Statistics and Probability Commons^™

When Three Points Aren't Enough: Parameter Estimation In Newton's Law Of Cooling, Alberto A. Condori, Cara D. Brooks, Madeline R. Goldberg

CODEE Journal

We begin with a paradoxical three-point problem where the standard parameter estimation formula fails because temperature data must satisfy a concavity condition reflecting Newton's Law of Cooling's exponential structure. Although a closed-form solution for A exists for equally-spaced measurements, high sensitivity to error motivates the use of overdetermined systems with many measurements. The "profiling over A" technique transforms this three-parameter nonlinear problem into a sequence of simple linear regressions, providing computational efficiency and conceptual transparency. This approach can be generalized to many parameter estimation problems in science and engineering, making it a valuable tool for undergraduates interested in applied mathematics. …

Analysis Of The Influence Of Anthropometric Dimensions Of Postural Ergonomics Using Multiple Linear Regression, Gashbeen Faisal Najmaddin, Edrees Muhammed Tahir Harki

Al-Bahir

Ergonomics is the study of designing and arranging a workspace or product to optimize the “fit” between people and their work, ensuring safety, comfort, and efficiency. The scientific literature indicates that ergonomic perspectives on the workplace are connected to the anthropometrics of societies. This study primarily aims to create a model that integrates multiple predictive variables to estimate the target variable. Multiple linear regression analysis is used to identify how different anthropometric dimensions predict postural ergonomics during prolonged sitting. Based on the regression models’ results, the predicted can be calculated using user anthropometry and existing chair dimensions. Furthermore, the primary …

Bank Soundness Index For Indonesia: The Generalized Dynamic Principal Component Analysis Approach, Yusita Octina Budiyanti, Nasrudin Nasrudin

Bulletin of Monetary Economics and Banking

In Indonesia, the Bank Soundness Index (BSI) serves as an early warning instrument for assessing the stability of Conventional Commercial Banks (CCBs) and Islamic Commercial Banks (ICBs). This study develops the BSI employing the Generalized Dynamic Principal Component Analysis (GDPCA) methodology and incorporates the fundamental indicators from the Financial Soundness Indicators released by the IMF. The BSI for CCBs is formulated using three primary components, with the Operating Expense to Operating Income ratio assigned the greatest weight. Likewise, the BSI for ICBs is constituted by three primary components, with the Liquid Asset ratio carrying the greatest weight. The developed BSI …

Validation Of A Home-Based Tool For Preschool Children Fall Prevention: A Rasch Analysis, Devie Fitri Octaviani, Fatma Lestari, Indang Trihandini, Dadan Erwandi

Kesmas

Unintentional falls are a leading cause of injury among preschool children, primarily occurring in home environments, yet validated tools to assess household fall prevention capacity in low- and middle-income countries remain limited. This study aimed to develop and psychometrically validate the Home-Based Preschool Fall Prevention Instrument using the Rasch Measurement Model. A cross-sectional validation study was conducted in Depok City, Indonesia, involving 167 primary caregivers of preschool children enrolled in kindergartens selected through multistage cluster random sampling. The instrument was developed based on an etiological injury model, socio-ecological perspectives, and risk management principles, and comprised four main factors: child, home, …

Provincial Disparities In Adolescent Fertility In Indonesia: An Ecological Analysis Of Child Marriage, Median Age At First Marriage, And Family Development Index, Andi Nisa Fathimiyah Afidah, Milla Herdayati

Kesmas

Adolescent fertility remains a public health concern in Indonesia, with substantial variations across provinces. However, the evidence explaining provincial disparities using population-level indicators remains limited. This study aimed to examine provincial disparities in adolescent fertility and assess the association of child marriage, median age at first marriage among women, and the Family Development Index called iBangga with adolescent fertility across Indonesia. This ecological, cross-sectional study used aggregated data from 34 Indonesian provinces. Descriptive statistics, spatial visualization, Pearson’s correlation, and multiple linear regression analyses were performed. The mean adolescent fertility rate was 25.0 births per 1,000 female adolescents aged 15–19 years, …

