113 research outputs found

    A Manga-Driven System Requirements Development PBL Exercise

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    We conducted a Project-Based Learning (PBL)-type exercise incorporating Japanese cartoon (manga) techniques into Requirements Development (RD) processes. Manga has established techniques, such as those for character setting and story development, that we thought are also valid for RD processes. Using this manga-driven method, students were able to clarify high-level project goals early in the development life-cycle, and succeeded in defining high quality and unique system ideas.Comment: SEEM201

    A Logical Investigation on Global Reading of Diagrams (Technical Note)

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    Abstract In graphical or diagrammatic representations, not only a basic component of a diagram, but also a collection of multiple components can form a semantic unit, and it often helps reasoning with that diagram. For example, a row and a column in a table, or transitively closed nodes in a directed graph can be regarded as a semantic unit on its own. Designers have long noticed the importance of information conveyed by these global object

    Exact spin dynamics of the 1/r^2 supersymmetric t-J model in a magnetic field

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    The dynamical spin structure factor S^{zz}(Q,omega) in the small momentum region is derived analytically for the one-dimensional supersymmetric t-J model with 1/r^2 interaction. Strong spin-charge separation is found in the spin dynamics. The structure factor S^{zz}(Q,omega) with a given spin polarization does not depend on the electron density in the small momentum region. In the thermodynamic limit, only two spinons and one antispinon (magnon) contribute to S^{zz}(Q,omega). These results are derived via solution of the SU(2,1) Sutherland model in the strong coupling limit.Comment: 20 pages, 8 figures. Accepted for publication in J.Phys.

    Analysis of the Motivation in the Programming Education for the Students Who Perform IT Work that Requires Artistic Skills

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    Programming education is considered to be important for the students in the art faculty, who perform the IT works that require artistic skills, to enrich their environments of creation and to carry out effective activities of creation. The motivation of the students is considered to be an important part of programming education in which active participation of students is crucial. In this research, we analyzed the transition of the motivation in the programming education using the ARCS motivation model in order to carry out effective programming education. Furthermore, we focused on the three sublevel categories of each factor of the ARCS model, and analyzed the transition and the factor of the transition of them. We have also proposed the method of analysis in which 3D bubble graphs ware drawn in such a way that each axis corresponds to each of the three sublevel categories in a factor of the ARCS model. We consider that it will be possible to apply the proposed methods to grasp the relation among the sublevel categories of each factor and the cause of the transition of them as the learning progresses.芸術系技能を必要とするIT作業において、作業環境を充実させて効率的な制作活動を展開するには、プログラミング教育が効果的であると考えられる。そして、知識の運用を必要とするプログラミング教育においては学習者自身のモチベーションが重要である。本研究では、効果的なプログラミング教育を行うためにプログラミング教育のモチベーションの変化を、ARCS動機付けモデルを用いて分析した。さらに、ARCS動機付けモデルの因子の下位カテゴリーに着目し、その遷移と遷移の要因を解析した。下位カテゴリーの遷移要因の解析では、ARCS動機付けモデルの一つの因子に属する3つの下位カテゴリーを3Dバブルグラフの3軸に対応させて描画する手法も提案した。本提案手法は、一つの因子の下位カテゴリー間の関係や、学習フェーズの進行による遷移要因の総合的な把握に適用できる可能性があると考えられる

    A disk-type dose imaging detector based on blue and orange RPL in Ag-activated phosphate glass for 2D and 3D dose imaging applications

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    A disk-type two- and three-dimensional (2D, 3D) X-ray dose imaging detector was developed based on the radiation-induced silver (Ag)-related species in Ag-activated phosphate glass. This luminescent detector is based on the blue and orange radiophotoluminescence (RPL) phenomena. A comparative study of the steady- and transient-state optical properties of blue and orange RPL, such as the time-resolved luminescence spectra and the RPL decay curves, was performed. In addition, the combination of a confocal optical detection system with a transparent glass detector enables 3D reconstruction through the stacking of dose images collected at different depths within the material. The capabilities of this detector for 2D and 3D dose imaging applications are discussed. © 2015 Published by Elsevier Ltd.Embargo Period 24 month

    Electron temperature profile collapse induced by double-odd-parity MHD mode in the Large Helical Device

