視覚マスキング効果を考慮した電子ディスプレイのアドレス駆動電力削減に関する研究

電子ディスプレイの消費電力削減は昔からの大きな研究テーマであるが，昨今の画素数の増加はアドレス駆動回路の電力の増加を促し，これを削減することが重要な課題となっている．本論文は，映像信号に視覚マスキングを主体とした視覚特性を利用した画像処理を施すことにより，画質を保持しながらアドレス駆動電力の削減を可能とする表示方式の構築と，その有効性を確認するために実施した主観評価実験についてまとめたものである．視覚マスキング効果の定量的評価手法，プラズマディスプレイおよびMEMS シャッター方式ディスレイのアドレス駆動電力の削減を目指した表示方式の構築について以下の7 章にまとめた．第1 章では，電子ディスプレイの消費電力の削減が求められている研究の背景と目的などを述べた．第2 章では，視覚マスキングの概要と先行研究において明らかにされている視覚マスキングの特徴を述べた．本論文で提案する手法では，アドレスデータを平滑化することで信号の遷移回数を減らし消費電力を低減する．この際に画素値の誤差（以降平滑化誤差と称する）が生じる．この平滑化誤差と背景画像との間に働く視覚マスキングについて考察した．平滑化誤差はランダムノイズに似た空間周波数特性を有する．平滑化誤差と背景画像との間で視覚マスキングが生じる要因について考察し，その中から本論文では空間周波数特性，コントラスト，平均輝度の3 つの特徴量に着目することにした．第3 章では，平滑化誤差と背景画像間の視覚マスキング効果を定量的に判定する手法を提案した．まず，コントラストと平均輝度をブロック状に段階的に変化させた画像を背景画像とし，それに平滑化誤差を想定した信号（白色ガウスノイズあるいはインパルスノイズ）を加え，その信号が視覚マスキングにより視認されなくなる平均画素値とコントラストの条件を求めた．なお2 つの刺激の空間周波数特性が一致する時に最も視覚マスキングが強くなるという知見に基づいて，コントラストと平均輝度を変化させた画像と加える信号の空間周波数特性は一致させている．次に自然画像において，求まった条件に該当する領域を抽出する手法を述べた．この領域のみでアドレスデータの平滑化処理を行うことにより画質の低下を防ぐことが可能となる．領域抽出のために，類似輝度セグメントと呼称する指標を導入した．これは，画像を局所的に類似した濃度を有するセグメントに分割し，セグメントの大きさで3 つの特徴量を間接的に取得できる指標で，3 つの特徴量を直接演算で取得するよりも容易に求めることができる．第4 章では，ノイズを含んだ画像からノイズを除去して画像を復元するという画像処理において，第3 章で提案した視覚マスキング領域抽出手法を応用しその効果の検証を行った．視覚マスキングの強さに従って画像をいくつかの領域に分け，領域ごとにノイズフィルタの強度を調整する．視覚マスキング効果によりノイズが視認されないと判定された領域では，スムージングを行わないことで，細かいテクスチャなどの高周波情報を保存できることを示した．これによりノイズが効果的に除去され，提案手法が有効であることを確認した．第5 章では，視覚マスキングにより平滑化誤差が視認されない領域の抽出手法をプラズマディスプレイに適用した表示方法を提案した．アドレスデータの平滑化を行う際に平滑化誤差が生じ画質劣化の原因となるが，抽出された領域のみでアドレスデータを平滑化することで，平滑化後の画質を維持しつつアドレス駆動回路の容量性負荷で生じる電力損失を削減する．241 枚の評価画像に提案手法を適用し，電力損失と比例関係にあるアドレスデータの遷移回数がおよそ50%削減できることを確認した．この結果から，アドレス駆動回路での電力損失を半減できる見込みを得た．また，主観評価実験により，平滑化後の画質は平均オピニオン評点が4 以上と高い評価であることを確認した．第6 章では，提案方式をMEMS シャッター方式ディスプレイへ応用し，アドレス駆動回路の電力を削減する表示方式を提案した．平滑化誤差が視認されない領域のみでサブフィールド間のアドレスデータを平滑化することで，1 フィールド期間のシャッターの開閉回数を減らし，シャッターを制御している静電容量型アクチュエータの駆動電力を削減する．241 枚の評価画像に提案手法を適用して，アドレスデータの平滑化後のシャッターの開閉回数の削減率がおよそ25%になること，および平滑化後の画像で画質が維持されていることを確認した．第7 章では纏めとして，本研究の成果，残された課題，および将来への展望について記した．電気通信大学201