Spatial Association Of Acute Respiratory Infection, Diarrhea, And Low Birth Weight With Stunting Prevalence In Indonesia, 2024, Dian Rosadi, Husaini Husaini, Triawanti Triawanti, Musafaah Musafaah

Kesmas

Stunting remains unevenly distributed across Indonesia, but national evidence integrating spatial analysis and spatial regression is limited. This study examined the spatial distribution of stunting and its associations with acute respiratory infection (ARI), diarrhea, and low birth weight (LBW) across Indonesian provinces. An ecological cross-sectional study used data from the 2024 Indonesian Nutritional Status Survey. Stunting-only analyses included all 38 provinces, whereas analyses involving ARI, diarrhea, and LBW included 37 provinces with complete data. Spatial analyses used a row-standardized symmetric four-nearest-neighbor spatial weights matrix and included Global Moran’s I, bivariate spatial analysis, Local Indicators of Spatial Association, ordinary least squares, …

The Association Between Rapid Growth In Children Under The Age Of Five And Adolescent Obesity, Ratu Ayu Dewi Sartika, Fadila Wirawan, Iche Andriyani Liberty, Nurul Husna Mohd Shukri, Siti Arifah Pujonarti, Edy Purwanto, Munaya Fauziah

Kesmas

Early-life nutrition is a critical predictor of long-term health, yet the association between rapid early-childhood growth and adolescent obesity, particularly in relation to the “double burden of malnutrition,” remains under-researched in Indonesia. This study aimed to analyze the association between rapid growth and adolescent obesity. Data were obtained from the 1997, 2000, and 2014 waves of the Indonesian Family Life Survey (IFLS). This study included 641 children (aged 0–23 months at baseline) with complete anthropometric measurements across all three waves. Rapid growth was defined as an increase in z-scores of >0.67 in weight-for-age (WAZ), height-for-age (HAZ), or weight-for-height (WHZ) between …

Environmental Perspective For System Dynamics Modeling Of Stunting Mitigation To Achieve The Sustainable Development Goals In West Sumatra, Indonesia, Elsa Yuniarti, Nabila Azzahra, Yulhendri Yulhendri, Heldi Heldi, Mery Delvina, Saskia Putri Azeli

Kesmas

This study developed a system dynamics model to simulate stunting reduction in West Sumatra Province, Indonesia, by integrating infant and toddler health, maternal health, and environmental determinants. Secondary data from 2020–2024 on low birth weight, immunization, malnutrition, exclusive breastfeeding, maternal chronic energy deficiency, iron and folic acid supplement distribution, sanitation, and safe drinking water access were compiled from West Sumatra Provincial Health Office and Statistics Indonesia, and validated through consultation with five stakeholder institutions. Causal Loop Diagrams mapped feedback relationships among determinants and were translated into Stock Flow Diagrams using Powersim Studio 10. The model was validated through structural verification, …

Modeling Of Supersonic Wave And Shock Propagation Using The Lattice Boltzmann Method, Timothy P. Schroeder

Beyond: Undergraduate Research Journal

The lattice Boltzmann method (LBM) has emerged as a mesoscopic alternative to traditional Navier-Stokes solvers for modeling fluid dynamics offering advantages in computational efficiency, parallelization, and handling of complex boundaries. Despite these strengths, accurately reproducing compressible, shock-driven phenomena remains challenging. This study investigates the performance of LBM in simulating the Sod shock tube problem, a classical benchmark for compressible flow-using both single and double distribution function formulations across one- and two-dimensional lattice stencils. A MATLAB-based solver was developed to model the flow under isothermal conditions and compared to the analytical solution using the L2 norm error. The one-dimensional models achieved …

Wavelet-Based Multiscale Analysis Of Cave Co₂ Concentration In Response To Short-Term High-Intensity Tourism Activities: Spatiotemporal Heterogeneity And Lag Characteristics, Mingda Cao, Wenwen Song, Yan Zhang, Jie Zhang, Zhiqiang Yao

