Combined Frequency Research Articles

Vision Deficit Is a New Marker of Cognitive Impairment

Despite the frequent combination of cognitive impairments in patients with cataracts and glaucoma, the latter remain insufficiently studied with various visual deficits. The purpose: to study the association of visual deficits in cataracts and primary open–angle glaucoma with cognitive impairment. The clinical study involved 326 elderly patients with cataracts and 318 elderly patients with primary open­angle glaucoma. The diagnosis of this ophthalmology was performed according to generally accepted methods. The degree of cognitive impairment was determined according to the Mini­-Mental­-State­-Examination (MMSE) scale. Visual deficit was assessed by visual acuity without correction. It was found that with low visual deficit (visual acuity without correction of 0,51–0,60 and over 0,61) in the examined patients with cataract, the average score on the MMSE scale varied from 28,7 ± 0,4 to 28,8 ± 0,6 points, and in patients with primary open­-angle glaucoma from 28,3 ± 0.5 to 28,5 ± 0.6 points with no significant differences in both cases. With severe visual deficit (visual acuity without correction to 0,20 and 0,21–0,30), the average score on the MMSE scale varied from 15,2 ± 0,3 to 17,4 ± 0,4 and from 13,8 ± 0,4 to 17,6 ± 0,3, respectively. The correlation coefficient between visual acuity without correction and the average MMSE score in patients with cataract was +0,436, and in patients with glaucoma — r = +0,482. The presence of an association of visual acuity without correction with cognitive dysfunction is also confirmed by regression analysis, which allows us to consider vision deficiency as a marker of cognitive impairment and can be used in monitoring them in patients with cataracts and glaucoma.

Calibration complex of radio measuring equipment

Modern trends in the development of radio measuring equipment require improvement of the principles of metrological support of these devices and corresponding reference base. The new approach is based on the digitalisation of equipment, programming of measurement procedures, and the transition from single measurement standards to measurement complexes. The paper describes the complex developed at the NSC “Institute of Metrology” and designed for verification and calibration of a wide range of radio measuring equipment, where all these approaches are realised, presents methodological, software and hardware features of its construction, as well as the advantages and possibilities of this approach in metrological practice. On the example of the method of “Bessel Function Zeros”, which was somewhat forgotten due to the cumbersome nature of its implementation by analogue methods and equipment, it is shown that with the new approach this method gets a “second birth”, moreover, at a higher metrological level. It is shown that the use of direct digital synthesis oscillators can significantly improve the “electronic counting frequency meter” method, in particular, prevent the phenomenon of “frequency capture”, which limited the capabilities of the method and introduced additional measurement uncertainty. Moreover, the additional properties of the complex associated with the use of the R&S FSL spectrum analyser with the K7 analogue signal demodulator option are explained in more detail. A list of other methods realised in the complex is given, among which the “combination frequencies” method, deserves a special attention, providing the highest resolution in measuring nonlinear distortions of both quasi-harmonic and modulated signals. It is shown that the complex is a flexible apparatus, the work programme of which can be adjusted and supplemented. Information on the structure of the complex, hardware solution of a number of nodes, programming language, etc. is given.

Antihypertensive drug prescription patterns and their impact on blood pressure outcomes in a tertiary care teaching hospital

Background: The guidelines from the Joint National Committee (JNC-8) emphasize the importance of rapid blood pressure (BP) control to reduce morbidity and mortality. The success of hypertension treatment depends on various factors, with irrational prescription being strongly linked to poor BP control. This study aimed to evaluate the patterns of antihypertensive drug prescriptions among patients in a tertiary care teaching hospital. Methods: A hospital-based observational study was conducted in 2018, including all hypertensive patients on medication. Their prescription patterns were analyzed. Results: The study analyzed prescriptions from 240 hypertensive patients. The mean ages for male and female patients were 56.68±15.32 and 62.29±12.65 years, respectively. Physicians commonly prescribed monotherapy (34.60%) followed by two-drug (18.40%), three-drug (11.80%), and four-drug combinations (3.00%). The most frequent two-drug combination was ACE inhibitors + diuretics (4.40%), followed by angiotensin receptor blockers (ARBs) + diuretics (3.60%) and calcium channel blockers (CCBs) + ACE inhibitors (2.60%). Adherence to JNC 8 guidelines was 19.3% for pre-hypertension, 88.70% for stage 1 hypertension, and 73.29% for stage 2 hypertension. Conclusions: Monotherapies were the most commonly prescribed regimens. Twice-daily dosing and monthly appointments were associated with lower incidences of uncontrolled BP. However, complete adherence to standard guidelines was not observed in all cases, especially in patients with comorbid conditions.

