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An Income Subsystem as a Discrete Stochastic Leslie System: A Simulation-Based Approach
No full textThis thesis formulates the household-income engine of an integrated population sim- ulator as a Discrete Stochastic Leslie System (DSLS). The nonnegative state vector nt ∈ Rk + aggregates income, savings, debt, employment, and transfers. (Here, the subscript + denotes the positive cone, i.e., vectors with nonnegative components). Annual evolution is linear in state, stochastic in coefficients: nt+1 = Ttnt + εt, with Tt : Rk + → Rk + cone-preserving. Exogenous macro drivers (inflation, employment, tax, salary inflation, mortgage) are forecast via ARIMA; forecasts multiply entries of Tt, preserving linearity in expectation while introducing realistic temporal correlation. The discrete-event implemented in the Python library Salabim aligns events (births, deaths, employment, taxes) with DSLS updates. A mathematically explicit coupling maps income to fertility, mortality, education, and migration operators, yielding a closed, tractable economy–demography feedback. The system reproduces lifelike inequality gradients and business cycles using strictly linear, cone-preserving trans- formations
The Effects of Off-Season Evidence-based Training Block Periodization Program on The Performance of Soccer Athletes in a DI School: An Exploratory Study
No full textThe investigators explored the effects of a two-year evidence-based block periodization strength training program on performance outcomes in NCAA Division I male soccer athletes. The investigators aimed to examine longitudinal changes in body composition, explosive strength, and match-play physical demands, as well as the associations between field-based performance assessment and GPS-derived metrics. Using a retrospective design, data were drawn from a research data repository for athletes who participated in a long-term sport science monitoring program under the same head coach and training conditions. Performance measures included vertical jump assessments (static and counter movement jumps under bodyweight and external load), isometric mid-thigh pull testing, and athlete tracking data collected during competitive matches. Body composition was evaluated using standard anthropometric procedures. Statistical analysis was conducted to determine the significance of pre- and post-program changes and to identify potential relationships between laboratory and match performance indicators. The findings revealed improvements in body composition and vertical jump performance, particularly under load, indicating favorable adaptations to the block periodization model. While no statistically significant changes were observed in isometric force output or GPS-derived variables, positive trends in match-related sprint and running metrics were noted. These outcomes suggest that structured strength training can contribute to enhanced physical readiness and sports-specific performance in soccer athletes. The study also raises consideration of potential type I error due to sample size and the exploratory nature of the analysis. Although, subject number was limited, this research supports the implementation of block periodization in collegiate soccer settings and highlights the importance of long-term monitoring for evaluating training effectiveness. Recommendations for future work include comparison groups, larger samples, and expanded performance testing to further validate these findings and optimize athlete development strategies
2025 May - Tennessee Monthly Climate Report
No full textHi All,
For May 2025, the main weather/climate stories were the continued pattern of severe weather impacting Tennessee as well as Chattanooga recording their wettest May in the 147-year weather history of the city. Starting with the record rainfall in Chattanooga, the Chattanooga airport weather station recorded a total of 12.02-inches of rainfall over May 2025, 8.08-inches above normal and 0.02-inches above the previous record wettest May in 1929. Many other areas of East Tennessee and the Cumberland Plateau also had well above normal rainfall this month, but they were emerging out of a drought from last fall and winter so minimal flooding issues were reported despite the heavy rainfall. Over the previous 12 months (June 1, 2024 – May 31, 2025) Chattanooga is still reporting below normal precipitation, with a deficit of 6.43-inches compared to normal precipitation.
Looking at severe weather in May and so far through 2025, Tennessee has seen an active year for storms across the state. May 2025 had 10 days with severe storm reports in Tennessee, producing a total of 8 tornado reports, 131 severe thunderstorm wind damage reports, and 78 reports of severe hail (1-inch diameter or larger). So far this year there have been a total of 47 surveyed tornado paths that have impacted some part of Tennessee, with two EF3 tornadoes, seven EF2 tornadoes, 20 EF1 tornadoes, and 18 EF0 tornadoes. With such a high number of tornadoes, 2025 is already tied for the 4th most tornadoes in Tennessee in a year since 1950. Historically, the majority of tornadoes in Tennessee occur from January to May but they can still occur through the summer and early fall months with a slight uptick again in November and December.
Stay safe everybody and enjoy the last few days of spring!
Andrew & Wil
Tennessee Climate OfficeEast Tennessee State UniversityDepartment of Geoscience
