• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.498-504
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• 1998

This paper presents an optimal control algorithm for the overhead crane. To control the swing motion and the position tracking of the payload of the overhead crane a state feedback control algorithm is applied. by using a hybrid genetic algorithm the feedback gains of the state feedback is optimized to minimize the cost function composed of position errors and payload swing angle under unknown constant disturbances. Computer simulation is performed to demonstrate the effectiveness of the proposed control algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.443-443
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• 2000

A systematic scheme is developed fer the design of new adaptive feedback linearizing controllers for nonlinear systems. The developed adaptation law estimates the uncertain time-varying parameters using the structure of diffeomorphisrn. Our scheme is applicable to a class of nonlinear systems which violates the restrictive parametric-pure-feedback condition [4]-[6].

• Asia pacific journal of information systems
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• v.17 no.4
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• pp.61-95
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• 2007

Small-and-medium sized enterprises(SMEs) represent quite a large proportion of the industry as a whole in terms of the number of enterprises or employees. However researches on information system so far have focused on large companies, probably because SMEs were not so active in introducing information systems as larger enterprises. SMEs are now increasingly bringing in information systems such as ERP(Enterprise Resource Planning Systems) and some of the companies already entered the stage of ongoing use. Accordingly, researches should deal with the use of information systems by SME s operating under different conditions from large companies. This study examined factors and mechanism inducing faithful appropriation of information systems, in particular integrative systems such as ERP, in view of individuals` active feedback-seeking behavior. There are three factors expected to affect end users` feedback-seeking behavior for faithful appropriation of information systems. They are management support, peer IT champ support, and IT staff support. The main focus of the study is on how these factors affect feedback-seeking behavior and whether the feedback-seeking behavior plays the role of mediator for realizing faithful appropriation of information systems by end users. To examine the research model and the hypotheses, this study employed an empirical method based on a field survey. The survey used measurements mostly employed and verified by previous researches, while some of the measurements had gone through minor modifications for the purpose of the study. The survey respondents are individual employees of SMEs that have been using ERP for one year or longer. To prevent common method bias, Task-Technology Fit items used as the control variable were made to be answered by different respondents. In total, 127 pairs of valid questionnaires were collected and used for the analysis. The PLS(Partial Least Squares) approach to structural equation modeling(PLS-Graph v.3.0) was used as our data analysis strategy because of its ability to model both formative and reflective latent constructs under small-and medium-size samples. The analysis shows Reliability, Construct Validity and Discriminant Validity are appropriate. The path analysis results are as follows; first, the more there is peer IT champ support, the more the end user is likely to show feedback-seeking behavior(path-coefficient=0.230, t=2.28, p<0.05). In other words, if colleagues proficient in information system use recognize the importance of their help, pass on what they have found to be an effective way of using the system or correct others' misuse, ordinary end users will be able to seek feedback on the faithfulness of their appropriation of information system without hesitation, because they know the convenience of getting help. Second, management support encourages ordinary end users to seek more feedback(path-coefficient=0.271, t=3.06, p<0.01) by affecting the end users' perceived value of feedback(path-coefficient=0.401, t=6.01, p<0.01). Management support is far more influential than other factors that when the management of an SME well understands the benefit of ERP, promotes its faithful appropriation and pays attention to employees' satisfaction with the system, employees will make deliberate efforts for faithful appropriation of the system. However, the third factor, IT staff support was found not to be conducive to feedback-seeking behavior from end users(path-coefficient=0.174, t=1.83). This is partly attributable to the fundamental reason that there is little support for end users from IT staff in SMEs. Even when IT staff provides support, end users may find it less important than that from coworkers more familiar with the end users' job. Meanwhile, the more end users seek feedback and attempt to find ways of faithful appropriation of information systems, the more likely the users will be able to deploy the system according to the purpose the system was originally meant for(path-coefficient=0.35, t=2.88, p<0.01). Finally, the mediation effect analysis confirmed the mediation effect of feedback-seeking behavior. By confirming the mediation effect of feedback-seeking behavior, this study draws attention to the importance of feedback-seeking behavior that has long been overlooked in research about information system use. This study also explores the factors that promote feedback-seeking behavior which in result could affect end user`s faithful appropriation of information systems. In addition, this study provides insight about which inducements or resources SMEs should offer to promote individual users' feedback-seeking behavior when formal and sufficient support from IT staff or an outside information system provider is hardly expected. As the study results show, under the business environment of SMEs, help from skilled colleagues and the management plays a critical role. Therefore, SMEs should seriously consider how to utilize skilled peer information system users, while the management should pay keen attention to end users and support them to make the most of information systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1249-1256
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• 2019

