Sagar Sikdar

Indian Statistical Institute | ISI · Statistical Quality Control and Operations Research Division Mumbai

The primary objective of this study is to propose and verify a new synergistic prediction-based multivariate process quality control (MPQC) approach for manufacturing processes. The proposed approach considers the influence of covariates (e.g. uncontrollable inputs) and output (or response) uncertainties to predict, monitor, diagnose, and adjust fo...

In manufacturing process, quality of an end product or component is often assessed by multiple critical output characteristics (or responses). These responses are often correlated or interacting. Change in process setting condition, with an intention to improve a particular response characteristic, may adversely affect another response. In this con...

In various abrasive machining processes, output product quality is defined in terms of multiple critical characteristics (or responses) and their deviations from target values. These multiple characteristics or responses are often interacting or correlated. In such a situation, changing the process operating conditions for improving or controlling...

One of the most common processes that consumers engage with service providers is for service request. This is the first process that the customers engage with service provider. Service quality evaluation at service request stage, for a multistage service process, may have a cascade impact on overall service quality. Now a day’s consumers have acces...

Purpose The objective of this paper is to develop a new easy-to-implement distribution-free integrated multivariate statistical process control (MSPC) approach with an ability to recognize out-of-control points, identify the key influential variable for out-of-control state, and determine necessary changes to achieve state of statistical control....

Developing a single control chart for monitoring correlated multiple quality characteristics (or responses) is always a challenging research endeavor. In this context, various classical approaches, such as  2 and Hotelling T2 control chart are recommended by researchers. However, interpretation, understanding of out-of-control state, and developin...

A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between August 1992 and December 1994. A cohort of rural children below 4 years of age was prospectively observed to determine the clinico-epidemiological aspects of mucoid diarrhoea and examine propensity to invasiveness. Overall, the incidence of diarrhoea wa...

A total of 498 children, aged 0-14 years, admitted at the B.C. Roy Memorial Hospital for Children, Calcutta, were investigated for the occurrence of Clostridium difficile and its cytotoxin. Of the children in the investigation, 369 suffered from acute diarrhea. Only 8.4% of these children had C. difficile in fecal samples and in vitro cytotoxin was...

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at mo...

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at mo...

In a double-blind, randomized clinical trial with 78 adults with acute watery diarrhea and severe dehydration, 37 subjects were positive for Vibrio cholerae. In conjunction with rehydration therapy, 13 patients received norfloxacin, 12 received trimethoprim-sulfamethoxazole (TMP-SMX), and 12 received a placebo. Norfloxacin was superior to TMP-SMX a...

The adhesive capability of Vibrio cholerae 01 strains to isolated rabbit intestinal epithelial cells was maximally expressed when the bacteria were grown in synthetic broth and was enhanced by the presence of Ca2+ in the growth media. N-Acetyl-D-glucosamine could inhibit the adhesion of the bacteria to rabbit intestinal epithelial cells as could li...

A longitudinal study was conducted to determine the profile of diarrheal diseases in a group of 383 children below 5 years of age in 2 typical slums of Calcutta (India). The overall annual incidence of diarrheal illness in these children during the 1st year of the study was found to be 1.1/child. However, the incidence was higher (1.9/child) in chi...

A double blind study on determination of ABO blood groups of 210 cholera patients, 44 diarrhoea cases due to Vibrio parahaemolyticus, and 148 diarrhoea cases from whom no vibrios could be isolated (control group), was conducted in Calcutta: A statistically significant difference was found in blood group ‘O’ when comparison was made between control...

A controlled field trial to determine the efficacy of a single dose of an aluminium phosphate-adsorbed cholera vaccine was conducted in Calcutta during 1975-77. An aluminium phosphate-adsorbed tetanus toxoid was used as the placebo. Follow-up of the immunized volunteers for a period of two years showed that the adsorbed cholera vaccine provided 100...

Sulfadoxine, a long-acting sulfonamide, and tetracycline were compared as regards their effectiveness in reducing transmission of cholera infection among the contacts of cholera patients in Calcutta. A total of 109 healthy family contacts of confirmed hospitalized cholera patients were treated with a single oral dose of sulfadoxine graded according...