• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.51-68
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• 2020

Purpose: The primary objective of this research is to develop the optimal operating conditions as well as their associated design spaces for a Cryogenic Submerged Arc Welding(SAW) process by improving its quality and productivity simultaneously. Methods: In order to investigate functional relationships among quality characteristics and their associated control factors of an SAW process, a stepwise design of experiment(DoE) method is proposed in this paper. Based on the DoE results, not only a multi-dimensional design space but also a safe operating space and normal acceptable range(NAR) by integrating statistical confidence intervals were demonstrated. In addition, the optimal operating conditions within the proposed NAR can be obtained by a robust optimal design method. Results: This study provides a customized stepwise DoE method (i.e., a sequential set of DoE such as a factorial design and a central composite design) for Cryogenic SAW process and its statistical analysis results. DoE results can then provide both the main and interaction effects of input control factors and the functional relationships between the input factors and their associated output responses. Maximizing both the product quality with high impact strength and the productivity with minimum processing times simultaneously in a case study, we proposed a design space which can provide both acceptable productivity and quality levels and NARs of input control factors. In order to confirm the optimal factor settings and the proposed NARs, validation experiments were performed. Conclusion: This research may provide significant contributions and applications to many SAW problems by preparing a standardization of the functional relationship between the input factors and their associated output response. Moreover, the proposed design space based on DoE and NAR methods can simultaneously consider a number of quality characteristics including tradeoff between productivity and quality levels.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.63-69
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• 2009

For the effective and efficient system development, it is provided of complex and diverse disciplines, analysis and design, points of views for decisions making, technical information management, assurance of products, and so on to be integrated and ensured. Systems engineering is conducted through a process and is implemented by tools based on relevant methodologies. Systems engineering environment should be provided to support the systems engineering process, method, and tools used on the project. In this paper, the essential environment in performing works in a organization applying systems engineering on the basis of system life cycle was reviewed. The present states on establishment of the systems engineering in Korea Railroad Research Institute were also examined with some reviews of other cases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.91-99
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• 2019

Naval Ships have a number of requirements related to performance. Naval ship acquisition takes a long time from initial planning to delivery, and various products such as drawings and reports are created. In complex systems, such as naval ships, it is difficult to maintain the required traceability through these outputs. The basic design of the ship is an important step to determine the specifications, performance, and equipment of the ship. It is necessary to apply the systematic requirements management process. The basic design manages the requirements in accordance with the systems engineering-based technical review process, but the actual system architecture design process is not presented. The traceability between the requirements and the functional and physical architectures of components is unclear. This paper examined how to design the system architecture required for specification and system design, and the design results were verified using SE-based technical review process for requirements management. A step-by-step process for designing a submarine system architecture is presented and verified using the SE technical review. This facilitates the specification of the requirements and system architecture design, and supports traceability management and verification of the requirements. The proposed process can be applied in various ships including submarines.

• Journal of the Ergonomics Society of Korea
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• v.23 no.3
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• pp.73-88
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• 2004

This study was contrived Hierarchical Information Search (HIS) model. HIS model is based on a “cognitive process” in which model, comprising basic human information processing mechanize and information interaction. Its process include 3 semantic cognitive processes: Schema-Association LTM, Form Domain, and Alternative Selection. Design methodology consists to elicitate memory, thinking and cognitive response variables. In case study, menu structure of mobile phone was applied. In result, a correlation between predictive error rate and real error rate was .892. and a correlation between selective and real reaction time was .697. This present to suggest a model of how the methodology could be applied to real system design effectively when this was used. HIS model could become one of the most important factors for success of product design. In the perspective, the systemic methodology would contribute to design a quantitative and predictive system.

• Industrial Engineering and Management Systems
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• v.14 no.4
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• pp.325-334
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• 2015

Nowadays, crowdsourcing has become a popular concept and is widely used in many social, economical and technological areas. For consumer product design, crowdsourcing is implemented extensively with many cases. Although there has been a lot of research on the application of crowdsourcing for product design, the big picture of how factors influence the participartion of individuals from the crowd in a crowdsourcing project for product design has not yet been understood. This paper aims to investigate the relationships of crowd participation and influencing factors including: process, product, and reward. To do this, we conducted a survey on a crowd of engineering individuals and analyzed the collected data with data mining techniques. Main findings include the relationships of crowd participation versus process, product, and reward factors as well as regression models to predict crowd participation.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.171-181
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• 2015

