可变形灾难救援机器人控制站系统的设计与实现

针对灾难救援应用领域具体需求,提出了控制站系统的设计原则.基于人机交互技术,设计了可变形灾难救援机器人控制站系统,该系统具有感知信息完整、操控灵活、界面友好、交互性强等特点.通过灾难救援模拟环境进行实验,验证丁该控制站系统可以实现机器人在复杂环境中的运动控制、多通道信息交互等功能,在灾难救援等领域具有可行性及有效性.     

Electron-phonon interaction in nanowires: A Monte Carlo study of the effect of the field

The femtosecond dynamics of highly non-equilibrium, confined carriers is analyzed within a Monte Carlo approach. The physical process considered corresponds to a locally excited or injected into a semiconductor nanowire distribution of heated carriers, which evolve under the action of an applied electric field. The carriers are cooled down by dissipation processes caused by phonons. The process is described by a quantum-kinetic equation which generalizes the classical Boltzmann equation with respect to two classical assumptions, namely for temporal and spatial locality of the carrier-phonon interaction. We investigate the effect of the field on the electron-phonon interaction—the intra-collisional field effect (ICFE). A Monte Carlo method for simulation of the considered process has been utilized. Simulation results for carrier evolution in a GaAs nanowire are obtained and analyzed for phenomena related to the ICFE.     

Adsorption behavior of acetone solvent at the HMX crystal faces: A molecular dynamics study

Molecular dynamics simulations have been performed to understand the adsorption behavior of acetone (AC) solvent at the three surfaces of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctan (HMX) crystal, i.e. (011), (110), and (020) faces. The simulation results show that the structural features and electrostatic potentials of crystal faces are determined by the HMX molecular packing, inducing distinct mass density distribution, dipole orientation, and diffusion of solvent molecules in the interfacial regions. The solvent adsorption is mainly governed by the van der Waals forces, and the crystal-solvent interaction energies among three systems are ranked as (020) ≈ (110) > (011). The adsorption sites for solvent incorporation at the crystal surface were found and visualized with the aid of occupancy analysis. A uniform arrangement of adsorption sites is observed at the rough (020) surface as a result of ordered adsorption motif.     

Emotions and the microcomputer: An exploratory study of young children's responses

The emotional effects of early microcomputer use are of interest to educators and child development researchers. This study took a microanalytic emotion coding system which has been used in basic child development research, and applied it to exploring the effects of computer use on children's emotional responses. Sixteen 5-year-old children were videotaped while using three pieces of software (a drawing program, a face construction program, and a counting program). All three pieces elicited more active, positive, and complex facial expressions than did a comparison segment of television watching. Greater levels of concentration and more socially responsive behavior were also seen in the computer conditions. The drawing program tended to elicit more indicators of concentration and social engagement than the other two, although individual preferences and sample size made conclusions tentative. Results appear to reflect the motivational value of emotions and children's interest in experiences which offer autonomy and control. On the basis of this exploratory study, the methodology seems to have potential for investigating other aspects of children's emotional responses to computers.     

Change the face of software engineering education: A field report from Taiwan

Context: In Taiwan, the supply of software engineers provided by universities has suffered from both a quantity problem and a quality problem. An effort to change the software engineering education is in need.Objective: The Software Engineering Consortium (SEC) of Taiwan sets its objective to increase the number of college graduates that are better prepared for filling software development and maintenance jobs.Method: Four dysfunctions: avoidance of process, inattention to modeling, lack of awareness to software quality, and chasm between application domains and software engineering, of the current situation are identified. The effort to correct the dysfunctions involves design of a module-oriented software engineering curriculum, and organization of people, resource, and activities.Results: In the academic years from 2003 to 2008, both the number of software engineering courses offered and the enrollment size increased significantly by a space of some 250 courses and 5000 enrollments, respectively.Conclusion: The SEC effort to establishing software engineering modules has been received with enthusiasm by faculty members and students of the participating institutes. Inspired by the important foundational work such as SWEBOK and SE2004, we believe that the adopted strategy of identifying dysfunctions and then designing remedies to address these dysfunctions contributed significantly to the success of the SEC effort.     

Interactive Videoconferencing for collaborative learning at a distance in the school of 21st century: A case study in elementary schools in Greece

The aim of this paper is to present the design, implementation and evaluation of the methodology which focuses on the pedagogical utilization of Interactive Videoconferencing (IVC) in the contemporary elementary school.     

A scalable approach to mapping annual land cover at 250 m using MODIS time series data: A case study in the Dry Chaco ecoregion of South America

Land use and land cover (LULC) maps from remote sensing are vital for monitoring, understanding and predicting the effects of complex human-nature interactions that span local, regional and global scales. We present a method to map annual LULC at a regional spatial scale with source data and processing techniques that permit scaling to broader spatial and temporal scales, while maintaining a consistent classification scheme and accuracy. Using the Dry Chaco ecoregion in Argentina, Bolivia and Paraguay as a test site, we derived a suite of predictor variables from 2001 to 2007 from the MODIS 250 m vegetation index product (MOD13Q1). These variables included: annual statistics of red, near infrared, and enhanced vegetation index (EVI), phenological metrics derived from EVI time series data, and slope and elevation. For reference data, we visually interpreted percent cover of eight classes at locations with high-resolution QuickBird imagery in Google Earth. An adjustable majority cover threshold was used to assign samples to a dominant class. When compared to field data, we found this imagery to have georeferencing error < 5% the length of a MODIS pixel, while most class interpretation error was related to confusion between agriculture and herbaceous vegetation. We used the Random Forests classifier to identify the best sets of predictor variables and percent cover thresholds for discriminating our LULC classes. The best variable set included all predictor variables and a cover threshold of 80%. This optimal Random Forests was used to map LULC for each year between 2001 and 2007, followed by a per-pixel, 3-year temporal filter to remove disallowed LULC transitions. Our sequence of maps had an overall accuracy of 79.3%, producer accuracy from 51.4% (plantation) to 95.8% (woody vegetation), and user accuracy from 58.9% (herbaceous vegetation) to 100.0% (water). We attributed map class confusion to limited spectral information, sub-pixel spectral mixing, georeferencing error and human error in interpreting reference samples. We used our maps to assess woody vegetation change in the Dry Chaco from 2002 to 2006, which was characterized by rapid deforestation related to soybean and planted pasture expansion. This method can be easily applied to other regions or continents to produce spatially and temporally consistent information on annual LULC.