In this paper, we propose a new algorithm to remove acoustic feedback and noise in hearing aids. Instead of using the conventional FIR structure, this algorithm is a deep learning algorithm using neural network adaptive prediction filter to improve the feedback and noise reduction performance. The feedback canceller first removes the feedback signal from the microphone signal and then removes the noise using the Wiener filter technique. Noise elimination is to estimate the speech from the speech signal containing noise using the linear prediction model according to the periodicity of the speech signal. In order to ensure stable convergence of two adaptive systems in a loop, coefficient updates of the feedback canceller and noise canceller are separated and converged using the residual error signal generated after the cancellation. In order to verify the performance of the feedback and noise canceller proposed in this study, a simulation program was written and simulated. Experimental results show that the proposed deep learning algorithm improves the signal to feedback ratio(: SFR) of about 10 dB in the feedback canceller and the signal to noise ratio enhancement(: SNRE) of about 3 dB in the noise canceller than the conventional FIR structure.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.969-978
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• 2016

The purpose of this study is to figure out gifted elementary science students' improvement in performing open inquiry after peer review. In this study, gifted fifth-grade students performed open inquiry and review of each other as peers after the inquiry. Students' inquiries were evaluated and the influences of the feedback from the peer reviews were analyzed in relation to the inquiry performances. As a result of this study, three key points were discovered: First, the evaluation score increased with frequent feedback or long discussions. On the other hand, with less feedback, the evaluation score didn't rise. Second, there were three types of improvement in inquiry related to peer review: No. 1 was improvement after feedback given by themselves. No. 2 was reflection of feedback given to other groups. As a last type, No. 3 was that the students learned from other groups' presentation without any feedback and improved their inquiry. Third, there were five kinds of giving feedback; (1) feedback understanding the inquiry correctly, (2) insufficiency of peer's inquiry without deep thought. (3) on the usefulness of the inquiry, (4) on the scientific and logic validity through critical thinking, and (5) how to develop the inquiry. In these kinds of feedback, the fourth kind of feedback (4) occurred most frequently but the fifth (5) occurred rarely. It means peer review helps students develop their critical thinking ability and teachers should encourage students to give peers feedback of the fifth kind.

• The Journal of Korean Association of Computer Education
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• v.7 no.1
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• pp.141-149
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• 2004

Today there are many Web courseware systems for formative evaluation and feedback. Formative evaluation and feedback provided according to users' response in most Web courseware systems, however, are simple texts showing only whether correct or wrong, correct answers, relevant information, etc., far deviated from actual context. Thus such a system may weaken the corrective function of feedback and, as a result, reduce learners' understanding of contents and the possibility of learning transfer. In addition, according to the learning theory of constructivism, learning is influenced by the situation, in which it happens, and knowledge is learned and transferred differently depending on the context in which it is learned. In the background, this study designed and implemented a contextual error-correction feedback system that can provide feedback in a context closely related and similar to the relevant situation according to the response of learners when formative evaluation is carried out in Web courseware. In addition, it applied 'correction/correct-answer-providing feedback', 'relevant information providing feedback' and 'contextual error-correction feedback' to Web courseware for learning actual productivity S/W and verified if 'contextual error-correction feedback' is more effective than other two types of feedback for learners' academic achievement.

• Journal of the Korean School Mathematics Society
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• v.10 no.1
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• pp.71-89
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• 2007

The present study was investigate the effects of feedback on mathematical achievement and attitude toward mathematics. Referring to the improvement of mathematics achievement, feedback groups(group I and II) turns out to be more efficient than the normal learning group(group III)(p<.05), there found no significant differ between group I and II(p>.05). As for the poor level of mathematics achievement, feedback groups(group I and II) turns out to be more efficient than the normal learning group(group III)(p<.05), there for fine level, found no significant differ between feedback group(group I and II)and the normal learning group(group III)(p>.05). Referring to the improvement of attitude toward mathematics, feedback groups(group I and II) turns out to be more efficient than the normal learning group(group III)(p<.05), there found no significant differ between feedback groups(group I and II)and the normal learning group(group III)(p>.05). As for the level(find or poor) of mathematics achievement, feedback groups(group I and II) turns out to be more efficient than the normal learning group(group III)(p<.05), there found no significant differ between feedback group(group I and II) and the normal learning group(groupIII)(p>.05).

