Miracle-dz/UniFAR-FTUs huggingface dataset:
Applications of DC Transformer in DC Distributed Generations System

DC transformer with high frequency and efficiency under a fixed duty cycle is widely used in dc distributed generations. In this paper, the topologies and equivalent circuits of single /bidirectional full-bridge non-resonant DC transformers are presented. And the configurations of the input-series output-parallel and input-parallel output-series DC transformers are also proposed for reducing voltage stress of power devices. The example consisting of DC transformers in a distributed generation system based on DC grid is shown. Finally, simulation results verify the feasibility.
Native and alien plant species inventory and diversity in disturbed forests and its economic value.

The study was conducted to assess the native and alien plant species in one of the highly disturbed forest (S1) and less disturbed forest (S2) in Mt. Manunggal, Cebu Island, Philippines. Twenty-four quadrats with a size of 20mx20 m were established using a quadrat sampling technique to identify and record all plant species. Diversity indices were utilized to determine species abundance, richness, evenness, and diversity. There was also the characterization of sites concerning anthropogenic activities and economic uses of native and alien plant species. Results showed that there was apparent domination of alien plants in terms of species richness and abundance in both sites (S1; R=62 species; N=10519; S2; R=55; N=32739). However, there was higher species richness (S1; R=62 and S2; R=30) and diversity (S1; H’=2.76, D=0.10 and S1; H’=2.41, D=0.11) but lower abundance (S1; N=10519 and S2; N=32739) and evenness (S1; PE=0.67 and S2; PE=0.73) in S1 than in S2. The high abundance and evenness of alien plant species in S2 could be due to high anthropogenic activities and its economic value. These factors indirectly assist in the introduction and persistence of alien plant species in disturbed ecosystems by increasing alien plant invasion which usually results in a higher diversity of alien plant species in highly disturbed sites. Assessment on the negative impacts to native plant species by alien plant invasion, enhanced by anthropogenic activities, must, therefore, serve as bases in future directions and implication for restoration and conservation of the remaining forests of Mt. Manunggal, Cebu Island, Philippines.
Optimisation of single-queue service delivery systems using a Markovian approach

Service delivery systems, such as banks and airport checking terminals, are faced with the daunting task of processing an increasing demand of customers. At the same time, customers have to make accept, reject or reprocess decisions for the service being offered (when given a choice). Single-server systems are simple and can be utilised as preliminary models, but most organisations generally use multi-server service delivery systems, which require more complex modelling. Modelling of the systems state using Markovian and queuing models provides a more robust approach to better understand the dynamics of the service delivery system, thereby enabling improved services based on anticipated demand variations. In addition, it provides a means to ensure an effective cost minimisation and an increased profit for the service delivery organisation. Therefore, this research proposes a Markovian-based conceptual model to optimise general service delivery systems. To illustrate the model, a numerical example for both.
Dynamic Buckling of Single-Walled Carbon Nanotubes under Axial Impact Loading

Based on the Budiansky-Roth motion criterion, a thin cylinder shell finite element model is established using the finite element software (ABAQUS) to systemically investigate the dynamic bucking behavior of single-walled carbon nanotubes, which is validated by the molecular dynamic model. It is shown that both the magnitude and duration of the impact load have a great influence on the critical buckling load. By comparing the buckling modes, it can be found that the stress wave propagation plays an important role on the buckling deformation. A local axisymmetrical buckling mode is observed at the beginning and then an asymmetrical buckling mode occurs because of the stress wave superposition.
Architectural and engineering issues for building an optical Internet

Recent developments in high density Wave Division Multiplexing fiber systems allows for the deployment of a dedicated optical Internet network for large volume backbone pipes that does not require an underlying multi-service SONET/SDH and ATM transport protocol. Some intrinsic characteristics of Internet traffic such as its self similar nature, server bound congestion, routing and data asymmetry allow for highly optimized traffic engineered networks using individual wavelengths. By transmitting GigaBit Ethernet or SONET/SDH frames natively over WDM wavelengths that directly interconnect high performance routers the original concept of the Internet as an intrinsically survivable datagram network is possible. Traffic engineering, restoral, protection and bandwidth management of the network must now be carried out at the IP layer and so new routing or switching protocols such as MPLS that allow for uni- directional paths with fast restoral and protection at the IP layer become essential for a reliable production network. The deployment of high density WDM municipal and campus networks also gives carriers and ISPs the flexibility to offer customers as integrated and seamless set of optical Internet services. © (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Biogeography-based Optimization for Economic Load Dispatch Problems

