Note 15. Segment, Geographic, Product and Significant Customer Information

The Company has one operating segment, which is the sale, design, manufacture, marketing and support of optical critical dimension and thin film systems. The following tables summarize total net revenues and long-lived assets (excluding intangible assets) attributed to significant countries (in thousands):

	Three Months Ended
	March 26, 2016		March 28, 2015
Total net revenues^(1):
United States	$	7,191	$	9,078
South Korea		8,436		14,643
China		6,506		4,001
Taiwan		5,477		14,428
Singapore		9,902		2,794
Other		9,977		5,432
Total net revenues	$	47,489	$	50,376

	March 26, 2016		December 26, 2015
Long-lived tangible assets:
United States	$	41,281	$	42,581
Japan		63		59
South Korea		664		697
All Other		1,060		1,156
Total long-lived tangible assets	$	43,068	$	44,493

The following customers accounted for 10% or more of total accounts receivable, net:

	At
	March 26, 2016			December 26, 2015
Micron		30.7	%	***
SK Hynix		12.7	%	***
Taiwan Semiconductor Manufacturing Company Limited		12.6	%		25.6	%
Intel		11.1	%	***
Toshiba Corporation		11.1	%		27.1	%
Samsung Electronics Co. Ltd.	***			***

***	The customer accounted for less than 10% of total accounts receivable, net, as of that period end.

The following customers accounted for 10% or more of total net revenues:

	Three Months Ended
	March 26, 2016			March 28, 2015
Micron		25.9	%	***
SK Hynix		16.7	%		13.4	%
Intel Corporation		15.7	%	***
Toshiba Corporation		11.9	%	***
Taiwan Semiconductor Manufacturing Company Limited		10.1	%		22.3	%
Samsung Electronics Co. Ltd.	***				30.3	%

***	The customer accounted for less than 10% of total net revenues during the period.