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Getaran Akibat Gangguan Secara Alami
No full textThis paper discusses the phenomenon of self-excited vibration in some physical model including its applications in some different engineering field. The referred physical model include the impact damper and its application for damping the vibration of shear building, chatter phenomenon on machine tools, ride comfort on agricultural machinery and stick-slip phenomenon and its benefit on vibration subsoiler. It is intended that this paper could provide a global overview on phenomenon-of self-excited vibration. Keywords: self-excited, vibration, stick-slip, subsoile Diterima: 03 Januari 2008; Disetujui: 12 Mei 200
RANCANG BANGUN DAN PENGUJIAN ALAT TANAM MURBEI
Get PDFMulberry (Morus Sp.) is widely used in sericulture as silkworms’ fodder. Aside from being a silkworm feed, mulberry plants can also be used as food crops, animal feed and medicine. Mulberry plant breeding can be done by two methods, generative method (through seeds) and vegetative method (part of the plant itself). Vegetative seedlings methods have been done by many silk farmers. Vegetative techniques are relatively easier to do and quickly get leaf production. Vegetative techniques that are mostly used is stake. In mulberry cultivation, one of the processes that consumes a lot of energy is the planting process. Planting mulberry stake is still done manually. In this study planter will be designed which are expected to increase the capacity and efficiency of planting. The design process includes a preliminary study in the form of a study of material characteristics to determine design criteria. After that, the selection of components and mechanisms is carried out, followed by making drawings and prototypes. Planter prototypes tested with static test to evaluate the function of metering device. The Result obtained collecting function error is 0.5 % with one case where metering device fail to collect and zero case of more than one stake collected. The average of damaged stake is 2 % but mostly happen in left metering device with 4 %. The number indicates that modification is needed.Tanaman murbei (Morus Sp.) banyak digunakan dalam serikultur sebagai pakan ulat sutera. Selain sebagai pakan ulat sutera, tanaman murbei juga dapat dimanfaatkan sebagai tanaman pangan, pakan ternak dan obat-obatan. Pengembangbiakan tanaman murbei dapat dilakukan dengan dua cara, yaitu cara generatif (melalui biji) dan cara vegetatif (bagian dari tanaman itu sendiri). Metode pembibitan vegetatif telah banyak dilakukan oleh petani sutra. Teknik vegetatif relatif lebih mudah dilakukan serta lebih cepat untuk berproduksi. Teknik vegetatif yang banyak digunakan adalah stek. Dalam budidaya tanaman murbei, salah satu proses yang memakan banyak energi adalah pada proses penanaman. Penanaman stek murbei masih dilakukan secara manual. Pada penelitian ini akan dirancang alat tanam yang diharapkan mampu meningkatkan kapasitas dan efisiensi pada proses penanaman. Proses desain meliputi studi pendahuluan berupa studi karakteristik material untuk menentukan kriteria desain. Setelah itu dilakukan pemilihan komponen dan mekanisme, dilanjutkan dengan pembuatan gambar dan prototipe. Prototipe alat tanam diuji dengan uji statis untuk mengevaluasi fungsi penjatah. Dari hasil pengujian didapatkan persentase kegagalan kerja penjatah adalah 0,5% dimana terjadi pengambilan lebih dari satu stek dan tidak ditemukan kasus dimana stek tidak terambil oleh penjatah . Rata-rata stek yang rusak adalah 2% dan paling banyak terjadi pada penjatah kiri dengan tingkat kerusakan 4%. Angka tersebut menunjukkan bahwa perlu untuk dilakukan modifikasi
Sistem Pengendali Kemudi Traktor Otomatis Empat Roda pada Pengujian Lintasan Lurus
Get PDFThis research is the development of autonomous tractor. Although research for automatic tractor have been carried out, but it is still developed to get more precision and optimal method. The purpose of this research is to develop a trajectory control system tractor to follow a straight-line when the working soil tillage. Model that was developed to be able calculate steering angle correction of the tractor position so that the tractor will run on a reference trajectory. Tractor position is determined from RTK DGPS. Tractor direction is calculated from two position of tractor. Control algorithm consists of the arrangement of commands to control the tractor move the reference trajectory. Simulations were performed to determine controlling algorithm ability the tractor to follow reference trajectory. The algorithm ability is tested in real conditions on a straight- line path along 30 m with a speed of tractor 0.5 m/s in a field. The test results obtained in the field of performance accuracy rate is 97.13% control and average deviation with reference trajectory is 8.62 cm.ABSTRAKPenelitian ini merupakan penelitian pengembangan traktor otomatis. Meskipun penelitian mengenai traktor otomatis telah banyak dilakukan, namun pengembangan masih terus dilakukan untuk mendapatkan presisi yang lebih tinggi dan metode yang optimal. Tujuan penelitian ini adalah mengembangkan sistem pengendali kemudi traktor agar dapat mengikuti jalur kerja lintasan lurus ketika melakukan kegiatan pengolahan tanah. Model yang dikembangkan harus mampu menghitung sudut setir koreksi dari posisi traktor agar traktor mampu berjalan pada lintasan lurus yang telah ditentukan. Arah pergerakan traktor diketahui dari perbandingan dua posisi traktor yang diperoleh dari RTK DGPS. Algoritma pengendalian terdiri dari susunan perintah-perintah untuk mengendalikan traktor bergerak mengikuti lintasan acuan. Simulasi dilakukan untuk mengetahui kemampuan algoritma yang telah dibuat untuk mengendalikan traktor agar dapat berjalan mengikuti lintasan acuan. Kemampuan algoritma tersebut kemudian diuji dalam kondisi riil dilapangan pada lintasan lurus sepanjang 30 m dengan kecepatan traktor 0.5 m/s. Hasil pengujian di lapangan diperoleh tingkat akurasi kinerja kontrol sebesar 97.13% dan besar simpangan rata-rata terhadap lintasan acuan sebesar 8.62 cm
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
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
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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