A parametric insurance framework based on remote-sensing observations to mitigate drought impacts through risk financing

<p>Agricultural production is highly sensitive to extreme weather events such as droughts, floods and storms. According to the Food and Agriculture Organization, between 2005 and 2015 natural disasters cost the agricultural sectors of developing country economies a staggering $96 billion in damaged or lost crop and livestock production. Drought was one of the leading culprits. Eighty-three percent of all drought-caused economic losses documented by FAO's study were absorbed by agriculture, with a price tag of $29 billion. Since extreme droughts are expected to increase worldwide both in number and severity, the development of appropriate strategies to reduce and mitigate drought impacts on agricultural production will be essential to enable farmers to quickly recover from the disaster. There is growing interest in insurance as an instrument for managing drought risk in agriculture. Insurance is a self-reliant mitigation measure that increases society's resilience, particularly in the financial sector. There are two main options of crop risk transfer solutions: indemnity-based programs, in which the basis for compensation is the actual loss; and weather index-based (or parametric) programs. Parametric programs are based on variables called indices, often retrieved from remote-sensing observations. Indices should be highly correlated with agricultural losses. A parametric policy for drought pays out if a specific value of the index is achieved in a specific period. Index-based insurance shows various attractive features: the value of the index cannot be influenced by farmers, indemnities are based on observable variables (the indices), on-farm inspections to assess the damages are no more necessary and finally funds to recover from the disaster are provided quickly.</p><p>The aim of this work is the design of a parametric insurance framework against drought to be applied in the Caribbean region as well as in other regions with similar conditions. Initially a new drought index, the Probabilistic Precipitation and Vegetation Index (PPVI) was developed to identify drought. PPVI was computed combining two consolidated drought indices, the Standardized Precipitation Index (SPI) and the Vegetation Health Index (VHI). SPI was calculated from precipitation retrieved from satellite (the Climate Hazard Group Infrared Precipitation dataset was used) and VHI is already a remote-sensing product. Then a framework allowing an objective identification of drought weeks was implemented. The framework was used in combination with PPVI and the model was calibrated in order to reproduce past drought events at specific locations. A relationship between drought and negative crop yield anomalies was established. Significant crop growth periods were taken into consideration: establishment, vegetative, flowering and yield formation. The probability of having a negative crop yield anomaly when a significant growth period was in drought was computed. The sensitivity to drought of each crop growth period was evaluated based on this probability. In the end a loss index to relate drought with yield reduction suffered by farmers was developed. The entire framework was tested in the Dominican Republic and cereals losses (maize and sorghum) were evaluated. Results were promising.</p>

The possibility of cutting shapes on CNC machine tools

The development of computer technology has enabled it to be introduced to machine tools. The widespread use of CNC machine tools has resulted in a rapid development of the processing industry. So far, obtaining the profile of the curve has required the use of a complicated machine tool kinematic design, or it has been impossible to implement it otherwise than by copying. The numerical control of machine tools is based on the mathematical description of motion. This provides the capability to form curves of the same shape but with different dimensions using parametric programs. The article describes the practical use of parameters in machining on an FYS milling machine with Mitsubishi control.

A Secondary Development System on Grader Working Device Oriented to Mechanism Optimization

Because of the complex structure of grader working device, its optimization is a repeated, continuously improved process. A new model has to be set up before each optimization. In order to solve the problem of repeating modeling and improve the product optimization efficiency, a second development system of working device is established. Parametric driving about working device is realized in term of spatial mechanism. At first, the overall design framework of this second development system was established, then customized user interface was completed based on UG/Open API and parametric programs about the working device system were complied based on UG/Open Grip subsequently. The connection among customized user interface, parametric programs and human-computer interaction was realized by using Visual C++, the integrated second development system design of working device was eventually completed. This second development system could not only provide engineers with a rapid design method to shorten the new product development cycle, but solve the problem of repeating modeling during optimization design as well.

Comparative Evaluation of Finite Element Models and Types of Analyses for a Bolted Joint

The present work is aimed at evaluating different ways in which a given joint can be analyzed using the Finite Element Method. The bolt is modeled using line elements (link) or area elements (continuum) and a comparative evaluation is carried out. Each of these types is further subdivided into three categories viz., plane stress, axisymmetric, and three-dimensional models. Thus a total of six models are proposed to be analyzed and compared. As the bolt shares only a small fraction of external load in a well-tightened joint, the relative flexibility of a bracket is also studied as an example in the present work. Comparing the results of these analyses it was found that the type of model used for the bolt is more important than the type of analysis. This aspect is probed further to find the essential difference between bolt as link and bolt as continuum. The analysis is carried out using ANSYS, which enables writing many parametric programs.