Supplier-retailer inventory coordination with credit term for inventory-dependent and linear-trend demand

2013 ◽  
Vol 21 (5) ◽  
pp. 797-818 ◽  
Author(s):  
Chengfeng Wu ◽  
Qiuhong Zhao
Author(s):  
Stevan Prohaska ◽  
◽  
Aleksandra Ilić ◽  
Pavla Pekarova ◽  
◽  
...  

Data on historic floods along the Danube River exist since the year 1012. In the Middle Ages, floods were estimated based on historical documents, including original handwritten notes, newspaper articles, chronicles, formal letters, books, maps and photographs. From 1500 until the beginning of organized water regime observations, floods were hydraulically reconstructed based on water marks on old buildings in cities along the Danube (Passau, Melk, Emmersdorf an der Donau, Spilz, Schonbuhen and Bratislava). The paper presents a procedure for assessing the statistical significance of registered historic floods using a comprehensive method for defining theoretical flood hydrographs at hydrological stations. The approach is based on correlation analysis of two basic flood hydrograph parameters – maximum hydrograph ordinate (peak) and flood wave volume. The PROIL model is used to define the probability of simultaneous occurrence of these parameters. It defines the exceedance probability of two random variables, in the specific case two hydrograph parameters of the form: P{Qmax more equal to qmax,p)∩(Wmax more equal to wmax,p)} = P (1) where: Qmax – maximum hydrograph ordinate (peak); qmax,p – maximum discharge of the probability of occurrence p; Wmax – maximum hydrograph volume; wmax,p – maximum flood wave volume of the probability of occurrence p; P – exceedance probability. Spatial positions of the lines of exceedance of two flood hydrograph parameters and the empirical points of the corresponding parameters of the considered historic flood in the correlation field Qmax - Wmax, allow direct assessment of the exceedance probability of a historic flood, or its statistical significance. The proposed procedure was applied in practice to assess the statistical significance of the biggest floods registered along the Danube in the sector from its mouth to the Djerdap 1 Dam. The linear trend in the time-series of maximum annual flows at a representative hydrological station and the frequency of historic floods in the considered sector of the Danube are discussed at the end of the paper.


2019 ◽  
Vol 3 (4) ◽  
pp. 250-252 ◽  
Author(s):  
David M Hille

ObjectiveTo identify changes in the linear trend of the age-standardized incidence of melanoma in Australia for all persons, males, and females. MethodsA two-piece piecewise linear regression was fitted to the data. The piecewise breakpoint varied through an iterative process to determine the model that best fits the data.ResultsStatistically significant changes in the trendof the age-standardized incidence of melanoma in Australia were found for all persons, males, and females. The optimal breakpoint for all persons and males was at 1998. For females, the optimal breakpoint was at 2005. The trend after these breakpoints was flatter than prior to the breakpoints, but still positive.ConclusionMelanoma is a significant public health issue in Australia. Overall incidence continues to increase. However, the rate at which the incidence is increasing appears to be decreasing.


2015 ◽  
Vol 15 (2) ◽  
pp. 37-52
Author(s):  
Mahpud Sujai

This paper is intended to analyze the effect of oil price changes on potential output and actual output in the state budget cycle and identifies the output gap which is the difference between potential output and actual output. The research methodology uses a quantitative approach to analyze problems that occur related to the impact of oil price changes to the state budget cycle. Data analysis was carried out through the approach cyclically adjusted fiscal balance with a simplified approach. This research identified that the potential output is likely to continue increasing in line with Indonesia's oil price trends which is continue to rise following the world oil price movements. In calculating the output gap using a linear trend and HP filter, the result is fuctuating depend on the percentage changes in both potential output and actual output. This paper concludes that Indonesian oil price (ICP) has a significant impact on changes in the state budget cycle. If oil prices rise, the output gap between potential output and actual output is greater, and vice versa. This will make the budget vulnerable to shock that occurs as an external infuence.


