44 research outputs found

    Reliable Multivalued Conductance States in TaOx, Memristors through Oxygen Plasma-Assisted Electrode Deposition with in Situ-Biased Conductance State Transmission Electron Microscopy Analysis

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    Transition metal oxide-based memristors have widely been proposed for applications toward artificial synapses. In general, memristors have two or more electrically switchable stable resistance states that device researchers see as an analogue to the ion channels found in biological synapses. The mechanism behind resistive switching in metal oxides has been divided into electrochemical metallization models and valence change models. The stability of the resistance states in the memristor vary widely depending on: oxide material, electrode material, deposition conditions, film thickness, and programming conditions. So far, it has been extremely challenging to obtain reliable memristors with more than two stable multivalued states along with endurances greater than similar to 1000 cycles for each of those states. Using an oxygen plasma-assisted sputter deposition method of noble metal electrodes, we found that the metal-oxide interface could be deposited with substantially lower interface roughness observable at the nanometer scale. This markedly improved device reliability and function, allowing for a demonstration of memristors with four completely distinct levels from similar to 6 x 10(-6) to similar to 4 x 10(-8) S that were tested up to 10(4) cycles per level. Furthermore through a unique in situ transmission electron microscopy study, we were able to verify a redox reaction-type model to be dominant in our samples, leading to the higher degree of electrical state controllability. For solid-state synapse applications, the improvements to electrical properties will lead to simple device structures, with an overall power and area reduction of at least 1000 times when compared to SRAM.11Ysciescopu

    Changing school from the outside: teenage girl feminist activism in the South Korean SchoolMeToo Movement

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    This thesis explores how girl activists change school culture in the context of the South Korean SchoolMeToo movement through their teenage girl feminist activism. Specifically, the study intends to understand the ways through which girl activists challenge school culture that silences sexual harassment against schoolgirls and promote a culture of equality in schools through their activism from the outside. The study is situated within academic scholarship which views school-based sexual harassment as a structural problem upheld by multiple axes of power relations in play (Robinson, 2012), distinct from school violence due to its focus on gender and sexuality in nature (Meyer, 2008). In line with the childhood studies paradigm which emphasises the significance of studying with girl activists as social actors in their own lives (Prout & James, 1990), the study discusses how girl activists identify, critique, and resist the adultist structures and heterosexual gender orders that regulate both their experiences in schools and participation in activism. Against the backdrop of ever-increasing scholarly attention on childrenā€™s participation rights and child activism (Tisdall & Cuevas-Parra, 2022), the study contributes to a growing body of literature by incorporating gender lens and everyday practices within their daily contexts as essential elements in constructing teenage girl feminist activism (Taft, 2010). A one-year ethnography was conducted with eleven girl activists in the social movement organisation ā€˜Teenager Feminist Network: WeTeeā€™ in South Korea. Data was generated by fieldnotes and documents (e.g. statements, essays, workshop activity materials, and project proposals) gathered by conducting participant observation in various settings where teenage girl feminist activism was organised and practised (e.g. activist projects addressing teenage girl sexuality, political participation, and feminist education, book seminars, weekly group meetings, protests, and workshops). Semi-structured individual interviews with each activist based on the fieldnotes followed. The findings of the study showed how adultist structures reinforced and conflicted with heterocentric gender orders in schools to construct ambivalent schoolgirl femininities and sexualities, and obstruct schoolgirlsā€™ critical awareness against them to be raised. Additionally, girl activistsā€™ experiences revealed how adultism, coupled with anti-feminism, limited schoolgirlsā€™ resistances against sexual harassment inside schools and within the SchoolMeToo movement. By identifying these structural forces regulating schoolgirls, girl activists set their aims of teenage girl feminist activism, which was to position schoolgirls as social agents of change, and transform the school culture by paying attention to the multiple and intersecting power relations that sustain silencing of schoolgirls. Teenage girl feminist activism was practised in two distinct but interrelated ways: everyday activism inside the organisation aiming for a culture of equality and collegial relationships among themselves, and demands-based approaches to generate structural changes in schools. Pursuing feminist and childist principles as core drivers for their teenage girl feminist activism, girl activists developed ways to practise feminism in teenage activist-centred ways and further demanded reconstruction of teenage girls as sexual subjects and political agents, and argued for a childist turn in feminist education. The key contribution of the study has been to highlight why teenage girl feminist activism aiming to challenge the school culture was organised from outside schools by identifying multiple axes of power relations manifest in schools through girl activistsā€™ reflections on schools. Additionally, by interpreting the SchoolMeToo movement and remaining challenges through teenage girl feminist activism lens, the study suggests what changes need to be made in schools so that schoolgirls have the ability to participate in challenging the sexual harassment culture inside schools

