270 research outputs found
Fly-by-Logic: Control of Multi-Drone Fleets with Temporal Logic Objectives
The problem of safe planning and control for multi- drone systems across a variety of missions is of critical impor- tance, as the scope of tasks assigned to such systems increases. In this paper, we present an approach to solve this problem for multi-quadrotor missions. Given a mission expressed in Signal Temporal Logic (STL), our controller maximizes robustness to generate trajectories for the quadrotors that satisfy the STL spec- ification in continuous-time. We also show that the constraints on our optimization guarantees that these trajectories can be tracked nearly perfectly by lower level off-the-shelf position and attitude controllers. Our approach avoids the oversimplifying abstractions found in many planning methods, while retaining the expressiveness of missions encoded in STL allowing us to handle complex spatial, temporal and reactive requirements. Through experiments, both in simulation and on actual quadrotors, we show the performance, scalability and real-time applicability of our method
Thoracic segmental spinal anaesthesia vs general anaesthesia for laparoscopic cholecystectomy: a comparative study
Background: Regional anaesthesia techniques are now being preferred over General anaesthesia in patients with major medical problems and those at high risk for GA. Thoracic segmental spinal anaesthesia has recently gained popularity because of its safety and efficacy in procedures like laparoscopic cholecystectomy, breast surgeries etc.
Methods: A comparative study involving 50 patients of ASA grade I & II of both genders with age group of 25-55 years, weighing between 50-85 kg posted for lap. Cholecystectomy in GGH, Kakinada for a study period of 5 months. 50 Patients were divided into Group A & Group B with 25 patients in each group. After taking informed & written conscent, Group A patients were given Thoracic Segmental Spinal Anaesthesia at T10 level with Inj.0.5% isobaric Levo-bupivacaine 1.75 ml (13.75 mg) with Inj. Fentanyl 0.25 ml (25 mcg) and Group B patients were given GA with fentanyl, propofol, sevoflurane, succinylcholine and vecuronium.
Results: conscious patients with less hemodynamic variability, greater duration of post operative analgesia, greater duration for first rescue analgesia were observed in Group A. Whereas greater hemodynamic variability, intubation response, more requirement of intraoperative opioid, less duration of post operative analgesia, lesser time for first rescue analgesia were observed in Group B.
Conclusions: TSSA is safe alternative as it provides excellent analgesia. With TSSA, GA can be avoided in patents with comorbidities
A PUBLIC APPRAISAL SCHEME WITH DATA DYNAMICS SUPPORT AND EQUALITY MEDIATION OF POTENTIAL DISPUTES
This proposes an open review plan that supports data dynamics and fair arbitration of potential disputes. Cloud users no longer actually have their data, just how they ensure the integrity of the data being outsourced becomes a difficult task. Recently, proposed plans, for example, "possess verifiable data" and "recovery tests" have been implemented to address this problem, but are being performed to review static file data, which for this reason does not support sufficient data dynamics. In addition, threat models typically assume a true data owner and focus on the discovery of a dishonest cloud company, although customers also misbehave. In particular, we designed a catalog selector to eliminate the limitation of the use of indexes in calculating labels in current schemas and to obtain effective management of information dynamics. The security analysis shows that our plan may be safe, and the performance evaluation shows that the overloading of information dynamics and arbitration in disputes is reasonable. To address the equity issue to ensure that no party is acting without disclosure, we expand existing threat models and adopt the idea of ​​signature exchange to create fair arbitration protocols to ensure that any possible dispute can be resolved in a fair manner
Genetic relatidness and In vitro antimicrobial activities of alkaloids isolated from Indian varieties of Catharanthus roseus (L.)
