Markov Model Research Articles

Projecting Long-Term Care Costs Among Older Adults With ADL Disabilities and Cognitive Impairment in China.

Mounting evidence suggests that cognitive impairment is strongly associated with disability in activities of daily living (ADL disability) and long-term care (LTC) costs. However, studies forecasting future LTC costs often overlook these relationships. Consequently, this study aims to more accurately project future LTC costs in China over the next 20 years by considering the intertwined association between disability and cognitive impairment on future LTC costs. Data were from 10 959 adults ≥65 years from the 2005-2018 waves of the Chinese Longitudinal Healthy Longevity Surveys. We used the Markov model to project the population of China and track the transition of older adults in the next 20 years between 4 disability-cognition states. We employed a 2-part model to estimate LTC costs (direct and indirect LTC costs) per capita. The proportion of disabled older adults with cognitive impairment was projected to increase from 1.4% in 2021 to 3.4% in 2040, while that of those without cognitive impairment was projected to decrease from 4.7% in 2021 to 4.5% in 2040. The direct and indirect LTC costs were projected to increase from 0.3% and 0.2% of gross domestic product (GDP) in 2021 to 1.4% and 0.7% in 2040 for disabled persons without cognitive impairment and from 0.1% and 0.1% of GDP in 2021 to 1.3% and 1.3% in 2040 for those with cognitive impairment, respectively. Policy-makers could include the assessment of cognition in the LTC needs assessment and allocate more compensation to LTC insurance participants with cognitive impairment.

Forecasting Financial Expenditures for Long Term Care Insurance Evidence from the Typical Pilot Cities in C

Purpose: This study aims to provide decision-makers with a reference by predicting the financial expenditures and trends of long-term care insurance in China over the next thirty years. Approach/Methodology/Design: This study employs Markov chains and overall simulation model to forecast the extent of financial expenditures on long-term care for employees and residents. It examines the financial outlay levels under various entitlement payment scenarios and estimates the discrepancies in financial expenditures between employees and residents from 2021 to 2050. Findings: The results show that (1) The number of disabled elderly employees aged 60 and above will be about 14,288 thousand, and the number of disabled elderly residents will be about 68,176 thousand in 2050. (2) Under the low scenario, the financial expenditures of elderly employees and residents in 2050 will reach 29,636.87 million yuan and 17,597.92 million yuan respectively, which are 2.86 and 10.24 times as much as those in 2021. The total financial expenditures under the medium and high scenarios will be 2.38 and 5.51 times as much as those under the low scenario respectively. (3) The scale of financial expenditure on long-term care insurance for residents far exceeds that of employees, and the trend is expanding. Practical Implications: This study may provide theoretical support for the full implementation of long-term care insurance policies. Originality/value: This study uses Markov models and overall simulation models, along with typical representative plans from pilot areas in China, to differentiate the insurance identity of elderly employees and residents and to estimate the scale and trend of financial expenditures for long-term care insurance in China from 2021 to 2050.

Mobile stroke units services in Germany: A cost-effectiveness modeling perspective on catchment zones, operating modes, and staffing.

Investigating the cost-effectiveness of future mobile stroke unit (MSU) services with respect to local idiosyncrasies is essential for enabling large-scale implementation of MSU services. The aim of this study was to assess the cost-effectiveness for varying urban German settings and modes of operation. Costs of different operating times together with different personnel configurations were simulated. Different possible catchment zones, ischemic stroke incidence, circadian distribution, rates of alternative diagnoses, as well as missed cases were incorporated to model case coverage and patient numbers. Based on internationally reported clinical outcomes of MSUs, a 5-year Markov model was applied to analyze the cost-effectiveness for the different program setups. Compared with standard stroke care, MSUs achieved an additional 0.06 quality-adjusted life years (QALYs) over a 5-year time horizon. Assuming a catchment zone of 750,000 inhabitants and 8 h/7 day operation resulted in an incremental cost-effectiveness ratio (ICER) of €37,182 per QALY from a societal perspective and €45,104 per QALY from a healthcare perspective. Lower ICERs were possible when coverage was expanded to 16 h service on 7 days per week and larger populations. Sensitivity analyses revealed that missing ischemic strokes significantly deteriorated economic performance of MSU. Major determinants of cost-effectiveness should be addressed when setting up novel MSU programs. Catchment zones of more than 500,000-700,000 inhabitants and operating times of at least 12-16 h per day, 7 days per week could enable the most cost-effective MSU services in the German healthcare system.

