• Title/Summary/Keyword: Low-contrast Image

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Inverse Effects of Information: The Influence of Personality Congruence on Preference for High Technology Products

  • Sohn, Yong Seok;Kim, Sung Eun
    • Asia Marketing Journal
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    • v.14 no.4
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    • pp.167-188
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    • 2013
  • In today's society with its emphasis on unlimited information access, control of available information about high-technology products is often vital to their success. When a product is released, consumers may initially be attracted through information about its remarkable internal and external features. They may also perceive a degree of congruence between their own personalities and the product image as more information becomes available over time. Consumers' changing impressions of the product may influence personality congruence negatively or positively. These changes and their effects on preference for high-technology products are the focus of this paper. A survey was given to a sample of 206 students at K University to investigate the degree to which consumer behavior can be influenced by personality congruence. The need for clear and definite product knowledge in this process and the effect of product information on preference were also investigated. Three analyses were conducted. The results of Analysis 1 showed the influence of personality congruence on preference for high-technology products. Judgments about personality congruence were based on non-compensatory rather than compensatory information processing. The respondents considered certain aspects of a product's personality rather than the product as a whole when making preference decisions. The results of Analysis 2 indicated that when less information was available about a product, consumers who perceived high personality congruence with the product tended to have higher preference for it compared to those who perceived low personality congruence with the product. On the other hand, when consumers were given more information, no difference was observed in the impact of personality on preference between perceived high and low personality congruence. Lastly, the results of Analysis 3 showed that when consumers with high need for closure (NFC) perceived high congruence between their own personalities and a product, objective information regarding the product was not used in decision-making: instead, judgments about the product were based on perceived personality congruence. On the other hand, high-NFC consumers who perceived low personality congruence between themselves and the product tended to require more information about the product in order to give it a positive evaluation. In contrast, low-NFC consumers who perceived high personality congruence felt comfortable with large amounts of information. For low-NFC consumers who perceived low congruence, the level of information had no influence on preference.

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Usability Evaluation of Applied Low-dose CT When Examining Urinary Calculus Using Computed Tomography (컴퓨터 단층촬영을 이용한 요로결석 검사에서 저선량 CT의 적용에 대한 유용성 평가)

  • Kim, Hyeon-Jin;Ji, Tae-Jeong
    • The Journal of the Korea Contents Association
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    • v.17 no.6
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    • pp.81-85
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    • 2017
  • The aim of this study was to evaluate the usability of applied Low dose Computed Tomography(LDCT) protocol in examining urinary calculus using computed tomography. The subjects of this study were urological patients who visited a medical institution located in Busan from June to December 2016 and the protocol used in this study was Adaptive Statistical Iterative Reconstruction: low-dose CT with 50% Adaptive Statistical Iterative Reconstruction (ASIR). As results of quantitative analysis, the mean pixel value and standard deviation within kidney region of image(ROI)of the axial image were $26.21{\pm}7.08$ in abdomen CT pre scan and $20.03{\pm}8.16$ in low-dose CT. Also the mean pixel value and standard deviation within kidney ROI of the coronal image were $22.07{\pm}7.35$ in abdomen CT pre scan and $21.67{\pm}6.11$ in low dose CT. The results of qualitative analysis showed that four raters' mean values of observed kidney artifacts were $19.14{\pm}0.36$ when using abdomen CT protocol and $19.17{\pm}0.43$ in low-dose CT, and the mean value of resolution and contrast was $19.35{\pm}0.70$ when using abdomen CT protocol and $19.29{\pm}0.58$ in low-dose CT. Also the results of a exposure dose analysis showed that the mean values of CTDIvol and DLP in abdomen CT pre scan were 18.02 mGy and $887.51mGy{\cdot}cm$ respectively and the mean values of CTDIvol and DLP when using low-dose CT protocol were 7.412 mGy and $361.22mGy{\cdot}cm$ respectively. The resulting dose reduction rate was 58.82% and 59.29%, respectively.

Evaluation of Image Quality according to the Use of Attachable X-ray Table Equipped with Heating Device (가열장치를 구비한 부착형 X선 촬영대의 사용에 따른 화질 평가)

  • Song, Jongnam;Kim, Eungkon
    • Journal of the Korean Society of Radiology
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    • v.9 no.4
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    • pp.219-225
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    • 2015
  • This study aims to evaluates the image quality of CR and DR that are scanned with the use of the attachable carbon heater X-ray scanner table equipped with heating device by measuring SNR and CNR before and after the attachment of the said table. In the aluminum staircase testing, CR increased SNR and CNR when attached with the table, while DR decreased SNR and CNR. In the human-body model phantom testing, CR increased SNR and CNR only in the low-energy low-dose radiation and the high-energy high-dose radiation, but decreased SNR and CNR under all other conditions. In conclusion, the use of such table can make the patient feel comfortable by removing his or her anxiety, thus helping the testing, but in the actual clinical application thereof, if the thickness and material of the bottom film and the protective film, including the carbon heater, are not considered, it affects the picture quality, thereby requiring continuous research on the use of such table.

