• Journal of KIBIM
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• v.1 no.1
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• pp.6-12
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• 2011

BIM(Building Information Modeling) technologies are the most effective for the maintenance of infrastructures because they provide information sharing througout the life-cycle of structures and support close communication between different project stages. Systematic and well-organized data play a fundamental role for the effective maintenance of subway tunnel. In this paper, 3D information models for maintenance of BIM-based subway tunnel structures are developed. Standard classifications for the maintenance and construction information classification system were adopted. A classification system based on construction information classification system was built considering procedures of maintenance work. It provides optimization and standardization of the work flow for the maintenance of subway structures by applying information modeling processes instead of the current maintenance practices. It can effectively reduces the life cycle cost and time for the maintenance. The proposed system can be utilized for the maintenance history management to enhance current maintenance system.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.7
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• pp.1050-1060
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• 2009

This study develops a scale for consumer clothing satisfaction based on Lee et al. 's (2002) five stages of the consumer life cycle (acquisition, possession, consumption, maintenance, and disposal). Data were gathered by surveying college students using convenience sampling, and 419 questionnaires were used in the statistical analysis. In analyzing the data, an exploratory factor analysis and a confirmatory factor analysis using a structural equation modeling were conducted. The proposed scale, which identified various sources of satisfaction and dissatisfaction associated with the 5 consumption cycles of clothing, suggests some guidelines for marketers in enhancing consumer clothing satisfaction across consumption stages. The model test for the scale also identified that consumption satisfaction had the greatest effect on consumer clothing satisfaction showing the strongest loading and squared multiple correlation.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.258-269
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• 1999

It is important to evaluate fatigue damage of in-service material in respect to assure safety and remaining fatigue life in structure and mechanical components under cyclic load . Fatigue damage is represented by mathematical modelling with crack growth rate da/dN and cycle ration N/Nf and is detected by X-ray diffraction and ultrasonic wave method etc. But this is estimated generally by single parameter but influenced by many test conditions The characteristics of it indicates fatigue damage has complex fracture mechanism. Therefore, in this study we propose that back-propagation neural networks on the basis of ration of X-ray half-value breath B/Bo, fractal dimension Df and fracture mechanical parameters can construct artificial intelligent networks estimating crack growth rate da/dN and cycle ratio N/Nf without regard to stress amplitude Δ $\sigma$.

• Journal of the Korean housing association
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• v.1 no.1
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• pp.37-48
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• 1990

The objective of this study is to suggest a housing life cycle of Korean families which adds to the establishment of reasonable housing standards and to the prediction of fufure-oriented family housing behavior by reviewing published papers. Following model is suggested as a housing life cycle suitable to assess the family housing behavior in Korea. 1st stage : period of house searching 2nd stage : period of house changing 3rd stage : period of house stabilizing \circled1 size enlargement phase \circled2 quality improvement phase \circled3 stable settlement phase 4th siage : period of house contracting 5th stage : period of house depending Since the proposed model is hypothetical, it must be tested and modified by the extensive social survey research on the real housing event history.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.871-879
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• 1998

The refrigerator consists of many components such as compressor condenser expansion valve evaporator and the cabinet which filled by urethane foam. In this paper the heat leakage of refriger-ator is measured by the new experiment method which is different from a present method, The devi-ation of the UA(overall heat transfer coefficient times area) between the simulation and experiments is about 7-8%. Using the modeling of various components of refrigeration system a performance analysos of CFC 12 and HFC 134a is performed numerically on the UA. As the results of this study according to increase the heat leakage the refrigeration load and mass flow rate of refrigerant are increased. And the increase of the mass flow rate results in the increase of the condensing and evapo-rating temperature. Therefore according to increase of the heat leakage the COP leads to increase because the increase of refrigeration capacity is larger than the increase if compressor power.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.313-318
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• 2003

The vibration of washing machine at spinning cycle is important problem that affects the performance of a product. In this raper, the inner structure of the washing machine is modeled as a rigid body suspension system and transfer farce caused by rotating unbalance mass is obtained using Newton's the 2nd law. and this model is used to predict the verge of walking instability during the spinning cycle. The walk of the drum washing machine is suggested by calculating the force transmissibility between drum and the cabinet. As calculating the resultant force exerted for cabinet, the friction coefficient of the pad is suggested to avoid the walk. In addition, relation between translational slip and rotational slip is derived and method to avoid the rotational slip is introduced.

• Journal of Hydrogen and New Energy
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• v.30 no.5
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• pp.473-477
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• 2019

In this paper, cold heat price contained in the 1 ton/h of LNG has been evaluated using PRO/II with PROVISION release 10.2 from Aveva company when LNG is used to liquefy several refrigerants instead of using vapor recompression refrigeration cycle. Normal butane, R134a, NH3, R22, propane and propylene refrigerants were selected for the modeling of refrigeration cycle. It was concluded that LNG cold heat price was inversely proportional to the refrigerant supply temperature, even though LNG supply flow rate is not varied according to the refrigerant supply temperature.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.547-550
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• 2011

The purpose of this paper is to verify and validate the maintenance tasks of the construction of a nuclear facility using a digital mock-up and simulation technology instead of a physical mock-up. Prior to the construction of a nuclear facility, a remote simulator that provides the opportunity to produce a complete digital mock-up of the PRIDE (Pyroprocess Integrated Inactive DEmonstration Facility) region and its remote handling equipment, including operations and maintenance procedures has been developed. In this paper, the system architecture and graphic user interface of a remote simulator that coincides with the extraordinary nature of a nuclear fuel cycle facility is introduced. In order to analyze the remote accessibility of a remote manipulator, virtual prototyping that was performed it by using haptic device of external input devices under a 3D full-scale digital mock-up is explained.

• Journal of The Korean Association For Science Education
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• v.36 no.3
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• pp.361-369
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• 2016

In this study, we investigated the characteristics of group discussion and classroom discussion in the scientific modeling of the particulate model of matter. 7th graders in Seoul participated in this study. We implemented science instructions based on the GEM cycle of scientific modeling. We analyzed the differences between group discussion and classroom discussion in three steps: exploring thoughts, comparing thoughts, and drawing conclusions. We also looked into the level of argumentations of the students in the modeling activities. The analysis of the results indicated that students generated a group model by extracting commonalities from each model of their group members, and then they evaluated and modified the group model by comparing the differences among the models in classroom discussion. The main step involved in group discussion was 'exploring thoughts', whereas in classroom discussion it was 'comparing thoughts'. Although the levels of argumentation among the students were generally low, most students participated with enthusiasm, as they expressed their interest and had positive perception in the modeling activities. As a result, the modeling activities were found to have positive influences on concept development. Some suggestions to implement the modeling activities in science teaching effectively were discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.sup1
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• pp.11-11
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• 2009