In TAG, an epoch is Ponatinib divided into time slots SB203580 HCC so that sensors’ activities are synchronized according to their depth in the routing tree. Any algorithm can be relied on to create the routing tree, as long as it allows data to flow in both directions of the tree and does not send duplicates [10].The TAG service focuses on low-rate data collection tasks which permits loose synchronization of the sensor nodes. The overhead implied by the synchronization is therefore assumed to be low. The goal of synchronization is to minimize the amount of time spent by sensors in powering their different components and to maximize the time spent in the idle mode, in which all electronic components are off except the clock.

Since the energy consumption is Inhibitors,Modulators,Libraries several orders of magnitude lower Inhibitors,Modulators,Libraries in the idle mode than when the CPU or the radio is active, synchronization Inhibitors,Modulators,Libraries significantly extends the wireless sensors’ lifetime. An illustration of the sensors’ activities during an epoch is given Inhibitors,Modulators,Libraries in Figure 2 for a network of four nodes with a routing Inhibitors,Modulators,Libraries tree of depth three. Note that the synchronization is maintained at the transport Inhibitors,Modulators,Libraries layer of the network stack, and does not require precise synchronization constraints as in TDMA. Rather, nodes are synchronized by timing information included in
Agriculture is an important economic sector in Guangdong province of China, where precipitation distributes unevenly in both spatial and temporal dimensions.

More than 60% of annual rainfall drops in the short period from June to August, leading to frequent occurrence of agro-drought in other months of the year.

Seasonal droughts usually occur in winter and Brefeldin_A spring to shape a significant impact on agricultural harvest. Drought monitoring has thus been a necessary Inhibitors,Modulators,Libraries effort to alleviate the impact. Generally drought can be monitored through either ground observation or remote sensing. Ground observation Inhibitors,Modulators,Libraries is a direct and accurate way for drought monitoring but relatively slow to get enough information for the monitoring in the whole region. It also needs a lot of labor to obtain the necessary information, hence is also expensive. As a contrast, remote sensing from space represents a fast and economic way for the monitoring, but needs to elaborately develop an applicable approach for the region under study.

There were two main approaches to monitor agro-drought with remote sensing Carfilzomib data.

The first one was based on the assumption that changes of soil moisture under drought would lead to significant changes of soil spectral reference 2 Nilotinib reflectance observed on remote sensing images. Bowers and Hanks (1965) found that the increase of soil humidity in bare surface would lead to the decrease of soil reflectivity [1]. Thus they suggested a linear correlation between soil moisture and the moisture’s absorption bands for remote sensing of soil moisture intensity [2].