Effectiveness of a Mobile Plant Learning System in a science curriculum in Taiwanese elementary education

This study developed a Mobile Plant Learning System (MPLS) that provides instructors with the ways and means to facilitate student learning in an elementary-school-level botany course. The MPLS represented in this study was implemented to address problems that arise with the use of a didactic approach to teaching and learning botany, as is typically used in elementary schools in Taiwan. To extend opportunities for learning beyond the classroom, this study used personal digital assistants (PDAs) equipped with the MPLS, which provided both teachers and students access to plant information while in the field. A quasi-experimental research design was used to investigate the effectiveness of using the MPLS to support student learning. The responses to questionnaires and interviews indicate that students valued the outdoor learning activities made possible by use of the PDA and its functions. Pre- and post-test results demonstrated that students also benefitted academically from the use of the MPLS and the PDA.     

Structural Insight in the Interfacial Effect in Ferroelectric Polymer Nanocomposites

Both experimental results and theoretical models suggest the decisive role of the filler–matrix interfaces on the dielectric, piezoelectric, pyroelectric, and electrocaloric properties of ferroelectric polymer nanocomposites. However, there remains a lack of direct structural evidence to support the so-called interfacial effect in dielectric nanocomposites. Here, a chemical mapping of the interfacial coupling between the nanofiller and the polymer matrix in ferroelectric polymer nanocomposites by combining atomic force microscopy–infrared spectroscopy (AFM–IR) with first-principles calculations and phase-field simulations is provided. The addition of ceramic fillers into a ferroelectric polymer leads to augmentation of the local conformational disorder in the vicinity of the interface, resulting in the local stabilization of the all-trans conformation (i.e., the polar β phase). The formation of highly polar and inhomogeneous interfacial regions, which is further enhanced with a decrease of the filler size, has been identified experimentally and verified by phase-field simulations and density functional theory (DFT) calculations. This work offers unprecedented structural insights into the configurational disorder-induced interfacial effect and will enable rational design and molecular engineering of the filler–matrix interfaces of electroactive polymer nanocomposites to boost their collective properties.     

S100A8/A9 Enhances Immunomodulatory and Tissue-Repairing Properties of Human Amniotic Mesenchymal Stem Cells in Myocardial Ischemia-Reperfusion Injury

Paracrine factors of human mesenchymal stem cells (hMSCs) have the potential of preventing adverse cardiac remodeling after myocardial infarction (MI). S100A8 and S100A9 are calcium-binding proteins playing essential roles in the regulation of inflammation and fibrous tissue formation, and they might modulate the paracrine effect of hMSCs. We isolated human amniotic mesenchymal stem cells (hAMSCs) and examined the changes in the expression level of regulatory genes of inflammation and fibrosis after hAMSCs were treated with S100A8/A9. The anti-inflammatory and anti-fibrotic effects of hAMSCs pretreated with S100A8/A9 were shown to be superior to those of hAMSCs without S100A8/A9 pretreatment in the cardiomyocyte hypoxia/reoxygenation experiment. We established a murine myocardial ischemia/reperfusion model to compare the therapeutic effects of the conditioned medium of hAMSCs with or without S100A8/A9 pretreatment. We found the hearts administered with a conditioned medium of hAMSCs with S100A8/A9 pretreatment had better left ventricular systolic function on day 7, 14, and 28 after MI. These results suggest S100A8/A9 enhances the paracrine therapeutic effects of hAMSCs in aspects of anti-inflammation, anti-fibrosis, and cardiac function preservation after MI.     

A grain preservation translation algorithm: From ER diagram to multidimensional model

Many IT practitioners and researchers advocate that data models of data warehouses should incorporate the sources of their data in order to achieve maximum efficiency. As the source data are probably derived from system designed with ER diagrams, a great deal of research has been devoted to the design of methodologies for building multidimensional models based on source ER diagrams. However, to the best of our knowledge, no algorithm has been proposed that can systematically translate an entire ER diagram into a multidimensional model with hierarchical snowflake structures. In this paper, we propose an algorithm that achieves the above goal because it incorporates two features, namely, grain preservation and the minimal distance from each dimension table to the fact table. The grain preservation feature guarantees that the translated multidimensional model will maintain cohesive granularity among the entities. Meanwhile, the minimal distance feature guarantees that if an entity can be connected to the fact table in the multidimensional model by more than one path, the path with the smallest number of hops will always be chosen. The first feature is derived by translating ambiguous relationships between entities into weighting factors stored in bridge tables and enhancing fact tables with unique primary keys. The second feature results from including a revised shortest path algorithm in the translating algorithm, with the distance being calculated as the number of relationships required between entities. A prototype system based on the methodology is also developed, and snapshots of the screens used for the system’s execution are presented.     

