Stochastic Geometry-Based Throughput Analysis of User-Specific Power-Level-Constrained GF-NOMA

Hirai T., Ueda Y., Wakamiya N.. Stochastic Geometry-Based Throughput Analysis of User-Specific Power-Level-Constrained GF-NOMA. IEEE Internet of Things Journal, (2024); https://doi.org/10.1109/JIOT.2024.3409698.This paper proposes a stochastic geometry-based analytical framework for the throughput of the grant-free power-domain non-orthogonal multiple access (GF-NOMA) with user-specific constraints of selectable power levels and analyzes the achievable throughput. Our analytical framework uses stochastic geometry to reflect selectable power levels constrained by the maximum transmission power and channel of each user to an inhomogeneous offered load per level. This key idea enables our framework to analyze the throughput bounded by the geographical user distribution and derive a suitable selection strategy of power levels under the constraint more accurately than the existing models. Our analytical results showed that our framework analyzed the throughput with only an analysis error of 0.1% compared with the Monte Carlo simulations, although the existing model overestimated 58% higher throughput. By using the proposed analytical model, our results presented decreasing the achievable throughput with increasing the coverage range. This paper also proposes a heuristic method based on our proposed analytical model to derive a suitable selection strategy of power levels. Our results highlight that the derived selection strategy on our analytical framework achieved 20 higher throughput than the baseline strategy, where each user randomly selects a power level under the power level constraint

Focal Surface Projection: Extending Projector Depth-of-Field Using a Phase-Only Spatial Light Modulator

We present a focal surface projection to solve the narrow depth-of-field problem in projection mapping applications. We apply a phase-only spatial light modulator to realize nonuniform focusing distances, whereby the projected contents appear focused on a surface with considerable depth variations. The feasibility of the proposed technique was validated through a physical experiment

Research into Development of Beliefs about the Goals and Purposes of Science Teaching : Analysis of Life Stories of Five Experienced Science Teachers

本研究では，理科教師の信念に関する先行研究の精査と５名の熟練理科教師のライフストーリーの分析により，理科教授の目的・目標についての信念の発達を明らかにすることを通じて，現職教育及び教員養成教育において理科教授の目的・目標についての信念を発達させることの価値とその具現化に向けた示唆を得ることを目的とした。まず，先行研究を精査し，理科教授の目的・目標についての信念という概念を明確化した。次に，信念の発達を明らかにすることに適した研究の方法論としてライフストーリーを採用し，それに基づいたインタビュー調査を計画・実施した。さらに，得られた語りを分析し，学校の内外を問わず様々な経験が理科教授の目的・目標についての信念を明確にするような影響を与えていること，学校外での経験をきっかけとして新たな概念が理科教授の目的・目標についての信念に加わる場合があること，理科教師になった時点で保持していた理科教授の目的・目標についての信念が教職生活を通じて変わっていないことを明らかにした。以上の結果を踏まえ，教職生活における理科教授の目的・目標についての信念の発達が学校内外における理科教師の連続的な学びとして捉えられること，教員養成教育が理科教授の目的・目標についての信念を構築する場として重要な役割を担っていること，という現職教育及び教員養成教育において理科教授の目的・目標についての信念を発達させることの価値とその具現化に向けた示唆を得た。This research, through analysis of five experienced science teachers’ life stories, was done to further evaluate prior research into beliefs of science teachers. Furthermore, it attempts to clarify the development of beliefs about the goals and purposes of science teaching to show how beliefs about the goals and purposes of science teaching develop through pre- and in-service teacher education/training, the value of this, and suggestions towards the realization of this. First, an overall concept of beliefs about the goals and purposes of science teaching is clarified by further evaluation of prior research. Next, life story was utilized as a research methodology for the clarification of belief development, and an interview survey was planned and conducted based on this methodology. The stories gained were analyzed, and the facts that various experiences, whether in or out of school, have an influence to clarify beliefs about the goals and purposes of science teaching, that there are cases where experiences outside of school can provide motivation for adding new concepts to one’s beliefs about the goals and purposes of science teaching, and that beliefs about the goals and purposes of science teaching that were held at the time of becoming a science teacher do not change throughout a professional career, were all made clear. Based on the above results, the development throughout one’s professional career concerning beliefs about the goals and purposes of science teaching is perceived as part of a science teacher’s consecutive professional learning, which happens in and out of school. Pre-service teacher education should make a vital role as giving an opportunity for developing beliefs about goals and purposes of science teaching. Suggestions were gained for how to realize development of beliefs about the goals or purposes of science teaching through pre- and in-service teacher education, as well as the value of this

