RFID Context Data Management: The Missing Link to EPCIS-Based Supply Chain Monitoring

The potential of Radio Frequency Identification (RFID) for increasing supply chain efficiency has been stressed by practitioners and researchers alike. For the cross-company exchange of RFID-related data, the industry consortium EPCglobal has specified the EPC Information Services (EPCIS). According to EPCglobal, all RFID-related data recorded by an organization should be stored as EPCIS events in a dedicated database. The information that can be inferred from the EPCIS events stored in the EPCIS repositories will be sufficient to monitor the flow of goods. However, generating an EPCIS event does not only require the data that is provided by the RFID readers but also the corresponding context data (e.g. physical locations, related business process steps and related transactions). For this missing link, i.e. the association of read events and context data, we propose an architectural component called Event Capturing Application (ECA). In this paper we propose a data model for storing and exchanging EPCIS context data in an efficient and standardizable way. We also present an algorithm that can be used to assemble EPCIS events from read events and context data. The functionality of our prototypical ECA was evaluated using noFilis’ RFID middleware CrossTalk and the Fosstrack EPCIS implementation

THE VALUE OF VISIBILITY AND RFID IN TRANSSHIPMENT OPERATIONS – A SIMULATION STUDY

Shrinkage can lead to inventory record inaccuracy which in turn may negatively affect the performance of supply chain control policies. In this paper the impact of shrinkage on the efficiency of transshipment operations is demonstrated using stochastic simulation. In particular, the value of full inventory visibility which could be achieved using RFID is approximated. This value is shown to be relatively low given the assumed properties of the transshipment policy. Our preliminary results suggest waiting for further tangible benefits of RFID before building its business case in transshipment environments

International financial reporting standards and earnings Quality: the myth of voluntary vs. mandatory adoption

We revisit evidence whether incentives or IFRS drive earnings quality changes, analyzing a large sample of German firms in the period from 1998 to 2008. Consistent with previous studies we find that voluntary and mandatory adopters differ distinctively in terms of essential firm characteristics and that size, leverage, age, bank ownership and ownership concentration influenced the decision to voluntarily adopt IFRS. However, regardless of the decision to voluntarily adopt IFRS, we find that conditional conservatism increased under IFRS for both groups of adopters, while evidence does not suggest an increase in value relevance under IFRS. Results on earnings management in the post-adoption period are mixed. While income smoothing decreases for voluntary but not for mandatory adopters, discretionary accruals only decrease for mandatory but not for voluntary adopters. However, further analyses suggest that the capital market environment and the economic cycle during the adoption period seem to be a more powerful explanation for this evidence than voluntary or mandatory IFRS adoption. Therefore, we conclude that incentives to voluntarily adopt IFRS did not unambiguously dominate accounting standards in determining earnings quality in the case of German firms. --IAS regulation,IFRS,corporate ownership structures,insider ownership,incentives,earnings quality

Influence of pressure on droplet splashing behaviour inside gas turbine compressors during wet compression

International audienceThe injection of water sprays into the compressor inlet of gas turbines is used to augment power output and perform fast load changes. During wet compression, many drops enter the compressor and since droplets above a specific size cannot follow the flow of air, they are likely to collide with compressor blades and disintegrate. To apprehend the occurring splashing phenomena, impacts of single droplets on substrates with different surface roughness are studied under gas pressures from 100 to 500 kPa. For these disintegrations, the quantity of secondary droplets as well as their size and velocity distributions are measured using backlit high-speed video recordings. Analysis shows that the secondary droplet diameter distribution is dependent on surface roughness as well as pressure. Surface roughness increases the quantity of large secondary droplets, while the number of droplets with small diameters is unaltered. Increasing pressure increases the quantity of secondary droplets of all sizes. Both variations lead to significant increase in overall ejected volume of the primary drop. The evaluation of the influence of surface roughness and pressure on the secondary droplet velocity showed that there is a minor dependency on variations in both parameters

Višerazinska procjena faznih i kodnih pomaka satelitskog signala

Precise point positioning with satellite navigation signals requires knowledge of satellite code and phase biases. In this paper, a new multi-stage method is proposed for estimating of these biases using measurements from a geodetic network. Themethod first subtracts all available a priori knowledge on orbits, satellite clocks andmultipath from the measurements to reduce their dynamics. Secondly, satellite phase biases, ionospheric delays, carrier phase integer ambiguities and the geometry combining all non-dispersive parameters are jointly estimated in a Kalman filter. Finally, the a posteriori geometry estimates are refined in a second Kalman filter for the computation of orbital errors, code biases and tropospheric delays. As the first Kalman filter introduces time correlation, a generalized Kalman filter for colored measurement noise is applied in the second stage. The proposed algorithm is applied to dual frequency GPS measurements from a local geodetic network in Germany. A remarkable bias stability with variations of less than 3 cm over 4 hours is observed.Precizno odre.ivanje položaja uporabom satelitske navigacije zahtjeva poznavanje satelitskog koda te fazna mjerenja. U ovom radu predložena je nova metoda za procjenu faznih pomaka signala uporabom rezultata mjerenja iz geodetske mreže. U prvom koraku iz mjerenja se izuzimaju poznati podaci o orbitama, satelitskim satovima i višestrukim putevima, kako bi se smanjila njihova dinamika. U drugom se koraku uporabom Kalmanovog filtra procjenjuju fazni pomaci, ionosferska kašnjenja, neodre.enost broja valnih duljina nosioca i geometrija koja uključuje sve nedisperzivne parametre. Konačno, odre.uje se korigirana geometrija u drugom Kalmanovom filtru radi proračuna orbitalnih pogrešaka, pogrešaka koda i troposferskog kašnjenja. S obzirom na to da prvi Kalmanov filtar unosi vremensku korelaciju, opći Kalmanov filtar primjenjuje se u drugom koraku. Predloženi algoritam primijenjen je u dvofrekvencijskim GPS-mjerenjima u lokalnoj geodetskoj mreži u Njemačkoj. Postignuta je visoka stabilnost rezultata uz varijacije manje od 3 cm tijekom 4 sata