Cost-Effectiveness of Radiofrequency Renal Denervation for Uncontrolled Hypertension in Japan.

Radiofrequency renal denervation (RF RDN) is a novel therapy for uncontrolled hypertension. In the recent sham-controlled SPYRAL HTN-ON MED study, office-based systolic blood pressure (oSBP) and nighttime BP were reduced significantly. This study examined the cost-effectiveness of RF RDN in the context of the Japanese healthcare system based on this latest clinical evidence. Clinical events, costs, and quality-adjusted life-years (QALYs) were projected using a decision-analytic Markov model adjusted to Japanese incidence data. Risk reduction in clinical events from changes in oSBP was calculated based on a published meta-regression of 47 trials of intentional hypertension treatment. Demographics and results from the SPYRAL HTN-ON MED trial (oSBP effect size -4.9mmHg vs. sham) were utilized in the base case analysis. Additional scenarios were explored including the potential added benefit of improved night-time control. Costs were sourced from claims data and published literature. The incremental cost-effectiveness ratio (ICER) was evaluated against a cost-effectiveness threshold of ¥5000000 per QALY gained. RF RDN was projected to reduce clinical events (10-year relative risks: 0.80 for stroke, 0.88 for myocardial infarction, and 0.75 for heart failure). Over lifetime, RF RDN added 0.36 QALYs at the incremental cost of ¥923723, resulting in an ICER of ¥2565236 per QALY gained. Under the assumption of added night-time benefit, the ICER decreased to ¥2155895 per QALY. Cost-effectiveness findings were robust across all tested scenarios. The findings of this model-based analysis suggest that RF RDN can provide meaningful clinical event reductions and is a cost-effective treatment option in the Japanese healthcare system.

Cost-effectiveness of radiofrequency echographic multi-spectrometry (REMS) for the diagnosis of osteoporosis in the United States

Abstract Radiofrequency echographic multi spectrometry (REMS) is an innovative, non-ionizing diagnostic technique that has shown high accuracy and precision, making it a promising alternative to dual-energy X-ray absorptiometry (DXA) for osteoporosis diagnosis in clinical settings. With economic considerations playing an increasingly crucial role in healthcare decisions, this study aims to evaluate the cost-effectiveness and economic impact of improved osteoporosis diagnosis using REMS followed by treatment in the United States (US). A microsimulation-based Markov model was constructed to estimate the cost per quality-adjusted life year (QALY) gained (in US$2022) for REMS followed by treatment versus no diagnosis and treatment in US women aged 50 years and older with osteoporosis. Women were categorized as high risk (receiving alendronate monotherapy for 5 years) or very high risk (receiving an 18-month course of anabolic treatment, abaloparatide, followed by 5 years of alendronate). The study evaluated two medication adherence scenarios: one assuming full adherence to treatment and the other reflecting real-world adherence. The results indicate that REMS followed by treatment is associated with improved health outcomes, including more QALYs and fewer fractures, and reduced fracture-related costs compared to no diagnosis and treatment. The incremental cost-effectiveness ratio of REMS was estimated at $33 891 and $49 198 per QALY gained, under the full adherence and real-world adherence scenarios, respectively. These values are below the US cost-effectiveness thresholds of $100 000 to $150 000 per QALY. Moreover, a 5% increase in the diagnosis and treatment of women over 50 years at high and very high risk of fractures using REMS is projected to save approximately 30 000 life years, 43 500 QALYs, and prevent 100 000 fractures over a lifetime under real-world medication adherence. In conclusion, this study suggests that REMS is a cost-effective strategy for the diagnosis and management of osteoporosis in US women, offering substantial potential economic benefits and improved health outcomes.

