In this paper we evaluate the performance of singlefrequency, single-point positioning processors with an emphasis on ionospheric delay handling. A number of least-squares processors with singlefrequency code-only and code-and-carrier-phase observables were developed. Processing model hierarchy is based on measurement error handling, starting with a basic code-based navigation solution and prog...

We present a hybrid technique of N-body simulation to deal with collisionless stellar systems having an inhomogeneous global structure. We combine a treecode and a selfconsistent field code such that each of the codes model a different component of the system being investigated. The treecode is suited to treatment of dynamically cold or clumpy systems which may undergo significant evolution wit...

MetaKlaim is a case study in modeling the spatial, temporal and security aspects necessary for global computing. MetaKlaim integrates MetaML (an extension of SML for multi-stage programming) and Klaim (a Kernel Language for Agents Interaction and Mobility), in order to allow interleaving of meta-programming activities (like assembly and linking of code fragments), security checks (like typechec...

A Global Navigation Satellite System (GNSS) receiver provides essentially two independent measurements of pseudorange through the estimation of code delay and carrier phase. Although the code delay estimate is an absolute (unambiguous) measurement its accuracy is hindered by noise; on the contrary, the phase estimate has, in general, better accuracy but is ambiguous. The Hatch filter has been u...

In this example, a code segment f has input a and sends output b to a code segment g. There is no return from code segment b, b should call another continuation using goto. Any control structure in C is allowed in CwC language, but in case of CbC, we restrict ourselves to use if statement only, because it is sufficient to implement C to CbC translation. In this case, code segment has one input ...

This research proposes a language independent intra-process framework for object based composition of unmodified code modules. Intuitively, the two major programming models threads and processes can be considered as extremes along a sharing axis. Multiple threads through a process share all global state, whereas instances of a process (or independent processes) share no global state. Weaves pro...

Modern processors can provide large amounts of processing power with vector SIMD units if the compiler or programmer can vectorize their code. With the advance of SIMD support in commodity processors, more and more advanced features are introduced, such as flexible SIMD lane-wise operations (e.g. blend instructions). However, existing vectorizing techniques fail to apply global SIMD lane-wise o...

This paper describes the experience gained while parallelizing the global medium range weather forecasting application called TSO on a PARAM machine based on a distributed memory parallel architecture. The TSO code employs the spectral method for horizontal directions and finite differencing in the vertical direction and time marching. The parallel implementation takes care of the easy portabil...

The member countries of World Tourism Organization (WTO) at its 13th General Assembly in Santiago, Chile adopted the new Global Code of Ethics for Tourism on 1 October 1999. Acclaimed for its lofty goals and coverage, the Code soon became the reference point for debates on a wide spectrum of issues relating to tourism such as sustainable development, equity and protection of local cultures. The...

In Codeplay’s Sieve C++, the programmer can place code inside a “sieve block” thereby instructing the compiler to delay writes to global memory and apply them in order on exit from the block. The semantics of sieve blocks makes code more amenable to automatic parallelisation. However, strictly queueing writes until the end of a sieve block incurs overheads and is typically unnecessary. If the p...