Estimation Formula Research Articles

Determination of body length regression formulas for the golden grey mullet (Chelon auratus, Risso 1810) based on otoliths found in the feces of the Caspian Seal (Pusa caspica Gmelin, 1788)

The Caspian Seal, the sole mammal endemic to the Caspian Sea, is listed in the IUCN Red List as a species facing the threat of extinction, a status similarly recognized and/or assigned in all countries in the Caspian region.The study of seal nutrition using caprological methods is of great interest for understanding animal adaptation to deteriorating habitat conditions and assessing the adequacy of their food base in the sea. This method involves analyzing the contents of feces from ichthyophages to detect undigested fish otoliths.The results of studying the seal's diet during periods of haulout on breeding grounds showed that the frequency of occurrence of Chelon auratus otoliths ranged from 2-3% to 27.7% of all fish otoliths detected in feces.This study aims to assess changes in Chelon auratus otoliths as they pass through seals' gastrointestinal tracts and estimate formulas for recovering the linear dimensions of fish consumed by these seals.The research indicates that otolith growth slows with fish growth but does not cease entirely. Allometry is evident in the different ratios of otolith length and width to fish length in various size groups and the change in otolith shape as fish grow.To recover the body length of fish consumed by seals based on otoliths found in their feces, applying inverse calculation formulas obtained when studying the relationship between otolith growth and fish body growth using collection material obtained directly from fish is possible.Further research should focus on refining the recovery formula for the length of large fish by dividing the length into several segments, each described by separate formulas describing the relationship between fish body length and otolith length and width growth.

Comparison of the Effectiveness of Body Surface Area Estimation Formulas in Predicting the Risk of Death in Patients with Heart Failure.

Background/Objectives: Body surface area is one of the most important anthropometric parameters in medicine. The study's primary objective is to compare the consistency of the BSA estimation results through applying available formulas. Other objectives include determining the ability of these formulas to discriminate between death and survival in patients, comparing the formulas' diagnostic features, and investigating whether the risk associated with a low BSA is independent of BMI. Methods: This study included 1029 patients (median age, 54 years; female, 13.7%; NYHA I/II/III/IV, 6.3%/36.5%/47.7%/9.5%) diagnosed with heart failure. For each patient, BSA was calculated using 25 formulas. Over the 3-year observation period, 31.2% of the patients died. Results: The average BSA value of the optimal discrimination thresholds was 1.79 m2 ± 0.084 m2 and the BSA difference between the estimators with the lowest (BSAMeeh1879) and the highest (BSANwoye1989) optimal discrimination thresholds was 0.42 m2. The lowest mortality rate was 35.2% and occurred in the subgroup of individuals with BSA values below the optimal discrimination threshold using the BSASchlich2010 estimator. The highest mortality was predicted when the estimator BSAMeeh1879 or BSALivingston&Lee2001 was used. Conclusions: Our study showed a relatively good concordance of 25 BSA estimators in BSA assessment in patients, without extremes of weight or height being known to disrupt it. All BSA estimators presented a significant, although weak, ability to discriminate death from survival at 3-year follow-up; however, BSA is not a very good predictor of HF mortality at 3 years. The higher risk of death in smaller patients, as shown by BSA, was independent of BMI in all but two BSA estimators.

Fixed-Time Control and Estimation of Discontinuous Fuzzy Neural Networks: Novel Lyapunov Method of Fixed-Time Stability.

This article considers the fixed-time stability (FXTS) issue for discontinuous system described by differential equation (DE) with time-varying parameters. Using the tool of differential inclusion (DI), several improved FXTS criteria and estimation formulas of settling time (SET) are derived by employing a relaxed Lyapunov method. The special novelty of the developed Lyapunov method is that the derivative of Lyapunov function possesses indefiniteness. As an important application, the established FXTS theorems are utilized to deal with fixed-time (FXT) synchronization issue for fuzzy neural networks (FNNs) possessing state discontinuity, where the fuzzy operation is used in the synaptic law computing, and one typical time-varying switching control protocol is designed. Moreover, a series of estimations of SET for FXT synchronization are given out. Finally, the simulation examples are present to substantiate the validity of the obtained results.

Frequency-domain sound field from the perspective of band-limited functions.

