We model international trade in renewable resources between a single buyer and competitive sellers as a Stackelberg differential game. The buyer uses unit and ad valorem tariffs to indirectly encourage conservation of the renewable resource under study. First, we show that the efficacy of these trade policy instruments in promoting conservation depends fundamentally on whether harvesting costs ...

Mechanized reasoning uses computers to verify proofs and to help discover new theorems. Computer scientists have applied mechanized reasoning to economic problems but – to date – this work has not yet been properly presented in economics journals. We introduce mechanized reasoning to economists in three ways. First, we introduce mechanized reasoning in general, describing both the techniques an...

In recent years, there have been several outbreaks of extensive flooding in northern provinces, and asparagus stem blight disease brown spot diseases become increasingly serious, significantly reducing the yield grown large fields, so production has developed toward facility agriculture. order to solve problems high labor cost, shortage, low efficiency faced by agriculture, it is an inevitable ...

The purpose of this study is to substantiate the concept express assessment potato tubers for mechanized harvesting using fluorimetric and RAMAN lidar, as well conduct a quantitative structural damage varieties hybrids, device that simulates process operation combine separator, depending on type machine conditions. In addition, calibration lidar was undertaken assess magnitude physical impact d...

Photosynthetic systems harness sunlight to power most life on Earth. In the initial steps of photosynthetic light harvesting, absorbed energy is converted to chemical energy with near-unity quantum efficiency. This is achieved by an efficient, directional and regulated flow of energy through a network of proteins. Here, we discuss the following three key principles of this flow and of photosynt...

sugar beet is one of the main crops in iranthat provides primary materials for sugar industries and so, its economic aspects are very important. one of these aspects is employment; it has begged to draw policy maker attentions. nevertheless, there hasnot been any survey study on this matter in iranyet. in this study, the current value of labor use in sugar beet cultivation (direct employment) i...

In mechanized ground-based forestry, machines operate on rough soils that, ideally, should remain unaffected by the operation. This implies small (that is, light) loads and careful driving are required. However, economical rationality implies large loads and high speeds. Recently, the concept of adding a trailer to a conventional forwarder has been revived, with the objective of addressing both...