International Journal of Speleology

High-intensity tourism activities can cause a significant increase in cave air CO₂ concentration, thereby affecting the cave micro-environment and secondary carbonate deposition. During the 2023 National Day Golden Week, high-frequency continuous monitoring of cave air CO₂ partial pressure (PCO_2(A)) and visitor numbers was conducted in Dawang Cave, Anhui Province. Wavelet transform and cross-correlation analyses were used to reveal the multi-scale response characteristics of CO₂ concentration to tourism activities. The results show that: (1) PCO_2(A) exhibited clear diurnal variations (higher during the day, lower at night) and decreased spatially with enhanced ventilation, controlled jointly by …

Volatility Spillovers Between Stock Prices And Exchange Rates: Insights For Risk Management And Investment Strategies: Evidence From China, India, And Pakistan Using Bekk-Garch Models, Samreen Fatima, Humera Sultana, Muhammad Najamuddin Dr., Saba Naz

The Indonesian Capital Market Review

This study investigates the dynamics of volatility and its spillover effects between the stock markets of China, India, and Pakistan, and their respective exchange rates (USD/CNY, USD/INR, and USD/ PKR). Volatility is modeled using the Symmetric and Asymmetric BEKK-GARCH (1,1) and DCCGARCH (1,1) models, based on daily return series covering the period from January 1, 2019, to January 31, 2025. The empirical results indicate that both the employed models are adequate for capturing the volatility dynamics. The findings reveal that the highest value of portfolio weights and hedging efficiency of KSE-100 Index–USD/PKR provide optimal portfolio allocation and highest hedging performance …

Urban Carbon Emission Early Warning Research Based On The Dpsir Framework And Deep Learning, Xiaochun Zhao, Lingyang Xu, Ying Zhou

Journal of Scientific Information Research

[Purpose/significance] In line with the national requirements for building a carbon emission early warning mechanism, conducting the urban carbon emission early warning research is of great significance for achieving the “dual-carbon” goals. [Method/process] This paper selected 16 prefecture-level cities in Anhui Province as research samples. A carbon emission early warning indicator system was constructed based on the DPSIR framework. By using data from urban statistical yearbooks, the LSTM model was employed with parameter optimization via genetic algorithms to forecast various early warning indicators for 2024-2025.On this basis, a combined subjective-objective weighting method was then applied to calculate the urban carbon …

A Multi-Dimensional Analysis Of China's Future Industry Development Policy Documents, Tianxiang Yao, Wang Xu

Journal of Scientific Information Research

[Purpose/significance] Future industries are important carriers of new quality productive forces which can play a leading role in the economic and social development. Quantitative analysis and evaluation of China's future industry policies can provide support and reference for the formulation, optimization and adjustment of subsequent policies. [Method/process] Taking a total of 84 policy texts at the central, provincial, municipal and county levels in China as the research objects, a three-dimensional analysis framework of "theme-tool-effectiveness" was constructed. By comprehensively applying LDA thematic analysis, content analysis and PMC index model, theme distribution, content characteristics and comprehensive effectiveness of policy texts were deeply …

What We Know About Accounting Ratios: Methodological Considerations, Wojciech Kuryłek, Oskar Kowalewski

Studia i Materiały Wydział Zarządzania Uniwersytet Warszawski

Purpose: This paper provides a comprehensive literature review of the methodological aspects of financial ratio analysis, consolidating dispersed knowledge on the computation, statistical properties, and appropriate usage of accounting ratios.

Design/Methodology/Approach: The study adopts a narrative literature review methodology, systematically surveying published research on financial ratio distributions, normality testing, data transformations, outlier handling, the proportionality assumption, dimensionality reduction techniques, compositional data analysis, and recommended ratio sets for corporate financial research.

Findings: Financial ratios predominantly deviate from normal distributions, exhibiting skewness, excess kurtosis, and sensitivity to outliers. Transformation techniques such as logarithmic, square root, and Box‑Cox methods yield mixed results in …

Mengukur Capaian Dan Identifikasi Konvergensi Pembangunan Infrastruktur Antarprovinsi Di Indonesia, Ressa Isnaini Arumnisaa', Aisyah Fitri Yuniasih

