منابع مشابه
Growing degree-days: one equation, two interpretations
Heat units, expressed in growing degree-days (GDD), are frequently used to describe the timing of biological processes. The basic equation used is GDD = [(T,,, + TM,,)/2] T,,,,, where T, and T,,, are daily maximum and minimum air temperature, respectively, and T,, is the base temperature. Two methods of interpreting this equation for calculating GDD are: (1) if the daily mean temperature is les...
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This study used air temperatures from a suite of regional climate models participating in the North American Climate Change Assessment Program (NARCCAP) together with two atmospheric reanalysis datasets to investigate changes in freezing days (defined as days with daily average temperature below freezing) likely to occur between 30-yr baseline (I97I-2000) and midcentury (2041-70) periods across...
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We introduce and study the problem of optimizing arbitrary functions over degree sequences of hypergraphs and multihypergraphs. We show that over multihypergraphs the problem can be solved in polynomial time. For hypergraphs, we show that deciding if a given sequence is the degree sequence of a 3-hypergraph is computationally prohibitive, thereby solving a 30 year long open problem. This implie...
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One of the key principles in rangeland management is determination of suitable times for exploitation and grazing of rangeland plants in summer and winter pasturelands. This determination of time not only prevents degradation of plant species, but also leads to optimal usage of plant yield. Multiple factors affect plant phenology among which temperature regime has the highest effect on plant de...
متن کاملCan Growing Degree Days and Photoperiod Predict Spring Wheat Phenology?
Wheat (Triticum aestivum) production in the rainfed area of Pothwar Pakistan is extremely vulnerable to high temperature. The expected increase in temperature due to global warming should result in shorter crop life cycles, and thus lower biomass and grain yield. Two major factors control wheat phenological development: temperature and photoperiod. To evaluate wheat development in response to t...
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ژورنال
عنوان ژورنال: Journal of the Japanese Society of Snow and Ice
سال: 1962
ISSN: 0373-1006,1883-6267
DOI: 10.5331/seppyo.24.185