2,258 research outputs found

    The digital simulation of a turbo-charged diesel engine

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    A mathematical simulation of a six cylinder four stroke water cooled diesel engine is described and then used to study the changes in performance caused by variations of engine paramters and operating conditions. The results are discussed with reference to the mathematical model employed and the physical system. A limited study, to demonstrate the applicability of the simulation, considers the optimisation of a variable geometry system to achieve a performance target

    Voluntary Disclosure and Information Asymmetry: Evidence from the 2005 Securities Offering Reform

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    In 2005, the Securities and Exchange Commission enacted the Securities Offering Reform (Reform), which relaxes “gun-jumping” restrictions, thereby allowing firms to more freely disclose information before equity offerings. We examine the effect of the Reform on voluntary disclosure behavior before equity offerings and the associated economic consequences. We find that firms provide significantly more preoffering disclosures after the Reform. Further, we find that these preoffering disclosures are associated with a decrease in information asymmetry and a reduction in the cost of raising equity capital. Our findings not only inform the debate on the market effect of the Reform, but also speak to the literature on the relation between voluntary disclosure and information asymmetry by examining the effect of quasi-exogenous changes in voluntary disclosure on information asymmetry, and thus a firm's cost of capital

    Update or Wait: How to Keep Your Data Fresh

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    In this work, we study how to optimally manage the freshness of information updates sent from a source node to a destination via a channel. A proper metric for data freshness at the destination is the age-of-information, or simply age, which is defined as how old the freshest received update is since the moment that this update was generated at the source node (e.g., a sensor). A reasonable update policy is the zero-wait policy, i.e., the source node submits a fresh update once the previous update is delivered and the channel becomes free, which achieves the maximum throughput and the minimum delay. Surprisingly, this zero-wait policy does not always minimize the age. This counter-intuitive phenomenon motivates us to study how to optimally control information updates to keep the data fresh and to understand when the zero-wait policy is optimal. We introduce a general age penalty function to characterize the level of dissatisfaction on data staleness and formulate the average age penalty minimization problem as a constrained semi-Markov decision problem (SMDP) with an uncountable state space. We develop efficient algorithms to find the optimal update policy among all causal policies, and establish sufficient and necessary conditions for the optimality of the zero-wait policy. Our investigation shows that the zero-wait policy is far from the optimum if (i) the age penalty function grows quickly with respect to the age, (ii) the packet transmission times over the channel are positively correlated over time, or (iii) the packet transmission times are highly random (e.g., following a heavy-tail distribution)

    Effects of Effluents of Industrial Waste on Soil Properties (A Case Study of Nandesari Area, Vadodara)

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    Around Vadodara City (Gujarat) number of chemical industries dispose of water, air and oil based pollutant everyday. The pollution process in soil due to the industrial effluent discharge on to the land and its effect on the geotechnical properties of soil arc discussed in the present case study. Uncontrolled exploitation of the natural resources have resulted in an unanticipated soil behaviour due to environmental degradation. This resulted in an increased interest in the study of environmental geotechnics which is a means of forecasting soil behaviour to the changing environment

    Likelihood of rising stroke in populace of western India: a case control study

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    Background: Cerebrovascular accident (Stroke) is a non-communicable disease of increasing importance. According to the World Health Organization, 15 million people suffer from stroke worldwide each year. The National Commission on Macroeconomics and Health, India, has estimated 1.67 million stroke cases in India. Due to the increasing prevalence of hypertension, diabetes, dyslipidemia, fast changing lifestyle and re-structuring of population, stroke will be an epidemic in India in the days to come. Few studies have been carried out in developing countries like India. So, this study intended to know the presentation in addition to risk factors, patterns of warning signs and symptoms of stroke in patients admitted to state tertiary care Hospital. Methods: Assuming the power ratio of the number of controls same as numbers of cases specifying values for two sided confidence level 95% and odd ratio 2.15 which was the minimum risk factor in previous study was taken to calculate sample size. Results: After studying of 148 cases of stroke and same controls, we conclude that most common type of stroke is ischemic stroke followed by haemorrhagic stroke. After multivariate analysis we found, modifiable risk factors were mainly mental stress, active and passive smoking, hypertension and obesity. Conclusions: Due to the sheer magnitude, devastating consequences and residual sequelae of the stroke, early intervention in the form of patient education, modification of the lifestyle, non-pharmacological and pharmacological interventions for modifiable risk factors should be an integral aspect of patient care

