In this paper we describe the OpenGeoSys (OGS) project, which is a scientific open-source initiative for numerical simulation of thermo-hydro-mechanical-chemical processes in porous media. The basic ...concept is to provide a flexible numerical framework (using primarily the Finite Element Method (FEM)) for solving multifield problems in porous and fractured media for applications in geoscience and hydrology. To this purpose OGS is based on an object-oriented FEM concept including a broad spectrum of interfaces for pre- and postprocessing. The OGS idea has been in development since the mid-eighties. We provide a short historical note about the continuous process of concept and software development having evolved through Fortran, C, and C++ implementations. The idea behind OGS is to provide an open platform to the community, outfitted with professional software-engineering tools such as platform-independent compiling and automated benchmarking. A comprehensive benchmarking book has been prepared for publication. Benchmarking has been proven to be a valuable tool for cooperation between different developer teams, for example, for code comparison and validation purposes (DEVOVALEX and CO
2
BENCH projects). On one hand, object-orientation (OO) provides a suitable framework for distributed code development; however, the parallelization of OO codes still lacks efficiency. High-performance-computing efficiency of OO codes is subject to future research.
Volume rendering methods enable the user to explore interactively scalar data on regularly spaced three-dimensional grids. This article discusses how to use this method to explore and analyse ...three-dimensional tensor fields. The proposed visualization makes use of the programmability of modern graphics hardware and of “Line Integral Convolution”, a texture-based technique for the visualization of vector fields. While an example from geomechanics is used for presentation purposes, the rendering methods introduced are generic and would suit other application areas that involve volumetric data with several attributes equally well.
Thoracic endovascular aortic repair (TEVAR) is the optimal therapy for complicated acute type B aortic dissection (aTBAD). This study examined clinical outcomes and aortic remodeling parameters after ...TEVAR for patients with complicated aTBAD.
From January 2012 to December 2015, 51 patients underwent TEVAR for complicated aTBAD. Preoperative and postoperative imaging studies were analyzed for sizes of the true lumen (TL) and false lumen (FL) and for the FL thrombosis status at five locations in the thoracic and abdominal aorta.
In-hospital and 1-year mortality rates were 3.9% and 5.8%, respectively. The incidence of stroke and paraparesis were 3.9% and 5.8%, respectively. In DeBakey 3a patients, TEVAR resulted in complete FL thrombosis and/or obliteration in 73% of patients. In DeBakey 3b patients, TEVAR resulted in complete FL thrombosis and/or obliteration in 100% of patients in the proximal descending thoracic aorta and 78% in the midpoint of the descending thoracic aorta. The infrarenal FL remained patent in 78% of patients. TEVAR stabilized the size of the proximal descending thoracic aorta (pre-TEVAR 43 ± 9 mm vs post-TEVAR 39 ± 7 mm; p = 0.07). However, significant aortic expansion was observed in all other downstream aortic segments. TEVAR resulted in a significant expansion in the TL volume (pre-TEVAR 99 ± 51 cm
vs post-TEVAR 185 ± 70 cm
; p < 0.01) and total aortic volume (pre-TEVAR 314 ± 97 cm
vs post-TEVAR 391 ± 120 cm
; p = 0.02) while inhibiting expansion of FL volume (pre-TEVAR 215 ± 67 cm
vs post-TEVAR 204 ± 79 cm
; p = 0.91).
TEVAR for complicated aTBAD results in low 30-day and 1-year mortality rates, with higher reintervention rates than observed with open operations. TEVAR is effective in thrombosing and stabilizing the size of the thoracic FL. The abdominal aortic FL remains patent and must be carefully scrutinized for long-term aneurysm formation.
A single-chip adaptive DPCM video codec Schobinger, M.; Zehner, B.; Matthiesen, F. ...
