• Korean Journal of Computational Design and Engineering
• /
• v.17 no.4
• /
• pp.274-281
• /
• 2012

This paper proposed a control simulation method for design and verification of the transport system in an automobile assembly line based on digital manufacturing system. The design of the transport system involves two major activities: mechanical design (device specification) and electrical design (device behavior and system control). Conventionally, the simulation and emulation system of the transport system focuses on the abstract level, which mainly deals with design verification, alternative comparison, and system diagnosis. Although it can provide overall system visibility in monitoring how well it works in the process and view, its simulation models are not sufficiently realistic to be used for a detailed design or for implementation purposes. In this paper, a digital simulation model for a transport system in an automotive assembly line is constructed by adapting a digital manufacturing methodology. We use the concept of the "Virtual Probe", which transport a carrier instead of the belt of the conveyor. In conclusion, the proposed method is valuable in the process of test run in the shop floor. This method would reduce the time and effort for validating the manufacturing system and improve the productivity and integrity of the control program.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.12
• /
• pp.1613-1618
• /
• 2011

Analysis method for mechanism has been fully developed and relatively easy work compared to mechanism synthesis. Developing or creating a new mechanism for a given task is a creative job. In this case, a few theories are developed such as type synthesis. However, these methods are not sufficient for mechanism designers to sufficientely take into account alternative mechanism models during the initial phase of the mechanism design process. This paper presents the configuration design of mechanisms using graphical representation in the conceptual design stage. In this stage of kinematic synthesis, one needs to select mechanisms and configure appropriately to realize the desired motion of a machine. Graphical representation of mechanisms is proposed in this paper to help a designer to be highly creative and efficient in the initial design process. It is possible to easily design and analyze the mechanism of a machine by using this method.

• Journal of Distribution Science
• /
• v.13 no.4
• /
• pp.9-19
• /
• 2015

Purpose - This study focuses on the use of evaluative criteria software for imprecise market information, and product mapping relationships between design parameters and customer requirements. Research design, data, and methodology - This study involved using the product predicted value method, synthesizing design alternatives through a morphological analysis and plan, realizing the synthesis in multi-criteria decision-making (MCDM), and using its searching software capacity to obtain optimal solutions. Results - The establishment of product designs conforms to the customer demand, and promotes the optimization of several designs. In this study, the construction level analytic method and the simple multi attribute comment, or the quantity analytic method are used. Conclusions - This study provides a solution for enterprise products' multi-goals decision-making, because the product design lacks determinism, complexity, risk, conflict, and so on. In addition, the changeable factor renders the entire decision-making process more difficult. It uses Fuzzy deduction and the correlation technology for appraising the feasible method and multi-goals decision-making, to solve situations of the products' multi-goals and limited resources, and assigns resources for the best product design.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.49 no.2
• /
• pp.68-73
• /
• 2000

This paper addresses the analysis and design of fuzzy control systems for a class of complex nonlinear systems. Firstly, the nonlinear system is represented by Takagi-Sugeno(TS) fuzzy model and the global controller is constructed by compensating each linear model in the rule of TS fuzzy model. The design of conventional TS fuzzy-model-based controller is composed of two processes. One is to determine the static state feedback gain of each local model and the other is to validate the stability of the designed fuzzy controller. In this paper, we propose an alternative methods for the design of TS fuzzy-model-based controller. The design scheme is based on the extension of conventional optimal control theory to the design of TS fuzzy-model-based controller. By using the proposed method, the design and stability analysis of the TS fuzzy model-based controller is reduced to the problem of finding the solution of a set of algebraic Riccati equations. And we use the recently developed interior point method to find the solution of AREs, where AREs are recast as the LMI formulation. A numerical simulation example is given to show the effectiveness and feasibiltiy of the proposed fuzzy controller design method.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.6
• /
• pp.62-71
• /
• 2002

How parks are to be made in the twenty-first century should certainly be different. This is the inevitable conclusion of the recent significant international design competition for Downsview Park in Toronto, 2000. The purpose of this critical study is to investigate new strategies for urban park design manifested in the proposals of that competition and to explore alternative ways of landscape design that could solve the recent crisis of urban parks. Tree City, the winning entry, and other final entries proclaim that city is park and park is city. In this sense, Downsview Park marks the end of traditional Olmstedian parks and the dichotomy between city(culture) and park(nature). Rem Koolhaas and Bruce Mau's Tree City will become the model for urban park design in the near future. There are three reasons for this. First, its design is a strategy rather than a form. We can interpret that Tree City is to be developed over time as directed by six strategies: grow the park, manufacture nature, 1000 pathways, sacrifice and save, curate culture, destination and dispersal. Second, it places faith in landscape as a revenue generator instead of a fiscal liability. Third, its implementation is possible with crude installation, requiring virtually no craft. Koolhaas and Mau intend for Downsview to be an environment that is never actually designed but is formed through natural succession, cultural action, and programmatical insertions. Rather than designed objects and formal solutions, their strategy is to allow the landscape to evolve with changing uses.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.3
• /
• pp.221-229
• /
• 2003

