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Modeling of state of vegetation and soil erosion over large areas

International Journal of Sediment research 2008年第3期23卷 181-196页

作者： Zhao-Yin WANG1*, Guangqian WANG2, and Guohe HUANG31 Prof., State Key Laboratory of Hydroscience and engineering, Tsinghua University, Beijing 100084, China2 Prof., State Key Laboratory of Hydroscience and engineering, Tsinghua University, Beijing 100084, China3 Prof. and Canada research Chair, Environmental systems engineering program, Faculty of engineering, University of Regina, Regina, Sask S4S 0A2, Canada [a]Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China [b]Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Tel: 86-10-62781748 Fax: 86-10-62772463 [c]Prof. and Canada Research Chair Environmental Systems Engineering Program Faculty of Engineering University of Regina Regina Sask S4S 0A2 Canada

A vegetation-erosion model was developed to assess the extent of soil erosion and development trend of vegetation in the context of existing and contemplated vegetation-based soil erosion controls under different climatic, topographical and soil conditions. The model recognizes four vegetation-mediated soil erosion states: (i) an expanding vegetation coverage coupled with reduced erosion (C), (ii) a deteriorating vegetation coverage coupled with increased erosion (A), (iii) two transitional states between A and C, one with increasing erosion and vegetation coverage (B) and the other with decreasing erosion and vegetation coverage (D). With the model, the vegetation-erosion state of any particular area can be quantitatively described, by way of a vegetation-erosion chart, for varying climate, soil and topographic conditions, as demonstrated for the Xishan region, the East River basin, the Wangjiagou and Anjiagou watersheds (Loess Plateau), and the Xiaojiang watersheds (hot and dry valleys in the upper Yangtze River basin) in China. This paper presents the principles and results of area-specific investigations that track the fractions of the areas covered by vegetation and experiencing soil erosion (with soil loss determined in t/km2yr). This is done within the context of local soil erosion control initiatives via re-vegetation efforts, or the lack thereof, over the course of 30 years. The effectiveness of reforestation and erosion-control measures vary under different climatic, topographical and soil conditions. The vegetation may be quickly restored in the hot and wet East River basin but is very difficult on the dry and cold Loess Plateau. In the hot and dry valleys the vegetation can be restored if erosion is controlled and intensive reforestations for small watersheds are performed.

关键词： Soil erosion Vegetation coverage Loess Plateau Vegetation-erosion chart Reforestation

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Selective Attention in Normal and Impaired Hearing

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Trends in Amplification 2008年第4期12卷 283-299页

作者： Shinn-Cunningham, Barbara G. Best, Virginia Hearing Research Center Departments of Cognitive and Neural Systems and Biomedical Engineering Boston University Boston United States Speech and Hearing Bioscience and Technology Program Harvard-MIT Division of Health Sciences and Technology Cambridge Massachusetts United States University of Sydney Sydney Australia

A common complaint among listeners with hearing loss (HL) is that they have difficulty communicating in common social settings. This article reviews how normal-hearing listeners cope in such settings, especially how they focus attention on a source of interest. Results of experiments with normal-hearing listeners suggest that the ability to selectively attend depends on the ability to analyze the acoustic scene and to form perceptual auditory objects properly. Unfortunately, sound features important for auditory object formation may not be robustly encoded in the auditory periphery of HL listeners. In turn, impaired auditory object formation may interfere with the ability to filter out competing sound sources. Peripheral degradations are also likely to reduce the salience of higher-order auditory cues such as location, pitch, and timbre, which enable normal-hearing listeners to select a desired sound source out of a sound mixture. Degraded peripheral processing is also likely to increase the time required to form auditory objects and focus selective attention so that listeners with HL lose the ability to switch attention rapidly (a skill that is particularly important when trying to participate in a lively conversation). Finally, peripheral deficits may interfere with strategies that normal-hearing listeners employ in complex acoustic settings, including the use of memory to fill in bits of the conversation that are missed. Thus, peripheral hearing deficits are likely to cause a number of interrelated problems that challenge the ability of HL listeners to communicate in social settings requiring selective attention. © 2008, SAGE Publications. All rights reserved.

