Evaluation of EWMA Control Charts for Monitoring Spread of Transformed Observations of COVID-19 in India

COVID-19 a pandemic due to novel corona virus emerged from Wuhan, China in December 2019 and now the whole world facing its threat. This is a disaster pandemic for almost every nation on the earth. Such novel corona virus impacts on every country in the world irrespective of race, ethnicity, environment and economic status. In this study, an attempt has been made to use statistical process control technique to understand spread of COVID-19 in some major states of India as well as India. Warning limits and control limits has been estimated and discussed for average weekly growth index of COVID-19 pandemic. Study indicates that there is no hope for controlling the pandemic in near future because the average weekly growth index of COVID-19 pandemic is far from zero.

Anthropogenic Impact on Tropical Perennial River in South India: Snapshot of Carbon Dynamics and Bacterial Community Composition

Riverine systems play an important role in the global carbon cycle, and they are considered hotspots for bacterial activities such as organic matter decomposition. However, our knowledge about these processes in tropical or subtropical regions is limited. The aim of this study was to investigate anthropogenically induced changes of water quality, the distribution of selected pharmaceuticals, and the effects of pollution on greenhouse gas concentrations and bacterial community composition along the 800 km long Cauvery river, the main river serving as a potable and irrigation water supply in Southern India. We found that in situ measured pCO2 and pCH4 concentrations were supersaturated relative to the atmosphere and ranged from 7.9 to 168.7 μmol L−1, and from 0.01 to 2.76 μmol L−1, respectively. Pharmaceuticals like triclosan, carbamazepine, ibuprofen, naproxen, propylparaben, and diclofenac exceeded warning limits along the Cauvery. Proteobacteria was the major phylum in all samples, ranging between 26.1% and 82.2% relative abundance, and it coincided with the accumulation of nutrients in the flowing water. Results emphasized the impact of industrialization and increased population density on changes in water quality, riverine carbon fluxes, and bacterial community structure.

Early Warning Method for Regional Water Resources Carrying Capacity Based on the Logical Curve and Aggregate Warning Index

The sustainable utilization of water resources is a significant factor in the development of the national economy and society. Regional water resources carrying capacity (RWRCC) is an appropriate method for evaluating the balance in such utilization. In this paper, we combined time difference correlation analysis and set pair analysis firstly to identify the early warning sign index (EWSI) for RWRCC, and warning limits were determined using a logical curve. Analytic hierarchy process based on the accelerating genetic algorithm (AGA-AHP) method was used to improve the KLR model by determining weights objectively. We took advantage of the new improved model to build the aggregate warning index (AWI). Then, according to the corresponding relationship between EWSI and AWI, the early warning system for regional water resources carrying capacity (EWS-RWRCC) was established, and a case study was carried out in Anhui Province. The results showed there are eight effective EWSI obtained through the early warning analysis process of RWRCC in Anhui Province, among which the repetitive use rate of industrial water and average daily coefficient have a greater impact on AWI. Basically, the EWS-RWRCC can describe RWRCC changes in Anhui Province. From 2006 to 2014, more than half the signal lights in Anhui Province were yellow and orange, which indicated a poor state. It has been proved that the constraints of population, GDP growth and water supply capacity on the utilization of water resources in the future will be further tightened, which should be considered for future monitoring and early warning. The early warning method we used here can be widely applied into other fields; the results will enhance monitoring capacity and scientifically guide regional water resources management.

RESEARCH OF THE LIMITING STATE OF THE MARINE MEDIUM-SPEED DIESEL CRANKSHAFT

The limiting state of the marine medium speed diesel engine crankshaft occurs as a result of the influence of three basic factors: kinematics error, plain bearings wear, and fatigue of material. A kinematics error causes deformation of the crankshaft, uneven wear of bearings and material fatigue. The crankshaft deformation is monitored by radial runout of the crank journal and change of distance between crankwebs. The legitimate values of deformation are defined by the manufacturer and tested in practice. According to the data taken from the literature, there has been analyzed the process of the crankshaft bearings wearing. The main reason is found an abrasive wear of plain bearings. The uneven wear of crankshaft necks results in their ovality and conicity. Non-cylindrical shape of the neck is the principal reason of plain bearings faults. The phenomenon of the crankshaft fatigue has been studied. Exceeding warning limits of crack length and area on the neck surface, which is mentioned in diesel technical service and repair manual, will result in changing crankshafts with cracked necks. The different types of diesel crankshaft fatigue destruction have been educed. The problem of crack development inside a crankshaft has been studied. The estimations of limiting depth of neck craking are offered based on the results of emergency fatigue fracture of crankshaft, taking into account recommendations of firms-manufacturers and experience of repair. The estimations of crankshaft neck cracking average speed have been given on the basis of study of emergency situations. An example of successful renewal of crankshaft with deep cracks has been demonstrated. After magnetic particle or dye penetrant testing it has been recommended to use the crack depth gauge RMG 4015. Crack control experience has been investigated in the course of the process of 8NVD48A2-U diesel crankshaft neck surface cracking by a decreasing of diesel load.