Abstract This article presents a biogeography-based optimization technique for solving constrained economic dispatch problems in a power system, considering the non-linear characteristics of generators such as valve point loading, ramp rate limits, prohibited operating zones, and multiple fuels cost functions. In this article, the proposed algorithm has been tested in different systems under various simulated conditions. A comparison of simulation results reveals optimization efficacy of the proposed scheme over the genetic algorithm, particle swarm optimization, the Hopfield model, etc., for the global optimization of multi-objective constrained economic load dispatch problems.
Linked data: what is it and why should you care?a

The semantic web and linked data technologies show great promise for organising and integrating information on the Web. As custodians of bibliographic information, libraries are ideally placed to play a leading role by providing authoritative information in this domain. The semantic web and linked data have been hyped as the solution for everything from integrating legacy data-sets and improving search through to working with big data problems. However, the vision of the semantic web is a long way from being realised. This paper explores how linked data is being used in libraries and related institutions in Australia and globally. Examples are given of linked data in practice and what makes some projects more successful than others.
Implementing a dynamically reconfigurable ATM switch on the VIRTEX FPGA of the FPX platform

This paper shows how a reconfigurable ATM switch (RECATS) has been implemented on a single VIRTEX FPGA, present in the Field Programmable Port Extender board (FPX). The switch architecture is outlined and the FPX platform is described in detail. Finally, the modifications applied to the FPX components and the methodology used to validate the reconfigurable switch are explained.
VERTICAL AND HORIZONTAL AIRFLOW CHARACTERISTICS OF WOOD/COMPOST MIXTURES

For design purposes, the relation between flow rate through biofilter media and pressure drop across biofilter media is necessary. Vertical and horizontal chambers were constructed to study the effects of airflow direction on the resistance to airflow through biofilter media. The effects of wood–aggregate:compost ratio (100:0, 80:20 and 60:40% measured on a wet mass basis), type of wood aggregate (chips and mulch), two moisture levels, and two compaction levels on the resistance to airflow were measured. Ten airflow rates (ranging between 0.054 and 0.511 m3 s–1 m–2) were used throughout the experiments. Pressure drop was linearly correlated with bed depth for both wood aggregates regardless of the airflow direction. When pressure drop per unit depth was plotted against airflow rate, on a log–log scale, the data displayed the same linear trend as reported by previous researchers for both biofilter media and grains. Resistance to airflow in the horizontal direction was approximately 0.65 times the resistance to airflow in the vertical direction for media mixtures containing wood chips. Based on lower resistance to airflow, wood chips were observed to be a better aggregate than wood mulch.
Dynamic Testing for Structural Identification of a Bridge

Structural identification via modal analysis in structural mechanics is gaining popularity in recent years, despite conceptual difficulties connected with its use. This paper is devoted to illustrating the advantages and also the indeterminacy characterizing structural identification problems for bridge structures, even in rather simple instances. In particular, an identification procedure based on modal analysis and finite-element model updating is presented for the characterization of a concrete bridge whose constructive typology is quite diffuse in the area of Friuli Venezia Giulia, Italy. Experience has suggested (so as to restrict the indeterminacy frequently affecting identification issues) resorting to all the a priori information on the system and mindfully selecting the parameters to be identified. The analysis pointed out some particularities in the modeling of bridge typology under study, otherwise not a priori detectable from an analytical point of view.
Development of an electro static lubrication system for drilling of SCM 440 steel

Abstract The growing demands for high productivity of machining require the use of high cutting speeds and feed rates. Such machining inherently produces a high cutting temperature, which not only reduces tool life, but also impairs the product quality. Application of cutting fluid influences the performance of machining because of its lubrication and cooling actions but the environmental concerns call for the reduced use of cutting fluids in machining operations. Near-dry machining, such as minimum quantity lubrication, is regarded as one of the solutions to this difficulty. In the current work, cutting fluid was applied as a continuous high-velocity jet at the machining zone, at an extreme low rate using a fluid application system, by electro static lubrication (ESL), during the drilling of SCM 440 (hardened) steel. In the first stage of this work, experiments were carried out to investigate the role of the ESL system on tool wear, hole diameter, thrust force, and surface finish of the product in machining of SCM 440 steel. In the second stage, a comparative performance analysis of the ESL system with minimum quantity of lubricant (MQL) and dry machining was conducted. Results indicate that there is a considerable improvement in the performance of machining SCM 440 steel using the ESL setup when compared with MQL and dry machining in terms of considered parameters.
Force‐guided robot in automated assembly of mobile phone