A model that approximates the sound field well is useful in various fields, such as acoustic signal processing and numerical simulation. We have proposed an effective model in which the wideband instantaneous sound field is regarded as an element of a spherically band-limited function space, using the reproducing kernel of that space. In this paper, the frequency-domain sound field is regarded as an element of some band-limited function space, and a representation of the field as a linear combination of the reproducing kernel in that space is proposed. This model has the strongest representational capacity of all function systems when we know only the sound pressure information at arbitrary positions. The proposed model can be considered a generalization of the existing three-dimensional sound field model using the reproducing kernel of the solution space of the Helmholtz equation to the spatial dimension. One of the advantages of capturing the frequency-domain sound field in this way is the simplicity achieved for the estimation formula of the wavenumber spectrum. Two numerical simulations were conducted to validate the proposed methods.

An Experimental Study of Wave Impact Loads on an FPSO Bow in 2D Wave-Tank

In harsh environments, an floating production storage and offloading (FPSO) is occasionally damaged by impact loads, such as bow flare slamming and green water. This study conducted an impact load measurement experiment on a model of an FPSO bow in a 2D wave tank. Three types of frequency-focused waves (steep, spilling, and plunging) were generated, and the speed and slope of the waves were measured. Seven wave probes were placed in a row, and the wave elevation was measured to determine the speed and slope of the waves. In addition, the side of the 2D wave tank was photographed with a high-speed camera. The speed and slope of the waves obtained from the wave probe array agreed well with those obtained from the photographs taken using a high-speed camera. In the case of a steep wave, wave runup occurred at the bow before the wave reached the bow of the FPSO, so no impact load was generated, and only hydrostatic pressure was measured. Impact loads were generated in the spilling and plunging waves, and the magnitude of impact loads using the Von Karman’s estimation formula and the impact loads measured in model tests showed similar values.

Estimated glomerular filtration rate versus creatinine clearance to determine anticoagulant dosage after lower-limb orthopedic surgery.

Anticoagulation is recommended for thromboprophylaxis after lower-limb orthopedic surgery. The suggested dosage is based on creatinine clearance (CCr) in the labels. However, most facilities only provide estimated glomerular filtration rate (eGFR) as laboratory data. Because the eGFR equation adjusts for a body surface area (BSA) of 1.73 m2, it may overestimate renal function in patients with a small BSA. This retrospective study aimed to determine whether different renal function estimation formulas affect the incidences of venous thromboembolism (VTE) and bleeding when determining anticoagulant dosages. This study included patients who underwent lower-limb orthopedic surgery and received anticoagulants (edoxaban, enoxaparin, and fondaparinux) between 2017 and 2020 at Yaizu City Hospital. Anticoagulant dosing was evaluated using CCr, eGFR, and de-indexed eGFR (without correction for BSA), and the incidences of VTE and bleeding were compared among these formulas. The median values for BSA, CCr, eGFR, and de-indexed eGFR were 1.40 m2, 56.0mL/min, 73.0mL/min/1.73m2, and 60.9mL/min, respectively. There was no significant difference in the VTE incidence among these formulas. However, when dose reduction or contraindication threshold was determined by eGFR vs. CCr, the bleeding incidence was significantly higher in the group that was overdosed by CCr (6.0% vs. 25.7%, p < 0.05). Similarly, using de-indexed eGFR vs. CCr, the bleeding incidence was significantly higher in the group that was overdosed by CCr (7.5% vs. 28.6%, p < 0.05). In orthopedic surgery, anticoagulant dosages should be based on CCr for patients with a small BSA to avoid bleeding risks.

Comparison of cardiovascular disease risk assessment tools in primary prevention patients with raised lipoprotein(a)

