Abstract: A home network system and a method of providing operation history data for the same are disclosed. The home network system includes at least one slave device and a master device, which includes a microprocessor, a memory, and a display unit. The microprocessor repeatedly sends a status request signal to the slave device and receives one or more response signal from the slave device in response to the request signal. The microprocessor constructs an operation history database in the memory by accumulatively storing operation status data included in each response signal. Finally, the microprocessor extracts data from the database when requested by a user, and the display unit displays the extracted data.

Abstract: Provided is an advertisement apparatus using a light switching device which transmits or shields light according as a power source or heat is supplied or not. The advertisement apparatus includes a light switching device transmitting light when a power source or heat is supplied thereto and shielding light of less than predetermined brightness when a power source or heat is not supplied thereto, or operating in a reverse manner, and an illuminator for illuminating an image onto the light switching device with light whose brightness is greater than the predetermined brightness. The light switching device can be used as the window of a building, and can present images of an advertisement using the illuminator for irradiating light from a projector, for example, to the light switching device. Therefore, the advertisement apparatus using a light switching device can be used for both indoor and outdoor advertising displays.

Abstract: A polymer assemble liquid crystal includes equal to or less than 40 wt % of a liquid crystal mixture of ferroelectric and antiferroelectric liquid crystals and equal to or more than 60 wt % of a polymer. The polymer is obtained by polymerizing urethane acrylate oligomer and (meth)acrylate. A ratio of the ferroelectric liquid crystal to the antiferroelectric liquid crystal in the liquid crystal mixture is about 3:1.

Abstract: A cholesteric liquid crystal compound containing a central biphenyl ester group having a rigid central group, increased molecular stability and a wide liquid crystalline phase temperature range. Accordingly, display devices employing the cholesteric liquid crystal compound can be operated at high temperatures and has good multi-color characteristics.