This paper describes how force‐guided robot can be implemented in the automated assembly of mobile phone. A case study was carried out to investigate the assembly operations and strategies involved. Force‐guided robot was developed and implemented in the real environment. Proportional‐based external force control with hybrid framework was developed and implemented to perform the compliant motion. In order to perform assembly operations, three basic force‐guided robotic skills are identified. These are stopping, alignment and sliding skills, where the motions are guided by the force feedback. The force‐guided robotic skills are combined and reprogrammed with fine motion planning to perform notch‐locked assembly. The system is optimized for high assembly speed while considering the constraints and limitations involved.
ARQ-based switched antenna diversity in Markov channels

Since a switch and stay combining (SSC) scheme performs at the block level, it can be combined with an automatic repeat request (ARQ) scheme. Performance of an ARQ based SSC scheme in a Markov channel is analysed. It demonstrates the performance benefit with SSC-ARQ and the conditions set on the channel state for the scheme to be feasible.
Distributed framework for yard planning in container terminals

This study discusses a yard planning system, which considers various resources such as storage space, yard cranes, and traffic areas in container terminals. The system is based on the function for estimating resource requirements of yard plans. For a given yard plan, the proposed system allows planners to check the feasibility of the plan which requires a certain amount of workload of resources in related blocks during a planning horizon. The yard planning system in this study is aimed at balancing workloads among the blocks and providing the ability to modify current yard plans by detecting blocks and periods with overloaded workloads. The system implements its planning function in a distributed manner in which planners construct yard plans under their individual control and send and receive only limited necessary information for the negotiation.
Measuring the heart's output

Measurement of the heart's flow output can be of particular value in the diagnosis and treatment of patients with cardiac disorders. One technique applicable to such patients is the thermal-dilution method, which involves measurement of a small temperature change in the bloodstream resulting from injection of a bolus of cool liquid upstream of the observation point. Simple analogue-computing techniques can provide a direct reading of cardiac output, and rapid serial measurements are obtainable.
MOSFET Scaling Trends, Challenges, and Key Associated Metrology Issues Through the End of the Roadmap

The overall issues and trends in logic MOSFET scaling are discussed from the perspective of the 2003 and 2004 editions of the International Technology Roadmap for Semiconductors. Critical challenges with scaling include managing gate leakage current, polysilicon gate depletion, and short channel effects. Key innovations to address these challenges include high‐k gate dielectric, metal gate electrode, strained silicon channel for enhanced mobility, and eventually, non‐classical CMOS devices (e.g., FinFETs). These innovations will present significant metrology and characterization challenges as well.
Study of the effects of processing parameters on the sound absorption of open-cell microcellular polymeric foams

Various researchers have investigated microcellular polymeric foams extensively over the last twenty years or so; however, little work has been conducted on the acoustic performance of these foams when their microstructural components are modified by controlling the manufacturing process parameters. The studies discussed in this paper represent an initial stage in the development of open cell foams that exhibit optimized acoustic performance as a result of controlling processing parameters. This study was focused to understand and control certain parameters that dictate the material's microstructure, such as cell size, and link them to the main macroscopic parameters, such as the airflow resistivity and porosity, which govern the overall sound absorption of an open cell material. In this paper, we investigate a new processing technology to manufacture open-cell sound absorbing PMMA (Poly Methyl Methacrylate) materials using a gas foaming/particulate leaching method. An acoustic parametric study is conducted by altering the main processing parameters such as foaming temperature, particle size, and percentage of foaming agent, which affect the cell morphologies and thus control the macroscopic properties. As such, we explore the effects of the adjusted processing parameters on the acoustic performance of the manufactured PMMA samples. The correlations between the resulting cell morphologies and the sound absorption properties indicate that understanding and controlling the porous material's inner structure is crucial for developing any type of open-cell porous material with optimal acoustical efficiency.
An alternative desirability function for achieving ‘six sigma’ quality

To achieve high process yields or ‘six sigma’ quality, engineers often need to evaluate and optimize processes that are characterized by multiple quality characteristics. Existing desirability functions weigh together multiple objectives but they have a number of limitations. Most importantly, available desirability functions do not explicitly account for the combined effect of the mean and the dispersion of the quality characteristic. Therefore, it is easy to incur excessive expenditures or unknowingly to fail to achieve targeted yields. In this paper, a desirability function is proposed that addresses these limitations. This function conservatively estimates the ‘effective yield’ under assumptions described in the ‘six sigma’ literature. We use an arc‐welding application to illustrate how the proposed desirability function can yield a substantially higher level of quality as well as a more accurate assessment of the process capability than available alternatives. We suggest that the proposed desirability function should be used to facilitate multicriterion optimization when dispersion data are available. Copyright © 2003 John Wiley & Sons, Ltd.
Design guidelines for medical ultrasonic arrays