Abstract Background Genetically inherited lipoprotein (a) (lp(a)) is an independent cardiac risk factor. The approach to cardiovascular disease (CVD) risk modification is, however, uncertain. Current CVD risk calculators do not take lp(a) into account and guidance suggests binary treatment decisions based on presentation of lp(a) without considering other risk factors. A new CVD risk assessment tool has been developed which includes lp(a) concentration, Lp(a) Clinical Guidance (lpaclinicalguidance.com). Purpose The aim was to compare the CVD risk estimations and management impact, over both 10 years and lifetime, using the HEART UK consensus statement, QRISK3, Lp(a) Score, Score-2, Score-2 OP, and LIFE-CVD assessment tools in 20 primary prevention patients with raised lp(a). Methods This was a retrospective analysis from an existing database, recruited through lipid and cardiology outpatient services, with raised lp(a), and no history of CVD. A random selection with a broad range of lp(a) concentrations were chosen. The 10-year risk threshold to treat was based on current NICE guidance at 10% and, in the absence of consensus, a lifetime risk threshold of 25%. Lp(a) was measured by a reference clinical laboratory using a Roche platform (Denka Seiken reagent, isoform insensitive). Results The subset (n=20) included patients with lp(a) ranging from 64 nmol/L to &amp;gt;720 nmol/L, aged 20 to 78 (12 females). Risk assessment tool age restrictions prohibited risk estimation in all patients (explaining the variation in denominator below). Figure 1 shows a comparison of 10-year risk assessment tools, figure 2 lifetime risk. HEART UK guidance would indicate 90% of patients (18/20) were eligible to commence lipid lowering therapy, however, all patients would have treatment indicated based on Lp(a) Score (16/16). Using Score-2, no patients would have treatment indicated (0/6). Only 25% of patients (1/4) would have treatment indicated using Score-2 OP despite a minimum age criterion that alone introduces a major CVD risk factor. Of the remaining risk estimation tools: LIFE-CVD, QRISK3 lifetime risk, and QRISK3 10-year risk indicated 85% (11/13), 50% (8/16), and 38% (6/16) of patients, respectively, would have treatment indicated. Conclusions In primary prevention patients with raised lp(a), CVD risk estimation and decision-making is impaired by discrepancies in risk assessment tools. There may be underestimation in CVD risk, and subsequently under-treatment, with principal use of QRISK3 10-year risk to guide lipid lowering therapy. Lifetime CVD risk may be underestimated by QRISK and LIFE-CVD proportionally to the degree of elevation of lp(a). Risk assessment is imperfect; population data can only provide limited information when applied to an individual and the wide discrepancy found here calls into question the validity of risk estimation formulae in this population, or alternatively provides a range of tools for clinicians to select to suit the question asked.

Advanced Prediction Models for Scouring Around Bridge Abutments: A Comparative Study of Empirical and AI Techniques

Scouring is a major concern affecting the overall stability and safety of a bridge. The current research investigated the effectiveness of the various artificial intelligence (AI) techniques, such as artificial neural networks (ANNs), the adaptive neuro-fuzzy inference system (ANFIS), and random forest (RF), for scouring depth prediction around a bridge abutment. This study attempted to make a comparative analysis between these AI models and empirical equations developed by various researchers. The current research paper utilized a dataset of water depth (Y), flow velocity (V), discharge (Q), and sediment particle diameter (d50) from a controlled laboratory setting. An efficient optimization tool (MATLAB Optimization Tool (version R2023a)) was used to develop a scour estimation formula around bridge abutments. The findings of the current investigation demonstrated the superior performance of the AI models, especially the ANFIS model, over empirical equations by precisely capturing the non-linear and complex interactions between these parameters. Moreover, the result of the sensitivity analysis demonstrated flow velocity and discharge to be the most influencing parameters affecting the scouring depth around a bridge abutment. The results of the current research highlight the precise and accurate prediction of the scouring depth around a bridge abutment using AI models. However, the empirical equation (Equation 2) demonstrated better performance with a higher R-value of 0.90 and a lower MSE value of 0.0012 compared to other empirical equations. The findings revealed that ANFIS, when combined with neural networks and fuzzy logic systems, produced highly accurate and precise results compared to the ANN models.

Development of an estimation formula for preparation time of anesthesia induction and surgery accounting for clinical department factors in optimal surgery schedule management

Efficient operating room management is essential and requires precise surgery scheduling. We hypothesized that an estimation formula for the preparation time for anesthesia induction and surgery could be developed by incorporating anesthesia and surgical factors, as well as the ‘clinical department,’ into the formula. This retrospective observational study analyzed 12,528 scheduled surgical cases. A regression analysis that included the clinical department, six anesthesia factors, and five surgical factors was conducted. This analysis aimed to develop both an analytical framework and an equation for estimating the time required for both anesthesia induction and surgical preparation. Our estimation formula wielded high accuracy (R2 = 0.801). Particularly, there was only a difference of less than 3 min for surgeries under general anesthesia. In addition, modeling preparation time using “medical interventions performed in the operating room” as a factor instead of patient characteristics was found to be beneficial. It was possible to develop a highly accurate formula for estimating preparation time of anesthesia induction and surgery by analyzing the anesthesia factors and the surgical factors and incorporating the clinical department as an estimation factor. However, this study represents the development phase of the estimation formula. A multicenter study is essential to validate its generalizability and robustness across different settings before broader application.