Aging trajectories of subscales in higher-level functional capacity among community-dwelling older Japanese adults: the Otassha study

BackgroundMaintaining higher-level functional capacity is important for independent living in older age. The aging trajectory of the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) has three patterns; however, the subscale patterns are unclear.AimsThis study aimed to clarify the aging trajectory patterns of the TMIG-IC subscales among community-dwelling older Japanese.MethodsParticipants were 3,169 community-dwelling older Japanese who participated in the 2012–2022 mail survey of the Otassha study. The aging trajectory patterns of the TMIG-IC total and subscale scores for those aged 65–90 years were identified using group-based trajectory modeling. Further, the combination frequency of the subscale trajectory patterns was determined.ResultsThree patterns were identified: early-onset decreasing, late-onset decreasing, and high-stable.DiscussionThe instrumental activities of daily living (IADL) trajectory was maintained until approximately 80 years of age; however, chronic disease prevailed the most in the early-onset decreasing pattern. The early-onset decreasing pattern of intellectual activity (IA) was present in 25% of participants, showing impaired IA from 65 years of age. The late-onset decreasing pattern of social roles (SR) was present in 30% of participants, showing a sharp decline compared to other subscales. For many people, the patterns of decrease in SR and IA overlapped.ConclusionsTo maintain higher-level functional capacity, interventions that include disease management and prevention of decline in IADL and increase the awareness of the social support provided throughout old age and interventions for people with an early decline in IA should be implemented.

Explaining the impact of parameter combinations in agent-based models

Simulation is a useful and effective way to analyze and study complex, real-world systems, allowing researchers, practitioners, and decision makers to make sense of the inner working of a system involving many factors, often resulting in some sort of emergent behavior. The number of parameter value combinations grows exponentially and it quickly becomes infeasible to test them all or even to explore a suitable subset. How does one then efficiently identify the parameter value combinations that matter for a particular simulation study, and determine their impact on the result? In addition, is it possible to train a machine learning model to predict the outcome of an agent-based model (ABM) with a systematically chosen small subset of parameter value combinations, such that the result could be predicted without running the ABM? We use covering arrays to create t-way (t = 2, 3, etc.) combinations of parameter values to significantly reduce an ABM’s parameter value exploration space, which is supported by our prior work. In our ICCS 2023 paper (Olsen et al., 2023) we built on that work by applying it to Wilensky’s Heatbugs model and training a random forest machine learning model to predict simulation results by using the covering arrays to select our training and test data. Our results show that a 2-way covering array provides sufficient training data to train our random forest to predict three different simulation outcomes. Our process of using covering arrays to decrease parameter space to then predict ABM results using machine learning is successful. In this paper that extends the ICCS 2023 paper (Olsen et al., 2023), we analyze the role of parameter combinations and parameter values in determining model output via combination frequency difference (CFD) analysis and Shapley values. CFD has not previously been applied to agent-based models; we provide a process for using this approach and compare and contrast with Shapley values and random forest feature importance.