The basics of ultrasonic transducer array design in the frequency range useful for medical imaging are discussed. Performance parameters of importance in transducer design are considered, including sensitivity, coupling constant, band width, frequency downshift, pulse duration, beam focusing properties, and electrical matching. 2D and 3D effects must also be taken into account. The advantages of computer modeling in 3D with finite element analysis code are highlighted. The principles of multi-element array transducers useful for 2D real-time scanning are reviewed. 2D arrays provide the opportunity of focusing the elevation beam dimension in the short axis, or make possible full 3D scanning volumes.
Exploring barriers in lean implementation

Purpose – The purpose of this paper is to present an analysis of research on lean focusing on barriers in its implementation through a systematic literature survey. Design/methodology/approach – A literature survey of peer-reviewed journal articles, survey reports, master theses, doctoral theses and paradigmatic books with managerial impact is used as the research methodology. Findings – The findings derived from the evaluation of the publications analyzed have led to the identification of 24 lean barriers. The success of lean implementation will not be entirely based on application of appropriate tools and techniques alone but also on the top managements' involvement and leadership, workers' attitude, resources and the organizational culture. Research limitations/implications – This literature survey is primarily focused on lean implementation in the manufacturing sector. Practical implications – This paper explores barriers for successful lean implementation and provides a concise description of the bar.
Spatial Patterns of Lightning at Different Spatial Scales in the Western United States during August of 1990 – A Case Study Using the Geographic Information Systems Technology

Geographic information systems (GIS) have been widely used to study spatial variability in different atmospheric processes. In this study, we used a GIS approach to explore the potential to examine variation patterns of lightning strikes at different scales so that micro-, synoptic-, and planetary-scale processes can be linked in explaining and modeling the distribution patterns of lightning strikes. The data collected by the ground-based lightning detection system for an entire month in the western United States were used as an example. Lightning strike density surfaces were generated using different kernel bandwidths, or search radii. It has been recognized that density surfaces are useful in visual interpretation of spatial patterns at different scales, but there are insufficient data on how well such surfaces can be used in quantitative analysis of point distribution patterns. In our study, the resulting surfaces were compared quantitatively with gridded lightning strikes using meshes, or fishnets, of different cell sizes. The fishnet cell sizes ranged from 1 km for micro-scale processes to 50 km for synoptic- and planetary-scale processes. The results suggest that there is a threshold in the search radius or kernel bandwidth, above which a significant amount of errors would be introduced in quantitative analysis. It could be argued that it is possible to achieve a balance between the need for visual interpretation of distribution patterns and the need for quantitative analysis at different scales. We used the lightning data of August 1990 and digital elevation models of 1 km resolution to perform a case study on the relationship between lightning occurrence and topography. Our results indicate that at different spatial scales, the relationships between lightning density and topography may reflect different processes that influenced the spatial distribution pattern of the lightning occurrence.
Experimental assessment of post-processed kinematic Precise Point Positioning method for structural health monitoring

Monitoring the response of engineering structures, such as tall buildings, tower and large-scale bridges, under severe loading conditions, such as strong earthquake or wind storm, is an important requirement to verify their design and construction and to evaluate structural condition and reliability. In the last two decades, high-rate real-time or post-processed kinematic differential Global Positioning System (DGPS) has been widely used in dynamic displacement measurements of civil engineering structures. In recent years, interest has increased for Precise Point Positioning (PPP) due to its capability to generate positioning solutions as accurate as DGPS. In this study, the potential of post-processed kinematic PPP in terms of monitoring dynamic displacement response of a structure has been explored based on free damped oscillation events obtained from a model structure, which is able to vibrate in the fundamental and higher modes of vibration. A number of experiments have been carried out and five events, each of which is different character, have been selected to compare PPP results with DPGS results in the time and frequency domain. The results clearly demonstrate that the PPP method, like the DGPS method, offers great potential for the measurement of horizontal and vertical dynamic movement of structures. The impact of a short period (one minute) of observation length on the result of the kinematic PPP method was also investigated in terms of sensing the dynamic movement of a structure. Twenty selected one-minute data-sets extracted from a one-hour original data-set were processed by Canadian spatial reference system PPP and each one-minute PPP solution was compared with the corresponding segment obtained from the one-hour PPP solution. The results show that the one-minute PPP solution is able to extract the fundamental natural frequency of the oscillation in the horizontal and vertical component just like the one-hour PPP solution after the offset is removed and the lower frequency trend component is filtered out.