Comparison of selected methods for the determination of the center of gravity in surface mining machines

2017 ◽  
Vol 4 (5) ◽  
pp. 5877-5882 ◽  
Author(s):  
Pawel Maslak ◽  
Grzegorz Przybylek ◽  
Tadeusz Smolnicki
Keyword(s):  
Surface Mining ◽  
Center Of Gravity

Experimental Determination of Horizontal Motion of Human Center of Gravity During Squatting

2011 ◽  
Vol 37 (6) ◽  
pp. 66-76
Author(s):  
G. Fekete ◽  
B.M. Csizmadia ◽  
M.A. Wahab ◽  
P.D. Baets
Keyword(s):  
Experimental Determination ◽  
Center Of Gravity ◽  
Horizontal Motion

New Methodology for the Determination of the Vertical Center of Gravity of In-Service Semisubmersibles: Proposal and Numerical Assessment

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Ivan N. Porciuncula ◽  
Claudio A. Rodríguez ◽  
Paulo T. T. Esperança
Keyword(s):  
Accurate Determination ◽  
Center Of Gravity ◽  
Practical Implementation ◽  
Numerical Assessment ◽  
Neutral Equilibrium ◽  
Inclination Angles ◽  
Numerical Tools ◽  
The Stability ◽  
Metacentric Height

Along its lifetime, an offshore unit is subjected to several equipment interventions. These modifications may include large conversions in loco that usually are not adequately documented. Hence, the accurate determination of the platform's center of gravity (KG) is not possible. For vessels with low metacentric height (GM), such as semisubmersibles, Classification Societies penalize the platform's KG, inhibiting the installation of new equipment until an accurate measurement of KG is provided, i.e., until an updated inclining test is performed. For an operating semisubmersible, the execution of this type of test is not an alternative because it implies in removing the vessel from its in-service location to sheltered waters. Relatively recently, some methods have been proposed for the estimation of KG for in-service vessels. However, as all of the methods depend on accurate measurements of inclination angles and, eventually, on numerical tools for the simulation of vessel dynamics onboard, they are not straightforward for practical implementation. The objective of the paper is to present a practical methodology for the experimental determination of KG, without the need of accurate measurements of inclinations and/or complex numerical simulations, but based on actual operations that can be performed onboard. Indeed, the proposed methodology relies on the search, identification, and execution of a neutral equilibrium condition where, for instance, KG = KM. The method is exemplified using actual data of a typical semisubmersible. The paper also numerically explores and discusses the stability of the platform under various conditions with unstable initial GM, as well as the effect of mooring and risers.

Determination of production rate in large surface mining areas

2004 ◽  
pp. 69-72
Author(s):  
Changsheng Ji ◽  
Songlin Xia ◽  
Youdi Zhang
Keyword(s):  
Production Rate ◽  
Surface Mining ◽  
Mining Areas

scholarly journals Introducing a particular mathematical model for predicting the resistance and performance of prismatic planing hulls in calm water by means of total pressure distribution

2015 ◽  
Vol 12 (2) ◽  
pp. 73-94 ◽  
Author(s):  
P. Ghadimi ◽  
S. Tavakoli ◽  
M. A. Feizi Chekab ◽  
A. Dashtimanesh
Keyword(s):  
Mathematical Model ◽  
Pressure Distribution ◽  
Total Pressure ◽  
Center Of Gravity ◽  
Governing Equations ◽  
Calm Water ◽  
Hydrodynamic Study ◽  
Pass Through ◽  
And Performance

Mathematical modeling of planing hulls and determination of their characteristics are the most important subjects in hydrodynamic study of planing vessels. In this paper, a new mathematical model has been developed based on pressure distribution. This model has been provided for two different situations: (1) for a situation in which all forces pass through the center of gravity and (2) for a situation in which forces don not necessarily pass through the center of gravity. Two algorithms have been designed for the governing equations. Computational results have been presented in the form of trim angle, total pressure, hydrodynamic and hydrostatic lift coefficients, spray apex and total resistance which includes frictional, spray and induced resistances. Accuracy of the model has been verified by comparing the numerical findings against the results of Savitsky's method and available experimental data. Good accuracy is displayed. Furthermore, effects of deadrise angle on trim angle of the craft, position of spray apex and resistance have been investigated.

scholarly journals Penentuan Lokasi Sentra IKM Galendo untuk Meningkatkan Perekonomian Masyarakat Kabupaten Ciamis

2020 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Maria Nurhayaty ◽  
Devy Dwi Orshella
Keyword(s):  
Central Government ◽  
Center Of Gravity ◽  
Transportation Costs ◽  
Traditional Food ◽  
Wholesale Market ◽  
Total Cost ◽  
Initial Location ◽  
Production Output ◽  
Economic Improvement

Abstract— Traditional food can provide a good image and economic improvement in an area. Ciamis Regency is known as a region producing traditional food, one of which is Galendo. The center of the sale and purchase of Galendo products in Ciamis Regency is still centered in a wholesale market that is less strategic. This research proposes the determination of the location of the Galendo IKM center and the development of various integrated facilities and infrastructure by the central government, which can be shared by other Galendo IKM. The determination of the location of the Galendo IKM center is analyzed by the center of gravity method. The distance of IKM location, production output, and transportation costs from 21 Galendo producers in the Cijeungjing, Cilame, Jendral Soedirman, Pawindan, Pamalayan, Sadananya, and Baregbeg areas are used to calculate the total transportation costs from each IKM location. The initial coordinate point is the location of the Ciamis Main Market which is compared with the 4 proposed coordinate points in order to produce the lowest total transportation costs. The total cost from the initial location of the Main Market is IDR 95,532,205. Whereas the total cost at proposed location 1 is only around Rp 80,015,976 which is lower than the initial location in the wholesale market. Keywords— center of gravity; galendo; distance; IKM centers; total cost. Abstrak— Keberadaan makanan tradisional suatu daerah dapat mengangkat citra positif daerah tersebut. Kabupaten Ciamis dikenal akan daerah penghasil berbagai jenis makanan tradisional, salah satu diantaranya adalah galendo. Kegiatan jual beli produk galendo di Kabupaten Ciamis masih berpusat di pasar induk yang lokasinya dinilai kurang strategis. Penentuan lokasi sentra IKM galendo diperlukan berikut dengan pengembangan berbagai sarana dan prasarana terpadu oleh pemerintah pusat, yang dapat digunakan bersama oleh para pelaku IKM. Penentuan lokasi sentra IKM galendo dilakukan menggunakan metode center of gravity. Jarak antar lokasi IKM, beban berupa output produksi, dan biaya transportasi dari 21 produsen Galendo yang tersebar di daerah Cijeungjing, Cilame, Jendral Soedirman, Pawindan, Pamalayan, Sadananya, dan Baregbeg digunakan untuk mengitung total biaya transportasi dari masing-masing titik lokasi IKM. Titik koordinat awal adalah lokasi Pasar Induk Ciamis yang dibandingkan dengan 4 titik koordinat usulan guna menghasilkan total biaya transportasi yang paling rendah. Total biaya jika sentra berada di lokasi awal yakni Pasar Induk, adalah mencapai Rp 95.532.205. Sedangkan total biaya di lokasi usulan 1 hanya berkisar Rp 80.015.976 yang lebih rendah dibandingkan dengan lokasi awal di pasar induk.   Kata kunci— center of gravity; galendo; jarak; sentra IKM; total biaya.

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