| 1. |
- Zheng, Lirong, et al.
(författare)
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Photocatalytic activity of ZnO/Sn1-xZnxO2-x nanocatalysts : A synergistic effect of doping and heterojunction
- 2014
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Ingår i: Applied Catalysis B. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 148, s. 44-50
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Tidskriftsartikel (refereegranskat)abstract
- A novel configuration of porous ZnO/Sn1-xZnxO2-x, heterojunction nanocatalyst with high photocatalytic activity was successfully synthesized through a simple two-step solvothermal method. Porous Sn1-xZnxO2, was synthesized from Zn2+ and Sn4+ precursors with the Zn/Sn ratio of 2:1 in the absence of alkali, and then intermolecular dehydrolysis led to the formation of heterointerface between Sn1-xZnxO2, and ZnO. The results show that Zn2+ doping exhibits a significant influence on particle size of SnO2 leading to much higher specific surface area and larger band gap, which is in favor of the photocatalytic activity of SnO2 under UV light irradiation. In addition, the formation of ZnO/Sn1-xZnxO2 heterostructure improves the separation of photogenerated electron hole pairs due to the potential difference between Sn1-xZnxO2, and ZnO, which also benefits to photocatalysis. By taking account of them together, these results provide further insight into the synergistic effects of metal ion doping and semiconductor/semiconductor heterostructure on the activity of photocatalysts in environmental remediation applications. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Liu, Zhiying, et al.
(författare)
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Solution-Processable Nanotube/Polymer Composite for High-Performance TFTs
- 2011
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 32:9, s. 1299-1301
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Tidskriftsartikel (refereegranskat)abstract
- Thin-film field-effect transistors (TFTs) are readily fabricated using a semiconductor composite that is solution processed under ambient conditions for the conduction channel. The composite comprises single-walled carbon nanotubes (SWCNTs) embedded in poly-9,9' dioctyl-fluorene-co-bithiophene. Carrier mobility values approaching 10 cm(2)V(-1)s(-1) are obtained for the composite with relatively high SWCNT concentrations. When the SWCNT concentration is reduced for a large ON/OFF current ratio > 10(6), the mobility remains decent around 0.3 cm(2)V(-1)s(-1). The resultant TFTs display remarkable environmental and operational reliability. Nanotube-based composites are therefore of significance in printed electronics owing to their simplicity in device fabrication and competitiveness in device performance.
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| 3. |
- Yang, Geng, et al.
(författare)
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A Health-IoT Platform Based on the Integration of Intelligent Packaging, Unobtrusive Bio-Sensor, and Intelligent Medicine Box
- 2014
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Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE. - 1551-3203 .- 1941-0050. ; 10:4, s. 2180-2191
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Tidskriftsartikel (refereegranskat)abstract
- In-home healthcare services based on the Internet-of-Things (IoT) have great business potential; however, a comprehensive platform is still missing. In this paper, an intelligent home-based platform, the iHome Health-IoT, is proposed and implemented. In particular, the platform involves an open-platform-based intelligent medicine box (iMedBox) with enhanced connectivity and interchangeability for the integration of devices and services; intelligent pharmaceutical packaging (iMedPack) with communication capability enabled by passive radio-frequency identification (RFID) and actuation capability enabled by functional materials; and a flexible and wearable bio-medical sensor device (Bio-Patch) enabled by the state-of-the-art inkjet printing technology and system-on-chip. The proposed platform seamlessly fuses IoT devices (e. g., wearable sensors and intelligent medicine packages) with in-home healthcare services (e. g., telemedicine) for an improved user experience and service efficiency. The feasibility of the implemented iHome Health-IoT platform has been proven in field trials.
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| 4. |
- Zhu, Zikai, et al.
(författare)
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Using a VAE-SOM architecture for anomaly detection of flexible sensors in limb prosthesis
- 2023
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Ingår i: Journal of Industrial Information Integration. - : Elsevier BV. - 2452-414X .- 2467-964X. ; 35
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Tidskriftsartikel (refereegranskat)abstract
- Flexible wearable sensor electronics, combined with advanced software functions, pave the way toward increasingly intelligent healthcare devices. One important application area is limb prosthesis, where printed flexible sensor solutions enable efficient monitoring and assessing of the actual intra-socket dynamic operation conditions in clinical and other more natural environments. However, the data collected by such sensors suffer from variations and errors, leading to difficulty in perceiving the actual operational conditions. This paper proposes a novel method for detecting anomalies in the data that are collected for measuring the intra-socket dynamic operation conditions by printed flexible wearable sensors. A discrete generative model based on Variational AutoEncoder (VAE) is used first to encode the collected multi-variant time-series data in terms of latent states. After that, a clustering method based on the Self-Organizing Map (SOM) is used to acquire discrete and interpretable representations of the VAE encoded latent states. An adaptive Markov chain is utilized to detect anomalies by quantifying state transitions and revealing temporal dependencies. The contributions of the proposed architecture conclude as follows: (1) Using the VAE-SOM hybrid model to regularize the continues data as discrete states, supporting interpreting the operational data to analytic models. (2) Employing adaptive Markov chains to generalize the transitions of these states, allowing to model the complex operational conditions. Compared with benchmark methods, our architecture is validated via two public datasets and achieves the best F1 scores. Moreover, we measure the run-time performance of this lightweight architecture. The results indicate that the proposed method performs low computational complexity, facilitating the applications on real-life productions.
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| 5. |
- Zou, Zhuo, et al.