关键词： attention auditory object auditory scene analysis segregation

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Streamflow scaling properties: investigating characteristic scales from different statistical approaches (vol 22, pg 3462, 2008)

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HYDROLOGICAL PROCESSES 2008年第24期22卷 4802-4802页

作者： Sauquet, Eric Ramos, Maria-Helena Chapel, Laetitia Bernardara, Pietro Cemagref Hydrology - Hydraulics Research Unit 3 bis quai Chauveau CP220 69336 Lyon cedex 09 France Cemagref Laboratory of Engineering for Complex Systems 24 avenue des Landais BP 50085 63172 Aubière cedex 1 France Laboratoire National d'Hydraulique et Environnement d'EDF R&D 6quai Watier 78401 CHATOU Cedex France

This paper studies the links between scaling properties of river flow time series by comparing the results of three techniques applied to an extended data set of 34 French discharge gauging stations. The three approaches used are based on different mathematical tools and hypotheses: (1) shape analysis of flood hydrographs; (2) a multifractal framework through spectral and moment analyses, and (3) flood frequency analysis through the fitting of flood duration frequency curves (QdF). The general aim is to test the hypothesis of scaling invariance of river flow and the shape invariance of the hydrographs, in order to investigate the link between scaling properties and flow dynamics. In particular, the coherence between different approaches widely used in the literature to describe these characteristics is evaluated through the estimation of parameters defining the range of time-scales on which the scaling properties are valid. The results show that most of these timescale parameters are linked to the flow dynamics and suggest that the approaches applied are interrelated.

关键词： time-scale hydrograph shape invariance multifractal analysis flood-frequency-duration curve

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Model-Based Predictive Control of an Electro-Pneumatic Exhaust Valve for Internal Combustion Engines

Model-Based Predictive Control of an Electro-Pneumatic Exhau...

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2008 American Control Conference (ACC), vol.4

作者： Jia Ma Guoming Zhu Andrew Hartsig Harold Schock Delphi Communications Systems Inc. USA Mechanical Engineering Engineering Research Complex South Michigan State University East Lansing MI USA

Variable valve actuation of Internal Combustion (IC) engines is capable of significantly improving their performance. Variable valve actuation can be divided into two main categories: variable valve timing with cam shaft(s) and camless valve actuation. For camless valve actuation, research has been centered in electro-magnetic, electro-hydraulic, and electro-pneumatic valve actuators. This research studies the control of the electro-pneumatic valve actuator. The modeling and control of intake valves for the Electro-Pneumatic Valve Actuators (EPVA) was shown in early publications and this paper extends the EPVA modeling and control development to exhaust valves for both valve timing and lift control. The control strategy developed utilizes model-based predictive techniques to overcome the randomly variable in-cylinder pressure against which the exhaust valve opens.

关键词： Predictive models Predictive control Valves Internal combustion engines Electric variables control Timing Open loop systems Actuators Pressure control Mechanical variables control

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Development of product model management system for naval shipbuilding

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Journal of Ship Production 2008年第2期24卷 82-91页

作者： Oh, Dae Kyun Jeong, Yeon Hwan Kim, Yong Gyun Shin, Jong Gye Yeo, Yong Hwan Ryu, Cheolho Department of Naval Architecture and Ocean Engineering Seoul National University Seoul Korea Republic of LTCD Republic of Korea Navy Jinhae Korea Republic of Xinnos Co. Seoul Korea Republic of Research Institute of Marine Systems Engineering Department of Naval Architecture and Ocean Engineering Seoul National University Seoul Korea Republic of CDMR Korea Defense Acquisition Program Administration Office Republic of Korea Navy Seoul Korea Republic of Department of Naval Architecture and Ocean Engineering Inha University Incheon Korea Republic of

Since the concept of integrated product development environment (IPDE) was introduced from the US Department of Defense, the Korean navy has made efforts to apply the concept to its naval design and production. Recently, the Korean navy has supported a project for naval shipbuilding to achieve the advanced defense acquisition program. This project focuses on the integration of naval shipbuilding information. The Product Model Management System (PMMS) for Korean naval acquisition was a partial result of the project. The architecture of PMMS and the product structure of a naval ship are proposed in this paper. Also, the data acquisition process among acquisition program administration offices and contractors is defined for the construction of three-dimensional naval ship product models in PMMS. By constructing the product model on previous Korean naval ships, the PMMS was confirmed to a suitable innovative acquisition strategy. PMMS is on the leading edge of new product and process innovations in the Korean naval shipbuilding.

关键词： Product design

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Fuzzy identification of dynamic systems with adaptive structure

Fuzzy identification of dynamic systems with adaptive struct...

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IEEE SSD International Multi-Conference on systems, Signals and Devices

作者： Sonia Alimi Mohamed Chtourou Research unit on Intelligent Control design and Optimization of complex Systems (lCOS) Department of Electrical Engineering National School of Engineers of Sfax Sfax Tunisia

This paper deals with two approaches for on line structure identification of fuzzy models. In the first one, a constructive algorithm is adopted to generate the fuzzy rules: it starts with a single pattern and a single fuzzy rule and grows progressively to reduce the system error within the specified tolerance. In the second one, an evolutionary algorithm is applied based on an alternation between incremental and pruning criteria. Indeed, the rule base is expanded when the model can not reduce the system error and one rule is removed if it has a petty contribution in the model output along some patterns. The presented approaches have been applied for two examples of dynamic systems to compare the identification performance.

