348 research outputs found

    MEASURING THE EFFICIENCY OF INDEX FUNDS: EVIDENCE FROM INDIA

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    The purpose of this study is to analyse the technical efficiency of Index funds using data envelopment analysis (DEA) and to assess the reasons of inefficiency. Based on secondary data collected from the annual reports of the Association of Mutual Funds in India, this study examined the efficiency performance of the top Index funds available to Indian investors from the year 2018 to 2022 using radial measurers (BCC) of data envelopment analysis. The results show that the average efficiency of Index funds was 83.04 percent during the study period, and the average efficiency of index funds was almost stable during the study period. Only 10 percent of the index funds operated efficiently during the study period. The least amount of slack was found in the input "expense ratio". This reiterates that investment risk is the cause of the funds' inefficiency and not the associated expenses.  This study is first of its kind that has assessed the of Indian index funds and therefore holds important insights for regulators, policy makers and practitioners

    LEGOBench: Scientific Leaderboard Generation Benchmark

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    The ever-increasing volume of paper submissions makes it difficult to stay informed about the latest state-of-the-art research. To address this challenge, we introduce LEGOBench, a benchmark for evaluating systems that generate scientific leaderboards. LEGOBench is curated from 22 years of preprint submission data on arXiv and more than 11k machine learning leaderboards on the PapersWithCode portal. We present four graph-based and two language model-based leaderboard generation task configurations. We evaluate popular encoder-only scientific language models as well as decoder-only large language models across these task configurations. State-of-the-art models showcase significant performance gaps in automatic leaderboard generation on LEGOBench. The code is available on GitHub ( https://github.com/lingo-iitgn/LEGOBench ) and the dataset is hosted on OSF ( https://osf.io/9v2py/?view_only=6f91b0b510df498ba01595f8f278f94c )

    Recent Advances in Uncertainty Quantification Methods for Engineering Problems

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    In the last few decades, uncertainty quantification (UQ) methods have been used widely to ensure the robustness of engineering designs. This chapter aims to detail recent advances in popular uncertainty quantification methods used in engineering applications. This chapter describes the two most popular meta-modeling methods for uncertainty quantification suitable for engineering applications (Polynomial Chaos Method and Gaussian Process). Further, the UQ methods are applied to an engineering test problem under multiple uncertainties. The test problem considered here is a supersonic nozzle under operational uncertainties. For the deterministic solution, an open-source computational fluid dynamics (CFD) solver SU2 is used. The UQ methods are developed in Matlab and are further combined with SU2 for the uncertainty and sensitivity estimates. The results are presented in terms of the mean and standard deviation of the output quantities

    Surrogate Modeling-Driven Physics-Informed Multi-fidelity Kriging: Path Forward to Digital Twin Enabling Simulation for Accident Tolerant Fuel

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    The Gaussian Process (GP)-based surrogate model has the inherent capability of capturing the anomaly arising from limited data, lack of data, missing data, and data inconsistencies (noisy/erroneous data) present in the modeling and simulation component of the digital twin framework, specifically for the accident tolerant fuel (ATF) concepts. However, GP will not be very accurate when we have limited high-fidelity (experimental) data. In addition, it is challenging to apply higher dimensional functions (>20-dimensional function) to approximate predictions with the GP. Furthermore, noisy data or data containing erroneous observations and outliers are major challenges for advanced ATF concepts. Also, the governing differential equation is empirical for longer-term ATF candidates, and data availability is an issue. Physics-informed multi-fidelity Kriging (MFK) can be useful for identifying and predicting the required material properties. MFK is particularly useful with low-fidelity physics (approximating physics) and limited high-fidelity data - which is the case for ATF candidates since there is limited data availability. This chapter explores the method and presents its application to experimental thermal conductivity measurement data for ATF. The MFK method showed its significance for a small number of data that could not be modeled by the conventional Kriging method. Mathematical models constructed with this method can be easily connected to later-stage analysis such as uncertainty quantification and sensitivity analysis and are expected to be applied to fundamental research and a wide range of product development fields. The overarching objective of this chapter is to show the capability of MFK surrogates that can be embedded in a digital twin system for ATF

    Data-driven multi-scale modeling and robust optimization of composite structure with uncertainty quantification

