• Journal of the Korean Society of Physical Medicine
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• v.12 no.3
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• pp.33-42
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• 2017

PURPOSE: To compare postural vertical training with and without visual feedback for improving functional recovery in post-stroke hemiparesis patients with pusher syndrome. METHODS: This study used a single-subject research with alternating design with multiple baselines. Three patients with hemiparetic post-stroke diagnosed with pusher syndrome were selected from the inpatients at the department of physical therapy of a local rehabilitation hospital. For subjective postural vertical (SPV) training with and without visual feedback, an alternating treatment was used. The subjects were randomly selected using the sequence of the two training methods upon starting the intervention, and then the training was alternated. SPV training was performed twice a day, once in the morning and again in the afternoon. Scale for contraversive pushing (SCP), postural assessment scale for stroke, and Barthel index score were used to determine the intervention-related changes. RESULTS: Compared to the average score at baseline, the average SCP score for the SPV training without visual feedback decreased from 5.3 to 2.8, from 4.6 to 3, and from 3.5 to 2.7 for subjects 1, 2, and 3, respectively. However, the average score for the SPV training with visual feedback decreased from 5.3 to 3.1, from 4.6 to 3.5, and from 3.5 to 3.3 for subjects 1, 2, and 3, respectively. CONCLUSION: Postural vertical training without visual feedback may be more beneficial than postural vertical training with visual feedback for improving pushing behavior and functional activity in stroke patients with pusher syndrome.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.203-213
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• 2009

Medicine is one of great application fields where Virtual Reality (VR) technologies have been successfully utilized. The VR technologies in medicine bring together an interdisciplinary community of computer scientists and engineers, physicians and surgeon, medical educator and students, military medical specialists, and biomedical futurists. The primary feedback of a VR system has been visual feedback. The complex geometry for graphic objects and utilizing hardware acceleration can be incorporated with in order to produce realistic virtual environments. To enhance human-computer interaction (HCI), in term of immersive experiences perceived by users, haptic, speech, olfactory and other non-traditional interfaces should also be exploited. Among those, hapic feedback has been tightly coupled with visual feedback. The combination of the two sensory feedbacks can give users more immersive, realistic and perceptive VR environments. Haptic feedback has been studied over decades and many haptic based VR systems have been developed. This paper focuses on haptic feedback in term of its medical usages. It presents a survey of haptic feedback techniques with their applications in medicine.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.207-214
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• 2011

The purpose of this study was to investigate effect of feedback methods and ambulatory assistive aids on accuracy of partial weight bearing in healthy adults. Twenty subjects were recruited and trained to 30% weight bearing of body weight (BW) using 3-point gait crutches and wheeled walker pattern. Dynamic feedback group (n=11) was received dynamic postresponse feedback and static group (n=9) received static feedback. Force plate was used to measure %BW and GAITRite used to measure gait parameters in immediately and after 3 days of training. Immediately after training, there was not significantly at 30%BW target load in dynamic group with crutch gait (p>.05). There were significantly differences in %BW according to feedback methods and ambulatory aids (p<.05). There was not significant difference between immediately and after 3 days of training (p>0.05). There were significantly differences in gait velocity and stance ratio between crutches and wheeled walker gait (p<.05). Thus, it was suggested that if possible, use crutches, training for partial weight bearing via dynamic feedback is necessary.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1036-1055
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• 1992

In this paper the feedback linearization of the valve-controlled nonlinear hydraulic velocity control system and the implementation of the digital state feedback controller is studied. The $C^{\infty}$ nonlinear transfomation to the electro-hydraulic velocity control system, which transforms nonlinear system to linear equivalent one, is obtained. It is shown that this transformation is global one. The digital controller to this linearized model is obtained by using the one-step ahead state estimator and implemented to real plant. The proposed implementation method is easier than the other proposed methods and it is possible to control in real time. The experiment and simulation study show that the implementation of the digital state feedback controller based on the feedback linearized model is successful..

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.63-70
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• 2017

Recently, as user feedback such as social reading become active, demand has been increased on e-book contents making which is based on user feedback. However, to reflect the user feedback onto the e-book, direct coding is required, which was difficult to the author who was not good at programming. To resolve this problem, Block assembly style feedback editor system, using Blockly was developed. This editor enables to reflect the user feedback by area allocation, component allocation, block editing, and code generating insertion, contrary to the existing way of programming realization in which direct coding was required for input, processing and output separately. This system was developed by using HTML. Javascript, PHP, and Codeigniter. Block editing is enabled to do provision and assembly of blocks by Blockly. The function of code generation & insertion allows to insert the Library function code. Through this system, the general users who are not capable of coding also can reflect feedback without doing actual coding.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.673-676
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• 2015

