466 research outputs found

    A STUDY OF LONG-TERM SUNSPOTS AND K-INDEX GEOMETRIC CYCLES USING PROBABILISTIC MODELING

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    The research work done in this paper comprises the application of different well-known probability distribution models. This includes the understanding of the behavior and dynamics of 24 sunspot cycles with total data. The time-series data sets were selected from 1749 to 2014. To observe the solar activity effects on K-index activity the double cycles from 1932 to 2014 were also incorporated in the study. The comparative study is useful to observe the long-term solar-terrestrial connection. The magnetic field of the sun reverses its polarity after every 11 years of the cycle. So after every 22 years, the north pole becomes again north pole. By using the two well-known tests Kolmogorov-Smirnov (KST) and Anderson-Darling test (ADT) the probability distribution models were obtained for each sunspot cycles and compare. The significant probability models for all the sunspot cycles have been obtained. The fitted probability distribution models on selected data sets may be useful to understand the trend of solar and geomagnetic activity

    POWER ALLOCATION ALGORITHM FOR MIMO BASED MULTI-HOP COOPERATIVE SENSOR NETWORK

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    Cooperative transmission is a new breed of wireless communication systems that enables the cooperating node in a wireless sensor network to share their radio resources by employing a distributed transmission and processing operation. This new technique offers substantial spatial diversity gains as the cooperating nodes help one another to send data over several independent paths to the destination node. In recent times, an extensive effort has been made to incorporate these systems in the future wireless networks like LTE (Long Term Evolution), IEEE 802.16j (Mobile Multi-hop Relay (MMR) Networks) and IEEE 802.16m (Mobile WiMAX Release 2 or WirelessMAN-Advanced). But, there are few technical issues which need to be addressed before this promising technique is integrated into future wireless networks. Among them, managing transmission power is a critical issue, which needs to be resolved to fully exploit the benefits of cooperative relaying. Optimal Power Allocation, is one such technique that optimally distributes the total transmission power between the source and relaying nodes thus saving a lot of power while maintaining the link quality. In the first part of the thesis, mathematical expressions of the received signals have been derived for different phases of cooperative transmission. Average-Bit-error-rate (ABER), has been taken as a performance metric to show the efficiency of cooperative relaying protocols. In the second part of this Chapter, a multi-hop framework has been presented for the power allocation algorithm with Amplify-and-Forward relaying protocol. The efficiency of the power allocation algorithm has been discussed with different scenarios i.e. First for a three node (2-Hop) wireless network configuration and then for a four node (3-Hop) wireless network configuration. The transmission scenarios (2-Hop and 3-Hop) have been further categorized into multiple cases on the basis of channel quality between source-to-destination, source-to-relay, relay-to-relay and relay-to-destination links.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    STATISTICAL ANALYSIS OF COVID-19 VACCINATIONS: KARACHI AS A CASE STUDY

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    The entire world has started to vaccinate their respective countries' citizens to get rid of COVID-19 from their country. Likewise other countries, Pakistan has also started the vaccination process for its citizens and unlike the rest of the world, there have been different types of vaccines in Pakistan with different manufacturers and with different immunity booster levels. Through statistical analysis of vaccination in this research paper, we have tried to understand the diverse level of vaccines in Karachi and tried to get an understanding of the vaccination process happening in Karachi. For this kind of research, we have maintained the questionnaire and spread it through emails, WhatsApp, and Facebook.  The questionnaire was sent to about 500 people from July to August 2021. The results obtained depict the satisfaction of the vaccination process with normal side effects. Unlike other countries, Pakistan is among the countries where the mass vaccination process has always been very difficult to conduct. Further using the data of seven stations for prediction purposes Multiple Linear Regression (MLR) models were constructed. A better future trend analysis of COVID-19 can be observed using these constructed models. The data for the time series modeling from, 1st January 2021 to 25 August 2021, was taken from National Command and Control (NCOC) Pakistan

    Prevalence of diabetes mellitus and its relation to diet and physical work in Azad Jammu and Kashmir

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    The prevalence of diabetes mellitus and its relation to diet and physical work was studied in three selected districts namely Muzaffarabad, Bagh and Poonch of Azad Jammu and Kashmir. A city, a town and a village were selected from each selected district, and hundred households (families) from each city, town and village were randomly selected for the study. A total 900 households were selected for interview. A responsible individual of 40 years or older of each household was interviewed and information about diabetes, occupation and diet were recorded in the questionnaire. The mean prevalence of diabetes mellitus was 0.95% in the selected region of the state. The prevalence of the disease was higher in cities than towns and villages. The disease was slightly higher in males than females. The milk and meat consumption of the residents of the area was lower than the recommended amount. The exercise level/physical work status of majority of the residents was almost equal to heavy exercise level. The data suggest that at present, the prevalence of diabetes is not of great concern in Azad Jammu and Kashmir. The prevalence of the disease is linked with diet and exercise level/physical work. The residents have marginal deficiency of food intake

    Satellite Derived Sea surface temperature fronts in relation with Tuna catch In EEZ of Pakistan

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    Sea surface temperature (SST) is an important parameter in marine ecosystem studies as its relations of Fishery and other marine resources. In this study SST fronts have also been studied with relate to tuna fish catch data of April and August 2014 was acquired. Satellite derived MODIS daily products have been used to derive thermal fronts in the exclusive economic zone (EEZ) of Pakistan. Research results indicated that the Sea surface temperature gradually changed from 22C to 24C where Tuna catch is high and By Catch is low in frontal region. The further Relationship between these two data are discussed in this study and also made recommendations for in what way these two datasets should be handled. Remote sensing data and GIS tools are efficient and less time consuming for mapping and classifying sea surface temperature in a broader way. Survey of fishing resources is really time consumed and costly, Satellite Remote sensing data shows a promising tool to monitor fishery resources in a cost effective manner. Satellite data play an important role to identify fish aggregation zones and these techniques could also be used to forecast potential fishing zones by measuring oceanic parameters which influence on fish distribution on a broader scale and these techniques can help to local fisherman and fishery organizations to observe fishery resources

