• Research in Mathematical Education
• /
• v.19 no.1
• /
• pp.1-17
• /
• 2015

In this study, we examined the prompted reflections of four middle school mathematics teachers after their lessons. We used Cohen and Ball's instructional triangle (1999) to investigate teachers' reflections. With this framework, we addressed questions of what characteristics in reflections the participant teachers have and how the reflections differ over time. Findings indicated that the teachers showed differences in the instances of assessing and changes over time in the ways they gained more insights about students' understanding.

• KIEAE Journal
• /
• v.7 no.3
• /
• pp.63-70
• /
• 2007

It is known that early reflections, their energy and delay times after the arrival of direct sound are important factors for speech intelligibility. In this basis, acoustical parameters like D50 and C80 had been proposed and are widely used for assessing the listening condition of rooms. These parameters are focused on the fraction of the early energy to the total, regardless of the spatial characteristics of the early reflections. This means that all the early reflections, arrived in certain time boundary. from front, behind, down and upside have the same impact on speech intelligibility. From the questionable simplicity, the influence of the direction of early reflections on speech intelligibility is examined in this study. A computer simulation speech intelligibility test, conducted for 22 university students, found that the reflection of vertical direction with method of the Paired comparison also the preference of 0.746 degree was visible an increase.

• Korean Journal of Crystallography
• /
• v.14 no.1
• /
• pp.13-15
• /
• 2003

For all primitive centric space groups in the triclinic, monoclinic and orthorhombic systems, either phase 0 or π can be allocated to three different kinds of reflections in order to specify the origin at one of the eight centers of symmetry. and the same holds for all primitive acentric space groups belonging to the point group 222. If these phased reflections are used as a basic set, more and more phased reflections with better accuracy could emerge in the process of direct methods.

• Journal of the HCI Society of Korea
• /
• v.1 no.1
• /
• pp.37-44
• /
• 2006

Specular reflections provide the visual feedback that describes the material type of an object, its local shape, and lighting environment. In photorealistic rendering, there have been a number of research available to render specular reflections effectively based on a local reflection model. In traditional cel animations and cartoons, specular reflections plays important role in representing artistic intentions for an object and its related environment reflections, so the shapes of highlights are quite stylistic. In this paper, we present a method to render and control stylized specular reflections using projective textures based on principal curvature analysis. Specifying a texture as a pattern of a highlight and projecting the texture on the specular region of a given 3D model, we can obtain a stylized representation of specular reflections. For a given polygonal model, a view point, and a light source, we first find the maximum specular intensity point, and then locate the texture projector along the line parallel to the normal vector and passing through the point. The orientation of the projector is determined by the principal directions at the point. Finally, the size of the projection frustum is determined by the principal curvatures corresponding to the principal directions. The proposed method can control the position, orientation, and size of the specular reflection efficiently by translating the projector along the principal directions, rotating the projector about the normal vector, and scaling the principal curvatures, respectively. The method is be applicable to real-time applications such as cartoon style 3D games. We implement the method by Microsoft DirectX 9.0c SDK and programmable vertex/pixel shaders on Nvidia GeForce FX 7800 graphics subsystems. According to our experimental results, we can render and control the stylized specular reflections for a 3D model of several ten thousands of triangles in real-time.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.439-442
• /
• 2000

When we measure the acoustical properties of a room using multiple microphone system, it is important to grasp exact time delay of the early reflections from impulse response pair. But it is often very difficult to identify the early reflections in natural shape, because a waveform may be deformed due to the characteristics of a sound source loudspeaker, microphone and reflected wall and overlapping of plural waveform. In this paper to obtain more accurate and enough early reflections, we propose the brand-new five-channel sound receiving system and introduce peak-detecting algorithm. The system has microphones mounted at the origin and four points of a regular tetrahedron. The newly introduced peak-detecting algorithm can show exact peak position in each channel, in spite of deformation due to reflected walls, loudspeaker and microphone.