    Religious Engagement and Successful Aging among Korean Older Adults

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    The rate of aging is growing faster than ever. The global society must prepare adequate measures to support this imminent change. Following this social trend, research has been conducted on the quality of life of the aging population in a different fields, including gerontology. Since the idea of successful aging was conceptualised, research on the quality of life of older adults has been actively conducted. The current study aims to contribute to the aging research field by adding a factor (religious engagement) to Rowe and Kahnā€™s model. We utilized the longitudinal design to examine the longstanding effect of demographic, physical, social, psychological, and religious factors on life satisfaction among older Korean adults (N = 4013). Hierarchical regression analyses were employed to understand how these factors influence older adultsā€™ life satisfaction in a nationally representative sample. Study findings indicated (a) after controlling for demographic background, all subdimensions of physical, social, psychological, and religious factors exerted a significant effect on later life satisfaction; (b) the final model showed that highly educated, regular exercise, frequent meeting with friends and family, less depressed, feeling less lonely, and higher religious engagement ultimately affected the subsequent life satisfaction of Korean older adults; (c) among different variables, psychological health and religious engagement were found to be crucial factors. The findings confirm the explanatory power of successful aging theory while providing empirical evidence that religious engagement may be an additional factor contributing to enhancing the life satisfaction of older adults

    Captivate! Contextual Language Guidance for Parentā€“Child Interaction

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    Ā© 2022 ACM.To acquire language, children need rich language input. However, many parents find it difficult to provide children with sufficient language input, which risks delaying their language development. To aid these parents, we design Captivate!, the first system that provides contextual language guidance to parents during play. Our system tracks both visual and spoken language cues to infer targets of joint attention, enabling the real-time suggestion of situation-relevant phrases for the parent. We design our system through a user-centered process with immigrant families - a highly vulnerable yet understudied population - as well as professional speech language therapists. Next, we evaluate Captivate! on parents with children aged 1-3 to observe improvements in responsive language use. We share insights into developing contextual guidance technology for linguistically diverse families1.N

    Rheumatoid Meningoencephalitis: A Feared Condition in the Era of TNF Blockers

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    Central nervous system (CNS) involvement in rheumatoid arthritis (RA) is uncommon, and most of the times, it is secondary to vasculitic processes or extra-articular rheumatoid nodules. Meningeal involvement is extremely rare. In the literature, there are a few case reports, series, and retrospective studies which have demonstrated the association of rheumatoid (aseptic) meningoencephalitis after starting tumor necrosis factor (TNF) inhibitors. We present a case of rheumatoid meningoencephalitis (RME) in a 52-year-old male with a history of RA on adalimumab who presented with headaches associated with motor and sensory deficits, all of which resolved after this diagnosis was achieved and received appropriate therapy with high-dose glucocorticoids. We also present an update with high yield points summarizing clinical features, diagnostic workup, and management of RME. Finally, we post a literature review of relevant CNS rheumatoid disease in patients with and without exposure to TNF inhibitors

    Gender differences and socioeconomic status in relation to overweight among older Korean people.

