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2nd AIAA "Unmanned Unlimited" conference and Workshop and Exhibit 2003

作者： Chen, Won-Zon Portilla, Eric Clough, Bruce Molnar, Thomas J. Northrop Grumman Integrated Syste MS 9L40/W6 El Segundo CA 90245-2804 United States AFRL/VACC WPAFB OH 45433-7542 United States

ISBN: (纸本)9781624100949

Under the USAF-sponsored Autonomous Flight control Sensing Technologies (AFCST) program, Northrop Grumman investigated "see and avoid" (S&A) sensing requirements and preferred system designs along with other military scenarios such as autonomous formation flight and visual landing for future advanced unmanned air vehicles (UAVs). In the first part of this two-paper series, an S&A sensor coverage assessment method and the associated field-of-view (FOV) and time-to-go (TTG) modeling tools as developed are described. In this second part, the use of the coverage models to assess the overall system reliability of a number of sensor system configurations and their cost/benefit trades are discussed. The system reliability analysis method and the knowledge gained as described in the paper are expected to be extremely valuable for specifying and tailoring S&A requirements for operating UAVs safely in FAA-controlled airspace and military theaters. © 2003 by Northrop Grumman.

关键词： systems analysis

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Simulating the ares aircraft in the mars environment

Simulating the ares aircraft in the mars environment

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2nd AIAA "Unmanned Unlimited" conference and Workshop and Exhibit 2003

作者： Sean Kenney, P. Croom, Mark A. Systems Development Branch NASA Langley Research Center Mail Stop 125B Hampton VA 23681 United States Vehicle Dynamics Branch NASA Langley Research Center Mail Stop 153 Hampton VA 23681 United States

ISBN: (纸本)9781624100949

NASA Langley proposed the Aerial Regional-scale Environmental Survey (ARES) of Mars science mission in response to the NASA Office of Space Science 2002 Mars Scout Opportunity. The science-driven mission proposal began with trade studies and determined that a rocket powered aircraft was the best suited platform to complete the ARES science objectives. A high fidelity six degree of freedom flight simulation was required to provide credible evidence that the aircraft design fulfilled mission objectives and to support the aircraft design process by providing performance evaluations. The aircraft was initially modeled using the aero, propulsion, and flight control system components of other aircraft models. As the proposed aircraft design evolved, the borrowed components were replaced with new models. This allowed performance evaluations to be performed as the design was maturing. Basic autopilot features were also developed for the ARES aircraft * Aerospace Engineer, Member AIAA. † ARES Airplane Chief Engineer, Member AIAA model. Altitude hold and track hold modes allowed different mission scenarios to be evaluated for both science merit and aircraft performance. Platform stability and data rate requirements were identified for each of the instruments and the aircraft performance was evaluated against those requirements. The results of the simulation evaluations indicate that the ARES design and mission profiles are sound and meet the science objectives.

关键词： Antennas

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Processing and scheduling components in an innovative network processor architecture 16

Processing and scheduling components in an innovative networ...

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16th International conference on VLSI design/2nd International conference on Embedded systems design

作者： Vlachos, K Nikolaou, N Orphanoudakis, T Perissakis, S Pnevmatikatos, D Kornaros, G Sanchez, JA Konstantoulakis, G Bell Labs at EMEA Lucent Technologies United States Ellemedia Technologies United States Technical University of Crete Greece InAccess Networks Greece

ISBN: (纸本)0769518680

In this paper, we describe the architecture of an innovative network processor aiming at the acceleration of packet processing in high speed network interfaces and at the tight coupling of low and high level protocols. The proposed design uses programmable hard-wired components with line rate throughput and is capable of executing protocols and handling efficiently high and low level streaming operations. We discuss the details of the main innovation of the proposed design, which incorporates a three stage RISC-based pipelined module and a composite scheduling unit for internal resource management and outgoing traffic shaping. When both components are integrated on the same platform then maximum and fair utilization of the available resources is achieved. Quantitative performance results are given, both by means of microcode profiling and simulation for indicative applications of the protocol processor.

关键词： Acceleration Hardware Intelligent networks Job shop scheduling Processor scheduling Protocols Reduced instruction set computing Telecommunication traffic Throughput Traffic control

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See and avoid sensor system design part I - Coverage modeling

See and avoid sensor system design part I - Coverage modelin...