Standard Errors for Calibrated Parameters

Abstract Calibration, the practice of choosing the parameters of a structural model to match certain empirical moments, can be viewed as minimum distance estimation. Existing standard error formulas for such estimators require a consistent estimate of the correlation structure of the empirical moments, which is often unavailable in practice. Instead, the variances of the individual empirical moments are usually readily estimable. Using only these variances, we derive conservative standard errors and confidence intervals for the structural parameters that are valid even under the worst-case correlation structure. In the over-identified case, we show that the moment weighting scheme that minimizes the worst-case estimator variance amounts to a moment selection problem with a simple solution. Finally, we develop tests of over-identifying or parameter restrictions. We apply our methods empirically to a model of menu cost pricing for multi-product firms and to a heterogeneous agent New Keynesian model.

Estimation of Periodontal Inflamed Surface Area by Salivary Lactate Dehydrogenase Level Using a Test Kit.

Background: Salivary lactate dehydrogenase (LD) levels are a feasible and useful parameter for screening periodontal diseases. The periodontal inflamed surface area (PISA) is useful to clinically assess periodontal diseases. However, PISA is difficult to calculate and PISA-compatible screening kits are required. We aimed to investigate the association between salivary LD levels, using a test kit, and PISA and PISA-Japanese and determine the feasibility and reliability of the salivary LD test kit for evaluation of periodontal status. Methods: This study included 110 patients (66.4% female, median and 25-75 percentiles of age were 66.5 and 53.0-75.0 years, respectively) who visited the Dental University Clinic in Japan. Resting saliva samples were collected from each participant and LD levels were evaluated in real time using a kit featuring an integer scale ranging from 1 to 10. PISA and PISA-Japanese were calculated using periodontal parameters. Results: The median salivary LD level was 4.0. The medians of PISA and PISA-Japanese were 46.9 and 61.0, respectively. Salivary LD levels were positively correlated with the bleeding on probing rate (r = 0.626, p < 0.001), PISA (r = 0.560, p < 0.001), and PISA-Japanese (r = 0.581, p < 0.001). Conclusions: Our results suggest that salivary LD levels assessed using the salivary LD kit showed a significantly positive correlation with PISA and PISA-Japanese. In addition, we developed the PISA estimation formula using salivary LD levels measured with a test kit, sex, and age.

Heat Stress Metrics, Trends, and Extremes in the Southeastern United States

Abstract Humid heat and associated heat stress have increased in frequency, intensity, and duration across the globe, particularly at lower latitudes. One of the more robust metrics for heat stress impacts on the human body is wet-bulb globe temperature (WBGT), because it incorporates temperature, humidity, wind speed, and solar radiation. WBGT can typically only be measured using nonstandard instrumentation (e.g., black globe thermometers). However, estimation formulas have been developed to calculate WBGT using standard surface meteorological variables. This study evaluates several WBGT estimation formulas for the southeastern United States using North Carolina Environment and Climate Observing Network (ECONet) and U.S. Military measurement campaign data as verification. The estimation algorithm with the smallest mean absolute error was subsequently chosen to evaluate summer WBGT trends and extremes at 39 ASOS stations with long continuous (1950–2023) data records. Trend results showed that summer WBGT has increased throughout much of the southeastern United States, with larger increases at night than during the day. Although there were some surprisingly large WBGT trends at higher elevation locations far from coastlines, the greatest increases were predominantly located in the Florida Peninsula and Louisiana. Increases in the intensity and frequency of extreme (90th percentile) WBGTs were particularly stark in large coastal urban centers (e.g., New Orleans, Tampa, and Miami). Some locations like New Orleans and Tampa have experienced more than two additional extreme heat stress days and nights per decade since 1950, with an exponential escalation in the number of extreme summer nights during the most recent decade. Significance Statement Humid heat and associated heat stress pose threats to health in the moist subtropical climate of the southeastern United States. Wet-bulb globe temperature (WBGT) is a robust metric for heat stress but must be estimated using complex algorithms. We first evaluated the accuracy of three WBGT algorithms in the southeastern United States, using measured verification data. Subsequently, we used the most accurate algorithm to investigate WBGT trends and extremes since 1950 in 39 cities. Results showed that summer heat stress has increased throughout the region, especially at night. Increases in the intensity and frequency of extreme heat stress were most prevalent at urban coastal locations in Florida and Louisiana, emphasizing the impacts of increased urbanization and evaporation on heat stress.