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    It is important to accurately model materials' properties at lower length scales (micro-level) while translating the effects to the components and/or system level (macro-level) can significantly reduce the amount of experimentation required to develop new technologies. Robustness analysis of fuel and structural performance for harsh environments (such as power uprated reactor systems or aerospace applications) using machine learning-based multi-scale modeling and robust optimization under uncertainties are required. The fiber and matrix material characteristics are potential sources of uncertainty at the microscale. The stacking sequence (angles of stacking and thickness of layers) of composite layers causes meso-scale uncertainties. It is also possible for macro-scale uncertainties to arise from system properties, like the load or the initial conditions. This chapter demonstrates advanced data-driven methods and outlines the specific capability that must be developed/added for the multi-scale modeling of advanced composite materials. This chapter proposes a multi-scale modeling method for composite structures based on a finite element method (FEM) simulation driven by surrogate models/emulators based on microstructurally informed meso-scale materials models to study the impact of operational parameters/uncertainties using machine learning approaches. To ensure optimal composite materials, composite properties are optimized with respect to initial materials volume fraction using data-driven numerical algorithms

    Shaping Sustainable Entrepreneurial Intentions among Business Graduates in Developing Countries through Social Media Adoption: A Moderating-Mediated Mechanism in Pakistan

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    Entrepreneurship is crucial for alleviating job challenges among business graduates and for sustaining a growing local economy. However, different factors support and encourage students to be entrepreneurs. Modern technologies such as social media are becoming more popular with young people in enterprise creation. However, the connection between social media use and business among the youth of developing countries has yet to be noticed. This study examines the relationship between entrepreneurial education (EE), attitudes toward sustainable entrepreneurship (ATSE), and sustainable entrepreneurial intentions (SEIs); as well as examining the moderating effect of social media adoption on this relationship. To put the proposed concept to the test, data was collected from 314 business graduates from Pakistani universities. Structural equation modeling using AMOS (Version 26) was utilized to test the proposed hypotheses. The study findings show that student attitudes concerning sustainable entrepreneurship mediate the association between EE and sustainable entrepreneurial intention. Furthermore, the results illustrate that social media moderated the relationship between the research participants’ attitudes concerning sustainable entrepreneurship and their desire to practice sustainable entrepreneurship. The study makes significant contributions to the field that scholars can use to initiate future research projects

    Experimental Evaluation of the Deadtime Phenomenon for GM Detector: Deadtime Dependence on Operating Voltages

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    A detailed analysis of Geiger Mueller counter deadtime dependence on operating voltage is presented in the manuscript using four pairs of radiation sources. Based on two-source method, detector deadtime is calculated for a wide range of operating voltages which revealed a peculiar relationship between the operating voltage and the detector deadtime. In the low voltage range, a distinct drop in deadtime was observed where deadtime reached a value as low as a few microseconds (22 µs for 204Tl, 26 µs for 137Cs, 9 µs for 22Na). This sharp drop in the deadtime is possibly due to reduced recombination with increasing voltage. After the lowest point, the deadtime generally increased rapidly to reach a maximum (292 µs for 204Tl, 277 µs for 137Cs, 258 µs for 22Na). This rapid increase in the deadtime is mainly due to the on-set of charge multiplication. After the maximum deadtime values, there was an exponential decrease in the deadtime reaching an asymptotic low where the manufacturer recommended voltage for operation falls. This pattern of deadtime voltage dependence was repeated for all sources tested with the exception of 54Mn. Low count rates leading to a negative deadtime suggested poor statistical nature of the data collected for 54Mn and the data while being presented here is not used for any inference

