Development of a robotic device for facilitating learning by children who have severe disabilities

This paper presents technical aspects of a robot manipulator developed to facilitate learning by young children who are generally unable to grasp objects or speak. The severity of these physical disabilities also limits assessment of their cognitive and language skills and abilities. The CRS robot manipulator was adapted for use by children who have disabilities. Our emphasis is on the technical control aspects of the development of an interface and communication environment between the child and the robot arm. The system is designed so that each child has user control and control procedures that are individually adapted. Control interfaces include large push buttons, keyboards, laser pointer, and head-controlled switches. Preliminary results have shown that young children who have severe disabilities can use the robotic arm system to complete functional play-related tasks. Developed software allows the child to accomplish a series of multistep tasks by activating one or more single switches. Through a single switch press the child can replay a series of preprogrammed movements that have a development sequence. Children using this system engaged in three-step sequential activities and were highly responsive to the robotic tasks. This was in marked contrast to other interventions using toys and computer games.     

A new class of intelligent knowledge-based systems with an optimisation-based inference engine

In this paper we describe a new class of intelligent knowledge-based system (IKBS) which can be used principally for managerial decision making applications. This class of applications often requires a framework for knowledge acquisition which allows the system to use the knowledge of several experts. In addition, since in most business decision making the objective is maximise profits, there is a need for an inference engine which allows optimisation to be carried out. The new class of IKBS which is described in this paper has both these properties, i.e., the ability to use the knowledge of multiple experts in a convenient way and an inference engine which by performing optimisations is able to pick out the profit maximising decisions. As an illustration of these concepts, a system for allocation decision making is described. The system ‘Retail-opt’ allows the user to solve problems like allocation of space in retail outlets, allocation of space in mail order catalogues, pricing policy decisions for discounted airline tickets, etc. In the paper, the basic concepts behind ‘Retail-opt’ are described and an application of ‘Retail-opt’ to the problem of retail space allocation in a Scandinavian Department Store is given. A number of other systems which use these concepts for more complicated competitive decision making situations are also described.     

Acute opiate overdose: characteristics of 190 consecutive cases

AIMS: To characterize the population of drug users consulting the Emergency Room (ER) of a university hospital with acute opiate overdose (AOO) and to assess rate of referral to specialized treatment programme. DESIGN: Survey of a 12-month sample of AOO patients. MEASUREMENTS: Medical and psychosocial features of the drug users, details of emergency treatment and referral by a mobile resuscitation team (SMUR) and the ER of our hospital (CHUV-Lausanne, Switzerland). In addition fatal AOO cases were collected by the Institute of Forensic Medicine (IFM) during the same period. FINDINGS: One hundred and eighty-four cases of AOO (134 patients) were treated. The files of the IFM detailed six additional deceased cases. This population of drug users was characterized by an over-representation of men (73%), by young age (27.4 years), by a high rate of multi-drugs use (90%) and by a high rate of multiple previous overdoses (2.6). Average length of stay was 20.1 hours but 41% of cases stayed less than 8 hours. Only one patient was readmitted within an 8-hour period. When discharged, 78% returned home. Unexpectedly, 67% of patients were not referred to any therapeutic programme for drug addiction. CONCLUSION: This study shows the low mortality of AOO when treated but also demonstrates the need to improve psychosocial evaluation and referral of drug addicts admitted with AOO.     

Hydration of dibarium silicate I. Stoicheiometry of hydration

Dibarium silicate, Ba₂SiO₄, was hydrated in two ways: in paste form at 25° using a water/solid weight ratio of 0.7:1, and in a polyethylene bottle rotated on a wheel at 5°, 25° and 50°, using a water/solid weight ratio of 9.0:1. When Ba₂SiO₄ is hydrated in paste form, the stoicheiometry of the reaction at 25° is the same as in bottle-hydration at 50°: 2BaO.SiO₂+2.2H₂O = 1.2BaO.SiO₂.1.4H₂O+0.8Ba(OH)₂. The stoicheiometry of bottle-hydration at 5° and 25° is represented by the equation: 2BaO.SiO₂+2.2H₂O = BaO.SiO.1.2H₂O+Ba(OH)₂. Barium silicate hydrate, 1.2BaO.SiO₂.1.4H₂O, is well crystallised and has a specific surface area of ? 3m²/g. The crystals are plate-like and have a tendency to form clusters. The low-baria hydrate, BaO.SiO₂.1.2H₂O, is poorly crystallised and consists of thin platelets. It has a specific surface area of ? 35m²/g. The thermal dehydration of fully hydrated barium silicate and of the barium silicate hydrates was investigated by thermogravimetric and differential thermal analysis techniques. The similarities and differences between the barium silicate hydrates obtained in the hydration of barium silicate and the calcium silicate hydrates obtained in the hydration of β-dicalcium silicate and Ca₃SiO₅ are discussed. A mechanism of hydration of barium silicate is proposed which involves solution, precipitation and crystallisation steps.     

Long-term continental U.S. timing system via television networks

Hundreds of atomic frequency standards and precision crystal oscillators exist in remote locations throughout the continental U.S. that are synchronized through fairly complex and costly means. Today, however, an inexpensive synchronization system is available in the form of live television broadcasts by commercial networks. In precision and accuracy, the television method is comparable to the portable atomic clock and/or Loran-C, with average day-to-day differential delays less than 1?s. Based on the results of the tests presented here, the use of nearly any solid-state television receiver and a low-cost horizontal sync pulse generator can provide 10-?s synchronizations at all times. The operation of a TV line-10 timing system, including the circuitry of auxiliary equipment, is also included. This article gives about 1? years of substantiating data for the three major commercial networks (ABC, CBS, and NBC). There is also provision for synchronization with the NBS and/or USNO Coordinated Universal Time (UTC) scales through regularly published reports.