• 한국의학물리학회지:의학물리
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• 제19권4호
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• pp.201-208
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• 2008

물리적 평가(physical evaluation)가 영상품질의 객관화와 정량화를 위한 토대를 제공함에도 불구하고, 부정확하고 가변적인 특성을 지닌 주관적 평가(subjective evaluation)가 영상평가에 중요한 역할을 하게 된다. 본 연구에서는 디지털 방사선 영상의 물리적 평가와 주간적 평가의 단점을 상호 보완하고 객관적 정량화를 위한 새로운 방법을 제안하고자 한다. 임상에 사용되고 있는 4대의 디지털 방사선 영상 촬영장치로부터 동일한 임상조건에서 흉부 팬톰 영상을 획득하였다. 물리적 영상평가를 위하여 디지털 흉부 팬톰 내에서 3개의 영역(폐, 심장, 그리고 복부)에 존재하는 CNR (contrast-to-noise ratio)를 측정하였고 분할(segmentation)과 정합(registration)등 다양한 영상처리기술이 적용되었다. 주관적 평가는 5명의 관찰자에 의한 저 대조도 물체의 식별 정도를 점수화 하였다. 두 평가의 특성을 보완 및 결합하고자 퍼지적분 이론이 도입되었다. 4대의 시스템으로부터의 평가결과가 비교되었으며, 물리적 평가와 주관적 평가가 항상 비례하지 않음을 보였다. 물리적 평가에서는 높은 점수를 보였던 시스템이 주관적 평가에서는 상대적으로 낮은 평가를 보였다. 본 연구에서 제안한 퍼지적분에 의한 영상평가의 정량화는 물리적 평가와 주관적 평가를 모두 포함하는 총체적인 평가 방법이며, 다양한 영상품질 평가에 유용할 것이라 사료된다.

• Journal of Information Processing Systems
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• 제13권3호
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• pp.448-463
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• 2017

Multimedia is a ubiquitous and indispensable part of our daily life and learning such as audio, image, and video. Objective and subjective quality evaluations play an important role in various multimedia applications. Blind image quality assessment (BIQA) is used to indicate the perceptual quality of a distorted image, while its reference image is not considered and used. Blur is one of the common image distortions. In this paper, we propose a novel BIQA index for Gaussian blur distortion based on the fact that images with different blur degree will have different changes through the same blur. We describe this discrimination from three aspects: color, edge, and structure. For color, we adopt color histogram; for edge, we use edge intensity map, and saliency map is used as the weighting function to be consistent with human visual system (HVS); for structure, we use structure tensor and structural similarity (SSIM) index. Numerous experiments based on four benchmark databases show that our proposed index is highly consistent with the subjective quality assessment.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.163-177
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• 2024

The fingerprint image quality relies on the clearness of separated ridges by valleys and the uniformity of the separation. The condition of skin still dominate the overall quality of the fingerprint. However, the identification performance of such system is very sensitive to the quality of the captured fingerprint image. Fingerprint image quality analysis and enhancement are useful in improving the performance of fingerprint identification systems. A fuzzy technique is introduced in this paper for both fingerprint image quality analysis and enhancement. First, the quality analysis is performed by extracting four features from a fingerprint image which are the local clarity score (LCS), global clarity score (GCS), ridge_valley thickness ratio (RVTR), and the Global Contrast Factor (GCF). A fuzzy logic technique that uses Mamdani fuzzy rule model is designed. The fuzzy inference system is able to analyse and determinate the fingerprint image type (oily, dry or neutral) based on the extracted feature values and the fuzzy inference rules. The percentages of the test fuzzy inference system for each type is as follow: For dry fingerprint the percentage is 81.33, for oily the percentage is 54.75, and for neutral the percentage is 68.48. Secondly, a fuzzy morphology is applied to enhance the dry and oily fingerprint images. The fuzzy morphology method improves the quality of a fingerprint image, thus improving the performance of the fingerprint identification system significantly. All experimental work which was done for both quality analysis and image enhancement was done using the DB_ITS_2009 database which is a private database collected by the department of electrical engineering, institute of technology Sepuluh Nopember Surabaya, Indonesia. The performance evaluation was done using the Feature Similarity index (FSIM). Where the FSIM is an image quality assessment (IQA) metric, which uses computational models to measure the image quality consistently with subjective evaluations. The new proposed system outperformed the classical system by 900% for the dry fingerprint images and 14% for the oily fingerprint images.

