Static Characteristics Of System Research Articles

Soft Sensor Model Derived from Wiener Model Structure: Modeling and Identification

The processes of building dynamic and static relationships between secondary and primary variables are usually integrated in most of nonlinear dynamic soft sensor models. However, such integration limits the estimation accuracy of soft sensor models. Wiener model effectively describes dynamic and static characteristics of a system with the structure of dynamic and static submodels in cascade. We propose a soft sensor model derived from Wiener model structure, which is an extension of Wiener model. Dynamic and static relationships between secondary and primary variables are built respectively to describe the dynamic and static characteristics of system. The feasibility of this model is verified. Then the expression of discrete model is derived for soft sensor system. Conjugate gradient algorithm is applied to identify the dynamic and static model parameters alternately. Corresponding update method for soft sensor system is also given. Case studies confirm the effectiveness of the proposed model, alternate identification algorithm, and update method.

Load balancing in a locally distributed DB system

Most previous work on query optimization in distributed database systems has focused on finding optimal or near-optimal processing plans based solely on static system characteristics, and few researchers have addressed the problem of copy selection when data is replicated. This paper describes a new approach to query processing for locally distributed database systems. Our approach uses load information to select the processing site(s) for a query, dynamically choosing from among those sites that have copies of relations referenced by the query. Query compilation is used to produce a statically-optimized logical plan for the query, and then a dynamic optimization phase converts this logical plan into an executable physical plan at runtime. This paper motivates the separation of static and dynamic optimization, presents algorithms for the various phases of the optimization process, and describes a simulation study that was undertaken to investigate the performance of this approach. Our simulation results indicate that load-balanced query processing can provide improvements in both query response times and overall system throughput as compared to schemes where execution sites are either statistically or randomly selected.

The Snow Ski as a Dynamic System

Paper reports research on dynamic system characteristics of snow skis. Laboratory and field measurements of frequency response, running surface pressure excitation, and static system characteristics are intended to provide a data base of physical information to guide future design and research. Laboratory testing procedures used give meaningful information for “straight running” but not for “turning.” In general, the turning and straight running maneuvers must be examined independently. This paper summarizes the general research observations with a minimum of detail included.