• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.323-336
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• 2009

The purpose of the current study was to research scientific basis and necessity of supplementary materials for field lesson out of golf swing teaching methods. As the subject of study, skillful tour pro golfers were chosen to reinterpret field lesson results for driver swing from the viewpoint of kinematics. In addition, through precise analysis, this study developed a case to verify the validity and error of field lesson. As a result, field lesson showed a slight difference among qualitative evaluation of kinematical analysis of techniques, subjects of study, and items. Accordingly, there was a little difference between two methods in view of evaluation of errors that 5 subjects of the study have shown. However, there was a significant difference in compensation to prevent causes of error and errors. Based on instructor's experience most errors could be evaluated. Therefore, feedback for error correction based on instructor's experience showed a significant difference from qualitative evaluation of kinematical analysis of techniques. In conclusion, the following are required for correct golf swing lesson; instant feedback through field lesson and qualitative evaluation of kinematical analysis of techniques to determine fundamental causes correctly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2775-2782
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• 2010

In this paper, we propose a web-based programming class support system to help a lecturer to teach a programming language to students effectively. The proposed system is composed of a error analysis step and a verification step. The error analysis step checks whether there are compile time errors or run time errors in each student's submitted program. Given some errors, the system provides helpful feedback for the student to fix the errors. On the contrary, the system provides quick feedback after checking the source code style, comments, and plagiarism in the submitted program. As soon as the student submits the program, the student can see the check results. According to the result of utilizing the proposed system in a C programming language class, students tend to submit program assignments actively.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.237-264
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• 2009

The present study explores patterns of teachers' corrective feedback and learners' uptake in Korean EFL undergraduate classroom setting. It also examines consistencies and discrepancies in the perception of corrective feedback by teachers and learners. Teachers' and learners' preferences and perception of corrective feedback are further analyzed to determine whether or not those differ from actual practices in English language learning classrooms. The results of the study are as follows. First of all, teachers' corrective feedback type varied according to the learners' error type and English proficiency level. There was a lack of consistency between the teachers' feedback practices and the learners' error types. Second, for the phonological errors, learners' data witnessed the most frequent uptake on recast. For the other error types, however, the learners' uptake rates were high for the explicit corrective feedback. Third, the teachers' explicit knowledge of corrective feedback was rather low and the preferences differed from teacher to teacher. The teachers' feedback perception and preferences did not consistently reflect their actual practices. Finally, patterns of the learners' expectations of corrective feedback varied according to learners' proficiency level. Teachers' and learners' expectations of corrective feedback were also compared and some mismatches were detected.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.885-905
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• 2010

This study questions that mathematical evaluations strive to memorize fragmentary knowledge and have an objective test. To solve these problems on mathematical education We did descriptive test. Through the descriptive test, students think and express their ideas freely using mathematical terms. We want to know if that procedure is correct or not, and, if they understand what was being presented. We studied this because We want to analyze where and what kinds of faults they committed, and be able to correct an error so as to establish a correct mathematical concept. The result from this study can be summarized as the following; First, the mistakes students make when solving the descriptive tests can be divided into six things: error of question understanding, error of concept principle, error of data using, error of solving procedure, error of recording procedure, and solving procedure omissions. Second, students had difficulty with the part of the descriptive test that used logical thinking defined by mathematical terms. Third, errors pattern varied as did students' ability level. For high level students, there were a lot of cases of the solving procedure being correct, but simple calculations were not correct. There were also some mistakes due to some students' lack of concept understanding. For middle level students, they couldn't understand questions well, and they analyzed questions arbitrarily. They also have a tendency to solve questions using a wrong strategy with data that only they can understand. Low level students generally had difficulty understanding questions. Even when they understood questions, they couldn't derive the answers because they have a shortage of related knowledge as well as low enthusiasm on the subject.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.550-552
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• 2002

표준 비디오 압축 기법은 프레임 간의 시간적, 공간적 중복성을 이용하여 데이터를 압축한다. 압축된 프레임이 인터넷을 통하여 전송되는 중에 네트워크의 상태에 따라 패킷의 손실이 발생할 수 있다. 이러한 오류가 발생하면 손실된 블록을 포함하는 프레임의 화질 뿐 아니라, 이 프레임을 참조하여 압축된 이후의 프레임에도 영향을 미친다. 본 논문에서는 전송오류가 발생한 경우, 디코더에서의 오류전파를 최소화하기 위해 보조 모션벡터를 이용한 압축 기법을 제안한다. 즉, 여러 개의 후보 프레임 중 현재 압축하려는 매크로블록과 가장 가까운 값을 가진 두 개의 매크로 블록을 선택하여 그 위치를 기본 모션벡터와 보조 모션벡터로 지정한다. 이때, 두 모션벡터는 서로 다른 프레임에 속한다. 디코더에서 압축해제를 위해 참조하는 기본 모션벡터의 프레임이 손실된 경우, 보조모션 벡터를 이용하여 원래의 화질에 가깝게 디코딩 할 수 있다. 이 기법은 오류제어를 위한 피드백 채널이 필요하지 않으며, 네트워크상의 전송오류 발생시 표준 H.263 압축보다 높은 성능을 보인다.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.530-541
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• 2011

