Sensitivity Analysis and Optimization of Undamped Rotor Critical Speeds to Supports Stiffness

2002 ◽  
Vol 124 (2) ◽  
pp. 296-301 ◽  
Author(s):  
Shyh-Chin Huang ◽  
Chin-Ann Lin
Keyword(s):  
Sensitivity Analysis ◽  
Solution Process ◽  
Optimal Solution ◽  
Frequency Equation ◽  
Sensitivity Matrix ◽  
Variable Metric ◽  
Critical Speeds ◽  
Rotor Design ◽  
Receptance Method ◽  
Variable Metric Method

This paper introduced a new approach that employed the assumed-modes method and the receptance method, to the sensitivity analysis and the optimization of rotor-bearing systems. First, the frequency equation in terms of receptances was derived. The natural frequencies and the critical speeds for a typical rotor system were then illustrated. Beginning with the receptance equation, the authors, for the first time, derived a sensitivity matrix and employed it into an optimization process. The topographical method in conjunction with the variable metric method followed for the optimal solution. In the solution process, the sensitivity matrix provided important information for search direction. Examples of critical speeds adjustment via supports change in an optimal sense were illustrated. Numerical results showed that the approach was very efficient and the solutions were very accurate. This approach, in addition, provided such valuable information as which supports dominated specific critical speeds. The developed approach proved to be very helpful to rotor engineers in both rotor modification and rotor design.

Aplikasi Metode Hungarian Dalam Optimalisasi Waktu Penugasan Karyawan dan Keuntungan Produksi Home Industry

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Empya Charlie ◽  
Siti Rusdiana ◽  
Rini Oktavia
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Solution ◽  
Optimal Scheduling ◽  
Total Work ◽  
Work Time ◽  
Hungarian Method ◽  
Total Work Time

Penelitian ini bertujuan untuk mengoptimalkan penjadwalan karyawan di CV. Karya Indah Bordir dalam melakukan tugas-tugas tertentu menggunakan metode Hungaria, serta menganalisis sensitivitas solusi optimal jika ada pengurangan waktu karyawan untuk menyelesaikan tugas-tugas. Metode Hongaria diterapkan pada proses bordir yang melibatkan 11 karyawan dan 10 tugas. Hasil penjadwalan yang optimal meminimalkan waktu produksi bordir perusahaan. Hasil penjadwalan optimal yang ditemukan adalah: karyawan 1 mengerjakan tas Mambo, karyawan 2 mengerjakan tas Elli, karyawan 3 mengerjakan tas Lonjong, karyawan 4 mengerjakan tas Tampang bunga, karyawan 6 mengerjakan tas Ransel, karyawan 7 mengerjakan tas Tima, karyawan 8 mengerjakan tas Keong, karyawan 9 mengerjakan tas Alexa, karyawan 10 mengerjakan tas Luna, dan karyawan 11 mengerjakan tas Mikha, dengan total waktu kerja adalah 13,7 jam. Setelah metode Hongaria diterapkan, CV. Karya Indah Bordir mendapat peningkatan pendapatan sebanyak 9,09%. Analisis sensitivitas dilakukan dengan mengurangi waktu karyawan dalam menyulam tas. Hasil analisis sensitivitas adalah beberapa batasan untuk variabel basis dan non basis untuk mempertahankan solusi optimal.   This research has a purpose to optimize the scheduling of employees in CV. Karya Indah Bordir in doing certain tasks using Hungarian method, as well as analyzing the sensitivity of the optimal solution if there is a reduction on the employees time to finish the tasks. The Hungarian method was applied on the embroidery process involving 11 employees and 10 tasks. The optimal scheduling result minimize the time of the embroidery production of the company. The optimal scheduling result found is: employee 1 does the Mambo bag, employee 2 does the Elli bag, employee 3 does the Lonjong bag, employee 4 does the Tampang bunga bag, employee 6 does the Ransel, employee 7 does the Tima bag, employee 8 does the Keong bag, employee 9 does the Alexa bag, employees 10 does the Luna bag, and employee 11 does the Mikha bag, with the total work time is 13,7 hours. After the Hungarian method was applied, CV. Karya Indah Bordir got the increasing revenue as much as 9,09 %. The sensitivity analysis was conducted by reducing the time of the employees take in embroidery the bags. The results of the sensitivity analysis are some boundaries for basis and non basis variables to maintain the optimal solution. 

