Technical note - On optimization approach for multidisk vertical allocation problems
نویسندگان
چکیده
Multidisk vertical allocation (MDVA) problems intend to find an allocation of relations to disks such that the expected query cost is minimized. Recently, Chang [European Journal of Operational Research 143 (2002) 210] modified Rotem et al.’s [IEEE Transactions on Knowledge and Data Engineering 5 (1993) 882] method for solving an MDVA problem using a smaller number of binary variables. Chang’s method however is unable to treat MDVA problems with possible replication of relations. This paper proposes another method to solve MDVA problems, which is more effective than Rotem et al.’s and is able to treat replication problems insolvable by Chang’s method. 2004 Elsevier B.V. All rights reserved.
منابع مشابه
Reliability Optimization for Complicated Systems with a Choice of Redundancy Strategies (TECHNICAL NOTE)
Redundancy allocation is one of the common techniques to increase the reliability of the bridge systems. Many studies on the general redundancy allocation problems assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in real world, a particular system design contains both active and col...
متن کاملOptimization of Meshless Local Petrov-Galerkin Parameters using Genetic Algorithm for 3D Elasto-static Problems (TECHNICAL NOTE)
A truly Meshless Local Petrov-Galerkin (MLPG) method is developed for solving 3D elasto-static problems. Using the general MLPG concept, this method is derived through the local weak forms of the equilibrium equations, by using a test function, namely, the Heaviside step function. The Moving Least Squares (MLS) are chosen to construct the shape functions. The penalty approach is used to impose ...
متن کاملOptimized Fuzzy Logic for Nonlinear Vibration Control of Aircraft Semi-active Shock Absorber with Input Constraint (TECHNICAL NOTE)
Landing impact and runway unevenness have proximate consequence on performance of landing gear system and conduce to discomfort of passengers and reduction of the pilot’s capability to control aircraft. Finally, vibrations caused by them result in structure fatigue. Fuzzy logic controller is used frequently in different applications because of simplicity in design and implementation. In the pre...
متن کاملThe Comparison of Imperialist Competitive Algorithm Applied and Genetic Algorithm for Machining Allocation of Clutch Assembly (TECHNICAL NOTE)
The allocation of design tolerances between the components of a mechanical assembly and manufacturing tolerances can significantly affect the functionality of products and related production costs. This paper introduces Imperialist Competitive Algorithm (ICA) approach to solve the machining tolerance allocation of an overrunning clutch assembly. The objective is to obtain optimum tolerances of...
متن کاملEffect of Material Wet on Silo Obstruction Solution by Impact (TECHNICAL NOTE)
Vertical silos are large cylinders used for material storage in agriculture and mineral industries. One of the silo problems is its obstruction due to dome and dense packing. Depend on the material properties and silo dimensions several techniques are used to solve this problem. In the present work, possibility of obstruction solution of a laboratory silo by ball impact is investigated. Test ma...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- European Journal of Operational Research
دوره 165 شماره
صفحات -
تاریخ انتشار 2005