1,721,016 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Wearable fabric-based hybrid energy harvester from body motion and body heat
No full textWe demonstrate a wearable fabric-based energy harvester (Fab-EH) to hybridize a triboelectric generator (TrG) and a thermoelectric generator (ThG). Using a liquid-phase aluminum (Al) coating technique, we fabricate Al-coated fabrics with high electrical and thermal conductivity while maintaining the original texture. By adopting the Al-coated fabric material as both the electrodes of the TrG and the heat-transport layer of the ThG, the fabricated Fab-EH effectively scavenges electrical energy from body motion and body heat. The Fab-EH charges a storage capacitor with capacitance of 3.3 mF to 3 V within 240 sec with the designed transforming system. Moreover, a smartphone can be partially charged using the harvested energy. The Fab-EH thus has the potential to alleviate the recharging issue for portable and wearable devices.
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Self-sustainable wind speed sensor system with omni-directional wind basedtriboelectric generator
No full textA stable power supply is critical for wireless sensor systems. While various energy harvesting devices have been studied, there has been limited discussion of circuit design for a self-powered sensor system. This study introduces a self-sustainable wind speed sensor system (SSWSSS) with an omni-directional wind-based triboelectric generator (OW-TEG) along with a 2-dimensional co-planar surface. The OW-TEG simultaneously provides both signal sensing and energy harvesting without interference. The SSWSSS consists of an OW-TEG and a control circuit that senses wind speed and manages the harvested energy storage. Wind speed is extracted from the frequency of the electrical signals from the OW-TEG, which operates by wind actuation of a flat triboelectric film which flutters between two electrodes. The frequency is characterized by counting the number of induced voltage peaks above a reference voltage. Meanwhile, omni-directional energy harvesting is accomplished by using control circuit functions to count frequency, convert power, and store energy. Realization of this self-sustainable sensor system represents a forward step towards achieving a self-powered sensor platform.
A Primary Study on the Development of Evaluation Model for Marine Traffic Safety Assessment
Get PDFCollision between Xing Guang No.7 and Neo Blue which happened in front of the Incheon lock gate indicates that Korean coastal water is classified as dangerous area due to heavy traffic in confined waters. This may lead to severe accident such as collision, grounding, sinking and environmental pollution.
According to the Marine Traffic Safety Law, revised in 2009, Marine Traffic Safety Diagnosis System is introduced to secure the safe navigation, prevent the marine accident and to maximize the efficiency of the port. The diagnosis system aims to investigate, measure and evaluate the effect of the various development project such as the construction of bridge and/or piers, etc. and to reflect the diagnostic results for the safe navigation.
In the process of this system, the most important part is the marine traffic safety assessment, and evaluation model is required in order to implement the assessment.
However, the evaluation model used in Korea is highly limited, and these models are made in foreign countries such as Japan. There are some problems to apply these models to Korean coastal waters. So the development of the proper evaluation model for Korea is required as early as possible.
The purpose of this research is implementing marine traffic assessment of Korean coastal waters by using ES(Environmental Stress) model which is formal assessment model for marine traffic flow simulation in the Diagnosis System and IWRAP(IALA Waterway Risk Assessment Program) recommended by IALA, and analyze the results for the basic reference to develop independent evaluation model.제 1 장 서 론 1
1.1 연구의 배경 및 목적 1
1.2 연구의 방법 2
제 2 장 해상교통 안전진단제도의 개념과 절차 4
2.1 해상교통 안전진단의 용어 정의 4
2.1.1 해상교통의 개념 4
2.1.2 안전의 개념 4
2.1.3 진단의 개념 5
2.2 해상교통 안전진단제도 6
2.2.1 해상교통 안전진단의 개념 6
2.2.2 해상교통 안전진단 절차 9
제 3 장 해상교통 안전성 평가 절차 및 평가모델 조사 11
3.1 해상교통 안전성 평가의 개념 11
3.2 해상교통 안전성 평가 절차 12
3.2.1 해상교통현상 파악 13
3.2.2 해상교통현상 기술 13
3.2.3 해상교통현상 예측 14
3.2.4 해상교통현상 재현 14
3.2.5 해상교통현상 평가 15
3.3 해상교통 안전성 평가모델 16
3.3.1 IWRAP 16
3.3.2 ES Model 22
3.3.3 PAWSA 26
3.3.4 FSA 30
3.3.5 US Model 35
3.3.6 일본의 안전대책 평가 가이드라인 36
3.3.7 기타 평가모델 39
3.3.8 종합 분석 40
제 4 장 IWRAP 및 ES Model을 활용한 울산항 해역 해상교통 안전성 평가 42
4.1 기초 자료 조사 42
4.1.1 자연 환경 42
4.1.2 항행 환경 44
4.2 IWRAP을 이용한 울산항 해상교통 안전성 평가 46
4.2.1 Leg 지정 46
4.2.2 교통량 및 분산치 입력 48
4.2.3 기타 변수 입력 57
4.2.4 안전성 평가 결과 분석 58
4.3 ES Model을 이용한 울산항 해상교통 안전성 평가 60
4.4 해양사고 통계자료 비교 분석 62
제 5 장 결 론 6
Design Strategy for a Piezoelectric Nanogenerator with a Well-Ordered Nanoshell Array
No full textThe piezoelectric nanogenerator (PNG) has been spotlighted as a promising candidate for use as a sustainable power source in wireless system applications. For the further development of PNGs, structural optimization is essential, but the structural analysis progress in this area has been scant. In the present study, we proposed a PNG with a well-ordered nanoshell array structure. The nanoshell structure has been considered as an effective core nanostructure for PNGs due to its effective stress confinement effect but has not been experimentally introduced thus far due to the challenging fabrication method required. To produce a controllable nanoshell structure, a top-down silicon nanofabrication technique which involves advanced spacer lithography is introduced. A comprehensive design strategy to enhance the piezoelectric performance is proposed in terms of the nanoshell diameter and shell-to-shell space. Both simulated and measured data confirm that an extremely high density of a structure is not always the best answer to maximize the performance. The highest amount of power can be achieved when the shell diameter and shell-to-shell space are within their proper ranges. The structural design strategy studied in this work provides a guideline for the further structural developments of PNG
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