We present a new approach to modeling the execution costs of user-defined functions (UDFs) for the query optimizer of an object-relational DBMS (ORDBMS). Our approach self-tunes a cost model incrementally based on the costs of the recent executions of a UDF. The approach is centered on a feedback loop in which the feedback information comprises individual UDF execution records. Each execution r...

This paper explores the nonlinear characteristics of self-excited aerodynamic forces a semi-closed box deck section to perfect theory aeroelastic response analysis. A numerical wind tunnel model was established based on computational fluid dynamics (CFD) method. The heaving-pitching coupled motion is realized by loading user-defined function (UDF) and dynamic grid technology. varying with ampli...

Objective Pregnancy in women with surgically corrected tetralogy of Fallot (ToF) is associated with cardiac, obstetric and neonatal complications. We compared uteroplacental Doppler flow (UDF) measurements and pregnancy outcome in women with ToF and in healthy women and aimed to assess whether a relationship exists between cardiac function and UDF in women with ToF. Methods We evaluated prospec...

A coupled thermal-microstructural simulation model was developed to estimate the thermal history in a eutectoid steel wire rod under continuous cooling and forced-convection. The phenomena of heat transfer, phase transformation estimation boundary condition. histories were analyzed at different rates emulate forced-convection conditions by air-jet as controlled conveyor. acquired used calculate...

Advances in digital design and fabrication technologies are leading toward single fabrication systems capable of producing almost any complete functional object. We are proposing a new paradigm for manufacturing, which we call Universal Desktop Fabrication (UDF), and a framework for its development. UDF will be a coherent system of volumetric digital design software able to handle infinite comp...

As the research on hybrid rocket motors advances, more accurate tools are needed to estimate performance of system by determining its fundamental parameters. One them is certainly regression rate solid fuel. Unfortunately, it depends many complex physical phenomena and interactions which vary with time, space scale, making task predicting evolution very difficult. To address this issue, Computa...

Despite the wide-spread applications of spray drying in production chemicals, food, and pharmaceuticals, accurate control development this unit remains an elusive task because complex interactions variables phenomena. In paper, we offer a computationally efficient closed-loop system with model predictive controller (MPC) where computational fluid dynamics (CFD) process is utilized to represent ...

Bike-sharing systems are a rapidly developing mode of transportation and provide an efficient alternative to passive, motorized personal mobility. The asymmetric nature bike demand causes the need for rebalancing stations, which is typically done during nighttime. To determine optimal starting inventory level station given day, User Dissatisfaction Function (UDF) models user pickups returns as ...

Waste heat recovery along with low-grade energy can be utilized for numerous applications in our daily life. This manuscript presents a novel idea of utilizing the waste from domestic cooking devices assisting solar desalination system through simulation and validated experimentally. To assess potential 2D axisymmetric model water jacket has made using ANSYS Fluent while applying user-defined f...

In this work, an existing method of capturing Fe-based fine particles by magnetic fiber is improved, and a weaving for the filter material further determined. Different combinations fields could form around fibers, which change interaction between orthogonal fibers when uniform field applied along X-, Y-, Z-axes. Therefore, process particle capture under three configurations was compared using ...