WHOLE BODY AND HAND-ARM VIBRATIONS ON OFF-ROAD VEHICLE USED IN ACADEMICALS COMPETITIONS

Off-road vehicles, baja type, are designed for locomotion on irregular terrains with several obstacles, to pull loads with effciency, furthermore, are compact and easy to operate. Such vehicles have wide use in agriculture, construction, transportation and military operations. Baja vehicle provide to pilot an exposure to high levels of mechanical vibrations. With the present work aimed to determine the whole body vibration and hand-arm vibration in the pilot using the vehicle designed by UFVbaja team. The vibrations levels incident on the pilot was measured in three different terrain conditions and different forward speeds. It was determinate the root mean square acceleration and daily vibration exposure at the seat pad and hand-arm of pilot. For whole body vibration was obtained the daily vibration dose value. The values were confronted with standards ISO 2631-1. The acceleration level, normalized to 8 hour, exceeded the warning limits for all worked conditions. To Baja vehicle operating in plowing soil, the transverse and vertical accelerations exceeded the limit level. In general, incident acceleration levels on the pilot were considered high, which reinforces the need for seats projects of suspension, steering and seat that effectively reduce the vibration transmitted to pilot body and hand-arm system.

Determination of level of correlation for products of pharmaceutical industry by using modified X-bar chart

Purpose – It is found that the process outputs from most of the industries are correlated and the performance of X-bar chart deteriorates when the level of correlation increases. The purpose of this paper is to compute the level of correlation among the observations of the weights of tablets of a pharmaceutical industry by using modified X-bar chart. Design/methodology/approach – The design of the modified X-bar chart is based upon the sum of χ2s, using warning limits and the performance of the chart is measured in terms of average run lengths (ARLs). The ARLs at various sets of parameters of the modified X-bar chart are computed; using MATLAB software at the given mean and standard deviation. Findings – The performance of the modified X-bar chart is computed for sample sizes of four. ARLs of optimal schemes of X-bar chart for sample size of four are computed. Various optimal schemes of modified X-bar chart for sample size (n) of four at the levels of correlation (Φ) of 0.00, 0.25, 0.50, 0.75 and 1.00 are presented in this paper. Samples of weights of the tablets are taken from a pharmaceutical industry and computed the level of correlation among the observations of the weights of the tablets. It is found that the observations are closely resembled with the simulated observations for the level of correlation of 0.75 in this case study. The performance of modified X-bar chart for sample size (n) of four at the levels of correlation (Φ) of 0.50 and 0.75 is also compared with the conventional (Shewhart) X-bar chart and it is concluded that the modified X-bar chart performs better than Shewhart X-bar chart. Research limitations/implications – All the schemes are optimized by assuming the normal distribution. But this assumption may also be relaxed to design theses schemes for autocorrelated data. The optimal schemes for modified X-bar chart can also be used for other industries; where the manufacturing time of products is small. This scheme may also be used for any sample sizes suitable for the industries Practical implications – The optimal scheme of modified X-bar chart for sample size (n) of four is used according to the computed level of correlation in the observations. The simple design of modified X-bar chart makes it more useful at the shop floor level for many industries where correlation exists. The correlation among the process outputs of any industry can be find out and corresponding to that level of correlation, the suggested control chart parameters can be used. Social implications – The design of modified X-bar chart uses very less numbers of parameters so it can be used at the shop floor level with ease. The rejection level of products in the industries can be reduced by designing the better control chart schemes which will also reduce the loss to the society as suggested by Taguchi (1985). Originality/value – Although; it is the extension of previous work but it can be applied to various manufacturing and service industries; where the data are correlated and normally distributed.

Modified chart with optimized ARLs in autocorrelated processes

Purpose – The purpose of this paper is to counter autocorrelation by designing the chart, using warning limits. Various optimal schemes of modified chart are proposed for various sample sizes (n) at levels of correlation (Φ) of 0.00, 0.475 and 0.95. These optimal schemes of modified chart are compared with the double sampling (DS) chart, suggested by Costa and Claro (2008). Design/methodology/approach – The performance of the chart is measured in terms of the average run length (ARL) that is the average number of samples before getting an out-of-control signal. Ultimately, due to the effect of autocorrelation among the data, the performance of the chart is suspected. The ARLs at various sets of parameters of the chart are computed by simulation, using MATLAB. The suggested optimal schemes are simpler schemes with limited number of parameters and smaller sample size (n=4) and this simplicity makes them very helpful in quality control. Findings – The suggested optimal schemes of modified chart are compared with the DS chart, suggested by Costa and Claro (2008). It is concluded that the modified chart outperforms the DS chart at various levels of correlation (Φ) and shifts in the process mean. The simplicity in the design of modified chart, makes it versatile for many industries. Research limitations/implications – Both the schemes are optimized by assuming the normal distribution. But this assumption may also be relaxed to design theses schemes for autocorrelated data. The optimal schemes for chart can be developed for variable sample size and for variable sampling intervals. The optimal schemes can also be explored for cumulative sum and exponentially weighted moving average charts. Practical implications – The correlation among the process outputs of any industry can be find out and corresponding to that level of correlation the suggested control chart parameters can be applied. The understandable and robust design of modified chart makes it usable for industrial quality control. Social implications – The rejection level of products in the industries can be reduced by designing the better control chart schemes which will also reduce the loss to the society, as suggested by Taguchi (1985). Originality/value – Although it is the extension of previous work but it can be applied to various manufacturing industries as well as service industries, where the data are positively correlated and normally distributed.