Coupled Ostrovsky equations for internal waves in a shear flow

In the context of fluid flows, the coupled Ostrovsky equations arise when two distinct linear long wave modes have nearly coincident phase speeds in the presence of background rotation. In this paper, nonlinear waves in a stratified fluid in the presence of shear flow are investigated both analytically, using techniques from asymptotic perturbation theory, and through numerical simulations. The dispersion relation of the system, based on a three-layer model of a stratified shear flow, reveals various dynamical behaviours, including the existence of unsteady and steady envelope wave packets.Comment: 47 pages, 39 figures, accepted to Physics of Fluid

A conducting domain surface boundary applied to hybrid FEM-FDTD Electromagnetic Models

A modified boundary surface between the two domains in the hybrid FEM-FDTD technique is presented. This permits a heterogeneous surface to be imposed, allowing selected parts to be represented as being conducting or non-conducting. This enables a reduced surface size to be used in cases where an antenna is above a conducting plane, as well as facilitating a range of other practical scenarios. Examples presented show stable results and good agreement with published data

Comparison between controlled and uncontrolled spray-DIC modeling for dehydration process

The work reported here focuses on the controllability expressions in the mathematical modeling of dehydration process of food concentrates in producing powder using spray-DIC (spray-Détente Instantaneé Controlee or spray-instant controlled pressure drop). This paper presents the second-order partial differential equations for mathematical modeling of moisture and heat transfer in spray-DIC process. This paper proposes the enhancement in the simple model of DIC technique with controllability expression to be used in the spray-DIC. The controllability expression in the drying process models gives better results when compared to the models without the controllability expression. The results were computed and shown by MATLAB 2013 with Windows 8 operating systems. The controllability expression in dehydration process model using the spray-DIC drier manage to succesfully control the dehydration process

Space-times which are asymptotic to certain Friedman-Robertson-Walker space-times at timelike infinity

We define space-times which are asymptotic to radiation dominant Friedman-Robertson-Walker space-times at timelike infinity and study the asymptotic structure. We discuss the local asymptotic symmetry and give a definition of the total energy from the electric part of the Weyl tensor.Comment: 8 pages, Revte

Assessment of chain-of-custody certification costs for sawnwood manufacturers in Peninsular Malaysia

In response to environmental concerns, over the past two decades, many environmental organisations, government entities, wood product manufacturers and other companies in wood products supply chains have developed standards to encourage consumers to purchase wood originating from certified sustainable forests. This paper focuses on the chain-of-custody (CoC) component of certification. A study involving sawnwood manufacturers in Malaysia was conducted to determine an accurate cost of obtaining a Malaysian Timber Certification Council (MTCC) CoC certificate. There are three types of costs to obtain a MTCC–CoC certificate: (1) cost to meet CoC standard or requirement (an indirect cost), (2) auditing cost (a direct cost) and (3) surveillance visit cost (a direct cost). Results indicated that the cost to meet CoC standard is the major component involving 96% of the total cost of certification, whereas the auditing and surveillance visit each only involved 2% of the total certification cost. None of the three CoC costs were statistically correlated with company size (as measured by annual sales) but there was a statistically significant relationship between cost of surveillance visit and company size when measured by annual production

Experimental of surface roughness and tool wear on coolant condition technique using Aluminium alloy 319 used in automotive industries

The present day the applications of machining part tolerances, like the automotive industries aimed to reduce the fuel consumption of their vehicle by reducing the total mass per vehicle and the method process for machining. Understanding of the interaction and significance machining parameters are important to improve the efficiency of any machining process and the accuracy part produced. The objective of this research is to analyze the machining parameters (spindle speed, depth of cut and feed rates) in a three machining conditions (dry, wet and 1.0 mm coolant nozzle size on the surface roughness and tool wear using Respond Surface Method (RSM) on the CNC Lathe machine with 2 axes movements. The synthetic soluble oils, and coated cemented carbide Al2 O3 insert were used as a workpiece material and cutting tool respectively. The result of the machining experiment for Aluminum alloy 319 was investigated to analyze the main factor affecting surface roughness using the analysis of Variance (ANOVA) method. The optimum selection of the cutting conditions effectively contributes to the increase in the productivity and reduction in the production cost; therefore almost attention is paid to this problem. In cutting process, optimization of cutting parameters is considered to be a vital tool for improvement in output quality of a product as well as reducing the overall production time. The acquired results showed that the coated cemented carbide Al2 O3 insert gives the optimum overall performance in terms of surface roughness and tool wear with the smallest orifice size coolant. The research also beneficial in minimizing the costs incurred and improving productivity of manufacturing firms using the mathematical model and equations, generated by CCD based on RSM method

Walking Activity Recognition with sEMG Sensor Array on Thigh Circumference using Convolutional Neural Network

In recognition of walking gait modes using surface electromyography (sEMG), the use of sEMG sensor array can provide sensor redundancy and less rigorous identification of sEMG electrode placements as compared to the conventional sEMG electrode placements right in the middle of muscle bellies. However, the potentially lesser discriminative and noisier sEMG signals from the sEMG sensor array pose the challenge in developing accurate and robust machine learning classifier for walking activity recognition. In this paper, we explore the use of convolution neural network (CNN) classifier with frequency gradient feature derived from EMG signal spectrogram for detecting different walking activities using an sEMG sensor array on thigh circumference. EMG dataset from five healthy subjects and an amputee for five walking activities namely walking at slow, normal and fast speed, ramp ascending and ramp descending are used to train and test the CNN-based classifier. Our preliminary findings suggest that frequency gradient feature can improve the CNN-based classifier performance for walking activity recognition using EMG sensor array on thigh circumference

Business intelligence readiness factors for higher education institution

Higher Education Institution (HEI) have embarked on the new style of decision-making with the aim to enhance the speed and reliability of decision-making capabilities. One of the hardest challenges in implementing Business Intelligence (BI) is the organization’s readiness towards adopting and implementing BI systems. Currently, few published studies have examined BI readiness in HEI environment. Seeing this challenge, this study aims to contribute in determining the BI readiness factors in HEI specifically in the deployment strategies. Through inductive attention to BI in HEI environment, three broad factors have been identified: a) Organizational – that concerning on business strategies, process and structure, b) Technology – involves the BI system and knowledge for managing including the sources and c) Social – the culture within organization that may influence decision-making and its processes. This paper also makes recommendations for future research

The METAFOR project: preserving data through metadata standards for climate models and simulations

Climate modeling is a complex process, requiring accurate and complete metadata in order to identify, assess and use climate data stored in digital repositories. The preservation of such data is increasingly important given the development of ever-increasingly complex models to predict the effects of global climate change. The EU METAFOR project has developed a Common Information Model (CIM) to describe climate data and the models and modelling environments that produce this data. There is a wide degree of variability between different climate models and modelling groups. To accommodate this, the CIM has been designed to be highly generic and flexible, with extensibility built in. METAFOR describes the climate modelling process simply as "an activity undertaken using software on computers to produce data." This process has been described as separate UML packages (and, ultimately, XML schemas). This fairly generic structure canbe paired with more specific "controlled vocabularies" in order to restrict the range of valid CIM instances. The CIM will aid digital preservation of climate models as it will provide an accepted standard structure for the model metadata. Tools to write and manage CIM instances, and to allow convenient and powerful searches of CIM databases,. Are also under development. Community buy-in of the CIM has been achieved through a continual process of consultation with the climate modelling community, and through the METAFOR team’s development of a questionnaire that will be used to collect the metadata for the Intergovernmental Panel on Climate Change’s (IPCC) Coupled Model Intercomparison Project Phase 5 (CMIP5) model runs