A hybrid cooling system for an engine is provided. The multiplex gathering device includes a first gatherer forming first gathered printed products on a first finishing line, the first finishing line having a trimmer and a second gatherer forming a second gathered printed products on a second finishing line, the second finishing line having a second trimmer. The presence system aggregates and analyzes the collected presence information to determine a telephonyconference activity presence state which is then published to watchers andor an automated interaction management system in order to inform them if the person happens to be an \u201cactive participant\u201d or a \u201cpassive participant\u201d in the telephone call. When the still image is to be displayed, the signal controller also controls leakage current of a thin film transistor of a pixel based on a representative value of the image data, such that positive leakage current applied for a positive data voltage is equal to negative leakage current applied for a negative data voltage. The manager 4 then transmits an associated information service message 18b to the customer agent 9. The semiconductor light emitting device comprises a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer comprising a plurality of recesses on the active layer.