Abstract: An apparatus and method are provided, which predict total nitrogen using general water quality data measured in real time. The total nitrogen prediction apparatus may include a regression model selection unit to select a regression model comprising general data of at least one water quality based on a correlation coefficient of the general data of at least one water quality, a quality-of-fit evaluation unit to evaluate quality of fit of the selected regression model, a regression model change unit to determine whether to change the regression model based on the quality of fit and change the regression model according to the determination result, and a total nitrogen prediction unit to predict total nitrogen of a body of water based on the regression model.

Abstract: Disclosed is an apparatus for mounting a keyboard to a portable computer, made up of an elastic member for lifting upwardly the keyboard from the bottom of the base; an indented part formed on at least one of the sides of the base plate; a setting member forming symmetrically on the opposite surface to the indented part, which will engage a locking hole formed on the side of the pocket; and a locking member, which is mounted inside the base, for coming out of the base to the pocket to engage the indented part through elasticity or release out of it to remove the keyboard from the base. Therefore, the keyboard mounting apparatus permits a user to easily attach a keyboard to and detach it from a pocket using a simple tool, such as a pen and resulting in preventing damage to a keyboard or base due to use of any metal tools.