• 한국통신학회논문지
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• 제27권6B호
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• pp.625-637
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• 2002

This study extends the modified linear feedback equalizer (MLFE), normally used for differentially coherent DPSK systems, to the equalization of double differentially coherent PSK (DDPSK) signals. By feeding back into the feedback part after modifying the equalizer output using decision feedback-based demodulation, the proposed equalizer can operate like an equalizer with a decision feedback structure. Simulation results showthat performances of the decision feedback demodulation-based feedback equalizer (DFD-FE) approach those of the DFE/coherent.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.955-959
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• 2011

In this paper, we assume that an output sensor of a ball and beam system is coupled with AC measurement noise. We propose an output feedback controller for a ball and beam system under measurement noise of feedback sensor. Measurement noise makes feedback signals distorted, and results in performance degradation or even system failure. Therefore, we need to design a robust controller to accommodate the possible measurement noise in the feedback information. Our controller is equipped with a gain-scaling factor to minimize the effect of measurement noise in output feedback information. We give an analysis of the controlled system and illustrate the improved control performance via simulation and experiment for a ball and beam system.

• Educational Technology International
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• 제12권2호
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• pp.71-94
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• 2011

How can an automated essay scoring (AES) program, which provides feedback for essays, be a formative tool for improving ESL writing? In spite of the increasing demands for English writing proficiency, English writing instruction has not been effective for teaching and learning because of a lack of timely and accurate feedback. In this context, AES as a possible solution has been gaining the attention of educators and scholars in ESL/EFL writing education because it can provide consistent and prompt feedback for student writers. This experimental study examined the impact of different types of feedback for a college ESL writing program using the Criterion AES system. The results reveal the positive impact of AES in a college-level ESL course and differences between the teacher's feedback and the AES feedback. The findings suggest that AES can be effectively integrated into ESL writing instruction as a formative assessment tool.

• 영어어문교육
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• 제17권3호
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• pp.73-98
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• 2011

This study investigated the feasibility and effectiveness of incorporating oral corrective feedback into the content-based business English writing class. Two types of oral corrective feedback, recasts and metalinguistic feedback, were integrated into business English writing classes to help low intermediate-proficiency Korean university students improve the ability to use the simple past, present progressive, and present perfect tenses correctly in their written production. Prior to the treatments, the subjects had basic grammatical knowledge of the target verb tenses, but they had only limited control over them in their written production. Three groups were formed: recast group that received corrective recasting, metalinguistic group that received metalinguistic clues, and control group that received no oral corrective feedback. The study demonstrated that it was feasible to incorporate recasts and metalinguistic feedback into content-based business English writing classes and that metalinguistic feedback had greater and more endurable effects than recasts on promoting the correct use of the target verb tenses in written production. It can be concluded that oral corrective feedback, metalinguistic feedback in particular, can be used in the business English writing classroom to help students gain greater control over already partially acquired forms and therefore improve their writing accuracy.

• 한국멀티미디어학회논문지
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• 제20권2호
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• pp.313-321
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• 2017

The emergence of E-book have allowed readers to interact with other readers and to actively participate (e.g. social reading). Furthermore, there is a growing demand in writer's community to take the advantage of the feedback from their readers to update the content of E-book. To do that, they require the service that utilizes the user feedback while creating or updating the e-book content. This study aims to let authors collect and to apply the reader's feedback on E-book content. However, in order to apply the user feedback, users first need to explicitly type the feedback, and even if they do, authors need to develop the software to automatically analyze and to apply the user feedback. This makes difficult for authors without programming background to produce E-book with automatic content adaptation. In this paper, we propose Feedback Clue Model to generate, analyze and apply the user feedback into E-book content. Based on this model, we develop the block editor which allows easy implementation of E-book that can be dynamically updated.

