• 제목/요약/키워드: Dark Images

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Effects of Contrast Agent Concentration on the Signal Intensity and Turbo Factor of TSE and Slice-selective IR in T1-weighted Contrast Imaging

  • Han, Yong Soo;Lee, Soo Chul;Lee, Dong Yong;Choi, Jiwon;Lee, Jong Woong;Kweon, Dae Cheol
    • Journal of Magnetics
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    • 제21권1호
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    • pp.115-124
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    • 2016
  • The present study analyzes T1 TSE and T1 slice sel. IR (dark_fluid) signal strength according to the degree of gadolinium contrast agent dilution and analyzes the turbo factors with regard to changes in the maximum and overall signal strength to study correlations between changes and signal-to-noise ratios (SNRs) and compare peak-to-peak SNR (PSNR) enhancement in order to improve the quality of T1-weighted images. Enhancement TR (600 msec) evaluated to determine the T1 TSE turbo factor and obtain the maximum signal strength, T1WI were used sequentially to experiment with turbo factors_1-4. T1 slice sel. IR (dark-fluid) was used to sequentially test turbo factors_2-5 but not turbo factor_1 at a TR (1500 msec) and compare data at an increase in T1 of 900 msec. The T1 TSE was reduced according to the contrast agent concentration. Phantom signal strength increased, whereas turbo factors_1-4 exhibited maximum signal strength at a concentration of 3 mmol, followed by a gradual decrease. In the turbo factors_2-5, the signal strength increased sharply to maximum signal strength at 0.7 mmol, followed by a reduction. T1 TSE had a greater maximum signal strength than did T1 slice sel. IR (dark_fluid). A comparison of SNR found that T1 TSE imaging was superior (33.3 dB) in turbo factor_1 and T1 slice sel. IR (dark_fluid) was highest (33.9 dB) at turbo factor_5. A PSNR comparison analysis was not sufficient to distinguish between the images obtained with both techniques at 30 dB or higher under all experimental conditions.

저 복잡도 전달량 추정 및 픽셀 기반 JBDCP에 의한 효율적인 단일 영상 안개 제거 방법 (Efficient Single Image Dehazing by Pixel-based JBDCP and Low Complexity Transmission Estimation)

  • 김종호
    • 한국전자통신학회논문지
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    • 제14권5호
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    • pp.977-984
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    • 2019
  • 본 논문에서는 안개 성분을 포함한 실외영상의 효과적인 응용을 위하여 저 복잡도를 갖는 전달량 추정 및 픽셀 기반 JBDCP(: Joint Bright and Dark Channel Prior)를 이용한 단일 영상 기반 안개 제거 방법을 제안한다. 기존의 전달량 추정은 계산량과 메모리 요구량이 큰 정련과정을 포함하는 반면, 제안하는 안개 제거 방법은 픽셀단위 및 블록단위 dark channel 정보를 결합하여 에지 정보가 보존되는 전달량을 추정하고 복잡도를 크게 감소시킨다. 또한 픽셀 기반 JBDCP를 이용하여 영상의 각 위치마다 다른 안개값을 구함으로써 영상의 특성을 반영한 전달량 추정이 가능하다. 다양한 안개 영상에 대해 수행한 실험 결과는 제안하는 방법이 기존의 방법에 비해 저 복잡도로 실행되면서 우수한 안개 제거 성능을 보여 실시간 기기를 포함한 다양한 분야에 응용될 수 있음을 나타낸다.

VENGEANCE, VIOLENCE, VAMPIRES: Dark Humour in the Films of Park Chan-wook

  • Hughes, Jessica
    • 비교문화연구
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    • 제28권
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    • pp.17-36
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    • 2012
  • This essay places the South Korean film Thirst (2009) within Park Chan-wook's oeuvre as a filmmaker notorious for graphic depictions of violence and revenge. Park's use of dark humour in his films, which is emphasized in Thirst perhaps more than ever, allows for a more self-aware depiction of violence, where both the viewer and the protagonist are awakened to the futility of revenge. This ultimately paints his characters as fascinatingly crazy - simultaneously heroes, villains, and victims. Film theorist Wes D. Gehring's three themes of dark humour ('man as beast,' 'the absurdity of the world,' and 'the omnipresence of death') become most obvious in Park's most recent film, which pays closer attention to character development through narrative detail. Rather than portraying the characters as sentimental, dark humour depicts their misfortunes in an alternative way, allowing for consideration of such taboo subjects as religion, adultery, and death/suicide. These issues are further tackled through Thirst's portrayal of its vampire protagonist, which ultimately de-mystifies the traditional vampire figure. While this character has more often been associated with romance, exoticism and the mystical powers of the supernatural, Thirst takes relatively little from the demons of Nosferatu (Murnau, 1922) and various other Dracula adaptations, nor the romantic figures of Interview with the Vampire (Jordan, 1994), and Twilight (Hardwicke, 2008). Instead, it is part of a much smaller group of contemporary vampire films, which are rather informed by a postmodern reconfiguration of the monster. Thus, this paper examines Thirst as an important contribution to the global and hybrid nature of those films in which postmodern vampires are sympathetic and de-mystified, exhibiting symptoms stemming from a natural illness or misfortune. Park's undertaking of a vampire film allows for a complex balance between narrative and visuals through his focus on the Western implications of this myth within Korean cinema. This combination of international references and traditional Korean culture marks it as highly conscious of New Korean Cinema's focus on globalization. With Thirst, Park successfully unites familiar images of the vampire hunting and feeding, with more stylistically distinct, grotesque images of violence and revenge. In this sense, dark humour highlights the less charming aspects of the vampire struggling to survive, most effective in scenes depicting the protagonist feeding from his friend's IV in the hospital, and sitting in the sunlight, slowly turning to ash, in the final minutes of the film. The international appeal of Park's style, combining conventions of the horror/thriller genre with his own mixture of dark humour and non-linear narrative, is epitomized in Thirst, which underscores South Korea's growing global interest with its overt international framework. Furthermore, he portrayal of the vampire as a sympathetic figure allows for a shift away from the conventional focus on myth and the exotic, toward a renewed construction of the vampire in terms of its contribution to generic hybridization and cultural adaptation.

