UMTS radio-over-fiber pico-cell interconnection employing uncooled DFB lasers for multi-mode fibre modulation bandwidth enhancement

This paper analyzes experimentally the use of distributed feedback lasers (DFB) in order to increase modulation bandwidth in multimode fibres, enabling 3 km bidirectional radio-over-multimode fibre UMTS transmission in a frequency-division duplexing (FDD) configuration

Performance of MB-OFDM UWB and WiMAX IEEE 802.16e converged radio-over-fiber in PON

Experimental results about the performance of converged radio-over- fiber transmission including multiband- OFDM UWB and WiMAX 802.16e wireless over a passive optical network are reported in this paper. The experimental study indicates that UWB and WiMAX converged transmission is feasible over the proposed distribution set-up employing a single wavelength. However, the results indicate that there is an EVM penalty of 3.2 dB for a UWB 10 km SSMF transmission in presence of WiMAX wireless

UWB wireless coexistence by fibre-based photonic ADC interference monitoring

The interference monitoring of UWB wireless picocell clusters through an in-house fibre installation is proposed and evaluated in a proof-of-concept experiment. UWB clusters enable range extension of UWB technology providing Gbit/s communications in home or office buildings. Coexistence of a large number of UWB clusters with other wireless services is guaranteed by a photonic analog-to-digital converter employing the in-house optical fiber installation

Joint distribution of polarization-multiplexed UWB and WiMAX radio in PON

In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper

Vpliv podhlajevanja na lomno žilavost martenzitnega nerjavečega jekla AISI 420

Cryogenic treatments have been employed over the last three decades in both tool and high-alloy steels to improve wear resistance, mainly through the transformation of retained austenite and the precipitation of fine carbides. The application of these treatments to low-alloy steels and even to non-ferrous materials is becoming the subject of several investigations, due to their potentiality to reduce wear.The objective of the present work is to characterize the wear behavior of a cryogenically treated low-carbon AISI 420 martensitic stainless steel, by means of pin-on-disk tribological tests. Wear tests were performed according to ASTM G99 standard, under a range of applied normal loads and in two different environments, namely a vaseline bath and an argon atmosphere. Wear tracks were analyzed by optical microscopy and scanning electron microscopy (SEM) to evaluate wear volume, track geometry, surface features and the tribolayers generated after testing.In this study, it has been experimentally demonstrated that cryogenically treated specimens showed a wear resistance improvement ranging from 35 to 90% compared to conventionally treated ones.Obdelava s podhlajevanjem v zadnjih treh desetletjih, tako za orodja kot za visokolegirana jekla, pomeni izboljsanje njihove odpornosti proti obrabi, predvsem zaradi preoblikovanja zadrzanega avstenita in zgoscevanja finih delcev. Kakorkoli ze, izbolj{anje enega materiala je pogosto, vendar na racun drugega, zato je zanimivo oceniti ucinek takega tipa obdelave na lomno zilavost. Predmet pricujocega dela je bila dolocitev lomne zilavosti kriogensko obdelanega nizkoogljikovega martenzitnega nerjavecega jekla AISI 420, s pomocjo standardiziranih testov zlomov, izvedenih v skladu s standardoma ASTM E399 in ASTM E1820. V studiji je bilo s poizkusi dokazano, da so kriogensko obdelani vzorci pokazali hkratno povecanje KCI in trdote za 30 % in 5 %, v primerjavi s konvencionalno obdelanimi vzorci.Fil: Prieto, Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería; ArgentinaFil: Tuckart, Walter Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería. Laboratorio de Estudio y Ensayo de Materiales; ArgentinaFil: Perez Ipiña, Juan Elias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Comahue. Facultad de Ingeniería; Argentin

Eliciting and representing a supply chain strategy

Purpose. The purpose of this paper is two-fold: first, to propose a framework that can be used to represent a supply chain strategy for a business unit in a clear and actionable manner; second, to propose a method that can be used to elicit the factual as is supply chain strategy that a business unit currently has in place. Approach. A framework to represent a supply chain strategy for a business unit was developed through an inductive theory-generation approach. A method to elicit the current as is supply chain strategy of a business unit was developed through collaborative management research projects and validated by several third party projects. Findings. The proposed method and framework were used to elicit the as is supply chain strategy of business units in nine different projects, mostly conducted by third parties. In every case, the validity of the result was confirmed by the business unit. Research limitations. The proposed framework and method have limited scalability beyond a single business unit. Also, they may be less useful when the supply chain strategy is undergoing a dramatic transformation. Originality. The paper proposes a novel way to characterize the supply chain strategy of a business unit as a conceptual system. The paper also proposes an innovative approach to tap into the tacit knowledge of the organization to reveal the patterns of decisions underpinning its current supply chain strategy