Search results for "PASS"
showing 10 items of 1629 documents
Doing Mathematics with Tools: One Task, Four Tools
2016
This chapter illustrates a variety of mathematical and educational issues arising from doing a single task with different tools. One task is considered, bisect an angle. The chapter has four sections, each devoted to issues in using one tool to complete this task: a straight edge and compass; a protractor; a dynamic geometry system; and a book.
A DSP-Based Resolver-To-Digital Converter for High-Performance Electrical Drive Applications
2016
This paper presents a low cost, simple, and highly accurate resolver-to-digital converter (RDC) for electrical drive applications based on an integrated software approach, thus allowing a significant reduction of hardware components count with significant improvements in terms of reliability, reduction of fault rate, and susceptibility to electromagnetic interference (EMI). Particular attention has been addressed to cost which is 25% off over conventional RDC. Simulations and experimental tests confirm the high quality of the proposed system.
Configurable bandwidth imaging spectrometer based on acousto-optic tunable filter
2005
This paper presents a new portable instrument called Autonomous Tunable Filtering System (ATFS), developed for highly customisable imaging spectrometry in the VIS-NIR range. The ATFS instrument consists of an Acousto-Optic Tunable Filter (AOTF), an optical system, a Radio Frequency (RF) driver based on a Direct Digital Synthesiser (DDS) and control software. The ATFS can be attached to a variety of high-performance monochrome cameras. The system works as a spectral bandpass filter whose wavelength can be selected between 400nm and 1000nm and whose bandwidth can be adjusted between 4nm and 50nm. The filter can be tuned electronically at a very high speed and accuracy, thanks to the DDS versa…
Numerical Modelling of Room Thermal Comfort Conditions
2006
Particular heat transfer coefficients of building elements gives quantitative notion only about heat losses through this building element. Analysis of the overall heat balance and heat losses of complete building and study of particular contribution of building elements in overall balance allows one to figure out the state of the building and find the building elements of bounding construction with most significant heat losses. Project variants of the buildings (or rebuilding in case of renovation), which ensure the desirable economy of energy and proportions of investments can be find varying the proportions of the surface area of building elements (e.g., windows and doors). A lot of facto…
The potential of rotorcraft for intercity passenger transport
2007
Abstract There are many high-speed rail projects in Europe at different stages of development. They are supported on environmental grounds and as a means of reducing congestion on other modes, including aviation. High-speed rail, however requires major investment costs, takes a long time to come online, and involves considerable financial risks. A potential alternative that overcomes some of these problems makes use of rotorcrafts. This paper assesses the potentiality of civil rotorcrafts as part of the air transport system. Discrete mode choice models are used to forecast traveller choice behaviour when the rotorcraft is introduced and financial evaluations performed looking at the operati…
RF Breakdown Prediction for Microwave Passive Components in Multi-carrier Operation
2010
This work addresses the multipactor problem for multi-carrier operation inside rectangular waveguide based devices, by means of numerical simulations of the electron trajectories and multiplication inside the structure. Accurate field calculation and taking into account space charge effects are mandatory. For this, a PIC-FDTD method has been employed. As a result, novel software has been implemented offering the possibility of predicting multipactor in multicarrier systems for a wide variety of situations. Simulation results show that multipactor can occur even for short pulse durations if an inter-period charge accumulation is present.
The Effect of Friction in Passive and Active Heave Compensators of Crown Block Mounted Compensators
2012
Abstract This paper studies the effects of friction model during passive and active heave compensation of offshore drilling equipment. The main purpose of heave compensation while drilling from vessels or semi-submersible platforms is to maintain the drilling operation unaffected by the wave induced motion. The investigated system is of an existing crown mounted compensator. A model of the system is developed which includes mechanics, hydraulics and pneumatics. The passive heave compensation scheme is described including force equalising hydraulic cylinders. In this paper the detrimental effect of friction on the heave compensation performance in both passive and active heave compensation i…
APPLICATION OF MATHEMATICAL MODELS FOR THE SIMULATION OF THERMAL COMFORT CONDITIONS IN A LIVING ROOM
2005
The paper deals with the distributions of temperature and averaged turbulent airflows in living rooms in 2D and 3D approximations using Ansys/Flotran and Ansys/CFX software respectively. The distributions are calculated depending on the placement and temperature of heaters, heat transfer coefficients of the building structures and ventilation conditions. The authors analyse the influence of these factors on the air circulation and the related heat flows through building structures. The thermal balance of a room and its dependence on various external factors is also considered. As thermal comfort conditions’ parameters are analysed, the airflow velocities and indoor temperatures with its gra…
Thermal comfort condition assessment in test buildings with different heating/cooling systems and wall envelopes
2017
Abstract The main aim of this study is a comprehensive analysis of long-term monitoring data of thermal comfort and discomfort parameters in small identical test buildings equipped with different heating/cooling systems. Calculations of PPD index expressed the human perception of thermal comfort and such discomfort factors like draught rate and vertical air temperature difference are provided for the room in winter season running three different heating systems – electric heater, air-air heat pump and air-water heat pump, as well as for the summer cooling with split type air conditioning systems. It is shown that the type of heating/cooling system and its working regime has a significant im…
Vibration control for adjacent structures using local state information
2014
In this paper, a novel strategy for structural vibration control of multi-structure systems is presented. This strategy pays particular attention to mitigating negative interstructure interactions. Moreover, it is based on recent advances in static output–feedback control, which make possible the efficient computation of decentralized velocity-feedback controllers by solving a single-step optimization problem with Linear Matrix Inequality constraints. To illustrate the main ideas, a local velocity-feedback energy-to-peak controller is designed for the seismic protection of a two-building system. This controller is remarkably effective and extremely simple. Moreover, it can also be implement…