1,721,005 research outputs found
Ordered microdomain morphologies in saccharide-containing block copolymers
No full textHybrid block copolymers containing both oligosaccharide and synthetic polymer components have attracted much interest in recent years as sustainable material alternatives. In particular block copolymers containing saccharides are capable of microphase separation at small molecular weights, leading to the formation of ordered morphologies with sub-10 nm feature sizes. We synthesize ABA-type triblock copolymers containing polystyrene as the synthetic mid-block and either trisaccharide maltotriose (MT) or disaccharide maltose (Mal) as the end blocks. The polymers are prepared by a combination of atom transfer radical polymerization (ATRP) and click reaction, and their bulk morphologies are examined by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The MT-containing triblocks are found to form well-ordered domain structures with sub-10 nm periodicity, and morphology transition from cylinders to spheres to disordered spheres is observed with decreasing saccharide weight fraction. The Mal-containing triblocks also show microphase separation. However, the observed domain morphologies lack regular packing due to the close proximity of polymer glass transition temperature and order-disorder transition temperature. The saccharide components of the block copolymers are also found to undergo different degrees of dehydration when exposed to high temperatures. The dehydration reaction leads to the molecular change of the triblocks to form pentablock copolymers, resulting in the emergence of less ordered secondary morphologies in an irreversible manner
Pride and Prejudice in Progressive Web Apps
No full textProgressive Web App (PWA) is a new generation of Web application designed to provide native app-like browsing experiences even when a browser is offline. PWAs make full use of new HTML5 features which include push notification, cache, and service worker to provide short-latency and rich Web browsing experiences.
We conduct the first systematic study of the security and privacy aspects unique to PWAs. We identify security flaws in main browsers as well as design flaws in popular third-party push services, that exacerbate the phishing risk. We introduce a new sidechannel attack that infers the victim’s history of visited PWAs. The proposed attack exploits the offline browsing feature of PWAs using a cache. We demonstrate a cryptocurrency mining attack which abuses service workers. Defenses and recommendations to mitigate the identified security and privacy risks are suggested with in-depth understanding
JMC: Jitter-Based Mixed-Criticality Scheduling for Distributed Real-Time Systems
No full textThese days, the term of Internet of Things (IoT) becomes popular to interact and cooperate with individual smart objects, and one of the most critical challenges for IoT is to achieve efficient resource sharing as well as ensure safetystringent timing constraints. To design such reliable real-time IoT, this paper focuses on the concept of mixed-criticality (MC) introduced to address the low processor utilization on traditional real-time systems. Although different worst-case execution time estimates depending on criticality are proven effective on processor scheduling, the MC concept is not yet mature on distributed systems (such as IoT), especially with end-to-end deadline guarantee. To the best of our knowledge, this paper presents the first attempt to apply the MC concept into interference (or jitter), which is a complicated source of pessimism when analyzing the schedulability of distributed systems. Our goal is to guarantee the end-to-end deadlines of high-criticality flows and minimize the deadline miss ratio of low-criticality flows in distributed systems. To achieve this goal, we introduce a jitter-based MC (JMC) scheduling framework, which supports node-level mode changes in distributed systems. We present an optimal feasibility condition (subject to given schedulability analysis) and two policies to determine jitter-threshold values to achieve the goal in different conditions. Via simulation results for randomly generated workloads, JMC outperforms an existing criticality-monotonic scheme in terms of achieving higher schedulability and fewer deadline misses. ⓒ 2019 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.FALS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Analysis of Research Trends on Character Education in Ethics Education
Full text link본 연구는 인성교육의 핵심 교과이자 주관 교과인 도덕과 교육에서의 인성교육에 대한 연구 동향을 분석하는 것을 목적으로 한다. 이에 도덕과 교육 분야의 대표적인 학술지에 나타난 인성교육 연구의 양적 내용 분석을 시도한 결과는 다음과 같다. 첫째, 연구 시기와 관련하여, 국가 교육과정 및 교육 정책에 큰 영향을 받고 있다. 둘째, 연구 목적과 관련하여, 탐색적 연구가 가장 많았고 기술적 연구와 설명적 연구가 증가하는 추세에 있다. 셋째, 연구 방법과 관련하여, 이론 연구가 가장 높은 비중을 차지하고, 실증 연구는 최근 점차 증가하는 추세에 있지만, 양적 연구에 비해 질적 연구는 부족한 것으로 나타났다. 넷째, 연구 주제는 `인성교육의 방향과 실천 방안`에 집중되어 있다. 다섯째, 배경 학문과 관련하여, 교과 교육학에서의 연구는 매우 활발하고 꾸준한 반면 교과 내용학에서는 비교적 적게 이루어지고 있다.This study aims to analyze the research trends of character education in ethics education. The results of quantitative content analysis of the five academic journals of ethics education are as follows : First, in relation to the timing of the study, it is greatly influenced by national curriculum and educational policies. Second, in relation to research purposes, research has shown that there is a lot of exploratory research, and technological studies and descriptive studies are increasing. Third, theoretical studies have shown that theoretical studies have become fairly high, and empirical studies have shown that qualitative research is insufficient compared to quantitative studies. Fourth, the topic of research focuses on the direction of character education and implementation. Fifth, in relation to background studies, studies in subject matter education are very active and consistent, whereas studies are relatively small in subject contents
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