Time In American High Modernism: Reading Fitzgerald, Hemingway, And Faulkner

There were important changes about understanding of time in the early 20th century. Newtonian view of time that supports linearity and irreversibility of time was challenged in various fields. This trend promoted high modernists to seek new representations of time. On the whole, high modernists denied Newtonian view of time and tried to describe merging of the past, the present, and the future. They often envisioned a romantic moment, in which this merging is perfectly achieved. But unlike European high modernists, American high modernists were more attracted to a traditional understanding of time that emphasizes a decisive difference between the past and the present, or the present and the future. As a result, two almost contradictory ideas about time, the traditional and the advanced, coexist in their works, which gives uniqueness to the works of American high modernists. Also, in their works, a romantic moment appears in the past, which is decisively different from the present, while it often appears in the present in the works of European high modernists. In The Great Gatsby Scott Fitzgerald depicts Nick, a modern man who has a complex sense of time. Nick tries to dramatize Gatsby, create a meaningful time by telling a mythic tale, and redeem his past, which proves futile in the end. However, the novel also shows a romantic moment in the past, in which the present and the past merge and time is redeemed. In his short stories, Hemingway tried to achieve the merging of time by imposing the present on the past or the future on the present with his unique style. But this style also makes clearer the boundary between each tense. This representation of time, which embraces internal contradiction, clearly shows conflict of Hemingway as a high modernist, who was torn between new and old understandings of time. The Sound and the Fury shows that Faulkner was obviously conscious of how the previous high modernists represent time. He examines problems concerning various ways of recognition of time, including paradox inherent in recognition of time, and proposes Bergsonian view of time to overcome those problems

A FUNDAMENTAL STUDY ON BASEBALL BATTING MOVEMENT FOCUS ON SLAPPING

The purpose of this study is to generate baseball batting style to hit more certainly and to investigate effectiveness it. The idea for new batting referred to bunt and slap hitting used by softball. This new batting style was named A Kourituteki Batting (AKB). 4 male university students participate in this experiment. Subject tried to swing 30 fast balls thrown from pitching machine. 30 trials were divided into 3 groups (right-handed, left-handed, AKB). The result of AKB is higher than left-handed groups. And, the height of loin for AKB is higher than the other groups. This result shows that it may be possible for a using AKB hit a ball more in batter box him always in. This experiment will be useful for considering more developed batting technique in baseball after this

An Extension of Proof Graphs for Disjunctive Parameterised Boolean Equation Systems

A parameterised Boolean equation system (PBES) is a set of equations that defines sets as the least and/or greatest fixed-points that satisfy the equations. This system is regarded as a declarative program defining functions that take a datum and returns a Boolean value. The membership problem of PBESs is a problem to decide whether a given element is in the defined set or not, which corresponds to an execution of the program. This paper introduces reduced proof graphs, and studies a technique to solve the membership problem of PBESs, which is undecidable in general, by transforming it into a reduced proof graph. A vertex X(v) in a proof graph represents that the data v is in the set X, if the graph satisfies conditions induced from a given PBES. Proof graphs are, however, infinite in general. Thus we introduce vertices each of which stands for a set of vertices of the original ones, which possibly results in a finite graph. For a subclass of disjunctive PBESs, we clarify some conditions which reduced proof graphs should satisfy. We also show some examples having no finite proof graph except for reduced one. We further propose a reduced dependency space, which contains reduced proof graphs as sub-graphs if a proof graph exists. We provide a procedure to construct finite reduced dependency spaces, and show the soundness and completeness of the procedure

A Questionnaire System with an Authentication Framework Considering Online Activities of Users

It is difficult to distribute online questionnaire adequately to those subjects who satisfy requirements of investigations. In addition, low questionnaire response rates, because of factors such as overlooking request emails and noncooperation to answer the questionnaires, sometimes annoy the investigators. Now that today’s organizational systems adopt a unified authentication framework of which logging function stores authentication records of users in federated systems, the possible solution for these problems arises by utilizing the log data and adding the questionnaire process to the framework. The present paper proposes a flow controlling mechanism arranged in a major unified authentication framework and describes how to utilize log data on the framework to select target persons for questionnaires and increase the response rates

Periostin-expressing cell-specific transforming growth factor-β inhibition in pulmonary artery prevents pulmonary arterial hypertension

Transforming growth factor beta (TGF-β) has been shown to play a critical role in pathogenesis of pulmonary arterial hypertension (PAH) although the precise role of TGF-β signaling remains uncertain. A recent report has shown that periostin (Pn) is one of the most upregulated proteins in human PAH lung compared with healthy lungs. We established type I TGF-β receptor knockout mice specifically with Pn expressing cell (Pn-Cre/Tgfb1fl/fl mice). Increases in PA pressure and pulmonary artery muscularization were induced by hypoxia of 10% oxygen for 4 weeks. Lung Pn expression was markedly induced by 4 week-hypoxia. Pn-Cre/Tgfb1fl/fl mice showed lower right ventricular pressure elevation, inhibition of PA medial thickening. Fluorescent co-immunostaining showed that Smad3 activation in Pn expressing cell is attenuated. These results suggest that TGF-β signaling in Pn expressing cell may have an important role in the pathogenesis of PAH by controlling medial thickening

Specific gene expression in unmyelinated dorsal root ganglion neurons in nonhuman primates by intra-nerve injection of AAV 6 vector

