Learning algorithms for multi-class pattern classification and problems associated with on-line handwritten character recognition

On-line handwritten alphanumeric character recognition system and learning algorithm for multiclass pattern classificatio

Assessing Learner Autonomy and EFL Vocabulary Acquisition: a Case Study

The importance of autonomy learning is widely acknowledged in teaching English as a Foreign Language (EFL) in Asian contexts. The present study attempted to report low proficiency level students\u27 autonomous vocabulary learning. The first part of the present study focused on exploring how learners perceived and experienced their autonomous vocabulary learning, with a questionnaire and group discussion applied to collect data. During the second part of the study, the data were discussed collaboratively by six teachers to identify the different approaches utilized by learners. Priorities included setting weekly goals, self-planning and self-monitoring the process of learning vocabulary. Results also revealed that a weak ‘top-down\u27 approach in implementing learner autonomy is inadequate. Teachers need to provide scaffolding skills tailored to learners\u27 context-specific needs, for which a strong ‘bottom-up\u27 approach is more appropriate in supporting autonomous learning. In this case, classroom time should be allocated to demonstrate the strategies and teachers should work collaboratively to develop resources and materials for learners\u27 autonomous vocabulary learning. The present study also addressed the need for establishing an effective intervention for supporting learner autonomy. Keywords: learner autonomy, vocabulary learning, self-plan, self-monito

Bioavailable Iron in Equatorial Pacific Ocean Aerosol Samples

Oceanic iron (Fe) fertilization experiments performed in remote regions have established that Fe additions draw carbon into the ocean, at least over the months-long time frame of the experiments. However, the mechanisms that control Fe speciation in atmospheric aerosol particles before and after deposition into the surface ocean remain largely unknown. This is in part due to the analytical challenge of quantifying Fe at environmentally significant sub-nano molar levels. The flow injection analysis method combined with the luminol chemiluminescence analytical system allows us to explore the near-real time determination of pico-molar levels of both Fe(II) and H2O2 produced from real marine aerosol particles collected over the Equatorial Pacific Ocean, as a function of both sunlight and electron donors (EDs) such as dimethyl sulfide and organic acids. Detection limits were as low as 40 pM Fe(II) and 100 pM H2O2. Fe(II)in aerosol concentration was found to be 0.29 ± 1.48 pg m-3 in large, 19.14 ± 18.31 pg m-3 in coarse, 38.80 ± 37.87 pg m-3 in fine, and 43.61 ± 42.93 pg m-3 in ultrafine size aerosol samples. A typical analysis of photochemical reaction with addition of EDs can be performed in five minutes. Results indicate that Fe(III) is reduced in the presence of light with ED that are already present in the collected aerosols, the external additions of ED have an enhancing effect in some of the samples, and the Fe(II) concentration shows positive corrected to non-sea-salt sulfate (NSS-SO42-) and some other anions. Fe(II) is found to be 3% of total Fe in the aerosols. These results contribute to resolving current inconsistencies in chemical models on the speciation of Fe and sulfur cycles in the marine atmosphere

A two-dimensional ultrasonic model study of compressional and shear-wave diffraction patterns produced by a circular cavity

Diffraction patterns of compressional (P) and shear (SV) waves produced by a circular hole were experimentally obtained on a two-dimensional ultrasonic model. The shapes of the Fresnel patterns were found to depend on, 1) α/λ, the ratio of the radius of the cylinder to the wavelength; and, 2) the wave type. The transitional zone between the illuminated and the shadow regions broadens, and the half-amplitude point shifts away from the geometrical shadow as α/λ decreases. For comparable α/λ, the shadow boundary of the SV wave appears to start much earlier than that of the P wave

Buckling without bending: a new paradigm in morphogenesis

A curious feature of organ and organoid morphogenesis is that in certain cases, spatial oscillations in the thickness of the growing "film" are out-of-phase with the deformation of the slower-growing "substrate," while in other cases, the oscillations are in-phase. The former cannot be explained by elastic bilayer instability, and contradict the notion that there is a universal mechanism by which brains, intestines, teeth, and other organs develop surface wrinkles and folds. Inspired by the microstructure of the embryonic cerebellum, we develop a new model of 2d morphogenesis in which system-spanning elastic fibers endow the organ with a preferred radius, while a separate fiber network resides in the otherwise fluid-like film at the outer edge of the organ and resists thickness gradients thereof. The tendency of the film to uniformly thicken or thin is described via a "growth potential". Several features of cerebellum, +blebbistatin organoid, and retinal fovea morphogenesis, including out-of-phase behavior and a film thickness amplitude that is comparable to the radius amplitude, are readily explained by our simple analytical model, as may be an observed scale-invariance in the number of folds in the cerebellum. We also study a nonlinear variant of the model, propose further biological and bio-inspired applications, and address how our model is and is not unique to the developing nervous system.Comment: version accepted by Physical Review