Momentum transport due to a squall line system over the tropical oceans

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1988.Includes bibliographical references.by Chia-Yung Chang.M.S

Breast augmentation with autologous fat grafting: literature review and case report

INTRODUCTION: The technique and technology lipoaspirate autotransplantation to the breast with the aim of aesthetic appearance and reconstruction has strongly advanced; further, its acceptance by doctors and patients has also improved. The author reports cosmetic breast augmentation and performed a literature review, focusing on the efficacy, carcinogenic potential, and imaging diagnosis. METHOD:A literature review was performed using English-language articles from the PubMed database and the Brazilian Journal of Plastic Surgery (RBCP); in addition, case series of the initial experience of the author has been described. RESULTS: The volume remained stable from the second month, and there were no postoperative complications. Imaging did not show any pathological alterations. In all, 24-related articles were selected. DISCUSSION: Among the 24 articles, only two prospective non-controlled studies were found, but overall, imaging diagnostic tests did not reveal problems, the carcinogenic potential was not increased, and case series had positive results. CONCLUSION: The procedure is reproducible, safe and effective, and reinforces the use of this technique in breast reconstruction and as an option in cosmetic breast augmentation. However, it may require a longer learning curve to avoid complications and achieve good results

Low-complexity face-assisted video coding

[[abstract]]This paper presents a novel face-assisted video coding scheme to enhance the visual quality of the face regions in video telephony applications. A skin-color based face detection and tracking scheme is proposed to locate the face regions in real-time. After classifying the macroblocks into the face and non-face regions, we present a dynamic distortion weighting adjustment (DDWA) scheme to drop the static non-face macroblocks, and the saved bits are used to compensate the face region by adjusting the distortion weighting of the face macroblocks. The quality of face regions will thus be enhanced. Moreover, the computation originally required for the skipped macroblocks can also be saved. The experimental results show that the proposed method can significantly improve the PSNR and the subjective quality of face regions, while the degradation introduced on the non-face areas is relatively insensitive to human perception. The proposed algorithm is fully compatible with the H.263 standard, and the low complexity feature makes it well suited to implement for real-time applications[[fileno]]2030144030041[[department]]電機工程學

Dynamic region of interest transcoding for multipoint video conferencing

This paper presents a region of interest transcoding scheme for multipoint video conferencing to enhance the visual quality. In a multipoint videoconference, usually there are only one or two active conferees at one time which are the regions of interest to the other conferees involved. We propose a Dynamic Sub-Window Skipping (DSWS) scheme to firstly identify the active participants from the multiple incoming encoded video streams by calculating the motion activity of each sub-window, and secondly reduce the frame-rates of the motion inactive participants by skipping these less-important subwindows. The bits saved by the skipping operation are reallocated to the active sub-windows to enhance the regions of interest. We also propose a low-complexity scheme to compose and trace the unavailable motion vectors with a good accuracy in the dropped inactive sub-windows after performing the DSWS. Simulation results show that the proposed methods not only significantly improve the visual quality on the active subwindows without introducing serious visual quality degradation in the inactive ones, but also reduce the computational complexity and avoid whole-frame skipping. Moreover, the proposed algorithm is fully compatible with the H.263 video coding standard. 1

Realtime object extraction and tracking with an active camera using image mosaics

[[abstract]]Moving object extraction plays a key role in applications such as object-based videoconference, surveillance, and so on. The dimculties of moving object segmentation lie in the fact that physical objects are normally not homogeneous with to low-level features and it's usually tough to segment them accnrately and efficiently. Object segmentation based on prestored background information has proved to be effective and efficient in several applications such as videophone, video conferencing, and surveillance, etc. The previous works, however, were mainly concentrated on object segmentation with a static camera and in a stationary background. In this paper, we propose a robust and fast segmentation algorithm and a reliable tracking strategy without knowing the shape of the object in advance. The proposed system can real-time extract the foreground from the background and track the moving object with an active (pan-tilt) camera such that the moving object always stays around the center of images.[[fileno]]2030144030033[[department]]電機工程學