Eno-Osher schemes for Euler equations

The combination of the Osher approximate Riemann solver for the Euler equations and various ENO schemes is discussed for one-dimensional flow. The three basic approaches, viz. the ENO scheme using primitive variable reconstruction, either with Cauchy-Kowalewski procedure for time integration or the TVD Runge-Kutta scheme, and the flux-ENO method are tested on different shock tube cases. The shock tube cases were chosen to present a serious challenge to the ENO schemes in order to test their ability to capture flow discontinuities, such as shocks. Also the effect of the ordering of the eigen values, viz. natural or reversed ordering, in the Osher scheme is investigated. The ENO schemes are tested up to fifth order accuracy in space and time. The ENO-Osher scheme using the Cauchy-Kowalewski procedure for time integration is found to be the most accurate and robust compared with the other methods and is also computationally efficient. The tests showed that the ENO schemes perform reasonably well, but have problems in cases where two discontinuities are close together. In that case there are not enough points in the smooth part of the flow to create a non-oscillatory interpolation

Penerapan Metode Support Vector Machine pada Sistem Deteksi Intrusi secara Real-time

Intrusion detection system is a system for detecting attacks or intrusions in a network or computer system, generally intrusion detection is done with comparing network traffic pattern with known attack pattern or with finding unnormal pattern of network traffic. The raise of internet activity has increase the number of packet data that must be analyzed for build the attack or normal pattern, this situation led to the possibility that the system can not detect the intrusion with a new technique, so it needs a system that can automaticaly build a pattern or model.This research have a goal to build an intrusion detection system with ability to create a model automaticaly and can detect the intrusion in real-time environment with using support vector machine method as a one of data mining method for classifying network traffic audit data in 3 classes, namely: normal, probe, and DoS. Audit data was established from preprocessing of network packet capture files that obtained from Tshark. Based on the test result, the sistem can help system administrator to build a model or pattern automaticaly with high accuracy, high attack detection rate, and low false positive rate. The sistem also can run in real-time environment

Liquid co-fluidization of cylinders and spheres

open access via UoA Wiley agreement The peer review history for this article is available at https://publons.com/publon/10.1002/cjce.24410.Peer reviewedPublisher PD

Orbital navigation, docking and obstacle avoidance as a form of three dimensional model-based image understanding

Range imagery from a laser scanner can be used to provide sufficient information for docking and obstacle avoidance procedures to be performed automatically. Three dimensional model-based computer vision algorithms in development can perform these tasks even with targets which may not be cooperative (that is, objects without special targets or markers to provide unambiguous points). Role, pitch, and yaw of a vehicle can be taken into account as image scanning takes place, so that these can be correlated when the image is converted from egocentric to world coordinated. Other attributes of the sensor, such as the registered reflectance and texture channels, provide additional data sources for algorithm robustness

Gradient flows without blow-up for Lefschetz thimbles

We propose new gradient flows that define Lefschetz thimbles and do not blow up in a finite flow time. We study analytic properties of these gradient flows, and confirm them by numerical tests in simple examples.Comment: 31 pages, 11 figures, (v2) conclusion part is expande

Implementation issues for a compact 6 degree of freedom force reflecting handcontroller with cueing of modes

Teleoperated control requires a master human interface device that can provide haptic input and output which reflect the responses of a slave robotic system. The effort reported in this paper addresses the design and prototyping of a six degree-of-freedom (DOF) Cartesian coordinate hand controller for this purpose. The device design recommended is an XYZ stage attached to a three-roll wrist which positions a flight-type handgrip. Six degrees of freedom are transduced and control brushless DC motor servo electronics similar in design to those used in computer controlled robotic manipulators. This general approach supports scaled force, velocity, and position feedback to aid an operator in achieving telepresence. The generality of the device and control system characteristics allow the use of inverse dynamics robotic control methodology to project slave robot system forces and inertias to the operator (in scaled form) and at the same time to reduce the apparent inertia of the robotic handcontroller itself. The current control design, which is not multiple fault tolerant, can be extended to make flight control or space use possible. The proposed handcontroller will have advantages in space-based applications where an operator must control several robot arms in a simultaneous and coordinated fashion. It will also have applications in intravehicular activities (within the Space Station) such as microgravity experiments in metallurgy and biological experiments that require isolation from the astronauts' environment. For ground applications, the handcontroller will be useful in underwater activities where the generality of the proposed handcontroller becomes an asset for operation of many different manipulator types. Also applications will emerge in the Military, Construction, and Maintenance/Manufacturing areas including ordnance handling, mine removal, NBC (Nuclear, Chemical, Biological) operations, control of vehicles, and operating strength and agility enhanced machines. Future avionics applications including advanced helicopter and aircraft control may also become important

