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The Albuquerque (New Mexico) Public Schools conducted a three-year study of integrated computer-based learning systems, including WICAT, Dolphin, PLATO, CCC, and DEGEM. Through cooperation with the Education Consolidation Improvement Act Chapter 1 program, four large integrated learning systems (ILS) were purchased and studied. They were installed and implemented in 1984. Due to budget constraints, the PLATO program was dropped from the study. The DEGEM system will be evaluated during the second year of the project and is not included here. The primary application of the ILS was to provide Chapter 1 students with supplemental instruction in reading, language arts, and mathematics through computer assisted instruction (CAI). The evaluation compared the four systems' effectiveness. Aspects of the evaluation included the match between ILS, curriculum content, and standardized achievement test content; instructional and technical characteristics; documentation; management systems; diagnostic placement; programming; staffing and training; cost effectiveness; and student and teacher perceptions of value. Results indicated the CAI programs were under-utilized during their first year, largely due to staffing patterns. Mathematics impact was generally greater than reading. The importance of a full-time laboratory operator was repeatedly noted. (GDC)

In this paper an active modal TMD control logic for the vibration suppression is presented. Starting from the traditional TMD theory, a closed loop formulation is proposed to calculate the active control force. The possibility to describe every mechanical systems or civil structures with a set of modal coordinates allows to act independently on each d.o.f. The technique is compared with different solutions already present in literature, such as the IMSC and the PPF. Numerical simulations, based on a FEM linear model, are carried out to investigate the pro and con of each logic. [ABSTRACT FROM AUTHOR]

The independent modal control to suppress the vibration of nonlinear flexible structures is applied in this paper. Technological improvements in the mechanical field showed during the recent years have led to high-performance systems with low weight and, as a consequence, high flexibility and low damping. Here active control quickly bettered the traditional passive damping systems. The structure investigated in this paper is a multi-body flexible boom moved by hydraulic actuators. The nonlinear system dynamic was numerically modeled and a control strategy, based on the use of the same actuators, was developed. Finally a test rig was created to experimentally validate the proposed approach. [ABSTRACT FROM AUTHOR]

Concrete pump booms are subjected to vibrations that increase mechanical stress and shorten their lifespan. This paper aims to study the problem by considering the two subsystems, the boom and the concrete pump, that have the greatest effect on the phenomenon. The authors supply numerical and experimental tools that can analyze the problem in depth in all its complexity. First, the systems were investigated independently, to identify their individual aspects. Then a numerical model was created to reproduce the behavior of the whole system and the interaction between boom and pump. The result was a new powerful tool for investigating passive and active solutions for suppressing vibration. [ABSTRACT FROM AUTHOR]