• Journal of The Korean Association For Science Education
• /
• v.27 no.9
• /
• pp.893-906
• /
• 2007

The purposes of this study are to understand pre-service science teachers' areas of practice concern and reflections on the science classes during student-teaching, and to grasp the factors affecting their concerns and reflections. Four pre-service science teachers participated in this study. Data were collected from four pre-service science teachers' practice journals, instructional materials, and semi-structured individual interviews after their student-teaching. The results are as follows: firstly, the pre-service teachers' concern is focused on the teaching environment and strategies, particularly classroom atmosphere and class management. On the other hand, they pay little attention to science content. Secondly, pre-service teachers' reflections are confined within the limited areas such as classroom management, the proper role as science teachers, or various teaching materials. The level of their reflections is low, mostly concentrated on 'routine' or 'technical' level. Higher levels of reflections, such as 'dialogic' or 'transformative' are not revealed at all. Thirdly, the mentor teachers have the biggest influence upon the concerns and reflections of pre-service teachers during student-teaching.

• Perspectives in Nursing Science
• /
• v.11 no.2
• /
• pp.94-100
• /
• 2014

Purpose: This article is aimed at broadening the perspectives of nursing by applying Heidegger's philosophical reasoning and views to nursing beliefs. Methods: Heidegger's main concepts on a human's way of being were the source for examining the encounter between care-receiver and care-giver in nursing. In addition, the paper illustrates the attitudes that nurses must present to their care-receiver in existential nursing. Results: As nurses and care-receivers experience existential crises due to anxiety about death and fear over uncontrollable situations, they both raise questions about the significance of their existences. By putting their deep reflections on these questions into nursing practice, nurses can exist as "Mitdasein" and be open to a number of possibilities in nursing. Conclusion: Nurses must be open to a number of possibilities in nursing by embracing various experiences of life and individuality without criticism, and pursuing the existing lives of their counterparts as well as their owns. They are able to take this attitude by raising fundamental questions about life and the existence of human beings through ceaseless reflections on their experiences, then implementing the result of these reflections in their lives and nursing practices.

• Journal of The Korean Association For Science Education
• /
• v.31 no.3
• /
• pp.455-474
• /
• 2011

The purpose of this study is to explore the ways in which scientists reflect on the scientific practices, based on the premise that reflection is one of key elements for shaping scientific identities. This paper specifically considers scientists' reflections as the processes in which their senses of ethical issues and the value of science are articulated. To do so, the study developed a narrative inquiry for exploring the value of scientists' stories. Fourteen professional scientists' stories were collected in the context of the stem cell research, in ways that foreground their reflections on current scientific practices and the surrounding socio-cultural conditions. As for ethical issues, scientists' stories were analysed in terms of four claims regarding the themes of bioethics, integrity, scientific issues and communication. Furthermore, scientists' reflections on the value of science were analysed in relation to the elements of nature of science. Based on the results, discussion focused on the value of science stories as an instrument with which to guide students into the enculturation in the practices of scientific culture.

• Applied Microscopy
• /
• v.37 no.4
• /
• pp.259-269
• /
• 2007

In this paper we explored a possibility of observation for effects of higher-order Laue zone(HOLZ) reflections on high resolution transmission electron microscope(HRTEM) images for illumination along an off-zone axis of a crystal. The analysis of the observation could give useful three dimensional crystal structure information. For the image simulation the Howie-Whelan equation was used with modification of including HOLZ reflections. This study clearly indicates that HRTEM images for a very thin crystal tilted by a few degrees from a zone axis show the effects of HOLZ reflections and contain some information of atomic arrangements along the zone axis.

• Communications of Mathematical Education
• /
• v.32 no.1
• /
• pp.59-77
• /
• 2018

This study aims to investigate reflections of secondary pre-service mathematics teachers and their changes through practicing as assistant teacher in mathematics classrooms. For the purpose of this study, research questions are addressed on the reflections and their changes. During the 2015 Spring semester, secondary pre-service mathematics teachers took a course related to working as assistant teachers in regular mathematics lessons in a middle school. This study selected cases of two pre-service teachers. The data such as reports on their practices and final meeting report with teachers were collected during the semester. The results showed that the secondary pre-service mathematics teachers reflected teachers, students, mathematics contents, and themselves in their reports. In addition, each participant showed different contents of reflections. This difference implied that secondary pre-service mathematics teachers could have different reflections according to the types of lessons that they participated in.