A novel polysilicon field-enhanced nanowire thin-film transistor with the TiN-hafnia-nitride-vacuum-silicon (THNVAS) structure for nonvolatile memory applications

A novel poly-Si field-enhanced nanowire (FEN) TFT memory with the TiN-hafnia-nitride-vacuum-silicon (THNVAS) structure fabricated simply via a sidewall spacer formation has been presented. The THNVAS devices with superior memory performance were demonstrated by introducing the hafnia as blocking oxide and the vacuum, the lowest-k in nature, as tunneling layer. According to the simulation results, the memory device with oxide/nitride/vacuum gate dielectric exhibited a higher local electric-field of 4.72 x 10(7) V/cm as compared to 2.55 x 10(7) V/cm for the conventional oxide/nitride/oxide counterpart. In addition, the electric-field of tunneling layer could be further increased to 7.06 x 10(7) V/cm while the blocking oxide was substituted for hafnia. The experimental data showed that THNVAS possessed a greater threshold voltage shift of 3.75 V in 10 ms at V(GS) = 12 V, whereas the shift only 2.5 V for THNOS ones. These considerable improvements for THNVAS devices could be attributed to the evident field enhancement across the vacuum tunneling layer. Furthermore, owing to the empty feature of vacuum tunneling layer, the THNVAS demonstrated much-improved endurance performance and preferable data retention property. Hence, such excellent characteristics of THNVAS will be an attractive nonvolatile memory for future system-on-panel and 3-D Flash applications.     

MQ: an integrated mechanism for multimedia multicasting

This paper studies the integration of multimedia multicasting, with the consideration of multicast with end-to-end QoS guarantees by resource reservation, dynamic join and departure of participants, user heterogeneity, scalability, robustness, and loop-free control. A protocol called MQ, Multicast with QoS, is proposed to support multimedia group communications with QoS guarantees for heterogeneous recipients. With MQ, while resource reservation is de-coupled from QoS multicast routing, they are integrated in a way to avoid the problem of “sender-oriented” path determination, a problem that occurs when RSVP is used in conjunction with QoS routing for heterogeneous reservations. Being a truly receiver-oriented and integrated scheme for multimedia multicasting, MQ supports such integration in a robust, scalable and loop-free way. It also accommodates heterogeneous users with varied QoS, dynamically adjusts QoS trees to improve resource utilization, and guarantees end-to-end QoS requirements. We have conducted simulations to evaluate the performance of the proposed mechanism. MQ demonstrates its advantages over the conventional loosely coupled integration of TP multicasting, resource reservation and QoS routing, in terms of better accommodation of heterogeneous users, higher scalability, lower blocking probability for users to join groups with service guarantees, and more efficient resource utilization to enhance system performance     

An adaptive testing system for supporting versatile educational assessment

With the rapid growth of computer and mobile technology, it is a challenge to integrate computer based test (CBT) with mobile learning (m-learning) especially for formative assessment and self-assessment. In terms of self-assessment, computer adaptive test (CAT) is a proper way to enable students to evaluate themselves. In CAT, students are assessed through a process that uses item response theory (IRT), a well-founded psychometric theory. Furthermore, a large item bank is indispensable to a test, but when a CAT system has a large item bank, the test item selection of IRT becomes more tedious. Besides the large item bank, item exposure mechanism is also essential to a testing system. However, IRT all lack the above-mentioned points. These reasons have motivated the authors to carry out this study. This paper describes a design issue aimed at the development and implementation of an adaptive testing system. The system can support several assessment functions and different devices. Moreover, the researchers apply a novel approach, particle swarm optimization (PSO) to alleviate the computational complexity and resolve the problem of item exposure. Throughout the development of the system, a formative evaluation was embedded into an integral part of the design methodology that was used for improving the system. After the system was formally released onto the web, some questionnaires and experiments were conducted to evaluate the usability, precision, and efficiency of the system. The results of these evaluations indicated that the system provides an adaptive testing for different devices and supports versatile assessment functions. Moreover, the system can estimate students’ ability reliably and validly and conduct an adaptive test efficiently. Furthermore, the computational complexity of the system was alleviated by the PSO approach. By the approach, the test item selection procedure becomes efficient and the average best fitness values are very close to the optimal solutions.     

Conformal self-organizing map for a genus-zero manifold

This paper presents the implementation of a surface mesh on a genus-zero manifold with 3D scattered data of sculpture surfaces using the conformal self-organizing map (CSM). It starts with a regular mesh on a sphere and gradually shapes the regular mesh to match its object’s surface by using the CSM. It can drape a uniform mesh on an object with a high degree of conformality. It accomplishes the surface reconstruction and also defines a conformal mapping from a sphere to the object’s manifold.     

Improving cephalogram analysis through feature subimage extraction

A multilayer perceptron (MLP) with a genetic algorithm (GA) is proposed to extract feature subimages containing orthodontic landmarks. Simulated images and cephalograms were used to investigate its performance in comparison with the cross-correlation method. From the results of simulated image containing shapes with different geometrical conditions, it was shown that the fault tolerance of the MLP for rotation, scaling, brightness variety, and other anomalous deformations is good enough to overcome the clinical application problems. It was also shown that the stability, accuracy, and speed of this proposed algorithm are very promising. Moreover, the performance of the MLP can be significantly improved by collecting more “representative” false patterns. The GA is a good approach to speed up the process of feature subimage extraction based on the fitness evaluated using the MLP