52 research outputs found
Sourcing decision under interconnected risks: an application of mean–variance preferences approach
Get PDFSupply chains are customarily associated with multiple interconnected risks originated from supply side, demand side, or from the unanticipated background uncertainties faced by a firm. Also, effective functioning of supply chain hinges on sourcing decisions of inputs (raw materials). Therefore, there is a striking need to analyse the risk preference of the decision maker while going for optimal sourcing decision under varying degree of interconnected supply chain risks. This study addresses this issue by analysing the comparative static effects under interconnected supply chain risks for a risk averse decision-maker, manufacturing and selling products in a regulated market under perfect competition. The decision-maker faces not only supply-side risk (due to random input material prices) but also interconnected risks arising out of background risk (setup costs risk) and demand-side risk (output prices risk). With preferences defined over the mean and standard deviation of the uncertain final profit, this study illustrates the effects of the changes in the pairwise correlations between the three above mentioned risks on the optimum input choice of the manufacturer. To contextualise this study, an India-based generic drug manufacturer cum seller has been considered as a case in the parametric example of our model. Adaptation of the mean–variance framework helps obtaining all the results in terms of the relative trade-off between risk and return, with simple yet intuitive interpretations. © 2022, The Author(s).University of NottinghamThe authors are grateful to the guest editors (Prof. (Dr) Jean-Luc Prigent, Prof. (Dr) Ephraim Clark, and Prof. (Dr) Giovanni Barone Adesi) and two anonymous referees for their constructive comments on its submitted version of December 2019. The authors are also grateful to Prof. (Dr) Stephen M. Wagner (ETH Zurich) and Prof. (Dr) Udo Broll (TU Dresden) for their inputs on another past version of this research, which had been drafted as a CREDIT WP version [Mukherjee, S. & Padhi, S.S. (2018). Risk Connectivity and Risk Mitigation: An Analytical Framework , CREDIT WP Series No. 18/11, University of Nottingham (UK). Available at: ]. Both the submitted version of December 2019 and this present revision are substantially different from the above-mentioned draft. The usual disclaimers are applicable
Major sporting events amid monkeypox and COVID-19 outbreaks: Considering the impact upon the traveller
No full textAcross 2022, international travel began to return to more typical patterns, including spectators at major sporting events. For example, in October 2022, the T20 cricket world cup is being held in Australia, and the football world cup begins in Qatar in the Middle East in November 2022. These events would be attended by several hundred thousand visitors from multiple countries. However, the COVID-19 pandemic is far from over, and the monkeypox outbreak has also been declared a global emergency. Organizing sports events under such conditions pose specific challenges for organizers. However, measures taken to prevent the spread of these infections also influence the ability of spectators to travel and their experiences when they arrive..
Developing a Model for Iso 9000:2000 Certification of Course Material Development in Open and Distance Learning: An Indian Study
Get PDFPCF3 // Realising the importance of quality of products/services in every sector including education, a sincere effort has been made in this article by the author to develop a model for obtaining ISO 9000:2000 certification for course material development in an open and distance learning university in India. This is a tentative model hence cannot be generalised
Advanced Optimal Control Design for Nonlinear Systems including Impulsive Inputs with Applications to Automatic Cancer Treatment
Get PDFThe motivation of this research is to propose innovative nonlinear and optimal control design algorithms, which can be used in real life. The algorithms need to be computationally efficient, should deal with control constraints and should operate under state feedback. To show the efficacy of algorithms, automatic therapy for different cancer problems is chosen to be the field of application.
In this thesis, first an advanced control design technique called ’optimal dynamic in-version’ has been successfully experimented with control constraints. The proposed approach has subsequently been shown to be quite effective in proposing automatic drug delivery schemes with simultaneous application of chemo and immunotherapy drugs for complete elimination of cancer cells in melanoma (a skin cancer) as well as glioma (a brain cancer). As per the current practice, the amount of drug dosages are generally given based on some apriori statistical study with a very small sample size, which in reality may either also lead to drug toxicity (due to excessive drug) or may become ineffective (due to insufficient drug) for a particular patient. Subject to the fidelity of the mathematical model (which has been taken from published literature), it has been shown in this thesis that nonlinear control theory can be used for computation of drug dosages, which can then be used in a feedback strategy, thereby customizing the drug for the patient’s condition, to cure the disease successfully.
