and mathematical literacy performance

This study aimed to investigate eighth-grade students’ mathematical communication competency and mathematical literacy performance in a classroom experiment designed based on the mathematical modeling approach. Accordingly, a teaching experiment methodology was applied. Data were collected from three eighth-grade students through the Mathematical Communication Competency Measurement Tools, video recordings of the teaching episodes, student products, and clinical interviews before and after the teaching experiment. PISA mathematics proficiency level and communication competency level assessment schemes were used in the data analysis process. A deductive analysis was performed on the data collected through the clinical interviews, whereas a retrospective analysis was conducted to examine the data collected through teaching episodes. The results showed that the modeling-based teaching experiment helped develop the mathematical communication competency of all participating students. The results also showed that improving students’ mathematical communication competencies increased their mathematical literacy performances.

Adverse Blood Transfusion Reaction Reporting at a Tertiary Care Hospital, Bhutan

Background and Objectives: Even though Blood Transfusion Service is considered as life-saving intervention, it is associated with the occurrence of uneventful reactions from the transfusion of blood and blood units. Bhutan Blood Bank is fragmented with different levels of services provided which leads to varied levels of adverse blood transfusion reaction reported. Study on the hemovigilance system at tertiary care hospital is conducted so as to study the frequency and types of reactions over a period of three years from 1st January 2019 to 31st December 2021. Methods: All ATRs occurring within a period of 3 years were studied according to the Blood Bank standard operating procedure. Adverse transfusion events related to blood and blood units were analyzed and classified on the basis of their clinical features and laboratory tests. Descriptive statistics were used to represent the adverse transfusion reactions. Results: During this period, a total of 19,961 blood and blood components were issued and 120 adverse transfusion events were reported. Most reaction reported were febrile non-hemolytic transfusion reaction, FNHTR (59.2%) followed by allergic reaction (22.5%) occurring predominantly in females (93%). Packed red cells were the common component causing adverse events (83 %) with most observable in Group A (42.5%) blood units. Conclusion: Febrile and allergic reactions are the most common type of reaction reported. Although such reaction type is least harmful but fatal reaction can occur and preventive measures must be taken to avoid such reactions. This preliminary study indicates the importance of having continuous monitoring and quality assessment scheme in addressing the issues of adverse transfusion reaction. Furthermore, establishing a hospital transfusion committee is vital for delivery of safe and efficient blood transfusion services.

Performance evaluation of SARS-CoV-2 antigen detection in the post-pandemic era: multi-laboratory assessment.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen detection is an indispensable tool for epidemic surveillance in the post-pandemic era. Faced with irregular performance, a comprehensive external quality assessment (EQA) scheme was conducted by the National Center for Clinical Laboratories (NCCL) to evaluate the analytical performance and status of SARS-CoV-2 antigen tests. The EQA panel included ten lyophilized samples containing serial 5-fold dilutions of inactivated SARS-CoV-2-positive supernatants of the Omicron BA.1 and BA.5 strains and negative samples, which were classified into "validating" samples and "educational" samples. Data were analyzed according to qualitative results for each sample. A total of 339 laboratories in China participated in this EQA scheme, and 378 effective results were collected. All validating samples were correctly reported by 90.56 % (307/339) of the participants and 90.21 % (341/378) of the datasets. The positive percent agreement (PPA) was >99 % for samples with concentrations of 2×107 copies/mL but was 92.20 % (697/756) for 4×106 copies/mL and 25.26 % (382/1,512) for 8×105 copies/mL samples. Colloidal gold was the most frequently used (84.66 %, 320/378) but showed the lowest PPAs (57.11 %, 1,462/2,560) for positive samples compared with fluorescence immunochromatography (90 %, 36/40) and latex chromatography (79.01 %, 335/424). Among 11 assays used in more than 10 clinical laboratories, ACON showed a higher sensitivity than other assays. The EQA study can help to validate whether it's necessary to update antigen detection assays for manufacturers and provide participants with information about the performance of assays to take the first step toward routine post-market surveillance.