An exactly solvable model for RNA polymerase during the elongation stage

We consider a Markovian model for the kinetics of RNA Polymerase (RNAP) which provides a physical explanation for the phenomenon of cooperative pushing during transcription elongation observed in biochemical experiments onEscherichia coliand yeast RNAP. To study how backtracking of RNAP affects cooperative pushing we incorporate into this model backward (upstream) RNAP moves. With a rigorous mathematical treatment of the model we derive conditions on the mutual static and kinetic interactions between RNAP under which backtracking preserves cooperative pushing. This is achieved by exact computation of several key properties in the steady state of this model, including the distribution of headway between two RNAP along the DNA template and the average RNAP velocity and flux.

Factors influencing the cost-effectiveness of radiofrequency ablation for Barrett's esophagus with low-grade dysplasia in Australia.

Endoscopic eradication therapy using radiofrequency ablation (RFA) is considered an acceptable alternative to surveillance monitoring for Barrett's esophagus with low-grade dysplasia (LGD). This study aimed to estimate whether RFA for LGD is cost-effective and to determine which factors influence cost-effectiveness. A Markov model was developed to estimate the incremental cost per quality-adjusted life year (QALY) gained for RFA compared with endoscopic surveillance. An Australian longitudinal cohort study (PROBE-NET) provides the basis of the model. Replacing surveillance with RFA yields 10 fewer cases of HGD and 9 fewer esophageal adenocarcinoma (EAC)-related deaths per 1000 patients' treatment, given on average 0.192 QALYs at an additional cost of AU$9211 (€5689; US$6262) per patient (incremental cost-effectiveness ratio AU$47,815 per QALY). The model is sensitive to the rate of EAC from LGD health state, the utility values, and the number of RFA sessions. Hence, the incremental benefit ranges from 0.080 QALYs to 0.198 QALYs leading to uncertainty in the cost-effectiveness estimates. When the cancerous progression rate of LGD falls <0.47% per annum, the cost-effectiveness of RFA becomes questionable. RFA treatment of LGD provides significantly better clinical outcomes than surveillance. The additional cost of RFA is acceptable if the LGD to EAC rate is >0.47% per annum and no more than three RFA treatment sessions are provided. Accurate estimates of the risk of developing EAC in patients with LGD are needed to validate the analyses.

Economic analysis of implementing Systemic Coronary Risk Estimation (SCORE2) scale and long-term consequences

Objective: to assess the demand for pharmacotherapy in risk groups on adverse cardiovascular (CV) events identified during prophylactic medical examination of the adult population according to the SCORE2 (Systemic Coronary Risk Estimation) scale, which is being introduced into clinical practice.Material and methods. To analyze the economic consequences of including diagnostic examinations to assess the risk by SCORE and SCORE2 scales, a Markov model was developed, which described the course of lipid metabolism disorders in adult patients aged 40 to 69 years without concomitant diseases identified during prophylactic medical examination. The model cycle was 2 months (the average waiting time for response to therapy); the modeling horizon was 3 years; the calculated values were estimated for the period 2024–2026. The economic analysis of long-term consequences involved calculating the cost of pharmacotherapy and the costs associated with CV events at outpatient and inpatient stages of medical care. The costs of drug therapy were determined based on dosage regimens presented in instructions for medical use in Russia, and clinical guidelines.Results. According to the modeling results, in the period 2024–2026, the administration of pharmacotherapy to reduce the risks of CV events will enable to achieve 23,224 potentially saved lives through exclusively government funding or 23,605 through mixed sources of funding (government and citizens’ own funds). The cost of the analyzed pharmacotherapy upon the introduction of the SCORE2 scale will be from 50.18 billion rubles (with government funding) to 318.14 billion rubles. Concurrently, pharmacocorrection will provide a reduction in the costs of inpatient treatment and outpatient medical services to 4.1 billion rubles due to the achieving of intended low-density lipoprotein level, and 1.6 billion rubles due to the achieving of intended triglyceride levels.Conclusion. Using new SCORE2 scale may lead to changes in the practice of prescribing lipid-lowering prophylaxis of CV diseases, as well as to a sharp increase in the number of patients who may require earlier prescription of pharmacotherapy to prevent CV events.