• 한국의학물리학회지:의학물리
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• 제23권4호
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• pp.292-302
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• 2012

최근 방사선치료 분야에 있어서 환자 선량이 중요한 쟁점이 되고 있다. 선량 감소를 위해 선진 기술을 이용한 방사선치료 시 사용하는 진단영상 장비에 대한 평가가 이루어져야 한다. 특히 CT는 방사선치료 분야에서 널리 사용되는 영상 장비이며, 본 연구에서는 CT의 선량과 영상에 대한 평가를 실시하였다. 선량과 영상을 동시에 비교할 수 있도록 동일한 조건 하에서 평가를 실시하였다. 또한 몬테카를로 시뮬레이션 툴인 MCNPX를 이용한 선량과 영상 평가가 가능하다는 것을 확인하였다. 저 선량 CT 영상의 질을 향상시키기 위하여 MLEM기법을 이용한 반복적 영상재구성 기법을 구축하였다. 본 연구의 평가 방법을 통해 방사선 치료 분야에서의 환자 선량을 줄이는 것뿐만 아니라 산업 연구 분야에서의 영상장비들의 총체적인 평가가 가능할 것이다.

• 대한가정학회지
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• 제30권3호
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• pp.33-43
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• 1992

The objective of this study were to (1) investigate the relationship between evaluations of apparel advertising, fashion involvement, and social attitudes, (2) examine how evaluation of apparel advertising, fashion involvement, and social attitudes vary according to gender, and (3) investigate the possible differences in purchase attitudes toward the advertised apparels according to gender and advertisement slogan. Questionnaire for evaluations of apparel advertising was comprised of four sections; apparel advertising acceptance, evaluation of advertisement slogan, purchase attitude toward the advertised apparels, and perception of effective media for apparel advertising. For evaluation of advertisement slogan, 5 sets of apparel advertisements were selected. Each set had two advertisements; one advertisement contained an image-oriented slogan, while the other had a quality-oriented slogan. "The Social Attitude Scale' by Kerlinger and 'Fashion Involvement Index' by Tigert, Ring & King were used. All the items were selected on the Cronbach's alpha reliability. The subjects were 217 college male and famale students in Seoul; 60 were asked about purchase attitude toward the image-oriented slogan, 60 purchase attitude toward the quality-oriented slogan, and 97 all the items included in evaluation of the two slogans. The data were analyzed using Pearson's correlation coefficient, X2-test, t-test, two-way ANOVA, and multiple regression analysis. The results of the study were the followings. 1. Fashion involvement had positive relationship with apparel advertising acceptance. The higher the level of conservative attitude males had, the more positive attitude they had in fashion involvement and apparel advertising acceptance. Subjects high in conservative attitude, fashion involvement, and apparel advertising acceptance. Subjects high in conservative attitude, fashion involvement, and apparel advertising acceptance had more positive in purchase of the advertised apparels. 2. Females high in apparel advertising acceptance were more favorable toward image-oriented advertisements. 3. Fashion involvement and apparel advertising acceptance were significantly higher in females than in males. Liberal attitude was significantly higher in males than in females. Evaluation of advertisement slogan did not differ according to gender. 4. Males perceived 'TV' was the most effective media for apparel advertising while females perceived 'display' was the most effective. 5. No significant interactions between advertisement slogan and gender were found in purchase attitude of the advertising apparels. 6. Apparel advertising acceptance was influenced by fashion involvement, social attitude, and sex. The explanatory power of the three variables was 17%.

• Imaging Science in Dentistry
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• 제49권2호
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• pp.139-151
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• 2019

Purpose: This study was performed to investigate the effect of exposure parameters on image quality obtained using a cone-beam computed tomography (CBCT) scanner and the relationship between physical factors and clinical image quality depending on the diagnostic task. Materials and Methods: CBCT images of a SedentexCT IQ phantom and a real skull phantom were obtained under different combinations of tube voltage and tube current (Alphard 3030 CBCT scanner, 78-90 kVp and 2-8 mA). The images obtained using a SedentexCT IQ phantom were analyzed technically, and the physical factors of image noise, contrast resolution, spatial resolution, and metal artifacts were measured. The images obtained using a real skull phantom were evaluated for each diagnostic task by 6 oral and maxillofacial radiologists, and each setting was classified as acceptable or unacceptable based on those evaluations. A statistical analysis of the relationships of exposure parameters and physical factors with observer scores was conducted. Results: For periapical diagnosis and implant planning, the tube current of the acceptable images was significantly higher than that of the unacceptable images. Image noise, the contrast-to-noise ratio (CNR), the line pair chart on the Z axis, and modulation transfer function (MTF) values showed statistically significant differences between the acceptable and unacceptable image groups. The cut-off values obtained using receiver operating characteristic curves for CNR and MTF 10 were useful for determining acceptability. Conclusion: Tube current had a major influence on clinical image quality. CNR and MTF 10 were useful physical factors that showed significantly associations with clinical image quality.