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2nd AIAA "Unmanned Unlimited" conference and Workshop and Exhibit 2003

作者： O'Neil, William F. Chen, Won-Zon Northrop Grumman Integrated Systems MS 9L40/W6 El Segundo CA 90245-2804 United States

ISBN: (纸本)9781624100949

Under the USAF-sponsored Autonomous Flight control Sensing Technologies (AFCST) program, Northrop Grumman investigated "see and avoid" (S&A) sensing requirements and preferred system designs along with other military scenarios such as autonomous formation flight and visual landing for future advanced unmanned air vehicles (UAVs). In this first part of a two-paper series, an S&A sensor coverage assessment method and the associated fieldof- view (FOV) and time-to-go (TTG) modeling tools as developed are described. These modeling tools enable a comprehensive quantitative performance analysis of candidate S&A sensor system designs. The modeling and analysis results obtained for a mid-wave IR sensor and Ka radar show great promises for their S&A applications. The sensors must combine a large FOV with good angular and range resolution to provide for a wide range of encounter scenarios. © 2003 by Northrop Grumman.

关键词： systems analysis

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design of a 2D DCT/IDCT application specific VLIW processor supporting scaled and sub-sampled blocks 16

Design of a 2D DCT/IDCT application specific VLIW processor ...

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16th International conference on VLSI design/2nd International conference on Embedded systems design

作者： Krishnan, R Gangwal, OP von Eijndhoven, J Kumar, A Philips Res Labs Eindhoven Netherlands

ISBN: (纸本)0769518680

We present an, innovative design of an accurate, 2D DCT IDCT processor, which handles scaled and sub-sampled input blocks efficiently. In the IDCT mode, the latency of the processor scales. with the size of the input blocks varying from 7 cycles for an 1x1 block to 38 cycles for an W block. This scalability is possible because the processor has input data dependant control by which it can exploit the reduced computational needs of sub-sampled blocks and blocks of smaller sizes to work in lesser cycles. This is a very useful feature for MPEG and HDTV decoders and has hitherto not been exploited. Clocking at 150 Mhz, the processor satisfies the high sample rate requirement of dual MPEG stream HD decoding with a picture size of 1920 x 1080 at 30 frames per second. Fixed word length and accuracy simulations of our design shows that it conforms to the accuracy specifications of the CCITT standard within a 16 bit data path. A methodology based on architecture level synthesis is used to design the VLIW processor core. The VLIW design exploits the Instruction Level Parallelism present in the DCT/IDCT application, efficiently. The processor core is characterised by an area of 0.834 mm sq. and a frequency of 150 Mhz in 0.18 micron CMOS technology.

关键词： Clocks CMOS technology Decoding Delay Discrete cosine transforms HDTV High definition video Scalability Size control VLIW

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A low-cost and very small wireless terminal integrated on the back of a flat panel array for 26GHz band fixed wireless access systems

A low-cost and very small wireless terminal integrated on th...

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IEEE Topical conference on Wireless Communication Technology/2nd Wireless Grantees Workshop

作者： Miura, Y Shirosaki, T Taniguchi, T Kazama, Y Kimura, Y Hirokawa, J Ando, M Japan Radio Co Ltd Dept Res & Dev Mobile Commun R D Grp Mitaka Tokyo 1818510 Japan

ISBN: (纸本)0780381963

A compact wireless terminal(WT) with a high gain planar array has been developed for the Wireless IP Access System(WIPAS), which is a point-to-multipoint FWA(fixed wireless access) system in 26GHz frequency band. Drastic cost reduction and downsizing are realized by using an alternating phase fed single layer waveguide array antenna and MMIC(Microwave Monolithic IC) technologies. This terminal is 190x190x55mm(3) in volume and less than 2.0kg in weight which accommodates over 31dBi very high efficiency antenna with radome, RF module, IF modules, ASIC(Application Specific IC) for modem, TDMA(Time Division Multiple Access) equipment control, and MAC(Medium Access control). Only an Ethernet cable with 24 DC power supply is attached on the terminal. This paper describes the design of WT with the focus upon the unique antenna and RF module.

关键词： Access control

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An efficient multi-level partitioning algorithm for VLSI circuits 16

An efficient multi-level partitioning algorithm for VLSI cir...

