• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.187-192
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• 2001

High-Rise Building Construction Project which has high uncertainty and complexity, causes lots of problems under construction. In particular, the integration between design phase and construction phase highly affects a construction project in terms of cost and time. To possibly make the flexible response and preliminary verification against the construction planning problems in high rise building project, this paper proposes the Engineering-Construction Management System based on 4D CAD that put the time factor together with 3D CAD. The usefulness of this system has been verified through the actual project. It could helps the reducing trials and errors during construction phase by catching the factors on problems of project. Ultimately it will allow users to save project cost and duration by field application.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.102-110
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• 2009

The cost for maintenance of bridge structures such as repair or reinforcement is increasing. In addition, the efforts for inspection of bridge structures is becoming more important since the proper repair or reinforcement should be performed to save the maintenance cost and ensure the safety for public infrastructure. Therefore, it is studied on this paper to estimate the repair or reinforcement cycles using probabilistic approach for the steel-box girders of bridge superstructure. In addition, a computer simulation program is uniquely developed based on probabilistic approach to calculate the cycles derived from the function of age of bridge and performance rating curve which were previously studied. In order to ensure the reliability of results and appropriateness of the model, statistical analyses were performed. Also, the results were compared and proved to be similar with ones from previous statistical data related to the repair or reinforcement cycles. The results from this study is expected to be useful for the determination of proper time to repair or reinforce the bridge structure and raise the safetyness of bridge structure in advance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1718-1724
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• 2017

Recently, Smart plugs for real time monitoring of household appliances based on IoT(Internet of Things) have been activated. Through this, consumers are able to save energy by monitoring real-time energy consumption at all times, and reduce power consumption through alarm function based on consumer setting. In this paper, we measure the alternating current from a wall power outlet for real-time monitoring. At this time, the current pattern for each household appliance was classified and it was experimented with deep learning to determine which product works. As a result, we used a cross validation method and a bootstrap verification method in order to the classification performance according to the type of appliances. Also, it is confirmed that the cost function and the learning success rate are the same as the train data and test data.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.3
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• pp.220-227
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• 2009

A self oscillation DC/DC converter which has a very desirable characteristics of the high input-output voltage conversion ratio for high voltage DC power supply applications is proposed in this paper. The proposed converter is composed of one power switch, one inductor, several capacitors and diodes. Compared with conventional high-voltage DC/DC converters, it performs the high- voltage power conversion using the inductor instead of the bulky step-up transformer. Therefore, it can reduce the size of magnetic device and save the cost. Moreover, since it needs no control IC by using self oscillation circuit and has lower voltage stress on output diodes, it features a lower cost, simpler structure and more improved performance. Finally, a comparative analysis and experimental results are presented to show the validity of the proposed converter.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.496-505
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• 2016

The purpose of this study was to investigate the economic effects of a flame retardant aluminum screen developed by a company Economic effects were analyzed in terms of micro and macro-economic aspects. In the macro-economic aspect, economic effects were analyzed under the assumptions that the total import volume of flame retardant aluminum screen was approximately $50m^2$ in 2015 and that possible import substitution rates were 100%, 80%, and 60%. Results showed economic values of 2.25 billion won (100% import substitution rates), 1.8 billion won (80% import substitution rates), and 1.35 billion won (60% import substitution rates). If existing farms which had been using imported flame retardant aluminum screen replaced it newly developed with the flame-retardant aluminum screen developed in this study at rates of 100%, 80%, and 60%, the farms could save 750 million won, 60 million won, and 45 million won, respectively. Furthermore, the social cost savings from fire prevention could be 1.184 billion won. In the micro-economic aspect, if a farm with a typical-size ($1,000m^2$) greenhouse growing red pepper wanted to install flame retardant aluminum screen instead of generic aluminum screen, the farm may only pay an additional cost of 720,000 won. In comparison, if the farm chose fire insurance instead of flame-retardant aluminum screen, then the farm would pay 21,000,000 won for fire insurance. The above results show that the economic effect of flame retardant aluminum screen developed by the company would be be very efficient compared to the imported one.

