Two-stage Design Process Research Articles

METAPHORICAL APPROACH TOWARDS THE INTERIOR DESIGN OF KAMPUNG LANGIT, BALI

Kampung Langit is an educational tourist spot located on the top floor of The Keranjang, Bali. Kampung Langit is aimed for children where they can enjoy various educational activities related to Balinese culture as well as providing retail areas where visitors can shop for souvenirs and snacks. Kampung Langit is a 1600 meter square area with various activities in each corner. The renovated area is one of the retail areas for sweets products, such as candies, ice cream, marshmallows, cotton candy and many other kinds of sweets. The design process was carried out by using a two-stage design process pioneered by William M. Pena and descriptive analysis process was also done by literature study on the metaphorical approach towards architecture and interior design. In this interior retail project, tangible metaphor is implemented directly towards the visual aspect of the interior. This metaphorical approach can be seen in the interior elements of Kampung Langit which are created according to the original shape of the sweets which will be sold. Metaphorical approach is also used in determining the colors used in the design, which are pastel colors inspired from marshmallows. By using a metaphorical approach towards the interior design of Kampung Langit, additional selling and commercial value is present. Metaphorical approach on the interior design improves the selling and commercial value of Kampung Langit.

Robust design of an adaptive cycle engine performance under component performance uncertainty

The adaptive cycle engine can vary the cycle in wider range and meet the requirement of mixed missions. It is expected to be the propulsion system for the next generation of aircraft and has therefore attracted a lot of attention. The uncertainty in component performance can offset the performance benefits of adaptive cycle engine. Therefore, the robust design should be applied at the engine performance design stage to reduce the effect of component performance uncertainty. Compared with conventional engines, the adaptive cycle engine has more variable geometry components. It causes two major difficulties for the robust design: one is the high computation cost and the other is the complex control law design. In this paper, a robust design method based on a two-level surrogate model and a two-stage design process is presented to overcome these difficulties. In this method, the probabilistic method is applied to quantify uncertainty and the selection principle of optimization target is studied. The cycle parameters and control law are optimized through a two-stage design process. The optimization is developed based on a two-level surrogate model to reduce the computational cost. This robust design method is validated by the Monte Carlo method. According to this study, performance under confidence probability is a better optimization target than the signal-to-noise ratio of performance. Using this method, the probability of engine performance meeting demand can be improved from about 50% to over 96%. The computational cost of uncertainty quantification is only 0.5% of the Monte Carlo method and the computational cost of whole optimization design process is less than the cost of once uncertainty quantification through Monte Carlo method. This method can improve the robustness of adaptive cycle engine performance and reduce the computational cost significantly. It can also be applied to the robust design of other complex gas turbine engines performance.

Design Optimization of Interior Permanent Magnet Synchronous Motor for Electric Compressors of Air-Conditioning Systems Mounted on EVs and HEVs

This paper deals with the optimization design process of an interior-type permanent magnet synchronous motor (IPMSM) for electric compressors of air conditioners applied to electric cars and hybrid vehicles. Based on a prototype IPMSM, we identified the current level for efficiency and cogging torque using finite-element analysis (FEA). The IPMSM’s main design variables are optimized to primarily satisfy the target of efficiency and cogging torque. A second optimization design is carried out using the response surface method (RSM) for the main design variables obtained from the Taguchi method analysis. As a result, the optimization design is carried out through a two-step optimization design process using the Taguchi method and RSM. The IPMSMs are analyzed using FEA, and their validity is confirmed by comparing the test results against each step-by-step model. We validate an effective optimization design process using a two-stage design process. We conclude that the proposed approach provides an effective design method for engineers.

A Machine Learning Approach for the Segmentation of Driving Maneuvers and its Application in Autonomous Parking

Abstract A classification system for the segmentation of driving maneuvers and its validation in autonomous parking using a small-scale vehicle are presented in this work. The classifiers are designed to detect points that are crucial for the path-planning task, thus enabling the implementation of efficient autonomous parking maneuvers. The training data set is generated by simulations using appropriate vehicle-dynamics models and the resulting classifiers are validated with the small-scale autonomous vehicle. To achieve both a high classification performance and a classification system that can be implemented on a microcontroller with limited computational resources, a two-stage design process is applied. In a first step an ensemble classifier, the Random Forest (RF) algorithm, is constructed and based on the RF-kernel a General Radial Basis Function (GRBF) classifier is generated. The GRBF-classifier is integrated into the small-scale autonomous vehicle leading to excellent performance in parallel-, cross- and oblique-parking maneuvers. The work shows that segmentation using classifies and open-loop control are an efficient approach in autonomous driving for the implementation of driving maneuvers.