How Freely Moving Mind Wandering Relates to Creativity: Behavioral and Neural Evidence

Background: Previous studies have demonstrated that mind wandering during incubation phases enhances post-incubation creative performance. Recent empirical evidence, however, has highlighted a specific form of mind wandering closely related to creativity, termed freely moving mind wandering (FMMW). In this study, we examined the behavioral and neural associations between FMMW and creativity. Methods: We initially validated a questionnaire measuring FMMW by comparing its results with those from the Sustained Attention to Response Task (SART). Data were collected from 1316 participants who completed resting-state fMRI scans, the FMMW questionnaire, and creative tasks. Correlation analysis and Bayes factors indicated that FMMW was associated with creative thinking (AUT). To elucidate the neural mechanisms underlying the relationship between FMMW and creativity, Hidden Markov Models (HMM) were employed to analyze the temporal dynamics of the resting-state fMRI data. Results: Our findings indicated that brain dynamics associated with FMMW involve integration within multiple networks and between networks (r = −0.11, pFDR &lt; 0.05). The links between brain dynamics associated with FMMW and creativity were mediated by FMMW (c’ = 0.01, [−0.0181, −0.0029]). Conclusions: These findings demonstrate the relationship between FMMW and creativity, offering insights into the neural mechanisms underpinning this relationship.

Evaluating nivolumab plus gemcitabine–cisplatin’s cost-effectiveness for aUC in China

AimsAssessing the cost-effectiveness of Nivolumab with Gemcitabine–Cisplatin for Advanced Urothelial Carcinoma (aUC) treatment from the perspective of Chinese payers.MethodsA Markov model assessed economic outcomes, estimating health outcomes in quality-adjusted life years (QALYs). One-way and probabilistic sensitivity analyses were conducted to assess the impact of uncertainties on the results.ResultsThe base-case analysis showed Nivolumab plus Gemcitabine–Cisplatin yielded 0.59 QALYs at an extra cost of $78,780.61, leading to an incremental cost-effectiveness ratios (ICER) of $133,526.46/QALY. One-way sensitivity analysis highlighted Nivolumab’s cost as the key factor, while probabilistic sensitivity analysis showed a 0% chance of cost-effectiveness for Nivolumab plus Gemcitabine–Cisplatin in aUC treatment.ConclusionNivolumab plus Gemcitabine–Cisplatin is not cost-effective in the treatment of aUC.

Analysis of the dynamics of transition from non-colonization to colonization and Staphylococcus aureus bacteremia in hemodialysis patients using Markov models.

Background Hemodialysis patients are frequently colonized by Staphylococcus aureus, leading to severe infections with high mortality rates. However, little is known about transition from non-colonization to colonization or bacteremia over time. The aim was to analyze the behavior of S. aureus colonization, identifying the probability of transition from non-colonized to colonized state or bacteremia, and the influence of specific covariates. Methods The study was conducted in a dialysis unit associated with a tertiary care hospital in Medellín between October 2017 and October 2019. An initial measurement was taken to evaluate S. aureus colonization, and follow-up measurements were performed 2 and 6 months later. Bacteremia evolution was monitored for 12 months. A two-state recurrent continuous-time Markov model was constructed to model transition dynamics from non-colonization to S. aureus colonization in hemodialysis patients. Subsequently, the model was applied to a third state of bacteremia. Results Of 178 patients on hemodialysis, 30.3% were colonized by S. aureus. Transition intensity from non-colonization to colonization was three times higher (0.21; CI: 0.14-0.29) than from colonization to non-colonization (0.07; CI: 0.05-0.11). The colonization risk increased in patients with previous infections (HR: 2.28; CI: 0.78-6.68), hospitalization (HR: 1.29; CI: 0.56-2.99) and antibiotics consumption (HR: 1.17; CI: 0.53-2.58). Mean non-colonized state duration was 10.9 months, while in the colonized state was 5.2 months. In the 3-state model, it was found that patients colonized were more likely to develop S. aureus infection (13.9%). Conclusion A more likely transition from non-colonization to colonization was found, which increases with factors such as previous infection. In addition, the development of bacteremia was more likely in colonized than in non-colonized patients. These results underline the importance of surveillance and proper management of S. aureus colonization to prevent serious complications, such as bacteremia, and improve prognosis in this vulnerable population.

