Expectations of Grassroots Community Leadership in Times of Normality and Crisis

The article compares the preferences of community members for the transformational and transactional leadership styles of grassroots leaders at times of normality with those during a crisis. A structured questionnaire was administered to members of a community that experienced security crises on the Lebanese border of Israel before the 2006 Lebanon War. It reveals differences in the dominance of preferred leadership styles depending on the type of situation – normality or crisis. The article discusses these differences, compares the findings with those of other studies and considers their practical implications.     

Adapting to the times [review of Adaptive Techniques for Dynamic Processor Optimization: Theory and Practice (Wang, A. and Naffziger, S., Eds.; 2008)]

The focus of this volume is on postsilicon adaption to overcome process and environmental variations, to ensure that a design operates to specifications even in the presence of process and environmental variations. Some of the topics covered include: an introduction, discussing sources of variation and the notion of a control system with a feedback loop to adaptively compensate for variations; adaptively changing body biases, processor frequencies, and supply voltages to react to variations; an Intel view, demonstrated on the design of a TCP/IP processor with dynamic and adaptive supply voltage, body bias, and frequency optimization, including measurement results; building ultradynamic-voltage-scaled (UDVS) systems; the design of the XScale embedded processor; the design of sensors for monitoring critical-path delays under variations, including control and calibration mechanisms; architectural methods for adaptive computing; asynchronous systems and adaptation; and SRAM design and optimization and testing techniques specific to adaptive systems, as demonstrated on the Intel Montecito processor. The book brings together a variety of voices, explaining various views regarding on-chip adaptation. The overall story comes across extraordinarily well and lucidly.     

QoS研究的理论框架以及研究现状(1)

文章从分布式多媒体应用端到端QoS控制的角度,首先介绍了QoS的定义和标准,而后分阶段、分层次地阐述了QoS的控制和管理框架,包括QoS控制机制的设计原则、QoS的描述、QoS控制和管理机制以及QoS的控制层次。     

Evaluation of MODIS Gross Primary Productivity (GPP) in tropical monsoon regions

Near real-time vegetation indices derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations (http://modis.gsfc.nasa.gov) provide a first opportunity to monitor ecohydrological systems globally at a spatial resolution consistent with biophysical processes at the field scale. Here, we present work toward the quantitative estimation of the uncertainty associated with MODIS Gross Primary Productivity (GPP), an end-product that depends on several MODIS derived vegetation indices. GPP products, available at 8-day and 1-km resolutions, were evaluated in two representative tropical ecosystems: a mixed forest site in the humid tropics (the Marsyandi river basin in the Nepalese Himalayas), and an open shrubland site in a semi-arid region (the Sonora river basin in northern Mexico). The MODIS-GPP products were compared against simulations made with a process-based biochemical-hydrology model driven by flux tower meteorological observations. Whereas the temporal march of vegetation indices and GPP products is consistent between the model and the algorithm, our study indicates that that there is a positive bias in the case of the mixed forest biome in the Marsyandi basin, and a negative bias in the case of open shrublands in the Sonora basin. We examined the error contribution from the DAO meteorological data used in the standard MODIS GPP products. The bias between the GPP estimates using DAO and tower meteorology is − 2.77 gC/m²/day (i.e., − 77% of the mean of the tower-based GPP) in the Marsyandi, and 0.33 gC/m²/day (i.e., 18% of the mean of the tower-based GPP) in Sonora. Analysis of the temporal evolution of the discrepancies between the model and the MODIS algorithm points to the need for examining the light use efficiency parameterization, especially with regard to the representation of nonlinear functional dependencies on vapor pressure deficit (VPD), photosynthetically available radiation (PAR), and seasonal evolution of the productive capacity of vegetation as influenced by water stress.     

