scholarly journals Agricultural Supply Chain Risk Management Under Price and Demand Uncertainty

2021 ◽  
Vol 10 (2) ◽  
pp. 17-32
Author(s):  
Pritee Ray

Agricultural supply chain (ASC) plays a vital role for sustainability as it is the main source of food supply. ASC encounters more sources of risk due to seasonality, perishability, and weather conditions, which makes the global food security system complex. This paper develops an optimization model for a perishable product supply chain to decide the optimal risk management strategy that maximizes the decision maker's expected profit under demand and price uncertainty. A base-case scenario is considered to show the impact of risk management strategy on performance improvement. The expected profit of the decision maker is obtained for different combination of strategies, and sensitivity analysis is performed to show the impact of perishability on the percentage of improvement from the base case scenario. The results show that backup supplier strategy is very effective during the yield disruption, but it is not as effective during harvest disruption. Hence, a single approach is inadequate to provide solution in all types of risk scenarios; thus, the combination of approaches is most effective.

2009 ◽  
Vol 13 (1) ◽  
pp. 69-77 ◽  
Author(s):  
E. Kalbus ◽  
C. Schmidt ◽  
J. W. Molson ◽  
F. Reinstorf ◽  
M. Schirmer

Abstract. The spatial distribution of groundwater fluxes through a streambed can be highly variable, most often resulting from a heterogeneous distribution of aquifer and streambed permeabilities along the flow pathways. Using a groundwater flow and heat transport model, we defined four scenarios of aquifer and streambed permeability distributions to simulate and assess the impact of subsurface heterogeneity on the distribution of groundwater fluxes through the streambed: (a) a homogeneous low-K streambed within a heterogeneous aquifer; (b) a heterogeneous streambed within a homogeneous aquifer; (c) a well connected heterogeneous low-K streambed within a heterogeneous aquifer; and (d) a poorly connected heterogeneous low-K streambed within a heterogeneous aquifer. The simulation results were compared with a base case scenario, in which the streambed had the same properties as the aquifer, and with observed data. The results indicated that the aquifer has a stronger influence on the distribution of groundwater fluxes through the streambed than the streambed itself. However, a homogeneous low-K streambed, a case often implemented in regional-scale groundwater flow models, resulted in a strong homogenization of fluxes, which may have important implications for the estimation of peak mass flows. The flux distributions simulated with heterogeneous low-K streambeds were similar to the flux distributions of the base case scenario, despite the lower permeability. The representation of heterogeneous distributions of aquifer and streambed properties in the model has been proven to be beneficial for the accuracy of flow simulations.


Author(s):  
Mariam El Hiri ◽  
Abdelali En-Nadi ◽  
Anas Chafi

The big challenge for each company is the implementation of an appropriate risk management strategy. Through this work, we seek to draw up an inventory of Moroccan companies supply chain. The objective is to identify the main risks, their relationship with the performance of the supply chain and to establish an overview of the risk management systems. For this reason, a research model was developed and concretized by quantitative data collected from 29 Moroccan companies. The analysis of the data show that the performance of the supply chain is strongly influenced by the importance of supply chain risk in particular the supplier and demand risks, and leads to insist on the importance of integrating a device adapted to the management of these Risks, especially in the upstream part of the supply chain.


Author(s):  
Trystan Leng ◽  
Connor White ◽  
Joe Hilton ◽  
Adam Kucharski ◽  
Lorenzo Pellis ◽  
...  

AbstractBackgroundDuring the Covid-19 lockdown, contact clustering in social bubbles may allow extending contacts beyond the household at minimal additional risk and hence has been considered as part of modified lockdown policy or a gradual lockdown exit strategy. We estimated the impact of such strategies on epidemic and mortality risk using the UK as a case study.MethodsWe used an individual based model for a synthetic population similar to the UK, that is stratified into transmission risks from the community, within the household and from other households in the same social bubble. The base case considers a situation where non-essential shops and schools are closed, the secondary household attack rate is 20% and the initial reproduction number is 0.8. We simulate a number of strategies including variations of social bubbles, i.e. the forming of exclusive pairs of households, for particular subsets of households (households including children and single occupancy households), as well as for all households. We test the sensitivity of the results to a range of alternative model assumptions and parameters.ResultsClustering contacts outside the household into exclusive social bubbles is an effective strategy of increasing contacts while limiting some of the associated increase in epidemic risk. In the base case scenario social bubbles reduced cases and fatalities by 17% compared to an unclustered increase of contacts. We find that if all households were to form social bubbles the reproduction number would likely increase to 1.1 and therefore beyond the epidemic threshold of one. However, strategies that allow households with young children or single occupancy households to form social bubbles only increased the reproduction number by less than 10%. The corresponding increase in morbidity and mortality is proportional to the increase in the epidemic risk but is largely focussed in older adults independently of whether these are included in the social bubbles.ConclusionsSocial bubbles can be an effective way of extending contacts beyond the household limiting the increase in epidemic risk, if managed appropriately.


