Alternative scenarios

2015 ◽  
Author(s):  
Constance Lever-Tracy
Keyword(s):  
Alternative Scenarios

Impact of COVID-19 on India: alternative scenarios for economic and social development

2021 ◽  
Vol 26 (2) ◽  
pp. 319-343
Author(s):  
Purnamita Dasgupta ◽  
Manoj Panda ◽  
Rohan Bansal ◽  
Samraj Sahay
Keyword(s):  
Social Development ◽  
Alternative Scenarios

scholarly journals Spectral index-flux relation for investigating the origins of steep decay in γ-ray bursts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Samuele Ronchini ◽  
Gor Oganesyan ◽  
Marica Branchesi ◽  
Stefano Ascenzi ◽  
Maria Grazia Bernardini ◽  
...  
Keyword(s):  
Spectral Index ◽  
Proton Synchrotron ◽  
Relativistic Jets ◽  
Time Resolved ◽  
X Ray ◽  
Compact Binary ◽  
Internal Dissipation ◽  
Adiabatic Cooling ◽  
Alternative Scenarios ◽  
Steep Decay

Abstractγ-ray bursts (GRBs) are short-lived transients releasing a large amount of energy (1051 − 1053 erg) in the keV-MeV energy range. GRBs are thought to originate from internal dissipation of the energy carried by ultra-relativistic jets launched by the remnant of a massive star’s death or a compact binary coalescence. While thousands of GRBs have been observed over the last thirty years, we still have an incomplete understanding of where and how the radiation is generated in the jet. Here we show a relation between the spectral index and the flux found by investigating the X-ray tails of bright GRB pulses via time-resolved spectral analysis. This relation is incompatible with the long standing scenario which invokes the delayed arrival of photons from high-latitude parts of the jet. While the alternative scenarios cannot be firmly excluded, the adiabatic cooling of the emitting particles is the most plausible explanation for the discovered relation, suggesting a proton-synchrotron origin of the GRB emission.

scholarly journals Combining regional to local restoration goals in the Brazilian Atlantic forest

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Cassia M.G. Lemos ◽  
Pedro R. Andrade ◽  
Ricardo R. Rodrigues ◽  
Leticia Hissa ◽  
Ana P. D. Aguiar
Keyword(s):  
Cost Effectiveness ◽  
Atlantic Forest ◽  
Natural Regeneration ◽  
Regional Level ◽  
Target Area ◽  
Brazilian Atlantic Forest ◽  
Regeneration Potential ◽  
Allocation Model ◽  
Alternative Scenarios ◽  
The Cost

AbstractTo achieve regional and international large-scale restoration goals with minimum costs, several restoration commitments rely on natural regeneration, a passive and inexpensive strategy. However, natural regeneration potential may vary within the landscape, mainly due to its historical context. In this work, we use spatially explicit restoration scenarios to explore how and where, within a given region, multiple restoration commitments could be combined to achieve cost-effectiveness outcomes. Our goal is to facilitate the elaboration of forest restoration plans at the regional level, taking into consideration the costs for active and passive restoration methods. The approach includes (1) a statistical analysis to estimate the natural regeneration potential for a given area based on alternative sets of biophysical, land cover, and/or socioeconomic factors and (2) the use of a land change allocation model to explore the cost-effectiveness of combining multiple restoration commitments in a given area through alternative scenarios. We test our approach in a strategic region in the Brazilian Atlantic Forest Biome, the Paraiba Valley in São Paulo State. Using the available data for 2011, calibrated for 2015, we build alternative scenarios for allocating natural regeneration until 2025. Our models indicate that the natural regeneration potential of the region is actually very low, and the cost-effectiveness outcomes are similar for all scenarios. We believe our approach can be used to support the regional-level decision-making about the implementation of multiple commitments aiming at the same target area. It can also be combined with other approaches for more refined analysis (e.g., optimization models).

scholarly journals A Metro-Based System as Sustainable Alternative for Urban Logistics in the Era of E-Commerce

2021 ◽  
Vol 13 (8) ◽  
pp. 4479
Author(s):  
Rafael Villa ◽  
Andrés Monzón
Keyword(s):  
Traffic Congestion ◽  
Ghg Emissions ◽  
Distribution Model ◽  
Rolling Stock ◽  
Load Optimization ◽  
Big City ◽  
Train Services ◽  
Delivery Services ◽  
Business To Consumer ◽  
Alternative Scenarios