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    BACKGROUND: The ever-increasing older population and its association with serious overweight problems have garnered much attention. The correlation between being overweight and socioeconomic status factors could be helpful for understanding the inequalities among the overweight population. We examined the correlation between being overweight and some key variables, such as demographics, socioeconomic status, general health status, and health behavior in a large sample of older individuals, by each gender. METHODS: We used data from the 2008 Korean Longitudinal Study of Aging and it included 8,157 participants who were 45 years or older. To understand the relationship between the overweight participants in accordance to demographic and socioeconomic characteristics, health status, and health behaviors, a weighted chi-square test and logistic regression analysis were conducted by separating variables related to overweight, according to the genders. RESULTS: The number of people in the normal group was 6,347 (77.8%), while the people who were considered overweight were 1,810 (22.2%). Women (nā€Š=ā€Š4,583) constituted 52.7% of the subject, 24.9% of whom were classified as overweight. Meanwhile, 20.6% of the 47.3% (nā€Š=ā€Š3,574) of the sample who were men were classified as overweight. Participants between the ages of 45 and 64 with chronic diseases were more likely to be overweight. Men in the 4th quartile of household income were more likely to be overweight than those who were in the 1st quartile, in contrast, while unemployed women with lower education levels and urban residents were at greater risk for being overweight. CONCLUSIONS: Among the men, health status and health behavior appeared to show a correlation with being overweight; however, among women, socioeconomic status factors were strongly related to being overweight. These findings appear to support the association of gender-specifics with the prevalence of being overweight

    Nanomaterial-Based Synaptic Optoelectronic Devices for In-Sensor Preprocessing of Image Data

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    With the advance in information technologies involving machine vision applications, the demand for energyand time-efficient acquisition, transfer, and processing of a large amount of image data has rapidly increased. However, current architectures of the machine vision system have inherent limitations in terms of power consumption and data latency owing to the physical isolation of image sensors and processors. Meanwhile, synaptic optoelectronic devices that exhibit photoresponse similar to the behaviors of the human synapse enable insensor preprocessing, which makes the front-end part of the image recognition process more efficient. Herein, we review recent progress in the development of synaptic optoelectronic devices using functional nanomaterials and their unique interfacial characteristics. First, we provide an overview of representative functional nanomaterials and device configurations for the synaptic optoelectronic devices. Then, we discuss the underlying physics of each nanomaterial in the synaptic optoelectronic device and explain related device characteristics that allow for the in-sensor preprocessing. We also discuss advantages achieved by the application of the synaptic optoelectronic devices to image preprocessing, such as contrast enhancement and image filtering. Finally, we conclude this review and present a short prospect

    The effects of actual human size display and stereoscopic presentation on users' sense of being together with and of psychological immersion in a virtual character

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    This study examined the role of display size and mode in increasing users' sense of being together with and of their psychological immersion in a virtual character. Using a high-resolution three-dimensional virtual character, this study employed a 2Ɨ2 (stereoscopic mode vs. monoscopic modeƗactual human size vs. small size display) factorial design in an experiment with 144 participants randomly assigned to each condition. Findings showed that stereoscopic mode had a significant effect on both users' sense of being together and psychological immersion. However, display size affected only the sense of being together. Furthermore, display size was not found to moderate the effect of stereoscopic mode.Accepted versio

    Electroluminescence from graphene quantum dots prepared by amidative cutting of tattered graphite

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    Size-controlled graphene quantum dots (GQDs) are prepared via amidative cutting of tattered graphite. The power of this method is that the size of the GQDs could be varied from 2 to over 10 nm by simply regulating the amine concentration. The energy gaps in such GQDs are narrowed down with increasing their size, showing colorful photoluminescence from blue to brown. We also reveal the roles of defect sites in photoluminescence, developing long-wavelength emission and reducing exciton lifetime. To assess the viability of the present method, organic light-emitting diodes employing our GQDs as a dopant are first demonstrated with the thorough studies in their energy levels. This is to our best knowledge the first meaningful report on the electroluminescence of GQDs, successfully rendering white light with the external quantum efficiency of ca. 0.1%.X11126101sciescopu
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