16 research outputs found
Bayesian Spatial Quantile Regression for Earthquake Risk Assessment and Insurance Pricing in Indonesia
Get PDFIndonesia’s geographical location along the Pacific Ring of Fire makes it one of the most seismically active countries in the world, with earthquakes causing recurrent and significant economic losses. To address the need for more accurate and regionally sensitive insurance pricing, this study develops a Bayesian spatial quantile regression model that estimates the 90th percentile of earthquake-induced economic losses. Unlike conventional models that focus on mean losses, this approach captures the upper tail of the loss distribution, which is essential for designing risk financing instruments that can withstand catastrophic events. The model incorporates two main predictors: earthquake magnitude (on the Richter scale) and a provincial risk exposure index constructed from population and GDP per capita. Spatial effects are modelled using a Gaussian kernel with multiple bandwidths. Based on Leave-One-Out Cross-Validation, a bandwidth of 500 kilometers yields the best model performance, effectively capturing regional dependence in earthquake loss data. Historical data from 1930 to 2024 are used to estimate parameters via Markov Chain Monte Carlo sampling with the No-U-Turn Sampler. Results indicate that both earthquake magnitude and socioeconomic exposure are significant drivers of high-end losses. For instance, the model estimates that West Sumatra and Yogyakarta could experience annual benefit payouts exceeding USD 300,000 in high-severity scenarios. Earthquake insurance premiums are then derived using the expected payout values and a 10% premium loading factor. Premium estimates range from USD 0 to over USD 50,000 across provinces, with 20 out of 34 provinces requiring positive premiums. This study contributes a novel modelling framework that integrates quantile regression, spatial weighting, and exposure-based risk assessment. The results provide a data-driven basis for setting premiums and allocating disaster risk financing more equitably across regions. Limitations include reliance on proxy variables for exposure and the exclusion of building-level vulnerability data, which may affect precision in highly localized assessments
A Posteriori Premium Rate Calculation using Poisson-Gamma Hierarchical Generalized Linear Model for Vehicle Insurance
Get PDFThis study develops and applies the Poisson-Gamma Hierarchical Generalized Linear Model (PGHGLM) to address the challenge of determining accurate and fair premium rates in vehicle insurance. The PGHGLM models a mixture distribution for the response variable, influenced by random effects, and employs a logarithmic link function. Parameter estimation is conducted using the maximum likelihood method. However, since analytical estimation is not feasible, the numerical conjugate gradient method, specifically the Fletcher-Reeves algorithm, is utilized. The implementation of the PGHGLM uses the longitudinal Claimslong dataset, incorporating driver age as a covariate. The main contribution of this research lies in integrating a priori risk classification with a posteriori adjustment based on longitudinal claim frequency data. For datasets without covariates, trend parameters are incorporated into the model. For datasets with covariates, such as driver age, the average claim frequency is computed for each age category. Results show that posteriori premium rates increase with rising claim frequency from the previous year, with higher claim frequencies leading to larger rate adjustments in the subsequent year. Through the PGHGLM, a posteriori premium rate estimates are obtained for each age group of vehicle insurance policyholders. This study demonstrates the practical application of the PGHGLM in calculating precise premium rates. By analyzing a longitudinal vehicle insurance dataset, the model generates annual a posteriori premium rates tailored to age groups. These findings underscore the PGHGLM’s robust methodological framework and its potential to enhance premium fairness, enable risk-adjusted pricing, and better tailor insurance products to diverse policyholder profiles.
Urgensi Pengenalan Konsep Literasi Numerasi pada Anak Usia Dini
No full textThis study discusses the urgency of introducing the concept of numeracy literacy in early childhood. Numerical literacy is one of the most needed skills in facing the 21st century, especially for the young generation. The question still remains, when should these skills be introduced and trained to the young generation candidates. Should it be introduced and taught from an early age? The purpose of this study was to determine the urgency of introducing the concept of numeracy literacy in early childhood. This study uses a literature review method where the authors collect 7 studies related to numeracy literacy in early childhood. From the results of the review that the author conducted on the seven related articles, there are 3 (three) important reasons why numeracy literacy should be introduced to early childhood. Based on these reasons, the authors conclude that the urgency of introducing the concept of literacy to early childhood is quite high, because numeracy literacy is a basic skill that must be possessed in the 21st century and early childhood is a golden age where the level of intellectual maturity of children is formed up to 80%
Urgensi Pengenalan Konsep Literasi Numerasi pada Anak Usia Dini
Get PDFThis study discusses the urgency of introducing the concept of numeracy literacy in early childhood. Numerical literacy is one of the most needed skills in facing the 21st century, especially for the young generation. The question still remains, when should these skills be introduced and trained to the young generation candidates. Should it be introduced and taught from an early age? The purpose of this study was to determine the urgency of introducing the concept of numeracy literacy in early childhood. This study uses a literature review method where the authors collect 7 studies related to numeracy literacy in early childhood. From the results of the review that the author conducted on the seven related articles, there are 3 (three) important reasons why numeracy literacy should be introduced to early childhood. Based on these reasons, the authors conclude that the urgency of introducing the concept of literacy to early childhood is quite high, because numeracy literacy is a basic skill that must be possessed in the 21st century and early childhood is a golden age where the level of intellectual maturity of children is formed up to 80%
Problem based learning to improve proportional reasoning of students in mathematics learning
No full textDevelopment of Malay Deli Songket Motifs Based on Symmetry Groups
Get PDFOne of the tribes in North Sumatra Province that has a wide variety of art is the Deli Malays, especially the Songket motifs. Songket is a type of traditional Indonesian weaving that should be preserved to maintain Indonesia’s wealth. The motifs in the Malay Deli Songket can be analyzed because of its symmetrical pattern. In this study, the author developed the Malay Deli Songket motif based on the concept of the symmetry group. The motif development was carried out with the Matlab program based on the frieze group pattern and the crystallography group pattern. The Frieze pattern, often called the Frieze Group, is a symmetry group created from one-way translation, forming a linear pattern that repeats one way. The crystallography group has 17 crystallographic patterns formed by a specific transformation from each type of unit lattice. Through the development of motifs, 6 new Songket motifs were obtained based on the Frieze pattern in 11 observed Malay Deli Songket motifs, namely the Moon Orchid motif, the Orchid motif, the Balong Ayam motif, the Coffee Flowers motif, the Tobacco Leaves 1 and 2 motifs, the Corn motif, the Paddy motif, the Tampuk Manggis motif, the Tobacco motif, and the Ulam Raja motif. In 4 previously observed Malay Deli Songket motifs, 11 new Songket motifs were obtained for crystallography patterns: the Deli Tobacco Leaves motif, the Coffee motif, the Tampuk Gelugor motif, and the Undang Kupu-Kupu motif.
