50 research outputs found
Studies on facial recognition in the cooperatively breeding fish, Neolamprologus pulcher
No full textThe Union Wage Premium, Voice, and Nonunion Workers' Attitudes: Before and After Japan's Lost Decade
No full textUsing microdata derived from the same questionnaire surveys conducted in 1992 and 2007, this paper examines changes in the economic effects of labor unions and attitudes toward unionization among nonunion workers in Japan. The main findings are as follows. First, while no union wage effects were observed in 1992, a wage premium for male workers was found in 2007. However, no change was observed for female workers. Second, with regard to union voice effects, no such effect was evident in 1992, but in 2007, a decline among men in the propensity for voluntary quitting (and, to some extent, job satisfaction) was found. In contrast, among women, no such union voice effects could be detected. Third, among male nonunion workers, support for unionization had increased between 1992 and 2007. On the other hand, the increase in support for unionization among female nonunion workers was scant when compared with that for their male counterparts. Furthermore, if there were other, nonunion forms of representing employees' voice at the workplace, this largely substituted for female support for unionization.
Electrochemistry of room temperature ionic Liquids with applications to electrospray propulsion
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 168-182).Room Temperature Ionic Liquids (RTILs) exhibit a number of physical properties that have opened new doors for technological advancements in space-based micropropulsion, focused ion beam, energy storage, and other research and industrial applications. As a family of concentrated electrolytes, RTIL electrochemical properties deviate from classical theories whose mean-field approach glossed over effects arising from the constituent ions' size and shape. Further development in the understanding of RTIL electrochemistry will drive better design towards enabling technologies, and this research contributes to the growing body of experimental data for RTIL electrochemical behavior with particular focus on applications towards electrospray propulsion devices. Electrochemical system behavior is governed by interfacial properties, in particular the electrical double layer (EDL).With no neutral solvent to fill the space between ions, the RTIL EDL takes on a complex, multilayered structure which lead to properties distinct from traditional aqueous electrolytes. A direct consequence of the layered structure is a differential capacitance curve that exhibits a local minimum at the potential of zero charge, flanked by two peaks followed by decaying wings. Recent modeling efforts have begun to capture these effects qualitatively, but require further tuning in order to quantitatively describe real systems. An electrochemical cell was designed to allow experimental measurement of capacitance curves, and the curves for two previously unreported RTILs are presented. The electro-chemical window is a limiting potential at which electrochemical reactions start. RTILs typically have large windows on the order of 4-6V, as compared to the 1.229V at which water begins electrolysis.In micropropulsion, a large electrochemical window allows for longer continuous operation without adverse reactions. In energy storage, this allows for higher energy capacity by the square of potential. Another way to increase emission duration or capacity is by increasing the available electrode surface area, so that more charge can be stored before breaching the stability window. Porous materials can provide enormous specific areas, with the carbonized resorcinol-formaldehyde synthesized in this work giving approximately 1m² g-¹ of electrode surface. Through a systematic comparison of this porous electrode and a flat metal electrode, it was confirmed that an electrode with mean pore size of approximately 2 [mu]m locally exhibits the same impedance as at a nonporous surface. Two electrospray emitter devices were used to study the charging dynamics of flat and porous electrodes under constant current charging.Electrode charging was observed to be governed not only by capacitance, but also by ion species, current polarity, current magnitude, and ion transport dynamics. Using the Scalable ion Electrospray Propulsion System, a 480-emitter thruster developed in the Space Propulsion Laboratory at the Massachusetts Institute of Technology, it was also shown that large charging currents saturated the effects of current magnitude and resulted in charging dynamics that collapse together when parametrized by surface charge density. The work concludes by using the observed trends to propose several guidelines for future electrode design in electrospray applications. Electrospray propulsion in particular promises to become an area of concentrated research as micro- and nano-satellites enter the market. Current propulsion systems cannot be effectively miniaturized for use on such platforms, but electrospray thrusters have demonstrated packaging in the 1 cm3 range including the fuel reservoir.In addition, the next step in the recently popular field of gravitational waves will employ space-based observatories, with the LISA Pathfinder technology demonstrator testing an RTIL-based propulsion system for its fine resolution control. It is the hope of the author that the work presented here will contribute to the further refinement of theoretical understanding of RTILs and provide guidance in the design of future RTIL-based technologies.by Kento Masuyama.Ph. D
College Quality and Earnings in the Japanese Labor Market
No full textThe motivations underlying the pursuit of college prestige in Japan presumes a labor market that rewards workers according to the quality of the college that they attended. Yet, studies that examine the relationship between college quality and earnings in Japan remain few and riddled with shortcomings. This paper examines the returns to college education among Japanese men. Using a 1995 cross-sectional data of Japanese workers, I find that college quality significantly improves earnings. My findings confirm that college quality plays a crucial role in shaping both incentives and earnings in the Japanese labor market. The paper also examines the so-called distinctive features of the Japanese labor market, and confirms the significant impact of tenure and firm-size on earnings, and the similarity in the earnings profiles between blue- and white-collar workers.human capital formation; returns to education
