Time-response of a second-order system
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| Image reference |
This graph illustrates the time-response of a second-order system to a unit step input. There is several information in this graph which describes the behaviors and characteristics of the system. The rise time tr, is the time it takes for the response of the system to go from 10% to 90% of its final value. The settling time indicates the time it takes for the response to settle within 2-5% of its steady-state value. The smaller this value is, the faster response the system has to unit step input. Overshoot b, is the height of the first peak. The smaller the overshoot is, the smoother the system behaves. The damping factor of the system fd ,is related to the overshoot ratio and the time it takes for the overshoot to appear in the response (tp). The main characteristics of any system which could be represented by a second-order transfer function, can be explained through this response. This is a general graph which explaines a family of second-order systems. That is why it is described in terms of parameters rather than specific values or numbers.
Northbound Gray Whales Statistics by Week
The above graph is the Northbound gray whales counted by week in spring migration 2010 in Los Angles, California.
As can be seen, the graph approximates a normal distribution of whales migrations during the months of February to May. As shown in the graph, we have the least counts of whales close to the margins of the count period, i.e. the first week of February and the last week of May. It can be clearly seen that the number of whales migrated, has an increasing trend till the third week of March. The graph has its peak at the third week of March. There is a dip of 60 between the first and third week of March which is an exception to this upward movement. Then passing the peak of the graph in the third week of March, the number of whales migrated will start declining until the end of the report period. There is again an exception between April 12 and April 18 to this trend.
This increasing and then decreasing trends could be explained by the fact that, as we approach the mid March, the environmental changes in this region are more ideal for the migration of gray whales. So most of the gray whales migrate in this period.
Northbound Gray Whales Statistics by Week
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| Image reference Click on the image to enlarge |
As can be seen, the graph approximates a normal distribution of whales migrations during the months of February to May. As shown in the graph, we have the least counts of whales close to the margins of the count period, i.e. the first week of February and the last week of May. It can be clearly seen that the number of whales migrated, has an increasing trend till the third week of March. The graph has its peak at the third week of March. There is a dip of 60 between the first and third week of March which is an exception to this upward movement. Then passing the peak of the graph in the third week of March, the number of whales migrated will start declining until the end of the report period. There is again an exception between April 12 and April 18 to this trend.
This increasing and then decreasing trends could be explained by the fact that, as we approach the mid March, the environmental changes in this region are more ideal for the migration of gray whales. So most of the gray whales migrate in this period.
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