Context.
Until recently, the 3D shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (
D
≥ 100 ...km) main-belt asteroids have remained poorly constrained. The improved capabilities of the SPHERE/ZIMPOL instrument have opened new doors into ground-based asteroid exploration.
Aims.
To constrain the formation and evolution of a representative sample of large asteroids, we conducted a high-angular-resolution imaging survey of 42 large main-belt asteroids with VLT/SPHERE/ZIMPOL. Our asteroid sample comprises 39 bodies with
D
≥ 100 km and in particular most
D
≥ 200 km main-belt asteroids (20/23). Furthermore, it nicely reflects the compositional diversity present in the main belt as the sampled bodies belong to the following taxonomic classes: A, B, C, Ch/Cgh, E/M/X, K, P/T, S, and V.
Methods.
The SPHERE/ZIMPOL images were first used to reconstruct the 3D shape of all targets with both the ADAM and MPCD reconstruction methods. We subsequently performed a detailed shape analysis and constrained the density of each target using available mass estimates including our own mass estimates in the case of multiple systems.
Results.
The analysis of the reconstructed shapes allowed us to identify two families of objects as a function of their diameters, namely “spherical” and “elongated” bodies. A difference in rotation period appears to be the main origin of this bimodality. In addition, all but one object (216 Kleopatra) are located along the Maclaurin sequence with large volatile-rich bodies being the closest to the latter. Our results further reveal that the primaries of most multiple systems possess a rotation period of shorter than 6 h and an elongated shape (
c
∕
a
≤ 0.65). Densities in our sample range from ~1.3 g cm
−3
(87 Sylvia) to ~4.3 g cm
−3
(22 Kalliope). Furthermore, the density distribution appears to be strongly bimodal with volatile-poor (
ρ
≥ 2.7 g cm
−3
) and volatile-rich (
ρ
≤ 2.2 g cm
−3
) bodies. Finally, our survey along with previous observations provides evidence in support of the possibility that some C-complex bodies could be intrinsically related to IDP-like P- and D-type asteroids, representing different layers of a same body (C: core; P/D: outer shell). We therefore propose that P/ D-types and some C-types may have the same origin in the primordial trans-Neptunian disk.
Tablet adoption is massive and increasing. Many applications are leveraging this marked widespread, including digital interactive books. A proposal for an educational and accessible digital book ...reader in mobile devices is presented, focusing on people with visual impairment. An implementation was developed, aiming to complement digital accessible books for education. The work presents a digital book with support for knowledge assessing, text reading, worksheets, drawing and tactile images and maps.
A domain engineering for interactive learning modules Danilo L Dalmon; Leonidas O Brandao; Anarosa AF Brandao ...
Journal of research and practice in information technology,
08/2012, Letnik:
44, Številka:
3
Journal Article
Recenzirano
For creating educational systems, each developer usually applies different approaches to specific situations, including advanced software engineering techniques. In the case of systems that provide ...interactivity-intense assignments, problems during their development include difficulties to manage component repositories and the absence of a systematic process to support code reuse. Interactive Learning Modules (iLM) are systems designed in this context, which also provide key functionalities to facilitate the teacher's work. To address the problems faced during their development, a Domain Engineering is proposed to build iLM. In order to define the iLM software family, this paper presents the core features of existing systems, describes the method used to produce an application framework and how to instantiate it. Restructuration of existing iLM using the proposed Domain Engineering is reported with initial high gains in productivity and system quality.
Intelligent Tutoring Systems (ITS) provide many features that improve learning and teaching experiences. ITS are usually interactivity-intense and content-specific. Interactivity-intense assignments ...are recommended for scaffolding learning, while content-specific systems can offer low flexibility regarding its possible pedagogical approaches and its uses by teachers. In order to overcome this limited flexibility, there are systems which let content-specific interactivity aside to provide authoring tools, with which teachers can author intelligent tutored assignments without programming. The generic model proposed herein intends to address this problem providing flexible authoring tools for interactivity-intense assignments with tutoring features, letting teachers benefit from the flexibility of content authoring tools as well as the interactivity usually restricted to content-specific ITS. We introduce an application framework which implements this model, which is available as free software.
