法新社：NewsML 标准的同路人

参加IPTC北京年会的法新社多媒体实验室主任、资深媒体技术、新闻技术标准专家Laurent Le Meur先生4月3日在新华社的技术研讨会上,首先介绍了法新社的新闻业务和技术概况,他说：法新社每天播发及时、精确、深度报道,每天有遍及世界165个国家的2900名员工为其工作,每天播发视频、图片、图表和多媒体稿件,法新社每天发布的多媒体稿件达350～600篇左右,每天播发的各类新闻大多遵循了NewsML标准。     

Skiing, Cheese Fondue and Swiss Watches: Analogical Discourse in Vocational Training Interactions

When trainers or teachers in the field of initial vocational education explain abstract notions, refer to technical objects or emphasize the specificities of technical skills, they often call forth concepts and practices different from those that are directly salient in the training situations in which they engage. The aim of this paper is to contribute to a better understanding of the empirical realities associated with such phenomena by promoting a discursive and interactional approach of what we propose to term “analogical discourse”. Considering that analogies are performed and shared trough language and speech, we propose that concepts and methodological tools borrowed from the field of linguistics can be profitably applied to the analysis of analogical discourse. Not only can they reveal the dynamic and collective nature of analogies as they are performed, disseminated and sometimes negotiated amongst participants, but they can also help reflect about the complexities of vocational learning as it takes place in specific material, practical and socio-cultural environments. From that standpoint, the paper proposes to see analogies not only as related to conceptual development and cognitive dimensions of learning, but as a substantial contribution to the social, cultural and relational dimensions of it.     

Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor

In this paper, the characteristics of fluid mixing time in a novel extra-loop fluidized bed were studied. The results showed that the mixing time was shortened with the increase of fluid velocity. All the discrete numbers of the reactor were above 0.2. The serial number n was 2.5 -3.0. It was judged accordingly that the reactor fluid state was continous stirred tank reactor （CSTR） mainly. When the inspiratory capacity increased the mixing time of the reactor was shortened. Thus the air input was beneficial for the fluid mixing. During the three phases mixing process, the mixing time of the reactor could be decreased by the n increase of carrier and air loading together, but the change was not significant. The parameters affecting the reactor fluid state were fluid velocity, inspiratory capacity and carrier. KLa could be increased with the air loading increase, and at the same gas/liquid ratio when the pressure drop was high, KL~ value was increased. The amount of carrier complex influence on KLa. As the carrier loading continued to increase, its value had been dropped but the changes was not significant, and optimization condition was found at above 800 1 000 g carrier loading （pouzzolane） or 600 g PVC. Under gas/liquid ratio of 0.8% -5.2%, KLa was （0.62-1.37）×10^-2· s^-1.     

Coplanar electrowetting-induced stirring as a tool to manipulate biological samples in lubricated digital microfluidics. Impact of ambient phase on drop internal flow pattern

Oscillating electrowetting on dielectrics (EWOD) with coplanar electrodes is investigated in this paper as a way to provide efficient stirring within a drop with biological content. A supporting model inspired from Ko et al. [Appl. Phys. Lett. 94, 194102 (2009)] is proposed allowing to interpret oscillating EWOD-induced drop internal flow as the result of a current streaming along the drop surface deformed by capillary waves. Current streaming behaves essentially as a surface flow generator and the momentum it sustains within the (viscous) drop is even more significant as the surface to volume ratio is small. With the circular electrode pair considered in this paper, oscillating EWOD sustains toroidal vortical flows when the experiments are conducted with aqueous drops in air as ambient phase. But when oil is used as ambient phase, it is demonstrated that the presence of an electrode gap is responsible for a change in drop shape: a pinch-off at the electrode gap yields a peanut-shaped drop and a symmetry break-up of the EWOD-induced flow pattern. Viscosity of oil is also responsible for promoting an efficient damping of the capillary waves which populate the surface of the actuated drop. As a result, the capillary network switches from one standing wave to two superimposed traveling waves of different mechanical energy, provided that actuation frequency is large enough, for instance, as large as the one commonly used in electrowetting applications (f ∼ 500 Hz and beyond). Special emphasis is put on stirring of biological samples. As a typical application, it is demonstrated how beads or cell clusters can be focused under flow either at mid-height of the drop or near the wetting plane, depending on how the nature of the capillary waves is (standing or traveling), and therefore, depending on the actuation frequency (150 Hz–1 KHz).     