Jurnal Ekonomi dan Pembangunan Indonesia

Indonesia’s economic challenges are characterized by stagnant economic growth and regional development disparities. This study analyzes the achievement and convergence of infrastructure development across provinces in Indonesia during 2011–2021 through the construction of an Infrastructure Development Index (IPI). The study employs panel data from 33 provinces, using factor analysis to construct the IPI and the First Difference Generalized Method of Moments (FD-GMM) to examine convergence and its determinants. The results show that many provinces still have IDI scores below the national average. Furthermore, the FD-GMM model shows that σ-convergence and β-convergence occur in Indonesia. In addition, GRDP per capita, inflation, …

Estimasi Underground Economy Triwulanan Di Indonesia Pada Tahun 2010–2023, Ghina Anandhia, Hardius Usman

Jurnal Ekonomi dan Pembangunan Indonesia

Underground economics have a significant impact on economy. Underground economy leads to low potential state revenues from the tax sector. This study estimates the quarterly value of the underground economy in Indonesia from 2010 to 2023 using the Error Correction Model (ECM) method. The results show that the average value of the underground economy in Indonesia is IDR138,392.32 billion, equivalent to 5.36 percent of Gross Domestic Product (GDP) and 35.72 percent of tax revenue from 2010 to 2023. GDP and tax burden variables have a positive influence on currency demand.

Stochastic Analysis Of Epidemic Size And Peak Infection In An Svir Model With Imperfect Vaccine And External Source Of Infection, María Gamboa Pérez

Mathematical Modelling and Numerical Simulation with Applications

The dynamics of an infectious disease outbreak are studied under a stochastic framework in a closed population where individuals are homogeneously mixed. A vaccination program is implemented in the community prior to the start of the epidemic. The administered vaccine is imperfect, meaning that vaccinated individuals may still become infected upon contact with infected individuals. The mathematical Susceptible-Vaccinated-Infected-Recovered (SVIR) model describing the evolution of the epidemic is formulated as an absorbing, continuous-time, three-dimensional Markov chain with compartments for vaccinated, susceptible, infected and recovered individuals. The aim of this study is to characterize two fundamental epidemiological quantities: the maximum number of …

Study On Deformation Characteristics Of Kaolin Under Dry-Wet And Freeze-Thaw Cycles, Yang Shang, Xiao Dingyuan

Journal of China & Foreign Highway

In seasonally frozen areas, surface soil is subjected to prolonged and drastic fluctuations in temperature and humidity, causing excessive deformation and resulting in engineering issues such as subgrade settlement and building deformation. The deformation characteristics of kaolin in seasonally frozen areas under the combined influence of freeze-thaw and dry-wet cycles were studied. Through a self-designed experimental setup, experiments with interleaved dry-wet and freeze-thaw cycles were conducted on compacted specimens, and wetting-freezing-thawing-drying cycle experiments were performed to explore the swelling-shrinkage deformation characteristics of kaolin under the combined action of different freeze-thaw and dry-wet cycles. The results indicate that intermittent freeze-thaw cycles …

Influence Of Geocell Technical Parameters On Bearing Characteristics Of Highway Subgrades In Oasis Areas, Zhu Chunsheng, Shu Xingyu, Lu Huiyu, Yang Xiaohua

Journal of China & Foreign Highway

To study the effects of technical parameters, such as geocell specifications and laying types, on the bearing capacity and deformation of highway subgrades in oasis flood irrigation areas, the shear properties of plain soil and geocell-reinforced layers with different specifications were studied through large-scale direct shear tests. Based on indoor compression tests and field load tests, numerical simulation parameters, such as the deformation modulus of different foundation soil layers, were calibrated. A numerical model of the geocell-reinforced highway subgrade was established using, and the effects of geocell specifications and laying types on the vertical settlement of the subgrade, the displacement …

Study On Effects Of Phase Change Materials On Thermal Erosion Resistance Of Airport Pavement, Li Ping, Li Yunlong, Zheng Zhipeng, Wang Zhijian, Yi Chengxi

Journal of China & Foreign Highway

To investigate the effect of phase change materials (PCMs ) on improving the thermal erosion resistance of airport pavements and to provide recommendations for selecting optimal PCMs to obtain airport pavements with longer service lives, three PCMs, PCM-G- 98 (A), LB- 2 (B), and TH-HC- 120 (C), were purchased based on literature summaries and market research. Based on microscopic test results and the actual preparation conditions of modified asphalt, PCMs A and B were selected. Subsequently, based on a self-made high-content SBS modified asphalt (S), four groups of composite modified asphalts (S-A- 5, S-A- 10, S-B- 5, and S-B- 10) …