Study on Structure Sensitivity Analysis Using ANSYS PDS

2011 ◽  
Vol 243-249 ◽  
pp. 1830-1834
Author(s):  
Ke Ke Peng
Keyword(s):  
Sensitivity Analysis ◽  
Structure Sensitivity ◽  
Design System ◽  
Complex Structures ◽  
Probabilistic Design ◽  
Sensitivity Matrix ◽  
Arch Bridge ◽  
Cfst Arch Bridge ◽  
Sensitive Factor ◽  
Incremental Form

As to sensitivity analysis, based on traditional sensitive factor definition and concept of reliability vector, two kinds of sensitivity problems are putted forward in this paper. And factor sensitivity matrix is defined. As far as large and complex structures are concerned, factor sensitivity matrix of incremental form is given. Furthermore, sensitivity surface is putted forward. ANSYS PDS（ANSYS Probabilistic Design System）can solve the above two kinds of sensitivity problems efficiently. The example bridge is a CFST arch bridge with 83.6 meter-span, which operated for 10 years. The analysis result shows that the definitions enhance the maneuverability of sensitivity analysis, and ANSYS PDS is practical.

scholarly journals Two – Warehouse Inventory System Model for Deteriorating Items Considering Partial Upstream Trade Credit Financing

2021 ◽  
pp. 69-80
Author(s):  
Z. H. Aliyu ◽  
B. Sani
Keyword(s):  
Sensitivity Analysis ◽  
Credit Risk ◽  
Trade Credit ◽  
Optimal Solution ◽  
Inventory System ◽  
System Model ◽  
Credit Period ◽  
Business Transaction ◽  
Credit Financing ◽  
Relevant Cost

In this study, we developed an inventory system model under two – level trade credit where the supplier considers the retailer as credit risk but the retailer considers the customers as credit worthy. Therefore, the retailer is given a trade credit period on  proportion of the goods ordered whenever he/she pays for proportion of the goods immediately after delivery. In the same vein, the retailer passes the same grace to the customers but without attaching any condition as the customers are assumed credit worthy. This partial upstream trade credit is offered to reduce the risk of failure in payment on the business transaction especially that most retailers are involved in bulk orders. The relevant cost functions are determined and a numerical example is given. Sensitivity analysis was carried out to see the effect of changes in parameters on the optimal solution of the model.

scholarly journals Sensitivity Analysis of Road Freight Transportation of a Mega Non-Alcoholic Beverage Industry

2020 ◽  
Vol 24 (3) ◽  
pp. 449-454
Author(s):  
T. Latunde ◽  
J.O. Richard ◽  
O.O. Esan ◽  
O.O. Dare
Keyword(s):  
Sensitivity Analysis ◽  
Alcoholic Beverage ◽  
Optimal Solution ◽  
Transportation Cost ◽  
Demand And Supply ◽  
North West ◽  
The North ◽  
Beverage Industry ◽  
Road Freight ◽  
Road Freight Transportation

Re-optimization can be very costly for gathering and obtaining more data for a particular problem, to curb this very expensive investment.  Sensitivity analysis has been used in this work to determine the behaviour of input parameters of the formulated problem. The main goal of the study is to respectively provide, derive, observe, compare and discuss the sensitivity analysis of data that has been optimized using different methods of the optimal solution. The best method, saving the highest percentage of transportation cost, for the formulated problem is determined to be the North-West Corner method. This was carried out by arbitrarily assigning values to the available warehouses to determine the best possible demand and supply cases rather than the initial cases. Thus, more cases are advised to be supplied to FID from the Asejire plant for the optimum reduced value of transportation cost. Keywords: Sensitivity, Parameters, Transportation Problem.

scholarly journals Random perturbation of the projected variable metric method for nonsmooth nonconvex optimization problems with linear constraints

2011 ◽  
Vol 21 (2) ◽  
pp. 317-329 ◽  
Author(s):  
Abdelkrim El Mouatasim ◽  
Rachid Ellaia ◽  
Eduardo de Cursi
Keyword(s):  
Nonconvex Optimization ◽  
Optimization Problems ◽  
Random Perturbation ◽  
Linear Constraints ◽  
Nonconvex Optimization Problems ◽  
Variable Metric ◽  
Lipschitz Continuous ◽  
Nonsmooth Nonconvex Optimization ◽  
Variable Metric Method ◽  
Set Of Points

Random perturbation of the projected variable metric method for nonsmooth nonconvex optimization problems with linear constraintsWe present a random perturbation of the projected variable metric method for solving linearly constrained nonsmooth (i.e., nondifferentiable) nonconvex optimization problems, and we establish the convergence to a global minimum for a locally Lipschitz continuous objective function which may be nondifferentiable on a countable set of points. Numerical results show the effectiveness of the proposed approach.

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