고화질 영상에서 고속 안개 제거를 위한 SIMD 구조에 적합한 병렬메모리 (A Parallel Memory Suitable for SIMD Architecture Processing High-Definition Image Haze Removal in High-Speed)

  • 이형
    • 한국컴퓨터정보학회논문지
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    • 제19권7호
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    • pp.9-16
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    • 2014
  • Dark channel prior를 이용한 안개제거 알고리즘으로 만족할만한 연구결과가 발표된 이후로 이 알고리즘의 처리 속도를 높이기 위한 많은 연구들이 진행되었다. 이들 중에서 median dark channel prior를 이용한 알고리즘이 주목을 받고 있지만 여전히 낮은 처리속도의 한계를 갖고 있다. 그래서 본 논문에서는 고화질 영상에서 고속 안개 제거를 위한 SIMD 구조에 적합한 병렬메모리 모델을 제안한다. 제안하는 병렬메모리 모델은 n개의 화소들에 동시에 접근할 수 있으며, 3, 5, 7 또는 11의 크기를 갖는 4가지 종류의 median filter를 위한 간격들을 허용한다. 그래서 충분한 데이터 대역폭을 지원하기에 median dark channel prior를 이용한 알고리즘을 고속으로 처리할 수 있다.

AN ANALYSIS OF INFRARED IMAGES OF JUPITER IMPACTED BY P/SHOEMAKER-LEVY 9

  • KIM YONG HA;SUNG KIYUN;KIM SANG JOON;COCHRAN W. D.;LESTER D. F.;TRAFTON L.;CLARK B. E.
    • 천문학회지
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    • 제29권2호
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    • pp.245-253
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    • 1996
  • We have analyzed infrared (IR) images of Jupiter which was observed at the McDonald Observatory, Texas, U.S.A., during the P/SHoemaker-LEvy 9 (SL9) impact period and about one week after the last impact. The IR images were obtained on the 2.7m telescope using a NICMOS array with filters to isolate the $1.5{\mu}m\;NH_3\; band,\;the\;2.3{\mu}m\;CH_4\;band,\;the\;2.12{\mu}m\;H_2\;S(0)$ pressure-induced absorption, and the continua at $1.58{\mu}m\;and\;2.0{\mu}m$ (short K-band). All images except those with the $1.58{\mu}m$ continuum filter show bright impact sites against the relatively dark Jovian disk near the impact latitude of about $45^{\circ}$ S. This implies that dusts originated from the impacts reflect the solar radiation at high altitudes before absorbed by stratospheric $CH_4,\;NH_3 \;or\;H_2$. The impact sites observed with the $2.3{\mu}m$ filter are conspicuously bright against a very dark background. The morphology of impact sites, G, L, and H at 2.3 and $2.12{\mu}m$ filters shows clearly an asymmetric structure toward the incident direction of the comet fragments, in agreement with the studies of visible impact images obtained with the Hubble Space Telescope. Comparisons of reflectances of G, L, and H sites with simple radiative transfer models suggest that optically thick dust layers were formed at high altitudes at which methane absorption attenuates incoming sunlight only by about $1\%$. The dust layers in these sites seem to form at about the same altitude regardless of the magnitude of the impacts, but they appear to descend gradually after the impacts. The dust layers have optical depths of 2-5, according to the models.

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이안식 입체영상 관찰자 조절과 공동기능에 관한 인간공학적인 연구 (An egornomic study on visual accomodation and pupil functions during the observation of binocular 3-D images)

  • 조암
    • 대한인간공학회지
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    • 제11권1호
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    • pp.3-12
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    • 1992
  • To put the binocular 3-D images system into practical use, it is required to investigate the relationship between the system and men and to make ergonomic evaluation of the system. In this study, we perform a comparative analysis of the changes in the accommodation and pupil functions before and afer observing binocular 3-D images a sthe visual distance varies. From the experiment, we obtained the following results: (1) The discordance in the distance informatioons on the accommodation and pupil functions when obwerving 3-D images is compensated by the miosis and altering the focal depth. (2) From the consideration of the effect of the visual distance condition on the visual functions, it is thoughth that the visual functions are stabilized at the dark focus in the sense that the changes in the tension and relazation afer observing the 3-D images are minimized.

