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ON TWO APPROACHES FOR CONSTRUCTION …<br />

2. Determine and take of point u∈or ∩D(M,M) and put vector u=u−o.<br />

3. Construct the sets D(M′,M) and D(M′,M(u)).<br />

4. Compute the intersection I(u)=D(M′,M)∩D(M′,M(u)).<br />

5. Take one point from the set I(u) and put vector v=v−o.<br />

6. The two polygons M, M'(v) generate the two-periodical placement Uu.<br />

R e m a r k. The set D(M′,M(u)) is congruent to the set D(M′,M) and it is<br />

a copy of the set D(M′,M) under translation given by the vector u. Dense<br />

two-periodical placement MM'u=Uu can be made as the set all copies of the<br />

union U=M∪M'(v) under all translations iu for i∈Z.<br />

Complexity of this algorithm depends again on the complexity of the<br />

constructions D(M,M) and D(M′,M) and on the complexity of the<br />

determining of the intersection or∩D(M,M) and I(u). It can be expected<br />

that we obtain the optimal (total) dense two-periodical placement either for<br />

some regular point from the set I R (u) or for some point from the set I(u).<br />

5 Conclusions<br />

For the current stage of production in many branches of industry it is typical<br />

the robotization and automation not only of the whole production process,<br />

but also in process technological preparation of procedures, too. One of<br />

technological preparation is creation of (optimal) cutting planes. These<br />

problems are very current at present times above all from minimizing of<br />

production costs viewpoint, especially in connection with important<br />

development of the automobile industry in Slovakia.<br />

The two presented constructions for dense two-periodical placement of<br />

rectangular polygon M along a line resulted from theoretical research with<br />

respect to applications in engineering in the sheet metal cutting process (the<br />

production of rectangular cutting pieces) - in solving (optimal) direct<br />

alternate layout for stamping. We will study and publish the criterions and<br />

conditions of optimization for both described ways in future.<br />

The reviewed cutting plans are used often in engineering practice,<br />

especially in production of rectangular pieces with smaller dimensions and<br />

for bigger series. The tools with bigger number blades have shortest utility,<br />

the rotation of strip impedes for a change operate of tool [2]. A choice on<br />

procedure for mentioned direct alternate layout depends consequently on<br />

concrete demands of production, material and technological conditions.<br />

Acknowledgement<br />

The research was supported by the grant VEGA No 1/2006/05.<br />

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