In the recent past, different multidimensional data models were introduced to model OLAP (‘Online Analytical Processing’) scenarios. Design problems arise, when the modeled OLAP scenarios become very large and the dimensionality increases, which greatly decreases the support for an efficient ad-hoc data analysis process. Therefore, we extend the classical multidimensional model by grouping functionally dependent attributes within single dimensions, yielding in real orthogonal dimensions, which are easy to create and to maintain on schema design level. During the multidimensional data analysis phase, this technique yields in nested data cubes reflecting an intuitive two-step navigation process: classification-oriented ‘drill-down’/ ‘roll-up’ and description-oriented‘split’/ ‘merge’ operators on data cubes. Thus, the proposed Nested Multidimensional Data Model provides great modeling flexibility during the schema design phase and application-oriented restrictiveness during the data analysis phase.

Schema design is one of the fundamentals in database theory and practice as well. In this paper, we discuss the problem of locally valid dimensional attributes in a classification hierarchy of a typical OLAP scenario. In a first step, we show that the traditional star and snowflake schema approach is not feasible in this very natural case of a hierarchy. Therefore, we sketch two alternative modeling approaches resulting in practical solutions and a seamless extension of the traditional star and snowflake schema approach: In a pure relational approach, we replace each dimension table of a star / snowflake schema by a set of views directly reflecting the classification hierarchy. The second approach takes advantage of the object-relational extensions. Using object-relational techniques in the context for the relational representation of a multidimensional OLAP scenario is a novel approach and promises a clean and smooth schema design.

The concept of multidimensional modeling has proven extremely successful in the area of Online Analytical Processing (OLAP) as one of many applications running on top of a data warehouse installation. Although many different modeling techniques expressed in extended multidimensional data models were proposed in the recent past, we feel that many hot issues are not properly reflected. In this paper we address ten common problems reaching from defects within dimensional structures over multidimensional structures to new analytical requirements and more.

A gas turbine engine design process was developed for the design of a common core engine family. The process considers initial and projected variant engine applications, likely technology maturation, and various sources of uncertainty when making initial core design considerations. A physics based modeling and simulation environment was developed to enforce geometric core commonality between the core defining design engine and a common core variant engine. The environment also allows for upgrade options and technology to be infused into the variant engine design. The relationships established in the model enable commonality to be implicitly enforced when performing simultaneous design space explorations of the common core design and all corresponding variant engine designs. A robust design simulation process was also developed, enabling probabilistic surrogate model representations of the common core engine family design space to be produced. The probabilistic models provide confidence interval performance estimates with a single function call for an inputted set of core and variant design settings and the uncertainty distribution shape parameter settings representative of an uncertainty scenario of interest. The unique form of the probabilistic surrogate models enables large numbers of common core engine family applications to be considered simultaneously, each being simulated under a unique uncertainty scenario. Implications of core design options can be instantaneously predicted for all engine applications considered, allowing for favorable common core design regions to be identified in a highly efficient manner.

This diploma thesis is focused on the design of a product family of portable veterinary x-ray generators. The thesis deals with the possibilities of using parameterization when designing products which are part of a product series. The main body of the thesis lies in the design of a parametric script which generates variations of portable veterinary x-ray generators depending on the size and position of the inner components. The outer surfaces are defined by algorithms from the input parameters. It is possible to alter the individual attributes (e.g. the progresion of curves, the dimensions of component parts and the proportions between the individual parts). The output from the parametric script is three size-variations of the product.

Kundanpassning är ett ökande problem för tillverkare och det gäller även för Zetterbergs därproblemet nu är att konstruera lastbilsprodukter som ska passa till alla kunder vars lastbils-fabrikat varierar. Syftet med studien var att utveckla CAD-modeller för en ljusanordning medbred kundanpassning, lågt komponentantal och mindre skador vid tillämpning.För att utföra arbetet användes teori inom DFM (Design For Manufacturing), regelverk ochde tillverkningsmetoder som fanns till godo hos företaget. Datainsamlingen bestod av inter-vjuer, litteraturstudier och observationer. Arbetet följde en generell produktutvecklingspro-cess som började med konceptgenerering. Valet av vinnande koncept för vidareutvecklingbestämdes med Pughs matris. Vidareutvecklingen utfördes i Solidworks där även FEM-ana-lyser och topologioptimerings-analyser utfördes i syfte att förbättra konstruktionerna utanatt förlora hållfasthet och vibrationskänslighet.Resultatet blev två CAD-ritade ljusanordningar vars vikt var lägre än den nuvarande anord-ningen. Distansen mellan skadepunkter och lastbilens ände ökade jämfört med originalet. Enav konstruktionerna hade färre komponenter än originalet. De resulterande ljusanordning-arna visade goda egenskaper, men det finns rum för korrigeringar, som delvis missades imån av tidsbrist. Vidare var de utförda FEM-analyser och topologioptimeringar förenklingarav verkligheten och därför är det svårt att bedöma om dessa adekvat representerar praktiskanvändbarhet utan verkliga tester. Det är därför av framtida intresse att tillverka ljusanord-ningarna i resultatet och testa prestandan i verkliga scenarion, men också för att identifieraeventuella tillverkning och monteringsproblem som omedvetet har negligerats. / Product-customization is a growing problem for manufacturers which is also true for Zetterbergs where the problem currently is to construct lorry products that fit the customers varying lorry-types. The purpose of the study is to develop CAD-models for a back light ordinance with broad customer adaptability, lower assembly component quantity and less damage occurrence during use of the product. To complete the task, design theory including DFM (Design For Manufacturing), manufacturing methods available at the company and regulatory limitations were researched. The data collection consisted of interviews, literature studies and observations. The work followed a general product development process that began with concept generation. Choosing the winning concepts for further development was done through Pugh’s decision matrix. Further development was conducted in SolidWorks where FEM analyses and topology optimizations also were conducted with the purpose of improving the constructions without losing strength and vibratory properties. The result of the study were two light ordinances with their respective construction drawings. The weight of the two ordinances were lower than the original. The distance between damage-points and the endpoint of the lorries both increased. One construction had lower component quantity than the original. Both constructions showed good characteristics. There is room for improvement however as some aspects may have been missed due to time restrictions. Furthermore, the FEM and topology analyses were simplifications of reality. It would be valuable to create real prototypes from the result and conduct tests in more realistic scenarios and simultaneously identify subconsciously neglected manufacturing and assembly issues.