• 한국경영과학회지
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• 제37권1호
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• pp.73-88
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• 2012

This study examines the role of perceived feedback and motivations on the use for contribution in Knowledge Management Systems (KMS). An individual expects responses from others when he or she posts the knowledge or questions of soliciting knowledge in KMS. If an individual posts a message and there are many responses, motivation to use KMS will develop. Prior research has considered feedback a potential factor that would affect an individual's motivation, such as self-efficacy, but there is few prior works that have tested empirically on how feedback can influence an individual's motivations as well as the use for contribution in KMS. Perceived feedback can be categorized into feedback on posted knowledge and feedback on knowledge request postings. The results of the study show that motivations such as organizational reward, knowledge self-efficacy, and enjoyment of helping, except for social reward, are associated with the use for contribution. Our results also show that among perceived feedback, feedback on posted knowledge affects motivation and use for contribution while feedback on knowledge request postings directly influences the use for contribution.

• Journal of Communications and Networks
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• 제15권6호
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• pp.589-600
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• 2013

In this paper, we propose a new feedback scheme called mode selection-based feedback by scheduling probability prediction (SPP-MF) for channel state feedback in OFDMA downlink system. We design the scheme such that it determines the more desirable feedback mode among selective feedback by scheduling probability prediction (SPP-SF) mode and bitmap feedback by scheduling probability prediction (SPP-BF) mode, by calculating and comparing the throughputs of the two modes. In both feedback modes, each user first calculates the scheduling probability of each subchannel (i.e., the probability that a user wins the scheduling competition for a subchannel) and then forms a feedback message based on the scheduling probability. Specifically, in the SPP-SF mode, each user reports the modulation and coding scheme (MCS) levels and indices of its best S subchannels in terms of the scheduling probability. In the SPP-BF mode, each user determines its scheduling probability threshold. Then, it forms a bitmap for the subchannels according to the scheduling probability threshold and sends the bitmap along with the threshold. Numerical results reveal that the proposed SPP-MF scheme achieves significant performance gain over the existing feedback schemes.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.219-222
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• 2017

본 연구에서는 음성 사용자 인터페이스가 적용된 시스템 사용 중 오류가 발생했을 때 제공되는 피드백이 시스템에 대한 사용자의 평가에 어떠한 영향을 줄 것인지에 대해 알아보았다. 피드백 유형(확인 피드백, 정교화 피드백)과 오류 유형(인식 실패, 수행 실패)을 독립 변수로 하고 사용자의 주관적 평가와 피드백 수용성, 향후 이용 의도를 종속 변수로 하는 요인설계 실험연구를 진행하였다. 이원 다변량 분산분석을 한 결과, 피드백 유형만 사용자의 주관적 평가와 피드백 수용성, 향후 이용의도에 영향을 미치는 것으로 나타났다. 또한, 피드백 수용성에 대해 피드백 유형과 오류 유형의 상호작용 효과가 발견되었다. 따라서 VUI 설계 시, 오류 정보를 자세히 알려주는 피드백을 제공하는 것을 고려해 볼 수 있을 것이다.

• 국제물리치료학회지
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• 제9권4호
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• pp.1602-1607
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• 2018

This study examined the correlation between power error (PE) and velocity error (VE) according to the condition and frequency of self-controlled feedback (SCF) during knee extension. One hundred participants were randomly assigned to 30% SCF, 70% SCF, 30% yoked feedback (YF), 70% YF and control group, respectively. The SCF group was provided with feedback when they requested it, whereas the YF group did not influence the feedback schedule. Participants in the control group were not given any visual feedback during the experiment. The isotonic, isometric, and isokinetic dynamometer (PRIMUS RS, BTE, USA) was used to measure the power and velocity error during knee extension. The collected data was analyzed using a Pearson test and SPSS 21.0. The correlation between PE and VE according to the condition and frequency of feedback on each phase during knee extension was significant. Both PE and VE were significantly higher when the feedback was provided with high frequency, passive, and no feedback. Our study suggests that application of SCF can help to improve the proprioception of the healthy person while reducing errors through low frequency and active feedback.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.202-205
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• 2000

본 논문에서는 IMT-2000용 고전력 중폭기에 사용할수 있근 전치 왜곡기를 feedback 방식을 이용하여 설계하였다. 여기서 feedback 방식을 사용함으로써 기존의 전치 왜곡기와는 달리 증폭기의 이득을 조절하기 위해 감쇄기를 사용하지 않고 feedback에 사용한 저항값을 사용하여 이득을 조절하도록 설계하였다.