Design and initial validation of the Raster method for telecom service availability risk assessment

Crisis organisations depend on telecommunication services; unavailability of these services reduces the effectiveness of crisis response. Crisis organisations should therefore be aware of availability risks, and need a suitable risk assessment method. Such a method needs to be aware of the exceptional circumstances in which crisis organisations operate, and of the commercial structure of modern telecom services. We found that existing risk assessment methods are unsuitable for this problem domain. Hence, crisis organisations do not perform any risk assessment, trust their supplier, or rely on service level agreements, which are not meaningful during crisis situations. We have therefore developed a new risk assessment method, which we call RASTER. We have tested RASTER using a case study at the crisis organisation of a government agency, and improved the method based on the analysis of case results. Our initial validation suggests that the method can yield practical results

Constructing Restoration Strategies with Availability Risk Constraints

System restoration strategies are established and implemented based on the availabilities of components of a system. However, due to lack of accurate information, availabilities of some components may not be known during establishment of restoration strategies after a blackout. In this paper, a novel risk-based methodology is proposed for constructing restoration strategies with stochastic availability constraints for both individual components and restoration paths. Based on a stochastic model of the availability, a multistage stochastic optimization model is constructed. A bi-level method is used to solve the proposed model. The established restoration strategy is to achieve a reasonable restoration duration subjects to operating constraints and acceptable risk levels. The proposed risk constraints are introduced into the EPRI's System Restoration Navigator (SRN) with a little modification. Case studies demonstrate the proposed model and methods.published_or_final_versio

Food Insecurity, Food Storage, and Obesity

Although individuals with poor food security might be expected to have reduced food intake, and therefore a lower likelihood of being overweight, some empirical evidence has indicated that overweight status is actually more prevalent among the food insecure. As obesity is associated with excessive energy intake, and hunger reflects an inadequate food supply, such observations would appear to be paradoxical. We develop an economic model that shows that this apparently paradoxical result is consistent with rational behavior regarding food availability risk and the effectiveness of food storage options. The amount of internal storage increases as the variance of food productivity in the second period increases, which is consistent with the empirical observation of a positive relationship between food insecurity and the incidence of overweight.Food Security and Poverty,

Participation in Off-Farm Employment, Risk Preferences, and Weather Variability: The Case of Ethiopia

This article assesses the relative importance of risk preferences and rainfall availability on households’ decision to engage in off-farm employment. Devoting time for off-farm activities, while it helps households earn additional incomes, involves a number of uncertainties. Unique panel data from Ethiopia which includes experimentally generated risk preference measures combined with longitudinal rainfall data is used in the analysis. An off farm participation decision and activity choice showed that both variability and reduced availability of rainfall as well as neutral risk preferences increase the likelihood of off-farm participation. From policy perspective, the results imply that expanding off farm opportunities could act as safety nets in the face of weather uncertainty. In addition, policy initiatives geared towards encouraging income diversification through off farm employment need to address underlying factor that condition risk bearing ability of households.Off-farm employment, labor supply, rainfall variability/reduced availability, risk preferences, GLLAMM, Ethiopia, Labor and Human Capital, Q13, D81, C35, C93,

Modeling Water Availability, Risk and Resilience in a Semi-Arid Basin in Southern Africa

Climate variability need to be incorporated into the management and planning of water resources, particularly in arid and semi-arid regions, where water availability is more sensitive to rainfall and air temperature. This study used modified Man-Kendall trend analysis test and ArcGIS to process data. Annual means of rainfall, minimum temperature and maximum temperature in the Limpopo River Basin (LRB) varied between 160 and 1109 mm, 8 °C to 20 °C and 23 °C to 32 °C respectively. The spatial pattern is generally increasing from west to east for rainfall and minimum temperature while maximum temperature increases from south to north and west to east. Coefficient of variation (CV) shows an opposite pattern to the annual pattern, with rainfall showing the highest variation compared to other variables. Rainfall and minimum temperature showed an increasing pattern in most of the basin while maximum temperature showed a decreasing pattern. In-depth understanding of the hydrological processes is important for balancing availability and demand for water. As part of this basin-wide and the basin nations concern, this study examined blue and green freshwater availability and identified water sensitive areas by balancing water availability and demand for the Limpopo River Basin (LRB). The Soil and Water Assessment Tool (SWAT) model, calibrated at multiple locations in the basin for monthly streamflow simulation showed satisfactory results, given the scale and variability in physical characteristics of the basin. Spatial analysis showed a decreasing pattern in freshwater availability from east to west, and from north to south while temporal variation showed alternate episodes between wet and dry years, with deviations from the normal cycle every one to two years for the wet periods and three to five years for dry periods during the study period. 20% in the east of the basin show excess wetness while the rest of the basin is dry areas. Understanding the rate, timing, and location of groundwater recharge, groundwater levels and discharge characteristics are crucial for efficient development and management of groundwater resources, as well as for minimizing pollution risks to the aquifer and connected surface water resources. SWAT-MODFLOW was used to characterise the distribution of annual and seasonal groundwater recharge, groundwater level, groundwater–surface water interactions in the LRB from 1984 to 2013. The impacts of Low Impact Developments (LID’s) and Best Management Practices (BMP’s) on groundwater recharge and water table elevations were also assessed for the Gaborone catchment as a case study in the LRB. Simulation results show relatively high annual recharge along the Limpopo main river and at the outlet of the basin. The groundwater table is generally shallow in the rainy east and along the basin’s river network. Seasonal analysis reveals high variability in both groundwater recharge and level. The summer season has the highest groundwater recharge, followed by autumn, spring, and winter as the lowest recharge during the 30-year study period (1984 to 2013). Water table elevations are low in the summer and highest in the autumn. In terms of groundwater-surface water interactions, rivers in the south showed input from groundwater discharge while west river channels appeared to seep to the underlying aquifers. Implementation of the LID practices resulted in 0 to 6% increase in annual groundwater recharge and 0 to 0.11% increase in annual water table elevations

