162 research outputs found
Generating B-spline curves with points, normals and curvature constraints: A constructive approach
No full textThis paper presents a constructive method for generating a uniform cubic B-spline curve interpolating a set of data points simultaneously controlled by normal and curvature constraints. By comparison, currently published methods have addressed one or two of those constraints (point, normal or cross-curvature interpolation), but not all three constraints simultaneously with C2 continuity. Combining these constraints provides better control of the generated curve in particular for feature curves on free-form surfaces. Our approach is local and provides exact interpolation of these constraints. © Springer-Verlag 2010.CATMULL E, 1978, COMPUT AIDED DESIGN, V10, P350, DOI 10.1016-0010-4485(78)90110-0; Farin G., 2002, CURVES SURFACES COMP; GOFUKU S, 2009, COMPUT AIDED DES; Halstead M., 1993, SIGGRAPH 93 C P, P35; Hoschek J., 1993, FUNDAMENTALS COMPUTE; Hoschek J, 1999, SHAPE PRESERVING REPRESENTATIONS IN COMPUTER-AIDED GEOMETRIC DESIGN, P163; Ye XZ, 1996, COMPUT AIDED DESIGN, V28, P741, DOI 10.1016-0010-4485(95)00080-1; Maekawa T, 2007, COMPUT AIDED DESIGN, V39, P313, DOI 10.1016-j.cad.2006.12.008; NASRI A, 2003, PACIFIC GRAPHICS; NASRI A, 2006, COMPUTER GRAPHICS IN, P761; Nasri AH, 2002, VISUAL COMPUT, V18, P259, DOI 10.1007-s003710100154; Nasri AH, 2002, VISUAL COMPUT, V18, P382, DOI 10.1007-s003710100155; Nasri AH, 2002, COMPUT GRAPH-UK, V26, P393, DOI 10.1016-S0097-8493(02)00082-1; Piegl L., 1997, NURBS BOOK; Prautzsch H., 2002, BEZIER B SPLINE TECH; SCHAEFER S, 2004, S GEOM PROC, P105; Weiss V, 2002, COMPUT AIDED GEOM D, V19, P19, DOI 10.1016-S0167-8396(01)00086-355
The demand for foreign workers in the manufacturing sector in Malaysia
No full textThe objective of this study is to investigate the demand for foreign workers in the manufacturing sector in Malaysia. In order to achieve this objective, the simultaneous equation model is developed and the analyses are based on data from the Industrial Survey conducted by the Department of Statistics Malaysia for the period of 1994-2005. The Labor demand model is derived from the Cobb-Douglas production function. The results from the estimation of the production function show that foreign workers in the category of professional significantly contributed to the output growth of ISIC35, ISIC 36 and ISIC 38, while skilled workers and technical-supervisors also give a significant contribution to output growth in ISIC 31. The demand for foreign workers reveals that professionals and technical-supervisors are positively related to output level and wage rates. However, they are negatively related to the price of capital and local wage rate. It means that the professional and technical-supervisor foreign workers complement the local workers and capital
Response-Time Analysis of Limited-Preemptive Parallel DAG Tasks Under Global Scheduling
No full textMost recurrent real-time applications can be modeled as a set of sequential code segments (or blocks) that must be (repeatedly) executed in a specific order. This paper provides a schedulability analysis for such systems modeled as a set of parallel DAG tasks executed under any limited-preemptive global job-level fixed priority scheduling policy. More precisely, we derive response-time bounds for a set of jobs subject to precedence constraints, release jitter, and execution-time uncertainty, which enables support for a wide variety of parallel, limited-preemptive execution models (e.g., periodic DAG tasks, transactional tasks, generalized multi-frame tasks, etc.). Our analysis explores the space of all possible schedules using a powerful new state abstraction and state-pruning technique. An empirical evaluation shows the analysis to identify between 10 to 90 percentage points more schedulable task sets than the state-of-the-art schedulability test for limited-preemptive sporadic DAG tasks. It scales to systems of up to 64 cores with 20 DAG tasks. Moreover, while our analysis is almost as accurate as the state-of-the-art exact schedulability test based on model checking (for sequential non-preemptive tasks), it is three orders of magnitude faster and hence capable of analyzing task sets with more than 60 tasks on 8 cores in a few seconds
Local T-spline surface skinning
No full textSkinning or lofting remains a challenging problem in computer graphics and free-form surface design. Although it was addressed by many researchers, no sufficiently general solution has been proposed yet. In the interpolating approach, the incompatibility of the input NURBS curves are solved by knot insertion. This process leads to an explosion in the number of control points defining the skinned surface. Other methods avoid this problem by generating skinned surfaces that approximate rather than interpolate the input curves. In this paper, we provide a solution to this problem using T-splines. Compared with existing approaches, a T-spline skinned surface interpolates a set of incompatible curves with a control mesh of fewer vertices. Typically, the linear system involved could be solved globally. However, our approach provides a local solution for each skinned curve. As such, local modification could be used to meet additional constraints such as given normal and-or predefined curvature across the skinned curves. © 2012 Springer-Verlag.Bajaj