| 1. |
- Andrae, Anders, 1973, et al.
(författare)
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Uncertainty estimation by Monte Carlo simulation applied to life cycle inventory of cordless phones and microscale metallization processes
- 2004
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Ingår i: IEEE transactions on electronics packaging manufacturing (Print). - 1521-334X .- 1558-0822. ; 27:4, s. 233-245, s. 206-217
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Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on uncertainty analysis, that is, how the input data uncertainty affects the output data uncertainty in small but realistic product systems. The motivation for the study is to apply the Monte Carlo simulation for uncertainty estimation in life cycle inventory and environmental assessment of microelectronics applications. The present paper addresses the question whether there is an environmental advantage of using digital enhanced cordless telecommunications (DECT) phones instead of global system for mobile (GSM) phones in offices. This paper also addresses the environmental compatibility of electrochemical pattern replication (ECPR) compared to classical photolithography-based microscale metallization (CL) for pattern transfer. Both environmental assessments in this paper consider electricity consumption and CO2 emissions and the projects undertaken are two comparative studies of DECT phone/GSM phone and ECPR/CL, respectively. The research method used was probabilistic uncertainty modeling with a limited number of inventory parameters used in the MATLAB tool. For the DECT/GSM study the results reflects the longer DECT technical life which is an environmental advantage. For the electrochemical pattern replication (ECPR)/classical photolithography based microscale metallization (CL) study the results reflects the fewer number of process steps and the lower electricity consumption needed by the ECPR to reach the functional unit. The difference in results is large enough to be able to draw conclusions, as the processes, having the highest electricity consumption within the system boundaries have been determined. Based on an earlier work, a straightforward method to include uncertainty for input life cycle inventory data is used to quantify the influence of realistic errors for input data in two microelectronic applications. The conclusion is that the ECPR technology is more electricity efficient than CL in producing one layer of copper on a silicon wafer having a diameter of 20.32 cm. Furthermore, the longer technical life of a cordless DECT phone is reflected in an electricity/CO2 comparison with a GSM phone, if office use is considered. Reasonable uncertainty intervals, used for the input life cycle inventory data for the studied DECT/GSM and ECPR/CL system, does affect the outcome of calculation of emission of CO2, but not to the degree that conclusions are not valid. Different uncertainty intervals and probability distributions could apply for different types of data and the interrelated input data dependencies should be investigated. Today there exist very few life cycle inventory (LCI) data with the range of uncertainty for input and output elements. It must be emphasized that the upcoming LCI databases should have standard deviation characterized LCI data just as the Swiss ecoinvent LCI database. More inventory parameters and probability distributions characteristic for microsystems could be included and error analysis should be applied to future life inventory methodology, especially for future packaging concepts such as system-in-a-package and system-on-a-chip comparisons.
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| 2. |
- Andrae, Anders, 1973, et al.
