1,721,421 research outputs found
Optimization of process-property relations of 3D printed ceramics using extrusion-based additive manufacturing
Full text linkThe capability and applicability of additive manufacturing have mesmerized the entire manufacturing world. One major technique of additive manufacturing is extrusion-based additive manufacturing (EAM), which has been recently employed for the rapid production of ceramic components, among other applications. This study focused on establishing the process-property relations for extrusion-based additively manufactured ceramics, namely Alumina (Al2O3) and Zirconia (ZrO2), and then optimization of the relations to get the desired mechanical properties for applicability. Extrusion-based additive manufacturing was used to obtain the ceramic sample parts from ceramic-binder mixtures and by subsequent post-processing. The process parameters chosen for the study were extrusion velocity and part orientation whereas the mechanical properties selected were hardness and flexural strength. Extrusion velocity was varied at three levels i.e. 7.5 mm/s, 12.5 mm/s and 17.5 mm/s. Two levels selected for part orientation were horizontal and vertical. The design of experiments technique was used to establish the process-property relations by highlighting the most significant process parameters affecting the selected mechanical properties. Optimization was achieved by highlighting those levels of significant process parameters that provided the desired values of mechanical properties. Part orientation came out to be a significant factor affecting both the hardness and flexural strength of the two ceramics whereas extrusion velocity was found to be insignificant for both mechanical properties. Among the two levels of part orientation, vertical orientation samples showed higher values of hardness while horizontal samples showed higher flexural strength thus, aiding in the optimization of the process-property relations
ANALISIS SENTIMEN TWITTER DAN KORELASI TERHADAP INDEKS SAHAM LQ 45 MENGGUNAKAN ALGORITMA SUPER VECTOR MACHINE
Full text linkFARID MUHAMMAD NAUFAL (2022) : ANALISIS SENTIMEN TWITTER DAN KORELASI
TERHADAP INDEKS SAHAM LQ 45 MENGGUNAKAN
ALGORITMA SUPER VECTOR MACHINE
Media sosial sebagai penyedia informasi penting bagi investor dan sebagai tempat investor
melakukan interaksi sosial. Sentimen merupakan gambaran dari emosi dan pikiran investor yang
disalurkan melalui interaksi sosial pada media sosial. Sentimen positif pada media sosial mampu
meningkatkan brand image dan reputasi perusahaan, sedangkan sentimen negatif mampu merusak
brand image dan reputasi perusahaan. Menyadari informasi mengenai pasar saham perusahaan
swasta, multinasional, maupun BUMN masih banyak diperbincangkan di platform Twitter, dan
indeks saham perusahaan yang tergolong LQ 45 banyak dibicarakan di platform media sosial
Twitter. Tujuan penelitan ini menganalisis sentimen Twitter dan korelasinya terhadap indeks
saham LQ 45 menggunakan algoritma SVM. Sumber data yang dijadikan acuan adalah cuitan
indeks perusahaan yang berada didalam LQ 45 dari media sosial Twitter. Sebagai hasilnya penulis
mendapatkan korelasi dengan nilai koefisien korelasi r=-0,108 dan P-value=0,508. Nilai korelasi
menyatakan bahwa sentimen publik yang diperoleh dari media sosial Twitter tidak memiliki
korelasi, sedangkan nilai signifikasi P-value menyatakan tidak adanya pengaruh sentimen analisis
pada pergerakan nilai saham LQ 45.
Kata Kunci: Analisis Sentimen, Data Mining, Klasifikasi, LQ 45, Twitte
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
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
The effect of printing parameters on sintered properties of extrusion-based additively manufactured stainless steel 316L parts
Full text linkExtrusion-based additive manufacturing (EAM) is a relatively new process developed for the production of complex metallic and ceramic parts needed in smaller quantities. The debinding and sintering step of EAM is adopted from a well-known powder injection molding process. However, the 3D printing step needs special consideration to make EAM competent in the era of rapid manufacturing. This study is intended to investigate the effect of common printing parameters on the microstructure and mechanical properties of sintered stainless steel 316L (SS316L) parts manufactured through the EAM process. Part orientation (Ori), extrusion velocity (Ve), and layer height (h) were changed in experimental runs by following a full factorial design. Extrusion pressure as an indicator of melt stability and a grey relational grade as a combined response of sintered properties were analyzed against varying printing parameters. Physical characteristics measured during debinding and sintering show near isotopic shrinkage and the process is stable. Metallographic characterization in terms of porosity and grain size indicated minor differences when Ve and h were altered. Sintered parts showed improved properties when printed with vertical part orientation and h = 0.5 mm, whereas Ve which contributes significantly to the build-up rate was found to be responsible for melt stability. Ve at 12.5 mm/s exhibited melt stability and higher sintered properties
- …
