Papers by Krishna Chakraborty
Sanskrit Pustak Bhandar eBooks, 2009
Geotextiles and Geomembranes, 1994
Synthetic geotextiles have already been widely used in bank-protection works but are too costly t... more Synthetic geotextiles have already been widely used in bank-protection works but are too costly to be used on a larger scale in developing countries. That is why an indigenous jute geotextile, comparatively much cheaper and easily available, has been substituted in bank-protection works on the Hooghly estuary in the state of West Bengal, India. This estuary is plagued by eroding banks of submerged sand J7ats and numerous unstable islands, one of which is Nayachara Island. The western face of this island has been undergoing severe erosion, leading to deterioration of the navigable channel that leads to the port of Haldia.
Journal of Indian Philosophy, Aug 1, 1978
is a source and condition of our practical behaviour and the ground of our day-today business. Bu... more is a source and condition of our practical behaviour and the ground of our day-today business. But the problem of arriving at this universal generalisation has been a subject of threadbare discussion. Cadgesa, the most remarkable exponent of NavyanyZya, in the section of v~@tigr&op~~a of his Tattvacintamani initiates a detailed discussion on this problem, first of all from the Mimgmsaka standpoint and then proceeds to refute it. The Mimgmsakas hold that repeated observation (bhii,vodu&zna) of coexistence between two phenomena is competent enough to lead us to the ascertainment of universal concomitance. These Mimamsakas are known as Jarannaiyayikas in the circle of neologicians. And in fact Gadgdhara Bhattacgrya ascribes this theory of repeated observation serving as the condition of universal concomitance to the Jarannaiygyikas.' Kumarila Bhatta in his magnum opus &okavrTrttika clearly states that it is repeated observation which is alone capable of leading us to universal concomitance.2 But this theory of repeated observation has not the sanction of most of the philosophical schools in India and the opponent tries to throw it overboard in the following way: It has been contended that repeated observation is the ground of determination of vy@ti, but such an expression is vague, in view of the fact that if one single observation is not competent enough to ascertain the concomitance, repeated observation would share also the same fate, simple repetition does not add anything new. And when on the Vaisesika viewpoint a cognition ceases to exist in the third moment after its emergence it is well-nigh impossible to have a collocation of all these different individual cognitions. As a result each individual cognition will have its own individual efficacy without being supplemented by any prior instance of observation of coexistence. Hence it should be admitted that if one single observation is not competent, collocation of all observations would also fail to lead us to the ascertainment of universal concomitance. Moreover, in the Nyaya-VaiSesika system, simultaniety of knowledge is an impossibility. On this supposition it would be highly improper to assume the emergence of repeated observations in the same moment.
Journal of Indian Philosophy, Aug 1, 1978
THE NYAYA CONCEPT OF SVABHAVIKA SAMBANDHA: A HISTORICAL RETROSPECT Vrsagana, an early samkhya tea... more THE NYAYA CONCEPT OF SVABHAVIKA SAMBANDHA: A HISTORICAL RETROSPECT Vrsagana, an early samkhya teacher formulated for the first time a definition of inference: 'Szmbandh~d ekasmrit pratyak$it ~e@ddhiranumdnam "r [inference is the establishment of the other from the one on the basis of a relation (between the two)]. This definition of inference clearly points to a relation holding between the hetu and the siidhya serving at the root of inference. &arakrsna defines inference as a 'cognition derived through the previous knowledge of the relation between the hetu and the s&ihya, (Tallirigalihgi~ piuvakam SK. V.). Gotama in his Nygyastitra 1 .l-5 characterises inference in a similar vein: Inference is preceded by that (tatpfirvakam), which the commentator VZtsyHyana explains as 'the knowledge of the mark and that of the relation between the mark and mark-possessor.2 During Vgtsyayana's time the question as to how this relation can be ascertained had not been raised and he considered his duty to give his opinion on the same. He prefers the terms 1i;Zga and tirigin, for such logical concepts as vy@pya and vy@zzka have not yet taken a concrete shape. But still he is conscious of the value of joint method which has, in a later period, been accepted as determinant to the ascertainment of universal relation. He'is also conscious of the services rendered by positive (sapok.