Monitoring manufacturing system availability

The monitoring of production line availability on a day-to-day basis and for continuous improvement is approached from a control charting point of view. Control limits are developed along with the length of time between monitoring periods to control accuracy. This provides a convenient way to monitor the availability measure at any desired level of accuracy.     

An exploratory study for investigating the critical success factors for cloud migration in the Saudi Arabian higher education context

Saudi universities have at their disposal a huge number of low cost IT resources to aid in teaching, research and learning. By migrating to cloud services, Saudi universities will be moving data and programs from local servers to the internet, thereby providing users with the ability to access and share information at any time from multiple devices. The migration to cloud-based IT resources is not yet widespread in Saudi universities due to several challenges including security, legal policies and implementation. At present, there is lack of research and guidance for Saudi universities on how to overcome these challenges and how contextual factors can influence the successful migration to the educational clouds.This research presents a framework for the successful migration to cloud technology in the Saudi Arabian universities. In this research, a set of key critical success factors (CSFs) were identified by synthesizing components from studies concerned with the migration of cloud for higher education and factors identified from the successful implementation of WBL (Web Based Learning) and ERP (Enterprise Resource Planning) on higher education in Saudi Arabia. Based on this knowledge, the proposed framework was evaluated via expert review and a survey by IT specialists from the Saudi universities. The initial CSFs were updated based on the expert reviews and the results were analysed. Based on the findings at this stage, additional CSFs were added to the framework as suggested by the experts. Subsequently, in order to confirm the reviewed CSFs, additional investigation via a structured online questionnaire was conducted and the outcome was analysed via one-sample t-test with the data integrity analysed via Cronbach’s alpha. The outcome indicated the majority of CSFs to be statistically significant except the Physical Location CSF. Potential future study and contributions are discussed.     

Real-time tool control and job dispatching in flexible manufacturing systems

A method of loading a set of tools to the different machining centres of a shop is presented, where each part visits only one of the machining centres for its entire processing. Any tools which are required but unavailable for the processing of a part are borrowed from other machining centres. As a real-time control, the tool-returning policies for those borrowed tools and the job-dispatching rules at the machining centres are evaluated to maximize the throughput performance of the shop. Some experimental results are provided.     

Determination of moisture content of polyamide 66 directly from combination region near‐infrared spectra

The hygroscopic nature of polyamide (PA) polymers motivates the development of analysis tools for use in assessing their moisture content. Among possible analysis techniques, near‐infrared (near‐IR) spectroscopy is non‐destructive, requires little or no sample preparation, and is compatible with sample thicknesses on the order of mm. The work reported here makes use of transmission near‐IR spectroscopy in the combination region (5000–4000 cm^?1) to develop a protocol for assessing the moisture content of PA 66 samples directly from their spectral intensities after preprocessing with the standard normal variate transform and partial least‐squares. The method is compatible with online or continuous monitoring applications and can be calibrated without the use of destructive reference measurements such as thermogravimetric analysis. The long‐term calibration performance of the technique is evaluated, and on a scale of 0–100% moisture uptake, the standard error of prediction is found to average 1.4% over 6 months. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40645.     

Determining the Strength of Coarse‐Grained AlON and Spinel

The strength of two coarse‐grained (grain size > 200 μm) cubic ceramics, a magnesium aluminate spinel (MgAl₂O₄) and an AlON , along with a fine‐grained (1.5 μm) MgAl₂O₄, was determined by conducting a series of four‐point and equibiaxial flexure tests on specimens of different sizes. Weibull strength size scaling revealed a linear relationship on a log–log plot between average flexure strength and effective specimen area for the fine‐grained spinel, but a nonlinear relationship for both coarse‐grained materials. Initial fractography showed that each material had a single flaw population limiting the strength over the entire specimen size range, which does not account for the nonlinear size scaling relationship in the two coarse‐grained materials. However, further fractography revealed that in both materials there was an initial flaw and a critical flaw. The former appears to be machining/polishing damage that started the fracture process while the latter was a cleaved grain in AlON or a cracked grain boundary in the HP/HIP spinel that lead to fracture of the specimen. The difference between the initial and critical flaw size coupled with a detailed analysis of the strength as a function of test specimen thickness accounted for the nonlinear strength size scaling relationship. As a result, strength values obtained using thin test specimens can lead to an erroneous strength prediction for large components made of these ceramics. The implication of these findings is that strength tests must be conducted using appropriately thick specimens to obtain a representative strength value. If appropriately thick specimens cannot be tested, then fractography must be conducted to determine the flaw size. If the flaw size is sufficiently large, compared with the specimen thickness, then the strength must be adjusted according to a stress field correction factor to obtain a more accurate strength value.     

Linear quadratic performance with worst case disturbance rejection

The method of the calculus of variations and the maximum principle are preposed for the design of 'LQR' controllers with the worst case disturbance rejection for a linear time-varying (LTV) plant on finite horizon. The disturbance is bounded by either the windowed L     

Enterprise Performance Management: Making it Work

Abstract

Enterprise performance management (EPM) is the integration of control and improvement methods imbedded with analytics. Its methods include the strategy map, balanced scorecards, costing (including activity based cost management), budgeting, forecasting and resource capacity requirements planning. These methods fuel other core solutions such as customer relationship management (CRM), supply chain management (SCM), risk management, and human capital management systems, as well as lean management and Six Sigma initiatives.     

MOCVD Growth of Erbium Monoantimonide Thin Film and Nanocomposites for Thermoelectrics

We report the growth of erbium monoantimonide (ErSb) thin films on indium antimonide (100) substrates by low-pressure metalorganic chemical vapor deposition. The growth rate of ErSb thin films shows strong dependency on the growth temperature and the Sb/Er precursor molar flow rate ratio. Scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffractometry (XRD) were employed to study the ErSb thin films grown under the growth conditions that gave the maximum growth rate in the range we investigated. We also report the growth of two types of nanocomposites in which ErSb nanocolumns or nanoslabs with lengths ~500 nm and diameters 20 nm to 30 nm are embedded in Zn-doped InGaSb (ErSb/InGaSb:Zn) and ErSb nanoparticles with diameters of ~30 nm are embedded in Zn-doped InSbAs (ErSb/InSbAs:Zn). These nanocomposites were intended to increase phonon scattering in a mid-to-long phonon wavelength range to reduce lattice thermal conductivity. We used time-domain thermoreflectance to measure total thermal conductivity for the two types of nanocomposites, obtaining 4.0 ± 0.6 W/mK and 6.7 ± 0.8 W/mK for the ErSb/InAsSb:Zn and ErSb/InGaSb:Zn nanocomposites, respectively, which suggests that the thermal conductivity was close to or slightly smaller than the alloy limit of the two ternary alloy hosts. The two nanocomposites were further studied by transmission electron microscopy (TEM) to reveal their microscopic features and by XRD to assess their crystalline structures.     

Atomic Bond Deficiency Defects in Amorphous Metals

Atomic bond deficiency (BD) is considered to be characteristic structural defects in amorphous metals. They are the necessary feature of local atomic configurations that facilitate various atomic transports under different driving forces. Compared with vacancies in crystalline solids, they are ??small?? in terms of their formation energies, volume costs, and elementary steps involved in atomic transport. This article reviews the authors?? recent efforts made to analyze how various local configurations containing BD are related to amorphous metal??s unique characteristics, such as glass transition, diffusion, shear flow, and structural relaxation.