33 research outputs found

    Vertical and horizontal gradients in aerosol black carbon and its mass fraction to composite aerosols over the east coast of peninsular India from aircraft measurements

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    During the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) experiment of ISRO-GBP, altitude profiles of mass concentrations of aerosol black carbon (M) and total (composite) aerosols (M) in the lower troposphere were made onboard an aircraft from an urban location, Chennai (13.04 °N, 80.17 °E). The profiling was carried out up to 3 km (AGL) in eight levels to obtain higher resolution in altitude. Besides, to explore the horizontal gradient in the vertical profiles,measurements were made at two levels [500m (within ABL) and 1500m (above ABL)] from ~10 °N to 16°N and ~80 °E to 84°E. The profiles showed a significant vertical extent of aerosols over coastal and offshore regions around Chennai with BC concentrations (~2 μg m) and its contribution to composite aerosols remaining at the same level (between 8 to 10% for FBC) as at the surface. Even though the values are not unusually high as far as an urban location is concerned, but their constancy throughout the vertical column will have important implications to climate impact of aerosols

    Detecting the Anti-Social Activity on Twitter using EGBDT with BCM

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    The rise of social media and its consequences is a hot topic on research platforms. Twitter has drawn the attention of the research community in recent years due to various qualities it possesses. They include Twitter's open nature, which, unlike other platforms, allows visitors to see posts posted by Twitter users without having to register. In twitter the sentiment analysis of tweets are used for detecting the anti-social activity event which is one of the challenging tasks in existing works. There are many classification algorithms are used to detect the anti-social activities but they obtains less accuracy. The EGBDT (Enhanced Gradient-Boosted Decision Tree) is used to optimize the best features from the NSD dataset and it is given as input to BCM (Bayesian Certainty Method) for detecting the anti-social activities. In this work, tweets from NSD dataset are used for analyzing the sentiment polarity i.e. positive or negative. The efficiency of the proposed work is compared with SVM, KNN and C4.5. From this analysis the proposed EGBDT and BCM obtained better results than other techniques

    Radiative forcing by aerosols over the Bay of Bengal region derived from shipborne, island-based, and satellite (moderate-resolution imaging spectroradiometer) observations

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    Measurements of spectral aerosol optical depths (AODs) were made over the Bay of Bengal region (adjacent to the Indian landmass) on board the oceanographic research vessel Sagar Kanya during February 2003. Simultaneous measurements of spectral AODs and mass concentrations of the composite aerosols and aerosol black carbon (BC) were made at an island location, Port Blair (11.63°N, 92.71°E), also in the Bay of Bengal. At the cruise locations the AODs were in the range of ~0.3-0.6 at 500 nm (with a mean value of 0.41 ± 0.14) and Angstrom wavelength exponent of ~1.1 ± 0.1; while at Port Blair the AODs were in the range of 0.11-0.48 at 500 nm and Angstrom wavelength exponent of 0.98 ± 0.07. Aerosol BC constituted 5.8 ± 0.6% of the composite aerosol mass concentration with a single-scattering albedo of ~0.88, indicating the presence of a significant amount of submicron absorbing aerosols. Comparisons of AODs measured at Port Blair during cruise 188 and an earlier cruise (cruise 161B) during March 2001 (over the Bay of Bengal, Arabian Sea, and Indian Ocean) with those derived from Moderate-Resolution Imaging Spectroradiometer (MODIS) (on board the TERRA platform) showed excellent agreement with a mean difference of ~0.01 and a root-meansquare difference of ~0.03. Regionally averaged aerosol (net) forcing over the Bay of Bengal was in the range -15 to -24 W m-2 at the surface and -2 to -4 W m-2 at the top of the atmosphere in February 2003; these values were smaller in magnitude than those observed over this region during March 2001 and larger than that observed over the Arabian Sea and the Indian Ocean. The resulting atmospheric heating due to aerosol absorption was ~0.5°K/d

    Vertical distribution of aerosols over the east coast of India inferred from airborne LIDAR measurements

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    The information on altitude distribution of aerosols in the atmosphere is essential in assessing the impact of aerosol warming on thermal structure and stability of the atmosphere. In addition, aerosol altitude distribution is needed to address complex problems such as the radiative interaction of aerosols in the presence of clouds. With this objective, an extensive, multi-institutional and multi-platform field experiment (ICARB-Integrated Campaign for Aerosols, gases and Radiation Budget) was carried out under the Geosphere Biosphere Programme of the Indian Space Research Organization (ISRO-GBP) over continental India and adjoining oceans during March to May 2006. Here, we present airborne LIDAR measurements carried out over the east Coast of the India during the ICARB field campaign. An increase in aerosol extinction (scattering + absorption) was observed from the surface upwards with a maximum around 2 to 4 km. Aerosol extinction at higher atmospheric layers (>2 km) was two to three times larger compared to that of the surface. A large fraction (75-85%) of aerosol column optical depth was contributed by aerosols located above 1 km. The aerosol layer heights (defined in this paper as the height at which the gradient in extinction coefficient changes sign) showed a gradual decrease with an increase in the offshore distance. A large fraction (60-75%) of aerosol was found located above clouds indicating enhanced aerosol absorption above clouds. Our study implies that a detailed statistical evaluation of the temporal frequency and spatial extent of elevated aerosol layers is necessary to assess their significance to the climate. This is feasible using data from space-borne lidars such as CALIPSO, which fly in formation with other satellites like MODIS AQUA and MISR, as part of the A-Train constellation

    Effective Scheduling of Multi-Load Automated Guided Vehicle in Spinning Mill: A Case Study

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    In the Flexible Manufacturing System (FMS), where material processing is carried out in the form of tasks from one department to another, the use of Automated Guided Vehicles (AGVs) is significant. The application of multiple-load AGVs can be understood to boost FMS throughput by multiple orders of magnitude. For the transportation of materials and items inside a warehouse or manufacturing plant, an AGV, a mobile robot, offers extraordinary industrial capabilities. The technique of allocating AGVs to tasks while taking into account the cost and time of operations is known as AGV scheduling. Most research has exclusively addressed single-objective optimization, whereas multi-objective scheduling of AGVs is a complex combinatorial process without a single solution, in contrast to single-objective scheduling. This paper presents the integrated Local Search Probability-based Memetic Water Cycle (LSPM-WC) algorithm using a spinning mill as a case study. The scheduling model’s goal is to maximize machine efficiency. The scheduling of the statistical tests demonstrated the applicability of the proposed model in lowering the makespan and fitness values. The mean AGV operating efficiency was higher than the other estimated models, and the LSPM-WC surpassed the different algorithms to produce the best result

    Contact tracing for COVID-19 in a healthcare institution: Our experience and lessons learned

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    During the initial phases of the COVID-19 pandemic contact tracing was used to control spread of the disease. It played a key role in health care institute which continued to work even during lockdown. In this piece of work, we share the lessons learnt from the contact tracing activity done in the health care institution during April to July 2020. The training needs of persons involved in contact tracing, the follow of activities, use of technology, methods to fill the missing gaps were the key lessons learnt. Its documentation supports in setting up contact tracing activity for any emerging infectious disease outbreaks in future
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