• Journal of the Optical Society of Korea
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• v.8 no.4
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• pp.174-181
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• 2004

Various kinds of systems, that can do target recognition and position detection simultaneously by using infrared sensing detectors, have been developed. In this paper, the detection system TRSS (Thermal target Recognition by Spiral Scanning) adopts linear array shaped uncooled IR detector and uses spiral type fast scanning method for relative position detection of target objects, which radiate an IR region wavelength spectrum. It can detect thermal energy radiating from a 9 m-size target object as far as 200 m distance. And the maximum field of a detector is fully filled with the same size of target object at the minimum approaching distance 50 m. We investigate two types of lens systems. One is a singlet lens and the other is a doublet lens system. Every system includes one aspheric surface and free positioned aperture stop. Many designs of F/1.5 system with ${\pm}5.2^{\circ}$ field at the Efl=20, 30 mm conditions for single element and double elements lens system respectively are compared in their resolution performance [MTF] according to the aspheric surface and stop position changing on their optimization process. Optimum design is established including mechanical boundary conditions and manufacturing considerations.

• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.65-71
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• 2018

Using mobile technology in educational and learning environments has attracted a lot of attention in recent years. In this mobile environment, mobile phones have been used to enhance the effectiveness of education in the field, which has been recognized through numerous experimental studies so far. The study was proposed and conducted to find out how much the use of mobile phones can have to improve the grammatical knowledge of EFL students. Introduction of 95 intermediate courses to Chungnam area The second grade students of 4-year college participated in this study. Everyone in the experimental and control groups was given the opportunity to review and recur to use the six grammar formats, including the current complete tense, simple past tense, direct and indirect question sentences, and comparative and superative-based methods. During the class discussion, the participants of the group record their voice on their cell phones, analyze the mistakes in the expressions recorded as a task after the class, and explain the results in the next session. However, in the class of the control group participants, this recording process is omitted. Participants benefited from mobile learning were much more positive in multidimensional grammar tests than those in control groups.

• Journal of Multimedia Information System
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• v.6 no.1
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• pp.23-30
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• 2019

A communications profile is a system that acquires information from communication links to an ambulance or other vehicle moving on a road and compiles a database based on this information. The equipment (six sets of HDTVs, fish-eye camera, satellite antenna with tracking system, and receiving power from the satellite beacon of the N-star) mounted on the roof of the vehicle, image data were obtained at Yokohama Japan. From these data, the polygon of the building was actually produced and has arranged on the map of the Geographical Survey Institute of a 50 m-mesh. The optical study (relationship between visibility rate and elevation angle) were performed on actual data taken by fish-eye lens, and simulated data by 3D-Map with polygons. There was no big difference. This 3D map system then predicts the communication links that will be available at a given location. For line-of-sight communication, optical analysis allows approximation if the frequency is sufficiently high. For non-line-of-sight communication, previously obtained electric power data can be used as reference information for approximation in certain cases when combined with predicted values calculated based on a 3D map. 3D maps are more effective than 2D maps for landing emergency medical helicopters on public roadways in the event of a disaster. Using advanced imaging technologies, we have produced a semi-automatic creation of a high-precision 3D map at Yokohama Yamashita Park and vicinity and assessed its effectiveness on telecommunications and ambulatory merits.

• Journal of Multimedia Information System
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• v.6 no.2
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• pp.107-118
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• 2019

This paper deals with actual optical data from rural as well as urban areas in a nationwide study captured with Fisheye cameras. Simultaneously data was collected (of the receiving power density) from the mobile communications satellite N-STAR. The visibility of the satellite is easily determined by checking the value of the pixels in the binarized fisheye image of its position. The process of determining the visible satellite is automatically performed. Based on the analyses of the field data measured in Japan, we are expecting HEOs (Highly inclined Elliptical Orbiters) that would reduce blockage in the extreme northern region of Wakkanai City well as in the most crowded urban area, in Tokyo Ginza. In case of HEOs operation, the elevation angle will improve from 37 with N-STAR GEO to 75 degrees. HEOs could replace 5G/Ka-band or support in rural areas where broadband circuit is not available. We are proposing combination operations with HEOs and 5G/Ka-band to solve blockage problems, because HEOs can keep line-of-sight propagation with high elevation angle for long duration. In such operations, the communications profile on the vehicle based on actual optical data will be very useful to predict blockages and to select/switch a suitable circuit.

• Asia Pacific Journal of Corpus Research
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• v.1 no.2
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• pp.57-72
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• 2020

This study seeks to add to the current understanding of learners' use of modality in argumentative writing. A learner corpus of argumentative essays on four topics was created and compared to native English speaker data from the International Corpus Network of Asian Learners of English (ICNALE). The relationship between learners' use of modal devices (MDs) and the devices' appearance in the school's curriculum was also examined. The results showed that learners relied on a very narrow range of MDs compared to those in previous studies. The frequency of use of MDs varied based on the topic and did not seem to be driven by cultural factors as has been previously suggested. Learners used more hedges than boosters on all topics, contradicting most previous studies. Curriculum was determined to have a direct correlation with MD use, and other important factors may include perception of topic and overreliance on certain MDs over others (the One-to-One principal). This research implies that learners' perception of topic should be explored further as a variable affecting MD use. Curricula should be designed based on frequency of MD use by English native speakers, and learners should receive instruction that teaches the norms of MD use in academic writing. The methodology used in the study to determine correlations between MD use and the curriculum has a wide range of potential applications in the field of Contrastive Interlanguage Analysis.

