53235297
A monolithic CMOS L band DAB receiver
10474493
Calculation of intermodulation distortion in CMOS transconductance stage
The linearity of the transconductance stage is of major concern in the design of some analog circuits. In this paper, Volterra series expansion is used to compute the intermodulation distortion of high frequency CMOS transconductance stage with source degeneration resistor. The MOS model used in this paper includes short-channel effects and gate-source capacitance, gate-drain capacitance, and output resistance of the MOS transistor. Analytical results are compared with simulation results and the influences of circuit parameters on circuit linearity are discussed.
6531657
A new high gain low voltage 1.45 GHz CMOS mixer
A new architecture of CMOS downconversion mixer for low voltage and high gain communication applications is proposed. This topology avoids the stacking of transistors between the power and ground lines, thus it can work on a low supply voltage. It does not need inductors, so it is relatively easy to fabricate. This mixer is implemented using a 0.25 /spl mu/m CMOS technology with supply voltage of 2 V. With 1.452 GHz LO input and 1.45 GHz RF input, simulation result show that the conversion gain is 15 dB, IIP3 is -4.5 dBm, noise figure is 17 dB, the maximum transient power dissipation is 9.3 mW and DC power dissipation is 9.2 mW. The mixer's noise and linearity analyses are also presented.
13426917
Dependable Dynamic Service Integration on Service-Oriented Peer-to-Peer Networks
For provision of dependable search and rescue capability in dynamic and unpredictable disaster areas, the networked nodes should have the ability to autonomously support and co-operate with each other in a peer-to-peer (P2P) manner to quickly configure any services available on the disaster area to deliver a real-time capability. In this paper, we present an innovative architectural approach which is able to proactively self-diagnose and self-adapt evolution occurring in provision of search and rescue capabilities in service-oriented P2P (ServP2P) networks. This architecture provides flexibility and agility in handling dynamic changes and evolution encountered in the delivery of rescue capability. The experimental results indicate that the proposed approach provides a high-level of reliability and sustainability to achieve dependable service integration for capability provision.
7638849
Efficient and scalable search on scale-free P2P networks
Unstructured peer-to-peer (P2P) systems (e.g. Gnutella) are characterized by uneven distributions of node connectivity and file sharing. The existence of “hub” nodes that have a large number of connections and “generous” nodes that share many files significantly influences performance of information search over P2P file-sharing networks. In this paper, we present a novel Scalable Peer-to-Peer Search (SP2PS) method with low maintenance overhead for resource discovery in scale-free P2P networks. Different from existing search methods which employ one heuristic to direct searches, SP2PS achieves better performance by considering both of the number of shared files and the connectivity of each neighbouring node. SP2PS enables peer nodes to forward queries to the neighbours that are more likely to have the requested files and also can help in finding the requested files in the future hops. The proposed method has been simulated in different power-law networks with different forwarding degrees and distances. From our analytic and simulation results, SP2PS achieves better performance when compared to other related methods.
14631888
An automatic approach to integrate routing-relevant information from different resources
With the growing demand on multi-purpose or multi-modal navigation, the route calculation becomes more and more complex. The currently operational route planning algorithms reveal rather limited performances due to unavailable or insufficient interoperation among the underlying datasets that are separately maintained in different spatial databases. This paper introduces an operational approach to integrate routing-relevant information from different data sources. It involves three processes: (a) automatic matching to identify the corresponding road objects between different datasets; (b) interaction to refine the result of automatic matching; and (c) transferring the routing-relevant information from one dataset to another. In process (a), our Delimited Stroke Oriented (DSO) algorithm is employed to achieve the automatic data matching. It has revealed a high matching rate and certainty. However uncertain matching problems occur in areas where topological conditions are too complicated or inconsistent. The remaining unmatched or wrongly matched objects are treated in process (b) with the help of a series of our interaction tools plugged in Arc GIS 9.0. On the basis of the refined matching results, process (c) is dedicated to automatic integration of the routing-relevant information from different data sources. In large test areas from a number of federal states in Germany, the proposed automatic approach has been successfully applied to transfer the routing-relevant information from the dataset of Tele Atlas to DLM De. The enriched DLM De thus gains added value for route calculations.
41392373
Small-World Peer-to-Peer for Resource Discovery
Small-world phenomenon is potentially useful to improve the performance of resource discovery in decentralized peer-to-peer (P2P) networks. The theory of small-world networks can be adopted in the design of P2P networks: each peer node is connected to some neighbouring nodes, and a group of peer nodes keep a small number of long links to randomly chosen distant peer nodes. However, current unstructured search algorithms have difficulty distinguishing among these random long-range shortcuts and efficiently finding a set of proper long-range links located in itself or its local group for a specific resource search. This paper presents a semi-structured P2P model to efficiently create and find long-range shortcuts toward remote peer groups.
13366067
Tarsal and Metatarsal Bone Mineral Density Measurement Using Volumetric Quantitative Computed Tomography
A new method for measuring bone mineral density (BMD) of the tarsal and metatarsals is described using volumetric quantitative computed tomography (VQCT) in subjects with diabetes mellitus and peripheral neuropathy. VQCT images of a single foot were acquired twice from eight subjects (mean age 51 [11 SD], seven males, one female). The cortical shells of the seven tarsal and five metatarsal bones were identified and semiautomatically segmented from adjacent bones. Volume and BMD of each bone were measured separately from the two acquired scans for each subject. Whole-bone semiautomatic segmentation measurement errors were determined as the root mean square coefficient of variation for the volume and BMD of 0.8% and 0.9%, respectively. In addition to the whole-bone segmentation methods, we performed atlas-based partitioning of subregions within the second metatarsal for all subjects, from which the volumes and BMDs were obtained for each subregion. The subregion measurement BMD errors (root mean square coefficient of variation) within the shaft, proximal end, and distal end were shown to vary by approximately 1% between the two scans of each subject. The new methods demonstrated large variations in BMDs between the 12 bones of the foot within a subject and between subjects, and between subregions within the second metatarsal. These methods can provide an important outcome measure for clinical research trials investigating the effects of interventions, aging, or disease progression on bone loss, or gain, in individual foot bones.