The Impact of Student Location in a Global Design Project

Various engineering programs in North America enable students to immerse in international projects. Some students travel with NGOs and perform engineering work as part of their curriculum, and some design projects for hypothetical clients in other parts of the world. The authors designed a charcoal press for Kenyan farmers as part of their 2nd year design class. Due to the success of the design, the project was brought to Kenya, and was modified to be built to the materials and equipment that were available in the rural communities. One of the authors travelled to deliver the design, participated in building the device, as well as trained the clients to perform the process. The second author stayed in Canada.The authors present their experience on this two-stage design process, where the students were exposed in both designing from a distance and being immersed in the international setting of the project. Writing from students’ perspective, different points on how the project was effective on engraving design principles to students were shared. Students also reflected on their experience and developed recommendations on how the experience can be improved for future students who will take similar programs

Systematic topology optimization of solid–solid phononic crystals for multiple separate band-gaps with different polarizations

Phononic crystals (PnCs) have attracted considerable interest due to their unique and outstanding band-gap characteristics. In many applications, it is desirable to have a unit cell with specific band-gaps. The distribution of elastic materials within a unit cell has significant effect on the band-gaps, which is extremely difficult to be determined without systematic synthesis method. In this paper, topology optimization techniques are utilized to obtain two-dimensional (2D) square lattice PnCs with maximized relative band-gaps between multiple consecutive bands. The optimization follows two-stage design process using Genetic algorithms (GAs) in combination with finite element method (FEM). Three numerical examples are given to optimize 2D steel/epoxy PnCs in one-eighth symmetry for coupled mode, shear mode and mixed mode respectively. The results show that the optimized PnCs with different band-gaps, which can easily be found by the developed method, have different materials layout, and the PnCs with the lowest order band-gap are simple lattice and have the highest value of application in noise reduction and vibration isolation. Some optimized PnCs with higher order band-gaps have the same lattice as those with the lowest order band-gap, and whose absolute band-gaps are inversely proportional to the minimum feature size of primitive cells.

Performance-Based Seismic Design Research of a Super High-Rise Building

The application of performance-based seismic design method in super high-rise building is studied in this article. The two-stage design process of a super high-rise building is introduced. On the base of proposing the performance standards and objectives of the super high-rise building under earthquake actions of different levels, optimal solution is provided after computational analyses with different softwares. Computational analyses indicate that the design could satisfy all seismic fortification requirements and seismic performance objectives of China's seismic codes in force. The performance-based design idea can provide a reference for similar projects.

Two-stage design process of a frame-panel land vehicle structure employing topology and cross section optimization

A new structural design technology has been recently developed to build a new type of land vehicle in military use. While thick panels are only employed in conventional land vehicle structures, solid frames combined with relatively thin composite panels are employed for the new type of vehicle. The structural integrity of the new vehicle structure type is mainly guaranteed by the solid frames while composite panels are used to protect passengers and equipments of the vehicle. To design such a frame-panel structure, frame design needs to be done first. In this paper, a two-stage design process is proposed employing topology and cross section optimization methods. Overall frame arrangement of the new vehicle structure is obtained by the topology optimization in the first design stage and the detailed dimensions of the frames are obtained by the cross section optimization in the second design stage.

PROBLEMS AND FEATURES OF INTELLIGENT DESIGN OF ROOFS/INTELEKTINIO PROJEKTAVIMO PROBLEMOS IR YPATYBĖS RENOVUOJANT STOGUS

Intelligent computer-aided design is impossible without the object of design, component parts, participants of the process and analysis of their relations. The control of these relations was performed without computer. Therefore the processes flew without optimal criteria and technics of optimisation. Renovation of a building will depend on three most important concerned groups involved in the process: customers; designing organisations; building and constructing organisations. The entire process of design—from the idea to complete documentation—must be planned and executed with consideration of goals aspired by the interested parties—customers, designers and construction organisations. This process should realise the cycles of design, co-ordination and expertise of final solution. There are one-stage or two-stage design processes in traditional design process (Fig 2). Development of the project by one or two stages is pointed out by the design task of customer and depends upon technical complexity of the object. Complex objects are designed by a two-stage design process. One-stage design (Fig 3) is used, when the object is not complicated and includes many typical constructions. A great deal of graphics, economical data, accepted standards, rules are used in today's design process. While designing a building, the information flow could be controlled with the help of intelligent systems of design. Some information systems can be applied to different parts of a building. Fig 4 represents the structure of information system for roof design. Any part of information system is a complex object. Parts of information system for roof design are related to graphical-geometrical information. Relations between elements of roof intelligent design system are represented in Fig 5. Structure of some elements of information system (Fig 6) and internal relations are complex and manifold, so managing is possible only by intelligent design system. During the process of intelligent system design the same participants take part as in the traditional process: customers, design organisations, building and constructing organisations, but the relations between these participants are of a new quality. Fig 7 represents the relations between traditional participants and the flow of up-to-date information. The process of intelligent design differs from the traditional one by the following features: the intelligent system includes features of traditional design (design, expertise, coordination, renewing), but it is the system of new technology and quality due to the possibility of real optimisation; the process of renovation of dwelling houses roofs has an important feature, namely, a possibility for the unification of the design process. Rational composition of unificated projects can and must be supported by computer aided graphical and non-graphical databases with possibilities of the intelligent design; relations between data groups of a design object (Fig 7—A, B, C and D) can be managed by computer intelligent software. The intelligent process has some problems: the main stages of the roof design are related to considerations and financial possibilities of customers, aesthetical and architectural evaluation. These stages are related by three main interested groups (customers, design organisations, building and constructing organisations) and other institutions of the government. They can be optimised only by computer at intelligent level; the problem of information flowing, because methods of presentation of data must be co-ordinated with customers, design organisations, building and constructing organisations. Control techniques must be provided for its managing; data and knowledge bases must be continuously formed and renewed until using “Internet” and other modern methods for information transmission.