Carrier screening for 223 monogenic diseases in Chinese population: a multi-center study in 33 104 individuals

To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale, multicenter carrier screening. This study was conducted among a total of 33 104 participants (16 610 females) from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods. The overall combined carrier frequency was 55.58% for 197 autosomal genes and 1.84% for 26 X-linked genes in these participants.Among the 16 669 families, 874 at-risk couples (5.24%) were identified.Specifically, 584 couples (3.50%) were at risk for autosomal genes, 306(1.84%) for X-linked genes, and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A, 393 couples), HBA1/HBA2(α-thalassemia, 36 couples), PAH (phenylketonuria, 14 couples), and SMN1(spinal muscular atrophy, 14 couples).The most frequently detected X-linked at-risk genes were G6PD (G6PD deficiency, 236 couples), DMD (Duchenne muscular dystrophy, 23 couples), and FMR1(fragile X syndrome, 17 couples).After excluding GJB2 c.109G>A, the detection rate of at-risk couples was 3.91%(651/16 669), which was lowered to 1.72%(287/16 669) after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95% of at-risk couples, while screening for the top 54 genes further increased the detection rate to over 99%. This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing, genetic counseling for specific genes or gene variants can be challenging, and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

Гендерная и коммуникативная специфика двойной пространственной ориентации говорящего в виртуальной реальности

A clear and unambiguous rendering of spatial relations is the key cognitive function of communication. Spatial relationships reflect the categories and experience shared by all people. The paper introduces the first-of-its-kind attempt to describe the dual spatial orientation of the speaker in virtual reality as depending on two factors: the communicative situation and the gender. Dual spatial orientation combines egocentric, allocentric, or geocentric orientations and their varieties. The combination depends on various factors. The experiment in virtual environment involved 24 informants and five scenarios (scenes) with different communicative parameters. It yielded 725 responses with combinations of double orientations, which went through the IS Semograph. The combination of allocentric and geocentric orientation domineered; the extra-linguistic gender factor and some communicative parameters affected the frequency of combinations of dual spatial orientation. The core of the speaker’s dual spatial orientation in virtual reality combined allocentric and geocentric orientations to the topos of GE \ T + AL and AL + GE \ T.

An optimal operation strategy of wind farm for frequency regulation reserve considering wake effects

When wind farms (WFs) participate in power system frequency regulation, deloaded control can increase the stored rotational kinetic energy in the wind turbines (WTs), thereby enhancing their frequency support capability. However, due to the wake effects and deloaded control of turbines, this method can also lead to increased power losses. An optimal operation strategy has been proposed to balance power generation and frequency regulation reserve in WFs, taking wake effects into account. Initially, a WF deloaded control model that considers wake effects, and an adaptive combined frequency control model based on kinetic energy reserve, are established for participation in power system frequency regulation. Subsequently, the Covariance Matrix Adaptation Evolution Strategy (CMAES) is utilized to determine the optimal operation allocation of maximum WF output power within the FLORIS wake model, meeting frequency regulation reserve requirements. A comparative analysis of the optimal allocation results under various wind conditions is conducted to test the frequency support capabilities. The results indicate that the proposed strategy can achieve varying levels of frequency regulation reserve, reduce wake losses to maximize output power under deloaded control, and improve frequency support capability.

Dynamic stability of the Mindlin-Reissner plate using a time-modulated axial force

A time-periodic axial force acting on a continuous structure can be destabilized by parametric excitation. Moreover, it is capable of increasing the equivalent damping and shortening the transient vibrations. In this work, this concept is extended, and dynamic stability of a Mindlin-Reissner plate is analyzed. The FE formulation for the four-node plate element is derived by employing the variational approach including the action of an axial force. The stability of the time-periodic system is evaluated both numerically and analytically, using Floquet theory and first-order approximation based on the averaging method, respectively. The influence of plate length, thickness, and aspect ratio on dynamic stability is highlighted. It is demonstrated that the instability tongue at a parametric combination resonance frequency of the summation type is shifted toward higher axial force amplitudes by increasing the plate width and decreasing the plate length. Alternatively, the axial force acting in the vicinity of a parametric combination frequency of the difference type shows a parametric antiresonance which is maximized by exactly the opposite tuning of the plate design. This guideline is important when plate design under the action of a harmonic axial force is considered.