Single Image Dehazing Based on Depth Map Estimation via Generative Adversarial Networks (생성적 대립쌍 신경망을 이용한 깊이지도 기반 연무제거)

  • Wang, Yao;Jeong, Woojin;Moon, Young Shik
    • Journal of Internet Computing and Services
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    • v.19 no.5
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    • pp.43-54
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    • 2018
  • Images taken in haze weather are characteristic of low contrast and poor visibility. The process of reconstructing clear-weather image from a hazy image is called dehazing. The main challenge of image dehazing is to estimate the transmission map or depth map for an input hazy image. In this paper, we propose a single image dehazing method by utilizing the Generative Adversarial Network(GAN) for accurate depth map estimation. The proposed GAN model is trained to learn a nonlinear mapping between the input hazy image and corresponding depth map. With the trained model, first the depth map of the input hazy image is estimated and used to compute the transmission map. Then a guided filter is utilized to preserve the important edge information of the hazy image, thus obtaining a refined transmission map. Finally, the haze-free image is recovered via atmospheric scattering model. Although the proposed GAN model is trained on synthetic indoor images, it can be applied to real hazy images. The experimental results demonstrate that the proposed method achieves superior dehazing results against the state-of-the-art algorithms on both the real hazy images and the synthetic hazy images, in terms of quantitative performance and visual performance.

Improvement of Hysteresis Characteristics of Low Temperature Poly-Si TFTs (저온 Poly-Si TFT 소자의 Hysteresis 특성 개선)

  • Chung, Hoon-Ju;Cho, Bong-Rae;Kim, Byeong-Koo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.1
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    • pp.3-9
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    • 2009
  • Although Active matrix organic light emitting diode (AMOLED) display has a better image quality in terms of viewing angle, contrast ratio, and response time than liquid crystal displays (LCDs), it still has some critical issues such as lifetime, residual images, and brightness non-uniformity due to non-uniformity in electrical characteristics of driving TFTs and IR drops on supplied power line. Among them, we improved irrecoverable residual images of AMOLED displays which is mainly related to the hysteresis characteristics of driving TFTs. We consider four kinds of surface treatment conditions before gate oxide deposition for improving hysteresis characteristics. We can reduce the hysteresis level of p-channel TFT to 0.23 V, interface trap states between the poly-Si layer and gate insulator to $3.11{\times}10^{11}cm^{-2}$, and output current variation of p-channel TFT to 3.65 % through the surface treatment using ultraviolet light and H2 plasma. Therefore, the recoverable residual image problem of AMOLED displays can be improved by surface treatment using ultraviolet light and $H_2$ plasma.

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3-D Lossy Volumetric Medical Image Compression with Overlapping method and SPIHT Algorithm and Lifting Steps (Overlapping method와 SPIHT Algorithm과 Lifting Steps을 이용한 3차원 손실 의료 영상 압축 방법)

  • 김영섭
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.4 no.3
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    • pp.263-269
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    • 2003
  • This paper focuses on lossy medical image compression methods for medical images that operate on three-dimensional(3D) irreversible integer wavelet transform. We offer an application of the Set Partitioning in Hierarchical Trees(SPIHT) algorithm〔l-3〕to medical images, using a 3-D wavelet decomposition and a 3-D spatial dependence tree. The wavelet decomposition is accomplished with integer wavelet filters implemented with the lifting method, where careful scaling and truncations keep the integer precision small and the transform unitary. As the compression rate increases, the boundaries between adjacent coding units become increasingly visible. Unlike video, the volume image is examined under static condition, and must not exhibit such boundary artifacts. In order to eliminate them, we utilize overlapping at axial boundaries between adjacent coding units. We have tested our encoder on medical images using different integer filters. Results show that our algorithm with certain filters performs as well. The improvement is visibly manifested as fewer ringing artifacts and noticeably better reconstruction of low contrast.