The development of good quality educational software is expensive, time-consuming and faces some underlying issues. In order to deal with such issues, many attempts were made, mainly on code reuse. ...Following a similar approach, the development of an application framework for implementing a family of interactivity-intense educational software called Interactive Learning Modules - iLM is presented. The framework main goal is to reduce development efforts while being part of a Software Product Line - SPL, an innovative technique regarding interactivity-intense educational software. The framework specification is presented by analyzing the common features of existing iLM. Therefore, the resulting component architecture is outlined. Currently, the design phase is finished and the implementation ongoing. Also, its instantiation is planned for an existing iLM, as a proof of concept.
There are different approaches that drive the development and use of educational software, such as Interactive Geometry Systems - IGS and Intelligent Tutoring Systems - ITS. Considering their ...benefits to teachers and students, these systems may be used to complement each other. The ongoing development of ITS features in an existing IGS called iGeom is presented. First, the limitations of both approaches are listed, describing possible benefits of using them together. Then, the resulting component architecture of the conducted analysis and software design is outlined. The ITS paradigm chosen was Example-tracing Tutors. The current state of research is the tutoring features implementation and planning for testing in classrooms and in distance learning courses.
A domain engineering for interactive learning modules Danilo L Dalmon; Leonidas O Brandao; Anarosa AF Brandao ...
Journal of research and practice in information technology,
08/2012, Letnik:
44, Številka:
3
Journal Article
Recenzirano
For creating educational systems, each developer usually applies different approaches to specific situations, including advanced software engineering techniques. In the case of systems that provide ...interactivity-intense assignments, problems during their development include difficulties to manage component repositories and the absence of a systematic process to support code reuse. Interactive Learning Modules (iLM) are systems designed in this context, which also provide key functionalities to facilitate the teacher's work. To address the problems faced during their development, a Domain Engineering is proposed to build iLM. In order to define the iLM software family, this paper presents the core features of existing systems, describes the method used to produce an application framework and how to instantiate it. Restructuration of existing iLM using the proposed Domain Engineering is reported with initial high gains in productivity and system quality.
For creating educational systems, each developer usually applies different approaches to specific situations, including advanced software engineering techniques. In the case of systems that provide ...interactivity-intense assignments, problems during their development include difficulties to manage component repositories and the absence of a systematic process to support code reuse. Interactive Uarning Modules (iLM) are systems designed in this context, which also provide key functionalities to facilitate the teacher's work. To address the problems faced during their development, a Domain Engineering is proposed to build iLM. In order to define the iLM software family, this paper presents the core features of existing systems, describes the method used to produce an application framework and how to instantiate it. Restructuration of existing iLM using the proposed Domain Engineering is reported with initial high gains in productivity and system quality.
A Domain Engineering for Interactive Learning Modules Dalmon, Danilo L; Brandao, Leonidas O; Brandio, Anarosa A F ...
Journal of research and practice in information technology,
03/2013, Letnik:
44, Številka:
3
Journal Article
Recenzirano
For creating educational systems, each developer usually applies different approaches to specific situations, including advanced software engineering techniques. In the case of systems that provide ...interactivity-intense assignments, problems during their development include difficulties to manage component repositories and the absence of a systematic process to support code reuse. Interactive learning Modules (il.M) are systems designed in this context, which also provide key functionalities to facilitate the teacher's work. To address the problems faced during their development, a Domain Engineering is proposed to build iLM. In order to define the iLM software family, this paper presents the core features of existing systems, describes the method used to produce an application framework and how to instantiate it. Restructuralion of existing iLM using the proposed Domain Engineering is reported with initial high gains in productivity and system quality.
Two of the most important characteristics to support learning of geometric concepts are (a) the possibility of allowing students to interact with geometric objects and (b) the capability of guiding ...these students during the process of interaction by helping them to discover interesting properties and to make “plausible” conjectures. Available interactive/dynamic geometry software allow for rich interaction between geometric objects and users, but with no computational support for guiding students. This work presents an on-going effort to design an interactive geometry software, referred to iGeom, that have both interactive geometric objects that students can fully manipulate and the capability of helping students by providing personalized guidance and feedback when needed. iGeom have been developed in Java, freely available on internet (http://www.matematica.br/igeom), and can be easily incorporated into other programs such as learning managements systems or ITSs. To provide guidance capabilities we have been using CTAT (http://ctat.pact.cs.cmu.edu/), an authoring tool that facilitates fast development of cognitive tutors.
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