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자기 공명 영상장치를 이용한 악관절 기능 장애에 관한 연구 (A STUDY ON TEMPOROMANDIBULAR JOINT DYSFUNCTION WITH MAGNETIC RESONANCE IMAGING AND ARTHROGRAM)

  • 김재덕
    • 치과방사선
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    • 제23권1호
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    • pp.7-14
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    • 1993
  • The Internal derangement of temporomandibular joint disc was evaluated by using magnetic resonance imaging and arthrogram in 5 patients having reciprocal clicking or locking and in 5 normal subjects. Parasagittal multisections on both closed and open mouth were serially obtained by using a 1.5 Tesla MR system and surface coil with CSMEMP, MPGR. MR images obtained were analized by correlating with images of arthrograms. The obtained results were as follows: 1. Displaced meniscus was clearly delineated as dark structure on MR images other than on arthrograms of closed mouth view of patient having clicking or locking. 2. The deltoid white images of synovial fluid were identified in the glenoid fossa and on the posterior surface of condyle on open mouth view and partly depicted on closed mouth view, of parasagittal sections by MPGR. 3. The greyish image of joint fluid was identified on the posterior surface of condyle on the open mouth view of parasagittal sections by CSMEMP. 4. The structural relationship among condyle, meniscus, and fluid showed the variety of images on each parasagitta1 view.

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Color Enhancement in Images with Single CCD camera in Night Vision Environment

  • Hwang, Wonjun;Ko, Hanseok
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.58-61
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    • 2000
  • In this paper, we describe an effective method to enhance the color night images with spatio-temporal multi-scale retinex focused to the Intelligent Transportation System (ITS) applications such as in the single CCD based Electronic Toll Collection System (ETCS). The basic spatial retinex is known to provide color constancy while effectively removing local shades. However, it is relatively ineffective in night vision enhancement. Our proposed method, STMSR, exploits the iterative time averaging of image sequences to suppress the noise in consideration of the moving vehicles in image frame. In the STMSR method, the spatial term makes the dark images distinguishable and preserves the color information day and night while the temporal term reduces the noise effect for sharper and clearer reconstruction of the contents in each image frame. We show through representative simulations that incorporating both terms in the modeling produces the output sequential images visually more pleasing than the original dim images.

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Support Vector Machine을 이용한 실시간 도로기상 검지 방법 (A Realtime Road Weather Recognition Method Using Support Vector Machine)

  • 서민호;육동빈;박새롬;전진호;박정훈
    • 한국산업융합학회 논문집
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    • 제23권6_2호
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    • pp.1025-1032
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    • 2020
  • In this paper, we propose a method to classify road weather conditions into rain, fog, and sun using a SVM (Support Vector Machine) classifier after extracting weather features from images acquired in real time using an optical sensor installed on a roadside post. A multi-dimensional weather feature vector consisting of factors such as image sharpeness, image entropy, Michelson contrast, MSCN (Mean Subtraction and Contrast Normalization), dark channel prior, image colorfulness, and local binary pattern as global features of weather-related images was extracted from road images, and then a road weather classifier was created by performing machine learning on 700 sun images, 2,000 rain images, and 1,000 fog images. Finally, the classification performance was tested for 140 sun images, 510 rain images, and 240 fog images. Overall classification performance is assessed to be applicable in real road services and can be enhanced further with optimization along with year-round data collection and training.

공동주택 커뮤니티시설의 공간별 감성색채배색 이미지에 따른 청소년의 뇌파분석 (An Analysis of Youth EEG based on the Emotional Color Scheme Images by Different Space of Community Facilities)

  • 황연숙;김선영;김주연
    • 한국실내디자인학회논문집
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    • 제22권5호
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    • pp.171-178
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    • 2013
  • In this study, we sought to find out the effect of different emotional interior images of the community facilities in an apartment complex on a youth brain wave by analyzing an Electroencephalograph (EEG). Based on the frequency of usage, we selected learning facilities, cultural facilities, and sport facilities. For brain stimulation, the visual stimulants with three different emotional words, cheerful, gentle, and elegant, were used based on I.R.I image scale. Overall, total nine different emotional images were used. Based on our findings, we conclude that: first, in order to improve learning concentration of the youth, a learning facility for the youth needs to be designed by skillfully combining the soft and comfortable colors from the gentle image and the murky and dark colors from the elegant image. Second, when designing a cultural facility, it is preferable to consider the elegant image for a calm and comfortable space. Third, a sport facility design needs to preclude dark colors and apply light colors to create a dynamic and lively space. Furthermore, we found out that the youth has established static images of each functionally different facility through their experience and learning. Therefore, it is imperative to plan community facilities in an apartment complex in a way to connect the space function with the emotional characteristics of the youth in order to support and encourage energetic activities and learning of the community youth.