| 1. |
|
|
| 2. |
- Pattabiraman, M., et al.
(författare)
-
Annealing effect on transport properties of Nd0.67Sr0.33MnO3 thin films
- 2000
-
Ingår i: Pramana (Bangalore). - : Springer Science and Business Media LLC. - 0304-4289 .- 0973-7111. ; 55:3, s. 455-469
-
Tidskriftsartikel (refereegranskat)abstract
- Annealing dependence of the lattice parameter, resistivity, magnetoresistance and thermopower have been studied on Nd0.87Sr0.33MnO3 thin films deposited on LaAlO3 and alumina substrates by pulsed laser ablation. Upon annealing at 800 degrees C and 1000 degrees C the lattice constant of the LaAlO3 film tends toward that of the bulk target due to reduction in oxygen vacancies. This results in a metal-insulator transition at temperatures which increase with progressive annealing along with a decrease in the observed low temperature MR. Using a magnon scattering model we estimate the e(g) bandwidth of the film annealed at 1000 degrees C and show that the magnon contribution to the resistivity is suppressed in a highly oxygen deficient film and gains prominence only upon subsequent annealing. We also show that upon annealing, the polaron concentration and the spin cluster size increases in the paramagnetic phase, using an adiabatic polaron hopping model which takes into account an exchange dependent activation energy above the resistivity peak.
|
|
| 3. |
|
|
| 4. |
- Ostrovsky, Karol, 1975, et al.
(författare)
-
Towards a Primitive Higher Order Calculus of Broadcasting Systems
- 2002
-
Ingår i: PPDP '02. - New York, NY : ACM Press. - 1581135289 ; , s. 2-13
-
Konferensbidrag (refereegranskat)abstract
- Ethernet-style broadcast is a pervasive style of computer communication. In this style, the medium is a single nameless channel. Previous work on modelling such systems proposed a first order process calculus called CBS. In this paper, we propose a fundamentally different calculus called HOBS. Compared to CBS, HOBS 1) is higher order rather than first order, 2) supports dynamic subsystem encapsulation rather than static, and 3) does not require an "underlying language" to be Turing-complete. Moving to a higher order calculus is key to increasing the expressivity of the primitive calculus and alleviating the need for an underlying language. The move, however, raises the need for significantly more machinery to establish the basic properties of the new calculus. This paper develops the basic theory for HOBS and presents two example programs that illustrate programming in this language. The key technical underpinning is an adaptation of Howe's method to HOBS to prove that bisimulation is a congruence. From this result, HOBS is shown to embed the lazy λ-calculus.
|
|
| 5. |
- Prasad, K V S, 1952
(författare)
-
Broadcast Calculus Interpreted in CCS upto Bisimulation
- 2001
-
Ingår i: Electronic Notes in Theoretical Computer Science. - 1571-0661. ; 52:1, s. 83-100
-
Tidskriftsartikel (refereegranskat)abstract
- A function M is given that takes any process p in the calculus of broadcasting systems CBS and returns a CCS process M(p) with special actions {hear?, heard!, say?, said!} such that a broadcast of ω by p is matched by the sequence say? τ∗said(ω) by M(p) and a reception of υ by hear(v) τ∗heard!. It is shown that p ∼ M(p), where ∼ is a bisimulation equivalence using the above matches, and that M(p) has no CCS behaviour not covered by ∼. Thus the abstraction of a globally synchronising broadcast can be implemented by sequences of local synchronisations. The criteria of correctness are unusual, and arguably stronger than requiring equivalences to be preserved — the latter does not guarantee that meaning is preserved. Since ∼ is not a native CCS equivalence, it is a matter of dicussion what the result says about Holmer's (CONCUR'93) conjecture, partially proved by Ene and Muntean (FCT'99), that CCS cannot interpret CBS upto preservation of equivalence.
|
|
