1,720,958 research outputs found
Penerapan Kombinasi Pemodelan-Optimasi Response Surface Method- Genetic Algorithm (RSM-GA) Dalam Mengoptimalkan Hasil Transesterifikasi Minyak Kelapa Sawit (Elaeis guineensis) Menjadi Biodiesel.
Full text linkPengembangan penelitian biodiesel sekarang ini lebih banyak pada perlakuan treatment transesterifikasi. Salah satunya adalah penelitian Sholikah (2010) yang melakukan penelitian menggunakan gelombang ultrasonik pada treatment transesterfikasi minyak sawit menjadi metil ester. Penelitian ini masih dalam tahap eksperimen skala laboratorium dan belum dilakukan penelitian tahap lanjut untuk optimasi menggunakan metode pemodelan statistika maupun matematis. Salah satu metode pemodelan-optimasi yang dapat dilakukan adalah kombinasi Response Surface Method-Genetic Algorithm (RSM-GA). Penelitian ini bertujuan untuk mengoptimalkan hasil transesterifikasi dengan algoritma genetika, mengetahui parameter genetika yang tepat dalam mengoptimasi hasil transesterifikasi, dan mengetahui kualitas solusi yang dihasilkan algoritma genetika. Penelitian ini menggunakan data sekunder yang didapat dari penelitian sholikhah (2010). Penelitian ini akan memodelkan dan mengoptimasi variabel bebas (waktu transesterfikasi dan volume minyak sawit) untuk satu variabel terikat yaitu metil ester dengan metode RSM-GA. Optimasi menggunakan algoritma genetika ini menggunakan teknik crossover satu titik, dan mutasi dengan proses seleksi elitisme. Ukuran populasi yang digunakan 40 – 120 dengan kelipatan 20. Probabilitas crossover dan Probabilitas mutasi yang digunakan adalah 0,3-0,7. Penelitian ini terdapat 28 kromosom sebagai data untuk waktu transesterifikasi dan volume minyak sawit yang direpresentasikan menggunakan representasi biner. Pemodelan RSM didapatkan nilai R2 sebesar 0,9421. Pada optimasi algoritma didapatkan nilai fitness optimal sebesar 125,6382 mL. Solusi optimal ini didapatkan pada parameter genetika ukuran populasi sebanyak 60, kombinasi probabilitas crossover dan probabilitas mutasi adalah 0,5 dan 0,6 dengan Kecepatan konvergensi sebanyak 10 kal
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Pengaruh Pretreatment Alkali Hidroksida Terhadap Produksi Gula Reduksi dari Limbah Kulit Kopi
Full text linkCoffee husks are abundant agroindustrial lignocellulosic materials that can be used to produce reducing sugar. Coffee husks waste composition consist of cellulose, hemicellulose and lignin. However, its highly lignin content make the pretreatment step necessary. This study produced reducing sugars from coffee husks through chemical pretreatments using combined alkaline hydroxide (NaOH-H2O2). Hydrogen peroxide (H2O2) at various concentrations (2.5, 5, and 7.5% (v/v) was mixed into 1% (w/v) of NaOH solution with pH 11.5. The concentration of lignocellulosic content, crystallinity index and reducing sugar content were investigated. The results showed that the highest lignin removal was achieved at the addition of 2.5% H2O2 .The highest crystallinity index of coffee husks waste-treated was achieved 49,87% at variable of 7.5% (v/v) H2O2. It can be concluded that alkaline hydroxide pretreatment useful for lignin removal and can be applied in reducing sugar.Limbah kulit kopi merupakan bahan lignoselulosa agroindustri yang melimpah yang dapat digunakan untuk menghasilkan gula reduksi. Komposisi limbah kulit kopi terdiri dari selulosa, hemiselulosa dan lignin. Namun, kandungan lignin yang tinggi diperlukan pretreatment. Penelitian ini menghasilkan gula reduksi dari limbah kulit kopi melalui pretreatment kimia menggunakan kombinasi alkali hidroksida (NaOH-H2O2). Hidrogen peroksida pada berbagai konsentrasi (2.5, 5 dan 7.5% v/v) dicampurkan ke dalam larutan NaOH 1% (m/v) dengan pH 11.5. konsentrasi kandungan lignoselulosa, indeks kristalinitas dan kandungan gula reduksi diteliti. Hasil penelitian menunjukkan bahwa penyisihan lignin tertinggi dicapai pada penambahan 2.5% hidrogen peroksida. Indeks kristalinitas tertinggi pada limbah kulit kopi yang telah diolah yaitu 49.87% pada variabel 7.5% (v/v). dapat disimpulkan bahwa pretreatment alkali hidroksida berguna untuk menghilangkan lignin dan dapat diterapkan untuk gula reduksi
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