PROBLEMS AND FEATURES OF INTELLIGENT DESIGN OF ROOFS

Summary Intelligent computer-aided design is impossible without the object of design, component parts, participants of the process and analysis of their relations. The control of these relations was performed without computer. Therefore the processes flew without optimal criteria and technics of optimisation. Renovation of a building will depend on three most important concerned groups involved in the process: • customers • designing organisations • building and constructing organisations. The entire process of design—from the idea to complete documentation—must be planned and executed with consideration of goals aspired by the interested parties—customers, designers and construction organisations. This process should realise the cycles of design, co-ordination and expertise of final solution. There are one-stage or two-stage design processes in traditional design process (Fig 2). Development of the project by one or two stages is pointed out by the design task of customer and depends upon technical complexity of the object. Complex objects are designed by a two-stage design process. One-stage design (Fig 3) is used, when the object is not complicated and includes many typical constructions. A great deal of graphics, economical data, accepted standards, rules are used in today's design process. While designing a building, the information flow could be controlled with the help of intelligent systems of design. Some information systems can be applied to different parts of a building. Fig 4 represents the structure of information system for roof design. Any part of information system is a complex object. Parts of information system for roof design are related to graphical-geometrical information. Relations between elements of roof intelligent design system are represented in Fig 5. Structure of some elements of information system (Fig 6) and internal relations are complex and manifold, so managing is possible only by intelligent design system. During the process of intelligent system design the same participants take part as in the traditional process: customers, design organisations, building and constructing organisations, but the relations between these participants are of a new quality. Fig 7 represents the relations between traditional participants and the flow of up-to-date information. The process of intelligent design differs from the traditional one by the following features: • the intelligent system includes features of traditional design (design, expertise, coordination, renewing), but it is the system of new technology and quality due to the possibility of real optimisation. • the process of renovation of dwelling houses roofs has an important feature, namely, a possibility for the unification of the design process. Rational composition of unificated projects can and must be supported by computer aided graphical and non-graphical databases with possibilities of the intelligent design. • relations between data groups of a design object (Fig 7—A, B, C and D) can be managed by computer intelligent software. The intelligent process has some problems: • the main stages of the roof design are related to considerations and financial possibilities of customers, aesthetical and architectural evaluation. These stages are related by three main interested groups (customers, design organisations, building and constructing organisations) and other institutions of the government. They can be optimised only by computer at intelligent level. • the problem of information flowing, because methods of presentation of data must be co-ordinated with customers, design organisations, building and constructing organisations. Control techniques must be provided for its managing. • data and knowledge bases must be continuously formed and renewed until using “Internet” and other modern methods for information transmission.

Deciding between Sequential and Concurrent Tasks in Engineering Design

It is generally desirable to complete design tasks concurrently in order to reduce the overall development time However, com pleting tasks concurrently may sometimes increase the total amount of rework that must be done, thereby increasing the total engineering effort, the development cost, and the lead time. The technique descnbed in this paper helps to decide between serial and concurrent sched uling of multiple tasks in a two-stage design process. Using information about task interdependencies, this method calculates the amount of time and the amount of effort (in engineer-weeks) required for any suggested assignment of tasks to the two stages. The paper suggests an approach for minimizing time, or effort, or both, by adjusting the schedule of which tasks should be completed at which time. The method is applied to data from a computer workstation design problem.

Multilevel phase-only array generators with a trapezoidal phase topology

The implementation of a two-stage design process for the design of diffractive optical elements for array illumination is described. Results are presented for on-axis two-dimensional array illuminators for which this method is used. The final designs are theoretically within 5% of the calculated diffraction efficiency upper bound, and theoretical signal reconstruction error is below 1%. Experimental verification of the design theory is given, with experimental diffraction efficiencies within 4% of design values and signal reconstruction error below 6%.