=) and negative (vipaksa) instances. Vztsyzyana also informs US how through different stages knowledge of universal relation makes inference possible. In Trilocana we meet with a more comprehensive theory of Vyapti 'pervasion'. The old tradition of coexistence was replaced by a more consciously well-defined relation. Trilocana rejected the theory of external association and laid greater stress on the internal aspect of this relation; it is not merely a mechanical but a natural relation (Svabhiivika sambandha). Unfortunately no work of Trilocana has come down to us except a number of fragments preserved by JtianaSrimitra and Ratnakirti. It is clear that Trilocana had a far reaching impact on the contemporary logicians and Vgcaspati clearly admits his indebtedness to this doyen of logicians3 Trilocana asserts that if the relation of two terms (i.e. the hetu and the sadhya) is natural (Svrfbtivika) it will have the status of universal concomitance
Journal of Indian Philosophy, 1978
A CRITICAL SURVEY Gaflge~a, who is universally regarded as an epoch maker in the domain of Navyan... more A CRITICAL SURVEY Gaflge~a, who is universally regarded as an epoch maker in the domain of Navyany~ya philosophy, shows ingenuity as a faithful reporter of the viewpoints of his predecessors. In the p~rvapakm. Section of the Tattvacintdman.i, Gafigega discusses the different definitions of vy~pti of his predecessors and ultimately refutes them. We shall make an attempt to bring out the implications of those definitions and finally deal with that of Gafigega's own. DEFINITION I The first definition runs as follows: "s~dhy~s~m~nadhikara.nyanadhikara.natve sati sadhikara.natvarh vyaptil3" [TC (BI), p. 251 ]. This implies that the hetu is co-existent with the s~lhya and on the other hand not co-existent with that which is not co-existent with the s~dhya. 'Co-existent' means to be present in the same locus. It is obvious that in the case of universal concomitance between smoke and fire, fire is the s~dhya. Fire does not co-exist with those entities, e.g. aquatic animals, etc., which have the negative instance as their locus, and smoke is conspicuous by its absence in the locus of these entities. It is evident that this is a negative definition which for its formulation takes into account the absence of the s~dhya. Gafigega's objection to this def'mition is that for its application it demands that something should be found which does not co-exist with the s~lhya and hence the obvious difficulty will be that such a definition would hardly include the cases where Universal Concomitance is ascertained between two ever-present properties) The formulation of the definition under consideration attempts to obviate the difficulty on the ground that we find a case where non-coexistence with the s~dhya is predicable; for example, the sky (~k~£a), which, in the Ny~ya-Vai~esika view is an ubiquitous substance and hence a locus of all non-ubiquitous substances, cannot have any locus of its own. Hence the sky is non-co-existent with all ever-present properties. The charge of a too narrow definition could thus be easily obviated. Gafige~a fails to see eye to eye with this definition. Introducing two different
Some of tho statistical mechanical properties of two-sublattice cubic antiferromagnets with aniso... more Some of tho statistical mechanical properties of two-sublattice cubic antiferromagnets with anisotropic exchange have been discussed. After transforming the usual spin-Hamiltonian to a Bose operator Hamiltonian by Dyson-Maleov transformation, tho Green's fimction methods have been applied with properly chosen decoupling scheme t(j derive the magnon energy spectrum, the sublattice magnetization and the relation between the Noel temperature and the anisotropy parameter y. Results for 8 1, 3/2, 5/2, 7/2 have been studied and it is shown that the general nature of variation of T with ?/ resembles closely with the variation of Curio temperature with the antisotroi)y parameter for fcrromagnets. The heat capacity for antiforromagnetic magiKuis has been derived and is found to obey a law, while the spinwave contribution to thermal conductivity is roughly proportional to 1 /r/.
