This excerpt taken from the LPL 20-F filed Jun 23, 2009.
Impairment of Long-Lived Assets
Long-lived assets, such as property, plant and equipment, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, management first compares the undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment loss is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary.
LG DISPLAY CO., LTD. AND SUBSIDIARIES
Notes to Consolidated Financial Statements
December 31, 2006, 2007 and 2008