Facial skin color assessment and proposed skin shade guide for maxillofacial prosthesis using cluster analysis in a cohort of Indian adults

Aim: The precise estimation and replication of skin color are crucial for maxillofacial prosthesis. The study aimed to evaluate facial skin color with a colorimeter and suggest a skin shade guide and formula for color estimation. Settings and Design: An observational study conducted in the department of prosthodontics. Materials and Methods: Study was conducted on 368 individuals of Indian origin in age range of 20–45 years. The facial skin color was assessed in malar regions using SkinColorCatch colorimetric device and individual topography angle (ITA) and CIELAB L*a*b* values were noted. Statistical Analysis Used: K-means clustering was utilized to propose a shade guide for maxillofacial prosthesis with 24 skin shades. Logistic regression analysis was conducted to propose a formula to estimate skin shade of the individuals. Results: Based on cluster analysis, 368 subjects were divided into three clusters with similar characteristic as Cluster 1 with dark skin color in 88 (23.91%) subjects, Cluster 2 with medium skin color in 224 (60.87%) subjects, and Cluster 3 with light skin color in 56 (15.22%) subjects. The mean ITA and L*a*b* values for cluster 1 were −47.04° ±14.77°, 34.53 ± 4.31, 8.55 ± 2, 11.42 ± 3.7033, respectively. The mean ITA angle and L*a*b* values for Cluster 2 were 4.29° ±11.34° 51.67 ± 3.42, 8.79 ± 3.13, 21.36 ± 2.38, respectively. The mean ITA and L*a*b* values for Cluster 3 were 34.65 ± 4.29°, 62.66 ± 3.08, 6.53 ± 1.79, 17.73 ± 2.39, respectively. The proposed shade guide comprised a total of 24 different shades that were categorized into three primary colors according to three distinct clusters, each of which was further broken down into eight subclusters containing various shades within each cluster. Logistic regression analysis gave an equation as follows: Y =12.43 + 0.186X (Y = Predicted skin color, X = ITA angle). Conclusions: Twenty-four facial skin shade tabs have been proposed based on ITA angle and CIELAB values. This comprehensive approach to categorize the shades will ensure a detailed and organized system for selecting and matching colors in maxillofacial prosthesis.

Performance of the New CKD-EPI Creatinine-and Cystatin C-based Glomerular Filtration Rate Estimation Equation in Living Kidney Donor Candidate.

Accurate preoperative evaluation of renal function in living kidney donor candidates (LKDCs) is crucial to prevent kidney failure after nephrectomy. We examined the performance of various estimated glomerular filtration rate (eGFR) equations, including the new chronic kidney disease epidemiology collaboration (CKD-EPI) equation in LKDCs. We analyzed 752 LKDCs who were assessed for measured GFR by inulin clearance as part of routine pretransplant examination from 2006 to 2020. CKD-EPI2012 from cystatin C (CKD-EPI12cys), CKD-EPI2021 from creatinine (CKD-EPI21cr), CKD-EPI21cr-cys, Japanese modified (JPN) eGFRcr, and JPN eGFRcys were compared in determining the suitability for LKDCs. CKD-EPI12cys had the lowest absolute and relative biases, with higher P30 and P10, followed by JPN eGFRcys, CKD-EPI21cr, and CKD-EPI21cr-cys. The root mean square error was least for CKD-EPI12cys, then JPN eGFRcys, CKD-EPI21cr-cys, CKD-EPI21cr, and JPN eGFRcr. CKD-EPI21cr, CKD-EPI12cys, and CKD-EPI21cr-cys estimated GFR higher, whereas JPN eGFRcr estimated GFR lower. At the threshold of 90 mL/min/1.73 m2, CKD-EPI21cr had the highest percentage of misclassification at 37.37%, whereas JPN eGFRcr had the lowest percentage of misclassification at 6.91%. Using the age-adapted approach, JPN eGFRcr had the lowest percentage of misclassification into overestimation at 7.31%. All eGFR had >5.0%, and CKD-EPI21cr had the highest percentage of misclassification at 21.94%. Conversely, CKD-EPI21cr-cys had the lowest percentage of misclassification into underestimation at 3.19%, both at the threshold of 90 mL/min/1.73 m2 and the age-adapted approach. JPN eGFRcr had the highest percentage at 33.38% and 40.69%, respectively. In evaluating the renal function of Japanese LKDCs, the new CKD-EPI equation had a lower rate of underestimation but a relatively high rate of overestimation. New GFR estimation formulas are needed to be tailored to each ethnic group to enhance the accuracy and reliability of donor selection processes.