In this article, we propose the implementation of a Cloud Radio Access Network (C-RAN) on a multi... more In this article, we propose the implementation of a Cloud Radio Access Network (C-RAN) on a multicore unified device that facilitates the processing of multiple distributed antennas in the base band. In order to decrease their runtime, we present a parallel processing model based on both functional and data decomposition of virtualized Base Band Unit (BBU) functions. We are investigating two parallel running BBU work scheduling techniques, where computational resources can be distributed by user equipment (UE) or by code blocks (CB). We implement a batch queuing model by using data obtained while running an open source RAN code to determine the necessary processing power in a data center while following tight latency criteria in the downlink and uplink directions. When processing a hundred LTE-cells in a multicore device, the proposed model is validated by simulation. The findings provide useful advice on the sizing and implementation of Cloud-RAN applications such as cryptography [9].
Internet Protocol (IP) is becoming a dominant network layer protocol in the current network. Due ... more Internet Protocol (IP) is becoming a dominant network layer protocol in the current network. Due to some limitations, mainly the shortage of address space in IP version 4 (IPv4), the newer version of the protocol named IPv6 is increasingly getting its popularity. But there is already a huge investment made towards the implementation of IPv4. Also, new applications have started developing using IPv6. So, there is a great confusion among users of IP based network whether to deploy IPv6 or stay back with IPv4. This paper is a general comparative study of both the versions of IP and intended to outline few scenarios that may be considered during the selection of IP version as a network layer protocol. The findings of this work are presented in the form of graphs which focus few positive sides of using IPv4. The advantages of IPv6 over IPv4 are tabulated to realize the benefits of using IPv6 as well. The conclusion drawn from the work carried out may be considered as a basis for the prop...
2009 4th International Conference on Computers and Devices for Communication (CODEC), 2009
IPv6 offers variety of enhancements including increased addressing capacity, Quality of Service (... more IPv6 offers variety of enhancements including increased addressing capacity, Quality of Service (QoS) provisioning, built in security through IPSec and improved routing efficiency, over IPv4. But moving from the current version of IPv4 to the future version of IPv6 is not a straightforward process due to their incompatibility and will consume significant amount of time. So for the coming years both the protocols need to coexist. For the smooth interoperation of the two protocols, various well defined transition mechanisms have been proposed so far. In this paper a comparative study of the behavior of IPv4-only network with that of Dual Stack Transition Mechanism (DSTM) under various types of traffic patterns is carried out. In the proposed DSTM enabled network architecture, the hosts in IPv4 network initiates connection with hosts in the IPv4 network over an integrated IPv4/IPv6 network. The performance metric considered in this work is mean end-to-end delay for both the scenarios. ...
Physica A: Statistical Mechanics and its Applications, 1996
The power series coherent anomaly method is applied to study the critical properties of a classic... more The power series coherent anomaly method is applied to study the critical properties of a classical Heisenberg model. The values of true critical temperature T* are obtained. Using these results the estimation of critical exponent y for the zero-field static susceptibility has been made. The results for T* are in good agreement with those obtained from the ratio method and the Pad6 approximant analysis of the direct susceptibility series. But the results for y are found to be different. It is seen that ? for bcc and fcc lattices is approximately equal to 4/3, while for the sc lattice y >> 4/3, in disagreement with the mean experimental value of 4/3. With the proposal of a possible correction due to confluent singularities for sc model we obtain the following expression for susceptibility: X = a(1-tc)-4/3[1 + B(1-to) 3.] , with tc = xc/x*, xc = J/kB Tc, k~ being the Boltzmann constant, J the nearest-neighbour exchange constant, T~ the critical temperature. B and a are numerical constants. A*, the confluent correction has been found to be 0.42 for the sc lattice and non-existent in bcc and fcc lattices.
