• Journal of Korean Institute of Industrial Engineers
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• v.40 no.2
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• pp.205-214
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• 2014

As a result of the rapid economic growth and birth control policy, China is experiencing low fertility rates and increasing life expectancy, which makes Chinese population aging very quickly and unprepared for their retired life. The reverse mortgage may be an attractive option for the elderly because it is a loan against a house that they do not have to pay back as long as they live there. In this paper, in order to introduce the reverse mortgage scheme in China the factors that could influence the demand of reverse mortgage are reviewed and the Chinese market environment is analyzed. Then the principal component analysis is performed in order to recommend the regions or cities that have higher potential for successful implementation of a reverse mortgage than any other ones in China.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.2
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• pp.103-111
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• 2020

Recently, the use of transfer slab system has increased greatly. However, several construction problems are being encountered owing to its excessive thickness. Therefore, in this study, a transfer slab system that uses a reverse drop panel, which can utilize the facility space of the pit floor by reducing the transfer slab thickness, was considered. To investigate the shear behavior of transfer slab system that uses the reverse drop panel, the two-way shear strength of transfer slab-column connection with the reverse drop panel was analyzed using nonlinear FE analysis. In addition, the two-way shear strength evaluations of transfer slab with the reverse drop panel conducted using the existing evaluation methods were verified by comparing the strengths predicted by those methods with the results of nonlinear FE analysis.

• Tunnel and Underground Space
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• v.26 no.4
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• pp.253-265
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• 2016

In this study, travel time data collection of mine equipments was conducted in an underground mine using a reverse Radio Frequency IDentification (RFID) system. In the reverse RFID system, RFID readers and antennas are mounted on mine equipments, and RFID tags are attached to the underground mine gallery. Indoor experiments were performed to analyze how RFID reader transmission power levels affect tag readable area and tag recognition rates. The results showed that travel time measurement become precise when the reader transmission power was reduced, however tag recognition rates were reduced. The field experiments indicated that setting the reader transmission power to 28 dBm maintained the tag recognition rate while minimizing the tracking location error. In addition, the results revealed that the reverse RFID system can be used successfully in an underground mine to collect the travel time data of haulage trucks.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2207-2220
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• 2021

Lead alloy is used as coolant in Lead-based cooled Fast Reactor (LFR). The natural characteristics of lead alloy are combined with the simple structural design of LFR. This constitutes the inherent safety characteristics of LFR. The main work of this paper is to take the main coolant pump (MCP) in the lead-cooled fast reactor (LFR) as the research object, and to study the flow pattern distribution of the internal flow field under the reverse rotation pump condition, the reverse rotation positive-flow braking condition and the reverse rotation negative-flow braking condition. In this paper, the double-outlet volute type and the space guide vane are selected as the potential designs of the CLEAR-I MCP. In this paper, the CFD method is used to study the potential reverse accident of the MCP. It is found that the highest flow velocity in the impeller appears at the impeller outlet, and the Q-H curves of the two design programs basically coincide. The space guide vane type MCP has better hydraulic performance under the reverse rotation positive-flow condition, the Q-H curves of the two designs gradually separate with increasing flow rate, and the maximum flow velocity inside the space guide vane type MCP is obviously lower than that of the double-outlet volute type. For the reverse rotation test of MCP, only the condition of the forward rotating pump of the main coolant pump is tested and verified. For the simulation of the MCP in LBE medium, it proved that the turbulence model and basic settings selected in the simulation are reliable.

• Journal of Mechanical Science and Technology
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• v.20 no.1
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• pp.19-28
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• 2006

This paper describes rapid prototyping (RP) and reverse engineering (RE) application for orthopedic surgery planning to improve the efficiency and accuracy of the orthopedic surgery. Using the symmetrical characteristics of the human body, CAD data of undamaged bone of the injured area are generated from a mirror transformation of undamaged bone data for the uninjured area. The physical model before the injury is manufactured from Poly jet RP process. The surgical plan, including the selection of the proper implant, pre-forming of the implant and decision of fixation positions, etc., is determined by a physical simulation using the physical model. In order to examine the applicability and efficiency of the surgical planning technology, two case studies, such as a distal tibia comminuted fracture and an iliac wing fracture of pelvis, are carried out. From the results of the examination, it has been shown that the RP and RE can be applied to orthopedic surgical planning and can be an efficient surgical tool.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.5
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• pp.415-422
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• 2017

Finding influential factors from given clustering result is a typical data science problem. Genetic Algorithm based method is proposed to derive influential factors and its performance is compared with two conventional methods, Classification and Regression Tree (CART) and Chi-Squared Automatic Interaction Detection (CHAID), by using Dunn's index measure. To extract the influential factors of preference towards political parties in South Korea, the vote result of $18^{th}$ presidential election and 'Demographic', 'Health and Welfare', 'Economic' and 'Business' related data were used. Based on the analysis, reverse engineering was implemented. Implementation of reverse engineering based approach for influential factor analysis can provide new set of influential variables which can present new insight towards the data mining field.

• Membrane and Water Treatment
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• v.5 no.3
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• pp.221-233
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• 2014

Simulations were conducted to predict supersaturation along Reverse Osmosis (RO) modules for seawater desalination. The modeling approach is based on the use of conservation principles and chemical equilibria equations along RO modules. Full Pitzer ion interactive forces model for concentrated solutions was implement to calculate activity coefficients. An average rejection rate for all ionic species was considered. Supersaturation has been used to assess scaling. Supersaturations with respect to all calcium carbonate forms and calcium sulfate were calculated up to 50% recovery rate in seawater RO desalination. The results for four different seawater qualities are shown. The predictions were in a good agreement with the experimental results.

• Journal of Information Technology Services
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• v.2 no.1
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• pp.111-121
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• 2003

This paper intents to suggest the re-engineering methodology to transform and integrate the legacy systems to new system in modern environment. While existing reverse engineering and re-engineering approaches have focused on analyzing and maintaining the source code of program. our methodology can provide the procedures and techniques for evolving into new system by recovering the reverse engineering informations and transforming them into component informations. Our methodology for componentization of legacy system is consisted of plan step, reverse engineering step, componentization step, and delivery step, and we describes activities and detail procedures about each step.

• Journal of Power System Engineering
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• v.16 no.3
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• pp.5-9
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• 2012

Novel mechanisms for Energy Recovery Devices are proposed to diminish the pressure loss in the high-pressure reverse-osmosis system. In the beginning, the state-of-the-art in the design of Energy Recovery Devices is reviewed and the features of each model are investigated. The direct-coupled axial piston pump(APP) and axial piston motor(APM) showed 39% energy recovery at operating pressure of reverse osmosis desalination systems, 60 bar. Meanwhile, the developed PM2D model, in which APM pistons are arranged parallel to those of APP, is more compact and showed higher efficiency in a preliminary test. Loss-reduction mechanisms employing rod piston and double raw valve port are additionally proposed to enhance the efficiency and durability of the device.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.31-38
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• 2014

The purpose of this study is to make virtual machine using a 3D modeller to perform reverse engineering. Through the intuitive designer's ability, approximated model of the object is created and used to extract the data and NC tool path. The extracted data make approximated curve by using NURBS curve fitting. And the curve is used to remodel. From these series of process, the final reverse engineering data of the objects can be obtained. Two conclusions are drawn from this study. First, initial deviation of the intuitive model is one of the important factors that determine the number of repetitions of the experiment. Due to the characteristic of intuitive curve, after a certain number of repetitions the average deviation increase and radiate rather than decrease.