Building Information Modeling (BIM) provides many advantages when it is adopted in virtual design construction, to analyze constructability, etc. For this reason, advanced countries have made it mandatory to adopt BIM in public construction projects. The Korea Public Procurement Service announced that from 2016, BIM adoption will be mandatory in every construction project in Korea. Currently, however, it is not possible to fully adopt BIM in the building design process domestically because BIM-based systems have not been used broadly in Korea's building approval system (Seumter). In this research, four challenges were drawn from a focus group interview. Focusing on tackling one challenge, this paper reviewed previous research into building approval systems and the building approval systems of Singapore, the U.K. and the U.S., and identified elements of the building approval application process and presents a system to create and manage the information. The system supports the creation and management of information and 2D drawings from an IFC-based BIM model. We expect that the system will encourage designers to use BIM from the beginning of the design process and ultimately increase the efficiency of design in a BIM-based project.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.883-890
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• 2003

Two GOS (Generalized Observer Scheme) type Fault Detection Isolation Schemes (FDIS), employing the bank of unknown input functional observers (UIFO) as a residual generator, are proposed to make the practical use of the multiple observer based FDIS. The one is IFD (Instrument Fault Detection) scheme and the other is PFD (Process Fault Detection) scheme. A design method of UIFO is suggested for robust residual generation and reducing the size of the observer bank. Several design objectives that can be achieved by the FDI schemes and the design methods to meet the objectives are described. An IFD system is constructed for the Boeing 929 Jetfoil boat system to show the effectiveness of the propositions. Major contributions of this paper are two folds. Firstly, the proposed UIFO approaches considerably reduce the size of residual generator in the GOS type FDI systems. Secondly, the FDI schemes, in addition to the basic functions of the conventional observer-based FDI schemes, can reconstruct the failed signal or give the estimates of fault magnitude that can be used for compensating fault effects. The schemes are directly applicable to the design of a fault tolerant control systems.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.11-19
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• 2013

In modern systems design and development, one of the key issues is considered to be related with how to reflect faithfully the stakeholder requirements including customer requirements therein, thereby successfully implementing the system functions derived from the requirements. On the other hand, the issue of safety management is also becoming greatly important these days, particularly in the operational phase of the systems under development. An approach to safety management can be based on the use of the failure mode effect and analysis (FMEA), which has been a core method adopted in automotive industry to reduce the potential failure. The fact that a successful development of cars needs to consider both the complexity and failure throughout the whole life cycle calls for the necessity of applying the systems engineering (SE) process. To meet such a need, in this paper a method of FMEA is developed based on the SE concept. To do so, a process model is derived first in order to identify the required activities that must be satisfied in automotive design while reducing the possibility of failure. Specifically, the stakeholder requirements were analyzed first to derive a set of functions, which subsequentially leads to the task of identifying necessary HW/SW components. Then the derived functions were allocated to appropriate HW/SW components. During this design process, the traceability between the functions and HW/SW components were generated. The traceability can play a key role when FMEA is performed to predict the potential failure that can be described with the routes from the components through the linked functions. As a case study, the developed process model has been applied in a project carried out in practice. The results turned out to demonstrate the usefulness of the approach.

• The Journal of Information Systems
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• v.9 no.1
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• pp.217-234
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• 2000

This paper is to develop an information infrastructure to support managing process in design, planning, production, and quality control. Multi-media data set of design, product, and management information flow between organizational units of a virtual enterprise. The process is the logical organization of people, technology and practices incorporated into work activities to make an end product. The core of the infrastructure is the enterprise framework which coordinates activities and controls the process. The proposed framework manages collaborative activities across space and time, and between users and computers who share information in virtual community. It utilizes knowledge distributed through virtual community and fosters cooperation between organizations. The framework provides the following facilities； coordinating activities, sharing data and processes, visualizing multi-media data, customizing and updating processes, reusing data and processes. This paper covers design and manufacturing activities but our focus is initially targeted at design area.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.2
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• pp.13-29
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• 2015

With the era of big data, the big data has been expected to have a large impact in the NPP safety areas. Although high interests of the big data for the NPP safety, only a limited researches concerning this issue are revealed. Especially, researches on the logical/physical structure and systematic design methods for the big data platform for the NPP safety were not dealt with. In this research, we design a new big data pilot platform for the NPP safety especially focusing on health monitoring and early warning services. For this, we propose a tailored design process based on SE approaches to manage inherent high complexities of the platform design. The proposed design process is consist of several steps from elicitate stakeholders to integration test via define operational concept and scenarios, and system requirements, design a conceptual functional architecture, select alternative physical modules for the derived functions and assess the applicability of the alternative modules, design a conceptual physical architecture, implement and integrate the physical modules. From the design process, this paper covers until the conceptual physical architecture design. In the following paper, the rest of the design process and results of the field test will be shown.