Communications in Computer and Information Science, 2011
In this paper, a robust digital image watermarking algorithm based on joint Discrete Wavelet Tran... more In this paper, a robust digital image watermarking algorithm based on joint Discrete Wavelet Transform and Discrete Cosine Transform (DWT-DCT) is proposed. The proposed system provides imperceptibility and higher robustness against common signal processing attacks. A binary watermarked image is embedded in certain subbands of a 3-level DWT transformed coefficients of a host image. Then, DCT coefficients of each selected DWT subband is computed. A randomly generated two-dimensional key is used to encrypt the watermark. This 2D key provides security to the image and ownership copyrights. The PN-sequences of the encrypted watermark bits are embedded in the coefficients of the corresponding DCT middle frequencies providing higher security. In extraction stage, the same approach as that of the embedding process is used to extract the DCT middle frequencies of each subband. Finally, correlation between mid-band coefficients and PN-sequences is calculated to determine watermark bit which is again post-processed by the two-dimensional key generated to derive the actual watermark. Experimental results show that the proposed method based on joint procedure of DWT-DCT may be used for watermarking the digital images.
Journal of Physics: Condensed Matter, 1997
This paper presents a discussion about a spin model arising out of singleand double-electron exch... more This paper presents a discussion about a spin model arising out of singleand double-electron exchange processes. The Hamiltonian which consists of the usual Heisenberg exchange, biquadratic exchange and three-atom coupling is studied using the Green function equation-of-motion method within the random-phase approximation. The effects of biquadratic exchange and three-atom coupling on the magnetization curves, quadrupolar ordering and the transition temperature TC are studied. It is shown that the magnetization changes from second to first order at TC depending on the strengths of the biquadratic and three-atom coupling. It is also seen that TC becomes equal to zero at certain values of the parameters. The results are compared with those of molecular-field theory.
Journal of Indian Philosophy, 1978
THE NYAYA CONCEPT OF SVABHAVIKA SAMBANDHA: A HISTORICAL RETROSPECT Vrsagana, an early samkhya tea... more THE NYAYA CONCEPT OF SVABHAVIKA SAMBANDHA: A HISTORICAL RETROSPECT Vrsagana, an early samkhya teacher formulated for the first time a definition of inference: 'Szmbandh~d ekasmrit pratyak$it ~e@ddhiranumdnam "r [inference is the establishment of the other from the one on the basis of a relation (between the two)]. This definition of inference clearly points to a relation holding between the hetu and the siidhya serving at the root of inference. &arakrsna defines inference as a 'cognition derived through the previous knowledge of the relation between the hetu and the s&ihya, (Tallirigalihgi~ piuvakam SK. V.). Gotama in his Nygyastitra 1 .l-5 characterises inference in a similar vein: Inference is preceded by that (tatpfirvakam), which the commentator VZtsyHyana explains as 'the knowledge of the mark and that of the relation between the mark and mark-possessor.2 During Vgtsyayana's time the question as to how this relation can be ascertained had not been raised and he considered his duty to give his opinion on the same. He prefers the terms 1i;Zga and tirigin, for such logical concepts as vy@pya and vy@zzka have not yet taken a concrete shape. But still he is conscious of the value of joint method which has, in a later period, been accepted as determinant to the ascertainment of universal relation. He'is also conscious of the services rendered by positive (sapok.=) and negative (vipaksa) instances. Vztsyzyana also informs US how through different stages knowledge of universal relation makes inference possible. In Trilocana we meet with a more comprehensive theory of Vyapti 'pervasion'. The old tradition of coexistence was replaced by a more consciously well-defined relation. Trilocana rejected the theory of external association and laid greater stress on the internal aspect of this relation; it is not merely a mechanical but a natural relation (Svabhiivika sambandha). Unfortunately no work of Trilocana has come down to us except a number of fragments preserved by JtianaSrimitra and Ratnakirti. It is clear that Trilocana had a far reaching impact on the contemporary logicians and Vgcaspati clearly admits his indebtedness to this doyen of logicians3 Trilocana asserts that if the relation of two terms (i.e. the hetu and the sadhya) is natural (Svrfbtivika) it will have the status of universal concomitance