The effect of chalk on the finger–hold friction coefficient in rock climbing

The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were performed. Participants hung from holds which were fixed on a specially designed hang board. The inclination of the hang board was progressively increased until the climber's hand slipped from the holds. The angle of the hang board was simultaneously recorded by using a gyroscopic sensor and the friction coefficient was calculated at the moment of slip. The results showed that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone). Moreover sandstone had a higher coefficient of friction than limestone (+15.6% without chalk, +18.4% with chalk). These results confirmed climbers' belief that chalk enhances friction. However, no correlation with humidity/temperature and friction coefficient was noted which suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing.     

Kinematic optimization of 2D plunging airfoil motion using the response surface methodology

The propulsive efficiency of a plunging NACA0012 airfoil is maximized by means of a simple numerical optimization method based on the response surface methodology (RSM). The control parameters are the amplitude and the reduced frequency of the harmonic sinusoidal motion. The 2D unsteady laminar flow around the plunging airfoil is computed by solving the Navier-Stokes equations for three Reynolds number values (Re = 3.3×10³, 1.1×10⁴, and 2.2×10⁴). The Nelder-Mead algorithm is used to find the best control parameters leading to the optimal propulsive efficiency over the constructed response surfaces. It is found that, for a given efficiency level and regardless of the considered Re value, it is possible either to obtain high thrust by selecting a high oscillation frequency or to reduce the input power by adopting a low plunging amplitude.     

Fingertip force and electromyography of finger flexor muscles during a prolonged intermittent exercise in elite climbers and sedentary individuals

The aim of this study was to characterize forearm muscle fatigue identified by the decrease in electromyogram median frequency and/or fingertip force during intermittent exercise. Nine elite climbers (international competitive level, USA 5.14a on sight) and ten non-climbers were instructed to maintain a fingertip force of 80% of their maximal voluntary contraction force on a dynamometer mimicking a rock climbing grip during a 5 s effort/5 s rest cycle for 36 repetitions (i.e. 6 min of exercise). Elite climbers lasted twice as long as non-climbers (climbers: 3 min; non-climbers: 1 min 30 s) before the force could no longer be maintained (i.e. the failure point). After this moment, fingertip force decreased and stabilized until the end of the exercise around 50% maximum voluntary contraction force in non-climbers and 63% in elite climbers. Electromyogram median frequency showed a greater decrease in non-climbers than in elite climbers before the failure point. No change in median frequency was observed after the failure point in elite climbers or in non-climbers. These results confirm that elite climbers are better adapted than non-climbers for performing the intermittent fingertip effort before the failure point. After this point, the better fingertip force of elite climbers suggests different forearm muscle properties, while the electromyography results do not provide any indication about the fatigue process.     

Volunteers in Australian archives

Why do volunteers choose to contribute thousands of unpaid hours per week to Australian archives? This paper presents the results of a nationwide web survey that provides insight into the demographics, motivations and experiences of volunteers in Australian archives. The findings provide a representative overview of formal volunteers in Australian archives, determining ‘who’ they are, the value of the contributions they provide and the level of training and support offered to them. This study is a continuation of existing discussions about volunteers in Australian archives and represents an opportunity for the development of stronger relationships with Australian archival volunteers and, through them, the communities our archives serve.     

A critic looks at reviewing

Mr. Laurent is the widely‐syndicated Television‐Radio Editor of the Washington Post. This quotation is from a letter to the editor of the Journal in response to an article by Jules Rossman titled “What Do Reviewers Actually Review?” that appeared in the Spring, 1965, issue of the Journal of Broadcasting.     

An Architecture for Case-based Learning

We report on the design, development, implementation, and evaluation of a case-based instructional environment designed for learning network engineering skills for cybersecurity. We describe the societal problem addressed, the theory-based solution, and the preliminary testing and evaluation of that solution. We identify an architecture for scaffolding case-based learning for problem-solving to inform design of case-based learning environments.