Next, attention has been shifted to impulsive control of systems. Such impulsive con-trol systems appear in many other applications such as control of swings, control of spacecrafts and rockets using reaction control system, radiotherapy in cancer treatment and so on. Two impulsive control design philosophies are proposed in this thesis. In one approach, recently proposed model predictive static programming (MPSP) has been extended for impulsive control systems and has been named as impulsive-MPSP (I-MPSP). In other approach, another recent development, namely the Pseudospectral method has been utilized to consider both the magnitude of the control impulses as well as the time instants at which they are applied as the decision variables. It can be noted, that to the best of the knowledge of the author, the time instants of control application, being considered as decision variables is being proposed for the first time in the nonlinear and optimal control framework. Both I-MPSP and Pseudospectral methods are computationally quite efficient and hence can be used for feedback control (I-MPSP happens to be computationally more efficient than the Pseudospectral method). Applicability of the proposed extensions have been shown by solving various benchmark problems such as (i) a scalar linear problem, (ii) Van der Pol’s oscillator problem and (iii) an inverted pendulum problem. Finally the applicability of the proposed I-MPSP strategy has been shown by solving challenging problems such as radiotherapy treatment of head and neck and adenocarcimona cancers. Radio-therapy model is considered with oxygen effect, in which radiosensitivity parameters are considered in different forms. Head and neck cancer is considered with constant radiosensitivity parameters and adenocarcinoma is considered with constant, linear, quadratic and saturation model of radiosensitivity parameters. Note that toxicity constraints on normal tissue, which are nonlinear control constraints, are also successfully incorporated in this control design
Investigation, evaluation and analysis of SiCp nano particle metal matrix nano composite using a hybrid process
No full textDevelopment, characterization and machining of Al and SiCp nano particles metal matrix nano composite
No full textAuthor Correction: Force-exerting perpendicular lateral protrusions in fibroblastic cell contraction
Get PDFAuthor Correction to "Force-exerting perpendicular lateral protrusions in fibroblastic cell contraction
Feedback linearization based computer controlled medication design for automatic treatment of parturient paresis of cows
No full textBased on an existing model for calcium homeostatis (dynamics) and taking the help of feedback linearization philosophy of nonlinear control theory, two control design (medication) strategies are presented for automatic treatment of parturient paresis (milk fever) disease of cows. An important advantage of the new approach is that it results in a simple and straightforward method and eliminates the necessity of a significantly more complex neural network based nonlinear optimal control technique, as proposed by the author earlier. As an added advantage, unlike the neural network technique, the new approach leads to ‘closed form solution’ for the nonlinear controller. Moreover, global asymptotic stability of the closed loop system is always guaranteed. Besides theoretical justifications, the resulting controllers (medication strategies) are validated from numerical simulation studies of the nonlinear system as well. Moreover, from a numerical study about the robustness of the algorithms with respect to parametric uncertainty, it was observed that the optimal control formulation is a better option over the dynamic inversion formulation
Subordination levels in CMBS
No full textThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaves 50-52).The CMBS market has been in existence since the mid 1980s; however, it was during the mid 1990s that the market began to grow. A combination of favorable interest rate environment, entry of new players in the market and the amount of demand for commercial real estate assets, led to a record US CMBS issuance in 2004, with the 2005 outlook being even better. However, the subordination or credit enhancement level of these securities has been on a downward trend since 1995. The thesis attempts to analyze the risk factors such as loan to value ratio, debt service coverage ratio, floating versus fixed rate, large and conduit deal types, as well as diversification factors (property type and geographic location), and their impact on subordination levels. Finally, market forces such as spreads on CMBS are also analyzed for their influence on subordination levels. For the analysis, data were collected on 430 commercial mortgage backed securities issued from 1995 through mid 2005. The information was obtained from Trepp, which tracks all the commercial mortgage backed securities issued in the market. The trend in subordination levels of each of the tranches or bond classes was analyzed over the period of study and a quantitative regression analysis was performed to analyze the influence of the above mentioned factors on the subordination levels.(cont.) The results indicate that the loan to value ratio, interest rate type (fixed versus floating) and the deal type (conduit and large loans) have a significant impact on the subordination levels. Also, certain other market factors, including the spread differential between CMBS and corporate bonds, strong property market performance, increased liquidity and increased number of investors may also have influence the subordination levels of these securities.by Romina Padhi.S.M
SAFE-ICU/APO_Dashboard 1.0
No full text<p><strong>A Bayesian Artificial Intelligence Dashboard for learning the best policy decisions for decreasing adverse pregnancy outcomes in India.</strong></p>
<p>Author: Tavpritesh Sethi</p>
<p>Email: [email protected]; [email protected]</p>
<p>(Manuscript forthcoming)</p>
<p>Background Publication: </p>
<pre>Padhi BK, Baker KK, Dutta A, Cumming O, Freeman MC, Satpathy R, Das BS,
Panigrahi P. Risk of Adverse Pregnancy Outcomes among Women Practicing Poor
Sanitation in Rural India: A Population-Based Prospective Cohort Study. PLoS Med.
2015 Jul 7;12(7):e1001851. doi: 10.1371/journal.pmed.1001851. eCollection 2015
Jul. </pre>
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