The present study examines the features of communicative functions in middle school English textbooks, identifying whether or not they are presented based on the spiral structure. It also compares the communicative functions of 15 different middle school English textbooks and investigates whether the National English Listening Tests (NELTs) reflect the communicative functions presented in the textbooks. Two corpora were compiled using the 15 middle school English textbooks and the NELTs, and they were analyzed using WordSmith Tools. The results show that all the textbooks included communicative functions that the National Curriculum recommends; however, the textbooks presented a limited number of functions. Nonetheless, the communicative functions were presented relatively in a spiral way. The majority number of communicative functions in the textbooks and the NELTs were similar to each other, but there were some functions in the tests that were not covered in the textbooks. These results imply that more diverse communicative functions should be included in textbooks in order to help improve students’ communicative competence. The communicative functions not presented in the textbooks should not be included in the NELTs.

A rectangle-based relative localization method is proposed for a mobile robot based on a novel geometric formulation. In an artificial environment where a mobile robot navigates, rectangular shapes are ubiquitous. When a scene rectangle is captured using a camera attached to a mobile robot, localization can be performed and described in the relative coordinates of the scene rectangle. Especially, our method works with a single image for a scene rectangle whose aspect ratio is not known. Moreover, a camera calibration is unnecessary with an assumption of the pinhole camera model. The proposed method is largely based on the theory of coupled line cameras (CLC), which provides a basis for efficient computation with analytic solutions and intuitive geometric interpretation. We introduce the fundamentals of CLC and describe the proposed method with some experimental results in simulation environment.