关键词： Mathematical model Training Adaptation model Evolution (biology) Equations Heuristic algorithms Artificial neural networks

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Spike-based acoustic signal processing chips for detection and localization

Spike-based acoustic signal processing chips for detection a...

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IEEE Biomedical Circuits and systems (BIOCAS)

作者： Hisham Abdalla Timothy K. Horiuchi Electrical and Computer Engineering Department Institute for Systems Research University of Maryland College Park MD USA Electrical and Computer Engineering Department Institute for Systems Research Neuroscience and Cognitive Science Program University of Maryland College Park MD USA

Voltage spikes are ubiquitous in biological nervous systems. How spikes can be used to encode signals, facilitate communication, and implement important computations is an important question of contemporary neuroscience. Acoustic processing tasks provide a rich range of applications for this encoding scheme. As a summary of the Ph.D. research of the first author, we present two analog VLSI spike-based example systems that process acoustic information using spikes: a model of the neural signal processing involved in bat echolocation, and a low-power, time-domain acoustic periodicity detector.

关键词： Acoustic signal processing Acoustic signal detection Voltage Biological information theory Nervous system Biology computing Pervasive computing Neuroscience Acoustic applications Encoding

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Binaural Spectral Cues for Ultrasonic Localization

Binaural Spectral Cues for Ultrasonic Localization

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2008 IEEE International Symposium on Circuits and systems (ISCAS 2008), vol.6

作者： Hisham Abdalla Timothy K Horiuchi Electrical and Computer Engineering Department Institute for systems research University of Maryland College Park MD USA Electrical and Computer Engineering dept Insitute for Systems Research Neuroscience and Cognitive Science Program University of Maryland College Park MD USA

To support our ongoing work in modeling bat echolocation, an artificial bat head was designed and fabricated using a 3D printer, an ultrasonic cochlea-like filter bank with 16 channels was designed with moderate quality (Q) factor, and 128 spiking neurons convert these signals to spike trains. A two-dimensional address-event arbiter is used to transmit these spikes off of the chip. We demonstrate that the population of spiking neurons can be decoded to estimate azimuth and elevation of ultrasonic chirps. This chip was fabricated in a commercially-available 0.5(mu)m CMOS process and consumes approximately 36(mu)W.

关键词： Hafnium

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Feature extraction and relevance evaluation for heterogeneous image database recognition

Feature extraction and relevance evaluation for heterogeneou...

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Workshops on Image Processing Theory, Tools and Applications, IPTA

作者： R. Kachouri K. Djemal H. Maaref D. Sellami Masmoudi N. Derbel Research unit on Computers Imaging Electronics and Systems (CIELS) National Engineering school of Sfax (ENIS) Tunisia Computer Integrative Biology and Complex Systems Laboratory (IBISC) University of Evry Val d'Essonne (UEVE) France

Content-based image retrieval (CBIR) techniques are becoming increasingly important in various fields. One of the most important steps in CBIR systems is feature extraction. However, using not appropriate features in heterogeneous image database during retrieval process does not provide a complete description of an image. Indeed, each feature is able to describe some characteristics related to the shape, the color or the texture of the objects in image, but it can not cover the entire visual characteristics of the image. Therefore, many researchers have explored the use of multiple features to describe an image. In this paper, we propose the extraction and the relevance evaluation of several features for an heterogeneous image database classification and recognition, then we study the image retrieval system effectiveness with a new hierarchical feature model. The obtained results prove that using the new hierarchical feature model is more efficient than the use of the classical aggregated features in an image retrieval system.

关键词： Feature extraction Image databases Image recognition Image retrieval Information retrieval Biology computing Image processing Application software Data engineering systems engineering and theory

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A sliding mode control applied to whirling pendulum

A sliding mode control applied to whirling pendulum

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International Conference on Signals, Circuits and systems, SCS

作者： Sonia Mahjoub Faical Mnif Nabil Derbel Control design Optimization of complex Systems (ICOS) Research unit on Intelligent France Department of Electrical and Computer Engineering Sultan Qaboos University Muscat Oman

In this paper, we present a VSS-based tracking control for a fixed point regulation of 2-DOF underactuated manipulators. The design approach is systematic and relies on the selection of appropriate choice of two sliding surface. The controller is designed for the both sliding surfaces are attractive. Lyapunov theory is used to study and demonstrate the stability of the system. Convergence of state space is proved and robustness issues to bounded disturbances are also investigated. Simulation results on 2-DOF whirling pendulum are presented to chow the effectiveness of this approach.

关键词： Sliding mode control Control systems Manipulators Actuators Linear feedback control systems Torque control Intelligent control Design optimization Mechanical systems Robust control

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