• Title/Summary/Keyword: Visual Depth

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Crosstalk Reduction of Glasses-free 3D Displays using Multiview Image Processing (다시점 영상처리를 이용한 무안경 3차원 디스플레이의 크로스톡 저감 방법)

  • Kim, Sung-Yeol;Lee, Jin-Sung;Choi, Sang Mi
    • Journal of Broadcast Engineering
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    • v.21 no.1
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    • pp.66-75
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    • 2016
  • In this paper, we present a new method to reduce crosstalk of a glasses-free three-dimensional (3D) display using a multi-view image processing technique. Since crosstalk makes the current view image mixed with its neighboring ones, the output 3D image becomes severely blurred. We apply adaptive depth retargeting and view gradient-based crosstalk inverse filtering onto a multi-view image to minimize crosstalk of the glasses-free 3D display. In addition, overflow and underflow pixels are compensated by epipolar image pixel interpolation so that visual artifacts are minimized. Experimental results show that the proposed method reduces crosstalk more efficiently than the previous work while improving 3D image quality.

An Interactive Image Transmission For Mobile Devices (모바일 시스템을 위한 인터랙터브 이미지 전송)

  • Lim, Nak-Won;Kim, Dae-Young;Lee, Hae-Young
    • Journal of the Korea Computer Graphics Society
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    • v.17 no.2
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    • pp.17-26
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    • 2011
  • This paper presents an interactive progressive image transmission method, which enables a remote user to interactively select and transmit preferred regions from an index image. Our enhanced quadtree decomposition using PSNR-based rules and new implicit quadtree coding provide better rate-distortion performance than previous quadtree coders as well as leading bit plane methods. An adaptive traversal of child nodes is introduced for better visual display of restored images. Depth-first traversal combined with breadth-first traversal of the quadtree to accomplish interactive transmission as presented, results in a method that provides competitive performance at a low level of computational complexity. Moreover, our decoding requires only simple arithmetic which is enabling our method to be used for real-time mobile applications.

Distribution and Abundance of Finless Porpoise (Neophocaena phocaenoides) in the West Coast of Korea (한국 서해안 상괭이 (Neophocaena phocaenoides)의 분포와 풍도)

  • ZHANG Chang Ik;PARK Kyum Joon;KIM Zang Geun;SOHN Hawsun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.2
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    • pp.129-136
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    • 2004
  • Visual line-transect surveys for the finless porpoise (Neophocaena phocaenoides) were conducted in the offshore of the west coast of Korea (WCOK) from 18 April to 17 May 2001 $(34^{\circ}18'\;to\;37^{\circ}18'N,\;123^{\circ}00'\;to\;126^{\circ}00'E),$ and in the inshore of the west coast of Korea (WCIK) from 29 July to 2 August 2003 $(35^{\circ}17'\;to\;36^{\circ}17'N,\;126^{\circ}00'\;to\;126^{\circ}25'E).$ A total of transect survey efforts were 810.27 n.m. in 2001 and 216.09 n.m. in 2003, which cover a survey areas of $23,012\;n.m^2\;and\;1,550\;n.m^2,$ respectively. There were 76 and 24 sightings for the finless porpoise during the surveys in the WCOK (2001) and the WCIK (2003), respectively. More than $80\%$ of the finless porpoise occurred near the coast within 15 n.m. from the land. Porpoise were observed mainly in a depth range from 20 to 50 m $(78\%).$ Few porpoise were observed in a depth shallower than 10 m or deeper than 60 m. The hazard-rate model, truncated at the largest $5\%$ distance, showed the best fitting from the frequency distribution of perpendicular distance of the finless porpoise sighted from the trackline in the WCOK (2001), while the uniform model showed the best fitting from in the WCIK (2003). Abundance of finless porpoises were estimated to be 58,650 individuals ($95\%$ CI=34,961-98,389) in the WCOK (2001) and 1,571 individuals ($95\%$ CI=881-2,800) in the WCIK (2003), respectively.

Implementation of Real-time Stereoscopic Image Conversion Algorithm Using Luminance and Vertical Position (휘도와 수직 위치 정보를 이용한 입체 변환 알고리즘 구현)

  • Yun, Jong-Ho;Choi, Myul-Rul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.5
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    • pp.1225-1233
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    • 2008
  • In this paper, the 2D/3D converting algorithm is proposed. The single frame of 2D image is used fur the real-time processing of the proposed algorithm. The proposed algorithm creates a 3D image with the depth map by using the vertical position information of a object in a single frame. In order to real-time processing and improve the hardware complexity, it performs the generation of a depth map using the image sampling, the object segmentation with the luminance standardization and the boundary scan. It might be suitable to a still image and a moving image, and it can provide a good 3D effect on a image such as a long distance image, a landscape, or a panorama photo because it uses a vertical position information. The proposed algorithm can adapt a 3D effect to a image without the restrictions of the direction, velocity or scene change of an object. It has been evaluated with the visual test and the comparing to the MTD(Modified Time Difference) method using the APD(Absolute Parallax Difference).

