This study aims to investigate the effects of using AI chatbots in Korean English education from a macro perspective. For this purpose, 19 experimental studies are selected to conduct a meta-analysis, synthesizing the results of 51 individual study cases. The results of this study are as follows: First, it is found that the overall effect size of using chatbots is more than medium size meaning that a chatbot is an effective tool to learn English. Second, in the aspects of linguistic competence and affective categories, each shows over medium sizes like the overall effect size. In details of the dependent variables, vocabulary and speaking in linguistic competence and motivation in affective categories, large effect sizes are shown. Third, the effect sizes are getting larger, as the younger the students are, the longer the experiment period lasts, and the more purpose-built the chatbot is. But the differences in the effect sizes in terms of these moderators (e.g., school level, experiment period, and chatbot type) are not significant. Lastly, it is suggested that follow-up studies are needed to collect a sufficient number of experimental study cases and subdivide the variables for performing a more detailed meta-anlysis.

This study is to explore and analyze three current English teachers’ thoughts and attitudes on their TEE practices in elementary English classroom settings. Adopting a qualitative approach, data were collected through interviews, teachers’ journals, and informal communications from the three elementary school English teachers. The analysis of data revealed three main themes: 1) thoughts on effective TEE classes, 2) factors affecting TEE classes, 3) the difficulties of conducting TEE classes. The participants presented their views on effective TEE classes. They also expressed their opinion on the timing and usage of TEE. The teachers said TEE classes are influenced by teachers’ English communication ability and willingness to use English as the instructional language, students’ English proficiency and the class atmosphere. Finally, the participants said that TEE classes were difficult due to the same factors influencing TEE class effectiveness. This study has implications for the direction of TEE implementation in elementary education.

The purpose of this study is to explore inter-grade dividing criteria of the 2015 grade group elementary English textbooks. Elementary English textbooks consist of two grade groups: the 3rd and 4th grade group and the 5th and 6th grade group. L2 Syntactic Complexity Analyzer(L2SCA) is utilized to investigate the dividing criteria of the communicative functions implemented in these textbooks. Subjects of the analysis were the listening dialogues for their structural sequencing of 3rd to 4th graders and 5th to 6th graders separately within their own grade groups. Data were processed and analyzed using SPSS 25.0 and independent sample t tests for inter-grade textbooks for 14 L2SCA statistical indices. The findings are: 6 indices out of the 14 L2SCA statistical indices turn out to be critical for dividing the 2015 grade group elementary English textbooks. The 6 indices are mean clause length, mean sentence length, mean t-unit length, mean complex noun phrasal number per phrase and per t-unit and mean number of verb phrases per t-unit. Based on the findings, it is suggested that a standardized criteria derived from these 6 indices can be provided as an inter-grade dividing criteria of the 2015 grade group elementary English textbooks.

This study analyses the communicative functions of listening scripts extracted from the 2015 elementary school English 6 and middle school English 1 textbooks in terms of continuity. Auditory data corpora were drawn from all five elementary school English textbooks and five most widely used middle school English textbooks. Each sentence of listening scripts was manually tagged based on the classification of communication functions presented in the 2015 Revised National Curriculum. The corpora were analyzed using 14 syntactic complexity measures with the L2 Syntactic Complexity Analyzer (Lu, 2010). The findings of this study show that the continuity between the elementary school English 6 and the middle school English 1 textbooks is relatively well-organized. However, concerning the sequence, the elementary school English 6 was found to be more complex than the middle school English 1 in terms of syntactic complexity. It is suggested that future textbook development should correct the reversed complexity in listening scripts found in this study.

갭색법(gap & sag method)은 선박 건조과정에서 축을 조립하기 전 최종적으로 축이 축계정렬 설계치와 동일한 위치에 거치되었는지의 여부를 확인하기 위해 사용되고 있는 방법이며, 조립 전 프로펠러축을 기준축으로 하여 양 축의 플랜지에서 축 자중에 의해 발생하는 갭색값을 통해 나머지 축계의 위치를 순차적으로 확정해 나간다. 만일 설계치와 다르게 기준축이 거치되는 경우 연쇄적으로 나머지 축의 거치에 영향을 주게 된다. 또한, 축 조립 후 검증과정에서 측정된 베어링 반력이 설령 설계치를 만족하더라도 선미관 후부측에서의 프로펠러축과 베어링간 상대적경사각을 추정할 수 없게 됨으로써 결과적으로 축계의 안정성에 부정적인 영향을 미칠 수 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 실제 선미관 베어링 발열 및 개방검사 사례를 통해 선미관 베어링 유효지지점에 관한 이론계산 및 실측치분석 연구를 수행하고 이를 바탕으로 축계 정렬오차를 최소화하기 위한 축계 시공방법을 제안하였다.