Clinical features of flare in Japanese patients with new-onset SLE and risk factors for SLE flare in daily clinical practice: a single-center cohort study

This study aimed to elucidate the clinical features, outcomes and risk factors of flares in patients with systemic lupus erythematosus (SLE). Data were collected from patients with newly diagnosed SLE at the Fukushima Medical University Hospital between 2011 and 2022. Patients who experienced a flare during the study period constituted the flare group, and their clinical features were compared with those of the no-flare group. The cumulative flare-free survival regarding several clinical items was compared between the two groups using Kaplan–Meier’s curves. Among 387 patients with SLE, 83 patients with newly diagnosed SLE were included. Their mean age was 37.9 years, and 29 patients experienced flares during the study period. The general characteristics were similar between the two groups, with the exception of the observation period and anti-SS-A antibody positivity. Regarding therapy, a significantly increased frequency of hydroxychloroquine intake and combination with immunosuppressive agents were observed in the no-flare group. The Kaplan–Meier analysis revealed a significantly higher cumulative flare-free survival in the anti-SS-A negative group and combination immunosuppressive therapy group. In conclusion, anti-SS-A positivity may be a risk factor for SLE flare. In turn, combination immunosuppressive therapy may be beneficial for SLE treatment in daily clinical practice.

Extramedullary Intracranial Plasmacytomas: A Systematic Review of Literature.

Extramedullary plasmacytoma (EMP) is an uncommon disorder characterized by the development of abnormal plasma cell tumors outside the bone marrow. These tumors are typically observed in various locations, including the upper respiratory tract, gastrointestinal tract, and other soft tissues. Among the less explored manifestations of EMP is intracranial EMP, which remains poorly understood due to the limited literature available on the subject. The objective was to comprehend the population characteristics, localization, type, treatment, and outcomes of intracranial EMP. A systematic review of the literature for EMPs was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The strategy "extramedullary plasmacytoma AND multiple myeloma" was used for the search. The search terms were queried using PubMed, Embase, Scopus, Cochrane, and Web of Science databases. We included only those studies that presented clinical studies with patients diagnosed with intracranial plasmacytomas. In this study, a total of 84 patients from 25 studies were analyzed. The average age of diagnosis was 57.25 years, with a slightly higher proportion of females (57%) compared to male patients (43%). The most common locations of intracranial plasmacytomas were the clivus (29.7%), frontal lobe (18.9%), parietal lobe (8.1%), occipital lobe (6.7%), temporal lobe (6.7%), and sphenoid (4%). Chordoma and meningioma were the most common differential diagnoses encountered during clinical investigations. Treatment modalities included radiotherapy (RT), chemotherapy (QT), surgical resection (SR), and conservative approaches. The most frequent treatment combinations were SR + RT (19%) and RT only (17.8%). Mortality was reported in 48% of the cases, with complete resolution observed in 10 cases and partial resolution in 3 cases. The average follow-up duration was 37.5 months. The clivus is the most frequently reported site of extramedullary intracranial plasmacytoma (EMIP) occurrence, representing 29.7% of cases. Chordomas were commonly observed alongside EMIPs and emerged as the primary differential diagnosis. RT was the predominant treatment modality, with SR considered when feasible. RT alone demonstrated the highest effectiveness in managing EMIPs (30%), while QT as a sole intervention showed lower efficacy. However, a combination of dexamethasone, lenalidomide, and targeted RT displayed promising results, offering improved tumor response and increased safety.

Analysis of power system frequency and active power based on wind-storage combined frequency modulation system

Abstract To solve the problem of frequency and active power regulation of power systems, this paper proposes a wind-storage combined frequency modulation strategy. The mathematical models of doubly-fed induction machines, pump turbines, and wind turbines are established. Based on wind power frequency modulation, the doubly-fed variable-speed pumped storage unit is added to establish a combined frequency modulation system, and a simulation model on Simulink to analyze the participation of different parts of the combined system in frequency modulation and the active power output of the unit when the load changes. The simulation results show that when the load increases or decreases, the addition of a doubly-fed variable speed pumped storage unit can effectively improve the frequency modulation performance of the system, reduce the fluctuation numbers and amplitude, and reduce the deviation after stabilization. By changing its active power output, a new balance of the system power can be reached, which is conducive to the secure and steady functioning of the power system.

