• Journal of KIISE:Databases
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• v.36 no.6
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• pp.434-445
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• 2009

Content-based image retrieval(CBIR) is the retrieval technique which uses the contents of images. However, in contrast to text data, multimedia data are ambiguous and there is a big difference between system's low-level representation and human's high-level concept. So it doesn't always mean that near points in the vector space are similar to user. We call this the semantic-gap problem. Due to this problem, performance of image retrieval is not good. To solve this problem, the relevance feedback(RF) which uses user's feedback information is used. But existing RF doesn't consider user's region-of-interest(ROI), and therefore, irrelevant regions are used in computing new query points. Because the system doesn't know user's ROI, RF is proceeded in the image-level. We propose a new ROI RF method which guides a user to select ROI from relevant images for the retrieval of complex satellite image, and this improves the accuracy of the image retrieval by computing more accurate query points in this paper. Also we propose a pruning technique which improves the accuracy of the image retrieval by using images not selected by the user in this paper. Experiments show the efficiency of the proposed ROI RF and the pruning technique.

• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1312-1320
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• 2004

Recently, even if a lot of visual feature representations have been studied and systems have been built, there is a limit to existing content-based image retrieval mechanism in its availability. One of the limits is the gap between a user's high-level concepts and a system's low-level features. And human beings' subjectivity in perceiving similarity is excluded. Therefore, correct visual information delivery and a method that can retrieve the data efficiently are required. Relevance feedback can increase the efficiency of image retrieval because it responds of a user's information needs in multimedia retrieval. This paper proposes an efficient CBIR introducing positive and negative relevance feedback with threshold value and pre-fetching to improve the performance of conventional relevance feedback mechanisms. With this Proposed feedback strategy, we implement an image retrieval system that improves the conventional retrieval system.

• 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.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.61-67
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• 2000

Generally, relevance, feedback reflecting user's intention has been used to refine the refine the query conditions in image retrieval. However, in this paper, the usage of the relevance feedback is extended to the image database categorization so as to be accommodated to the user independent image retrieval. In our approach, to guarantee a desirable user-satisfactory performance descriptors and the elements of the descriptors corresponding unique features associatiated with of each image are weighted using the relevance feedback where experts can more lead rather than beginners do. In this paper, we propose a proper image description scheme consisting of global information, local information, descriptor weights and element weights based on color and texture descriptors. In addition, we also introduce an appropriate learning method based on the reliability scheme preventing wrong learning from abusive feedback.

• 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.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.287-290
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• 2011

분산 동영상 부호화 시스템에서는 복호기에서 움직임 보상 보간 기법을 이용하여 부가정보를 생성한다. 생성된 부가정보와 원 Wyner-Ziv 프레임간의 차이를 채널 부호로 오류 정정하게 되는데 이때 부호기에서는 복호기에서의 오류 정정을 위하여 패리티 비트인 Wyner-Ziv 비트를 복호기로 보내게 되고 복호기에서는 이 Wyner-Ziv 비트를 이용하여 Wyner-Ziv 프레임을 복원하는데 더 많은 Wyner-Ziv 비트가 필요할 경우 피드백 채널을 통해 Wyner-Ziv 비트를 요청하게 된다. 이때 부호기에서 조건부 엔트로피를 구할 수 있다면 이를 이용하여 Wyner-Ziv 비트 전송량을 제어함으로써 피드백 채널을 제거 할 수 있다. 이를 위해 부호기에서도 부가정보를 알아야하는데 복호기에서 사용하는 부가정보 생성 기법은 복잡도가 높기 때문에 사용할 수 없다. 본 논문에서는 부호기에서 간단한 부가정보를 생성하는 방법을 제안하고 분산 동영상 부호화 시스템에 적용하여 피드백 채널을 제거하였을 때의 성능을 분석하였다.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.231-232
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• 2011

마이크로티칭은 교사들의 모의수업을 녹화한 후 피드백, 평가, 성찰의 과정을 통하여 수업 스킬을 개선하는 교수-학습방법으로 교직수업 및 교원연수 등에 활용되고 있다. 그러나 마이크로티칭을 진행하는 데에는 상당한 시간적, 물리적 부담이 부가되며, 때문에 더욱 의미있는 학습, 평가와 성찰의 기회가 허락되지 않기도 한다. 따라서 이를 효율적, 효과적으로 지원할 수 있는 방안이 모색되어야 한다는 요구가 있다. 본 연구에서는 동영상 위키 시스템에 기반을 둔 마이크로티칭 지원도구를 개발하였다. 이 시스템은 텍스트, 음성 기반 피드백 기능을 지원하여 교수자의 피드백을 보다 원활하게 도우며, 동영상 위키의 속성을 활용하여 동료피드백을 지원하여 능동적 상호작용이 이루어질 수 있다.

• The KIPS Transactions:PartB
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• v.13B no.4 s.107
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• pp.383-392
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• 2006

In this paper, we propose a new relevance feedback algorithm using Probabilistic Neural Networks(PNN) while supporting multi-class learning. Then, to validate the effectiveness of our feedback approach, we incorporate the proposed algorithm into our region-based image retrieval tool, FRIP(Finding Regions In the Pictures). In our feedback approach, there is no need to assume that feature vectors are independent, and as well as it allows the system to insert additional classes for detail classification. In addition, it does not have a long computation time for training because it only has four layers. In the PNN classification process, we store the user's entire past feedback actions as a history in order to improve performance for future iterations. By using a history, our approach can capture the user's subjective intension more precisely and prevent retrieval performance errors which originate from fluctuating or degrading in the next iteration. The efficacy of our method is validated using a set of 3000 images derived from a Corel-photo CD.

• Smart Media Journal
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• v.13 no.5
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• pp.62-71
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• 2024

This study conducted a team-based CPR simulation with 32 fourth-year emergency rescue students to determine the effectiveness of training feedback using body cameras used at emergency rescue sites, and measured awareness, training feedback effectiveness, and satisfactio+n before and after body camera feedback. , preferences and difficulties in using body camera devices were identified. Data analysis was performed using SPSS 27.0 program, including descriptive statistics, frequency analysis, paried t-test, and Wilcoxon signed rank test. As a result of the study, the perception of body camera use showed a positive change from 3.73±0.62 points to 4.45±0.54 points, and a positive satisfaction level of 3.98±0.51 was shown (p<.001). Additionally, there was a significant increase in self-check accuracy and performance score after body camera feedback (p<.001). Therefore, during team-based simulation resuscitation training, positive feedback effects in improving self-inspection ability and performance can be achieved by watching body camera videos and using self-checklists without direct feedback from the instructor.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.101-104
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• 2002

본 문서에서는 사용자 적합성 피드백을 적용한 멀티미디어검색 기법을 제안한다. 적합성 피드백은 멀티미디어검색에 있어 사용자가 요구하는 정보를 반영할 수 있어 영상의 검색 효율을 높일 수 있다. 이 실험에서는 긍정적 피드백과 부정적 피드백을 함께 사용하였다. 실험결과, 적합성 피드백을 이용하면 적은 횟수의 반복검색으로 우수한 결과를 얻을 수 있음을 알 수 있다.