A joint self-information and Markovian model-driven deep channel estimation and feedback model for millimeter-wave massive MIMO systems

A joint self-information and Markovian model-driven deep channel estimation and feedback model for millimeter-wave massive MIMO systems

Tracking and Transition Probability of Blood Pressure From Childhood to Midadulthood.

Despite its relevance for pediatric blood pressure (BP) screening, the long-term predictive utility and natural progression of pediatric BP classification remain understudied. To evaluate BP tracking from childhood to midadulthood using the American Academy of Pediatrics (AAP) thresholds and estimate transition probabilities among BP classifications over time considering multiple time points. The analyses were performed in 2023 using data gathered from September 1980 to August 2018 within the longitudinal Cardiovascular Risk in Young Finns Study. Participants had BP examined 9 times over 38 years, from childhood (aged 6-12 years) or adolescence (15-18 years) to young adulthood (21-27 years), late young adulthood (30-37 years), and midadulthood (39-56 years). BP classifications (normal, elevated, hypertension) were based on AAP guidelines for children and adolescents and the 2017 American College of Cardiology/American Heart Association guidelines for adults. Outcomes were BP classifications at follow-up visits. Tracking coefficients were calculated using generalized estimated equations. Transition probabilities among BP classifications were estimated using multistate Markov models. This study included 2918 participants (mean [SD] baseline age, 10.7 [5.0] years; 1553 female [53.2%]). Over 38 years, the tracking coefficient (odds ratio [OR]) for maintaining elevated BP/hypertension was 2.16 (95% CI, 1.95-2.39). Males had a higher probability than females of progressing to and maintaining hypertension and a lower probability of reverting to normal BP from childhood to midadulthood (transition probability: from normal BP to stage 2 hypertension, 0.20; 95% CI, 0.17-0.22 vs 0.08; 95% CI, 0.07-0.10; maintaining stage 2 BP, 0.32; 95% CI, 0.27-0.39 vs 0.14; 95% CI, 0.09-0.21; from stage 2 hypertension to normal BP, 0.23; 95% CI, 0.19-0.26 vs 0.58; 95% CI, 0.52-0.62. For both sexes, the probability of transitioning from adolescent hypertension to normal BP in midadulthood was lower (transition probability, ranging from 0.16; 95% CI, 0.14-0.19 to 0.44; 95% CI, 0.39-0.48) compared with childhood hypertension (transition probability, ranging from 0.23; 95% CI, 0.19-0.26 to 0.63; 95% CI, 0.61-0.66). The probability of maintaining normal BP sharply decreased in the first 5 to 10 years, stabilizing thereafter. Children with normal BP generally maintained this status into adolescence (male: transition probability, 0.64; 95% CI, 0.60-0.67; female: transition probability, 0.81; 95% CI, 0.79-0.84) but decreased by young adulthood (male: transition probability, 0.41; 95% CI, 0.39-0.44; female: transition probability, 0.69; 95% CI, 0.67-0.71). Results of this cohort study reveal an enduring association of childhood and adolescent BP (AAP thresholds) with later BP. Although childhood normal BP tends to be maintained into adolescence, the probability of reverting to and sustaining normal BP decreases notably from adolescence to young adulthood. The findings of this study underscore the importance of prevention to maintain normal BP starting in childhood, suggesting adolescence as a potential critical period. The results suggest the potential for less frequent screenings for children with initially normal BP.

