Methodology for input data modelling in the simulation of manufacturing systems.

Computer simulation is a well-established decision support tool in manufacturing industry. However, factors such as wrong conceptualisation, inefficient input data modelling, inadequate verification and validation, poorly planned experimentation and lengthy model documentation inhibit the rapid development and deployment of simulation models. A serious limitation among the above factors is inefficient data modelling. Typically, more than one third of project time is spent on identification, collection, validation and analysis of input data.This study investigated potential problems which influence inefficient data modelling. On the basis of a detailed analysis of data modelling problems, the study recommends a methodology to address many of these difficulties. The proposed methodology, discussed in this thesis, is called MMOD (Methodology for Modelling Of input Data). An activity module library and a reference data model, both developed using the IDEF family of constructs, are the core elements of the methodology. The methodology provides guidance on the best way of implementation and provide a tool kit to accelerate the data modelling exercise. It assists the modeller to generate a customised data model (entity model), according to the knowledge gained from the conceptualisation phase of the simulation project. The resulting customised data model can then be converted into a relational database which shows how the entities and relationships will be transformed into an actual database implementation. The application of the MMOD through simulation life cycle also enables the modeller to deal with important phases in the simulation project, such as system investigation, problems and objective definitions and the level of detail definitions. A sample production cell with different level of detail has been used to illustrate the use of the methodology. In addition, a number of useful methods of data collection and the benefits of using a MMOD approach to support these methods and data rationalisation which accelerates the data collection exercise are also covered. The aim of data rationalisation is to reduce the volume of input data needed by simulation models. This work develops two useful data rationalisation methods which accelerate the data collection exercise and reduce the model complexity. This work produced a novel approach to support input data modelling in simulation of manufacturing system. This method is particularly useful when the complex systems are modelled

Updates on the Morphometric Characterization of Indian Pangolin (Manis crassicaudata) in Sri Lanka

An accurate morphological description and analysis based on reliable data are unavailable for the geographically isolated population of M. crassicaudata in Sri Lanka. This study provides the most updated morphological description of M. crassicaudata with special reference to body measurements directly obtained from 27 specimens collected island-wide. Morphological parameters were recorded under three age classes that were defined based on their body weight (BW) and total body length (TBL); juvenile (BW: 7.3 kg TBL: >101 cm) and gender to reveal sexual dimorphism based on morphometric parameters. The TBL of adult males ranged between 137 and 177 cm while body weight ranged between 20.4 and 48.8 kg. The average count of body scales was 511 ± 21. The body scales were found arranged in 13 longitudinal rows with the highest number of scales observed on the vertebral scale row (16 ± 1). Three major scale morphs were identified; broad rhombic scales, elongated kite-shaped scales, and folded shaped scales. Broad rhombic shaped scales was the dominant scale type (80.49%) on the body (405 ± 7). The tail-length to body-length ratio of an Indian pangolin was 0.87. The tail length of an Indian pangolin is a reliable predictor of the TBL and has potential implications in quick field data gathering

Moments of the Neutron \u3cem\u3eg\u3c/em\u3e\u3csub\u3e2\u3c/sub\u3e Structure Function at Intermediate \u3cem\u3eQ\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e

We present new experimental results for the 3He spin structure function g2 in the resonance region at Q2 values between 1.2 and 3.0(GeV/c)2. Spin dependent moments of the neutron were extracted. Our main result, the inelastic contribution to the neutron d2 matrix element, was found to be small at ⟨Q2⟩=2.4(GeV/c)2 and in agreement with the lattice QCD calculation. The Burkhardt-Cottingham sum rule for 3He and the neutron was tested with the measured data and using the Wandzura-Wilczek relation for the low x unmeasured region

Weak charge form factor and radius of 208Pb through parity violation in electron scattering

We use distorted wave electron scattering calculations to extract the weak charge form factor F_W(q), the weak charge radius R_W, and the point neutron radius R_n, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer q=0.475 fm$^{-1}$. We find F_W(q) =0.204 \pm 0.028 (exp) \pm 0.001 (model). We use the Helm model to infer the weak radius from F_W(q). We find R_W= 5.826 \pm 0.181 (exp) \pm 0.027 (model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in R_W from uncertainties in the surface thickness \sigma of the weak charge density. The weak radius is larger than the charge radius, implying a "weak charge skin" where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius R_n=5.751 \pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm$, from R_W. Here there is only a very small error (strange) from possible strange quark contributions. We find R_n to be slightly smaller than R_W because of the nucleon's size. Finally, we find a neutron skin thickness of R_n-R_p=0.302\pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm, where R_p is the point proton radius.Comment: 5 pages, 1 figure, published in Phys Rev. C. Only one change in this version: we have added one author, also to metadat