Movement Of Cutting Edge Research Articles

Культурно-историческая теория деятельности и ее современные смысл и значимость: Идеи, растущие в контексте и времени

<p>Alexey N. Leontiev’s legacy – as part of cultural-historical activity theory – is discussed as an open-ended, dynamic, and <em>continuously emerging</em> system of ideas. The meaning and import of these ideas are becoming transparent in the context of contemporary <em>conceptual revolution</em> in psychology. Various trends within this cutting-edge movement have converged on the notion of relationality – in opposition to traditional “substance” metaphysics that posits self-contained, independent entities as the exclusive analytical focus. CHAT is revealed to be a <em>pioneer </em>in this conceptual revolution, contributing conceptual advances such as on embodied, situated, distributed, and enacted cognition/mind and on a (non-dual) “natureculture.” In CHAT, human development is an open-ended, dynamic, non-linear, and ever-unfolding, that is, <em>emergent process</em> with no preprogrammed blueprints. This process is composed of embodied bi-directional interactivities of persons-acting-in-the-world, embedded in fluid contexts – soft assemblages contingent on situational demands and affordances. Moreover, CHAT foregrounds <em>collective dynamics </em>of meaningful shared activities extending through history as a unified onto-epistemology of human development and mind. In addition, CHAT also offers, in outlines, steps to move beyond the relational paradigm towards a transformative worldview premised on the notion of a simultaneous persons-and-the-world co-realizing.</p>

POTENTIAL POSSIBILITIES OF ENHANCING ONLINE COMMUNICATION OF EDUCATORS IN CONFERENCES

Communication using Twitter by educators who attended a conference of a centralized position was investigated to better understand the possibility to expand their Twitter communication in the backchannel of the conference. As a target, conferences for ICT educators organized by Ministry of Education, Thailand were selected. Data were collected through an application programming interface (API) by NodeXL, and a social-graph analysis was executed. Extensional investigation was continuously introduced to include personal tweets history of educators by tracing Twitter accounts, which appeared in their profiles as keys of data collection. Results were compared with the findings of preceding studies. The results showed rather inactive Twitter communication of participants during conference days. However, from the result of extensional investigation, integral bridge and hub users, who were expected to enlighten rural educators, were found. Finally, we present three feasible strategies using social group graph analysis that challenged enhancement of awareness regarding the cutting-edge movement in ICT education of rural educators who could not attend a conference. Bridge users were able to forward messages from the conference organizer using deliberate modification of content to adapt their group culture.

Research on Helical Milling Specialized Tool Based on Chip-Splitting Mechanism

Compared with conventional push drilling, helical milling (orbital drilling) shows great advantages in aeronautical hard-machining materials hole making. However, helical milling of titanium alloy and carbon fiber reinforced plastic (CFRP) under dry cut condition still faces challenges such as burr of titanium alloy hole exit and CFRP hole delamination. In order to solve these problems, an innovative helical milling tool with distributed multi-point front cutting edge is designed based on the chip-splitting mechanism and tool movement feature. The description of cutting edge movement track and simulation of chip shape is used to analyze different functions of front and peripheral cutting edges, the chip-splitting result and the specialized tool's service life. The helical milling experiments are aimed to test the performance of the specialized tool compared with that of traditional end mill. Results show that the specialized tool can machine titanium hole free of burr and CFRP hole without delamination under dry cut condition. The specialized tool has a longer service life with its machining capacity amounting to 80 titanium holes and 65 CFRP holes..

ＴｉＮコーティングドリルによる純チタンの微細穴加工の切削挙動

In this study titanium nitride coated high speed steel drills of diameter 0.3 mm are employed to clarify the behaviors of titanium coated micro drill during the drilling of minute holes, the geometrical relationship between the cutting edge and feed, wear of the cutting edge, chip shape, cutting edge movement in quick stop test and burr shape are investigated. Results reveal that a plane about 10 μm in diameter exist at the cutting edge of a micro drill at the portion connecting the face and the flank, and that the edge of this plane is responsible for the cutting action. The cutting mechanism is indicative of the resulting large negative rake angle created across the entire cutting edge which as is evident in the study greatly influences chip shape, cutting edge wear and peeling off of the coating layer.

Theoretical Estimation of Machined Surface Profile Based on Cutting Edge Movement and Tool Orientation in Ball-nosed End Milling

This paper presents the theoretical estimation method of machined surface profile without actual machining in ball-nosed end miling. The fundamental simultaneous equations of identifying the cusp height at any point of a workpiece in the simulated surface have been successfully derived from the geometric relationship between the cutting edge movement and the normal line at the point. By the numerical calculation, the machined surface profile can be estimated and illustrated graphically. It was found that the maximum and minimum cusp heights exist in a narrow range of tool orientation less than 3 degrees near the normal direction.