The 18th International HLA & Immunogenetics workshop project report: Creating fully representative MHC reference haplotypes.

A fundamental endeavor of the International Histocompatibility and Immunogenetics Workshop (IHIW) was assembling a collection of DNA samples homozygous through the MHC genomic region. This collection proved invaluable for assay development in the histocompatibility and immunogenetics field, for generating the human reference genome, and furthered our understanding of MHC diversity. Defined by their HLA‐A, ‐B, ‐C and ‐DRB1 alleles, the combined frequency of the haplotypes from these individuals is ∼20% in Europe. Thus, a significant proportion of MHC haplotypes, both common and rare throughout the world, and including many associated with disease, are not yet represented. In this workshop component, we are collecting the next generation of MHC‐homozygous samples, to expand, diversify and modernize this critical community resource that has been foundational to the field. We asked laboratories worldwide to identify samples homozygous through all HLA class I and/or HLA class II genes, or through whole‐genome SNP genotyping or sequencing, to have extensive homozygosity tracts within the MHC region. The focus is non‐Europeans or those having HLA haplotypes less common in Europeans. Through this effort, we have obtained samples from 537 individuals representing 294 distinct haplotypes, as determined by their HLA class I and II alleles, and an additional 50 haplotypes distinct in HLA class I or II alleles. Although we have expanded the diversity, many populations remain underrepresented, particularly from Africa, and we encourage further participation. The data will serve as a resource for investigators seeking to characterise variation across the MHC genomic region for disease and population studies. [Correction added on [24 July 2024], after first online publication: the Abstract was inadvertently remove and has been reinstated in this version.]

Patient- and parent-reported diagnostic delay in children with central nervous system tumors in Denmark.

Diagnostic delays in childhood tumors of the central nervous system (CNS) pose a significant challenge. The aim of this study was to map diagnostic delay and presenting symptoms in Denmark. The study was a retrospective questionnaire study, mapping delay and symptoms in pediatric patients (0-17years), diagnosed with a CNS tumor from 2015 to 2019. Descriptive analysis was performed to measure delay in days, reported as total diagnostic interval (TDI), patient interval (PI), and diagnostic interval (DI). Analysis of symptoms, contacts to healthcare professionals, and socioeconomic status was also performed. We included 89 patients (median age 7.0years, 54% male). The TDI was median of 106days (range: 0-2694days). Low-grade tumors had longer TDI than high-grade tumors (125 vs. 43days; p≤.02). Patients aged 15-17 displayed the longest TDI (median 665days). Number of symptoms at onset were inversely associated with longer TDI in patients presenting one symptom (247days) and patients presenting two to three (110days) or greater than three complaints (66days). PI was not associated with sex (p=.14), tumor grade (p=.63), location (p=.32), or socioeconomic status (p=.82). Most frequent single complaint at onset was headache (19%), most frequent combination of symptoms was headache and vomiting (60%). We found TDIs longer than reported in contemporary publications. TDI was longer in patients with low-grade tumors and only few symptoms at the time of onset. The findings support the crucial need of awareness and improved diagnostic tools to recognize and interpret symptoms to promote timely diagnosis.