In the early phases of the product life cycle, Life Cycle Assessment (LCA) is recently used to support the decision-making fer the conceptual product design and the best alternative can be selected based on its estimated LCA and its benefits. Both the lack of detailed information and time for a full LCA fur a various range of design concepts need the new approach fer the environmental analysis. This paper suggests a novel approximate LCA methodology for the conceptual design stage by grouping products according to their environmental characteristics and by mapping product attributes into impact driver index. The relationship is statistically verified by exploring the correlation between total impact indicator and energy impact category. Then a neural network approach is developed to predict an approximate LCA of grouping products in conceptual design. Trained learning algorithms for the known characteristics of existing products will quickly give the result of LCA for new design products. The training is generalized by using product attributes for an ID in a group as well as another product attributes for another IDs in other groups. The neural network model with back propagation algorithm is used and the results are compared with those of multiple regression analysis. The proposed approach does not replace the full LCA but it would give some useful guidelines fer the design of environmentally conscious products in conceptual design phase.

• Nuclear Engineering and Technology
• /
• v.51 no.2
• /
• pp.588-599
• /
• 2019

This research presents a structural design of high-level waste (HLW) container using ultra-high performance fiber reinforced concrete (UHP-FRC) material. The proposed design aims to overcome the drawbacks of the existing concrete containers which are heavy, difficult to fabricate, and expensive. In this study, the dry storage container (DSC) that commonly used at Canadian Nuclear facilities is selected to present the proposed design. The design has been performed such that the new UHP-FRC alternative has a structural stiffness equivalent to the existing steel-concrete-steel container under various loading scenarios. Size optimization technique is used with the aim of maximizing stiffness, and minimizing the cost while satisfying both the design stresses and construction requirements. Then, the integrity of the new design has been evaluated against accidental drop-impact events based on realistic drop scenarios. The optimization results showed: the stiffness of the UHP-FRC container (300 mm wall thick) is being in the range of 1.35-1.75 times the stiffness of existing DSC (550 mm wall thick). The use of UHP-FRC leads to decrease the container weight by more than 60%. The UHP-FRC container showed a significant enhancement in performance in comparison to the existing DSC design under considered accidental drop impact scenarios.

• Wind and Structures
• /
• v.32 no.4
• /
• pp.283-292
• /
• 2021

Performance-based seismic design (PBSD) is currently used for retrofitting of older buildings and the design of new buildings. Whereas, application of performance-based design for wind load is still under development. The tendency has been in the codes to increase wind hazard based on recent recorded events. Since tall buildings are highly susceptible to wind load, necessity for developing a framework for performance-based wind design (PBWD) has intensified. Only a few guidelines such as ASCE (2019) provide information on using PBWD as an alternative for code prescriptive wind design. Though wind hazards, performance objectives, analysis techniques, and acceptance criteria are explained, no recommendations are provided for several aspects like how to select a proper level of wind hazard for each target performance criterion. This paper is an attempt to explain current design philosophy for wind and seismic loads and inherent connection between the components of PBSD for development of a framework for PBWD of tall buildings. Recognizing this connection, a framework for PBWD based on limits set for serviceability and strength is also proposed. Also, the potential for carrying out PBWD in line with ASCE 7-16 is investigated and proposed in this paper.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.25-32
• /
• 2022

As a project delivery method, Design-Build (DB) has provided owner, architect, and contractor groups with a process of early design and rapid construction for the past three decades. Although there are many benefits to using standard DB, dissatisfaction has arisen due to limitations to innovate, limited owner involvement during design, and often lengthy procurement. Progressive Design-Build (PDB) has become an appealing alternative providing benefits not seen with standard DB. This paper investigates how PDB impacts a project and how it compares against standard DB; it also presents a proposed framework for evaluating the owner's responsibility and assessment of a project, which we named the "Four Pillars of Project Success". The four pillars are defined with respect to an owner's responsibility and assessment of a project, including project predictability, project risk, project schedule, and project cost. We conducted a literature review, examined several public project case studies, analyzed PDB project information collected by the Design-Build Institute of America (DBIA), and held stakeholder interviews with owners, contractors, and architects who have used both PDB and standard DB. This paper offers insight into PDB's structure and outcomes so an owner group can make an informed decision when considering PDB as their next construction contracting method.

• Geomechanics and Engineering
• /
• v.32 no.2
• /
• pp.209-232
• /
• 2023

A comprehensive study was conducted to design economical foundations for a number of buildings on soft cohesive soil in the southern coastal regions of Iran. Both static and seismic loads were considered in the design process. Cyclic experiments indicated that the cohesive soil of the area has potential for softening. Consequently, the major challenge in the design stages was relatively high dimensions of settlement, under both static and seismic loadings. Routine soil-improvement methods were too costly for the vast area of the project. After detailed numerical modeling of different scenarios, we concluded that, in following a performance-based design approach and applying a special time schedule of construction, most of the settlement would dissipate during the construction of the buildings. Making the foundation as rigid as possible was another way to prevent any probable differential settlement. Stiff subgrade of stone and lime mortar under the grid foundation and a reinforced concrete slab on the foundation were considered as appropriate to this effect. In favor of an economical design, in case the design earthquake strikes the site, the estimations indicate no collapse of the buildings even if considerable uniform settlements may occur. This is a considerable alternative design to costly soil-improvement methods.