The research of the An Ho-san's Educational Activities --around the time between 1945 and 1950--
No full text本研究は, 韓国の初代文教部長官(日本の文部科学大臣に相当)である安浩相(アンホサン)の教育思想の実現に関する研究である. 具体的には1945年(日本の植民地支配から解放された年)から文教部長官に就任する1948年までの教育に関する安浩相の考えを分析し, 文教部長官に在任した2年間にかけて自らの考えを実際の政策及び法律の実現に向けてどのように行動し実現させたのかを検証することである. 筆者は, 安浩相の考えは, 教育法の制定や学生団体の設立において多くが実現されたという仮説を提示した. 同仮説に基づいて分析を行った結果, 6・3・3・4 制の学制や「弘益人間」概念の導入, 民族主義教育や義務教育について一貫した考えを持っており, 実際の法律制定や政策としての文盲退治運動とハングル使用の奨励, 学徒護国団の設立において彼の考えが反映されたことが明らかになった.This article is researched about the educational ideas of An Ho-san who is the first education minister in Korea. Especially, it is to analyze An Ho-san ʻs thoughts on education from 1945 to 1948, the year of liberation from Japan's colonial rule, and researched how much realized his ideas into actual law for two years before stepping down after taking office as education minister. The author suggested that An Ho-san's idea was largely realized in the establishment of educational laws and student organizations. As a result of the analysis based on this hypothesis, it became clear that he had a consistent idea about the introduction of the 6/3/4 school system, the concept of "Hongik Ingan" and nationalist and compulsory education, and his idea was reflected in the actual legislation, the promotion of the eradication of literary blindness and the use of Hangul as a policy, and the establishment of a student protection group
3‐Azafluorenone Derivatives with Small HOMO–LUMO Gaps, Allowing Visible‐Light Absorption
No full textThis is the accepted version of the following article: Kobayashi Toshimichi, Itabashi Yuki, Iwai Kento, et al. 3‐Azafluorenone Derivatives with Small HOMO–LUMO Gaps, Allowing Visible‐Light Absorption. Chemistry – An Asian Journal, e70415 (2025),which has been published in final form at https://doi.org/10.1002/asia.70415. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html]A versatile synthetic strategy for 3-azafluorenone derivatives was developed. The strategy enabled efficient access to previously inaccessible structural analogs. Crucially, tert-butyl protection of ketocarboxylic acid intermediates significantly improved isolated yields and enabled the incorporation of electron-donating, electron-withdrawing, and π-extended substituents. The photophysical properties of the compounds were characterized by UV–Vis absorption and fluorescence spectroscopic measurements, and the electrochemical behavior was monitored using cyclic voltammetry. The electron-donating and π-extended substituents induced pronounced bathochromic shifts in absorption and emission, consistent with the narrowing of the HOMO–LUMO gap, whereas strong electron-withdrawing groups or 6-methoxy substitution caused a slight hypsochromic shift. Nitrogen incorporation and electron-withdrawing substituents stabilized the LUMO, affording more positive ground- and excited-state reduction potentials. Most derivatives exhibited higher excited-state reduction potentials than fluorenone, with the majority exceeding +1.6 V versus saturated calomel electrode (SCE). Further, time-dependent density functional theory (TD-DFT) calculations reproduced the observed spectral trends and oscillator strengths, confirming the π–π* nature of the lowest-energy transitions. All derivatives exhibited intense, red-shifted visible light absorption, and most showed high excited-state reduction potentials, demonstrating their potential for photoredox applications. These results establish detailed structure–property relationships for 3-azafluorenones, providing design principles for the rational tuning of optical and redox properties
Fabrication of amorphous InGaZnO thin-film transistor with solution processed SrZrO3 gate insulator
No full textRefined topological recursion revisited -- properties and conjectures
No full textFor any (possibly singular) hyperelliptic curve, we give the definition of a hyperelliptic refined spectral curve and the hyperelliptic refined topological recursion, generalising the formulation for a special class of genus-zero curves by Kidwai and the author, and also improving the proposal by Chekhov and Eynard. Along the way, we uncover a fundamental geometric structure underlying the hyperelliptic refined topological recursion and investigate its properties -- parts of which remain conjectural due to computational difficulties. Moreover, we establish a new recursion valid in the so-called Nekrasov-Shatashivili limit and prove existence of the corresponding quantum curve.minor changes in presentation, accepted version to CM
Previous mating experience increases fighting success during male-male contests in the hermit crab Pagurus nigrofascia
No full textPrior social experience often affects subsequent competitive interactions and their outcomes. Although the effects of prior contest experience have been widely examined, effects of mating experience remain less well examined. We examined, in males of the hermit crab Pagurus nigrofascia, whether males successively copulated with more than one female and whether males with copulation experience differed in their subsequent contest behaviors and probability of winning in male-male contests compared to males without copulation experience. The copulation experience of intruders was manipulated and the contest behaviors compared between mated and unmated groups. Males mated with several females regardless of the male body size. Compared with unmated intruders, intruders with mating experience succeeded more often in taking over females and did so within a shorter period particularly when the male-male contests occurred over females with a long time to molt. These results suggest that mated males of P. nigrofascia overestimate the female quality and/or enhance the competitive performance similar to the "winner effect" that is a positive feedback from prior winning experience to future contests
