• Smart Structures and Systems
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• v.6 no.9
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• pp.1079-1105
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• 2010

Railway transport of goods and passengers is effective in terms of energy conservation and travel time savings. Safety and ride quality have become important issues as train speeds have increased. Due to increased speeds, minor damage to railway structures and abnormal interactions between trains and structures have given rise to increasingly serious accidents. Therefore, structural health and operational conditions must be monitored continuously in all service environments. Currently, various health and operation management systems are being developed and these are reducing both maintenance frequency and costs associated with disassembly. In this review, major damage and malfunctions and their locations are first analyzed based on numerous references. Then advanced train health and operation management technologies are classified into wayside detection methods and advanced integrated sensor methods and their operating principle and functions are reviewed and analyzed.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.531-539
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• 2010

Mega-Y project is very important for a company to gain a competitive advantage in markets or to achieve drastic change in the internal processes. It stems from the company strategy and annual management goals or key performance measures, and is proceeded by the cross-functional team. This paper presents the success factors and implementation process of the Mega-Y projects. The implementation process is presented in 5 steps, including project selection, cross-functional team building, establishment of the master plan, development and execution of sub-projects, and project completion. A case study on the cost reduction project of aircraft development is presented to help for the practitioners to deploy the implementation process introduced in this paper.

• Journal of Korean Society for Quality Management
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• v.48 no.3
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• pp.395-408
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• 2020

Purpose: This study was performed for advancement of aviation security equipments certification system. Methods: We investigated aviation security equipments certification-related registrations and the latest research trends of explosive detection technologies. Based on the literature studies, we draw the critical issues of the aviation security equipment certification system and suggested improvement direction. Results: We found some inaccuracies of the definition of explosive trace detection equipments, accreditation review committee, and performance evaluation test method. These problems should be modified to suit being practical. Conclusion: The present results would be useful for basic data for modifying aviation security equipments certification systems.

• Journal of Korean Society for Quality Management
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• v.28 no.2
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• pp.70-88
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• 2000

Short runs where it is neither possible nor practical to obtain sufficient subgroups to estimate accurately the control limit are common in modem business environments. In this study, the standardized control chart, Hillier's exact method, Q chart, EWMA(Exponentially Weighted Moving Average) chart for Q statistics and EWMA chart for mean and absolute deviation among many SPC(Statistical Process Control) techniques for short runs have been reviewed and advantages and disadvantages of these techniques are discussed. The simulation experiments to compare performances of these variable charts for process mean and variations are conducted for combination of subgroup size, scale and timing of shifts of process mean an/or standard deviation. Based upon simulation results, some guidelines for practitioners to choose short run SPC techniques are recommended.

• Industrial Engineering and Management Systems
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• v.11 no.4
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• pp.346-352
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• 2012

While systems engineering has been widely applied to complex system development, some evidences are reported about major budget and schedule overruns in systems engineering applied. On the other hand, many organizations have been deploying Design for Six Sigma (DFSS) to build Six Sigma momentums in the area of design and development for their products and processes. To explore the possibility of having a DFSS complement systems engineering process, this process reviews the systems engineering with their categories of effort and DFSS with its methodologies. A comparison of the systems engineering process and DFSS indicates that DFSS can be a complement to systems engineering for delivering higher quality products to customers faster at a lower cost. We suggest a simplified framework of systems engineering process, that is, PADOV which was derived from the generic systems engineering process which has been applied to the development of T-50 advanced supersonic trainer aircraft by Korea Aerospace Industries (KAI) with technical assistance of Lockheed Martin. We demonstrated that each phase of PADOV framework is comprehensively matched to the pertinent categories of systems engineering effort from various standards.

• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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• pp.19-25
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• 2012

As modern weapon systems have evolved into embedded software systems, the capability to develop, install, and maintain high-quality software products is becoming increasingly valuable in today's competitive aerospace and defense industry. It is desirable, especially for government-contracted projects whose end-users are military personnel, that specific types of software quality elements are assured early during product development; namely, functionality and usability. Motivated by this need to approach improving software quality from a user's perspective, this paper presents a case study that analyzes system-level software integration testing results for a weapon system indigenously developed in the Republic of Korea. Quantitative data, such as software defect ratios and configuration change rates, are computed to observe meaningful trends with respect to functionality - represented by tests designed to verify the system's electrical signal interfaces - and usability, which is evaluated in terms of how often the initial human-computer interface had to be re-designed. Insights gained from these exercises are subsequently presented as a set of "lessons learned" to take into account when developing new software items for complex weapon systems.

• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.341-358
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• 2015

Purpose: This paper presents graphic methods and desirability function approach to determine best vibration reducing configuration for Surion helicopter. Many flight tests were executed and nine vibration levels in cockpit, cabin, and engine room were measured in each test and analyzed to find optimal configuration. Methods: Graphic analysis methods such as matrix, scatter, and box plots are used to identify better vibration-reducing flight test conditions. As an integrated measure of the performance of 9 vibration levels desirability function approach is adopted. Results: Three vibration reducing configurations are found to be proper and one configuration is recommended. Conclusion: It is expected to be helpful to adopt graphic and desirability function methods presented in this paper in developing new products or systems like helicopters. For efficient and effective flight testing of helicopters, it will be necessary to have consistently homogeneous environment for flight testing and applying design of experiments techniques and analyzing test data.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.62-68
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• 2019

The software installed on an aircraft is directly related to its safety. Therefore, it shall comply with the standards of the airworthiness certification to ensure safety of flight. Airborne software should be developed in accordance with the DO-178 (Software Consideration in Airborne Systems and Equipment Certification) to comply with the airworthiness certification criterion. However, the military airborne software has been developed in accordance with the DAPA weapons system software development and management manual. In this paper, we completed a questionnaire survey of software experts. We also suggest a military airborne software development/certification process based on DO-178.

• Journal of Korean Society for Quality Management
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• v.41 no.4
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• pp.725-735
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• 2013

Purpose: The purpose of this study is to propose an Integrated Safety Evaluation Process (ISEP) that can enhances the safety aspect of the safety-critical system. This process utilizes the advantages of the iterative Systems Engineering process combined with the safety assessment process that is commonly and well defined in many standards and/or guidelines for railway, aerospace, and other safety-critical systems. Methods: The proposed process model is based on the predefined system lifecycle, in each phase of which the appropriate safety assessment activities and the safety data are identified. The interfaces between Systems Engineering process and the safety assessment process are identified before the two processes are integrated. For the integration, the elements at lower level of Systems Engineering process are combined with the relevant elements of safety assessment process. This combined process model is represented as Enhanced Functional Flow Block Diagram (EFFBD) by using CORE(R) that is commercial modelling tool. Results: The proposed model is applied to the lifecycle and management process of the United States aircraft system. The US aircraft systems engineering process are composed of twelve key elements, among which the requirements management, functional analysis, and Synthesis processes are considered for examplenary application of the proposed process. To synchronize the Systems Engineering process and the safety assessment process, the Systems Engineering milestones are utilized, where the US aircraft system has thirteen milestones. Taking into account of the nine steps in the maturity level, the integrated process models are proposed in some phases of lifecycle. The flows of processes are simulated using CORE(R), confirming the flows are timelined without any conflict between the Systems Engineering process and the safety assessment process. Conclusion: ISEP allows the timeline analysis for identifying activity and data flows. Also, the use of CORE(R) is shown to be effective in the management and change of process data, which helps for the ISEP to apply for the development of safety critical system. In this study, only the first few phases of lifecyle are considered, however, the implementation through operation phases can be revised by combining the elements of safety activities regarding those phases.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.168-176
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• 2015

Trends of integrating products and services lead to the emergence of Product-Service System (PSS). To implement and embody a PSS solution in new product development, a comprehensive design framework is allowed designers to facilitate the design factors of the PSS in complex business environments. A physical product, containing functionalities for services, is the role of medium between customers and a manufactures. Customers can access those metaphysical interfaces to utilize the product fully or expand its performances. The PSS is aiming to prolong its lifecycle while maintaining its expected quality. Since the quality can be represented as a measure which belongs to user's perspective, guaranteeing certain level of quality can be interpreted to sustaining customer satisfaction. The objective of this paper is to propose a PSS design framework to identify design factors for developing products and services by integrating object-oriented concepts and blueprinting in context of a business ecosystem. The proposed model is developed based on relationship products and services matching with their design factors. The products and the services are then brought together to form a PSS. Functions and processes can be categorized to identify the design factors in different levels using the object-oriented concepts. Objected-oriented concepts provide PSS analysis tools for describing a business process or a workflow process in the PSS. The blueprint is used to identify the relationships between the products functions and the service processes that are offered as part of a job. To demonstrate of the effectiveness of the proposed model, we use a case study involving a smart phone.