A hybrid IFR-IDY conjugate gradient algorithm for unconstrained optimization and its application in portfolio selection
Get PDFThis study introduces the Improved Fletcher-Reeves (IFR)-Improved Dai-Yuan (IDY) hybrid conjugate gradient method, which combines the strengths of the IFR and IDY parameters through a minimum-operator strategy to enhance robustness in unconstrained optimization. The method is shown to satisfy descent and global convergence properties under the strong Wolfe line search. Numerical experiments on 134 benchmark functions demonstrate that IFR-IDY achieves superior performance, solving 98 problems more than IFR and IDY and exhibiting faster CPU times and fewer iterations in most cases. The method is also used to solve an IDX30 portfolio optimization problem, which results in an optimal allocation with an expected return of 0.00042 and a risk of 0.000050545. These results highlight the efficiency of IFR-IDY and its practical applicability in real-world decision-making
Social Structure Analysis in Management of South Sumatra Inland Waters
Get PDFAbstract
The social structure of inland fisheries communities tends to place powerful elites in important positions, while local fishermen are subordinate actors. Patronage is a form of social relationship that describes the unequal social structure between these actors. This research aimed to analyze social structure in the inland waters of South Sumatra in the practice of the Lebak Lebung and River Auction (L3S) in OKI District. To achieve this goal, a constructivist paradigm with qualitative research methods was employed, and the sample comprised 39 informants selected as subjects. The data analysis was conducted in three distinct stages, namely data reduction, presentation, and drawing conclusions. The results showed that the regulation of open access for all parties in the local government regime after 1982 created an institutionalized social relations structure where the government, investors, traders, middlemen, and non-fishing actors dominated compared to the fishermen. The participants in this social landscape strived to accumulate capital to enhance their competitiveness within the L3S domain. A patronage system was implemented with middlemen assuming the role of patron and the fishermen acting as their clients. The current institutional social structure has created an unfair distribution of resource benefits for fishing workers. The novelty theories were found in the working relations of the inland waters community of South Sumatra, namely stratified distribution of rights, dual status, multi-stage patronage, and the positive function of patronage for chief fisherman. Further research should be conducted to research policy revitalization and develop strategic inland water management models.
Highlight Research
The author mentioned 3 highlights from their results research:
• Auction system in inland waters in South Sumatra presents an unfair distribution for fishermen.
• Structure of the working relationship formed is an asymmetric patron-client relationship but with novel theories such as the stratified distribution of rights model, dual status, multi-stage patronage, and the positive function of patronage.
• An imbalance in local access to auction objects due to their weak ability to accumulate capital
Reliability on Various Indices of Ventilatory Function in Patients of Pulmonary Tuberculosis and A New Analytic Method for Fast Vital Capapcity Curve.
Get PDFAt present percentage FEVI (FEV1/VC × 100) is used widely as the index of expiratory imcompetency, but there is some doubt as to its usefulness especially in patients with decreased VC such as in pulmonary tuberculosis. First in this report 169 patients with pulmonary tuberculosis were studied with reference to ventilatory functions, and consequently it was considered that the previous indices of ventilatory function were not useful particularly on account of the following. 1) MBC was deficient in reappearance and was influenced by VC. 2) MMF showed a wide distribution in cases with not so decreased VC. 3) Percentage FEV1 showed high values in cases with decreased VC in spite of check valve observations. Secondly 43 normal cases were studied similarly, and it was found that the time required for rapid expiration was shorter in decreased VC. This fact suggested that a suitable time for VC must be determined for each individual case. Accordingly the author has set forth developed a new analytic method as an index for expiratory imcompetency in this report. At the outset a nomogram showing the relationship between the percentage VC and the time required for rapid expiration up till 85.0% of VC (expiration time (t)) was prepared in normal subjects. From this nomogram the suitable expiration time (t) for percentage VC was obtained for each individual case, and then timed VC (FEVt) for the expiration time is calculated from the fast vital capacity curve. The ratio of FEVt to VC have been estimated in percentage FEVt (FEVt/VC×100) . Lastly this percentage FEVt was examined on the same patients, and the author believes this index is useful and may replace the method used hitherto.departmental bulletin pape