Online and Offline Information for Omnichannel Retailing

This paper studies how retailers can effectively deliver online and offline information to omnichannel consumers who strategically choose whether to gather information online or offline and whether to buy products online or offline. Information resolves two types of uncertainty: product value uncertainty (i.e., consumers realize valuations when they inspect the product in store, but may end up returning the product when they purchase online) and availability uncertainty (i.e., store visits are futile when consumers encounter stockouts). We consider three information mechanisms: physical showrooms allow consumers to learn valuations anytime they visit the store, even during stockouts; virtual showrooms give consumers online access to an imperfect signal of their valuations; availability information provides real-time information about whether the store has a product in stock. Our main results follow. First, physical showrooms may prompt retailers to reduce store inventory, which increases availability risk and discourages store patronage. Second, virtual showrooms may increase online returns and hurt profits, if they induce excessive customer migration from store to online channels. Third, availability information may be redundant when availability risk is low and may render physical showrooms ineffective when implemented jointly. Finally, when customers are homogeneous, these mechanisms may not exhibit significant complementarities and the optimal information structure may involve choosing only one of the three

Low Energy Availability Risk in Female Triathletes

Background: The highly complex syndromes of the Female Athlete Triad (Triad) and Relative Energy Deficiency in Sport (RED-S) are underpinned by low energy availability (LEA). LEA has been defined as the imbalance between dietary energy intake (EI) and exercise energy expenditure (EEE), leading to inadequate energy available to optimally support physiological function and health. Chronic LEA, with or without disordered eating (DE) or eating disorder (ED), has been associated with direct and indirect links to the development of menstrual disturbances and impaired bone health. It has also been proposed that chronic LEA may result in impairments to several other health (i.e., cardiovascular, endocrine) and performance (i.e., muscle strength, cognitive function), factors, however limited evidence exists to support these findings. Endurance sports athletes have been reported to be at an increased risk of developing LEA and the subsequent health and performance impairments due to high daily EEE. High daily EEE may arise from high training volumes and/or an increased risk of DE/ED, and/or an increased risk of exercise dependence (EXD). Although it has been accepted endurance athletes may be at an increased risk of developing LEA, to date limited data exists in female athletes particularly from multi-sport endurance athletes. Aim: The main purpose of this thesis was to investigate the prevalence of risk of LEA and associated risk factors (i.e., DE, ED, and EXD) in female triathletes

The private finance initiative (PFI) and finance capital: A note on gaps in the "accountability" debate

During recent years, a wide spectrum of research has questioned whether public services/infrastructure procurement through private finance, as exemplified by the UK Private Finance Initiative (PFI), meets minimum standard of democratic accountability. While broadly agreeing with some of these arguments, this paper suggests that this debate is flawed on two grounds. Firstly, PFI is not about effective procurement, or even about a pragmatic choice of procurement mechanisms which can potentially compromise public involvement and input; rather it is about a process where the state creates new profit opportunities at a time when the international financial system is increasingly lacking in safe investment opportunities. Secondly, because of its primary function as investment opportunity, PFI, by its very nature, prioritises the risk-return criteria of private finance over the needs of the public sector client and its stakeholders. Using two case studies of recent PFI projects, the paper illustrates some of the mechanisms through which finance capital exercises control over the PFI procurement process. The paper concludes that recent proposals aimed at “reforming” or “democratising” PFI fail to recognise the objective constraints which this type of state-finance capital nexus imposes on political process