Механизмы поражения соединительной ткани при фибромускулярной дисплазии и атеросклерозе: возможности визуализации

Multifocality, high prevalence and lack of consensus on the etiopathogenesis of atherosclerosis and fibromuscular dysplasia (FMD) in the human population are well known. However, the issues of comorbidity and mechanisms of connective tissue damage in these pathologies remain unclear. The purpose of this study was to determine the leading causes of pathological arterial stenosis in patients with clinical signs of vascular disorders. Materials and methods. The research involved 67 patients (mean age 51.12 ± 13.12 years) with clinical signs of vascular disorders, who had received neurological or neurosurgical treatment at Surgut Clinical Trauma Hospital. The subjects underwent computed tomography angiography of brachiocephalic and intracranial vessels. To assess the internal stigmatization of the processes under study, author’s scales were developed. Results. The data of the author’s scales clearly indicate the influence of the genetically determined FMD process on the manifestations of atherosclerosis. The most frequent combinations of FMD stigmas and atherosclerotic lesions identified in the course of the study can serve as markers of the severity of these pathologies. The results allow us to view FMD and atherosclerosis in the context of morphofunctional connective tissue disorders. Paradoxically, despite the systemic nature of the two processes, their gross manifestations were clearly localized. This is probably due to the time interval of connective tissue cell damage and its nature. In our opinion, pathology in atherosclerosis develops during postnatal ontogenesis due to the increasing cytokinetic activity of connective tissue cells under the influence of various factors (atherogenic lipoproteins circulating in the vascular bed, microbiome disturbance, etc.). In FMD, fibroblasts get damaged by genetic mutations at the stage of embryonic development (vasculogenesis), gross stigmas are formed in areas of blood vessels with the most rapid growth due to the haemodynamic conditions of the onset of blood circulation (angiogenesis).

A novel predictive optimal control strategy for renewable penetrated interconnected power system

AbstractThe stable and efficient regulation of voltage and frequency is a critical issue associated with the functioning of modern power system network having renewable integration. This manuscript focuses on the concurrent regulation of voltage and frequency in a power network comprising multiple generating sources. Herein, along with conventional thermal and diesel plants, renewable generations from different sources have been considered such as wind and solar photovoltaic (PV) resources. Further, in a fresh attempt, the authors have modeled wind and solar PV generation using two different stochastic modeling methods concerning combined voltage and frequency loops in the regulated power system model. Furthermore, the novel Leader Harris Hawks Optimized Model Predictive Controller (MPC‐LHHO) has been applied to concurrently minimize the voltage and frequency deviations in the given power network. To address the intermittent nature of load and renewable generations, various auxiliary frequency controllers, such as the unified power flow controller (UPFC) and electric vehicle (EV) integration with the grid, have been implemented. The robustness of the proposed control method has been successfully validated through diverse scenarios of random loadings.

Predictors of valproic acid steady-state serum levels in adult and pediatric psychiatric inpatients: a comparative analysis.

Valproic acid (VPA) is commonly used as a second-line mood stabilizer or augmentative agent in severe mental illnesses. However, population pharmacokinetic studies specific to psychiatric populations are limited, and clinical predictors for the precision application of VPA remain undefined. To identify steady-state serum VPA level predictors in pediatric/adolescent and adult psychiatric inpatients. We analyzed data from 634 patients and 1,068 steady-state therapeutic drug monitoring (TDM) data points recorded from 2015 to 2021. Steady-state VPA levels were obtained after tapering during each hospitalization episode. Electronic patient records were screened for routine clinical parameters and co-medication. Generalized additive mixed models were employed to identify independent predictors. Most TDM episodes involved patients with psychotic disorders, including schizophrenia (29.2%) and schizoaffective disorder (17.3%). Polypharmacy was common, with the most frequent combinations being VPA + quetiapine and VPA + promethazine. Age was significantly associated with VPA levels, with pediatric/adolescent patients (< 18 years) demonstrating higher dose-adjusted serum levels of VPA (β = 7.6±2.34, p < 0.001) after accounting for BMI. Women tended to have higher adjusted VPA serum levels than men (β = 5.08±1.62, p < 0.001). The formulation of VPA (Immediate-release vs. extended-release) showed no association with VPA levels. Co-administration of diazepam exhibited a dose-dependent decrease in VPA levels (F = 15.7, p < 0.001), suggesting a potential pharmacokinetic interaction. This study highlights the utility of population-specific pharmacokinetic data for VPA in psychiatric populations. Age, gender, and co-administration of diazepam were identified as predictors of VPA levels. Further research is warranted to establish additional predictors and optimize the precision application of VPA in psychiatric patients.