Reduction Characteristics of Pool Top Radiation Level in HANARO (하나로 수조 방사선 준위의 저감 특성)

  • Park, Yong-Chul
    • The KSFM Journal of Fluid Machinery
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    • v.5 no.1 s.14
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    • pp.49-54
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    • 2002
  • HANARO, 30 MW of research reactor, was installed at the depth of 13m in an open pool. The $90\%$ of primary coolant was designed to pass through the core and to remove the reaction heat of the cote. The rest, $10\%$, of the primary coolant was designed to bypass the core. And the reactor coolant through and bypass the core was inhaled at the top of chimney by the coolant pump to prevent the radiated gas from being lifted to the top of reactor pool. But, the part of core bypass coolant was not inhaled by the reactor coolant pump and reached at the top of reactor pool by natural convection, and increased the radiation lovel on the top of reactor pool. To reduce the radiation level by protecting the natural convection of the core bypass flow, the hot water layer (HWL, hereinafter) was installed with the depth of 1.2 m from the top of reactor pool. As the HWL was normally operated, the radiation level was reduced to five percent ($5\%$) in comparing with that before the installation of the HWL. When HANARO was operated at a higher temperature than the normal temperature of the HWL by operating the standby heater, it was found that the radiation level was more reduced than that before operation. To verify the reason, the heat loss of the HWL was calculated by Visual Basic Program. It was confirmed through the results that the larger the temperature difference between the HWL and reactor hall was, the more the evaporation loss increased. And it was verified that the radiation level above was reduced mote safely by increasing the capacity of heater.

Standardizing the evaluation criteria on treatment outcomes of mandibular implant overdentures: a systematic review

  • Kim, Ha-Young;Shin, Sang-Wan;Lee, Jeong-Yol
    • The Journal of Advanced Prosthodontics
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    • v.6 no.5
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    • pp.325-332
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    • 2014
  • PURPOSE. The aim of this review was to analyze the evaluation criteria on mandibular implant overdentures through a systematic review and suggest standardized evaluation criteria. MATERIALS AND METHODS. A systematic literature search was conducted by PubMed search strategy and hand-searching of relevant journals from included studies considering inclusion and exclusion criteria. Randomized clinical trials (RCT) and clinical trial studies comparing attachment systems on mandibular implant overdentures until December, 2011 were selected. Twenty nine studies were finally selected and the data about evaluation methods were collected. RESULTS. Evaluation criteria could be classified into 4 groups (implant survival, peri-implant tissue evaluation, prosthetic evaluation, and patient satisfaction). Among 29 studies, 21 studies presented implant survival rate, while any studies reporting implant failure did not present cumulative implant survival rate. Seventeen studies evaluating peri-implant tissue status presented following items as evaluation criteria; marginal bone level (14), plaque Index (13), probing depth (8), bleeding index (8), attachment gingiva level (8), gingival index (6), amount of keratinized gingiva (1). Eighteen studies evaluating prosthetic maintenance and complication also presented following items as evaluation criteria; loose matrix (17), female detachment (15), denture fracture (15), denture relining (14), abutment fracture (14), abutment screw loosening (11), and occlusal adjustment (9). Atypical questionnaire (9), Visual analog scales (VAS) (4), and Oral Health Impact Profile (OHIP) (1) were used as the format of criteria to evaluate patients satisfaction in 14 studies. CONCLUSION. For evaluation of implant overdenture, it is necessary to include cumulative survival rate for implant evaluation. It is suggested that peri-implant tissue evaluation criteria include marginal bone level, plaque index, bleeding index, probing depth, and attached gingiva level. It is also suggested that prosthetic evaluation criteria include loose matrix, female detachment, denture fracture, denture relining, abutment fracture, abutment screw loosening, and occlusal adjustment. Finally standardized criteria like OHIP-EDENT or VAS are required for patient satisfaction.

Changes in longitudinal craniofacial growth in subjects with normal occlusions using the Ricketts analysis

  • Bae, Eun-Ju;Kwon, Hye-Jin;Kwon, Oh-Won
    • The korean journal of orthodontics
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    • v.44 no.2
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    • pp.77-87
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    • 2014
  • Objectives: This study was designed to define the Korean norm values for the Ricketts analysis. Methods: In this longitudinal study, lateral cephalograms of 31 subjects with normal occlusion were taken biennially from ages 9-19 years. Cephalometric measurements were performed. Parameters for which the 10-year change did not exceed one standard deviation were defined as unchanged. The means and standard deviations for the measured parameters were determined for each age group. Results: No significant changes in growth were observed in the molar relationship, incisor overjet, incisor overbite, mandibular incisor extrusion, interincisor angle, lower incisor tip (B1) to A point-Pogonion (A-PO) plane, upper incisor tip (A1) to A-PO plane, B1 inclination to A-PO, A1 inclination to A-PO, B1 inclination to Frankfurt plane (FH), convexity, lower facial height, facial axis, maxillary depth, maxillary height, palatal plane to FH, cranial deflection, ramus Xi position, or porion location. Continual changes over the 10 years of growth were observed in the maxillary first molar distal position to pterygoid true vertical plane, facial depth, mandibular plane to FH, anterior cranial length, mandibular arc, and corpus length. Conclusions: Clinicians can apply the Korean norms at age 9 as determined in this study when using the Ricketts analysis. The patient's age at the beginning of treatment and their sex should be taken into consideration when drawing visual treatment objectives.

