• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.543-553
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• 2008

Shipbuilding is a kind of ETO(Engineering To Order) industry which designs and produces a product in accordance to various requirement of customers, rules and regulations. Recently, the number of ordered ships has been increased by up to two or three times in each domestic shipyards. Most shipyards have been adopted 3D ship CAD, ERP(Enterprise Resource Planning) and APS(Advanced Planning System) to get an efficient product development and manufacturing system. However, not only the effective operation of 3D ship CAD, ERP and APS but also the production efficiency can be achieved only if product information management which can manages the product data is implemented in an integrated environment. Present study has suggested a systematic approach to implement a PLM system to manage the product data in early design shipbuilding. Also, a prototype of PLM is implemented to manage the product data in a basic ship-design. In the prototype system, a product structure and architecture of PLM is considered.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.483-493
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• 2021

Urban overcrowding has created an explosive supply and demand for high-rise buildings. High-rise buildings are contributing to enhancing the image of the city by serving as focal points, but due to the stack effect, malfunction of elevator doors, difficulties in opening and closing the doors and windows of the outer wall, smoke and odors spreading to the upper floors, noise, energy loss, fire and pollutants have been causing various unexpected problems such as rapid spread of fire. This study classified high-rise buildings according to their vertical zoning, analyzed the causes of and solutions to the stack effect, and derived design and construction methods. Through the initial plan to block the outside air and securing airtightness through precise construction, we sought ways to secure the airtightness inside and outside the building by actively blocking the airflow from the lower floors. In addition, the facility solution can be a measure to reduce the specific phenomena caused by the stack effect, but it should only be applied to the minimum extent because the potential for secondary damage is high. This study emphasized the need for systematic stack effect management by suggesting design and construction measures for each vertical zoning of the causes and countermeasures of the stack effect. It is expected that this study will be helpful not only for design and construction, but also for building maintenance.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.1-20
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• 2018

Despite many measures, still from time to time catastrophic events occur, even after reviewing potential scenarios with HAZID tools. Therefore, it is evident that in order to prevent such events, answering the question: "What can go wrong?" requires more enhanced HAZID tools. Recently, new system based approaches have been proposed, such as STPA (system-theoretic process analysis) and Blended Hazid, but for the time being for several reasons their availability for general use is very limited. However, by making use of available advanced software and technology, traditional HAZID tools can still be improved in degree of completeness of identifying possible hazards and in work time efficiency. The new HAZID methodology proposed here, the Data-based semi-Automatic HAZard IDentification (DAHAZID), seeks to identify possible scenarios with a semi-automated system approach. Based on the two traditional HAZID tools, Hazard Operability (HAZOP) Study and Failure Modes, Effects, and Criticality Analysis (FMECA), the new method will minimize the limitations of each method. This will occur by means of a thorough systematic preparation before the tools are applied. Rather than depending on reading drawings to obtain connectivity information of process system equipment elements, this research is generating and presenting in prepopulated work sheets linked components together with all required information and space to note HAZID results. Next, this method can be integrated with proper guidelines regarding process safer design and hazard analysis. To examine its usefulness, the method will be applied to a case study.

• Ocean Systems Engineering
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• v.7 no.2
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• pp.143-155
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• 2017

For complex flexible structures such as nets, the determination of drag forces and its deformation is a challenging task. The accurate prediction of loads on cages is one of the key steps in designing fish farm facilities. The basic physics with a simple cage, can be addressed by the use of experimental studies. However, to design more complex cage system for various environmental conditions, a reliable numerical simulation tool is essential. In this work, the current load on a cage is calculated using a Morison-force model applied at instantaneous positions of equivalent-net modeling. Variations of solidity ratio ($S_n$) of the net and current speed are considered. An equivalent array of cylinders is built to represent the physical netting. Based on the systematic comparisons between the published experimental data for Raschel nets and the current numerical simulations, carried out using the commercial software OrcaFlex, a new formulation for $C_d$ values, used in the equivalent-net model, is presented. The similar approach can also be applied to other netting materials following the same procedure. In case of high solidity ratio and current speed, the hybrid model defines $C_d$ as a function of Re (Reynolds number) and $S_n$ to better represent the corresponding weak diffraction effects. Otherwise, the conventional $C_d$ values depending only on Re can be used with including shielding effects for downstream elements. This new methodology significantly improves the agreement between numerical and experimental data.