Developing (Meta)Theory of λ-calculus in the Theory of Contexts

We present a case study on the formal development of a non trivial (meta)theory in the Theory of Contexts using the Coq proof assistant. The methodology underlying the Theory of Contexts for reasoning on systems presented in HOAS is based on an axiomatic syntactic standpoint. We feel that one of the main advantages of this approach, is that it requires a very low logical overhead.The object system we focus on is the lazy, call-by-name λ-calculus (λ_cbn), both untyped and simply typed. We will see that the formal, fully detailed development of the theory of (λ_cbn) in the Theory of Contexts introduces a small, sustainable overhead with respect to the proofs “on the paper”. Moreover, this will allow for comparison with similar case studies developed in other approaches to the metatheoretical reasoning in higher-order abstract syntax.     

Design,fabrication, and testing of a 3-DOF HARM micromanipulator on (1 1 1) silicon substrate

In this study, a novel HARM (high aspect ratio micromachining) micromanipulator fabricated on (1 1 1) silicon wafer is reported. The micromanipulator consists of a positioning stage, a robot arm, supporting platforms, conducting wires, and bonding pads. These components are monolithically integrated on a chip through the presented processes. The three-degrees-of-freedom (3-DOF) positioning of the micromanipulator is realized by using the integration of two linear comb actuators and a vertical comb actuator. The robot arm is used to manipulate samples with dimension in the order of several microns to several hundred microns, for instance, optical fibers and biological samples. The robot arm could be a gripper, a needle, a probe, or even a pipette. Since the micromanipulator is made of single crystal silicon, it has superior mechanical properties. A micro gripper has also been successfully designed and fabricated.     

Crisis Management and Strategic Orientation in Small and Medium‐Sized Enterprises (SMEs) in Peru,Mexico and the United States

This study addresses the link between management concern for organizational crises and competitive strategy in small and medium‐sized enterprises in Peru, Mexico and the United States. Surveys were completed by 270 Peruvian, 218 Mexican and 256 American managers. Strategic orientation in Peru did not mirror the broad pattern found in Mexico and in the United States. Levels of concern for crises were significantly higher in both Mexico and Peru than in the United States for 12 of 21 crises. The level of concern for crises tended to increase with management level more in Mexico and Peru than in the United States. Correlations between competitive strategy and crisis concern were significant in 26 of 126 instances.     

Compatibility Condition in Theory of Solid Mechanics (Elasticity,Structures, and Design Optimization)

The strain formulation in elasticity and the compatibility condition in structural mechanics have neither been understood nor have they been utilized. This shortcoming prevented the formulation of a direct method to calculate stress and strain, which are currently obtained indirectly by differentiating the displacement. We have researched and understood the compatibility condition for linear problems in elasticity and in finite element structural analysis. This has lead to the completion of the “method of force” with stress (or stress resultant) as the primary unknown. The method in elasticity is referred to as the completed Beltrami-Michell formulation (CBMF), and it is the integrated force method (IFM) in the finite element analysis. The dual integrated force method (IFMD) with displacement as the primary unknown had been formulated. Both the IFM and IFMD produce identical responses. The IFMD can utilize the equation solver of the traditional stiffness method. The variational derivation of the CBMF produced the existing sets of elasticity equations along with the new boundary compatibility conditions, which were missed since the time of Saint-Venant, who formulated the field equations about 1860. The CBMF, which can be used to solve stress, displacement, and mixed boundary value problems, has eliminated the restriction of the classical method that was applicable only to stress boundary value problem. The IFM in structures produced high-fidelity response even with a modest finite element model. Because structural design is stress driven, the IFM has influenced it considerably. A fully utilized design method for strength and stiffness limitation was developed via the IFM analysis tool. The method has identified the singularity condition in structural optimization and furnished a strategy that alleviated the limitation and reduced substantially the computation time to reach the optimum solution. The CBMF and IFM tensorial approaches are robust formulations because both methods simultaneously emphasize the equilibrium equation and the compatibility condition. The vectorial displacement method emphasized the equilibrium, while the compatibility condition became the basis of the scalar stress-function approach. The tensorial approach can be transformed to obtain the vector and the scalar methods, but the reverse course cannot be followed. The tensorial approach outperformed other methods as expected. This paper introduces the new concepts in elasticity, in finite element analysis, and in design optimization with numerical illustrations.