3D motion aftereffect in a static region after adaptation to an adjacent counterphase flickering region (역 위상 깜박임 영역 순응에 의해 유도된 인접 영역의 3차원 운동잔여 효과)

  • 김정훈;남종호;정찬섭
    • Korean Journal of Cognitive Science
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    • v.10 no.3
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    • pp.29-37
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    • 1999
  • Murakami and Cavanagh (1998a,b, 1999) reported a jitter aftereffect in a static random noise after a period of adaptation to a patch of dynamic random noise. To a account for this phenomenon. they proposed the retinal slip caused by a small eye movements in the unadapted area, which is usually compensated by the visual system to stabilize images but is unsuppressed due to the adaptation. We tested this hypothesis with new experimental method and stimuli that were supposed to nullify or reduce the effect. However. the aftereffect was still observed even under these stimuls conditions More importantly, the perceived aftereffect was rather different from Murakami and Cavanagh's. After adaptation to a counterphase flickering cosine grating, the adjacent unadapted region seems to move away from the observer during the test period instead of jittering in the frontoparallel plane. We proposed a possible explanation for this new phenomenon noting the severe contrast reduction of the adapted region during flickering period. The aftereffect might be due to the flicker-inducing contrast reduction during adaptation that produces different depth planes for the adapted and unadapted region and its restoration during the test period.

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Clinical Study for Chuna Treatment on Neck Pain Patient with Hypolordotic Cervical Spine (과소전만된 경항통 환자에 대한 추나요법 임상연구)

  • Ryu, Heon-Sik;Jeon, Seong-Ha;Park, Dong-Soo;Lee, Soo-Keel
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.1 no.2
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    • pp.11-20
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    • 2006
  • Objectives: The aim of this study is to investigate clinical effects of Chuna treatment on the neck pain patient with hypolordotic cervical spine. Methods: From June 2006 to August 2006, 20 cases of neck pain patient with hypolordotic cervical spine were divided into 2 groups. Control group(n=10) was treated only acupuncture therapy, and sample group(n=10) was treated Chuna after acupuncture therapy same as control group. Degrees of pain were measured with Visual Analogue Scale(VAS), and the change of cervical curvature was assessed Depth of cervical curve, Method of Jochumsen, and Angle of cervical curve. Results: 1. After 3th and 5th treatment, there was statistical significance between control and sample group in VAS. 2. After 5th treatment, there was not statistical significance between control and sample group in Depth of cervical curve, Method of Jochumsen, and Angle of cervical curve. Conclusions: On treating the neck pain patient with hypolordotic cervical spine, Chuna treatment is more effective than only acupuncture therapy in reducing neck pain, but Chuna treatment for short-term is not more effective than only acupuncture therapy in restoring cervical curvature.

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A Comparison of the Effects of Concomitant Analgesics with Midazolam for Sedative Dental Therapy

  • Kim, Ju-Won;Lee, Chang-Youn;Oh, Seung-Min;Kim, Jwa-Young;Yang, Byoung-Eun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.34 no.6
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    • pp.449-454
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    • 2012
  • Purpose: Intravenous sedation with midazolam is common in contemporary dentistry. That is effective for anxious patients, but additional analgesic agent needs to be used, because midazolam alone doesn't have an analgesic effect. This study was performed to select an analgesic agent between an opioid agent, and nonsteroidal anti-inflammatory drugs as adjunctives in intravenous sedation with midazolam. Methods: The subjects were 60 patients who visited the Department of Oral and Maxillofacial Surgery, Sacred Heart Hospital, Hallym University, between August 2009 and February 2010. Conscious sedation was performed on 20 patients of 3 groups (control group, ketorolac group, and fentanyl group), who were divided randomly. The analgesic agent was administrated preoperatively. For sedation, vital signs were recorded. After sedation and operation, subjective questionnaires of the patient and operator were implemented. Results: All of the $SPO_2$, blood pressure, and heart rates stayed within the normal range for sedation. The sedation depth and analgesic effect of the ketorolac group and fentanyl group were similar. In the case of sedation depth, 12 patients in the ketorolac group and 14 patients in the fentanyl group had no memory of surgery. In the case of analgesic effect, the visual analogue scale of pain scored 2~3 in 13 patients in the ketorolac group, and 0~2 in 12 patients in the fentanyl group. The satisfaction of patients and doctors was also similar. Conclusion: Considering the management and complication of an opioid agent, non-steroidal anti-inflammatory drugs is more effective than an opioid agent.