Author(s):  
Евгений Николаевич Коровин ◽  
Юлия Викторовна Сиромашенко ◽  
Владимир Николаевич Коровин

В статье приведены анализ и прогнозирование основных статистических показателей, характеризующих развитие эпидемической ситуации по вирусу иммунодефицита человека (ВИЧ) в Воронежской области, а именно распределение по путям инфицирования. В качестве данных для прогнозирования были использованы показатели заболеваемости прошлых лет. Применяемый метод прогнозирования основан на методах экстраполяции. Все методы экстраполяции объединяет то, что они проецируют на будущее ход событий, сложившийся в прошлом. При этом не устанавливаются никакие причинные связи - принимается, что действующие в прошлом силы без существенных изменений будут действовать и в будущем. При формировании прогнозов с помощью экстраполяции исходят из статистически складывающихся тенденций изменения тех или иных количественных характеристик объекта за определённый период. Прогнозирование заболеваемости ВИЧ осуществляется с помощью метода экспоненциального сглаживания с использованием линейного тренда и выбором оптимальных параметров сглаживания. Трендом называют аналитическое или графическое представление изменения переменной во времени, полученное в результате выделения регулярной (систематической) составляющей динамического ряда. Основной целью анализа и прогнозирования является выявление основных тенденций по распространению ВИЧ-инфекции, определение основных путей инфицирование, а также выделение ключевых групп риска среди населения Воронежской области The article analyzes and predicts the main statistical indicators that characterize the development of the epidemic situation of human immunodeficiency virus (HIV) in the Voronezh region, namely, the distribution by infection pathways. Previous years ' morbidity rates were used as data for forecasting. The applied forecasting method is based on extrapolation methods. What all extrapolation methods have in common is that they project the course of events in the past into the future. At the same time, no causal relationships are established - it is assumed that the forces operating in the past will continue to operate in the future without significant changes. When forming forecasts using extrapolation, they are based on statistically developing trends in changes in certain quantitative characteristics of an object over a certain period. Predicting the incidence of HIV is carried out using the exponential smoothing method using a linear trend and choosing the optimal smoothing parameters. A trend is an analytical or graphical representation of changes in a variable over time, resulting from the allocation of a regular (systematic) component of a dynamic series. The main goal of the analysis and forecasting is to identify the main trends in the spread of HIV infection, identify the main routes of infection, and identify key risk groups among the population of the Voronezh region


2013 ◽  
Vol 31 (3) ◽  
pp. 413 ◽  
Author(s):  
André Becker Nunes ◽  
Gilson Carlos Da Silva

ABSTRACT. The eastern region of Santa Catarina State (Brazil) has an important history of natural disasters due to extreme rainfall events. Floods and landslides are enhancedby local features such as orography and urbanization: the replacement of natural surface coverage causing more surface runoff and, hence, flooding. Thus, studies of this type of events – which directly influence life in the towns – take on increasing importance. This work makes a quantitative analysis of occurrences of extreme rainfall events in the eastern and northern regions of Santa Catarina State in the last 60 years, through individual analysis, considering the history of floods ineach selected town, as well as an estimate through to the end of century following regional climate modeling. A positive linear trend, in most of the towns studied, was observed in the results, indicating greater frequency of these events in recent decades, and the HadRM3P climate model shows a heterogeneous increase of events for all towns in the period from 2071 to 2100.Keywords: floods, climate modeling, linear trend. RESUMO. A região leste do Estado de Santa Catarina tem um importante histórico de desastres naturais ocasionados por eventos extremos de precipitação. Inundações e deslizamentos de terra são potencializados pelo relevo acidentado e pela urbanização das cidades da região: a vegetação nativa vem sendo removida acarretando um maior escoamento superficial e, consequentemente, em inundações. Desta forma, torna-se de suma importância os estudos acerca deste tipo de evento que influencia diretamente a sociedade em geral. Neste trabalho é realizada uma análise quantitativa do número de eventos severos de precipitação ocorridos nas regiões leste e norte de Santa Catarina dos últimos 60 anos, por meio de uma análise pontual, considerandoo histórico de inundações de cada cidade selecionada, além de uma projeção para o fim do século de acordo com modelagem climática regional. Na análise dos resultados observou-se uma tendência linear positiva na maioria das cidades, indicando uma maior frequência deste tipo de evento nas últimas décadas, e o modelo climático HadRM3P mostra um aumento heterogêneo no número de eventos para todas as cidades no período de 2071 a 2100.Palavras-chave: inundações, modelagem climática, tendência linear.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 205-206
Author(s):  
Kenneth Lam ◽  
Siqi Gan ◽  
Bocheng Jing ◽  
Brian Nguyen ◽  
Sei Lee