This study is to investigate the correlation between language aptitude and vocabulary levels of 5th graders of a Korean elementary school. The participants of the study were 39 elementary school students in Daejeon Metropolitan City. Language aptitude was elicited using LLAMA B, D, E and F classified respectively into memory retention, sound recognition, sound-symbol correspondence, and inference and application. A vocabulary size test modified from the vocabulary size test (Nation, 1990) was injected to the students to investigate their vocabulary levels. A correlation between each LLAMA score and vocabulary size of students was tabulated for their correlationship along with their statistical significance of 95% probability rate. The findings are: Positive correlations were found between each language aptitude ability and vocabulary ability. Among them, the correlation between memory retention and vocabulary ability is only statistically significant. This finding implicates that memory retention is an important factor to learn and retain new words, and learning vocabulary with pictures is recommended to reinforce the connection between meanings and forms of new words.

Morphological competence plays an important role in extending one’s vocabulary in grammatical context. This study is to explore the developmental distribution of English grammatical morphemes appearing in elementary English textbooks. To this end, the study developed grammatical morpheme recognition and elicitation tests based on the bilingual syntax measurement (BSM). The tests are given to 114 fifth graders and 126 sixth graders across small, medium and metropolitan cities. The students were stratified into high, mid and low English ability groups by their English achievement scores. The result shows that English grammatical morpheme awareness was positively correlated with students’ English ability. The grammatical morphological development of Korean students was more in alignment with that of English learners as a foreign language than that of native speakers. Pedagogical implications are provided at the end of the paper.

This study examined the effectiveness of integrated language instruction using dictogloss on vocabulary knowledge and retention. Forty EFL students from two classes of an elementary school participated in the study. The integrated language class and segregated language class were examined by looking into the effect of each instructional type on the vocabulary knowledge development and retention. A total of 10 target words were selected from a storybook related to their textbook. Four types of vocabulary knowledge were measured: passive recognition, passive recall, active recognition, and active recall. The pretest and posttest were performed to measure the vocabulary growth. The retention rate of each instruction was examined by conducting a delayed posttest on the same words after two weeks. The results of this study indicate that integrated language instruction using dictogloss works better in vocabulary retention. They also suggest that further classroom research is required to prove that dictogloss is an effective way for vocabulary learning.

선박엔진은 잔사유를 에너지원으로 활용하여 운항할 수 있으며, 이를 활용한 선박에서 환경 규제와 경제성을 모두 만족시키는 다양한 방안들이 모색되고 있다. 그 중에 한 방안으로 연료 첨가제를 활용하는 기술이 있을 수 있다. 분산제와 연소촉진제는 잔사유활용 시 엔진의 연소특성 촉진에 기여할 것이라는 기대를 받고 있다. 따라서, 본 연구에서는 연소성 분석 장비(FIA/FCA)와 열 중량 분석 장비(TGA)를 활용하여 잔사유 연료첨가제가 혼합된 잔사유의 연소성을 분석하였다. 연소성 분석 장비(FIA/FCA)의 결과로는 연소에 의한 일의 총량을 분석하도록 분석법이 개발되었으며, 이 때문에 본 연구를 통하여 동일 장비를 활용하면서도 연소 효율을 간단하게 평가할 수 있는 방안을 제시하였다. 연소성 분석 결과인 ROHR 곡선으로부터, 단순한 삼각함수를 활용하여 연소특성을 예측할 수 있는 방안을 제시하였으며, 이 기법을 활용하여 기존의 압력 곡선과 유사한 결론을 도출할 수 있었다. 열 중량 분석(TGA)의 경우 연료유의 증발 특성에 민감하게 반응함을 확인하였고, 첨가제가 연료유 증발에 효과적으로 작용함을 확인하였다.

This study explores the morphological awareness of different graders with different vocabulary levels. A total of 275 elementary students (148 5th graders and 127 6th graders) across small, midium and large cities are selected to test their morphological awareness. First, they were divided into 30%, 40% and 30% of students according to their vocabulary levels. Second, they were tested on the recognition tests, the production tests and the distributional tests of English derivational morphemes divided by the prefixes and the suffixes appeared in the English textbooks. The results are: The recognition and production tests show significant differences for both vocabulary levels and different English levels across different grades. However, the distributional test shows no clear difference like the other two tests. Based on the results, the study draws the conclusion that morphological awareness is developing in the order of recognition, production and distribution of morphologized words in sentences. In other words, recognition of forms precedes the production of forms, and the production is followed by the functional awareness of morphologized words.