Fault tolerant hypercube computer system architecture

A fault-tolerant multiprocessor computer system of the hypercube type comprising a hierarchy of computers of like kind which can be functionally substituted for one another as necessary is disclosed. Communication between the working nodes is via one communications network while communications between the working nodes and watch dog nodes and load balancing nodes higher in the structure is via another communications network separate from the first. A typical branch of the hierarchy reporting to a master node or host computer comprises, a plurality of first computing nodes; a first network of message conducting paths for interconnecting the first computing nodes as a hypercube. The first network provides a path for message transfer between the first computing nodes; a first watch dog node; and a second network of message connecting paths for connecting the first computing nodes to the first watch dog node independent from the first network, the second network provides an independent path for test message and reconfiguration affecting transfers between the first computing nodes and the first switch watch dog node. There is additionally, a plurality of second computing nodes; a third network of message conducting paths for interconnecting the second computing nodes as a hypercube. The third network provides a path for message transfer between the second computing nodes; a fourth network of message conducting paths for connecting the second computing nodes to the first watch dog node independent from the third network. The fourth network provides an independent path for test message and reconfiguration affecting transfers between the second computing nodes and the first watch dog node; and a first multiplexer disposed between the first watch dog node and the second and fourth networks for allowing the first watch dog node to selectively communicate with individual ones of the computing nodes through the second and fourth networks; as well as, a second watch dog node operably connected to the first multiplexer whereby the second watch dog node can selectively communicate with individual ones of the computing nodes through the second and fourth networks. The branch is completed by a first load balancing node; and a second multiplexer connected between the first load balancing node and the first and second watch dog nodes, allowing the first load balancing node to selectively communicate with the first and second watch dog nodes

Self-Employment Dynamics and Self-Employment Trends: A Study of Canadian Men and Women, 1982-1995

Self-employment has risen dramatically in Canada, accounting for a disproportionate share of job growth since the 1980's. Using hitherto-unexploited information on labour force transitions from 13 waves of the Survey of Consumer Finances between 1982 and 1995, we show that the changes in transition patterns underlying these increases were very different for women and men. For women, most of the increase in self-employment is attributable to an increase in their retention rates in self-employment. For men, most is attributable to a decrease in the stability of paid employment, i.e. a rise in transitions from employment to non-employment. This generates an increase in self-employment because non-employed men are much more likely than employed men to enter self-employment. Changes in demographic characteristics account for very little of these altered transition probabilities. Somewhat paradoxically, self-employment thus rose both in secularly improving (women's) and deteriorating (men's) labour markets, due to different changes in the underlying transition processes.