Digital Pre-Distortion (DPD) is a linearization technique for nonlinear power amplifiers (PAs) by implementing inverse function of the PA at baseband digital stage. To obtain proper DPD parameters, a feedback path is required to convert the PA output to a baseband signal, and a memory is also needed to store the feedback signals. DPD parameters are usually found by an adaptive algorithm from the feedback samples. However, for the adaptive algorithm to converge to a reliable solution, long feedback samples are required, which increases convergence time and hardware complexity. In this paper, we propose a DPD technique that requires relatively short feedback samples. From the observation that the convergence time of the adaptive algorithm highly depends on the initial condition, this paper iteratively utilizes the feedback samples while keeping and using the converged DPD parameters at the former iteration as the initial condition at the current iteration. Computer simulation results show that the proposed method performs better than the conventional technique while the former requires much shorter feedback samples than the latter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.798-803
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• 2006

An opportunistic scheduling is adopted to improve the capacity of the system by exploiting the multiuser diversity of multiuser MIMO(MU-MIMO) systems. However it requires the large amount of feedback carrying the channel quality information(CQI) of each user to the transmitter, The considered per user unitary and rate control(PU2RC) needs to feedback the preferred preceding index and its CQIs, and it has a defect in scheduling the streams for the grouped user. In order to overcome these drawbacks, a novel feedback reduction scheme is proposed in this paper. It employs transmitter controlled preceding and opportunistic feedback(TCP-OFB). The simulation results demonstrate that TCP-OFB shows comparable performance to PU2RC while it only requires far reduced feedback load.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.503-510
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• 2019

This study aimed to analyze the effects of nursing students' learning motivation, learning attitude and academic self-efficacy on their application of reflective journal with teaching feedback. For this retrospective comparative study data from 190 undergraduate students in the health assessment skills course from 2018 to 2019. The collected data were analyzed by chi-square test, independent t-test, Ancova. After writing reflection journal with teaching feedback showed significant difference in learning motivation(t=2.10, p=.037) and learning attitude (t= 4.54, p=.034) compared to writing reflection journal without teaching feedback. However, no significant difference was found between reflection journal with teaching feedback and reflection journal without teaching feedback. These results suggest writing reflection with teaching feedback is an effective strategy for improving learning motivation and learning attitude.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.74-86
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• 2002

This paper proposes a VLSI architecture for high-speed data processing of the differential phase detectors with the decision feedback. To improve the BER performance of the conventional differential phase detection, DF-DPD, DPD-RGPR and DFDPD-SA have been proposed. These detection methods have the architecture feedbacking the detected phase to reduce the noise of the previous symbol as phase reference. However, the feedback of the detected phase results in lower data processing speed than that of the conventional differential phase detection. In this paper, the VLSI architecture was proposed for high-speed data processing of the differential phase detectors with decision feedback. The Proposed architecture has the pre-calculation method to previously calculate the results on 'N'th step at 'M-1'th step and the pre-decision feedback method to previously feedback the predicted phases at 'M-1'th step. The architecture proposed in this paper was implemented to RTL using VHDL. The simulation results show that the Proposed architecture obtains the high-speed data processing.

• BMB Reports
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• v.32 no.1
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• pp.20-24
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• 1999

The first step of the branch pathway in tryptophan biosynthesis is catalyzed by anthranilate synthase, which is subjected to feedback inhibition by the end product of the pathway. The $trpE^{FBR}$ gene from a mutant Escherichia coli strain coding for anthranilate synthase that was insensitive to feedback inhibition by tryptophan has been cloned. To identify the amino acid changes involved in the feedback regulation of anthranilate synthase, the nucleotide sequence of the mutant $trpE^{FBR}$ gene was determined. Sequence analysis of the $trpE^{FBR}$ gene revealed that four bases were changed in the structural gene while alteration was not found in the 5' control region. Among these base changes, only two base substitutions caused the alterations in amino acid sequences. From the results of restriction fragment exchange mapping, the 61st nucleotide, C to A substitution, that changed $Pro^{21}{\rightarrow}Ser$ was identified as the cause of the desensitization to feedback inhibition by tryptophan. Additional feedback-resistant enzymes of the E. coli anthranilate synthases were constructed by site-directed mutagenesis to examine the effect of the $Ser^{40}\;{\rightarrow}\;Arg^{40}$ change found in the $trpE^{FBR}$ gene of Brevibacterium lactofermentum. From the feedback inhibition analysis, the $Pro^{21}{\rightarrow}Ser$ and $Ser^{40}{\rightarrow}Arg$ mutants maintained about 50% and 90% of their maximal activities, respectively, even at the extreme concentration of 10 mM tryptophan. From these results, we suggest that the $Pro^{21}$ and $Ser^{40}$ residues are involved in the tryptophan binding in the E. coli enzyme.