MANDIBULAR PARAMETERS FOR AGE ESTIMATION: A DIGITAL ORTHOPANTOMOGRAPHIC STUDY IN HYDERABAD POPULATION

Background: Mandible is one of the strongest facial bones, which exhibits great changes in size and morphology during growth and aging. The mandibular ramus and gonial angle in particular show notable alterations with aging. Orthopantomographywhich is a regularly used, non-invasive procedure can be used to assess mandibular morphology with ease. Aim and objectives: To assess the correlation of dimensions of condylar ramus height, coronoid ramus height and gonial angle with chronological age of the individual, andevaluatetheirefficacy in estimating age of the individual. Materials and methods: The study sample included 200 digital orthopantomographs of individuals of diverse age groups. Measurements of condylar ramus height, coronoid ramus height and gonial angle were made on the digital orthopantomographs and data was tabulated. Age estimation formulae were derived for each of the three parameters and age was estimated for each individual using the formulae. Results: No statisticallysignificant difference was found on comparing the chronological age and estimated age obtained using condylar ramus height, coronoid ramus height, and gonial angle. Among the three parameters,coronoid ramus height displayed a statistically significant correlation with chronological age. Conclusion:Present study indicates that coronoid ramus height can be used as a reliable indicator for age estimation.

Research on Sediment Erosion and Anti-Wear Coating Materials for Water-Intake Components of Hydraulic Turbines in Sandy Rivers

The operational efficiency, stability, and lifespan of hydroelectric power plants operating on sediment-laden rivers are affected by sediment erosion. A numerical simulation of the sand–water flow in the water-intake components of a turbine at a specific power station was conducted using the Euler–Lagrange method. Additionally, sediment erosion tests were carried out on the water-intake components coated with epoxy mortar material. The results indicate that sediment erosion on the stay vane surface mainly occurs on the front face, with the most severe erosion at the head, while sediment erosion on the stay ring surface primarily occurs near the stay vane head. The extent of erosion is mainly influenced by the distribution characteristics of sediment particles. The wear of epoxy mortar coating material is minimally affected by the spraying thickness. Adding 30% hardener to the epoxy mortar material can significantly improve the erosion resistance of the stay vane surface by about 30%. The erosion rate on the frontside of the stay vane is approximately 2.6 times that of the backside. Based on the sediment erosion tests and numerical simulation results of the sand–water flow, an estimation formula for the sediment erosion rate of the epoxy mortar erosion-resistant coating was established. This formula can be used to predict the anti-sediment erosion performance of epoxy mortar materials applied to the water-intake components of this turbine and similar river turbines.

Deception mechanisms of FDA‒AWACS against passive monopulse angle measurements

AbstractAirborne warning and control systems (AWACS) serve as critical command and control centres in air combat operations, making them prime targets for strategic attacks. These enemy attacks typically rely on the accurate determination of AWACS combat positions using different direction‐finding devices. In particular, passive monopulse angle measurement systems locate AWACS by measuring the angles of signals emitted by AWACS radiation sources, thus rendering them vulnerable to attacks. Given the criticality of the airborne radars of AWACS in battle command and control operations, they must function continuously to monitor air and sea targets. Hence, AWACS cannot effectively evade electronic reconnaissance systems through tactics such as radar shutdown. To explore alternative measures, the authors investigate the deception mechanisms of an integrated frequency diverse array AWACS (FDA‒AWACS) against passive monopulse angle measurements. Using an established FDA signal model, the principles underlying two common monopulse angle measurement methods are first outlined. Subsequently, the angle estimation formulae typically used by these monopulse angle measurement systems to interpret received FDA radiation signals are derived. Additionally, the transmit beampatterns, amplitude patterns, and angle measurement deception capabilities of several typical FDAs are examined. Simulation results indicate that the FDA‒AWACS can theoretically deceive passive monopulse angle measurement systems to a certain extent. However, one‐dimensional uniform linear FDAs and other arrays using sinusoidal frequency offsets exhibit limited deception abilities. In contrast, arrays utilising cubic and quartic frequency offset achieve angle measurement errors exceeding 2° in far‐field scenarios.

