• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.263-271
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• 2013

Change orders have been widespread in both the private and public construction sectors. In particular, in the case of G2B (Government to Business) contracts, adjustment of contract price and/or schedule extension is a frequent occurrence due to change orders. To uncover the causes of change orders and suggest an appropriate strategy, this study analyzed 296 cases of change orders in military facility construction projects from 2008 to 2010. The analysis revealed that the major causes of change orders are users' additional requirements (28.38%), a change of finishing materials (23.99%), and change of footing type (17.57%), in that order. Building on the results of this analysis, the authors suggest plans for practical improvements. Specific recommendations include 1) reflect user requirements at the early stage, 2) minimize the use of additional budget due to change orders, and 3) reduce the process and time for contract amendment, among others. The results of this study may provide significant implications to those involved in military construction projects, particularly project owners (i.e., the Ministry of Defense) and contractors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.127-132
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• 2005

Despite all efforts, many product development projects fail and lead to an introduction of products that do not meet customers' expectations. In general, designers usually relies upon their past experiences of similar products as a source of design knowledge when they work on a new design project. Designers need a set of practical step-by-step tools and methods which ensure a understanding of customers' needs and requirements, as well as a past design experience knowledge. In this paper we propose a design initial value module for an excavator that proposes a key initial design parameter value in an early design stage to improve a design process on Customer Requirements. It makes possible to support designers more effectively, objectively, and easily. Also it can propose better products in terms of a customer satisfaction.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.3
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• pp.8-15
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• 2011

The computer-based simulation tools are currently used overwhelmingly to simulate the performance of automotive designs. Then, the search for an optimal solution that satisfies a number of performance requirements usually involves numerous iterations among several simulation tools. Therefore, meta-modeling techniques are becoming widely used to build approximations of computationally expensive computer analysis tools. The set-based approach proposed in the first report of a four-part paper has been a test bed for the innovation of vehicle structure design process in the Structural Design and Fabrication Committee of JSAE(Society of Automotive Engineers of Japan). In the second report, the proposed design approach is illustrated with a side-door impact beam design example using meta-modeling techniques.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.251-259
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• 2021

Due to the characteristic that early childhood education is a process of nurturing children's senses by a leader rather than the transfer of knowledge, even in the era of with Corona, early childhood distance education is not one-to-one non-face-to-face education, but rather through distributed materials such as early childhood education packages or media such as TV. Distance education was conducted in a self-care method. Through a review of prior research and intensive parent interviews, the researcher identified the requirements for distance education, such as the expansion and accessibility of educational contents, understanding of basic knowledge of early childhood distance education, and the need to increase children's social skills through real-time distance education. It was identified that the current distance education-related solutions are not suitable for early childhood education. Accordingly, the researcher presents the basic direction (VERI) of the early childhood distance education solution of diversity, ease, real-time communication, and integration, and provides a Web/App platform that allows children, parents, and teachers to share content and communicate in real time and in non-real time. The development of a solution was proposed. This distance education solution is expected to effectively support early childhood distance education in the era of With Corona as infants, parents, and teachers communicate and share the current situation, which is only presenting guidelines and materials.

• Korean Journal of Construction Engineering and Management
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• v.14 no.6
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• pp.61-69
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• 2013

In the mixed-use development program, several conflicts occur due to the characteristics of construction program, such as large-scale, variety of stakeholders, long periods of time, etc. In particular, since the characteristics of the construction program having various complex projects lead to different requirements depending on stakeholders, it is crucial to plan the appropriate type and size of facilities. Therefore, it is necessary to derive solutions suitable for the needs of owner by conducting VE in the planning phase. In this study, a multi-dimensional quality model is developed to present proper facilities necessary for the construction program by clearly identifying the owner's requirements in performing VE in the planning phase. Through the development of the multi-dimensional quality model, the characteristics distribution of 15 major facilities by 12 performance indicators for mixed-use development programs is presented. The deduction method of appropriate facilities based on the requirements of owner and the multi-dimensional synthesis method among the performance indicators are also suggested. This study is significant as a basic research for the application of VE in the planning phase of construction program. It is expected that the multi-dimensional quality model proposed in this study could facilitate presentation and review of appropriate facilities based on the analysis of requirements of various stakeholders in the early stage of the construction program.

