1,194 research outputs found
Unified Angular Momentum of Dyons
Unified quaternionic angular momentum for the fields of dyons and
gravito-dyons has been developed and the commutation relations for dynamical
variables are obtained in compact and consistent manner. Demonstrating the
quaternion forms of unified fields of dyons (electromagnetic fields) and
gravito-dyons (gravito-Heavisidian fields of linear gravity), corresponding
quantum equations are reformulated in compact, simpler and manifestly covariant
way
Observations of Multiple Surges Associated with Magnetic Activities in AR10484 on 25 October 2003
We present a multiwavelength study of recurrent surges observed in H{\alpha},
UV (SOHO/EIT) and Radio (Learmonth, Australia) from the super-active region
NOAA 10484 on 25 October, 2003. Several bright structures visible in H{\alpha}
and UV corresponding to subflares are also observed at the base of each surge.
Type III bursts are triggered and RHESSI X-ray sources are evident with surge
activity. The major surge consists of the bunches of ejective paths forming a
fan-shape region with an angular size of (\approx 65\degree) during its maximum
phase. The ejection speed reaches upto \sim200 km/s. The SOHO/MDI magnetograms
reveal that a large dipole emerges east side of the active region on 18-20
October 2003, a few days before the surges. On October 25, 2003, the major
sunspots were surrounded by "moat regions" with moving magnetic features
(MMFs). Parasitic fragmented positive polarities were pushed by the ambient
dispersion motion of the MMFs and annihilated with negative polarities at the
borders of the moat region of the following spot to produce flares and surges.
A topology analysis of the global Sun using PFSS shows that the fan structures
visible in the EIT 171 A images follow magnetic field lines connecting the
present AR to a preceding AR in the South East. Radio observations of type III
bursts indicate that they are coincident with the surges, suggesting that
magnetic reconnection is the driver mechanism. The magnetic energy released by
reconnection is transformed into plasma heating and provides the kinetic energy
for the ejections. A lack of a radio signature in the high corona suggests that
the surges are confined to follow the closed field lines in the fans. We
conclude that these cool surges may have some local heating effects in the
closed loops, but probably play a minor role in global coronal heating and the
surge material does not escape to the solar wind.Comment: Accepted for the Publication in ApJ; 25 pages, 10 Figures, and 1
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Modelling and Simulation of Tactical Team Behaviour
Realistic military simulations are needed for analysis, planning, and training. Intelligentagent technology is a valuable software concept with the potential of being widely used inmilitary simulation applications. They provide a powerful abstraction mechanism required fordesigning simulations of complex and dynamic battlefields. Their ability to model the tacticaldecision-making behaviour of simulated battlefield entities gives them an edge over othertechniques. During battlefield simulation, these entities generally represent individualisticbehaviour, taking operational order from higher control and executing relevant plans. However,since a complex battlefield scenario typically involves thousands of entities, their coordinatedteam behaviour should also be considered to make the simulation more realistic. This paperdemonstrates the use of intelligent agent-based team behaviour modelling concepts in simulatingthe armoured tanks in a tactical masking scenario
Tumačenja oktonionske valne jednadžbe
The interpretations of octonion wave equations in eight-dimensional space-time is studied. We made an attempt to consider the octonion field equation as the equation of motion for particles carrying simultaneously electric and magnetic charges (i.e. dyons) in external and internal spaces. It has been concluded that the component of octonion potential wave equations behaves neither as the generalized electromagnetic fields of monopoles nor of the dyons. Rather, it has a mixed behaviour of electromagnetic fields associated with the electric and magnetic charges in external and internal spaces. We have also made an attempt to investigate the split octonion wave equation and its interpretation in classical electrodynamics, and accordingly the consistent and compact forms of eight-dimensional potential and current equation of dyons are obtained in terms of Zorn\u27s vector matrix realization of split octonions. Visualizing the external four-space as the localization space for tachyons, it is shown that the split octonion wave equation reduces to the Maxwell\u27s equation (field equation) for bradyons in R4-space as well as that for tachyons in T4- space in the absence of other.Raspravljamo tumačenja oktonionske valne jednadžbe u osmodimenzijskom prostoru-vremenu. Pokušavamo raspraviti oktonionsku jednadžbu polja kao jednadžbu za gibanje čestica koje istovremeno nose električan i magnetski naboj (tj. diona) u vanjskom i unutarnjem prostoru. Zaključujemo da komponenta oktonionskog potencijala nema svojstva kako poopćenog elektromagnetskog polja, tako i diona. Zapravo, ona ima miješana svojstva elektromagnetskih polja pridruženih vanjskom i unutarnjim prostorima. Također, smo pokušali istražiti podvojenu oktonionsku jednadžbu i njeno tumačenje u klasičnoj elektrodinamici, te smo izveli skladne i sažete oblike osmodimenzijskog potencijala i jednadžbe za struju za dione koje smo izveli preko Zornove vektorske matrice za podvojene oktonione. Predstavljajući vanjski četveroprostor kao prostor za smještaj tahiona, pokazujemo da se podvojena oktonionska jednadžba svodi na Maxwellovu jednadžbu (jednadžbu polja) za bradione u R4 -prostoru, a u odsustvu ovih za tahione u T 4 -prostoru
Efficient absolute aspect determination of a balloon borne far infrared telescope using a solid state optical photometer
The observational and operational efficiency of the TIFR 1 meter balloon
borne far infrared telescope has been improved by incorporating a multielement
solid state optical photometer (SSOP) at the Cassegrain focus of the telescope.