Study On Influence Of Elastic Modulus Of Fiber On Compaction Characteristics Of Asphalt Mixtures, Zou Zexi, Luo Kaiyan, Lin Zhiming, Qiu Xiang, Lu Xudong, Yao Xiaoyang, Wang Yaolong

Journal of China & Foreign Highway

To investigate the influence mechanism of fiber incorporation on the compaction characteristics of asphalt mixtures, six types of typical road fibers (polyester fiber, polyacrylonitrile fiber, aramid fiber, basalt fiber, polypropylene fiber, and polyvinyl alcohol fiber) were selected in this paper, and gyratory compaction tests were conducted based on AC- 20 graded mixtures. The compaction coefficient (a larger compaction coefficient indicates easier compaction) was used as the core evaluation index. The results indicate that the elastic modulus of the fiber is the key influencing factor. When the fiber modulus is 50% lower than the aggregate modulus (such as polyester fiber and …

Angularity Evaluation Of Coarse Aggregates Based On Local Feature Extraction Of Point Clouds, Ma Quanzhuo, Feng Ponan, Feng Zezhong, Lei Mingyu, Wang Zhenfeng, Li Jiange

Journal of China & Foreign Highway

The morphological characteristics of coarse aggregates significantly affect the mechanical properties of asphalt mixtures and thus directly influence their road performance and durability. This paper aims to innovatively propose an evaluation method for the angularity of coarse aggregates. A three-dimensional (3D) scanner was used to acquire the surface profile information of coarse aggregates, and local angularity features were extracted through point cloud data analysis. Subsequently, a comprehensive 3D angularity evaluation index for coarse aggregates (A3D) was proposed by combining local normal vectors and curvature characteristics. The results indicate that A3D can be more accurately and independently used for angularity evaluation. …

Optimization Design And Experimental Study On Strength Of Ternary Industrial Solid Waste Mixtures, Yang Shu, Ai Yi, Sheng Shanwang, Li Chuangmin

Journal of China & Foreign Highway

This paper aims to explore whether fly ash, lithium slag, and slag powder (ternary industrial solid wastes) can effectively replace cement as cementitious materials for interlocking large-particle crushed stone bases. A uniform design table U9(94) was used to design the test scheme for the mixing ratios of ternary industrial solid waste mixtures; the correlation between the mortar strength and the ternary industrial solid waste mixtures was analyzed by Pearson correlation; with the help of the mathematical statistical software SPSS 26.0, mathematical models for the flexural strength and compressive strength of the ternary industrial solid waste mixture mortar specimens were established. …

Calculation Of Tensile Force For Cable-Stayed Buckling Bracket Combined With Temporary Tie Rod Structure Of V-Shaped Pier, Zhao Xiaolu, Yang Guang, Liu Junle, Qiu Zhiwei, Meng Lingxin, Peng Weibing

Journal of China & Foreign Highway

To solve the problem of excessive tensile stress of the cross-section during the cantilever casting process of high piers with inclined legs, a determination method of tensile force based on the linear programming theory and unstressed state control was proposed. Based on the internal force equilibrium method and the principle of influence matrix, the method optimized the tensile force with “stress control as the primary and alignment control as the auxiliary”. The unstressed state control method was adopted for forward iteration, and the effect of tangential displacement between segments was considered to verify the alignment of the inclined legs. Finally, …

Analysis Of Influence Of Cable Clamp Slippage On Internal Force And Alignment Of Main Cable, Zhu Kun, Liao Dinghui, Hu Chengze, Shen Heshun, Cao Hongyou

Journal of China & Foreign Highway

To investigate the influence of cable clamp slippage on alignment and internal force of the main cable, a theoretical analysis method based on node coordinates of the main cable after cable clamp slippage was proposed in this paper. Based on segmented catenary theory, the influence of hanger inclination caused by hanger slippage on the horizontal force of the main cable was considered. The segmental cable element of the main cable was equivalently expressed as expressions of hanger tension and unstressed length. With total unstressed length kept constant as a control condition, the horizontal force of the main cable was iteratively …