Journal of Indian Philosophy, 1978
is a source and condition of our practical behaviour and the ground of our day-today business. Bu... more is a source and condition of our practical behaviour and the ground of our day-today business. But the problem of arriving at this universal generalisation has been a subject of threadbare discussion. Cadgesa, the most remarkable exponent of NavyanyZya, in the section of v~@tigr&op~~a of his Tattvacintamani initiates a detailed discussion on this problem, first of all from the Mimgmsaka standpoint and then proceeds to refute it. The Mimgmsakas hold that repeated observation (bhii,vodu&zna) of coexistence between two phenomena is competent enough to lead us to the ascertainment of universal concomitance. These Mimamsakas are known as Jarannaiyayikas in the circle of neologicians. And in fact Gadgdhara Bhattacgrya ascribes this theory of repeated observation serving as the condition of universal concomitance to the Jarannaiygyikas.' Kumarila Bhatta in his magnum opus &okavrTrttika clearly states that it is repeated observation which is alone capable of leading us to universal concomitance.2 But this theory of repeated observation has not the sanction of most of the philosophical schools in India and the opponent tries to throw it overboard in the following way: It has been contended that repeated observation is the ground of determination of vy@ti, but such an expression is vague, in view of the fact that if one single observation is not competent enough to ascertain the concomitance, repeated observation would share also the same fate, simple repetition does not add anything new. And when on the Vaisesika viewpoint a cognition ceases to exist in the third moment after its emergence it is well-nigh impossible to have a collocation of all these different individual cognitions. As a result each individual cognition will have its own individual efficacy without being supplemented by any prior instance of observation of coexistence. Hence it should be admitted that if one single observation is not competent, collocation of all observations would also fail to lead us to the ascertainment of universal concomitance. Moreover, in the Nyaya-VaiSesika system, simultaniety of knowledge is an impossibility. On this supposition it would be highly improper to assume the emergence of repeated observations in the same moment.
Journal of Indian Philosophy, 1978
A CRITICAL SURVEY Gaflge~a, who is universally regarded as an epoch maker in the domain of Navyan... more A CRITICAL SURVEY Gaflge~a, who is universally regarded as an epoch maker in the domain of Navyany~ya philosophy, shows ingenuity as a faithful reporter of the viewpoints of his predecessors. In the p~rvapakm. Section of the Tattvacintdman.i, Gafigega discusses the different definitions of vy~pti of his predecessors and ultimately refutes them. We shall make an attempt to bring out the implications of those definitions and finally deal with that of Gafigega's own. DEFINITION I The first definition runs as follows: "s~dhy~s~m~nadhikara.nyanadhikara.natve sati sadhikara.natvarh vyaptil3" [TC (BI), p. 251 ]. This implies that the hetu is co-existent with the s~lhya and on the other hand not co-existent with that which is not co-existent with the s~dhya. 'Co-existent' means to be present in the same locus. It is obvious that in the case of universal concomitance between smoke and fire, fire is the s~dhya. Fire does not co-exist with those entities, e.g. aquatic animals, etc., which have the negative instance as their locus, and smoke is conspicuous by its absence in the locus of these entities. It is evident that this is a negative definition which for its formulation takes into account the absence of the s~dhya. Gafigega's objection to this def'mition is that for its application it demands that something should be found which does not co-exist with the s~lhya and hence the obvious difficulty will be that such a definition would hardly include the cases where Universal Concomitance is ascertained between two ever-present properties) The formulation of the definition under consideration attempts to obviate the difficulty on the ground that we find a case where non-coexistence with the s~dhya is predicable; for example, the sky (~k~£a), which, in the Ny~ya-Vai~esika view is an ubiquitous substance and hence a locus of all non-ubiquitous substances, cannot have any locus of its own. Hence the sky is non-co-existent with all ever-present properties. The charge of a too narrow definition could thus be easily obviated. Gafige~a fails to see eye to eye with this definition. Introducing two different
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Papers by Krishna Chakraborty