    Externalities of public firm presence: Evidence from private firms' investment decisions

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    Public firms provide a large amount of information through their disclosures. In addition, information intermediaries publicly analyze, discuss, and disseminate these disclosures. Thus, greater public firm presence in an industry should reduce uncertainty in that industry. Following the theoretical prediction of investment under uncertainty, we hypothesize and find that private firms are more responsive to their investment opportunities when they operate in industries with greater public firm presence. Further, we find that the effect of public firm presence is greater in industries with better information quality and in industries characterized by a greater degree of investment irreversibility. Our results suggest that public firms generate positive externalities by reducing industry uncertainty and facilitating more efficient private firm investment.MIT Junior Faculty Research Assistance ProgramErnst & YoungPrice Waterhouse (Firm)University of Notre Dam

    Epoxy Resin Grout System for Solutions to Traditional Geotechnical Problems

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    Use of chemicals for foundation treatment and sealing of crack is of recent origin. The aim of this paper is to find time-viscosity and time-strength relationships of epoxy grout system for proper flow mechanism and strength interaction with rock collected from dam sites of India. The bonding mechanism of gel in the injected mass is explained with the help of Scanning electron microscopy and Infra-red spectroscopy. After trial field grouting the stratascopy has revealed better bonds of moist surface with flexibility to accommodate movement before bond or shear failure occurred and had lower volumetric shrinkage during curing

    Lining of Perennial Canals Under Flowing Conditions by Ulomat Grouted Mattress Technique

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    Irrigation water is made available to the farmers by means of construction of a dam/weir and a canal system taking off from the reservoir impounded behind the dam. This water is therefore very precious. If the canal system is not lined, about 25 to 30 per cent of water released in the canal is lost by way of seepage through canals. Canals should therefore be lined not only to save this water but also to irrigate additional area. A pilot project of providing such lining on experimental basis was taken up for the first time in India by Irrigation Department of the Government of Gujarat. The lining has been provided on their canals of different capacities in the Ukai-Kakrapar command. Also a special experimental model has been developed in the laboratory to evaluate the interacted efficiency of grout and geotextile mattress from the consideration of strength and permeability

    Management Forecast Quality and Capital Investment Decisions

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    Corporate investment decisions require managers to forecast expected future cash flows from potential investments. Although these forecasts are a critical component of successful investing, they are not directly observable by external stakeholders. In this study, we investigate whether the quality of managers' externally reported earnings forecasts can be used to infer the quality of their corporate investment decisions. Relying on the intuition that managers draw on similar skills when generating external earnings forecasts and internal payoff forecasts for their investment decisions, we predict that managers with higher quality external earnings forecasts make better investment decisions. Consistent with our prediction, we find that forecasting quality is positively associated with the quality of both acquisition and capital expenditure decisions. Our evidence suggests that externally observed forecasting quality can be used to infer the quality of capital budgeting decisions within firms

    Voluntary Disclosure and Information Asymmetry: Evidence from the 2005 Securities Offering Reform

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    In 2005, the Securities and Exchange Commission enacted the Securities Offering Reform (Reform), which relaxes “gun‐jumping” restrictions, thereby allowing firms to more freely disclose information before equity offerings. We examine the effect of the Reform on voluntary disclosure behavior before equity offerings and the associated economic consequences. We find that firms provide significantly more preoffering disclosures after the Reform. Further, we find that these preoffering disclosures are associated with a decrease in information asymmetry and a reduction in the cost of raising equity capital. Our findings not only inform the debate on the market effect of the Reform, but also speak to the literature on the relation between voluntary disclosure and information asymmetry by examining the effect of quasi‐exogenous changes in voluntary disclosure on information asymmetry, and thus a firm's cost of capital.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100337/1/joar12022.pd
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