IEEE journal of solid-state circuits,
08/1989, Letnik:
24, Številka:
4
Journal Article
Recenzirano
A differential pulse-code modulation (DPCM) video codec with two-dimensional intrafield prediction and adaptive quantizer is presented. An approach for the arithmetic implementation of the DPCM ...structure and the design of a test chip, fabricated in a 1.5 mu m CMOS technology, is described. This is the first VLSI realization of a DPCM codec with adaptive quantizer. For the test chip transmitter or receiver mode, application as part of a three-dimensional interframe codec and processing of luminance or chrominance signals are optional. A line buffer and ten different quantizer characteristics are realized on-chip. Correct operation has been verified up to 26 MHz.< >
Low-cost digital transmission of color TV signals over the channels of a future broad-band network (Integrated Services Digital Network, or ISDN) requires data reduction by digital low-pass filters. ...Low-pass filtering of a TV picture amounts to process pixels which are adjacent in either the horizontal or vertical direction. For this purpose, the pixels must be stored in a delay unit. A VLSI chip with a delay unit is reported that is based on a resettable first-in-first-out (FIFO) memory and a pipelined arithmetic unit. The FIFO concept starts from a three-transistor cell array which is accessed by a pointer and customized to a FIFO memory by suitable second-layer metal wiring. Rather than cascade registers, the FIFO memory can be adapted to different standards by the reset signal for the pointer. The approach results in a regular compact design (80-kbit transistors, 31 mm/SUP 2/). An experimental chip fabricated with 1.5-/spl mu/m CMOS technology operates up to 22 MHz (typical values). A data stream of 22/spl times/32 Mb/s is exchanged between the memory and the arithmetic basic unit.
Abstract
Elevated process temperatures can accompany current high extrusion rates of rigid poly(vinyl chloride). Various colored weatherable siding compounds were studied in the processing ...temperature range of 193°C to 227°C. The extruded compounds showed only minor color shifts due to increased melt temperatures. Outdoor exposure through four years in Arizona, Florida, and Ohio demonstrated typical color change but did not exhibit significant color shift relating to the initial processing temperatures. The samples extruded at elevated melt temperatures did demonstrate reduced impact strengths prior to outdoor exposure. Florida‐exposed and Ohio‐exposed samples lost impact strength throughout five years of exposure, with the samples processed at higher temperatures continuing to show lower impacts over time.
Previous res on interviewer effects has indicated that when young adults are confronted with questions whose content is sexual or sensitive in nature their responses are more inhibited when ...interviewed by a young interviewer of the opposite sex. Similar effects in response to questions about premarital intercourse were hyp'ed in a random sample survey admin'ed to 196 undergraduates at a mid-western U. Results did not confirm the hyp. questionaire R's' answers were unaffected by the sex of the interviewer while F R's were signif'ly more inhibited when being interviewed by another F. A further analysis of the earlier study in light of the apparently contradictory recent results suggests that the responses may best be understood when the explicitness of the sexual content of the questions is considered. In this study explicit reference to sexual behavior in the same sex interview situations appeared most conducive to eliciting the most 'moral' & inhibited responses from F R's. The absence of a parallel effect among M's is attributed to the lack of similar 'moral' expectations about M's' behavior by other men or women. AA.
This article examines a new degree, the Management of Technology (MOT). To create customer value and competitive advantage in today's technological environment, bridges must be built between managers ...who know what needs to be done and technologists who know how to do it. The traditional MBA program has focused on defining what needs to be done vis-a-vis customers and competitors. The traditional MS in technology program focused on how to do it. The emerging MOT programs bridge the two perspectives. Forces creating demand for MOT programs are explored and current MOT programs examined. This paper describes the MS in Technology Management program at Pepperdine University's George L. Graziadio Graduate School of Business and Management as representative of MOT programs. The author has taught in Pepperdine University's MS in Technology Management program since 1989.
In the context of a trend toward increasing moderate density townhouse construction in suburban areas, ths report makes use of survey research data to explore differences in the quality of residents' ...lives in new town townhouse areas compared to more conventional neighborhoods of lower density single family detached housing. Results indicate that while town-house neighborhoods were associated with relatively less expensive housing (at a ratio of housing cost to income) and better access to selected facilities and services, they were also perceived as less attractive, less well maintained, more noisy, and less well provided with play areas for children. Overall, however, the ratings of new-town townhouse neighborhoods were as high or higher as those of traditional single family neighborhoods in the less planned control communities.
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