• Science of Emotion and Sensibility
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• v.8 no.4
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• pp.423-433
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• 2005

The computer hardware development has provided many chances of emergence between art and technology. In many cases today's interactive artworks cannot be completed without audience's participation. The interactive production process with technical supplementation can be celled feedback. Mr. Nam Jun Paik showed 'Participant TV' that interacts with audience's response in real time. It means artwork changes with the constantly changing value from the data set from human visual perception. Dan Graham showed another feedback related work, which delays 5second playback in mirror that implies consequence of time. Today's media art has to sublimate coincidence, time ant audience into philosophical artwork through consonance that comes with video and sound as we can see from Bill Viola. Stelarc produced artworks. That use input data that is weak signals from brain, muscles. Through a terminal display with player, body expanded meaning of media. Jeffrey Shaw's 'Legible City' provided a fabrication of the reality with the interaction of bicycle's pedal speed and steering direction that is controlled by 4river. RE:MARK used microphone as input device as Edmond Couchot's 'Je same a la vent' and Nam Jun Paik's 'Participant TV' did. There is no communication without feedback between human being. The reality makes audience involved into artworks. That is the reason why feedback has to be natural. Through the feedback process, the originality of the idea is altered by audience. The feedback is not just part of flesh of artwork rather skeleton of it. Technological showoff cannot be art itself The perfection of technological application plan helps feedback that interacts with audience naturally in order that audience hoes not feel the feedback as artificial plan. Interactive media art has to be evolved into new media form with new integration feedback technology.

• Physical Therapy Korea
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• v.5 no.3
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• pp.1-10
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• 1998

In motor learning, the relative frequency of external feedback is the proportion of external feedback presentations divided by the total number of practice trials. In earlier studies, increasing the percentage of body weight loading on the affected leg of hemiplegic patients, external feedback was continuously produced as the patient attempted to perform a movement. This feedback was produced to enhance the learning effect. However, recent studies in nondisabled populations have suggested that compared with 100% relative frequency conditions, practice with lower relative frequencies is more effective. My study compared the effect of 100% relative frequency conditions with 67% relative frequency conditions to determine what effect they exerted on motor learning for increasing the percentage of body weight loading on the affected lower limbs of patients with hemiplegia. Twenty-four hemiplegic patients were randomly assigned to one of two experimental groups. Each group practiced weight transfer motor learning on a machine. During practice, visual feedback was offered to all subjects. The experiment was carried out with full visual feedback for patients in group one but only 67% visual feedback for patients in group two. The percentage of loading on the affected leg was recorded four times: before learning (baseline value), immediately after learning, 30 minutes after learning, 24 hours after learning. The results were as follows: 1. In the 100% visual feedback group, the percentage of loading on the affected leg increased significantly in all three testing modes over the baseline value. 2. In the 67% visual feedback group, the percentage of loading on the affected leg increased significantly in all three measurements. 3. Immediately after learning, the learning effect was not significantly different between the two groups, but was significantly greater after both the 30 minutes delay and the 24 hours period. These results suggest that the 33% reduction in the provision of visual feedback may enhance the learning effect of increasing the percentage of body weight loading on the affected leg in patients with hemiplegia.

• Journal of English Language & Literature
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• v.57 no.6
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• pp.977-998
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• 2011

The purpose of this study is to investigate prospective teachers' perceptions of the peer review comments readily available to them during the writing process in a teacher training class. Given these needs, we employ a qualitative method of inquiry giving voice to the learner's own view of peer feedback. The data we wish to consider is first-person narratives elicited from four EFL college students, who are prospective teachers of English. With regard to the EFL students' narrative considered here, all were attentive to the feedback they received. Moreover, the way in which these EFL writers talk about peer response activity reflects that they still welcome peer feedback because of the benefits to be accrued from it. Although this study, covering only four EFL students in total, can hardly be considered conclusive, we attempt to offer a synthesis of their stories. First of all, students indicate that they received responses from "authentic readers" (Mittan 1989, 209). We do note, consequently, that students gain a clear understanding of readers' needs by receiving feedback on what they did well and on what seems unclear. Perhaps the greater effect of peer feedback claimed by these students is that they take active roles in utilizing peer comments. Since they feel uncertain about the validity of their classmates' responses, students feel that they have autonomy over their own text and can make their own decisions on whether they should accept their peer comments or not. This contrasts with their treatment of teacher comments that they accept begrudgingly even if they disagree with them. Four EFL writers talked a lot, typically in a positive way, about peer response to their writing, yet they have expressed reservations about the extent to which they should put any credence in comments offered by their fellow students. Perhaps this is because their fellow students are still developing writers and EFL learners. In turn, they were sometimes reluctant to accept the peers' comments. Thus, in EFL contexts, L1 use can be suggested during peer feedback sessions. In particular, we have come to feel that L1 use enables both reviewers and receivers to have more productive peer review experiences. Additionally, we need to train students not "to see peer feedback as potentially bad advice" (Silva et al. 2003, 111). Teachers should focus on training students to utilize their peers' comments. Without such training, students will either ignore feedback or fail to use it constructively.