(författare)
-
Uncertainty estimation by Monte Carlo Simulation applied to Life Cycle Inventory of Cordless Phones and Microscale Metallization Processes
- 2004
-
Ingår i: IEEE Transactions on Electronics Packaging Manufacturing. ; 27:4, s. 233-245
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on uncertainty analysis, that is, how the input data uncertainty affects the output data uncertainty in small but realistic product systems is modeled. The motivation for the study is to apply the Monte Carlo simulation for uncertainty estimation in life cycle inventory and environmental assessment of microelectronics applications. This paper addresses the question whether there is an environmental advantage of using DECT phones instead of GSM phones in offices. The paper also addresses the environmental compatibility of Electrochemical Pattern Replication (ECPR) compared to classical photolithography based microscale metallization (CL) for pattern transfer. Both environmental assessments in this paper consider electricity consumption and CO2 emissions. The projects undertaken are two comparative studies of DECT phone/GSM phone and ECPR/CL respectively. The research method used was probabilistic uncertainty modelling with a limited number of inventory parameters used in the MATLAB tool. For the DECT/GSM study the results reflects the longer DECT technical life which is an environmental advantage. For the Electrochemical Pattern Replication (ECPR)/classical photolithography based microscale metallization (CL) study the results reflects the fewer number of process steps and the lower electricity consumption needed by the ECPR to reach the functional unit. The difference in results is large enough to be able to draw conclusions, as the processes with the highest electricity consumption within the system boundaries have been determined. Based on earlier work a straightforward method to include uncertainty for input life cycle inventory data is used to quantify the influence of realistic errors for input data in two microelectronic applications. The conclusion is that the ECPR technology is more electricity efficient than CL in producing one layer of copper on a silicon wafer having a diameter of 20.32 cm. The conclusion is that the longer technical life of a cordless DECT phone is reflected in an electricity/CO2 comparison with a GSM phone, if use in an office is considered. Reasonable uncertainty intervals used for the input life cycle inventory data for the studied DECT/GSM and ECPR/CL system does affect the outcome of calculation of emission of CO2 but not to the degree that conclusions are not valid.Different uncertainty intervals and probability distributions could apply for different types of data and the interrelated input data dependence should be investigated. Today there exist very few life cycle inventory (LCI) data with the range of uncertainty for input and output elements. It must be emphasized that the upcoming LCI databases should have standard deviation characterized LCI data just as the Swiss ecoinvent LCI database.More inventory parameters and probability distributions characteristic for microsystems could be included and error analysis should be applied to future life inventory methodology, especially for future packaging concepts such as System-In-a-Package and System-On-a-Chip comparisons.
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| 3. |
- Möller, Niels, et al.
(författare)
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Supporting end-to-end applications over HSDPA by cross-layer signalling
- 2007
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Ingår i: IEEE WIRELESS COMMUNICATIONS & NETWORKING CONFERENCE, VOLS 1-9. - NEW YORK : IEEE. - 9781424406586 ; , s. 3858-3863
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Konferensbidrag (refereegranskat)abstract
- A new control structure is proposed to improve user experience of wireless Internet. Information on radio bandwidth and queue length available in the radio network, close to the base station, is used in a proxy that resides between the Internet and the cellular system. The control algorithm in the proxy sets the window size according to event-triggered information on radio bandwidth changes and time-triggered information on the queue length at the wireless link. The mechanism is compared to TCP Reno in two simulation scenarios. The first scenario models a dedicated channel with stepwise changes in the bandwidth, while the second scenario models the High-speed Downlink Shared Channel recently introduced by 3GPP. The proposed mechanism significantly reduces the amount of buffer space needed in the radio network, and it also gives modest improvements to user response time and link utilization. Reduced buffering is particularly beneficial for third-party end-to-end real-time services such as voice, video, and online gaming.
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| 4. |
- Novac, Bucur M., et al.
(författare)
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A 10-GW pulsed power supply for HPM sources
- 2006
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Ingår i: IEEE TRANS PLASMA SCI. ; , s. 1814-1821
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Konferensbidrag (refereegranskat)abstract
- A research activity involving the detailed consideration of novel high-voltage transformers for pulsed-power applications has recently begun at Loughborough University. Although the main goal is the demonstration of a compact and lightweight unit employing magnetic insulation under vacuum conditions, the initial stage of the work is directed toward the development of a conventional air-cored transformer as a main component in a compact power supply for high power microwave sources. In cooperation with the Swedish Defence Research Agency (FOI), the power supply has been tested with a microwave source of the vircator type. The power generator for the system uses a 70-kJ/25-kV capacitor bank and an exploding wire array to generate a 150-kV voltage pulse in the primary circuit of a transformer. A pressurized SF6 spark gap in the secondary circuit sharpens the high-voltage output so that pulses approaching 500 kV and with a rise time well below 100 ns are generated on a 20-Omega high-power resistors With the peak power in excess of 10 GW. Experimental results are presented from final testing of the system, where a reflex triode vircator replaces the 20-Omega resistor. Measurements of the microwave emission using free-field sensors are presented, and comments are made with the microwave emission from the same vircator when powered by a Marx generator at FOI.
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