2021 ◽  
Author(s):  
Rojhat Ibrahim ◽  
Bálint Baranyai

AbstractNatural and man-made disasters are vital issues that led to the increasing number of migrants, many of them stayed displaced for decades this requires more permanent dwellings. The main aim of the study is to investigate the impact of the bottom-up construction method on developing migrant’s shelters energy and thermal comfort performance. Dynamic simulation tool Indoor Climate and Energy (IDA ICE 4.8) has been used to assess nine different scenarios. The results quantified that the annually delivered energy and thermal comfort accepted hours of proposed scenario nine (S9) is better compared to base-case scenario one (S1) by 63% kWh and 4,215 h respectively. Methodologies and results of this paper can be adopted and applied for various places of the world affected by migration issue.


2021 ◽  
Author(s):  
Chloe Bracis ◽  
Mia Moore ◽  
David A Swan ◽  
Laura Matrajt ◽  
Larissa Anderson ◽  
...  

Background: The mass rollout of COVID vaccination in early 2021 allowed local and state authorities to relax mobility and social interaction regulations in spring 2021 including lifting all restrictions for vaccinated people and restoring in-person schooling. However, the emergence and rapid spread of highly transmissible variants combined with slowing down the pace of vaccination created uncertainty around the future trajectory of the epidemic. In this study we analyze the expected benefits of offering vaccination to children age 5-11 under differing conditions for in-person schooling. Methods: We adapted a mathematical model of SARS-CoV-2 transmission, calibrated to data from King County, Washington, to handle multiple variants with increased transmissibility and virulence as well as differential vaccine efficacies against each variant. Reactive social distancing is implemented driven by fluctuations in the number of hospitalizations in the county. We simulate scenarios offering vaccination to children aged 5-11 with different starting dates and different proportions of physical interactions (PPI) in schools being restored. The impact of improving overall vaccination coverage among the eligible population is also explored. Cumulative hospitalizations, percentage reduction of hospitalizations and proportion of time at maximum social distancing over the 2021-2022 school year are reported. Findings: In the base-case scenario with 85% vaccination coverage of 12+ year-olds, our model projects 4945 (median, IQR 4622-5341) total COVID-19 hospitalizations and 325 (median, IQR 264-400) pediatric hospitalizations if physical contacts at schools are fully restored (100% PPI) for the entire school year compared to 3675 (median, IQR 2311-4725) and 163 (median, IQR 95-226) if schools remained closed. Reducing contacts in schools to 75% PPI or 50% PPI through masking, ventilation and distancing is expected to decrease the overall cumulative hospitalizations by 2% and 4% respectively and youth hospitalizations by 8% and 23% respectively. Offering early vaccination to children aged 5-11 with 75% PPI is expected to prevent 756 (median, IQR 301-1434) hospitalizations and cut hospitalizations in the youngest age group in half compared to no vaccination. It will largely reduce the need of additional social distancing over the school year. If, in addition, 90% overall vaccination coverage is reached, 60% of remaining hospitalizations will be averted and the need of extra mitigation measures almost certainly avoided. Conclusions: Our work highlights that in-person schooling is possible if reasonable precaution measures are taken at schools to reduced infectious contacts. Rapid vaccination of all school-aged children will provide meaningful reduction of the COVID health burden over this school year but only if implemented early. Finally, it remains critical to vaccinate as many people as possible to limit the morbidity and mortality associated with the current surge in Delta variant cases.