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    In this paper, we report new results of a beam switching experiment aiming at a reversed magnetic shear profile formation for the study of an MHD-mode-induced profile collapse event. A transient MHD mode, whose oscillation frequency chirps down, is observed. The electron temperature profile collapse is induced by the mode activity, leading to the flattening of the central electron temperature profile. The radial mode structure is the double-oddparity at the beginning, but it transits to the even-parity in its final stage. The central electron temperature profile recovers after the radial mode structure changes to the even-parity, even though the mode itself does not disappear

    Non-resonant global mode in LHD partial collapse with net toroidal current

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    A transition from an interchange mode to a non-resonant mode is found in the nonlinear magnetohydrodynamic simulation for the partial collapse in a large helical device (LHD) plasma with a net toroidal current. This transition can occur when the magnetic shear is weak and the rotational transform is close to unity in the core region. In this transition, the mode number of the dominant Fourier component is reduced. As a result of the nonlinear evolution, the (m, n) = (1, 1) component can be dominant, where m and n are the poloidal and the toroidal mode numbers, respectively. This transition is considered to be a candidate to explain the observation in the LHD experiments with the net toroidal current that show partial collapses are caused by the (1, 1) mode

    Electron Addition Spectrum in the Supersymmetric t-J Model with Inverse-Square Interaction

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    The electron addition spectrum A^+(k,omega) is obtained analytically for the one-dimensional (1D) supersymmetric t-J model with 1/r^2 interaction. The result is obtained first for a small-sized system and its validity is checked against the numerical calculation. Then the general expression is found which is valid for arbitrary size of the system. The thermodynamic limit of A^+(k,omega) has a simple analytic form with contributions from one spinon, one holon and one antiholon all of which obey fractional statistics. The upper edge of A^+(k,omega) in the (k,omega) plane includes a delta-function peak which reduces to that of the single-electron band in the low-density limit.Comment: 5 pages, 1 figure, accepted for publication in Phys. Rev. Let

    Dependence of the resonant magnetic perturbation penetration threshold on plasma parameters and ions in helical plasmas

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    We investigate the penetration threshold of resonant magnetic perturbation (RMP) by the external coils in the Large Helical Device (LHD) for various plasma aspect ratio configurations. The qualitative dependence on the collisionality is opposite to that in a high plasma aspect configuration; this is a quite unique property first found in the LHD. We also investigate the threshold dependence on the ion species, and find that the threshold in deuterium discharges is much smaller than that in hydrogen discharges. In all cases the thresholds are higher as the poloidal rotation becomes faster, which shows that poloidal rotation is the dominant driver to the RMP shielding. This is qualitatively consistent with the torque balance model between the electromagnetic and poloidal viscous torques. In a configuration of the LHD, the dependence of the threshold on the density is qualitatively similar to that in Ohmic tokamak plasmas, but the beta dependence is opposite to that of tokamaks. The difference arises from the cause of the viscous torque

    Magnetohydrodynamic stability at the edge region in H-mode plasmas with long edge-localized-mode-free phases in the large helical device

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    Clear suppression of magnetic fluctuations associated with resistive interchange modes (RICs) is observed during long edge-localized-mode (ELM)-free phases of the H-mode plasma in an outward-shifted configuration of the Large Helical Decice, in which a steep pressure gradient is generated at the plasma edge in the magnetic hill. The ELM-free H-phase is interrupted by large amplitude ELMs which are thought to be induced through nonlinear evolution of the RICs having m  =  1/n  =  1 dominant component (m: poloidal mode number, n: toroidal one). The m  =  1/n  =  1 RIC amplitude is enhanced about 10 times compared with the H-phase level during each ELM. In most of the H-mode shots, the final ELM-free phase returns to L-phase by a large amplitude ELM. In the L-phase, the RIC amplitude is enhanced by a factor of ~3 compared with that in the H-phase, although the edge pressure gradient is reduced considerably. Linear resistive magnetohydrodynamic stability analysis is attempted using experimentally obtained equilibrium profiles. From the numerical analysis, the distance between the location of the steepest pressure gradient and the main mode resonance surface, i.e. the rotational transform ι  =  1, is found to be important for a large growth of the m  =  1/n  =  1 RIC in the H-phase
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