1,720,981 research outputs found
Structural analysis for in-service gas pipeline lowering using numerical method
No full textConstruction of new highways, buildings, airport runways and other facilities is often planned at locations where aboveground pipelines are present. Relocating such lines can be extremely expensive in terms of shutdown time and new pipeline materials. Lowering this existing pipeline can have big cost benefits. The line can be lowered while remaining in service with no lost production and the cost of such lowering an existing pipeline section is relatively cheap. In this paper, the calculation method with both analytically and numerically are discussed and explained in a 28 in pipeline lowering process while keep the pipeline is safe and still in-service
KONTROL SUDUT ATTITUDE MENGGUNAKAN LINEAR QUADRATIC REGULATOR (LQR) UNTUK QUADROTOR DENGAN PAYLOAD
No full textQuadrotor telah dikembangkan oleh peneliti di dunia ini sebagai aerial object interaction/aerial manipulation. Agar quadrotor bisa terbang mengangkat beban, maka dibutuhkan sistem kontrol yang dapat mengkompensasi perubahan pusat gravitasi. Pada penelitian ini, model matematika quadrotor dengan efek beban/payload akan dikembangkan. Untuk mengkompensasi perubahan lokasi pusat gravitasi karena efek beban, Linear Quadratic Regulator (LQR) akan digunakan untuk stabilisasi sudut Euler.Model linear state space dihitung menggunakan persmaan gerak onlinear quadrotor tanpa beban, kemudian disintesis sistem kontrol LQR. Kontrol tersebut diterapkan dalam model matematika nonlinear dengan beban/payload. Berdasarkan hasil simulasi integral action dari kontrol LQR dapat menghilangkan steady state error setelah diberikan step input, dan kondisi sudut awal sebesar 50. Variasi beban dari 0 gr sampai dengan 200 gr tidak akan memberikan steady state error</jats:p
ANFIS application for calculating inverse kinematics of programmable universal machine for assembly (PUMA) robot
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Aplikasi Pilot In the Loop (PIL) untuk uji unjuk kerja dan kekokohan sistem kontrol proportional-derivative (PD) dengan Hardware in The Loop (HIL)
No full textPengembangan quadrotor telah banyak dikembangkan dalam berbagai bidang diantaranya adalah sebagai traffic monitoring, alat pelacak dan penyelamatan, alat pengintai dan sebagainya. Untuk itu diperlukan sistem kontrol yang kokoh dan teruji serta dapat dikendalikan dengan menggunakan remote kontrol. Dalam penelitian ini dilakukan pembuatan dan pengujian sistem kontrol proportional- derivative (PD) untuk quadrotor terhadap ketidakpastian masa dan inersia dengan Hardware In the Loop System (HIL) serta dikembangkan Pilot in The Loop System (PIL) untuk sistem kendalinya. Identifikasi parameter merupakan hal pertama yang perlu dilakukan untuk pembuatan quadrotor, kemudian dilakukan desain sistem kontrol dengan menggunakan MATLAB/Simulink untuk melakukan simulasi desain sistem kontrol dan PIL yang dibuat. Langkah selanjutnya adalah mengalikasikan desain sistem kontrol kedalam quadrotor. Hasil penelitian menunjukkan bahwa dalam simulasi desain kontrol PD terhadap ketidakpastian masa dan inersia dengan settling time 0.7s dan PO 3% diperoleh kondisi roll dan pitch respon dengan PO 0% dan settling time 0.7s; alt respon PO 3.3% dan settling time 0.7s; yaw respon PO 0%, settling time 0.9s dan error steady state 0.1o. Dalam aplikasinya pengujian dengan HIL pada respon roll diperoleh error steady state sekitar 1o. Sedangkan dalam aplikasi Pilot In the Loop (PIL) respon roll quadrotor sesuai dengan perintah yang diberikan, namun terdapat error steady state dan osilasi pada control PD</jats:p
Pengembangan Wearable Robotic Arm Input dan Virtual Instrument untuk Pengendalian dan Pemantauan Lengan Robot
No full textThis paper investigate the integration of wearable robotic arm input (WRAI) with virtual instrument (VI) for controlling and monitoring the manipulator. The WRAI was designed by following the contours of human arms and equipped with five potentiometers as the sensor. The sensors were placed properly on WRAI by considering the ergonomic aspect. Each sensor on WRAI actuate each joint on the manipulator. The manipulator has five degrees of freedom (DOF) which consists of five revolute joints. For monitoring process, control panel of VI was created suitably by LabVIEW, and its block diagram was mainly programmed by following the forward kinematics approach. The VI obtains the input signal from the rotation of potentiometer on WRAI, and then transmitted to the receiver on manipulator to actuate the joints. By monitoring the control panel, the user can observe each angle joint on manipulator and also the position and orientation of end effector. The test results show the WRAI performs good controllability and ergonomic. The WRAI can control the manipulator easier than using remote control and joystick. Further, the control panel of VI is able to simplify the monitoring process by the friendly user interface
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
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