2016 ◽  
Vol 23 ◽  
pp. 20
Author(s):  
Odia Bintou Cissé

On June 27, 2013, the Senate passed the Border Security, Economic Opportunity, and Immigration Modernization Act of 2013 (referred to as S.744). The bill addresses key elements of the immigration process through five sections. This analysis serves as an ex-ante Cost-Benefit Analysis (CBA) of the proposed Registered Provisional Immigrant (RPI) program under Section II of S.744, which would allow undocumented immigrants in the US to obtain legal status. The CBA looks at a 10-year timeframe from 2015 through 2025 and estimates the costs and benefits to four groups: undocumented immigrants, US taxpayers, employers of undocumented immigrants, and the United States Citizenship and Immigration Services (USCIS) under a base case scenario, a distributional weight scenario, and a worst-case scenario. Given the positive net benefits observed under the three scenarios, significant evidence recommends the implementation of the RPI program.


2018 ◽  
Author(s):  
Albert Jan van Hoek ◽  
Mirjam Knol ◽  
Hester de Melker ◽  
Jacco Wallinga

AbstractBackgroundThere is a developing outbreak of Neisseria meningitidis serotype W (MenW) in the Netherlands. In response, those aged 14 months and 14 years are vaccinated with the conjugated MenACWY vaccine. In the spring of 2018 we aimed to explore the impact of adding a one-off catch-up campaign targeting those aged 15-18 years on the transmission of MenW and the cost-effectiveness of such a campaign.MethodsWe estimated the growth rate of the MenW outbreak and quantified the impact of various targeted vaccination strategies on the reproductive number, and subsequently projected the future incidence with and without vaccination. Future cases were expressed in costs and QALYS and the incremental cost-effectiveness ratio was obtained.ResultsWe estimate a reproductive number of around 1.4 (95%CI 1.2-1.7) over the period February 2016-February 2018. Adding the catch-up campaign reduces the reproductive number five years earlier than without a catch-up campaign, to a level around 1.2. The vaccination campaign, including the catch-up, will prevent around 100 cases per year in our base case scenario. Given the projected impact and realistic assumptions on costs and QALYs, adding the catch-up can be considered cost-effective using a threshold of €20,000 per QALY.ConclusionAdding the catch-up campaign targeting those aged 15-18 brings the impact of vaccination on reducing transmission five years forward and directly prevents a high-incidence age group from carriage and disease. Such a campaign can be considered cost-effective. Our study did underpin the decision to introduce a catch-up campaign in spring 2019. Furthermore, our applied method can be of interest for anyone solving vaccine allocation questions in a developing outbreak.


2022 ◽  
Vol 13 (1) ◽  
pp. 15
Author(s):  
Tim Jonas ◽  
Christopher D. Hunter ◽  
Gretchen A. Macht

While the influence of several factors on battery electric vehicle (BEV) efficiency has been investigated in the past, their impact on traffic is not yet fully understood, especially when driving in a natural environment. This paper investigates the influence of driving in intense traffic conditions while considering the ambient temperature and driving behavior on BEV energy efficiency in a field study. A total of 30 BEV inexperienced drivers test drove a 2017 Volkswagen eGolf on a route with various road types in two different traffic intensity scenarios: During morning commute hours with higher traffic congestion and lower congestion hours throughout the middle of the day. Results support the hypothesis that traffic conditions significantly impact the vehicle’s efficiency, with additional consumption of approximately 4–5% in the high traffic scenario. By creating and comparing driving in traffic to an underlying base case scenario, the additional range potential by avoiding traffic for this particular vehicle can be quantified as up to seven miles. New patterns of BEV efficiencies emerged, which can help stakeholders understand how eco-driving can be strategically improved by selecting trip times and routes that avoid high traffic intensity.


TEME ◽  
2017 ◽  
pp. 489
Author(s):  
Aleksandra Anđelković ◽  
Nada Barac ◽  
Marija Radosavljević

In the modern business environment risk management has become a key assistant to enterprise management. Considering that, supply chain management, as part of enterprise management, cannot ignore the risks and the need for implementation of an adequate risk management strategy. Supply chain, as well as inter-organizational network, is the source of competitive advantage. However, inadequate risk management within a supply chain can lead to interruptions of the chain and to the lack of results at the level of the whole supply chain, as well as at the level of individual partners. Upstream supply chain represents the part of supply chain from suppliers to producer. The objective of this paper is to analyse how and to what extent the structure and the number of partners in this part of the supply chain influence (increase or decrease) supply chain vulnerability. The authors analyse the factors which most commonly affect to upstream supply chain and threaten its functioning. By analysing the supply chains from different area, the authors suggest that the size of the supplier's base can be treated as the resistance factor, but also as a factor of vulnerability.


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