2,361 research outputs found
Competence building in complex systems in the developing countries: the case of satellite building in India
Since 1975, India has built 25 satellites under the satellite programme. By judicially combining the foreign technological imports and local knowledge, India appears to have acquired a high level of capability to build very complex and world-class satellites for remote sensing and communications. This paper analyses the process of technological learning in satellite building in India. Particularly, it illustrates the role of foreign imports and the local efforts at different phases during this process. This paper demonstrates that achieving the goal of technological self-reliance in a developing country like India, particularly in a complex area like satellite systems, is unlikely to be possible without significant foreign imports in the formative period. It also demonstrates that without strong indigenous effort India would not have reached threshold capability in the accumulative phase. Foreign imports and local knowledge appears to have played a complementary role in competence building in satellite technology in India
An assessment of nuclear and missile developments in South Asia.
Since conducting nuclear tests in 1998, both India and Pakistan have decided to build a “minimum nuclear
deterrence”, replacing the policy of “non-weaponized nuclear deterrence”, followed since 1970s. Both
countries appear to have accelerated their nuclear and missile programmes, particularly since 2001, while
the international attention has been focused elsewhere such as Afghanistan and Iraq. Free from intensive
international scrutiny, India and Pakistan continued to develop, test and deploy different types of ballistic
missiles. The nuclear and missile developments in South Asia are gaining greater momentum rather than slowing down and India and Pakistan appear to be in danger of being trapped into a costly strategic arms race. This paper discusses various nuclear and missile developments in India and Pakistan and their technological capabilities. It also analyses the likely medium and long-term nuclear and missile developments or trends in South Asia and their implications for regional and global security, particularly
from the view of nuclear and missile non-proliferation
Technology accumulation in India’s space programme ground systems: the contribution of foreign and indigenous inputs.
Since the late 1960s, India appears to have accumulated a high level of technological capabilities in the area of ground systems in India’s space programme. This paper
analyses the process of technological learning and focuses on the role of international collaboration, foreign imports and indigenous efforts in building capabilities in different areas of ground systems technology such as rocket launching systems, satellite control and tracking systems, and earth stations during this process. This paper illustrates the importance of foreign technological inputs, particularly in the formative phase, for competence building in a developing country like India. It also demonstrates that strong indigenous efforts along with foreign imports were necessary for India to achieve threshold capability and sustain technological change in the accumulative phase. It appears that both foreign
imports and indigenous efforts have played a complementary role in competence building in ground systems technology in India
The impact of export controls on indigenous technology development: the case of India’s space programme.
The timing of export controls and the state of technological capability of a ‘target’ country at a given time
appear to determine the degree of impact of export controls on a ‘target’ country. The impact is likely to be
much greater in the formative phase than in the accumulative phase of technology accumulation. Also, the
export controls, instead of hampering, could provide an incentive for a strong indigenous effort in building
capabilities, eventually making a ‘target country more independent and more immune to export controls.
India’s space programme makes an interesting case study of the impact of export controls on capability
building, as India has been one of the targets for export control regimes. The technology developments in
India’s space programme suggests that the export controls have caused only small delays and did not affect
the programme seriously. It appears that the Missile Technology Control Regime (MTCR) came into force
too late to have a serious adverse impact on India, as India has already attained threshold capabilities. It
also appears that export controls have forced India to plan and strategically manage indigenous technology
development to overcome problems posed by these controls
RVB gauge theory and the Topological degeneracy in the Honeycomb Kitaev model
We relate the Z gauge theory formalism of the Kitaev model to the SU(2)
gauge theory of the resonating valence bond (RVB) physics. Further, we
reformulate a known Jordan-Wigner transformation of Kitaev model on a torus in
a general way that shows that it can be thought of as a Z gauge fixing
procedure. The conserved quantities simplify in terms of the gauge invariant
Jordan-Wigner fermions, enabling us to construct exact eigen states and
calculate physical quantities. We calculate the fermionic spectrum for flux
free sector for different gauge field configurations and show that the ground
state is four-fold degenerate on a torus in thermodynamic limit. Further on a
torus we construct four mutually anti-commuting operators which enable us to
prove that all eigenstates of this model are four fold degenerate in
thermodynamic limit.Comment: 12 pages, 3 figures. Added affiliation and a new section,
'Acknowledgements'.Typos correcte
Exact results for spin dynamics and fractionization in the Kitaev Model
We present certain exact analytical results for dynamical spin correlation
functions in the Kitaev Model. It is the first result of its kind in
non-trivial quantum spin models. The result is also novel: in spite of presence
of gapless propagating Majorana fermion excitations, dynamical two spin
correlation functions are identically zero beyond nearest neighbor separation,
showing existence of a gapless but short range spin liquid. An unusual,
\emph{all energy scale fractionization}of a spin -flip quanta, into two
infinitely massive -fluxes and a dynamical Majorana fermion, is shown to
occur. As the Kitaev Model exemplifies topological quantum computation, our
result presents new insights into qubit dynamics and generation of topological
excitations.Comment: 4 pages, 2 figures. Typose corrected, figure made better, clarifying
statements and references adde
Photoinduced Floquet topological magnons in Kitaev magnets
We study periodically driven pure Kitaev model and ferromagnetic phase of the
Kitaev-Heisenberg model on the honeycomb lattice by off-resonant linearly and
circularly-polarized lights at zero magnetic field. Using a combination of
linear spin wave and Floquet theories, we show that the effective
time-independent Hamiltonians in the off-resonant regime map onto the
corresponding anisotropic static spin model, plus a tunable photoinduced
magnetic field along the direction, which precipitates Floquet
topological magnons and chiral magnon edge modes. They are tunable by the light
amplitude and polarization. Similarly, we show that the thermal Hall effect
induced by the Berry curvature of the Floquet topological magnons can also be
tuned by the laser field. Our results pave the way for ultrafast manipulation
of topological magnons in irradiated Kitaev magnets, and could play a pivotal
role in the investigation of ultrafast magnon spin current generation in Kitaev
materials.Comment: 7 pages, 5 figures + Supplemental Materia
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