Random Matrix Models for Dirac Operators at finite Lattice Spacing

We study discretization effects of the Wilson and staggered Dirac operator with $N_{\rm c}>2$ using chiral random matrix theory (chRMT). We obtain analytical results for the joint probability density of Wilson-chRMT in terms of a determinantal expression over complex pairs of eigenvalues, and real eigenvalues corresponding to eigenvectors of positive or negative chirality as well as for the eigenvalue densities. The explicit dependence on the lattice spacing can be readily read off from our results which are compared to numerical simulations of Wilson-chRMT. For the staggered Dirac operator we have studied random matrices modeling the transition from non-degenerate eigenvalues at non-zero lattice spacing to degenerate ones in the continuum limit.Comment: 7 pages, 6 figures, Proceedings for the XXIX International Symposium on Lattice Field Theory, July 10 -- 16 2011, Squaw Valley, Lake Tahoe, California, PACS: 12.38.Gc, 05.50.+q, 02.10.Yn, 11.15.H

Two essays on the universal and particular dimensions of culture

The first of the two essays was presented at the conference 'Ethnicity in an Age of Globalisation', held at Uganda Martyrs University, Kampala, Uganda, from 3-6 September 2001.Thesis (MA)--University of Stellenbosch, 2002.Babel or Piraeus? : globalisation, culture and tradition -- Between freedom and culture : Alain Finkielkraut's critique of multiculturalism.ENGLISH ABSTRACT: The conception of globalisation as a "programme" or "project" driven by a group of people or companies with a set agenda underlies much of the antagonistic discussion of globalisation. Protagonists of globalisation, in turn, often describe the process as inevitable progress. This paper analyses the process of globalisation and argues that it should not be understood as such a singular process. Rather, the concept "complex connectivity" - where the local and the global come' into closer contact and influence, or interpenetrate, one another more directly - facilitates a more nuanced analysis of globalisation -.This understanding of globalisation will be tested against the phenomenon of culture by posing two questions: Does globalisation lead to the destruction of local culture( s) by an encroaching singular global culture (i.e. is globalisation cultural imperialism)? Or alternatively: Does globalisation represent an opening .up and exchange between previously isolated cultures and societies? This paper argues in favour of the second position by employing John Tomlinson's existential definition of culture and his understanding of the dialectic that exists between the local and the global in complex connectivity. Instead of global culture, we can more properly speak of . "globalized" culture, which looks different in every local situation. This is a more optimistic answer to the cultural' effects of globalisation, and although some concerns remain, it seems clear that to understand globalisation as complex connectivity rules out many of the charges of cultural imperialism lodged against globalisation.AFRIKAANSE OPSOMMING: Baie van die hedendaagse antagonistiese diskussie oor globalisasie gaan uit van die veronderstelling dat globalisasie 'n 'program' of 'n 'projek' is wat deur 'n groep individue of maatskappye gedryf word. Voorstanders van globalisasie, daarenteen, beskou die proses dikwels as 'onafwendbare vooruitgang.' Hierdie opstel analiseer die proses van globalisasie en argumenteer dat globalisasie nie as so 'n eenduidige process verstaan moet word nie. Die konsep "complex connectivity" word ingespan om 'n meer genuanseerde analise van globalisasie te bied aangesien dit dui op die komplekse interaksie, of selfs interpenetrasie, tussen plaaslike en globale prosesse. Hierdie opvatting oor globalisasie word getoets aan die hand van kultuur deur twee teenstellende vrae te stel: Is globalisasie 'n enkelvoudige globale kultuur wat dreig om plaaslike kulture oor te neem en uiteindelik te vernietig (ook genoem kultuurimperialisme)? Of eerder: Is globalisasie 'n geleentheid tot groter openheid en interaksie tussen kulture en gemeenskappe wat voorheen van mekaar geïsoleer was? Die opstel argumenteer ten gunste van die tweede posisie deur gebruik te maak van John Tomlinson se eksistensiële definisie van kultuur en sy opvatting oor die interaksie tussen die plaaslike en die globale. Instede van globale kultuur kan ons eerder praat van 'geglobaliseerde' kultuur, wat telkens anders lyk in elke plaaslike opset. Hierdie posisie bied 'n versigtige, maar meer optimistiese antwoord op die kulturele impak van globalisasie deurdat veel van die aanklagte van kultuurimperialsime teen globalisasie afgewys word