• Journal of KIISE:Software and Applications
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• v.35 no.7
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• pp.424-430
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• 2008

Identifying crosscutting concerns during requirements engineering phase is one of the most essential parts in Aspect-Oriented Software Development. Considering crosscutting concerns in the earlier phase of the development improves consistency among requirements so that it can help maintain software systems efficiently and effectively. It also provides a systematic way to manage requirements changes by supporting traceability throughout the software lifecycle. Thus, identifying tangled and scattered concerns, and encapsulating them into separate entities must be addressed from the early phase of the development. To do so, first, functional and non-functional concerns must be clearly separated. Second, a pointcut where a main concern meets crosscutting concerns should be defined and specified precisely. Third, it is required to detect conflicts being occurred during composition of crosscutting concerns from the earlier phase. Therefore, this paper proposes a systematic approach to identifying and specifying crosscutting concerns using goal-scenario based requirements analysis. And we demonstrate the applicability of the approach by applying it into the intelligent service robot system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.2
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• pp.82-87
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• 2017

This paper presents performance improvement of CO gas sensor signal conditioner for early fire warning system. The warning system is based on the CO sensor and its advanced signal conditioning modules network that employ electochemical gas sensor. The electochemical has advantage of having a linear output and operating with a low consumption and fast response. This electrochemical gas sensor contains a gas membrane and three electrodes(working, counter, reference electrode) in contact with an electrolyte. To use a three-electrode sensor, a voltage has to be applied between the working and the reference electrode according to the specification of the sensor. In this paper, we designed these requirements that should be considered in temperature compensation algorithm and electrode measurement of CO sensor modules by using advanced signal conditioning method included 3-electrode. Simulation and experimental results show that signal conditioner of CO sensor module using 3-electrode have a advantage linearity, sensitivity and stability, fast response etc..

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.12-20
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• 2018

As facilities have become larger, more complex, and advanced, the importance of the facility management in the operation phase of the building is increasing. As a result, the scope of the facility management function is expanding, and the requirements of information are ever-increasing. However, inefficient exchange of information occurs due to duplicated tasks and lack of collaboration among the construction life cycle phases, resulting in cost loss. These low interoperability issues can be complemented by construction information management from a life cycle perspective. Efficient construction information management at each life-cycle stage is derived from the owner's will and is materialized through the construction information handover requirements by the owner. The purpose of this study is to develop an evaluation method of construction information handover requirements for facility management. In order to develop the method, facility management types and business functions are also classified and defined in this paper. Using the methodology proposed by this study, a case-study of evaluating the 'takeover items' submitted by contractors was performed for the purpose of research validation. The results of the case-study found that the most effective areas are in the order of 'legal informations', 'drawings', 'guides', etc. This study can be used as a reference data for deriving handover requirements for construction information at the early stage of the project.

• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.59-64
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• 2004

Functional requirements and design parameters were not clarified in the early design process. Design axiom shows some difficulty for larger system designs, such as the butterfly valve, which is basically carried out by an incremental and iterative process. A numerical analysis was carried out on fluid flows in a butterfly valve, by using ANSYS-FLOTRAN. Characteristics of the butterfly flows at different valve disk opening angles, with a uniform incoming velocity, were investigated. The entire analysis is decomposed to satisfy the independence axiom. This paper resolves the problems associated with the establishment of a systematic design process.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.609-612
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• 2008

Ultra Super Early Strength Cement is a material that satisfies these requirements. early hydration heat however, is significant over regular concrete, thus discretion is advised for thermal cracks in accordance with heat generation when constructing a large-scale structures. In addition, the negative point that it is difficult to achieve required strength in a short period of time following rubbing process while retaining workability, the cement is being used conditionally for engineering material and Ultra Super Early Strength Cement for maintenance material for construction doesn't exist. Magnesia Phosphate Cement, which is currently under studies in overseas uses no extra admixture and has strong points of Ultra Super Early Strength as well as favorable construction-ability and adhesive stability to the prototype concrete. These factors stem recognition that it could be used as maintenance material for construction of diverse applicability. In order to provide necessary data to increase practicality of the magnesia phosphate cement for Ultra Super Early Strength Mortar, the study carried out simulate experiment on member of framework to review field applicability.