The Effect of Domain Terms on Password Security

The predominant authentication method still relies on usernames and passwords. To enhance memorability, domain terms may have been opted to include as part of passwords. However, there is little analysis of the extent to which such practice affects password security, so there is a lack of guidance on how users use domain terms on websites with different domain characteristics. To address the problem, we propose a novel approach to analyze the security effect of using domain terms in passwords. The methodology primarily consists of three stages. Firstly, we utilize Web crawlers to harvest domain vocabularies, subsequently leveraging the TextRank algorithm to rank their importance. Afterward, we propose an algorithm for constructing a simulated domain-specific password dataset by replacing password elements with domain terms. Finally, password guessing experiments are done on the dataset using PCFG and Markov model to evaluate the impact of domain terms on password security. The experimental results indicate that, for systems without clear domain, 20% domain terms replacement in the test set can reduce the cracking rate by up to 5.45%. In contrast, for domain-specific systems, 20% domain terms replacement in the training set can increase the cracking rate by 6.45%. These findings provide practical guidance on the application of domain knowledge in password creation for different types of systems. In summary, this study offers a novel perspective for exploring the security implications of passwords influenced by specific domains.

MIPPIS: protein–protein interaction site prediction network with multi-information fusion

BackgroundThe prediction of protein–protein interaction sites plays a crucial role in biochemical processes. Investigating the interaction between viruses and receptor proteins through biological techniques aids in understanding disease mechanisms and guides the development of corresponding drugs. While various methods have been proposed in the past, they often suffer from drawbacks such as long processing times, high costs, and low accuracy.ResultsAddressing these challenges, we propose a novel protein–protein interaction site prediction network based on multi-information fusion. In our approach, the initial amino acid features are depicted by the position-specific scoring matrix, hidden Markov model, dictionary of protein secondary structure, and one-hot encoding. Simultaneously, we adopt a multi-channel approach to extract deep-level amino acids features from different perspectives. The graph convolutional network channel effectively extracts spatial structural information. The bidirectional long short-term memory channel treats the amino acid sequence as natural language, capturing the protein’s primary structure information. The ProtT5 protein large language model channel outputs a more comprehensive amino acid embedding representation, providing a robust complement to the two aforementioned channels. Finally, the obtained amino acid features are fed into the prediction layer for the final prediction.ConclusionCompared with six protein structure-based methods and six protein sequence-based methods, our model achieves optimal performance across evaluation metrics, including accuracy, precision, F1, Matthews correlation coefficient, and area under the precision recall curve, which demonstrates the superiority of our model.

Large-scale dependent multiple testing via higher-order hidden Markov models

ABSTRACT Taking into account the local dependence structure in large-scale multiple testing is expected to improve both the efficiency of the testing procedure and the interpretability of scientific findings. The hidden Markov model (HMM), as an effective model to describe the sequential dependence, has been successfully applied to large-scale multiple testing with local correlations. However, in many applications, the first-order Markov chain is not flexible enough to capture the complexity of local correlations. To address this issue, this paper proposes a novel multiple testing procedure that uses a higher-order Markov chain to better characterize local correlations among tests. The proposed procedure is validated by theoretical results and simulation studies, which show that it outperforms its competitors in terms of power. Finally, a real data analysis is presented to demonstrate the favorable performance of the proposed procedure.

Estimated health benefits, costs, and cost-effectiveness of implementing WHO's sodium benchmarks for packaged foods in India: a modelling study.

Excess dietary sodium intake has been associated with death and disability. WHO has released global sodium benchmarks for packaged foods to support countries to reduce population sodium intake. This study aimed to assess the potential health effect, costs, and cost effectiveness of implementing these WHO sodium benchmarks in India. We used a multiple cohort, proportional multistate, life table (Markov) model to estimate the health gains and cost effectiveness for adults if sodium content in packaged foods complied with the WHO benchmarks compared to the status quo. We used India-specific dietary surveys, food composition tables, foods sales data, and sodium content data from packaged food labels to estimate sodium intake before and after the intervention. Data on blood pressure, cardiovascular disease, and chronic kidney disease burden were obtained from the Global Burden of Diseases, Injuries, and Risk Factors study, and the effect of sodium reduction on blood pressure and disease risk was modelled on the basis of meta-analyses of randomised trials and cohort studies. Intervention and health-care costs were used to estimate net costs, and calculate the incremental cost per health-adjusted life-year (HALY) gained. Costs and HALYs were discounted at 3%. In the first 10 years, compliance with the WHO sodium benchmarks was estimated to avert a mean of 0·3 (95% uncertainty interval [UI] 0·2-0·5) million deaths from cardiovascular diseases and chronic kidney disease, a mean of 1·7 (95% UI 1·0-2·4) million incident cardiovascular disease events, and 0·7 (0·4-1·0) million new chronic kidney disease cases, compared with current practice. Over 10 years, the intervention was projected to be cost saving (100·0% probability), generating 1·0 (0·6 to 1·4) billion HALYs and US$0·8 (95% UI 0·3 to 1·4) million in cost savings. Over the population lifetime, the intervention could prevent 4·2 (2·4-6·0) million deaths from cardiovascular diseases and chronic kidney disease, 14·0 (8·2-20·1) million incident cardiovascular disease events, and 4·8 (2·8-6·8) new chronic kidney disease cases, with an 84·2% probability of being cost-saving and 100·0% probability of being cost-effective. Our modelling data suggest a high potential for compliance with WHO sodium benchmarks for packaged food being associated with substantial health gains and cost savings, making a strong case for India to mandate the implementation of the WHO sodium benchmarks, particularly as packaged food consumption continues to rise. WHO Country Office India.