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Local Current Distribution in a Ferromagnetic Tunnel Junction Fabricated Using Microwave Excited Plasma Method (마이크로파 여기 프라즈마법으로 제조한 강자성 터널링 접합의 국소전도특성)

  • Yoon, Tae-Sick;Kim, Cheol-Gi;Kim, Chong-Oh;Masakiyo Tsunoda;Migaku Takahashi;Ying Li
    • Journal of the Korean Magnetics Society
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    • v.13 no.2
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    • pp.47-52
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    • 2003
  • Ferromagnetic tunnel junctions were fabricated by dc magnetron sputtering and plasma oxidation process. The local transport properties of the ferromagnetic tunnel junctions were studied using contact-mode Atomic Force Microscopy (AFM) and the local current-voltage analysis. Tunnel junctions with the structure of sub./Ta/Cu/Ta/NiFe/Cu/Mn$\_$75/Ir$\_$25//Co$\_$70/Fe$\_$30//Al-oxide were prepared on thermally oxidized Si wafers. Al-oxide layers were formed with microwave excited plasma using radial line slot antenna (RLSA) for 5 and 7 sec. Kr gas was used as the inert gas mixed with $O_2$ gas for the plasma oxidization. No correlation between topography and current image was observed while they were measured simultaneously. The local current distribution was well identified with the distribution of local barrier height. Assuming the gaussian distribution of the local barrier height, the ferromagnetic tunnel junction with longer oxidation time was well fitted with the experimental results. As contrast, in the case of the shorter time oxidation junction, the current mainly flow through the low barrier height area for its insufficient oxygen. Such leakage current might result in the decrease of tunnel magnetoresistance (TMR) ratio.

Novel Defog Algorithm via Evaluation of Local Color Saturation (국부영역 색포화 평가 방법을 통한 안개제거 알고리즘)

  • Park, Hyungjo;Park, Dubok;Ko, Hanseok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.3
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    • pp.119-128
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    • 2014
  • This paper presents a new method for improving the quality of images corrupted by an external source that generates an attenuation and scattering of light like dust, water droplets and fog. Conventional defog methods typically encounter a distortion such that the restored image has low contrast and oversaturation of color in some regions because of the mis-estimated airlight and wrong media transmission. Therefore, in order to mitigate these problems, we propose a robust airlight selection method and local saturation evaluation method for estimating media transmission. The proposed method addresses the wrong media transmission and over-saturation problems caused by the mis-estimated airlight and thereby improves the restored image quality. The results of relevant experiments of the proposed method against conventional ones confirm the improved accuracy of atmospheric light estimation and the quality of restored images with regard to objective and subjective performance measures.

Detecting Incipient Caries Using Front-illuminated Infrared Light Scattering Imaging

  • Kim, Ji-Young;Ro, Jung-Hoon;Jeon, Gye-Rok;Kim, Jin-Bom;Ye, Soo-Young
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.6
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    • pp.310-316
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    • 2012
  • A new method for early caries diagnosis was proposed and tested through a home-made optical examination system that used quantitative light fluorescence (QLF) and digital imaging fiber optic transillumination (FOTI) (DIFOTI), with light sources across a wide spectral range, from 350 nm to 1,000 nm. The front-illuminated infrared light scattering image (FIR) showed similar diagnostic abilities to that of DIFOTI. The FIR method was invented based on the observation that caries lesions lose the high transmittance and low scattering properties of benign enamel tissue. There are various methods for the early diagnosis of caries, such as visual examination, exploration, X-ray radiography, QLF, FOTI, and infrared fluorescence (diagnodent). Among them, methods based on optical properties are regarded as having the most potential. A comparative study was performed between the FOTI, QLF, diagnodent, optical coherence tomography, and FIR scattering image methods, using 20 extracted teeth samples with early caries. A scale of lesion measurement based on optical image contrast was proposed. The statistical analysis showed a significant correlation between the DIFOTI and FIR methods (r = 0.35, p < 0.05). However, the QLF and diagnodent methods showed little association with FIR images, as they have different detection principles as compared with FIR. Tomographic images obtained by OCT, using 1,330 nm super luminescent LED as a gold standard of tooth structure, verified that the FOTI and FIR results correctly represented the lack of homogeneity in dental tissue. The newly proposed FIR method attained similar diagnostic results to those of FOTI, but with an easier approach.

Color Image Segmentation Based on Edge Salience Map and Region Merging (경계 중요도 맵 및 영역 병합에 기반한 칼라 영상 분할)

  • Kim, Sung-Young
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.3
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    • pp.105-113
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    • 2007
  • In this paper, an image segmentation method which is based on edge salience map and region merging is presented. The edge salience map is calculated by combining a texture edge map with a color edge map. The texture edge map is computed over multiple spatial orientations and frequencies by using Gabor filter. A color edge is computed over the H component of the HSI color model. Then the Watershed transformation technique is applied to the edge salience map to and homogeneous regions where the dissimilarity of color and texture distribution is relatively low. The Watershed transformation tends to over-segment images. To merge the over-segmented regions, first of all, morphological operation is applied to the edge salience map to enhance a contrast of it and also to find mark regions. Then the region characteristics, a Gabor texture vector and a mean color, in the segmented regions is defined and regions that have the similar characteristics, are merged. Experimental results have demonstrated the superiority in segmentation results for various images.

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