Systems and methods for queuing and de-queuing packets in a two-dimensional link list data structure. The gradation of each pixel is influenced by gradation signals of adjacent pixels through an electric field interference between pixels. A first cache memory is connected to the first cluster and a second cache memory is connected to the second cluster. A management interface transmits forwarding updates to the network interfaces. A shared contact plug may be formed through the inter-layer dielectric, to be in contact with the gate electrode, corner protection pattern and sourcedrain regions. The first and second collimators are aligned by the tube such that incident light is transmitted through the first collimator, the tube, and the second collimator to a spectrometer.