• Title/Summary/Keyword: Image Quality Analysis

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3차원 안모분석을 위한 저선량 Multi-detector CT 영상의 유효선량 및 화질 평가 (Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning)

  • 정기정;한원정;김은경
    • Imaging Science in Dentistry
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    • 제40권1호
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    • pp.15-23
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    • 2010
  • Purpose : This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. Materials and Methods : 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Results : Effective doses in ${\mu}Sv$ ($E_{2007}$) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. Conclusion : From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

미세내시경용 광섬유 영상가이드의 영상광도 측정 및 분석 (Measurement and Analysis of Image Brightness in Fiber-optic Imageguide for Ultrathin Endoscope)

  • 이봉수
    • 대한의용생체공학회:의공학회지
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    • 제23권4호
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    • pp.263-268
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    • 2002
  • 내시경 영상의 질을 결정하는데는 많은 요소들 즉 내시경 영상가이드가 포함하고 있는 광섬유들의 숫자 및 광섬유 각각의 형태, 재료, 길이 등의 측정, 분석이 필요하지만 그 각각의 요소들은 서로 상관관계를 가지고 있기 때문에 각 요소들에 대한 독립적 분석은 불가능한 것으로 평가되어 지고 있다. 그래서 크게 2가지 특성 즉 영상가이드의 영상분해능(image resolution)과 영상광도(image brightness)를 측정, 분석함으로써 내시경 영상의 질을 판단하려는 연구가 진행되고 있으나 아직 그 정확한 분석 방법이 확립되어 있지 않은 실정이다. 본 연구에서는 의료용 내시경에 사용되는 미세 영상가이드의 영상광도를 정량화하기 위해서 영상가이드 자체의 PF(Packing fraction), 개구수(numerical aperture) 및 광감쇠율의 측정방법을 개발하였고, 실제 미세내시경에 사용되고 있는 영상가이드의 광도를 측정하고 정량화였다 특히 영상가이드 전체의 개구수를 측정함으로써 기존의 개구수 계산값에 의한 방법보다 정확한 영상광도의 정량화가 가능하였고 그 결과 직경이 $3.1\mu m$인 광섬유를 포함하는 영상가이드의 광도는 직경이 $4.1\mu m$인 광섬유를 포함하는 영상가이드 보다 약 37% 만큼 낮다는 결론을 얻었다.

The effects of store image components on consumers purchasing retailer brands in Korea

  • Chung, Lak-Chae;Cho, Young-Sang
    • 유통과학연구
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    • 제9권4호
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    • pp.15-27
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    • 2011
  • Although a huge number of academic researchers have paid considerable attention to exploring both the degree to which store image influences retailer brand customers and how to develop store personality, they have overlooked the contemporary retail context in which retailers have developed many different types of retailer brands, that is, price-oriented or quality-oriented retailer brands. Rather than focusing on the latter, much literature has looked at the former. Accordingly, even though there are many articles related to store image, a few authors have shown their interest in identifying the extent to which store personality affects customers purchasing retailer brands at lower prices. As a result, their efforts have been to illustrate the relationship between store image and consumer behaviours buying retailer brands. In that multiple retailers over the world such as E-Mart, Lotte-Mart, Tesco Korea and Tesco UK have actively introduced not only the quality-focused retailer brands that quality is better than, or equal to national brands, and prices are slightly higher than, or equal to them, but also price-focused retailer brands, academicians should make an effort to investigate how store image affects customers purchasing a quality-oriented retailer brand, comparing with previous research results. That is why the authors illustrate the extent to which store personality components influence retailer brand customers, including particularly quality-oriented retailer brand customers through an empirical research. By adopting a questionnaire method as a research technique to illuminate the relationship between store image components and retailer brand customers, research validity increases and further, data gathered through a field survey are analysed through a few statistic analysis methods, in order to minimise statistical deviations. Compared with the prior research concentrated on price-focused retailer brands, the authors have significantly shed light on customer behaviours purchasing retailer brand products with higher quality. When it comes to store personality components, the research suggests the following five items: merchandise attributes, services, physical facilities, promotions, and institutional image, considering the subcomponents mentioned by the previous research. Proposing the conceptual research model which those elements are differently hypothesised, according to retailer brand types: PR (Price-oriented Retailer brand) and QR (Quality-oriented Retailer brand), the research is proceeded. Through empirical research, the authors found that amongst the five items, only promotion influenced retailer brand customers in the Korean retailing marketplace, unlike other countries explored by many researchers, such as UK. Although much literature emphasises that those elements are closely related to retailer brand buying proneness, it is completely not fit to the Korean market. Also, research findings provide new insights into the degree of store image effects on retailer brand customers for academiciansand practitioners. Whether the retailer brand development program that a retailer has carried simultaneously both price-focused and quality-focused retailer brand types is practically profitable should be explored in the future.