Study On Structural Design And Load Transfer Performance Of 6-Hole Flat Anchor Plate, Liao Yuanyuan, Ling Lihua, Wu Qibin, Cheng Bin, Dai Dongming

Journal of China & Foreign Highway

For negative bending moment prestressed tendons in simply supported-to-structurally-continuous bridges, the flat anchorage method of flange plate is more reasonable, but its widespread application is limited due to the anchoring capacity restrictions of flat anchor plates. To improve the anchoring capacity of a single anchorage zone, reduce the number of prestressed ducts, save concrete, and improve construction efficiency, a novel 6-hole flat anchor plate was developed, designed, and manufactured in this paper. By combining finite element analysis and experimental methods, a finite element analysis model of the concrete load transfer specimen beneath the novel 6-hole flat anchor plate was established, …

Analysis Of Shear Bearing Mechanism And Influencing Factors Of Mcl-Shaped Composite Dowel Connector, Zeng Zhuo, Zhou Baicheng, Cheng Xianjie, Cao Zhengxing, Gao Rongxiong, Wang Zichao

Journal of China & Foreign Highway

To investigate the bearing mechanism of modified clothoid (MCL)-shaped composite dowel shear connectors and the influence laws of various factors on their shear bearing capacity, the stress states and failure modes of the steel dowel, concrete dowel, and transverse through-reinforcement that constitute the MCL-shaped shear connector were deeply analyzed in this paper based on an experimentally validated finite element model. Furthermore, the influence laws of transverse through-reinforcement, steel dowel thickness, and concrete strength on the shear bearing capacity of the MCL-shaped composite dowel were explored. The research results indicate that the bearing process of the MCL-shaped composite dowel exhibits elastic, …

Research On Improving Bearing Capacity Of Full-Scale Prestressed Concrete Small Box Girders, Huang Jianyun, Gao Linli, Liu Zufeng, Ma Jinku, Ma Ming, Wang Xiaoguang

Journal of China & Foreign Highway

To solve the problems of lacking comparative research on the improvement effects of different reinforcement methods when formulating reinforcement schemes for prestressed concrete small box girders and that existing bearing capacity improvement tests mostly focus on scale models with insufficient reliability of results, full-scale model tests and numerical simulation analysis of five 30 m span prestressed concrete small box girders with different joint reinforcement measures were conducted in this paper. Finite element models for two single reinforcement measures were established, and the improvement effects of different reinforcement methods on the bearing capacity of prestressed concrete small box girders were studied. …

Key Construction Technologies For Single-Tower Rotating-Cable Suspension Bridges With Steel Truss Girders In Mountainous Regions, Gao Shuangjian, Zhang Weichao, Fu Lihong, Zhu Shuo

Journal of China & Foreign Highway

Given the problems of narrow construction sites, difficult construction organization, and high safety and quality risks faced in the construction of bridges in steep canyon regions of mountainous areas, this paper carried out research on key technologies for bridge construction in mountainous areas based on the Yellow River Three Gorges Bridge of the Jiyuan‒Xin’an Expressway. For the excavation of deep and large anchorage foundation pits in mountainous areas, a technical scheme of “loosening controlled blasting combined mainly with mechanical excavation and supplemented by manual excavation” was adopted. As this project is a single-tower single-span ground-anchored rotating-cable suspension bridge, the technologies …

Mix Proportion Design Of Tunnel Shotcrete Based On Diorite Manufactured Sand, Song Funing, Wang Zegang, Liu Naifei, Song Zhanping

Journal of China & Foreign Highway

Tunnel construction produces a large amount of waste slag, which cannot be effectively utilized due to various factors. By using tunnel slag to prepare manufactured sand to replace natural sand, resources can be saved; costs can be reduced, and the environment can be protected. Based on the Xi’an‒Shiyan high-speed railway project, the physical and mechanical properties of diorite along the tunnel were tested; the physical properties and concrete performance of manufactured sand and natural sand were comparatively studied, and the effects of water-binder ratio and sand ratio on the performance of shotcrete were analyzed by designing multiple sets of mix …