    Dividend Policy as a Core Determinant of Earning Management: Evidence from Pakistan

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    The current study estimated the impact of dividend policy on earnings management for the non-financial firms of Pakistan listed at the Karachi Stock Exchange. The data covering the period from 2005 to 2017 were estimated by using a random effect-generalized least square regression. The study findings report that dividend policy is a significant determinant of earning management and limits the probability of a firm’s earning management practices. This research gives us some empirical evidence regarding the role of key contributing factors in the scope of earnings management. Regulators can implement corporate governance rules and regulations based on empirical tracts in place of motivational debates on politics. This study results offer a compact platform for investors to eradicate ambiguity by recognizing the likelihoods of resourceful goals and improving their policymaking process. The research findings will help to give investors a clear idea about the various factors that play a contributing part for making financial reporting and misreporting of profits.  These contributing factors allow investors to be careful about the ingenious purpose and effectiveness of management to obtain returns for their benefit

    A projected finite element update method for inverse identification of material constitutive parameters in transversely isotropic laminates

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    In this paper, a novel application of Finite Element Update Method (FEUM) is proposed for the inverse identification of material constitutive parameters in transversely isotropic laminates. Two-dimensional Digital Image Correlation (2D–DIC) is used for full-field measurements which is required for the identification process. Instead of measuring the in-plane displacements, which is a well-known application of 2D–DIC, we seek to measure the pseudo-displacements resulting from out-of-plane (towards camera) deflection of plate under a point load. These pseudo-displacements are basically the perspective projection of the three dimensional displacement fields on the image-plane of the image acquisition system. The cost function in this method is defined in terms of these projections instead of the true displacements – and hence the name Projected Finite Element Update Method (PFEUM). In this article, identification of in-plane elastic moduli of Carbon Fiber Reinforced Plastic (CFRP) plate has been performed using plate bending experiments which show pre-dominantly out-of-plane deflection with little contribution from the in-plane displacements. Identification results are validated by direct experimental measurements of the unknown elastic constants as well as theoretical estimates based on volume ratio of constituents. The results show good conformance between estimated and target values for at least three material parameters namely E1, E2 and G12. Effects of experimental noise on parameter estimates has also been evaluated to explain the observed deviation in estimated parameters with current test configuration

    Solutions for the Power Distribution System of Karachi Electric (K- Electric) to Prevent Deaths in Rainy Season

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    Karachi is the metropolitan city of Pakistan. In rainy or flood season many deaths occurred due to electric shock. For the prevention, we suggest here to K-Electric (Karachi Electric Supply Distribution company) to control death casualties due to electric shock in rainy season. In suggestion paper providing some suggestions to the big power supplier of Karachi (K-Electric) about safety, maintenance, and monitoring for the prevention from deaths occur in metropolitan city due to electric shock. Those deaths occur due to faults in electric pole and touch the fallen live wire. When people touch the pole, they got electric shock in rainy and storm condition due to these electric faults occur in this condition provides enough loss to humans in the form to lose their lives. For the prevention or overcome the loss of life and danger here are giving some suggestions, if do work on following safety, maintenance and monitoring system then get the control on that loss will occur in heavy rain or flood

    Methyl 2-(but-3-en­yl)-4-hy­droxy-1,1-dioxo-2H-1λ6,2-benzothia­zine-3-carboxyl­ate

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    In the title compound, C14H15NO5S, the thia­zine ring adopts a sofa conformation and an intra­molecular O—H⋯O hydrogen bond forms an S(6) ring. In the crystal, molecules are linked viaC—H⋯O inter­actions

    GeoChat: Grounded Large Vision-Language Model for Remote Sensing

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    Recent advancements in Large Vision-Language Models (VLMs) have shown great promise in natural image domains, allowing users to hold a dialogue about given visual content. However, such general-domain VLMs perform poorly for Remote Sensing (RS) scenarios, leading to inaccurate or fabricated information when presented with RS domain-specific queries. Such a behavior emerges due to the unique challenges introduced by RS imagery. For example, to handle high-resolution RS imagery with diverse scale changes across categories and many small objects, region-level reasoning is necessary alongside holistic scene interpretation. Furthermore, the lack of domain-specific multimodal instruction following data as well as strong backbone models for RS make it hard for the models to align their behavior with user queries. To address these limitations, we propose GeoChat - the first versatile remote sensing VLM that offers multitask conversational capabilities with high-resolution RS images. Specifically, GeoChat can not only answer image-level queries but also accepts region inputs to hold region-specific dialogue. Furthermore, it can visually ground objects in its responses by referring to their spatial coordinates. To address the lack of domain-specific datasets, we generate a novel RS multimodal instruction-following dataset by extending image-text pairs from existing diverse RS datasets. We establish a comprehensive benchmark for RS multitask conversations and compare with a number of baseline methods. GeoChat demonstrates robust zero-shot performance on various RS tasks, e.g., image and region captioning, visual question answering, scene classification, visually grounded conversations and referring detection. Our code is available at https://github.com/mbzuai-oryx/geochat.Comment: 10 pages, 4 figure
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