• Title/Summary/Keyword: Inverse contrast

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Obstacle Detection Algorithm Using Forward-Viewing Mono Camera (전방 모노카메라 기반 장애물 검출 기술)

  • Lee, Tae-Jae;Lee, Hoon;Cho, Dong-Il Dan
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.9
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    • pp.858-862
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    • 2015
  • This paper presents a new forward-viewing mono-camera based obstacle detection algorithm for mobile robots. The proposed method extracts the coarse location of an obstacle in an image using inverse perspective mapping technique from sequential images. In the next step, graph-cut based image labeling is conducted for estimating the exact obstacle boundary. The graph-cut based labeling algorithm labels the image pixels as either obstacle or floor as the final outcome. Experiments are performed to verify the obstacle detection performance of the developed algorithm in several examples, including a book, box, towel, and flower pot. The low illumination condition, low color contrast between floor and obstacle, and floor pattern cases are also tested.

The Lago Sofia Conglomerate : Debris Flow to Hyperconcentrated Flow Deposits in a Cretaceous Submarine Channel, Southern Chile

  • Choe, Moon-Young;Sohn, Young-Kwan;Jo, Hyung-Rae;Kim, Yea-Dong
    • Ocean and Polar Research
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    • v.24 no.3
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    • pp.289-300
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    • 2002
  • The Lago Sofia conglomerates encased in the Cretaceous Cerro Toro Formation, southern Chile, represent a gigantic submarine channel system developed along a foredeep trough. The channel system consists of several tributaries along the trough margin and a trunk channel along the trough axis. Voluminous debris flows were generated ubiquitously along the tract of the submarine channel mainly by the failure of nearby channel banks or slopes. The flows transformed immediately into multiphase flows and resulted in very thick-bedded mass-flow deposits with a peculiar structure sequence. The mass-flow deposits commonly overlie fluted or grooved surfaces and consist of a lower division of clast-supported and imbricated pebble-cobble conglomerate with common basal inverse grading, and an upper division of clast- to matrix-supported and disorganized pebble conglomerate or pebbly mudstone with abundant intraformational clasts. The structure sequence suggests a temporal succession of a turbidity current, a bipartite hyperconcentrapted flow with active clast collisions near the flow base, and a cohesive debris flow probably with a rigid plug. The multiphase flow is interpreted to have resulted from transformation of clast-rich but cohesive debris flows. Cohesive debris flows appear to transform more easily into dilute flow types in subaqueous environments because they are apt to hydroplane. This is in contrast to the flow transitions in subaerial environments where noncohesive debris flows are dominant and difficult to hydroplane.

Speaker-specific Implementation of VOT Values in Korean

  • Han, Jeong-Im;Kim, Joo-Yeon
    • Speech Sciences
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    • v.15 no.4
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    • pp.7-18
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    • 2008
  • The purpose of the present study is to test whether VOT values of the Korean plain stops in intervocalic position are encoded differently by individual speakers. In Scobbie (2006), the VOT values to the /p/-/b/ voicing contrast in Shetland Isles English were found to demonstrate a high degree of inter-speaker variation. More importantly such variation was not arbitrary: first, there was an inverse relationship between the amount of prevoicing for /b/ and the duration of aspiration for /p/. Second, the inter-speaker variation was shown to be similar between the subjects and their parents. These results suggest that the phonetic targets for VOT are specified in fine detail by speakers. The present study further explores this issue in terms of testing 1) whether the likelihood and the amount of voicing for the intervocalic plain stops in Korean show inter-speaker variation; 2) whether the likelihood and the exact amount of voicing for the intervocalic plain stops in Korean are closely related to the amount of aspiration for the Korean intervocalic aspirated stops. The results of the study suggest that the voicing of intervocalic plain stops in Korean varied according to the individual speakers, but it did not seem to be directly interrelated with the amount of aspiration of the aspirated stop sin the same phonological position.

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Board Governance and Bank's Performance: Does Size Matter?

  • ALAM, Atia;ABBAS, Syeda Fizza;HAFEEZ, Ameena
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.817-825
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    • 2020
  • Over the last few decades, corporate frauds have highlighted the significance of corporate governance in deriving firm performance. By using different sample data, extensive research has examined how corporate governance structure influences firm's profitability, but limited research was undertaken on the banking sector of Pakistan. This research adds to the literature by testing how board structure derives bank's performance by using sample data of 19 banks for the period from 2010 to 2017. In addition, the study analyzes the controlling part of size on the link between board governance and bank performance. Findings reveal that banks having small board size, fewer non-executive directors and minimum activity level perform better. Analysis related to bank size illustrates that board size has value in increasing benefits in large size banks in contrast to small size one, while higher participation by board members enhances performance of small size banks more. The correlation results and findings showed that there existed no multicollinearity issue between independent variables. Board size showed positive correlation with the market variable, while board activity tended to correlated negatively with the market performance. Inverse correlation between board size and independent directors indicated that Pakistani banks with greater board size had fewer independent directors.

