Volume: 6
Number: 1
January-June 2007

To see an article directly, click its Title. To see abstract, click its [Abstract] link.

• Content Based Searching Framework in Super PeerP2P Network
  Muhammad Nazrul Islam, Md. Ashiqul Islam, Imam Jafar Shadaque, Md. Razib Hayat Khan
  Abstract PDF
  Content Based Searching Framework in Super PeerP2P Network
  Muhammad Nazrul Islam, Md. Ashiqul Islam, Imam Jafar Shadaque, Md. Razib Hayat Khan

  Abstract

  Most existing Peer-to-Peer systems support only title based searches and are limited in functionality when compared to today’s search engines. Moreover, searching is an important factor in p2p network for content retrieval. That’s why without knowing the unique filename we can’t retrieve the content of the file in title based search. In this paper, we designed the super peer p2p network that supports content-based search for relevant documents. First, we propose a general and extensible framework which is based on hierarchical summary structure for searching similar documents in p2p network. Second, based on the framework, we develop an effective document searching system, by effectively summarizing and maintaining all documents within the network with different factors. Finally, the experimental result is verified on a real p2p prototype and large-scale network is further simulated. The results show the effectiveness, efficiency and scalability of the proposed system.
• Natural Convection in a Vee-corrugated Square Enclosure with Discrete Heating from below
  Goutam Saha, Sumon Saha, Mohammad Ali, Md. Quamrul Islam
  Abstract PDF
  Natural Convection in a Vee-corrugated Square Enclosure with Discrete Heating from below
  Goutam Saha, Sumon Saha, Mohammad Ali, Md. Quamrul Islam

  Abstract

  A study on steady-state natural convection heat transfer and fluid flow in a square enclosure with Vee-corrugated vertical walls has been carried out using finite element based adapting meshing technique. The present study is based on a configuration where a constant flux heat source is discretely embedded at the bottom wall. The length of the heat source is 20% of the total length of the bottom wall. The non-heated parts of the bottom wall and entire upper wall are considered adiabatic. The pressure-velocity form of the Navier-Stokes equations and energy equation are used to represent the mass, momentum, and energy conservations of the fluid medium in the cavity. The finite element formulations of the dimensionless governing equations with the associated boundary conditions are solved by a nonlinear coupled solution algorithm using a six nodded triangular element discretization scheme for all the field variables. The Grashof number based on the enclosure height is varied from 10s to 106, corrugated frequency is varied from 0.5 to 2 and Prandtl number is taken as 0.71. In this work, we examine the effect of corrugation frequency and the buoyancy force parameter on the flow and heat transfer characteristics. Results are presented in the form of streamlines and isotherm plots. The investigation shows that the average Nusselt number is maximum for low corrugation frequency but the reverse trend is found for high corrugation frequency.
• Optimization of Blank Holding Force in Deep Drawing Process by Fuzzy Logic
  S.L. Mahmood, N. A. Chowdhury, A.U. Patwari, M. H. Banna, M.R. Hossain
  Abstract PDF
  Optimization of Blank Holding Force in Deep Drawing Process by Fuzzy Logic
  S.L. Mahmood, N. A. Chowdhury, A.U. Patwari, M. H. Banna, M.R. Hossain

  Abstract

  In deep drawing process, if the blank holding force (BHF) is too low, the draw depth is restricted by the limits of wrinkling and if the blank holding force is too high, the draw depth is limited by fracture. In this paper an optimization technique by fuzzy logic is proposed to optimize the blank holding force so that the maximum draw depth can be achieved. In this technique, at first blank holding force and draw depth are inter-related by fuzzy rules (patches) and from there optimum blank holding force is computed by standard mathematical curve fitting procedure.
• Numerical Simulation of the Effect of Shock Strength on Normal Shock/Homogeneous Turbulence Interaction
  Mohammad Ali Jinnah, Kazuyoshi Takayama
  Abstract PDF
  Numerical Simulation of the Effect of Shock Strength on Normal Shock/Homogeneous Turbulence Interaction
  Mohammad Ali Jinnah, Kazuyoshi Takayama

  Abstract

  Shock wave interactions with grid-generated homogeneous and isotropic turbulence are observed numerically by solving the time-dependent three- dimensional Navier-Stokes equations with k-£turbulence model for a compressible fluid. Numerical measurements are taken before and after the interaction of turbulent regime with the normal shock wave reflected from the end wall. All turbulent fluctuations are measured during the compression by the reflected shock on the turbulent field and it is observed that the longitudinal turbulent velocity fluctuations are amplified after the shock/turbulence interaction. The amplification of turbulent fluctuations and turbulent kinetic energy level depend on the shock strength and the shock induced flow conditions behind the shock wave. The amplification factor of longitudinal turbulence intensity is 1.985-2.120 and the amplification factor of turbulent kinetic energy level is 3.086-3.410 in interaction of normal shock with homogeneous, isotropic turbulence for incident shock Macli number 1.50 and the amplification magnitude of longitudinal turbulence intensity and turbulent kinetic energy level decrease for incident shock Mach number 2.20 where the dissipation rate of turbulent kinetic energy decrease in all the cases of shock/turbulence interaction.