• Journal of the Ergonomics Society of Korea
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• v.20 no.2
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• pp.59-70
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• 2001

White uniformity is one of the important inspection factors determining the image quality of CRT screen. In the full white pattern, white uniformity means the degree of uniform distribution of white color across the whole screen. To elicit the sensitivity factors affecting the decision of the white uniformity quality, experiments in which participants were confronted with 6 evaluation points embedded in 3 measurement groups on a CRT screen were conducted to gather the psychophysical data that are the level of white uniformity subjects perceived and CA100 produced. These data were used to develop a modified CIE1976 equation for calculating white uniformity. Performance comparison between the original CIE1976 equation and the modified equation was conducted in terms of accuracy test and magnitude estimation. It was concluded the modified equation is more sensitive in the change of white uniformity, compared to the original CIE1976 equation.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4591-4596
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• 2023

Single-photon emission computed tomography SPECT image reconstruction methods have a significant influence on image quality, with filtered back projection (FBP) and ordered subset expectation maximization (OSEM) being the most commonly used methods. In this study, we proposed newly-designed adaptive non-blind deconvolution with a structural similarity (SSIM) index that can take advantage of the FBP and OSEM image reconstruction methods. After acquiring brain SPECT images, the proposed image was obtained using an algorithm that applied the SSIM metric, defined by predicting the distribution and amount of blurring. As a result of the contrast to noise ratio (CNR) and coefficient of variation evaluation (COV), the resulting image of the proposed algorithm showed a similar trend in spatial resolution to that of FBP, while obtaining values similar to those of OSEM. In addition, we confirmed that the CNR and COV values of the proposed algorithm improved by approximately 1.69 and 1.59 times, respectively, compared with those of the algorithm involving an inappropriate deblurring process. To summarize, we proposed a new type of algorithm that combines the advantages of SPECT image reconstruction techniques and is expected to be applicable in various fields.

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.253-260
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• 2003

In this study, the feasibility of magnetic resonance techniques for nondestructive internal quality evaluation of Korean red ginseng was examined. Relaxation time constants were measured using various grades of red ginsengs. Solid state magnetic resonance imaging technique was applied to image dried red ginsengs which have low moisture contents (about 13%). A 7 tesla magnetic resonance imaging system operating at a proton resonant frequency of 300 ㎒ was used for acquiring MR images of dried Korean red ginseng. The comparison test of cross cut digital images and magnetic resonance images of heaven grade, good grade with cavity inside, and good grade with white part inside red ginseng suggested the feasibility of the internal quality evaluation of Korean red ginsengs using MRI techniques. A good grade red ginseng included abnormal tissues such as cavities or white parts inside was observed by the signal intensity of MR image based on magnetic resonance properties of proton nucleus. Analysis on an one dimensional profile of acquired MR image of Korean red ginseng showed easy discrimination of normal and abnormal tissues. MR techniques suggested ways to detect internal defects of red ginsengs effectively.

• Korean Journal of Artificial Intelligence
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• v.9 no.2
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• pp.1-5
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• 2021

Although CT has an advantage in describing the three-dimensional anatomical structure of the human body, it also has a disadvantage in that high doses are exposed to the patient. Recently, a deep learning-based image reconstruction method has been used to reduce patient dose. The purpose of this study is to analyze the dose reduction and image quality improvement of deep learning-based reconstruction (DLR) on the adult's chest CT examination. Adult lung phantom was used for image acquisition and analysis. Lung phantom was scanned at ultra-low-dose (ULD), low-dose (LD), and standard dose (SD) modes, and images were reconstructed using FBP (Filtered back projection), IR (Iterative reconstruction), DLR (Deep learning reconstruction) algorithms. Image quality variations with respect to varying imaging doses were evaluated using noise and SNR. At ULD mode, the noise of the DLR image was reduced by 62.42% compared to the FBP image, and at SD mode, the SNR of the DLR image was increased by 159.60% compared to the SNR of the FBP image. Based on this study, it is anticipated that the DLR will not only substantially reduce the chest CT dose but also drastic improvement of the image quality.

• Journal of Digital Convergence
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• v.10 no.2
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• pp.249-254
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• 2012

Assessing the exposure dose and the obtained image during the abdominal radiography with 128-slice MDCT scanner and 4-slice MDCT scanner which are recently being used in clinics using the body tissue-equivalent phantom and the glass dosimeter, the results were as follows. During the CT test for the abdomen, the absorbed dose was $35.8{\pm}0.46mGy$ in 4-MDCT, and $19.03{\pm}0.25mGy$ in 128-MDCT, which indicated that the radiation dose necessary to obtain the image meaningful to diagnosis was required less by 128-MDCT(P<0.05). As a result of analyzing the image obtained from the abdominal test using MDCT with a 5-point Likert scale, 4-MDCT showed the result of 3.52 points, and 128-MDCT showed the result of 4.01 points, that is, the image quality of 128-MDCT was evaluated high, and there was a statistically significant difference. In the results above, it is considered that 128 slice MDCT scanner will be much used later as it can reduce the radiation exposure, and make us obtain the high quality of image.

• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.76-82
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• 2017

An image hash, a discriminative and robust summary of an image, should be robust against quality-preserving signal processing steps, while being pairwise independent for perceptually different inputs. In order to improve the hash matching performance, this paper proposes a probabilistic dissimilarity matching. Instead of extracting the binary hash from the query image, we compute the probability that the intermediate hash vector of the query image belongs to each quantization bin, which is referred to as soft quantization binning. The probability is used as a weight in comparing the binary hash of the query with that stored in a database. A performance evaluation over sets of image distortions shows that the proposed probabilistic matching method effectively improves the hash matching performance as compared with the conventional Hamming distance.

• Journal of the Korean Society of Costume
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• v.62 no.5
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• pp.171-180
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• 2012

Purchasing behavior of brand clothes in internet shopping mall is largely used on the purpose of having a good quality of clothing, price advantage and shopping efficiency. This study aims to find out consumer's evaluation on the properties of brand clothes in internet shopping mall according to consumer's brand attitude(brand identification and brand pursue value). The influences consumers' evaluation of the properties of brand clothes on the purchase satisfaction and off-line brand image evaluation were also investigated. This study surveyed male and female consumers in their 20s~40s for empirical analysis in August 2011 who have purchased brand clothing through internet shopping malls. The survey was conducted on 254 subjects who were selected through online convenience sampling. Data were analyzed by using SPSS for Windows 12.0, and descriptive statistics, reliability analysis, factor analysis, and regression analysis were done as well. The results are as follows. First, it was identified that consumers' brand identification and brand pursue value had significant influence on the evaluation of physical, functional, and expressional product properties. Second, it was identified that consumers' evaluation on the brand clothing properties significantly influenced on internet purchase satisfaction and brand image evaluation. Especially, expressive property of brand clothes appeared to be the most influential factor on purchase satisfaction and brand image evaluation. The results of this study will help clothing companies with prestigious brand names to administer the product qualities with differentiation policy from off-line sales and satisfy the consumer needs in internet shopping, hence enhancing the brand image of the company.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.999-1005
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• 2021

The object of this research is CS, which increases resolution while shortening inspection time, is applied to MRA to compare the quality of images for SENSE and CS techniques and to evaluate SNR and CNR to find out the optimal techniques and to provide them as clinical basic data based on this information. Data were analyzed on 32 patients who performed TOF MRA tests at a university hospital in Chung cheong-do (15 males, 17 females), ICA stenosis:10, M1 Aneurysm:10, and average age 53 ± 4.15). In the inspection, the inspection equipment was Ingenia CX 3.0T, Archieva 3.0T, and 32 channel head coil and 3D gradient echo as a method for equipment data. SNR and CNR of each image were measured by quantitative analysis, and the quality of the image was evaluated by dividing the observer's observation into 5 grades for qualitative evaluation. Imaging evaluation is described as being significant when the p-value is 0.05 or less when the paired T-test and Wilcoxon test are performed. Quantitative analysis of SNR and CNR in TOF MRA images Compared to the SENSE method, the CS method is a method measurement method (p <0.05). As an observer's evaluation, the sharpness of blood vessels: CS (4.45 ± 0.41), overall image quality: CS (4.77 ± 0.18), background suppression of images: CS (4.57 ± 0.18) all resulted in high CS technique (p = 0.000). In conclusion, the Compressed SENSE TOF MRA technique shows superior results when comparing and evaluating the SENSE and Compressed SENSE techniques in increased flow rate magnetic resonance angiography. The results are thought to be the clinical basis material in the 3D TOF MRA examination for brain disease.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.40-47
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• 2011

Image analysis algorithm for the quality evaluation of ginseng seedling was investigated. The images of ginseng seedling were acquired with a color CCD camera and processed with the image analysis methods, such as binary conversion, labeling, and thinning. The processed images were used to calculate the length and weight of ginseng seedlings. The length and weight of the samples could be predicted with standard errors of 0.343 mm, and 0.0214 g respectively, $R^2$ values of 0.8738 and 0.9835 respectively. For the evaluation of the three quality grades of Gab, Eul, and abnormal ginseng seedlings, features from the processed images were extracted. The features combined with the ratio of the lengths and areas of the ginseng seedlings efficiently differentiate the abnormal shapes from the normal ones of the samples. The grade levels were evaluated with an efficient pattern recognition method of support vector machine analysis. The quality grade of ginseng seedling could be evaluated with an accuracy of 95% and 97% for training and validation, respectively. The result indicates that color image analysis with support vector machine algorithm has good potential to be used for the development of an automatic sorting system for ginseng seedling.

• Journal of Radiation Industry
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• v.11 no.3
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• pp.139-144
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• 2017

To evaluation of clinical usefulness for B1+RMS limits, we compared image quality of Routine, Specific absorption rate (SAR) and Root mean square (RMS) protocol. 5 volunteers underwent Magnetic Resonance Imaging (MRI) scan of the brain using three different protocols. We draw Region of interest ROI in cortex, white matter, gray matter, putamen and thalamus of axial plan. Signal to noise ratio (SNR) were evaluated in each area and Contrast to noise ration (CNR) were evaluated between white matter and gray matter. Qualitative evaluation was used to score each ROI. B1+RMS is confirmed its usefulness compared to conventional SAR standard on the aspect of improvement of image quality, reduction of scan time and easy adjusting parameter.