1,720,967 research outputs found
Pendeteksian Tumpahan Minyak di Laut Timor dengan Metode Filter Frost dan Gamma Terhadap Citra ALOS PALSAR di Ladang Minyak Montara
No full textAktifitas manusia di daratan dan sekitar pesisir lautan akan menghasilkan limbah yang akan dibuang ke lingkungan. Menurut Group of Expert on Scientific Aspect of Marine Pollution (GESAMP) bahwa 6,44 juta ton/ tahun hidrokarbon masuk ke dalam perairan yang berasal dari kegiatan transportasi laut, pengoperasian pertambangan minyak di anjungan serta kegiatan industri oleh manusia (Hartanto, 2008). Kegiatan operasional pertambangan minyak di lepas pantai memiliki kemungkinan terjadinya kecelakaan yang menyebabkan munculnya tumpahan minyak berupa kegiatan (1) pengoperasian kapal tanker da lam proses deballasting (sistem kestabilan kapal menggunakan bongkar-muat air) (2) kecelakaan kapal maupun tanker dan (3) munculnya semburan sumur minyak yang disebabkan oleh kerusakan struktur platform ataupun peralatan. Kejadian tumpahan minyak yang dikaji pada penelitian ini terjadi di Laut Timor pada tanggal 21 Agustus 2009–3 November 2009 tepatnya di sekitar lepa s pantai utara dari Australia bagian Barat dan berada di perairan bagian selatan dari Indo nesia. Kejadian tumpahnya minyak ke perairan ini dapat memberikan dampak negatif terhadap ekosistem lingkunga n laut beserta biota di dalamnya . Oleh karena itu dibutuhkan penelitian dengan memanfaatkan teknologi penginderaan jauh untuk mengidentifikasi dan memantau penyebaran tumpahan minyak di wilayah Republik Indonesia
Kajian Tumpahan Minyak Montara di Laut Timor Berdasarkan Metode Pengenalan Pola Spektral Citra Satelit ALOS-PALSAR
No full textPencemaran perairan yang diakibatkan tumpahan minyak dapat merusak lingkungan laut dan sumber daya hayati. Dampak pencemaran dapat mengganggu kegiatan ekonomi masyarakat pesisir. Penelitian ini bertujuan untuk menduga tumpahan minyak yang terdapat di perairan lokasi penelitian berdasarkan citra ALOS-PALSAR, mengidentifikasi tumpahan minyak, dan mengklasifikasikan tumpahan minyak Montara di Laut Timor berdasarkan nilai hambur balik dan indeks sebaran tumpahan minyak. Citra di-filter dengan berbagai ukuran kernel filter sehingga diperoleh nilai hambur balik citra yang tidak mengandung noise. Tumpahan minyak diklasifikasikan menjadi tiga kelas berdasarkan nilai hambur balik masing-masing piksel pada citra. Selang nilai hambur balik untuk masingmasing kelas tumpahan minyak, yaitu: tumpahan minyak berat adalah -34.00 s/d -31.52 dB, tumpahan minyak sedang adalah -31.52 s/d -30.18 dB, dan tumpahan minyak ringan adalah -30.18 s/d -27.49 dB. Berdasarkan nilai index sebaran tumpahan minyak (OSI), tumpahan minyak diklasifikasikan menjadi tiga kelas. Nilai index sebaran tumpahan minyak untuk masing-masing kelas tumpahan minyak, yaitu: tumpahan minyak berat adalah 0.17-0.34, tumpahan minyak sedang adalah 0.67-0.96, dan tumpahan minyak ringan adalah 1.03-1.25.Water pollution caused by oil spills could harm marine environment and biological resources. The impact of pollution can disrupt economic activities of coastal communities. This study aimed at suspected the oil spill in the waters research site based on the image data of the ALOS-PALSAR, identify and classify the Montara oil spill in the Timor Sea based on backscatter value and oil spread index. Image filtered with different filter kernel size in order to obtain the value of backscatter images that does not contain noise. Oil spills are classified into three classes based on backscatter of each pixel in the image. The range of Backscatter values for each class of oil spills, i.e.: heavy oil spill is -34.00 to -31.52 dB, medium oil spill is -31.52 to -30.18 dB, and light oil spill is -30.18 to -27.49 dB. Based on oil spread index (OSI), oil spills are classified into three classes. Oil spread index value for each class of oil spills, i.e: heavy oil spill is 0.17-0.34, medium oil spill is 0.67-0.96, and light oil spill is 1.03-1.25
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
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