Multimodal communication and audience directedness in the greeting behaviour of semi-captive African savannah elephants

Many species communicate by combining signals into multimodal combinations. Elephants live in multi-level societies where individuals regularly separate and reunite. Upon reunion, elephants often engage in elaborate greeting rituals, where they use vocalisations and body acts produced with different body parts and of various sensory modalities (e.g., audible, tactile). However, whether these body acts represent communicative gestures and whether elephants combine vocalisations and gestures during greeting is still unknown. Here we use separation-reunion events to explore the greeting behaviour of semi-captive elephants (Loxodonta africana). We investigate whether elephants use silent-visual, audible, and tactile gestures directing them at their audience based on their state of visual attention and how they combine these gestures with vocalisations during greeting. We show that elephants select gesture modality appropriately according to their audience’s visual attention, suggesting evidence of first-order intentional communicative use. We further show that elephants integrate vocalisations and gestures into different combinations and orders. The most frequent combination consists of rumble vocalisations with ear-flapping gestures, used most often between females. By showing that a species evolutionarily distant to our own primate lineage shows sensitivity to their audience’s visual attention in their gesturing and combines gestures with vocalisations, our study advances our understanding of the emergence of first-order intentionality and multimodal communication across taxa.

Analysis of Nonlinear Vibration Characteristics and Whirl Behavior of Dual-Rotor Systems with Inter-Shaft Rub Impact

Previous studies on rub-impact faults have mainly focused on the rub-impact between rotors and stators, with less research on inter-rotor rub impact. The impact of inter-rotor rub impact on rotor nonlinear vibration is particularly significant. This study investigates the effects of inter-shaft rub impact on the vibration characteristics and whirl behavior of dual-rotor systems. Initially, a dual-rotor model with inter-shaft bearings is established using the finite element method, and inter-shaft rub-impact forces are derived based on contact mechanics. Next, the system response is solved using the Newmark method. Vibration characteristics are analyzed through Campbell diagrams, 3D waterfall plots, time-frequency domain plots, and steady-state rub-impact force plots. Finally, the influence of inter-shaft rub impact on the whirl behavior of the dual-rotor system is studied based on the theory of full-spectrum analysis. The study concludes that inter-shaft rub-impact faults shift the system’s resonance points backward, increase harmonic and combination frequency components, and significantly affect the system response under dual-rotor co-rotation. Excessive friction can lead to self-excited vibrations and sudden amplitude increases, particularly in the LP rotor frequency. Additionally, inter-shaft rub impact primarily affects the whirl behavior of the LP-compressor disk1, showing multiple cycles of forward and backward whirl alternation during acceleration due to combined unbalanced and rub-impact excitations.

PENERAPAN DATA MINING TERHADAP DATA PENJUALAN DENGAN MENGGUNAKAN ALGORITMA APRIORI PADA TOKO CITRA UTAMA

Citra Utama Store is a retail and wholesale business aimed at meeting the needs of local residents for their daily household shopping. The problem lies in the difficulty of identifying consumer shopping trends for products in the store, and the inefficiency of the stock placement system. In a competitive business environment, it is crucial for us to obtain information that can help develop our business. One source of such information is the sales transaction history. Using data mining with the apriori algorithm and association rule, we can extract sales transaction data to derive information that can be used to identify frequent itemset combinations, which can then be analyzed to determine products frequently sold together, the most popular items, and customer preferences. The analysis of association rules formed from the apriori algorithm calculation yielded the highest itemset combination pattern, namely EGGS → AQUA GLN, with a support value of 2.84% and a confidence value of 34.13%. By setting minimum support &gt;1.5% and minimum confidence &gt;30%, this research can assist the store in devising sales strategies and managing stock inventory, and uncover association rules that can be used as purchasing patterns by consumers