• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.67-74
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• 2016

The primary aim for using a Korean Condition Based Maintenance (CBM) system is to maintain military operational readiness using Interactive Collection Analysis Systems (ICAS) installed on naval vessels. Other aims are to preemptively provision maintenance and supply functions, to guarantee economical management of logistical assets, and to implement data driven equipment life cycle management. In order to accomplish these aims, it is necessary to establish standard system conditions. However, because manufacturers do not provide the technology necessary for maintenance management, it is required to retain component performance maps for each piece of equipment, and to accumulate data about frequently occurring fault patterns. This study confirms the validity of component performance maps using micro gas turbines and provides accumulated data on machine break downs. This would allow real time equipment performance checks and present performance trends. Then analysis would provide solutions for maintaining the best machine operating conditions with detailed maintenance manuals for operators. This study is a basis for further research to investigate additional ways to develop CBM using data obtained from naval vessels used in actual military operations.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.355-358
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• 2005

In this paper, an actual behavior of the pylon of Seohae Grand Bridge which is a cable stayed bridge and has been constructed 4 years ago was analyzed by using data acquisition system. As a result, the pylon of cable stayed bridge behaved normally with respect to the change of temperature. The annual displacement of the top of pylon(PY1) ranged from -71.4mm to +181.7mm in the longitudinal direction of the bridge. In the case of the longitudinal displacement, the displacement of PY1 was bigger than that of PY2 because PY1 is movable and PY2 is fixed in terms of the constraint condition of super structure. For the long term, PY1 will be sloped gently to the direction of Dangjin and PY2 will be also sloped gently to the direction of Pyongtaek by the effect of creep and shrinkage in the case of the longitudinal direction. The result of structural analysis showed good agreement with the result mentioned above.

• Structural Monitoring and Maintenance
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• v.7 no.2
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• pp.149-166
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• 2020

This paper presents the results of an experimental investigation on a vibration-based damage identification framework for a steel girder type and a truss bridge based on acceleration responses to operational loading. The method relies on sensor clustering-based time-series analysis of the operational acceleration response of the bridge to the passage of a moving vehicle. The results are presented in terms of Damage Features from each sensor, which are obtained by comparing the actual acceleration response from the sensors to the predicted response from the time-series model. The damage in the bridge is detected by observing the change in damage features of the bridge as structural changes occur in the bridge. The relative severity of the damage can also be quantitatively assessed by observing the magnitude of the changes in the damage features. The experimental results show the potential usefulness of the proposed method for future applications on condition assessment of real-life bridge infrastructures.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.361-366
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• 2002

The deterioration of concrete structure due to corrosion of the reinforcement has created big financial losses on the overall industries. The volume expansion of the corrosion products causes internal pressure to concrete wall around reinforcing bar. If the maximum principal stress induced by internal pressure exceeds the tensile strength of the concrete at any point of time, a crack forms at any point of material. Therefore, in terms of life assessment of concrete structure, it is very important to predict the amount of corrosion products which induces initial concrete cracking. With this objective, this paper proposes the critical amount of corrosion products at interface between reinforcement and concrete using finite element analysis. If an actual survey of corrosion rates could be made, the model might supply information for condition assessment of existing concrete structure. As the mechanical properties of corrosion product and instantaneous geometry of corroded steel are considered in the analysis, the value obtained will be more realistic.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.216-223
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• 2005

The coefficient of consolidation has been evaluated using the conventional oedometer tests based on the one-dimensional consolidation theory. In the field, however, the actual response of the soil will be subject to the three-dimensional condition during consolidation. In this research, a new estimation method of the coefficient of consolidation for the various stress-deformation conditions was proposed. The good agreement between the computed dissipation of pore pressure and the measured data confirms the usefulness and the applicability of the proposed method to predict the exact rate of consolidation.