    Enteric coating of ibuprofen tablets (200 mg) using an aqueous dispersion system

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    Ibuprofen is a propionic acid derivative that belongs to the class NSAIDs. Major adverse reactions associated with Ibuprofen are related to GIT and include peptic and mucosal ulcers, dyspepsia, severe gastric pain and bleeding, that results in excessive treatment failure. The goal of this study was to develop enteric coated ibuprofen tablets in order to avoid gastric mucosal irritation, diffusion of drug across mucosal lining and to let active ingredient be absorbed easily in small intestine. The formulation was developed and manufactured through the direct compression process, the simplest, easiest and most economical method of manufacturing. Enteric coating was done using an Opadry white subcoating and an aqueous coating dispersion of Acryl-Eze. Enteric coated formulation was subjected to disintegration and dissolution tests by placing in 0.1 M hydrochloric acid for 2 h and then 1 h in phosphate buffer with a pH of 6.8. About 0.04% of drug was released in the acidic phase and 99.05% in the basic medium. These results reflect that ibuprofen can be successfully enteric coated in order to prevent its release in the stomach and facilitate rapid release of the drug in the duodenum, due to the presence of superdisintegrant. Formulating this enteric coated tablets could increase patient compliance by decreasing adverse drug reactions (ADR S) associated with Ibuprofen therapy.Ibuprofeno é um derivado do ácido propiônico, que pertence à classe dos fármacos não-esteróides (AINES). As principais reações adversas associadas com o ibuprofeno se referem àquelas do trato gastrintestinal (TGI), como úlceras pépticas e da mucosa, dispepsia, dor gástrica grave e sangramento, que resultam em muitas falhas de tratamento. O objetivo do estudo foi desenvolver comprimidos revestidos de ibuprofeno que impeçam a irritação da mucosa gástrica, difusão do fármaco através da mucosa e permitam, facilmente, a absorção do princípio ativo do intestino delgado. A formulação foi desenvolvida e manufaturada por meio de processo de compressão direta, método mais simples e econômico de preparação. O revestimento entérico foi efetuado utilizando-se subrevestimento com Opadry branco e revestimento por dispersão aquosa de Acryl-Eze. A formulação de revestimento para liberação entérica foi submetida a testes de desintegração e de dissolução, em ácido clorídrico 0,1 M, por 2 h, e, então, a h, em tampão fosfato pH 6,8. Cerca de 0,04% do fármaco foi liberado na fase ácida e 99,05%, no meio básico. Estes resultados refletem o fato de que o ibuprofeno pode ser revestido com sucesso, a fim de impedir sua liberação no estômago e facilitar a rápida liberação do fármaco no duodeno, devido à presença de superdesintegrante. A formulação de tais comprimidos aumentaria a adesão do paciente pela diminuição das reações adversas (RAs), associadas à terapia com ibuprofeno

    Simultaneous Experimental Evaluation of Pulse Shape and Deadtime Phenomenon of GM Detector

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    Analysis of several pulse shape properties generated by a Geiger Mueller (GM) detector and its dependence on applied voltage was performed. The two-source method was utilized to measure deadtime while simultaneously capturing pulse shape parameters on an oscilloscope. A wide range of operating voltages (600-1200 V) beyond the recommended operating voltage of 900 V was investigated using three radioactive sources (204Tl, 137Cs, 22Na). This study investigates the relationship between operating voltage, pulse shape properties, and deadtime of the detector. Based on the data, it is found that deadtime decreases with increasing voltage from 600 to 650 V. At these low voltages (600–650 V), the collection time was long, allowing sufficient time for some recombination to take place. Increasing the voltage in this range decreased the collection time, and hence deadtime decreased. It is also observed that rise and fall time were at their highest at these applied voltages. Increasing the voltage further would result in gas multiplication, where deadtime and pulse width are observed to be increasing. After reaching the maximum point of deadtime (~ 250 µs at ~ 700 V), deadtime started to exponentially decrease until a plateau was reached. In this region, it is observed that detector deadtime and operating voltage show a strong correlation with positive pulse width, rise and fall time, cycle mean, and area. Therefore, this study confirms a correlation between detector deadtime, operating voltage, and pulse shape properties. The results will validate our hypothesis that deadtime phenomena at different operating voltages are phenomenologically different

    Impact of Surface and Physical Property on Multiphase Flow in Sealed Vessel: Liquid Dropdown Performance

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    This study explores multi-phase (i.e., liquid-gas) and multi-fluid (i.e., air-water, and water-silicone oil) flow-pattern and flow-blockage physics phenomena for wall wettability conditions ranging from superhydrophilic to superhydrophobic cases in sealed vessels utilizing computational fluid dynamics (CFD) simulation tools and volume-of-fluid (VOF) method with sharp interface modeling. Detailed modeling and simulation (M&S) of such physics phenomena—in which liquid (e.g., water) stands over top of gas (e.g., air or steam) in a closed channel and exhibited flow blockage, flow reversal related challenges—are pivotal for design, analysis, and qualification of component-level (e.g., heat pipes, heat exchangers) to system-level (e.g., emergency core cooling systems in nuclear reactors) heating and cooling industrial applications. Results show that, these physics phenomena are dependent on factors like contact angle (CA), channel diameter, gravity, and viscosity which impact the flow behavior in an adiabatic, and closed environment. Key observations include the role of CA (for 10-, 50-, 90-, 130-, and 170-degree) in dropdown time: (a) a quicker dropdown for higher wettability surfaces (CA \u3c 90 degrees); and (b) a slower dropdown for normal (CA = 90 degrees) and lower wettability surfaces (CA \u3e 90 degrees). Other important observations are: (a) channel diameter (for 3, 10, and 100 mm) emerges as a crucial factor, a completely blocking flow case; (b) gravity variations introduce further complexities, leading to more unpredictable and unsteady flows under reduced gravity conditions. These findings, observations, and insights, including quantitative, qualitative, and nondimensional analysis supports design optimization, enhanced components-to-system level heat-transfer performance f or relevant engineering applications
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