In this paper, we propose an effective network-adaptive ARQ based error control scheme to provide video streaming services through IP networks where packet error usually occurs. If time delay and feedback channel are allowed, client can request server to retransmit lost packets through IP networks. However, if retransmission is unconditionally requested without considering network condition and number of simultaneous feedback messages, retransmitted packets may not arrive in a timely manner so that decoding may not occur. In the proposed ARQ, a client conditionally requests retransmission based on assumed network condition, and it further determines valid retransmission time so that effective ARQ can be applied. In order to verify the performance of the proposed adaptive ARQ based error control, NIST-Net is used to emulate packet-loss network environment. It is shown by simulations that the proposed scheme provides noticeable error resilience with significantly reduced traffics required for ARQ.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6475-6482
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• 2015

The purpose of the study was two folded: to examine whether form-focused instruction (FFI) with corrective feedback (CF) is effective for the acquisition of the target linguistic forms and to find out the extent to which of the students' perceptions as well as their attitudes towards English instruction that they received. Tests and questionnaires were implemented to 122 Korean EFL students from eight classes enrolled in an English communication course. They were randomly assigned to three groups: the input-based group, who received typographical input enhancement materials, so-called the TIE group, the output-based group, who performed dictogloss tasks, so-called the DICT group, and the control group (CG). The data analysis was made on both tests and questionnaires by using SPSS 21.0 for Windows. The study found that different types of FFI with CF contributed to the improvement of students' grammatical knowledge and both the TIE and DICT task group students positively changed their perceptions and understanding as well as their attitudes towards the English instruction given, and students in all groups preferred pair work activities. In addition, most of the TIE and DICT students showed their interest and satisfaction with English class, whereas the CG group students did not. Based on the findings, this study suggested that well-planned and properly-chosen FFI in the form of pair work activities should be applied in classrooms with consideration of students' instructional preference in Korean EFL contextual settings.

• Progress in Medical Physics
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• v.25 no.2
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• pp.72-78
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• 2014

The aim of the study is to test a hypothesis that quasi-breath-hold (QBH) biofeedback improves the residual respiratory motion management in gated 3D thoracic MR imaging, reducing respiratory motion artifacts with insignificant acquisition time alteration. To test the hypothesis five healthy human subjects underwent two gated MR imaging studies based on a T2 weighted SPACE MR pulse sequence using a respiratory navigator of a 3T Siemens MRI: one under free breathing and the other under QBH biofeedback breathing. The QBH biofeedback system utilized the external marker position on the abdomen obtained with an RPM system (Real-time Position Management, Varian) to audio-visually guide a human subject for 2s breath-hold at 90% exhalation position in each respiratory cycle. The improvement in the upper liver breath-hold motion reproducibility within the gating window using the QBH biofeedback system has been assessed for a group of volunteers. We assessed the residual respiratory motion management within the gating window and respiratory motion artifacts in 3D thoracic MRI both with/without QBH biofeedback. In addition, the RMSE (root mean square error) of abdominal displacement has been investigated. The QBH biofeedback reduced the residual upper liver motion within the gating window during MR acquisitions (~6 minutes) compared to that for free breathing, resulting in the reduction of respiratory motion artifacts in lung and liver of gated 3D thoracic MR images. The abdominal motion reduction in the gated window was consistent with the residual motion reduction of the diaphragm with QBH biofeedback. Consequently, average RMSE (root mean square error) of abdominal displacement obtained from the RPM has been also reduced from 2.0 mm of free breathing to 0.7 mm of QBH biofeedback breathing over the entire cycle (67% reduction, p-value=0.02) and from 1.7 mm of free breathing to 0.7 mm of QBH biofeedback breathing in the gated window (58% reduction, p-value=0.14). The average baseline drift obtained using a linear fit was reduced from 5.5 mm/min with free breathing to 0.6 mm/min (89% reduction, p-value=0.017) with QBH biofeedback. The study demonstrated that the QBH biofeedback improved the upper liver breath-hold motion reproducibility during the gated 3D thoracic MR imaging. This system can provide clinically applicable motion management of the internal anatomy for gated medical imaging as well as gated radiotherapy.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.247-253
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• 2021

There are various programming errors that occur in the course of programming practice for beginners in computer programming. At this time, since it is difficult for learners to recognize errors by themselves, they correct program errors through the instructor's feedback. However, as students learn programming techniques in an online learning environment due to the COVID-19 pandemic, there is a limit to interaction between the students and the instructor in comparison with offline classes, so it is necessary for learners to develop their own ability to solve programming errors by themselves. Therefore, in this study, error cases in online programming classes using the Python language are analyzed and an online programming education method that can improve learners' ability to correct programming errors is proposed based on the analysis results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1201-1208
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• 2014

As the wireless communication technologies are being studied for application to marine communication networks in a fusion of marine industries and IT technology, this paper proposes a HARQ-ARQ interaction scheme for reliable communication between the smart ships. Moreover, this paper evaluates the performance of the HARQ-ARQ interaction schemes through the computer simulation. In the HARQ-ARQ interaction scheme for marine network systems, as a HARQ acknowledgement is implicitly utilized as an ARQ acknowledgement. Hence, the HARQ-ARQ interaction scheme can reduce the packet delay. However, the HARQ-ARQ interaction scheme has problems caused by the error of HARQ feedback messages. Hence, this paper considers the effect of error of HARQ feedback messages on the performance of the HARQ-ARQ interaction scheme, in marine network systems. The simulation results show that the HARQ-ARQ interaction scheme can improve the delay performance of the ships in the marine network systems.