For a wearable device to distinguish walking from a brief swing of the arm, it must recognize how movement changes over time. Korean researchers have developed a technology that stacks semiconductor devices with different response speeds, allowing them to recognize both a change that has just occurred and earlier changes.For a wearable device to distinguish walking from a brief swing of the arm, it must recognize how movement changes over time. Korean researchers have developed a technology that stacks semiconductor devices with different response speeds, allowing them to recognize both a change that has just occurred and earlier changes.Hardware[#item_full_content]