Basis Risk Analysis and Countermeasures for Enterprises’ Commodity Price Risk Management by Using Futures Hedging Strategy -- A Case Study of “Metallgesellschaft” Hedging Failure

As the international economic situation was risingly unsteady and turbulent, many enterprises have come up to make use of the futures market to minimize commodity price fluctuation risks, however, not a few suffering massively high hedging losses. These events has showed that numbers of enterprises had a lack of incisivel comprehension of the basis risk of hedging and made no fully preparation on how to control and erode losses in time as soon as the basis transfers deviated from expection. This article intends to make an in-depth discussion on basis risk through the analysis of the well-known huge losses case of the Metallgesellschaft and put forward effective and logical countermeasures, for enterprises grasping potently of basic risk resisting financial damage. In short, in order to lesson the high financial loss which exceeds the expectation caused by the unusual basis, the enterprises must establish a reasonable and supportive hedging risk assessment and optimal protective stop-loss scheme.

An Assessment Scheme for Road Network Capacity under Demand Uncertainty

Network capacity is a vital index with which to assess the operation of traffic networks. The majority of existing traffic network capacity models are formed as bi-level programming, which maximizes the traffic flows under equilibrium constraints and is extremely dependent on the current origin–destination (O–D) travel demand. However, an accurate O–D matrix is not easy to obtain in practice. This article aims to provide an assessment method for traffic network capacity under demand uncertainty. To consider the variation in real demand in traffic networks, the current travel demand is treated as unknown parameters that are defined inside a restricted set. Based on the hypothesis of different probability distributions, the road network capacity is calculated by repeated capacity loading experiments with a random sampling of uncertain parameters. To improve the efficiency of the repeated calculations of the traffic assignment model, a sensitivity-analysis-based (SAB) approximation method was developed to avoid the double calculation of the network capacity model for each random O–D matrix. The SAB method significantly improved the calculation efficiency while ensuring accuracy. Using simulation experiments, we researched the reliability of road network capacity and the probabilities of high congestion for each link under uncertain demand.

A Multifactor Ring Signature based Authentication Scheme for Quality Assessment of IoMT Environment in COVID-19 Scenario

The quality of the healthcare environment has become an essential factor for healthcare users to access quality services. Smart healthcare systems use the Internet of Medical Things (IoMT) devices to capture patients’ health data for treatment or diagnostic purposes. This sensitive collected patient data is shared between the different stakeholders across the network to provide quality services. Due to this, healthcare systems are vulnerable to confidentiality, integrity and privacy threats. In the COVID-19 scenario, when collaborative medical consultation is required, the quality assessment of the framework is essential to protect the privacy of doctors and patients. In this paper, a ring signature-based anonymous authentication and quality assessment scheme is designed for collaborative medical consultation environments for quality assessment and protection of the privacy of doctors and patients. This scheme also uses a new KMOV Cryptosystem to ensure the quality of the network and protect the system from different attacks that hamper data confidentiality.

O-285 The 6th edition of the WHO manual for the examination and processing of human semen: How should it affect our practice?