The Role of Parents in Preventing Teenage Pregnancy in Rural Areas of Banyumas District

Background:One of the factors contributing to Indonesia's high maternal mortality rate is the high incidence of teenage pregnancy in Banyumas. The family, particularly parents, plays a crucial role in influencing teenage pregnancy, as they are expected to act as educators, motivators, supervisors, communicators, and counselors for their teenagers. Objective:The purpose of this study was to identify the factors that influence the role of parents in the prevention of teenage pregnancy. Methods:A cross-sectional study design was employed, focusing on female participants. A cluster random sampling technique was used to obtain a sample size of 150 parents from the study population, using the proportion estimation formula. The validity and reliability of the questionnaire used were tested. Data were analyzed using logistic regression. Results:The univariate analysis revealed that 93.2% of respondents were female, 25.3% were aged between 38 and 42, 61.3% had only completed elementary school, 63.3% were housewives, 58% had incomes below IDR 1.350.000, 52% had monthly family expenses under IDR 1.350.000, and 42.7% had five or more dependents. The bivariate chi-square test showed an association between parental resources, the role of health professionals, knowledge, attitudes, and societal values in the prevention of teenage pregnancy. The multivariate analysis using logistic regression indicated that the value of people and resources significantly impacts the role of parents in this regard. Conclusion:The role of parents in preventing teenage pregnancy is influenced by the value placed on people and resources. Keywords: Maternal mortality; adolescent pregnancy; role of parents; knowledge; attitudes

Comparison of the accuracy and bias of Demirjian’s method for East Asian children and development of Japanese population-specific age estimation formulae

Despite the increased global mobility owing to the development of the international community, there remains a need for population-specific methods to estimate children’s ages. Therefore, this study aimed to substantiate the necessity for a Japanese-specific age estimation method by contrasting the formerly reported age estimation accuracy and bias using Demirjian’s method for Chinese, Taiwanese, South Korean, and Japanese children. We analyzed 1,558 panoramic radiographs from Japanese children (777 boys and 781 girls), assessed the maturity of seven left permanent teeth using Demirjian’s criteria, and calculated the estimated age using Demirjian’s method. The accuracy of the estimated ages was compared with previous reports of children from other East Asian countries which used the same age estimation method. Chinese, Taiwanese, and South Korean boys and girls were all reported to be older than their chronological ages, with the Eastern and Northern Chinese regions being the only exceptions. The same was true for Japanese children: the estimated ages of both sexes tended to be higher than their chronological age. However, there were significant variations in the values, indicating the differences in tooth growth and development between East Asian countries and sexes. Therefore, new regression equations specific to the Japanese population were formulated, and their accuracy was evaluated as the final result of this study.

A Fusion Tracking Algorithm for Electro-Optical Theodolite Based on the Three-State Transition Model.

This study presents a novel approach to address the autonomous stable tracking issue in electro-optical theodolite operating in closed-loop mode. The proposed methodology includes a multi-sensor adaptive weighted fusion algorithm and a fusion tracking algorithm based on a three-state transition model. A refined recursive formula for error covariance estimation is developed by integrating attenuation factors and least squares extrapolation. This formula is employed to formulate a multi-sensor weighted fusion algorithm that utilizes error covariance estimation. By assigning weighted coefficients to calculate the residual of the newly introduced error term and defining the sensor's unique states based on these coefficients, a fusion tracking algorithm grounded on the three-state transition model is introduced. In cases of interference or sensor failure, the algorithm either computes the weighted fusion value of the multi-sensor measurement or triggers autonomous sensor switching to ensure the autonomous and stable measurement of the theodolite. Experimental results indicate that when a specific sensor is affected by interference or the off-target amount cannot be extracted, the algorithm can swiftly switch to an alternative sensor. This capability facilitates the precise and consistent generation of data, thereby ensuring the stable operation of the tracking system. Furthermore, the algorithm demonstrates robustness across various measurement scenarios.