Optimized Architecture for Efficient OFDMA Network Design

This study presents a novel approach to enhancing the design and performance of OFDMA (Orthogonal Frequency Division Multiple Access) networks, with a particular focus on WiMAX (Worldwide Interoperability for Microwave Access) for Best Effort (BE) services. The proposed method integrates a robust Markovian analytical model with four advanced scheduling algorithms: throughput fairness, resource fairness, opportunistic scheduling, and throttling. A sophisticated simulator was developed, incorporating an ON/OFF traffic generator, user-specific wireless channels, and a dynamic central scheduler to validate the model’s accuracy and evaluate its robustness by dynamically allocating radio resources per frame. The validation study showed that the proposed model reduced simulation time by over 90%, completing analytical calculations in just 15 min, compared to nearly 2 days for simulations using conventional scheduling algorithms. Performance metrics such as the average number of active users and resource utilization closely matched those from the validation study, confirming the model’s accuracy. In the robustness study, the model consistently performed well across diverse traffic distributions (exponential and Pareto) and channel conditions. The proposed architecture increased network throughput by up to 25% and reduced latency under dynamic conditions, demonstrating its scalability, adaptability, and efficiency as a crucial solution for next-generation wireless communication systems.

Potential climate predictability of renewable energy supply and demand for Texas given the ENSO hidden state.

Climate variability influences renewable electricity supply and demand and hence system reliability. Using the hidden states of the sea surface temperature of tropical Pacific Ocean that reflect El Niño-Southern Oscillation (ENSO) dynamics that is objectively identified by a nonhomogeneous hidden Markov model, we provide a first example of the potential predictability of monthly wind and solar energy and heating and cooling energy demand for 1 to 6 months ahead for Texas, United States, a region that has a high penetration of renewable electricity and is susceptible to disruption by climate-driven supply-demand imbalances. We find a statistically significant potential for oversupply or undersupply of energy and anomalous heating/cooling demand depending on the ENSO state and the calendar month. Implications for financial securitization and the potential application of forecasts are discussed.

UTILIZING DISCRETE HIDDEN MARKOV MODELS TO ANALYZE TETRAPLOID PLANT BREEDING

In plant heredity, the phenotype is the result of observation that can be directly observed, while the genotype is the underlying hidden factor that underlies the expression of the phenotype. The genotype is an important aspect that needs to be understood to explain the pattern of trait inheritance and predict trait inheritance in subsequent generations. The discrete hidden Markov model is a model generated by pair of an unobserved Markov chain and an observation process. This model can be applied to tetraploid plant crosses by modeling genotypes as hidden state and phenotypes as the obeservation process. The probability of dominant phenotype in monohybrid, dihybrid and trihybrid crosses occurring over ten generations during that period is as follows 61,305%, 37,583%, and 23,041%. Furthermore, as more traits are crossed, the probability of dominant phenotype appearing within ten generations decreases. When the dominant phenotype occurs over ten generations, the same genotype can be obtained in monohybrid, dihybrid, and trihybrid crosses, which is heterozygous in the first and second generations, while from the third to the tenth generation it is homozygous dominant.