7 research outputs found
CLOVES: A cluster-and-search heuristic to solve the vehicle routing problem with delivery and pick-up
Suzhal – An Alternative Layout to Improve Productivity and Worker Well-being in Labor Demanded Lean Environment
AbstractErgonomics continues to be relevant in work-places in which a significant amount of manual labor exists, such as in some of the Cellular manufacturing Systems (CMS). In order to distribute the workload evenly over all the workers in the line, some of the industries resorted to the practice of rotating all the workers through all workstations in the cell (Nagare cell) that prevents monotony and boredom. The presence of automated equipment in the cell will hamper this strategy for job rotation. This study aims to demonstrate the application of ergonomically designed looping layout in the assembly cell in the labor demanded lean manufacturing environment. The study was conducted in a process line in an automobile ancillary unit. The current process line which was conventional U-shaped line was simulated and the productivity has been verified and validated with the real life environment. Process map showed that the operators walked long distances, felt stress in certain workstations and that inventory piled up at the bottleneck workstation. We identify sub-cells within the cell. With the same manpower, we develop a new layout (Suzhal) and make workers rotate within each sub-cell. The proposed layout was simulated and results have been compared with the current layout. The analysis shows a reduction in the total operating cycle time, higher alertness among operators, better distribution of workloads in the group and hence higher productivity
Tactical locomotive fleet sizing for freight train operations
Determination of fleet size of locomotives and of a policy to deadhead them are tactical issues that influence the level of customer service in a rail network. This paper considers a railroad system in which a priori freight train schedule does not exist. A simulation-based approach is proposed for tactical locomotive fleet sizing. The study shows that the throughput increases with the number of locomotives upto a certain level; after that the congestion caused by the movements of large number of locomotives in the capacity-constrained rail network offsets the potential benefit of a large fleet.Freight train operations Locomotive fleet sizing Simulation modeling
Drug inventory management at public healthcare institutions â a case study
Public healthcare institutions in India continue to be the major source of healthcare in both rural and urban areas. This study has considered resource utilisation in the context of drug supplies to the public healthcare. Drug inventory management assessment tool (DIMAT) is developed to quantify the shortcomings of the drug supply/management in terms of performance indicators. This is followed by a simulation study to access the performance of the system with the set of measurable parameters used in DIMAT and develops an approach to model inventory policies of public distribution system. The study also provides an insight into the causes of the outcomes of the public drug distribution in the state of TamilNadu, India. The primary healthcare centre (PHC) constitutes the sample for the study. This study can be extended beyond PHCs and can be used for estimating the budget for pre-specified service levels.drug inventory, simulation, inventory management, public healthcare, India, drug supply, drug management, performance indicators, drug distribution,
A model for planning the product portfolio and launch timings under resource constraints
Abnormal left ventricular torsion and cardiac autonomic dysfunction in subjects with type 1 diabetes mellitus
Left ventricular torsion is increased and cardiac energetics are reduced in uncomplicated type 1 diabetes mellitus (T1DM). Our aim was to determine the relationships of these abnormalities to cardiovascular autonomic neuropathy (CAN) in subjects with T1DM. A cross-sectional study was conducted in 20 subjects with T1DM free of known coronary heart disease attending an outpatient clinic. Cardiovascular autonomic neuropathy was assessed using heart rate variability studies and the continuous wavelet transform method. Left ventricular function was determined by speckle tracking echocardiography. Magnetic resonance spectroscopy and stress magnetic resonance imaging were used to measure cardiac energetics and myocardial perfusion reserve index, respectively. Twenty subjects (age, 35 ± 8 years; diabetes duration, 16 ± 9 years; hemoglobin A1c, 8.0% ± 1.1%) were recruited. Forty percent of the subjects exhibited definite or borderline CAN. Log peak radial strain was significantly increased in subjects with CAN compared with those without (1.56 ± 0.06 vs 1.43 ± 0.14, respectively; P = .011). Data were adjusted for log duration of diabetes, and log left ventricular torsion correlated (r = 0.593, P = .01) with log low-frequency to high-frequency ratio during the Valsalva maneuver. Log isovolumic relaxation time correlated significantly with log Valsalva ratio and log proportion of differences in consecutive RR intervals of normal beats greater than 50 milliseconds during deep breathing. However, CAN did not correlate with cardiac energetics or myocardial perfusion reserve index. Spectral analysis of low-frequency to high-frequency ratio power during the Valsalva maneuver is associated with altered left ventricular torsion in subjects with T1DM. Parasympathetic dysfunction is closely associated with diastolic deficits. Cardiovascular autonomic neuropathy is not however the principal cause of impaired cardiac energetics. The role of CAN in the development of cardiomyopathy warrants further evaluation