• Korean Journal of Construction Engineering and Management
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• v.15 no.2
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• pp.71-78
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• 2014

Value Engineering methodology was introduced about 30years ago and has significant achievement in Korea. However, many of workshop still focus on cost down process and do not spend enough time on function analysis and expert cooperation. As a result, limited range of creative ideas were produced. To improve effectiveness of VE workshop, this study developed web-based value engineering process and system. And this study applied it to real case study to evaluate effectiveness of proposed system. Developed VE system also provides automated FAST diagram function and decision-making supporting tools. The authors found that this developed web-based VE system can significantly help to save cost and improve performance of VE workshop by using the appropriate VE process, and quick cooperation between experts. In addition, this study shows an example of a VE case study that applies the web-based VE system process, which led to a very innovative and effective way to lead workshop.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1761-1768
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• 2013

Digital shipbuilding is a technology to reduce the total cost and lead time inevitably made by reschedule and rework in a shipyard. Strategic planning should be undertaken in order to have an effect on the applicable field. We aim at planning a strategy of digital shipbuilding technology by analysis of production planning workflow in this paper. In the basis of BPR methodology, the as-is business process is analyzed to build an workflow model, and derive the bottleneck business process. We dig into the inside details of the process to illustrate an diagram of the core improvement opportunities, and perform process simulation not only to create the application scenarios but also to expect the main effects. The application strategy will make a basic sketch to save both the production cost and time for high quality products in the shipyards.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.192-196
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• 2005

Key part of main equipment in a gas turbine may be likely to be damaged due to operation under high temperature, high pressure, high-speed rotation, etc. Accordingly, the cost for maintenance increases and the damaged parts may cause generation to stop. The number of parts for maintenance also increases, but diagnostics technology fur the maintenance actually does not catch up with the demand. Blades are made of precipitation hardening Ni superalloy IN738 and the like for keeping hot strength. The surface of a blade is thermal-sprayed, using powder with main compositions such as Ni, Cr, Al, etc. in order to inhibit hot oxidation. Conventional regular maintenance of the coating layer of a blade is made by FPI (Fluorescent Penetrant Inspection) and MTP (Magnetic Particle Testing). Such methods, however, are complicated and take long time and also require much cost. In this study, defect diagnostics were tested for the coating layer of an industrial gas turbine blade, using an infraredthermography camera. Since the infrared thermography method can check a temperature distribution on a wide range of area by means of non-contact, it can advantageously save expenses and time as compared to conventional test methods. For the infrared thermography method, however, thermo-load must be applied onto a tested specimen and it is difficult to quantify the measured data. To solve the problems, this essay includes description about producing a specimen of a gas turbine blade (bucket), applying thermo-load onto the produced specimen, photographing thermography images by an infrared thermography camera, analyzing the thermography images, and pre-testing for analyzing defects on the coating layer of the gas turbine blade.

• Korean Journal of Remote Sensing
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• v.35 no.5_2
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• pp.873-881
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• 2019

There are limitations to the manager's investigation of all damage sites and establishment of management plan in terms of manpower and cost. Community mapping can be used to overcome these problems with the information. However, it is difficult to make decisions when multiple information are registered in multiple areas of damage. Because community mapping information are registered only with pictures and simple contents, it is so difficult for the manager to clearly understand the site situation. This study suggests a methodology to support decision-making processes during disaster management through system integration between the community mapping and the drone mapping. By applying the proposed method, decision makers can make a timely judgment effectively on the damage situation. It is expected that the proposed method will save time, manpower, and cost in the recovery phase.

• Journal of KIBIM
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• v.12 no.2
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• pp.49-59
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• 2022

The main idea of this study is to propose a BIM-based automation system drawing up a report of energy conservation plan in the architecture division. In order to obtain a building permit, an energy conservation plan must be prepared for buildings with a total floor area of 500m² or more under the current law. Currently, it is adopted as a general method to complete a report by obtaining data and drawings necessary for an energy conservation plan through manual work and input them directly into the verification system. This method takes a lot of effort and time in the design phase which ultimately increases the initial cost of the business, including the services of companies specialized in the environmental field. However, in preparation for mandatory BIM work process in the future, it is necessary to introduce BIM-based automatic creation system that has an advantage for shortening the whole process to enable rapid permission of energy-saving designs for buildings. There may be many methods of automation, but this study introduces how to build an application using Dynamo of Revit, in terms of utilizing BIM, and write an energy conservation plan by automatic completion of report through Dynamo and Excel's VBA algorithm, which can save time and cost in preparing the report of energy conservation plan compared with the manual process. Also we have insisted that the digital transformation of architectural process is a necessary for an efficient use of our automation system in the current energy conservation plan workflow.