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비만이 소아의 삶의 질에 미치는 영향 (Impact of Obesity on Health-Related Quality of Life among Children)

  • 권윤정;정조은;허휴정;조현;김대진
    • 생물정신의학
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    • 제22권3호
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    • pp.128-134
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    • 2015
  • Objectives To examine the relationship between health-related quality of life (HRQoL) and body mass index (BMI) of obese children. Methods This cross-sectional study included 387 children. HRQoL was measured with the PedsQLTM 4.0 Generic Core Scale. BMI was classified according to the World Health Organization Asia-Pacific obesity guidelines. Psychosocial factors (body image, self-esteem, and depression/anxiety) were also measured. Data were analyzed using one-way analysis of variance, Pearson's correlation and Path analysis. Results Obese participants reported lower score for physical evaluation, self-esteem, appearance evaluation component of body image, total HRQoL score, and physical/emotional/social function components of HRQoL ; they reported higher score for depression/anxiety. In addition, results indicated that as BMI increased, appearance evaluation, total HRQoL score, and social function component of HRQoL dropped. Path analysis revealed that BMI did not directly affect HRQoL ; however, BMI directly affects body image and self-esteem, indirectly mediates depression/anxiety, and thereby impacts on an individual's HRQoL. Conclusions Body image and self-esteem, rather than BMI itself, have more influence on HRQoL. This reinforces the importance of therapeutic intervention to enhance body image and self-esteem among obese children.

방한 외국인 한국에 대한 국가이미지가 패션문화상품 선호도에 미치는 영향 (Foreign Visitors' Korean National Image Influencing Preference of Fashion Cultural Products)

  • 장세정;이유리
    • 한국의류학회지
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    • 제32권4호
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    • pp.669-680
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    • 2008
  • Korea's national image can be delivered through cultural products, and cultural products can finally contribute to the affirmative attitude and recognition towards Korea. In an empirical study, a questionnaire was developed based on literature review and focus group interviews with foreigners who visit Korea were executed. Subjects of this study were foreign visitors from US, China, and Japan. Finally, a total of 247 copies were used for analyses. Descriptive analyses, factor analysis, regression analysis, ANOVA, Duncan test, and paired sample t-test were conducted for data analysis, Results are as follows. Firstly, as a result of factor analysis, I found that there were seven factors to form the image of Korea; culture/art, openness, lechnology/quality, food culture, passionate narcissism, conservativeness, and pursuit of quality of life. Secondly, Several image factors were found to influence positively or negatively on their attitude toward fashion cultural products. Especially, culture/art factor was found to influence positively to Chinese and Japanese and lechnology/quality factor was found to influence positively to Japanese and American. Meanwhile, conservativeness factor was found to influence negatively to Chinese. This study will be of help to practitioners of the fashion cultural product industry for building marketing strategies whose target market is foreign visitors from different cultural backgrounds.

Breast Conserving Therapy and Quality of Life in Thai Females: a Mixed Methods Study

  • Peerawong, Thanarpan;Phenwan, Tharin;Supanitwatthana, Sojirat;Mahattanobon, Somrit;Kongkamol, Chanon
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2917-2921
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    • 2016
  • Background: To explore factors that influence quality of life (QOL) in patients receiving breast conserving therapy (BCT). Materials and Methods: In this sequential mixed methods study, 118 women from Songklanagarind Hospital were included. We used participants' characteristics, Body Image Scale (BIS), and Functional Assessment of Cancer Therapy with the Breast Cancer Subscale (FACT-B) for analysis. The BIS transformed into presence of body image disturbance (BID). Factors that influenced QOL were determined by stepwise multiple linear regression. Forty-one participants were selected for qualitative analysis. Our female researcher performed the semi-structured interviews with questions based on the symbolic interaction theory. Final codes were analysed using thematic analysis along with investigator triangulation methods. Results: Ninety percent had early stage breast cancer with post-completed BCT, for an average of 2.7 years. The median BIS score and FACT-B score were 2 (IQR=10) and 130 (IQR=39). In the regression analysis, an age of more than 50 years and BID were significant factors. As for the value of conserved breasts, two themes emerged: a conserved breast is an essential part of a participant's life and also the representation of her womanhood; the importance of a breast is related to age. Conclusions: Body image influenced QOL in post BCT participants. The conserved breasts also lead to positive and better impact on their body image as an essential part of their life.

