• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2748-2766
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• 2016

Compared with traditional patch-based sparse representation, recent studies have concluded that group-based sparse representation (GSR) can simultaneously enforce the intrinsic local sparsity and nonlocal self-similarity of images within a unified framework. This article investigates an accelerated split Bregman method (SBM) that is based on GSR which exploits image compressive sensing (CS). The computational efficiency of accelerated SBM for the measurement matrix of a partial Fourier matrix can be further improved by the introduction of a fast Fourier transform (FFT) to derive the enhanced algorithm. In addition, we provide convergence analysis for the proposed method. Experimental results demonstrate that accelerated SBM is potentially faster than some existing image CS reconstruction methods.

• 대한의용생체공학회:의공학회지
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• 제8권2호
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• pp.151-160
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• 1987

An algorithm is suggested that truncted projection among the incomplete projections can be recovered from non-iterative extrapolation matrix by band-limited function. After the image being reconstructed from the recovered signals by non-iterative extrapolation, a known controur information and reprojection algorithm are used. It is shown that the reconstructed image using these algorithms is close to the original image. The effectiveness for these algorithms is proved by computer simulation.

• 디지털콘텐츠학회 논문지
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• 제6권2호
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• pp.113-118
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• 2005

본 논문에서는 블록 코딩된 영상을 전송할 때 손실 블록을 재구성하는 기법을 제안한다. JPEG 영상이 무선 통신 상에서 전송될 때, 오류는 영상 전체 블록에 영향을 미칠 수 있다. 이는 JPEG 영상에서 dc 계수를 차분 코딩하기 때문이다. 이에 본 논문은 손실 블록과 인근 블록들 사이의 상관성을 이용하여 손실 정보를 재구성한다. 제안된 기법의 성능 평가를 위해 의도적인 블록 오류를 추가하여 실험한 결과, 객관적으로나 주관적으로 모두 좋은 결과를 얻었다.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.33-40
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• 2023

The mainstay of current image recovery frameworks is Content-Based Image Retrieval (CBIR). The most distinctive retrieval method involves the submission of an image query, after which the system extracts visual characteristics such as shape, color, and texture from the images. Most of the techniques use RGB color space to extract and classify images as it is the default color space of the images when those techniques fail to change the color space of the images. To determine the most effective color space for retrieving images, this research discusses the transformation of RGB to different color spaces, feature extraction, and usage of Convolutional Neural Networks for retrieval.

• 근관절건강학회지
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• 제28권2호
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• pp.183-191
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• 2021

Purpose: This study was conducted to identify factors associated with stroke patients' quality of life (QOL) and examine the mediating effects of interpersonal relations in the relationships of activities of daily living (ADL) and body image with QOL. Methods: In this study, 160 stroke patients were recruited from an outpatient clinic of a university hospital and rehabilitation clinic of a long-term care hospital. Participants completed a questionnaire which included sociodemographic characteristics, ADL, body image, interpersonal relation, and QOL. Descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficients, multiple regression analysis, and process macro mediation analysis were conducted using SPSS. Results: The mean scores were 91.01 (range 6~100) for ADL, 61.19 (range 40~79) for body image, 87.53 (range 29~123) for interpersonal relations, and 186.67 (range 71~243) for QOL. Multiple regression analyses showed that ADL, body image, interpersonal relations, and participation in group activities after stroke were significantly associated with QOL among stroke patients (p<.05). There were no mediating effects of interpersonal relations in the relationships of ADL and body image with QOL (p>.05). Conclusion: This study showed that there is a need for physical, psychological, and social recovery to improve the QOL of stroke patients.

• 한국정보처리학회논문지
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• 제7권2호
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• pp.365-372
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• 2000

프랙탈 영상 압축(Fractral Image Compression:FIC)의 진화 계산(Evolution Computation)을 이용한 영상 분할(Image Partition)을 소개한다. 프랙탈 영상 압축에서 지역(Ranges)의 영상 분할은 꼭 필요하다[1]. 프랙탈 영상 압축은 쉽고 빠르게 복원된다는 장점을 갖는 데 비해 반복적인 프랙탈 변환의 적용으로 많은 계산량을 필요로 한다는 단점을 가지고 있다. 위와 같은 문제점을 해결하기 위한 방법으로 영상 분할을 하는데 있어 진화 계산을 적용하는 것에 대해 제안한다. 치역 영상(Ranges Image)은 작은 사각(Square) 영상 블록들의 결합된 집합으로 구성할 수 있다. 모집단을 구성하는 하나의 $N_p$는 분할되어진 하나의 코드들이다. 진화 계산에서 각각의 구성은 두 개의 이웃하는 치역은 제외하고 그들의 부모(Parent)로부터 분할을 상속받은 자식 $\sigma$를 생성한다. 자손들의 최적의 영상은 콜라주 정리(Collage Theorem)에 기초를 둔 다음 세대 모집단을 위해 선택되어지고 처리된다. 최적의 영상은 영상 데이터에 포함된 중복성을 포함함으로서 적은 저장 공간을 차지하고 속도 문제에 있어서 효율적이고 영상의 화질에 있어서 다른 부호화를 사용한 기법보다 우수한 성능을 갖는다. 멀티미디어 영상 처리(Multimedia Image Processing)의 진화 계산을 이용한 프렉탈 영상 압축은 영상의 복원과 영상의 질, 고 압축률을 요하는 동영상의 적용등의 많은 분야에 적용된다.