霊長類においてウイルスベクターを用いた痛覚神経への遺伝子導入に成功 --神経障害性疼痛治療への応用に期待--. 京都大学プレスリリース. 2021-08-12.Adeno-associated virus 6 has been proposed as a potential vector candidate for specific gene expression in pain-related dorsal root ganglion neurons, but this has not been confirmed in nonhuman primates. The aim of our study was to analyze the transduction efficiency and target specificity of this viral vector in the common marmoset by comparing with those in the rat. When green fluorescent protein-expressing serotype-6 vector was injected into the sciatic nerve, the efficiency of gene expression in dorsal root ganglion neurons was comparable in both species. We found that the serotype-6 vector was largely specific to the pain-related ganglion neurons in the marmoset as well as in the rat, whereas the serotype-9 vector resulted in contrasting effects in the two species. Neither AAV6 nor AAV9 resulted in DRG toxicity when administered via the sciatic nerve, suggesting this as a safer route of sensory nerve transduction than the currently used intrathecal or intravenous administrative routes. Furthermore, the adeno-associated virus 6 vector could be an optimal serotype for gene therapy for human chronic pain that has minimal effect on other somatosensory functions of dorsal root ganglion neurons

Magnetohydrodynamic hybrid simulation model with kinetic thermal ions and energetic particles

A new kinetic-magnetohydrodynamic hybrid simulation model where the gyrokinetic particle-in-cell simulation is applied to both thermal ions and energetic particles is presented. Toroidal Alfvén eigenmodes (TAEs) destabilized by energetic ions in tokamak plasmas are simulated with the new simulation model. Energy channeling from energetic ions to thermal ions through Alfvén eigenmodes (AEs) is demonstrated by the simulation. The distribution function fluctuations and the resonance condition are analyzed for both thermal ions and energetic ions. The strong energy transfer between the particles and the AE and the strong particle transport occur when the following conditions are satisfied at the resonance location in phase space: (1) the poloidal resonance number is close to the poloidal mode number of the AE, (2) the AE has a substantial amplitude, (3) the distribution function has a substantial gradient along the $E^{^{\prime}} = \textrm{const.}$ line, where $E^{^{\prime}}$ is a conserved variable for the wave-particle interaction. While the distribution function fluctuations for energetic ions are consistent with the resonance condition with the TAEs, the distribution function fluctuations for thermal ions do not satisfy the resonance condition when the bulk plasma beta is 1%. This indicates that the resonance does not play an important role in the interaction between thermal ions and the TAE for the relatively low bulk plasma temperature. On the other hand, when the bulk plasma beta is 4%, the resonance between thermal ions and the TAEs become important leading to Landau damping

Improvement of Automatic Physics Data Analysis Environment for the LHD Experiment

The physical data of the Large Helical Device (LHD) project have been serviced by the Analyzed Data Server system, and approximately 600 kinds of physical data are served. In order to execute simulation programs for the LHD experiment, one must gather sets of physical data. Because the Automatic Analyzed Server (AutoAna) calculates the physical data automatically, it eases the scientist’s task of collecting these physical data. The AutoAna has provided better computing environments for the scientists. Thus, the scientists, having recognized its benefits, make various requests as issues arise. In this paper, the authors introduce the current status of the AutoAna system

Precession drift reversal and rapid transport of trapped energetic particles due to an energetic particle driven instability in the Large Helical Device

Energetic particle transport by a magnetohydrodynamic (MHD) instability driven by helically trapped energetic particles is studied for a high-performance Large Helical Device plasma with kinetic-MHD hybrid simulations. It is observed in the simulation that an MHD mode with poloidal/toroidal mode numbers ????/????=2/1driven by helically trapped energetic particles causes a significant redistribution of perpendicular energetic particle pressure profile. The frequency of the MHD mode decreases rapidly at the saturation of the instability and changes sign, which indicates a reversal of the mode propagation direction. It is found that the helically trapped energetic particles interacting strongly with the MHD mode change the precession drift direction at the same time as the reversal of the MHD mode propagation direction. The helically trapped energetic particles with the precession drift reversal are transported rapidly in the radially outward direction before the original precession drift direction is recovered. The precession drift reversal and the outward transport are caused by interaction with the electric field of the MHD mode. The vast majority of trapped energetic particles which interact strongly with the MHD mode experience precession drift reversal, leading to a significant redistribution of the perpendicular energetic particle pressure profile.Numerical computations were performed on the Plasma Simulator (NEC SX-Aurora TSUBASA) of NIFS with the support and under the auspices of the NIFS Collaboration Research program (No. NIFS20KNST169), the JFRS-1 of the International Fusion Energy Research Centre, and the Supercomputer Fugaku of the RIKEN Center for Computational Science (Project ID: hp210178). This work was supported by MEXT as Program for Promoting Research studies on the Supercomputer Fugaku (Exploration of burning plasma confinement physics)