보정을 위한 고해상도 360° 프로젝션 영상 분석 방법 (360° Projection Image Analysis Method for the Calibration)

  • 한정수;김귀정
    • 디지털융복합연구
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    • 제13권12호
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    • pp.203-208
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    • 2015
  • 테마파크, 홍보관, 과학관 등의 다면 영상시스템에서 초기 설치 시 빔 프로젝터들간의 하드웨어적 특성 및 설치 후 시간이 경과함에 따라 발생되는 영상의 열화 현상이 발생한다. 본 연구에서는 영상관의 품질과 유지보수의 어려움을 해결하기 위해 10비트 High-depth 및 고해상도 $360^{\circ}$ 프로젝션 영상 분석 기술을 연구하였다. 그 목적은 경제적 손실을 최소화하고, 영상의 품질을 효율적으로 지원할 수 있는 특수영상관 캘리브레이션 시스템 개발을 목표로 한다. 이를 위해 영상 분석 기술의 방법을 제안하였고, 영상 분석 기술에 대한 세부 기능과 평가방법 등을 설명하였다. 평가방법은 평가 항목별로 제시하였고, 실험 방법과 목표치에 대한 추정 값을 제시하였다.

Off-Site Distortion and Color Compensation of Underwater Archaeological Images Photographed in the Very Turbid Yellow Sea

  • Jung, Young-Hwa;Kim, Gyuho;Yoo, Woo Sik
    • 보존과학회지
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    • 제38권1호
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    • pp.14-32
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    • 2022
  • Underwater photographing and image recording are essential for pre-excavation survey and during excavation in underwater archaeology. Unlike photographing on land, all underwater images suffer various quality degradations such as shape distortions, color shift, blur, low contrast, high noise levels and so on. Outcome is very often heavily photographing equipment and photographer dependent. Excavation schedule, weather conditions, and water conditions can put burdens on divers. Usable images are very limited compared to the efforts. In underwater archaeological study in very turbid water such as in the Yellow Sea (between mainland China and the Korean peninsula), underwater photographing is very challenging. In this study, off-site image distortion and color compensation techniques using an image processing/analysis software is investigated as an alternative image quality enhancement method. As sample images, photographs taken during the excavation of 800-year-old Taean Mado Shipwrecks in the Yellow Sea in 2008-2010 were mainly used. Significant enhancement in distortion and color compensation of archived images were obtained by simple post image processing using image processing/analysis software (PicMan) customized for given view ports, lenses and cameras with and without optical axis offsets. Post image processing is found to be very effective in distortion and color compensation of both recent and archived images from various photographing equipment models and configurations. Merits and demerit of in-situ, distortion and color compensated photographing with sophisticated equipment and conventional photographing equipment, which requires post image processing, are compared.

An Adaptive Histogram Equalization Based Local Technique for Contrast Preserving Image Enhancement

  • Lee, Joonwhoan;Pant, Suresh Raj;Lee, Hee-Sin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제15권1호
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    • pp.35-44
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    • 2015
  • The main purpose of image enhancement is to improve certain characteristics of an image to improve its visual quality. This paper proposes a method for image contrast enhancement that can be applied to both medical and natural images. The proposed algorithm is designed to achieve contrast enhancement while also preserving the local image details. To achieve this, the proposed method combines local image contrast preserving dynamic range compression and contrast limited adaptive histogram equalization (CLAHE). Global gain parameters for contrast enhancement are inadequate for preserving local image details. Therefore, in the proposed method, in order to preserve local image details, local contrast enhancement at any pixel position is performed based on the corresponding local gain parameter, which is calculated according to the current pixel neighborhood edge density. Different image quality measures are used for evaluating the performance of the proposed method. Experimental results show that the proposed method provides more information about the image details, which can help facilitate further image analysis.

A Study on Design Preference for the Sales Spaces of Duty-Free Shops by the Examination of Image Evaluation - Cases of Duty-Free Shops in Jeju Special Self-governing Province -

  • Moon, Jung-Eun;Kim, Bong-Ae
    • 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.