Research into Development of Beliefs about the Goals and Purposes of Science Teaching : Analysis of Life Stories of Five Experienced Science Teachers

This research, through analysis of five experienced science teachers’ life stories, was done to further evaluate prior research into beliefs of science teachers. Furthermore, it attempts to clarify the development of beliefs about the goals and purposes of science teaching to show how beliefs about the goals and purposes of science teaching develop through pre- and in-service teacher education/training, the value of this, and suggestions towards the realization of this. First, an overall concept of beliefs about the goals and purposes of science teaching is clarified by further evaluation of prior research. Next, life story was utilized as a research methodology for the clarification of belief development, and an interview survey was planned and conducted based on this methodology. The stories gained were analyzed, and the facts that various experiences, whether in or out of school, have an influence to clarify beliefs about the goals and purposes of science teaching, that there are cases where experiences outside of school can provide motivation for adding new concepts to one’s beliefs about the goals and purposes of science teaching, and that beliefs about the goals and purposes of science teaching that were held at the time of becoming a science teacher do not change throughout a professional career, were all made clear. Based on the above results, the development throughout one’s professional career concerning beliefs about the goals and purposes of science teaching is perceived as part of a science teacher’s consecutive professional learning, which happens in and out of school. Pre-service teacher education should make a vital role as giving an opportunity for developing beliefs about goals and purposes of science teaching. Suggestions were gained for how to realize development of beliefs about the goals and purposes of science teaching through pre- and in-service teacher education, as well as the value of this.This article translated into Japanese is published in the journal Gakushu Shisutemu Kenkyu, Vol.3

Dehydrocostus lactone, a naturally occurring polar auxin transport inhibitor, inhibits epicotyl growth by interacting with auxin in etiolated Pisum sativum seedlings

We have isolated germacranolide-type sesquiterpene lactones with an α-methylene-γ-lactone moiety, dehydrocostus lactone (DHCL), costunolide, santamarine, and a novel compound denoted artabolide [3-hydroxy-4,6,7(H)-germacra-1(10),11(13)-dien-6,12-olide] from oriental medicinal Asteraceae plants as novel naturally occurring inhibitors of polar auxin transport detected by the radish hypocotyl bioassay. To investigate the mode of action of natural sesquiterpene lactones on the inhibition of polar auxin transport as well as its relation to the growth of seedlings, the function of DHCL on growth and auxin dynamics in etiolated pea seedlings was studied intensively. DHCL reduced polar auxin transport in a dose-dependent manner together with the inhibition of the accumulation of mRNA of PsAUX1 and PsPIN1 genes encoding influx and efflux carrier proteins of auxin, respectively. DHCL applied to the apical hook region as a lanolin paste substantially inhibited elongation growth in the subapical region of epicotyls in intact etiolated pea seedlings, coupled with a significant reduction of endogenous levels of indole-3-acetic acid (IAA). DHCL also revealed the inhibition of IAA-induced cell elongation in etiolated pea epicotyl segments by affecting IAA-induced changes in the mechanical properties of cell walls. These facts suggest that germacranolide-type sesquiterpene lactones with an α-methylene-γ-lactone moiety affect the expression of PsAUX1 and PsPINs genes, and then inhibit polar auxin transport and reduce endogenous levels of IAA necessary for stem growth in etiolated pea seedlings. These compounds are also suggested to show the inhibitory effects on auxin action in pea stem growth

Feasibility Study of a Wearable Haptic knob System

In this study, we develop an event-based wearable haptic knob system that can be used in three-dimensional space. The first step involves building custom-built brakes and attaching them to a human forearm to achieve a wearable haptic knob. The display is built using a carbon-fiber frame. As our system is experiment-based, target torque curves are collected by a force sensor before using the torque representation. We confirm the effectiveness of our developed display through three operations, namely doorknob rotation, valve closing, and valve opening by the test subject. In the first step, the rotational axis was fixed on a table. These results are then used to develop the perfect wearable haptic system that includes a rotational axis in the display