Baigiamajame magistro darbe nagrinėjami struktūrų modeliavimo, diskretizavimo ir optimizavimo uždaviniai, jų sprendimo būdai ir algoritmai. Pasiūlyta originali strypinių struktūrų optimizavimo ir diskretizavimo technika, kurioje naudojami vaizdų algebros metodai ir baigtinių elementų metodo (toliau – BEM) programiniai paketai. Atlikta BEM programinių paketų apžvalga, parinkti tinkamiausi paketai darbo tikslams realizuoti ir rezultatams verifikuoti. Išanalizuoti skaitmeninių vaizdų skeletų išgavimo metodai. Pasiūlytas originalus vaizdo skeleto apdorojimo algoritmas skerspjūvio charakteristikoms nustatyti. Sudarytas ir programiškai realizuotas strypinių struktūrų optimizavimo-diskretizavimo algoritmas. Realizuota programinė sistema susideda iš vaizdų apdorojimo ir duomenų paruošimo dalies (MATLAB kalba) bei BEM skaičiavimų dalies (ANSYS vidine programavimo kalba APDL). Skaičiavimo rezultatai atvaizduojami ir verifikuojami STAAD.Pro paketu. Diskretizavimo metu strypinės struktūros mazgų vieta randama vaizdo skeleto segmentų sankirtos taškuose, o segmentų skerspjūvių plotai randami atkarpų, jungiančių šiuos mazgus, vidurio taškuose. Kai struktūros mazgų padėtis fiksuota arba mazgai yra per arti vienas kito atliekamas mazgų padėties koregavimas. Darbe atlikti testiniai skaičiavimai, rezultatų analizė ir verifikavimas, suformuluotos išvados. / In the master thesis the problems of structure modeling, discretization-optimization and their solution methods and algorithms are analyzed. The original technique for optimization and discretization of beam structures has been suggested; The packages of image algebra methods and of the finite element methods were employed for that. Several packages of finite element method have been reviewed and the most suitable packages for the current problems were identified. The methods for obtaining skeletons of digital images were explored. The algorithms for optimization and discretization of beam structures has been suggested and coded. The program created consents of the part for image processing and input data preparing, and the part for image the finite element via method. The results obtained are represented and verified by STAAD.Pro package. During the discretization, the positions of structure nodes are obtained in the intersection of skeleton segments. The segments' cross-section areas are obtained in the middle-points between two adjacent nodes. The positions of nodes may be corrected if the nodes close to each other. The test-calculation, analysis of results and verification are presented and conclusions are drawn.

The task of the work is to investigate efficiency and effectiveness of measurement operations due to possibilities to select an optimal pitch of measurement and change it in-operation according to the newly developed algorithm or strategy of measurement. The task of the investigation would also be to present recommendations for measurements of planes or 3D measurements in machine engineering and instrumentation, geodesy and surveying, structure industry. The present work pursues the following objectives: • the analysis of the ways leading to the most cost-effective selection of planar and three-dimensional surface measurement tests; • the identification of optimal frequency in the tested space by determining the measurement discretization pitch and associating its value with the nature of the deviations measured; • cutting down the measurement time without any loss in deviations’ assessment accuracy by undertaking investigations into the effect of the nature of the deviation function upon the value of the discretization pitch as well as by developing new procedures and algorithms to cut down measurement time; • the submission of the recommendations how to reduce the number of measurement tests and ensure optimal measurement time in machine and instrument manufacture process, in construction and geodesy. The created integrally and differentially modified discretization methods make it possible to cut down the time of measurement of the object without any loss of quality of... [to full text]

The task of the work is to investigate efficiency and effectiveness of measurement operations due to possibilities to select an optimal pitch of measurement and change it in-operation according to the newly developed algorithm or strategy of measurement. The task of the investigation would also be to present recommendations for measurements of planes or 3D measurements in machine engineering and instrumentation, geodesy and surveying, structure industry. The present work pursues the following objectives: • the analysis of the ways leading to the most cost-effective selection of planar and three-dimensional surface measurement tests; • the identification of optimal frequency in the tested space by determining the measurement discretization pitch and associating its value with the nature of the deviations measured; • cutting down the measurement time without any loss in deviations’ assessment accuracy by undertaking investigations into the effect of the nature of the deviation function upon the value of the discretization pitch as well as by developing new procedures and algorithms to cut down measurement time; • the submission of the recommendations how to reduce the number of measurement tests and ensure optimal measurement time in machine and instrument manufacture process, in construction and geodesy. The created integrally and differentially modified discretization methods make it possible to cut down the time of measurement of the object without any loss of quality of... [to full text]

Šiame darbe buvo analizuojama programinė įranga skirta diskretizuoti sritį į baigtinius elementus. Analizuotos MATLAB sistemos ir COMSOL programos diskretzavimo galimybės. Sukurta programa sujungianti COMSOL ir MATLAB, kuri leidžia diskretizuoti sritį į baigtinius elementus. / In this work was done study of software for domain discretization by finite elements. Created program that connects MATLAB and COMSOL, which allows domain discretization by finite elements.

Pristatomas duomenų gavybos ir grupavimo naudojimas paplitusiose sistemose bei sukurtas IT žinių portalo statistikos prototipas duomenų saugojimui, analizei ir peržiūrai atlikti. Siūlomas statistikos modulis duomenų saugykloje periodiškais laiko momentais vykdantis duomenų transformacijas. Portale prieinami statistiniai duomenys gali būti grupuoti. Sugrupuotą informaciją pateikus grafiškai, duomenys gali būti interpretuojami ir stebimi veiklos mastai. Panašių objektų grupėms išskirti pritaikytas vienas iš žinomiausių duomenų grupavimo metodų – lygiagretusis k-vidurkių metodas. / Presented data mining methods and clustering usage in current statistical systems and created statistics module prototype for data storage, analysis and visualization for IT knowledge portal. In suggested statistics prototype database periodical data transformations are performed. Statistical data accessed in portal can be clustered. Clustered information represented graphically may serve for interpreting information when trends may be noticed. One of the best known data clustering methods – parallel k-means method – is adapted for separating similar data clusters.