The stomach temperature analyse
This analysis module is designed to identify the ingested food (mass and time) of sea-animals by analyzing the stomach temperature. If cold food is ingested (such as fishes) then the stomach temperature decreases and it is possible to estimate the ingested mass of the food by specific integrals.The software scans the recorded stomach-temperature data channel and searches feeding (decrease of temperature) events according to the 'Parameters for the temperature analysis' (see below) set by the user.
MT searches the begin and end of the feeding event. It visualizes the found temeperature event and the user can correct each of the MT-proposals (e.g. end-of-event). The user can accept or reject the entire event . If the user acceptes the event then MT analyzes the current event and exports into a text file (each event into one line) this result.
Then MT searches the next event, analyzes it ...and so on.There is also an 'automatic mode'. In this mode the user selects a section of the channel (e.g. the entire channel), then MT rapidly scans the entire section for temp. events, anlyzes each event and exports the results. This is a very fast method. Disadvantage: the user cannot check and - if neccessary - correct single events
Results of the stomach temp. analysis
|#||Nr of event|
|Onset||Onset of the event as dd.mm.yy hh:mm:ss|
|Min. temp.||Minmal temperature of the event [deg]|
|Integral||Integral of the event [deg*h]|
|Nr small events||Amount of small temp. drops inside temp event|
|Temp. onset||Temperature at onset [deg]|
|Duration||Duration of the event [sec]|
Fig 1. MT has found a temperature event and calculates - among other charcteristics - the integral and the duration. The integral correlates directly with the ingested food. If desired, the user can move the vertical cursor lines which indicates the begin and the end of the event as well as the horizontal integral base.
Fig 2 The user can modify anytime the settings for the event-finding procedure.
Fig 3) MT has detected the next stomach temperature event.
Parameters for the temperature analysis
Drop Gradient This parameter is to detect the onset of a temperature drop. If the temperature decreases more than G degrees per second at a time x, then MT assumes that at x a temperature drop started (=a food ingestion).
Asy. slope This is a parameter to detect the end of an temp. event. If the temperature rises only slow, slower than S degree per second - than MT assumes that at this time the food ingestion ended. In other words: S defines the slope of an asymptote.
Asy Length This parameter belongs to S. MT compares the current data against an asymptote. This parameter defines the 'length' of the asymptote, thus the number of data points to be compared.
SE drop This parameter is for detecting small temperature events during a big temperature decline (the animal resumes feeding small amounts of food before the current main food is totally digested.)
Level [%] This is also a parameter to detect the end of an temp. event. The program assumes the end of the event if the current temperature is greater than L*100 percent of the max. amplitude.
Method to find end of event
Choose the method for detecting the end of a temperature event. MT can find the end of an event by an asymptotic method (see above Asy. slope and Asy. points) and by an level-oriented method (see above Level) or by a mixture of both events.
When pressing this button MT makes proposals about the parameters above.
W Window size (time axis) To adjust the visible window around the current event.