• Journal of Korean Society for Quality Management
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• v.41 no.4
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• pp.683-692
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• 2013

Purpose: Car seats affect customer satisfaction greatly when the seats' design is changed because car holders are in close contact with the seats. However, the improvement of the current seats' design involves risks such as investment cost, and therefore it needs strategic operating measures from the perspective of customers. Until now, operations of seats' specification have been decided by technical-push rather than market-pull, and carried out based on professionals' experience without measuring customer satisfaction correctly. The purpose of this study is to present a systematic approach to measure customers' perception on the car seats using the Kano model and pairwise comparison technique. Methods: The authors derive 17 major functions of a car seat by analyzing major components of car seats, and conduct a survey of 141 adults who hold a car(s). Results: The results show that consumers perceive the adjustable functions of front seats as must-be while the same functions for rear seats are perceived as attractive. In particular, motor operated functions for both front and rear seats increase customer satisfaction greatly if they are presented. Conclusion: This study shows that how much customer (dis)satisfaction will increase if a function of car seats (non)fulfilled, and therefore, the results of this study will provide practitioners and R&D personnel in new automobile seats development projects with useful information.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.231-243
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• 2009

Currently interests of embedded software in various areas such as automotive field, ship field, robot field is increasing according to expand market of embedded systems. Various researches such as embedded operating systems, embedded software modeling technique, embedded software testing, and so on are going in progress. However systematic engineering approach in embedded system development is poor because embedded areas focus on hardware parts until now. Furthermore, framework-based de sign technique considering reusability is not reflected in embedded system development. Those development results in many of dead codes scattered in system, and results in poor reusability of system. This paper suggests a framework of embedded system for reusability and a static meta-model for reuse framework. Proposed meta-model expresses not only the structure of reuse framework, but also allows a designer to extend and design easily models of embedded system based on reuse framework according to various embedded system types.

• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.407-418
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• 2007

Service science is a new application area that implements services in an interdisciplinary area of management, economics, and engineering. Service systems provide functionalities of traditional software systems, moreover the functionalities are more intellectual in that they require dynamic context awareness, analysis, and decision making based on the recognized and analyzed contexts. However, conventional software development approaches do not sufficiently provide methods to model the service requirements and to design service-intensive systems. Therefore, there is a great demand on effective methodologies for developing service systems. In this paper, we compare traditional software systems with service-intensive systems in order to identify characteristics of the service systems. And, we propose a step-wise process to model service systems, in terms of architecture, components, and workflows. Then, we show a case study on an emergency handling system which is a type of living assistant systems. We believe that the proposed approach can be used in developing high-quality service systems effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.382-391
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• 2016

For safety-critical systems including railways, there has been a growing need for effective and systematic safety management processes. The outcomes of efforts in this area are international safety standards, such as IEC 61508, 62278, and ISO 26262. One of the principal activities in the safety process is hazard analysis. For this reason, considerable efforts have been directed toward methods of hazard analysis. On the other hand, the hazard analysis methods reported thus far appear to be unclear in terms of their relationship with the system design process. In addition, in some cases, the methods appear to rely heavily on information regarding the hardware and software components, the number of which is increasing. These aspects can become troublesome when design changes are necessary. To improve the situation, in this paper, hazard analysis was carried out using the result of functional analysis early in the concept development stage for a safety-critical system design. Because hazard analysis is carried out at the system level and the result is then used to develop the safety requirements, improvements can be expected in terms of the development time and cost when design changes are required due to changes in the requirements. As a case study, the generation of safety requirements for the development of light rail transit stations is presented.

• Journal of KIISE:Software and Applications
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• v.29 no.4
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• pp.211-224
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• 2002

As system become larger and more complex, it is important to correctly analyze and specify user's requirements. Use case modeling is widely used in Object-Oriented Analysis and Design(OOAD) and Component-Based Development(CBD). It is useful to mitigate the complexity of the requirements analysis. However, use cases are difficult to be structured, to explicitly represent non-functional requirements, and to analyze what is affected by changes of use cases. To alleviate these problems, we propose scenario-based goal-oriented approach for use case modeling. The approach is to apply goal-oriented analysis method to use case model. Since goal-oriented analysis method is not systematic and heuristics is considerably involved, we adopted scenarios as the basis for the goal extraction. The proposed method is applied to City Bus Information Subsystem(CBIS) in Intelligent Transport Systems(ITS) domain. The proposed approach helps software engineer to analyze what is affected by use case's changes and represent non-functional requirements.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.1-12
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• 2015

Well-designed bolted connections can exhibit excellent ductile behavior through bearing mechanism until the occurrence of bolt shear rupture. The ultimate strength analysis of eccentric bolted connections is an economical and mechanistic approach which uses such ductility. However, the bolt load-deformation relationship, which forms basis of the current practice, is based on very limited combinations of bolt and steel materials. The primary objective of this study was to establish the general bolt force-deformation relationship based on systematic single-bolt bearing connection tests. The test results showed that the projected area of the bolt hole and the strength and thickness of the plate to be connected are the main factors affecting the force-deformation relationship. The results of this study can be used for the instantaneous center of rotation method (ICRM) to achieve more accurate analysis and economical design of a variety of group-bolted connections subjected to eccentric shear.