Polygon scheduling

Consider a set of circles of the same length and r irregular polygons with vertices on a circle of this length. Each of the polygons has to be arranged on a given subset of all circles and the positions of the polygon on the different circles are depending on each other. How should the polygons be arranged relative to each other to minimize some criterion function depending on the distances between adjacent vertices on all circles? A decomposition of the set of all arrangements of the polygons into local regions in which the optimization problem is convex is given. An exact description of the local regions and a sharp bound on the number of local regions are derived. For the criterion functions minimizing the maximum weighted distance, maximizing the minimum weighted distance, and minimizing the sum of weighted distances the local optimization problems can be reduced to polynomially solvable network flow problems

Making the Department of National Defence Work in the 1970s: The Deputy Minister and the CDS Remember

In the aftermath of unification, the Canadian Forces were struggling to deal with the changes that overtook them, not least the Trudeau government’s relative indifference to the military, the impact of bilingualism, and massive reorganization. General Jacques Dextraze, who became chief of the defence staff in 1972, and Sylvain Cloutier, the deputy minister in the Department of National Defence from 1971 to 1975, played key roles in managing the changes. Interviews conducted by J.L. Granatstein in 1988 indicate where they agreed—and disagreed—and tell us much about the characters of these two key figures

\u3cem\u3eIke and Monty: Generals at War\u3c/em\u3e by Norman Gelb [Review]

Review of Norman Gelb, Ike and Monty: Generals at War. New York: William Morrow & Co., 1994

The influence of fibre length and concentration on the properties of glass fibre reinforced polypropylene : 6. the properties of injection moulded long fibre PP at high fibre content

The results of an investigation of the mechanical performance of injection moulded long glass fibre reinforced polypropylene with a glass fibre content in the range 0-73 weight % are presented. The composite modulus exhibited a linear dependence on fibre content over the full range of the study. Composite strength and impact resistance exhibited a maximum in performance in the 40-50 weight % reinforcement content range. The residual fibre length and fibre orientation in the samples has also been characterised. These parameters were also found to be fibre concentration dependent. Modeling of the composite strength using the measured fibre length and orientation data did enable a maximum in strength to be predicted. However, the position and absolute level of the predicted maximum did not correlate well with the experimental data. Further analysis indicated that deeper investigation of the dependence of the interfacial shear strength and fibre stress at composite failure on the fibre content are required to fully elucidate these results

The American Influence on the Canadian Military, 1939–1963

On Armistice Day in 1927, officials of the Canadian and United States governments dedicated a monument at Arlington Cemetery near Washington to commemorate the service of those Americans who had fought with Canadian forces before their country became a belligerent in the Great War. The occasion, stage-managed by Vincent Massey, Canada’s first Minister to the United States, was a glittering ceremony featuring permanent force infantry of the Royal Canadian Regiment and the Royal 22nd Regiment in their British-pattern scarlet tunics, as well as the pipes and drums of the 48th Highlanders, a well-known kilted Toronto militia regiment. Everyone was on their best bahviour, and the occasion was a great success, even the review of the infantry at the White House by the taciturn, if not comatose, President Calvin Coolidge

The CIA on Canadian Defence Policy

At the request of the Pentagon, in the spring of 1985 the Central Intelligence Agency prepared an assessment of Canadian defence policy. Brian Mulroney’s Progressive Conservatives had formed the government in the election of 4 September 1984 and, in the CIA’s view, the new administration was likely to be more interested in defence than the Liberals. Even so, the assessment observed that “Canadians generally think little about defense and when they do, reject outright the idea of giving defense priority over maintaining the social welfare system.

Why are natural fibres failing to deliver on composite performance?

The poor performance of natural fibres as composite reinforcements where the focus on chemical aspects has not yet delivered the "holy grail" of glass fibre replacement in volume applications is discussed. An explanation is proposed based on the anisotropic structure of these fibres and its influence the composite interphase