• Journal of the military operations research society of Korea
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• v.31 no.2
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• pp.105-115
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• 2005

To ensure interoperability among TADILs, we need inter-operational system of tactical data link that allows sharing of specific, planned information among different TADILs. In this paper, we have proposed the design of a conceptual software architecture of inter-operational system. For developing of a conceptual software architecture, we analyze the actual condition of ADSI used in the US military and identify functions and quality-attributes. Based on these factors, we design the conceptual software architecture for inter-operational system of tactical data link using Attribute-Driven Design(ADD) method. ADD is consist of three phases - choose the module to decompose, refine the module, repeat the steps for every module that needs further decomposition. To evaluate of ADD results, we apply the Software Architecture Analysis Method(SAAM) which is consist of making evaluation scenarios, choosing indirect scenarios, evaluation scenarios' interaction, and creating an overall evaluation. Through the evaluation, we verify the conceptual software architecture of inter-operational system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.92-99
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• 2021

In the case of precise safety inspection and precise safety diagnosis of a building, a condition evaluation must be conducted to determine the safety grade. Since 2004, an evaluation method using fuzzy theory has been introduced for quantitative condition evaluation,and the relationship and importance of reinforced concrete members using fuzzy theory have been applied. Generally, fuzzy theory is a method used to deal with ambiguous expressions with unclear correlations, but at the time of development, it seems that it was developed by applying fuzzy theory as an alternative in a situation where inspection and diagnosis result data were insufficient. Therefore, it is necessary to verify the relationship and importance of evaluation items derived based on the current fuzzy theory using actual inspection and diagnosis result data.In this study, the correlation between the evaluation items was derived by using the results of 19 precision safety inspections and 9 precision safety inspections and the performance score function formula, and using this, a reasonable durability score calculation formula of the member was presented.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.215-222
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• 2003

When constructing buildings, planning, design, construction, using & maintenance as building life cycle. Due to industrialization in 1960s and development of new town from the late 1980s to the early 1990s, Korean housing supply rate reaches almost 100%. After construction companies confronted limit of new building construction, they recognized remodeling as a part of construction, and organized remodeling team or FM team to improve sustainable industrial area. However, since companies in Korea are lack of experience and research activities for remodeling, it makes obstacle to improvement of remodeling business. So the objective of this study is to help carry out remodeling business by suggesting the counterplan through investigation of a risk of apartment remodeling business.

• Journal of Fashion Business
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• v.2 no.2
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• pp.46-53
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• 1998

The purpose of this study is to survey and analyze the conditions and automation of sewing machines and thereby, address the problems and their solutions to help local sewn products enhance their international competitiveness. The results of study can be summarized as follows : 1. It was found that most of the sample companies were getting smaller scale or pettier in terms of capital, number of employees or scale of factory. The interest in facility investment was relatively higher, which suggests high interest of our sewing companies in facility investment. 2. Most of the sample companies were well equipped with the essential and several auxiliary sewing machines, but poorly equipped with the special or automated sewing machines. 3. The ratio of idle machines was highest in sewing work, compared with cutting or finishing work, primarily due to decreased orders, aging machines or reduced manpower.

• Tuberculosis and Respiratory Diseases
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• v.80 no.3
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• pp.241-246
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• 2017

Chronic obstructive pulmonary disease (COPD) is an ambulatory care-sensitive condition, and effective treatment of outpatients can prevent worsening of the illness and hospitalization. Current COPD guidelines provide appropriate guidance for the diagnosis and treatment of patients with COPD. In fact, it has been shown that when appropriate guidance and treatment are performed, the morbidity and mortality rates of COPD patients are reduced. However, there is a gap between the clinical guidelines and the actual clinical treatment. Therefore, the Health Insurance Review and Assessment Service (HIRA) conducted an evaluation of the adequacy of COPD diagnosis and treatment using the Claims Database of HIRA. This review provides a summary of the COPD adequacy assessment results reported by the HIRA and some brief comments on the results.