Recently, the medical industry’s use of biomaterial has taken an important place. A biomaterial is a semi-permanent material that can be used instead of a specific part of the body when there is a disability. Among them, Nitinol alloy has used in the human body, the material surface quality is very important, and research on processing methods is important to improve the surface quality. Therefore, in this study, a study was conducted to obtain high-quality surface quality using the MR polishing process. As a result, high-quality surface roughness was obtained at a wheel rotation speed of 400rpm(Ra=3.5nm).

The present study aimed at investigating the effects of the two types of teacher feedback―direct corrective feedback (DCF) and metalinguistic explanation (ME)―on the development of EFL learners’ knowledge of the English indefinite article and on their use of it in writing. For this study, 58 college students classified into three groups (two experimental groups and one control group) took the error correction test and performed three writing tasks. The results of the study are 1) there was no group effect of the two types of feedback in the development of their explicit knowledge of the target feature in the test, whereas a time effect was found that their knowledge of the target feature developed significantly after the treatment; and 2) no group differences were found between the two types of feedback in the use of the target feature in the revised writing and among the three writings, though the DCF group outperformed the ME group in the accurate use of the target feature in writing. Theoretical and pedagogical relevance of the findings is addressed.

The present study aimed at investigating the effectiveness of bottom-up (BU) and top-down (TD) approaches on EFL learners’ vocabulary learning, the difference in the effects of the two approaches depending upon their level of vocabulary proficiency, and their perception of the approaches. For this study, 122 college students were divided into two approach groups and to two levels in each group depending upon their level of vocabulary knowledge. They were trained with either of the approaches for one semester. The results were that 1) there was no statistically significant differences between the BU and TD approaches, even though the two approaches were effective to improve the students’ vocabulary knowledge; 2) high-level students failed to show any significant differences between the two approaches in the two tests, whereas low-level students in the BU group performed significantly better than those in the TD group in the production test; and 3) they preferred the BU or TD approach to the traditional method in vocabulary learning, and they listed some advantages and disadvantages of the approaches.

The present study aimed at exploring the differences in EFL learners’ writing performance in two writing modes (direct and translated writing) in two writing genres (argumentation and narration) depending upon their L2 writing proficiency. For this study, 46 college freshmen (43.5% of high level and 56.5% of low level) performed four writing tasks individually. The results of the study are as follows: 1) their writing performance in the direct mode was significantly better regardless of genre and L2 writing proficiency, although there were substantial differences between the two genres in the degree of significance; 2) their writing performance in argumentative prose was significantly better only in the direct mode; and 3) only for low-level learners in the direct mode, there were significant differences in their performance in the writing genre, favoring argumentation. Theoretical and pedagogical relevance of the findings is addressed.

The present study examined the comparative role of vocabulary and grammar in different test measures of L2 reading comprehension. A total of 83 students were asked to take three reading tests with a different technique each (multiple-choice, cloze, and recall), a vocabulary test, and a grammar test, and to respond to a questionnaire. The findings were as follows: 1) learners’ reading performance differed across the three reading test measures, and the two language variables exerted different influences in L2 reading as measured by the cloze test technique; and 2) concerning the comparative contribution of the two language variables to L2 reading comprehension according to learners’ L2 proficiency, the contribution was significant exclusively in the recall test, and it varied depending upon their L2 proficiency. This research demonstrates the importance of taking into account the type of test techniques in studies of the relative role of vocabulary and grammar knowledge in L2 reading.

This study examined how four different constructed response formats of reading comprehension tests (cloze, recall, summary, and translation), developed based on the two texts with different reading difficulty, exert effects on EFL students’ reading test performance; and also investigated how those effects, if any, are differentiated with respect to the participants’ language proficiency levels. The total of 437 college students (220 male and 217 female students) participated in the current study. The test data was submitted to statistical treatment. The findings were that the four different response formats assessed different aspects of reading comprehension; the two texts with different text difficulty elicited different reading comprehension performance; and there were complicated interactions between the two variables of response format and text difficulty across the participants’ language proficiency levels. It is suggested that classroom teachers have to take it into consideration when planning to develop a reading comprehension test for EFL learners: how to choose reading texts that will be included in the test, considering an appropriate level of text difficulty and test formats to be engaged in order to assess students’ reading comprehension ability more accurately.