Catharanthus roseus (L.) is one of the most intensively studied for its anticancerous property but phytopathogenic activity of the plant has not been much studied. Callus induction from C. roseus was optimized by varying various harmone concentrations and the best result was obtanined in MS medium fortified with 2mgL-1 2, 4-D and 0.1 mgL-1 kinetin. Antimicrobial activity and minimum inhibitory concentration showed that the 20, 40, and 80% leaves, shoot, and root extract inhibits Gram positive B. subtilis and phytopathogenic fungus F. oxysporium, A. niger, Rhizoctonia solani, Colletotrichum falcatum, Cylindrocladium scoparium respectively. Genetic relatidness was determined by RAPD analysis revealed that, white and violet colored C.roseus flowered plant was closely related than rosy pink coloured flower
Co-design of Control and Planning for Multi-rotor UAVs with Signal Temporal Logic Specifications
Urban Air Mobility (UAM), or the scenario where multiple manned and Unmanned
Aerial Vehicles (UAVs) carry out various tasks over urban airspaces, is a
transportation concept of the future that is gaining prominence. UAM missions
with complex spatial, temporal and reactive requirements can be succinctly
represented using Signal Temporal Logic (STL), a behavioral specification
language. However, planning and control of systems with STL specifications is
computationally intensive, usually resulting in planning approaches that do not
guarantee dynamical feasibility, or control approaches that cannot handle
complex STL specifications. Here, we present an approach to co-design the
planner and control such that a given STL specification (possibly over multiple
UAVs) is satisfied with trajectories that are dynamically feasible and our
controller can track them with a bounded tracking-error that the planner
accounts for. The tracking controller is formulated for the non-linear dynamics
of the individual UAVs, and the tracking error bound is computed for this
controller when the trajectories satisfy some kinematic constraints. We also
augment an existing multi-UAV STL-based trajectory generator in order to
generate trajectories that satisfy such constraints. We show that this
co-design allows for trajectories that satisfy a given STL specification, and
are also dynamically feasible in the sense that they can be tracked with
bounded error. The applicability of this approach is demonstrated through
simulations of multi-UAV missions
Low latitude ionospheric response to March 2015 geomagnetic storm using multi-instrument TEC observations over India
The regional ionospheric models are successful in capturing the variability of ionosphere with the inclusion of local ground-based GPS observations and location dependent ionospheric dynamics. In this context, there is a need to develop regional ionospheric maps that aids in improving the consistency of global models. In this paper, an attempt is made to understand the potentiality of multi-instrument observations over Indian region. Four different Total Electron Content (TEC) data sources namely from network of GPS receivers, Ionosonde stations, space based COSMIC radio occultation profiles and SWARM mission data is utilized. The multi-source data is chosen for the geo-magnetic storm conditions prevailed during March 2015. Data from multiple-sources is observed over the period from 15th March 2015 to 20th March 2015. Validation of ground and space-based TEC data with International GNSS service (IGS) station data is significantly observed
Sustainable Production of Guava Based Hortipasture System with Different In-Situ Soil and Moisture Conservation in Semi-Arid Region of India
In India, about 60 % of net sown area is rainfed, contributing 40 % of the total food production; it supports 40% of human and 60% of livestock population. Under such situation, incorporation of fruit trees along with animal husbandry in common farming system is advisable to improve income and nutritional security of the farmers. Horti- pasture system is the most ideal strategy to provide food, nutrition and income security to the people living in rainfed areas. System is socially accepted, ecologically feasible and economically viable for this region (Singh, 1996; Sharma, 2004; Kumar and Chaubey, 2008).
Guava (Psidium guajava L.), is one of the most common and nutritious and hardy fruits of India, can thrive on all types of soil from alluvial to lateritic with pH value as low as 4.5 and on limestone with a value up to 8.2. It occupies about 1, 15,000-1, 62000 ha area in the country (Shikhamany, 2004). Two new cultivars viz., Lalit (CISH-G-3) and Shweta (CISH-G-4) were taken in this experiment. Stylosanthes hamata (Caribbean stylo) is an important range legume for semiarid region (Chandra et al., 2006). Similarly Cenchrus ciliaris (Buffel grass) is most suitable species for arid and semiarid region with rainfall range from 125-1250 mm (Trivedi, 2010). Establishment of hortipasture system is quite difficult task in rainfed region because of moisture stress. Providing regular irrigation is neither practically possible nor economical in rainfed region. Harvesting of rainwater and in-situ moisture conservation is only viable alternative to artificial irrigation. Shaping the surface in the immediate vicinity of the trees so that runoff collects at the root zone can enhance availability of moisture for long duration (Samra, 2010). Keeping these facts in view an experiment was conducted to sustain the productivity of guava based hortipastoral system with different in-situ soil and moisture conservation measures under rainfed situations
Synthesizing Program Input Grammars
We present an algorithm for synthesizing a context-free grammar encoding the
language of valid program inputs from a set of input examples and blackbox
access to the program. Our algorithm addresses shortcomings of existing grammar
inference algorithms, which both severely overgeneralize and are prohibitively
slow. Our implementation, GLADE, leverages the grammar synthesized by our
algorithm to fuzz test programs with structured inputs. We show that GLADE
substantially increases the incremental coverage on valid inputs compared to
two baseline fuzzers
Abstract Learning Frameworks for Synthesis
We develop abstract learning frameworks (ALFs) for synthesis that embody the
principles of CEGIS (counter-example based inductive synthesis) strategies that
have become widely applicable in recent years. Our framework defines a general
abstract framework of iterative learning, based on a hypothesis space that
captures the synthesized objects, a sample space that forms the space on which
induction is performed, and a concept space that abstractly defines the
semantics of the learning process. We show that a variety of synthesis
algorithms in current literature can be embedded in this general framework.
While studying these embeddings, we also generalize some of the synthesis
problems these instances are of, resulting in new ways of looking at synthesis
problems using learning. We also investigate convergence issues for the general
framework, and exhibit three recipes for convergence in finite time. The first
two recipes generalize current techniques for convergence used by existing
synthesis engines. The third technique is a more involved technique of which we
know of no existing instantiation, and we instantiate it to concrete synthesis
problems
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