CL, 1996, GRAPH MODEL IM PROC, V58, P524, DOI 10.1006-gmip.1996.0044; Ball A. A., 1974, Computer Aided Design, V6, DOI 10.1016-0010-4485(74)90009-8; Ball A. A., 1975, Computer Aided Design, V7, DOI 10.1016-0010-4485(75)90068-8; BOISSONNAT JD, 1988, COMPUT VISION GRAPH, V44, P1, DOI 10.1016-S0734-189X(88)80028-8; Farin G., 2000, ESSENTIALS CAGD; Faux ID, 1979, COMPUTATIONAL GEOMET; Nasri A., 2003, Proceedings 11th Pacific Conference on Computer Graphics and Applications; Park H, 2003, COMPUT AIDED DESIGN, V35, P1261, DOI 10.1016-S0010-4485(03)00040-X; Piegl LA, 2002, VISUAL COMPUT, V18, P273, DOI 10.1007-s003710100156; Sederberg TN, 2003, ACM T GRAPHIC, V22, P477, DOI 10.1145-882262.882295; Sederberg TW, 2004, ACM T GRAPHIC, V23, P276, DOI 10.1145-1015706.1015715; Wang WK, 2008, COMPUT AIDED DESIGN, V40, P999, DOI 10.1016-j.cad.2008.08.001; WOODWARD CD, 1988, COMPUT AIDED DESIGN, V20, P441, DOI 10.1016-0010-4485(88)90002-422
The liminar status of begaguien novel’s principal personage Béni ou le pardis privé Dr Zoulikha NASRI
No full textLe travail que nous menons ici autour de la question de la liminalité a pour originela lecture de Béni ou le paradis privé (1989) d’Azouz Begag. Appliqué comme outil d’analysedu personnage, ce concept issu de la réflexion de Van Gennep ([1981 1909]) sur les rites depassage permettra de comprendre à travers le texte de l’auteur franco-algérien la situationdans laquelle se retrouvent les « enfants de la postcolonie ».The reflexion conducted here about the liminality notion hasfor origin thebegaguien novel’s, Béni ou le paradis privé (1989). Applicated as read grid, this concept of VanGennep ([1981] 1909) exploited in anthropology’s domain, precisely around passage rites, willhelp us to understand trought author French-algerian’s text the no easy situation of thepostcolonie’s children
Partial-Order Reduction in Reachability-based Response-Time Analyses
No full textThe temporal correctness of safety-critical systems is typically guaranteed via a response-time analysis, whose goal is to determine the worst-case response time (WCRT) of a set of input jobs when they are scheduled by a given scheduling policy on a computing resource. However, response-time analysis is a hard problem to solve, with most variations of the problem being NP-hard. Recently, Nasri et al. have introduced an exact reachability-based response-time analysis that is based on exploring the space of possible decisions that a scheduler can take for a set of jobs/tasks. Their solution is at least three orders of magnitude faster than other exact response-time analyses and scales well. Despite its current success in scalability, the schedule-abstraction-based analysis still faces one big fundamental limitation: in the reachability graph that it builds, each edge can only include one single scheduling decision. As a result, as soon as there are large uncertainties in the release time or execution time of the jobs in the input job set, the number of states generated by the schedule-abstraction graph grows exponentially because the analysis will try to explore all (valid) combinations of ordering between jobs.We improve the scalability of the schedule-abstraction-based analysis by introducing partial-order reduction (POR) rules that allow combining multiple scheduling decisions on one edge and hence avoiding combinatorial exploration of all possible orderings between jobs in cases where there are large uncertainties. Our solution is an exact schedulability analysis and provides a safe response-time analysis that reduces the size of the graph while only introducing a small overestimation on the WCRT of the jobs. Our key idea is to identify subsets of jobs for which the combinatorial exploration of all orderings is irrelevant to the schedulability of the job set. Exploring these combinations is irrelevant when all scenarios lead to a system state without encountering a deadline miss in any of those scenarios. Dispatching such jobs can be considered in a single step (that combines all those scheduling decisions), which further defers the state-space explosion.We show that our solution is able to reduce the runtime of the analysis by five orders of magnitude on average, and the number of explored states by 98% on average in comparison to the original schedule-abstraction-based analysis of Nasri et al. for randomly generated periodic task sets. This achievement comes with a negligible cost of an average 0.1% increase in the WCRT of the jobs. This shows that POR allows us to analyze even more task sets than the original and has the potential to scale even further. Computer Scienc
Exacerbation of an undiagnosed pre-existing lupus nephritis following an inactivated COVID-19 vaccination
No full textImplication for health policy/practice/research/medical education: There are reports of various renal complications following the administration of different types of COVID-19 vaccines. Further studies are required to investigate the associations and underlying pathogeneses. Please cite this paper as: Hassanzadeh S, Mubarak M, Akhavan Sepahi M, Nasri H. Exacerbation of an undiagnosed pre-existing lupus nephritis following an inactivated COVID-19 vaccination. J Nephropharmacol. 2022;11(1):e02. DOI: 10.34172/npj.2022.02. © 2022 The Author(s); Published by Society of Diabetic Nephropathy Prevention
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