Abstract The WHO laboratory manual (World Health Organization 2021) has widened the scope of semen examination from primarily a prognostic tool for Medically Assisted Reproduction (MAR) by indicating the importance of evaluating men with possible disorders in male reproductive functions. Practical instructions for basic examination have been clarified and focused to measures of sperm production and motility as judged from sperm number, motility (vitality if poor motility) and sperm morphology. In addition to the recommendations by the WHO, an international standard based on the same laboratory science as the WHO manual has been published (International Organization for Standardization 2021) to facilitate for laboratories to provide reliable results of semen examination. Each ejaculate must be handled with great care before analysis begins. Time and temperature between sample collection and start of assessments is crucial. To reduce assessment variability, it is essential to ascertain that the examined aliquots are representative for the entire ejaculate and that the number of observations is sufficient to reduce the risk for significant influence of random factors. The former is handled both by aliquot volume (at least 50 µL for sperm concentration) and replicate assessment and comparison that the two assessments don’t differ too much. Regarding number of observations, 400 sperm counted in sperm concentration and in sperm motility assessments is required to reduce this source of errors to ± 10%. For assessment of sperm morphology and vitality a minimum number of observations is 200 spermatozoa. To achieve acceptable performance, thorough in-house training is necessary. There are protocols how to set up and run such schemes (Mortimer 1994, 1994). Basic medical laboratory standards also require that the laboratory regularly performs internal quality control to monitor that inter- and intra-personal variability is under control. Each laboratory should also participate in an external scheme for quality assessment (EQA) (International Organization for Standardization 2012). For the proper interpretation of semen examination results reference limits are important. However, the reference limits suggested by the WHO (World Health Organization 2021) come from a very mixed group of men and should therefore not be mistaken for true limits between fertility and infertility. The new WHO manual therefore argues for development of decision limits (when is it reasonable to act?) that are much more important than limits from a mixed population. It has been argued that semen examination must be better standardized (Björndahl et al. 2016), but the compliance has been almost non-existent (Vasconcelos et al. 2022) leading to even stronger appeals for stronger improvement of basic laboratory investigations of male reproductive functions (Björndahl et al. 2022) References Björndahl L, Barratt CL, Mortimer D, and Jouannet P. ‘How to count sperm properly': checklist for acceptability of studies based on human semen analysis. Hum Reprod 2016: 31; 227-232. Björndahl L, Barratt CLR, Mortimer D, Agarwal A, Aitken RJ, Alvarez JG, Aneck-Hahn N, Arver S, Baldi E, Bassas L, et al. Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology. Hum Reprod 2022. International Organization for Standardization. ISO 15189:2012 Medical Laboratories – Requirements for Quality and Competence 2012. Geneva. International Organization for Standardization. ISO 23162:2021 Basic semen examination — Specification and test methods 2021. ISO, Geneva. Mortimer D. Laboratory standards in routine clinical andrology. Reproductive Medicine Review 1994: 3; 97-111. Mortimer D. Practical Laboratory Andrology 1994. Oxford University Press, Oxford. Vasconcelos AL, Campbell MJ, Barratt CLR, and Gellatly SA. Do studies published in two leading reproduction journals between 2011 and 2020 demonstrate that they followed WHO5 recommendations for basic semen analysis? Hum Reprod 2022. World Health Organization. WHO laboratory manual for the examination and processing of human semen. 6th edn, 2021. World Health Organization, Geneva.

Gas path deterioration observation based on stochastic dynamics for reliability assessment of aeroengines

Gas path deterioration seriously reduces the reliability of aeroengine systems. Accurate observation of gas path deterioration parameters is the key to ensuring the reliable operation and safety control of aeroengines. It is a significant challenge to accurately observe the deterioration state under multi-source uncertainties. This work provides a novel assessment technique to accurately master the gas path deterioration from the perspective of stochastic dynamics for the first time, in contrast to the previous assessment schemes based on the aerothermodynamics model and filtering theory. Based on the state parameters and stochastic optimal inputs, a full-dimensional performance observation equation is created. The construction of the stochastic optimal inputs ensures the tracking of the gas path deteriorating state through the negative feedback of state parameters and the rectification of measurement data. The observation principle and algorithm are also thoroughly presented. Three common deterioration modes serve as proof of the proposed method's effectiveness. The evaluation accuracy is increased by at least 22.75% when compared to the conventional method, and the maximum improvement rate reaches 52.45%. The proposed method is free from multi-source uncertainty interference and has higher accuracy and robustness. It offers a fresh approach to master gas path deterioration and ensures safe and reliable operation.