Johann Chiang

the concept of “ultra vires” has been studied in two specific areas: in company law and in discussions on the issues of capacity and acts of representatives. historically, in english law, ultra vires acts were considered as void, and neither representatives nor shareholders could approve them at a later time. subsequently, judges in common law system changed their approach from a restricted cap...

In this paper a novel very high performance current mirror is presented. It favorably benefits from such excellent parameters as: Ultra high output resistance (36.9GΩ), extremely low input resistance (0.0058Ω), low output (~0.18V) and low input voltage (~0.18V) operation, very low power consumption (20μW), very low offset current (1pA), ultra wide current dynamic range (150dB), and ultra high a...

air spindles are one of the main elements of precise machine tools. vibration of these spindles is one of the vital issues necessary for investigation. among parameters which influence air spindle vibrations are rotational speed, compression air method, input nozzle diameter, air gap pressure. in this study using ansys, the effects of air gap thickness on air spindle vibrations have been invest...

the austenitic stainless steel (ss) has been used as a material for  building  ultra  high  vacuum  (uhv)  chamber.  recently significant  efforts  have  been  concerned  a  comparing  the standard  cleaned  for  ultra  high  vacuum,  passivity  stainless. in  this work austenitic  nanocomposites were  synthesize by sol-  gel method. the morphologies  and  topographies  of  the samples  have  b...

We describe some constructions of orthonormal lattices in totally real subfields of cyclotomic fields, obtained by endowing their ring of integers with a trace form. We also describe constructions of quaternion division algebras over such fields. Orthonormal lattices and quaternion division algebras over totally real fields find use in wireless networks in ultra wideband communication, and we d...

Ultra Wide Band (UWB) communications offers a radically different approach to wireless communication compared to conventional narrow band systems. Global interest in the technology is huge. This white paper reports on the state of the art of UWB wireless technology and highlights key application areas, technological challenges, higher layer protocol issues, spectrum operating zones and future d...

This paper describes the measurement techniques of emissions from UWB devices discussed in ITU-R task group (TG) 1/8 to study the compatibility between ultra-wideband (UWB) devices and radiocommunication services. This paper also provides the background idea behind the measurement methods, as the final output of the discussion, i.e. ITU-R Recommendation, will not contain any citations to the re...