• Computers and Concrete
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• 제24권3호
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• pp.249-258
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• 2019

In order to investigate the strength recovery of fire-damaged concrete after post-fire curing, concrete specimens were heating at $2^{\circ}C/min$ or $5^{\circ}C/min$ to 400, 600 and $800^{\circ}C$, and these exposed specimens were soaked in the water for 24 hours and following by 29-day post-fire curing. The compressive strength and split tensile strength of the high-temperature-exposed specimens before and after post-fire curing were tested. The proportion of split aggregate in the split surfaces was analyzed to evaluate the mortar-aggregate interfacial strength. After the post-fire curing process, the split tensile strength of specimens exposed to all temperatures was recovered significantly, while the recovery of compressive strength was only obvious within the specimens exposed to $600^{\circ}C$. The tensile strength is more sensitive to the mortar-aggregate interfacial cracks, which caused that the split tensile strength decreased more after high-temperature exposure and recovery more after post-fire curing than the compressive strength. The mortar-aggregate interfacial strength also showed remarkable recovery after post-fire curing, and it contributed to the recovery of split tensile strength.

• 한국인쇄학회지
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• 제21권2호
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• pp.75-87
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• 2003

Printing inks are mainly composed of pigment and vehicles. Among these components, the Vehicle affect the rheologic property of the ink the most but pigment content of characteristic also after to the fluidity property not less than the vehicle. In the study, It is tested effect to the ink fluidity and structure recovery according to change the pigment particle size. The ink fluidity have been observed by using rheometer at the various conditions and it has been tested to observe what the ink fluidity has different means. In result We have found that the viscosity value of the low shear rate range has relatively higher value with decreasing the pigment particle size in the ink. Also, it has been found that when the pigment particle size decreases, the yield stress gradually increase. In the case of ink's structure recovery, when the pigment particle size decreases in the ink, the less changing shear rate, and it takes less time to recover.

• IEIE Transactions on Smart Processing and Computing
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• 제3권1호
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• pp.10-18
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• 2014

From the perspective of reducing the sampling cost of color images at high resolution, block-based compressive sensing (CS) has attracted considerable attention as a promising alternative to conventional Nyquist/Shannon sampling. On the other hand, for storing/transmitting applications, CS requires a very efficient way of representing the measurement data in terms of data volume. This paper addresses this problem by developing a measurement-coding method with the proposed customized Huffman coding. In addition, by noting the difference in visual importance between the luma and chroma channels, this paper proposes measurement coding in YCbCr space rather than in conventional RGB color space for better rate allocation. Furthermore, as the proper use of the image property in pursuing smoothness improves the CS recovery, this paper proposes the integration of a low pass filter to the CS recovery of color images, which is the block-based ${\ell}_{20}$-norm minimization. The proposed coding scheme shows considerable gain compared to conventional measurement coding.

• 한국가시화정보학회지
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• 제7권1호
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• pp.9-13
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• 2009

Fluorescence recovery after photobleaching (FRAP) has been widely used for the measurement of molecular diffusion in living cells and tissues. We developed an image-based FRAP (iFRAP) technique using a modified real-time microscope and a 488 nm Ar-ion laser. A fractional intensity curve was obtained from the time-lapse images of fluorescence recovery in the bleached spot to determine the diffusion coefficient of fluorescently labeled macromolecules in porous medium. We validated iFRAP through experiments with agar gels (0.5% and 1.5% w/v) containing FITC-Dextrans (10, 70 and 500 kDa MW). Further validation was performed by a Monte Carlo approach, where we simulated the three-dimensional random walk of macromolecules in agar gel model. Diffusion coefficients were deduced from the mean square displacement curves and showed good agreements with those measured by iFRAP.