Intraovarian vascular enhancement via stromal injection of platelet-derived growth factors: Exploring subsequent oocyte chromosomal status and in vitro fertilization outcomes

  • Wood, Samuel H.;Sills, E. Scott
    • Clinical and Experimental Reproductive Medicine
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    • v.47 no.2
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    • pp.94-100
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    • 2020
  • The inverse correlation between maternal age and pregnancy rate represents a major challenge for reproductive endocrinology. The high embryo ploidy error rate in failed in vitro fertilization (IVF) cycles reflects genetic misfires accumulated by older oocytes over time. Despite the application of different follicular recruitment protocols during IVF, gonadotropin modifications are generally futile in addressing such damage. Even when additional oocytes are retrieved, quality is frequently poor. Older oocytes with serious cytoplasmic and/or chromosomal errors are often harvested from poorly perfused follicles, and ovarian vascularity and follicular oxygenation impact embryonic chromosomal competency. Because stimulation regimens exert their effects briefly and immediately before ovulation, gonadotropins alone are an ineffective antidote to long-term hypoxic pathology. In contrast, the tissue repair properties (and particularly the angiogenic effects) of platelet-rich plasma (PRP) are well known, with applications in other clinical contexts. Injection of conventional PRP and/or its components (e.g., isolated platelet-derived growth factors as a cell-free substrate) into ovarian tissue prior to IVF has been reported to improve reproductive outcomes. Any derivative neovascularity may modulate oocyte competence by increasing cellular oxygenation and/or lowering concentrations of intraovarian reactive oxygen species. We propose a mechanism to support intrastromal angiogenesis, improved follicular perfusion, and, crucially, embryo ploidy rescue. This last effect may be explained by mRNA upregulation coordinated by PRP-associated molecular signaling, as in other tissue systems. Additionally, we outline an intraovarian injection technique for platelet-derived growth factors and present this method to help minimize reliance on donor oocytes and conventional hormone replacement therapy.

A Study on the Relationships between Complex and Preference by Perceptual-cognitive and Affective Judgement - Focused on the Commercial Interior Design - (지각적-인지적 판단과 감정적 판단에 따른 복잡성과 선호도의 관계 - 상업공간의 실내디자인을 중심으로 -)

  • Choi Eun-Hee;Kwon Young-Gull
    • Korean Institute of Interior Design Journal
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    • v.15 no.3 s.56
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    • pp.173-183
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    • 2006
  • Design is inseparably related to aesthetics. In spite of that, it is difficult to explain the precise aesthetic variables that affect the aesthetic value of space or environment. Therefore, this study intended to find the relationships between aesthetic variables by perceptual and affective judgement for space design with focus on complexity and preference variables. The research found low level of 'arousing' as well as high levels of affective dimension variables 'pleasant' and 'relaxing' evoked high preference. High preference also appeared in space design cases with high unity, order, and clarity with low contrast and complexity, which are variables of perceptual dimension. Complexity, one variables of preference by Kaplan, is in an inverse proportion to space preference. Thus, space design with high complexity has high level of 'exciting' and 'arousing' affective responses and relatively low level of 'relaxing' response. Additionally, it was confirmed that the most importantly influential factor on complexity was diverse components rather than visual richness and ornamentation.

Stereo Image Quality Assessment Using Visual Attention and Distortion Predictors

  • Hwang, Jae-Jeong;Wu, Hong Ren
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.9
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    • pp.1613-1631
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    • 2011
  • Several metrics have been reported in the literature to assess stereo image quality, mostly based on visual attention or human visual sensitivity based distortion prediction with the help of disparity information, which do not consider the combined aspects of human visual processing. In this paper, visual attention and depth assisted stereo image quality assessment model (VAD-SIQAM) is devised that consists of three main components, i.e., stereo attention predictor (SAP), depth variation (DV), and stereo distortion predictor (SDP). Visual attention is modeled based on entropy and inverse contrast to detect regions or objects of interest/attention. Depth variation is fused into the attention probability to account for the amount of changed depth in distorted stereo images. Finally, the stereo distortion predictor is designed by integrating distortion probability, which is based on low-level human visual system (HVS), responses into actual attention probabilities. The results show that regions of attention are detected among the visually significant distortions in the stereo image pair. Drawbacks of human visual sensitivity based picture quality metrics are alleviated by integrating visual attention and depth information. We also show that positive correlation with ground-truth attention and depth maps are increased by up to 0.949 and 0.936 in terms of the Pearson and the Spearman correlation coefficients, respectively.