Business to consumer e-commerce (B2C) has increased sharply in recent years driven by a growing online population and changes in consumer behavior. In metropolitan areas, the “Amazon effect” (online retailers’ vast selection, fast shipping, free returns, and low prices) has led to an increased use of light goods vehicles. This is affecting the rational functioning of the transport system, including a high degree of fragmentation, low load optimization, and, among other externalities, higher traffic congestion. This paper investigates the potential of a metro system, in a big city like Madrid, to provide delivery services by leveraging its existing carrying capacity and using the metro stations to collect parcels in lockers. It would be a new mixed distribution model for last-mile deliveries associated with e-commerce. To that end, the paper evaluates the cost and impacts of two alternative scenarios for managing the unused space in rolling stock (shared trains) or specific full train services (dedicated trains) on existing lines. The external costs of the proposed scenarios are compared with current e-commerce delivery scenario (parcel delivery by road). The results show that underground transport of parcels could significantly reduce congestion costs, accidents, noise, GHG emissions, and air pollution.

scholarly journals Coping with Criticism and Embracing Change—Further Reflexions on the Debate on a Mental Health Care System without Coercion

Laws ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 22
Author(s):  
Sebastian von Peter ◽  
Martin Zinkler
Keyword(s):  
Mental Health ◽  
Health Care ◽  
Mental Health Care ◽  
Health Care System ◽  
Police Custody ◽  
Judicial Control ◽  
Mental Health Care System ◽  
The Will ◽  
Alternative Scenarios ◽  
Care System

In August 2019, a manuscript was published in this journal that aimed at imagining a mental health care system that renounces the judicial control to better focus on the will and preferences of those who require support. Alternative scenarios for dealing with risk, inpatient care, and police custody were presented that elicited strong and emotionally laden reactions. This article adds further reflections to this debate, aiming at contributing explanations for this unsettlement. A productive notion of criticism is discussed, and ways to achieve change toward a more human rights-oriented psychiatric practice are outlined.

scholarly journals Predictive performance of international COVID-19 mortality forecasting models

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joseph Friedman ◽  
Patrick Liu ◽  
Christopher E. Troeger ◽  
Austin Carter ◽  
Robert C. Reiner ◽  
...  
Keyword(s):  
Predictive Performance ◽  
Absolute Error ◽  
Decision Makers ◽  
Government Interventions ◽  
World Region ◽  
Mortality Forecasting ◽  
Forecasting Models ◽  
Pandemic Response ◽  
Alternative Scenarios ◽  
Absolute Percent Error

AbstractForecasts and alternative scenarios of COVID-19 mortality have been critical inputs for pandemic response efforts, and decision-makers need information about predictive performance. We screen n = 386 public COVID-19 forecasting models, identifying n = 7 that are global in scope and provide public, date-versioned forecasts. We examine their predictive performance for mortality by weeks of extrapolation, world region, and estimation month. We additionally assess prediction of the timing of peak daily mortality. Globally, models released in October show a median absolute percent error (MAPE) of 7 to 13% at six weeks, reflecting surprisingly good performance despite the complexities of modelling human behavioural responses and government interventions. Median absolute error for peak timing increased from 8 days at one week of forecasting to 29 days at eight weeks and is similar for first and subsequent peaks. The framework and public codebase (https://github.com/pyliu47/covidcompare) can be used to compare predictions and evaluate predictive performance going forward.

scholarly journals Modelling improved efficiency in healthcare referral systems for the urban poor using a geo-referenced health facility data: the case of Sylhet City Corporation, Bangladesh

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Alayne M. Adams ◽  
Rushdia Ahmed ◽  
Shakil Ahmed ◽  
Sifat Shahana Yusuf ◽  
Rubana Islam ◽  
...  
Keyword(s):  
Critical Care ◽  
Urban Poor ◽  
Emergency Services ◽  
Census Data ◽  
Service Providers ◽  
Healthcare Services ◽  
Tertiary Hospital ◽  
Care Services ◽  
Referral Systems ◽  
Alternative Scenarios