Abstract The American Medical Directors Association and the American Diabetes Association discourage the use of sliding scale insulin (SSI) in nursing home residents with diabetes due to its association with hypoglycemia, hyperglycemia, nursing burden, and patient discomfort. However, prevalence of SSI use is unclear. We used Veterans Affairs (VA) data from October 2013 to September 2016 to determine the weekly prevalence of SSI among 22,847 veterans with diabetes admitted to VA nursing homes (NHs). Average age was 75.3 (SD 8.3) years, mean A1c was 7.3% (SD 1.6%) and 57% were admitted from hospital. We first identified residents receiving any short-acting insulin. We then classified short-acting insulin use into three mutually exclusive regimens: (1) fixed scheduled doses, (2) SSI, defined as a variable dose of short-acting insulin without a concurrent fixed dose or (3) bolus with correction (BWC), defined as a variable dose given concurrently with a fixed dose that day. During the first week of NH admission, 64.7% of residents with diabetes received no short-acting insulin, 7.4% received fixed scheduled doses, 6.3% received BWC and 21.4% were on SSI. At week 12, the prevalence of fixed dose and BWC regimens was unchanged from baseline (fixed dose = 8.4%; BWC = 7.0%). In contrast, the prevalence of SSI decreased weekly to 15.8% (p for linear trend < 0.0001). Although SSI prevalence decreased from week 1 to week 12, 51% of residents on short-acting insulin were still using SSI in their 12th week of their NH stay.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sébastien Czernichow ◽  
Adeline Renuy ◽  
Claire Rives-Lange ◽  
Claire Carette ◽  
Guillaume Airagnes ◽  
...  

AbstractThis study provides trends in obesity prevalence in adults from 2013 to 2016 in France. 63,582 men and women from independent samples upon inclusion from the Constances cohort were included. Anthropometrics were measured at Health Screening Centers and obesity defined as a Body mass index (BMI) ≥ 30 kg/m2; obesity classes according to BMI are as follows: class 1 [30–34.9]; class 2 [35–39.9]; class 3 [≥ 40 kg/m2]. Linear trends across obesity classes by sex and age groups were examined in regression models and percentage point change from 2013 to 2016 for each age category calculated. All analyses accounted for sample weights for non-response, age and sex-calibrated to the French population. Prevalence of obesity ranged from 14.2 to 15.2% and from 14 to 15.3% in women and men respectively from 2013 to 2016. Class 1 obesity category prevalence was the only one to increase significantly across survey years in both men and women (p for linear trend = 0.04 and 0.01 in women and men respectively). The only significant increase for obesity was observed in the age group 18–29 y in both women and men (+ 2.71% and + 3.26% point increase respectively, equivalent to an approximate rise of 50% in women and 93% in men, p = 0.03 and 0.02 respectively). After adjustment for survey non-response and for age and sex distribution, the results show that class 1 obesity prevalence has significantly increased in both women and men from 2013 to 2016, and only in young adults in a representative sample of the French population aged 18–69 years old.


Author(s):  
Kingsley Okoye ◽  
Jorge Alfonso Rodriguez-Tort ◽  
Jose Escamilla ◽  
Samira Hosseini

AbstractThe COVID-19 pandemic has disrupted many areas of the human and organizational ventures worldwide. This includes new innovative technologies and strategies being developed by educators to foster the rapid learning-recovery and reinstatement of the stakeholders (e.g., teachers and students). Indeed, the main challenge for educators has been on what appropriate steps should be taken to prevent learning loss for the students; ranging from how to provide efficient learning tools/curriculum that ensures continuity of learning, to provision of methods that incorporate coping mechanisms and acceleration of education in general. For several higher educational institutions (HEIs), technology-mediated education has become an integral part of the modern teaching/learning instruction amidst the Covid-19 pandemic, when digital technologies have consequently become an inevitable and indispensable part of learning. To this effect, this study defines a hybrid educational model (HyFlex + Tec) used to enable virtual and in-person education in the HEIs. Practically, the study utilized data usage report from Massive Open Online Courses (MOOCs) and Emotions and Experience Survey questionnaire in a higher education setting for its experiments. To this end, we applied an Exponential Linear trend model and Forecasting method to determine overall progress and statistics for the learners during the Covid-19 pandemic, and subsequently performed a Text Mining and Univariate Analysis of Variance (ANOVA) to determine effects and significant differences that the teaching–learning experiences for the teachers and students have on their energy (learning motivation) levels. From the results, we note that the hybrid learning model supports continuity of education/learning for teachers and students during the Covid-19 pandemic. The study also discusses its innovative importance for future monitoring (tracking) of learning experiences and emotional well-being for the stakeholders in leu (aftermath) of the Covid-19 pandemic.


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