• 한국의류산업학회지
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• 제18권1호
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• pp.27-37
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• 2016

This study examined consumer perceptions towards outdoor wear differentiation and product attributes for outdoor wear differentiation to develop an outdoor wear differentiation strategy. It also investigated how consumer's evaluated product attributes according to consumer's demographic characteristics. Data were acquired from a survey of 454 adult respondents aged over 20 that was analyzed with descriptives, frequency, t-test, one-way ANOVA, factor analysis, and reliability. The results were as follows. First, it showed that consumers did not have a positive or a negative perception toward outdoor wear differentiation, and they thought outdoor wear should be differentiated. Those married and older tended to think that outdoor wear should be differentiated more than that for those single and younger. Consumer evaluations were significantly different on the necessity of outdoor wear differentiation according to age and total income. Second, consumers assessed that color, pattern and textiles had similar characteristics among outdoor wear brands; in addition, brand recognition and brand image had very different characteristics. Third, product attributes for outdoor wear differentiation were service and store, product quality, brand and popularity, and product designs with mean values of product quality, product design, service and store, and brand and popularity, respectively. Fourth, consumers were significantly different in the importance assessment of product attributes for differentiation according to gender, marital status and age.

• 대한방사선기술학회지:방사선기술과학
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• 제46권1호
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• pp.29-36
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• 2023

To have highly reliable diagnostic performance of it, this study comparatively analyzed spatial resolution of SPECT images and interrelationship depending on the changes of system uniformity of ga㎜a camera through phantom analysis. This study chose 6 kinds of results from quality control (uniformity) of triple head SPECT scanner operated in an university hospital in Seoul for six months. Then, study measured spatial resolutions (FWHM) of the images restructured by injecting radiopharmaceuticals to Jaszczak phantom, and doing SPECT scanning under the same conditions as clinical ones using the analytical program (image J). Quality controls performed by the experimental institution showed that differential uniformity of UFOV ranged from 2.76% to 7.61% (4.46±2.07), and integral uniformity of UFOV ranged from 1.98% to 5.42% (3.01±1.43). Meanwhile, Quantitative analysis evaluations of phantom images depending on the changes of uniformity of SPECT scanner detector showed that as the uniformity values of UFOV and CFOV decreased, FWHM values of phantom images decreased from 8.5 ㎜ to 5.8 ㎜. That is, it was quantitatively identified that the higher uniformity of detector is, the better spatial resolution of images gets (P<0.05). It is very important to perform continuous and consistent quality control of the nuclear medicinal system, and users should be clearly conscious of it.

• Nuclear Engineering and Technology
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• 제55권12호
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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.

• Architectural research
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• 제12권2호
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• pp.53-62
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• 2010

The purpose of this study is to examine design preferences for the sales spaces of duty-free shops (DFSs) by conducting image evaluations. The results will help improve quality by influencing designs for the construction, extension or remodeling of these shops. An image measurement method, the semantic differential method, was used to measure cognitive structure using photos of shops. Photos were collected of the DFS at Jeju Island, as well as photos of brand stores designed by architects. Two sets of 16 photos (32 different photos in all) were selected according to photo classification standards and design concepts, both decided by reviewing previous studies and related materials. The evaluation and survey were done by two sets of subjects: sales employees, who have experience and special knowledge of the evaluation of sales space; and students majoring in architecture. To strengthen the evaluation results, I conducted a preliminary survey and a main survey, verifying and complementing findings. 116 surveys were conducted, of which 14 were of poor quality and rejected, leaving and 102 to be analyzed. The collected surveys were statistically analyzed, using SPSS 12.0 for Windows. Reliability, image profile, factor and multi-dimensional scaling analyses were conducted. As a result, image evaluation structure and characteristics were obtained for sales spaces of DFSs, confirming the difference between them and other spaces.