• International Journal of Contents
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• v.16 no.4
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• pp.50-67
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• 2020

This study investigated whether writing weekly listening logs could influence college English learners' metacognitive awareness and listening proficiency. In addition, the Metacognitive Awareness Listening Questionnaire (MALQ) was applied to examine the learners' knowledge of their listening process. It is process-oriented research conducted by analyzing the MALQ and students' listening logs as to how their metacognitive awareness and listening proficiency have changed during the semester. Eighty-nine students who took an English listening practice course at a university participated in this study. The research findings are as follows. First, it turned out that there was a significant relationship between EFL university students' listening comprehension and some subscales of metacognitive awareness. Second, the students had an opportunity to reflect on learning through regular listening activities, and weekly listening logs, which included important information about listening process and practice. Third, as the students' listening proficiency increased at the end of the semester, it was found that introducing listening logs along with classroom lessons helped the students improve their listening ability. Finally, the high proficiency group students used multiple strategies simultaneously, regardless of the type of listening strategies, while the low proficiency group students used one or two limited listening strategies. However, the low proficiency group students may have had trouble expressing their ideas in English or recognizing the listening strategies they used, not because they did not use a lot of listening strategies. Therefore, teachers should regularly check if students are following their instructions and help them use appropriate strategies for better understanding.

• Asia Pacific Journal of Corpus Research
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• v.2 no.1
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• pp.23-34
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• 2021

This research examines Japanese non-native speakers' (JNNS) modal auxiliary verb use from two different perspectives: frequency of use and preferences for modalities. Additionally, error analysis is carried out to identify errors in modal use common among JNNSs. Their modal use is compared to that of English native speakers within a spoken dialogue corpus which is part of the International Corpus Network of Asian Learners' English. Research findings show at a statistically significant level that when compared to native speakers, JNNSs underuse past forms of modals and infrequently convey epistemic modality, indicating the possibility that JNNSs fail to express their opinions or thoughts indirectly when needed or to convey politeness appropriately. Error analysis identifies the following three types of common errors: (1) the use of incorrect tenses of modal verb phrases, (2) the use of inflected verb forms after modals, and (3) the non-use of main verbs after modals. The first type of error is largely because JNNSs do not master how to express past meanings of modals. The second and third types of errors seem to be due to first language transfer into second language acquisition and JNNSs' overgeneralization of the subject-verb agreement rules to modals respectively.

• International Journal of Contents
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• v.17 no.4
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• pp.62-78
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• 2021

This ethnographic multiple case study, based on Zappa-Hollman and Duff's construct of individual networks of practice (INoPs), explored English as a second language (L2) competence development and socialization process of a group of English-major undergraduates through their social connections and interactions at a public university located in an underdeveloped city in Northwest China. The study lasted for one academic semester and three students were selected as primary participants. Semi-structured interviews, student observations in English-related micro-settings, and associated texts were used to collect data. These data were coded to identify the thematic categories, and then data triangulation and member checking were conducted to select the most representative evidence to provide an in-depth description of students' perspective about mediating their English L2 socialization by their INoPs. Findings showed that factors in the formation of students' INoPs, including intensity, density, and nature, played significant roles in their academic or affective returns from their English learning, both of which had a substantial influence on the students' English L2 socialization. Considering that the macro-setting was a non-English, underdeveloped monolingual society, both educational institutions and individual students need to seek and create more English-mediated interactional opportunities to develop their English proficiency and adapt to local English learning communities.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.44-52
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• 2022

With recent scientific advances and growing interest in AI technologies, AI-based chatbots have been viewed as a practical learning aid for English language development. The purpose of this study is to examine preservice teachers' perceptions on the potential benefits of employing AI chatbots in English instruction and its pedagogical aspects. 28 preservice teachers majoring in English education were asked to use Kuki chatbots for a week with a guidance of a researcher and then report on their perceptions of AI chatbots in terms of perceived usefulness after use, applicability, and educational benefits and drawbacks. Emerging codes and themes were identified and evaluated using Thematic Analysis(TA) based on qualitative data from surveys and interviews. The findings show that six emerging themes were identified, encompassing perspectives on teacher, learner, communication, linguistic, affective, and assessment. The overall findings of this study revealed that AI-based chatbots can play a significant role as learning tools for stimulating interactive communication in a target language. Most preservice primary teachers acknowledge that AI chatbots can be useful as teaching and learning aids for both teachers and students. Furthermore, when applying various learner data to chatbot technology, such as learner assessment and diagnosis, a guided approach is necessary to perform a conversation appropriate for the learner's level and characteristics. Finally, as chatbots have a variety of benefits in terms of affective aspects, they may improve EFL learners' confidence in speaking English and learning motivation.

• Asia Pacific Journal of Corpus Research
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• v.3 no.1
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• pp.35-49
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• 2022

This study examines crosslinguistic influence on the use of concessive conditionals by Japanese EFL learners. Contrastive analysis suggests that Japanese native speakers may overuse the concessive conditional even if due to partial similarities to Japanese concessive conditionals, whose formal and semantic restrictions are fewer than those of English concessive conditionals. This hypothesis is tested using data from the written module of the International Corpus Network of Asian Learners of English (ICNALE). Comparison of Japanese native speakers with English native speakers and Chinese native speakers reveals the following trends. First, Japanese native speakers tend to overuse concessive conditionals compared to native speakers, while similar overuse is not observed in Chinese native speaker data. Second, non-nativelike uses of even if appear in contexts allowing the use of concessive conditionals in Japanese. Third, while overuse and infelicitous use of even if is observed at all proficiency levels, formal errors are restricted to learners at lower proficiency levels. These findings suggest that crosslinguistic influence does occur in the use of concessive conditionals, and that its particular realization is affected by L2 proficiency, with formal crosslinguistic influence mediated at an earlier stage than semantic cross-linguistic influence.