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16th International conference on VLSI design, VLSI 2003 - concurrently with the 2nd International conference on Embedded systems design

作者： Cherng, Jong-Sheng Chen, Sao-Jie Department of Electrical Engineering Da Yeh University Changhwa Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan

ISBN: (纸本)0769518680

In this paper, a new multi-level bipartitioning algorithm MLP, which integrates a clustering technique and an iterative improvement based partitioning process, is proposed to enhance the stability and the quality of partitioning results. The proposed clustering algorithm is used to reduce the partitioning complexity and improved the performance of partitioning. To generate a high-quality partitioning solution, a module migration based partitioning algorithm MMP is also proposed as the based partitioner for the MLP algorithm. The MMP algorithm implicitly promotes the move of clusters during the module migration processes by paying more attention to the neighbors of moved modules, relaxing the size constraints temporarily during the migration process, and controlling the module migration direction. Experimental results obtained show that the MLP algorithm generates high-quality partitioning results. The MLP algorithm outperforms MELO and CDIPLA3 by 23% and 10%, respectively and is competitive with hMetis and MLc which have generated better results than many recent state-of-the-art partitioning algorithms. © 2003 IEEE.

关键词： Process control

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RChord: An enhanced chord system resilient to routing attacks

RChord: An enhanced chord system resilient to routing attack...

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2nd International conference on Computer Networks and Mobile Computing

作者： Xuan, D Chellappan, S Krishnamoorthy, M Ohio State Univ Dept Comp & Informat Sci Columbus OH 43210 USA

ISBN: (纸本)0769520332

In this paper, we propose a variant of Chord system that is resilient to routing attacks. By routing attacks, we mean the attacks which detour the looking up messages, aiming to disrupt the performance of data look-up systems by increasing the path length of queries. Chord routes messages uni-directionally and has no bi-directional edges. While its performance in the absence of routing attacks is acceptable, it degrades dramatically under routing attacks. Following this observation, we introduce the concept of reverse edges to the Chord system. We named the new Chord system as RChord. We propose several deterministic and randomized algorithms to construct reverse edges. We design a routing algorithm for the new system, which is simple, efficient and backward compatible with the original system. We then analyze the performance of the RChord under routing attacks. We find that its performance is significantly improved in terms of average path length, even by adding very few reverse edges.

关键词： Algorithm design and analysis Bidirectional control Degradation Electronic mail Information science Internet Peer to peer computing Performance analysis Resilience Routing

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2nd International Workshop on Self-Adaptive Software, IWSAS 2001

2nd International Workshop on Self-Adaptive Software, IWSAS ...

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2nd International Workshop on Self-Adaptive Software, IWSAS 2001

ISBN: (纸本)3540007318

The proceedings contain 20 papers. The special focus in this conference is on Self-Adaptive Software. The topics include: Introduction to self-adaptive software;managing online self-adaptation in real-time environments;an approach to self-adaptive software based on supervisory control;constraint-guided self-adaptation;model-based adaptivity in real-time scheduling;adaptive agent based system for state estimation using dynamic multidimensional information sources;confidence from self-knowledge and domain knowledge;FDTS in self-adaptive protocol specification;frame-based self-adaptive test case selection;model-based diagnosis for information survivability;exercising qualitative control in autonomous adaptive survivable systems;dynamic change in workflow-based coordination of distributed services;a smart spell checker system implementation using adaptive software architecture;design principles for resource management systems for intelligent spaces;adaptivity in agent-based systems via interplay between action selection and norm selection;probabilistic dispatch, dynamic domain architecture, and self-adaptive software;a cybernetic perspective of self-adaptive software and results of the second international workshop on self-adaptive software.

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Minimum Time PD-controller design

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ifac Proceedings Volumes 2003年第18期36卷 65-70页

作者： Mikuláš Huba Pavol Bisták Slovak University of Technology in Bratislava Faculty of Electrical Eng. and Information Technology Ilkovičova 3 812 19 Bratislava Slovakia

This work deals with the minimum time sampled-data control algorithms for linear 2nd order systems. Based on the general theory (Desoer and Wing, 1961) and its modification for the non-symmetrical amplitude constraints and the fully digital implementation (Huba, 1992), it is focused to the control processes having more than one sign variation of the optimal control. A till now unknown non-uniqueness of the optimal control arising at specific sampling periods in systems with complex poles is analyzed and possibilities for further simplification of the minimum time (pole assignment) control are shown.

关键词： control system design minimum time control optimal control saturation

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