(författare)
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An efficient passive RFID system for ubiquitous identification and sensing using impulse UWB radio
- 2007
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Ingår i: Elektrotechnik und Informationstechnik. - : Springer Science and Business Media LLC. - 0932-383X. ; 124:11, s. 397-403
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Tidskriftsartikel (refereegranskat)abstract
- The next generation RFID system for ubiquitous identification and sensing requires both energy and system efficiency. This paper describes an efficient passive RFID system using impulse ultra-wideband radio (IR-UWB), at a 10 m operation range. Unlike conventional passive RFID systems which rely on backscatter and narrowband radio, IR-UWB is introduced as the uplink (communication from a tag to a reader). By utilizing a specialized communication protocol and a novel ALOHA-based anti-collision algorithm, such semi-UWB systems enable a high network throughput (2000 tag/sec) under the low power and low cost constraint. A low power tag design for proof of concept is finally presented.
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| 6. |
- Ahmad, Waqar, et al.
(författare)
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Decoupling capacitance for the power integrity of 3D-DRAM-over-logic system
- 2012
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Ingår i: IEEE 13th Electronics Packaging Technology Conference (EPTC), 2011. - : IEEE conference proceedings. - 9781457719813 ; , s. 590-594
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Konferensbidrag (refereegranskat)abstract
- The 3D-DRAM stacked over the processor is a vibrant technique in order to overcome the memory wall as well as the bandwidth wall problems. We considered a system with two DRAM dies over a single processor die. We assumed the decoupling capacitors to be placed on each DRAM die and connected to the power distribution TSV pairs, where the TSVs pass through the DRAM stack. In this paper we proposed a mathematical model for the optimum value of the decoupling capacitance on each DRAM die along with the optimum values of the effective resistance of the interconnecting power distribution TSV pairs in order to ensure the power integrity of the logic load during switching. The proposed model has a maximum of 1.1% error as compared to the Ansoft Nexxim4.1.
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| 7. |
- Ahmad, Waqar, et al.
(författare)
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Fast Transient Simulation Algorithm for a 3D Power distribution Bus
- 2010
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Ingår i: Proceedings of IEEE Asia Symposium on Quality Electronic Design. ; , s. 343-350
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Konferensbidrag (refereegranskat)abstract
- Extensive transient simulations for on-chip power delivery networks are required to analyze power delivery fluctuations caused by dynamic IR and Ldi/dt drops. Speed and memory has become a bottleneck for simulation of power distribution networks in modern VLSI design where clock frequency is of the order of GHz. The traditional SPICE based tools are very slow and consume a lot of memory during simulation. The problem is further aggravated for huge networks like power distribution network within a stack of ICs inter-connected through TSVs. This type of 3D power distribution network may contain billions of nodes at a time. In this paper we proposed a faster transient simulation algorithm using visual C++. First we reduce 3D power distribution bus containing n nodes to a two terminal 7 network. Then we solve this two terminal reduced network for voltages and currents. After this, we apply back solving algorithm to the network to solve it for each of the intermediate nodes using visual C++. The proposed algorithm is quite accurate with 1-2% error when compared with Ansoft Nexxim4.1. The proposed algorithm is several times faster than Ansoft Nexxim as well as consumes significantly less memory as compared to Nexxim.
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| 8. |
- Ahmad, Waqar, et al.
(författare)
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Peak-to-peak Switching Noise and LC Resonance on a Power Distribution TSV Pair
- 2010
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Ingår i: 2010 IEEE 19th Conference on Electrical Performance of Electronic Packaging and Systems, EPEPS 2010. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 173-176
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Konferensbidrag (refereegranskat)abstract
- How peak-to-peak switching noise as well as the LC resonance term varies by varying different circuit parameters of a power distribution TSV pair (having decoupling capacitance and logic load), within a 3D stack of ICs interconnected through TSVs.
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| 9. |
- Ahmad, Waqar, et al.
(författare)
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Power distribution TSVs induced core switching noise
- 2011
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Ingår i: Electrical Design of Advanced Packaging & Systems Symposium (EDAPS), 2010 IEEE. - : IEEE conference proceedings. - 9781424490691
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Konferensbidrag (refereegranskat)abstract
- Size of on-chip interconnects as well as the supply voltage is reducing with each technology node whereas the operating speed is increasing in modern VLSI design. Today, the package inductance and resistance has been reduced to such an extent that core switching noise caused by on-chip inductance and on-chip resistance is gaining importance as compared to I/O drivers switching noise. Both on-chip inductance and skin effect are prime players at frequencies of the order of GHz. The problem is further aggravated when chips are interconnected through TSVs to form a 3D integrated stack in order to achieve low form factor and high integration density. In this paper we analysed peak core switching noise in a 3D stack of integrated chips interconnected through power distribution TSV pairs, through our comprehensive mathematical model which has been proved to be quite accurate as compared to SPICE. We analysed the effect of number of chips in a 3D stack, rise time, decoupling capacitance, and skin effect on power distribution TSVs induced core switching noise in this paper.
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| 10. |
- Amin, Yasar, et al.
(författare)
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Blueprint and integration of vastly efficient 802.11A WLAN front-end
- 2006
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Ingår i: WSEAS Transactions on Electronics. - 1109-9445. ; 3:4, s. 258-261
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Tidskriftsartikel (refereegranskat)abstract
- Next generation wireless communications terminals will demand the use of advanced component integration processes and high density packaging technologies in order to reduce size and to increase performance. This paper presents high density multilayer interconnects and integrated passives used to design high performance prototype filter for 5GHz wireless LAN receiver realized on MCM-D substrate. The thin film implementation of Multichip Module technology is identified as a useful platform for the integration of GaAs MMIC and silicon device technologies for microwave applications where performance, size and weight are critical factors. The ability of the MCM-D technology to provide controlled impedance, microstrip structures and integrated thin film passive components with useful performance in the microwave frequency regime has now been demonstrated.
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