A Noisy Infrared and Visible Light Image Fusion Algorithm

  • Shen, Yu;Xiang, Keyun;Chen, Xiaopeng;Liu, Cheng
    • Journal of Information Processing Systems
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    • v.17 no.5
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    • pp.1004-1019
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    • 2021
  • To solve the problems of the low image contrast, fuzzy edge details and edge details missing in noisy image fusion, this study proposes a noisy infrared and visible light image fusion algorithm based on non-subsample contourlet transform (NSCT) and an improved bilateral filter, which uses NSCT to decompose an image into a low-frequency component and high-frequency component. High-frequency noise and edge information are mainly distributed in the high-frequency component, and the improved bilateral filtering method is used to process the high-frequency component of two images, filtering the noise of the images and calculating the image detail of the infrared image's high-frequency component. It can extract the edge details of the infrared image and visible image as much as possible by superimposing the high-frequency component of infrared image and visible image. At the same time, edge information is enhanced and the visual effect is clearer. For the fusion rule of low-frequency coefficient, the local area standard variance coefficient method is adopted. At last, we decompose the high- and low-frequency coefficient to obtain the fusion image according to the inverse transformation of NSCT. The fusion results show that the edge, contour, texture and other details are maintained and enhanced while the noise is filtered, and the fusion image with a clear edge is obtained. The algorithm could better filter noise and obtain clear fused images in noisy infrared and visible light image fusion.

A multisource image fusion method for multimodal pig-body feature detection

  • Zhong, Zhen;Wang, Minjuan;Gao, Wanlin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4395-4412
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    • 2020
  • The multisource image fusion has become an active topic in the last few years owing to its higher segmentation rate. To enhance the accuracy of multimodal pig-body feature segmentation, a multisource image fusion method was employed. Nevertheless, the conventional multisource image fusion methods can not extract superior contrast and abundant details of fused image. To superior segment shape feature and detect temperature feature, a new multisource image fusion method was presented and entitled as NSST-GF-IPCNN. Firstly, the multisource images were resolved into a range of multiscale and multidirectional subbands by Nonsubsampled Shearlet Transform (NSST). Then, to superior describe fine-scale texture and edge information, even-symmetrical Gabor filter and Improved Pulse Coupled Neural Network (IPCNN) were used to fuse low and high-frequency subbands, respectively. Next, the fused coefficients were reconstructed into a fusion image using inverse NSST. Finally, the shape feature was extracted using automatic threshold algorithm and optimized using morphological operation. Nevertheless, the highest temperature of pig-body was gained in view of segmentation results. Experiments revealed that the presented fusion algorithm was able to realize 2.102-4.066% higher average accuracy rate than the traditional algorithms and also enhanced efficiency.

A Cannabinoid Receptor Agonist N-Arachidonoyl Dopamine Inhibits Adipocyte Differentiation in Human Mesenchymal Stem Cells

  • Ahn, Seyeon;Yi, Sodam;Seo, Won Jong;Lee, Myeong Jung;Song, Young Keun;Baek, Seung Yong;Yu, Jinha;Hong, Soo Hyun;Lee, Jinyoung;Shin, Dong Wook;Jeong, Lak Shin;Noh, Minsoo
    • Biomolecules & Therapeutics
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    • v.23 no.3
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    • pp.218-224
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    • 2015
  • Endocannabinoids can affect multiple cellular targets, such as cannabinoid (CB) receptors, transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and peroxisome proliferator-activated receptor ${\gamma}$($PPAR{\gamma}$). The stimuli to induce adipocyte differentiation in hBM-MSCs increase the gene transcription of the $CB_1$ receptor, TRPV1 and $PPAR{\gamma}$. In this study, the effects of three endocannabinoids, N-arachidonoyl ethanolamine (AEA), N-arachidonoyl dopamine (NADA) and 2-arachidonoyl glycerol (2-AG), on adipogenesis in hBM-MSCs were evaluated. The adipocyte differentiation was promoted by AEA whereas inhibited by NADA. No change was observed by the treatment of non-cytotoxic concentrations of 2-AG. The difference between AEA and NADA in the regulation of adipogenesis is associated with their effects on $PPAR{\gamma}$ transactivation. AEA can directly activate $PPAR{\gamma}$. The effect of AEA on $PPAR{\gamma}$ in hBM-MSCs may prevail over that on the $CB_1$ receptor mediated signal transduction, giving rise to the AEA-induced promotion of adipogenesis. In contrast, NADA had no effect on the $PPAR{\gamma}$ activity in the $PPAR{\gamma}$ transactivation assay. The inhibitory effect of NADA on adipogenesis in hBM-MSCs was reversed not by capsazepine, a TRPV1 antagonist, but by rimonabant, a $CB_1$ antagonist/inverse agonist. Rimonabant by itself promoted adipogenesis in hBM-MSCs, which may be interpreted as the result of the inverse agonism of the $CB_1$ receptor. This result suggests that the constantly active $CB_1$ receptor may contribute to suppress the adipocyte differentiation of hBM-MSCs. Therefore, the selective $CB_1$ agonists that are unable to affect cellular $PPAR{\gamma}$ activity inhibit adipogenesis in hBM-MSCs.