Abstract Background An effective referral system is critical to ensuring access to appropriate and timely healthcare services. In pluralistic healthcare systems such as Bangladesh, referral inefficiencies due to distance, diversion to inappropriate facilities and unsuitable hours of service are common, particularly for the urban poor. This study explores the reported referral networks of urban facilities and models alternative scenarios that increase referral efficiency in terms of distance and service hours. Methods Road network and geo-referenced facility census data from Sylhet City Corporation were used to examine referral linkages between public, private and NGO facilities for maternal and emergency/critical care services, respectively. Geographic distances were calculated using ArcGIS Network Analyst extension through a “distance matrix” which was imported into a relational database. For each reported referral linkage, an alternative referral destination was identified that provided the same service at a closer distance as indicated by facility geo-location and distance analysis. Independent sample t-tests with unequal variances were performed to analyze differences in distance for each alternate scenario modelled. Results The large majority of reported referrals were received by public facilities. Taking into account distance, cost and hours of service, alternative scenarios for emergency services can augment referral efficiencies by 1.5–1.9 km (p < 0.05) compared to 2.5–2.7 km in the current scenario. For maternal health services, modeled alternate referrals enabled greater referral efficiency if directed to private and NGO-managed facilities, while still ensuring availability after working-hours. These referral alternatives also decreased the burden on Sylhet City’s major public tertiary hospital, where most referrals were directed. Nevertheless, associated costs may be disadvantageous for the urban poor. Conclusions For both maternal and emergency/critical care services, significant distance reductions can be achieved for public, NGO and private facilities that avert burden on Sylhet City’s largest public tertiary hospital. GIS-informed analyses can help strengthen coordination between service providers and contribute to more effective and equitable referral systems in Bangladesh and similar countries.

scholarly journals Risks inherent in the digital surveillance economy: A research agenda

2019 ◽  
Vol 34 (1) ◽  
pp. 59-80 ◽  
Author(s):  
Roger Clarke
Keyword(s):  
Research Agenda ◽  
Personal Data ◽  
Social Dimension ◽  
Goods And Services ◽  
Digital Surveillance ◽  
The Social ◽  
Alternative Scenarios ◽  
Negative Impacts ◽  
Surveillance Society ◽  
New Phase

The digitisation of data about the world relevant to business has given rise to a new phase of digitalisation of business itself. The digitisation of data about people has linked with the notions of information society, surveillance society, surveillance state and surveillance capitalism, and given rise to what is referred to in this article as the digital surveillance economy. At the heart of this is a new form of business model that is predicated on the acquisition and consolidation of very large volumes of personal data, and its exploitation to target advertisements, manipulate consumer behaviour, and price goods and services at the highest level that each individual is willing to bear. In the words of the model’s architects, users are ‘bribed’ and ‘induced’ to make their data available at minimal cost to marketers. The digital surveillance economy harbours serious threats to the interests of individuals, societies and polities. That in turn creates risks for corporations. The new economic wave may prove to be a tsunami that swamps the social dimension and washes away the last five centuries’ individualism and humanism. Alternatively, institutional adaptation might occur, overcoming the worst of the negative impacts; or a breaking-point could be reached and consumers might rebel against corporate domination. A research agenda is proposed, to provide a framework within which alternative scenarios can be investigated.

Mobility-as-a-Service: Simulation of Multi-Modal Operations in Low-Density Cities

2021 ◽  
pp. 036119812110398
Author(s):  
Mohamed El-Agroudy ◽  
Hatem Abou-Senna ◽  
Essam Radwan
Keyword(s):  
Performance Measures ◽  
Magic Bullet ◽  
Low Density ◽  
The Novel ◽  
Review Of The Literature ◽  
Modal Interactions ◽  
New Approach ◽  
Novel Interactions ◽  
Alternative Scenarios ◽  
Urban Characteristics

In the case of the low-density city, empirical evidence continuously demonstrates that transit investment is not a magic bullet. Desirable outcomes are not guaranteed and are often dependent on development density and other urban characteristics. Mobility-as-a-service (MaaS) presents a new approach: a digital platform providing access to multi-modal travel alternatives and totally comprehensive integrated trip-making, planning, and payment services. Review of the literature highlights shortcomings in traditional transportation planning by examining aspects of multi-modal planning such as adoption, parterships, operations, integration, capacity implications, and impact analyses. To enhance the practice of multi-modal planning, the following experiment evaluates various performance measures and inter-modal interactions on International Drive in Orlando, Florida, U.S., via D- and I-optimal experimental designs in a simulated MaaS network. Alternative scenarios are developed comparing varied modal shares across five travel modes: personal vehicles, transit, ridesourcing (or ride-hailing), micro-mobility, and walking. The modal effects are analyzed to highlight the strengths and weakness of each mode under a variety of congestion conditions. While transit enjoys the lowest impact per person, ridesourcing demonstrates adverse effects across all measures. Based on the novel interactions of transit and ridesourcing with directional demand, strategies are outlined for optimizing ridesourcing-transit integration to reduce route travel time, queuing, and overall network delay. The performance impacts of curbside facilities are also discussed for improved multi-modal integration at the street level. These findings are applied to propose a framework for effective planning and implementation of mobility services in low-density cities, focused on operations, city-level connectivity, and curbside management.

Sign in / Sign up

Export Citation Format

Share Document