The SSOP is based on a 1-D linear photo diode array (PDA). The online and
offline processing schemes of the PDA signals which have been developed, lead
to improvement in the determination of absolute telescope aspect (
0\farcm8), which is very crucial for carrying out the observations as well as
offline analysis. The SSOP and its performance during a recent balloon flight
are presented here.Comment: To appear in the February 2000 issue of the PAS
Command Agent Belief Architecture to Support Commander Decision Making in Military Simulation
In the war, military conflicts have many aspects that are consistent with complexity theory e.g., the higher commander’s decision is directed at animate entity that react under hierarchical and self-organised structure in decentralised command and control for the collectivist dynamism of decomposed elements due to nonlinear complexity of warfare on the battlefield. Agent technology have been found to be suitable for modelling tactical behaviour of entities at multiple level of resolution under hierarchical command and control (C2) structure and provide a powerful abstraction mechanism required for designing simulations of complex and dynamic battlefield situations. Intelligent agents can potentially reduce the overhead on such experiments and studies. Command agents, plan how to carry out the operation and assign tasks to subordinate agents. They receive information from battlefield environment and use such information to build situation awareness and also to respond to unforeseen situations. In the paper, we have proposed a mechanism for modelling tactical behaviour of an intelligent agent by which higher command level entities should be able to synthesize their beliefs derived from the lower level sub ordinates entities. This paper presents a role-based belief, desire and intention mechanism to facilitate in the representation of military hierarchy, modelling of tactical behaviour based on agent current belief, teammate’s belief propagation, and coordination issues. Higher commander can view the battlefield information at different levels of abstraction based on concept of aggregation and disaggregation and take appropriate reactive response to any unforeseen circumstances happening in battlefield
Studies on the age and growth of Labeo calbasu (Hamilton) with an exploitation pattern from the Ganga River system, Uttar Pradesh (India)
Samples were collected to study the age and growth of Labeo calbasu (Hamilton) from the river Ghaghra (Guptarghat centre, Faizabad). The scales of L. calbasu have been used for age and growth studies in present paper. Study of the marginal rings on the scales of L. calbasu indicates their annual nature. The fish attained growth in 1st 18.7 cm, 2nd 27.8 cm, 3rd 35.7 cm, 4th 41.8 cm, 5th 46.9 cm, 6th 54.9 cm and 7th 57.4 cm years of the life. The growth rate was observed 18.7, 9.1, 7.9, 6.7, 5.1, 8.0 and 2.5 cm for 1st to 7th age classes respectively. The age groups 1+ to 4+ constituted 91.17% of the total exploited population and 8.83% of remaining age groups (5+ to 7+). The maximum exploited population was observed in 2+ age group with 33.68%. Overall exploitation pattern was systematic and a good indicator for heavy recruitment
Morphological, cultural and pathogenic variability in Alternaria brassicae, the causing agent of black spot of rapeseed and mustard
The study on pathogenic diversity of twenty isolates of Alternaria brassicae collected from different locations of Uttarakhand and Central Uttar Pradesh infecting Brassica species (Brassica rapa, Brassica juncea and Eruca sativa) revealed that there was a distinct difference among isolates in terms of mycelial growth, spore length, width, spore beak length and width. The average spore length varied from 21.23?m to 38.13?m with minimum of isolate AUA-19, AUA-43 i.e 21.23?m and maximum of AUA-47 i.e. 38.13?m . The isolates tested on Brassica juncea var.Varuna in green house conditions revealed that all the twenty isolates behaved differently. Among all the isolates, Brassica juncea isolates i.e. AUA-25, AUA-39, AUA-41, AUA-47, AUA-19, AUA-24, AUA-22, AUA-21, AUA-31, AUA-43 and AUA-45 from Uttarakhand, and AUP-29 from Central Uttar Pradesh can be grouped into highly pathogenic with range of Alternaria spot size i.e. 5.03-8.30mm in diameter, while isolate of Eruca sativa i.e. AUA-38 was found least pathogenic with 1.63mm in dia. and eight isolates AUA-18, AUA-20, AUA-23, AUP-28, AUA-32, AUA-33 and AUA-36 were found moderately pathogenic. This study will be useful in developing integrated management strategies of Alternaria leaf spot and breeding programs of oilseed crops (Brassica sp.)
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